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   2538374篇
  免费   184448篇
  国内免费   3714篇
耳鼻咽喉   34674篇
儿科学   81617篇
妇产科学   66920篇
基础医学   375469篇
口腔科学   68547篇
临床医学   227317篇
内科学   497483篇
皮肤病学   56587篇
神经病学   202745篇
特种医学   93707篇
外国民族医学   574篇
外科学   378172篇
综合类   48281篇
现状与发展   12篇
一般理论   906篇
预防医学   200946篇
眼科学   58115篇
药学   188745篇
  10篇
中国医学   5140篇
肿瘤学   140569篇
  2021年   22156篇
  2019年   22971篇
  2018年   33375篇
  2017年   24620篇
  2016年   27022篇
  2015年   30461篇
  2014年   41157篇
  2013年   61886篇
  2012年   88591篇
  2011年   93381篇
  2010年   53977篇
  2009年   49764篇
  2008年   86470篇
  2007年   92225篇
  2006年   91930篇
  2005年   89416篇
  2004年   85167篇
  2003年   81635篇
  2002年   78605篇
  2001年   112277篇
  2000年   115060篇
  1999年   96654篇
  1998年   27702篇
  1997年   24280篇
  1996年   24640篇
  1995年   23244篇
  1994年   21347篇
  1993年   20127篇
  1992年   74033篇
  1991年   71923篇
  1990年   70185篇
  1989年   67355篇
  1988年   61930篇
  1987年   60671篇
  1986年   56700篇
  1985年   54343篇
  1984年   40343篇
  1983年   34296篇
  1982年   20407篇
  1979年   36827篇
  1978年   26315篇
  1977年   21887篇
  1976年   20843篇
  1975年   22473篇
  1974年   26975篇
  1973年   25622篇
  1972年   24017篇
  1971年   22792篇
  1970年   20983篇
  1969年   20091篇
排序方式: 共有10000条查询结果,搜索用时 802 毫秒
991.
992.
Differentiation of cardiac murmurs by dynamic auscultation   总被引:1,自引:0,他引:1  
The techniques described in this monograph will aid in the accurate identification of the origin of a cardiac murmur or abnormal heart sound. They do not necessarily reveal the presence or severity of cardiac disease. No maneuver is 100% accurate in elucidation of cardiac abnormalities, and a given maneuver's effectiveness varies in its application. The systematic application of a combination of maneuvers improves the accuracy of diagnosis. Auscultatory findings must be interpreted with consideration of the total clinical examination including history, other physical findings, ECG, chest x-ray, and possibly an echocardiogram. Thus, the careful physiological approach to the physical examination represents a powerful noninvasive tool that can be used in combination with other information to accurately diagnose cardiac disease in many patients and efficiently direct further evaluation when necessary.  相似文献   
993.
Among the enzymes capable of degrading thyrotropin-releasing hormone (TRH) in vitro, two pyroglutamate aminopeptidases (PGA) are specific for TRH: thyroliberinase, a seric enzyme and PGAII, a membrane-bound peptidase. The effect of thyroid hormone status on the activity of these enzymes was evaluated in serum and various tissues. Only in adenohypophysis, triiodothyronine treatment increased PGAII to 376% of control; hypothyroidism produced the reverse effect (decrease to 23% of control). As previously reported, similar changes were observed for thyroliberinase. TRH degradation at the adenohypophysis level may participate in the negative feedback control of thyroid hormones.  相似文献   
994.
A murine monoclonal antibody PASE/4LJ to prostatic acid phosphatase (PAP) was used to immunostain a wide variety of sections of benign and malignant tissues (654 blocks). Non-neoplastic adult and fetal prostatic glands, primary and metastatic prostatic carcinomas, and scattered cells in prostatic and penile urethra were positive. Rat, dog and rabbit prostates were negative. Nine of 400 tumours of non-prostatic origin showed some positivity: 6/36 carcinoids, 1/9 islet cell tumours, 1/55 ovarian adenocarcinomas (serous) and one carcinosarcoma of the lung (epithelial portion). Positive staining was seen in islet cells in 4/5 specimens of normal pancreas, and in 4/9 blocks of normal pancreas surrounding a pancreatic tumour. Loops of Henle, maculae densae, and distal tubules in 10/10 fetal and 2/9 adult kidneys were also positive, with proximal tubules and collecting ducts negative. All other 159 blocks of non-neoplastic adult and fetal tissues were negative. The antibody was also affinity purified from ascitic fluid, and shown not to inhibit the enzyme activity of prostatic acid phosphatase.  相似文献   
995.
Summary. In this study, we have examined our records for the isolation of Candida tropicalis from clinical specimens of patients with heterogeneous clinical presentations during the past 5 years. We have found that this species ranks third among all yeasts in frequency of isolation from clinical specimens and that the trend of recovery from the specimens is rising over the years. The isolation rate of C. tropicalis was highest from urine specimens (36%) followed by respiratory specimens (22%). The frequency of isolation of C. tropicalis from vaginal specimens was relatively high (14%), however the trend was declining over the years. In general, the high recovery of Candida tropicalis from clinical specimens of patients with variable disease supports the views of this organism being a major pathogen.
Zusammenfassung. Die Studie basiert auf einer Durchsicht der Patientenarchive der letzten fünf Jahre auf die Isolationshäufigkeit von Candida tropicalis aus klinischen Untersuchungsmaterialien von Patienten mit unterschiedlichen klinischen Krankheitsbildern. Diese Hefeart war die dritthäufigste mit steigender Tendenz über die Jahre. Die Isolierungsrate von C. tropicalis war am höchsten aus Urin (36%), gefolgt von Respirationstrakt-Materialien (22%). Die Isolationshäufigkeit aus dem hinteren Scheidengewölbe war relativ hoch (14%), nahm jedoch mit den jahren ab. Allgemein unterstreicht die hohe Isolationsrate von C. tropicalis aus klinischen Untersuchungsmaterialien die ätiologische Bedeutung dieses Erregers.  相似文献   
996.
997.
998.
There has been a remarkable change in the scenario of therapeutic apheresis in the last 14 years in India. The crude method of manual removal of blood followed by separation of plasma by gravity, keeping it in the bottle for a long time, has now been totally replaced by plasmapheresis, centrifugation, membrane filtration, and immunoadsorption techniques. The indications for use have also changed from a list of limited indications in the beginning to include all immune complex disorders. The clinical beneficiaries have also increased from blood bankers to nephrologists and immunologists in addition to oncologists. Efforts are now underway with the help of the Indian Society for Apheresis (founded in 1985) to popularize the newer methods of cryofiltration, photopheresis and heparin extracorporeal low-density lipoprotein (HELP) and DALI apheresis systems besides the specialized techniques of immunoadsorption using filters, columns, or ligands. This is suggestive of a positive trend for the treatment of immune complex disorders.  相似文献   
999.
1000.
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