首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   64523篇
  免费   6857篇
  国内免费   4720篇
耳鼻咽喉   504篇
儿科学   610篇
妇产科学   616篇
基础医学   7513篇
口腔科学   1227篇
临床医学   8663篇
内科学   10127篇
皮肤病学   618篇
神经病学   3642篇
特种医学   2271篇
外国民族医学   52篇
外科学   6628篇
综合类   11257篇
现状与发展   19篇
一般理论   5篇
预防医学   4465篇
眼科学   1908篇
药学   6930篇
  58篇
中国医学   3529篇
肿瘤学   5458篇
  2025年   23篇
  2024年   870篇
  2023年   1477篇
  2022年   2804篇
  2021年   3506篇
  2020年   2751篇
  2019年   2278篇
  2018年   2263篇
  2017年   2121篇
  2016年   2002篇
  2015年   2986篇
  2014年   3712篇
  2013年   3167篇
  2012年   4907篇
  2011年   5281篇
  2010年   3135篇
  2009年   2418篇
  2008年   3345篇
  2007年   3206篇
  2006年   3162篇
  2005年   3110篇
  2004年   2031篇
  2003年   1973篇
  2002年   1633篇
  2001年   1392篇
  2000年   1429篇
  1999年   1639篇
  1998年   1000篇
  1997年   970篇
  1996年   698篇
  1995年   644篇
  1994年   646篇
  1993年   394篇
  1992年   564篇
  1991年   426篇
  1990年   389篇
  1989年   326篇
  1988年   317篇
  1987年   256篇
  1986年   217篇
  1985年   181篇
  1984年   98篇
  1983年   60篇
  1982年   45篇
  1981年   41篇
  1980年   19篇
  1979年   42篇
  1978年   15篇
  1977年   14篇
  1936年   8篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
Recently, we created a family of engineered G protein-coupled receptors (GPCRs) called DREADD (designer receptors exclusively activated by designer drugs) which can precisely control three major GPCR signaling pathways (Gq, Gi, and Gs). DREADD technology has been successfully applied in a variety of in vivo studies to control GPCR signaling, and here we describe recent advances of DREADD technology and discuss its potential application in drug discovery, gene therapy, and tissue engineering.  相似文献   
962.
Background:This study aims to assess the therapeutic effects of a well-known component (puerarin) obtained from a Chinese herb root in patients with polycystic ovary syndrome (PCOS).Methods:Women with premature ovarian failure (POF) were assigned to the obese group (body mass index [BMI] ≥24 kg/m2 and waist hip ratio [WHR] >0.85) or non-obese group (group 3, n = 21). Obese patients were further randomly assigned to the obese treatment group (group 1, n = 15) and obese control group (group 1, n = 15). All patients received standard treatment (Diane-35, 1 tablet/d, orally, plus metformin, 1.5 g/d, orally). In addition to the standard modality, patients in group 1 and group 3 also orally received 150 mg/d of puerarin tablets for 3 months. Venous blood was drawn before and after treatment. Then, the metabolic and antioxidant biomarkers were measured. The normality of distribution of the data was tested using the Kolmogorov–Smirnov method. The baseline characteristics were analyzed using one-factor analysis of variance (ANOVA), and post-hoc was performed using the least significance difference (LSD)-t test.Results:Significantly improved blood levels of sex hormone binding globulin (SHBG) and superoxide dismutase (SOD) were observed in patients who received the additional treatment of puerarin, regardless of their lean or obese status, while these were not observed in patients who did not receive puerarin. Furthermore, obese patients with PCOS had significantly lower systolic blood pressure, total cholesterol, and testosterone blood levels, when compared with before treatment.Conclusion:The addition of puerarin to the present treatment protocol can be considered for the management of metabolic disorders and hyperandrogenism in PCOS patients.  相似文献   
963.
964.
965.
Wenzhou had the highest number of confirmed novel coronavirus 2019 (COVID-19) cases outside the Hubei province. The aim of this study was to identify the difference in clinical features and viral RNA shedding between the imported and local COVID-19 cases in Wenzhou.All patients with confirmed COVID-19 admitted to Wenzhou Sixth People''s Hospital, Wenzhou Central Hospital Medical Group, from January 17 to February 11, 2020, were enrolled in this study. Data was analyzed and compared for the imported and local cases with regard to epidemiological, demographic, clinical, radiological features, and laboratory findings. Outcomes for the enrolled participants were followed up until May 7, 2020.Of the 136 cases, 50 were imported from Wuhan. The median age was 45 years and 73 (53.7%) were men. The most common symptoms at onset were fever (104 [76.5%]) and cough (85[62.5%]). Pleural effusion was more common among imported cases compared to local cases. The white blood cell count, neutrophil count, lymphocyte count and platelet count of the imported cases were significantly lower than those of the local cases, while the prothrombin time was significantly longer than that of the local cases. Severe and critically ill patients accounted for 15.4% and 2.9%, respectively. The median duration of SARS-CoV-2 RNA shedding from symptom onset was 26 days (IQR 17–32.3 days) and there were no significant differences in duration of viral RNA shedding between the two groups.The study findings suggest that imported cases from Wuhan were more likely to be severe compared to the local cases in Wenzhou. However, there was no difference between imported and local cases on the viral shedding among the COVID patients.  相似文献   
966.
Wang  Shaofan  Chen  Duqun  Zuo  Ke  Xu  Feng  Hu  Weixin 《Clinical rheumatology》2022,41(2):429-436
Clinical Rheumatology - This study aimed to explore the long-term outcomes of mesangial proliferative lupus nephritis (LN class II) and the factors associated with its relapse and histological...  相似文献   
967.
He  Xuxia  Wen  Yubing  Hu  Rongrong  Wu  Haiting  Ye  Wei  Yue  Cai  Qin  Yan  Xia  Peng  Chen  Limeng 《Clinical rheumatology》2022,41(11):3551-3563
Clinical Rheumatology - The typical nephrological presentation of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) is rapidly progressive glomerulonephritis....  相似文献   
968.
Wang  Fan  Zhou  Zhuochao  Teng  Jialin  Sun  Yue  You  Yijun  Su  Yutong  Hu  Qiongyi  Liu  Honglei  Cheng  Xiaobing  Shi  Hui  Yang  Chengde  Ye  Junna 《Clinical rheumatology》2022,41(11):3439-3449
Clinical Rheumatology - Patients with infective endocarditis (IE) may present rheumatic manifestations concurrent with various autoantibodies and thus mimic antineutrophil cytoplasmic antibody...  相似文献   
969.
Chain‐end‐functionalized polyethylenes (Cef‐PEs: PE? S? SH (Cef1), PE? S? furfuryl (Cef2), PE? S? NH2 (Cef4), PE? S? NH2?HCl (Cef5), PE? S? COONa (Cef6), PE? S? CHA(Cef7), PE? S? SO3Na (Cef8), PE? S? OH (Cef9) and PE? S? COOH (Cef10)) are synthesized by thiol‐ene addition of vinyl‐terminated polyethylene (v‐PE) with 1,2‐ethanedithiol, furfurylmercaptan, cysteamine, cysteamine hydrochloride, sodium thioglycolate, L‐cysteine hydrochloride, sodium 2‐mercaptoethanesulfonate, mercaptoethanol, and thioglycolic acid, respectively. PE? S? t? NCO (Cef3) is obtained by subsequent reaction of Cef9 with anhydrous 4,4′‐MDI. Cef‐PE1–8 are reported for the first time. The conversions of all the reactions are up to 95%–100%. All the Cef‐PEs are characterized by NMR, GPC, DSC, FT‐IR, and TGA. In the experiments, it is found that alkaline mercaptans and solvents are adverse to the thiol‐ene click reactions.

  相似文献   

970.
Inhibition of mouse hepatocyte apoptosis via anti-Fas ribozyme   总被引:3,自引:0,他引:3  
AIM: To investigate the effects of anti-Fas ribozyme on Fas expression and apoptosis in primary cultured mouse hepatocytes. METHODS: Mouse hepatocytes were isolated by using collagenase irrigation. A hammerhead ribozyme targeting the Fas mRNA was constructed, and transfected into mouse hepatocytes via Effectene. Then Fas expression in mouse hepatocytes was detected by RT-PCR and western blotting. After being treated with anti-Fas antibody (JO2), hepatocytes viability was measured with MTT assay. Caspase-3 proteolytic activity was detected, and cell apoptosis was measured according to Annexin V-FITC apoptosis detection kit. RESULTS: Fas expressed in primary mouse hepatocytes. Fas expression in hepatocytes transfected with anti-Fas ribozyme was decreased remarkably and correlated with the resistance to Fas-mediated apoptosis as determined by flow cytometry and caspase-3 proteolytic activity. CONCLUSION: Anti-Fas ribozyme can remarkably decrease the Fas expression in mouse hepatocytes, thus inhibit Fas-mediated apoptosis in hepatocytes. It is suggested that anti-Fas ribozyme could significantly increase the resistance of transplanted hepatocytes to apoptosis and improve the survival of transplanted hepatocytes.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号