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Toropova AP, Toropov AA. The coefficient of conformism of a correlative prediction (CCCP): Building up reliable nano-QSPRs/QSARs for endpoints of nanoparticles in different experimental conditions encoded via quasi-SMILES. Sci Total Environ 2024; 927:172119. [PMID: 38569951 DOI: 10.1016/j.scitotenv.2024.172119] [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: 01/26/2024] [Revised: 03/12/2024] [Accepted: 03/29/2024] [Indexed: 04/05/2024]
Abstract
Simulation of the physicochemical and biochemical behavior of nanomaterials has its own specifics. However, the main goal of modeling for both traditional substances and nanomaterials is the same. This is an ecologic risk assessment. The universal indicator of toxicity is the n-octanol/water partition coefficient. Mutagenicity indicates the possibility of future undesirable environmental effects, possibly greater than toxicity. Models have been proposed for the octanol/water distribution coefficient of gold nanoparticles and the mutagenicity of silver nanoparticles. Unlike the previous studies, here the models are built using an updated scheme, which includes two improvements. Firstly, the computing involves a new criterion for prediction potential, the so-called coefficient of conformism of a correlative prediction (CCCP); secondly, the Las Vegas algorithm is used to select the potentially most promising models from a group of models obtained by the Monte Carlo algorithm. Apparently, CCCP is a measure of the predictive potential (not only correlation). This can give an advantage in developing a model in comparison to using the classic determination coefficient. Likely, CCCP can be more informative than the classical determination coefficient. The Las Vegas algorithm is able to improve the model obtained by the Monte Carlo method.
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Affiliation(s)
- Alla P Toropova
- Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy.
| | - Andrey A Toropov
- Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
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Toropova AP, Toropov AA, Roncaglioni A, Benfenati E. Does the accounting of the local symmetry fragments in quasi-SMILES improve the predictive potential of the QSAR models of toxicity toward tadpoles? Toxicol Mech Methods 2024:1-6. [PMID: 38572596 DOI: 10.1080/15376516.2024.2332617] [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: 01/20/2024] [Accepted: 03/14/2024] [Indexed: 04/05/2024]
Abstract
Models of toxicity to tadpoles have been developed as single parameters based on special descriptors which are sums of correlation weights, molecular features, and experimental conditions. This information is presented by quasi-SMILES. Fragments of local symmetry (FLS) are involved in the development of the model and the use of FLS correlation weights improves their predictive potential. In addition, the index of ideality correlation (IIC) and correlation intensity index (CII) are compared. These two potential predictive criteria were tested in models built through Monte Carlo optimization. The CII was more effective than IIC for the models considered here.
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Affiliation(s)
- Alla P Toropova
- Department of Environmental Health Science, Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Andrey A Toropov
- Department of Environmental Health Science, Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Alessandra Roncaglioni
- Department of Environmental Health Science, Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Emilio Benfenati
- Department of Environmental Health Science, Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
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Xu Y, Zhao Y, Li Z, Wu J. [Research Photon Energy Spectrum of Medical Linear Accelerator by Monte Carlo Method]. Zhongguo Yi Liao Qi Xie Za Zhi 2024; 48:156-159. [PMID: 38605614 DOI: 10.12455/j.issn.1671-7104.230387] [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] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Objective The distribution of the photon energy spectrum in isocenter plane of the medical linear accelerator and the influence of secondary collimator on the photon energy spectrum are studied. Methods Use the BEAMnrc program to simulate the transmission of the 6 MeV electrons and photons in 5 cm×5 cm,10 cm×10 cm,15 cm×15 cm and 20 cm×20 cm fields in treatment head of the medical linear accelerator, where a phase space file was set up at the isocenter plane to record the particle information passing through this plane. The BEAMdp program is used to analyze the phase space file, in order to obtain the distribution of the photon energy spectrum in isocenter plane and the influence of secondary collimator on the photon energy spectrum. Results By analyzing the photon energy spectrum of a medical linear accelerator with a nominal energy of 6 MV, it is found that the secondary collimator has little effect on the photon energy spectrum; different fields have different photon energy spectrum distributions; the photon energy spectrum in different central regions of the same field have the same normalized distribution. Conclusion In the dose calculation of radiation therapy, the influence of photon energy spectrum should be carefully considered.
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Affiliation(s)
- Yun Xu
- Oncology Department, West China Hospital of Sichuan University Ya'an People's Hospital, Ya'an, 625000
| | - Yu Zhao
- Oncology Department, West China Hospital of Sichuan University Ya'an People's Hospital, Ya'an, 625000
| | - Zikang Li
- Oncology Department, West China Hospital of Sichuan University Ya'an People's Hospital, Ya'an, 625000
| | - Junxiang Wu
- Radiotherapy Center, Sichuan Cancer Hospital , Chengdu, 610041
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Pesigan IJA, Cheung SF. Monte Carlo confidence intervals for the indirect effect with missing data. Behav Res Methods 2024; 56:1678-1696. [PMID: 37550469 DOI: 10.3758/s13428-023-02114-4] [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] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2023] [Indexed: 08/09/2023]
Abstract
Missing data is a common occurrence in mediation analysis. As a result, the methods used to construct confidence intervals around the indirect effect should consider missing data. Previous research has demonstrated that, for the indirect effect in data with complete cases, the Monte Carlo method performs as well as nonparametric bootstrap confidence intervals (see MacKinnon et al., Multivariate Behavioral Research, 39(1), 99-128, 2004; Preacher & Selig, Communication Methods and Measures, 6(2), 77-98, 2012; Tofighi & MacKinnon, Structural Equation Modeling: A Multidisciplinary Journal, 23(2), 194-205, 2015). In this manuscript, we propose a simple, fast, and accurate two-step approach for generating confidence intervals for the indirect effect, in the presence of missing data, based on the Monte Carlo method. In the first step, an appropriate method, for example, full-information maximum likelihood or multiple imputation, is used to estimate the parameters and their corresponding sampling variance-covariance matrix in a mediation model. In the second step, the sampling distribution of the indirect effect is simulated using estimates from the first step. A confidence interval is constructed from the resulting sampling distribution. A simulation study with various conditions is presented. Implications of the results for applied research are discussed.
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Affiliation(s)
- Ivan Jacob Agaloos Pesigan
- Department of Psychology, Faculty of Social Sciences, University of Macau, Avenida da Universidade, Taipa, Macao SAR, China.
| | - Shu Fai Cheung
- Department of Psychology, Faculty of Social Sciences, University of Macau, Avenida da Universidade, Taipa, Macao SAR, China
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Passarin PBS, Lourenço FR. Enhancing analytical development in the pharmaceutical industry: A DoE-QSRR model for virtual Method Operable Design Region assessment. J Pharm Biomed Anal 2024; 239:115907. [PMID: 38103415 DOI: 10.1016/j.jpba.2023.115907] [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: 10/11/2023] [Revised: 11/17/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023]
Abstract
Recently, the pharmaceutical industry has increasingly adopted the Analytical Quality by Design (AQbD) approach for analytical development. To facilitate AQbD approach implementation in the development of chromatographic methods for determining cephalosporin antibiotics, an in silico tool capable of performing virtual DoEs was developed enabling to obtain virtual operable regions of method. To this end, the drugs cephalexin, cefazolin, cefotaxime and ceftriaxone were analyzed using four experimental designs, deriving a DoE-QSRR model and employing Monte Carlo method. The DoE-QSRR model and virtual DoEs were validated using data not used in model's construction, obtaining coefficients of determination of 84.72 % for DoE-QSRR model and over 77 % for virtual DoEs. Virtual MODRs were constructed using data from the virtual DoEs. The virtual MODRs were validated by comparing them with experimental MODRs under various scenarios, with overlap areas reaching values exceeding 84 %. Therefore, the in silico tool was considered suitable for indicating analyte trends under different analytical conditions, being capable of performing virtual DoEs for cephalosporin drugs with sufficient assertiveness to guide analytical development and allow obtaining a MODR capable of providing results of adequate quality.
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Affiliation(s)
- Paula Beatriz Silva Passarin
- Faculty of Pharmaceutical Sciences, Department of Pharmacy, University of São Paulo, Avenida Professor Lineu Prestes 508, Butantan, São Paulo, SP, Brazil
| | - Felipe Rebello Lourenço
- Faculty of Pharmaceutical Sciences, Department of Pharmacy, University of São Paulo, Avenida Professor Lineu Prestes 508, Butantan, São Paulo, SP, Brazil.
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Xu Z, Gao F, Fa A, Qu W, Zhang Z. Statistical power analysis and sample size planning for moderated mediation models. Behav Res Methods 2024:10.3758/s13428-024-02342-2. [PMID: 38308148 DOI: 10.3758/s13428-024-02342-2] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2024] [Indexed: 02/04/2024]
Abstract
Conditional process models, including moderated mediation models and mediated moderation models, are widely used in behavioral science research. However, few studies have examined approaches to conduct statistical power analysis for such models and there is also a lack of software packages that provide such power analysis functionalities. In this paper, we introduce new simulation-based methods for power analysis of conditional process models with a focus on moderated mediation models. These simulation-based methods provide intuitive ways for sample-size planning based on regression coefficients in a moderated mediation model as well as selected variance and covariance components. We demonstrate how the methods can be applied to five commonly used moderated mediation models using a simulation study, and we also assess the performance of the methods through the five models. We implement our approaches in the WebPower R package and also in Web apps to ease their application.
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Affiliation(s)
- Ziqian Xu
- University of Notre Dame, South Bend, IN, USA.
| | - Fei Gao
- Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Anqi Fa
- Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Wen Qu
- Fudan University, Shanghai, China
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Gurau D, Stanga D, Done L, Sima O, Ilie G. Calibrating GESPECOR model of computing the full-energy peak efficiency of coaxial high-purity germanium detectors by Monte Carlo simulation. Appl Radiat Isot 2024; 204:111135. [PMID: 38071857 DOI: 10.1016/j.apradiso.2023.111135] [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: 05/11/2023] [Revised: 11/13/2023] [Accepted: 11/27/2023] [Indexed: 12/31/2023]
Abstract
In this work, a classical approach was used for calibrating the GESPECOR detector model for computing the full-energy peak efficiency of p-type coaxial HPGe detectors that is based on the use of linear least squares optimization. The key element of the work is the multiplicative model developed for approximating the values of the full-energy peak efficiency provided by GESPECOR code. It was linearized using the logarithmic transformation to allow an easy use of the linear least squares optimization. A procedure was also developed to estimate the optimal values of the parameters, describing the p-type coaxial HPGe detectors. Its application to a Canberra detector GC3018 showed that it is possible to determine accurate values of the full-energy peak efficiency computed by GESPECOR code using the optimized parameter values.
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Affiliation(s)
- D Gurau
- National Institute of R&D for Physics and Nuclear Engineering-Horia Hulubei (IFIN-HH), Bucharest-Magurele, P.O.Box MG-6, RO-077125, Romania
| | - D Stanga
- National Institute of R&D for Physics and Nuclear Engineering-Horia Hulubei (IFIN-HH), Bucharest-Magurele, P.O.Box MG-6, RO-077125, Romania.
| | - L Done
- National Institute of R&D for Physics and Nuclear Engineering-Horia Hulubei (IFIN-HH), Bucharest-Magurele, P.O.Box MG-6, RO-077125, Romania
| | - O Sima
- National Institute of R&D for Physics and Nuclear Engineering-Horia Hulubei (IFIN-HH), Bucharest-Magurele, P.O.Box MG-6, RO-077125, Romania; University of Bucharest, Physics Department, Bucharest-Magurele, P. O. Box MG-12, Romania
| | - G Ilie
- Mirion Technologies, 800 Research Parkway, Meriden, CT, 06450, USA
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Demeler B. Methods for the Design and Analysis of Analytical Ultracentrifugation Experiments. Curr Protoc 2024; 4:e974. [PMID: 38319042 PMCID: PMC10857736 DOI: 10.1002/cpz1.974] [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] [Indexed: 02/07/2024]
Abstract
Analytical ultracentrifugation experiments play an integral role in the solution-phase characterization of biological macromolecules and their interactions. This unit discusses the design of sedimentation velocity and sedimentation equilibrium experiments performed with a Beckman Proteomelab XL-A or XL-I analytical ultracentrifuge and with a Beckman Optima AUC. Instrument settings and experimental design considerations are explained, and strategies for the analysis of experimental data with the UltraScan data analysis software package are presented. Special attention is paid to the strengths and weaknesses of the available detectors, and guidance is provided on how to extract maximum information from analytical ultracentrifugation experiments. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC.
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Affiliation(s)
- Borries Demeler
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada
- Department of Chemistry and Biochemistry, University of Montana, Missoula, Montana
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Nojiri M, Takata T, Hu N, Sakurai Y, Suzuki M, Tanaka H. Neutron flux evaluation algorithm with a combination of Monte Carlo and removal-diffusion calculation methods for boron neutron capture therapy. Med Phys 2024. [PMID: 38205862 DOI: 10.1002/mp.16931] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/05/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND In Japan, the clinical treatment of boron neutron capture therapy (BNCT) has been applied to unresectable, locally advanced, and recurrent head and neck carcinomas using an accelerator-based neutron source since June of 2020. Considering the increase in the number of patients receiving BNCT, efficiency of the treatment planning procedure is becoming increasingly important. Therefore, novel and rapid dose calculation algorithms must be developed. We developed a novel algorithm for calculating neutron flux, which comprises of a combination of a Monte Carlo (MC) method and a method based on the removal-diffusion (RD) theory (RD calculation method) for the purpose of dose calculation of BNCT. PURPOSE We present the details of our novel algorithm and the verification results of the calculation accuracy based on the MC calculation result. METHODS In this study, the "MC-RD" calculation method was developed, wherein the RD calculation method was used to calculate the thermalization process of neutrons and the MC method was used to calculate the moderation process. The RD parameters were determined by MC calculations in advance. The MC-RD calculation accuracy was verified by comparing the results of the MC-RD and MC calculations with respect to the neutron flux distributions in each of the cubic and head phantoms filled with water. RESULTS Comparing the MC-RD calculation results with those of MC calculations, it was found that the MC-RD calculation accurately reproduced the thermal neutron flux distribution inside the phantom, with the exception of the region near the surface of the phantom. CONCLUSIONS The MC-RD calculation method is useful for the evaluation of the neutron flux distribution for the purpose of BNCT dose calculation, except for the region near the surface.
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Affiliation(s)
- Mai Nojiri
- Department of Nuclear Engineering, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Takushi Takata
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Naonori Hu
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
- Kansai BNCT Medical Center, Osaka Medical and Pharmaceutical University, Takatsuki, Osaka, Japan
| | - Yoshinori Sakurai
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Minoru Suzuki
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Hiroki Tanaka
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
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Terashima S, Sano J, Osanai M, Toshima K, Ohuchi K, Hosokawa Y. Monte Carlo simulations of organ and effective doses and dose-length product for dental cone-beam CT. Oral Radiol 2024; 40:37-48. [PMID: 37597068 DOI: 10.1007/s11282-023-00705-7] [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: 03/14/2023] [Accepted: 08/03/2023] [Indexed: 08/21/2023]
Abstract
OBJECTIVES The use of dental cone-beam CT (CBCT) has increased in recent years. We aimed to calculate the organ and effective doses in dental CBCT using Monte Carlo simulation (MCS) and to correlate the effective dose with the dose-length product (DLP), which is a radiation dose index. METHODS Organ and effective doses were calculated by MCS using the adult male and female reference phantoms of the International Commission on Radiological Protection publication 110 in a half-rotation scan of the CBCT scanner Veraviewepocs 3Df. The simulations were performed by setting nine protocols in combination with the field-of-view (FOV) and imaging region. In addition, DLPs were calculated by MCS using the virtual CT Dose Index (CTDI) and CBCT phantoms, with the same protocol. RESULTS The effective doses were 55 and 195 μSv at the minimum FOV of Φ40 × H40 mm and maximum FOV of Φ 80 × H80 mm, respectively. The organs with the major contribution to the effective dose were the red bone marrow (11.0‒12.8%), thyroid gland (4.0‒12.7%), salivary gland (21.8‒33.2%), and remaining tissues (35.1‒45.7%). Positive correlations were obtained between the effective dose and calculated DLP using the CTDI and CBCT phantoms. CONCLUSIONS Organ and effective doses for each protocol of dental CBCT could be estimated using MCS. There was a positive correlation between the effective dose and DLP, suggesting that DLP can be used to estimate the effective dose of CBCT.
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Affiliation(s)
- Shingo Terashima
- Department of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1, Hon-cho, Hirosaki, 036-8564, Japan.
| | - Junta Sano
- Graduate School of Biomedical Science and Engineering, Hokkaido University, Kita15, Nishi7, Kita-ku, Sapporo, 060-8638, Japan
| | - Minoru Osanai
- Department of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1, Hon-cho, Hirosaki, 036-8564, Japan
| | - Keisuke Toshima
- Department of Radiology, Akita University Hospital, 44-2, Hiroomote Hasunuma, Akita, 010-8543, Japan
| | - Kentaro Ohuchi
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Health Sciences University of Hokkaido, Tobetsu-Cho, Ishikari-gun, Hokkaido, 061-0293, Japan
| | - Yoichiro Hosokawa
- Department of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1, Hon-cho, Hirosaki, 036-8564, Japan
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Nattino G, Paganuzzi MM, Ghilardi GI, Costantino G, Rossi C, Cortellaro F, Cosentini R, Paglia S, Migliori M, Bertolini G. Strategies to convert hospital beds for COVID-19 patients to minimize emergency department overcrowding. Health Serv Manage Res 2023:9514848231218648. [PMID: 38059353 DOI: 10.1177/09514848231218648] [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] [Indexed: 12/08/2023]
Abstract
Background: The shortage of hospital beds for COVID-19 patients has been one critical cause of Emergency Department (ED) overcrowding. Purpose: We aimed at elaborating a strategy of conversion of hospital beds, from non-COVID-19 to COVID-19 care, minimizing both ED overcrowding and the number of beds eventually converted. Research Design: Observational retrospective study. Study Sample: We considered the centralized database of all ED admissions in the Lombardy region of Italy during the second "COVID-19 wave" (October to December 2020). Data collection and Analysis: We analyzed all admissions to 82 EDs. We devised a family of Monte Carlo simulations to evaluate the performance of hospital beds' conversion strategies triggered by ED crowding of COVID-19 patients, determining a critical number of beds to be converted when passing an ED-specific crowding threshold. Results: Our results suggest that the maximum number of patients waiting for hospitalization could have been decreased by 70% with the proposed strategy. Such a reduction would have been achieved by converting 30% more hospital beds than the total number converted in the region. Conclusions: The disproportion between reduction in ED crowding and additionally converted beds suggests that a wide margin to improve the efficiency of the conversions exists. The proposed simulation apparatus can be easily generalized to study management policies synchronizing ED output and in-hospital bed availability.
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Affiliation(s)
- Giovanni Nattino
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Ranica (BG), Italy
| | | | | | - Giorgio Costantino
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico di Milano, Milano, Italy
- Università degli Studi di Milano, Milano, Italy
| | - Carlotta Rossi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Ranica (BG), Italy
| | | | | | | | | | - Guido Bertolini
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Ranica (BG), Italy
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Lan Z, Turchin A. Impact of possible errors in natural language processing-derived data on downstream epidemiologic analysis. JAMIA Open 2023; 6:ooad111. [PMID: 38152447 PMCID: PMC10752385 DOI: 10.1093/jamiaopen/ooad111] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 12/29/2023] Open
Abstract
Objective To assess the impact of potential errors in natural language processing (NLP) on the results of epidemiologic studies. Materials and Methods We utilized data from three outcomes research studies where the primary predictor variable was generated using NLP. For each of these studies, Monte Carlo simulations were applied to generate datasets simulating potential errors in NLP-derived variables. We subsequently fit the original regression models to these partially simulated datasets and compared the distribution of coefficient estimates to the original study results. Results Among the four models evaluated, the mean change in the point estimate of the relationship between the predictor variable and the outcome ranged from -21.9% to 4.12%. In three of the four models, significance of this relationship was not eliminated in a single of the 500 simulations, and in one model it was eliminated in 12% of simulations. Mean changes in the estimates for confounder variables ranged from 0.27% to 2.27% and significance of the relationship was eliminated between 0% and 9.25% of the time. No variables underwent a shift in the direction of its interpretation. Discussion Impact of simulated NLP errors on the results of epidemiologic studies was modest, with only small changes in effect estimates and no changes in the interpretation of the findings (direction and significance of association with the outcome) for either the NLP-generated variables or other variables in the models. Conclusion NLP errors are unlikely to affect the results of studies that use NLP as the source of data.
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Affiliation(s)
- Zhou Lan
- Center for Clinical Investigation, Brigham & Women’s Hospital, Boston, MA 02115, United States
- Harvard Medical School, Boston, MA 02115, United States
| | - Alexander Turchin
- Harvard Medical School, Boston, MA 02115, United States
- Division of Endocrinology, Brigham & Women’s Hospital, Boston, MA 02115, United States
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Salimi Y, Akhavanallaf A, Mansouri Z, Shiri I, Zaidi H. Real-time, acquisition parameter-free voxel-wise patient-specific Monte Carlo dose reconstruction in whole-body CT scanning using deep neural networks. Eur Radiol 2023; 33:9411-9424. [PMID: 37368113 PMCID: PMC10667156 DOI: 10.1007/s00330-023-09839-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 12/07/2022] [Revised: 03/28/2023] [Accepted: 04/14/2023] [Indexed: 06/28/2023]
Abstract
OBJECTIVE We propose a deep learning-guided approach to generate voxel-based absorbed dose maps from whole-body CT acquisitions. METHODS The voxel-wise dose maps corresponding to each source position/angle were calculated using Monte Carlo (MC) simulations considering patient- and scanner-specific characteristics (SP_MC). The dose distribution in a uniform cylinder was computed through MC calculations (SP_uniform). The density map and SP_uniform dose maps were fed into a residual deep neural network (DNN) to predict SP_MC through an image regression task. The whole-body dose maps reconstructed by the DNN and MC were compared in the 11 test cases scanned with two tube voltages through transfer learning with/without tube current modulation (TCM). The voxel-wise and organ-wise dose evaluations, such as mean error (ME, mGy), mean absolute error (MAE, mGy), relative error (RE, %), and relative absolute error (RAE, %), were performed. RESULTS The model performance for the 120 kVp and TCM test set in terms of ME, MAE, RE, and RAE voxel-wise parameters was - 0.0302 ± 0.0244 mGy, 0.0854 ± 0.0279 mGy, - 1.13 ± 1.41%, and 7.17 ± 0.44%, respectively. The organ-wise errors for 120 kVp and TCM scenario averaged over all segmented organs in terms of ME, MAE, RE, and RAE were - 0.144 ± 0.342 mGy, and 0.23 ± 0.28 mGy, - 1.11 ± 2.90%, 2.34 ± 2.03%, respectively. CONCLUSION Our proposed deep learning model is able to generate voxel-level dose maps from a whole-body CT scan with reasonable accuracy suitable for organ-level absorbed dose estimation. CLINICAL RELEVANCE STATEMENT We proposed a novel method for voxel dose map calculation using deep neural networks. This work is clinically relevant since accurate dose calculation for patients can be carried out within acceptable computational time compared to lengthy Monte Carlo calculations. KEY POINTS • We proposed a deep neural network approach as an alternative to Monte Carlo dose calculation. • Our proposed deep learning model is able to generate voxel-level dose maps from a whole-body CT scan with reasonable accuracy, suitable for organ-level dose estimation. • By generating a dose distribution from a single source position, our model can generate accurate and personalized dose maps for a wide range of acquisition parameters.
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Affiliation(s)
- Yazdan Salimi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Azadeh Akhavanallaf
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Zahra Mansouri
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Isaac Shiri
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland.
- Geneva University Neurocenter, Geneva University, CH_1205, Geneva, Switzerland.
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, Netherlands.
- Department of Nuclear Medicine, University of Southern Denmark, DK-500, Odense, Denmark.
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14
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Maleyeff L, Wang R, Haneuse S, Li F. Sample size requirements for testing treatment effect heterogeneity in cluster randomized trials with binary outcomes. Stat Med 2023; 42:5054-5083. [PMID: 37974475 PMCID: PMC10659142 DOI: 10.1002/sim.9901] [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: 02/15/2023] [Revised: 08/24/2023] [Accepted: 09/01/2023] [Indexed: 11/19/2023]
Abstract
Cluster randomized trials (CRTs) refer to a popular class of experiments in which randomization is carried out at the group level. While methods have been developed for planning CRTs to study the average treatment effect, and more recently, to study the heterogeneous treatment effect, the development for the latter objective has currently been limited to a continuous outcome. Despite the prevalence of binary outcomes in CRTs, determining the necessary sample size and statistical power for detecting differential treatment effects in CRTs with a binary outcome remain unclear. To address this methodological gap, we develop sample size procedures for testing treatment effect heterogeneity in two-level CRTs under a generalized linear mixed model. Closed-form sample size expressions are derived for a binary effect modifier, and in addition, a computationally efficient Monte Carlo approach is developed for a continuous effect modifier. Extensions to multiple effect modifiers are also discussed. We conduct simulations to examine the accuracy of the proposed sample size methods. We present several numerical illustrations to elucidate features of the proposed formulas and to compare our method to the approximate sample size calculation under a linear mixed model. Finally, we use data from the Strategies and Opportunities to Stop Colon Cancer in Priority Populations (STOP CRC) CRT to illustrate the proposed sample size procedure for testing treatment effect heterogeneity.
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Affiliation(s)
- Lara Maleyeff
- Department of Biostatistics, Harvard T. H. Chan School of Public Health, Massachusetts, USA
| | - Rui Wang
- Department of Biostatistics, Harvard T. H. Chan School of Public Health, Massachusetts, USA
- Department of Population Medicine, Harvard Pilgrim Health Care Institute and Harvard Medical School Boston, Massachusetts, USA
| | - Sebastien Haneuse
- Department of Biostatistics, Harvard T. H. Chan School of Public Health, Massachusetts, USA
| | - Fan Li
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, USA
- Center for Methods in Implementation and Prevention Science, Yale School of Public Health, Connecticut, United States
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15
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Zhu G, Yang Y, Xiao B, Gan Z. Evolution Mechanism of Sputtered Film Uniformity with the Erosion Groove Size: Integrated Simulation and Experiment. Molecules 2023; 28:7660. [PMID: 38005382 PMCID: PMC10674600 DOI: 10.3390/molecules28227660] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/13/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023] Open
Abstract
In this work, Cu thin films were experimentally fabricated at different target-substrate distances by 2-inch and 4-inch circular planar magnetron targets. Meanwhile, the sputtering deposition of Cu thin films was investigated via an integrated multiscale simulation, where the magnetron sputtering discharge was modeled using the Monte Carlo (MC) method, and the sputtered particle transport was simulated using a coupled Monte Carlo (MC) and molecular dynamics (MD) method. Experimental results indicated that, as the target-substrate distance increased from 30 to 120 mm, the film thickness distribution of the 2-inch target sputtering changed from a bell-shaped curve to a line-shaped curve, while that of the 4-inch target sputtering varied from a saddle-shaped curve to a line-shaped curve. The simulation results were accordant with the experimental results. The simulation results revealed that, at a target-substrate distance of 30 mm, the sputtering particle flow from the 2-inch target overlapped strongly near the substrate center, leading to a bell-shaped film thickness distribution, while the increased diameter of the erosion groove on the 4-inch target reduced the superposition effect of the sputtering particle flow near the substrate center, resulting in a saddle-shaped film thickness distribution. In addition, when the target-substrate distance ranged from 30 to 120 mm, the film thickness uniformity of 4-inch target sputtering was superior to that of 2-inch target sputtering, and the underlying mechanism was discussed in detail.
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Affiliation(s)
- Guo Zhu
- School of Mechanical & Electrical Engineering, Hunan City University, Yiyang 413000, China; (Y.Y.); (B.X.)
| | - Yutong Yang
- School of Mechanical & Electrical Engineering, Hunan City University, Yiyang 413000, China; (Y.Y.); (B.X.)
| | - Baijun Xiao
- School of Mechanical & Electrical Engineering, Hunan City University, Yiyang 413000, China; (Y.Y.); (B.X.)
| | - Zhiyin Gan
- School of Mechanical Science & Engineering, Huazhong University of Science & Technology, Wuhan 430074, China;
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16
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Toropov AA, Toropova AP, Roncaglioni A, Benfenati E, Leszczynska D, Leszczynski J. The System of Self-Consistent Models: The Case of Henry's Law Constants. Molecules 2023; 28:7231. [PMID: 37894710 PMCID: PMC10609047 DOI: 10.3390/molecules28207231] [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: 09/13/2023] [Revised: 10/07/2023] [Accepted: 10/21/2023] [Indexed: 10/29/2023] Open
Abstract
Data on Henry's law constants make it possible to systematize geochemical conditions affecting atmosphere status and consequently triggering climate changes. The constants of Henry's law are desired for assessing the processes related to atmospheric contaminations caused by pollutants. The most important are those that are capable of long-term movements over long distances. This ability is closely related to the values of Henry's law constants. Chemical changes in gaseous mixtures affect the fate of atmospheric pollutants and ecology, climate, and human health. Since the number of organic compounds present in the atmosphere is extremely large, it is desirable to develop models suitable for predictions for the large pool of organic molecules that may be present in the atmosphere. Here, we report the development of such a model for Henry's law constants predictions of 29,439 compounds using the CORAL software (2023). The statistical quality of the model is characterized by the value of the coefficient of determination for the training and validation sets of about 0.81 (on average).
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Affiliation(s)
- Andrey A. Toropov
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (A.A.T.); (A.R.); (E.B.)
| | - Alla P. Toropova
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (A.A.T.); (A.R.); (E.B.)
| | - Alessandra Roncaglioni
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (A.A.T.); (A.R.); (E.B.)
| | - Emilio Benfenati
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (A.A.T.); (A.R.); (E.B.)
| | - Danuta Leszczynska
- Interdisciplinary Nanotoxicity Center, Department of Civil and Environmental Engineering, Jackson State University, 1325 Lynch Street, Jackson, MS 39217-0510, USA;
| | - Jerzy Leszczynski
- Interdisciplinary Nanotoxicity Center, Department of Chemistry, Physics and Atmospheric Sciences, Jackson State University, 1400 J. R. Lynch Street, Jackson, MS 39217-0510, USA;
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17
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Zhao Y, Zhang F, Ai Y, Tian J, Wang Z. Structural Uncertainty Analysis of High-Temperature Strain Gauge Based on Monte Carlo Stochastic Finite Element Method. Sensors (Basel) 2023; 23:8647. [PMID: 37896740 PMCID: PMC10610717 DOI: 10.3390/s23208647] [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] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/01/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023]
Abstract
The high-temperature strain gauge is a sensor for strain measurement in high-temperature environments. The measurement results often have a certain divergence, so the uncertainty of the high-temperature strain gauge system is analyzed theoretically. Firstly, in the conducted research, a deterministic finite element analysis of the temperature field of the strain gauge is carried out using MATLAB software. Then, the primary sub-model method is used to model the system; an equivalent thermal load and force are loaded onto the model. The thermal response of the grid wire is calculated by the finite element method (FEM). Thermal-mechanical coupling analysis is carried out by ANSYS, and the MATLAB program is verified. Finally, the stochastic finite element method (SFEM) combined with the Monte Carlo method (MCM) is used to analyze the effects of the physical parameters, geometric parameters, and load uncertainties on the thermal response of the grid wire. The results show that the difference of temperature and strain calculated by ANSYS and MATLAB is 1.34% and 0.64%, respectively. The calculation program is accurate and effective. The primary sub-model method is suitable for the finite element modeling of strain gauge systems, and the number of elements is reduced effectively. The stochastic uncertainty analysis of the thermal response on the grid wire of a high-temperature strain gauge provides a theoretical basis for the dispersion of the measurement results of the strain gauge.
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Affiliation(s)
| | - Fengling Zhang
- Liaoning Key Laboratory of Advanced Measurement and Test Technology for Aviation Propulsion System, School of Aero-Engine of Shenyang Aerospace University, Shenyang 110136, China; (Y.Z.); (Y.A.); (J.T.); (Z.W.)
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18
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Gorshkov VN, Stretovych MO, Semeniuk VF, Kruglenko MP, Semeniuk NI, Styopkin VI, Gabovich AM, Boiger GK. Hierarchical Structuring of Black Silicon Wafers by Ion-Flow-Stimulated Roughening Transition: Fundamentals and Applications for Photovoltaics. Nanomaterials (Basel) 2023; 13:2715. [PMID: 37836356 PMCID: PMC10574651 DOI: 10.3390/nano13192715] [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] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/27/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023]
Abstract
Ion-flow-stimulated roughening transition is a phenomenon that may prove useful in the hierarchical structuring of nanostructures. In this work, we have investigated theoretically and experimentally the surface texturing of single-crystal and multi-crystalline silicon wafers irradiated using ion-beam flows. In contrast to previous studies, ions had relatively low energies, whereas flow densities were high enough to induce a quasi-liquid state in the upper silicon layers. The resulting surface modifications reduced the wafer light reflectance to values characteristic of black silicon, widely used in solar energetics. Features of nanostructures on different faces of silicon single crystals were studied numerically based on the mesoscopic Monte Carlo model. We established that the formation of nano-pyramids, ridges, and twisting dune-like structures is due to the stimulated roughening transition effect. The aforementioned variety of modified surface morphologies arises due to the fact that the effects of stimulated surface diffusion of atoms and re-deposition of free atoms on the wafer surface from the near-surface region are manifested to different degrees on different Si faces. It is these two factors that determine the selection of the allowable "trajectories" (evolution paths) of the thermodynamic system along which its Helmholtz free energy, F, decreases, concomitant with an increase in the surface area of the wafer and the corresponding changes in its internal energy, U (dU>0), and entropy, S (dS>0), so that dF=dU - TdS<0, where T is the absolute temperature. The basic theoretical concepts developed were confirmed in experimental studies, the results of which showed that our method could produce, abundantly, black silicon wafers in an environmentally friendly manner compared to traditional chemical etching.
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Affiliation(s)
- Vyacheslav N. Gorshkov
- Igor Sikorsky Kyiv Polytechnic Institute, National Technical University of Ukraine, Prospect Beresteiskyi, 37, 03056 Kyiv, Ukraine;
- G.V. Kurdyumov Institute for Metal Physics, National Academy of Sciences of Ukraine, 36 Academician Vernadsky Boulevard, 03142 Kyiv, Ukraine
- Department of Mechanical and Aerospace Engineering, University of Liverpool, Liverpool L69 3GH, UK
| | - Mykola O. Stretovych
- Igor Sikorsky Kyiv Polytechnic Institute, National Technical University of Ukraine, Prospect Beresteiskyi, 37, 03056 Kyiv, Ukraine;
| | - Valerii F. Semeniuk
- Institute of Physics of the Ukrainian National Academy of Sciences, Nauka Avenue, 46, 03028 Kyiv, Ukraine; (V.F.S.); (M.P.K.); (V.I.S.); (A.M.G.)
- GreSem Innovation LLC, Vyzvolyteliv Avenue, 13, 02660 Kyiv, Ukraine;
| | - Mikhail P. Kruglenko
- Institute of Physics of the Ukrainian National Academy of Sciences, Nauka Avenue, 46, 03028 Kyiv, Ukraine; (V.F.S.); (M.P.K.); (V.I.S.); (A.M.G.)
- GreSem Innovation LLC, Vyzvolyteliv Avenue, 13, 02660 Kyiv, Ukraine;
| | | | - Victor I. Styopkin
- Institute of Physics of the Ukrainian National Academy of Sciences, Nauka Avenue, 46, 03028 Kyiv, Ukraine; (V.F.S.); (M.P.K.); (V.I.S.); (A.M.G.)
| | - Alexander M. Gabovich
- Institute of Physics of the Ukrainian National Academy of Sciences, Nauka Avenue, 46, 03028 Kyiv, Ukraine; (V.F.S.); (M.P.K.); (V.I.S.); (A.M.G.)
| | - Gernot K. Boiger
- ICP Institute of Computational Physics, ZHAW Zürich University of Applied Sciences, Wildbachstrasse 21, CH-8401 Winterthur, Switzerland
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Toropova AP, Toropov AA. Using the local symmetry in amino acids sequences of polypeptides to improve the predictive potential of models of their inhibitor activity. Amino Acids 2023; 55:1437-1445. [PMID: 37707646 DOI: 10.1007/s00726-023-03322-0] [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: 01/03/2023] [Accepted: 08/24/2023] [Indexed: 09/15/2023]
Abstract
The minimal inhibitory concentrations (pMIC) are a valuable measure of the biological activity of polypeptides. Numerical data on the pMIC are necessary to systematize knowledge on polypeptides' biochemical behaviour. The model of negative decimal logarithm of pMIC of polypeptides in the form of a mathematical function of a sequence of amino acids is suggested. The suggested model is based on the so-called correlation weights of amino acids together with the correlation weights of fragments of local symmetry (FLS). Three kinds of the FLS are considered: (i) three-symbol fragments '…xyx…', (ii) four-symbol fragments '…xyyx…', and (iii) five-symbol fragments '…xyzyx…'. The models built using the Monte Carlo technique improved by applying the index of ideality of correlation (IIC) and correlation intensity index (CII).
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Affiliation(s)
- Alla P Toropova
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milan, Italy.
| | - Andrey A Toropov
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milan, Italy
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20
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Toropov AA, Toropova AP, Roncaglioni A, Benfenati E. In silico prediction of the mutagenicity of nitroaromatic compounds using correlation weights of fragments of local symmetry. Mutat Res Genet Toxicol Environ Mutagen 2023; 891:503684. [PMID: 37770141 DOI: 10.1016/j.mrgentox.2023.503684] [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] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/24/2023] [Accepted: 08/17/2023] [Indexed: 10/03/2023]
Abstract
Most quantitative structure-property/activity relationships (QSPRs/QSARs) techniques involve using different programs separately for generating molecular descriptors and separately for building models based on available descriptors. Here, the capabilities of the CORAL program are evaluated. A user of the program should apply as the basis for models the representation of the molecular structure by means of the simplified molecular input-line entry system (SMILES) as well as experimental data on the endpoint of interest. The local symmetry of SMILES is a novel composition of symmetrically represented symbols, which are three 'xyx', four 'xyyx', or five symbols 'xyzyx'. We updated our CORAL software using this optimal, new flexible descriptor, sensitive to the symmetric composition of a specific part of the molecule. Computational experiments have shown that taking account of these attributes of SMILES can improve the predictive potential of models for the mutagenicity of nitroaromatic compounds. In addition, the above computational experiments have confirmed the advantage of using the index of ideality of correlation (IIC) and the correlation intensity index (CII) for Monte Carlo optimization of the correlation weights for various attributes of SMILES, including the local symmetry. The average value of the coefficient of determination for the validation set (five different models) without fragments of local symmetry is 0.8589 ± 0.025, whereas using fragments of local symmetry improves this criterion of the predictive potential up to 0.9055 ± 0.010.
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Affiliation(s)
- Andrey A Toropov
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
| | - Alla P Toropova
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy.
| | - Alessandra Roncaglioni
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
| | - Emilio Benfenati
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
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Kim SY, Shin DW, Hyun J, Kwon NH, Cheong JC, Paeng KJ, Lee J, Kim JY. Uncertainty Evaluation for the Quantification of Urinary Amphetamine and 4-Hydroxyamphetamine Using Liquid Chromatography-Tandem Mass Spectrometry: Comparison of the Guide to the Expression of Uncertainty in Measurement Approach and the Monte Carlo Method with R. Molecules 2023; 28:6803. [PMID: 37836646 PMCID: PMC10574584 DOI: 10.3390/molecules28196803] [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: 08/18/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023] Open
Abstract
Estimating the measurement uncertainty (MU) is becoming increasingly mandatory in analytical toxicology. This study evaluates the uncertainty in the quantitative determination of urinary amphetamine (AP) and 4-hydroxyamphetamine (4HA) using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method based on the dilute-and-shoot approach. Urine sample dilution, preparation of calibrators, calibration curve, and method repeatability were identified as the sources of uncertainty. To evaluate the MU, the Guide to the Expression of Uncertainty in Measurement (GUM) approach and the Monte Carlo method (MCM) were compared using the R programming language. The MCM afforded a smaller coverage interval for both AP (94.83, 104.74) and 4HA (10.52, 12.14) than that produced by the GUM (AP (92.06, 107.41) and 4HA (10.21, 12.45)). The GUM approach offers an underestimated coverage interval for Type A evaluation, whereas the MCM provides an exact coverage interval under an abnormal probability distribution of the measurand. The MCM is useful in complex settings where the measurand is combined with numerous distributions because it is generated from the uncertainties of input quantities based on the propagation of the distribution. Therefore, the MCM is more practical than the GUM for evaluating the MU of urinary AP and 4HA concentrations using LC-MS/MS.
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Affiliation(s)
- Seon Yeong Kim
- Forensic Genetics & Chemistry Division, Supreme Prosecutors’ Office, Seoul 06590, Republic of Korea
| | - Dong Won Shin
- Forensic Genetics & Chemistry Division, Supreme Prosecutors’ Office, Seoul 06590, Republic of Korea
| | - Jihye Hyun
- Department of Applied Statistics, Chung-Ang University, Seoul 06590, Republic of Korea;
| | - Nam Hee Kwon
- Forensic Genetics & Chemistry Division, Supreme Prosecutors’ Office, Seoul 06590, Republic of Korea
| | - Jae Chul Cheong
- Forensic Genetics & Chemistry Division, Supreme Prosecutors’ Office, Seoul 06590, Republic of Korea
| | - Ki-Jung Paeng
- Department of Chemistry, Yonsei University, Wonju 26493, Republic of Korea
| | - Jooyoung Lee
- Department of Applied Statistics, Chung-Ang University, Seoul 06590, Republic of Korea;
| | - Jin Young Kim
- Forensic Genetics & Chemistry Division, Supreme Prosecutors’ Office, Seoul 06590, Republic of Korea
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Marković G, Manojlović V, Ružić J, Sokić M. Predicting Low-Modulus Biocompatible Titanium Alloys Using Machine Learning. Materials (Basel) 2023; 16:6355. [PMID: 37834492 PMCID: PMC10573332 DOI: 10.3390/ma16196355] [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] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/10/2023] [Accepted: 09/18/2023] [Indexed: 10/15/2023]
Abstract
Titanium alloys have been present for decades as the main components for the production of various orthopedic and dental elements. However, modern times require titanium alloys with a low Young's modulus, and without the presence of cytotoxic alloying elements. Machine learning was used with aim to analyze biocompatible titanium alloys and predict the composition of Ti alloys with a low Young's modulus. A database was created using experimental data for alloy composition, Young's modulus, and mechanical and thermal properties of biocompatible titanium alloys. The Extra Tree Regression model was built to predict the Young's modulus of titanium alloys. By processing data of 246 alloys, the specific heat was discovered to be the most influential parameter that contributes to the lowering of the Young's modulus of titanium alloys. Further, the Monte Carlo method was used to predict the composition of future alloys with the desired properties. Simulation results of ten million samples, with predefined conditions for obtaining titanium alloys with a Young's modulus lower than 70 GPa, show that it is possible to obtain several multicomponent alloys, consisting of five main elements: titanium, zirconium, tin, manganese and niobium.
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Affiliation(s)
- Gordana Marković
- Institute for Technology of Nuclear and Other Mineral Raw Materials, 11000 Belgrade, Serbia; (G.M.); (M.S.)
| | - Vaso Manojlović
- Faculty of Technology and Metallurgy, University of Belgrade, 11000 Belgrade, Serbia
| | - Jovana Ružić
- Department of Materials, “Vinča” Institute of Nuclear Sciences—National Institute of the Republic of Serbia, University of Belgrade, 11000 Belgrade, Serbia;
| | - Miroslav Sokić
- Institute for Technology of Nuclear and Other Mineral Raw Materials, 11000 Belgrade, Serbia; (G.M.); (M.S.)
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23
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Toropova AP, Toropov AA, Roncaglioni A, Benfenati E. Using the Correlation Intensity Index to Build a Model of Cardiotoxicity of Piperidine Derivatives. Molecules 2023; 28:6587. [PMID: 37764363 PMCID: PMC10535953 DOI: 10.3390/molecules28186587] [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: 08/01/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
The assessment of cardiotoxicity is a persistent problem in medicinal chemistry. Quantitative structure-activity relationships (QSAR) are one possible way to build up models for cardiotoxicity. Here, we describe the results obtained with the Monte Carlo technique to develop hybrid optimal descriptors correlated with cardiotoxicity. The predictive potential of the cardiotoxicity models (pIC50, Ki in nM) of piperidine derivatives obtained using this approach provided quite good determination coefficients for the external validation set, in the range of 0.90-0.94. The results were best when applying the so-called correlation intensity index, which improves the predictive potential of a model.
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Affiliation(s)
- Alla P. Toropova
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Environmental, Health Science, Via Mario Negri 2, 20156 Milano, Italy; (A.A.T.); (A.R.); (E.B.)
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Wu J, Zhang G, Zhao Q, Wang L, Yang J, Cui J. In vitro Antimicrobial Activity and Dose Optimization of Eravacycline and Other Tetracycline Derivatives Against Levofloxacin-Non-Susceptible and/or Trimethoprim-Sulfamethoxazole-Resistant Stenotrophomonas maltophilia. Infect Drug Resist 2023; 16:6005-6015. [PMID: 37705512 PMCID: PMC10497097 DOI: 10.2147/idr.s425061] [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: 06/26/2023] [Accepted: 08/31/2023] [Indexed: 09/15/2023] Open
Abstract
Purpose To better guide clinical use, we determined the in vitro antimicrobial activity of the new drug eravacycline and other tetracycline derivatives against levofloxacin (LVFX)-non-susceptible and/or trimethoprim-sulfamethoxazole (TMP-SMZ)-resistant Stenotrophomonas maltophilia and evaluated their dosing regimens. Methods Seventy-seven unique strains of S. maltophilia were isolated from sputa samples and airway aspirate samples that were either LVFX-non-susceptible and/or TMP-SMZ-resistant. Monte Carlo simulations were performed for different dosing regimens according to the population pharmacokinetic parameters of antibiotics in patients with respiratory tract infections at the minimum inhibitory concentration (MIC). Results Eravacycline had excellent in vitro antibacterial activity against LVFX-non-susceptible and/or TMP-SMZ-resistant S. maltophilia. Monte Carlo simulations showed that for LVFX-non-susceptible strains, the cumulative fraction of response (CFR) of minocycline at the conventional recommended dose of 100 mg q12 h was 90.90%; for TMP-SMZ-resistant strains, the CFR of minocycline at a high dose of 200 mg q12 h was only 91.64%. For strains resistant to both LVFX and TMP-SMZ, the CFR of minocycline at a high dose of 200 mg q12 h was 89.81%. In contrast, the CFR of tigecycline was less than 40%, even at a dose of 100 mg q12 h. Conclusion For pneumonia, minocycline is better for S. maltophilia that is non-susceptible to LVFX; for TMP-SMZ-resistant strains and strains that are not susceptible to either LVFX or TMP-SMZ, the efficiency of eravacycline requires further evaluation. Eravacycline may be a better choice for extremely resistant S. maltophilia strains that are non-susceptible to LVFX, TMP-SMZ, and minocycline.
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Affiliation(s)
- Jie Wu
- Department of Respiratory Diseases, The Eighth Medical Center, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China
- Medical School of Chinese People’s Liberation Army, Beijing, People’s Republic of China
| | - Guangcun Zhang
- Laboratory Medicine Department, The First Medical Center, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China
| | - Qiang Zhao
- Laboratory Medicine Department, The First Medical Center, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China
| | - Lifeng Wang
- Laboratory Medicine Department, The First Medical Center, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China
| | - Jiyong Yang
- Laboratory Medicine Department, The First Medical Center, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China
| | - Junchang Cui
- Department of Respiratory Diseases, The Eighth Medical Center, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China
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Abstract
Reputation and reciprocity are key mechanisms for cooperation in human societies, often going hand in hand to favor prosocial behavior over selfish actions. Here we review recent researches at the interface of physics and evolutionary game theory that explored these two mechanisms. We focus on image scoring as the bearer of reputation, as well as on various types of reciprocity, including direct, indirect, and network reciprocity. We review different definitions of reputation and reciprocity dynamics, and we show how these affect the evolution of cooperation in social dilemmas. We consider first-order, second-order, as well as higher-order models in well-mixed and structured populations, and we review experimental works that support and inform the results of mathematical modeling and simulations. We also provide a synthesis of the reviewed researches along with an outlook in terms of six directions that seem particularly promising to explore in the future.
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Affiliation(s)
- Chengyi Xia
- School of Artificial Intelligence, Tiangong University, Tianjin 300384, China
| | - Juan Wang
- School of Electrical Engineering and Automation, Tianjin University of Technology, Tianjin 300384, China.
| | - Matjaž Perc
- Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, 2000 Maribor, Slovenia; Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 404332, Taiwan; Alma Mater Europaea, Slovenska ulica 17, 2000 Maribor, Slovenia; Complexity Science Hub Vienna, Josefstädterstraße 39, 1080 Vienna, Austria
| | - Zhen Wang
- Center for OPTical IMagery Analysis and Learning (OPTIMAL), Northwestern Polytechnical University, Xian 710072, China.
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26
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Toropov AA, Toropova AP, Roncaglioni A, Benfenati E. The system of self-consistent models for pesticide toxicity to Daphnia magna. Toxicol Mech Methods 2023; 33:578-583. [PMID: 36992571 DOI: 10.1080/15376516.2023.2197487] [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: 10/16/2022] [Revised: 03/20/2023] [Accepted: 03/25/2023] [Indexed: 03/31/2023]
Abstract
Quantitative structure-property/activity relationships (QSPRs/QSARs) are a tool of modern theoretical and computational chemistry. The self-consistent model system is both a method to build up a group of QSPR/QSAR models and an approach to checking the reliability of these models. Here, a group of models of pesticide toxicity toward Daphnia magna for different distributions into training and test sub-sets is compared. This comparison is the basis for formulating the system of self-consistent models. The so-called index of the ideality of correlation (IIC) has been used to improve the above models' predictive potential of pesticide toxicity. The predictive potential of the suggested models should be classified as high since the average value of the determination coefficient for the validation sets is 0.841, and the dispersion is 0.033 (on all five models). The best model (number 4) has an average determination coefficient of 0.89 for the external validation sets (related to all five splits).
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Affiliation(s)
- Andrey A Toropov
- Department of Environmental Health Science, Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Alla P Toropova
- Department of Environmental Health Science, Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Alessandra Roncaglioni
- Department of Environmental Health Science, Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Emilio Benfenati
- Department of Environmental Health Science, Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
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27
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Fleurence N, Demeyer S, Allard A, Douri S, Hay B. Quantitative Measurement of Thermal Conductivity by SThM Technique: Measurements, Calibration Protocols and Uncertainty Evaluation. Nanomaterials (Basel) 2023; 13:2424. [PMID: 37686932 PMCID: PMC10490493 DOI: 10.3390/nano13172424] [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] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/18/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023]
Abstract
Thermal management is a key issue for the downsizing of electronic components in order to optimise their performance. These devices incorporate more and more nanostructured materials, such as thin films or nanowires, requiring measurement techniques suitable to characterise thermal properties at the nanoscale, such as Scanning Thermal Microscopy (SThM). In active mode, a hot thermoresistive probe scans the sample surface, and its electrical resistance R changes as a function of heat transfers between the probe and sample. This paper presents the measurement and calibration protocols developed to perform quantitative and traceable measurements of thermal conductivity k using the SThM technique, provided that the heat transfer conditions between calibration and measurement are identical, i.e., diffusive thermal regime for this study. Calibration samples with a known k measured at the macroscale are used to establish the calibration curve linking the variation of R to k. A complete assessment of uncertainty (influencing factors and computational techniques) is detailed for both the calibration parameters and the estimated k value. Outcome analysis shows that quantitative measurements of thermal conductivity with SThM (with an uncertainty value of 10%) are limited to materials with low thermal conductivity (k<10Wm-1K-1).
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Affiliation(s)
- Nolwenn Fleurence
- Laboratoire National de Métrologie et d'Essais (LNE), 29, Avenue Roger Hennequin, 78197 Trappes, France
| | - Séverine Demeyer
- Laboratoire National de Métrologie et d'Essais (LNE), 29, Avenue Roger Hennequin, 78197 Trappes, France
| | - Alexandre Allard
- Detection, Sensors and Measurements Laboratory, Ifremer, 1625 Route de Sainte-Anne, 29280 Plouzané, France
| | - Sarah Douri
- Laboratoire National de Métrologie et d'Essais (LNE), 29, Avenue Roger Hennequin, 78197 Trappes, France
- CETHIL UMR5008, CNRS, INSA-Lyon, Université Claude Bernard Lyon 1, 69621 Villeurbanne, France
| | - Bruno Hay
- Laboratoire National de Métrologie et d'Essais (LNE), 29, Avenue Roger Hennequin, 78197 Trappes, France
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28
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Olczyk P, Sikorski A. Structure of Strongly Adsorbed Polymer Systems: A Computer Simulation Study. Materials (Basel) 2023; 16:5755. [PMID: 37687448 PMCID: PMC10488969 DOI: 10.3390/ma16175755] [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] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/02/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023]
Abstract
The structure of very thin polymer films formed by strongly adsorbed macromolecules was studied by computer simulation. A coarse-grained model of strictly two-dimensional polymer systems was built, and its properties determined by an efficient Monte Carlo simulation algorithm. Properties of the model system were determined by means of Monte Carlo simulations with a sampling algorithm that combines Verdier-Stockmayer, pivot and reputation moves. The effects of temperature, chain length and polymer concentration on the macromolecular structure were investigated. It was shown that at low temperatures, the chain size increases with the concentration, that is, inversely with high temperatures. This behavior should be explained by the influence of inter-chain interactions.
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Affiliation(s)
- Patrycja Olczyk
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Andrzej Sikorski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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29
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Knight J, Wang S, Mishra S. Adjusting for hidden biases in sexual behaviour data: a mechanistic approach. medRxiv 2023:2023.08.16.23294164. [PMID: 37645768 PMCID: PMC10462199 DOI: 10.1101/2023.08.16.23294164] [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] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Background Two required inputs to mathematical models of sexually transmitted infections are the average duration in epidemiological risk states (e.g., selling sex) and the average rates of sexual partnership change. These variables are often only available as aggregate estimates from published cross-sectional studies, and may be subject to distributional, sampling, censoring, and measurement biases. Methods We explore adjustments for these biases using aggregate estimates of duration in sex work and numbers of reported sexual partners from a published 2011 survey of female sex worker in Eswatini. We develop adjustments from first principles, and construct Bayesian hierarchical models to reflect our mechanistic assumptions about the bias-generating processes. Results We show that different mechanisms of bias for duration in sex work may "cancel out" by acting in opposite directions, but that failure to consider some mechanisms could over- or underestimate duration in sex work by factors approaching 2. We also show that conventional interpretations of sexual partner numbers are biased due to implicit assumptions about partnership duration, but that unbiased estimators of partnership change rate can be defined that explicitly incorporate a given partnership duration. We highlight how the unbiased estimator is most important when the survey recall period and partnership duration are similar in length. Conclusions While we explore these bias adjustments using a particular dataset, and in the context of deriving inputs for mathematical modelling, we expect that our approach and insights would be applicable to other datasets and motivations for quantifying sexual behaviour data.
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Affiliation(s)
- Jesse Knight
- Institute of Medical Science, University of Toronto
- MAP Centre for Urban Health Solutions, Unity Health Toronto
| | - Siyi Wang
- MAP Centre for Urban Health Solutions, Unity Health Toronto
| | - Sharmistha Mishra
- Institute of Medical Science, University of Toronto
- MAP Centre for Urban Health Solutions, Unity Health Toronto
- Division of Infectious Diseases, Department of Medicine, University of Toronto
- Institute of Health Policy, Management and Evaluation & Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto
- Institute for Clinical Evaluative Sciences, Toronto, Ontario
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30
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Kong X, Wang Y, Huang J, Zhang W, Du C, Yin Y, Xue H, Gao H, Liu K, Wu T, Sun L. Microdosimetric assessment about proton spread-out Bragg peak at different depths based on the normal human mesh-type cell population model. Phys Med Biol 2023; 68:175010. [PMID: 37578025 DOI: 10.1088/1361-6560/acec2b] [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: 02/09/2023] [Accepted: 07/31/2023] [Indexed: 08/15/2023]
Abstract
Objective.In clinical proton therapy, the spread-out Bragg peak (SOBP) is commonly used to fit the target shape. Dose depositions at microscopic sites vary, even with a consistent absorbed dose (D) in SOBP. In the present study, monolayer mesh-type cell population models were developed for microdosimetric assessment at different SOBP depths.Approach.Normal human bronchial epithelial (BEAS-2B) and hepatocytes (L-O2) mesh-type cell models were constructed based on fluorescence tomography images of normal human cells. Particle transport simulation in cell populations was performed coupled with Monte Carlo software PHITS. The relationship between microdosimetry and macrodosimetry of SOBP at different depths was described by analyzing the microdosimetric indicators such as specific energyz,specific energy distributionfz,D,and relative standard deviationσz/z¯within cells. Additionally, the microdosimetric distributions characteristics and their contributing factors were also discussed.Main results.The microscopic dose distribution is strongly influenced by cellular size, shape, and material. The mean specific energyz¯of nucleus and cytoplasm in the cell population is greater than the overall absorbed dose of the cell population model (Dp), with a maximumz¯/Dpof 1.1. The cellular dose distribution is different between the BEAS-2B mesh-type model and its concentric ellipsoid geometry-type model, which difference inz¯is about 10.3% for the nucleus and about 7.5% for the cytoplasm with the SOBP depth of 15 cm. WhenD= 2 Gy, the maximumzof L-O2 nucleus reaches 2.8 Gy andσz/z¯is 5.1% at the mid-depth SOBP (16-18 cm); while the maximumzof the BEAS-2B nucleus reaches 2.2 Gy with only 2.7% ofσz/z¯.Significance.The significant variation of microdosimetric distributions of SOBP different depths indicates the necessity to use mesh-type cell population models, which have the potential to be compared with biological results and build the bio-physical model.
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Affiliation(s)
- Xianghui Kong
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Yidi Wang
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Jiachen Huang
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Wenyue Zhang
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Chuansheng Du
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Yuchen Yin
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Huiyuan Xue
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Han Gao
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Kun Liu
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Tao Wu
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Liang Sun
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
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31
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Kim I, Kang HY, Khang YH. Comparison of Bayesian Spatiotemporal Models for Small-Area Life Expectancy: A Simulation Study. Am J Epidemiol 2023; 192:1396-1405. [PMID: 36963380 DOI: 10.1093/aje/kwad073] [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: 05/19/2022] [Revised: 12/28/2022] [Accepted: 03/23/2023] [Indexed: 03/26/2023] Open
Abstract
The purpose of this study was to assess the precision, uncertainty, and normality of small-area life expectancy estimates calculated using Bayesian spatiotemporal models. We hypothesized 6 scenarios in which all 247 districts of South Korea had the same year-specific female population of 500, 1,000, 2,000, 5,000, 10,000, and 25,000 individuals during the study period (2013-2017). We generated 1,000 hypothetical data sets for each scenario and calculated district-year life expectancies. The precision and uncertainty of life expectancy estimates were compared between 2 Bayesian spatiotemporal models and the traditional method and Bayesian spatial models. We examined the normality of the life expectancy distributions generated by each method and investigated an optimal cutoff value for the comparisons. The Bayesian spatiotemporal models produced precise life expectancy estimates. However, the 95% uncertainty interval contained the true value with a probability of less than 95%. The Bayesian spatiotemporal models violated the normality assumption in scenarios with small population sizes. Therefore, life expectancy comparisons should be conducted using a cutoff value that minimizes false-positive and false-negative rates. We propose 0.8 as a cutoff value for determining the statistical significance of the difference in life expectancy.
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32
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Fursov VV, Ananiev AV, Kuznetsov DA. Towards a Systemic Concept of the Brain Ishemia Stroke: Monte Carlo Driven in Silico Model. CNS Neurol Disord Drug Targets 2023; 22:CNSNDDT-EPUB-133003. [PMID: 37469160 DOI: 10.2174/1871527322666230719111903] [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] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 05/25/2023] [Accepted: 05/30/2023] [Indexed: 07/21/2023]
Abstract
BACKGROUND The work proposes a new mathematical model of dynamic processes of a typical spatially heterogeneous biological system, and sets and solves a mathematical problem of modeling the dynamics of the system of neurovascular units of the brain in conditions of ischemic stroke. There is a description of only a small number of mathematical models of stroke in the literature. This model is being studied and a numerical and software implementation of the corresponding mathematical problem is proposed. METHODS This work is the first attempt ever aiming to employ a Monte Carlo computational approach for In Silico simulation of the most critical parameters in molecular and cellular pathogenesis of the brain ischemic stroke. In this work, a new mathematical model of the development of ischemic stroke is proposed in the form of a discrete model based on neurovascular units (NVU) as elements. RESULTS As a result of testing the program with the assignment of empirically selected coefficients, data were obtained on the evolution of the states of the lattice of the cellular automaton of the model for the spread of stroke in a region of the brain tissue. A resulting new theoretical model of the particular pathologically altered biosystem might be taken as a promising tool for further studies in neurology; general pathology and cell biology. CONCLUSION For the first time, a mathematical model has been constructed that allows us to represent the spatial dynamics of the development of the affected area in ischemic stroke of the brain, taking into account neurovascular units as single morphofunctional structures.
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Affiliation(s)
- Valentin V Fursov
- D.I. Mendeleev University of Chemical Technology, Moscow, Russia
- N.I. Pirogov Russian National Research Medical University, Moscow, Russia
- Peoples' Friendship University of Russia, www.rudn.ru, Moscow, Russia
| | | | - Dmitry A Kuznetsov
- N.I. Pirogov Russian National Research Medical University, Moscow, Russia
- N.N. Semenov Federal Research Center for Chemical Physics, Moscow, Russia
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33
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Toropova AP, Toropov AA, Roncaglioni A, Benfenati E, Leszczynska D, Leszczynski J. The validation of predictive potential via the system of self-consistent models: the simulation of blood-brain barrier permeation of organic compounds. J Mol Model 2023; 29:218. [PMID: 37382683 DOI: 10.1007/s00894-023-05632-2] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/22/2023] [Indexed: 06/30/2023]
Abstract
CONTEXT To apply the quantitative relationships "structure-endpoint" approach, the reliability of prediction is necessary but sometimes challenging to achieve. In this work, an attempt is made to accomplish the reliability of forecasts by creating a set of random partitions of data into training and validation sets, followed by constructing random models. A system of random models for a helpful approach should be self-consistent, giving a similar or at least comparable statistical quality of the predictions for models obtained using different splits of available data into training and validation sets. METHOD The carried out computer experiments aimed at obtaining blood-brain barrier permeation models showed that, in principle, can be used such an approach (the Monte Carlo optimization of the correlation weights for different molecular features) for the above purpose taking advantage of specific algorithms to optimize the modelling steps with applying of new statistical criteria such as the index of ideality of correlation (IIC) and the correlation intensity index (CII). The results so obtained are good and better than what was reported previously. The suggested approach to validation of models is non-identic to traditionally applied manners of the checking up models. The concept of validation can be used for arbitrary models (not only for models of the blood-brain barrier).
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Affiliation(s)
- Alla P Toropova
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milano, Italy.
| | - Andrey A Toropov
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milano, Italy
| | - Alessandra Roncaglioni
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milano, Italy
| | - Emilio Benfenati
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Science, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milano, Italy
| | - Danuta Leszczynska
- Interdisciplinary Nanotoxicity Center, Department of Civil and Environmental Engineering, Jackson State University, 1325 Lynch Street, Jackson, MS, 39217-0510, USA
| | - Jerzy Leszczynski
- Interdisciplinary Nanotoxicity Center, Department of Chemistry, Physics and Atmospheric Sciences, Jackson, MS, 39217, USA
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Colmenares R, Carrión-Marchante R, Martín ME, Salinas Muñoz L, García-Bermejo ML, Oller JC, Muñoz A, Blanco F, Rosado J, Lozano AI, Álvarez S, García-Vicente F, García G. Dependence of Induced Biological Damage on the Energy Distribution and Intensity of Clinical Intra-Operative Radiotherapy Electron Beams. Int J Mol Sci 2023; 24:10816. [PMID: 37445992 DOI: 10.3390/ijms241310816] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
The survival fraction of epithelial HaCaT cells was analysed to assess the biological damage caused by intraoperative radiotherapy electron beams with varying energy spectra and intensities. These conditions were achieved by irradiating the cells at different depths in water using nominal 6 MeV electron beams while consistently delivering a dose of 5 Gy to the cell layer. Furthermore, a Monte Carlo simulation of the entire irradiation procedure was performed to evaluate the molecular damage in terms of molecular dissociations induced by the radiation. A significant agreement was found between the molecular damage predicted by the simulation and the damage derived from the analysis of the survival fraction. In both cases, a linear relationship was evident, indicating a clear tendency for increased damage as the averaged incident electron energy and intensity decreased for a constant absorbed dose, lowering the dose rate. This trend suggests that the radiation may have a more pronounced impact on surrounding healthy tissues than initially anticipated. However, it is crucial to conduct additional experiments with different target geometries to confirm this tendency and quantify the extent of this effect.
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Affiliation(s)
- Rafael Colmenares
- Servicio de Radiofísica, IRYCIS-Hospital Universitario Ramón y Cajal, Carretera de Colmenar Viejo km 9100, 28034 Madrid, Spain
| | - Rebeca Carrión-Marchante
- Grupo de Aptámeros, Departamento de Bioquímica-Investigación, IRYCIS-Hospital Universitario Ramón y Carretera de Colmenar Viejo km 9100, 28034 Madrid, Spain
| | - M Elena Martín
- Grupo de Aptámeros, Departamento de Bioquímica-Investigación, IRYCIS-Hospital Universitario Ramón y Carretera de Colmenar Viejo km 9100, 28034 Madrid, Spain
| | - Laura Salinas Muñoz
- Biomarkers and Therapeutic Targets Group, IRYCIS, RedinREN, Hospital Universitario Ramón y Cajal, Carretera de Colmenar km 9100, 28034 Madrid, Spain
| | - María Laura García-Bermejo
- Biomarkers and Therapeutic Targets Group, IRYCIS, RedinREN, Hospital Universitario Ramón y Cajal, Carretera de Colmenar km 9100, 28034 Madrid, Spain
| | - Juan C Oller
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas-CIEMAT, 28040 Madrid, Spain
| | - Antonio Muñoz
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas-CIEMAT, 28040 Madrid, Spain
| | - Francisco Blanco
- Departamento de Estructura de la Materia, Física Térmica y Electrónica e IPARCOS, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Jaime Rosado
- Departamento de Estructura de la Materia, Física Térmica y Electrónica e IPARCOS, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Ana I Lozano
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain
| | - Sofía Álvarez
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain
| | - Feliciano García-Vicente
- Servicio de Radiofísica, IRYCIS-Hospital Universitario Ramón y Cajal, Carretera de Colmenar Viejo km 9100, 28034 Madrid, Spain
| | - Gustavo García
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
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35
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Attarian E, Mohammadi F, Ebrahimpour K, Moazeni M, Maracy M, Ebrahimi A, Kelishadi R. Health risk assessment of exposure to triclosan in pregnant women using Monte Carlo simulation techniques: based on biomonitoring data. J Environ Sci Health C Toxicol Carcinog 2023; 41:61-75. [PMID: 37365949 DOI: 10.1080/26896583.2023.2226587] [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] [Indexed: 06/28/2023]
Abstract
This study aimed to assess the triclosan (TCS) health risk in an Iranian pregnant women sample by Monte Carlo simulation (MCS). The urinary TCS of 99 women after the 28th week of pregnancy was detected by gas chromatography/mass spectrometry detector (GC/MS), and the MCS model implemented a health risk assessment. The corresponding hazard quotient (HQ) and the sensitivity analysis were calculated. TCS was measured in 100% of the urine samples with a median concentration of 2.89 µg/L. The median of HQ was obtained at 1.93 × 10-4. The TCS exposure risk in the studied population was lower than the allowable limit. A comparison between HQ values in the two weight subgroups of pregnant women showed that the risk level is almost equal, and there was minimal health risk in pregnant women from exposure to TCS.
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Affiliation(s)
- Elham Attarian
- Student Research Committee, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Farzaneh Mohammadi
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
- Environment Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Karim Ebrahimpour
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
- Environment Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Malihe Moazeni
- Student Research Committee, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammadreza Maracy
- Environment Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Epidemiology and Biostatistics, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Afshin Ebrahimi
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
- Environment Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Roya Kelishadi
- Department of Pediatrics, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
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Margadant F, Almsherqi Z, Xu X, Deng Y. Optical Properties and Interference Effects of the Lens Mitochondrion. Membranes (Basel) 2023; 13:610. [PMID: 37367815 DOI: 10.3390/membranes13060610] [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] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/24/2023] [Accepted: 06/01/2023] [Indexed: 06/28/2023]
Abstract
The lens mitochondrion of the tree shrew, located along the optical pathway between the lens and photoreceptors, has been investigated. The results suggest that the lens mitochondrion acts as a quasi-bandgap or imperfect photonic crystal. Interference effects cause a shift in the focus and introduce wavelength-dependent behavior similar to dispersion. Optical channels within the mitochondrion form a mild waveguide, preferentially propagating light within certain compartments. The lens mitochondrion also functions as an imperfect UV-shielding interference filter. Overall, this study provides insights into the dual role of the lens mitochondrion and the complex behavior of light within biological systems.
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Affiliation(s)
- Felix Margadant
- Department of Molecular Cell Biology, Institute for Cancer Research, Radium University Hospital, 0379 Oslo, Norway
| | - Zakaria Almsherqi
- Department of Physiology, National University of Singapore, Singapore 117593, Singapore
| | - Xiaochun Xu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Yuru Deng
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
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37
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Salimi E, Jalali HB, Esfandi F. Shielding design aspects of SR in 3 GeV ILSF. J Radiol Prot 2023; 43:021513. [PMID: 37257434 DOI: 10.1088/1361-6498/acda42] [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: 04/24/2023] [Accepted: 05/31/2023] [Indexed: 06/02/2023]
Abstract
Iranian Light Source Facility (ILSF) is an under-construction synchrotron radiation accelerator consisting of a 150 MeV linac, a booster synchrotron operating from 150 MeV to 3 GeV, and a 3 GeV storage ring that stores a maximum of 400 mA current of electrons. As the stored beam circulates, a fraction of the beam is lost due to interactions with gas molecules, interactions among beam particles, and orbital bending, which produce radiation. The bulk shielding calculation for the ILSF and the input parameters used for this analysis are discussed in this paper. The potential of skyshine neutrons to cause radiation hazards is investigated as well. Moreover, the design and shielding simulation using the FLUKA Monte Carlo code is presented for the linac beam stop and primary and scattered gas bremsstrahlung for the first optics enclosure of the ILSF spectro microscopy beamline. Our designed radiation shielding system guarantees that the annual dose in all areas around the ILSF machine does not exceed the dose limit of 1 mSv.
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Affiliation(s)
- Ehsan Salimi
- Iranian Light Source Facility, ILSF, Institute for Research in Fundamental Sciences, IPM, Tehran, Iran
| | - Hamideh Beigzadeh Jalali
- Iranian Light Source Facility, ILSF, Institute for Research in Fundamental Sciences, IPM, Tehran, Iran
| | - Fatemeh Esfandi
- School of Particles and Accelerators, Institute for Research in Fundamental Sciences, IPM, Tehran, Iran
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Toropov AA, Toropova AP, Leszczynska D, Leszczynski J. Development of Self-Consistency Models of Anticancer Activity of Nanoparticles under Different Experimental Conditions Using Quasi-SMILES Approach. Nanomaterials (Basel) 2023; 13:1852. [PMID: 37368282 DOI: 10.3390/nano13121852] [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] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 05/30/2023] [Accepted: 06/08/2023] [Indexed: 06/28/2023]
Abstract
Algorithms of the simulation of the anticancer activity of nanoparticles under different experimental conditions toward cell lines A549 (lung cancer), THP-1 (leukemia), MCF-7 (breast cancer), Caco2 (cervical cancer), and hepG2 (hepatoma) have been developed using the quasi-SMILES approach. This approach is suggested as an efficient tool for the quantitative structure-property-activity relationships (QSPRs/QSARs) analysis of the above nanoparticles. The studied model is built up using the so-called vector of ideality of correlation. The components of this vector include the index of ideality of correlation (IIC) and the correlation intensity index (CII). The epistemological component of this study is the development of methods of registration, storage, and effective use of experimental situations that are comfortable for the researcher-experimentalist in order to be able to control the physicochemical and biochemical consequences of using nanomaterials. The proposed approach differs from the traditional models based on QSPR/QSAR in the following respects: (i) not molecules but experimental situations available in a database are considered; in other words, an answer is offered to the question of how to change the plot of the experiment in order to achieve the desired values of the endpoint being studied; and (ii) the user has the ability to select a list of controlled conditions available in the database that can affect the endpoint and evaluate how significant the influence of the selected controlled experimental conditions is.
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Affiliation(s)
- Andrey A Toropov
- Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
| | - Alla P Toropova
- Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
| | - Danuta Leszczynska
- Interdisciplinary Nanotoxicity Center, Department of Civil and Environmental Engineering, Jackson State University, 1325 Lynch Street, Jackson, MS 39217-0510, USA
| | - Jerzy Leszczynski
- Interdisciplinary Nanotoxicity Center, Department of Chemistry, Physics and Atmospheric Sciences, Jackson, MS 39217-0510, USA
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Strugari ME, DeBay DR, Beyea SD, Brewer KD. NEMA NU 1-2018 performance characterization and Monte Carlo model validation of the Cubresa Spark SiPM-based preclinical SPECT scanner. EJNMMI Phys 2023; 10:35. [PMID: 37261574 DOI: 10.1186/s40658-023-00555-6] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 05/15/2023] [Indexed: 06/02/2023] Open
Abstract
BACKGROUND The Cubresa Spark is a novel benchtop silicon-photomultiplier (SiPM)-based preclinical SPECT system. SiPMs in SPECT significantly improve resolution and reduce detector size compared to preclinical cameras with photomultiplier tubes requiring highly magnifying collimators. The NEMA NU 1 Standard for Performance Measurements of Gamma Cameras provides methods that can be readily applied or extended to characterize preclinical cameras with minor modifications. The primary objective of this study is to characterize the Spark according to the NEMA NU 1-2018 standard to gain insight into its nuclear medicine imaging capabilities. The secondary objective is to validate a GATE Monte Carlo simulation model of the Spark for use in preclinical SPECT studies. METHODS NEMA NU 1-2018 guidelines were applied to characterize the Spark's intrinsic, system, and tomographic performance with single- and multi-pinhole collimators. Phantoms were fabricated according to NEMA specifications with deviations involving high-resolution modifications. GATE was utilized to model the detector head with the single-pinhole collimator, and NEMA measurements were employed to tune and validate the model. Single-pinhole and multi-pinhole SPECT data were reconstructed with the Software for Tomographic Image Reconstruction and HiSPECT, respectively. RESULTS The limiting intrinsic resolution was measured as 0.85 mm owing to a high-resolution SiPM array combined with a 3 mm-thick scintillation crystal. The average limiting tomographic resolution was 1.37 mm and 1.19 mm for the single- and multi-pinhole collimators, respectively, which have magnification factors near unity at the center of rotation. The maximum observed count rate was 15,400 cps, and planar sensitivities of 34 cps/MBq and 150 cps/MBq were measured at the center of rotation for the single- and multi-pinhole collimators, respectively. All simulated tests agreed well with measurement, where the most considerable deviations were below 7%. CONCLUSIONS NEMA NU 1-2018 standards determined that a SiPM detector mitigates the need for highly magnifying pinhole collimators while preserving detailed information in projection images. Measured and simulated NEMA results were highly comparable with differences on the order of a few percent, confirming simulation accuracy and validating the GATE model. Of the collimators initially provided with the Spark, the multi-pinhole collimator offers high resolution and sensitivity for organ-specific imaging of small animals, and the single-pinhole collimator enables high-resolution whole-body imaging of small animals.
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Affiliation(s)
- Matthew E Strugari
- Biomedical Translational Imaging Centre, Halifax, NS, Canada.
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada.
| | - Drew R DeBay
- Biomedical Translational Imaging Centre, Halifax, NS, Canada
- Cubresa Inc., Winnipeg, MB, Canada
| | - Steven D Beyea
- Biomedical Translational Imaging Centre, Halifax, NS, Canada
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada
- Department of Diagnostic Radiology, Dalhousie University, Halifax, NS, Canada
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada
| | - Kimberly D Brewer
- Biomedical Translational Imaging Centre, Halifax, NS, Canada
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada
- Department of Diagnostic Radiology, Dalhousie University, Halifax, NS, Canada
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
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Cordeiro LP, de Sá LV, Kitamikado RA, Sapienza M, Baptista Bonifacio DA. Optimized Monte Carlo simulations for voxel-based internal dosimetry. Phys Med Biol 2023; 68. [PMID: 37141895 DOI: 10.1088/1361-6560/acd2a1] [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: 09/21/2022] [Accepted: 05/04/2023] [Indexed: 05/06/2023]
Abstract
OBJECTIVE The scientific community has considered internal dosimetry by the Monte Carlo method the gold standard. However, there is a trade-off between simulation processing time and the statistical quality of the results that makes it a challenge to obtain accurate absorbed dose values in some situations, such as dose estimation in organs affected by cross-irradiation or limited computing power. Variance reduction techniques are used to reduce computational processing time without impairing the statistical quality of the results, such as tracking energy cutoff, secondary particle production threshold, and parallelism of different types of emissions from radionuclides. APPROACH In this work, GATE Monte Carlo code and its variance reduction techniques were evaluated to calculate S values of organs from the International Commission on Radiological Protection (ICRP) report 110 male phantom for the lutetium-177, iodine-131, yttrium-90, and radium-223 radionuclides. The results are compared with the data from the OpenDose collaboration. MAIN RESULTS A cutoff of 5 MeV for local electron deposition and 2.0 mm of secondary particle production range resulted in a computational efficiency increase of 7.9 and 1.05 times, respectively. Simulation of ICRP 107 spectra-based source proved to be about 5 times more efficient when compared to a decay simulation using \verb|G4RadioactiveDecay| (Geant4-based radioactive decay processes). TLE (Track Length Estimator) and seTLE (Split Exponential Track Length Estimator) techniques were used to calculate the absorbed dose of photon emissions, resulting in computational efficiency up to 29.4 and 62.5 times higher when compared to traditional simulations, respectively. In particular, the seTLE technique accelerates the simulation time by up to 1426 times, achieving a statistical uncertainty of 10\% in volumes affected by cross-irradiation. SIGNIFICANCE The variance reduction techniques used in this work drastically reduced the simulation time and maintained the statistical quality of the calculated absorbed dose values, proving the feasibility of the use of the Monte Carlo method in internal dosimetry under challenging situations and making it viable for clinical routine or web applications.
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Affiliation(s)
- Leanderson Pereira Cordeiro
- IRD/DIFME, CNEN, Av. Salvador Allende, 3773, Barra da Tijuca, Rio de Janeiro, Rio de Janeiro, 22780-160, BRAZIL
| | - Lidia Vasconcelos de Sá
- IRD, CNEN, Av. Salvador Allende, 3773 - Barra da Tijuca, Rio de Janeiro, Rio de Janeiro, RJ, 22780-160, BRAZIL
| | - Rafael Akio Kitamikado
- Medical School, Nuclear Medicine Center, Universidade de São Paulo, Dr. Ovídio Pires de Campos Street, 872, São Paulo, São Paulo, 05403-911, BRAZIL
| | - Marcelo Sapienza
- Universidade de Sao Paulo Hospital das Clinicas, Rua, Av. Dr. Enéas Carvalho de Aguiar, 255 - Cerqueira César, Sao Paulo, São Paulo, 05403-000, BRAZIL
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Toropova AP, Toropov AA, Roncaglioni A, Benfenati E. The System of Self-Consistent Models: QSAR Analysis of Drug-Induced Liver Toxicity. Toxics 2023; 11:toxics11050419. [PMID: 37235234 DOI: 10.3390/toxics11050419] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/11/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023]
Abstract
Removing a drug-like substance that can cause drug-induced liver injury from the drug discovery process is a significant task for medicinal chemistry. In silico models can facilitate this process. Semi-correlation is an approach to building in silico models representing the prediction in the active (1)-inactive (0) format. The so-called system of self-consistent models has been suggested as an approach for two tasks: (i) building up a model and (ii) estimating its predictive potential. However, this approach has been tested so far for regression models. Here, the approach is applied to building up and estimating a categorical hepatotoxicity model using the CORAL software. This new process yields good results: sensitivity = 0.77, specificity = 0.75, accuracy = 0.76, and Matthew correlation coefficient = 0.51 (all compounds) and sensitivity = 0.83, specificity = 0.81, accuracy = 0.83 and Matthew correlation coefficient = 0.63 (validation set).
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Affiliation(s)
- Alla P Toropova
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
| | - Andrey A Toropov
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
| | - Alessandra Roncaglioni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
| | - Emilio Benfenati
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy
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Nojiri M, Takata T, Hu N, Sakurai Y, Suzuki M, Tanaka H. Development and evaluation of dose calculation algorithm with a combination of Monte Carlo and point-kernel methods for boron neutron capture therapy. Biomed Phys Eng Express 2023; 9. [PMID: 37021631 DOI: 10.1088/2057-1976/acc33c] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/10/2023] [Indexed: 04/07/2023]
Abstract
We developed a 'hybrid algorithm' that combines the Monte Carlo (MC) and point-kernel methods for fast dose calculation in boron neutron capture therapy. The objectives of this study were to experimentally verify the hybrid algorithm and to verify the calculation accuracy and time of a 'complementary approach' adopting both the hybrid algorithm and the full-energy MC method. In the latter verification, the results were compared with those obtained using the full-energy MC method alone. In the hybrid algorithm, the moderation process of neutrons is simulated using only the MC method, and the thermalization process is modeled as a kernel. The thermal neutron fluxes calculated using only this algorithm were compared with those measured in a cubic phantom. In addition, a complementary approach was used for dose calculation in a geometry simulating the head region, and its computation time and accuracy were verified. The experimental verification indicated that the thermal neutron fluxes calculated using only the hybrid algorithm reproduced the measured values at depths exceeding a few centimeters, whereas they overestimated those at shallower depths. Compared with the calculation using only the full-energy MC method, the complementary approach reduced the computation time by approximately half, maintaining nearly same accuracy. When focusing on the calculation only using the hybrid algorithm only for the boron dose attributed to the reaction of thermal neutrons, the computation time was expected to reduce by 95% compared with the calculation using only the full-energy MC method. In conclusion, modeling the thermalization process as a kernel was effective for reducing the computation time.
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Affiliation(s)
- Mai Nojiri
- Department of Nuclear Engineering, Graduate School of Engineering, Kyoto University, Kyoutodaigaku-Katsura, Kyoto, Japan
| | - Takushi Takata
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Osaka, Japan
| | - Naonori Hu
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Osaka, Japan
- Kansai BNCT Medical Center, Osaka Medical and Pharmaceutical University, Takatsuki, Japan
| | - Yoshinori Sakurai
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Osaka, Japan
| | - Minoru Suzuki
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Osaka, Japan
| | - Hiroki Tanaka
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Osaka, Japan
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Renil Mon P, Meena-Devi V, Bhasi S. Monte Carlo modelling and validation of the elekta synergy medical linear accelerator equipped with radiosurgical cones. Heliyon 2023; 9:e15328. [PMID: 37123913 PMCID: PMC10130217 DOI: 10.1016/j.heliyon.2023.e15328] [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: 10/29/2022] [Revised: 04/02/2023] [Accepted: 04/03/2023] [Indexed: 05/02/2023] Open
Abstract
Monte Carlo simulations of medical linear accelerator heads help in visualizing the energy spectrum and angular spread of photons and electrons, energy deposition, and scattering from each of the head components. Hence, the purpose of this study was to validate the Monte Carlo model of the Elekta synergy medical linear accelerator equipped with stereotactic radio surgical connical collimators. For this, the Elekta synergy medical linear accelerator was modelled using the EGSnrc Monte Carlo code. The model results were validated using the measured data. The primary electron beam parameters, beam size, and energy were tuned to match the measured data; a dose profile with a field size of 40 × 40 cm2 and percentage depth dose with a field size of 10 × 10 cm2 were matched during tuning. The validation of the modelled data with the measurement results was performed using gamma analysis, point dose, and field size comparisons. For small radiation fields, relative output factors were also compared. The gamma analysis revealed good agreement between the Monte Carlo modeling results and the measured data. A gamma pass rate of more than 95% was obtained for field sizes of 40 × 40 cm2 to 2 × 2 cm2 with gamma criteria of 1% and 1 mm for the dose difference (DD) and distance to agreement (DTA), respectively; this gamma pass rate was more than 98% for the corresponding values of 2% and 2 mm for the DD and DTA, respectively. A gamma pass rate of more than 99% was obtained for a percentage depth dose with 1 mm and 1% criteria. The field size was also in good agreement with the measurement results, and the maximum deviation observed was 1.1%. The stereotactic cone field also passed this analysis with a gamma pass rate of more than 98% for dose profiles and 99% for the percentage depth dose. The small field output factor exhibited a deviation of 4.3%, 3.4%, and 1.9% for field sizes of 5 mm, 7.5 mm, and 10 mm, respectively. Thus, the Monte Carlo model of the Elekta Linear accelerator was successfully validated. The validation of radio surgical cones passed the analysis in terms of the dose profiles and percentage depth dose. The small field relative output factors exhibited deviations of up to 4.3%, and to resolve this, detector-specific and field-specific correction factors must be derived.
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Affiliation(s)
- P.S. Renil Mon
- Department of Physics, Noorul Islam Centre for Higher Education, Kumarakoil, Kanyakumari District, Tamilnadu, India
- Corresponding author.
| | - V.N. Meena-Devi
- Department of Physics, Noorul Islam Centre for Higher Education, Kumarakoil, Kanyakumari District, Tamilnadu, India
| | - Saju Bhasi
- Department of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala, India
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Toropov AA, Barnes DA, Toropova AP, Roncaglioni A, Irvine AR, Masereeuw R, Benfenati E. CORAL Models for Drug-Induced Nephrotoxicity. Toxics 2023; 11:293. [PMID: 37112520 PMCID: PMC10142465 DOI: 10.3390/toxics11040293] [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] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 06/19/2023]
Abstract
Drug-induced nephrotoxicity is a major cause of kidney dysfunction with potentially fatal consequences. The poor prediction of clinical responses based on preclinical research hampers the development of new pharmaceuticals. This emphasises the need for new methods for earlier and more accurate diagnosis to avoid drug-induced kidney injuries. Computational predictions of drug-induced nephrotoxicity are an attractive approach to facilitate such an assessment and such models could serve as robust and reliable replacements for animal testing. To provide the chemical information for computational prediction, we used the convenient and common SMILES format. We examined several versions of so-called optimal SMILES-based descriptors. We obtained the highest statistical values, considering the specificity, sensitivity and accuracy of the prediction, by applying recently suggested atoms pairs proportions vectors and the index of ideality of correlation, which is a special statistical measure of the predictive potential. Implementation of this tool in the drug development process might lead to safer drugs in the future.
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Affiliation(s)
- Andrey A. Toropov
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (A.P.T.); (A.R.); (E.B.)
| | - Devon A. Barnes
- Utrecht Institute for Pharmaceutical Sciences, div. Pharmacology, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; (D.A.B.); (A.R.I.); (R.M.)
| | - Alla P. Toropova
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (A.P.T.); (A.R.); (E.B.)
| | - Alessandra Roncaglioni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (A.P.T.); (A.R.); (E.B.)
| | - Alasdair R. Irvine
- Utrecht Institute for Pharmaceutical Sciences, div. Pharmacology, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; (D.A.B.); (A.R.I.); (R.M.)
| | - Rosalinde Masereeuw
- Utrecht Institute for Pharmaceutical Sciences, div. Pharmacology, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; (D.A.B.); (A.R.I.); (R.M.)
| | - Emilio Benfenati
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (A.P.T.); (A.R.); (E.B.)
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Iseri T, Tanabe Y, Onizuka R, Torigoe Y, Horikirizono H, Itamoto K, Sunahara H, Itoh H, Tani K, Nakaichi M. A Monte Carlo study on dose distribution of an orthovoltage radiation therapy system. Phys Eng Sci Med 2023; 46:623-632. [PMID: 36940063 DOI: 10.1007/s13246-023-01237-4] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 02/23/2023] [Indexed: 03/21/2023]
Abstract
It is important to plan radiotherapy treatment and establish optimal dose distribution to reduce the chances of side effects and injury. Because there are no commercially available tools for calculating dose distribution in orthovoltage radiotherapy in companion animals, we developed an algorithm to accomplish this and verified its characteristics using tumor disease cases. First, we used the Monte Carlo method to develop an algorithm to calculate the dose distribution of orthovoltage radiotherapy (280 kVp; MBR-320, Hitachi Medical Corporation, Tokyo, Japan) using BEAMnrc at our clinic. Using development of Monte Carlo method, dose distribution for tumor and normal organs were evaluated in brain tumors, squamous cell carcinomas of the head, and feline nasal lymphomas. In all cases of brain tumors, the mean dose delivered to the GTV ranged from 36.2 to 76.1% of the prescribed dose due to the decrease through the skull. In the nasal lymphoma in cats, the eyes with covered a 2 mm-thick lead plate, the respective average dose to the eyes was 71.8% and 89.9% less than that to the uncovered eyes. The findings may be useful for informed decision making in orthovoltage radiotherapy with more effective and targeted irradiation and data collection allowing detailed informed consent.
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Affiliation(s)
- Toshie Iseri
- Department of Veterinary Radiology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi, Yamagishi, Japan.
| | - Yoshinori Tanabe
- Graduate School of Health Sciences, Okayama University, Okayama, Japan
| | - Ryouta Onizuka
- Department of Therapeutic Radiology, Yamaguchi University Hospital, Yamaguchi, Japan
| | - Yuri Torigoe
- Department of Veterinary Radiology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi, Yamagishi, Japan
| | - Hiro Horikirizono
- Department of Veterinary Radiology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi, Yamagishi, Japan
| | - Kazuhito Itamoto
- Animal medical center, Joint faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Hiroshi Sunahara
- Department of Veterinary Surgery, Joint faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Harumichi Itoh
- Animal medical center, Joint faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Kenji Tani
- Department of Veterinary Surgery, Joint faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Munekazu Nakaichi
- Department of Veterinary Radiology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi, Yamagishi, Japan
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Xiao M, Qin Q, He X, Li F, Wang X. Shielding Capability Research on Composite Base Materials in Hybrid Neutron-Gamma Mixed Radiation Fields. Materials (Basel) 2023; 16:2084. [PMID: 36903199 PMCID: PMC10004341 DOI: 10.3390/ma16052084] [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] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
The 16N monitoring system operates in a mixed neutron-gamma radiation field and is subject to high background radiation, thus triggering instability in the 16N monitoring system measurement data. Due to its property of actual physical process simulation, the Monte Carlo method was adopted to establish the model of the 16N monitoring system and design a structure-functionally integrated shield to realize neutron-gamma mixed radiation shielding. First, the optimal shielding layer with a thickness of 4 cm was determined in this working environment, which had a significant shielding effect on the background radiation and improved the measurement of the characteristic energy spectrum and the shielding effect on neutrons was better than gamma shielding with the increase in the shield thickness. Then, functional fillers such as B, Gd, W, and Pb were added to the matrix to compare the shielding rates of three matrix materials of polyethylene, epoxy resin, and 6061 aluminum alloy at 1 MeV neutron and gamma energy. The shielding performance of epoxy resin as the matrix material was better than that of the aluminum alloy and polyethylene, and the shielding rate of boron-containing epoxy resin was 44.8%. The γ-ray mass attenuation coefficients of lead and tungsten in the three matrix materials were simulated to determine the best material for the gamma shielding performance. Finally, the optimal materials for neutron shielding and gamma shielding were combined, and the shielding performance of single-layer shielding and double-layer shielding in mixed radiation field was compared. The optimal shielding material-boron-containing epoxy resin was determined as the shielding layer of the 16N monitoring system to realize the integration of structure and function, which provides a theoretical basis for the selection of shielding materials in a special working environment.
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Affiliation(s)
- Ming Xiao
- College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
| | - Qingao Qin
- College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
| | - Xin He
- College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
| | - Fei Li
- College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
- Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province, Chengdu 610059, China
| | - Xiaobo Wang
- College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
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Lockwood P, Mitchell M. An assessment of the dose and image quality difference between AP and PA positioned adult radiographic knee examinations. J Med Imaging Radiat Sci 2023; 54:123-134. [PMID: 36646545 DOI: 10.1016/j.jmir.2022.12.004] [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: 10/10/2022] [Revised: 11/10/2022] [Accepted: 12/07/2022] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Knee X-rays are a standard examination to diagnose multiple conditions ranging from traumatic injuries, degeneration, and cancer. This study explores the differences between adult Anterior-Posterior (AP) and Posterior-Anterior (PA) weight-bearing knee examinations using absorbed radiation dose data and image quality. METHODS The study modelled and compared AP and PA knee X-ray radiation dose data using Monte-Carlo software, an Ion Chamber, and thermoluminescence dosemeters (TLDs) on a Rando phantom. Imaging parameters used were 66kVp, 4mAs, 100cm distance and 13 × 24cm collimation. The interval data analysis used a two-tailed t-test. The image quality of a sample of the AP and PA knee X-rays was assessed using Likert 5-point ordinal Image Quality Scoring (IQS) and the Wilcoxon matched pairs test. RESULTS Monte-Carlo modelling provided limited results; the Ion Chamber data for absorbed dose provided no variation between AP and PA positions but was similar to the AP TLD dose. The absorbed doses recorded with batches of TLDs demonstrated a 27.4% reduction (46.1μGy; p=0.01) in Skin Entrance Dose (ESD) and 9 - 58% dose reduction (1.6 - 16.4μGy; p=0.00-0.2) to the tissues and organs while maintaining diagnostic image quality (p=0.67). CONCLUSION The study has highlighted the various challenges of using different dosimetry approaches to measure absorbed radiation dose in extremity (knee) X-ray imaging. The Monte-Carlo simulated absorbed knee dose was overestimated, but the simulated body organ/tissue doses were lower than the actual TLD absorbed doses. The Ion Chamber absorbed doses did not differentiate between the positions. The TLD organ/tissue absorbed doses demonstrated a reduction in dose in the PA position compared to the AP position, without a detrimental effect on image quality. The study findings in laboratory conditions raise awareness of opportunities and potential to lower radiation dose, with further study replicated in a clinical site recommended.
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Affiliation(s)
- Paul Lockwood
- School of Allied Health Professions, Faculty of Medicine, Health and Social Care, Canterbury Christ Church University, Kent, United Kingdom.
| | - Martin Mitchell
- School of Allied Health Professions, Faculty of Medicine, Health and Social Care, Canterbury Christ Church University, Kent, United Kingdom; Imaging Department, Medway Maritime Hospital, Medway NHS Foundation Trust, Gillingham, Kent, United Kingdom
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Zhao H, Datta S, Duan ZH. An Integrated Approach of Learning Genetic Networks From Genome-Wide Gene Expression Data Using Gaussian Graphical Model and Monte Carlo Method. Bioinform Biol Insights 2023; 17:11779322231152972. [PMID: 36865982 PMCID: PMC9972065 DOI: 10.1177/11779322231152972] [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: 09/11/2022] [Accepted: 01/02/2023] [Indexed: 03/02/2023] Open
Abstract
Global genetic networks provide additional information for the analysis of human diseases, beyond the traditional analysis that focuses on single genes or local networks. The Gaussian graphical model (GGM) is widely applied to learn genetic networks because it defines an undirected graph decoding the conditional dependence between genes. Many algorithms based on the GGM have been proposed for learning genetic network structures. Because the number of gene variables is typically far more than the number of samples collected, and a real genetic network is typically sparse, the graphical lasso implementation of GGM becomes a popular tool for inferring the conditional interdependence among genes. However, graphical lasso, although showing good performance in low dimensional data sets, is computationally expensive and inefficient or even unable to work directly on genome-wide gene expression data sets. In this study, the method of Monte Carlo Gaussian graphical model (MCGGM) was proposed to learn global genetic networks of genes. This method uses a Monte Carlo approach to sample subnetworks from genome-wide gene expression data and graphical lasso to learn the structures of the subnetworks. The learned subnetworks are then integrated to approximate a global genetic network. The proposed method was evaluated with a relatively small real data set of RNA-seq expression levels. The results indicate the proposed method shows a strong ability of decoding the interactions with high conditional dependences among genes. The method was then applied to genome-wide data sets of RNA-seq expression levels. The gene interactions with high interdependence from the estimated global networks show that most of the predicted gene-gene interactions have been reported in the literatures playing important roles in different human cancers. Also, the results validate the ability and reliability of the proposed method to identify high conditional dependences among genes in large-scale data sets.
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Affiliation(s)
- Haitao Zhao
- Department of Mathematics and Computer
Science, The University of North Carolina at Pembroke, Pembroke, NC, USA,Haitao Zhao, Department of Mathematics and
Computer Science, The University of North Carolina at Pembroke, Pembroke, NC,
USA.
| | - Sujay Datta
- Department of Statistics, The
University of Akron, Akron, OH, USA
| | - Zhong-Hui Duan
- Department of Computer Science, The
University of Akron, Akron, OH, USA
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da Silva FA, Lourenço FR, Calixto LA. Development and optimization of stability-indicating method of ethinylestradiol, levonorgestrel, and their main impurities using quality by design approach. J Pharm Biomed Anal 2023; 225:115208. [PMID: 36586384 DOI: 10.1016/j.jpba.2022.115208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 12/13/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
The association of Ethinylestradiol 0.03 mg and Levonorgestrel 0.15 mg is a hormonal contraceptive that combines estrogen and progestogen. According to a bibliographic survey, these combined drugs present at least 18 known degradation products, which are required to control the potential impurities harmful to human health. The high number of impurities and the low concentrations of the active pharmaceutical ingredients (APIs) and their respective degradation products increase the complexity of the stability-indicating method development for this medicine. Thus, this work aimed to develop and optimize the stability-indicating method using the quality by design (QbD) approach and in-silico tools for application in samples of oral contraceptives sold in Brazil. The analysis samples were initially subjected to a forced degradation study through 7 days of exposure under acid and alkali hydrolysis, oxidative condition, and oxidation by metal ions. In addition to the chemical exposure, the sample was subjected to physical stress through 10 days of exposure under dry heat, moisture, and photolytic degradation. These exposure samples were analyzed in the development and optimization of chromatographic conditions. As a result, the developed method was able to separate 20 known substances, including the two APIs and their respective 18 degradation products, as well as unknown degradation products obtained by the forced degradation study. Finally, this stability-indicating method was successfully applied for comparative analysis of contraceptive drugs marketed in Brazil, newly purchased and subjected to accelerated stability condition at 40 °C and 75% RH over the 6-month period.
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Wu J, Hu J, Wang K, Zhai Y, Wang Z, Feng Y, Fan H, Wang K, Duan Y. Flexible stretchable low-energy X-ray (30-80 keV) radiation shielding material: Low-melting-point Ga(1)In(1)Sn(7)Bi(1) alloy/thermoplastic polyurethane composite. Appl Radiat Isot 2023; 192:110603. [PMID: 36508958 DOI: 10.1016/j.apradiso.2022.110603] [Citation(s) in RCA: 1] [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: 09/01/2022] [Revised: 11/23/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022]
Abstract
A highly flexible stretchable thermoplastic polyurethane (TPU) composite loaded with a low-melting-point Ga1In1Sn7Bi1 multiprincipal element alloy (LMPEA) was prepared, and its radiation shielding performance was evaluated. The fluid characteristic of LMPEA and the flexibility of TPU enable good interface compatibility. Ga1In1Sn7Bi1 LMPEA consists of two eutectic structures, and the liquid gallium-rich phases are distributed at the boundary of the InBi intermetallic compound and Sn solid solution. In the low-photon energy range of 30-80 keV, LMPEA has a theoretical specific lead equivalent of 0.803 mmPb/mm and a theoretical weight reduction of 17.27% compared with lead. To evaluate the photon attenuation capability for the LMPEA/TPU composites, the Phy-X procedure and Monte Carlo simulations were used to determine the shielding parameters, such as the mass attenuation coefficient, linear attenuation coefficient, half-value layer, tenth-value layer, mean free path, effective atomic number, and fast neutron removal cross section. The attenuation performance test of X-ray protective materials measured the actual lead equivalent. At the same thickness, the LMPEA/TPU composite (66.667, 50.000 wt% LMPEA loading) has a higher measured lead equivalent than the in-service medical shielding materials, which meets the lead equivalent requirements of X-ray protective clothing. LMPEA/TPU composites are nontoxic, lightweight, and have excellent low-energy X-ray shielding ability, offering great potential for application in medical wearable materials.
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