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Numerical Simulation of Residual Stress during Microlayer Composite Material Processing by EBPVD Technique

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Journal of Materials Science & Technology 2003年第Z1期19卷 80-82页

作者： Liping SHI Yao LI Xiaodong HE centerfor Composite Materials Harbin Institute of Technology Harbin 150001 China Centerfor Composite Materials Harbin Institute of Technology Harbin 150001 China Centerfor Composite Materials Harbin Institute of Technology Harbin 150001 China

The preparation technology of microlayer composite material by the electron beam physical vapor deposition (EBPVD) technique was briefly introduced. Taking the advantage of the large-scale commercial softvare of finite element analysis, areasonable physical model was built up during the deposition processing and the distribution of residual stress was analyzedbetween substrate and deposition layer or among deposition layers. The results show that: with the increasing substrate preheating temperature, the interlaminar shear stress increases but the axial residual stress decreases. The probability of curlingup after de-bonding tends to enhance as the thickness of deposition film increases.

关键词： Microlayer composite material, EBPVD, Residual stress, Numerical simulation

The study of dry biological valve crosslinked with a combination of carbodiimide and polyphenol

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Regenerative Biomaterials 2021年第1期8卷 83-91页

作者： Li Yang Shuang Xie Kailei Ding Yang Lei YunbingWang National Engineering research centerfor Biomaterials Sichuan UniversityNo.29 Wangjiang RoadChengdu 610064China

The glutaraldehyde crosslinked pericardium has been used in bioprosthetic valves for about 50 ***,problems such as glutaraldehyde residue and calcification still exist in current commercial ***-glutar aldehyde crosslinked dry valve is an important strategy to solve those *** this study,a non-glutaraldehyde crosslinked dry biological valve material was obtained by the combined crosslinking of carbodimide(EDC)and *** results showed that the comprehensive properties of EDC and curcumin crosslinked pericardium were superior to glutaraldehyde crosslinked pericardium,including unfolding property,anti-calcification,cytotoxicity,anticoagulant properties,mechanical properties,enzyme degradation resistance and thermal shrinkage *** and curcumin crosslinked dry pericardium could flatten after being folded at 40℃ for 3 days while glutaraldehyde crosslinked pericardium could *** calcification of pericardium treated with EDC and curcumin was 1.21±0.36 mg/g in rats after 60 days'subdermal implantation,much lower than that of glutaraldehyde treated control group(22.06±3.17 mg/g).

关键词： dry biological valve carbodimide polyphe nol non-glutraldehyde

Association between cag-pathogenicity island in Helicobacter pylori isolates from peptic ulcer,gastric carcinoma,and non-ulcer dyspepsia subjects with histological changes

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World Journal of Gastroenterology 2005年第43期11卷 6815-6822页

作者： Mahaboob Ali Aleem A Khan Santosh K Tiwari Niyaz Ahmed L Venkateswar Rao CM Habibullah Center for Liver research and Diagnostics pathogen Evolution Group Department of Microbiology

AIM： To investigate the presence of the cag-pathogenicity island and the associated histological damage caused by strains with complete cag-PAI and with partial deletions in correlation to the disease status. METHODS： We analyzed the complete cag-PAI of 174 representative Helicobacter pylori （H pylori ） clinical isolates obtained from patients with duodenal ulcer, gastric ulcer, gastric cancer, and non-ulcer dyspepsia using eight different oligonucleotide primers viz cagA1, cagA2, cagAP1, cagAP2, cagE, cagT, LEC-1, LEC-2 spanning five different loci of the whole cag-PAI by polymerase chain reaction （PCR）. RESULTS： The complete screening of the genes comprising the cag-PAI showed that larger proportions of subjects with gastric ulcer （97.8%） inhabited strains with complete cag-PAI, followed by gastric cancer （85.7%）, non-ulcer dyspepsia （7.1%）, and duodenal ulcer （6.9%）, significant differences were found in the percentage distribution of the genes in all the clinical groups studied. It was found that strains with complete cag-PAI were able to cause severe histological damage than with the partially deleted ones. CONCLUSION： The cag-PAI is a strong virulent marker in the disease pathogenesis as it is shown that a large number of those infected with strain with complete cag-PAI had one or the other of the irreversible gastric pathologies and interestingly 18.5% of them developed gastric carcinoma. The presence of an intact cag- PAI correlates with the development of more severe pathology, and such strains were found more frequently in patients with severe gastroduodenal disease. Partial deletions of the cag-PAI appear to be sufficient to render the organism less pathogenic.

关键词： Helicobacter pylori cag-pathogenicity island Genetic diversity Gastro-duodenal diseases

Si_3N_4 nano-microsphere synthesized by cathode arc plasma and heat treatment

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中国有色金属学会会刊：英文版 2009年第S3期19卷 718-721页

作者：耿中荣闫鹏勋范多旺岳光辉 National Engineering research centerfor Technology and Equipment of Green Coating Lanzhou Jiaotong University Institute for Plasma and Metal Materials Lanzhou University

The Si3N4 microcrystals with a hollow sphere structure were prepared by using the simple heat treatment of the Si3N4 flakes, which were prepared by using the cathode arc plasma. The products were characterized by XRD, SEM and TEM. The photoluminescence (PL) spectrum of the Si3N4 nano-microsphere was studied. The obtained Si3N4 microcrystals, which show a hollow sphere structure, are up to several nanometers in diameter. During the process, the heat treatment and Ni catalyst play a key role in the forming structure and morphology. This result provides a possibility for mass producing Si3N4 microcrystals.

关键词： Si3N4 hollow sphere heat treatment photoluminescence cathode arc plasma

Dynamic micelles with detachable PEGylation at tumoral extracellular pH for enhanced chemotherapy

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Asian Journal of Pharmaceutical Sciences 2020年第6期15卷 728-738页

作者： Guoqing Yan Panpan Zhang Jun Wang Xin Wang Rupei Tang Engineering research centerfor Biomedical Materials School of Life ScienceAnhui UniversityHefei 230601China

Although surface PEGylation of nanomedicines can decrease serum protein adsorption in vivo,it also blocks uptake by tumor *** dilemma could be overcome by employing detachably PEGylated strategy at tumoral extracellular microenvironment to achieve improved cellular uptake while prolonged circulation ***,the amphiphilic graft copolymers with p H-sensitive ortho ester-linked m PEG in side chains and polyurethanes in backbone,can self-assemble into the free and doxorubicin(DOX)-loaded *** p H-sensitive micelles could undergo several characteristics as follows:(i)PEGylated shells for stability in sodium dodecyl sulfonate(SDS)solution;(ii)De PEGylation via degradation of ortho ester linkages at tumoral extracellular pH(6.5)for gradually dynamic size changes and effective release of DOX;and(iii)enhanced cellular uptake and cytotoxicity via positive ***,the dynamic micelles with detachable PEGylation could quickly penetrate the centers of SH-SY5 Y multicellular spheroids(MCs)and strongly inhibit tumor growth in vitro and in vivo,and might be considered as promising and effective drug carriers in tumor therapy.

关键词： Micelles Ortho ester PEGylation Size transition Antitumor

Propagation characteristics of vibration waves induced in surrounding rock by tunneling blasting

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Journal of Mountain Science 2017年第12期14卷 2620-2630页

作者： chen shi-hai hu shuai-wei zhang zi-hua wu jian Huaqiao University Xiamen 361021China Fujian research centerfor Tunneling and Urban Underground Space Engineering Huaqiao UniversityXiamen 361020China

The effect of blasting vibration waves on surrounding rock and supporting structures is an important field in underground engineering. In this paper, the separation variable method is used to solve the displacement potential function for the propagation of the blasting vibration waves. In the axis coordinate system, the particle motion and stress change with axial distance, radial distance and time is obtained in surrounding rock. The peak particle velocity law in surrounding rock under different blast loads and surrounding rock parameters is *** addition, the particle vibration characteristics in the surrounding rock are studied using numerical simulations method. The results shows that the peak particle velocity in surrounding rock appears negative exponent attenuation with the increase of axial distance, but it appears positive and negative fluctuations in radial direction. This phenomenon is a new discovery and it has been rarely investigated before. Moreover, the peak particle velocity attenuates more quickly and intensely in the near blasting field,which means that the supporting structure in a shorter distance away from the heading face is vulnerable to the impact of blasting vibration. Theattenuation of blasting vibration velocity is closely related to charge length, blasting load amplitude,attenuation index and rock elastic modulus. The numerical simulation accomplishes the same results and then demonstrates the validity of theoretical results.

关键词： Tunneling blasting Blasting vibration wave Surrounding rock Wave equation Vibration velocity

Sperm DNA damage and its clinical relevance in assessingreproductive outcome

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Asian Journal of Andrology 2004年第2期6卷 139-148页

作者： R. K. Sharma T. Said A. Agarwal centerfor Advanced research in Human Reproduction Infertility and Sexual Function Glickman Urological Institute The Cleveland Clinic Foundation Cleveland Ohio 44195 USA

The routine examination of semen, which assesses sperm concentration, percentage motility and morphology, does not identify subtle defects in sperm chromatin architecture. The focus on the genomic integrity of the male gamete has intensified recently due to the growing concern that genetic diseases may be transmitted via assisted reproductive techniques (ART). Accordingly, the intent of this review is to describe the details of the information pertaining to mitochondrial/nuclear sperm DNA damage with an emphasis on its clinical significance and its relation ship with male infertility. Assessment of sperm DNA damage appears to be a potential tool for evaluating semen samples prior to their use in ART. Testing DNA integrity may help select spermatozoa with intact DNA or with the least amount of DNA damage for use in assisted conception. In turn, this may alleviate the financial, social and emotional problems associated with failed ART attempts.

关键词： DNA damage human male infertility sperm

Cryo-EM structures of a prokaryotic heme transporter CydDC

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Protein & Cell 2023年第12期14卷 919-923页

作者： Chen Zhu Yanfeng Shi Jing Yu Wenhao Zhao Lingqiao Li Jingxi Liang Xiaolin Yang Bing Zhang Yao Zhao Yan Gao Xiaobo Chen Xiuna Yang Lu Zhang Luke W.Guddat Lei Liu Haitao Yang Zihe Rao Jun Li Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China National Clinical research Center for Infectious Disease Shenzhen Third People's HospitalShenzhen 518112China Laboratory of Structural Biology Tsinghua UniversityBeijing 100084China State Key Laboratory of Medicinal Chemical Biology Nankai UniversityTianjin 300353China innovative centerfor pathogen research Guangzhou LaboratoryGuangzhou 510005China School of Chemistry and Molecular Biosciences The University of QueenslandBrisbaneQLD 4072Australia

DearEditor,Heme is an essential cofactor required across all kingdoms of life utilized in numerous biological processes,including cellular *** is a prokaryotic ATP-binding cassette(ABC)transporter required for heme assembling in respiratory cytochrome bd oxidase(Georgiou et al.,1987;Poole et al.,1989),a promising target for drug discovery(Borisov et al.,2011).CydDC is thought to play a role in maintaining an optimum periplasmic redox poise that is required for the incorporation of heme cofactors(Yamashita et al.,2014).It also suggested that CydDC is involved in heme processing by mediating glutathione/cysteine translocation(Cook and Poole,2000;Cook et al.,2002),although a role in heme translocation seems unlikely(Yamashita et al.,2014).To date,CydDC has been shown to be important for disulfide bond formation,motility,respiration,and tolerance to nitric oxide and antibiotics(Poole et al.,2019).

关键词： utilized disulfide Poole

Vinylogous Fluorine Stabilizing Effect Enables Rational Design of a Novel Donor-Acceptor Cyclopropane and Its Applications in[3+2]Cycloaddition Reaction and Ring-Opening Polymerization

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Chinese Journal of Chemistry 2024年第22期42卷 2723-2727页

作者： Yue Li Dian-Feng Chen Hefei National research centerfor Physical Sciences at the Microscale and Department of Polymer Science and Engineering University of ScienceandTechnologyof ChinaHefeiAnhui 230026China

Comprehensive Summary Discovery of unprecedented donor-acceptor patterns can essentially enrich the chemistry of donor-acceptor *** herein introduce a concept of vinylogous fluorine stabilizing effect,which guides rational design of a novel donor-acceptor cyclopropane employing gem-difluorovinyl group as the electron donor,namely *** of such dFVCPs in a[3+2]cycloaddition with aldehydes and a controlled ring-opening polymerization by a Mg(OTf)2/DIPEA/C(sp3)-H initiator system have been demonstrated,providing direct access to fluorine-containing tetrahydrofurans and all-carbon main-chain polymers.

关键词： Donor-acceptor cyclopropane gem-Difluorovinyl group Vinylogous fluorine stabilizing effect [3+2]cycloaddition Ring-opening polymerization Strainedmolecules Monomers lonic polymerization