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   204篇
  免费   17篇
  221篇
  2022年   3篇
  2021年   3篇
  2019年   1篇
  2018年   1篇
  2017年   5篇
  2016年   3篇
  2015年   12篇
  2014年   15篇
  2013年   18篇
  2012年   17篇
  2011年   9篇
  2010年   7篇
  2009年   13篇
  2008年   10篇
  2007年   9篇
  2006年   13篇
  2005年   8篇
  2004年   5篇
  2003年   7篇
  2002年   2篇
  2001年   10篇
  2000年   9篇
  1999年   4篇
  1998年   11篇
  1997年   3篇
  1996年   3篇
  1995年   3篇
  1994年   2篇
  1993年   1篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1976年   2篇
  1971年   1篇
  1967年   1篇
排序方式: 共有221条查询结果,搜索用时 15 毫秒
131.

Background

Orthology is a central tenet of comparative genomics and ortholog identification is instrumental to protein function prediction. Major advances have been made to determine orthology relations among a set of homologous proteins. However, they depend on the comparison of individual sequences and do not take into account divergent orthologs.

Results

We have developed an iterative orthology prediction method, Ortho-Profile, that uses reciprocal best hits at the level of sequence profiles to infer orthology. It increases ortholog detection by 20% compared to sequence-to-sequence comparisons. Ortho-Profile predicts 598 human orthologs of mitochondrial proteins from Saccharomyces cerevisiae and Schizosaccharomyces pombe with 94% accuracy. Of these, 181 were not known to localize to mitochondria in mammals. Among the predictions of the Ortho-Profile method are 11 human cytochrome c oxidase (COX) assembly proteins that are implicated in mitochondrial function and disease. Their co-expression patterns, experimentally verified subcellular localization, and co-purification with human COX-associated proteins support these predictions. For the human gene C12orf62, the ortholog of S. cerevisiae COX14, we specifically confirm its role in negative regulation of the translation of cytochrome c oxidase.

Conclusions

Divergent homologs can often only be detected by comparing sequence profiles and profile-based hidden Markov models. The Ortho-Profile method takes advantage of these techniques in the quest for orthologs.  相似文献   
132.

Background  

Heterologous prime-boost immunization protocols using different gene expression systems have proven to be successful tools in protecting against various diseases in experimental animal models. The main reason for using this approach is to exploit the ability of expression cassettes to prime or boost the immune system in different ways during vaccination procedures. The purpose of the project was to study the ability of recombinant vaccinia virus (VV) and bacterial plasmid, both carrying the NS1 gene from tick-borne encephalitis (TBE) virus under the control of different promoters, to protect mice against lethal challenge using a heterologous prime-boost vaccination protocol.  相似文献   
133.
Structural genes of the mouse major urinary protein are on chromosome 4   总被引:10,自引:0,他引:10  
The major urinary proteins (MUPs) of mouse are a family of at least three major proteins which are synthesized in the liver of all strains of mice. The relative levels of synthesis of these proteins with respect to each other in the presence of testosterone is regulated by the Mup-a locus located on chromosome 4. In an effort to determine the mechanism of this regulation in molecular terms, a cDNA clone containing most of the coding region of a MUP protein has been isolated and identified by partial DNA sequence analysis. Using a combination of hybridization analysis and somatic cell genetics, the structural gene family has been unambiguously mapped to mouse chromosome 4. These data suggest that Mup-a regulation operates in a cis fashion and that models proposing trans regulation of MUP protein synthesis are unlikely.  相似文献   
134.

Background

In patients with epilepsy, poor adherence to anti-epileptic drugs has been shown to be the most important cause of poorly controlled epilepsy. Furthermore, it has been noted that the quality of life among patients with epilepsy can be improved by counseling and treatments aimed at increasing their self-efficacy and concordance, thus stimulating self-management skills. However, there is a need for evidence on the effectiveness of such programs, especially within epilepsy care. Therefore, we have developed a multi-component intervention (MCI) which combines a self-management/education program with e-Health interventions. Accordingly, the overall objective of this study is to assess the (cost)-effectiveness and feasibility of the MCI, aiming to improve self-efficacy and concordance in patients with epilepsy.

Methods

A RCT in two parallel groups will be conducted to compare the MCI with a control condition in epilepsy patients. One hundred eligible epilepsy patients will be recruited and allocated to either the intervention or control group. The intervention group will receive the MCI consisting of a self-management/education program of six meetings, including e-Health interventions, and will be followed for 12 months. The control group will receive care as usual and will be followed for 6 months, after which patients will be offered the possibility of participating in the MCI. The study will consist of three parts: 1) a clinical effectiveness study, 2) a cost-effectiveness study, and 3) process evaluation. The primary outcome will be self-efficacy. Secondary outcomes include adherence, side effects, change in seizure severity & frequency, improved quality of life, proactive coping, and societal costs. Outcome assessments will be done using questionnaires at baseline and after 3, 6, 9, and 12 months (last two applicable only for intervention group).

Discussion

In times of budget constraints, MCI could be a valuable addition to the current healthcare provision for epilepsy, as it is expected that higher concordance and self-efficacy will result in reduced use of healthcare resources and an increased QOL. Accordingly, this study is aimed helping patients to be their own provider of health care, shifting epilepsy management from professionals to self-care by patients equipped with appropriate skills and tools.

Trial registration number

NTR4484.
  相似文献   
135.
Amiodarone (AM) is an effective anti-arrhythmic drug. We investigated the role of mast cells and macrophages on AM induced pulmonary fibrosis and the action of atorvastatin on this fibrosis. Rats were allocated into four groups; negative control (1), positive control (2), 30 mg/kg body weight/day AM (3) and AM + 10 mg/kg/day atorvastatin (4). Lungs were harvested and prepared for histology and immunohistochemistry. Hematoxylin and eosin stained sections of group 3 exhibited disorganized lung architecture. We found cellular debris in the lumen of both intrapulmonary bronchi and bronchioles with partial disruption of the thickened epithelial lining and mononuclear cellular infiltration into the lamina propria. We also observed thickening of the epithelial lining and the smooth muscle layer. Congested, dilated and thickened blood capillaries and thickened inter-alveolar septa were observed with mononuclear cellular infiltrates in the lung of group 3. Most alveoli were collapsed, but some dilated ones were detected. In some alveoli, type ?? pneumocytes were increased, while type I cells were decreased. We observed significant increases in the amount of collagen in the thickened inter-alveolar septa, around bronchioles and around blood capillaries in sections from group 3. We found a significant increase in mast cells and alveolar macrophages in group 3 compared to group 1. Mast cells and macrophages appear to play important roles in AM induced pulmonary fibrosis. Atorvastatin appears to attenuate this condition.  相似文献   
136.
BACKGROUND: The DUET Study is a multicenter prospective efficacy and safety evaluation of the ACS MULTI-LINK DUET coronary stainless steel balloon-expandable stent. AIMS: The primary objective was to determine the one-month incidence of MACE (major adverse cardiac events). The secondary objectives were the acute success rate, the restenosis and reocclusion rates (assessed by quantitative coronary angiography (QCA)) at six months and the occurrence of MACE in hospital and at six months. METHODS: Two hundred and ten patients were enrolled between February and June 1998 in 18 European centers. Successful stent placement was achieved in 209 patients. All patients were treated with ticlopidine 500 mg/day for one month and with aspirin >/=100 mg/day. To allow the investigators to gain familiarity with the stent system, the first one to three patients per center formed a separate lead-in population leaving an intention-to-treat population of 157 patients. The majority of the intention-to-treat population were male (79%); 28% had unstable angina, 69% had stable angina, 44% had had a previous myocardial infarction, 15% had had a previous percutaneous transluminal coronary angioplasty, and 3% had a history of stroke. The target vessel was 38.5% left anterior descending artery, 20.5% left circumflex artery and 41.0% right coronary artery. RESULTS: All but one of the intention-to-treat patients were effectively stented (17 required multiple stents). Six-month angiographic follow-up was available in 90% of the intention-to-treat population. Minimal lumen diameter (MLD) postprocedure was 2.61 +/- 0.33 mm, with a residual diameter stenosis of 16%. Six-month follow-up data showed an MLD of 1.87 +/- 0.56 mm with a residual diameter stenosis of 36%. The binary restenosis rate (>/=50% residual stenosis) was 15.6%. Up to one month following the procedure 94.9% of the population was MACE-free, with two subacute occlusions. At six months all patients were alive, of whom 82.8% were MACE-free, and 73% were free of anginal complaints. CONCLUSION: The results observed in the current DUET registry are comparable to data of other balloon-expandable-stent trials, with a low incidence of clinical events at follow-up.  相似文献   
137.
138.
139.
A number of genera of soil fungi interact with plant roots to establish symbiotic associations whereby phosphate acquired by the fungus is exchanged for fixed carbon from the plant. Recent progress in investigating these associations, designated as mycorrhizae (sing., mycorrhiza), has led to the identification of specific steps in the establishment of the symbiosis in which the fungus and the plant interact in response to various molecular signals. Some of these signals are conserved with those of the Rhizobium-legume nitrogen-fixing symbiosis, suggesting that the two plant-microbe interactions share a common signal transduction pathway. Nevertheless, only legume hosts nodulate in response to Rhizobium, whereas the vast majority of flowering plants establish mycorrhizal associations. The key questions for the future are: what are the signal molecules produced by mycorrhizal fungi and how are they perceived by the plant? Copyright 1998 Academic Press.  相似文献   
140.

Background  

Intestinal threadworm Strongyloides stercoralis is a parasite of dog, cat and primates that occurs worldwide being most prevalent in tropical and subtropical countries. The adult parasitic worm is about 2 mm long and slender. It possesses both parasitic and free-living lifecycles. The parasitic worms are females. Strongyloides stercoralis infects the host via percutaneous, peroral or transmammary transmission in addition to autoinfection. Clinical disease varies from inapparent to severe enteritis and pneumonia. The diagnosis is based on demonstration of larvae in fresh faeces, which is best made by Baermann technique.  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