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   1186篇
  免费   62篇
  国内免费   11篇
耳鼻咽喉   7篇
儿科学   121篇
妇产科学   11篇
基础医学   101篇
口腔科学   36篇
临床医学   174篇
内科学   280篇
皮肤病学   15篇
神经病学   24篇
特种医学   214篇
外科学   72篇
综合类   35篇
预防医学   70篇
眼科学   7篇
药学   60篇
  1篇
肿瘤学   31篇
  2022年   4篇
  2021年   8篇
  2020年   9篇
  2019年   8篇
  2018年   11篇
  2017年   12篇
  2016年   10篇
  2015年   22篇
  2014年   21篇
  2013年   20篇
  2012年   21篇
  2011年   20篇
  2010年   43篇
  2009年   49篇
  2008年   27篇
  2007年   18篇
  2006年   21篇
  2005年   22篇
  2004年   21篇
  2003年   20篇
  2002年   23篇
  2001年   17篇
  2000年   16篇
  1999年   23篇
  1998年   83篇
  1997年   84篇
  1996年   89篇
  1995年   59篇
  1994年   52篇
  1993年   45篇
  1992年   23篇
  1991年   22篇
  1990年   11篇
  1989年   40篇
  1988年   31篇
  1987年   38篇
  1986年   22篇
  1985年   31篇
  1984年   23篇
  1983年   19篇
  1982年   17篇
  1981年   21篇
  1980年   10篇
  1979年   8篇
  1978年   7篇
  1977年   8篇
  1976年   9篇
  1975年   11篇
  1970年   5篇
  1968年   5篇
排序方式: 共有1259条查询结果,搜索用时 10 毫秒
951.
Infections in mice were initiated with trypomastigotes from two lines ofTrypanosoma brucei derived from the same primary isolate. Infections with one line were initiated by inoculation of metacyclic trypomastigotes from infected tsetse flies and the resulting infections were pleomorphic. The other line had been passaged 32 times in rodents and inoculation of blood-stream trypomastigotes gave rise to monomorphic infections. In both infections there were high levels of parasitaemia until death up to 4 weeks later if the infection was untreated. It was shown that after chemotherapy with 40 mg/kg diminazene aceturate (Berenil) relapses occurred in both types of infection after an aparasitaemic period of 2–3 weeks. Further, it was shown that 3 days after chemotherapy, brain tissue but neither spleen, liver nor blood was capable of transferring infection to normal recipient mice.There were two major differences in the response of the two infections to chemotherapy. First, treatment of the pleomorphic infection as soon as day 6 after infection resulted in a subsequent relapse while the monomorphic infection had to be at least 12 days old at the time of treatment before relapses occurred. Second, following treatment of the pleomorphic, but not of the monomorphic infection there was an early transient recrudescence of low numbers of trypanosomes which were found to be non-infective to recipient mice. The early transient relapse was followed by a further aparasitaemic period and then the late continuous relapse characterised by large numbers of infective trypanosomes.  相似文献   
952.
953.
954.
A term infant presented at birth with worsening respiratory distress which resulted in him requiring mechanical ventilation. A CT scan of the chest revealed a bronchogenic cyst, removal of which resulted in full recovery and, to date, no respiratory sequelae.  相似文献   
955.
SUMMARY A prospective study undertaken to examine bacterial contamination at presentation, frequency and type of antibiotic prescribed, and outcome, in 50 patients presenting with hand injuries of varying severity, is reported. Results of a national survey of trends in antibiotic prescribing for similar wounds in plastic surgery units are also recorded. Preoperative swabs cultured normal flora or no growth. Forty-eight patients received antibiotics with little consistency in the agent used, route of administration, or length of treatment. Clinical wound infection occurred in three crush injuries. No significant difference in the numbers of surgeons using antibiotics for clean and crushed injuries of all types was demonstrated. The state of the wound, rather than the tissue damaged, seemed to dictate antibiotic use. In dirty wounds, however, damage to deep structures appeared to be an indication for antibiotics — significantly fewer respondents treated dirty injuries of the skin alone. The authors believe that antibiotic use in open hand injury is of no proven benefit, and that this aspect of hand surgery requires further investigation.  相似文献   
956.
Varices from portal hypertension: correlation of CT and angiography   总被引:2,自引:0,他引:2  
Two hundred abdominal CT and angiographic examinations were performed on 137 patients with portal hypertension. These patients were being evaluated before or after a distal splenorenal shunt. CT increased the detection of umbilical and retroperitoneal varices. Angiography better detected peripancreatic varices and cavernous transformation. Both modalities together added more information than either alone in identification of coronary and/or gastroesophageal, retrogastric, and perisplenic-mesenteric varices. This additional anatomic information helped in the patient's management pre- and postoperatively.  相似文献   
957.
Platelet-associated IgG (PAIgG) has been reported to be elevated in nonthrombocytopenic patients who have a normal platelet lifespan. This has been interpreted as indicating that PAIgG is a nonspecific finding in these patients and not a determinant of platelet survival. It is important to recognize that the reticuloendothelial (RE) system plays an important role in the clearance of antibody-sensitized cells. In this study, we related the level of PAIgG and the platelet lifespan to the RE function in patients with: (A) idiopathic thrombocytopenic purpura (ITP), and (B) five patients with elevated levels of PAIgG yet normal or near-normal platelet counts. RE function was assessed by measuring the clearance of autologous chromium-labeled red cells sensitized with a precise amount of alloantibody (2,000-3,600 molecules of IgG/cell). Eight patients with immune thrombocytopenia had significantly shortened platelet survivals (less than 2-113 hr). In contrast, the five patients with elevated PAIgG, yet normal or near- normal platelet counts, all had normal autologous platelet survivals (186-222 hr). These patients also had significantly impaired clearance of IgG-sensitized red cells, with an average of 85% of the infused red cells remaining in the circulation at 60 min (normal 42% +/- 14%, n = 10). In this study, every patient with elevated PAIgG and normal RE function had a shortened platelet lifespan. Those patients with elevated PAIgG and impaired RE function did not invariably have a shortened platelet lifespan. The observation that the PAIgG is elevated in some patients whose platelet survival is normal does not indicate that PAIgG is not biologically relevant. It indicates that these patients may have RE blockade and do not clear IgG-sensitized cells.  相似文献   
958.
959.
Five children with cystic fibrosis complicated by hepatic cirrhosis received liver grafts. They all had portal hypertension with varices and three had variceal bleeding; respiratory function was only moderately impaired, but four were colonised with pseudomonas and one with aspergillus. Liver transplantation was well tolerated and there was no increase in respiratory or other early postoperative complications. Four of the children were fully well from 14 to 35 months after transplantation; the most recently transplanted had problems from a biliary stricture. In spite of the need for immunosuppression there was no increase in infection and respiratory function improved or remained stable. Once the children were stabilised after transplantation their nutrition and general health were greatly improved.  相似文献   
960.
Twenty two children were evaluated for small bowel transplantation between 1989 and 1994. Eight were unfit for transplantation and died within three months; a raised plasma bilirubin concentration (> 200 mumol/l) predicted death from liver failure within six months (p = 0.0001). The 11 children who were not managed by a multidisciplinary nutritional care team were less well nourished at referral, had more complications with intravenous feeding catheters, and greater early mortality while awaiting transplantation (p < 0.05). It is recommended that children with chronic intestinal failure be referred for assessment early, before liver dysfunction is established.  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