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   40450篇
  免费   4433篇
  国内免费   2981篇
耳鼻咽喉   370篇
儿科学   736篇
妇产科学   438篇
基础医学   3957篇
口腔科学   908篇
临床医学   5451篇
内科学   5191篇
皮肤病学   383篇
神经病学   1506篇
特种医学   1438篇
外国民族医学   10篇
外科学   3300篇
综合类   8583篇
现状与发展   11篇
一般理论   1篇
预防医学   3771篇
眼科学   1086篇
药学   4742篇
  57篇
中国医学   2889篇
肿瘤学   3036篇
  2024年   220篇
  2023年   781篇
  2022年   2064篇
  2021年   2474篇
  2020年   2097篇
  2019年   1407篇
  2018年   1443篇
  2017年   1440篇
  2016年   1302篇
  2015年   2094篇
  2014年   2463篇
  2013年   2443篇
  2012年   3421篇
  2011年   3504篇
  2010年   2502篇
  2009年   2013篇
  2008年   2173篇
  2007年   2147篇
  2006年   2004篇
  2005年   1811篇
  2004年   1148篇
  2003年   1034篇
  2002年   798篇
  2001年   681篇
  2000年   650篇
  1999年   691篇
  1998年   422篇
  1997年   427篇
  1996年   306篇
  1995年   319篇
  1994年   247篇
  1993年   154篇
  1992年   160篇
  1991年   188篇
  1990年   142篇
  1989年   130篇
  1988年   98篇
  1987年   93篇
  1986年   85篇
  1985年   53篇
  1984年   38篇
  1983年   34篇
  1982年   24篇
  1981年   13篇
  1980年   17篇
  1979年   18篇
  1976年   8篇
  1841年   7篇
  1840年   13篇
  1838年   8篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
髌骨关节面的应用解剖学研究   总被引:2,自引:0,他引:2  
本文利用150例髌骨(干燥髌骨100例,福尔马林固定膝关节内的髌骨50例)观测了髌骨关节面和关节软骨的形态及其与股骨内外侧髁关节面在屈膝0~135度范围的对应关系。结果发现中间纵嵴向后突起并由下向上逐渐变凸占100%;内侧纵嵴明显突起者占62%,此时其髌骨内侧部关节面与股骨关节面之间的间隙较大;在膝关节屈曲过程申两关节面接触的顺序为髌骨关节面自下而上、股骨内外侧关节面从前向后相对滑动,伸膝时则相反;髌骨关节面的表面积为1019±20(650~1540)mm~2。并讨论了髌骨关节面的解剖学特点及其临床意义。  相似文献   
13.
OBJECTIVE: To investigate the feasibility of intracoronary application of endothelial progenitor cells and the subsequent distribution within the heart. METHODS: Endothelial progenitors cells (EPCs) cultured from rat bone marrow were identified by double-positive staining with Dil-Ac-LDL and BS1-lectin. Twenty-four hours before cell transplantation, EPCs were labeled with 5-bromo-2'-deoxyuridine (BrdU). Cells (5 x 10(5) in 250-microl medium) were injected into healthy rats, either as intracoronary application (n=11) or as intramyocardial injection (n = 6). At 15 min or 3 days posttransplantation, hearts as well as other organs (lung, liver, kidney, and spleen) were collected and processed for subsequent BrdU immunohistochemistry. The number of BrdU-positive cells per tissue area was counted. RESULTS: Compared to intramyocardial injection, intracoronary administration resulted in more than twice as much positive cells in the heart (P < .05), with no local differences within the heart. Whereas after 15 min, EPCs were equally distributed in all examined organs (except for the spleen), cells that were still present after 3 days, approximately 10%, were selectively restricted to the heart. CONCLUSIONS: Our data indicate that the intracoronary application provides a promising technique for EPC transplantation in the rat heart.  相似文献   
14.
Summary: Purpose: We wished to determine the effect of renal impairment on the pharmacokinetics and tolerability of the new antiepileptic drug tiagabine (TGB).
Methods: We assessed TGB pharmacokinetics and tolerability in 25 subjects with various degrees of renal function (based on creatinine clearance, n = 4–6 per group) from healthy (group I) to requiring hemodialysis (group V) in a single and multiple dose (every 12h), one-period (groups I-IV) or a single dose, two-period (group V) study (4-mg oral doses of TGB · HCl). Blood samples were collected after the first dose (both periods for group V) and after the last dose on day 5 (groups I-IV). TGB plasma concentrations and plasma protein binding were determined by high-performance liquid chromatography (HPLC) and ultrafiltration, respectively.
Results: TGB was well tolerated by all study subjects. The pharmacokinetics of TGB were similar in all subjects; no pharmacokinetic parameter (based on either total or unbound concentrations) was statistically correlated with creatinine clearance. For total TGB in plasma, single-dose mean values of the maximum plasma concentration, clearance, and half-life (t1/2) ranged from 52 to 108 ng/ml, from 7.14 to 11.02 I/h, and from 6.4 to 8.4 h, respectively.
Conclusions: TGB pharmacokinetics and tolerability were independent of renal function; therefore, dosage adjustment is unnecessary for epilepsy patients with renal impairment.  相似文献   
15.
分析了60例垂体腺瘤的CT表现。1例垂体微腺瘤缺乏特异性征象,59例大腺瘤大多数表现典型,诊断依据为肿瘤位置和蝶鞍改变。垂体腺瘤的形态学表现无特异性。应加强对垂体瘤卒中和侵袭征象的认识。对成人鞍区肿瘤的鉴别诊断进行了简短讨论。  相似文献   
16.
Y Q Yang  J X Wu  J X Qian 《中国中药杂志》1989,14(5):259-61, 270, 317
Our study reveals that the earliest historical records of Sheng Mai Powder are found in "Yixue qiyuan" ("Origins of Medicine"), a medical book written by Zhang Yuansu and published in the beginning of 1186, 45 years earlier than the latest edition of "Neiwai shangbian huolun" ("Treaties on the identification of Internal Diseases and External Damages"), written by Li Gao in 1231. The study also suggests that the assertion of Sheng Mai Powder to be inaugurated by Sun Simiao is groundless.  相似文献   
17.
The aim of this study is to develop a technical quality evaluation system of electroencephalogram (EEG) recording in order to acquire technically satisfactory EEG records, which may contribute to the accuracy improvement of EEG interpretation. In our developed system, the evaluation of EEG recording comprises the detection of technical artifacts and physiological status, which indicates the recording status objectively. In addition, the caution signals to users are generated in the system according to the undesired status detected. The information displayed to users includes the updated EEG records and instant evaluation results. Two examples of evaluation results are introduced in this paper, illustrating unsatisfactory records and artifact free records, respectively. The experimental results are proposed to verify the effectiveness of the technical quality evaluation of EEG recording. The implementation of the technical quality evaluation of EEG recording is helpful to acquire technically satisfactory EEG records, which may improve the accuracy of results in both the visual and the automatic EEG interpretation, and ease the laborious work of EEG technicians in the recording progress.  相似文献   
18.
系统观察57例健康人口服灵芝(灵芝多糖体55mg/片)前后甲襞微循环的变化。结果显示:服药前后大、小动脉血压无显著变化;口服灵芝3天后输入枝口径及输出枝口径均有明显扩张;管袢密度、红细胞流速增加不显著。口服灵芝7天的动态变化显示,服药8h后输入枝、输出枝口径即有显著扩张,第7天管袢密度开始明显增加。服用不同剂量灵芝(2片、4片、8片,3次/日)3h后,管袢密度、输入枝、输出枝口径、流速均有增加趋向,但P>0.05,其中8片组管袢口径、管袢密度有显著增加(P<0.05),但红细胞流速却有显著下降(P<0.05)。结果提示:连续、适量(2片,3次~4次/日)服用灵芝,可显著改善微循环灌流量,从而改善和保护组织及脏器功能。  相似文献   
19.
20.
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