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   104578篇
  免费   6562篇
  国内免费   767篇
耳鼻咽喉   1272篇
儿科学   3063篇
妇产科学   2569篇
基础医学   14269篇
口腔科学   2822篇
临床医学   8460篇
内科学   22769篇
皮肤病学   2129篇
神经病学   9643篇
特种医学   3992篇
外国民族医学   23篇
外科学   14616篇
综合类   1757篇
现状与发展   1篇
一般理论   63篇
预防医学   6433篇
眼科学   1775篇
药学   8311篇
  3篇
中国医学   552篇
肿瘤学   7385篇
  2023年   501篇
  2022年   1203篇
  2021年   2105篇
  2020年   1358篇
  2019年   1960篇
  2018年   2374篇
  2017年   1771篇
  2016年   1833篇
  2015年   2170篇
  2014年   2813篇
  2013年   4132篇
  2012年   5493篇
  2011年   5773篇
  2010年   3627篇
  2009年   3213篇
  2008年   4953篇
  2007年   5245篇
  2006年   4898篇
  2005年   4708篇
  2004年   5023篇
  2003年   4810篇
  2002年   4841篇
  2001年   3829篇
  2000年   3756篇
  1999年   3059篇
  1998年   1201篇
  1997年   950篇
  1996年   865篇
  1995年   845篇
  1994年   746篇
  1993年   716篇
  1992年   1825篇
  1991年   1814篇
  1990年   1547篇
  1989年   1501篇
  1988年   1369篇
  1987年   1233篇
  1986年   1204篇
  1985年   1075篇
  1984年   801篇
  1983年   730篇
  1982年   483篇
  1981年   415篇
  1979年   601篇
  1978年   448篇
  1975年   452篇
  1974年   506篇
  1973年   492篇
  1972年   446篇
  1971年   418篇
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
71.
72.
Responses to a standardized respiratory symptom questionnaire, spirometry, and cross-shift decreases in lung function between 70 current employees of a polyvinylchloride (PVC) fabrication plant and a control group consisting of 48 men employed in a vegetable packing plant were compared. FEV1/FVC was significantly lower in the PVC workers. Cross-shift drops in Vmax75 of 15% or more were also more prevalent in the exposed group (p = .01). When examining the association between months of work within the exposed workforce and spirometric indices of airway obstruction, no relationship could be demonstrated. However, an inverse dose-response relationship was seen between level of FVC and duration of employment, suggesting a restrictive impairment. While the specific exposures have not been identified, it appears that employment in PVC fabrication may be associated with both obstructive and restrictive ventilatory effects.  相似文献   
73.
Lymphoma in immunocompromised transplant patients is a feared cause of morbidity and mortality. Superimposed on the lymphoma and the transplantation immunosuppression is a rare condition: hemophagocytic syndrome (HS). HS is characterized by fever, hepatosplenomegaly and lymphadenopathy, skin rashes, jaundice, coagulopathy, and phagocytosis of blood elements with pancytopenia. Here we describe a rare but fatal case of a kidney transplant patient who developed T-cell lymphoma and HS, without evidence of EBV replication. A short review of the diagnosis, treatment, and prognosis of HS is given. Received: 4 March 1997 Received after revision: 6 June 1997 Accepted: 30 June 1997  相似文献   
74.
Objective: To evaluate the effects of a new timing strategy of band adjustment on the short-term outcome of obese women operated with adjustable silicone gastric banding. Subjects: The outcome of 30 women without binge-eating disorder operated with laparoscopic adjustable silicone gastric banding with a wider intraoperatory band calibration (LAP-BAND) was compared to that of 30 body mass index-matched women without binge-eating disorder previously operated with adjustable silicone gastric banding (ASGB) applied by laparotomy with the usual intraoperatory band calibration. The patients were evaluated 3, 6 and 12 months after surgery. Measurements: (1) weight loss; (2) total daily energy intake; (3) percent as liquid, soft or solid food; (4) vomiting frequency; (5) rate of postoperative percutaneous band adjustments; (6) rate of band-related complications. Results: Both the weight loss and the daily energy intake did not differ between patients with LAP-BAND and patients with ASGB. After surgery, the patients with LAP-BAND ate more solid food and less liquid food than the patients with ASGB. Vomiting frequency was higher in patients with ASGB than in patients with LAP-BAND. The total number of percutaneous band adjustments was higher in women with LAP-BAND than in women with ASGB. Band inflation because of weight stabilization was performed in six (20.0%) women with ASGB and in 19 (63.3%) women with LAP-BAND. Neostoma stenosis occurred in one women with ASGB, but in none of the women with LAP-BAND. One patient with LAP-BAND presented band slippage. Conclusions: The wider intraoperatory band calibration performed in patients with LAP-BAND did not reduce the short-term efficacy of adjustable silicone gastric banding. This new timing strategy of band adjustment required more postoperative percutaneous band inflations, but it improved the eating pattern of the patients (low vomiting frequency and high intake of solid food).  相似文献   
75.
Underlining the importance of Profundus Femoral Artery and its capacity to make up for lower limb's haemodynamics during obliterative arteriopathy, the Authors conceive a funnel-shaped intravascular prosthesis, Goretex constructed (PTFE), to introduce, in case of obstruction, in the artery lumen with a suitable instrument. The research is performed through ten oldster dogs whose average weight is twenty-four kilograms. Isolated the deep Femoral Artery and carried out an arteriotomy of about two centimetres on the Common Femoral Artery, we bring the prothesis in Profundis Femoral Artery and we fix it to the wall of the Common Femoral Artery with 8/O microsurgical dots. After thirty days, the arteriographic test shows the patency of the endoprosthesis with normal peripheral flow in nine animals out of ten. By virtue of this preliminary experiment, the Authors point out the semplicity of this intervention, also feasible in local anaesthesia, the good tolerability of the prosthesis and its perfect integration with the surrounding arterious wall, without shifts or dissecting laminar flows between the external prosthesis wall and the vessel lumen of the animal.  相似文献   
76.
77.
To evaluate the effects of the aldose reductase inhibitor Ponalrestat (Statil) on diabetic autonomic neuropathy, a double-blind placebo controlled trial was carried out on a group of 34 diabetic patients with documented cardiac autonomic neuropathy. After a 4-week, placebo run-in period, patients were randomised for treatment with 600 mg Statil or placebo for another 24 weeks. Moreover, the reliability of the autonomic nerve function tests was investigated by comparing the results at onset and at week 4. Fifteen patients treated with Statil and 12 with placebo completed the study. Neither symptom scores nor cardiovascular reflexes, pupil reflexes and skin vasomotor reflexes improved after Statil therapy, which led us to conclude that Statil is not effective in the treatment of diabetic autonomic neuropathy. Reliability coefficients for cardiovascular reflexes and pupil reflex showed high values, ranging from 60% to 80%. Therefore these methods are recommended in future therapy trials.  相似文献   
78.
79.
80.
Tissues were obtained from 387 male pig fetuses ranging from 60 to 120 days of gestation. The relative wet mass and water content of the gubernaculum increased during and decreased after the period of testicular descent. The extracellular glycosaminoglycans (GAG) were assayed to determine whether these polyanionic macromolecules are responsible for the increased water content of the gubernaculum. The total GAG/wet tissue mass in the gubernaculum decreased during and increased after descent, while the total GAG/dry mass decreased during and after descent, indicating an accumulation of water during descent, with a loss of water and an increase in less hydrated tissue components after descent. The major GAG fraction in the gubernaculum was dermatan sulfate, but the percentage hyaluronate in the gubernaculum was two times higher than in striated muscle or umbilical cord, indicating that this GAG fraction may be responsible for the increased water content of the gubernaculum, which probably serves to dilate the inguinal canal and scrotum, thus facilitating descent.  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