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Hu J, Liu W, Xie F, Xu S, Huang Z, Li W. Study on imaging techniques and quantitative detection method for internal void defects in rubber based on terahertz reflection imaging. OPTICS EXPRESS 2025; 33:15661-15681. [PMID: 40219474 DOI: 10.1364/oe.546988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2024] [Accepted: 03/02/2025] [Indexed: 04/14/2025]
Abstract
This paper applies the reflection mode of terahertz time-domain spectroscopy technology to conduct research on the void defects in black silicone rubber samples. Algorithms such as power spectral density (PSD) integration imaging, homomorphic filtering, and the Otsu method are innovatively integrated to construct an efficient, high-precision defect characterization system. Different from traditional research, this paper deeply explores the advantages of each algorithm and optimizes them according to the characteristics of rubber materials and terahertz signals. By combining multiple features in the time-domain and frequency-domain to reconstruct terahertz images, and with the collaborative optimization of grayscale histogram equalization and filtering algorithms on the imaging quality, the optimal combination of PSD integration imaging, homomorphic filtering, and the Otsu method is determined, achieving precise defect imaging and quantification. In spectral analysis, a method combining wavelet signal denoising and time-domain spectroscopy is proposed. A formula based on time-of-flight was then used for quantitative analysis of the defects. In 3D imaging, an innovative alignment operation of denoised time-domain spectral curves is introduced. Combined with the maximum intensity projection, the clear visualization of void defects is realized.
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Yong J, Lu G, An Y, Lang S, Zhang H, Chen R. Characterization of cis-polyisoprene produced in Periploca sepium, a novel promising alternative source of natural rubber. Commun Biol 2025; 8:372. [PMID: 40045021 PMCID: PMC11882929 DOI: 10.1038/s42003-025-07734-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2024] [Accepted: 02/13/2025] [Indexed: 03/09/2025] Open
Abstract
Natural rubber is an important industrial raw material and is almost exclusively produced from Hevea brasiliensis latex. Because H. brasiliensis is limited its cultivation to specific tropical regions, the insufficient capacity of natural rubber has become increasingly urgent. To develop a novel alternative plant for natural rubber production, we selected a perennial shrub Periploca sepium, which is widely distributed from tropical to temperate regions. P. sepium can produce latex and contains the rubber component polyisoprene with a high-molecular-weight distribution ranging from 104-106. Its main chain structure was identified as cis-1,4-polyisoprene, similar to that of H. brasiliensis. The polyisoprenes were observed to be present mainly in the secondary phloem adjacent to the cambium and pith, and almost entirely overlapped with the distributions of three rubber particle-associated proteins, cis-prenyltransferase (CPT), small rubber particle protein (SRPP) and rubber elongation factor (REF). The three genes were genome edited via CRISPR-Cas9 in P. sepium, and the total contents and high-molecular-mass regions of the cis-polyisoprenes in the transgenic plants with mutations were reduced to different degrees, indicating that the three genes apparently play important roles in natural rubber biosynthesis. This research will promote the development of P. sepium as an alternative source of natural rubber.
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Affiliation(s)
- Jingjiao Yong
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, Ningxia, 750021, China
- School of Life Science, Ningxia University, Yinchuan, Ningxia, 750021, China
- School of Pharmacy, Ningxia Medical University, Yinchuan, Ningxia, 750004, China
| | - Guodong Lu
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, Ningxia, 750021, China
- School of Life Science, Ningxia University, Yinchuan, Ningxia, 750021, China
| | - Yingrui An
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, Ningxia, 750021, China
- School of Life Science, Ningxia University, Yinchuan, Ningxia, 750021, China
| | - Sirui Lang
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, Ningxia, 750021, China
- School of Life Science, Ningxia University, Yinchuan, Ningxia, 750021, China
| | - Hong Zhang
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, Ningxia, 750021, China
- School of Life Science, Ningxia University, Yinchuan, Ningxia, 750021, China
| | - Ren Chen
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, Ningxia, 750021, China.
- School of Life Science, Ningxia University, Yinchuan, Ningxia, 750021, China.
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Lordelo R, Branco R, Gama F, Morais PV. Assessment of antimicrobial resistance, biofilm formation, and surface modification potential in hospital strains of Pseudomonas aeruginosa and Klebsiella pneumoniae. Heliyon 2024; 10:e30464. [PMID: 38711646 PMCID: PMC11070870 DOI: 10.1016/j.heliyon.2024.e30464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 04/12/2024] [Accepted: 04/26/2024] [Indexed: 05/08/2024] Open
Abstract
The occurrence of healthcare-associated infections is a multifactorial phenomenon related to hospital space contamination by bacteria. The ESKAPE group, specifically Pseudomonas aeruginosa and Klebsiella pneumoniae, play a relevant role in the occurrence of these infections. Therefore, comprehensive research is needed to identify characteristics that justify the prevalence of these species in the healthcare environment. In this line, the study aimed to determine the antimicrobial resistance, biofilm formation, and the potential for polymer degradation in a collection of 33 P. aeruginosa strains and 2 K. pneumoniae strains sampled from various equipment and non-critical surfaces in a Portuguese hospital. Antimicrobial susceptibility tests revealed that none of the strains was categorized as multidrug-resistant (non-MDR). An assessment of their biofilm-forming capabilities indicated that 97 % of the strains exhibited biofilm-producing characteristics. Notably, within this group, the majority of P. aeruginosa and half of K. pneumoniae strains were classified as strong biofilm producers. Furthermore, the strains were evaluated for their potential to cause damage or change medical devices, namely infusion sets, nasal cannula, and urinary catheters. Three P. aeruginosa strains, two strong and one moderate biofilm producers, showed the highest ability to modify surfaces of the nasal cannula and infusion sets. Additionally, the Chi-square test revealed a statistically significant relationship between the presence of P. aeruginosa strains and the water accession spots. In conclusion, this work suggests that bacteria from this group hold a significant ability to grow in the healthcare environment through the degradation of non-critical materials. This suggests a potential concern for the persistence and proliferation of these organisms in hospital environments, emphasizing the importance of robust infection control measures to mitigate the risks associated with bacterial growth on such surfaces.
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Affiliation(s)
- Roberta Lordelo
- University of Coimbra, Centre for Mechanical Engineering Material and Processes, ARISE, Department of Life Sciences, Coimbra, Portugal
| | - Rita Branco
- University of Coimbra, Centre for Mechanical Engineering Material and Processes, ARISE, Department of Life Sciences, Coimbra, Portugal
| | - Fernando Gama
- Health Sciences Research Unit: Nursing (UICISA: E), Portugal and Health School of the Polytechnic Institute of Viseu, Portugal
| | - Paula V. Morais
- University of Coimbra, Centre for Mechanical Engineering Material and Processes, ARISE, Department of Life Sciences, Coimbra, Portugal
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Shinde J, Suresh S, Kavala V, Yao CF. Pd(II)-catalyzed hydroarylations/hydroalkenylations of terminal alkynes: regioselective synthesis of allylic, homoallylic, and 1,3-diene systems. Chem Commun (Camb) 2024; 60:3790-3793. [PMID: 38456475 DOI: 10.1039/d4cc00049h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
A Pd-catalyzed regioselective hydroarylation of terminal alkynes containing a heteroatom has been developed via carbopalladation for the synthesis of allylic ethers, amines, and homoallylic alcohols. Moreover, hydroalkenylation of alkynes produces a variety of stereodefined 1,4-dienes with high regioselectivity. The important features of the present protocol are that it is highly regioselective, operationally rapid, and scalable with a huge substrate scope using only 3 mol% of PdCl2(PPh3)2 catalyst in the presence of a mild base KOAc.
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Affiliation(s)
- Jivan Shinde
- Department of Chemistry, National Taiwan Normal University, No, 88, Sec 4, Ting-Zhou Rd, Taipei-11677, Taiwan, Republic of China.
| | - Sundaram Suresh
- Department of Chemistry, National Taiwan Normal University, No, 88, Sec 4, Ting-Zhou Rd, Taipei-11677, Taiwan, Republic of China.
| | - Veerababurao Kavala
- Department of Chemistry, National Taiwan Normal University, No, 88, Sec 4, Ting-Zhou Rd, Taipei-11677, Taiwan, Republic of China.
| | - Ching-Fa Yao
- Department of Chemistry, National Taiwan Normal University, No, 88, Sec 4, Ting-Zhou Rd, Taipei-11677, Taiwan, Republic of China.
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Gong L, Chen Y, Cai M, Li J, Lu Q, Hou D. Characterization and Analysis of Corrosion Resistance of Rubber Materials for Downhole Tools in a High-Stress Environment with Coupled H 2S-CO 2. MATERIALS (BASEL, SWITZERLAND) 2024; 17:863. [PMID: 38399114 PMCID: PMC10890510 DOI: 10.3390/ma17040863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/22/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024]
Abstract
In the process of constructing deep natural gas wells in Sichuan and Chongqing, gas wells encounter various technical challenges such as high temperature, high pressure, and a corrosive environment containing H2S and CO2. The corrosion of rubber materials in these acidic environments can easily lead to seal failure in downhole tools. To better investigate the corrosion resistance of rubber materials in acidic environments, we utilized a dynamic cyclic corrosion experimental device capable of simulating the service conditions experienced by downhole tools under high-temperature, high-pressure multiphase flow. Corrosion-resistance tests were conducted on fluororubbers (FKM) 1, 2, 3, and HNBR (hydrogenated nitrile-butadiene rubber) under acidic conditions (80 °C and 160 °C), along with sealing corrosion tests on O-rings. These tests aimed to analyze the mechanical properties, hardness, and corrosion resistance before and after exposure to acid media as well as the sealing performance of O-rings. Ultimately, our goal was to identify suitable rubber materials for acidic pressure environments. Experimental results revealed that all four types of rubber exhibited decreased elongation at break after undergoing corrosion testing; however, fluororubber 3 demonstrated significant susceptibility to temperature effects while the other three types showed minimal impact from temperature variations. Fluororubber 1 and fluororubber 3 displayed substantial deformation levels whereas mechanical properties greatly deteriorated for fluororubber 2. Overall, HNBR showcased superior comprehensive performance.
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Affiliation(s)
- Leilei Gong
- School of Mechanical Science and Engineering, Northeast Petroleum University, Daqing 163000, China
- Research Institute of Oil Production Engineering, Daqing Oilfield Co., Daqing 163000, China; (M.C.); (J.L.); (Q.L.)
- Heilongjiang Oil and Gas Reservoir Production and Increase Focus Laboratory, Daqing 163000, China
| | - Yulin Chen
- The First Oil Production Plant of Daqing Oilfield Co., Ltd., Daqing 163000, China;
| | - Meng Cai
- Research Institute of Oil Production Engineering, Daqing Oilfield Co., Daqing 163000, China; (M.C.); (J.L.); (Q.L.)
- Heilongjiang Oil and Gas Reservoir Production and Increase Focus Laboratory, Daqing 163000, China
| | - Junliang Li
- Research Institute of Oil Production Engineering, Daqing Oilfield Co., Daqing 163000, China; (M.C.); (J.L.); (Q.L.)
- Heilongjiang Oil and Gas Reservoir Production and Increase Focus Laboratory, Daqing 163000, China
| | - Qiuyu Lu
- Research Institute of Oil Production Engineering, Daqing Oilfield Co., Daqing 163000, China; (M.C.); (J.L.); (Q.L.)
- Heilongjiang Oil and Gas Reservoir Production and Increase Focus Laboratory, Daqing 163000, China
| | - Duo Hou
- School of Oil and Gas Engineering, Southwest Petroleum University, Chengdu 610000, China;
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Burelo M, Martínez A, Hernández-Varela JD, Stringer T, Ramírez-Melgarejo M, Yau AY, Luna-Bárcenas G, Treviño-Quintanilla CD. Recent Developments in Synthesis, Properties, Applications and Recycling of Bio-Based Elastomers. Molecules 2024; 29:387. [PMID: 38257300 PMCID: PMC10819226 DOI: 10.3390/molecules29020387] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 12/25/2023] [Accepted: 12/25/2023] [Indexed: 01/24/2024] Open
Abstract
In 2021, global plastics production was 390.7 Mt; in 2022, it was 400.3 Mt, showing an increase of 2.4%, and this rising tendency will increase yearly. Of this data, less than 2% correspond to bio-based plastics. Currently, polymers, including elastomers, are non-recyclable and come from non-renewable sources. Additionally, most elastomers are thermosets, making them complex to recycle and reuse. It takes hundreds to thousands of years to decompose or biodegrade, contributing to plastic waste accumulation, nano and microplastic formation, and environmental pollution. Due to this, the synthesis of elastomers from natural and renewable resources has attracted the attention of researchers and industries. In this review paper, new methods and strategies are proposed for the preparation of bio-based elastomers. The main goals are the advances and improvements in the synthesis, properties, and applications of bio-based elastomers from natural and industrial rubbers, polyurethanes, polyesters, and polyethers, and an approach to their circular economy and sustainability. Olefin metathesis is proposed as a novel and sustainable method for the synthesis of bio-based elastomers, which allows for the depolymerization or degradation of rubbers with the use of essential oils, terpenes, fatty acids, and fatty alcohols from natural resources such as chain transfer agents (CTA) or donors of the terminal groups in the main chain, which allow for control of the molecular weights and functional groups, obtaining new compounds, oligomers, and bio-based elastomers with an added value for the application of new polymers and materials. This tendency contributes to the development of bio-based elastomers that can reduce carbon emissions, avoid cross-contamination from fossil fuels, and obtain a greener material with biodegradable and/or compostable behavior.
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Affiliation(s)
- Manuel Burelo
- Institute of Advanced Materials for Sustainable Manufacturing, Tecnologico de Monterrey, Queretaro 76130, Mexico;
| | - Araceli Martínez
- Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex. Hacienda de San José de la Huerta, Morelia 58190, Michoacán, Mexico;
| | | | - Thomas Stringer
- School of Engineering and Sciences, Tecnologico de Monterrey, Queretaro 76130, Mexico; (T.S.); (M.R.-M.)
| | | | - Alice Y. Yau
- Department of Analytical and Environmental Chemistry, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, USA;
| | - Gabriel Luna-Bárcenas
- Institute of Advanced Materials for Sustainable Manufacturing, Tecnologico de Monterrey, Queretaro 76130, Mexico;
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