检索结果-南通市图书馆

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

昆明山海棠的苯丙素类成分研究

药学学报 2024年第6期59卷 1730-1740页

作者：林芷淇朱红波周堂王吉张荣平陈兴龙云南中医药大学中药学院暨云南省南药可持续利用研究重点实验室云南昆明650500

本文对昆明山海棠的苯丙素类成分进行研究,采用硅胶柱色谱、反相柱色谱、凝胶柱色谱、制备薄层色谱以及半制备高效液相色谱等分离纯化手段,从昆明山海棠的70%乙醇提取物中分离获得24个化合物。化合物1~3为苯丙素类新化合物,结合紫外光... 详细信息

本文对昆明山海棠的苯丙素类成分进行研究,采用硅胶柱色谱、反相柱色谱、凝胶柱色谱、制备薄层色谱以及半制备高效液相色谱等分离纯化手段,从昆明山海棠的70%乙醇提取物中分离获得24个化合物。化合物1~3为苯丙素类新化合物,结合紫外光谱、红外光谱、高分辨质谱和核磁共振波谱等结构鉴定方法,将其鉴定为:苏式-2-(4-羟基-3-甲氧基苯氧基)-3-(4-羟基-3-甲氧基苯基)-1,3-丙二醇(1)、赤式-2-(4-羟基-3-甲氧基苯氧基)-3-(4-羟基-3-甲氧基苯基)-1,3-丙二醇(2)、赤式-3-(4-羟基-3,5-二甲氧基苯基)-3-乙氧基-1,2-丙二醇(3)。化合物4~6、9、14、15、18、19、21~24为首次从雷公藤属植物中分离得到。生物学活性研究表明化合物20在50μmol·L^(-1)下对4T1乳腺癌细胞表现出抑制作用,测得其半数抑制浓度为125.60μmol·L^(-1)。

关键词：昆明山海棠化学成分苯丙素木脂素细胞毒性

Effects of Water Stress on Reactive Oxygen Species Generation and Protection System in Rice During Grain-Filling Stage

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2010年第5期9卷 633-641页

作者： WANG He-zheng zhang Lian-he MA Jun LI Xu-yi LI Yan zhang rong-ping WANG Ren-quan College of Agriculture Henan University of Science and Technology Luoyang 471003 P.R.China Rice Research Institute of Sichuan Agricultural University Wenjiang 611130 P.R.China

Rice is one of the main staple food crops in the world, but it may suffer serious water stress during growth period. Water stress during grain filling results in decreased grain yeild, but its mechanism generating and scavenging the active oxygen is unclear under continuance of the water stress. The experiment was carried out in growth chamber to investigate the effects of water stress on the production of superoxide free radical （O2）, hydrogen peroxide （H202）, malondialdehyde （MDA）, reduced glutathione （GSH）, ascorbic acid （AsA）, and antioxidative enzyme activities in three rice hybrids with differing drought resistant under both normal and drought conditions during grain-filling stage. The results showed that water stress aggravated the membrane lipid peroxidation in rice leaves, which was more severe in less drought resistant hybrids than that in more tolerant ones. Also O2＇ and H2O2 accumulated more rapidly in less drought resistant hybrids than that in more tolerant ones. During water stress, decreases of GSH, AsA, chlorophyll, and relative water contents in more drought resistant hybrids were obvious less than those in less tolerant ones. Activities of superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD） in/eaves increased obviously in 0-14 d after heading and subsequently decreased rapidly, and those in more drought resistant hybrids were more than those in less tolerant ones. The results showed that changes of O2, H2O2, MDA, GSH, and AsA contents and antioxidative enzyme activities correlated significantly to drought resistance of rice hybrids, and more drought resistant hybrids possessed high ant oxidation capacity.

关键词： rice water stress reactive oxygen species protection system

Sensing Escherichia coli O157:H7 via frequency shift through a self-assembled monolayer based QCM immunosensor

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第2期9卷 121-131页

作者： Li-jiang WANG Chun-sheng WU Zhao-ying HU Yuan-fan zhang rong LI ping WANG Biosensor National Special Laboratory Key Laboratory of Biomedical Engineering of Ministry of Education Department of Biomedical Engineering Zhejiang University Hangzhou 310027 China

By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157:H7 detection was developed in this work. As a suitable surfactant, 16-mercaptohexadecanoic acid (MHDA) was introduced onto the Au surface of QCM, and then self-assembled with N-hydroxysuccinimide (NHS) raster as a reactive intermediate to provide an active interface for the specific antibody immobilization. The binding of target bacteria with the immobilized antibodies decreased the sensor’s resonant frequency, and the frequency shift was correlated to the bacterial concentration. The stepwise assembly of the immunosensor was characterized by means of the electrochemical techniques. Using the immersion-dry-immersion procedure, this QCM biosensor could detect 2.0×102 colony forming units (CFU)/ml E. coli O157:H7. In order to reduce the fabrication time, a polyelectrolyte layer-by-layer self-assembly (LBL-SA) method was adopted for fast construction. Finally, the reproducibility of this biosensor was discussed.

关键词： Biosensor Escherichia coli O157:H7 Immunosensor Layer-by-layer self-assembly (LBL-SA) Quartz crystalmicrobalance (QCM)

Thermally Conductive,Healable Glass Fiber Cloth Reinforced Polymer Composite based onβ-Hydroxyester Bonds Crosslinked Epoxy with Improved Heat Resistance

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第5期42卷 643-654,I0009页

作者： Fang Chen Xiao-Yan Pang Ze-ping zhang Min-Zhi rong Ming-Qiu zhang Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education GD HPPC LabIGCMESchool of ChemistrySun Yat-sen UniversityGuangzhou510275China Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center Jieyang515200China

To simultaneously endow thermal conductivity,high glass transition temperature(Tg)and healing capability to glass fiber/epoxy(GFREP)composite,dynamic crosslinked epoxy resin bearing reversibleβ-hydroxyl ester bonds was reinforced with boron nitride nanosheets modified glass fiber cloth(GFC@BNNSs).The in-plane heat conduction paths were constructed by electrostatic self-assembly of polyacrylic acid treated GFC and polyethyleneimine decorated ***,the GFC@BNNSs were impregnated with the mixture of lower concentration(3-glycidyloxypropyl)trimethoxysilane grafted BN micron sheets,3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate and hexahydro-4-methylphthalic anhydride,which accounted for establishing the through-plane heat transport pathways and avoiding serious deterioration of mechanical *** resultant GFREP composite containing less boron nitride particles(17.6 wt%)exhibited superior in-plane(3.29 W·m^(-1)·K^(-1))and through-plane(1.16 W·m^(-1)·K^(-1))thermal conductivities,as well as high Tg of 204℃(Tg of the unfilled epoxy=177℃).The reversible transesterification reaction enabled closure of interlaminar cracks within the composite,achieving decent healing efficiencies estimated by means of tensile strength(71.2%),electrical breakdown strength(83.6%)and thermal conductivity(69.1%).The present work overcame the disadvantages of conventional thermally conductive composites,and provided an efficient approach to prolong the life span of thermally conductive GFREP laminate for high-temperature resistant integrated circuit application.

关键词： Thermally conductive composites Boron nitride High-temperature resistance β-Hydroxyl ester bond Healing

Validity and reliability testing of the Chinese (mainland) version of the 39-item Parkinson's Disease Questionnaire (PDQ-39)

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第7期11卷 531-538页

作者： Wei LUO Xiao-hong GUI Bo WANG Wen-ying zhang Zhi-yuan OUYANG Yi GUO Bao-rong zhang Mei-ping DING Department of Neurology the Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310009 China

The 39-item Parkinson's Disease Questionnaire (PDQ-39) has been tested in many languages, but not in Chinese mainland. We aimed to assess the Chinese (mainland) version of the PDQ-39. Seventy-one subjects with Parkinson's disease (PD) completed the PDQ-39 and the Medical Outcomes Study 36-item Short Form Health Survey (SF-36). All subjects were retested with the PDQ-39 a week later. The united Parkinson's disease rating scale (UPDRS) and the Hoehn and Yahr (H & Y) scale were also used to evaluate the subjects. Reliability was assessed by Cron- bach's α and intra-class correlation coefficient (ICC). Validity was examined in terms of agreement with SF-36, UPDRS, and H & Y scales. The Chinese (mainland) version of the PDQ-39 demonstrated acceptable reliability (Cronbach's α: 0.84-0.88; ICC: 0.56-0.82). The item-total correlations (0.33-0.88) and scaling success rates (77.56%) indicated satisfactory convergent and discriminant validity of the PDQ-39 items. The correlations between related constructs of the PDQ-39 and UPDRS (r=0.44-0.68) and between those of the PDQ-39 and SF-36 (r=(-0.46)-(-0.69)) were all statistically significant (P<0.01). Except for stigma, cognitions, and bodily discomfort, all other dimensions of the PDQ-39 significantly discriminated patients at different H & Y stages indicated by the H & Y scale. Although our observations indicate that some problematic subscales of this version of the PDQ-39 could be improved upon, this study suggests acceptable reliability and validity of the Chinese (mainland) version of the PDQ-39.

关键词： 39-item Parkinson’s Disease Questionnaire (PDQ-39) Quality of life Validity Reliability

An insulinoma with clinical and electroencephalographic features resembling complex partial seizures

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第6期9卷 496-499页

作者： Shuang WANG Hai-tao HU Shu-qun WEN Zhong-jin WANG Bao-rong zhang Mei-ping DING Department of Neurology the Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310009 China

We described a female patient with insulinoma who experienced recurrent episodes of automatism, confusion and convulsion. Furthermore, her electroencephalography （EEG） findings resembled the pattern in complex partial seizures with secondary generalization. The interictal EEG showed spikes and sharp waves, as well as focal slowing over the left temporal lobe, and the ictal EEG revealed generalized spikes and sharp waves associated with diffused slowing. She was initially misdiagnosed as pharmacoresistant epilepsy. After the insulinoma was found and surgically removed, her EEG turned normal and she was seizure-free during the 4-year follow-up. This report highlights the need for careful reassessment of all seizures refractory to medication, even for the oatients associated with eoileotiform discharges on EEG.

关键词： Insulinoma Hypoglycemia Electroencephalography (EEG) Seizure

在线全文

学校读者我要写书评

暂无评论

一起走私牛感染焦虫病的诊疗体会

中国牛业科学 2024年第2期50卷 85-87页

作者：陈景仙张海楠张容萍何德银李婷婷杨子江普洱市动物疫病预防控制中心云南普洱665000

焦虫病是牛常见的一种人畜共患寄生虫病,于1992年首次在我国发生,随后国内陆陆续续均有相关报道。该病是牛常见的一种人畜共患寄生虫病,主要通过媒介昆虫蜱叮咬传播,常见于森林茂密或放牧的地方,有明显的规律性。本文通过对普洱市某地... 详细信息

焦虫病是牛常见的一种人畜共患寄生虫病,于1992年首次在我国发生,随后国内陆陆续续均有相关报道。该病是牛常见的一种人畜共患寄生虫病,主要通过媒介昆虫蜱叮咬传播,常见于森林茂密或放牧的地方,有明显的规律性。本文通过对普洱市某地发生的一起走私牛通过临床检查、实验室检测等方法进行诊断,诊断结果显示该批牛患有焦虫病,且是一起典型的动物性输入性疫病。本文旨在为养殖场(户)对牛焦虫病防控提供指导,并提出边境地区肉牛贸易、流通风险防控意见建议,供肉牛养殖户和从业人员参考,从而保证养殖场(户)的经济利益。

关键词：牛焦虫病诊疗

维普期刊数据库博看期刊

Reinforcement of High Impact Polystyrene by Aramid Nanoparticle Fillers Prepared via an In situ Bottom-up Approach

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第8期42卷 1167-1176页

作者： Xiang-Jun Gong Zhi-ping Zhao Chang-Mei Sun Ying zhang rong-Jun Qu Ying Wang School of Chemistry and Materials Science Ludong UniversityYantai 264025China

In this work,aramid nanoparticles(ANPs)were prepared in dimethyl formamide(DMF)solution containing high impact polystyrene(HIPS)via a bottom-up *** electron microscopy(TEM)images showed that the obtained ANPs were evenly distributed in the HIPS matrix without any *** composition of the ANPs,i.e.,poly(p-phenyl-p-phenylenediamine)(PPTA),was confirmed by Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and X-ray diffractometer(XRD).The ANP/HIPS composites,obtained after ethanol precipitation,were added to neat HIPS as fillers to fabricate ANP/HIPS composite *** surface roughness and the glass transition temperature(T_g)of the sheets were characterized by atomic force microscope(AFM)and differential scanning calorimetry(DSC),*** with neat HIPS,the mechanical properties of the composite sheet were significantly improved,and the Young's modulus increased from 246.55 MPa to 2025.12 MPa,the tensile strength increased from 3.07 MPa to 29.76 MPa,and the toughness increased from 0.32 N/mm^2 to 3.92 N/mm^2,with an increase rate of 721%,869%and 1125%,***,the thermal stability of the composites improved with the increase in ANP content.

关键词： High impact polystyrene PPTA nanoparticle Reinforce Mechanical property

A SIMPLIFIED APPROACH TO EMBEDDING PROBLEMS IN NORMAL BORDISM FRAMEWORK

在线全文

学校读者我要写书评

暂无评论

Systems Science and Mathematical Sciences 1992年第2期5卷 180-192页

作者： LI Banghe LIU rong zhang ping (Institute of Systems Science,Academia Sinica,Beijing 100080,China)

The purpose of this paper is to simplify the computations of the nor-mal bordism groups Ωi（Wf,M×P∞;（?））and Ωi（Cf,（?）w;θf）which Salomonsenand Dax introduced respectively to study the existence and isotopy classificationof differential embeddings of manifolds in manifolds in the metastable *** space pair（Kf,M×P∞）is constructed to replace（Wf,M×P∞）.It isshown that（Kf,M×P∞）is homotopy equivalent to（Wf,M×P∞）and homotopy（n-1）-equivalent to（Cf,（?）W）.To demonstrate the efficacy of this simplification,the isotopy groups [Mn（?）RPn+k],if n（?）2k-4 and Mn is a closed（n-k+2）-connected manifold,and[Mn（?）L（p;q1…,qm）],if 3n（?）4m-2,Mn is a closed（2n-2m+1）-connected manifold and L is a （2m+1）-dimensional lens space,arespecifically computed.

关键词： Normal bordism group differential embedding isotopy