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The correlation between biotribological function and structural characteristics of bamboo rat teeth

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Biosurface and Biotribology 2022年第4期8卷 323-328页

作者： Zhenwu Ning Zhongrong Zhou jing zheng Tribology Research Institute Key Laboratory of Advanced Technologies of MaterialsMinistry of EducationSouthwest Jiaotong UniversityChengduChina

Chinese bamboo rats consume a diet that consists mainly mechanically demanding *** ability of the rats to process food depends on the capacity of their teeth to resist wear during biting and *** mechanisms of the bamboo rat teeth were determined by investigating and correlating the structure and tribological properties of the *** rat's incisor has a cutting-edge cusp and outer enamel iron pigmentation,making the teeth harder,more resistant to acid attacks,and improving the resistance to ***,the incisor is designed to *** complex morphology at the macroscale,and the three-dimensional fabric body formed by densely packed rods and inter-rods at the microscale of molar enamel benefit molar rapid capture and effective breaking of bamboo,resisting the high stresses required to process bamboo without *** results of the structure-function relations of bamboo rat teeth in this study may provide new ideas for improving plant cutting and grinding tools.

关键词： bamboo rat teeth biotribological function enamel mechanical properties microstructure

Volunteer rescue dispatch during the Coronavirus Disease 2019 epidemic:Using the recruitment of volunteers for pneumonia epidemic prevention and control in Chun’an County as an example

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Journal of Safety Science and Resilience 2022年第4期3卷 330-339页

作者： Liting Chen Shengqun Chen jing zheng Jianqing Gao College of Electronics and Information Science Fujian Jiangxia UniversityFuzhou 350108China Research Institute for Data Analysis and Intelligent Decision-Making Fujian Jiangxia UniversityFuzhou 350108China School of Information Engineering Fujian Business UniversityFuzhou 350012China Fujian Provincial Universities Engineering Research Center of Big Data Analytics for Business Intelligence Fujian Business UniversityFuzhou 350012China

To solve the problem of volunteer dispatch during the Coronavirus Disease 2019(COVID-19)epidemic,a many-to-many two-sided matching volunteer dispatch method based on an improved predator-search algorithm is ***,different evaluation index sets for volunteers and rescue tasks were developed,and weightings were determined using the analytic hierarchy ***,the actual and expected values of the different indicators of the two parties were determined,and the triangular fuzzy number was used to calculate the satis-faction of the two *** on this number,we used a linear weighting method to calculate the combined satisfaction and build a many-to-many two-sided matching model according to the demands of both ***-sequently,an improved predator-search algorithm was used to solve the ***,taking the recruitment of volunteers for pneumonia epidemic prevention and control in Chun’an County as an example,the method proposed in our study was verified.A comparison and analysis of the results further demonstrated the feasibility and advantages of this method.

关键词： Volunteer Many-to-many Two-sided matching Predator-search algorithm

Weighted cooperative routing for wireless mobile Ad-hoc network

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 16-21页

作者： ZHAO Xian-jing zheng Bao-yu CHEN Chao Institute of Signal and Information Processing Nanjing University of Posts and Telecommunications Nanjing 210003 China

A novel weighted cooperative routing algorithm （WCRA） is proposed in this article, which was on the basis of a weighted metric with maximal remaining energy （MRE） of the relays and the maximal received SNR （MRS） of the nodes. Moreover, a cooperative routing protocol was implemented on the basis of WCRA. Then simulation is done on network simulation （NS-2） platform to compare the performances of MRS, MRE and WCRA with that of noncooperative destination-sequenced destination-sequenced distance-vector （DSDV） protocol. The simulative results show that WCRA obtains a performance tradeoff between MRE and MRS in terms of delivery ratio and network lifetime, which can effectively improve the network lifetime at an acceptable loss of delivery ratio.

关键词： weighted cooperative routing Ad-hoc networks,quality of service DSDV routing protocol

基于Gln/GLS1/α-KG代谢轴和线粒体凋亡信号通路探讨木瓜总三萜抗D-半乳糖诱导GES-1细胞衰老的作用机制

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中国中药杂志 2024年第8期49卷 2230-2246页

作者：贺君宇杨家鑫覃诗颖郑婧琪国怡然马天行三峡大学基础医学院湖北宜昌443002 三峡大学生物与制药学院湖北宜昌443002 南通大学医学院江苏南通226001

木瓜总三萜(total triterpenoids from the fruits of Chaenomeles speciosa,TCS)是防治胃黏膜损伤的活性组分,具有潜在的抗衰老作用。然而,TCS是否改善胃衰老,尤其是对于其抗胃衰老的分子机制目前仍不清楚。基于此,该研究旨在探讨TCS... 详细信息

木瓜总三萜(total triterpenoids from the fruits of Chaenomeles speciosa,TCS)是防治胃黏膜损伤的活性组分,具有潜在的抗衰老作用。然而,TCS是否改善胃衰老,尤其是对于其抗胃衰老的分子机制目前仍不清楚。基于此,该研究旨在探讨TCS对D-半乳糖(D-galactose,D-gal)诱导人胃黏膜上皮细胞GES-1衰老的影响及作用机制,为TCS在临床上用于预防胃衰老提供科学数据。将体外培养的GES-1细胞和转染谷氨酰胺酶1(glutaminase 1,GLS1)过表达(overexpression GLS1,GLS1-OE)质粒的GES-1细胞用D-gal诱导衰老后,给予TCS和谷氨酰胺酶1(glutaminase 1,GLS1)抑制剂bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide(BPTES),考察各组细胞存活率、衰老标志物β-半乳糖苷酶(β-galactosidase,SA-β-gal)染色阳性细胞比例、线粒体膜电位(mitochondrial membrane potential,MMP)和细胞凋亡的变化;采用酶联免疫吸附测定(enzyme-linked immuno sorbent assay,ELISA)法和比色法检测各组细胞上清液和细胞内GLS1活性、谷氨酰胺(glutamine,Gln)、谷氨酸(glutamate,Glu)、α-酮戊二酸(α-ketoglutarate,α-KG)、尿素和氨水平;采用实时荧光定量PCR和Western blot法检测各组细胞中GLS1、线粒体凋亡信号通路相关基因mRNA和蛋白表达情况。结果显示,与D-gal模型组和GLS1-OE D-gal模型组相比,TCS可显著降低D-gal诱导衰老GES-1细胞和GLS1-OE衰老GES-1细胞SA-β-gal染色阳性细胞率和MMP,抑制衰老细胞存活,促进其细胞凋亡(P<0.01),降低上清液和细胞内GLS1活性和Gln、Glu、α-KG、尿素、氨含量(P<0.01),降低线粒体中细胞色素C(cytochrome C,Cyto C)浓度以及细胞中GLS1、增殖细胞核抗原mRNA和蛋白表达(P<0.01),降低细胞中Bcl-2、Bcl-xl mRNA表达和前体半胱氨酸蛋白酶(pro-caspase)-9、pro-caspase-3蛋白表达以及Bcl-2/Bax和Bcl-xl/Bad比值(P<0.01),升高胞质中Cyto C浓度和细胞中Bax、Bad、凋亡蛋白酶激活因子1(apoptosis protease activating factor 1,Apaf-1)mRNA表达及剪切型半胱氨酸蛋白酶(cleaved-caspase)-9、cleaved-caspase-3、剪切型聚ADP核糖聚合酶-1(cleaved-poly ADP ribose polymerase-1,cleaved-PARP-1)蛋白表达(P<0.01)。以上结果表明,TCS可对抗D-gal诱导GES-1细胞衰老,其作用机制与抑制Gln/GLS1/α-KG代谢轴、激活线粒体凋亡通路,进而促进衰老细胞凋亡、清除衰老细胞密切相关。

关键词：木瓜总三萜 GES-1细胞 D-半乳糖衰老谷氨酰胺/谷氨酰胺酶1/α-酮戊二酸代谢轴线粒体凋亡通路

Modeling stochastic mortality with O-U type processes

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Applied Mathematics(A Journal of Chinese Universities) 2018年第1期33卷 48-58页

作者： zheng jing TONG Chang-qing ZHANG Gui-jun College of Economics Hangzhou Dianzi University

Modeling log-mortality rates on O-U type processes and forecasting life expectancies are explored using U.S. data. In the classic Lee-Carter model of mortality, the time trend and the age-specific pattern of mortality over age group are linear, this is not the feature of mortality model. To avoid this disadvantage, O-U type processes will be used to model the log-mortality in this paper. In fact, this model is an AR(1) process, but with a nonlinear time drift *** on the mortality data of America from Human Mortality database(HMD), mortality projection consistently indicates a preference for mortality with O-U type processes over those with the classical Lee-Carter model. By means of this model, the low bounds of mortality rates at every age are given. Therefore, lengthening of maximum life expectancies span is estimated in this paper.

关键词： mortality stochastic forecasting O-U type process

填埋场及周边地下水中氯代有机物组成与风险研究

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环境工程技术学报 2024年第1期14卷 89-97页

作者：郑敬潘琦王玉欣沙浩群王宪革刘洪宝何小松桂林理工大学环境科学与工程学院环境基准与风险评估国家重点实验室中国环境科学研究院国家环境保护地下水污染模拟与控制重点实验室中国环境科学研究院

氯代有机物降解难、毒性大,填埋场是氯代有机物的重要汇集地。针对填埋场渗滤液泄漏进入地下水中氯代有机物风险不明现状,采集了一个非正规填埋场的地下水样品,并结合收集的中国、德国、美国、西班牙、波兰、挪威共6个国家13个填埋场附... 详细信息

氯代有机物降解难、毒性大,填埋场是氯代有机物的重要汇集地。针对填埋场渗滤液泄漏进入地下水中氯代有机物风险不明现状,采集了一个非正规填埋场的地下水样品,并结合收集的中国、德国、美国、西班牙、波兰、挪威共6个国家13个填埋场附近地下水氯代有机物组成与浓度数据,采用风险评价模型对其健康风险进行评估。结果显示:所研究填埋场地下水总共检出10类41种氯代有机物,这些氯代有机物中,氯代环烷烃类的致癌风险最大,均超过了10^(-4),远超人体可接受的水平,具有明确风险;氯代多氟烷基醚磺酸盐的F-53B的致癌风险最低,为10^(-6)~10^(-4),具有可能致癌风险。氯代烷烃类的非致癌风险最大,其中α-六氯环己烷的非致癌风险值均超过1,超过人类可接受水平;而氯代有机农药类如丙环唑和氯菊酯的非致癌风险最低,其非致癌风险值未超过人体可接受的水平。需要加强关注γ-六氯环己烷、氯苯、1,2-二氯苯等氯代有机物风险管控,可采用氧化脱氯、还原脱氯及共代谢脱氯等途径,加速其脱氯和降解,消除其风险。

关键词：氯代有机物地下水填埋场健康风险评估

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环境中微塑料检测方法的研究进展

环境化学 2024年第7期43卷 2166-2180页

作者：卢琦园马艳陈思帆郑晶任明忠于云江新污染物研究团队国家环境保护环境污染健康风险评价重点实验室生态环境部华南环境科学研究所广州510535

微塑料是指粒径小于5 mm的塑料碎片或颗粒,能够在大气、土壤和水体中迁移和富集,通过食物链累积,对人体健康产生严重危害.为了更好地评估环境中微塑料的污染,本文详细综述了微塑料检测方法和技术手段的应用现状,包括显微镜分析、扫描电... 详细信息

微塑料是指粒径小于5 mm的塑料碎片或颗粒,能够在大气、土壤和水体中迁移和富集,通过食物链累积,对人体健康产生严重危害.为了更好地评估环境中微塑料的污染,本文详细综述了微塑料检测方法和技术手段的应用现状,包括显微镜分析、扫描电镜能谱分析、光谱分析、热分析和质谱分析等微塑料常用检测方法并对比了各方法的优缺点.总结了近年来微塑料检测的新方法和新技术,重点讨论微塑料检测当前面临的技术挑战和未来的研究方向,对建立统一和标准化的微塑料分析方法进行展望,为系统地和进一步地开展微塑料的污染评价及风险评估提供指导.

关键词：微塑料检测方法应用前景

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Imaging cellular distribution of fluorescent supramolecular nanofibers

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Science China Chemistry 2016年第6期59卷 719-723页

作者： jingyu Wang jing zheng Yanbin Cai Jinxin zheng Jie Gao Qingqiu Gong Zhimou Yang School of Biomedical Engineering Tianjin Medical UniversityTianjin 300070China Tianjin Key Laboratory of Protein Science Department of Plant Biology and EcologyCollege of Life SciencesNankai UniversityTianjin 300071China Collaborative Innovation Center of Chemical Science and Engineering State Key Laboratory of Medicinal Chemical BiologyCollege of Life SciencesNankai UniversityTianjin 300071China

In this study, we used the 4-nitro-2,1,3-benzoxadiazole （NBD） as an aromatic capping group for a peptide to construct the su- pramolecular nanofibers. Taking the advantage of the fluorescence property of NBD, we could directly observe the cellular distribution of the self-assembled nanofibers. We found that the distributions of the nanofibers of NBD-FFETIGGY are dif- ferent in four mammalian cells and two plant cells. The nanofibers are mainly located at the surface of two mammalian cells and one plant cell, while in the intracellular space of other cells. Different distributions of nanofibers lead to different protein binding patterns o1! the nanofibers in two different cell lines. We believe that a useful and versatile platform has been offered to the image cellular distribution of nanofibers, which can provide useful information to the biological functions of the self-assembled nanostructures.

关键词： cellular distribution self-assembly peptide nanofiber

Microstructure,cracking behavior and control of Al-Fe-V-Si alloy produced by selective laser melting

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Rare Metals 2023年第4期42卷 1353-1362页

作者： Shao-Bo Sun Li-jing zheng Jin-Hui Liu Hu Zhang School of Materials Science and Engineering Beihang UniversityBeijing100191China Modern Manufacturing Engineering Center Heilongjiang Institute of Science and TechnologyHarbin150027China

Selective laser melting(SLM)technology based on atomized powder was used to fabricate Al-8.5Fe-1.3V-1.7Si(wt%)alloy *** microstructure and crack characterization of SLM samples fabricated at various conditions were *** show that the cracks appear periodically along the building direction,initiate preferably at the outer edges of the as-built samples and propagated along the remelting border zone(RBZ)into deposited ***-phase cracking is proposed according to the fracture *** thermal-induced residual stress during SLM combined with the precipitation of relatively large-sized Al_mFe phase in the RBZ results in the formation of *** scanning speed and hatch distance enable to reduce the cracking *** crack-free Al-8.5Fe-1.3V-1.7Si parts can be fabricated at optimized parameters of laser power of 320 W,scanning speed of 1000 mm·s^(-1)and hatch distance of0.10 mm along with proper laser pre-heating *** samples built horizontally show good ultimate tensile properties of 454 MPa in average with the elongation of7.2%.

关键词： Al-Fe-V-Si alloy Selective laser melting Microstructure Cracking behavior Mechanical properties