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   22999篇
  免费   1505篇
  国内免费   131篇
耳鼻咽喉   208篇
儿科学   621篇
妇产科学   589篇
基础医学   3615篇
口腔科学   347篇
临床医学   1908篇
内科学   5747篇
皮肤病学   567篇
神经病学   2501篇
特种医学   484篇
外科学   2128篇
综合类   93篇
一般理论   17篇
预防医学   1828篇
眼科学   460篇
药学   1578篇
中国医学   58篇
肿瘤学   1886篇
  2024年   20篇
  2023年   265篇
  2022年   525篇
  2021年   1055篇
  2020年   534篇
  2019年   808篇
  2018年   839篇
  2017年   636篇
  2016年   720篇
  2015年   779篇
  2014年   1079篇
  2013年   1235篇
  2012年   1892篇
  2011年   1974篇
  2010年   1100篇
  2009年   992篇
  2008年   1542篇
  2007年   1555篇
  2006年   1456篇
  2005年   1352篇
  2004年   1143篇
  2003年   1063篇
  2002年   883篇
  2001年   94篇
  2000年   60篇
  1999年   121篇
  1998年   152篇
  1997年   121篇
  1996年   95篇
  1995年   84篇
  1994年   56篇
  1993年   58篇
  1992年   38篇
  1991年   27篇
  1990年   21篇
  1989年   25篇
  1988年   18篇
  1987年   21篇
  1986年   17篇
  1985年   14篇
  1984年   10篇
  1983年   16篇
  1982年   15篇
  1981年   20篇
  1980年   15篇
  1978年   9篇
  1975年   9篇
  1974年   7篇
  1971年   9篇
  1966年   6篇
排序方式: 共有10000条查询结果,搜索用时 921 毫秒
1.
2.
3.
Obesity Surgery - Laparoscopic sleeve gastrectomy (LSG) is increasingly playing a key role in obesity management. Such operations, however, carry complications sometimes including leaks. The...  相似文献   
4.
5.
The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.  相似文献   
6.
7.
8.

Background

The Lancet Commission on Global Surgery highlighted global surgical need but offered little insight into the specific surgical challenges of children in low-resource settings. Efforts to strengthen the quality of global pediatric surgical care have resulted in a proliferation of partnerships between low-and middle-income countries (LMICs) and high-income countries (HICs). Standardized tools able to reliably measure gaps in delivery and quality of care are important aids for these partnerships. We undertook a systematic review (SR) of capacity assessment tools (CATs) focused on needs assessment in pediatric surgery.

Methods

A comprehensive search strategy of multiple electronic databases was conducted per PRISMA guidelines without linguistic or temporal restrictions. CATs were selected according to pre-defined inclusion criteria. Articles were assessed by two independent reviewers. Methodological quality of studies was appraised using the COSMIN checklist with 4-point scale.

Results

The search strategy generated 16,641 original publications, of which three CATs were deemed eligible. Eligible tools were either excessively detailed or oversimplified. None used weighted scores to identify finer granularity between institutions. No CATs comprehensively included measures of resources, outcomes, accessibility/impact and training.

Discussion

The results of this study identify the need for a CAT capable of objectively measuring key aspects of surgical capacity and performance in a weighted tool designed for pediatric surgical centers in LMICs.

Type of Study

Systematic Review.

Level of Evidence

II.  相似文献   
9.

Objective

This study assessed whether immediate postpartum insertion of levonorgestrel contraceptive implants is associated with a difference in infant growth from birth to 6 months, onset of lactogenesis, or breastfeeding continuation at 3 and 6 months postpartum compared to delayed insertion at 6 to 8 weeks postpartum.

Study design

We conducted a randomized trial of women in Uganda who desired contraceptive implants postpartum. We randomly assigned participants to receive either immediate (within 5 days of delivery) or delayed (6 to 8 weeks postpartum) insertion of a two-rod levonorgestrel contraceptive implant system. This is a prespecified secondary analysis evaluating breastfeeding outcomes. The primary outcome of this secondary analysis was change in infant weight; infants were weighed and measured at birth and 6 months. We used a validated questionnaire to assess onset of lactogenesis daily in person while participants were in the hospital, and then daily by phone after they left the hospital, until lactogenesis was documented. We used interviewer-administered questionnaires to assess breastfeeding continuation and concerns at 3 months and 6 months postpartum.

Results

Among the 96 women randomized to the immediate group and the 87 women to the delayed group, the mean change in infant weight from birth to 6 months was similar between groups: 4632?g in the immediate group and 4407?g in the delayed group (p=.26). Among the 97 women who had not experienced lactogenesis prior to randomization, the median time to onset of lactogenesis did not differ significantly between the immediate and delayed groups (65?h versus 63?h; p=.84). Similar proportions of women in the immediate and delayed groups reported exclusive breastfeeding at 3 months (74% versus 71%; p=.74) and 6 months (48% versus 52%; p=.58).

Conclusion

We found no association between the timing of postpartum initiation of levonorgestrel contraceptive implants and change in infant growth from birth to 6 months, onset of lactogenesis, or breastfeeding continuation at 3 or 6 months postpartum.

Implications

This study provides evidence that immediate postpartum initiation of contraception implants does not have a deleterious effect on infant growth or initiation or continuation of breastfeeding.  相似文献   
10.
Journal of Thrombosis and Thrombolysis - C1-inhibitor (C1INH) was shown to enhance thrombin generation (TG) in the presence of thrombomodulin (TM) by reducing production of activated protein C....  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