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   119篇
  免费   10篇
妇产科学   3篇
基础医学   6篇
口腔科学   1篇
临床医学   6篇
内科学   10篇
皮肤病学   2篇
神经病学   18篇
特种医学   5篇
外科学   27篇
综合类   1篇
预防医学   23篇
眼科学   3篇
药学   8篇
肿瘤学   16篇
  2023年   1篇
  2021年   3篇
  2020年   1篇
  2019年   2篇
  2017年   4篇
  2016年   2篇
  2015年   3篇
  2014年   6篇
  2013年   5篇
  2012年   9篇
  2011年   4篇
  2010年   4篇
  2009年   6篇
  2008年   6篇
  2007年   7篇
  2006年   4篇
  2005年   5篇
  2004年   5篇
  2003年   7篇
  2002年   1篇
  2001年   4篇
  2000年   6篇
  1997年   2篇
  1994年   2篇
  1993年   9篇
  1992年   5篇
  1991年   4篇
  1990年   3篇
  1989年   1篇
  1987年   1篇
  1983年   1篇
  1982年   1篇
  1971年   1篇
  1969年   1篇
  1968年   1篇
  1966年   1篇
  1939年   1篇
排序方式: 共有129条查询结果,搜索用时 301 毫秒
61.
An experimental project at Guy's Hospital to improve the quality and nutritional value of its food has involved some of the big names in cookery. Stella Yarrow reports.  相似文献   
62.
Due to the search for new methods of producing bimetallic nanoparticles, in this work, we have conducted a biological synthesis of Au-CuO and CuO-ZnO nanoparticles using Cnici benedicti. The synthesized Au-CuO and CuO-ZnO nanoparticles were also analyzed in terms of their antibacterial activity, as well as their influence on cell viability, using two specific cell lines: C6 rat brain glioma (ATCC® CCL-107?) and T98G human glioma (ATCC® CRL-1690?). The studies carried out by means of Atomic Force Microscopy helped to determine the presence Au-CuO nanoparticles whose size was about 13?nm. The size of CuO-ZnO nanoparticles was about 28?nm. The obtained nanoparticles showed cidal activity against glioma cells depending on the concentration of the substance and the time of culture. In the first stage, the nanoparticles limited the ability to divide cells; then, they blocked the cell cycle in the G2 – M phase, and finally led to massive cell death. The antimicrobial activity studies showed that Au-CuO nanoparticles inhibited the growth of microorganisms at lower concentrations than CuO-ZnO nanoparticles, and both kinds of nanoparticles showed excellent cidal properties.  相似文献   
63.

Background

One of the most important prognostic indicators in gastric cancer is the presence of metastases in lymph nodes. Even now, little is known about lymphangiogenesis in neoplastic tissue, and little is also known about the transmission of a neoplastic cell from the tumor mass into a lymphatic vessel.

Methods

This study examined the relationships between the density of lymphatic vessels (LVD) stained immunohistochemically with lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and D2-40 (podoplanin) antibodies, the expression of vascular endothelial growth factor (VEGF)-C/D, selected clinical and pathomorphological factors, and the 5-year overall survival of gastric cancer patients.

Results

Statistical analysis showed no impact of increased intratumoral or peritumoral LVD on gastric cancer patient survival, irrespective of the protein used to stain lymphatic vessels. Analysis showed that the probability of overall survival was decreased in the cases with enhanced VEGF-D immunoreactivity (P = 0.0045).

Conclusion

The study showed that the studied markers cannot be used to determine the required extent of the surgical procedure, as they have no statistically significant correlation with the degree of progression of the cancer, the stage of the disease assessed according to the TNM 5th classification of malignant tumors, clinicopathological features, and patient survival. VEGF-D is the only marker that can be regarded as an unfavorable prognostic indicator for patients with advanced gastric cancer.  相似文献   
64.
Background : Deep brain stimulation of the subthalamic nucleus is an effective treatment for patients with advanced Parkinson's disease. However, affective side effects following subthalamic deep brain stimulation have been reported. Here, we aim to elucidate the influence of affective state on emotional processing as indexed by local field potential activity and to identify neurophysiological markers in patients at risk of developing depressive symptoms during subthalamic deep brain stimulation. Methods : Subthalamic local field potentials were directly recorded via electrodes implanted for deep brain stimulation in 12 Parkinson's disease patients while viewing emotionally salient and neutral pictures. Parkinson's disease patients were assessed for depressive symptoms using the Beck depression inventory at the time of operation and 3 months after continuous subthalamic nucleus deep brain stimulation. Results : We found a significant event‐related desynchronization in the local alpha frequency band (8–12 Hz) for emotionally arousing but not neutral pictures. The the event‐related desynchronization (ERD) in the alpha frequency band was reduced for pleasant stimuli in patients with mild to moderate depressive symptoms compared with patients without depression. The alpha‐ERD to unpleasant stimuli showed the opposite pattern. Consistently, the index of event‐related alpha desynchronization (alpha ERD for pleasant stimuli minus alpha ERD for unpleasant stimuli) correlated with the Beck depression inventory at the time of the recordings and at 3 months after continuous deep brain stimulation. The alpha ERD to unpleasant pictures correlated significantly with the Beck depression inventory score at 3 months after chronic deep brain stimulation. Discusion : In conclusion, we found mood‐congruent stimulus processing in the subthalamic nucleus of Parkinson's disease patients. Electrophysiological markers such as event‐related desynchronization of subthalamic alpha activity reflect state‐dependent emotional processing and may potentially be used to predict depressive mood disturbances in Parkinson's disease patients with chronic subthalamic deep brain stimulation at an early stage. © 2011 Movement Disorder Society  相似文献   
65.
OBJECTIVE: Here, we investigate whether the event-related desynchronization (ERD) of spectral components of the cortical EEG in the beta (13-30 Hz) frequency range may, in part, index motor selection processes. Specifically, we sought evidence for a contralaterally dominant component of the beta ERD that is limited to trials in which motor selection is possible prior to any imperative cue to move, with attendant behavioural advantage. METHODS: We measured reaction time and assessed the lateralization of beta ERD in 12 healthy volunteers as they performed pre-cued choice reaction time tasks, in which warning S1 cues were either fully predictive about the laterality of a subsequent imperative S2 signal or provided no laterality information. We calculated 'lateralized ERD index' (LERDI), a parallel measure to the lateralized readiness potential in the time domain. RESULTS: Trials with 100% S1-S2 congruency produced significantly shorter reaction times than trials with 50% S1-S2 congruency, where laterality information was unreliable. Beta LERDI indicated significantly greater lateralisation of the ERD in the warning-go interval and of event-related synchronization (ERS) following movement in the 100% condition than in the 50% condition. The lateralization of the beta ERD with respect to hand persisted, even when subjects were instructed to make movements of opposite laterality to those prompted. CONCLUSIONS: Lateralized EEG changes occur in the beta band in the S1-S2 interval prior to movement, but only when informative warning cues allow early motor selection, as suggested by the shortening of reaction time. Furthermore, the enhanced contralateral ERS with 100% S1-S2 congruency suggests that this phenomenon is at least partly independent of afferent feedback, as the same movement was made in the 100 and 50% conditions. SIGNIFICANCE: Lateralized suppression of beta power prior to externally generated movements is associated with motor selection.  相似文献   
66.
67.
68.
69.
Hypogonadism is prevalent in older men and testosteronereplacement therapy(TRT) for older hypogonadal men is a promising therapy. However, a number of important clinical concerns over TRT safety remain unsolved due to a lack of large-scale randomized clinical trials directly comparing the health risks of untreated hypogonadism vs long-term use of TRT. Meta-analyses of clinical trials of TRT as of 2010 have identified three major adverse events resulting from TRT: polycythemia, an increase in prostate-related events, and a slight reduction in serum high-density lipoprotein cholesterol. There are other purported health risks but their incidence can be neither confirmed nor denied based on the small number of subjects that have been studied to date. Furthermore, subsequent literature is equivocal with regard to the safety and utility of TRT and this topic has been subject to contentious debate. Since January 2014, the United States Food and Drug Administration has released two official announcements regarding the safety of TRT and clinical monitoring the risks in TRT users. Additionally, the health risks related to the clinical presentation of low or declining testosterone levels not been resolved in the current literature. Because TRT is prescribed in the context of putative risks resulting from reduced testosterone levels, we reviewed the epidemiology and reported risks of low testosterone levels. We also highlight the current information about TRT utilization, the risks most often claimed to be associated with TRT, and current or emerging alternatives to TRT.  相似文献   
70.

Background

The use of topical negative pressure (TNP) dressings with dermal regeneration template (DRT), Integra, has improved outcomes and simplified aftercare. Previous clinical studies have suggested accelerated vascularisation; with a reduction in the duration of the 1st stage after the application of Integra, from 2 to 4 weeks to as little as 4 days, but with no histological evidence. However, histological studies, without TNP, have shown that vascularisation occurs between the second and the fourth week. This study set out to examine histologically the rate of DRT neovascularisation when combined with TNP.

Methods

Eight patients with nine reconstruction sites were enlisted. Unmeshed Integra and fibrin sealant to promote adherence were used. TNP was applied for the duration between the 1st and the 2nd stages. Patients underwent serial biopsies on days 7, 14, 21 and 28 post-application. The biopsies were stained with H&E and endothelial markers CD31 and CD34. Template vascularisation was assessed as a percentage of the template depth in which patent, canalised vascular channels could be demonstrated.

Results

The median percentage of the template depth which demonstrated canalised channels was 0%, 20%, 61% and 80% for days, 7, 14, 21 and 28, respectively.

Conclusion

The application of TNP dressings to dermal templates can reduce shearing forces, restrict seroma and haematoma formation, simplify wound care and improve patient tolerance. However, this study could not demonstrate that TNP accelerates neovascularisation as verified by the presence of histologically patent vascular channels.  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