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   3462414篇
  免费   255634篇
  国内免费   7803篇
耳鼻咽喉   47683篇
儿科学   109375篇
妇产科学   91515篇
基础医学   487163篇
口腔科学   97688篇
临床医学   318912篇
内科学   666038篇
皮肤病学   68194篇
神经病学   291920篇
特种医学   134514篇
外国民族医学   1128篇
外科学   505200篇
综合类   79122篇
现状与发展   2篇
一般理论   1381篇
预防医学   295389篇
眼科学   79865篇
药学   256072篇
  80篇
中国医学   7573篇
肿瘤学   187037篇
  2019年   27043篇
  2018年   55765篇
  2017年   42558篇
  2016年   47021篇
  2015年   36132篇
  2014年   50296篇
  2013年   76786篇
  2012年   110386篇
  2011年   127787篇
  2010年   79461篇
  2009年   69627篇
  2008年   118569篇
  2007年   126813篇
  2006年   110145篇
  2005年   108118篇
  2004年   104426篇
  2003年   101076篇
  2002年   97410篇
  2001年   146122篇
  2000年   151221篇
  1999年   127659篇
  1998年   37701篇
  1997年   34161篇
  1996年   33449篇
  1995年   32353篇
  1994年   30346篇
  1993年   28381篇
  1992年   102968篇
  1991年   100000篇
  1990年   96970篇
  1989年   92910篇
  1988年   86330篇
  1987年   84860篇
  1986年   80788篇
  1985年   77139篇
  1984年   58666篇
  1983年   50098篇
  1982年   30458篇
  1981年   27107篇
  1979年   54844篇
  1978年   38783篇
  1977年   32488篇
  1976年   30936篇
  1975年   32476篇
  1974年   39954篇
  1973年   38497篇
  1972年   35870篇
  1971年   33296篇
  1970年   31164篇
  1969年   28900篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
In 151 years since first described, there have been 112 reported cases of hernia through the foramen of Winslow (HFW). All thus far have described HFW as a primary entity. The case reported appears to be unique with HFW as a surgical complication. HFW is the least common of internal hernias. The primary symptom is pain referred from the herniated organ and the hepatoduodenal ligament. An interesting sign is that the patient is found curled up or stooped over for pain relief. Anatomic factors implicated in HFW are an enlarged epiploic foramen, a floppy cecum and ascending colon, or abnormal length of small bowel mesentery. Tension on these structures causes pain with the torso extended. Distention of bowel in the lesser sac mimics gastric obstruction. Organs herniated are: small bowel (63%); cecum, ascending colon, and terminal ileum (30%); and transverse colon (7%). Of 25 cases reported since 1966, cecal herniation comprised two-thirds. The diagnosis may be made radiologically and the treatment is surgical. The case and a review of the literature are presented with attention to the anatomy. Also provided are the signs and symptoms of this interesting and perplexing diagnosis.  相似文献   
994.
Fungus balls of the renal collecting system are rarely of organisms other than Candida. A case of obstructing aspergilloma associated with acute ureteral colic is presented. The clinical features of this case are characteristic of renal aspergillomas in 10 additional cases described in the literature. Ten of the 11 patients were male. Each of the patients had an underlying disease that predisposed to fungal infection. Although all 11 patients were cured, diagnostic evaluation was often protracted as commoner causes of ureteral obstruction were excluded. Successful therapy required evacuation of the obstructing hyphal mass; open surgical procedures were necessary in five instances. Systemic amphotericin B should be reserved for patients with residual infection following removal of the fungus ball. This report emphasizes the need to consider aspergilloma in the differential diagnosis of acute ureteropelvic obstruction in the appropriate patient population.  相似文献   
995.
996.
997.
998.
In order to determine if serial, noninvasive evaluation of polytetrafluoroethylene (PTFE) vascular access grafts could identify a subgroup of patients at risk for thrombosis, the authors studied flow characteristics, using duplex ultrasonic scanning, in 18 hemodialysis patients with forearm loop grafts. On average, five examinations were performed per patient over the 10-month study period. Seven episodes of thrombosis occurred in six patients. The mean Doppler flow in grafts that subsequently thrombosed was significantly lower than in those that did not (544 +/- 218 ml/min versus 843 +/- 391 ml/min, p less than 0.001). The interval from last examination to thrombosis ranged from 13 to 58 days. At a defined cut-off flow of 450 ml/min, this test yielded a sensitivity of 83% and a specificity of 75% for episodes of thrombosis occurring within 2 to 6 weeks. The authors conclude that episodes of thrombosis in PTFE arm loop grafts are usually preceded by significantly lower Doppler-measured flow than grafts that do not thrombose and that it may be possible, by this means, to identify grafts at risk.  相似文献   
999.
K Rehse  U Lükens  G Claus 《Archiv der Pharmazie》1987,320(12):1233-1238
Platelet Aggregation Inhibiting and Anticoagulant Effects of Oligoamines, VII: Benzene-1,3,5-trialkanamines Seventeen title compounds were synthesized. Platelet aggregation induced by collagen in vitro is inhibited by 9 of them at IC50 = 2–4 μmol/L. Seven compounds depress the formation of fibrin to ≦ 25 % of normal in concentrations below 50 μmol/L. Compound 15 [4-(2-thienylbutyl)benzene-1,3,5-trimethanamine is the first oligoamine which shows anticoagulant and antiplatelet effects at the same concentration (25 μmol/L).  相似文献   
1000.
The records of 29 consecutive patients treated by a pure, open, anterior acromioplasty were reviewed retrospectively. Excluded from consideration were patients with the following pathologic diagnoses or histories: (1) previously attempted acromioplasty on the same shoulder; (2) intraoperatively confirmed rotator cuff tear; (3) any surgically treatable biceps tendon or acromioclavicular abnormality; (4) lost to follow-up study. Three different techniques were employed to perform the acromioplasties. The first technique required partial deltoid origin detachment with an osteotome. The second technique spared the deltoid origin, while again using an osteotome to perform the acromioplasty. The third technique also spared the deltoid origin but used a high-speed burr to perform the acromioplasty. Evaluated in terms of patient satisfaction, residual pain, length of convalescence, suboptimal results, and complications, the first technique proved to be the least effective. The second technique produced early, excellent results. The third technique, in which a burr was employed through an intact deltoid origin, was most effective; technically, the method was also relatively simple and reliable.  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