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   41407篇
  免费   2279篇
  国内免费   279篇
耳鼻咽喉   153篇
儿科学   2620篇
妇产科学   912篇
基础医学   2575篇
口腔科学   597篇
临床医学   3313篇
内科学   8792篇
皮肤病学   537篇
神经病学   1302篇
特种医学   919篇
外科学   6218篇
综合类   4210篇
现状与发展   8篇
预防医学   7070篇
眼科学   681篇
药学   2255篇
  20篇
中国医学   951篇
肿瘤学   832篇
  2023年   370篇
  2022年   615篇
  2021年   1365篇
  2020年   1124篇
  2019年   4061篇
  2018年   3201篇
  2017年   1745篇
  2016年   812篇
  2015年   865篇
  2014年   1990篇
  2013年   1778篇
  2012年   1652篇
  2011年   1678篇
  2010年   1385篇
  2009年   1195篇
  2008年   1031篇
  2007年   1064篇
  2006年   843篇
  2005年   736篇
  2004年   601篇
  2003年   544篇
  2002年   363篇
  2001年   360篇
  2000年   272篇
  1999年   242篇
  1998年   209篇
  1997年   238篇
  1996年   146篇
  1995年   133篇
  1994年   106篇
  1993年   98篇
  1992年   84篇
  1991年   76篇
  1990年   60篇
  1989年   72篇
  1988年   55篇
  1987年   57篇
  1985年   1023篇
  1984年   1436篇
  1983年   1069篇
  1982年   1163篇
  1981年   1112篇
  1980年   976篇
  1979年   1070篇
  1978年   1001篇
  1977年   697篇
  1976年   892篇
  1975年   793篇
  1974年   702篇
  1973年   738篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Acute diarrhea is a condition of increased water stool content, stool volume, and number of bowel movements that lasts less than 14 days. Mild diarrhea is usually self-limiting; however, undertreated moderate to severe diarrhea may cause severe dehydration and lead to hypovolemic shock. In order to prevent severe dehydration and treat patients appropriately, it is crucial for health care providers to determine the right diagnosis of patients with acute diarrhea. This article focuses on pathophysiology, general patient presentation, diagnostic tests and differential diagnosis lists of acute diarrhea to discuss which diagnosis should be made based on patient presentation and objective data.  相似文献   
2.
《Vaccine》2022,40(7):1001-1009
Vaccination guidelines for dogs and cats indicate that core vaccines (for dogs, rabies, distemper, adenovirus, parvovirus; for cats, feline parvovirus, herpes virus-1, calicivirus) are essential to maintain health, and that non-core vaccines be administered according to a clinician’s assessment of a pet’s risk of exposure and susceptibility to infection. A reliance on individual risk assessment introduces the potential for between-practice inconsistencies in non-core vaccine recommendations. A study was initiated to determine non-core vaccination rates of dogs (Leptospira, Borrelia burgdorferi, Bordetella bronchiseptica, canine influenza virus) and cats (feline leukemia virus) in patients current for core vaccines in veterinary practices across the United States. Transactional data for 5,531,866 dogs (1,670 practices) and 1,914,373 cats (1,661 practices) were retrieved from practice management systems for the period November 1, 2016 through January 1, 2020, deidentified and normalized. Non-core vaccination status was evaluated in 2,798,875 dogs and 788,772 cats that were core-vaccine current. Nationally, median clinic vaccination rates for dogs were highest for leptospirosis (70.5%) and B. bronchiseptica (68.7%), and much lower for canine influenza (4.8%). In Lyme-endemic states, the median clinic borreliosis vaccination rate was 51.8%. Feline leukemia median clinic vaccination rates were low for adult cats (34.6%) and for kittens and 1-year old cats (36.8%). Individual clinic vaccination rates ranged from 0 to 100% for leptospirosis, B. bronchiseptica and feline leukemia, 0–96% for canine influenza, and 0–94% for borreliosis. Wide variation in non-core vaccination rates between clinics in similar geographies indicates that factors other than disease risk are driving the use of non-core vaccines in pet dogs and cats, highlighting a need for veterinary practices to address gaps in patient protection. Failure to implement effective non-core vaccination strategies leaves susceptible dogs and cats unprotected against vaccine-preventable diseases.  相似文献   
3.
4.
5.
6.
Purpose: To use polymerase chain reaction (PCR) and Goldmann-Witmer coefficient (GWC) calculation to diagnose infectious uveitis.

Methods: Prospective cross-sectional study.

Results: Twenty-seven of 106 patients had positive PCR and/or GWC results on aqueous humor (AH) sampling and 15 of 27 (55.6%) were HIV-positive. Patients with non-anterior uveitis (NAU) were more likely to be HIV+ (p = 0.005). More than 1 possible pathogen was identified in 9 of 27 patients of whom 7 were HIV+. The final clinical diagnosis was discordant with AH findings in 9 of 27 cases. A positive EBV PCR result was associated with a discordant diagnosis (p = 0.001). All cases of herpetic anterior uveitis (42.9% HIV+) tested PCR-/GWC+ while all cases of herpetic NAU tested PCR+/GWC- (83.3% HIV+). All rubella virus cases were PCR+/GWC+.

Conclusion: PCR is useful to diagnose herpetic NAU in HIV+ patients while GWC is useful to diagnose herpetic anterior uveitis.  相似文献   

7.
8.
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