检索结果-南通市图书馆

A screening assay for thyroid hormone signaling disruption based on thyroid hormone-response gene expression analysis in the frog Pelophylax nigromaculatus

引用

Journal of Environmental Sciences 2015年第8期27卷 143-154页

作者： yinfeng zhang Yuanyuan Li Zhanfen Qin Huili Wang Jianzhong Li State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-environmental Sciences Chinese Academy of Sciences Department of Environmental Bio-Technology Research Center for Eco-environmental Sciences Chinese Academy of Sciences

Amphibian metamorphosis provides a wonderful model to study the thyroid hormone（TH）signaling disrupting activity of environmental chemicals, with Xenopus laevis as the most commonly used species. This study aimed to establish a rapid and sensitive screening assay based on TH-response gene expression analysis using Pelophylax nigromaculatus, a native frog species distributed widely in East Asia, especially in China. To achieve this, five candidate TH-response genes that were sensitive to T3 induction were chosen as molecular markers, and T3 induction was determined as 0.2 nmol/L T3 exposure for 48 hr. The developed assay can detect the agonistic activity of T3 with a lowest observed effective concentration of 0.001 nmol/L and EC50 at around 0.118–1.229 nmol/L, exhibiting comparable or higher sensitivity than previously reported assays. We further validated the efficiency of the developed assay by detecting the TH signaling disrupting activity of tetrabromobisphenol A（TBBPA）, a known TH signaling disruptor. In accordance with previous reports, we found a weak TH agonistic activity for TBBPA in the absence of T3,whereas a TH antagonistic activity was found for TBBPA at higher concentrations in the presence of T3, showing that the P. nigromaculatus assay is effective for detecting TH signaling disrupting activity. Importantly, we observed non-monotonic dose-dependent disrupting activity of TBBPA in the presence of T3, which is difficult to detect with in vitro reporter gene assays. Overall, the developed P. nigromaculatus assay can be used to screen TH signaling disrupting activity of environmental chemicals with high sensitivity.

关键词： Thyroid hormone signaling disruptor Pelophylax nigromaculatus TH-response gene expression Screening assay Tetrabromobisphenol A

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

Hollow mesoporous polyaniline nanoparticles with high drug payload and robust photothermal capability for cancer combination therapy

引用

Chinese Journal of Chemical Engineering 2021年第10期34卷 221-228页

作者： yinfeng zhang Fang Fang Yongjie Chen Min Li Li Li Wenyue Li Jinfeng zhang International Medical Center Beijing Friendship HospitalCapital Medical UniversityBeijing100050China Key Laboratory of Molecular Medicine and Biotherapy School of Life SciencesBeijing Institute of TechnologyBeijing 100081China College of Pharmacy Chongqing Medical UniversityChongqing 400016China School of Electrical Computer and Energy EngineeringArizona State UniversityTempeArizonaUSA

In recent years,synergistic chemo-photothermal therapy has revealed promising potential in treatments against various kinds of ***,the development of superb photothermal agents with high drug loading capacity is still highly *** this work,a hollow mesoporous polyaniline nanoparticle(HPANI NP)has been developed for encapsulating chemotherapeutic drug doxorubicin(DOX)with an remarkable drug loading content as high as 37.5%.Additional PEG modification endowed the drugloaded HPANI NPs with improved water-dispersibility and *** PEG-HPANI-DOX NPs exhibited strong NIR absorbance and robust photothermal conversion capacity,exhibiting highly efficient synergistic cancer *** interestingly,the responsively released DOX molecules could emit strong red fluorescence,which could be employed to monitor the cellular endocytosis and drug release profile of PEG-HPANI-DOX ***,the as-fabricated NPs showed good biocompatibility and low toxicity,serving as a promising nanoagent for highly efficient drug delivery and cancer combination therapy.

关键词： Hollow mesoporous polyaniline nanoparticles Drug delivery Nanocarriers Chemo-photothermal therapy Cancer combination therapy

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

Molecular characterization and m RNA expression of ribosomal protein L8 in Rana nigromaculata during development and under exposure to hormones

引用

Journal of Environmental Sciences 2014年第11期26卷 2331-2339页

作者： Qinqin Lou Shan Cao Wei Xu yinfeng zhang Zhanfen Qin Wuji Wei State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-environmental Sciences Chinese Academy of Sciences College of Environment Nanjing University of Technology

Like Xenopus laeuis, some species of the Rang genus are also used to study endocrine disrupting chemicals （EDCs）. Although ribosomal protein L8 （rp18） is the most-used reference gene for analyzing gene expression by quantitative reverse transcription polymerase chain reaction in Rang, its suitability as the reference gene has never been validated in any species of the Rana genus. We characterized rp18 cDNA in Rana nigromaculata, a promising native species in East Asia for assaying endocrine disrupting effects. We found that the rp18 cDNA consisted of 919 bp and encoded 257 amino acids, exhibiting high identities of amino acid sequence with known rp18 in other Rana species. Then, we examined the stability of mRNA expression during development. Compared with elongation factor 1 alpha 1, another common housekeeping gene, neither stage-specific nor tissue-specific expression of the rp18 gene was found in all tissues examined （brain, liver, intestine, tail, testis and ovary） during R. nigromaculata development. Finally, we investigated rp18 expression under exposure to hormones. No change in rp18 mRNA expression was found under exposure to thyroid hormone （T4） and estrogen （estradiol）, whereas expression of the corresponding biomarker genes was induced. Our results show that rp18 is an appropriate reference gene for analyzing gene expression by quantitative reverse transcription polymerase chain reaction for assaying EDCs using R. nigromaculata, and might also provide support for using rp18 as a reference gene in other Rang species due to the high conservation of rp18 among the Rana genus.

关键词： Ribosomal protein L8 Rana nigromaculata Endocrine disrupting chemical Quantitative RT-PCR Reference gene

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

Optimization of the T3-induced Xenopus metamorphosis assay for detecting thyroid hormone signaling disruption of chemicals

引用

Journal of Environmental Sciences 2017年第2期29卷 314-324页

作者： Xiaofang Yao Xiaoying Chen yinfeng zhang Yuanyuan Li Yao Wang Zongming Zheng Zhanfen Qin Qingdong zhang School of Environment and Resource Southwest University of Science and TechnologyMianyang 621010China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

T3-induced Xenopus metamorphosis is an ideal model for detecting thyroid hormone（TH）signaling disruption of chemicals. To optimize the T3-induced Xenopus assay and improve its sensitivity and reproducibility, we intend to develop quantitatively morphological endpoints and choose appropriate concentrations and exposure durations for T3 *** laevis at stage 52 were exposed to series of concentrations of T3（0.31–2.5 nmol/L）for 6 days. By comparing morphological changes induced by T3, we propose head area,mouth width, unilateral brain width/brain length, and hindlimb length/snout-vent length as quantitative parameters for characterizing T3-induced morphological changes, with body weight as a parameter for indicating integrated changes. By analyzing time-response curves, we found that following 4-day exposure, T3-induced grossly morphological changes displayed linear concentration–response curves, with moderate morphological changes resulting from 1.25 nmol/L T3 exposure. When using grossly morphological endpoints to detect TH signaling disruption, we propose 4 days as exposure duration of T3, with concentrations close to 1.25 nmol/L as induction concentrations. However, it is appropriate to examine morphological and molecular changes of the intestine on day 2 due to their early response to T3. The quantitative endpoints and T3 induction concentrations and durations we determined would improve the sensitivity and the reproducibility of the T3-induced Xenopus metamorphosis assay.

关键词： Thyroid hormone signaling Disruption Xenopus laevis T3 induction Morphological endpoints TH-response gene expression

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

Molecular characterization and developmental expression patterns of thyroid hormone receptors(TRs) and their responsiveness to TR agonist and antagonist in Rana nigromaculata

引用

Journal of Environmental Sciences 2014年第10期26卷 2084-2094页

作者： Qinqin Lou yinfeng zhang Dongkai Ren Haiming Xu Yaxian Zhao Zhanfen Qin Wuji Wei State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-environmental SciencesChinese Academy of Sciences College of Environment Nanjing University of Technology

Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone（TH） signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor（TR） agonist（T3） and antagonist（amiodarone） by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic *** to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility.

关键词： Rana nigromaculata Thyroid hormone receptor Thyroid hormone signaling Developmental expression pattern Responsiveness

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

Preparation of Cordierite-mullite Ceramics for Solar Thermal Storage

引用

Journal of Wuhan University of Technology(Materials Science) 2019年第5期34卷 1062-1070页

作者： WU Jianfeng LU Chenglong State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology

We developed cordierite-mullite composite ceramic materials to package and encapsulate PCM, and presented a preparation process from raw materials of kaolin, talc and alumina. The properties and microstructre of cordierite-mullite composite ceramic were studied. Due to the strengthening effects of mullite, the sample C2(80 wt% of cordierite and 20 wt % of mullite) sintered at 1 420 ℃ possessed excellent physical properties. Determined by X-ray diffraction(XRD), scanning electron microscope(SEM) and energy dispersive spectroscopy(EDS) analysis, cuboid-shaped cordierite crystals and needle-like or long quadrilateral-prism mullite crystals with staggered patterns were found, which endowed the composites preferable mechanical strength. After 30 cycles of thermal shock(room temperature to about 1 100 ℃, air-cooled), the sample presented superior thermal shock resistance, which is suitable to be applied as solar thermal storage materials.

关键词： solar energy cordierite-mullite composite ceramics properties and microstructure

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

Ideal and actual childbearing in China: number, gender and timing

引用

China Population and Development Studies 2020年第1期3卷 99-112页

作者： Jiawei Hou yinfeng zhang Baochang Gu School of Sociology and Anthropology Sun Yat-sen UniversityGuangzhouChina School of Health Management Guangzhou Medical UniversityGuangzhou 511436China Center for Population and Development Studies Renmin University of ChinaBeijingChina

This paper uses a cross-temporal meta-analysis to summarize information about the ideal number of children,gender composition,and timing of childbirths during the years 1980-2015 in *** allows a comparison between ideas about the ideal number of children and actual childbearing *** results show that fertility and the ideal number of children both decreased,but that fertility was higher than the ideal number of children before 1990,and that fertility was lower than the ideal number of children *** preference weakened;however,the preference for sons decreased *** timing of childbearing became significantly later over the study period,while the ideal age of childbearing remained relatively *** findings provide evidence to aid understanding of the changes in childbearing in China.

关键词： Childbearing ideals Childbearing behavior Gender preference Childbearing timing Cross-temporal meta-analysis

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

“灰姑娘”范型的冷峻变奏——保罗·托马斯·安德森《魅影缝匠》爱情叙事读解

引用

电影评介 2021年第1期 95-98页

作者：张引丰北京电影学院文学系

一、经典爱情叙事中的“灰姑娘”范型在常规爱情类型电影中,总跳脱不开“灰姑娘”式的叙事范型,换言之,“灰姑娘”式的范型至少占据了爱情叙事光谱序列中相当数量的份额。“灰姑娘”范型本身已有着上百年的源流衍进史,这个叙事范本的原... 详细信息

一、经典爱情叙事中的“灰姑娘”范型在常规爱情类型电影中,总跳脱不开“灰姑娘”式的叙事范型,换言之,“灰姑娘”式的范型至少占据了爱情叙事光谱序列中相当数量的份额。“灰姑娘”范型本身已有着上百年的源流衍进史,这个叙事范本的原型甚至可以追溯到公元前1世纪的古希腊,历史学家斯特拉波记述了一位嫁到埃及的希腊少女洛多庇斯的故事——洛多庇斯在溪边浆洗衣服,一只老鹰突然掠过,将她的鞋子叼走并丢掷到了身处孟裴斯城内的法老脚边,法老发布命令要求国内所有女子试穿这只鞋,多番辗转后方才寻到洛多庇斯,与她一见钟情的法老最终娶其为妻——这可以算是“灰姑娘”范式的最早原型,而随着时间的推演,真正让这一范型在大众无意识之中传播并固化下来的,则是1697年法国作家夏尔·佩罗在其故事集《鹅妈妈的故事》中所收录的Cinderella以及其后德国的格林兄弟的童话版本,更不用说其后在世界范围内流传的不亚于1500种的类“灰姑娘”式的异文故事版本。

关键词：灰姑娘故事集范型发布命令变奏一见钟情斯特拉波托马斯

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

Sintering Densification Mechanism of Talc on Promoting Thermal Storage Andalusite Ceramics in Solar Thermal Power Generation

引用

Journal of the Chinese Ceramic Society 2015年第3期 111-117页

作者： WU Jianfeng CHENG Hao XU Xiaohong LAO Xinbing zhang yinfeng RAO Zhengang DENG Tengfei State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology

Mullite ceramic,as one of high-performance thermal storage ceramics for solar thermal power generation systems,was in-situ fabricated with talc as a sintering aid via semi-dry pressing and pressureless sintering in *** mullitization influence of talc as a sintering aid on the formation of andalusite was investigated,and its mechanism to promote the sintering densification of samples was *** results show that talc reacts with corundum at a low temperature to in-situ produce *** reacts in-situ to produce mullite and glass phase,which reduces the sintering temperature sharply when corundum reacts with rich silicon fluid directly and generates secondary *** resolves and produces magnesium oxide liquid phase,which contains active aluminium oxide lattice capable of reducing reaction activation energy and promoting remaining corundum to react with rich silicon fluid and produces secondary mullite.

关键词： andalusite talc mullite sintering densification thermal storage ceramics

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

线下零售企业电商投资影响电商能力的机理分析——考虑战略导向的调节效应

引用

商业经济研究 2023年第20期 146-150页

作者：张银凤马来西亚理科大学马来西亚滨城11800 郑州西亚斯学院河南郑州451150

线下零售企业商品品种单一、商品售卖成本高昂、服务质量低下等弊端日益显现,这推动了线下零售企业加速布局电商业务。而电商能力是决定线下零售企业线上业务水平与绩效的重要因素,因此,着力提升电商能力是线下零售企业拓展线上业务的... 详细信息

线下零售企业商品品种单一、商品售卖成本高昂、服务质量低下等弊端日益显现,这推动了线下零售企业加速布局电商业务。而电商能力是决定线下零售企业线上业务水平与绩效的重要因素,因此,着力提升电商能力是线下零售企业拓展线上业务的重要内容。而电商投资是推动线下零售企业电商能力提升的关键,但由于线下零售企业战略导向的不同,并非所有线下零售企业进行电商投资均能够带来电商能力的提升。因此,本文在实证分析线下零售企业电商投资影响电商能力的基础上,考虑了战略导向调节效应机理,旨在为线下零售企业实现线上线下高效融合发展提供指导依据。研究结果显示:客户导向在线下零售企业电商投资与电商能力的关系中存在正向调节效应;技术导向在线下零售企业电商投资与电商能力的关系中存在正向调节效应;创业导向在线下零售企业电商投资与电商能力的关系中存在正向调节效应。

关键词：战略导向线下零售企业电商投资电商能力客户导向技术导向

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

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：