全文获取类型
收费全文 | 6081篇 |
免费 | 411篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 104篇 |
妇产科学 | 62篇 |
基础医学 | 965篇 |
口腔科学 | 87篇 |
临床医学 | 568篇 |
内科学 | 1342篇 |
皮肤病学 | 141篇 |
神经病学 | 788篇 |
特种医学 | 305篇 |
外科学 | 640篇 |
综合类 | 47篇 |
预防医学 | 370篇 |
眼科学 | 137篇 |
药学 | 448篇 |
中国医学 | 15篇 |
肿瘤学 | 459篇 |
出版年
2023年 | 27篇 |
2022年 | 47篇 |
2021年 | 74篇 |
2020年 | 68篇 |
2019年 | 88篇 |
2018年 | 92篇 |
2017年 | 87篇 |
2016年 | 102篇 |
2015年 | 129篇 |
2014年 | 159篇 |
2013年 | 223篇 |
2012年 | 312篇 |
2011年 | 300篇 |
2010年 | 199篇 |
2009年 | 155篇 |
2008年 | 318篇 |
2007年 | 330篇 |
2006年 | 332篇 |
2005年 | 332篇 |
2004年 | 319篇 |
2003年 | 283篇 |
2002年 | 288篇 |
2001年 | 174篇 |
2000年 | 193篇 |
1999年 | 172篇 |
1998年 | 97篇 |
1997年 | 75篇 |
1996年 | 61篇 |
1995年 | 49篇 |
1994年 | 59篇 |
1993年 | 55篇 |
1992年 | 77篇 |
1991年 | 56篇 |
1990年 | 69篇 |
1989年 | 83篇 |
1988年 | 71篇 |
1987年 | 65篇 |
1986年 | 59篇 |
1985年 | 57篇 |
1984年 | 48篇 |
1983年 | 32篇 |
1979年 | 30篇 |
1978年 | 33篇 |
1977年 | 25篇 |
1974年 | 26篇 |
1973年 | 24篇 |
1972年 | 28篇 |
1971年 | 39篇 |
1968年 | 25篇 |
1967年 | 23篇 |
排序方式: 共有6511条查询结果,搜索用时 31 毫秒
61.
Monoclonal antibody (WT 1) directed against a T cell surface glycoprotein: characteristics and immunosuppressive activity 总被引:1,自引:2,他引:1
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
W J Tax N Tidman G Janossy L Trejdosiewicz R Willems J Leeuwenberg T J De Witte P J Capel R A Koene 《Clinical and experimental immunology》1984,55(2):427-436
WT 1, an IgG2a subclass monoclonal antibody, recognizes a human T lineage specific antigen (mol. wt 40,000). This antigen is strongly expressed on thymic T blasts, and on peripheral T cells activated by phytohaemagglutinin, whereas cortical thymocytes and peripheral T cells are moderately positive for WT 1. In contrast, B lymphocytes, myeloid and erythroid cells, including the progenitor cells of these lineages, and terminal deoxynucleotidyl transferase positive cells in the bone marrow, are all WT 1 negative. Binding of WT 1 to T cells is blocked by a previously described antibody (3A1) suggesting that both antibodies bind to the same antigen present on human T cells. WT 1, however, is also reactive with T lymphocytes from rhesus monkeys whereas 3A1 is not. Therefore, the biological effects of WT 1 could be studied in a monkey model. In a skin allograft model, WT 1 was immunosuppressive and induced a marked prolongation of graft survival. 相似文献
62.
CD8+ T cell populations in common variable immunodeficiency 总被引:1,自引:0,他引:1
In a subgroup of CVID T cell abnormalities have been reported. Peripheral blood T lymphocytes from patients with common variable immunodeficiency (CVID) and blood donors were examined for expression of CD8alpha, CD8beta and CD28. In CVID, three CD8+ T cells could be defined: CD8beta(high)CD28+ (expressing CD8beta at a high median fluorescence intensity), CD8beta(low)CD28+ and CD8beta(low) CD28- cells. The number of CD8beta(low) cells was markedly increased compared to blood donors. After activation, CD8beta(high)CD28+ cells from cord blood differentiated into CD8beta(low) CD28- cells. Therefore, CD8beta(low) cells are induced by activation even in normal donors, but may reflect inflammatory activity in CVID. 相似文献
63.
CMV complications in common variable immunodeficiency 总被引:1,自引:0,他引:1
A patient suffering from common variable immunodeficiency is described, who developed a myelitis under treatment with glucocorticosteroids. Later on, autoimmune complications had to be treated with azathioprine. An exacerbation of the myelitis, retinitis, encephalitis and colitis was observed and a cytomegalovirus infection diagnosed. This infection does not represent a typical complication of common variable immunodeficiency. A functional NK cell defect was detected that may contribute to susceptibility for cytomegalovirus infection in addition to immunosuppressive therapy. 相似文献
64.
Identification of the multiple endocrine neoplasia type 1 (MEN1) gene. The European Consortium on MEN1 总被引:10,自引:0,他引:10
Lemmens I; Van de Ven WJ; Kas K; Zhang CX; Giraud S; Wautot V; Buisson N; De Witte K; Salandre J; Lenoir G; Pugeat M; Calender A; Parente F; Quincey D; Gaudray P; De Wit MJ; Lips CJ; Hoppener JW; Khodaei S; Grant AL; Weber G; Kytola S; Teh BT; Farnebo F; Thakker RV 《Human molecular genetics》1997,6(7):1177-1183
65.
Siegfried Weiss Peter D. Burrows Jutta Meyer Matthias R. Wabl 《European journal of immunology》1984,14(8):744-748
A hybridoma is described that exhibits all the characteristic features of Mott cells. It has spherules (Russell bodies) in the cytoplasm made up of dilated rough endoplasmatic reticulum and containing condensed immunoglobulin (λ1 light chains). Some of the cells appear to be very fragile, and free spherules are often found on cell smears. Cells with the Mott cell characteristics are still able to divide, but they do not secrete immunoglobulin. Hybridomas of this kind should be useful for determining the place of the Mott cell within the scheme of B cell differentiation. 相似文献
66.
Distribution of glutamate receptor subunits in experimentally induced cortical malformations 总被引:9,自引:0,他引:9
Electrophysiological studies in humans and animal models have revealed an intrinsic epileptogenicity of cortical dysplasias which are a frequent cause of drug-resistant epilepsy. An imbalance of inhibition and excitation has been causative related. Receptor-binding studies in rodents demonstrated reduced binding to GABA and increased binding to glutamate receptors within cortical dysplasias and increments of AMPA- and kainate-receptor binding in its surround. Immunohistochemically a differential downregulation of GABA(A) receptor subunits could be demonstrated in widespread areas within and around dysplasias. As receptor binding critically depends on receptor subunit composition the observed changes in binding properties might be related to this. Here, we immunohistochemically analyzed the regional expression of four NMDA receptor subunits and two major AMPA- and kainate-receptor complexes in adult rats after neonatal freeze lesions. These lesions are characterized by a three- to four-layered cortex and a microsulcus which mimic human polymicrogyria. Using antibodies against NR1, NR2A, NR2B, NR2D, GluR2,3, and GluR5,6,7 receptor subunits we demonstrated a pronounced disturbance of cortical immunostaining pattern in the cortical malformation. These changes reflected the structural disorganization of the microgyrus with some distortion of the apical dendrites of paramicrogyral pyramidal cells, a decrease and disorganization of cells at the bottom of the microsulcus, and an inflection of apical dendrites toward the microsulcus. The neuronal staining pattern of large pyramidal cells in the neighborhood of the dysplasia did not differ for any subunit investigated. No remote or widespread changes of glutamate-receptor subunit distribution could be detected. The lack of gross and/or widespread alterations of glutamate-receptor subunit distribution in the surround of focal cortical dysplasia suggests the presence of other or additional mechanisms underlying the increased excitatory neurotransmitter binding and excitability in cortical malformations. 相似文献
67.
The effect of the neuroprotective drug lubeluzole on cortical receptor binding was investigated in animals with photothrombotic ischemic lesions. Control animals were treated with the inactive stereoisomer of the drug. Lubeluzole was applied intravenously as a single bolus (0.31 mg/kg) followed by a 1-h infusion of 0.31 mg/kg. Lubeluzole selectively increased gamma-amino-butyric acid(A) (GABA(A)) receptor binding but had no significant and/or consistent effects on N-methyl-D-aspartate (NMDA), (+/-)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), and kainate receptors. Lubeluzole caused a significant up-regulation of GABA(A) receptor binding in the lesioned area as well as in unimpaired cortical areas of both hemispheres. This effect appeared in the hours following the lesion and peaked at 24 h. Our findings suggest that reduced cortical excitability brought about by increased binding capacities of GABA(A) receptors may contribute to the neuroprotective effect of lubeluzole. 相似文献
68.
Development and evaluation of a rapid dipstick assay for serodiagnosis of acute human brucellosis
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Smits HL Basahi MA Díaz R Marrodan T Douglas JT Rocha A Veerman J Zheludkov MM Witte OW de Jong J Gussenhoven GC Goris MG van Der Hoorn MA 《Journal of clinical microbiology》1999,37(12):4179-4182
A dipstick assay for the detection of brucella-specific immunoglobulin M antibodies was evaluated with 707 sera from 247 laboratory-confirmed brucellosis patients and 342 control sera from brucellosis-free individuals. These sera were collected from six different countries. The assay was found to be highly sensitive and specific. In addition, the test is easy to use and does not require specialized training or equipment, and the components are stable without a requirement for refrigeration. All of these factors make the test ideal for developing countries and rural settings. 相似文献
69.
Evan D. Nair-Gill Chengyi J. Shu Caius G. Radu Owen N. Witte 《Immunological reviews》2008,221(1):214-228
Summary: Non-invasive monitoring of adaptive immunity in infection, cancer, and autoimmunity remains a major challenge. Current techniques to monitor lymphocytes involve numeric and functional determinations of immune cells isolated from the peripheral blood (most often) and tissue (rarely). Invasive measurements are prone to sampling errors and are poorly reflective of the dynamic changes in the location, number, and movement of lymphoid cells. These limitations indicate the need for non-invasive whole-body imaging methodologies that allow longitudinal, quantitative, and functional analyses of the immune system in vivo . Positron emission tomography (PET), a clinically based whole-body imaging modality, has the potential to revolutionize diagnostics and therapeutic monitoring in both clinical and pre-clinical settings. This review discusses studies using PET to image adaptive immune responses in small animal models. We address the challenges inherent in assessing whole-body immunity with PET and recent developments that can improve its performance. Finally, we discuss work to translate PET immune imaging into clinical practice. 相似文献
70.
Witte SB Chard-Bergstrom C Loughin TA Kapil S 《Clinical and diagnostic laboratory immunology》2000,7(4):700-702
A rapid, inexpensive enzyme-linked immunosorbent assay (ELISA) to quantitate antibodies to porcine respiratory and reproductive syndrome virus (PRRSV) in serum was developed using a recombinant PRRSV nucleoprotein (rN). The sensitivity (85.3%) and specificity (81.7%) of the Kansas State University ELISA were good, correlating well (82.4%) with the IDEXX HerdChek ELISA. 相似文献