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   2960篇
  免费   160篇
  国内免费   16篇
耳鼻咽喉   56篇
儿科学   101篇
妇产科学   87篇
基础医学   269篇
口腔科学   142篇
临床医学   232篇
内科学   648篇
皮肤病学   31篇
神经病学   238篇
特种医学   122篇
外科学   516篇
综合类   24篇
一般理论   2篇
预防医学   219篇
眼科学   48篇
药学   138篇
中国医学   5篇
肿瘤学   258篇
  2024年   3篇
  2023年   35篇
  2022年   46篇
  2021年   126篇
  2020年   95篇
  2019年   99篇
  2018年   144篇
  2017年   91篇
  2016年   103篇
  2015年   106篇
  2014年   152篇
  2013年   173篇
  2012年   288篇
  2011年   261篇
  2010年   125篇
  2009年   126篇
  2008年   187篇
  2007年   186篇
  2006年   173篇
  2005年   123篇
  2004年   95篇
  2003年   79篇
  2002年   74篇
  2001年   18篇
  2000年   18篇
  1999年   16篇
  1998年   16篇
  1997年   6篇
  1996年   9篇
  1995年   10篇
  1994年   7篇
  1993年   10篇
  1992年   13篇
  1991年   9篇
  1990年   16篇
  1989年   10篇
  1988年   10篇
  1987年   20篇
  1986年   10篇
  1985年   9篇
  1984年   11篇
  1980年   2篇
  1977年   3篇
  1975年   3篇
  1974年   2篇
  1973年   2篇
  1972年   3篇
  1969年   3篇
  1967年   3篇
  1936年   1篇
排序方式: 共有3136条查询结果,搜索用时 15 毫秒
91.
Strontium ranelate is claimed to be related with increased risk of thromboembolic events. No explanation of this increased incidence of thromboembolism has been identified. However, growing evidence has clearly demonstrated the involvement of blood rheology in any thrombotic process. The aim of this study was to assess hemorheological changes with strontium ranelate treatment in elderly women with osteoporosis. This study was designed in a prospective manner. Twenty-two elderly women diagnosed with osteoporosis were included. During a 2-month treatment period, participants received strontium ranelate 2 g/day. Hemorheological parameters including erythrocyte deformability, erythrocyte aggregation and plasma viscosity were measured before and after 2 months therapy with strontium ranelate. The median age of the patients was 70.0 (range = 65-80) years. After 60 days of treatment, there was no statistically significant change in hemorheological parameters. None of the subjects developed clinical venous thromboembolic event (VTE) during the 2-month period of strontium ranelate treatment. Our study demonstrated that in elderly women, treatment of osteoporosis with strontium ranelate did not change hemorheological parameters over 2 months of time. However, its long-term effects on hemorheologic parameters should be evaluated further with a larger sample.  相似文献   
92.
Cardiovascular disease (CVD) and OP are common age-related conditions. In both cross-sectional and longitudinal epidemiologic studies, low bone mass has been related to increased frequency of CVD. But available data in geriatric population is limited. In this study we aimed to seek the possible relationship between CAD and low bone mineral density (BMD) in a large number of geriatric patients. A total of 2235 patients aged 65 years or more were included in this cross-sectional study. All patients underwent a complete geriatric assessment and evaluated for CAD and cardiovascular risk factors. BMD was measured by dual-energy X-ray absorptiometry at the lumbar spine (L1-L4) and femoral neck. BMD results were classified into three groups; normal (T-score: ≥-1.0×S.D.), osteopenia (T-score between -1.0 and -2.5×S.D.), and OP (T-score: ≤-2.5×S.D.). CAD was present in 397 (29.7%) of 1335 patients with OP, in 199 (27.4%) of 726 patients with osteopenia and in 34 (19.5%) of 174 patients with normal BMD. Multivariate regression analysis revealed that presence of OP or osteopenia increased the prevalence of CAD as an independent correlate (OR=1.643; 95% CI=1.068-2.528, p=0.030). This study highlights the need for careful evaluation of elderly patients with low BMD for possible CAD.  相似文献   
93.
94.
95.
Narcolepsy is a rare disorder characterised by sleep disturbances, cataplexy, sleep paralysis and hypnagogic, hypnopompic hallucinations. Although several treatment modalities, such as tricyclic antidepressants or selective serotonin reuptake inhibitors, have been used to treat different symptoms, there is no definite treatment for narcolepsy. Modafinil or amphetamine-like stimulants, such as dexamphetamine or methylphenidate, are used to treat sleepiness. Our case was a 58-year-old woman who was diagnosed as narcolepsy cataplexy syndrome. Her Epworth Sleepiness Scale (ESS) score was 14 and Beck Depression Inventory (BDI) score was 29 in the first evaluation. Imipramine and modafinil were begun for the treatment, but there was no improvement in her symptoms. Subsequently, bupropion was started at 150 mg/day and then dosage was increased to 300 mg/day. She was asymptomatic at the end of 3 months. To our knowledge, this is the second depressive narcoleptic patient who has responded to 300 mg/day of bupropion.  相似文献   
96.
Abstract Objective. Isolated systolic hypertension (ISH) is generally encountered in elderly patients and there are scarce data regarding the renin-angiotensin-aldosterone system (RAAS) activity in patients with ISH. We aimed to determine the plasma renin activity (PRA), plasma aldosterone levels (PAL) and aldosterone/PRA ratio (PAL/PRA) in patients (age >50 years) with ISH and to compare these values with patients with essential hypertension (EH) as well as subjects with normal blood pressure values (control) who have similar age and cardiovascular risk profile. Methods. Consecutively, 42 untreated ISH patients, 30 patients with EH and 29 normal subjects were included in the study. Parameters were presented as median (interquartile range). Results. There were no significant differences regarding age, gender and other cardiovascular risk factors among groups. As expected, systolic, diastolic blood pressure and pulse pressure values were significantly different among groups. Besides, PRA values were found to be significantly lower in patients with ISH (0.4 [0.2-1.1] ng/ml/h) compared with the EH (0.95 [0.5-2.6] ng/ml/h, p =0.024) and control (1.3 [0.7-2.1] ng/ml/h, p =0.001) groups. Although, PAL were similar among groups, PAL/PRA ratio was significantly higher in ISH group (134.1 [73-224]) compared with those with EH (42.2 [35-84], p <0.001) and the control group (53.3 [30-106], p =0.001). No significant difference was present with respect to PAL/PRA ratio between EH and control groups. Conclusions. Our findings suggested that in patients with ISH, despite lower PRA levels, PAL/PRA ratio is significantly higher compared with the patients with EH and subjects with normal blood pressure. Since higher PAL/PRA levels is an indicator of relative aldosterone excess, medications blocking RAAS activity including aldosterone antagonists may have useful cardiovascular consequences in addition to their antihypertensive effects in ISH.  相似文献   
97.
98.
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   
99.
Endoscopic transsphenoidal surgery is emerging as a minimally invasive and maximally effective procedure for pituitary adenomas. In this report we analyzed the complications in 624 procedures of endonasal transsphenoidal endoscopic surgery in the treatment of 570 patients with pituitary adenomas. The leading author (MB) operated pituitary adenomas via pure endoscopic endonasal transsphenoidal surgery between January 2006 and August 2011 at the Hacettepe University, Department of Neurosurgery in Ankara. Complications were assessed in 624 surgical procedures under five groups; rhinological, CSF leaks, infection, vascular and endocrinologic complications. We observed a total of 76 complications (12.1%). Rhinological complications occurred in 8 patients (1.3%): 4 epistaxis (0.6%) and 4 hyposmia (0.6%). Postoperative CSF leaks occurred in 8 patients (1.3%), and infectious complications occurred in 8 patients: 3 cases of sphenoidal sinusitis (0.4%), 5 cases of meningitis (0.8%). Only 1 case of internal carotid aneurysm rupture during the opening of sellar floor (0.16%) was observed. Endocrinologic complications occurred in 51 (8.1%) patients: Anterior pituitary deficiency in 12 (1.9%), transient diabetes insipidus (DI) in 29 (4.6%), permanent DI in 3 (0.4%) and inappropriate antidiuretic hormone secretion syndrome occurred in 7 (1.1%). There was no mortality directly related to the surgical procedure. The complication rates observed in our study suggests that the endoscopic pituitary surgery is at least as safe as microscopic transphenoidal surgery. These rates were obtained with due experience and well-coordinated teamwork. To further improve these rates, new technological developments will be helpful.  相似文献   
100.
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