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   1040篇
  免费   64篇
  国内免费   5篇
耳鼻咽喉   7篇
儿科学   54篇
妇产科学   10篇
基础医学   94篇
口腔科学   41篇
临床医学   99篇
内科学   190篇
皮肤病学   11篇
神经病学   52篇
特种医学   78篇
外科学   271篇
综合类   12篇
一般理论   2篇
预防医学   69篇
眼科学   23篇
药学   27篇
肿瘤学   69篇
  2021年   6篇
  2020年   11篇
  2019年   15篇
  2018年   22篇
  2017年   14篇
  2016年   9篇
  2015年   16篇
  2014年   35篇
  2013年   30篇
  2012年   56篇
  2011年   41篇
  2010年   42篇
  2009年   34篇
  2008年   38篇
  2007年   66篇
  2006年   73篇
  2005年   60篇
  2004年   47篇
  2003年   43篇
  2002年   35篇
  2001年   29篇
  2000年   25篇
  1999年   21篇
  1998年   29篇
  1997年   19篇
  1996年   26篇
  1995年   23篇
  1994年   15篇
  1993年   13篇
  1992年   13篇
  1991年   14篇
  1990年   15篇
  1989年   19篇
  1988年   14篇
  1987年   7篇
  1986年   11篇
  1985年   15篇
  1984年   13篇
  1983年   10篇
  1982年   8篇
  1981年   12篇
  1980年   8篇
  1979年   5篇
  1978年   4篇
  1977年   8篇
  1976年   7篇
  1975年   5篇
  1974年   5篇
  1970年   2篇
  1968年   2篇
排序方式: 共有1109条查询结果,搜索用时 0 毫秒
1.
The use of computer technology for patient education has increased in recent years. This article describes a study that measures the attitudes and perceptions of healthcare professionals and laypeople regarding the effectiveness of a multimedia computer, the Brain Injury Resource Center? (BIRC), as an educational tool. The study focused on three major themes: (a) usefulness of the information presented, (b) effectiveness of the multimedia touch-screen computer methodology, and (c) the appropriate time for making this resource available. This prospective study, conducted in an acute care medical center, obtained healthcare professionals' evaluations using a written survey and responses from patients with brain injury and their families during interviews. The findings have yielded excellent ratings as to the ease of understanding and usefulness of the BIRC. By using sight, sound, and touch, such a multimedia learning center has the potential to simplify patient and family education.  相似文献   
2.
Background/aim  Theoretical considerations support the combination of cryosurgery and topical imiquimod to treat basal cell carcinomas (BCC). The aim of the present study was to test the feasibility and efficacy of 'cryosurgery during continued imiquimod application' ('immunocryosurgery') to treat 'high-risk-for-recurrence' BCCs.
Methods  Thirteen patients with 21 biopsy-proven tumours (4 of 21 relapses after prior surgery) were included. After 2–5 weeks (median, 3) of daily 5% imiquimod cream application, the tumours were treated by liquid N2 cryosurgery (spray, two cycles, 10–20 s) and imiquimod was continued for additional 2–12 weeks (median, 4). The outcome after at least 18 months of follow-up (18–24 months) is currently reported.
Results  Nineteen of 21 tumours responded promptly to immunocryosurgery; two tumours required additional treatment cycles to clear. Thus, the clinical clearance rate was 100%. Only 1 of 21(5%) tumour relapsed after at least 18 months of follow-up (cumulative efficacy: 95%).
Conclusions  'Immunocryosurgery' is a promising non-surgical combination modality to treat 'high-risk-for-recurrence BCCs'. Initial evidence is suggestive of an at least additive effect of the two combined modalities. Further studies comparing immunocryosurgery directly with cryosurgery and imiquimod monotherapies will confirm the reported results.  相似文献   
3.
We studied blood pressure and natriuretic responses to acute salt loading, and the effect of non-steroidal anti-inflammatory agents on these responses, in five healthy normotensive women aged 65 to 71 years. Five women aged 25 to 31 years acted as controls. Intravenous saline loading, with and without prior ingestion of ibuprofen, was 15 ml/kg/h for 3 h. Baseline blood pressures were higher in the elderly. Saline infusion without ibuprofen raised systolic blood pressure (SBP) by about 25 mmHg in the older group only. Ibuprofen increased baseline SBP in the elderly (129 +/- 6 vs. 116 +/- 5 mmHg, p < 0.05). Saline loading after ibuprofen again raised blood pressure by about 25 mmHg in the elderly only. The elderly group showed markedly increased sodium excretion during saline loading, but this was reduced by ibuprofen. Ibuprofen had no effect on SBP or sodium excretion in controls. Ageing appears to increase susceptibility to salt retention and hypertension from non-steroidal anti-inflammatory agents.   相似文献   
4.
5.
Surgical reinterventions following the Fontan procedure.   总被引:2,自引:0,他引:2  
OBJECTIVE: The Fontan procedure is utilized as a final reconstructive procedure for patients with functional single ventricle. Short- and long-term outcomes have improved significantly, however, some patients require additional cardiac procedures following the Fontan operation. The outcomes for these reinterventions are not known. METHODS: Cardiac Surgery and Cardiac Intensive Care Unit databases at The Children's Hospital of Philadelphia were reviewed to identify all patients who underwent cardiac surgery after a previous Fontan operation between January 1, 1995 and December 31, 2001. RESULTS: During the study period, 123 procedures were performed in 71 patients. The median time from Fontan to reoperation was 3.6 years (range 0.1-20 years). Indications for reintervention included arrhythmia, cyanosis, 'failing' Fontan circulation or exercise intolerance, protein losing enteropathy, atrioventricular valve (AVV) regurgitation, and other indications. Procedures included pacemaker insertion or revision (n = 59, 48%), reinclusion of previously excluded hepatic veins (n = 16, 13%), revision to either a lateral tunnel or extra-cardiac conduit Fontan (n = 13, 11%), cardiac transplantation (n = 9, 7%), enlargement or creation of a baffle fenestration (n = 6, 5%), isolated AVV repair or replacement (n = 2, 2%), and other procedures (n = 18, 14%). There were five early and five late deaths. Hospital mortality was greatest for patients undergoing cardiac transplantation (4/9, 44%), accounting for 80% of the early deaths. CONCLUSIONS: Surgical reinterventions following the Fontan procedure may be necessary for multiple indications which result in impairment of the Fontan circulation. Most reinterventions can be performed with minimal morbidity and mortality. Survival for patients requiring cardiac transplantation following the Fontan procedure remains poor.  相似文献   
6.
Uroscopy in the 21st century: high-field NMR spectroscopy   总被引:1,自引:1,他引:0  
From the experiments described, it can be seen that there are different research approaches that can be taken and these are summarized in Table 1. Whereas much scientific research is principally hypothesis led, there remains, nevertheless, an important place for exploratory research. High resolution NMR can measure, directly and simultaneously, a wide range of endogenous metabolites in biological fluids and has the unique capability of providing structural information on the metabolites detected. It has proved to be a powerful research tool with which to study inherited metabolic diseases, renal disease, drug metabolism, and toxicity, and can be used to monitor the effects of drug therapy. For instance, by using a library of experimental toxins one can map the metabolic profile of site-specific nephron injury. With this approach in man one could eventually take an unknown disease such as Balkan nephropathy and predict the initial site of tubular injury, the mode of injury and therefore the kind of toxin capable of producing that injury. NMR spectroscopic techniques are still advancing rapidly, with ever increasing sensitivity and sophistication of NMR pulse sequences to enhance structural elucidation in complex mixtures. Given the advances in directly coupled HPLC-NMR and even HPLC-NMR-mass spectroscopy it is likely that these technologies in conjunction with pattern recognition will make major contribution to our understanding of renal processes and provide new diagnostic insights in the 21st century.   相似文献   
7.
Autosomal dominant cerebellar ataxia with progressive macular degeneration is caused by a CAG/glutamine repeat expansion in the SCA7 gene/protein. Neuronal intranuclear inclusions were detected in the brain of an early onset SCA7 case with the 1C2 antibody directed against an expanded polyglutamine domain. Nuclear inclusions were most frequent in the inferior olivary complex, a site of severe neuronal loss in SCA7. They were also observed in other brain regions, including the cerebral cortex, not considered to be affected in the disease. Using confocal microscopy we showed that some inclusions were ubiquitinated, but to varying degrees, ranging from <1% in the cerebral cortex to 60% in the inferior olive. In addition, we also observed cytoplasmic staining using the 1C2 antibody, particularly in the supramarginal gyrus, the hippocampus, the thalamus, the lateral geniculate body and the pontine nuclei. These data confirm that the presence of intranuclear inclusions in neurons is a common characteristic of disorders caused by CAG/polyglutamine expansions, but unlike what has been reported for Huntington's disease, SCA1 and SCA3/MJD, in SCA7 the inclusions were not restricted to the sites of severe neuronal loss.   相似文献   
8.
Traditional approaches to generating tissue-engineered arteries in vitro rely on expansion of cells in culture to seed appropriate scaffolds. In most envisioned applications, small autologous blood vessels would be harvested and used as a source for these cells. We propose that small autologous arteries, not the cells derived from them, may be an attractive starting point for engineered arteries. This approach capitalizes on the ability of intact arteries to grow and remodel in response to chronic changes in their mechanical environment. Carotid arteries from juvenile (approximately 30-kg) pigs were stretched longitudinally in an ex vivo perfusion system over 9 days. This resulted in a 40% increase in artery length at physiological longitudinal stress and a 20 +/- 3% increase when unstressed. Control arteries were perfused for 9 days ex vivo at their physiological loaded length. Control and elongated arteries displayed native appearance (macroscopic and histological), excellent viability (cellularity and mitochondrial activity), normal vasoactivity, and similar mechanical properties (ultimate stress and ultimate strain) as compared with freshly harvested arteries. Growth, as opposed to just redistribution of existing mass, contributed to elongation as evidenced by an increase in artery weight. Results on elongation of arteries from neonatal and adolescent pigs are also presented and discussed.  相似文献   
9.
Some studies have reported associations between COMT and MAO genotypes and aggression, though results have been inconsistent. We examined the relationship between Overt aggression scale (OAS) scores, and both MAOA and MAOB polymorphisms in a well-powered sample of 346 subjects with schizophrenia. We also examined COMT in a Stage II replication sample of 150 individuals, and combined these results with our previously reported (Stage I) findings for COMT. We found no evidence of any associations between OAS ratings and any of the polymorphisms investigated under different genetic models. There was no evidence of epistatic interaction between MAOA and COMT on OAS scores. These results fail to support the theory that functional polymorphisms within the MAOA, MAOB, or COMT genes, as determinants of catecholamine enzymatic activity, are risk factors for aggressive behavior.  相似文献   
10.
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