全文获取类型
收费全文 | 2036篇 |
免费 | 171篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 82篇 |
妇产科学 | 15篇 |
基础医学 | 346篇 |
口腔科学 | 15篇 |
临床医学 | 249篇 |
内科学 | 643篇 |
皮肤病学 | 10篇 |
神经病学 | 102篇 |
特种医学 | 171篇 |
外科学 | 146篇 |
综合类 | 41篇 |
一般理论 | 2篇 |
预防医学 | 146篇 |
眼科学 | 32篇 |
药学 | 129篇 |
中国医学 | 2篇 |
肿瘤学 | 83篇 |
出版年
2022年 | 13篇 |
2021年 | 31篇 |
2019年 | 14篇 |
2018年 | 18篇 |
2017年 | 13篇 |
2016年 | 30篇 |
2015年 | 31篇 |
2014年 | 47篇 |
2013年 | 78篇 |
2012年 | 70篇 |
2011年 | 78篇 |
2010年 | 46篇 |
2009年 | 47篇 |
2008年 | 66篇 |
2007年 | 81篇 |
2006年 | 75篇 |
2005年 | 87篇 |
2004年 | 84篇 |
2003年 | 66篇 |
2002年 | 68篇 |
2001年 | 56篇 |
2000年 | 58篇 |
1999年 | 55篇 |
1998年 | 65篇 |
1997年 | 85篇 |
1996年 | 53篇 |
1995年 | 47篇 |
1994年 | 54篇 |
1993年 | 37篇 |
1992年 | 61篇 |
1991年 | 52篇 |
1990年 | 36篇 |
1989年 | 50篇 |
1988年 | 57篇 |
1987年 | 37篇 |
1986年 | 38篇 |
1985年 | 42篇 |
1984年 | 27篇 |
1983年 | 15篇 |
1982年 | 17篇 |
1981年 | 14篇 |
1980年 | 16篇 |
1979年 | 14篇 |
1978年 | 23篇 |
1977年 | 19篇 |
1976年 | 19篇 |
1975年 | 19篇 |
1974年 | 14篇 |
1971年 | 13篇 |
1969年 | 12篇 |
排序方式: 共有2218条查询结果,搜索用时 11 毫秒
61.
Inheritance of the mitral valve prolapse syndrome. Discussion of a three-dimensional penetrance model 总被引:1,自引:0,他引:1
N V Strahan E A Murphy N J Fortuin P C Come J O Humphries 《The American journal of medicine》1983,74(6):967-972
The families of 12 probands with classic mitral valve prolapse were studied for evidence of mitral valve prolapse. Seventy parents, sibs, and progeny were included in the analysis. Forty-seven percent (16 of 34) of progeny were affected compared with 30 percent (3 of 10) of parents. Thirty-eight percent (10 of 26) of sibs were affected. A three-compartmental penetrance model was devised to account for the variation in expression with age. This includes a latent stage (time before onset of signs), an affected stage, and a stage in which the subjects are withdrawn (because of treatment, regression, or death). The implications of this model are discussed. 相似文献
62.
Wallace AJ Mann JI Sutherland WH Williams S Chisholm A Skeaff CM Gudnason V Talmud PJ Humphries SE 《Atherosclerosis》2000,152(2):327-336
There are no definitive explanations as to why individuals with hypercholesterolemia, a major cardiovascular risk factor, respond differently to dietary change. Fifty five free-living individuals completed a double crossover trial with two dietary regimens, a high saturated fat diet (providing 21% energy from saturated fat and 3% energy from polyunsaturated fat) and a high polyunsaturated fat diet (providing 11% energy as saturated fat and 10% energy as polyunsaturated fat), each phase continuing for 4 weeks. Extensive genotyping and several measures of dietary compliance have provided further insights regarding the determinants of extent of cholesterol response to changes in the nature of dietary fat. Individuals with the CETP B1B1 genotype and the LPL X447+ allele showed an average 0. 44 (95% CI: 0.22, 0.66) and 0.45 (95% CI: 0.18, 0.72) mmol/l greater change in total cholesterol, respectively, than those with one or more CETP B2 allele or homozygous for the LPL S447 allele when comparing diets high and low in saturated fat. Indices of dietary compliance including changes in reported saturated and polyunsaturated fat intake and change in triglyceride linoleate were not significantly different between the CETP genotypes. Change in reported saturated (r=0.36, P=0.04) and polyunsaturated (r=0.22, P=0. 05) fat intake and change in triglyceride linoleate (reflecting polyunsaturated fat intake) (r=0.21, P=0.07), also predicted total cholesterol response to dietary fat changes. In multivariate analyses, variation in the cholesterol ester transfer protein and lipoprotein lipase genes predicted response independent of measures of dietary compliance, suggesting that these two genes are important determinants of variation in cholesterol response to dietary change in free-living individuals. 相似文献
63.
P A Bowen S A Lobel R J Caruana M S Leffell M A House J P Rissing A L Humphries 《Annals of internal medicine》1988,108(1):46-48
The human immunodeficiency virus (HIV) was transmitted to a patient who received a cadaveric renal transplant from a donor who had received massive blood component replacement. A negative HIV antibody test was obtained on serum drawn immediately after transfusion. After transplantation, pretransfusion sera and sera obtained several hours after transfusion tested positive for HIV antibody, suggesting that transfusions had transiently diluted the patient's serum and resulted in a false-negative HIV antibody test. Immediately after transplantation, the recipient showed a transient increase in HIV antigen levels followed by a more sustained increase representing de-novo antigen synthesis. Antibodies to HIV were detected 51 days after transplant. The recipient has shown no signs or symptoms of HIV infection after 1 year. In potential cadaveric organ donors, HIV antibody testing should be performed on pretransfusion sera or on sera obtained several hours after massive transfusion of blood products. 相似文献
64.
Homeobox genes in leukemogenesis 总被引:17,自引:0,他引:17
65.
Emily R. Watts Andrew J.M. Howden Tyler Morrison Pranvera Sadiku Jens Hukelmann Alex von Kriegsheim Bart Ghesquiere Fiona Murphy Ananda S. Mirchandani Duncan C. Humphries Robert Grecian Eilise M. Ryan Patricia Coelho Gio Rodriguez Blanco Tracie M. Plant Rebecca S. Dickinson Andy Finch Wesley Vermaelen Doreen A. Cantrell Moira K. Whyte Sarah R. Walmsley 《The Journal of clinical investigation》2021,131(10)
Limiting dysfunctional neutrophilic inflammation while preserving effective immunity requires a better understanding of the processes that dictate neutrophil function in the tissues. Quantitative mass-spectrometry identified how inflammatory murine neutrophils regulated expression of cell surface receptors, signal transduction networks, and metabolic machinery to shape neutrophil phenotypes in response to hypoxia. Through the tracing of labeled amino acids into metabolic enzymes, proinflammatory mediators, and granule proteins, we demonstrated that ongoing protein synthesis shapes the neutrophil proteome. To maintain energy supplies in the tissues, neutrophils consumed extracellular proteins to fuel central carbon metabolism. The physiological stresses of hypoxia and hypoglycemia, characteristic of inflamed tissues, promoted this extracellular protein scavenging with activation of the lysosomal compartment, further driving exploitation of the protein-rich inflammatory milieu. This study provides a comprehensive map of neutrophil proteomes, analysis of which has led to the identification of active catabolic and anabolic pathways that enable neutrophils to sustain synthetic and effector functions in the tissues. 相似文献
66.
Andrew James Anderson Douwe Kiela Jeffrey R. Binder Leonardo Fernandino Colin J. Humphries Lisa L. Conant Rajeev D. S. Raizada Scott Grimm Edmund C. Lalor 《The Journal of neuroscience》2021,41(18):4100
Understanding how and where in the brain sentence-level meaning is constructed from words presents a major scientific challenge. Recent advances have begun to explain brain activation elicited by sentences using vector models of word meaning derived from patterns of word co-occurrence in text corpora. These studies have helped map out semantic representation across a distributed brain network spanning temporal, parietal, and frontal cortex. However, it remains unclear whether activation patterns within regions reflect unified representations of sentence-level meaning, as opposed to superpositions of context-independent component words. This is because models have typically represented sentences as “bags-of-words” that neglect sentence-level structure. To address this issue, we interrogated fMRI activation elicited as 240 sentences were read by 14 participants (9 female, 5 male), using sentences encoded by a recurrent deep artificial neural-network trained on a sentence inference task (InferSent). Recurrent connections and nonlinear filters enable InferSent to transform sequences of word vectors into unified “propositional” sentence representations suitable for evaluating intersentence entailment relations. Using voxelwise encoding modeling, we demonstrate that InferSent predicts elements of fMRI activation that cannot be predicted by bag-of-words models and sentence models using grammatical rules to assemble word vectors. This effect occurs throughout a distributed network, which suggests that propositional sentence-level meaning is represented within and across multiple cortical regions rather than at any single site. In follow-up analyses, we place results in the context of other deep network approaches (ELMo and BERT) and estimate the degree of unpredicted neural signal using an “experiential” semantic model and cross-participant encoding.SIGNIFICANCE STATEMENT A modern-day scientific challenge is to understand how the human brain transforms word sequences into representations of sentence meaning. A recent approach, emerging from advances in functional neuroimaging, big data, and machine learning, is to computationally model meaning, and use models to predict brain activity. Such models have helped map a cortical semantic information-processing network. However, how unified sentence-level information, as opposed to word-level units, is represented throughout this network remains unclear. This is because models have typically represented sentences as unordered “bags-of-words.” Using a deep artificial neural network that recurrently and nonlinearly combines word representations into unified propositional sentence representations, we provide evidence that sentence-level information is encoded throughout a cortical network, rather than in a single region. 相似文献
67.
Gene transfer to primary normal and malignant human hemopoietic progenitors using recombinant retroviruses 总被引:10,自引:0,他引:10
To study the feasibility of using retroviruses for gene transfer into human hemopoietic cells, various cell types were exposed to virus carrying the gene for neomycin resistance (neor). In preliminary studies using K562 cells as targets, we found that high viral titer and co-cultivation with viral producer cells rather than incubation in medium exposed to viral producer cells were important variables for achieving high frequencies of G418 resistant (G418r) colonies. The maximum frequency of G418r K562 colonies after co-cultivation with cells producing a neor virus titer of 4 X 10(6) cfu/mL was 60%. When primary human progenitors from normal marrow, fetal liver, or chronic myelogenous leukemia blood were exposed to high titer viral stocks, both with and without helper virus, under conditions optimized for K562 cells, maximum frequencies of G418r colonies were 3% to 16% for granulocyte macrophage progenitors and 2% to 6% for primitive erythroid progenitors. The presence of the neor gene in both G418r K562 and primary hemopoietic colonies was verified by Southern blot. Expression of the neor gene was shown by RNA spot blot. These data demonstrate efficient transfer and expression of the neor gene in both K562 cells and primary human hemopoietic cells from normal and leukemic individuals. 相似文献
68.
Janet A. Hindler Annie Wong-Beringer Carmen L. Charlton Shelley A. Miller Theodoros Kelesidis Marissa Carvalho George Sakoulas Poochit Nonejuie Joseph Pogliano Victor Nizet Romney Humphries 《Antimicrobial agents and chemotherapy》2015,59(7):4279-4288
Enterococci that are nonsusceptible (NS; MIC > 4 μg/ml) to daptomycin are an emerging clinical concern. The synergistic combination of daptomycin plus beta-lactams has been shown to be effective against vancomycin-resistant Enterococcus (VRE) species in vitro. This study systematically evaluated by in vitro time-kill studies the effect of daptomycin in combination with ampicillin, cefazolin, ceftriaxone, ceftaroline, ertapenem, gentamicin, tigecycline, and rifampin, for a collection of 9 daptomycin-NS enterococci that exhibited a broad range of MICs and different resistance-conferring mutations. We found that ampicillin plus daptomycin yielded the most consistent synergy but did so only for isolates with mutations to the liaFSR system. Daptomycin binding was found to be enhanced by ampicillin in a representative isolate with such mutations but not for an isolate with mutation to the yycFGHIJ system. In contrast, ampicillin enhanced the killing of the LL-37 human antimicrobial peptide against daptomycin-NS E. faecium with either the liaFSR or yycFGHIJ mutation. Antagonism was noted only for rifampin and tigecycline and only for 2 or 3 isolates. These data add support to the growing body of evidence indicating that therapy combining daptomycin and ampicillin may be helpful in eradicating refractory VRE infections. 相似文献
69.
An antibody (DIL) from a patient with idiopathic thrombocytopenic purpura (ITP) was shown to have autospecificity on the basis of reactions with autologous platelets that were identical to those obtained with platelets from normal subjects. DIL antibody also reacted strongly in an immunofluorescence test with platelets from a patient with Glanzmann's thrombasthenia, but failed to react with platelets from a patient with the Bernard-Soulier syndrome who was known to be deficient in glycoprotein Ib (GPIb). Purified GPIb and control platelets, but not Bernard-Soulier platelets, inhibited the lytic activity of DIL. Using the GPIb-specific monoclonal antibody AP1 and one-dimensional rocket electrophoresis into gels containing rabbit antihuman platelet membrane antibody, it was shown that staphylococcal protein A-Sepharose beads coated with DIL antibody selectively remove GPIb from solubilized platelet preparations. By crossed immunoelectrophoresis it was found that DIL recognizes a determinant on GPIb on the membrane side of the cleavage site of the platelet calcium- activated protease (calpain). These studies provide direct evidence for binding of a platelet autoantibody to a determinant on GPIb relatively close to the site of insertion of this protein into the platelet membrane. 相似文献
70.