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   1279189篇
  免费   92883篇
  国内免费   1988篇
耳鼻咽喉   18207篇
儿科学   42376篇
妇产科学   37905篇
基础医学   187394篇
口腔科学   35401篇
临床医学   108268篇
内科学   252097篇
皮肤病学   26545篇
神经病学   99400篇
特种医学   50042篇
外国民族医学   366篇
外科学   197926篇
综合类   26520篇
现状与发展   1篇
一般理论   300篇
预防医学   92784篇
眼科学   29085篇
药学   97941篇
  1篇
中国医学   2504篇
肿瘤学   68997篇
  2018年   11872篇
  2015年   11659篇
  2014年   16063篇
  2013年   24456篇
  2012年   33666篇
  2011年   36096篇
  2010年   21291篇
  2009年   20107篇
  2008年   35104篇
  2007年   38069篇
  2006年   38634篇
  2005年   37926篇
  2004年   36514篇
  2003年   35506篇
  2002年   35045篇
  2001年   58189篇
  2000年   59681篇
  1999年   50766篇
  1998年   14261篇
  1997年   12827篇
  1996年   13095篇
  1995年   12372篇
  1994年   11770篇
  1993年   10876篇
  1992年   41030篇
  1991年   40410篇
  1990年   39910篇
  1989年   38749篇
  1988年   36144篇
  1987年   35381篇
  1986年   33752篇
  1985年   32163篇
  1984年   23942篇
  1983年   20836篇
  1982年   12382篇
  1981年   10942篇
  1980年   10217篇
  1979年   22655篇
  1978年   15886篇
  1977年   13736篇
  1976年   12976篇
  1975年   14213篇
  1974年   16692篇
  1973年   16086篇
  1972年   15327篇
  1971年   14235篇
  1970年   13215篇
  1969年   12734篇
  1968年   11980篇
  1967年   10482篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Because of the good results achieved with tamoxifen in the treatment of oligozoospermia and with kallikrein in the treatment of asthenozoospermia, a randomized study of the combined treatment of oligoasthenozoospermia suggested itself. 67 patients with idiopathic normogonadotropic oligoasthenozoospermia were treated with 30 mg tamoxifen/day (n = 33) or with 30 mg tamoxifen/day and additionally 600 IU kallikrein/day (n = 34). It was shown that, apart from a significant increase in sperm density in both groups, the combination therapy also resulted in an overall significant increase (p less than 0.02) in sperm motility. Sperm morphology and the swell test remained unaffected. After 3 months of therapy, 4 pregnancies occurred in each group. In ejaculates with a sperm density of less than 10 million/ml not even one sperm parameter was significantly affected in any of the groups, while with an initial value of more than 10 million/ml the increase in motility was more significant (p less than 0.008) in the group with additional kallikrein therapy (n = 18). In the monotherapy group, no significant therapeutic effect on sperm motility was seen even in patients with a sperm density of more than 10 million. The combination of tamoxifen and kallikrein therefore seems to constitute an improvement of the systemic therapy of male subfertility in patients with moderately severe oligoasthenozoospermia.  相似文献   
992.
993.
994.
995.
The authors conducted a clinical and radiographic study on a group of 43 patients with hip arthroprostheses selected from the three-year period from 1984 to 1987, characterized by no immediate postoperative complications, no positional defects on X-ray examination, and with a Renther test greater than 1. Prostheses were cemented, cementless and combined. Scintigraphy was evaluated for areas of subdivision in the proximal end of the femur and acetabulum, making a semi-quantitative comparison of the intensity of captation of each area with that of the skull and sacroiliac synchondrosis. The authors emphasize that this procedure is both reliable and easy for the early determination (pre-clinical and pre-radiographic) of any complications. A scintigraphic examination of the single areas was also capable of revealing the site and entity of prosthetic bone-to-implant interactions. According to the results reported, PCA prostheses seem to be characterized by better biocompatibility.  相似文献   
996.
The activity and principles of administration of Taurolin have been presented. That drug was used in 15 patients with chronic osteitis. Healing by first intention was obtained in 10 patients, necrosis of the skin occurred in 3 patients, recurrence of inflammation was found in one patient in whom accessory sequestroctomy was performed in the last case of osteitis and arteriosclerosis healing was obtained by second intention. The clinical observation of 15 patients has revealed: a) irritating influence of Taurolin on the soft tissue, b) increased phase of secretion of exudate since the 5 day after surgery, c) bactericidal influence of the drug. Sterilization of the focus occurred at 2 to 3 weeks after surgery. The use of Taurolin requires experience, complete abiding by the principles of use of this drug and equipment with a set of Charrier's drains. The authors are carrying on further observation of the use of Taurolin in the treatment of osteitis.  相似文献   
997.
Eighteen renal transplant recipients and sixteen volunteers were subjected to the physiological manoeuvre of head-out water immersion, in order to compare changes in electrolyte and humoral responses known to occur in healthy individuals with those arising as a result of renal denervation in the transplant recipients. Although the tubular sodium response to water immersion was normal, tubular potassium excretion was markedly different in the transplant patients. Plasma values of atrial natriuretic factor increased in both groups and showed a close temporal relationship to urinary excretion of cyclic GMP. The attenuation in transplant recipients of the well-documented suppression of plasma renin activity during water immersion was probably due to a combination of factors, namely lack of renal innervation and an increase in circulating ANF. The small but significant increase in the excretion of enzymically active urinary kallikrein observed only in the transplant recipients during immersion still requires explanation.  相似文献   
998.
Laparoscopic cholecystectomy (LC) using electrocoagulation was successfully performed in 56 out of 58 selected patients. Cholangiography was performed in 53 patients. Six patients had common duct stones; five were unsuspected preoperatively. After the gallbladder was removed, three patients underwent open common duct exploration. In another five cases, anatomical anomalies were discovered. Cholangiography performed via the cystic duct before any structures are divided can prevent the most serious complication--common duct injury. Cholangiography should be attempted on all patients undergoing LC.  相似文献   
999.
A postoperative questionnaire was used in 129 patients who had undergone a wide range of surgical procedures in order to investigate their personal experience of anaesthesia. The most frequent complaints were of feeling cold on waking up, sore throat, vomiting and muscle pains, all of which are capable of reduction by a change in anaesthetic technique. The total number of patients who had one or more complaints was 107 (82.9%). More than a third of the patients were afraid of the anaesthetic, as distinct from the operation. Most had received a pre-operative visit from the anaesthetist which was greatly appreciated. A few patients believed they could have been better informed of possible sequelae. More than 30% were not visited by the surgeon before the operation. A routine postoperative interview, using a preformulated questionnaire, is a good way to assess and maintain a high quality of anaesthesia.  相似文献   
1000.
Lifetime anticoagulation has become a therapeutic option for surgical patients with hypercoagulable states or prosthetic arterial bypass grafts. However, physicians may not achieve optimal anticoagulation or may attempt to limit the length of the therapy period because of the perceived morbidity from hemorrhagic complications of Coumadin therapy. A protocol for anticoagulant therapy monitored and regulated by a vascular nurse-clinician was reviewed. Coumadin was prescribed for 1,891 patient-months to 93 patients to maintain their prothrombin time 1.5 to 2 times control (range: 18 to 24 seconds). The mean (+/- SD) prothrombin time for the study population was 19.8 +/- 1.8 seconds. During follow-up, 472 (14%) of 3,479 prothrombin times measured were below the therapeutic range (n = 232) or prolonged (n = 240), prompting an adjustment in the Coumadin dose in 82 (88%) patients. Four patients developed recurrent vascular graft thrombosis while receiving anticoagulation. There were 6 major and 11 minor hemorrhagic complications. Patients with a chronic risk for arterial or venous thrombosis can have out-patient anticoagulant therapy administered at optimal intensity and regulated safely with a low incidence of hemorrhagic and thrombotic events.  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