检索结果-南通市图书馆

Diversity,bioactivities,and metabolic potentials of endophytic actinomycetes isolated from traditional medicinal plants in Sichuan,China

引用

Chinese Journal of Natural Medicines 2015年第12期13卷 942-953页

作者： QIU Peng FENG Zhi-Xiang TIAN Jie-Wei LEI Zu-Chao WANG Lei ZENG Zhi-Gang chu yi-wen TIAN Yong-Qiang Key laboratory of Leather Chemistry and Engineering Ministry of Education and College of Light IndustryTextile & Food EngineeringSichuan University Department of Pharmaceutical and Biological Engineering School of Chemical EngineeringSichuan University Sichuan Industrial Institute of Antibiotics Chengdu University

The present study was designed to determine the taxonomic diversity and metabolic activity of the actinomycetes community, including 13 traditional medicinal plants collected in Sichuan province, China, using multiple approaches such as morphological and molecular identification methods, bioactivity assays, and PCR screening for genes involved in antibiotics biosynthesis. 119 endophytic actinomycetes were recovered; 80 representative strains were chosen for 16 S r RNA gene partial sequence analyses, with 66 of them being affiliated to genus Streptomyces and the remaining 14 strains being rare actinomycetes. Antimicrobial tests showed that 12(15%) of the 80 endophytic actinomycetes displayed inhibitory effects against at least one indicator pathogens, which were all assigned to the genus Streptomyces. In addition, 87.5% and 58.8% of the isolates showed anticancer and anti-diabetic activities, respectively. Meanwhile, the anticancer activities of the isolates negatively correlated with their anti-diabetic activities. Based on the results of PCR screening, five genes, PKS-I, PKS-II, NRPS, ANSA, and oxy B, were detected in 55.0%, 58.8%, 90.0%, 18.8% and 8.8% of the 80 actinomycetes, respectively. In conclusion, the PCR screening method employed in the present study was conducive for screening and selection of potential actinomycetes and predicting potential secondary metabolites, which could overcome the limitations of traditional activity screening models.

关键词： Endophytic actinomycetes Medicinal plants Diversity Bioactivity PCR screening

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Differentially private SGD with random features

引用

Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 1-23页

作者： WANG yi-guang GUO Zheng-chu Polytechnic Institute of Zhejiang University Zhejiang UniversityHangzhou 310015China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China

In the realm of large-scale machine learning,it is crucial to explore methods for reducing computational complexity and memory demands while maintaining generalization ***,since the collected data may contain some sensitive information,it is also of great significance to study privacy-preserving machine learning *** paper focuses on the performance of the differentially private stochastic gradient descent(SGD)algorithm based on random *** begin,the algorithm maps the original data into a lowdimensional space,thereby avoiding the traditional kernel method for large-scale data storage ***,the algorithm iteratively optimizes parameters using the stochastic gradient descent ***,the output perturbation mechanism is employed to introduce random noise,ensuring algorithmic *** prove that the proposed algorithm satisfies the differential privacy while achieving fast convergence rates under some mild conditions.

关键词： learning theory differential privacy stochastic gradient descent random features reproducing kernel Hilbert spaces

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Multi-parameter Test of Gravitational Wave Dispersion with Principal Component Analysis

引用

Research in Astronomy and Astrophysics 2024年第5期24卷 140-150页

作者： Zhi-chu Ma Rui Niu wen Zhao CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

In this work, we consider a conventional test of gravitational wave(GW) propagation which is based on the phenomenological parameterized dispersion relation to describe potential departures from General Relativity(GR)along the propagation of GWs. But different from tests conventionally performed previously, we vary multiple deformation coefficients simultaneously and employ the principal component analysis(PCA) method to remedy the strong degeneracy among deformation coefficients and obtain informative posteriors. The dominant PCA components can be better measured and constrained, and thus are expected to be more sensitive to potential departures from the waveform model. Using this method we analyze ten selected events and get the result that the combined posteriors of the dominant PCA parameters are consistent with GR within 99.7% credible intervals. The standard deviation of the first dominant PCA parameter is three times smaller than that of the original dispersion parameter of the leading order. However, the multi-parameter test with PCA is more sensitive to not only potential deviations from GR but also systematic errors of waveform models. The difference in results obtained by using different waveform templates hints that the demands of waveform accuracy are higher to perform the multiparameter test with PCA. Whereas, it cannot be strictly proven that the deviation is indeed and only induced by systematic errors. It requires more thorough research in the future to exclude other possible reasons in parameter estimation and data processing.

关键词： gravitational waves-gravitation-black hole physics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

噻唑肽类抗生素研究进展

引用

中国抗生素杂志 2008年第2期33卷 69-74,105页

作者：王辂褚以文中国医药集团四川抗菌素工业研究所成都610051

多数噻唑肽类抗生素能与细菌的50s核糖体亚基相结合抑制其蛋白质的合成,有些还能抑制肾素-血管紧张素系统。产生抗性的链霉菌可以合成一种甲基转移酶,将自身的23SrRNA1067位点上的腺苷2’-OH转化成2’-CH3,阻碍噻唑肽类抗生素与50s核糖... 详细信息

多数噻唑肽类抗生素能与细菌的50s核糖体亚基相结合抑制其蛋白质的合成,有些还能抑制肾素-血管紧张素系统。产生抗性的链霉菌可以合成一种甲基转移酶,将自身的23SrRNA1067位点上的腺苷2’-OH转化成2’-CH3,阻碍噻唑肽类抗生素与50s核糖体亚基结合。通过研究噻唑肽类化合物生物合成基因发现,产生该类抗生素的劳伦链霉菌和活力链霉菌中均含有编码非核糖体合成酶的基因。因此噻唑肽类化合物极可能是由非核糖体肽合成酶(NRPS)根据巯基模板机制装配而成。本文重点就噻唑肽类化合物的作用机制、抗性机制以及合成途径的研究进展进行综述。

关键词：噻唑肽类抗生素生物合成非核糖体肽合成酶巯基模板诺西肽

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells

引用

World Journal of Stem Cells 2024年第2期16卷 176-190页

作者： Yu-Su Wang wen-Hui chu Jing-Jie Zhai wen-ying Wang Zhong-Mei He Quan-Min Zhao chun-yi Li Institute of Antler Science and Product Technology Changchun Sci-Tech UniversityChangchun 130000Jilin ProvinceChina College of Chinese Medicinal Materials Jilin Agricultural UniversityChangchun 130118Jilin ProvinceChina School of Life Science Taizhou UniversityTaizhou 318000Zhejiang ProvinceChina Department of Oral Implantology Hospital of StomatologyJilin UniversityChangchun 130000Jilin ProvinceChina

BACKGROUND Cartilage defects are some of the most common causes of *** lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral *** studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral *** To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral *** We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM *** sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the *** weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee *** The defects were successfully repaired by applying the *** highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem *** Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship.

关键词： Osteochondral defect repair Mesenchymal stem cells Extracellular matrix Decellularization Antler stem cells Reserve mesenchymal cells Xenogeneic

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Review on thermal management technologies for electronics in spacecraft environment

引用

Energy Storage and Saving 2024年第3期3卷 153-189页

作者： yi-Gao Lv Yao-Ting Wang Tong Meng Qiu-Wang Wang wen-Xiao chu Key Laboratory of Thermo-fluid Science and Engineering Ministry of EducationXi’an Jiaotong UniversityXi’an710049China Xi’an Institute of Space Radio Technology Xi’an710100China

Due to the rapid development of the space industry,ever higher demands are being made for the optimization and improvement of spacecraft thermal management *** control technology has become one of the key bottlenecks that restrict the level of spacecraft *** this paper,the thermal management technologies(TMTs)for spacecraft electronics are reviewed according to the different heat transfer processes,including heat acquisition,heat transport,and heat *** researches on efficient heat acquisition include the utilization of high thermal conductance materials,the development of novel package structure based on micro-/nanoelectromechanical system(MEMS/NEMS)technologies,and advanced near-junction microfluidic cooling *** the heat transport process,various heat pipes and mechanical pumped fluid loops(MPFLs)are widely implemented to transport heat from heat generation components to the ultimate heat *** heat pipes are divided into two categories based on their structure layout,i.e.,separated heat pipes and unseparated heat *** merits and demerits of these heat pipes and MPFLs(including the single-phase MPFL and the two-phase MPFL)are discussed and summarized *** terms of the heat rejection for spacecraft,thermal radiators are normally the sole option due to the unique space *** meet the requirements of large heat dissipation power and fluctuated thermal environment,research efforts on the radiators mainly focus on the development of deployable radiators,variable emissivity radiators,and the combination with other *** to the fluctuated characteristics of the heat power of internal electronics and the outer thermal environment,the phase change materials(PCMs)exhibit great advantages in this scenario and have attracted a lot of research *** review aims to serve as a reference guide for the development of thermal management system in the future spacecraft.

关键词： Thermal management Electronics Spacecraft Heat pipe Mechanically pumped fluid loop Radiator Phase change material

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

BMSC-derived Exosomes Ameliorate Peritoneal Dialysis-associated Peritoneal Fibrosis via the Mir-27a-3p/TP53 Pathway

引用

Current Medical Science 2024年第2期44卷 333-345页

作者： Jun-li ZHAO Lin ZHAO Qiu-nan ZHAN Miao LIU Ting ZHANG wen-wen chu Department of Nephrology Shanghai University of Medicine&Health Sciences Affiliated Zhoupu HospitalShanghai 201318China Orthopedic Department Guangming Traditional Chinese Medicine Hospital of Pudong New AreaShanghai 201399China

Objective:Peritoneal fibrosis(PF)is the main cause of declining efficiency and ultrafiltration failure of the peritoneum,which restricts the long-term application of peritoneal dialysis(PD).This study aimed to investigate the therapeutic effects and mechanisms of bone marrow mesenchymal stem cells-derived exosomes(BMSC-Exos)on PF in response to ***:Small RNA sequencing analysis of BMSC-Exos was performed by second-generation sequencing.C57BL/6J mice were infused with 4.25%glucose-based peritoneal dialysis fluid(PDF)for 6 consecutive weeks to establish a PF model.A total of 36 mice were randomly divided into 6 groups:control group,1.5%PDF group,2.5%PDF group,4.25%PDF group,BMSC-Exos treatment group,and BMSC-Exos+TP53 treatment *** transcription quantitative polymerase chain reaction(RT-qPCR)was performed to measure the expression level of miR-27a-3p in BMSC-Exos and peritoneum of mice treated with different concentrations of *** and Masson staining were performed to evaluate the extent of *** therapeutic potential of BMSC-Exos for PF was examined through pathological examination,RT-qPCR,Western blotting,and peritoneal function ***-mesenchymal transition(EMT)of HMrSV5 was induced with 4.25%*** were divided into control group,4.25%PDF group,BMSC-Exos treatment group,and BMSC-Exos+TP53 treatment *** Counting Kit-8 assay was used to measure cell viability,and transwell migration assay was used to verify the capacity of BMSC-Exos to inhibit EMT in HMrSV5 ***:Small RNA sequencing analysis showed that miR-27a-3p was highly expressed in BMSC-derived exosomes compared to *** RT-qPCR results showed that the expression of miR-27a-3p was upregulated in BMSC-Exos,but decreased in PD *** found that PF was glucose concentration-dependently enhanced in the peritoneum of the PD *** with the control mice,the PD mice showed high solute transport and decreased ultrafiltration volume as well as an obvious f

关键词： peritoneal fibrosis bone marrow mesenchymal stem cell-derived exosomes miR-27a-3p TP53 epithelialmesenchymal transition

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Complete kinetic model for esterification reaction of lauric acid with glycerol to synthesize glycerol monolaurate

引用

Chinese Journal of Chemical Engineering 2024年第6期70卷 211-221页

作者： Han-Qiao Hu Yue Zhang Ming Fan Yong Cai Guang-wen chu Liang-Liang Zhang Research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Petrochemical Research Institute China National Petroleum CorporationBeijing 102206China

Glycerol monolaurate(GML)is a widely used industrial chemical with excellent emulsification and antibacterial *** direct esterification of glycerol with lauric acid is the main method to synthesize *** this work,the kinetic process of direct esterification was systematically studied using p-toluenesulfonic acid as catalyst.A complete kinetic model of consecutive esterification reaction has been established,and the kinetic equation of acid catalysis was *** isomerization reactions of GML and glycerol dilaurate were *** was found that the reaction was an equilibrium reaction and the reaction rate was faster than the esterification *** kinetic equations of the consecutive esterification reaction were obtained by experiments as k_(1)=(276+92261Xcat)exp(-37720/RT)and k_(2)=(80+4413Xcat)exp(-32240/RT).The kinetic results are beneficial to the optimization of operating conditions and reactor design in GML production process.

关键词： Glycerol monolaurate p-Toluenesulfonic acid Esterification Kinetics Mass transfer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

弯孢马利亚霉SIIA-F12361产生的新代谢产物研究

引用

中国抗生素杂志 2011年第3期36卷 179-182,186页

作者：王辂郭义东褚以文抗生素研究与再评价四川省重点实验室中国医药集团总公司四川抗菌素工业研究所成都610052

目的对海洋生境来源菌株SIIA-F12361进行分类学鉴定以及次级代谢产物的化学研究。方法采用形态学与18S rDNA序列分析对菌株进行分类学鉴定。通过硅胶柱层析、LH-20分子筛层析和反相制备HPLC诸方法,对新化合物进行分离纯化,并根据高分辨... 详细信息

目的对海洋生境来源菌株SIIA-F12361进行分类学鉴定以及次级代谢产物的化学研究。方法采用形态学与18S rDNA序列分析对菌株进行分类学鉴定。通过硅胶柱层析、LH-20分子筛层析和反相制备HPLC诸方法,对新化合物进行分离纯化,并根据高分辨质谱、紫外、红外光谱和核磁共振数据对化合物SIIA-C12361进行结构鉴定。结果鉴定菌株SIIA-F12361为弯孢马利亚霉,其产生的新次级代谢产物属于倍半萜烯内酯类化合物。结论弯孢马利亚霉SIIA-F12361产生一新倍半萜烯内酯化合物。

关键词：弯孢马利亚霉倍半萜烯内酯分离纯化结构解析

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Movement of ACC oxidase 3 mRNA from seeds to flesh promotes fruit ripening in apple

引用

Molecular Plant 2024年第8期17卷 1221-1235页

作者： Ting Wang yi Zheng Chen Xu Yulin Deng Xinyi Hao Zicheng chu Ji Tian yi Wang Xinzhong Zhang Zhenhai Han Ting Wu College of Horticulture China Agricultural UniversityBeijingChina Plant Science and Technology College Bioinformatics CenterBeijing University of AgricultureBeijingChina

Xenia,the phenomenon in which the pollen genotype directly affects the phenotypic characteristics of maternal tissues(i.e.,fruit ripening),has applications in crop production and ***,the underlying molecular mechanism has yet to be ***,we investigated whether mobile mRNAs from the pollen affect the ripening and quality-related characteristics of the fruit using cross-pollination between distinct Malus domestica(apple)*** demonstrated that hundreds of mobile mRNAs originating fromthe seeds are deliveredto *** themovementof one of these mRNAs,AcC oxidase 3(MdAco3),is coordinated with fruit *** acid treatment,which can cause plasmodesmal closure,blocks MdAcO3 movement,indicating that MdAcO3 transcripts may move through the *** assess the role of mobile MdAcO3 transcripts in apple fruit,we created MdACO3-GFP-expressing apple seeds using MdACO3-GFP-overexpressing pollen for pollination and showed that MdACO3 transcripts in the transgenic seeds move to the flesh,where they promote fruit ***,we demonstrated that MdAco3 can be transported from the seeds to fruit in the fleshy-fruited species tomato and *** results underscore the potential of mobile mRNAs from seeds to influence fruit characteristics,providing an explanation for the xenia ***,our findings highlight the feasibility of leveraging diverse pollen genomic resources,without resorting to genome editing,to improve fruitquality.

关键词： fruit ripening xenia ACO3 mobile RNA seed(to flesh)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：