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   219869篇
  免费   11001篇
  国内免费   1806篇
耳鼻咽喉   3182篇
儿科学   6321篇
妇产科学   6598篇
基础医学   31610篇
口腔科学   6712篇
临床医学   15535篇
内科学   44744篇
皮肤病学   5353篇
神经病学   15816篇
特种医学   6249篇
外国民族医学   5篇
外科学   29776篇
综合类   5719篇
一般理论   60篇
预防医学   19660篇
眼科学   5195篇
药学   17517篇
中国医学   1156篇
肿瘤学   11468篇
  2021年   2700篇
  2020年   1499篇
  2019年   3006篇
  2018年   5032篇
  2017年   3223篇
  2016年   3217篇
  2015年   3769篇
  2014年   4398篇
  2013年   6472篇
  2012年   10197篇
  2011年   10528篇
  2010年   5764篇
  2009年   4535篇
  2008年   8890篇
  2007年   9470篇
  2006年   9310篇
  2005年   8903篇
  2004年   8273篇
  2003年   7676篇
  2002年   7280篇
  2001年   9953篇
  2000年   10284篇
  1999年   8378篇
  1998年   2331篇
  1997年   1697篇
  1996年   1285篇
  1992年   4959篇
  1991年   4877篇
  1990年   4576篇
  1989年   4465篇
  1988年   4253篇
  1987年   4100篇
  1986年   3841篇
  1985年   3681篇
  1984年   2580篇
  1983年   2208篇
  1982年   1177篇
  1979年   2445篇
  1978年   1503篇
  1977年   1264篇
  1976年   1214篇
  1975年   1493篇
  1974年   1848篇
  1973年   1865篇
  1972年   1756篇
  1971年   1620篇
  1970年   1575篇
  1969年   1525篇
  1968年   1414篇
  1967年   1250篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
Experience in the treatment of 30 cases with gas gangrene from war wounds   总被引:1,自引:0,他引:1  
Z Y Li  X L Wang  X S Wang 《中华外科杂志》1986,24(10):580-1, 637
  相似文献   
53.
54.
The production of progesterone from pregnenolone, of cortisol from cortisone and of prostaglandin E (PGE) under basal and arachidonic acid-stimulated conditions was measured in cells dispersed from chorion and decidua. The cells were obtained after delivery from four groups of women: following spontaneous labour at term (38-42 weeks gestation), at elective caesarean section at term before the onset of labour, after induced labour at term, and after uncomplicated preterm (27-36 weeks) labour. Chorionic cells had a high progesterone output with relatively low cortisol and PGE production, whereas decidual cells had a high cortisol and PGE production rate. Free arachidonic acid stimulated PGE production in both decidual and chorionic cells. There were no significant differences in either steroid or PGE production among the four groups studied. These data suggest that steroid dehydrogenase activity in choriodecidual cells is not related to the mode of onset of labour and that the increased prostaglandin production in intrauterine tissues associated with parturition is due to enhanced availability of arachidonic acid.  相似文献   
55.
PURPOSE: Temporomandibular joint (TMJ) arthroscopy has been considered a safe surgical procedure in the treatment of TMJ derangement. However, it is not exempt from complications. This study evaluates the complications of arthroscopy in patients with internal derangement of TMJ. PATIENTS AND METHODS: Five hundred consecutive patients (670 joints) with TMJ derangement who underwent arthroscopy between 1995 and 2004 were retrospectively analyzed. All the patients were classified as II to V in the Wilkes classification. Lysis and lavage, electrocautery of the posterior ligament, injection of corticoids, injection of ethanolamine, myotomy of lateral pterygoid muscle attachments, myotomy and electrocautery, motor debridement, injection of sodium hyaluronate, and meniscal suture were performed in different patients. RESULTS: Complications were recognized during or immediately after the surgery. They were observed in 5 of 341 (1.26%) arthroscopies of the right TMJ and 4 of 329 (1.21%) arthroscopies of the left TMJ. A 1.34% complication rate was found in the whole series. No blood clots within the external auditory canal were observed. Bleeding within the superior TMJ space was observed in 57 cases (8.5%), 36 of them in the right TMJ and 21 in the left TMJ, but they were not considered as true complications. Lacerations of the external auditory canal were found in 2 cases (0.3%), with no cases of perforation of the tympanic membrane. Lesion of the auriculotemporal nerve was observed in a case. Paresia of the facial nerve was found in 4 cases (0.6%). Alteration of visual accuracy of the ipsilateral eye was also observed in a patient immediately after the surgery. CONCLUSION: Special care must be taken to reduce complications within the upper joint space by means of an adequate instrumentation and by paying attention to essential points of the arthroscopic technique.  相似文献   
56.
To evaluate the impact of pregnancy on bone, we studied bone turnover at the first (T1) and third (T3) trimester of gestation in 58 adolescents and 28 healthy adolescents who had never been pregnant. Total body (TB) and lumbar spine (LS) bone mineral density (BMD) and body composition were evaluated by dual-energy X-ray absorptiometry in all control patients (C) and after parturition in 28 pregnant patients (G). Paired and unpaired t tests, Mann-Whitney and Pearson correlation tests were used. Bone turnover markers were above the reference range for adult women in more than 80% of the adolescents, with no difference between C and G patients at T1. Increase in urinary N-telopeptide crosslinks of type I collagen and serum bone-specific alkaline phosphatase, markers of bone turnover, was seen during pregnancy ( p < 0.0001). Body composition did not differ between groups, but LS BMD, percentage of expected LS BMD, LS Z-score, percentage of expected TB BMD and TB Z-score were lower in G than C patients ( p < 0.05). TB BMD was positively correlated with LS BMD (r2 = 0.52). The inverse correlations between bone markers and LS BMD suggest that the increased bone turnover during pregnancy probably explains the low bone density after parturition. The impact on future peak bone mass must be studied.  相似文献   
57.
58.
This paper reports on 1330 infants, from birth to 24 months old, suffering from diarrhoea and moderate to severe dehydration who were hospitalized in Tehran University Hospital over a period of 11 months. Fifteen per cent of them had signs of shock and 36% had marasmus. All patients were treated orally in two phases: rehydration therapy and maintenance therapy. For rehydration, an isotonic fluid (sodium 80 mmol l-1, potassium 20 mmol l-1) was administered at a rate of 40 ml kg-1 h-1 until all signs of dehydration disappeared. Following complete hydration, the patients were discharged and maintenance therapy was performed at home, by mothers, administering Maintenance Solution (sodium 40 mmol l-1, potassium 30 mmol l-1) ad libitum. Intravenous fluids were not used, even in severe dehydration. The efficacy and safety of this regimen were confirmed by rapid and successful rehydration in 99.7% of the patients and correction of a wide variety of electrolyte abnormalities present on admission, though some relapsed. The study suggests that this protocol could be employed in varied types and severities of dehydration and electrolyte abnormalities, and could also be used in both well nourished infants and in those with severe marasmus. It also demonstrates that mothers can serve as effective health workers and can perform successful maintenance therapy. Nine per cent of treated children required readmission to hospital within 24 h of discharge and a further 8% were hospitalized elsewhere with recurrent symptoms.  相似文献   
59.
60.
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