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   179篇
  免费   8篇
  国内免费   1篇
  2022年   3篇
  2021年   3篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   3篇
  2016年   5篇
  2015年   13篇
  2014年   8篇
  2013年   14篇
  2012年   11篇
  2011年   7篇
  2010年   12篇
  2009年   7篇
  2008年   15篇
  2007年   6篇
  2006年   10篇
  2005年   16篇
  2004年   5篇
  2003年   8篇
  2002年   7篇
  2001年   1篇
  2000年   1篇
  1998年   3篇
  1997年   5篇
  1996年   4篇
  1995年   4篇
  1994年   2篇
  1992年   1篇
  1991年   4篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1986年   1篇
  1985年   1篇
排序方式: 共有188条查询结果,搜索用时 53 毫秒
51.
Circulating levels of the neuro-hypophysial nonapeptide oxytocin increase during sexual arousal and orgasm in both men and women. A few studies have evaluated the effect of the menstrual cycle on plasma oxytocin in normally cycling, sexually active, healthy fertile women using or not using contraceptive pills. In 20 ovulating women and 10 women taking an oral contraceptive (group 1 and group 2, respectively), sexual function, hormonal profile, and plasma oxytocin (OT) were evaluated throughout the menstrual cycle. In group 1, plasma OT was significantly lower during the luteal phase in comparison with both the follicular and ovulatory phases. Plasma oxytocin was significantly correlated with the lubrication domain of the Female Sexual Function Index (FSFI) during the luteal phase and showed a trend towards statistical significance during the follicular phase. In group 2, plasma OT did not show any significant fluctuation throughout the menstrual cycle, even though a significant correlation was evident with both the arousal and the lubrication domain of the FSFI during the assumption of the contraceptive pill. These findings suggest that plasma OT fluctuates throughout the menstrual cycle in normally cycling healthy fertile women with adequate sexual activity but not taking any oral contraceptive pill. Moreover, plasma OT levels significantly relates to the genital lubrication in both women taking and not taking oral contraceptive pill apparently confirming its role in peripheral activation of sexual function.  相似文献   
52.
The possibility to study an organism in terms of system theory has been proposed in the past, but only the advancement of molecular biology techniques allow us to investigate the dynamical properties of a biological system in a more quantitative and rational way than before . These new techniques can gave only the basic level view of an organisms functionality. The comprehension of its dynamical behaviour depends on the possibility to perform a multiple level analysis. Functional genomics has stimulated the interest in the investigation the dynamical behaviour of an organism as a whole. These activities are commonly known as System Biology, and its interests ranges from molecules to organs. One of the more promising applications is the 'disease modeling'. The use of experimental models is a common procedure in pharmacological and clinical researches; today this approach is supported by 'in silico' predictive methods. This investigation can be improved by a combination of experimental and computational tools. The Machine Learning (ML) tools are able to process different heterogeneous data sources, taking into account this peculiarity, they could be fruitfully applied to support a multilevel data processing (molecular, cellular and morphological) that is the prerequisite for the formal model design; these techniques can allow us to extract the knowledge for mathematical model development. The aim of our work is the development and implementation of a system that combines ML and dynamical models simulations. The program is addressed to the virtual analysis of the pathways involved in neurodegenerative diseases. These pathologies are multifactorial diseases and the relevance of the different factors has not yet been well elucidated. This is a very complex task; in order to test the integrative approach our program has been limited to the analysis of the effects of a specific protein, the Cyclin dependent kinase 5 (CDK5) which relies on the induction of neuronal apoptosis. The system has a modular structure centred on a textual knowledge discovery approach. The text mining is the only way to enhance the capability to extract ,from multiple data sources, the information required for the dynamical simulator. The user may access the publically available modules through the following site: http://biocomp.ge.ismac.cnr.it.  相似文献   
53.
Recombinant antibody fragments represent useful tools for cancer diagnosis and therapy. Aberrant expression of the HER2 receptor is implicated in metastatic breast and ovary cancers, two malignancies with a high prevalence in young women. In this study, we focussed on a single-chain fragment of variable antibody regions specific for HER2 (scFv800E6) that can be expressed in a functional form in the cytoplasm of Escherichia coli. ScFv800E6 was extracted from bacterial cultures following induction at different temperatures and purified. The yield of both soluble and insoluble forms was measured. We found that scFv800E6 was functional when expressed in the soluble fraction in the bacteria cytosol. In addition, scFv800E6 extracted from inclusion bodies was easily refolded and largely recovered its functionality. Thus, scFv800E6 is intrinsically capable of efficient and functional folding in a reducing environment and represents one of the few described antibody fragments with a framework well adapted for cytoplasmic expression.  相似文献   
54.
Sets of isomeric thiazole derivatives 1 and 2 have been synthesised in a parallel iterative solution-phase synthesis approach guided by the SAR analysis derived from biological results and computer-aided design and analysis. This synergistic and streamlined working procedure led to highly active isomeric NPY5 receptor ligands. However, a 10-fold difference at least in their respective binding affinities was consistently found for all isomeric pairs 1 and 2. The analysis of conformational differences due to heteroatom interactions in 1 and 2 revealed a favourable C=O...S interaction in 1, whereas thiazoles 2 showed a repulsive C=O...N interaction.  相似文献   
55.
56.
Walking ability, though important for quality of life and participation in social and economic activities, can be adversely affected by neurological disorders, such as Spinal Cord Injury, Stroke, Multiple Sclerosis or Traumatic Brain Injury. The aim of this study is to evaluate if the energy cost of walking (CW), in a mixed group of chronic patients with neurological diseases almost 6 months after discharge from rehabilitation wards, can predict the walking performance and any walking restriction on community activities, as indicated by Walking Handicap Scale categories (WHS). One hundred and seven subjects were included in the study, 31 suffering from Stroke, 26 from Spinal Cord Injury and 50 from Multiple Sclerosis. The multivariable binary logistical regression analysis has produced a statistical model with good characteristics of fit and good predictability. This model generated a cut-off value of.40, which enabled us to classify correctly the cases with a percentage of 85.0%. Our research reveal that, in our subjects, CW is the only predictor of the walking performance of in the community, to be compared with the score of WHS. We have been also identifying a cut-off value of CW cost, which makes a distinction between those who can walk in the community and those who cannot do it. In particular, these values could be used to predict the ability to walk in the community when discharged from the rehabilitation units, and to adjust the rehabilitative treatment to improve the performance.  相似文献   
57.

Objective

The present study shows the results of a double-blind sham-controlled pilot trial to test whether measurable stimulus-specific functional connectivity changes exist after Automatic Mechanical Peripheral Stimulation (AMPS) in patients with idiopathic Parkinson Disease.

Methods

Eleven patients (6 women and 5 men) with idiopathic Parkinson Disease underwent brain fMRI immediately before and after sham or effective AMPS. Resting state Functional Connectivity (RSFC) was assessed using the seed-ROI based analysis. Seed ROIs were positioned on basal ganglia, on primary sensory-motor cortices, on the supplementary motor areas and on the cerebellum. Individual differences for pre- and post-effective AMPS and pre- and post-sham condition were obtained and first entered in respective one-sample t-test analyses, to evaluate the mean effect of condition.

Results

Effective AMPS, but not sham stimulation, induced increase of RSFC of the sensory motor cortex, nucleus striatum and cerebellum. Secondly, individual differences for both conditions were entered into paired group t-test analysis to rule out sub-threshold effects of sham stimulation, which showed stronger connectivity of the striatum nucleus with the right lateral occipital cortex and the cuneal cortex (max Z score 3.12) and with the right anterior temporal lobe (max Z score 3.42) and of the cerebellum with the right lateral occipital cortex and the right cerebellar cortex (max Z score 3.79).

Conclusions

Our results suggest that effective AMPS acutely increases RSFC of brain regions involved in visuo-spatial and sensory-motor integration.

Classification of Evidence

This study provides Class II evidence that automatic mechanical peripheral stimulation is effective in modulating brain functional connectivity of patients with Parkinson Disease at rest.

Trial Registration

Clinical Trials.gov NCT01815281  相似文献   
58.
59.

Background

Studies that aimed at comparing the clinical presentation of influenza patients across virus types and subtypes/lineages found divergent results, but this was never investigated using data collected over several years in a countrywide, primary care practitioners-based influenza surveillance system.

Methods

The IBVD (Influenza B in Vircases Database) study collected information on signs and symptoms at disease onset from laboratory-confirmed influenza patients of any age who consulted a sentinel practitioner in France. We compared the clinical presentation of influenza patients across age groups (0–4, 5–14, 15–64 and 65+ years), virus types (A, B) and subtypes/lineages (A(H3N2), pandemic A(H1N1), B Victoria, B Yamagata).

Results

Overall, 14,423 influenza cases (23.9% of which were influenza B) were included between 2003–2004 and 2012–2013. Influenza A and B accounted for over 50% of total influenza cases during eight and two seasons, respectively. There were minor differences in the distribution of signs and symptoms across influenza virus types and subtypes/lineages. Compared to patients aged 0–4 years, those aged 5–14 years were more likely to have been infected with type B viruses (OR 2.15, 95% CI 1.87–2.47) while those aged 15–64 years were less likely (OR 0.83, 95% CI 0.73–0.96). Males and influenza patients diagnosed during the epidemic period were less likely to be infected with type B viruses.

Conclusions

Despite differences in age distribution, the clinical illness produced by the different influenza virus types and subtypes is indistinguishable among patients that consult a general practitioner for acute respiratory infections.  相似文献   
60.
In our body, cells are continuously exposed to physical forces that can regulate different cell functions such as cell proliferation, differentiation and death. In this work, we employed two different strategies to mechanically stress cancer cells. The cancer and healthy cell populations were treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography) or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC) class I molecules expression on cancer cell membrane compared to different kinds of healthy cells (fibroblasts, macrophages, dendritic and lymphocyte cells) was observed, stimulating the cells with forces in the range of nano-newton, and pressures between 1 and 10 bar (1 bar = 100.000 Pascal), depending on the devices used. Moreover, Raman spectroscopy analysis, after mechanical treatment, in the range between 700–1800 cm−1, indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased susceptibility to Natural Killer (NK) cells cytotoxic recognition.  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