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   1392篇
  免费   70篇
  国内免费   27篇
耳鼻咽喉   8篇
儿科学   10篇
妇产科学   13篇
基础医学   165篇
口腔科学   39篇
临床医学   100篇
内科学   363篇
皮肤病学   15篇
神经病学   163篇
特种医学   81篇
外科学   230篇
预防医学   37篇
眼科学   8篇
药学   108篇
肿瘤学   149篇
  2023年   10篇
  2022年   25篇
  2021年   62篇
  2020年   24篇
  2019年   43篇
  2018年   35篇
  2017年   39篇
  2016年   46篇
  2015年   38篇
  2014年   46篇
  2013年   83篇
  2012年   104篇
  2011年   113篇
  2010年   62篇
  2009年   47篇
  2008年   57篇
  2007年   77篇
  2006年   72篇
  2005年   82篇
  2004年   64篇
  2003年   67篇
  2002年   60篇
  2001年   28篇
  2000年   35篇
  1999年   34篇
  1998年   13篇
  1997年   12篇
  1996年   12篇
  1995年   9篇
  1994年   10篇
  1992年   14篇
  1991年   3篇
  1990年   8篇
  1989年   7篇
  1988年   5篇
  1987年   9篇
  1986年   5篇
  1985年   5篇
  1984年   3篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1980年   3篇
  1979年   3篇
  1978年   3篇
  1977年   1篇
  1976年   1篇
  1975年   2篇
  1971年   1篇
  1965年   1篇
排序方式: 共有1489条查询结果,搜索用时 31 毫秒
71.
72.
73.
AIM To study the safety of insertion of metallic stents in elderly patients with unresectable distal malignant biliary obstruction.METHODS Of 272 patients with unresectable distal malignant biliary obstruction, 184 patients under the age of 80 were classified into Group A, and 88 subjects aged 80 years or more were classified into Group B. The safety of metallic stent insertion, metal stent patency period, and the obstruction rate were examined in each group.RESULTS In Group B, patients had a significantly worse per-formance status, high blood pressure, heart disease, cerebrovascular disease, and dementia; besides the rate of patients orally administered antiplatelet drugs or anticoagulants tended to be higher(P 0.05). Metallic stents were successfully inserted in all patients. The median patency period was 265.000 ± 26.779(1-965) d; 252.000 ± 35.998(1-618) d in Group A and 269.000 ± 47.885(1-965) d in Group B, with no significant difference between the two groups. Metallic stent obstruction occurred in 82 of the 272(30.15%) patients; in 53/184(28.80%) patients in Group A and in 29/88(32.95%) of those in Group B, showing no significant difference between the two groups. Procedural accidents due to metal stent insertion occurred in 24/272(8.8%) patients; in 17/184(9.2%) of patients in Group A and in 7/88(8.0%) of those in Group B, with no significant difference between the two groups, either.CONCLUSION These results suggested that metallic stents can be safely inserted to treat unresectable distal malignant biliary obstruction even in elderly patients aged 80 years or more.  相似文献   
74.
75.
Development of low‐clearance (CL) compounds that are slowly metabolized is a major goal in the pharmaceutical industry. However, the pursuit of low intrinsic CL (CLint) often leads to significant challenges in evaluating the pharmacokinetics of such compounds. Although in vitro–in vivo extrapolation is widely used to predict human CL, its application has been limited for low‐CLint compounds because of the low turnover of parent compounds in metabolic stability assays. To address this issue, we focused on chimeric mice with humanized livers (PXB‐mice), which have been increasingly reported to accurately predict human CL in recent years. The predictive accuracy for nine low‐CLint compounds with no significant turnover in a human hepatocyte assay was investigated using PXB‐mouse methods, such as single‐species allometric scaling (PXB‐SSS) approach and a novel physiologically based scaling (PXB‐PBS) approach that assumes that the CLint per hepatocyte is equal between humans and PXB‐mice. The percentages of compounds with predicted CL within 2‐ and 3‐fold ranges of the observed CL for low‐CLint compounds were 89% and 100%, respectively, for both PXB‐SSS and PXB‐PBS approaches. Moreover, the predicted CL was mostly consistent among the methods. Conversely, the percentages of compounds with predicted CL within 2‐ and 3‐fold ranges of the observed CL for low‐CLint compounds were 50% and 63%, respectively, for multispecies allometric (MA) scaling. Overall, these PXB‐mouse methods were much more accurate than conventional MA scaling approaches, suggesting that PXB‐mice are useful tools for predicting the human CL of low‐CLint compounds that are slowly metabolized.

Study Highlights
  • WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?
It is important to identify low‐clearance (CL) compounds that are slowly metabolized during the drug discovery process, but the ability of in vitro–in vivo extrapolation to predict human CL decreases as the value of intrinsic CL (CLint) decreases. Although chimeric mice with humanized livers (PXB‐mice) have been reported to be useful for predicting human CL, their applicability to low‐CLint compounds with no significant turnover in human hepatocyte assays has not been clarified.
  • WHAT QUESTION DID THIS STUDY ADDRESS?
This study examined the predictive accuracy of PXB‐mouse methods for low‐CLint compounds.
  • WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?
In addition to the previously reported single‐species allometric scaling approach, we proposed a novel physiologically based scaling approach. Both methods displayed much greater predictive accuracy for low‐CLint compounds than conventional multispecies allometric scaling approaches.
  • HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?
The findings should improve the accuracy of human pharmacokinetic prediction and enable efficient and safe first‐in‐human studies.  相似文献   
76.
77.
78.

Introduction and objectives

The angiographic and clinical efficacy of polymer-free sirolimus-eluting stents vs polymer-based paclitaxel-eluting stents remain a matter of debate. We sought to investigate angiographic and clinical measures of efficacy of polymer-free sirolimus-eluting stents vs polymer-based paclitaxel-eluting stents.

Methods

Patient data from the randomized intracoronary stenting and angiographic restenosis-test equivalence between the 2 drug-eluting stents (ISAR-TEST) clinical trial and the LIPSIA Yukon clinical trial (randomized comparison of a polymer-free sirolimus-eluting stent vs a polymer-based paclitaxel-eluting stent in patients with diabetes mellitus) were pooled. The angiographic (primary) endpoint was in-stent late lumen loss at 6 months to 9 months. The clinical (secondary) endpoints were death or myocardial infarction, cardiac death or myocardial infarction, target lesion revascularization, and myocardial infarction.

Results

A total of 686 patients (polymer-free sirolimus-eluting stents, n=345 vs polymer-based paclitaxel-eluting stents, n=341) and 751 lesions (polymer-free sirolimus-eluting stents, n=383 vs polymer-based paclitaxel-eluting stents, n=368) were included in the study. Control angiography (606 lesions, 80.6%) showed comparable in-stent late lumen loss for polymer-free sirolimus-eluting stents vs polymer-based paclitaxel-eluting stents (0,53 [0,59] mm vs 0,46 [0,57] mm; P=.15). Median follow-up was 34.8 months. Polymer-free sirolimus-eluting stents and polymer-based paclitaxel-eluting stents were associated with comparable risk of death or myocardial infarction (relative risk=1.17; 95% confidence interval, 0,49-2.80; P=.71), cardiac death or myocardial infarction (relative risk=1.17; 95% confidence interval, 0,72-1.89; P=.50), target lesion revascularization (relative risk=0,98; 95% confidence interval, 0,65-1.47; P=.93), and myocardial infarction (relative risk=1.79; 95% confidence interval, 0,85-3.76; P=.12).

Conclusions

In this pooled analysis, polymer-free sirolimus-eluting stents were comparable to polymer-based paclitaxel-eluting stents with respect to both angiographic and clinical efficacy.Full English text available from:www.revespcardiol.org.  相似文献   
79.
BACKGROUND: To diagnose left main trunk (LMT) infarction by 12-lead standard electrocardiogram (ECG) is an important emergency technique, but the features in LMT infarctions have not been clarified. METHODS AND RESULTS: The study enrolled 140 subjects who were divided into 4 groups according to the location of the culprit artery: 35 with LMT, 35 with left anterior descending artery (LAD), 35 with right coronary artery and 35 with left circumflex artery. Various parameters obtained from the ECGs were analyzed. Average QTc interval (0.51 +/- 0.06 s) in LMT group was markedly longer than that in the 3 other groups. Average QRS axis (-10 +/- 77 degrees) in LMT infarction showed a remarkable left deviation. ST-segment elevation in lead aVR occurred in 28 patients (80.0%) in the LMT group. The ECG features of the LMT group could be classified into 2 main groups: right bundle branch block (RBBB) with a marked left axis deviation (RBBB + LADEV type) and ST-segment elevation in leads V2-5, I and aVL without abnormal axis deviation (LAD type). CONCLUSION: Either ST-segment elevation in lead aVR and marked prolongation of both the QRS width and QTc interval with a prominent abnormal axis deviation or ST-segment elevation in the broad anterior precordial lead with a normal QRS axis strongly suggests LMT infarction.  相似文献   
80.
Hepatitis C virus (HCV) is a hepatotrophic virus and a major cause of chronic liver disease, including hepatocellular carcinoma, worldwide. The life cycle of HCV is closely associated with the metabolism of lipids and lipoproteins. The main function of lipoproteins is transporting lipids throughout the body. Triglycerides, free cholesterol, cholesteryl esters, and phospholipids are the major components of the transported lipids. The pathway of HCV assembly and secretion is closely linked to lipoprotein production and secretion, and the infectivity of HCV particles largely depends on the interaction of lipoproteins. Moreover, HCV entry into hepatocytes is strongly influenced by lipoproteins. The key lipoprotein molecules mediating these interactions are apolipoproteins. Apolipoproteins are amphipathic proteins on the surface of a lipoprotein particle, which help stabilize lipoprotein structure. They perform a key role in lipoprotein metabolism by serving as receptor ligands, enzyme co-factors, and lipid transport carriers. Understanding the association between the life cycle of HCV and lipoprotein metabolism is important because each step of the life cycle of HCV that is associated with lipoprotein metabolism is a potential target for anti-HCV therapy. In this article, we first concisely review the nature of lipoprotein and its metabolism to better understand the complicated interaction of HCV with lipoprotein. Then, we review the outline of the processes of HCV assembly, secretion, and entry into hepatocytes, focusing on the association with lipoproteins. Finally, we discuss the clinical aspects of disturbed lipid/lipoprotein metabolism and the significance of dyslipoproteinemia in chronic HCV infection with regard to abnormal apolipoproteins.  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