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   871570篇
  免费   72209篇
  国内免费   1857篇
耳鼻咽喉   12889篇
儿科学   25008篇
妇产科学   25296篇
基础医学   125470篇
口腔科学   25682篇
临床医学   76408篇
内科学   166863篇
皮肤病学   17043篇
神经病学   70981篇
特种医学   35560篇
外国民族医学   171篇
外科学   137756篇
综合类   24760篇
现状与发展   2篇
一般理论   266篇
预防医学   67783篇
眼科学   20957篇
药学   65282篇
中国医学   1618篇
肿瘤学   45841篇
  2018年   7491篇
  2015年   7920篇
  2014年   11375篇
  2013年   17180篇
  2012年   23257篇
  2011年   24494篇
  2010年   14231篇
  2009年   13413篇
  2008年   23167篇
  2007年   25300篇
  2006年   25156篇
  2005年   24781篇
  2004年   24336篇
  2003年   23471篇
  2002年   22469篇
  2001年   35925篇
  2000年   36549篇
  1999年   30992篇
  1998年   9338篇
  1997年   8656篇
  1996年   8571篇
  1995年   8108篇
  1994年   7808篇
  1992年   26761篇
  1991年   26173篇
  1990年   25677篇
  1989年   24743篇
  1988年   23276篇
  1987年   22972篇
  1986年   21822篇
  1985年   21174篇
  1984年   16497篇
  1983年   14097篇
  1982年   8970篇
  1981年   8293篇
  1980年   7778篇
  1979年   16787篇
  1978年   12173篇
  1977年   10254篇
  1976年   9377篇
  1975年   10187篇
  1974年   12688篇
  1973年   12176篇
  1972年   11561篇
  1971年   10702篇
  1970年   10240篇
  1969年   9919篇
  1968年   8913篇
  1967年   8244篇
  1966年   7663篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
211.
Using indirect immunohistochemistry and an antiserum raised against rat corticotrophin-releasing factor (CRF) we have outlined an asymmetric network of cells and varicose fibers in sheep adrenal cortex. This network was not associated with the larger splanchnic nerves, but was occasionally found in small bundles or with blood vessels; in most instances fibers were found weaving independently through cortical parenchyma. A plexus of fibers was found in the zona reticularis, with a few fibers ramifying into adjacent medulla. Uni or bipolar cells were found throughout the cortex, with the greatest frequency at the corticomedullary junction; a multipolar-type cell was also found in this area. Staining of varicose structures and most cells was abolished by incubation with excess rat CRF 1-41, but not by ovine CRF or a range of other peptides. Though the immunoreactive species has not as yet been identified, it may thus share homology with sequences present in rat but not ovine CRF.  相似文献   
212.
An epidemiologic study of coeliac disease in a geographically defined area of Sweden showed that the prevalence was 95.5/10(5) inhabitants aged 15 years or more. The highest prevalence, 178/10(5) inhabitants, was found in the age group 65-74 years. The lowest prevalence, 39/10(5) inhabitants, was found in patients aged 15-24 years. Among the associated diseases an especially high incidence of associated thyroid disease was observed: thyrotoxicosis occurred in 5.0% and hypothyroidism in 5.8% of the patients.  相似文献   
213.
In six patients suffering from severe early dumping and six patients with late dumping after peptic ulcer surgery, the effect of the somatostatin analogue SMS 201-995 was compared with placebo. In early dumpers subcutaneous administration of 50 micrograms SMS 201-995 prior to meal ingestion induced a strong improvement of dumping symptoms as reflected by a decrease of the Sigstad dumping score from 12 +/- 2 during placebo to 5 +/- 2 (p less than 0.05). Furthermore, the postprandial increase of pulse rate was abolished; maximum pulse rate decreased from 85 +/- 7 beats/min to 67 +/- 7 beats/min (p less than 0.05). SMS 201-995 did not significantly affect postprandial changes in packed cell volume. In late dumpers 50 micrograms SMS 201-995 reduced peak plasma insulin after oral glucose from 173 +/- 16 mU/L during placebo to 35 +/- 9 mU/L during SMS 201-995 (p less than 0.05) and increased individual plasma glucose nadirs from 1.9 +/- 0.3 mmol/L to 7.5 +/- 3.3 mmol/L (p less than 0.01). Both in early and late dumpers SMS 201-995 improved postprandial expiratory breath hydrogen excretion indicating slowing of gastrointestinal hurry. SMS 201-995 is a powerful therapeutic agent for the management of patients suffering from the dumping syndrome after gastric surgery.  相似文献   
214.
The use of additional epidural sympathetic block during and after microvascular surgery in the lower extremities to prevent vasospasm is generally agreed on. However, a significant fall in the perfusion rate of the transplants was seen after application of bupivacaine (Marcain) via the epidural catheter. This effect has, to our knowledge, not been described before and is probably caused by the sympathectomy effect of this type of analgesia.  相似文献   
215.
Median cervical cysts are congenital anomalies arising from remaining thyroglossal duct epithelium. A major problem in the surgical treatment of these cysts is the high frequency of recurrence. Embryonic considerations indicate an important causal role for the hyoid bone in these recurrences. We studied the relationship between operative techniques and the number of recurrences in 36 patients treated in our hospital. Fourteen patients sent from other hospitals had a recurrent fistula; in thirteen cases the hyoid bone was still in place. All patients who had the central part of the hyoid bone excised were cured. In 14 patients without adequate excisions of the hyoid bone we found four recurrences. To prevent recurrence a total excision of thyroglossal duct epithelium is necessary.  相似文献   
216.
217.
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   
218.
219.
Membrane-bound CD14 acts as a receptor for lipopolysaccharide (LPS) on monocytes/macrophages and neutrophils. Studies have suggested that the activation of monocytes/macrophages by the binding of LPS to membrane-bound CD14 may require the association of a signal-transducing molecule with membrane-bound CD14. The observation that non-CD14 expressing cells, such as endothelial cells, can nevertheless be activated by a complex of LPS and a soluble form of CD14 (sCD14) suggests that the receptor for this complex may be identical to the signal transducing molecule associated with membrane-bound CD14. The studies described show that two CD14-specific MoAb are able to block the LPS-induced activation of endothelial cells but do not affect the response of monocytes to LPS. This suggests that the interaction of the sCD14:LPS complex with endothelial cells is distinct from the interaction of membrane-bound CD14 with its putative signal-transducing molecule.  相似文献   
220.
Most prosthetic joint infections (PJI) are due to wound contamination at the time of surgery. Some infections occur due to the hematogenous spread of bacteria from distant sites of infection. A review of the literature fails to associate PJI with transient bacteremias from invasive dental procedures. Several authors have described conditions which, they believe, render patients with prosthetic joints more at risk for infection. Prosthetic joint patients with these "high risk" conditions have the same types of infecting organisms as other patients with PJI. This indicates that the infecting bacteria are from wound contamination or distant sites of infection and not related to dental procedure bacteremias. Based on this review, antibiotic prophylaxis is not indicated for patients with prosthetic joints when receiving invasive dental procedures, since there is no proven benefit and there are known risks involved with the use of antibiotics. However, the American Dental Association (ADA) and the American Academy of Orthopaedic Surgeons (AAOS), in an advisory statement, suggest prophylaxis for "high risk" patients. The ADA and AAOS recommend a single dose of amoxicillin, cephradine, or clindamycin when prophylaxis is selected. The dentist is ultimately responsible for making treatment recommendations for his or her patients.  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