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   1836篇
  免费   121篇
  国内免费   11篇
耳鼻咽喉   24篇
儿科学   163篇
妇产科学   63篇
基础医学   140篇
口腔科学   88篇
临床医学   179篇
内科学   427篇
皮肤病学   22篇
神经病学   149篇
特种医学   37篇
外科学   193篇
综合类   35篇
预防医学   106篇
眼科学   79篇
药学   123篇
中国医学   8篇
肿瘤学   132篇
  2024年   5篇
  2023年   40篇
  2022年   100篇
  2021年   153篇
  2020年   76篇
  2019年   89篇
  2018年   98篇
  2017年   64篇
  2016年   64篇
  2015年   68篇
  2014年   99篇
  2013年   114篇
  2012年   141篇
  2011年   125篇
  2010年   78篇
  2009年   37篇
  2008年   99篇
  2007年   96篇
  2006年   84篇
  2005年   72篇
  2004年   64篇
  2003年   63篇
  2002年   55篇
  2001年   10篇
  2000年   7篇
  1999年   11篇
  1998年   5篇
  1997年   5篇
  1996年   6篇
  1995年   5篇
  1994年   1篇
  1993年   4篇
  1992年   3篇
  1991年   2篇
  1990年   4篇
  1989年   4篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1983年   1篇
  1979年   1篇
  1975年   1篇
  1974年   1篇
  1966年   1篇
  1936年   2篇
  1923年   1篇
排序方式: 共有1968条查询结果,搜索用时 218 毫秒
61.
The determination of the approximately truest value in height measurement is important in many fields, but it is difficult to perform true measurements, especially in the elderly individuals. We planned to investigate the following items in geriatric Turkish population: to calculate the decrease in height with advancing age by using the standing height measurement and estimated height derived from the knee height; to evaluate the significance of difference between the two measurement methods in the calculation of body mass index (BMI) and waist/height ratio (WHtR); to determine the cut-off value of WHtR according to estimated height in elderly individuals. We studied 551 cases aged between 19 and 97 years. Knee height was measured using a sliding caliper in a sitting position. Linear regression analysis was carried out to derive predictive equations for the estimation of stature with adults (≤50 years of age) according to the gender. This equation was then used to estimate height among elderly subjects. Of the cases, 60.3% were <60 years (mean: 48.75 ± 7.50); 39.7% of the cases were >60 years (mean: 69.51 ± 7.12). Estimated BMI (EBMI) measurements in the females and males >60 years were in average 1.23 kg/m2 and 0.92 kg/m2 higher than their real BMIs, respectively. EBMI measurements in the females <60 years were 0.32 kg/m2 higher than their real BMIs (p < 0.01). There is a statistically significant difference between WHtR in the females of both age groups, and in the males >60 years, as compared to our estimated WHtR (EWHtR) measurements (p < 0.01). The cut-off point of WHtR was 0.61 and 0.58 in the female and male cases of >60 years in our study, respectively. WHtR seemed to be a better anthropometric index that could predict most cardiometabolic risk factors in our study. EWHtR emerged to be a better cardiometabolic risk index especially in the elderly group.  相似文献   
62.
Malign fibrous histiocytoma is one of the most observed soft tissue sarcomas seen in the adults. The most common metastasis region is the lung and metastasis. Mounier-Kuhn syndrome is characterized by the highly dilatation of the trachea and bronchi. We may encounter with the major airway obstruction in the endoluminal or extraluminal lung and mediastinal masses or those with both components together. In this article, we would like to highlight the occurrence of a rare seen clinical situation secondary to the giant mediastinal malign fibrous histiocytoma metastasis and the clinical difficulties experienced in resolving of the main airway obstruction caused by the mass. Since the lack of the similar studies conducted previously, we found the case worth presenting.  相似文献   
63.
INTRODUCTION: Few controlled data exist on the treatment of substancehaloperidol induced psychotic disorders. Our aim was to investigate the effects of risperidone and haloperidol. METHOD: 30 patients who met DSM-IV criteria for cannabis-induced psychotic disorder were randomly allocated to receive either risperidone or haloperidol in a 4-week randomized controlled double-blind clinical trial. RESULTS: There were no significant outcome differences between the two groups on any of the primary outcome measures, the Brief Psychiatric Rating Scale, Clinical Global Impression scale or the Global Assessment of Functioning Scale. No extrapyramidal side-effects (EPS), as measured by either the Simpson Angus Scale or the Barnes Akathisia Scale, emerged in the risperidone group; this was however not statistically different to the haloperidol group due to the low rate of EPS in that group. There were no significant differences between the two groups on the secondary outcome measures, use of lorazepam or biperidin. CONCLUSION: Risperidone appears to be as effective as haloperidol in the treatment of cannabis-induced psychotic disorder. (Int J Psych Clin Pract 2000; 4:139-142)  相似文献   
64.
AimThe partial pulpotomy can offer a successful outcome for the treatment of traumatic complicated crown fractures. The aim of this clinical report was to evaluate the effect of mineral trioxide aggregate (MTA) in apexogenesis of traumatized immature permanent incisors with pulp exposure.Case reportAccording to clinical and radiological examinations complicated crown fractures and open apices were identified in 13 permanent upper incisors in ten patients (age range 7–10 years). Partial pulpotomy procedures were performed and the teeth were treated with MTA. In this report, periodic clinical and radiological follow-ups were performed. At recall examinations, all teeth were asymptomatic, and clinical and radiological investigations revealed excellent healing patterns with continued apexogenesis.ConclusionRegular examination of immature traumatized permanent teeth is critical for vitality and apexification. In this report, clinical and radiological findings confirm that partial pulpotomy with MTA is a reliable and effective treatment approach in apexogenesis of traumatized immature permanent incisors with pulp exposure.  相似文献   
65.
66.
67.
Objective: Normosmic idiopathic hypogonadotropic hypogonadism (nIHH) is characterized by failure of initiation or maintenance of puberty due to insufficient gonadotropin release, which is not associated with anosmia/hyposmia. The objective of this study was to determine the distribution of causative mutations in a hereditary form of nIHH. Methods: In this prospective collaborative study, 22 families with more than one affected individual (i.e. multiplex families) with nIHH were recruited and screened for genes known or suspected to be strong candidates for nIHH. Results: Mutations were identified in five genes (GNRHR, TACR3, TAC3, KISS1R, and KISS1) in 77% of families with autosomal recessively inherited nIHH. GNRHR and TACR3 mutations were the most common two causative mutations occurring with about equal frequency. Conclusions: Mutations in these five genes account for about three quarters of the causative mutations in nIHH families with more than one affected individual. This frequency is significantly greater than the previously reported rates in all inclusive (familial plus sporadic) cohorts. GNRHR and TACR3 should be the first two genes to be screened for diagnostic purposes. Identification of causative mutations in the remaining families will shed light on the regulation of puberty.  相似文献   
68.

Objective

To investigate the role of endogenous neuronal nitric oxide synthase (nNOS) on brain injury after burn and the effects of the captopril.

Methods

Wistar albino rats (200–250 g) were exposed on the dorsal surface to 90 °C (burn) or 25 °C (sham) water for 10 s. The ACE group was treated with intraperitoneal 10 mg/kg captopril immediately after burn and this treatment was repeated twice daily. At the end of the 24 h brain samples were taken. nNOS was studied in brain areas by immunohistochemistry.

Results

There was no difference between the cerebellar and hypothalamic areas the nNOS expression of all groups. nNOS expression increased in the frontal cortex, striatum and midbrain in the burn group compared to the control group. In the frontal cortex, nNOS expression significantly decreased after ACE inhibitor treatment (p < 0.05). The striatal nNOS of the ACE group significantly increased when compared to the control group (p = 0.001). In the midbrain of the animals, nNOS decreased in the ACE group. Hippocampal nNOS expression did not change after burn and significantly increased after ACE inhibitor therapy (p < 0.05).

Conclusions

Our data showed that the pathophysiological events following burn appear to be related to an acute inflammatory reaction which is associated with nNOS in the frontal cortex, striatum and midbrain, and captopril treatment abrogates the nNOS response in the frontal cortex and midbrain.  相似文献   
69.
Although closing force of cobalt alloy clip is well studied, there is only little information of titanium alloy clip available in the literature. In the present study, we examined and compared closing forces of various types and points of cerebral titanium and cobalt aneurysm clips for cerebral aneurysms. Straight, temporary, bayonet, angled, and fenestrated titanium or cobalt alloy clips were tested by measuring the closing forces at various points along their blade length. Closing forces of all the tested clips linearly increased from tip to base of clip blades. Sugita Titanium II clips had bigger closing forces than Elgiloy clips in all type clips except for the temporary clips. The closing forces of Sugita Titanium II and Yasargil titanium clips were similar in straight permanent type clip although there were some differences in closing forces between other types of Sugita and Yasargil clips. Our data showed that the closing forces differed depending not only on manufacturers but also on materials and shapes.  相似文献   
70.
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