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   2936382篇
  免费   220664篇
  国内免费   4868篇
耳鼻咽喉   41720篇
儿科学   92837篇
妇产科学   80245篇
基础医学   431923篇
口腔科学   82419篇
临床医学   264202篇
内科学   563612篇
皮肤病学   63844篇
神经病学   233361篇
特种医学   111685篇
外国民族医学   653篇
外科学   446220篇
综合类   66419篇
现状与发展   13篇
一般理论   1053篇
预防医学   230670篇
眼科学   69558篇
药学   219325篇
  11篇
中国医学   5807篇
肿瘤学   156337篇
  2018年   31728篇
  2017年   24093篇
  2016年   26870篇
  2015年   30511篇
  2014年   43264篇
  2013年   65181篇
  2012年   89440篇
  2011年   94985篇
  2010年   56310篇
  2009年   53139篇
  2008年   89443篇
  2007年   95681篇
  2006年   96274篇
  2005年   93686篇
  2004年   90140篇
  2003年   86908篇
  2002年   84055篇
  2001年   130129篇
  2000年   133405篇
  1999年   112428篇
  1998年   33195篇
  1997年   29371篇
  1996年   29447篇
  1995年   27794篇
  1994年   25827篇
  1993年   24336篇
  1992年   88774篇
  1991年   86922篇
  1990年   85001篇
  1989年   81870篇
  1988年   75705篇
  1987年   74227篇
  1986年   69733篇
  1985年   67161篇
  1984年   50588篇
  1983年   43154篇
  1982年   26132篇
  1981年   23675篇
  1979年   47858篇
  1978年   34325篇
  1977年   28616篇
  1976年   27257篇
  1975年   29390篇
  1974年   35650篇
  1973年   33957篇
  1972年   32065篇
  1971年   30158篇
  1970年   28095篇
  1969年   27011篇
  1968年   24598篇
排序方式: 共有10000条查询结果,搜索用时 18 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