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Improvement on the Mechanical Performance and Resistance Towards Hydrolysis of Poly(glycolic acid)via Solid-state Drawing

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Chinese journal of Polymer Science 2023年第1期41卷 14-23页

作者： jia-Xuan Li De-Yu niu Bo Liu Peng-Wu Xu Wei-j.n Yang pieter j.n lemstra Pi-Ming Ma The Key Laboratory of Synthetic and Biological Colloids Ministry of EducationJiangnan UniversityWuxi214122China PlemPolco B.V. Roek 245508 KEVeldhoventhe Netherlands

Poly(glycolic acid)is a biocompatible as well as biocomposable polymer with superior mechanical and barrier properties and,consequently,has found important applications in both medical and packaging ***,the high hydrolysis rate in a high humidity environment restricts its *** this work,a solid-state drawing process after melt extrusion is applied in order to produce fibrous PGA with enhanced mechanical properties and a much better resistance towards *** crystal structure of PGA gradually transformed from spherulites into oriented fibrous crystals in the stretching direction upon solid-state ***,both the length of microfibril and the size of lamellae increased initially with the drawing ratio(DR),while the chain-folded lamellae transformed into extended-chain fibrils at high(er)*** oriented structures lead to an overall improvement of the mechanical properties of PGA,e.g.,the tensile strength increased from 62.0±1.4 MPa to 910±54 MPa and the elongation at break increased from around 7%to 50%.Meanwhile,the heat capacity of totally mobile amorphous PGA(∆C_(p)^(0)=0.64 j·g^(−1)·℃^(−1))was reported for the first time,which was used to analyze the content of mobile amorphous fraction(XMAF)and rigid amorphous fraction(XRAF).Both the oriented chain-folded lamellae crystals and the tightly arranged RAF are beneficial to prevent water molecules from penetrating the matrix,thus improving the resistance towards *** a consequence,the fibrous PGA with a DR of 5 showed a tensile strength retention rate of 17.3%higher in comparison with the undrawn sample after 7-days accelerated ***,this work provides a feasible method to improve the mechanical and resistance towards hydrolysis performance of PGA,which may broaden its application and prolong the shelf-life of PGA products.

关键词： Poly(glycolic acid) Solid-state drawing Fibrous crystal Mechanical property Hydrolysis resistance

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Dual Use and Biosecurity: the Case of the Avian Flu H5n1

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Open journal of Applied Sciences 2012年第3期2卷 123-127页

作者： pieter j. D. Drenth Department of Psychology University Amsterdam Amsterdam The Netherlands

The classical dual use problem—the potential for harmful as well as beneficial application of scientific findings—has become more immediate in biotechnology than in most other fields of science. Terrorist misuse of the information on the development of pathogenic organisms can lead to catastrophic outcomes. Therefore, particular in biosciences researchers are faced with the dilemma to find a proper balance between the right to know and the dangers of knowing. In this paper this dilemma is illustrated by the research on the influenza A virus subtype H5n1, commonly known as “bird flu”. The pros and cons of the full publication on the development of a dangerous airborne type are discussed.

关键词： Dual Use Biosecurity Biosafety Bird Flu

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Localization-limited exciton oscillator strength in colloidal CdSe nanoplatelets revealed by the optically induced stark effect

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Light(Science & Applications) 2021年第6期10卷 1122-1132页

作者： pieter Geiregat Carmelita Roda Ivo Tanghe Shalini Singh Alessio Di Giacomo Delphine Lebrun Gianluca Grimaldi jorick Maes Dries Van Thourhout Iwan Moreels Arj.n j.Houtepen Zeger Hens Physics and Chemistry of nanostructures Department of ChemistryGhent UniversityGentBelgium. Center for nano and Biophotonics Ghent UniversityGentBelgium. Photonics Research Group Ghent UniversityGentBelgium. Department of Chemical Sciences and Bernal Institute University of LimerickLimerickIreland. Center for nanophotonics NWO-lnstitute AMOLFScience Park 1041098 XG AmsterdamThe Netherlands. Opto-Electronic Materials Section Department of Chemical EngineeringDelft UniversityDelftThe Netherlands

2D materials are considered for applications that require strong light-matter interaction because of the apparently giant oscillator strength of the exciton transitions in the absorbance ***,the effective oscillator strengths of these transitions have bee n scarcely reported,nor is there a con sistent interpretati on of the obtained ***,we analyse the transition dipole moment and the ensuing oscillator strength of the exciton transition in 2D CdSe nanoplatelets by means of the optically induced Stark effect(OSE).Intriguingly,we find that the exciton absorption line reacts to a high intensity optical field as a transition with an oscillator strength FStark that is 50 times smaller than expected based on the linear absorption *** propose that the pronounced exciton absorption line should be seen as the sum of multiple,low oscillator strength transitions,rather than a single high oscillator strength one,a feat we assign to strong exciton center-of-mass *** the quantum mechanical description of excitons,this 50-fold difference between both oscillator strengths corresponds to the ratio between the cohere nee area of the exciton's center of mass and the total area,which yields a coherence area of a mere 6.1 *** we find that the coherence area in creases with reducing temperature,we conclude that thermal effects,related to lattice vibrations,contribute to exciton *** further support of this localization model,we show that FStark is in dependent of the n anoplatelet area,correctly predicts the radiative lifetime,and lines up for strongly confined quantum dot systems.

关键词： coefficient. spectrum. oscillator

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Adequate Diagnostic Performance of Combined [¹⁸F]-Fluormethylcholine PET-CT with Diffusion-Weighted MRI in Primary Staging of High Risk Prostate Cancer

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Advances in Molecular Imaging 2016年第1期6卷 1-9页

作者： pieter L. jager R. jorn Beukinga Tjard D. de Haan Martijn F Boomsma Ben E. Laddé Miranda van t Veer-ten Kate Ad H. j. Oostdijk Martijn G. Steffens Department of nuclear Medicine Zwolle Netherlands Department of Urology Zwolle Netherlands Department of Radiology Zwolle Netherlands Department of Pathology Zwolle Netherlands

Introduction: [18F]-fluoro-methylcholine (FCH) PET/CT and MRI with diffusion-weighted MRI (DW-MRI) have insufficient performance in lymph node staging of primary prostate cancer by themselves, but the combination may perform better. We aim to prospectively determine the diagnostic performance of combined FCH PET and MRI for lymph node staging. Methods: This was a single site study of diagnostic accuracy in a well-defined group of 21 consecutive high-risk primary prostate cancer patients (>30% chance of lymph node metastases) in a large community hospital. We performed FCH PET/CT and MRI with DW-MRI prior to endoscopic extended pelvic lymph node dissection (EPLnD). PET was fused and interpreted together with various MRI image sets (T1, T2, DWIBS) and was only scored positive when a lymph node seen on MRI coincided with increased focal FCH uptake on PET. Findings were compared with detailed histological evaluation, on a per-patient and per-region level. We calculated sensitivity, specificity, positive and negative predictive value of combined PET-MRI. Results: 14 out of 21 patients had metastatic lymph nodes with 37 out of 164 evaluable regions harboring metastases. On a per-patient analysis, PET-MRI had a sensitivity/specificity of 79/100% with a PPV/nPV of 100/77%. On a per-region analysis (n = 164) these figure were 65/99% and 96/91%, respectively. Conclusions: Combined DW-MRI and FCH PET/CT has a very high positive predictive value in high risk prostate cancer patients. If confirmed in larger series a positive combined scan may safely allow cancellation of surgical staging in selected patients, depending on local protocols in n1 M0 patients.

关键词： Positron Emission Tomography Diffusion-Weighted Imaging Fluor-Methyl-Choline Prostate Cancer Primary Staging

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吉兰-巴雷综合征诊治的10个步骤(Diagnosis and management of Guillain-Barrésyndrome in ten steps全译)

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中华诊断学电子杂志 2023年第3期11卷 198-211页

作者： Sonja E Leonhard Melissa R Mandarakas Francisco AA Gondim Kathleen Bateman Maria LB Ferreira David R Cornblath pieter A van Doorn Mario E Dourado Richard AC Hughes Badrul Islam Susumu Kusunoki Carlos A Pardo Ricardo Reisin james j Sejvar nortina Shahrizaila Cristiane Soares Thirugnanam Umapathi 王玉忠 Eppie M Yiu Hugh j Willison Bart C jacobs 伊拉斯姆斯大学医疗中心神经内科鹿特丹市3015 CE 福塔莱萨联邦大学沃尔特·坎迪奥大学医院塞阿拉州60430-370 开普敦大学格鲁特·舒尔医院开普敦市7925 累西腓市康复医院神经内科伯南布哥州52171-011 约翰·霍普金斯大学医学院神经病学系马里兰州21218 北里奥格兰德州联邦大学奥诺弗雷卢佩斯医院综合医学部纳塔尔市59012-300 伦敦大学学院皇后广场神经病学研究所伦敦市WC1N 3BG 国际腹泻病研究中心达卡市1212 金代大学医学院大阪市589-8511 不列颠医院布宜诺斯艾利斯市C1280AEB 亚特兰大市疾病预防控制中心乔治亚州30329 马来亚大学神经病学系吉隆坡市50603 埃斯塔多联邦医院里约热内卢市20221-903 国家神经科学研究所新加坡308433 济宁医学院附属医院神经内科济宁272029 墨尔本皇家儿童医院神经内科维多利亚州3052 默多克儿童研究所神经科学研究组维多利亚州3052 墨尔本大学儿科学系维多利亚州3052 格拉斯哥大学医学、兽医学与生命科学学院格拉斯哥市G611QH 伊拉斯姆斯大学医疗中心免疫科鹿特丹市3015 GD

吉兰-巴雷综合征(GBS)是一种少见但可危及生命的、自身免疫介导的周围神经病。GBS通常由感染引发,发病率可在感染性疾病暴发期间增加,如2013年法属波利尼西亚和2015年拉丁美洲的寨卡病毒流行期间,该病的发病率明显上升。由于GBS的临床... 详细信息

吉兰-巴雷综合征(GBS)是一种少见但可危及生命的、自身免疫介导的周围神经病。GBS通常由感染引发,发病率可在感染性疾病暴发期间增加,如2013年法属波利尼西亚和2015年拉丁美洲的寨卡病毒流行期间,该病的发病率明显上升。由于GBS的临床表现和病程多种多样,其诊疗存在一定的复杂性,而目前尚无可用的国际性临床诊疗指南。本文作者撰写了一份适用于全球的GBS诊疗指南,特别是在疾病暴发期间,以期为临床医生提供指导。本指南根据当前文献和专家共识撰写而成,采用10步式结构,以便在临床实践中更好地应用。本文首先介绍了GBS的诊断标准、临床变异和鉴别诊断;其次,通过10个步骤介绍了GBS的早期识别和诊断、收治重症监护室的指征、治疗指征和选择、疾病进展的监测和处理、临床病程和结局的预测,以及并发症和后遗症的处理。

关键词：吉兰-巴雷综合征诊断治疗

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