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   30441篇
  免费   2986篇
  国内免费   49篇
耳鼻咽喉   504篇
儿科学   923篇
妇产科学   729篇
基础医学   3680篇
口腔科学   971篇
临床医学   3986篇
内科学   5151篇
皮肤病学   399篇
神经病学   2500篇
特种医学   1075篇
外科学   5028篇
综合类   995篇
一般理论   20篇
预防医学   2981篇
眼科学   846篇
药学   2141篇
中国医学   26篇
肿瘤学   1521篇
  2022年   194篇
  2021年   460篇
  2020年   354篇
  2019年   436篇
  2018年   656篇
  2017年   511篇
  2016年   581篇
  2015年   602篇
  2014年   912篇
  2013年   1238篇
  2012年   1470篇
  2011年   1601篇
  2010年   1079篇
  2009年   1051篇
  2008年   1496篇
  2007年   1547篇
  2006年   1572篇
  2005年   1381篇
  2004年   1320篇
  2003年   1248篇
  2002年   1175篇
  2001年   803篇
  2000年   762篇
  1999年   645篇
  1998年   438篇
  1997年   368篇
  1996年   366篇
  1995年   354篇
  1994年   321篇
  1993年   344篇
  1992年   571篇
  1991年   516篇
  1990年   490篇
  1989年   516篇
  1988年   512篇
  1987年   384篇
  1986年   419篇
  1985年   430篇
  1984年   317篇
  1983年   250篇
  1982年   201篇
  1981年   190篇
  1979年   235篇
  1978年   211篇
  1977年   211篇
  1976年   186篇
  1975年   180篇
  1974年   184篇
  1973年   191篇
  1972年   176篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
SUMMARY A case congenital dislocation of both knees and dislocation of the left hip in an infant whose mother had a chronic amniotic fluid leakage after mid-trimester amniocentesis.  相似文献   
53.
54.
Three hundred and forty-nine methicillin resistant Staphylococcus aureus (MRSA) isolates from veterans were tested (by disc agar diffusion) for their in vitro activity against 18 antimicrobial agents. At least 90% of the isolates were susceptible to bacitracin, nitrofurantoin, hydrogen peroxide, novobiocin, netilmicin and vancomycin. We feel that the aminoglycoside, netilmicin, might provide an alternative agent (to intravenously administered vancomycin) for treating multiply-antimicrobial resistant MRSA. In addition, hydrogen peroxide exhibited very good activity against the test isolates and may have some use as a topical agent for reduction of MRSA on skin and some mucous membranes. This study suggests that further evaluation of netilmicin and hydrogen peroxide (topical only) might be useful.  相似文献   
55.
Clozapine plasma levels were monitored in 16 patients during a series of three consecutive treatments (single dose-multiple dose-single dose). Each patient received a single 75-mg dose (3 x 25 mg) with clozapine tablets, and serial plasma samples were collected over 48 hr after the dose. At 48 hr, a multiple-dose regimen was started, consisting of an initial dose escalation period followed by dosing at a constant regimen for at least 6 days. After the last dose, serial plasma samples were again obtained over 72 hr. Drug was then withheld for at least 7 days, a final single 75-mg dose was given, and plasma sampling was repeated. A subset of the patient population (N = 7) was used to test for a food effect during the single-dose treatments. The pharmacokinetic parameters between the initial and the final single dose periods were not significantly different. Similarly, there were no differences within patients when given the dose after fasting (fed 1 hr after dose) or with a meal. In contrast, the terminal elimination rate differed between the single-dose and the multiple-dose treatments (t1/2 m3 = 7.9 hr single dose and 14.2 hr multiple dose) (P less than 0.05) and the dose-normalized area under the plasma concentration/time curves increased 27% with multiple dosing. Since a previous study in patients (Choc et al., Pharm. Res. 4:402-405, 1987) showed dose proportionality of clozapine plasma concentrations during multiple-dose regimens, the present results cannot be described by Michaelis-Menten kinetics.  相似文献   
56.
57.
Cell cycling in bladder carcinoma determined by monoclonal antibody Ki67   总被引:4,自引:0,他引:4  
Current methods of predicting prognosis in transitional cell carcinoma of the bladder fail to provide consistently reliable information about future tumour behaviour. The monoclonal antibody Ki67 recognises an antigen present in actively dividing cells and Ki67 reactivity has been shown to correlate with conventional prognostic indicators in several tumours. In this study, Ki67 antibody was used to determine the proportions of cells undergoing active division in 26 transitional cell carcinomas of the bladder. The proportion of cells stained in muscle invasive tumours (12.3 +/- 5.4%) was significantly greater than in superficial tumours (4.3 +/- 1.9%) and poorly differentiated tumours showed significantly greater proportions of cells staining compared with well or moderately well differentiated tumours. These results show that Ki67 reactivity correlates with high tumour stage and poor differentiation. Ki67 staining provides an easy method of determining tumour cell turnover that might provide additional prognostic information.  相似文献   
58.
59.
60.
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