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   3221篇
  免费   226篇
  国内免费   152篇
耳鼻咽喉   28篇
儿科学   106篇
妇产科学   21篇
基础医学   449篇
口腔科学   39篇
临床医学   375篇
内科学   712篇
皮肤病学   48篇
神经病学   158篇
特种医学   422篇
外科学   460篇
综合类   75篇
一般理论   1篇
预防医学   186篇
眼科学   31篇
药学   226篇
  1篇
肿瘤学   261篇
  2021年   40篇
  2019年   31篇
  2018年   44篇
  2017年   31篇
  2016年   35篇
  2015年   35篇
  2014年   59篇
  2013年   90篇
  2012年   104篇
  2011年   126篇
  2010年   94篇
  2009年   97篇
  2008年   108篇
  2007年   197篇
  2006年   122篇
  2005年   119篇
  2004年   93篇
  2003年   93篇
  2002年   80篇
  2001年   103篇
  2000年   75篇
  1999年   77篇
  1998年   107篇
  1997年   99篇
  1996年   96篇
  1995年   75篇
  1994年   56篇
  1993年   70篇
  1992年   53篇
  1991年   68篇
  1990年   59篇
  1989年   99篇
  1988年   70篇
  1987年   79篇
  1986年   57篇
  1985年   66篇
  1984年   52篇
  1983年   44篇
  1982年   50篇
  1981年   31篇
  1980年   32篇
  1979年   51篇
  1978年   29篇
  1977年   37篇
  1976年   52篇
  1975年   32篇
  1974年   30篇
  1973年   30篇
  1972年   27篇
  1970年   28篇
排序方式: 共有3599条查询结果,搜索用时 15 毫秒
1.
BACKGROUND: Clinical practice guidelines recommend that the preferred method of surveillance for arteriovenous fistula (AVF) is the measurement of AVF blood flow (Qa). As these recommendations are based on observational studies, we conducted a randomized, prospective, double-blind, controlled trial to assess whether Qa surveillance results in an increased detection of AVF stenosis. METHODS: A total of 137 patients were randomly assigned to receive either continuing AVF surveillance using current clinical criteria (control, usual treatment) or usual treatment plus AVF blood-flow surveillance by ultrasound dilution (Qa surveillance group). The primary outcome measure was the detection of a significant (>50%) AVF stenosis. RESULTS: There were 67 and 68 patients assigned to the control and Qa surveillance groups, respectively. Patients in the Qa surveillance group were twice as likely to have a stenosis detected compared with the control hazard ratio (HR) confidence interval (CI) group (2.27, 95% 0.85-5.98, P = 0.09), with a trend for a significant stenosis to be detected earlier in the Qa surveillance group (P = 0.09, log rank test). However, using the Qa results alone prior to angiography, the area under the receiver operating characteristic curve demonstrated, at best, a moderate prediction of (>50%) AVF stenosis (0.78, 95% CI 0.63-0.94, P = 0.006). CONCLUSION: This study demonstrates that the addition of AVF Qa monitoring to clinical screening for AVF stenosis resulted in a non-significant doubling in the detection of angiographically significant AVF stenosis. Further, large multi-centre randomized trials are feasible and will be necessary to confirm whether Qa surveillance and the correction of detected AVF stenosis will lead to a reduction in AVF thrombosis and increased AVF survival.  相似文献   
2.
高效液相色谱法测定人血浆中阿莫西林浓度及药代动力学   总被引:6,自引:0,他引:6  
谭力  周继红  罗楠  袁倚盛 《药学学报》1997,32(7):558-560
高效液相色谱法测定人血浆中阿莫西林浓度及药代动力学谭力周继红罗楠袁倚盛(南京军区南京总医院中心仪器分析科,南京210001)阿莫西林(amoxicilin)为β内酰胺类抗生素,其抗菌谱广,口服受食物影响小,对大多数病人耐受性良好,因而在临床上得以广泛...  相似文献   
3.
Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m2 as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m2×2 doses of ara-C and 50 mg/m2 of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182  相似文献   
4.
Extramarital involvement (EMI) occurs with high prevalence among couples in clinical and community settings, frequently resulting in considerable distress both to participants and their spouses. The field lacks a synthesized review of this literature. Without such a synthesis, it has been difficult for researchers and clinicians to have an understanding of what is and is not known about EMI. This article reviews the large and scattered EMI literature using a framework that encompasses multiple source domains across the temporal process of engaging in and responding to EMI. In addition, this review delineates conceptual and methodological limitations to previous work in this area and articulates directions for further research.  相似文献   
5.
6.
The importance of certain positive crossmatches (CM+) in kidney transplantation remains controversial. Fifty consecutive kidney transplants were performed across a CM+ between Jan. 1990 – April 1994. In 19 cases there was an isolated B-cell CM+ (Group I), in 24 an historic T-cell IgM CM+ (Group II) and in 7 an historic T-cell IgG CM+ (Group III). Comparing groups I:II:III: early acute rejection affected 32%, 42%, 57% of grafts; mean serum creatinine at 3 months was 166, 150, 229 umol/l (p<0.05); 1 yr graft survival was 95 per cent, 96 per cent, 71 per cent (p=0.09). In group III both graft losses were in the setting of an additional current B-cell CM+. Conclusions: Transplantation performed in either the presence of an isolated B-cell CM+ or in the presence of an historic T-cell IgM CM+ was associated with acceptable outcomes at 1 yr. An historic T-cell IgG CM+ was confirmed as a contraindication to transplantation in most circumstances, especially when coupled with a current B-cell CM+.  相似文献   
7.
8.
Adverse reaction to intravenous gadoteridol   总被引:1,自引:0,他引:1  
  相似文献   
9.
10.
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