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   450篇
  免费   21篇
  2023年   3篇
  2022年   3篇
  2021年   15篇
  2020年   2篇
  2019年   6篇
  2018年   10篇
  2017年   12篇
  2016年   18篇
  2015年   17篇
  2014年   27篇
  2013年   45篇
  2012年   46篇
  2011年   31篇
  2010年   17篇
  2009年   21篇
  2008年   28篇
  2007年   27篇
  2006年   17篇
  2005年   30篇
  2004年   24篇
  2003年   19篇
  2002年   19篇
  2001年   9篇
  2000年   1篇
  1999年   3篇
  1998年   1篇
  1996年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1990年   3篇
  1989年   1篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1982年   1篇
  1981年   2篇
  1979年   1篇
排序方式: 共有471条查询结果,搜索用时 15 毫秒
221.
doi: 10.1111/j.1741‐2358.2012.00634.x Evaluation of satisfaction with Masticatory efficiency of new conventional complete dentures in edentulous patients. A survey Background: Knowing how patients really feel after treatment is, very often, as relevant as the success rate of the conventional dentures and it can even be the measurement of masticatory function. Aim and objectives: This questionnaire survey aimed to analyse the satisfaction level and masticatory efficiency of patients treated with conventional complete dentures. Design and setting: Thirty edentulous patients were considered in the study. Satisfaction level and masticatory efficiency were analysed based on specific questionnaires for edentulous patients and by a likert rating scale from 0 to 5, at three moments: Prior to treatment (edentulous period), after the insertion of the new dentures and at 30–45 days follow‐up. Materials and methods: Thirty patients including 12 male and 18 female patients (mean age 65 years), who voluntarily came for the services. T‐test was applied at three different levels. Results: The rehabilitation with conventional complete dentures produced an improvement (p < 0.05) in satisfaction level and masticatory efficiency. Conclusion: Thus, those patients who were edentulous previously and dissatisfied with their masticatory ability showed improvement after receiving a new set of conventional complete dentures.  相似文献   
222.
Rubella virus is the only member of the Rubivirus genus within the Togaviridae family and is the causative agent of the childhood disease known as rubella or German measles. Here, we report the use of cryo-electron tomography to examine the three-dimensional structure of rubella virions and compare their structure to that of Ross River virus, a togavirus belonging the genus Alphavirus. The ectodomains of the rubella virus glycoproteins, E1 and E2, are shown to be organized into extended rows of density, separated by 9 nm on the viral surface. We also show that the rubella virus nucleocapsid structure often forms a roughly spherical shell which lacks high density at its center. While many rubella virions are approximately spherical and have dimensions similar to that of the icosahedral Ross River virus, the present results indicate that rubella exhibits a large degree of pleomorphy. In addition, we used rotation function calculations and other analyses to show that approximately spherical rubella virions lack the icosahedral organization which characterizes Ross River and other alphaviruses. The present results indicate that the assembly mechanism of rubella virus, which has previously been shown to differ from that of the alphavirus assembly pathway, leads to an organization of the rubella virus structural proteins that is different from that of alphaviruses.  相似文献   
223.
224.
ABSTRACT: BACKGROUND: Malaria and HIV co-infection adversely impact the outcome of both diseases and previous studies have mostly focused on falciparum malaria. Plasmodium vivax contributes to almost half of the malaria cases in India, but the disease burden of HIV and P. vivax co-infection is unclear. METHODS: HIV-infected subjects (n=460) were randomly selected from the 4,611 individuals seen at a Voluntary Counseling and Testing Center in Chennai, India between Jan 2 to Dec 31 2008. Malaria testing was performed on stored plasma samples by both nested PCR using both genus-specific and species-specific primers and immunochromatography-based rapid diagnostic test for detecting antibodies against both Plasmodium falciparum and P. vivax. RESULTS: Recent malaria co-infection, defined by the presence of antibodies, was detected in 9.8% (45/460) participants. Plasmodium vivax accounted for majority of the infections (60%) followed by P. falciparum (27%) and mixed infections (13%). Individuals with HIV and malaria co-infection were more likely to be men (p=0.01). Between those with and without malaria, there was no difference in age (p=0.14), CD4+ T-cell counts (p=0.19) or proportion CD4+ T-cell below 200/mL (p=0.51). CONCLUSIONS: Retrospective testing of stored plasma samples for malaria antibodies can facilitate identification of populations with high rates of co-infection, and in this southern India HIVinfected cohort there was a considerable burden of malaria co-infection, predominantly due to P. vivax. However, the rate of P. falciparum infection was more than 6-fold higher among HIV-infected individuals than what would be expected in the general population in the region. Interestingly, individuals co-infected with malaria and HIV were not more likely to be immunosuppressed than individuals with HIV infection alone.  相似文献   
225.
226.
During the recent re-emergence of chikungunya, clinical complications and deaths were recorded. Persistent musculoskeletal pain, arthralgia, arthritis were among the most common complications. To understand pathogenesis of CHIKV induced disease, we developed suckling, outbred mouse model presenting with severe myopathology. Histopathology, dynamics of viral load, IgG antibodies/isotypes, serum cytokines by cytometric bead array and mRNA expression levels of immune response genes in the target tissue by Taqman Low Density Array were studied. Peak viral load was associated with peak serum levels of CCL-2,KC, CCL-4, RANTES, IL-6, IL-10, CSF-3, and locally very high mRNA expression of CCL-2, CXCL-10, CXCL-11 and concomitant IFNγ, IL-10, STAT-1, SOCS-1 and CSF-3 suggesting strong IFNγ program. Symptomatic phase correlated with peak serum levels of IL-2, IFNγ, IL-17, CCL-3, IL-1β, eotaxin, IL-9 and CSF-2 and locally with peak mRNA expression of macrophage induced pro inflammatory cytokines and immune infiltration biased towards Th1. IgG antibodies were detected on day 6PI, reaching high titres by day 11PI. IgG2a was the predominant isotype, indicating Th1 bias. This is the first report of comprehensive analysis of immune response genes expression in target tissue of CHIKV mouse model. The data would contribute significantly in understanding pathogenesis of CHIKV disease and viral myopathies.  相似文献   
227.
228.
Social organization of the Asian elephant (Elephas maximus) is not well understood in the absence of long-term studies of identified individuals. Adult Asian elephant females and their young offspring of both sexes form matriarchal groups, with pubertal males dispersing from natal groups, but whether these social groups represent families and whether males show locational or social dispersal were unknown. Using nuclear microsatellite loci amplified from dung-extracted DNA of free-ranging elephants in a large southern Indian population, we demonstrate that female-led herds comprise closely related individuals that are indeed families, and that males exhibit non-random locational dispersal.  相似文献   
229.
Roux-en-Y gastric bypass (RYGB) is an effective method to attain sustained weight loss and diabetes remission. We aimed to elucidate early changes in the plasma metabolome and lipidome after RYGB. Plasma samples from 16 insulin-resistant morbidly obese subjects, of whom 14 had diabetes, were subjected to global metabolomics and lipidomics analysis at pre-surgery and 4 and 42 days after RYGB. Metabolites and lipid species were compared between time points and between subjects who were in remission and not in remission from diabetes 2 years after surgery. We found that the variables that were most discriminatory between time points were decanoic acid and octanoic acid, which were elevated 42 days after surgery, and sphingomyelins (18:1/21:0 and 18:1/23:3), which were at their lowest level 42 days after surgery. Insulin levels were lower at 4 and 42 days after surgery compared with pre-surgery levels. At 4 days after surgery, insulin levels correlated positively with metabolites of branched chain and aromatic amino acid metabolism and negatively with triglycerides with long-chain fatty acids. Of the 14 subjects with diabetes prior to surgery, 7 were in remission 2 years after surgery. The subjects in remission displayed higher pre-surgery levels of tricarboxylic acid cycle intermediates and triglycerides with long-chain fatty acids compared with subjects not in remission. Thus, metabolic alterations are induced soon after surgery and subjects with diabetes remission differ in the metabolic profiles at pre- and early post-surgery time points compared to patients not in remission.  相似文献   
230.
Remarkable advances have been made in the drug therapy of tuberculosis. However much remains to be learned about the molecular and structural basis of drug resistance in Mycobacterium tuberculosis. It is known that, activation of Isoniazid (INH) is mediated by Mycobacterium tuberculosis catalase-peroxidase (MtBKatG) and mutation at position 315 (serine to threonine) leads to resistance. We have conducted studies on the drug resistance through docking and binding analysis supported by time-scale (∼1000 ps) and unrestrained all-atom molecular dynamics simulations of wild and mutant MtBKatG. The study showed conformational changes of binding residues. Mutant (S315T) showed high docking score and INH binding affinity as compared to wild enzyme. In molecular dynamics simulation, mutant enzyme exhibited less structure fluctuation at INH binding residues and more degree of fluctuation at C-terminal domain compared to wild enzyme. Our computational studies and data endorse that MtBKatG mutation (S315T) decrease the flexibility of binding residues and made them rigid by altering the conformational changes, in turn it hampers the INH activity. We ascertain from this work that, this study on structural mechanism of resistance development in Mycobacterium tuberculosis would lead to new therapeutics based on the result obtained in this study.  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