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   3241946篇
  免费   252226篇
  国内免费   7610篇
耳鼻咽喉   45629篇
儿科学   101820篇
妇产科学   87048篇
基础医学   462869篇
口腔科学   93105篇
临床医学   304891篇
内科学   624023篇
皮肤病学   65092篇
神经病学   272613篇
特种医学   125826篇
外国民族医学   1128篇
外科学   473841篇
综合类   76633篇
现状与发展   2篇
一般理论   1383篇
预防医学   270878篇
眼科学   75340篇
药学   242192篇
  10篇
中国医学   6522篇
肿瘤学   170937篇
  2018年   35007篇
  2017年   26810篇
  2016年   29347篇
  2015年   33417篇
  2014年   47473篇
  2013年   73050篇
  2012年   99208篇
  2011年   104994篇
  2010年   61644篇
  2009年   58201篇
  2008年   98490篇
  2007年   104600篇
  2006年   105470篇
  2005年   102509篇
  2004年   98179篇
  2003年   94403篇
  2002年   92523篇
  2001年   144804篇
  2000年   149603篇
  1999年   126633篇
  1998年   37468篇
  1997年   33952篇
  1996年   33391篇
  1995年   32267篇
  1994年   30278篇
  1993年   28337篇
  1992年   102328篇
  1991年   99390篇
  1990年   96282篇
  1989年   92337篇
  1988年   85833篇
  1987年   84378篇
  1986年   80278篇
  1985年   76725篇
  1984年   58348篇
  1983年   49818篇
  1982年   30386篇
  1981年   27044篇
  1979年   54394篇
  1978年   38511篇
  1977年   32204篇
  1976年   30678篇
  1975年   32136篇
  1974年   39464篇
  1973年   37987篇
  1972年   35389篇
  1971年   32824篇
  1970年   30702篇
  1969年   28406篇
  1968年   26282篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
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   
992.
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   
993.
994.
995.
996.
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   
997.
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   
998.
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   
999.
Several reports in the literature suggest a relationship between lead intoxication and thermoregulatory capacity. To investigate the effects of lead on the control of body temperature, mice of the BALB/c strain were injected intraperitoneally with lead acetate (0 to 100 mg/kg) while colonic temperature was measured 30, 60, and 90 min post-injection at ambient temperatures (Ta) of 20 and 30 degrees C. Lead acetate caused a transient hypothermia, an effect which was augmented at cooler Ta's. In a second experiment, mice were injected with 100 mg/kg lead acetate and placed in a longitudinal temperature gradient to measure their preferred Ta. Lead acetate significantly reduced the preferred Ta during the first 30 min post-injection which augmented the lead-induced hypothermia. In a third experiment it was found that lead acetate-induced lethality was potentiated with increasing Ta. Hence, the hypothermic response to acute lead acetate treatment may be beneficial to survival.  相似文献   
1000.
The Alaska mental health program is endowed with a 1-million-acre trust fund. A coalition of groups that make up the mental health constituency of the state united in a lawsuit to establish the trust. The history of this legacy, the struggle to realize its benefits, its current status, and some of its psychopolitical significance are discussed.  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