全文获取类型
收费全文 | 946篇 |
免费 | 72篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 23篇 |
妇产科学 | 10篇 |
基础医学 | 153篇 |
口腔科学 | 132篇 |
临床医学 | 48篇 |
内科学 | 183篇 |
皮肤病学 | 21篇 |
神经病学 | 105篇 |
特种医学 | 12篇 |
外科学 | 108篇 |
综合类 | 2篇 |
预防医学 | 90篇 |
眼科学 | 15篇 |
药学 | 24篇 |
中国医学 | 7篇 |
肿瘤学 | 78篇 |
出版年
2023年 | 8篇 |
2022年 | 16篇 |
2021年 | 20篇 |
2020年 | 18篇 |
2019年 | 21篇 |
2018年 | 28篇 |
2017年 | 22篇 |
2016年 | 20篇 |
2015年 | 26篇 |
2014年 | 42篇 |
2013年 | 39篇 |
2012年 | 55篇 |
2011年 | 85篇 |
2010年 | 31篇 |
2009年 | 39篇 |
2008年 | 57篇 |
2007年 | 57篇 |
2006年 | 38篇 |
2005年 | 44篇 |
2004年 | 41篇 |
2003年 | 45篇 |
2002年 | 34篇 |
2001年 | 34篇 |
2000年 | 39篇 |
1999年 | 30篇 |
1998年 | 14篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1971年 | 2篇 |
1970年 | 4篇 |
1969年 | 2篇 |
1962年 | 4篇 |
1960年 | 3篇 |
1959年 | 1篇 |
排序方式: 共有1022条查询结果,搜索用时 15 毫秒
1.
This study presents the case of a patient with necrobiosis or necrosing fascitis of the inguinal region, secondary to a complicated
Amyand’s hernia with a concomitant ipsilateral Richter’s hernia. The patient was treated with open trans-abdominal surgery
and hernia repair through the pre-peritoneal approach, plus anti-microbians, and thrice-daily wound cleansing and dressings
to the inguinal region. Evolution was satisfactory. There are no reports in the literature of a case such as this. 相似文献
2.
We compared several pharmacological and enzymatic effects induced by 11 snake venoms from seven species, six of them from different geographic areas of Antioquia and Choco, north-west of Colombia, South America (Bothrops atrox, B. nasutus, B. schlegelii, B. punctatus, Lachesis muta, Micrurus mipartitus), and Crotalus durissus terrificus venom, from specimens captured in other provinces of the country (Tolima, Huila, Meta and Atlantico). Differences were observed in edema-forming, hemorrhage, defibrination, indirect hemolysis, myonecrosis, proteolysis and lethal activity between venoms from different genera or species, as well as according to the geographic area of origin in B. atrox and B. nasutus snake venoms. Bothrops venoms, in particular B. atrox and L. muta, produced major local effects. All of the venoms, including M. mipartitus, had myotoxic effects. The most defibrinating venoms were B. atrox, L. muta, B. punctatus and C. d. terrificus. All of the venoms had indirect hemolytic activity; the venom of M. mipartitus being greatest. The most lethal venoms were those of C. d. terrificus and M. mipartitus. Within Bothrops species, the venom of B. schlegelii was the least active in terms of local and systemic pathologic effects. 相似文献
3.
Campos B Díez O Odefrey F Domènech M Moncoutier V Martínez-Ferrandis JI Osorio A Balmaña J Barroso A Armengod ME Benítez J Alonso C Stoppa-Lyonnet D Goldgar D Baiget M 《Human mutation》2003,21(4):452-452
A frame-shift 9254del5 mutation was independently identified in 12 families, eleven of them with Spanish ancestors, in a BRCA2 screening performed in 841 breast and/or ovarian cancer families and in 339 women with breast cancer diagnosed before the age of 40 at different centers in France and Spain. We sought to analyze in detail the haplotype and founder effects of the 9254del5 and to estimate the time of origin of the mutation. Eight polymorphic microsatellite markers and two BRCA2 polymorphisms were used for the haplotype analyses. The markers were located flanking the BRCA2 gene spanning a region of 6.1 cM. Our results suggest that these families shared a common ancestry with BRCA2 9254del5, which is a founder mutation originating in the Northeast Spanish, with an estimated age of 92 (95% CI 56-141) generations. 相似文献
4.
Fuentes V Toledano M Osorio R Carvalho RM 《Journal of biomedical materials research. Part A》2003,66(4):850-853
Our purpose in this study was to determine the microhardness of superficial and deep dentin by means of two indentation methods (Knoop and Vickers) under two different applied loads. Twelve dentin discs approximately 2-mm thick were obtained from both superficial and deep dentin by transversally sectioning the crowns of sound, extracted human third molars with a diamond blade under water irrigation. Dentin surfaces were sequentially polished, and indentations (n = 20 per surface) were performed with either Vickers indentor at loads of 300 and 500 g, respectively, or Knoop indentor at loads of 50 and 100 g, respectively. Average Vickers hardness number (VHN) and Knoop hardness number (KHN) were calculated and treated with two-way analysis of variance (ANOVA) and Student's t test. Microhardness of dentin was not influenced by the different loads applied for both indentation methods. Knoop hardness was significantly higher for superficial than for deep dentin (p < 0.05). Conversely, Vickers hardness was not significantly different for both substrates (p > 0.05). Differences in dentin hardness as a function of depth exist, but they might not be relevant, and no alteration of the distribution of stresses along the adhesive interface is expected. 相似文献
5.
Arancha C Ruíz-Llorente S Cascón A Osorio A Martínez-Delgado B Benítez J Robledo M 《Journal of human genetics》2002,47(4):190-195
Until now, the study of the multiple endocrine neoplasia type 1 (MEN1) gene in patients suspected of having the disease was expensive and laborious due to the large size of the gene. We have
optimized the conformation-sensitive gel electrophoresis (CSGE) technique to analyze by four rather simple multiplex PCR reactions,
and a single electrophoresis run, the entire coding region of the MEN1 gene, plus the exon–intron boundaries. This improvement of the CSGE technique was confirmed as an effective procedure for
screening for the MEN1 gene by detecting ten previously known MEN1 gene mutations and four polymorphisms. The MEN1 gene of 12 patients with unknown mutations was then screened, and an abnormal CSGE profile was identified in 10/12 cases.
Subsequent DNA sequencing demonstrated 3 of them to be novel mutations (E45K, 4479delACAG, 6073insC) and 7 to have been previously
reported; in the remaining 2 patients, we confirmed the absence of any alteration of the coding sequence of MEN1. Mutation screening of the MEN1 gene using CSGE was demonstrated to be a fast, simple, and inexpensive method to study patients suspected of having MEN1
disease.
Received: November 29, 2001 / Accepted: January 28, 2002 相似文献
6.
7.
Trypanosoma cruzi Infection in Tumor Necrosis Factor Receptor p55-Deficient Mice 总被引:2,自引:0,他引:2 下载免费PDF全文
Esmeralda Castaos-Velez Stephanie Maerlan Lyda M. Osorio Frederik berg Peter Biberfeld Anders
rn Martín E. Rottenberg 《Infection and immunity》1998,66(6):2960-2968
Tumor necrosis factor receptor p55 (TNFRp55) mediates host resistance to several pathogens by allowing microbicidal activities of phagocytes. In the studies reported here, TNFRp55−/− mice infected with the intracellular parasite Trypanosoma cruzi showed clearly higher parasitemia and cumulative mortality than wild-type (WT) controls did. However, gamma interferon (IFN-γ)-activated macrophages from TNFRp55−/− mice produced control levels of nitric oxide and killed the parasite efficiently in vitro. Trypanocidal mechanisms of nonphagocytic cells (myocardial fibroblasts) from both TNFRp55−/− and WT mice were also activated by IFN-γ in a dose-dependent way. However, IFN-γ-activated TNFRp55−/− nonphagocytes showed less effective killing of T. cruzi than WT control nonphagocytes, even when interleukin 1β (IL-1β) was added as a costimulator. In vivo, T. cruzi-infected TNFRp55−/− mice and WT mice released similar levels of NO and showed similar levels of IFN-γ mRNA and inducible nitric oxide synthase mRNA in their tissues. Instead, increased susceptibility to T. cruzi of TNFRp55−/− mice was associated with reduced levels of parasite-specific immunoglobulin G (IgG) (but not IgM) antibodies during infection, which is probably linked to abnormal B-cell differentiation in secondary lymphoid tissues of the mutant mice. Surprisingly, T. cruzi-infected TNFRp55−/− mice showed increased inflammatory and necrotic lesions in several tissues, especially in skeletal muscles, indicating that TNFRp55 plays an important role in controlling the inflammatory process. Accordingly, levels of Mn2+ superoxide dismutase mRNA, a TNF-induced enzyme which protects the cell from the toxic effects of superoxide, were lower in mutant than in WT infected mice. 相似文献
8.
Simultaneous cross-linking of CD6 and CD28 induces cell proliferation in resting T cells. 总被引:1,自引:0,他引:1 下载免费PDF全文
In the present study, we showed that simultaneous ligation of the monoclonal antibodies (mAb) against CD6 and CD28 induces T-cell proliferation in purified resting T lymphocytes in the absence of T-cell receptor (TCR) occupancy. No cell proliferation was observed when the mAb were cross-linked alone or used simultaneously in the soluble form. T-cell proliferation mediated through CD6/CD28 is accompanied by the up-regulation of interleukin-2 (IL-2) mRNA and expression of IL-2 receptors on the cell surface. In the presence of IL-2-neutralizing mAb the proliferative response of the T cell induced through CD6/CD28 was inhibited dose dependently. Cross-linking mAb to CD6 and CD28 alone or together did not down-regulate the CD3/TCR complex. T-cell proliferation mediated through CD6/CD28 was only partially blocked by the immunosuppressive drug, cyclosporin A (CsA), whereas anti-CD28-induced T-cell proliferation in the presence of the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), was unaffected. In sharp contrast T-cell proliferation mediated by anti-CD6 in the presence of TPA was efficiently blocked by CsA. In addition, two protein kinase C (PKC) inhibitors, GF 109203X and H-7 dose-dependently inhibited T-cell proliferation mediated through CD6/CD28, suggesting that PKC activation may be involved. Furthermore, there was a marked differential dose-dependent inhibitory effect of the PKC inhibitors on T-cell proliferation mediated by the co-ligation of anti-CD6 or anti-CD28 in the presence of anti-CD3, with the former being more sensitive to PKC inhibition. Taken collectively, our results suggest that T-cell activation can occur through an antigen-independent pathway by cross-linking the accessory molecules, CD6 and CD28, and that these two cell surface antigens may have distinct signalling pathways. 相似文献
9.
10.
Mutations in the genome of porcine reproductive and respiratory syndrome virus responsible for the attenuation phenotype 总被引:16,自引:0,他引:16
Allende R Kutish GF Laegreid W Lu Z Lewis TL Rock DL Friesen J Galeota JA Doster AR Osorio FA 《Archives of virology》2000,145(6):1149-1161
Summary. Although live-attenuated vaccines have been used for some time to control clinical symptoms of the porcine reproductive and
respiratory syndrome (PRRS), the molecular bases for the attenuated phenotype remain unclear. We had previously determined
the genomic sequence of the pathogenic PRRSV 16244B. Limited comparisons of the structural protein coding sequence of an attenuated
vaccine strain have shown 98% homology to the pathogenic 16244B. Here we have confirmed the attenuated phenotype and determined
the genomic sequence of that attenuated PRRSV vaccine and compared it to its parental VR-2332 and the 16244B strains. The
attenuated vaccine sequence was colinear with that of the strain 16244B sequence containing no gaps and 212 substitutions
over 15,374 determined nucleotide sequence. We identified nine amino acid changes distributed in Nsp1β, Nsp2, Nsp10, ORF2,
ORF3, ORF5 and ORF6. These changes may provide the molecular bases for the observed attenuated phenotype.
Received August 28, 1999 Accepted December 16, 1999 相似文献