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   1678篇
  免费   116篇
耳鼻咽喉   4篇
儿科学   105篇
妇产科学   51篇
基础医学   187篇
口腔科学   63篇
临床医学   155篇
内科学   251篇
皮肤病学   33篇
神经病学   383篇
特种医学   53篇
外科学   160篇
综合类   9篇
预防医学   94篇
眼科学   10篇
药学   106篇
中国医学   1篇
肿瘤学   129篇
  2024年   5篇
  2023年   21篇
  2022年   48篇
  2021年   48篇
  2020年   39篇
  2019年   42篇
  2018年   52篇
  2017年   33篇
  2016年   44篇
  2015年   37篇
  2014年   63篇
  2013年   85篇
  2012年   96篇
  2011年   123篇
  2010年   67篇
  2009年   69篇
  2008年   73篇
  2007年   87篇
  2006年   87篇
  2005年   87篇
  2004年   95篇
  2003年   77篇
  2002年   80篇
  2001年   38篇
  2000年   38篇
  1999年   27篇
  1998年   19篇
  1997年   20篇
  1996年   11篇
  1995年   21篇
  1994年   8篇
  1993年   5篇
  1992年   18篇
  1991年   16篇
  1990年   29篇
  1989年   22篇
  1988年   9篇
  1987年   4篇
  1986年   4篇
  1985年   12篇
  1984年   4篇
  1983年   4篇
  1982年   2篇
  1980年   2篇
  1979年   5篇
  1978年   7篇
  1976年   5篇
  1973年   1篇
  1972年   1篇
  1968年   1篇
排序方式: 共有1794条查询结果,搜索用时 31 毫秒
31.
32.
Diurnal 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) pattern was studied with RIA technique in 33 hypertensive patients in supine position and on normal sodium diet. The compound was evaluated every 2 h from 0800-2000 h. Simultaneously, plasma aldosterone and cortisol were measured. Abnormal 18-OH-DOC behavior was observed in only 2 out of 4 patients with Cushing's disease, while sporadic and slight elevations, synchronous with F, were seen in 5 out of 24 stable essential hypertensive patients [1 with normal plasma renin activity (PRA), 1 with low PRA, and 3 with high PRA]. 18-OH-DOC was normal in 2 cases of hypertension due to renal artery stenosis, in 1 patient with nephrosclerosis, and in 1 patient with horseshoe kidney. From these results, 18-OH-DOC does not seem to play an important pathogenetic role in stable essential hypertension, considering also the low mineralocorticoid activity of the compound.  相似文献   
33.
The aim was to assess 3-year longitudinal data using 6MWT in 26 ambulant boys affected by DMD carrying nonsense mutations and to compare their results to other small mutations. We also wished to establish, within the nonsense mutations group, patterns of change according to several variables. Patients with nonsense mutations were categorized according to the stop codon type newly created by the mutation and also including the adjacent 5′ (upstream) and 3′ (downstream) nucleotides. No significant difference was found between nonsense mutations and other small mutations (p > 0.05) on the 6MWT. Within the nonsense mutations group, there was no difference in 6MWT when the patients were subdivided according to: Type of stop codon, frame status of exons involved, protein domain affected. In contrast, there was a difference when the stop codon together with the 3′ adjacent nucleotide (“stop+4 model”) was considered (p < 0.05) with patients with stop codon TGA and 3′ adjacent nucleotide G (TGAG) having a more rapid decline. Our finding suggest that the stop+4 model may help in predicting functional changes. This data will be useful at the time of interpreting the long term follow up of patients treated with Ataluren that are becoming increasingly available.  相似文献   
34.
Patients with mucopolysaccharidosis type VI (MPS VI) present with a wide range of disease severity and clinical manifestations, with significant functional impairment and shortened lifespan. Enzyme replacement therapy (ERT) with galsulfase has been shown to improve clinical and biochemical parameters including patient survival, quality of life and growth. The present study is a resurvey of 34 Brazilian MPS VI patients with rapidly progressive disease (classical phenotype) who initiated ERT with galsulfase under five years of age and had been on ERT until data collection in 2019, with few exceptions (n = 4 patients who died before 2019).Anthropometric measures, urinary glycosaminoglycans, and data regarding cardiac, orthopedic, neurologic, sleep apnea, hearing and ophthalmologic outcomes were filled in by specialists. Pubertal development, clinical complications, hospitalizations, and surgeries were also assessed.In this resurvey study, treatment with galsulfase has shown to be safe and well tolerated in MPS VI patients who initiated ERT under the age of 5 years and who have been undergoing ERT for approximately 10 years. Mortality rate suggests that early initiation of ERT may have a positive impact on patients' survival, improving but not preventing disease progression and death. MPS VI patients on ERT also showed improved growth velocity and the pubertal development was normal in all surviving patients.Follow-up data on pneumonia and hospitalization suggest that early ERT may have a protective effect against major respiratory complications. Cardiac valve disease progressed since their prior evaluation and spinal cord compression was observed in a large number of patients, suggesting that these disease complications were not modified by ERT.  相似文献   
35.
The aim of the present study was to evaluate the effects of estrogens and androgens on hypothalamic beta-endorphin (beta-EP) concentrations. Intact or castrated female rats were chronically (2 weeks) treated with estrogen (estradiol benzoate) and/or antiestrogens (clomiphene, cyclophenil or epimestrol), and with androgens (dihydrotestosterone or dehydroepiandrosterone sulphate) and/or antiandrogen (cyproterone acetate). A group of rats treated with vehicle were studied as comparison. The beta-EP concentrations were measured by radioimmunoassay on acidic extracts of rat hypothalami. The administration of clomiphene and cyclophenil significantly reduced hypothalamic beta-EP concentrations in intact rats, while both drugs or estradiol benzoate increased the peptide concentration in castrated rats. Both intact and castrated rats treated with epimestrol showed hypothalamic beta-EP concentrations higher than vehicle treated rats. The estradiol-induced increase of beta-EP was not changed by the concomitant administration of antiestrogens. The administration of dihydrotestosterone significantly decreased beta-EP concentrations in both intact and castrated female rats, while the treatment with dehydroepiandrosterone sulphate only slightly decreased beta-EP levels in intact female rats. The cyproterone acetate-chronically treated rats showed higher beta-EP concentrations than vehicle-treated rats and these changes were reversed by the concomitant addition of dihydrotestosterone or dehydroepiandrosterone sulphate. These results showed that estrogens play a positive role while androgens negatively influence the hypothalamic beta-EP concentrations in female rats, supporting the view that central beta-EP might be a target of gonadal steroid feedback signals.  相似文献   
36.
37.
38.
Whether part of the blood pressure lowering effects of glyceryl trinitrate (GTN) is the result of centrally mediated reduction in sympathetic activity is debated. In humans, baroreflex activity potentially obscures the central sympatholytic effects of GTN. We examined this in a routine clinical tilt test in a patient with baroreflex failure secondary to previous neck radiotherapy. With reduced baroreflex function we observed an exaggerated fall in blood pressure and reduced sympathetic activity with GTN, supporting a peripheral vasodilation and central sympatholytic effect.  相似文献   
39.
40.
Graefe's Archive for Clinical and Experimental Ophthalmology - To assess the outcomes of vitrectomy with or without cataract surgery for the treatment of idiopathic ERM in phakic eyes and...  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