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   7148篇
  免费   499篇
  国内免费   21篇
耳鼻咽喉   45篇
儿科学   242篇
妇产科学   249篇
基础医学   1028篇
口腔科学   120篇
临床医学   966篇
内科学   1318篇
皮肤病学   155篇
神经病学   588篇
特种医学   150篇
外科学   624篇
综合类   72篇
现状与发展   1篇
一般理论   24篇
预防医学   833篇
眼科学   158篇
药学   518篇
中国医学   7篇
肿瘤学   570篇
  2023年   73篇
  2022年   103篇
  2021年   164篇
  2020年   164篇
  2019年   186篇
  2018年   193篇
  2017年   171篇
  2016年   153篇
  2015年   197篇
  2014年   304篇
  2013年   411篇
  2012年   540篇
  2011年   559篇
  2010年   295篇
  2009年   276篇
  2008年   479篇
  2007年   497篇
  2006年   450篇
  2005年   443篇
  2004年   405篇
  2003年   351篇
  2002年   316篇
  2001年   65篇
  2000年   49篇
  1999年   58篇
  1998年   66篇
  1997年   61篇
  1996年   41篇
  1995年   33篇
  1994年   41篇
  1993年   34篇
  1992年   33篇
  1991年   32篇
  1990年   24篇
  1989年   20篇
  1988年   18篇
  1987年   18篇
  1986年   15篇
  1985年   22篇
  1984年   24篇
  1983年   19篇
  1982年   21篇
  1981年   20篇
  1980年   18篇
  1979年   17篇
  1978年   18篇
  1977年   13篇
  1974年   15篇
  1973年   19篇
  1972年   14篇
排序方式: 共有7668条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.

Background

We have recently shown that human epididymis protein 4 (HE4) levels correlate with the severity of cystic fibrosis (CF) lung disease. However, there are no data on how HE4 levels alter in patients receiving CFTR modulating therapy.

Methods

In this retrospective clinical study, 3 independent CF patient cohorts (US-American: 29, Australian: 12 and Irish: 19 cases) were enrolled carrying at least one Class III CFTR CF-causing mutation (p.Gly551Asp) and being treated with CFTR potentiator ivacaftor. Plasma HE4 was measured by immunoassay before treatment (baseline) and 1–6?months after commencement of ivacaftor, and were correlated with FEV1 (% predicted), sweat chloride, C-reactive protein (CRP) and body mass index (BMI).

Results

After 1?month of therapy, HE4 levels were significantly lower than at baseline and remained decreased up to 6?months. A significant inverse correlation between absolute and delta values of HE4 and FEV1 (r?=??0.5376; P?<?.001 and r?=??0.3285; P?<?.001), was retrospectively observed in pooled groups, including an independent association of HE4 with FEV1 by multiple regression analysis (β?=??0.57, P?=?.019). Substantial area under the receiver operating characteristic curve (ROC-AUC) value was determined for HE4 when 7% mean change of FEV1 (0.722 [95% CI 0.581–0.863]; P?=?.029) were used as classifier, especially in the first 2?months of treatment (0.806 [95% CI 0.665–0.947]; P?<?.001).

Conclusions

This study shows that plasma HE4 levels inversely correlate with lung function improvement in CF patients receiving ivacaftor. Overall, this potential biomarker may be of value for routine clinical and laboratory follow-up of CFTR modulating therapy.  相似文献   
6.
7.
PURPOSE: To determine the maximum tolerated dose, dose-limiting toxicities, and pharmacokinetic characteristics of doxorubicin encapsulated in a low temperature sensitive liposome (LTSL) when given concurrently with local hyperthermia to canine solid tumors. EXPERIMENTAL DESIGN: Privately owned dogs with solid tumors (carcinomas or sarcomas) were treated. The tumors did not involve bone and were located at sites amenable to local hyperthermia. LTSL-doxorubicin was given (0.7-1.0 mg/kg i.v.) over 30 minutes during local tumor hyperthermia in a standard phase I dose escalation study. Three treatments, given 3 weeks apart, were scheduled. Toxicity was monitored for an additional month. Pharmacokinetics were evaluated during the first treatment cycle. RESULTS: Twenty-one patients were enrolled: 18 with sarcomas and 3 with carcinomas. Grade 4 neutropenia and acute death secondary to liver failure, possibly drug related, were the dose-limiting toxicities. The maximum tolerated dose was 0.93 mg/kg. Other toxicities, with the possible exception of renal damage, were consistent with those observed following free doxorubicin administration. Of the 20 dogs that received > or = 2 doses of LTSL-doxorubicin, 12 had stable disease, and 6 had a partial response to treatment. Pharmacokinetic variables were more similar to those of free doxorubicin than the marketed liposomal product. Tumor drug concentrations at a dose of 1.0 mg/kg averaged 9.12 +/- 6.17 ng/mg tissue. CONCLUSION: LTSL-doxorubicin offers a novel approach to improving drug delivery to solid tumors. It was well tolerated and resulted in favorable response profiles in these patients. Additional evaluation in human patients is warranted.  相似文献   
8.
Human histocompatibility leukocyte antigen E (HLA-E) and mouse major histocompatibility complex (MHC) class Ib antigen, Qa-1, share the same substitutions at two normally conserved positions 143 and 147, which are likely to affect binding of the C terminus of peptides. Qa-1 is able to bind a peptide derived from the leader sequence of H-2 D and H-2 L molecules. We developed a peptide binding assay in vitro to compare the binding specificity of HLA-E with the mouse MHC class Ib molecule Qa-1. We demonstrate that HLA-E binds, although poorly, the peptide which binds to Qa-1 and that it also binds nonamer signal sequence-derived peptides from human MHC class I molecules. Using alanine and glycine substitutions, we could define primary anchor residues at positions 2 and 9 and secondary anchor residues at position 7 and possibly 3.  相似文献   
9.
10.
This study evaluated the effects of tobacco Purchase, Use and Possession (PUP) laws on student perceptions of adolescent tobacco use within towns and schools. Twenty‐four towns were randomly assigned into two conditions, the experimental condition (E PUP) involved efforts to increase both PUP law enforcement and reduce minors' access to commercial sources of tobacco, whereas the control condition (C) focused only on efforts to reduce minors' access to commercial sources of tobacco. A hierarchical linear modeling analytical approach was selected due to the multilevel data and nested design. The present study found that over time, youth in the experimental PUP condition observed less youth tobacco usage at school and in their town, and perceived lower rates of tobacco among their peers at school and among friends than youth in the control condition. The findings suggest that PUP law enforcement might be used to strengthen community norms against youth tobacco use.  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