全文获取类型
收费全文 | 469篇 |
免费 | 25篇 |
国内免费 | 3篇 |
专业分类
497篇 |
出版年
2023年 | 8篇 |
2022年 | 7篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 20篇 |
2018年 | 17篇 |
2017年 | 15篇 |
2016年 | 17篇 |
2015年 | 33篇 |
2014年 | 27篇 |
2013年 | 33篇 |
2012年 | 32篇 |
2011年 | 40篇 |
2010年 | 22篇 |
2009年 | 22篇 |
2008年 | 20篇 |
2007年 | 18篇 |
2006年 | 19篇 |
2005年 | 17篇 |
2004年 | 13篇 |
2003年 | 14篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1997年 | 4篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1969年 | 2篇 |
排序方式: 共有497条查询结果,搜索用时 15 毫秒
81.
Felipe A. de Oliveira Mohamed H. Shahin Yan Gong Caitrin W. McDonough Amber L. Beitelshees John G. Gums Arlene B. Chapman Eric Boerwinkle Stephen T. Turner Reginald F. Frye Oliver Fiehn Rima Kaddurah-Daouk Julie A. Johnson Rhonda M. Cooper-DeHoff 《Metabolomics : Official journal of the Metabolomic Society》2016,12(8):129
Introduction
While atenolol is an effective antihypertensive agent, its use is also associated with adverse events including hyperglycemia and incident diabetes that may offset the benefits of blood pressure lowering. By combining metabolomic and genomic data acquired from hypertensive individuals treated with atenolol, it may be possible to better understand the pathways that most impact the development of an adverse glycemic state.Objective
To identify biomarkers that can help predict susceptibility to blood glucose excursions during exposure to atenolol.Methods
Plasma samples acquired from 234 Caucasian participants treated with atenolol in the Pharmacogenomic Evaluation of Antihypertensive Responses trial were analyzed by gas chromatography Time-Of-Flight Mass Spectroscopy. Metabolomics and genomics data were integrated by first correlating participant’s metabolomic profiles to change in glucose after treatment with atenolol, and then incorporating genotype information from genes involved in metabolite pathways associated with glucose response.Results
Our findings indicate that the baseline level of β-alanine was associated with glucose change after treatment with atenolol (Q = 0.007, β = 2.97 mg/dL). Analysis of genomic data revealed that carriers of the G allele for SNP rs2669429 in gene DPYS, which codes for dihydropyrimidinase, an enzyme involved in β-alanine formation, had significantly higher glucose levels after treatment with atenolol when compared with non-carriers (Q = 0.05, β = 2.76 mg/dL). This finding was replicated in participants who received atenolol as an add-on therapy (P = 0.04, β = 1.86 mg/dL).Conclusion
These results suggest that β-alanine and rs2669429 may be predictors of atenolol-induced hyperglycemia in Caucasian individuals and further investigation is warranted.82.
Objectives
Smoking during pregnancy may cause many health problems for pregnant women and their newborns. However, there is a paucity of research that has examined the predictors of smoking during pregnancy in Canada. This study used data from the 2009–2010 Canadian Community Health Survey (CCHS) to estimate the prevalence of smoking during pregnancy and examine the demographic, socioeconomic, health-related and behavioral determinants of this behavior.Methods and Findings
The data were obtained from the 2009–2010 CCHS master data file. Weighted estimates of the prevalence were calculated. Multivariable logistic regression was used to determine demographic, socioeconomic, health related and behavioral characteristics associated with smoking behavior during pregnancy. Women living in the Northern Territories had a high rate of smoking during pregnancy (59.3%). The prevalence of smoking during pregnancy was also high among women under 25 years old, of low socioeconomic status, who reported not having a regular medical doctor, being fair to poor in self-perceived health, having at least one chronic disease, having at least one mental illness, being heavy smokers, and being regular alcohol drinkers. Results from multivariable logistic regression revealed that the odds of smoking during pregnancy were decreased with increasing age (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.91–0.99), having a regular family doctor [OR, 0.24; 95% CI, 0.11–0.52], having highest level of family income [OR, 0.09; 95% CI, 0.03–0.29]. Mothers who reported poor or fair self-perceived health [OR, 2.13; 95% CI, 0.96–4.71] and those who had at least one mental illness [OR, 1.81; 95% CI, 1.00–3.28] had greater odds of smoking during pregnancy.Conclusions
There are a number of demographic, socio-economic, health-related and behavioral characteristics that should be considered in developing and implementing effective population health promotional strategies to prevent smoking during pregnancy, promoting health and well-being of pregnant women and their newborns. 相似文献83.
Functional and specific receptors for vasoactive intestinal peptide (VIP) (determined by their capacity to bind 125I-VIP and activate adenylate cyclase) and cyclic AMP-dependent phosphodiesterase activities were characterized in enterocytes of human fetal small intestine between 18 and 23 weeks of gestation. Half-maximal stimulation of the cyclase and inhibition of 125I-VIP binding in membrane preparations were respectively observed at 1.4 and 5 × 10−10 M VIP. The peptides structurally related to VIP activated the cyclic AMP generating system at pharmacological doses (10−7M and above) in the following order of potency: VIP> PHI> GRF> secretin. Other peptides or test substances, including GIP, pancreatic glucagon, somatostatin-14, gastrin, CCK, neurotensin, pancreatic polypeptide, PYY, substance P, histamine and isoproterenol are inactive in this system, while the ubiquitous adenylate cyclase activators NaF, forskolin and prostaglandins were effective. These results, combined with the appearance of intestinal VIP in nerve fibers at 8 weeks and with the morphological and enzymatic maturation at 9–12 weeks of the intestinal mucosa, indicate that this neuropeptide may regulate either the differentiation or function of enterocytes during the early development of human intestinal mucosa. 相似文献
84.
Shahsavandi S Salmanian AH Ghorashi SA Masoudi S Fotouhi F Ebrahimi MM 《Molecular biology reports》2011,38(5):3293-3298
Influenza A viruses are subtyped according to antigen characterization of hemagglutinin (HA) and neuraminidase surface glycoproteins.
The hemagglutination inhibition (HI) assay using reference antiserum is currently applied to serologic screening of subtype-specific
antibodies in sera. The reference antiserum is made by injecting chickens with live or inactivated whole virus preparations.
Nonspecific inhibitors of antisera prepared by the conventional method may affect the specificity of HI assay. In this study,
highly pure recombinant proteins generated using baculovirus expression vector system based on full-length of HA (HAF) and
antigenic region of HA1 genes of H9 subtype, and also inactivated whole virus were used to immunization of chickens. Measurable antibody titers were
present for treated birds after 3 weeks and generally increased after each boost. The performance of the prepared antisera
was evaluated by testing a panel of known standard strains of influenza virus representing five HA subtypes. Relative to the
conventional method using whole virus immunization and recombinant HAF protein, the antiserum prepared by recombinant HA1 had a specificity of 100% for all tested subtypes. The antiserum prepared by expression of HA1 protein in baculovirus has
the potential for rapid and specific HA subtyping of influenza viruses without producing antibodies specific to other viral
proteins. 相似文献
85.
Hadi Rezaei Yazdi Ghorban Behzadian Nejad Shahin Najar Peerayeh Mohammad Mostafaei 《Annals of microbiology》2007,57(2):293-295
Of the 126 isolates obtained from clinical specimens, seventy strains were selected because of resistance or reduced susceptibilities to imipenem and/or ceftazidime. Screening for detection of MBL-producing strains was performed in latter isolates by the Etest MBL strips. Isolates that were positive to Etest MBL strips were analysed by PCR. PCR was performed with specific DNA probes for detection of genes coding IMP or VIM enzymes and positive controls (MBL-producing strains). Finally, eight isolates ofPseudomonas aeruginosa were detected to carry a blaVIM gene. 相似文献
86.
The genus Vibrio is characterized by a large number of species and some of them are human pathogens causing gastrointestinal and wound infections through the ingestion or manipulation of contaminated fishes and shellfish including Vibrio parahaemolyticus and Vibrio alginolyticus. In this study, we reported the phenotypic and molecular characterization of 9 V. parahaemolyticus and 27 V. alginolyticus strains isolated from outbreaks affecting cultured Gilthead sea bream (Sparus aurata L.) and Sea bass (Dicentrarchus labrax) along the Tunisian coast from 2008 to 2009. All isolates were tested for the presence of DNase, caseinase, protease, lipase, amylase, gelatinase, hemolytic activity and antibacterial resistance to different drugs. Randomly amplified polymorphic DNA was used to examine the genetic relatedness among the V. parahaemolyticus and V. alginolyticus strains. 相似文献
87.
88.
In this issue of Cell Stem Cell, Kiel et al. (2007) demonstrate that N-cadherin is not expressed on repopulating hematopoietic stem cells (HSCs) and that reduction of osteoblasts does not affect HSC frequency, suggesting that other molecular pathways may also modulate the interaction of HSCs with their niches. 相似文献
89.
Hormonal Contraception and the Risk of HIV Acquisition: An Individual Participant Data Meta-analysis
Charles S. Morrison Pai-Lien Chen Cynthia Kwok Jared M. Baeten Joelle Brown Angela M. Crook Lut Van Damme Sinead Delany-Moretlwe Suzanna C. Francis Barbara A. Friedland Richard J. Hayes Renee Heffron Saidi Kapiga Quarraisha Abdool Karim Stephanie Karpoff Rupert Kaul R. Scott McClelland Sheena McCormack Nuala McGrath Landon Myer Helen Rees Ariane van der Straten Deborah Watson-Jones Janneke H. H. M. van de Wijgert Randy Stalter Nicola Low 《PLoS medicine》2015,12(1)
BackgroundObservational studies of a putative association between hormonal contraception (HC) and HIV acquisition have produced conflicting results. We conducted an individual participant data (IPD) meta-analysis of studies from sub-Saharan Africa to compare the incidence of HIV infection in women using combined oral contraceptives (COCs) or the injectable progestins depot-medroxyprogesterone acetate (DMPA) or norethisterone enanthate (NET-EN) with women not using HC.ConclusionsThis IPD meta-analysis found no evidence that COC or NET-EN use increases women’s risk of HIV but adds to the evidence that DMPA may increase HIV risk, underscoring the need for additional safe and effective contraceptive options for women at high HIV risk. A randomized controlled trial would provide more definitive evidence about the effects of hormonal contraception, particularly DMPA, on HIV risk. 相似文献
90.