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   22156篇
  免费   2180篇
  国内免费   1886篇
耳鼻咽喉   156篇
儿科学   178篇
妇产科学   279篇
基础医学   2827篇
口腔科学   242篇
临床医学   3105篇
内科学   3164篇
皮肤病学   194篇
神经病学   1287篇
特种医学   866篇
外国民族医学   13篇
外科学   2096篇
综合类   3745篇
现状与发展   5篇
一般理论   1篇
预防医学   1504篇
眼科学   656篇
药学   2542篇
  32篇
中国医学   1540篇
肿瘤学   1790篇
  2024年   75篇
  2023年   401篇
  2022年   985篇
  2021年   1224篇
  2020年   975篇
  2019年   743篇
  2018年   769篇
  2017年   765篇
  2016年   720篇
  2015年   1086篇
  2014年   1351篇
  2013年   1144篇
  2012年   1596篇
  2011年   1916篇
  2010年   1174篇
  2009年   993篇
  2008年   1174篇
  2007年   1153篇
  2006年   1140篇
  2005年   1155篇
  2004年   733篇
  2003年   710篇
  2002年   570篇
  2001年   492篇
  2000年   518篇
  1999年   534篇
  1998年   314篇
  1997年   326篇
  1996年   248篇
  1995年   248篇
  1994年   207篇
  1993年   123篇
  1992年   134篇
  1991年   93篇
  1990年   95篇
  1989年   80篇
  1988年   70篇
  1987年   69篇
  1986年   56篇
  1985年   27篇
  1984年   9篇
  1983年   8篇
  1982年   7篇
  1981年   5篇
  1980年   2篇
  1979年   5篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
目的:观察原发性高血压患者红细胞[Ca^2 ]i,多巴胺β羟化酶及ATP含量变化并分析其结果。方法:测定35例高血压患者的红细[Ca^2 ]i、ATP、血清多巴胺β羟化酶活性,血糖及血浆胰岛素含量,并以30例健康成年人为对照。结果:高血压患者的红细胞[Ca^2 ]i、ATP、多巴胺β羟化酶均明显高于对照组(P<0.05,P<0.01),但血糖与胰岛素未见明显变化。结论:高血压患者血清多巴胺β羟化酶活性增强伴随ATP与[Ca^2 ]i升高。  相似文献   
32.
Erectile dysfunction is considered an important health problem that impacts the quality of life of men. Yinyanghuo, also called Epimedium or Horny Goat Weed, is a frequently used Chinese traditional herbal medicine, commonly used in treating erectile dysfunction in China. A network pharmacology method was performed systematically, at a molecular level, to analyse the pharmacological mechanism of Yinyanghuo as erectile dysfunction therapy. The network pharmacology method used in this study primarily includes prescreening of the active compounds, prediction of targets, network analysis and gene enrichment analysis. This network analysis proved that 4 targets (AR, NR3C2, PDE5A and BMP2) could be the targets of Yinyanghuo therapy on erectile dysfunction. Besides, gene enrichment analysis predicted that Yinyanghuo might have a role in erectile dysfunction by regulating 10 molecular functions, 8 cellular components, 10 biological processes and 36 possible targets related to 10 signalling pathways. Our study demonstrated the molecular and pharmacological mechanisms of Yinyanghuo against erectile dysfunction with a holistic approach and demonstrated a powerful method for analysing pharmacological mechanisms and rational utilisation of Traditional Chinese Medicine clinically.  相似文献   
33.
The blood–testis barrier (BTB) of Sertoli cells (SCs) is an important biological barrier that maintains spermatogenesis and provides a favourable microenvironment for spermatogenesis. However, heat stress can directly damage the BTB structural proteins of testicular SCs, leading to dyszoospermia. Wuzi Yanzong Pills (WYP) is a traditional Chinese medicine formula used to treat male reproductive diseases. However, whether WYP could ameliorate heat stress injury in primary SCs extracted from rat testes and BTB proteins remains unknown. Here, treatment with WYP (low, medium and high dose) increased the SC viability and the proliferation of cell antigen Ki67 significantly. Additionally, it promoted SC maturation, which presented in the form of increased androgen receptors (ARs) and decreased cytokeratin 18 (CK-18) in three WYP dose groups. WYP upregulated BTB proteins such as zonula occludens 1 (ZO-1) and occludin across all WYP groups and decreased phosphorylated Akt (p-Akt) in the middle and high-dose groups; however, ZO-1 and occludin recovery were reduced with the presence of Akt inhibitor in WYP groups. WYP improved SC viability and proliferation, and ameliorated dedifferentiation and BTB-proteins damaged by heat stress via Akt signalling. The findings present theoretical support for the effects of WYP in the management of dyszoospermia and male infertility.  相似文献   
34.
35.
ObjectivesTo investigate the effect and mechanism of macrophage activation and graft damage caused by nucleoside triphosphate diphosphohydrolase 1 (NTPDase1) in acute antibody-mediated rejection (AMR).MethodsAcute AMR was induced in different skin-grafted nude mouse models with wild-type NTPDase1 expression, transgene-enhanced NTPDase1 expression, or NTPDase1 gene knockout. Several methods (eg, real-time fluorescence quantitative polymerase chain reaction, high-performance liquid chromatography [HPLC], immunofluorescence, flow cytometry, and luciferin/luciferase assays) were used to study (at the histologic and molecular levels) the extracellular adenosine diphosphate (ADP) concentration, macrophage proliferation, major histocompatibility complex (MHC) class II antigen expression on the surface of macrophages, B-cell activating factor (BAFF) expression in the peripheral blood serum, and the total number of SmIg-positive B cells during acute AMR. The relative activity of NTPDase1 in B cells and epithelial cells, pathologic changes, and the incidence of positive C4d deposition around the capillaries of skin grafts on the different nude mice were studied.ResultsMacrophages proliferated significantly when acute AMR occurred. The higher the NTPDase1 expression level, the lower the extracellular ADP concentration, the expression of MHC class II antigens on the surface of macrophages, the expression of BAFF in the peripheral blood serum, and the total number of SmIg-positive B cells, indicating negative correlations. The relative activity of NTPDase1 in B cells and epithelial cells of the skin graft was different among the different mice. The higher the NTPDase1 expression level, the lower the degree of pathologic damage to the skin graft.ConclusionsImbalance in extracellular ADP degradation by NTPDase1 may promote macrophage activation, and activated macrophages may be an important cause of graft damage.  相似文献   
36.
PurposeTo investigate the clinical characteristics, chemosensitivity, and outcome of metastatic upper tract urothelial carcinoma (UTUC).Patients and MethodsRecords of patients with metastatic UTUC since January 2005 were retrieved from a database that included clinical and survival data. Statistical analyses including survival and multivariate analyses of factors were respectively performed by the Kaplan-Meier method and Cox proportional hazard model.ResultsA total of 250 consecutive UTUC cases were evaluated. There were 56 patients (22.4%) with initially diagnosed stage IV disease. The most common metastatic sites were lung (39.6%), distant lymph nodes (39.2%), bone (19.6%), liver (18.0%), and adrenal gland (7.2%), respectively, and the local recurrence rate was 10.4%. Two hundred thirteen patients received first-line chemotherapy. The overall response rate was only 28.7% and the median progression-free survival time was only 5.0 months. The overall survival time of the cohort was 18.0 months. Multivariate analyses showed that initially diagnosed stage IV disease, number of metastatic organs ≥3, no response to chemotherapy and cycles of chemotherapy ≤2 were adverse prognosticators for overall survival.ConclusionUTUC presented to be more prone to metastasize than locally recur and thought to have low chemosensitivity. Stage IV disease at initial diagnosis, number of metastatic organs, response and cycles of chemotherapy were independent prognosticators for metastatic UTUC.  相似文献   
37.
38.
39.
王德光主任医师对许多较难治愈的体温升高的发热,用秦艽鳖甲散加减治疗,在临床上收到了良好的效果,文中列举两则病例以资说明。据王老经验,此方对发热者体温升高,日久不降;或发热者曾用抗菌素、激素、清热解毒类中药而无效;或者外感热病,呈现壮热骨蒸均可获效。  相似文献   
40.
Zhang Z  Jia Z  Zhu Z  Cui Y  Cheng J  Wang Q 《Planta medica》1990,56(3):293-294
Two new taxane diterpenes, decinnamoyltaxagifine ( 3) and decinnanioyltaxagifine acetate ( 2), have been isolated from the leaves and stems of TAXUS CHINENSIS. Their structures were elucidated by spectroscopic methods. Their (13)C-NMR chemical shifts were assigned.  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