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   62119篇
  免费   5816篇
  国内免费   3469篇
耳鼻咽喉   512篇
儿科学   941篇
妇产科学   1013篇
基础医学   7132篇
口腔科学   1100篇
临床医学   7272篇
内科学   10134篇
皮肤病学   784篇
神经病学   2932篇
特种医学   2821篇
外国民族医学   34篇
外科学   7377篇
综合类   9086篇
现状与发展   15篇
一般理论   16篇
预防医学   4003篇
眼科学   1490篇
药学   6565篇
  52篇
中国医学   3080篇
肿瘤学   5045篇
  2024年   176篇
  2023年   846篇
  2022年   2082篇
  2021年   2864篇
  2020年   2074篇
  2019年   1896篇
  2018年   2048篇
  2017年   1809篇
  2016年   1802篇
  2015年   2506篇
  2014年   3168篇
  2013年   3210篇
  2012年   4468篇
  2011年   4735篇
  2010年   3101篇
  2009年   2567篇
  2008年   3380篇
  2007年   3474篇
  2006年   3194篇
  2005年   2978篇
  2004年   2401篇
  2003年   2219篇
  2002年   2015篇
  2001年   1679篇
  2000年   1610篇
  1999年   1458篇
  1998年   844篇
  1997年   860篇
  1996年   730篇
  1995年   591篇
  1994年   520篇
  1993年   365篇
  1992年   522篇
  1991年   427篇
  1990年   408篇
  1989年   381篇
  1988年   310篇
  1987年   294篇
  1986年   249篇
  1985年   200篇
  1984年   125篇
  1983年   98篇
  1982年   73篇
  1981年   82篇
  1980年   50篇
  1979年   80篇
  1978年   49篇
  1976年   41篇
  1975年   40篇
  1972年   41篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
以辣根过氧化物酶(PO)和抗-PO作为免疫沉淀中的抗原和抗体,用光电比色法,对78例小儿肾脏疾病血清补体对免疫沉淀的抑制作用(IIPC)进行了研究,并同时检测补体成分C3、C4。结果,正常对照IIPCOD值为0.505±0.085,急性肾小球肾炎(0.137±0.108)显著降低(P<0.001);慢性肾小球肾炎(0.470±0.053)改变不明显(P>0.05);肾病综合征(0.401±0.038)明显低下(P<0.05)。IIPC低下的发生率依次为急性肾小球肾炎(83%)、肾病综合征(43%)、慢性肾小球肾炎(32%)。表明小儿肾小球疾病时IIPC大多降低并与疾病的活动性有关。因此认为IIPC低下在肾脏病的发生和发展中起一定作用。  相似文献   
122.
123.
124.
1. The effects of A02011-1, a pyrazole derivative, on the proliferation of rat vascular smooth muscle cells (VSMCs) were examined. 2. A02011-1 (1-100 microM) concentration-dependently inhibited [3H]-thymidine incorporation into DNA in rat VSMCs that were synchronized by 48 h serum depletion and then re-stimulated by addition of foetal calf serum (FCS, 10%), platelet-derived growth factor (PDGF, 10 ng ml-1), 5-hydroxytryptamine (10 microM) or ADP (10 microM). The inhibitory effect of A02011-1 was fully reversible. However, FCS-induced [3H]-thymidine incorporation into rat endothelial cells was unaffected by A02011-1. 3. The concentration of A02011-1 necessary for inhibition of the FCS-induced proliferation was similar to that necessary for adenosine 3':5'-cyclic monophosphate (cyclic AMP) formation. Adenylyl cyclase activity was increased in A02011-1-treated VSMCs, whereas cyclic AMP-specific phosphodiesterase activity was unchanged. 4. A02011-1 was equipotent with forskolin but was more potent than 8-bromo-cyclic AMP against FCS (10%)-induced proliferation. 5. The antiproliferative action of A02011-1 was mimicked by 8-bromo-cyclic AMP, a membrane-permeable cyclic AMP analogue and was antagonized by 2',5'-dideoxyadenosine, an adenylyl cyclase inhibitor and by Rp-cyclic AMPS, a competitive inhibitor of cyclic AMP-dependent protein kinase (PKA) type I and II. 3-Isobutyl-1-methylxanthine (IBMX) caused significant potentiation of the antiproliferative activity of A02011-1. However, Rp-8-bromo-cyclic GMPS and staurosporine did not affect the antiproliferative activity of A02011-1.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
125.
爱婴医院的文化氛围与爱婴医院的建立和发展密切相关。为搞好爱婴医院文化建设与管理,促进母乳喂养,本文对近几年发展起来的爱婴医院文化的构成、功能、特征和今后发展的标准进行了讨论。  相似文献   
126.
Laparoscopic nephrectomy was performed in 15 male pigs, the procedure was successful in 14. Extraction of the intact kidney through a 5-cm lower abdomen incision was done in 7 animals; complete destruction and evacuation of the kidney was accomplished by a round-knife suction device through a 1-cm port in another 7 pigs. Grossly, the specimen consisted of sausage-like tubular renal tissue and a small amount of tissue debris. Pathology revealed that the glomerular and tubular structures were well preserved, no interstitial hematoma could be found. Four ports were usually used, one 1-cm umbilical camera port, one 0.5-cm port for ureter traction, and two 1-cm working ports along the midclavicular line. All the pigs recovered uneventfully. The average operation time was 3 h 20 min. The application of endo-GIA (United States Surgical Corporation) for renal hilum reduced the operative time to 2 h 20 min. Complications included renal vein tear during endoclip application and cutting in the first case, mild subcutaneous emphysema in 2 cases. This first pig received exploratory laparotomy for the repair and ligation of the renal vein. No more major complications occurred with increasing experience. From this porcine experiment, we conclude that the combination of laparoscopy, a tissue destroyer and an endobag for the entrapment of kidney seem to be a promising technique for clinical nephrectomy.  相似文献   
127.
目的研究杜氏/贝氏进行性肌营养不良(DMD/BMD)携带者视网膜眼电图(ERG)的改变,探讨ERG对DMD/BMD携带者的诊断意义。方法对22个基因突变类型明确的DMD/BMD家系.用定量PCR法结合系谱分析将家系中女性成员分成肯定携带者和非携带者,对患者和家系女性成员进行详细的眼科检查和ERG检测,并用ERG国际测量标准记录结果。结果22名患者中17名出现异常ERG改变;11名肯定携带者中5名出现ERG异常,14名非携带者无ERG改变,两组无重叠。结论ERG是一项对DMD/BMD诊断非常敏感和特异的检查,而ERG对携带者的诊断也具有一定的临床意义。  相似文献   
128.
SARS家庭聚集型病例8例报告分析   总被引:1,自引:0,他引:1  
SARS是由变异冠状病毒引起的新型烈性传染病,具有在家庭和医院内聚集发病的特点。其影像学表现对于临床诊断和随诊观察具有重要价值。本文报告了分属3个家庭的8个病例发病早期(1周)影像学表现(包括胸部平片和CT)和部分临床表现资料,讨论并分析SARS早期影像学表现的若干特点及与临床表现之间的关系。  相似文献   
129.
Nuclear factor-kappaB (NF-kappaB) plays a key role in inflammation, which is involved in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). In the present study, we assessed the potential role of NF-kappaB in regulation of cerebral vasospasm. Nuclear factor-kappaB DNA-binding activity was measured in cultured vascular smooth muscle cells (VSMCs) treated with hemolysate and pyrrolidine dithiocarbamate (PDTC, 80 micromol/L), an inhibitor of NF-kappaB. Forty-two rabbits were divided into three groups: control, SAH, and PDTC groups (n=14 for each group). The caliber of the basilar artery was evaluated. Nuclear factor-kappaB DNA-binding activity and the gene expression levels of cytokines and adhesion molecules in the basilar artery were measured. Immunohistochemical study was performed to assess the expression and localization of tumor necrosis factor (TNF)-alpha, intercellular adhesion molecule (ICAM)-1, and myeloperoxidase (MPO). It was observed that NF-kappaB DNA-binding activity was significantly increased by treatment with hemolysate in cultured VSCMs, but this increase was suppressed by pretreatment with PDTC. Severe vasospasm was observed in the SAH group, which was attenuated in the PDTC group. Subarachnoid hemorrhage could induce increases of NF-kappaB DNA-binding activity and the gene expression levels of TNF-alpha, interleukin (IL)-1 beta, ICAM-1, and vascular cell adhesion molecule (VCAM)-1, which were reduced in the PDTC group. Immunohistochemical study demonstrated that the expression levels of TNF-alpha, ICAM-1, and MPO were all increased in the SAH group, but these increases were attenuated in the PDTC group. Our results suggest that NF-kappaB is activated in the arterial wall after SAH, which potentially leads to vasospasm development through induction of inflammatory response.  相似文献   
130.
Parkinson's disease (PD) is a major cause of disability. To date, there have been no large-scale efforts to measure the quality of PD care because of a lack of quality indicators for conducting an explicit review of PD care processes. We present a set of quality indicators for PD care. Based on a structured review of the medical literature, 79 potential indicators were drafted. Through a two-round modified Delphi process, an expert panel of seven movement disorders specialists rated each indicator on criteria of validity, feasibility, impact on outcomes, room for improvement, and overall utility. Seventy-one quality indicators met validity and feasibility thresholds. Applying thresholds for impact on outcomes, room for improvement, and overall utility, a subset of 29 indicators was identified, spanning dopaminergic therapy, assessment of functional status, assessment and treatment of depression, coordination of care, and medication use. Multivariable analysis showed that overall utility ratings were driven by validity and impact on outcomes (P < 0.01). An expert panel can reach consensus on a set of highly rated quality indicators for PD care, which can be used to assess quality of PD care and guide the design of quality improvement projects.  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