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   309794篇
  免费   18451篇
  国内免费   8589篇
耳鼻咽喉   3331篇
儿科学   9373篇
妇产科学   3693篇
基础医学   25852篇
口腔科学   6216篇
临床医学   35947篇
内科学   49558篇
皮肤病学   3510篇
神经病学   20575篇
特种医学   15650篇
外国民族医学   27篇
外科学   40497篇
综合类   34694篇
现状与发展   31篇
一般理论   5篇
预防医学   27959篇
眼科学   5337篇
药学   32761篇
  222篇
中国医学   7467篇
肿瘤学   14129篇
  2024年   667篇
  2023年   3808篇
  2022年   10769篇
  2021年   13645篇
  2020年   8635篇
  2019年   13585篇
  2018年   8212篇
  2017年   7408篇
  2016年   9658篇
  2015年   12627篇
  2014年   23658篇
  2013年   21566篇
  2012年   24185篇
  2011年   21320篇
  2010年   18895篇
  2009年   18145篇
  2008年   16823篇
  2007年   16606篇
  2006年   14273篇
  2005年   10080篇
  2004年   6093篇
  2003年   5270篇
  2002年   4186篇
  2001年   3498篇
  2000年   3008篇
  1999年   2168篇
  1998年   2577篇
  1997年   2391篇
  1996年   1973篇
  1995年   1979篇
  1994年   1895篇
  1993年   1509篇
  1992年   1707篇
  1991年   1548篇
  1990年   1497篇
  1989年   1428篇
  1988年   1367篇
  1987年   1222篇
  1986年   1044篇
  1985年   2081篇
  1984年   2153篇
  1983年   1516篇
  1982年   1629篇
  1981年   1582篇
  1980年   1374篇
  1979年   1144篇
  1978年   909篇
  1977年   890篇
  1976年   764篇
  1974年   509篇
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
21.
22.
《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   
23.
24.
25.
26.
Adjuvant irradiation is the standard treatment after breast conservative surgery. Normofractionated regimen with an overall treatment time of 5 to 6 weeks is often considered as a limiting factor for irradiation compliance. In order to answer this issue, moderate and more recently extreme hypofractionated protocols appeared. We report here oncological outcomes and toxicity of hypofractionated breast irradiation. After defining the frame of moderate and extreme hypofractionated breast irradiations based on overall treatment time, patient selection criteria were listed. According to their levels of proof, the results of moderate and extreme hypofractionated breast irradiation were analysed. Overall treatment time for moderate hypofractionated breast irradiation ranged from 3 to 4 weeks, while for extreme hypofractionated breast irradiation, it was less than 1 week. For moderate hypofractionated breast irradiation, whole breast irradiation was currently performed with or without lymph node irradiation. Moderate hypofractionated breast irradiation has proven to be as safe and as efficient as normofractionated breast irradiation with level IA evidence. For extreme hypofractionated breast irradiation, phase III randomized trials confirmed that accelerated partial breast irradiation was non-inferior in terms of local control compared to normofractionated whole breast irradiation (with external beam radiation therapy and multicatheter brachytherapy), with similar acute and late toxicity. While the use of intraoperative breast irradiation remains under debate, new very accelerated partial breast irradiation (overall treatment time not exceeding 2 days) protocols emerged with encouraging results. Accelerated partial breast irradiation is warranted for extreme hypofractionated breast irradiation and is indicated for low-risk breast cancers. Moderate and extreme hypofractionated breast irradiation regimens are validated and can be routinely proposed according to patient selection criteria.  相似文献   
27.
28.
29.
30.
正目前,临床上对于直肠癌常用的影像评估方法有MRI、螺旋CT、PET-CT、直肠腔内超声(ERUS)等。而MRI作为首选检查方式,对肿瘤位置、浸润深度、淋巴结转移、血管侵犯、环周切缘及周围器官侵犯等方面的评估均具有明显优势~([1-2])。通过MRI诊断淋巴结的方法通常是影像科医师逐层浏览每一幅图像,从中识别淋巴结的形状、界限及密度来判断,这种传统方式耗时较长且存在主观偏倚,导致  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