全文获取类型
收费全文 | 4112篇 |
免费 | 285篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 155篇 |
妇产科学 | 91篇 |
基础医学 | 737篇 |
口腔科学 | 17篇 |
临床医学 | 397篇 |
内科学 | 930篇 |
皮肤病学 | 96篇 |
神经病学 | 448篇 |
特种医学 | 82篇 |
外科学 | 389篇 |
综合类 | 25篇 |
一般理论 | 1篇 |
预防医学 | 337篇 |
眼科学 | 75篇 |
药学 | 260篇 |
中国医学 | 3篇 |
肿瘤学 | 363篇 |
出版年
2023年 | 28篇 |
2022年 | 50篇 |
2021年 | 101篇 |
2020年 | 64篇 |
2019年 | 108篇 |
2018年 | 99篇 |
2017年 | 65篇 |
2016年 | 86篇 |
2015年 | 116篇 |
2014年 | 138篇 |
2013年 | 209篇 |
2012年 | 339篇 |
2011年 | 349篇 |
2010年 | 175篇 |
2009年 | 161篇 |
2008年 | 266篇 |
2007年 | 287篇 |
2006年 | 274篇 |
2005年 | 268篇 |
2004年 | 265篇 |
2003年 | 276篇 |
2002年 | 216篇 |
2001年 | 41篇 |
2000年 | 24篇 |
1999年 | 48篇 |
1998年 | 49篇 |
1997年 | 43篇 |
1996年 | 32篇 |
1995年 | 35篇 |
1994年 | 19篇 |
1993年 | 19篇 |
1992年 | 16篇 |
1991年 | 18篇 |
1990年 | 16篇 |
1989年 | 11篇 |
1988年 | 10篇 |
1987年 | 12篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1979年 | 8篇 |
1977年 | 4篇 |
1973年 | 2篇 |
1972年 | 6篇 |
1971年 | 2篇 |
1970年 | 4篇 |
1968年 | 6篇 |
1966年 | 2篇 |
排序方式: 共有4415条查询结果,搜索用时 31 毫秒
41.
Christelle Rivas Aouatef Djeraba Eugène Musset Nico van Rooijen Bas Baaten Pascale Quéré 《Avian pathology》2003,32(2):139-149
In this study the functional effectiveness of in vivo macrophage depletion using liposome-encapsulateddichloromethylene bisphosphonate (C12MBP) was examined in the chicken. The main target organs forsystemic liposome-encapsulated C12MBP treatment are the spleen and the liver. Intravenous treatment withC12MBP of B21/B21 chickens, genetically resistant to Marek's disease (MD), before challenge with the very virulent strain RB-lB, increased viral load in the blood and spleen after the first week and up to 6 weeks postinfection. In addition, C12MBP treatment dramatically increased tumour incidence and tumour load, especially in the spleens and livers of sick animals, but without affecting MD-specific mortality of B21/B21 cickens infected with RB-1B at 12 days of age. Nitric oxide (NO) is an important effector of the macrophage and has antiviral and antitumoural properties. NO has been shown to be one of the mechanisms triggered in resistance to Marek's disease. Intravenous treatment with Cl2MBP before infection with RB-1B induced a long-lasting decrease in numbers of macrophages and reduction in splenic inducible NO production associated with an absence of nitrate induction in the serum (up to 6 weeks pi). These results do not identify macrophage and NO production as major effector components in genetic resistance to Marek's disease, but underline their roles in limiting viraemia and tumour development in organs such as the spleen and the liver. 相似文献
42.
Jehane Fadlallah Delphine Sterlin Claire Fieschi Christophe Parizot Karim Dorgham Hela El Kafsi Gaëlle Autaa Pascale Ghillani-Dalbin Catherine Juste Patricia Lepage Marion Malphettes Lionel Galicier David Boutboul Karine Clément Sébastien André Florian Marquet Christophe Tresallet Alexis Mathian Guy Gorochov 《The Journal of allergy and clinical immunology》2019,143(4):1575-1585.e4
43.
Random amplified polymorphic DNAs (RAPDs) were used as a genetic marker system to characterize recombinant strains following the parasexual cycle of Penicillium roqueforti. After protoplast fusion and haploidization of diploid hybrids, segregants characterized by a reassortment of the parental genetic markers displayed specific RAPD fingerprints. The appearance or the loss of RAPD fragments demonstrate that these markers provide an efficient method to analyze recombination and to characterize somatic hybrids. 相似文献
44.
Rodolphe Thiébaut Jérémie Guedj Hélène Jacqmin-Gadda Geneviève Chêne Pascale Trimoulet Didier Neau Daniel Commenges 《BMC medical research methodology》2006,6(1):38-9
Background
Mathematical models are widely used for studying the dynamic of infectious agents such as hepatitis C virus (HCV). Most often, model parameters are estimated using standard least-square procedures for each individual. Hierarchical models have been proposed in such applications. However, another issue is the left-censoring (undetectable values) of plasma viral load due to the lack of sensitivity of assays used for quantification. A method is proposed to take into account left-censored values for estimating parameters of non linear mixed models and its impact is demonstrated through a simulation study and an actual clinical trial of anti-HCV drugs. 相似文献45.
Mitral cell temporal response patterns evoked by odor mixtures in the rat olfactory bulb 总被引:3,自引:0,他引:3
Mammals generally have the ability to extract odor information contained in complex mixtures of molecular components. However, odor mixture processing has been studied electrophysiologically only in insects, crustaceans, and fish. As a first step toward a better understanding of this processing in high vertebrates, we studied the representation of odor mixtures in the rat olfactory bulb, i.e., the second-order level of the olfactory pathways. We compared the single-unit responses of mitral cells, the main cells of the olfactory bulb, to pure odors and to their binary mixtures. Eighty-six mitral cells were recorded in anesthetized freely breathing rats stimulated with five odorants and their 10 binary mixtures. The spontaneous activity and the odor-evoked responses were characterized by their temporal distribution of activity along the respiratory cycle, i.e., by cycle-triggered histograms. Ninety percent of the mixtures were found to evoke a response when at least one of their two components evoked a response. Mixture-evoked patterns were analyzed to describe the modalities of the combination of patterns evoked by the two components. In most of the cases, the mixture pattern was closely similar to one of the component patterns. This dominance of a component over the other one was related to the responsiveness of the cell to the individual components of the mixture, to the molecular nature of the stimulus, and to the coarse shape of individual response patterns. This suggests that the components of binary mixtures may be encoded simultaneously by different odor-specific temporal distributions of activity. 相似文献
46.
Ndembi N Takehisa J Zekeng L Kobayashi E Ngansop C Songok EM Kageyama S Takemura T Ido E Hayami M Kaptue L Ichimura H 《Journal of acquired immune deficiency syndromes (1999)》2004,37(5):1641-1650
To monitor the presence of genotypic HIV-1 variants circulating in eastern Cameroon, blood samples from 57 HIV-1-infected individuals attending 3 local health centers in the bordering rural villages with Central African Republic (CAR) were collected and analyzed phylogenetically. Out of the 40 HIV-1 strains with positive polymerase chain reaction (PCR) profile for both gag and env-C2V3,12 (30.0%) had discordant subtype or CRF designation: 2 subtype B/A (gag/env), 1 B/CRF01, 2 B/CRF02, 1 CRF01/CRF01.A, 2 CRF11/CRF01, 1 CRF13/A, 1 CRF13/CRF01, 1 CRF13/CRF11, and 1 G/U (unclassified). Twenty-eight strains (70.0%) had concordant subtypes or CRF designation between gag and env: 27 subtype A and 1 F2. Out of the remaining 17HIV-1 strains negative for PCR with the env-C2V3 primers used, 10 (58.8%) had discordant subtype or CRF, and 7 (41.2%) had concordant one based on gag/pol/env-gp41 analysis. Altogether, a high proportion (22/57, 38.6%) of the isolates were found to be recombinant strains. In addition, an emergence of new forms of HIV-1 strains, such as subtype B/A (gag/env), B/CRF01 and B/CRF02, was identified. The epidemiologic pattern of HIV-1 in eastern Cameroon, relatively low and high prevalence of CRF02 and CRF11, respectively, was more closely related to those of CAR and Chad than that of other regions of Cameroon, where CRF02 is the most predominant HIV-1 strain. These findings strongly suggest that this part of Cameroon is a potential hotspot of HIV-1 recombination, with a likelihood of an active generation of new forms of HIV-1 variants, though epidemiologic significance of new HIV-1 forms is unknown. 相似文献
47.
L Castellani H Nicaise J Piétri L Quilliet B Desveaux D Alison L Guillou 《Journal des maladies vasculaires》1987,12(1):64-69
Partial interruption of inferior vena cava (I.C.V.) forms an integral part of treatment of thromboembolic disease. The most frequently used filter worldwide is currently that of Greenfield, but although its effectiveness and permeability are remarkable it can be the subject of transfixions, sliding movements and migrations. A new model of the authors' own conception is presented which eliminates these faults. The "2612" filter is based on the same concepts, but has added to it 6 lateral flanges soldered to the base of the arms, these applying pressure to the I.V.C. and ensuring its perfect positioning, and 12 hooks (6 turned downwards and 6 upwards) ensuring perfect stability. Results of a multicentre trial in 35 patients, after insertion of the "2612" filter and follow up assessment after 3 months (28 cases) by cavography and in some patients by a scan, showed permeability of 93% and total efficacy. No side effects were reported. This filter appears to represent true progress in the means of interrupting I.V.C., and further studies are contemplated. 相似文献
48.
49.
Franois-Xavier Briand Eric Niqueux Audrey Schmitz Claire Martenot Martine Cherbonnel Pascale Massin Florian Kerbrat Marina Chatel Carole Guillemoto Cecile Guillou-Cloarec Katell Ogor Aurlie Le Prioux Chantal Alle Vronique Beven Edouard Hirchaud Yannick Blanchard Axelle Scoizec Sophie Le Bouquin Nicolas Eterradossi Batrice Grasland 《Emerging infectious diseases》2021,27(2):508
We detected 3 genotypes of highly pathogenic avian influenza A(H5N8) virus in France during winter 2016–17. Genotype A viruses caused dramatic economic losses in the domestic duck farm industry in southwestern France. Our phylogenetic analysis suggests that genotype A viruses formed 5 distinct geographic clusters in southwestern France. In some clusters, local secondary transmission might have been started by a single introduction. The intensity of the viral spread seems to correspond to the density of duck holdings in each production area. To avoid the introduction of disease into an unaffected area, it is crucial that authorities limit the movements of potentially infected birds. 相似文献
50.
Natacha Martin Anne Bergougnoux Nesrine Baatallah Benoit Chevalier Jessica Varilh David Baux Bruno Costes Pascale Fanen Caroline Raynal Isabelle Sermet-Gaudelus Emmanuelle Girodon Magali Taulan-Cadars Alexandre Hinzpeter 《Journal of cystic fibrosis》2021,20(3):464-472
BackgroundMinigenes and in silico prediction tools are commonly used to assess the impact on splicing of CFTR variants. Exon skipping is often neglected though it could impact the efficacy of targeted therapies. The aim of the study was to identify exon skipping associated with CFTR variants and to evaluate in silico predictions of seven freely available software.MethodsCFTR basal exon skipping was evaluated on endogenous mRNA extracted from non-CF nasal cells and on two CFTR minigene banks. In silico tools and minigene systems were used to evaluate the impact of CFTR exonic variants on exon skipping.ResultsData showed that out of 65 CFTR variants tested, 26 enhanced exon skipping and that in silico prediction efficacy was of 50%-66%. Some in silico tools presented predictions with a bias towards the occurrence of splicing events while others presented a bias towards the absence of splicing events (non-detection including true negatives and false negatives). Classification of exons depending on their basal exon skipping level increased prediction rates up to 80%.ConclusionThis study indicates that taking basal exon skipping into account could orientate the choice of the in silico tools to improve prediction rates. It also highlights the need to validate effects using in vitro assays or mRNA studies in patients. Eventually, it shows that variant-guided therapy should also target exon skipping associated with variants. 相似文献