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Gallitto E, Faggioli GL, Campana F, Feroldi FM, Cappiello A, Caputo S, Pini R, Gargiulo M. Type II endoleaks after fenestrated/branched endografting for juxtarenal and pararenal aortic aneurysms. J Vasc Surg 2024; 79:1295-1304.e2. [PMID: 38280685 DOI: 10.1016/j.jvs.2024.01.197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 12/28/2023] [Accepted: 01/01/2024] [Indexed: 01/29/2024]
Abstract
OBJECTIVE Persistent type II endoleaks (pEL2s) are not uncommon after endovascular aneurysm repair and their impact on long-term outcomes is well-documented. However, their occurrence and natural history after fenestrated/branched endografting (F/B-EVAR) for juxtarenal and pararenal aneurysms (J/P-AAAs) have been scarcely investigated. Aim of this study was to report incidence, risk factors, and natural history of pEL2 after F/B-EVAR in J/P-AAAs. METHODS Between 2016 and 2022, all J/P-AAAs undergoing F/B-EVAR were prospectively collected and retrospectively analyzed. EL2 were assessed at the completion angiography, at 30 days and after 6 months as primary outcomes. Preoperative risk factors for pEL2, follow-up survival, freedom from reinterventions (FFR) and aneurysm shrinkage (≥5 mm) were considered as secondary outcomes. RESULTS Of 132 patients, there were 88 (67%) JAAAs and 44 (33%) PAAAs. Seventeen EL2 (13%) were detected at the completion angiography and 36 (27%) at 30-day computed tomography angiography. The mean follow-up was 28 ± 23 months. Eleven (31%) EL2 sealed spontaneously within 6 months and three new cases were detected, for an overall of 28 pEL2/107 patients (26%) with available radiological follow-up of ≥6 months. Preoperative antiplatelet therapy (odds ratio, 4.7; 95% confidence interval [CI[, 1-22.1; P = .05), aneurysm thrombus volume of ≤40% and six or more patent aneurysm afferent vessels (odds ratio, 7.2; 95% CI, 1.8-29.1; P = .005) were independent risk factors for pEL2. The estimated 3-year survival was 80%, with no difference between cases with and without pEL2 (78% vs 85%; P = .08). The estimated 3-year FFR was 86%, with no difference between cases with and without pEL2 (81% vs 87%; P = .41). Four cases (3%) of EL2-related reinterventions were performed. In 65 cases (49%), aneurysm shrinkage was detected. pEL2 was an independent risk factor for absence of aneurysm shrinkage during follow-up (hazard ratio, 3.2; 95% CI, 1.2-8.3; P = .014). Patients without shrinkage had lower follow-up survival (64% vs 86% at 3-year; P = .009) and FFR (74% vs 90% at 3 years; P = .014) than patients with shrinkage. CONCLUSIONS PEL2 is not infrequent (26%) after F/B-EVAR for J/P-AAAs and is correlated with preoperative antiplatelet therapy, aneurysm thrombus volume of ≤40%, and six or more patent sac afferent vessels. Patients with pEL2 have a diminished aneurysm shrinkage, which is correlated with lower follow-up survival and FFR compared with patients with aneurysm shrinkage.
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Affiliation(s)
- Enrico Gallitto
- Vascular Surgery, University of Bologna, Bologna, Italy; Vascular Surgery, IRCCS, Sant'Orsola Malpighi, Bologna, Italy.
| | - Gian Luca Faggioli
- Vascular Surgery, University of Bologna, Bologna, Italy; Vascular Surgery, IRCCS, Sant'Orsola Malpighi, Bologna, Italy
| | | | | | | | | | - Rodolfo Pini
- Vascular Surgery, University of Bologna, Bologna, Italy; Vascular Surgery, IRCCS, Sant'Orsola Malpighi, Bologna, Italy
| | - Mauro Gargiulo
- Vascular Surgery, University of Bologna, Bologna, Italy; Vascular Surgery, IRCCS, Sant'Orsola Malpighi, Bologna, Italy
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Jang Y, Jang J, Kim BY, Song YS, Lee DY. Effect of Gelatin Content on Degradation Behavior of PLLA/Gelatin Hybrid Membranes. Tissue Eng Regen Med 2024; 21:557-569. [PMID: 38483778 PMCID: PMC11087404 DOI: 10.1007/s13770-024-00626-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/22/2023] [Accepted: 01/06/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND Poly(L-lactic acid) (PLLA) is a biodegradable polymer (BP) that replaces conventional petroleum-based polymers. The hydrophobicity of biodegradable PLLA periodontal barrier membrane in wet state can be solved by alloying it with natural polymers. Alloying PLLA with gelatin imparts wet mechanical properties, hydrophilicity, shrinkage, degradability and biocompatibility to the polymeric matrix. METHODS To investigate membrane performance in the wet state, PLLA/gelatin membranes were synthesized by varying the gelatin concentration from 0 to 80 wt%. The membrane was prepared by electrospinning. RESULTS At the macroscopic scale, PLLA containing gelatin can tune the wet mechanical properties, hydrophilicity, water uptake capacity (WUC), degradability and biocompatibility of PLLA/gelatin membranes. As the gelatin content increased from 0 to 80 wt%, the dry tensile strength of the membranes increased from 6.4 to 38.9 MPa and the dry strain at break decreased from 1.7 to 0.19. PLLA/gelatin membranes with a gelatin content exceeding 40% showed excellent biocompatibility and hydrophilicity. However, dimensional change (37.5% after 7 days of soaking), poor tensile stress in wet state (3.48 MPa) and rapid degradation rate (73.7%) were observed. The highest WUC, hydrophilicity, porosity, suitable mechanical properties and biocompatibility were observed for the PLLA/40% gelatin membrane. CONCLUSION PLLA/gelatin membranes with gelatin content less than 40% are suitable as barrier membranes for absorbable periodontal tissue regeneration due to their tunable wet mechanical properties, degradability, biocompatibility and lack of dimensional changes.
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Affiliation(s)
- Yunyoung Jang
- Department of Biomedical Engineering, Daelim University, 29 Imgok-ro, Dongan-gu, Anyang, 13916, South Korea
- Department of R&D Center, Renewmedical Co., Ltd., 28-7 Jeongju-ro, Bucheon, 14532, South Korea
| | - Juwoong Jang
- Department of R&D Center, Renewmedical Co., Ltd., 28-7 Jeongju-ro, Bucheon, 14532, South Korea
| | - Bae-Yeon Kim
- Department of Materials Science and Engineering, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon, 22012, South Korea
| | - Yo-Seung Song
- Department of Materials Science and Engineering, Korea Aviation University, 76 Hanggongdaehak-ro, Dukyang-gu, Goyang, 10540, South Korea.
| | - Deuk Yong Lee
- Department of Biomedical Engineering, Daelim University, 29 Imgok-ro, Dongan-gu, Anyang, 13916, South Korea.
- Department of R&D Center, Hass Co., Ltd, 60 Haan-ro, Gwangmyeong, 14322, South Korea.
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Al-Rousan RZ, Alnemrawi BR. Influence of overlay strength degradation on bond stresses of bridge deck system. Heliyon 2024; 10:e31037. [PMID: 38770328 PMCID: PMC11103516 DOI: 10.1016/j.heliyon.2024.e31037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/22/2024] Open
Abstract
This research paper intends to numerically investigate the impact of selected factors on the strength of the concrete overlay-bridge deck bond, directly and indirectly, using the nonlinear finite element analysis (NLFEA) method. Besides, the research introduces the guidelines necessary to attain adequate bond strength to eliminate the possibility of concrete detachment under the effect of different developed stresses. The NLFEA has been utilized in predicting and correlating the live applied loads and the induced shrinkage stresses at the interfacial region between the concrete overlay and the bridge deck. The developed stresses were related to the overlay's direct tensile bond strength. A total of 336 NLFEA models of overlay-bridge deck slab segments were designed and examined after being properly validated. The parameters of the study were as follows: the overlay degradation level (0 %, 19 %, 36 %, 51 %, 64 %, and 75 %); the ratio of the overlay's relative thickness-to-the bridge deck slab (toverlay/tslab); in addition to the age of the shrinkage induced stresses (early age (3 and 7 days) and moderate age (14 and 28 days)). The NLFEA live load and shrinkage stress values were validated using experimental results from the literature with difference percentages of less than 5 %. The numerical study results recommended that the thickness of the concrete's overlay should be within certain overlay thickness limits to be capable of handling the lower and higher stresses at the service and overloading conditions. The proposed guidelines enable the avoidance of unfavorable detachment between the interface parts under the effect of AASHTO HS-20 truck cyclic and impact loadings, as well as shrinkage loading.
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Affiliation(s)
- Rajai Z. Al-Rousan
- Department of Civil Engineering, Engineering, Jordan University of science and technology, P.O. Box 3030, Irbid 22110, Jordan
| | - Bara'a R. Alnemrawi
- Department of Civil Engineering, Engineering, Jordan University of science and technology, P.O. Box 3030, Irbid 22110, Jordan
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Knode V, Ludwig B, Hamadeh S, Pandis N, Fleming PS. An in vitro comparison of the dimensional stability of four 3D-printed models under various storage conditions. Angle Orthod 2024; 94:346-352. [PMID: 38639456 PMCID: PMC11050461 DOI: 10.2319/081223-557.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 01/01/2024] [Indexed: 04/20/2024] Open
Abstract
OBJECTIVES To investigate the dimensional stability of various 3D-printed models derived from resin and plant-based, biodegradable plastics (PLA) under specific storage conditions for a period of up to 21 weeks. MATERIALS AND METHODS Four different printing materials, including Draft V2, study model 2, and Ortho model OD01 resins as well as PLA mineral, were evaluated over a 21-week period. Eighty 3D-printed models were divided equally into two groups, with one group stored in darkness and the other exposed to daylight. All models were stored at a constant room temperature (20°C). Measurements were taken at 7-week intervals using the Inspect 3D module in OnyxCeph software (Image Instruments GmbH, Chemnitz, Germany). RESULTS Dimensional change was noted for all of the models with shrinkage of up to 0.26 mm over the study period. Most contraction occured from baseline to T1, although significant further contraction also arose from T1 to T2 (P < .001) and T1 to T3 (P < .001). More shrinkage was observed when exposed to daylight overall and for each resin type (P < .01). The least shrinkage was noted with Ortho model OD01 resin (0.16 mm, SD = 0.06), and the highest level of shrinkage was observed for Draft V2 resin (0.23 mm, SD = 0.06; P < .001). CONCLUSIONS Shrinkage of 3D-printed models is pervasive, arising regardless of the material used (PLA or resin) and being independent of the brand or storage conditions. Consequently, immediate utilization of 3D printing for orthodontic appliance purposes may be preferable, with prolonged storage risking the manufacture of inaccurate orthodontic retainers and appliances.
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Ahmad S, Al-Fakih A, Bahraq AA, Maslehuddin M, Al-Osta MA. Effect of silica fume substitution by limestone powder and cement kiln dust on the shrinkage, durability, and sustainability of UHPC. Environ Sci Pollut Res Int 2024; 31:26824-26838. [PMID: 38456977 DOI: 10.1007/s11356-024-32782-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 03/01/2024] [Indexed: 03/09/2024]
Abstract
Silica fume is usually used in UHPC, three times more than that for normal concrete, to enhance mechanical properties and durability. However, silica fume (SF) is an expensive material and has high production costs. This work is aimed at investigating the shrinkage and durability performance of previously developed UHPC mixtures utilizing the two calcareous waste materials, namely limestone powder (LSP) and cement kiln dust (CKD), by partially replacing the silica fume. The optimally selected mixtures of UHPC, having flow and strength above the minimum required, were used for detailed investigation in terms of shrinkage and durability characteristics. The results showed that by replacing SF with up to 20% of LSP and up to 20% of CKD, the mechanical properties of UHPC remained satisfactory compared to the control mixture with 100% SF. However, the ultimate shrinkage was higher for mixtures incorporating LSP or CKD, indicating the need for more volume of steel fibers to compensate for the shrinkage strains. The developed UHPCs also exhibited high resistance against reinforcement corrosion and sulfate attack, making them suitable for use in aggressive exposure conditions. However, special attention needs to be paid to the CKD content, where it is recommended to limit the content of CKD to about 15% or less to control the durability performance of the UHPCs. In addition, the sustainability analysis of developed UHPC mixtures was carried out using the life-cycle assessment and eco-strength intensity index. The results indicated that the UHPC mixtures possess a higher life-cycle and are therefore more sustainable.
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Affiliation(s)
- Shamsad Ahmad
- Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
- Interdisciplinary Research Center for Construction and Building Materials, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
| | - Amin Al-Fakih
- Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
- Interdisciplinary Research Center for Construction and Building Materials, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
| | - Ashraf A Bahraq
- Interdisciplinary Research Center for Construction and Building Materials, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia.
| | - Mohammed Maslehuddin
- Applied Research Center for Metrology, Standards and Testing, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
| | - Mohammed A Al-Osta
- Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
- Interdisciplinary Research Center for Construction and Building Materials, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
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Coldea A, Donmez MB, Stawarczyk B. Effect of final temperature and heating rate on the mechanical and optical properties of a zirconia veneering ceramic. J Mech Behav Biomed Mater 2024; 149:106235. [PMID: 37976995 DOI: 10.1016/j.jmbbm.2023.106235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 11/19/2023]
Abstract
PURPOSE To evaluate the effect of firing temperature and heating rate on the volumetric shrinkage, translucency, flexural strength, hardness, and fracture toughness of a zirconia veneering ceramic. MATERIAL AND METHODS Zirconia veneering ceramic specimens (N = 45) with varying final temperatures (730 °C, 750 °C, and 770 °C) and heating rates (70 °C/min, 55 °C/min, and 40 °C/min) were fabricated (n = 5). Each specimen's shrinkage, translucency, flexural strength, hardness, and fracture toughness were determined. Two-way analysis of variance, Scheffé test, and Pearson's correlation analysis were used to evaluate data (α = 0.05). RESULTS The shrinkage (44.9 ± 3.1-47.5 ± 1.6 vol%) and flexural strength (74.1 ± 17.4-107.0 ± 27.1 MPa) were not affected by tested parameters (P ≥ 0.288). The interaction between the main factors affected the translucency, hardness, and fracture toughness of the specimens (P ≤ 0.007). Specimens with 770 °C final temperature and 70 °C/min heating rate had the lowest (21.8 ± 3.2 %) translucency (P ≤ 0.039). The hardness ranged between 4.98 ± 0.51 GPa (730 °C; 70 °C/min) and 5.60 ± 0.37 GPa (770 °C; 70 °C/min). Fracture toughness ranged between 0.54 ± 0.04 MPa√m and 0.67 ± 0.08 MPa√m with the highest values for specimens fired at 730 °C with 70 °C/min (P ≤ 0.001). There was a positive correlation between translucency and hardness (r = 0.335, P = 0.012), and a negative correlation between fracture toughness and all parameters other than shrinkage (translucency: r = -0.693/P < 0.001, flexural strength: r = -0.258/P = 0.046, hardness: r = -0.457/P < 0.001). CONCLUSIONS Heating rate and final temperature should be considered while fabricating veneered zirconia restorations with tested ceramic as they affected the translucency, hardness, and fracture toughness.
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Affiliation(s)
- Andrea Coldea
- Department of Prosthetic Dentistry, Dental School, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mustafa Borga Donmez
- Department of Prosthodontics, Faculty of Dentistry, Istinye University, Istanbul, Turkey; Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
| | - Bogna Stawarczyk
- Department of Prosthetic Dentistry, Dental School, Ludwig-Maximilians-Universität München, Munich, Germany
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Narita M, Moriyoshi K, Yamaoka R, Hata H. The "Plug folding" may be a pathogenesis in chronic postoperative inguinal pain following mesh plug repair. Asian J Surg 2023; 46:5770-5772. [PMID: 37673739 DOI: 10.1016/j.asjsur.2023.08.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 08/22/2023] [Indexed: 09/08/2023] Open
Affiliation(s)
- Masato Narita
- Department of Surgery, National Hospital Organization, Kyoto Medical Center, 1-1 Fukakusamukaihata-cho, Fushimi-ku, Kyoto, 612-8555, Japan.
| | - Koki Moriyoshi
- Department of Diagnostic Pathology, National Hospital Organization, Kyoto Medical Center, 1-1 Fukakusamukaihata-cho, Fushimi-ku, Kyoto, 612-8555, Japan
| | - Ryoya Yamaoka
- Department of Surgery, National Hospital Organization, Kyoto Medical Center, 1-1 Fukakusamukaihata-cho, Fushimi-ku, Kyoto, 612-8555, Japan
| | - Hiroaki Hata
- Department of Surgery, National Hospital Organization, Kyoto Medical Center, 1-1 Fukakusamukaihata-cho, Fushimi-ku, Kyoto, 612-8555, Japan
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Liberato WF, Silikas N, Watts DC, Cavalcante LM, Schneider LFJ. Luting laminate veneers: Do resin-composites produce less polymerization stress than resin cements? Dent Mater 2023; 39:1190-1201. [PMID: 37858420 DOI: 10.1016/j.dental.2023.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/27/2023] [Accepted: 09/27/2023] [Indexed: 10/21/2023]
Abstract
OBJECTIVES Regular composites could produce less polymerization stress than resin cements when luting laminate veneers but there is no proper evidence to support this theory. The current study aimed to determine the degree of conversion, volumetric shrinkage, polymerization stress and the resultant elastic moduli of materials currently used for adhesive cementation and to determine possible correlations. METHODS The study considered (i) regular resin composites (Admira Fusion, Gradia, Grandioso, Palfique, Sirius Z, Viscalor and Z100) at room and pre-warmed (PW) at 69ºC, (ii) flowable composites (Sigma Flow and Grandioso Flow); (iii) solely light-activated cements (AllCem Veneer, Variolink Esthetic and RelyX Veneer); and (iv) one dual-activated resin cement (SpeedCEM). Degree of conversion (DC, n = 3) was accessed with FTIR 1 h after irradiation. Bonded-disk and Bioman II instruments were used to access polymerization shrinkage strain and shrinkage stress, respectively, for 60 min at 23 ± 1◦C (n = 3). The elastic modulus was determined by 3-point bending flexural test (n = 6). The results were submitted to analyse s of variance, Tukey's, and correlation tests. RESULTS For regular composites, the pre-warming did not affect DC, shrinkage and modulus but significantly increased the stress magnitude. Correlation tests indicated a significant relationship only between stress and polymerization shrinkage (r = 0.811343). SIGNIFICANCE Regular composites can produce less polymerization stress than resin cements when luting laminate veneers. Polymerization stress was dependent on the shrinkage magnitude, but not on the degree of conversion nor the elastic modulus.
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Affiliation(s)
- Walleska Feijó Liberato
- School of Dentistry, Federal Fluminense University, Niteroi, Rio de Janeiro, Brazil; Biomaterials Research Group, School of Medical Sciences, Division of Dentistry, The University of Manchester, Manchester, United Kingdom; Nucleus for Dental Biomaterials Research, Veiga de Almeida University, Rio de Janeiro, Brazil
| | - Nikolaos Silikas
- Biomaterials Research Group, School of Medical Sciences, Division of Dentistry, The University of Manchester, Manchester, United Kingdom
| | - David C Watts
- Biomaterials Research Group, School of Medical Sciences, Division of Dentistry, The University of Manchester, Manchester, United Kingdom
| | | | - Luis Felipe J Schneider
- School of Dentistry, Federal Fluminense University, Niteroi, Rio de Janeiro, Brazil; Nucleus for Dental Biomaterials Research, Veiga de Almeida University, Rio de Janeiro, Brazil.
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Vignesh R, Sharma V, Basu B. Computational nodal displacement analysis of acetabulum fossa for injection molded cemented polyethylene acetabular liner. J Mech Behav Biomed Mater 2023; 147:106109. [PMID: 37742598 DOI: 10.1016/j.jmbbm.2023.106109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 09/05/2023] [Accepted: 09/05/2023] [Indexed: 09/26/2023]
Abstract
The acetabular liner (AL) is one of the key components that determine the functionality and durability of the total hip joint replacement (THR) device. The performance of Ultra high molecular weight polyethylene (UHMWPE)-based AL depends critically on the manufacturing route and its properties, which are evaluated pre-clinically using a host of experimental and computational analyses. The conventional manufacturing of an AL involves multiple stages, including extrusion/compression molding followed by machining, which is time/cost intensive and leads to material loss. In such a scenario, injection molding is a promising alternative, yet its feasbility remains unexplored for the manufacturing of AL for THA applications. Against this backdrop, the two-fold objectives of this work are to report our recent efforts to establish the efficacy of the injection molding of new generation UHMWPE biomaterial; HU (60 wt% HDPE- 40 wt% UHMWPE blend) for manufacturing AL prototype and to present the key biomechanical response analysis of this prototype, in silico. A range of manufacturing relevant material properties, as well as customized mold design to manufacture HU-based AL with external design features, are discussed. Such guidelines are particularly relevant to mold polymeric parts with a higher thickness (>8 mm). As part of the pre-clinical validation of AL with new design features, a less explored in silico approach to assess biomechanical micro-strain in the acetabulum fossa is presented, and the results are analysed in accordance with the mechanostat theory. The outcomes revealed that for a 100 kg subject weight, average micro-strain in the remodelling region was 1132, while it was determined as 723 for a 55 kg subject weight. Such results highlight the influence of subject weight on micro-strain generation and distribution in the acetabulum fossa. The von Mises stress in AL also increased with subject weight from 17 MPa in a subject weight of 55 kg to 28 MPa in a subject weight of 100 kg. Taken together, this work demonstrates the feasibility and competence of this new generation biomaterial in terms of implant manufacturing via injection molding with a clinically desired biomechanical response.
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Affiliation(s)
- R Vignesh
- Laboratory for Biomaterials, Materials Research Centre, Indian Institute of Science, Bangalore 560012, India; Centre of Excellence for Dental and Orthopedic Applications, Material Research Centre, Indian Institute of Science, Bangalore 560012, India
| | - Vidushi Sharma
- Laboratory for Biomaterials, Materials Research Centre, Indian Institute of Science, Bangalore 560012, India; Centre of Excellence for Dental and Orthopedic Applications, Material Research Centre, Indian Institute of Science, Bangalore 560012, India
| | - Bikramjit Basu
- Laboratory for Biomaterials, Materials Research Centre, Indian Institute of Science, Bangalore 560012, India; Centre of Excellence for Dental and Orthopedic Applications, Material Research Centre, Indian Institute of Science, Bangalore 560012, India; Centre for Biosystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India.
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Ito A, Katagiri Y, Oigawa S, Amano K, Ichizawa K, Tokuda Y, Unagami M, Yoneyama M, Tsuchiya T, Sekiguchi M, Furui M, Nakaoka K, Umemura N, Hayashi Y, Tamaki Y, Nagao K, Nakata M. Effect of blastocyst shrinkage on assisted reproductive outcomes: a retrospective cohort study describing a new morphological evaluation of blastocyst pre-vitrification and post-warming. J Ovarian Res 2023; 16:192. [PMID: 37710287 PMCID: PMC10503151 DOI: 10.1186/s13048-023-01276-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 09/05/2023] [Indexed: 09/16/2023] Open
Abstract
BACKGROUND The failure of frozen-thawed blastocysts to re-expand adequately within a few hours after warming has been reported to have a negative impact on assisted reproductive technology (ART) outcomes. However, the extent to which this failure truly affects ART outcomes has not yet been presented in a manner that is easily understandable to medical practitioners and patients. This study aimed to assess the effects of blastocyst shrinkage on ART outcomes and determine a more effective morphological evaluation approach for use in clinical settings. METHODS This retrospective observational cohort study of frozen-thawed blastocyst transfer cycles was conducted from April 2017 to March 2022. Overall, 1,331 cycles were eligible for inclusion, of which 999 were good-quality blastocysts (GQB) and 332 were non-good-quality blastocysts (non-GQB). All frozen-thawed blastocyst transfer cycles performed during the specified study period were included in the study. Exclusion criteria were established to mitigate potential sources of bias as these cycles could impact implantations. We calculated rates and age-adjusted odds ratios of implantation, clinical pregnancy, ongoing pregnancy, and live birth of the re-expansion group, which showed sufficient expansion, and shrinkage group, which showed insufficient expansion. We also calculated the implantation, clinical pregnancy, ongoing pregnancy, and live birth rates of the re-expansion and shrinkage groups for each morphological scoring system parameter. RESULTS A reduced ART outcome was observed with use of blastocysts with shrinkage after vitrification/warming. The age-adjusted odds ratios for implantation, clinical pregnancy, ongoing pregnancy, and live birth were lower in the shrinkage group than in the re-expansion group. CONCLUSIONS This study examined the adverse effect of blastocyst shrinkage after warming and recovery culturing on reproductive outcomes in a clinically useful manner by retrospectively examining a substantial number of frozen-thawed embryo transfer cycles. The study findings can possibly reduce concerns regarding over- or under-estimation of blastocyst implantation by allowing providers and patients to refer to the data.
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Affiliation(s)
- Ayumu Ito
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan.
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan.
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan.
| | - Yukiko Katagiri
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Satoko Oigawa
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Kenji Amano
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Koichiro Ichizawa
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Yukiko Tokuda
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Mami Unagami
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Masato Yoneyama
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Takahiro Tsuchiya
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Mami Sekiguchi
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Mayuko Furui
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Kentaro Nakaoka
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Nahomi Umemura
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Yuko Hayashi
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Yuko Tamaki
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Koichi Nagao
- Reproduction Center, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
- Department of Urology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
| | - Masahiko Nakata
- Department of Obstetrics and Gynecology, Faculty of Medicine, Toho University, 5-21-16, Omorinishi, Ota-Ku, Tokyo, 143-0015, Japan
- Department of Obstetrics and Gynecology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-Ku, Tokyo, 143-8541, Japan
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Salehi F, Razavi Kamran H, Goharpour K. Effects of ultrasound time, xanthan gum, and sucrose levels on the osmosis dehydration and appearance characteristics of grapefruit slices: Process optimization using response surface methodology. Ultrason Sonochem 2023; 98:106505. [PMID: 37437368 PMCID: PMC10422107 DOI: 10.1016/j.ultsonch.2023.106505] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/15/2023] [Accepted: 06/24/2023] [Indexed: 07/14/2023]
Abstract
In this work, the novel use of ultrasonic pre-treatment and edible coating treatment during osmosis dehydration to optimize the weight reduction, moisture loss, sucrose gain, rehydration, and surface shrinkage using a response surface methodology (RSM) based on a central composite design (CCD) technique was successfully conducted on grapefruit slices. The process parameters include sonication pre-treatment time (5-10 min), xanthan-gum-based edible coating (0.1%-0.3%, w/w), and sucrose concentration (20-50 Brix), were examined and optimized for osmosis dehydration of grapefruit slices. At each step, three grapefruit slices were immersed in an ultrasonic water bath at 40 kHz, 150 W, and 20 C. Then, the sonicated slices were placed in a container contain sucrose and xanthan, and the container was put in a 50 C water-bath for 1 h. The optimum concentration of xanthan gum, sucrose, and time of treatment were predicted to be 0.15%, 20.0 Brix, and 10.0 min, respectively. Under this optimum condition, estimated values of response variables are as follows: weight reduction 14.14%, moisture loss 25.92%, solids gain 11.78%, rehydration ratio 203.40%, and shrinkage 2.90%. The weight reduction and moisture loss increased when the sonication time and sucrose concentration increased. Results demonstrated that the experimental data could be adequately fitted into a linear model with p-value ranging from 0.0001 to 0.0309 for all the variables examined. The rehydration of dried samples increased when xanthan concentration increased. Also, the weight reduction, moisture loss, sucrose absorption, and shrinkage declined with increasing in the xanthan levels.
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Affiliation(s)
- Fakhreddin Salehi
- Department of Food Science and Technology, Bu-Ali Sina University, Hamedan, Iran.
| | - Helia Razavi Kamran
- Department of Food Science and Technology, Bu-Ali Sina University, Hamedan, Iran
| | - Kimia Goharpour
- Department of Food Science and Technology, Bu-Ali Sina University, Hamedan, Iran
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Topa-Skwarczyńska M, Jankowska M, Gruchała-Hałat A, Petko F, Galek M, Ortyl J. High-performance photoinitiating systems for new generation dental fillings. Dent Mater 2023; 39:729. [PMID: 37393151 DOI: 10.1016/j.dental.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 06/10/2023] [Accepted: 06/14/2023] [Indexed: 07/03/2023]
Abstract
OBJECTIVES To obtain new generation dental composites with improved performance properties compared to currently available dental fillings on the market and to determine the influence of new initiating systems on final product parameters such as degree of cure, hardness, color, and shrinkage. METHODS In order to verify the effectiveness of the developed initiating systems, typical spectroscopic, electrochemical, and kinetic studies using the real-time FT-IR method were shown. Moreover, paste dental fillings were prepared, the compositions were irradiated with the dental lamp, and the degrees of cross-linking were measured by Raman spectroscopy. The polymerization shrinkage was also determined using the rheometer. In addition, their hardness was examined on the Shore scale. Finally, the color analysis of the composites in the L*a*b* color space was compared with the VITA CLASSIC colorant. RESULTS It was shown that, due to their excellent spectroscopic and electrochemical properties, new quinazolin-2-one can act as co-initiators in cationic and radical photopolymerization. It was demonstrated that the most effective composite containing the initiator system in the form of 3-SCH3Ph-Q, IOD, MDEA, and an inorganic filler as nanometric silica and a bonding agent is cured more than 90% after just 1 cycle of dental lamp exposure (30 s), the hardness of the composite after curing on the Shor Scale is 82 ± 4, and the polymerization shrinkage is less than 2.8%. SIGNIFICANCE The article demonstrates effective new initiator systems as an alternative to CQ/amine for obtaining new-generation dental composites. The developed dental composites are a big competition to the currently used dental fillings on the market.
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Affiliation(s)
- Monika Topa-Skwarczyńska
- Department of Biotechnology and Physical Chemistry, Faculty of Chemical Engineering and Technology, Cracow University of Technology, Warszawska 24, 30-155 Cracow, Poland; Photo4Chem Ltd., Lea 114, 30-133 Cracow, Poland.
| | - Magdalena Jankowska
- Department of Biotechnology and Physical Chemistry, Faculty of Chemical Engineering and Technology, Cracow University of Technology, Warszawska 24, 30-155 Cracow, Poland
| | - Alicja Gruchała-Hałat
- Department of Biotechnology and Physical Chemistry, Faculty of Chemical Engineering and Technology, Cracow University of Technology, Warszawska 24, 30-155 Cracow, Poland
| | - Filip Petko
- Department of Biotechnology and Physical Chemistry, Faculty of Chemical Engineering and Technology, Cracow University of Technology, Warszawska 24, 30-155 Cracow, Poland; Photo HiTech Ltd., Bobrzyńskiego 14, 30-348 Cracow, Poland
| | - Mariusz Galek
- Photo HiTech Ltd., Bobrzyńskiego 14, 30-348 Cracow, Poland
| | - Joanna Ortyl
- Department of Biotechnology and Physical Chemistry, Faculty of Chemical Engineering and Technology, Cracow University of Technology, Warszawska 24, 30-155 Cracow, Poland; Photo HiTech Ltd., Bobrzyńskiego 14, 30-348 Cracow, Poland; Photo4Chem Ltd., Lea 114, 30-133 Cracow, Poland.
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13
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Mydin MAO, Nawi MNM, Omar R, Khadimallah MA, Ali IM, Deraman R. The use of inorganic ferrous-ferric oxide nanoparticles to improve fresh and durability properties of foamed concrete. Chemosphere 2023; 317:137661. [PMID: 36608888 DOI: 10.1016/j.chemosphere.2022.137661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/10/2022] [Accepted: 12/24/2022] [Indexed: 06/17/2023]
Abstract
Efforts to modify cement-based mixtures have continuously engrossed the interest of academics. Favourable impacts of nanoparticles, for instance, fine particle size and great reactivity, have made them be utilized in concrete. Foamed concrete (FC) is immensely porous, and its properties diminish with an increase in the number of pores. To enhance its properties, the FC matrix could be attuned by integrating numerous nanoparticles. The influence of ferrous-ferric oxide nanoparticles (FFO-NP) in FC was not discovered previously in the present body of knowledge. Thus, there is some uncertainty contemplating the mechanism to which extent the FFO-NP can affect the durability properties of FC. Hence, this study focuses on utilizing FFO-NP in the FC matrix. FC specimens with a density of 1000 kg/m3 were cast and tested. The objective was to assess the influence of different FFO-NP weight fractions (0.10%, 0.15%, 0.20%, 0.25%, 0.30%, and 0.35%) on durability properties such as drying shrinkage, porosity, water absorption and ultrasonic wave propagation velocity of FC. The results implied that the presence of a 0.25% weight fraction of FFO-NP in FC facilitates optimal water absorption, porosity, ultrasonic pulse velocity and drying shrinkage of FC. The presence of FFO-NP alters the microstructural of FC from loose needle-like into a dense cohesive microstructure of the cementitious composite. Besides, FFO-NP augments the FC matrix by filling the voids, microcracks, and spaces within the structure. Further than the ideal weight fraction of FFO-NP addition, the accretion of the FFO-NP was found, which caused a decline in durability properties.
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Affiliation(s)
- Md Azree Othuman Mydin
- School of Housing, Building and Planning, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia.
| | - Mohd Nasrun Mohd Nawi
- Disaster Management Institute (DMI), School of Technology Management and Logistics, Universiti Utara Malaysia, 06010, Sintok, Kedah, Malaysia
| | - Roshartini Omar
- Department of Construction Management, Faculty of Technology Management and Business (FPTP), Universiti Tun Hussein Onn Malaysia (UTHM), Malaysia
| | - Mohamed Amine Khadimallah
- Department of Civil Engineering, College of Engineering in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj, 11942, Saudi Arabia.
| | - Irwan Mohammad Ali
- Department of Built Environment Studies and Technology, College of Built Environment, Universiti Teknologi MARA, Perak Branch, Seri Iskandar Campus, 32610, Seri Iskandar, Perak, Malaysia
| | - Rafikullah Deraman
- Faculty of Civil Engineering and Built Environment, Universiti Tun Hussein Onn Malaysia (UTHM), Malaysia
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Salami BA, Ibrahim M, Al-Osta MA, Nasir M, Ali MR, Bahraq AA, Wasiu A. Engineered and green natural pozzolan-nano silica-based alkali-activated concrete: shrinkage characteristics and life cycle assessment. Environ Sci Pollut Res Int 2023; 30:17840-17853. [PMID: 36201078 DOI: 10.1007/s11356-022-23424-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Alkali-activated concrete (AAC) or binders (AABs) have emerged as a substitute to conventional ordinary Portland cement (OPC)-based concrete owing to their techno-ecological merits. Saudi Arabia has vast resources of natural pozzolan whose impact on some fresh and hardened properties was encouraging; however, the long-term shrinkage behavior of AABs and life cycle assessment (LCA) of the developed product is yet to be explored. Therefore, this study evaluates shrinkage characteristics and LCA of Saudi natural pozzolan (NP)-based AAC. The synergistic impact of admixing nano-silica (NS) up to 7.5% dosage was also observed on the properties of engineered AABs in comparison with OPC-based concrete. The shrinkage properties were correlated with the microstructure and pore structure. The study revealed that the shrinkage properties of both NP-based AABs and OPC-based concrete are comparable. However, adding NS increased the drying shrinkage strain because of the finer pore structure than AABs without NS, which was confirmed through nuclear magnetic resonance (NMR). The maximum average drying shrinkage strain of 510 με was recorded in the OPC concrete, whereas in the engineered AAC with 0, 1, 2.5, 5, and 7.5% NS, it was 486, 537, 568, 601, and 651 με, respectively. It is postulated that the NP can be beneficially valorized in the production of green AABs without compromising the shrinkage characteristics, while the NS is favorable for enhancing the strength and refinement of the pore matrix. Besides, the LCA indicated the feasibility of recycling the high volume of natural waste by AAB technology, which significantly lowers the carbon footprints and minimizes the environmental implications in infrastructural applications.
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Affiliation(s)
- Babatunde Abiodun Salami
- Interdisciplinary Research Center for Construction and Building Materials, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia.
| | - Mohammed Ibrahim
- Applied Research Center for Metrology, Standards and Testing, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia
| | - Mohammed A Al-Osta
- Interdisciplinary Research Center for Construction and Building Materials, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia
- Department of Civil and Environmental Engineering, College of Engineering, King Fahd University of Petroleum and Minerals, Dammam, 31261, Saudi Arabia
| | - Muhammad Nasir
- Department of Civil and Construction Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, Dammam, 31451, Saudi Arabia
| | - Mohammed Rizwan Ali
- Applied Research Center for Metrology, Standards and Testing, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia
| | - Ashraf A Bahraq
- Interdisciplinary Research Center for Construction and Building Materials, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia
- Department of Civil and Environmental Engineering, College of Engineering, King Fahd University of Petroleum and Minerals, Dammam, 31261, Saudi Arabia
| | - Alimi Wasiu
- Department of Civil and Environmental Engineering, College of Engineering, King Fahd University of Petroleum and Minerals, Dammam, 31261, Saudi Arabia
- Civil and Architectural Engineering Department, University of Miami, Coral Gables, FL, 33146, USA
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Bordet M, Oliny A, Miasumu T, Tresson P, Lermusiaux P, Della Schiava N, Millon A. EndoSuture aneurysm repair versus fenestrated aneurysm repair in patients with short neck abdominal aortic aneurysm. J Vasc Surg 2023; 77:28-36.e3. [PMID: 36070845 DOI: 10.1016/j.jvs.2022.08.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/10/2022] [Accepted: 08/17/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The aim of this study was to compare midterm results of EndoAnchors in EndoSuture aneurysm repair (ESAR) versus fenestrated endovascular aneurysm repair (FEVAR) in short neck abdominal aortic aneurysm (AAA). METHODS All patients who underwent an ESAR procedure for a short neck AAA at our center between September 2017 and May 2020 were considered for analysis. To form the control group, preoperative computed tomography angiography of patients who underwent FEVAR for juxtarenal AAA between April 2012 and May 2020 were reviewed and patients who met short neck criteria selected. A propensity-matched score on neck length and neck diameter was calculated, resulting in 18 matched pairs. AAA shrinkage, type Ia endoleaks (EL), AAA-related reinterventions, and AAA-related deaths were compared. RESULTS The median AAA diameter was 54 mm (interquartile range [IQR], 52-61 mm) versus 58 mm (IQR, 53-63 mm) with a median neck length of 8 mm (IQR, 6-12 mm) vs 10 mm (IQR, 6-13 mm) in ESAR and FEVAR patients, respectively. Technical success was 100% in both groups. Procedural success was 94% in the ESAR group versus 100% in the FEVAR group. The median procedure duration was 138 mm (IQR, 113-182 mm) vs 240 mm (IQR, 199-293 mm) ( P < .001) and the median length of stay was 2 days (IQR, 2-3 days) vs 7 days (IQR, 6-7 days) (P < .001) in ESAR and FEVAR patients, respectively. No major hospital complications were observed in ESAR patients compared with two in FEVAR patients (11%) with one transient acute kidney injury and one transient paraplegia. The median follow-up was 23 months (IQR, 19-33 months) vs 36 months (IQR, 22-57 months) with 67% versus 61% AAA shrinkage in the ESAR and FEVAR groups, respectively (P = .73). No type Ia EL, proximal neck-related reinterventions, or AAA-related deaths were observed in either group. No AAA-related reintervention was observed in the ESAR group versus three reinterventions in the FEVAR group (P = .23). CONCLUSIONS ESAR seems to be a safe technique with no major postoperative complications or reinterventions observed during follow-up. It seems to offer similar midterm results as FEVAR in terms of type Ia EL, aneurysm shrinkage, and aneurysm-related mortality. ESAR seems to be a good off-the-shelf alternative to FEVAR in case of technical constraints.
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Affiliation(s)
- Marine Bordet
- Department of Vascular and Endovascular Surgery, Hospices Civils de Lyon, Louis Pradel University Hospital, Bron, France; Université Claude Bernard Lyon 1, F-69621, Villeurbanne, France.
| | - Alexandre Oliny
- Department of Vascular and Endovascular Surgery, Hospices Civils de Lyon, Louis Pradel University Hospital, Bron, France
| | - Tiphaine Miasumu
- Department of Vascular and Endovascular Surgery, Hospices Civils de Lyon, Louis Pradel University Hospital, Bron, France
| | - Philippe Tresson
- Department of Vascular and Endovascular Surgery, Hospices Civils de Lyon, Louis Pradel University Hospital, Bron, France
| | - Patrick Lermusiaux
- Department of Vascular and Endovascular Surgery, Hospices Civils de Lyon, Louis Pradel University Hospital, Bron, France; Université Claude Bernard Lyon 1, F-69621, Villeurbanne, France
| | - Nellie Della Schiava
- Department of Vascular and Endovascular Surgery, Hospices Civils de Lyon, Louis Pradel University Hospital, Bron, France
| | - Antoine Millon
- Department of Vascular and Endovascular Surgery, Hospices Civils de Lyon, Louis Pradel University Hospital, Bron, France; Université Claude Bernard Lyon 1, F-69621, Villeurbanne, France
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16
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Ward EJ, Marshall K, Scheuerell MD. Regularizing priors for Bayesian VAR applications to large ecological datasets. PeerJ 2022; 10:e14332. [PMID: 36389409 PMCID: PMC9651052 DOI: 10.7717/peerj.14332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/11/2022] [Indexed: 11/10/2022] Open
Abstract
Using multi-species time series data has long been of interest for estimating inter-specific interactions with vector autoregressive models (VAR) and state space VAR models (VARSS); these methods are also described in the ecological literature as multivariate autoregressive models (MAR, MARSS). To date, most studies have used these approaches on relatively small food webs where the total number of interactions to be estimated is relatively small. However, as the number of species or functional groups increases, the length of the time series must also increase to provide enough degrees of freedom with which to estimate the pairwise interactions. To address this issue, we use Bayesian methods to explore the potential benefits of using regularized priors, such as Laplace and regularized horseshoe, on estimating interspecific interactions with VAR and VARSS models. We first perform a large-scale simulation study, examining the performance of alternative priors across various levels of observation error. Results from these simulations show that for sparse matrices, the regularized horseshoe prior minimizes the bias and variance across all inter-specific interactions. We then apply the Bayesian VAR model with regularized priors to a output from a large marine food web model (37 species) from the west coast of the USA. Results from this analysis indicate that regularization improves predictive performance of the VAR model, while still identifying important inter-specific interactions.
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Affiliation(s)
- Eric J. Ward
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA, United States
| | - Kristin Marshall
- Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, Seattle, WA, USA
| | - Mark D. Scheuerell
- U.S. Geological Survey Washington Cooperative Fish and Wildlife Research Unit, School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, USA
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17
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Cai W, Bordoloi S, Ng CWW, Sarmah AK. Influence of pore fluid salinity on shrinkage and water retention characteristics of biochar amended kaolin for landfill liner application. Sci Total Environ 2022; 838:156493. [PMID: 35679946 DOI: 10.1016/j.scitotenv.2022.156493] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/18/2022] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
Biochar amended clay layer has emerged as a sustainable hydraulic barrier for hazardous municipal waste containment system. The effects of pore fluid salinity on soil shrinkage and water retention characteristics of biochar amended clay are unknown. This study aims to investigate the behavior of soil shrinkage and water retention of biochar amended kaolin under different pore fluid salinity. A series of volumetric shrinkage and water retention tests were conducted on biochar amended kaolin in sodium chloride solution at initial concentrations of 1 %, 5 %, and 10 %. Biochar addition increased the shrinkage limit and minimum void ratio of kaolin by up to 17 % and 11 %, respectively. Air entry value of kaolin increased by 6-88 times with an increase in pore fluid salinity, caused by interparticle aggregation. Micrographs showed that biochar intrapore was filled by kaolin particles, partially hindering the interparticle aggregation of clay in the salt solution. Biochar addition lowered zeta potential on the surface of kaolin particles by 50-75 %, indicating that the immobilisation of excess sodium ions was achieved by biochar. Correspondingly, osmotic suction of pore fluid decreased by 21-64 % due to biochar's ion absorption. The findings highlighted that biochar addition to kaolin specimens minimises NaCl-induced soil shrinkage and reduces the pore fluid salinity. This study indicates that biochar could be potentially helpful for desalinisation and mitigating volumetric change issues for geo-environmental infrastructures.
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Affiliation(s)
- W Cai
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong; Department of Civil and Environmental Engineering, Shantou University, China.
| | - S Bordoloi
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong; Illinois Sustainable Technology Centre, University of Illinois at Urbana Champaign, United States of America.
| | - C W W Ng
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong.
| | - A K Sarmah
- Department of Civil and Environmental Engineering, The Faculty of Engineering, The University of Auckland, Private Bag 92019, 1142 Auckland, New Zealand.
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Kar S, Tripathi A, Singh J, Ramkumar J. Comparison of dimensional accuracy of elastomeric impression materials using 3D laser scanner. Med J Armed Forces India 2022; 78:S55-S60. [PMID: 36147418 PMCID: PMC9485857 DOI: 10.1016/j.mjafi.2021.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 05/21/2021] [Indexed: 11/28/2022] Open
Abstract
Background The dimensional accuracy of elastomeric impression materials has been evaluated by different methods but their reliability is still questionable. The aim of this study was to evaluate the dimensional accuracy of elastomeric impression material using 3D laser scanner. Method In the present study, a metal die with its custom tray were designed. Using this die and tray, 10 impressions each were made from addition silicone (Aquasil LV; Dentsply), condensation silicone (Speedex coltene, Whaledent) and polyether (3M; ESPE). All the impressions were poured with Type IV die stone and total of 30 die replicas were obtained. These were scanned with a Picza 3D laser scanner (LPX 600, Roland,California) and the difference between the stone model was calculated by determining its volumetric changes using CAD-CAM pero version 2.0. One way analysis of variance (ANOVA) was used to compare the groups, whereas significance of mean difference between the groups was done by Tukey HSD. Results All the three groups showed mean decrease indicating a dimensional shrinkage from the master die. Mean percentage dimensional change in condensation silicone was maximum (-319.02 ±15.50) followed by polyether (-122.59 ± 0.64) and least in addition silicone (-23.83 ± 0.43). All the results were statistically significant (p<0.001). Conclusion Picza 3D laser scanner can precisely measure the volumetric changes in all the three elastomeric impression materials.
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Affiliation(s)
- Sushil Kar
- Professor (Prosthodontics), Saraswati Dental College & Hospital, Lucknow, India
| | - Arvind Tripathi
- Professor & Head (Prosthodontics), Saraswati Dental College & Hospital, Lucknow, India
| | - Juhi Singh
- Private Practice, Rewa, Madhya Pradesh, India
| | - J. Ramkumar
- Associate Professor (Mechanical Engineering), Indian Institute of Technology Kanpur, India
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Yuan B, Han S, Yang S, Zhang L, Jiang L, Wei F, Yuan H, Liu X, Liu Z. Radiologic and clinical changes after denosumab treatment for giant cell tumors of the mobile spine: a quantitative study. Insights Imaging 2022; 13:93. [PMID: 35616740 PMCID: PMC9135903 DOI: 10.1186/s13244-022-01226-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/18/2022] [Indexed: 11/10/2022] Open
Abstract
Objectives To analyze the radiologic and clinical changes after denosumab treatment in patients with giant cell tumors (GCTs) in the mobile spine. Methods Clinical data and images by computed tomography and magnetic resonance imaging at a single center were retrospectively reviewed before and after denosumab treatment. Results Pre- and post-treatment data from 24 patients were evaluated. On imaging, marginal ossification and/or bone formation was observed in 22 patients (91.7%). The median maximum diameter of the GCT reduced from 52.5 to 48.2 mm (p < 0.001), and the mean proportion of tumor to spinal canal area decreased from 36.8 to 18.5% (p < 0.001). Out of six patients with compression, three patients (50%) showed no compression after treatment. The signal intensity (SI) ratio between the solid part of the tumor and the normal spinal cord on T2-weighted MR images was 0.77 ± 0.22 and decreased to 0.58 ± 0.22 (p = 0.001). On clinical symptoms, the mean visual analog scale scores were reduced from 5.3 to 2.0 (p < 0.001) and the Karnofsky Performance Scale scores increased from a median of 65 to 80 (p < 0.001). Post-treatment, performance scores improved in eight patients (33.3%) (p = 0.003), and the neurological function of four patients improved according to Frankel grade (p = 0.046). Conclusions Bone formation, tumor reduction, regression of epidural lesion and the decrease in SI ratio on T2-weighted image should be considered as the effectiveness of denosumab in the treatment of spinal GCT. In clinical application, denosumab can relieve pain, improve neurological function, and improve the quality of life of spinal GCT patients.
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Affiliation(s)
- Bei Yuan
- Department of Orthopaedics, Peking University Third Hospital, No. 49 North Garden Road, Haidian District, Beijing, 100191, China.,Department of Orthopaedics, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, 102218, China
| | - Songbo Han
- Department of Radiology, Peking University Third Hospital, Haidian District, No. 49 North Garden Road, Beijing, 100191, China
| | - Shaomin Yang
- Department of Pathology, Peking University Third Hospital, No. 49 North Garden Road, Haidian District, Beijing, 100191, China
| | - Lihua Zhang
- Department of Radiology, Peking University Third Hospital, Haidian District, No. 49 North Garden Road, Beijing, 100191, China
| | - Liang Jiang
- Department of Orthopaedics, Peking University Third Hospital, No. 49 North Garden Road, Haidian District, Beijing, 100191, China. .,Engineering Research Center of Bone and Joint Precision Medicine, Beijing, China. .,Beijing Key Laboratory of Spinal Disease Research, Beijing, China.
| | - Feng Wei
- Department of Orthopaedics, Peking University Third Hospital, No. 49 North Garden Road, Haidian District, Beijing, 100191, China.,Engineering Research Center of Bone and Joint Precision Medicine, Beijing, China.,Beijing Key Laboratory of Spinal Disease Research, Beijing, China
| | - Huishu Yuan
- Department of Radiology, Peking University Third Hospital, Haidian District, No. 49 North Garden Road, Beijing, 100191, China
| | - Xiaoguang Liu
- Department of Orthopaedics, Peking University Third Hospital, No. 49 North Garden Road, Haidian District, Beijing, 100191, China.,Engineering Research Center of Bone and Joint Precision Medicine, Beijing, China.,Beijing Key Laboratory of Spinal Disease Research, Beijing, China
| | - Zhongjun Liu
- Department of Orthopaedics, Peking University Third Hospital, No. 49 North Garden Road, Haidian District, Beijing, 100191, China. .,Engineering Research Center of Bone and Joint Precision Medicine, Beijing, China. .,Beijing Key Laboratory of Spinal Disease Research, Beijing, China.
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Stelzner J, Stelzner I, Martinez-Garcia J, Gwerder D, Wittköpper M, Muskalla W, Cramer A, Heinz G, Egg M, Schuetz P. Stabilisation of waterlogged archaeological wood: the application of structured-light 3D scanning and micro computed tomography for analysing dimensional changes. Herit Sci 2022; 10:60. [PMID: 35578712 PMCID: PMC9098614 DOI: 10.1186/s40494-022-00686-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 03/31/2022] [Indexed: 06/15/2023]
Abstract
Cultural heritage objects made of wood can be preserved under waterlogged conditions for many years, where decay is slowed down and the wood structure is more or less completely filled with water. Depending on the degree of degradation, finds may collapse and shrink when they are allowed to dry in an uncontrolled manner after excavation, leading to total loss of the object and its information. Conservation measures are taken to prevent damage of objects and dimensional stability is an important criterion. In this study, structured-light 3D scanning and micro-computed tomography were used to analyse the dimensional stability of wood after conservation, as well as its long-term stability. 83 samples from a reference collection established between 2008 and 2011 allowed this comparative study of the most common conservation methods at that time. The effects of conservation methods using alcohol-ether resin, melamine-formaldehyde (Kauramin 800®), lactitol/trehalose, saccharose, and silicone oil on dimensional stability were investigated. In addition, different polyethylene glycol (PEG) treatments with subsequent freeze-drying were also investigated: one-stage with PEG 2000, two-stage with PEG 400 and PEG 4000 and three-stage with PEG 400, PEG 1500 and PEG 4000. The data received from analyses of both volume and surface gave detailed information about the success of each conservation method. Attempts were made to quantify the damage patterns, specifically shrinkage, collapse, and cracks. While PEG and freeze-drying, alcohol-ether-resin, as well as the Kauramin 800® method gave the best results, analysis also highlighted the failures of each method.
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Affiliation(s)
- Jörg Stelzner
- Römisch-Germanisches Zentralmuseum, Leibniz Research Institute for Archaeology, Ernst Ludwig Platz 2, 55116 Mainz, Germany
| | - Ingrid Stelzner
- Römisch-Germanisches Zentralmuseum, Leibniz Research Institute for Archaeology, Ernst Ludwig Platz 2, 55116 Mainz, Germany
| | - Jorge Martinez-Garcia
- Lucerne University of Applied Sciences and Arts-School of Engineering and Architecture, Technikumstrasse 21, Horw, Switzerland
| | - Damian Gwerder
- Lucerne University of Applied Sciences and Arts-School of Engineering and Architecture, Technikumstrasse 21, Horw, Switzerland
| | - Markus Wittköpper
- Römisch-Germanisches Zentralmuseum, Leibniz Research Institute for Archaeology, Ernst Ludwig Platz 2, 55116 Mainz, Germany
| | - Waldemar Muskalla
- Römisch-Germanisches Zentralmuseum, Leibniz Research Institute for Archaeology, Ernst Ludwig Platz 2, 55116 Mainz, Germany
| | - Anja Cramer
- Römisch-Germanisches Zentralmuseum, Leibniz Research Institute for Archaeology, Ernst Ludwig Platz 2, 55116 Mainz, Germany
| | - Guido Heinz
- Römisch-Germanisches Zentralmuseum, Leibniz Research Institute for Archaeology, Ernst Ludwig Platz 2, 55116 Mainz, Germany
| | - Markus Egg
- Römisch-Germanisches Zentralmuseum, Leibniz Research Institute for Archaeology, Ernst Ludwig Platz 2, 55116 Mainz, Germany
| | - Philipp Schuetz
- Lucerne University of Applied Sciences and Arts-School of Engineering and Architecture, Technikumstrasse 21, Horw, Switzerland
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Meador WD, Sugerman GP, Tepole AB, Rausch MK. Biaxial mechanics of thermally denaturing skin - Part 1: Experiments. Acta Biomater 2022; 140:412-20. [PMID: 34560301 DOI: 10.1016/j.actbio.2021.09.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 09/14/2021] [Accepted: 09/17/2021] [Indexed: 12/29/2022]
Abstract
The mechanics of collagenous soft tissues, such as skin, are sensitive to heat. Thus, quantifying and modeling thermo-mechanical coupling of skin is critical to our understanding of skin's physiology, pathophysiology, and its treatment. However, key gaps persist in our knowledge about skin's coupled thermo-mechanics. Among them, we haven't quantified the role of skin's microstructural organization in its response to superphysiological loading. To fill this gap, we conducted a comprehensive set of experiments in which we combined biaxial mechanical testing with histology and two-photon imaging under liquid heat treatment at temperatures ranging from 37∘C to 95∘C lasting between 2 seconds and 5 minutes. Among other observations, we found that unconstrained skin, when exposed to high temperatures, shrinks anisotropically with the principal direction of shrinkage being aligned with collagen's principal orientation. Additionally, we found that when skin is isometrically constrained, it produces significant forces during denaturation that are also anisotropic. Finally, we found that denaturation significantly alters the mechanical behavior of skin. For short exposure times, this alteration is reflected in a reduction of stiffness at high strains. At long exposure times, the tissue softened to a point where it became untestable. We supplemented our findings with confirmation of collagen denaturation in skin via loss of birefringence and second harmonic generation. Finally, we captured all time-, temperature-, and direction-dependent experimental findings in a hypothetical model. Thus, this work fills a fundamental gap in our current understanding of skin thermo-mechanics and will support future developments in thermal injury prevention, thermal injury management, and thermal therapeutics of skin. STATEMENT OF SIGNIFICANCE: Our work experimentally explores how skin reacts to being heated. That is, it measures how much skin shrinks, what forces it produces, and how its mechanical properties change; all as a function of temperature, but also of direction and time. Additionally, our work connects these measurements to changes in skin's microscopic make-up. This knowledge is important to our understanding of skin's function and dysfunction, especially during burn injuries or heat-dependent treatments.
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Ling L, Taremi N, Malyala R. A Novel Low- Shrinkage Resin for 3D Printing. J Dent 2022;:103957. [PMID: 35038476 DOI: 10.1016/j.jdent.2022.103957] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 01/08/2022] [Accepted: 01/12/2022] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE To evaluate the shrinkage, accuracy, and mechanical properties of a newly developed photo-polymerizable resin material for 3D printing dental applications and compare it with three commercially available resins. METHODS An experimental novel proprietary resin material for 3D printing was formulated. This new resin, Die and Model Tan (SprintRay), Formlabs Grey (FormLabs), and LCD Grey (Roxel 3D) were evaluated and tested for volumetric shrinkage, accuracy, and flexural and tensile properties. Volumetric shrinkage was measured using the AcuVol video imaging method. The accuracy of the 3D printed objects through the DLP (digital light processing) printing system was determined by the 3D deviation between the scanned model and the original CAD digital model. Parallelepiped specimens (2 × 2 × 25 mm, n= 5) were printed for flexural strength, flexural modulus, and modulus of resilience and measured in accordance with ISO-4049. Dumbbell-shaped specimens (Type V, n = 5) were printed to investigate the tensile strength and tested according to ASTM-D638. Data were analyzed using one-way ANOVA and post-hoc Tukey tests (p≤0.05). RESULTS The experimental resin exhibited significantly lower volumetric shrinkage and significantly higher accuracy than the other commercially available resins (p < 0.001). The experimental resin showed flexural strength, flexural modulus, and tensile strength similar to Die and Model Tan resin (SprintRay) (p > 0.05), and these parameters were significantly higher than those of Formlabs Grey resin (Formlabs) and lower than those of LCD Gray resin (Roxel3D)(p <0.001). CONCLUSION The newly formulated 3D printing resin demonstrated lower volumetric shrinkage, high accuracy, and adequate mechanical properties compared to the commercially available resin materials. CLINICAL SIGNIFICANCE The new 3D printed objects exhibited higher accuracy, good stability over time, and adequate mechanical properties. The new 3D printing resin is a good candidate for modeling applications for restoration, orthodontics and implants.
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Zhao NY, Lian JY, Wang PF, Xu ZB. Recent progress in minimizing the warpage and shrinkage deformations by the optimization of process parameters in plastic injection molding: a review. Int J Adv Manuf Technol 2022; 120:85-101. [PMID: 35194289 PMCID: PMC8831005 DOI: 10.1007/s00170-022-08859-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/01/2022] [Indexed: 05/13/2023]
Abstract
The quality control of plastic products is an essential aspect of the plastic injection molding (PIM) process. However, the warpage and shrinkage deformations continue to exist because the PIM process is easily interfered with by several related or independent process parameters. Thus, great efforts have been devoted to optimizing process parameters to minimize the warpage and shrinkage deformations of products during the last decades. In this review, we begin by introducing the manufacturing process in PIM and the cause of warpage and shrinkage deformations, followed by the mechanism about how process parameters, like mold temperature, melt temperature, injection rate, injection pressure, holding pressure, holding and cooling duration, affect those defects. Then, we summarize the recent progress of the design of experiments and four advanced methods (artificial neural networks, genetic algorithm, response surface methodology, and Kriging model) on optimizing process parameters to minimize the warpage and shrinkage deformations. In the end, future perspectives of quality control in injection molding machines are discussed.
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Affiliation(s)
- Nan-yang Zhao
- College of Energy Engineering, Zhejiang University, Hangzhou, 310027 China
| | - Jiao-yuan Lian
- School of Engineering, Zhejiang University City College, Hangzhou, 310015 China
| | - Peng-fei Wang
- School of Engineering, Zhejiang University City College, Hangzhou, 310015 China
| | - Zhong-bin Xu
- College of Energy Engineering, Zhejiang University, Hangzhou, 310027 China
- School of Engineering, Zhejiang University City College, Hangzhou, 310015 China
- Ningbo Research Institute, and Institute of Robotics, Zhejiang University, Ningbo, 315100 China
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24
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Aldhafyan M, Silikas N, Watts DC. Influence of curing modes on conversion and shrinkage of dual-cure resin-cements. Dent Mater 2021; 38:194-203. [PMID: 34924201 DOI: 10.1016/j.dental.2021.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/03/2021] [Accepted: 12/03/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To explore the effect of curing modes of dual-cure resin cements on their degree of conversion (DC) and polymerization shrinkage (PS) over specific post-activation periods. METHODS Five self-adhesive (PANAVIA SA, RelyX Universal Resin, RelyX Unicem 2, Bifix SE, and SpeedCEM Plus) and three conventional (PANAVIA V5, Nexus Third Generation, and RelyX Ultimate Universal) dual-cure resin cements were studied. Four specimens (n = 4) were made per curing mode (light/self-cure) to measure either DC or PS. FTIR was utilized to measure real-time DC (%) over 24 h. The Bonded Disk method was used to measure shrinkage at 23 °C over 1 h. The data were analyzed using one-way ANOVA, Tukey post-hoc tests and independent/ paired sample t-tests (a = 0.05). RESULTS After 1 h post-activation, the DC of light-cured (LC) specimens ranged between 66.6% and 77.4%, whereas for self-cured (SC) specimens DC ranged between 44.4% and 73.2%. After 24 h, the DC of LC specimens ranged between 74.8% and 82.4% and between 62.7% and 81.7% for SC specimens. After 24 h, the DC of three cements (BSE, PV5, and RXU) were comparable between their curing modes (p > 0.05), whereas five cements (CEM, NX3, PSA, RXU2, RXL) had significantly lower DC for SC compared to LC specimens (p < 0.05). After 1 h post-activation, shrinkage ranged between 5.9% and 8.5% for LC and between 4.9% and 8.3% for SC specimens. Most cements were not significantly different between curing modes. However, light-cured PAS, RXL and RXU2 had significantly higher shrinkage (p < 0.05). After 1 h post-activation, a strong positive correlation existed between conversion and shrinkage (LC: r2 = 0.95 and SC: r2 = 0.93). SIGNIFICANCE Whenever light access is possible, light-curing of resin-cements remains beneficial to the overall efficacy of their conversion and thus all factors that depend on that. Conversion and shrinkage behavior are intrinsically important factors in clinical selection of resin-cement products.
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Affiliation(s)
- Mohammed Aldhafyan
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Division of Dental Biomaterials Science, College of Dentistry, King Saud University, Saudi Arabia
| | - Nikolaos Silikas
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK.
| | - David C Watts
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Photon Science Institute, University of Manchester, UK.
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25
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Lancha JP, Colin J, Almeida G, Guerin C, Casalinho J, Perré P. A validated Distributed Activation Energy Model (DAEM) to predict the chemical degradation of biomass as a function of hydrothermal treatment conditions. Bioresour Technol 2021; 341:125831. [PMID: 34455246 DOI: 10.1016/j.biortech.2021.125831] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
This study proposes a DAEM (Distributed Activation Energy Model) approach to predict the chemical alterations of lignocellulosic biomass as a function of hydrothermal treatment conditions. The model is first tuned by an original device allowing the sample shrinkage to be continuously assessed during hydrothermal treatment in saturated water vapor up to 190 °C. The shrinkage dynamic is supplied in the DAEM model as an indicator of the degree of biomass conversion. A set of chemical analyses was performed at selected residence times and treatment temperatures to correlate this degree of conversion with the resulting chemical molecules. A set of functions was then derived from this database to correlate the degree of conversion with the components concentrations. Finally, a validation database was built with different combinations of temperature levels and residence times. The model was proved to be predictive on this new dataset.
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Affiliation(s)
- Julia P Lancha
- Université Paris-Saclay, CentraleSupélec, Laboratoire de Génie des Procédés et Matériaux, SFR Condorcet FR CNRS 3417, Centre Européen de Biotechnologie et de Bioéconomie (CEBB), 51110 Pomacle, France
| | - Julien Colin
- Université Paris-Saclay, CentraleSupélec, Laboratoire de Génie des Procédés et Matériaux, SFR Condorcet FR CNRS 3417, Centre Européen de Biotechnologie et de Bioéconomie (CEBB), 51110 Pomacle, France; Université Paris-Saclay, CentraleSupélec, Laboratoire de Génie des Procédés et Matériaux, 8-10 rue Joliot-Curie, 91190 Gif-sur-Yvette, France
| | - Giana Almeida
- Université Paris-Saclay, INRAE, AgroParisTech, UMR SayFood, 91300 Massy, France.
| | - Cédric Guerin
- Université Paris-Saclay, CentraleSupélec, Laboratoire de Génie des Procédés et Matériaux, SFR Condorcet FR CNRS 3417, Centre Européen de Biotechnologie et de Bioéconomie (CEBB), 51110 Pomacle, France
| | - Joel Casalinho
- Université Paris-Saclay, CentraleSupélec, Laboratoire de Génie des Procédés et Matériaux, 8-10 rue Joliot-Curie, 91190 Gif-sur-Yvette, France
| | - Patrick Perré
- Université Paris-Saclay, CentraleSupélec, Laboratoire de Génie des Procédés et Matériaux, SFR Condorcet FR CNRS 3417, Centre Européen de Biotechnologie et de Bioéconomie (CEBB), 51110 Pomacle, France; Université Paris-Saclay, CentraleSupélec, Laboratoire de Génie des Procédés et Matériaux, 8-10 rue Joliot-Curie, 91190 Gif-sur-Yvette, France.
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Samueli B, Nalbandyan K, Benharroch D, Levi I. Splenic Micronodular T-Cell/Histiocyte-Rich Large B-Cell Lymphoma: The Corticosteroid Pretreatment Hypothesis. Acta Haematol 2021; 145:310-317. [PMID: 34753138 DOI: 10.1159/000520791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 11/06/2021] [Indexed: 11/19/2022]
Abstract
Splenic micronodular T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is derived from diffuse large B-cell lymphoma N.O.S., perhaps with some affinity with nodal THRLBCL. Of note, in contrast with the latter, the only lymph nodes involved in association with the splenic micronodular pattern of the disease are the splenic hilar lymph nodes. The possibility that corticosteroids, when prescribed prior to splenectomy, cause histopathological and functional modulations, apoptosis, necrosis, tissue shrinkage, which may obscure the diagnostic morphological features of this variant lymphoma and cause an underdiagnosis of this condition. The indications for glucocorticoid therapy are either related to the lymphoma itself, or else to other comorbidities, like asthma and autoimmune disorders. We propose that patients with the splenic subset of the disease are likely to have been prescribed corticosteroids prior to histopathologic examination of the involved spleen, causing disparate morphologies. However, a reviewer might accidentally dismiss the corticosteroid pretreatment which is thus overlooked. Apoptosis, induced by corticosteroids, is hypothesized as the major mechanism initiating the histopathological and functional changes in the splenic micronodular variant of the lymphoma.
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Affiliation(s)
- Benzion Samueli
- Department of Pathology, Soroka University Medical Center, and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel,
| | - Karen Nalbandyan
- Department of Pathology, Soroka University Medical Center, and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Daniel Benharroch
- Department of Pathology, Soroka University Medical Center, and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Itai Levi
- Division of Hematology, Soroka University Medical Center, and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
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Li X, Zhang W, Zhang C, Wo Y, Ma A, Li Y, Zhang X. The role of bFGF in preventing the shrinkage of cardiac progenitor cell-engineered conduction tissue by downregulating α-SMA expression. Life Sci 2021; 282:119794. [PMID: 34237312 DOI: 10.1016/j.lfs.2021.119794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 06/26/2021] [Accepted: 06/27/2021] [Indexed: 11/30/2022]
Abstract
AIMS Engineered conduction tissues (ECTs) fabricated from cardiac progenitor cells (CPCs) and collagen sponges were precisely targeted for the treatment of atrioventricular conduction block in our previous studies. However, obvious shrinkage and deformation of ECTs was observed during in vitro culture. According to the literature, it can be speculated that basic fibroblast growth factor (bFGF) may downregulate alpha-smooth muscle actin (α-SMA) produced by CPCs to prevent the shrinkage of CPC-engineered conduction tissues. MAIN METHODS In this study, culture media with or without bFGF were used for both cell culture and 3D tissue construction. The expression of α-SMA and the size change of engineered tissue were analyzed to evaluate the feasibility of adding bFGF to regulate α-SMA expression and shrinkage of constructs. In addition, cardiac-specific examinations were performed to evaluate the effect of bFGF on cardiac tissue formation. KEY FINDINGS Supplementation with bFGF efficiently relieved shrinkage of engineered tissue by downregulating the expression of α-SMA at both the cellular and 3D tissue levels. Moreover, bFGF had a positive influence on cardiac tissue formation in terms of cell viability, tissue organization and electrical conduction velocity. SIGNIFICANCE This study provides a guide for both shape control and quality improvement of CPC-engineered cardiac tissues.
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Affiliation(s)
- Xiaotong Li
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Anatomy, Naval Medical University, Shanghai, China
| | - Wenbo Zhang
- Rheumatology Department of Changhai Hospital, Naval Medical University, Shanghai, China
| | - Chuansen Zhang
- Department of Anatomy, Naval Medical University, Shanghai, China
| | - Yan Wo
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Airong Ma
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Li
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xi Zhang
- Department of Anatomy, Naval Medical University, Shanghai, China.
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Šinkovec H, Heinze G, Blagus R, Geroldinger A. To tune or not to tune, a case study of ridge logistic regression in small or sparse datasets. BMC Med Res Methodol 2021; 21:199. [PMID: 34592945 PMCID: PMC8482588 DOI: 10.1186/s12874-021-01374-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 08/19/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND For finite samples with binary outcomes penalized logistic regression such as ridge logistic regression has the potential of achieving smaller mean squared errors (MSE) of coefficients and predictions than maximum likelihood estimation. There is evidence, however, that ridge logistic regression can result in highly variable calibration slopes in small or sparse data situations. METHODS In this paper, we elaborate this issue further by performing a comprehensive simulation study, investigating the performance of ridge logistic regression in terms of coefficients and predictions and comparing it to Firth's correction that has been shown to perform well in low-dimensional settings. In addition to tuned ridge regression where the penalty strength is estimated from the data by minimizing some measure of the out-of-sample prediction error or information criterion, we also considered ridge regression with pre-specified degree of shrinkage. We included 'oracle' models in the simulation study in which the complexity parameter was chosen based on the true event probabilities (prediction oracle) or regression coefficients (explanation oracle) to demonstrate the capability of ridge regression if truth was known. RESULTS Performance of ridge regression strongly depends on the choice of complexity parameter. As shown in our simulation and illustrated by a data example, values optimized in small or sparse datasets are negatively correlated with optimal values and suffer from substantial variability which translates into large MSE of coefficients and large variability of calibration slopes. In contrast, in our simulations pre-specifying the degree of shrinkage prior to fitting led to accurate coefficients and predictions even in non-ideal settings such as encountered in the context of rare outcomes or sparse predictors. CONCLUSIONS Applying tuned ridge regression in small or sparse datasets is problematic as it results in unstable coefficients and predictions. In contrast, determining the degree of shrinkage according to some meaningful prior assumptions about true effects has the potential to reduce bias and stabilize the estimates.
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Affiliation(s)
- Hana Šinkovec
- Section for Clinical Biometrics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Georg Heinze
- Section for Clinical Biometrics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Rok Blagus
- Institute for Biostatistics and Medical Informatics, University of Ljubljana, Ljubljana, Slovenia
| | - Angelika Geroldinger
- Section for Clinical Biometrics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
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Bernal V, Bischoff R, Horvatovich P, Guryev V, Grzegorczyk M. The 'un-shrunk' partial correlation in Gaussian graphical models. BMC Bioinformatics 2021; 22:424. [PMID: 34493207 PMCID: PMC8424921 DOI: 10.1186/s12859-021-04313-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 08/02/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In systems biology, it is important to reconstruct regulatory networks from quantitative molecular profiles. Gaussian graphical models (GGMs) are one of the most popular methods to this end. A GGM consists of nodes (representing the transcripts, metabolites or proteins) inter-connected by edges (reflecting their partial correlations). Learning the edges from quantitative molecular profiles is statistically challenging, as there are usually fewer samples than nodes ('high dimensional problem'). Shrinkage methods address this issue by learning a regularized GGM. However, it remains open to study how the shrinkage affects the final result and its interpretation. RESULTS We show that the shrinkage biases the partial correlation in a non-linear way. This bias does not only change the magnitudes of the partial correlations but also affects their order. Furthermore, it makes networks obtained from different experiments incomparable and hinders their biological interpretation. We propose a method, referred to as 'un-shrinking' the partial correlation, which corrects for this non-linear bias. Unlike traditional methods, which use a fixed shrinkage value, the new approach provides partial correlations that are closer to the actual (population) values and that are easier to interpret. This is demonstrated on two gene expression datasets from Escherichia coli and Mus musculus. CONCLUSIONS GGMs are popular undirected graphical models based on partial correlations. The application of GGMs to reconstruct regulatory networks is commonly performed using shrinkage to overcome the 'high-dimensional problem'. Besides it advantages, we have identified that the shrinkage introduces a non-linear bias in the partial correlations. Ignoring this type of effects caused by the shrinkage can obscure the interpretation of the network, and impede the validation of earlier reported results.
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Affiliation(s)
- Victor Bernal
- Bernoulli Institute, University of Groningen, Groningen, 9747 AG, The Netherlands.,Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, 9713 AV, The Netherlands
| | - Rainer Bischoff
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, 9713 AV, The Netherlands
| | - Peter Horvatovich
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, 9713 AV, The Netherlands.
| | - Victor Guryev
- European Research Institute for the Biology of Ageing, University Medical Center Groningen, University of Groningen, Groningen, 9713 AV, The Netherlands.
| | - Marco Grzegorczyk
- Bernoulli Institute, University of Groningen, Groningen, 9747 AG, The Netherlands.
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Zouvelou V, Vamvakaris I, Tentolouris-Piperas V, Potaris K, Velonakis G. The effect of glucocorticoids on radiology and histology of thymoma in myasthenia gravis. Acta Neurol Belg 2021. [PMID: 34169487 DOI: 10.1007/s13760-021-01731-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
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Abstract
This paper introduces a simple principle for robust statistical inference via appropriate shrinkage on the data. This widens the scope of high-dimensional techniques, reducing the distributional conditions from sub-exponential or sub-Gaussian to more relaxed bounded second or fourth moment. As an illustration of this principle, we focus on robust estimation of the low-rank matrix Θ* from the trace regression model Y = Tr(Θ*⊤ X) + ϵ. It encompasses four popular problems: sparse linear model, compressed sensing, matrix completion and multi-task learning. We propose to apply the penalized least-squares approach to the appropriately truncated or shrunk data. Under only bounded 2+δ moment condition on the response, the proposed robust methodology yields an estimator that possesses the same statistical error rates as previous literature with sub-Gaussian errors. For sparse linear model and multi-task regression, we further allow the design to have only bounded fourth moment and obtain the same statistical rates. As a byproduct, we give a robust covariance estimator with concentration inequality and optimal rate of convergence in terms of the spectral norm, when the samples only bear bounded fourth moment. This result is of its own interest and importance. We reveal that under high dimensions, the sample covariance matrix is not optimal whereas our proposed robust covariance can achieve optimality. Extensive simulations are carried out to support the theories.
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Affiliation(s)
- Jianqing Fan
- Department of Operations Research and Financial Engineering, Princeton University, Princeton, NJ 08544
| | - Weichen Wang
- Department of Operations Research and Financial Engineering, Princeton University, Princeton, NJ 08544
| | - Ziwei Zhu
- Department of Operations Research and Financial Engineering, Princeton University, Princeton, NJ 08544
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Franchin M, Serafini M, Tadiello M, Fontana F, Rivolta N, Venturini M, Curti M, Bush RL, Dorigo W, Piacentino F, Tozzi M, Piffaretti G. A morphovolumetric analysis of aneurysm sac evolution after elective endovascular abdominal aortic repair. J Vasc Surg 2021; 74:1222-1231.e2. [PMID: 33864827 DOI: 10.1016/j.jvs.2021.03.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 03/15/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Abdominal aortic aneurysm (AAA) sac shrinkage after endovascular aortic repair (EVAR) has been regarded as positive marker of EVAR success durability. The purpose of this study was to describe the morphovolumetric changes of the AAA sac during follow-up after elective EVAR and to analyze sac shrinkage-related variables. METHODS This is a single-center, retrospective, observational cohort study from a tertiary referral university hospital. All patients treated with EVAR between January 2013 and December 2018 were identified. Inclusion criteria were elective EVAR for AAA, preoperative computed tomography angiography within 6 months before EVAR and at least one postoperative computed tomography angiography during the follow-up, using a standardized protocol. Aneurysm sac shrinkage was defined as diameter decrease of 1 cm or more, volume shrinkage threshold was identified by a 16% decrease compared with the preoperative value. Primary outcomes were early (≤30 days) and late survival, and freedom from aneurysm-related mortality (ARM), and aortic reintervention. RESULTS There were 149 of the 325 patients (45.8%) who met the inclusion criteria: 133 (89.3%) were male and 16 (10.7%) female. The mean age was 74 ± 7 years (range, 55-87 years); the median AAA diameter was 56 mm (interquartile range, 50.0-61.2 mm) and the median volume was 138.8 cm3 (range, 99.0-178.3 cm3). Primary technical success was achieved in 145 patients (97.3%). The in-hospital mortality rate was 1.3%. The median follow-up was 42 months (interquartile range, 22.5-58.0 months). Both AAA diameter and volume decreased (P = .001 and P = .035, respectively) compared with preoperative measurements. Diameter shrinkage was adjudicated in 27 patients (18.1%), volume shrinkage was observed in 42 patients (28.2%). A Cox regression analysis demonstrated an association between the AAA diameter shrinkage and the preoperative diameter (P = .002; hazard ratio, 1.03; 95% confidence interval [CI], 1.011-1.052). The presence of a persistent endoleak predicted the absence of volume shrinkage (P = .001; hazard ratio, 7.75; 95% CI, 2.282-26.291). The estimated freedom from ARM was 97.5 ± 1.0% (95% CI, 93-99) at 12 months, and 96 ± 2% (95% CI, 90-98) at both 36 and 60 months. Aortic reintervention during the follow-up period was necessary in 7 patients (4.7%). ARM was only observed in the group characterized by the concomitant absence of diameter and volume shrinkage. CONCLUSIONS Volumetric analysis showed to have higher sensitivity than the simple two-dimensional measurement of the diameter to study AAA sac changes after EVAR. Although no predictor was found to be associated with AAA volume shrinkage, ARM occurred only in the group of AAAs with the absence of volume shrinkage.
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Affiliation(s)
- Marco Franchin
- Department of Medicine and Surgery, Vascular Surgery, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy
| | - Maddalena Serafini
- Department of Medicine and Surgery, Vascular Surgery, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy
| | - Marco Tadiello
- Department of Medicine and Surgery, Vascular Surgery, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy
| | - Federico Fontana
- Interventional Radiology, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy
| | - Nicola Rivolta
- Department of Medicine and Surgery, Vascular Surgery, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy
| | - Massimo Venturini
- Interventional Radiology, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy
| | - Marco Curti
- Interventional Radiology, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy
| | - Ruth L Bush
- University of Houston College of Medicine, Houston, Tex
| | - Walter Dorigo
- Department of Clinical and Experimental Medicine, Vascular Surgery, University of Florence School of Medicine, Careggi University Teaching Hospital, Florence, Italy
| | - Filippo Piacentino
- Interventional Radiology, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy
| | - Matteo Tozzi
- Department of Medicine and Surgery, Vascular Surgery, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy
| | - Gabriele Piffaretti
- Department of Medicine and Surgery, Vascular Surgery, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy.
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Vaskoska R, Ha M, Ong L, Chen G, White J, Gras S, Warner R. Myosin sensitivity to thermal denaturation explains differences in water loss and shrinkage during cooking in muscles of distinct fibre types. Meat Sci 2021; 179:108521. [PMID: 33964804 DOI: 10.1016/j.meatsci.2021.108521] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/11/2021] [Accepted: 04/08/2021] [Indexed: 12/26/2022]
Abstract
The effect of thermal protein denaturation on the structure and quality of muscles of different fibre types is not well understood. Unaged masseter (100% type I fibres) and cutaneous trunci (93% type II fibres) muscles (N = 10) were assessed for their characteristics, protein denaturation, cooking loss, Warner- Bratzler shear force (WBSF) and shrinkage after heating at 50 °C - 85 °C with a rate of 5 °C/ min. Raw masseter had a higher pH, collagen and water content, shorter sarcomere, comparable fibre diameter, and shorter and wider fragments upon homogenization, than cutaneous trunci. In cutaneous trunci, at 55 °C - 60 °C, the lower transition temperature of myosin and the greater cumulative enthalpy resulted in greater cooking loss in muscle cuboids, and greater transverse, longitudinal and volume shrinkage in fibres and fibre fragments, than in masseter. Protein denaturation explained 71% variability in fibre fragment volume and 58% in cooking loss of both muscles, as well as 47% variability in WBSF of masseter.
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Affiliation(s)
- Rozita Vaskoska
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, Australia.
| | - Minh Ha
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, Australia
| | - Lydia Ong
- Department of Chemical Engineering, The University of Melbourne, Victoria, Australia; The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia
| | - George Chen
- Department of Chemical Engineering, The University of Melbourne, Victoria, Australia
| | - Jason White
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, Australia; Charles Sturt University, Wagga Wagga, New South Wales, Australia
| | - Sally Gras
- Department of Chemical Engineering, The University of Melbourne, Victoria, Australia; The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia
| | - Robyn Warner
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, Australia
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Riley RD, Snell KIE, Martin GP, Whittle R, Archer L, Sperrin M, Collins GS. Penalization and shrinkage methods produced unreliable clinical prediction models especially when sample size was small. J Clin Epidemiol 2021; 132:88-96. [PMID: 33307188 PMCID: PMC8026952 DOI: 10.1016/j.jclinepi.2020.12.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 11/15/2020] [Accepted: 12/02/2020] [Indexed: 12/14/2022]
Abstract
OBJECTIVES When developing a clinical prediction model, penalization techniques are recommended to address overfitting, as they shrink predictor effect estimates toward the null and reduce mean-square prediction error in new individuals. However, shrinkage and penalty terms ('tuning parameters') are estimated with uncertainty from the development data set. We examined the magnitude of this uncertainty and the subsequent impact on prediction model performance. STUDY DESIGN AND SETTING This study comprises applied examples and a simulation study of the following methods: uniform shrinkage (estimated via a closed-form solution or bootstrapping), ridge regression, the lasso, and elastic net. RESULTS In a particular model development data set, penalization methods can be unreliable because tuning parameters are estimated with large uncertainty. This is of most concern when development data sets have a small effective sample size and the model's Cox-Snell R2 is low. The problem can lead to considerable miscalibration of model predictions in new individuals. CONCLUSION Penalization methods are not a 'carte blanche'; they do not guarantee a reliable prediction model is developed. They are more unreliable when needed most (i.e., when overfitting may be large). We recommend they are best applied with large effective sample sizes, as identified from recent sample size calculations that aim to minimize the potential for model overfitting and precisely estimate key parameters.
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Affiliation(s)
- Richard D Riley
- Centre for Prognosis Research, School of Medicine, Keele University, Staffordshire, UK, ST5 5BG.
| | - Kym I E Snell
- Centre for Prognosis Research, School of Medicine, Keele University, Staffordshire, UK, ST5 5BG
| | - Glen P Martin
- Division of Informatics, Imaging and Data Science, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Rebecca Whittle
- Centre for Prognosis Research, School of Medicine, Keele University, Staffordshire, UK, ST5 5BG
| | - Lucinda Archer
- Centre for Prognosis Research, School of Medicine, Keele University, Staffordshire, UK, ST5 5BG
| | - Matthew Sperrin
- Division of Informatics, Imaging and Data Science, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Gary S Collins
- Nuffield Department of Orthopaedics, Centre for Statistics in Medicine, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK, OX3 7LD; NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, OX3 9DU, UK
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Shah PK, Stansbury JW. Photopolymerization shrinkage-stress reduction in polymer-based dental restoratives by surface modification of fillers. Dent Mater 2021; 37:578-587. [PMID: 33573842 DOI: 10.1016/j.dental.2021.01.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/17/2021] [Accepted: 01/18/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVES This research explores the use of polymer brushes for surface treatment of fillers used in polymer-based dental restoratives with focus on shrinkage stress reduction. The influence of interfacial reactive groups on shrinkage stress is explored. METHODS Oligomers of varying lengths and with varying number of reactive groups along the length were synthesized by modifying commercial oligomers. Surface of silica fillers (OX50) was treated with methylaminopropyltrimethoxysilane and this was further reacted with the synthesized oligomers to obtain a series of polymer brushes on the surface. Fillers modified with γ-methacryloxypropyltrimethoxysilane were used as a control. Filler surface treatment was confirmed using diffuse reflectance spectroscopy and thermogravimetric analysis. Fillers were added at 30 wt % to a resin made of BisGMA/TEGDMA and polymerization kinetics, shrinkage stress, volumetric shrinkage, flexural strength and modulus, viscosity were measured. RESULTS Composites with polymer brush functionalized fillers showed up to a 30 % reduction in shrinkage stress as compared to the control, with no reduction in flexural strength and modulus. Shrinkage stress reduced with increasing length of the polymer brush and increased with increase in number of reactive groups along the length of the polymer brush. SIGNIFICANCE The interface between inorganic fillers and an organic polymer matrix has been utilized to reduce shrinkage stress in a composite with no compromise in mechanical properties. This study gives insights into the stress development mechanism at the interface.
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Affiliation(s)
- Parag K Shah
- Department of Chemical and Biological Engineering, University of Colorado Boulder, CO, United States.
| | - Jeffrey W Stansbury
- Department of Chemical and Biological Engineering, University of Colorado Boulder, CO, United States; Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
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Mariani C, Carta F, Tatti M, Marrosu V, Gerosa C, Puxeddu R. Shrinkage of specimens after CO 2 laser cordectomy: an objective intraoperative evaluation. Eur Arch Otorhinolaryngol 2021; 278:1515-21. [PMID: 33515084 DOI: 10.1007/s00405-021-06625-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/15/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE The margin status after CO2 laser cordectomy for glottic carcinoma may influence prognosis. There are no studies assessing the possible bias due to anatomic changes of the specimens for shrinkage. The authors evaluated the intraoperative shrinkage of specimens immediately after transoral CO2 laser microsurgery (CO2 TOLMS) to improve the understanding and the interpretation of surgical margins. METHODS This is a prospective study involving a consecutive cohort of 23 patients (19 males, 4 females, mean age 69.9 years, range 42-83 years) with early glottic carcinoma treated by CO2 TOLMS from February 2017 to April 2019. The anteroposterior shrinkage of the specimen, of the tumor, and of the anterior and posterior margins was measured intraoperatively with a cross table reticle glass micrometer ruler, inserted into the eyepiece of the surgical microscope. RESULTS The mean shrinkage of the mucosal specimen from intralaryngeal measurement to post-resection measurement was 3.8 ± 0.3 mm, resulting in an average loss of 29% of the anteroposterior length (p < 0.01). The anteroposterior length of both the tumor and the margins after resection significantly decreased, but the shrinkage of the anterior and posterior margins was significantly greater than the shrinkage of the tumor (49% versus 20% and 45% versus 20%, p < 0.01). CONCLUSION The present study demonstrates significant shrinkage of specimens after CO2 TOLMS, especially in the anteroposterior length of the vocal cords, and justifies the good oncological results for specimens with close and single positive superficial margins. Follow-up versus a second surgical look policy could be safely suggested in cases of close superficial and single positive superficial margins.
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Fischer SB, Koos E. Using an added liquid to suppress drying defects in hard particle coatings. J Colloid Interface Sci 2021; 582:1231-1242. [PMID: 32950839 DOI: 10.1016/j.jcis.2020.08.055] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 10/23/2022]
Abstract
HYPOTHESIS Lateral accumulation and film defects during drying of hard particle coatings is a common problem, typically solved using polymeric additives and surface active ingredients, which require further processing of the dried film. Capillary suspensions with their tunable physical properties, devoid of polymers, offer new pathways in producing uniform and defect free particulate coatings. EXPERIMENTS We investigated the effect of small amounts of secondary liquid on the coating's drying behavior. Stress build-up and weight loss in a temperature and humidity controlled drying chamber were simultaneously measured. Changes in the coating's reflectance and height profile over time were related with the weight loss and stress curve. FINDINGS Capillary suspensions dry uniformly without defects. Lateral drying is inhibited by the high yield stress, causing the coating to shrink to an even height. The bridges between particles prevent air invasion and extend the constant drying period. The liquid in the lower layers is transported to the interface via corner flow within surface pores, leading to a partially dry layer near the substrate while the pores above are still saturated. Using capillary suspensions for hard particle coatings results in more uniform, defect free films with better printing characteristics, rendering high additive content obsolete.
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Affiliation(s)
- Steffen B Fischer
- KU Leuven, Soft Matter, Rheology and Technology, Department of Chemical Engineering, Celestijnenlaan 200f, 3001 Leuven, Belgium; Karlsruhe Institute of Technology, Institute for Mechanical Process Engineering and Mechanics, Karlsruhe, Germany
| | - Erin Koos
- KU Leuven, Soft Matter, Rheology and Technology, Department of Chemical Engineering, Celestijnenlaan 200f, 3001 Leuven, Belgium.
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Lin X, Xu JL, Sun DW. Evaluating drying feature differences between ginger slices and splits during microwave-vacuum drying by hyperspectral imaging technique. Food Chem 2020; 332:127407. [PMID: 32645677 DOI: 10.1016/j.foodchem.2020.127407] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 06/20/2020] [Accepted: 06/21/2020] [Indexed: 01/11/2023]
Abstract
This study aimed to investigate the difference between ginger slices (vertically cut) and splits (horizontally cut) during microwave-vacuum drying (MVD) procedures. MVD ginger slices showed a higher shrinkage rate and a higher hardness value, with a more porous structure of the surface layer. MVD ginger splits had higher rehydration rates at the first 15 min of the rehydration. Nine optimal wavelengths were selected by regression coefficients (RC) from the partial least squares regression (PLSR) model based on the raw data. A simplified PLSR model based on optimal wavelengths showed a good performance with a coefficient of determination in prediction (Rp2) of 0.973 and a root mean square error in prediction (RMSEP) of 4.63%. Texture features of grey level co-occurrence matrix (GLCM) of moisture prediction maps demonstrated a more uniform moisture distribution in MVD ginger slices than that in splits in the original geometry.
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Affiliation(s)
- Xiaohui Lin
- Food Refrigeration and Computerized Food Technology (FRCFT), School of Biosystems and Food Engineering, Agriculture & Food Science Centre, University College Dublin (UCD), National University of Ireland, Belfield, Dublin 4, Ireland
| | - Jun-Li Xu
- Food Refrigeration and Computerized Food Technology (FRCFT), School of Biosystems and Food Engineering, Agriculture & Food Science Centre, University College Dublin (UCD), National University of Ireland, Belfield, Dublin 4, Ireland
| | - Da-Wen Sun
- Food Refrigeration and Computerized Food Technology (FRCFT), School of Biosystems and Food Engineering, Agriculture & Food Science Centre, University College Dublin (UCD), National University of Ireland, Belfield, Dublin 4, Ireland.
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Davoodi E, Montazerian H, Khademhosseini A, Toyserkani E. Sacrificial 3D printing of shrinkable silicone elastomers for enhanced feature resolution in flexible tissue scaffolds. Acta Biomater 2020; 117:261-272. [PMID: 33031967 DOI: 10.1016/j.actbio.2020.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/16/2020] [Accepted: 10/01/2020] [Indexed: 12/11/2022]
Abstract
Silicone implants and scaffolds are emerging as potential replacement of flexible tissues, cosmetic and biomedical device implants due to their bioinert and flexible characteristics. The state-of-the-art direct-write silicone three-dimensional (3D) printers however cannot easily 3D print structures with sub-millimeter dimensions because of high viscosity and long curing times of their prepolymers. In the present study, a template-assisted 3D printing of ordered porous silicone constructs is demonstrated. The sacrificial molds were fabricated by low-cost and well-accessible material extrusion 3D printers. The 3D printed molds represent interconnected tortuous high specific surface area porous architectures based on triply periodic minimal surfaces (TPMS) in which the silicone prepolymer is cast and cured. We engineered silicone prepolymer with additives allowing on-demand structural shrinkage upon solvent treatment. This enabled 3D printing at a larger scale compatible with extrusion 3D printer resolution followed by isotropic shrinkage. This procedure led to a volumetric shrinkage of up to ~70% in a highly controllable manner. In this way, pore sizes in the order of 500-600 µm were obtained. The porous constructs were characterized with full strain recovery under extreme compressive deformations of up to 85% of the initial scaffold length. We further demonstrated the ability to infill cell-laden hydrogels such as gelatin methacryloyl (GelMA) into the interconnected pores while maintaining the cell viability of ~90%.
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Affiliation(s)
- Elham Davoodi
- Multi-Scale Additive Manufacturing Lab, Mechanical and Mechatronics Engineering Department, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada; Department of Bioengineering, University of California, Los Angeles, 410 Westwood Plaza, Los Angeles, CA 90095, USA; Center for Minimally Invasive Therapeutics (C-MIT), California NanoSystems Institute (CNSI), University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, CA 90095, USA
| | - Hossein Montazerian
- Department of Bioengineering, University of California, Los Angeles, 410 Westwood Plaza, Los Angeles, CA 90095, USA; Center for Minimally Invasive Therapeutics (C-MIT), California NanoSystems Institute (CNSI), University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, CA 90095, USA; Terasaki Institute for Biomedical Innovation, Los Angeles, CA 90024, USA
| | - Ali Khademhosseini
- Department of Bioengineering, University of California, Los Angeles, 410 Westwood Plaza, Los Angeles, CA 90095, USA; Center for Minimally Invasive Therapeutics (C-MIT), California NanoSystems Institute (CNSI), University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, CA 90095, USA; Terasaki Institute for Biomedical Innovation, Los Angeles, CA 90024, USA
| | - Ehsan Toyserkani
- Multi-Scale Additive Manufacturing Lab, Mechanical and Mechatronics Engineering Department, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.
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Abstract
We develop a Bayesian methodology aimed at simultaneously estimating low-rank and row-sparse matrices in a high-dimensional multiple-response linear regression model. We consider a carefully devised shrinkage prior on the matrix of regression coefficients which obviates the need to specify a prior on the rank, and shrinks the regression matrix towards low-rank and row-sparse structures. We provide theoretical support to the proposed methodology by proving minimax optimality of the posterior mean under the prediction risk in ultra-high dimensional settings where the number of predictors can grow sub-exponentially relative to the sample size. A one-step post-processing scheme induced by group lasso penalties on the rows of the estimated coefficient matrix is proposed for variable selection, with default choices of tuning parameters. We additionally provide an estimate of the rank using a novel optimization function achieving dimension reduction in the covariate space. We exhibit the performance of the proposed methodology in an extensive simulation study and a real data example.
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Affiliation(s)
- Antik Chakraborty
- Department of Statistics, Texas A&M University, College Station, Texas, 77843, USA
| | - Anirban Bhattacharya
- Department of Statistics, Texas A&M University, College Station, Texas, 77843, USA
| | - Bani K Mallick
- Department of Statistics, Texas A&M University, College Station, Texas, 77843, USA
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Rani P, Tripathy PP. Modelling of moisture migration during convective drying of pineapple slice considering non-isotropic shrinkage and variable transport properties. J Food Sci Technol 2020; 57:3748-61. [PMID: 32904001 DOI: 10.1007/s13197-020-04407-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 01/21/2020] [Accepted: 04/02/2020] [Indexed: 10/24/2022]
Abstract
The present work aims to develop a 3-dimensional finite element (FE) model to analyze moisture migration during drying of pineapple ring considering moisture dependent diffusion coefficient (D) and mass transfer coefficient (hm) along with radial and longitudinal shrinkage. Pineapple rings were dried at 70 °C temperature and 0.6 m/s air velocity to study the moisture loss and shrinkage kinetics during drying. Thickness, outer radius and inner radius of hollow cylindrical pineapple slices were reduced by 79.3%, 32.2%, and 51.2%, respectively due to the occurrence of shrinkage during drying. Non-linear regression analysis showed the quadratic model to best fitted to the experimental moisture ratio data for explaining the shrinkage phenomenon in pineapple slice during drying. Shrinkage was accommodated into FE modelling using the arbitrary lagrange-eulerian method. Consideration of variable D showed better agreement with the experimental data than consideration of constant D, however constant and variable hm predicted similar results. Incorporation of shrinkage phenomena during modelling led to prediction of more accurate result showing 0.06% deviation from experimental curve, but neglecting the shrinkage resulted in a 17% deviation. Hence, model developed with consideration of shrinkage along with variable D and hm presented best fit with experimental drying curve. Developed model allowed the visualization of spatial moisture profile within the sample during drying, which would be useful for estimating the correct drying time, optimizing and designing of drying process.
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Verzola KC, Dressano D, Saraceni CHC, Gonçalves LS, Hadis M, Watts DC, Palin WM, Lima AF. Bis(4-methyl phenyl)iodonium as an alternative component to diphenyliodonium in camphorquinone-based ternary initiating systems. Dent Mater 2020; 36:1282-1288. [PMID: 32690220 DOI: 10.1016/j.dental.2020.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the influence of different co-initiators (diphenyliodonium hexafluorophosphate - DPI - and bis(4-methyl phenyl)iodonium hexafluorophosphate - BPI) on chemical and mechanical properties of resins. METHODS Nine experimental resins (50% Bis-GMA and 50% TEGDMA, w/w) with 60 wt% filler particles were formulated. The initiating system used was camphorquinone (CQ-1 mol%) and ethyl dimethylaminobenzoate (EDAB-2 mol%). Experimental groups were established according to DPI and BPI quantities (0.25, 0.5, 0.75, and 1 mol%). The control group was a resin containing only CQ-EDAB. Light transmission through the resin during polymerisation was analysed with a UV-vis spectrophotometer. Real-time polymerisation of the systems was evaluated using an FTIR spectrometer. Real-time polymerisation shrinkage strain was evaluated, and the flexural strength and modulus of materials were obtained by 3-point bending. Experimental groups were statistically analysed by Analysis of Variance and Tukey's test (α = 0.05). Dunnett's test was applied to compare experimental groups with control. RESULTS Light transmission rapidly increased initially for resins containing DPI or BPI. After 30 s cure, the irradiance on the lower surface of resin specimens was similar for all groups. After 10 s of light irradiation, groups containing DPI and BPI had higher conversion than the control. However, conversion after 120 s post-irradiation was similar for all groups. The rate of polymerisation, shrinkage strain, and the maximum strain rate were higher for groups containing DPI/BPI. The use of iodonium salts increased the flexural strength and flexural moduli of resins. SIGNIFICANCE DPI and BPI increased resin reactivity similarly. Increased rate of polymerization influenced light transmission through the resin in the first seconds of polymerisation and increased resin shrinkage and rate of shrinkage, as well as flexural strength and moduli.
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Affiliation(s)
- Karina C Verzola
- Dental Research Division, Paulista University, Rua Doutor Bacelar, 1212, CEP: 04026-002 Sao Paulo, Brazil.
| | - Diogo Dressano
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo 13414-903, Brazil.
| | | | - Luciano Souza Gonçalves
- Department of Restorative Dentistry, School of Dentistry, Federal University of Santa Maria, Av. Roraima, 1000 - Camobi, Santa Maria, RS, 97105-900, Brazil.
| | - Mohammed Hadis
- Biomaterials Unit, Birmingham Dental School and Hospital, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham B5 7EG, United Kingdom.
| | - David C Watts
- School of Medical Sciences and Photon Science Institute, Coupland 3 Building, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom.
| | - William M Palin
- Biomaterials Unit, Birmingham Dental School and Hospital, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham B5 7EG, United Kingdom.
| | - Adriano Fonseca Lima
- Dental Research Division, Paulista University, Rua Doutor Bacelar, 1212, CEP: 04026-002 Sao Paulo, Brazil.
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Sauerbrei W, Perperoglou A, Schmid M, Abrahamowicz M, Becher H, Binder H, Dunkler D, Harrell FE, Royston P, Heinze G. State of the art in selection of variables and functional forms in multivariable analysis-outstanding issues. Diagn Progn Res 2020; 4:3. [PMID: 32266321 PMCID: PMC7114804 DOI: 10.1186/s41512-020-00074-3] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/18/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND How to select variables and identify functional forms for continuous variables is a key concern when creating a multivariable model. Ad hoc 'traditional' approaches to variable selection have been in use for at least 50 years. Similarly, methods for determining functional forms for continuous variables were first suggested many years ago. More recently, many alternative approaches to address these two challenges have been proposed, but knowledge of their properties and meaningful comparisons between them are scarce. To define a state of the art and to provide evidence-supported guidance to researchers who have only a basic level of statistical knowledge, many outstanding issues in multivariable modelling remain. Our main aims are to identify and illustrate such gaps in the literature and present them at a moderate technical level to the wide community of practitioners, researchers and students of statistics. METHODS We briefly discuss general issues in building descriptive regression models, strategies for variable selection, different ways of choosing functional forms for continuous variables and methods for combining the selection of variables and functions. We discuss two examples, taken from the medical literature, to illustrate problems in the practice of modelling. RESULTS Our overview revealed that there is not yet enough evidence on which to base recommendations for the selection of variables and functional forms in multivariable analysis. Such evidence may come from comparisons between alternative methods. In particular, we highlight seven important topics that require further investigation and make suggestions for the direction of further research. CONCLUSIONS Selection of variables and of functional forms are important topics in multivariable analysis. To define a state of the art and to provide evidence-supported guidance to researchers who have only a basic level of statistical knowledge, further comparative research is required.
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Affiliation(s)
- Willi Sauerbrei
- Institute of Medical Biometry and Statistics, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Aris Perperoglou
- Data Science and Artificial Intelligence AstraZeneca, Cambridge, UK
| | - Matthias Schmid
- Department of Medical Biometry, Informatics and Epidemiology, Faculty of Medicine, University of Bonn, Bonn, Germany
| | | | - Heiko Becher
- Institute for Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Harald Binder
- Institute of Medical Biometry and Statistics, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Daniela Dunkler
- Section for Clinical Biometrics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Frank E. Harrell
- Department of Biostatistics, School of Medicine, Vanderbilt University, Nashville, TN USA
| | - Patrick Royston
- MRC Clinical Trials Unit at UCL, Institute of Clinical Trials and Methodology, University College London, London, UK
| | - Georg Heinze
- Section for Clinical Biometrics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
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Ohmori K, Tasaki T, Kimura S, Hori A, Sakaeda N, Hanabusa M, Yamamoto T. Residual polymerization stresses in human premolars generated with Class II composite restorations. J Mech Behav Biomed Mater 2020; 104:103643. [PMID: 32174402 DOI: 10.1016/j.jmbbm.2020.103643] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/13/2020] [Accepted: 01/15/2020] [Indexed: 11/19/2022]
Abstract
The objective of this study was to assess the influence of filling techniques on residual polymerization stresses in resin composite restorations of the tooth. Flat planes were ground in buccal enamel surfaces of extracted human premolars, followed by preparing Class II cavities. Indentation cracks were introduced in the planes and crack lengths were measured mesio-distally (x-direction) and cervico-incisally (y-direction). Cavities were filled with a resin composite and an adhesive using three methods; one with bulk filling and two with differing incremental filling techniques. The x- and y-tensile stresses were calculated from crack lengths measured repeatedly over 360 min after filling. Elastic modulus and polymerization shrinkage of the composite were also measured. Filling technique and time after fillings were statistically significant only for the y-stress. The incremental techniques generated smaller stresses than the bulk filling. The stresses developed for 60 min after filling, while the modulus and the shrinkage stopped developing within 10 min and 2 min after irradiation, respectively. The incremental technique, in which the proximal portion of the cavity was filled first, was effective in decreasing the residual tensile stress generated by the polymerization of resin composite.
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Affiliation(s)
- Kaoru Ohmori
- Department of Operative Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.
| | - Tatsuya Tasaki
- Department of Operative Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan
| | - Saori Kimura
- Department of Operative Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan
| | - Ayaka Hori
- Department of Operative Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan
| | - Nana Sakaeda
- Department of Operative Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan
| | - Masao Hanabusa
- Department of Operative Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan
| | - Takatsugu Yamamoto
- Department of Operative Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan
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Abstract
Prior information often takes the form of parameter constraints. Bayesian methods include such information through prior distributions having constrained support. By using posterior sampling algorithms, one can quantify uncertainty without relying on asymptotic approximations. However, sharply constrained priors are not necessary in some settings and tend to limit modelling scope to a narrow set of distributions that are tractable computationally. We propose to replace the sharp indicator function of the constraint with an exponential kernel, thereby creating a close-to-constrained neighbourhood within the Euclidean space in which the constrained subspace is embedded. This kernel decays with distance from the constrained space at a rate depending on a relaxation hyperparameter. By avoiding the sharp constraint, we enable use of off-the-shelf posterior sampling algorithms, such as Hamiltonian Monte Carlo, facilitating automatic computation in a broad range of models. We study the constrained and relaxed distributions under multiple settings and theoretically quantify their differences. Application of the method is illustrated through several novel modelling examples.
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Affiliation(s)
- Leo L Duan
- Department of Statistics, University of Florida, 101C Griffin-Floyd Hall, P.O. Box 118545, Gainesville, Florida 32611, U.S.A
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Abstract
The rationale leading to the present generation of resin composites is surveyed. There are many sub-classes such as flowable materials with specialized clinical indications. But a simplistic categorization of resin-composite materials is inappropriate. It is better to appreciate the factors that have driven recent developments. These include the search for low shrinkage composites and for greater depth of cure. Other necessary features are good handling behavior and sufficient strength for load-bearing situations. The esthetic challenge is for materials with superior and life-like optical properties and it is important to identify products that are good in every critical property. Nanotechnology has led to certain improvements, but the possibilities and limitations of nanoparticles must be appreciated. In all these developments, the structure and properties of the host tissues are a challenge and inspiration. Thus materials that can emulate the features of enamel and dentin are the goal of biomimetic design.
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Affiliation(s)
- David C Watts
- School of Medical Sciences and Photon Science Institute, University of Manchester
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Berzuini C, Guo H, Burgess S, Bernardinelli L. A Bayesian approach to Mendelian randomization with multiple pleiotropic variants. Biostatistics 2020; 21:86-101. [PMID: 30084873 PMCID: PMC6920542 DOI: 10.1093/biostatistics/kxy027] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Revised: 05/14/2018] [Accepted: 06/02/2018] [Indexed: 11/13/2022] Open
Abstract
We propose a Bayesian approach to Mendelian randomization (MR), where instruments are allowed to exert pleiotropic (i.e. not mediated by the exposure) effects on the outcome. By having these effects represented in the model by unknown parameters, and by imposing a shrinkage prior distribution that assumes an unspecified subset of the effects to be zero, we obtain a proper posterior distribution for the causal effect of interest. This posterior can be sampled via Markov chain Monte Carlo methods of inference to obtain point and interval estimates. The model priors require a minimal input from the user. We explore the performance of our method by means of a simulation experiment. Our results show that the method is reasonably robust to the presence of directional pleiotropy and moderate correlation between the instruments. One section of the article elaborates the model to deal with two exposures, and illustrates the possibility of using MR to estimate direct and indirect effects in this situation. A main objective of the article is to create a basis for developments in MR that exploit the potential offered by a Bayesian approach to the problem, in relation with the possibility of incorporating external information in the prior, handling multiple sources of uncertainty, and flexibly elaborating the basic model.
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Affiliation(s)
- Carlo Berzuini
- Centre for Biostatistics, The University of Manchester, Jean McFarlane Building, University Place, Oxford Road, Manchester M13 9PL, UK
| | - Hui Guo
- Centre for Biostatistics, The University of Manchester, Jean McFarlane Building, University Place, Oxford Road, Manchester M13 9PL, UK
| | - Stephen Burgess
- Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK and MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
| | - Luisa Bernardinelli
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
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Abstract
Elastic properties of the cell wall play a key role in regulating plant growth and morphogenesis; however, measuring them in vivo remains a challenge. Although several new methods have recently become available, they all have substantial drawbacks. Here we describe a detailed protocol for osmotic treatments, which is based on the idea of releasing the turgor pressure within the cell and measuring the resulting deformation. When placed in hyperosmotic solution, cells lose water via osmosis and shrink. Confocal images of the tissue, taken before and after this treatment, are quantified using high-resolution surface projections in MorphoGraphX. The cell shrinkage observed can then be used to estimate cell wall elasticity. This allows qualitative comparisons of cell wall properties within organs or between genotypes and can be combined with mechanical simulations to give quantitative estimates of the cells' Young's moduli. We use the abaxial sepal of Arabidopsis thaliana as an easily accessible model system to present our approach, but it can potentially be used on many other plant organs. The main challenges of this technique are choosing the optimal concentration of the hyperosmotic solution and producing high-quality confocal images (with cell walls visualized) good enough for segmentation in MorphoGraphX.
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Rani P, Tripathy PP. Effect of ultrasound and chemical pretreatment on drying characteristics and quality attributes of hot air dried pineapple slices. J Food Sci Technol 2019; 56:4911-24. [PMID: 31741515 DOI: 10.1007/s13197-019-03961-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 06/20/2019] [Accepted: 07/16/2019] [Indexed: 10/26/2022]
Abstract
Drying of food materials is a time consuming activity making the process cost and energy intensive and hence, several pretreatments are used to improve the drying rate. The present study aims to study the effect of potassium metabisulphite (KMS solution, 0.25% w/v) and ultrasound (20 and 30 min) pretreatment on hot air drying characteristics and quality of pineapple slices. The results indicated that pretreated samples provided higher drying rate, enhanced moisture diffusivity, brighter color and lower hardness than that of untreated dried sample. It was observed that KMS and ultrasound pretreatment for 20 and 30 min reduced the drying time by 23.8%, 19% and 14.3%, respectively. Further, ten thin layer drying models were applied to the experimental drying data and logarithmic model was best fitted to explain the drying behavior of pretreated and untreated samples. Additionally, the effect of shrinkage on moisture transfer mechanism was also studied. Results highlighted that instantaneous moisture diffusivity was increased during drying while shrinkage was not accounted. However, shrinkage consideration reduced the average moisture diffusivity values by 72-83%. Overall color change (13.95 ± 0.92) and browning index (36.02 ± 2.45) were found to be lowest in ultrasound (30 min) pretreated dried sample, highlighting better color stability. Scanning electron microscopy presented noticeable effects of pretreatment on alterations of microstructure of pineapple slices. It can be interpreted that KMS pretreatment was found to be more effective for improvement of drying characteristics of pineapple slices as compared to ultrasound pretreatment.
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Boldrini L, Chiloiro G, Pesce A, Romano A, Teodoli S, Placidi L, Campitelli M, Gambacorta M, Valentini V. Hybrid MRI guided radiotherapy in locally advanced cervical cancer: Case report of an innovative personalized therapeutic approach. Clin Transl Radiat Oncol 2019; 20:27-29. [PMID: 31768423 PMCID: PMC6872866 DOI: 10.1016/j.ctro.2019.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/17/2019] [Accepted: 10/17/2019] [Indexed: 01/28/2023] Open
Abstract
The case report of a patient affected by locally advanced cervical MRgRT is described. MRgRT appears to be feasible for cervical cancer and may improve treatment quality. MRgRT insights are discussed focusing on adaptive response and toxicity monitoring.
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Affiliation(s)
- L. Boldrini
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, U.O.C. di Radioterapia Oncologica, Roma, Italy
| | - G. Chiloiro
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, U.O.C. di Radioterapia Oncologica, Roma, Italy
| | - A. Pesce
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, U.O.C. di Radioterapia Oncologica, Roma, Italy
- Corresponding author at: U.O.C. di Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Roma, Italy.
| | - A. Romano
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, U.O.C. di Radioterapia Oncologica, Roma, Italy
| | - S. Teodoli
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, U.O.C. di Fisica Sanitaria, Roma, Italy
| | - L. Placidi
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, U.O.C. di Fisica Sanitaria, Roma, Italy
| | - M. Campitelli
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, U.O.C. di Radioterapia Oncologica, Roma, Italy
| | - M.A. Gambacorta
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, U.O.C. di Radioterapia Oncologica, Roma, Italy
| | - V. Valentini
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, U.O.C. di Radioterapia Oncologica, Roma, Italy
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