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PREDICTION OF THE THERAPEUTIC EFFECTIVENESS OF NEW DRUGS FROM CLINICAL PHARMACOLOGY STUDIES
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作者 Jan Koch-Weser M.D. 《中国临床药理学杂志》 CAS 1988年第2期101-104,共4页
The development of new drugs for therapeutic purposes has become very expensive and time-consuming in American and European countries.It is estimated that on the average 50 to 100 million dollars and 10 or more years ... The development of new drugs for therapeutic purposes has become very expensive and time-consuming in American and European countries.It is estimated that on the average 50 to 100 million dollars and 10 or more years from the time of patenting are required to make a new drug available for general prescription. Every new drug needs to be charac- 展开更多
关键词 PREDICTION OF THE THERAPEUTIC effectiveness OF NEW DRUGS FROM CLINICAL PHARMACOLOGY studies
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Assessing the Effectiveness of a Cervical Cancer Screening Program in a Hospital-based Study 被引量:11
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作者 YANG Yi LANG Jing He +5 位作者 WANG You Fang CHENG Xue Mei CAI Yu Pin LI Hui ZHU Bao Li ZHANG Rui Fen 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2015年第1期80-84,共5页
This study compared HPV testing and liquid-based cytology (LCT) as performance indicators for cervical cancer screening in a hospital-based study. A total of 61,193 outpatients were screened initially by LCT. Sample... This study compared HPV testing and liquid-based cytology (LCT) as performance indicators for cervical cancer screening in a hospital-based study. A total of 61,193 outpatients were screened initially by LCT. Samples with screening results showing atypical squamous cells of undetermined significance (ASC-US) or worse were referred for colposcopy, and some samples were tested for high-risk HPV types with the Hybrid Capture II system (HC II). Data on LCT (n=61,193) and HC II (n=1056) results were analysed. Overall test positivity for LCT was 2.53% using an ASC-US threshold, 3.11% using a low-grade squamous intraepithelial lesion (LSIL) threshold, and 0.67% using a high-grade squamous intraepithelial lesion (HSIL) threshold. A total of 1839 women (84% of the 3893 patients with abnormal cytology) underwent colposcopy-directed biopsy. HPV was positive in 80.3% of women with cervical intraepithelial neoplasia 1 (CIN1), 88.3% of those with CIN2, 79.2% of women with CIN3 and 50% (2 of 4) of women with invasive cancer. There was a significant increase in the detection of CIN2 or worse with adjunct HPV testing of women with ASC-US and LSIL However, there were detection of CIN2+ cases no differences in the with adjunct HPV testing of women with HSlI.. The results indicate that HPV testing for HSlL triage should not be recommended in cervical cancer screening. 展开更多
关键词 HPV HSIL Assessing the effectiveness of a Cervical Cancer Screening Program in a Hospital-based Study
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Studies on the Effects of Deltamethrin on Sodium Net Transport Through the in vivo Amphibian Skin 被引量:3
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作者 ALFREDO SALIBIAN AND JOSE L. MARAZZO(Programa de Ecofisiologia Aplicada, Departamento de Ciencias Basicas,Universidad Nacional de Lujan, Casilla de Correo 221, 6700-Lujaan (B),Argentina)(Comision de Investigaciones Cientificas, Provincia de Buenos Aires, 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1995年第2期164-168,共5页
The action of micromolar concentrations of Deltamethrin on sodium net transport through the in vivo skin of the South American toad Bufo arenarum was studied. The effect of pure ethanolic insecticide solutions and com... The action of micromolar concentrations of Deltamethrin on sodium net transport through the in vivo skin of the South American toad Bufo arenarum was studied. The effect of pure ethanolic insecticide solutions and commercial formulations when applied on the mucosal surface was assayed. Deltamethrin provoked a concentration-independent inhibition; the highest inhibition was found at the lowest concentrations. At highest concentrations of the insecticide the J Na was not altered 展开更多
关键词 studies on the Effects of Deltamethrin on Sodium Net Transport Through the in vivo Amphibian Skin
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POLAR SUBSTITUENT EFFECTS OF ORGANOPHOSPHORUS ESTERS IN STRUCTURE-REACTIVITY STUDIES 被引量:1
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作者 Wen Xiang HU Cheng Ye YUAN Shu Sen LI Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,345 Lingling Lu,Shanghai 200032 Institute of Pharmacology and Toxicology,Academy of Military Medical Sciences,Beijing 100850. 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第8期579-582,共4页
In order to study the polar substituent effect almost with no steric effect in organophosphorus chemistry,a series of 4-substituted-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane 1-oxides(1)and p-substituted phenylphospho... In order to study the polar substituent effect almost with no steric effect in organophosphorus chemistry,a series of 4-substituted-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane 1-oxides(1)and p-substituted phenylphosphonates(2)and corresponding mono hexyl esters(3)as model were synthesized.^(31)P-NMR chemical shifts of compounds(1)in methanol and deuterioacetone were determined.The Δδ values reflect 4-sbstituent po- lar effect.The ^(31)P-NMR of compounds(2)and(3)and the pKa of compounds(3)were also measured.The results showed that the trend of polar effects of substituents in both carboxylic and organophosphates chemistry are similar,and the change of polar effects in variation with the alkyl groups is not significant. 展开更多
关键词 MNDO POLAR SUBSTITUENT EFFECTS OF ORGANOPHOSPHORUS ESTERS IN STRUCTURE-REACTIVITY studies
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STUDIES ON FLUORESCENCE ENHANCING EFFECT AND ALKALINE DEGRADATION MECHANISM OF DOXYCYCLINE AND METHACYCLINE
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作者 Yi Bing ZHAO Department of Chemistry,Xiamen University,Xiamen 361005Wen Bao CHANG Yun Xiang CI Department of Chemistry,Peking University,Beijing 100871 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第9期791-792,共2页
Degradation reaction of doxycycline or methacycline was carried out in KOH solution and intense fluorescence was obtained.A degradation mechanism of doxycycline or methacycline was suggested.
关键词 HC DC studies ON FLUORESCENCE ENHANCING EFFECT AND ALKALINE DEGRADATION MECHANISM OF DOXYCYCLINE AND METHACYCLINE KOH
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Studies on the Hazardous Effects and the Maximum Allowable Concentration of Pyrophyllite Dust
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作者 ZHANG WEN-CHANG ZHANG QI-FEN SONG ZHI-FANG(Deportment of Occupotional Health, Fujian Medical University, 88 Jiaotong Road, Fuzhou 350004, China)(Division of Pneumoconiosis, Zhejiang Medical University, Yan an Road, Hangzhou 310006, China) 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1997年第4期377-386,共10页
Pyrophyllite (H2Al2,Si4 O22, ) dust (P-dust) is a mixture of silica (10-40% ), differentproportions of a luminium oxide (Al2O3 ), and various metal compounds. People with occupa-tions known to be associated with expos... Pyrophyllite (H2Al2,Si4 O22, ) dust (P-dust) is a mixture of silica (10-40% ), differentproportions of a luminium oxide (Al2O3 ), and various metal compounds. People with occupa-tions known to be associated with exposure to P-dust include miners, other industrial workersand persons engaged in artistic carving. Currently, little is known about pyrophyllite pneumo-coniosis from P-dust. This study was designed to investigate the hazardous effects of P-dustand to suggest a maximum allowable concentration (MAC) of the dust.This.study included four parts: (i) Occupational epidemiology surveys in 781 workersfrom 1 pyrophyllite mine (PM) and four pyrophyllite carving mills (PCM), with a registra-tion rate of 98 %. (ii) In vitro studies: Six groups of rats were expeed to different levels ofP-dust; the cytotoxicity of P-dust on rat alveolar macrophages (AM) was investigated by de-termining the potassium'content of AM and the activity levels of lactate dehydrogenase (LDH)in AM culture fluid. (iii) Mineralogical analysis of P-dust: The contents of silica (SiO2 ), alu-minium (Al), ferrum (Fe), niikel (Ni), zinc (Zn) and copper (Cu) in hath PM-dust andPCMdust were determined. (iv ) Determination of P-dust MAC: Using the life-talbemethod, an investigation of the hygiene standard of P-dust was carried out in 625 workers ex-POSed to either PM-dust or PCM-dust, uPon whom routine radiographs were Performed.The results suggest that the risk of developing pneumoconiosis from pyrophyllite dust issignificantly higher for PM workers than for PCM workers. The prevalence rate of PCM-dustpneumoconiosis is significantly higher in men than in women. The content of SiO2 and AlO3in the mixture of P-dust is the most important factor in the etiology of pyrophyllitosis. De-pending on the different P-dust MAC values, we suggest that 2 rng/m3 and 4 mg/m' shouldbe considered as the MAC for PM-dust and PCM-dust, respectively, and 3 mg/m' fOr P-dust. We believe that establishing different hygiene standards is more accurate even thoughworkers are exposured to the 'same' dust 展开更多
关键词 PCM studies on the Hazardous Effects and the Maximum Allowable Concentration of Pyrophyllite Dust PM ZHANG SiO
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A simple and effective method for RBC labeling and survival studies
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《中国输血杂志》 CAS CSCD 2001年第S1期388-,共1页
关键词 RBC A simple and effective method for RBC labeling and survival studies
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Advance in Matrix Effect Study of LA-MC-ICPMS U-Pb Dating on U-Bearing Oxide Minerals 被引量:1
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作者 CUI Yurong TU Jiarun +3 位作者 GENG Jianzhen YE Lijuan ZHOU Hongying LI Huimin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2018年第4期1680-1681,共2页
Objective With the development of analytic technologies, in-situ dating on U-bearing oxide minerals (e.g., cassiterite, rutile and baddeleyite) has been widely used in geological chronological researches and has at... Objective With the development of analytic technologies, in-situ dating on U-bearing oxide minerals (e.g., cassiterite, rutile and baddeleyite) has been widely used in geological chronological researches and has attracted remarkable attention to explore evolution of the earth and obtain age information of various geological processes. Matrix effect related studies are especially important during in-situ U- Pb dating based on Laser Ablation Multiple Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC- ICPMS). However, to our knowledge, only few thorough and systematical matrix effect study of U-bearing oxide minerals has been reported. In this study, we systematically analyzed the matrix effect of U-bearing oxide minerals in order to take place the standards which are difficult to prepare with available standards. 展开更多
关键词 ICPMS ID Pb Advance in Matrix Effect Study of LA-MC-ICPMS U-Pb Dating on U-Bearing Oxide Minerals MC
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Clinical and Experimental Study on Effect of Garlicin in Treating Angina Pectorls 被引量:2
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作者 史载祥 《Chinese Journal of Integrated Traditional and Western Medicine》 2003年第2期92-92,共1页
Objective: To observe the effect and mechanism of Garlicin in treating coronary heart disease (CHD) with angina pectoris. Methods: Clinical study: 55 patients were selected and randomized into the Garlicin group and t... Objective: To observe the effect and mechanism of Garlicin in treating coronary heart disease (CHD) with angina pectoris. Methods: Clinical study: 55 patients were selected and randomized into the Garlicin group and the nitroglycerin group. To Garlicin group, 60 mg of Garlicin was given by adding in 5% glucose solution for intravenous dripping once per day, the therapeutic course 展开更多
关键词 of in were Clinical and Experimental Study on Effect of Garlicin in Treating Angina Pectorls on
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Clinical Study on Effect of Shenmai Injection in Treating Congestive Heart Failure 被引量:1
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作者 龙明智 王迪斌 +1 位作者 杨季明 周丽英 《Chinese Journal of Integrated Traditional and Western Medicine》 2004年第1期62-62,共1页
Objective: To observe the therapeutic effect of Shenmai Injection (SI) in treating congestive heart failure (CHF). Methods: The changes in cAMP, cGMP, serum cardiac troponin T (cTnT, a specific marker reflecting myoca... Objective: To observe the therapeutic effect of Shenmai Injection (SI) in treating congestive heart failure (CHF). Methods: The changes in cAMP, cGMP, serum cardiac troponin T (cTnT, a specific marker reflecting myocardial injury), creatine kinase (CK) and creatine kinase isoenzyme (CK- 展开更多
关键词 CHF Clinical Study on Effect of Shenmai Injection in Treating Congestive Heart Failure
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A Comparative Study of Boron and Phosphorus Doping Effects in SiC: H Films Prepared by ECR-CVD 被引量:1
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作者 S.F. Yoon (School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue,Singapore 639798, Rep. of Singapore) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1998年第1期65-71,共7页
Hydrogenated silicon carbide films (SiC:H) were deposited using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) technique from a mixture of methane, silane and hydrogen, and using diborane and ph... Hydrogenated silicon carbide films (SiC:H) were deposited using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) technique from a mixture of methane, silane and hydrogen, and using diborane and phosphine as doping gases. The effects of changes in the microwave power on the deposition rate and optical bandgap were investigated, and variations in the photoand dark-conductivities and activation energy were studied in conjunction with film analysis using the Raman scattering technique. In the case of boron-doped samples, the conductivity increased rapidly to a maximum, followed by rapid reduction at high microwave power. The ratio of the photo- to dark-conductivity (σph/σd) peaked at microwave power of ~600 W. Under conditions of high microwave power, Raman scattering analysis showed evidence of the formation and increase in the silicon microcrystalline and diamond-like phases in the films, the former of which could account for the rapid increase and the latter the subsequent decrease in the conductivity.In the case of phosphorusdoped SiC:H samples, it was found that increase in the microwave power has the effect of enhancing the formation of the silicon microcrystalline phase in the films which occurred in correspondence to a rapid increase in the conductivity and reduction in the activation energy The conductivity increase stabilised in samples deposited at microwave power exceeding 500 W probably as a result of dopant saturation. Results from Raman scattering measurements also showed that phosphorus doping had the effect of enhancing the formation of the silicon microcrystals in the film whereas the presence of boron had the effect of preserving the amorphous structure. 展开更多
关键词 ECR A Comparative Study of Boron and Phosphorus Doping Effects in SiC H Films Prepared by ECR-CVD
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Comparison of four non-alcoholic fatty liver disease detection scores in a Caucasian population
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作者 Lars Lind Lars Johansson +5 位作者 Hakan Ahlstrom Jan W Eriksson Anders Larsson Ulf Risérus Joel Kullberg Jan Oscarsson 《World Journal of Hepatology》 CAS 2020年第4期149-159,共11页
BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a common disorder,with an estimated prevalence ranging from 20%to 35%in the general population.Several scores based on easily measurable biochemical and clinical p... BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a common disorder,with an estimated prevalence ranging from 20%to 35%in the general population.Several scores based on easily measurable biochemical and clinical parameters,including the fatty liver index(FLI),hepatic steatosis index(HSI),lipid accumulation product(LAP),and NAFLD liver fat score(LFS),have been developed for the detection of NAFLD.However,comparative information regarding the efficacy of these scores for predicting NAFLD in population-based samples comprising normal and high-risk individuals is lacking.AIM To evaluate four NAFLD detection scores in two samples with different NAFLD risks.METHODS NAFLD screening was performed in a population-based sample of 50-year-old individuals in Uppsala,Sweden[n=310;Prospective investigation of obesity,energy and metabolism(POEM)study]and a high-risk population comprising patients with a body mass index>25 kg/m2 and either high plasma triglycerides(≥1.7 mmol/L)or type 2 diabetes(n=310;EFFECT studies).NAFLD was defined as liver fat>5.5%using magnetic resonance imaging-proton density fat fraction.FLI,HSI,LAP,and NAFLD LFS were assessed.A logistic regression model was used to evaluate the effectiveness of the different scores.RESULTS The prevalence of NAFLD was 23%in POEM.FLI showed the highest receiver operating characteristic area under the curve(ROC AUC;0.82)and was significantly better than the LAP score(P=0.005 vs LAP,P=0.08 vs LFS,P=0.12 vs HSI)for detection of NAFLD.The other three indices performed equally in POEM(0.77-0.78).The prevalence of NAFLD was 74%in EFFECT;LFS performed best(ROC AUC 0.80)in this sample.The ROC AUC for LFS(0.80)was significantly higher than that for FLI(P=0.0019)and LAP(P=0.0022),but not HSI(P=0.11).We performed a sensitivity analysis with stratification for the two high-risk subgroups(patients with diabetes or hypertriglyceridemia)from the EFFECT studies.LAP performed best in patients with hypertriglyceridemia.No major differences were observed between the other scores.CONCLUSION The four investigated NAFLD scores performed differently in the populationbased vs high-risk setting.FLI was preferable in the population-based setting,while LFS performed best in the high-risk setting. 展开更多
关键词 COMPARISON EFFECT studies Fatty liver Non-alcoholic fatty liver disease Non-invasive indices SCREENING
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STUDY ON EFFECTS OF Yb^(3+) AND ITS COMPLEXES ON CELLS IN VITRO
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作者 Nie Yuxiu Chen Yulan(Department of Histology & Embryology,Norman Bethune University of Medical Sciences,Changchun 130021,P.R.China)Shi Feng Ni Jiazan(Changchun Institute of Applied Chemistry,Academia Sinica,Changchun 130022,P.R.China) 《Journal of Rare Earths》 SCIE EI CAS CSCD 1990年第1期61-66,共6页
This paper reports the effects of the Yh^(3+) and its four complexes on cultured cells.The results indicate that the 5 mmol YbCl_3 has evident toxicity on cultured cells,and after it is coordinated with ligands,its to... This paper reports the effects of the Yh^(3+) and its four complexes on cultured cells.The results indicate that the 5 mmol YbCl_3 has evident toxicity on cultured cells,and after it is coordinated with ligands,its toxicity is decreased.These.four complexes neither destroy the growth nor inhibit the adliesion of diploid cell to the surface of the flasket,but they inhibit the adhesion of cancer cells,and result in cell death.The complex of Yb~?(3+) with ligand(1) can destroy the cancer cells in division phase.forming aberrant mitotic cells,but the other three complexes of Yb^(3+) with ligands can destroy the cancer cells in interphase.These effects depend on the dose of the complex. 展开更多
关键词 STUDY ON EFFECTS OF Yb AND ITS COMPLEXES ON CELLS IN VITRO show ITS
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FOURIER TRANSFORM INFRARED SPECTROSCOPIC STUDY OF EFFECT OF LANTHANIDE IONS ON PHOSPHOLIPID MULTIBILAYERS
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作者 Wei WANG Lai Ming LI +1 位作者 Zhi Li LI Shi Quan XI 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第10期829-832,共4页
The molecular interactions between Nd^(3+), Gd^(3+)and Yb^(3+) and DPPC in multibilayer have been studied by Fourier transform infrared spectroscopy. The results show that incorporations of the lanthanide ions conside... The molecular interactions between Nd^(3+), Gd^(3+)and Yb^(3+) and DPPC in multibilayer have been studied by Fourier transform infrared spectroscopy. The results show that incorporations of the lanthanide ions considerably shift the gel to liquid-crystal phase transition to higher temperatures. The incorporations of Gd^(3+) and Yb^(3+) obviously reduce the cooperations of the transition. The phosphate region of the spectra indicates that the Ln^(3+) binding to DPPC forms DPPC-Ln^(3+)complex and the Lna^(3+)binding is not dependent on the phase state of DPPC. The C-H stretching region of the spectra suggests that the incorporation of Ln^(3+)increases the conformational order of DPPC both in gel and in liquid-crystal phase as a result of the reduction of gauche rotamers. 展开更多
关键词 DPPC ND FOURIER TRANSFORM INFRARED SPECTROSCOPIC STUDY OF EFFECT OF LANTHANIDE IONS ON PHOSPHOLIPID MULTIBILAYERS
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Study on Effect of Compound Salvia Pellet in Preventing Atrial Fibrillation with Left Atrial Thrombosis
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作者 连耀植 李玉光 +7 位作者 张汉灵 张元春 闫纯英 林建才 许端敏 张钰 郑宝群 麦芒 《Chinese Journal of Integrated Traditional and Western Medicine》 2004年第1期59-62,共4页
Atrial fibrillation (AF) is a kind of common arrhythmia, which, besides affecting cardiac function, has another serious outcome, that is, it is easy to form atrial thrombosis and induce thrombus/embolus, especially ce... Atrial fibrillation (AF) is a kind of common arrhythmia, which, besides affecting cardiac function, has another serious outcome, that is, it is easy to form atrial thrombosis and induce thrombus/embolus, especially cerebral embolus. The incidence of left atrial thrombosis ( LAT) could reach 25% - 30%(1) , the incidence of embol- 展开更多
关键词 Study on Effect of Compound Salvia Pellet in Preventing Atrial Fibrillation with Left Atrial Thrombosis CSP INR
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The Study of Health Effects of Vinyl Chloride AirPollution on Population
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作者 ZHAO MEI-YING YING CHEN-JIANG +3 位作者 SHAO NING YANG YING YANG CHENG-FENG SHI LEI AND LIU WEN-QING(Department of Environmental Health, School of Public Health, Tongji Medical University, Wuhan 430030)(Environmental Sanitation and Monitoring Station, Sanxi In 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1994年第2期136-143,共8页
A series of indicators, including serum lysozyme activity, G-banding chromosome aberration (G-banding CA) analysis, sister chromatid exchanges (SCEs), chromosome aberration (CA), T-lymphocyte transformation rate (TcTR... A series of indicators, including serum lysozyme activity, G-banding chromosome aberration (G-banding CA) analysis, sister chromatid exchanges (SCEs), chromosome aberration (CA), T-lymphocyte transformation rate (TcTR),-GT, GPT and AKP, were employed in the present survey among occupationally vinyl chloride (VC) exposed workers and inhabitants living in VC polluted area in a polyvinyl chloride (PVC) factory. The results showed that the serum lysozyme (S-LZM) activities in Group 3 (adult inhabitants exposed to 0.20 mg/m3 VC for at least 8 years), Group 2 (workers exposed to 4.1 mg/m3for at least 7 years occupationally), Group 1 (workers exposed to 25.7 mg/m3 for at least 2 years) were significantly higher than control. G-banding CA analysis showed that the total chromosome breakage rates in both Groups 1 and 2 were higher, but no difference existed between Group 3 and control. Only Group 1 was observed having higher SCEs, CA level and lower TcTR than control. AKP levels in Groups 1 and 2 were higher than control,but noγ-GT and GPT differences were found among groups. The study also suggests that G-banding CA analysis is more sensitive than CA and SCEs 展开更多
关键词 The Study of Health Effects of Vinyl Chloride AirPollution on Population RES
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A Study of the Radiation-Climate Effect of Aerosol over Beijing Area
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作者 邱金桓 王开祥 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1993年第2期147-154,共8页
In this paper, the monthly-averaged planetary albedo and equivalent blackbody temperature are calculated by using Gauss-Seidle numerical model to solve the equation of radiative transfer, based on measured aerosol dat... In this paper, the monthly-averaged planetary albedo and equivalent blackbody temperature are calculated by using Gauss-Seidle numerical model to solve the equation of radiative transfer, based on measured aerosol data over Beijing aera. With the increase of atmospheric turbidity, the planetary albedo has different characteristics in different seasons, and there is an evident decrease in the winter season. It means that the local aerosol has an heating effect to the atmosphere in winter. The correlation feature between the surface temperature and the horizontal visibility from 1963 to 1986 is analyzed, and anticorrelation is discovered in winter. It is found that surface temperature increases with the increase of aeresol. 展开更多
关键词 A Study of the Radiation-Climate Effect of Aerosol over Beijing Area OVER
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Study on effect of HDL on experimental atheroslerosis in rabbits
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《中国输血杂志》 CAS CSCD 2001年第S1期423-,共1页
关键词 HDL Study on effect of HDL on experimental atheroslerosis in rabbits
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A study of temperature effect on Ta+N ion-implanted hardalloy
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作者 赵青 赵峰 +2 位作者 童洪辉 耿漫 郑永真 《Plasma Science and Technology》 SCIE EI CAS CSCD 2001年第4期897-902,共6页
Hard alloy were implanted with a dudl-ion of nitrogen and tatalum at temperature of 100℃ and 400℃ at a dose of 8×1017 ions cm-2 .Auger electron spectroscopy (AES) was used to determine the nitrogen and tantalum... Hard alloy were implanted with a dudl-ion of nitrogen and tatalum at temperature of 100℃ and 400℃ at a dose of 8×1017 ions cm-2 .Auger electron spectroscopy (AES) was used to determine the nitrogen and tantalum concentration profiles. Microhardness measurements were performed to evaluate the improvements in surface property. The thickness of implanted layers increased by about an order of magnitude when the temperature was elevated from 100℃ to 400 ℃. A higher surface hardness was also obtained in the higher temperature implantation. Scanning electron microscopy (SEM) image showed distinct microstructural changes, and X-ray diffiaction (XRD) analysis showed the presence of nitrides of tantalum and tungsten on the surface implanted. 展开更多
关键词 A study of temperature effect on Ta+N ion-implanted hardalloy Ta
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A STUDY ON THE STRUCTURAL EFFECT OF DOUBLE BRIDGES CONJUGATED SYSTEMS I.CARBONYL-IMINO SYSTEM
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作者 Gui Ying LI cui chen Dai Ming Qian Jiang(M.C.chiang)Institute of chemistry,Academia sinica,Beijing 100080 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第3期197-200,共4页
The struetural effect of the conjugative system(C)with carbonyl-imino bridges has been studied.The results show that:In the conjugated system(C),there is no electronic absorption peak attributable to the whole system,... The struetural effect of the conjugative system(C)with carbonyl-imino bridges has been studied.The results show that:In the conjugated system(C),there is no electronic absorption peak attributable to the whole system,but there are three π-π* bands each nt which displays chacactecistics of its own independently.These indicate that the two bridges-carbonyl-and-imino-can block the tlanSmlSSion of the conjngative polarization of the whole system,so as to form three segments,this is verified by means of chemical synthesis and degradation. 展开更多
关键词 CHO A STUDY ON THE STRUCTURAL EFFECT OF DOUBLE BRIDGES CONJUGATED SYSTEMS I.CARBONYL-IMINO SYSTEM CI
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