检索结果-南通市图书馆

Journal of Environmental Sciences 2008年第8期20卷 1006-1011页

作者： ZHANG, Bo-Tao ZHAO, Li-Xia lin, jin-ming State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Department of Chemistry Tsinghua University Beijing 100084 China

The generation and transformation of radicals on the cathode of indirect electrochemical oxidation were studied by chemilumines- cence(CL)and UV-Visible spectra in the reactor with a salt bridge that connected the separated *** CL intensity of 4×10^(-9)mol/L luminol on the cathode with bubbling oxygen was about seven times that of the intensity without it,which was because of the generation of reactive oxygen species(ROS).The existence of ROS,especially the generation of the superoxide radical,coul...

关键词： chemiluminescence(CL) UV-Visible radical indirect electrochemical oxidation

Quantitative analysis of elements (C,N,O,Al,Si and Fe) in polyamide with wavelength dispersive X-ray fluorescence spectrometry

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2013年第8期56卷 1164-1170页

作者： LAI MeiShuang XIANG LeiWen lin jin-ming LI Hai-Fang Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety Department of ChemistryFuzhou University Beijing Key Laboratory of Microanalytical Methods and Instrumentation Department of ChemistryTsinghua University

A wavelength dispersive X-ray fluorescence （WD-XRF） spectrometry combined with calibration curve method was estab- lished for simultaneously analyzing low-Z elements （C, N, O） and A1, Si, Fe in polyamide. To investigate the origin of plastic material causing deposition and blocking in instrument engines and pipelines, polyamide 6 （PA 6, an engineering plastic） was chosen as the study object on account of its common use in industry. The sample preparation with pressed powder disk has been developed for determination of six elements in PA 6. Pure Cu metal was used as the matrix and PA 6 was regarded as standard sample for C, N, O elements. PA 6 particles were firstly smashed to uniform powder in liquid nitrogen, and then mixed with inorganic standard powders （Fe203, A1203, SIO2, and Na2SiO3）. The mixture was ground to obtain homogeneous calibration materials for WD-XRF analysis. The quantitative property of the calibration curve method for each element was re- liable. The limits of detection （S/N≤3） of C, N, O, A1, Si and Fe using WD-XRF were 249, 120, 101, 6.2, 3.3, and 1.8 μg/g, respectively. To confirm the accuracy of the proposed WD-XRF calibration curve method, inductively coupled plasma optical emission spectroscopy （ICP-OES） detection for A1, Si, Fe and elemental analyzer （EA） analysis for C, N, O were utilized. A good correlation of the WD-XRF results with the measurements of ICP-OES and EA was observed.

关键词： X-ray fluorescence low-Z elements polyamide 6

On-line enrichment and determination of polycyclic aromatic hydrocarbons in atmospheric particulates using high performance liquid chromatography with fluorescence as detector

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2007年第10期19卷 1261-1265页

作者： HASHI Yuki WANG Tian-ran LI Yue-qi lin jin-ming State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beifing 100085 China Shimadzu （Shanghai） Limited Beijing Office Analytical Application Center Beifing 100020 China

Seven polycyclic aromatic hydrocarbons （PAHs） in atmospheric particulates were determinated by high performance liquid chromatography （HPLC） with fluorescence detector using direction injection and an on-line enrichment trap column. The method simplified the sample pretreatment, saved time and increased the efficiency. With the on-line trap column, PAHs were separated availably even underground injecting 1.0 ml sample with relatively high column efficiency. The recoveries of the seven PAHs were from 85% to 120% for spiked atmospheric particulate sample. The limit of detection was 15.3-39.6 ng/L （S/N=3.3）. There were good linear correlations between the peak areas and concentrations of the seven kinds of PAHs in the range of 1-50 ng/ml with the correlation coefficients over 0.9970. Furthermore, it also indicated that the method is available to determine PAHs in atmospheric particulates well.

关键词： on-line enrichment on-line trap column high performance liquid chromatography (HPLC) atmospheric particulate polycyclic aromatic hydrocarbons (PAHs)

Studies of Solvent Effects on Structure and Low Frequency Vibrational Spectra of 2,4-Dinitrotoluene

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2009年第3期25卷 373-376页

作者： WANG lin jin ming-xing LIU Hang DING Da-jun Institute of Atomic and Molecular Physics Jilin University Changchun 130012 P. R. China

Solvent effects on 2,4-dinitrotoluene（2,4-DNT） molecule in different solvents（toluene, ethanol, and water） were studied via DFT PCM method at B3LYP/6-311＋G（d,p） level. The influences of these solvents on the molecular structure, vibrational spectra, charge distribution, and dipole moment were studied as well. The results show that PCM computations are successful in describing the vibrational spectra of 2,4-DNT molecules in these solutions and the solvent effects on the low frequency vibrational spectra are weak.

关键词： Density functional theory Solvent effect Polarizable continuum model 2,4-Dinitrotoluene

Molecularly imprinted polymer for pre-concentration of esculetin from tobacco followed by the UPLC analysis

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2014年第12期57卷 1751-1759,1-2页

作者： RAZWAN SARDAR M. jin Yan KONG Guang Hui LI Hai Fang lin jin-ming Department of Chemistry Beijing Key Laboratory of Microanalytical Methods and Instrumentation Tsinghua University Nova Med Pharmaceuticals Pvt. Ltd. Yunnan Academy of Tobacco Agricultural Science

Molecularly imprinted polymers(MIPs)for solid-phase extraction and pre-concentration of esculetin have been successfully prepared by the bulk polymerization method using esculetin as a template *** of varying composition were prepared using different monomers(4-vinylpyridine,methacrylic acid,and acrylamide),ethylene glycol dimethacrylate as the cross-linker,2,2-azobis(2-methylpropinitrile)as the initiator,and different porogen solvents(ethanol,acetone/methanol,and acetonitrile).The best polymer was obtained when 4-vinylpyridine was used as the monomer and acetone/methanol(3:2)as the porogen solvent,whereas the template:-monomer:-cross-linker ratio was 1:4:*** imprinting factor of the selected MIPs for esculetin was *** polymers were evaluated according to their selective recognition properties for esculetin and structurally-related compounds(esculin,scopoletin,coumarin,and 7-methoxycoumarin).Chemical and morphological characterizations of the polymers were investigated by FTIR and scanning electron microscope,which confirmed a high degree of *** area,pore volume,and pore size of the polymer were investigated by Brunauer-Emmett-Teller *** were also successfully used as solid-phase adsorbent materials for the extraction of esculetin from tobacco *** contents in dried tobacco leaves were found to be(9.27±0.17)μg g-1.

关键词： molecularly imprinted polymer esculetin tobacco UPLC

Development of analytical methods for polycyclic aromatic hydrocarbons (PAHs) in airborne particulates: A review

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2007年第1期19卷 1-11页

作者： LIU Li-bin LIU Yan lin jin-ming TANG Ning HAYAKAWA Kazuichi MAEDA Tsuneaki State Key Laboratory of Environmental Chemistry and Ecotoxicology. Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085. China Graduate School of Natural Science and Technology Faculty of Pharmaceutical Sciences Kanazawa University Kakuma-machi. Kanazawa 920-1192. Japan Innovation Center for Start-ups （INCS）. National Institute of Advanced Industrial Science and Technology. 2-2-2 Marunouchi ChiyodakuTokyo 100-0005 Japan

In the present work, the different sample collection, pretreatment and analytical methods for polycyclic aromatic hydrocarbons （PAHs） in airborne particulates is systematacially reviewed, and the applications of these pretreatment and analytical methods for PAHs are compared in detail. Some comments on the future expectation are also presented.

关键词： polycyclic aromatic hydrocarbons (PAHs) airborne particulates analytical methods review

Microplate chemiluminescence enzyme immunoassay for the quantitative evaluation of carbohydrate antigen 72-4 in human serum

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2008年第19期53卷 2958-2963页

作者： jin Hui WANG Xu XIN TianBing GAO Peng lin jin-ming LIANG ShuXuan College of Chemistry and Environmental Science Hebei University Baoding 071002 China Department of Chemistry Tsinghua University Beijing 100084 China Beijing Chemclin Biotech Co. Ltd. Beijing 100094 China

A highly sensitive and specific microplate chemiluminescence enzyme immunoassay (CLEIA) was developed for the quantitative evaluation of carbohydrate antigen 72-4 (CA72-4) in human serum, using luminol-H2O2 catalyzed by horseradish peroxidase (HRP) as the chemiluminescence system. The simple and quick determination was accomplished through a sandwich reaction mode. Several physico-chemical parameters of the immunoreaction, including incubation conditions, antibody coating conditions, dilution ratio of anti-CA72-4-HRP conjugate, and chemiluminescence reaction time, were studied and optimized. The proposed method exhibited a linear range of 0―200 U/mL with correlation coefficient and detection limit of 0.9995 and 0.18 U/mL, respectively. The inter-assay and intra-assay coeffi-cients of variation (CV) were both less than 10%. The average recovery of two clinical sera with low and high concentration CA72-4 was 99.3% and 98.7%, respectively. Normal tumor markers, including AFP, CEA, CA24-2, CA19-9 and CA15-3, did not cross-react with each other. The method's stability was evaluated by assessing its analytical performance after storing the immunoreagents at 4℃ and 37℃ for 7 days. Little difference was found, indicating satisfactory stability of the method. The present method has been successfully applied to the detection of CA72-4 human serum, and showed a good correlation with the commercially available ELISA kit (r 2=0.9383). This method showed great potential in the fabrication of diagnostic kit for CA72-4, and could be well used in diagnosis of cancer in clinical practice.

关键词：化学发光酶学免疫检测肿瘤标记

Combination of dynamic hollow fiber liquid-phase microextraction with HPLC analysis for the determination of UV filters in cosmetic products

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2011年第10期54卷 1627-1634页

作者： YANG HongYun LI HaiFang Masahito Ito lin jin-ming GUO GuangSheng DING mingYu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China Beijing Key Laboratory for Analytical Methods and Instrumentation Department of Chemistry Tsinghua University Beijing 100084 China Naka Division Hitachi High-Technologies Corporation Hitachinaka 312-8504 Japan

A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmetic products. A canular extractor was assembled by mounting a hollow fiber inside an external tube with a tee-connector. The organic solvent was immobilized into the fiber to form a liquid membrane as the acceptor phase. The sample was continuously injected into the extractor and the UV filters were extracted from the aqueous sample into organic acceptor phase. The main parameters affecting HF-LPME including extraction solvent, sample volume, sample flow rate, pH values and ionic strength were investigated. Toluene has been verified to be suitable as the acceptor phase. Under the optimized HF-LPME conditions, the enrichment factors of five UV filters varying from 24 to 57 were achieved. The limits of detection for the five UV filters were in the range of 1-100 μg L-1 .The relative standard deviations (RSDs) of HF-LPME and HPLC analysis were lower than 5.2%. The proposed method has been successfully applied to the analysis of the varied cosmetic products.

关键词： hollow fiber liquid-phase microextraction UV filter high performance liquid chromatography cosmetics

GEOSatDB:global civil earth observation satellite semantic database

在线全文

学校读者我要写书评

暂无评论

Big Earth Data 2024年第3期8卷 522-539页

作者： ming lin Meng jin Juanzi Li Yuqi Bai Department of Earth System Science Institute for Global Change StudiesMinistry of Education Ecological Field Station for East Asian Migratory BirdsTsinghua UniversityBeijingChina Department of Computer Science and Technology Tsinghua UniversityBeijingChina Tsinghua Urban Institute Tsinghua UniversityBeijingChina

Satellite remote sensing,characterized by extensive coverage,fre-quent revisits,and continuous monitoring,provides essential data support for addressing global *** the past six decades,thousands of Earth observation satellites and sensors have been deployed *** valuable Earth observation assets are contributed independently by various nations and organizations employing diverse *** poses a significant challenge in effectively discovering global Earth observation resources and realizing their full *** this paper,we describe the develop-ment of GEOSatDB,the most complete semantic database of civil Earth observation satellites developed based on a unified ontology model.A similarity matching method is used to integrate satellite information and a prompt strategy is used to extract unstructured sensor *** resulting semantic database contains 127,949 semantic statements for 2,340 remote sensing satellites and 1,021 observation *** global Earth observation capabil-ities of 195 countries worldwide have been analyzed in detail,and a concrete use case along with an associated query demonstration is *** database provides significant value in effectively facilitating the semantic understanding and sharing of Earth observa-tion resources.

关键词： Earth observation satellite sensor semantic representation information extraction

Drug repurposing for cancer therapy

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

Signal Transduction and Targeted Therapy 2024年第5期9卷 1981-2013页

作者： Ying Xia ming Sun Hai Huang Wei-lin jin Center for Clinical Laboratories The Affiliated Hospital of Guizhou Medical UniversityGuiyang 550004PR China The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine Guiyang 550001PR China School of Clinical Laboratory Science Guizhou Medical UniversityGuiyang 550004PR China Division of Gastroenterology and Hepatology Department of Medicine andDepartment of OncologySidney Kimmel Comprehensive Cancer CenterJohns Hopkins University School of MedicineBaltimoreMD 21287USA Institute of Cancer Neuroscience Medical Frontier Innovation Research CenterThe First Hospital of Lanzhou UniversityThe First Clinical Medical College of Lanzhou UniversityLanzhou 730000PR China

Cancer,a complex and multifactorial disease,presents a significant challenge to global *** significant advances in surgical,radiotherapeutic and immunological approaches,which have improved cancer treatment outcomes,drug therapy continues to serve as a key therapeutic ***,the clinical efficacy of drug therapy is often constrained by drug resistance and severe toxic side effects,and thus there remains a critical need to develop novel cancer *** promising strategy that has received widespread attention in recent years is drug repurposing:the identification of new applications for existing,clinically approved *** repurposing possesses several inherent advantages in the context of cancer treatment since repurposed drugs are typically cost-effective,proven to be safe,and can significantly expedite the drug development process due to their already established safety *** light of this,the present review offers a comprehensive overview of the various methods employed in drug repurposing,specifically focusing on the repurposing of drugs to treat *** describe the antitumor properties of candidate drugs,and discuss in detail how they target both the hallmarks of cancer in tumor cells and the surrounding tumor *** addition,we examine the innovative strategy of integrating drug repurposing with nanotechnology to enhance topical drug *** also emphasize the critical role that repurposed drugs can play when used as part of a combination therapy *** conclude,we outline the challenges associated with repurposing drugs and consider the future prospects of these repurposed drugs transitioning into clinical application.

关键词： drugs integrating spite