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   185672篇
  免费   53047篇
  国内免费   7028篇
耳鼻咽喉   2605篇
儿科学   5760篇
妇产科学   2908篇
基础医学   28598篇
口腔科学   7179篇
临床医学   27414篇
内科学   40009篇
皮肤病学   8346篇
神经病学   19053篇
特种医学   6052篇
外国民族医学   47篇
外科学   25508篇
综合类   16965篇
现状与发展   25篇
一般理论   42篇
预防医学   10784篇
眼科学   4429篇
药学   17109篇
  57篇
中国医学   6418篇
肿瘤学   16439篇
  2024年   276篇
  2023年   1520篇
  2022年   3676篇
  2021年   6724篇
  2020年   8807篇
  2019年   14053篇
  2018年   13681篇
  2017年   14382篇
  2016年   14914篇
  2015年   16469篇
  2014年   17676篇
  2013年   17428篇
  2012年   12185篇
  2011年   12983篇
  2010年   14163篇
  2009年   9318篇
  2008年   7774篇
  2007年   6877篇
  2006年   6748篇
  2005年   6856篇
  2004年   4894篇
  2003年   4467篇
  2002年   4103篇
  2001年   3552篇
  2000年   3667篇
  1999年   3281篇
  1998年   1846篇
  1997年   1712篇
  1996年   1471篇
  1995年   1333篇
  1994年   1092篇
  1993年   723篇
  1992年   1134篇
  1991年   901篇
  1990年   797篇
  1989年   682篇
  1988年   670篇
  1987年   591篇
  1986年   488篇
  1985年   380篇
  1984年   252篇
  1983年   176篇
  1982年   104篇
  1981年   115篇
  1980年   96篇
  1979年   127篇
  1978年   64篇
  1977年   60篇
  1975年   56篇
  1974年   55篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
111.
112.
113.
Zygomatic implant treatment is widely applied for severe maxillary atrophy to help rehabilitate the maxillary dentition. This retrospective study was performed to evaluate the actual radiographic bone–implant contact (rBIC) lengths of zygomatic implants. The records of 28 patients who underwent zygomatic implant surgery and subsequent follow-up examinations between August 2013 and September 2018 in the Department of Oral and Maxillofacial Surgery, Taipei Tzu Chi Hospital were reviewed. The surgeries were performed by a single surgeon using the same treatment protocol. All patients had a computed tomography scan at 1 year after the surgery. Using three-dimensional imaging software, an investigator measured the rBIC lengths of 66 implants and documented their clinical status. The implant survival rate was 100%. The mean rBIC length was significantly longer in male patients than in female patients (20.80 ± 5.88 mm versus 17.79 ± 6.34 mm; P = 0.028). The mean rBIC length of double zygomatic implants was significantly longer when compared to that of single implants (21.11 ± 6.23 mm versus 17.75 ± 5.85 mm; P = 0.027). This article is novel in reporting the exact rBIC lengths of zygomatic implants in a clinical setting. The results showed that zygomatic implants are a viable treatment modality for full-mouth rehabilitation.  相似文献   
114.
115.
116.
117.
Tuberculosis (TB) remains one of a major health problem worldwide. Tuberculosis vaccine research has made an extraordinary progress over the past few years. However, there is still no replacement for the Bacillus Calmette‐Guérin vaccine, the only TB vaccine licensed for human use. Therefore, the discovery and development of new TB vaccines remains a priority. This article discusses current strategies used to diversify TB vaccines and includes discussion of the status of efforts to improve protection against Mycobacterium tuberculosis (M tb) infection or TB disease by developing new and safe TB vaccines. This article also highlights the current research efforts in immune‐enhancing approaches to improve vaccination efficacy. The development of more effective TB vaccines might have significant impact on global TB control.  相似文献   
118.
Melatonin receptors play important roles in the regulation of circadian and seasonal rhythms, sleep, retinal functions, the immune system, depression, and type 2 diabetes development. Melatonin receptors are approved drug targets for insomnia, non‐24‐hour sleep‐wake disorders, and major depressive disorders. In mammals, two melatonin receptors (MTRs) exist, MT1 and MT2, belonging to the G protein‐coupled receptor (GPCR) superfamily. Similar to most other GPCRs, reliable antibodies recognizing melatonin receptors proved to be difficult to obtain. Here, we describe the development of the first monoclonal antibodies (mABs) for mouse MT1 and MT2. Purified antibodies were extensively characterized for specific reactivity with mouse, rat, and human MT1 and MT2 by Western blot, immunoprecipitation, immunofluorescence, and proximity ligation assay. Several mABs were specific for either mouse MT1 or MT2. None of the mABs cross‐reacted with rat MTRs, and some were able to react with human MTRs. The specificity of the selected mABs was validated by immunofluorescence microscopy in three established locations (retina, suprachiasmatic nuclei, pituitary gland) for MTR expression in mice using MTR‐KO mice as control. MT2 expression was not detected in mouse insulinoma MIN6 cells or pancreatic beta‐cells. Collectively, we report the first monoclonal antibodies recognizing recombinant and native mouse melatonin receptors that will be valuable tools for future studies.  相似文献   
119.
我国奶牛养殖规模不断扩大,奶业产值比重逐步提高,给奶牛疫病防治带来巨大压力。奶牛乳房炎及细菌性肺炎等呼吸系统疾病和细菌性肠炎等消化系统疾病最为常见,抗菌药物的使用成为主要防治手段。但抗菌药物的不当使用易使细菌产生耐药性,增加临床治疗的成本和难度,危害我国奶牛产业发展。本文对截至2021年7月我国和美国、英国、日本、欧盟批准用于奶牛的抗菌药物产品进行整理、统计与分析,包括抗菌药物的分类、剂型以及适应证等,旨在为我国奶牛用抗菌药物管理、合理用药和新兽药开发提供参考。  相似文献   
120.
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