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   10281篇
  免费   643篇
  国内免费   35篇
耳鼻咽喉   123篇
儿科学   265篇
妇产科学   254篇
基础医学   1455篇
口腔科学   151篇
临床医学   922篇
内科学   2422篇
皮肤病学   215篇
神经病学   1084篇
特种医学   213篇
外科学   1224篇
综合类   147篇
一般理论   12篇
预防医学   678篇
眼科学   234篇
药学   924篇
中国医学   26篇
肿瘤学   610篇
  2023年   51篇
  2022年   39篇
  2021年   206篇
  2020年   107篇
  2019年   153篇
  2018年   201篇
  2017年   154篇
  2016年   192篇
  2015年   228篇
  2014年   292篇
  2013年   413篇
  2012年   589篇
  2011年   608篇
  2010年   294篇
  2009年   336篇
  2008年   559篇
  2007年   602篇
  2006年   560篇
  2005年   557篇
  2004年   566篇
  2003年   495篇
  2002年   510篇
  2001年   254篇
  2000年   220篇
  1999年   203篇
  1998年   81篇
  1997年   65篇
  1996年   67篇
  1995年   69篇
  1994年   70篇
  1993年   75篇
  1992年   153篇
  1991年   157篇
  1990年   123篇
  1989年   139篇
  1988年   135篇
  1987年   120篇
  1986年   121篇
  1985年   86篇
  1984年   91篇
  1983年   72篇
  1982年   72篇
  1981年   57篇
  1980年   51篇
  1979年   48篇
  1978年   47篇
  1977年   44篇
  1976年   43篇
  1975年   62篇
  1971年   45篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
BackgroundCampylobacter spp. are one of the commonest causes of diarrhea in children under five and in resource poor settings also lead to malabsorption and stunting. The purpose of this systematic review was to understand the burden of Campylobacter spp. associated diarrhea among children in the South Asian countries.MethodsThis systematic review followed the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analysis) guidelines. Databases were searched with defined keywords for publications from the years 1998–2018. Data on proportion of positive samples was extracted to compare the rates of Campylobacter infection among children (under the age of 19) from different study populations.ResultsOf the 359 publications screened, 27 eligible articles were included in this systematic review and categorized based on study design. In 8 case-control studies, Campylobacter spp. was detected more frequently among diarrheal cases (range, 3.2–17.4%) than non-diarrheal cases (0–13%). Although there were variations in the study population, overall, children under the age of two years experienced Campylobacter diarrhea more often than older children. Most studies reported stool culture as the method used to detect Campylobacter spp. however retesting using PCR-based methods significantly increased detection rates. Limited data were available on Campylobacter species. In 4 studies that provided species data, C. jejuni (3.2–11.2%) was shown to be the most common species, followed by C. coli.ConclusionIn South Asia, Campylobacter spp. are one of the most common bacterial diarrheal pathogens affecting children but there is a paucity of data on species, risk factors and attributable sources. Although a few studies were available, the epidemiology of campylobacteriosis remains uncertain. To understand the true burden and sources of infection, more detailed studies are needed collecting data from human, animal and environmental sources and using both culture and genomic tools.  相似文献   
5.

Introduction

Stereotactic body radiation therapy (SBRT) is a promising curative treatment for early-stage NSCLC. It is unclear if survival outcomes for SBRT are influenced by a lack of pathological confirmation of malignancy and staging of disease in these patients. In this systematic review and meta-analysis, we assess survival outcomes after SBRT in studies with patients with clinically diagnosed versus biopsy-proven early-stage NSCLC.

Methods

The main databases were searched for trials and cohort studies without restrictions to publication status or language. Two independent researchers performed the screening and selection of eligible studies. Outcomes were overall survival, cancer-specific survival, and disease-free survival. The inverse variance method and the random effects method for meta-analysis were used to assess pooled survival estimates.

Results

A total of 11,195 nonduplicate records were identified by the original search strategy. After screening by title and abstract, 1051 potentially eligible records were identified. A total of 43 articles were included. The comparative studies showed lower 3-year overall survival and lower 2-year and 5-year cancer-specific survival for biopsy-proven disease compared to clinical disease. However, 5-year overall survival was the same for both groups. For the pooled estimates, 3-year disease-free survival and 2-year cancer-specific survival were lower for biopsied disease.

Conclusions

Results of this systematic review and meta-analysis show a discrepancy in oncological outcomes for patients undergoing SBRT for suspected early-stage NSCLC in whom there is pathologic conformation of malignancy and those who there is only a clinical diagnose of NSCLC. These results emphasize the importance of obtaining pathologic proof of malignancy.  相似文献   
6.
7.
8.
9.
Archives of Gynecology and Obstetrics - Studies have reported a surge in the prevalence of obesity among various demographic groups including pregnant women in the U.S. Given the association...  相似文献   
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