全文获取类型
收费全文 | 28007篇 |
免费 | 2355篇 |
国内免费 | 1000篇 |
专业分类
耳鼻咽喉 | 131篇 |
儿科学 | 532篇 |
妇产科学 | 273篇 |
基础医学 | 8678篇 |
口腔科学 | 446篇 |
临床医学 | 2395篇 |
内科学 | 4825篇 |
皮肤病学 | 879篇 |
神经病学 | 851篇 |
特种医学 | 352篇 |
外国民族医学 | 13篇 |
外科学 | 1724篇 |
综合类 | 3858篇 |
现状与发展 | 5篇 |
预防医学 | 904篇 |
眼科学 | 214篇 |
药学 | 1520篇 |
1篇 | |
中国医学 | 544篇 |
肿瘤学 | 3217篇 |
出版年
2024年 | 39篇 |
2023年 | 262篇 |
2022年 | 466篇 |
2021年 | 682篇 |
2020年 | 607篇 |
2019年 | 799篇 |
2018年 | 847篇 |
2017年 | 739篇 |
2016年 | 785篇 |
2015年 | 1028篇 |
2014年 | 1417篇 |
2013年 | 1728篇 |
2012年 | 1461篇 |
2011年 | 2030篇 |
2010年 | 1717篇 |
2009年 | 1884篇 |
2008年 | 1693篇 |
2007年 | 1673篇 |
2006年 | 1608篇 |
2005年 | 1458篇 |
2004年 | 1285篇 |
2003年 | 1156篇 |
2002年 | 960篇 |
2001年 | 782篇 |
2000年 | 682篇 |
1999年 | 591篇 |
1998年 | 562篇 |
1997年 | 424篇 |
1996年 | 431篇 |
1995年 | 433篇 |
1994年 | 340篇 |
1993年 | 256篇 |
1992年 | 139篇 |
1991年 | 132篇 |
1990年 | 64篇 |
1989年 | 43篇 |
1988年 | 23篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 13篇 |
1984年 | 25篇 |
1983年 | 20篇 |
1982年 | 12篇 |
1981年 | 21篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1973年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Danuta Wasserman Christer HellstrÖm Jerzy Wasserman Olof Beck Eva Andersson Marie Åsberg 《Archives of Suicide Research》1997,3(3):153-169
The aim of this study was to investigate markers of serotonin and immune function in suicidal patients. Cytotoxic activity of natural killer cells (NK) and CD16 lymphocytes were studied in 28 suicide attempters and 26 healthy controls, and related in patients to 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF). Patients with CSF 5-HIAA below the median had significantly lower NK cell activity than other patients. CD16 cell frequency was significantly lower in patients than in controls, and patients also tended to have lower NK cell cytotoxicity than healthy controls. There were no statistically significant correlations between 4-hydroxy-3methoxyphenyl glycol (HMPG), homovanillic acid (HVA), CSF cortisol and NK cell activity. The results support the hypothesis of compromised immune function in suicidal patients with evidence of disordered serotonin function. 相似文献
32.
A Comparative Study on the Effect of BCG-PSN and Thymopeptides on T-lymphocyte Subsets of Normal and Immunosuppressed Mice 总被引:2,自引:0,他引:2
Polysaccharidenucleicacidfractionofbacilluscalmetteguerin (BCG PSN ,SiqikangInjection)andthymopeptidesarenowtwowidelyusedimmunomod ulatorsinclinicalpractice .Theyareusuallyusedasanadjuvanttherapyforvirusinfection ,autoimmunediseasesandneoplasms ,whichhavebeenclinicallyprovedtobeeffective .Somereportsdemonstratedthattheybothcanstimulatetheproliferationanddif ferentiationofT lymphocytes.However ,theexactmechanismshavenotbeenelucidatedyet .InordertocomparetheirmodulatingmechanismsonT lympho c… 相似文献
33.
M. Müller R. Heicappell F. Habermann M. Kaufmann U. Steiner K. Miller 《Urological research》1997,25(3):187-192
CD44 is the principal cell surface receptor for hyaluronate. Variant forms of the receptor, produced by alternative splicing, have been found to be associated with tumor progression in a variety of cancers. Based on investigations at the RNA level, it has recently been proposed that expression of CD44 variant V2 was present in urothelial cancer but not in normal urothelium. Since a distinctive marker for urothelial cancer would be extremely useful, frozen sections of normal urothelium and urothelial cancer were examined for expression of standard CD44 and CD44V2. Frozen sections of specimens of 35 patients with transitional cell carcinoma of the bladder, 16 specimens of normal bladder and 5 ureters were examined. Immunohistochemical staining was performed using a polyclonal antibody to CD44V2 (PAB CD44V2), a monoclonal antibody to CD44V2 (MAB CD44V2) and a monoclonal antibody to CD44S (MAB CD44S). CD44V2 and CD44S were also measured in lysates of urine sediments from 21 patients by enzyme-linked immunoabsorbent assay (ELISA). All investigated transitional cell carcinomas expressed CD44V2. There was no differentiation between invasive and noninvasive carcinoma. CD44V2 was also expressed in normal urothelium. Standard CD44 was expressed by the transitional cell carcinoma, normal urothelium, musculature and interstitial tissue. The amount of CD44V2 and CD44S in lysates of urine sediments is not correlated to diagnosis. In contrast to investigations at the RNA level, CD44V2 on the protein level seems not to be a distinctive marker for urothelial cancer. Therefore, CD44V2 will not be a useful diagnostic marker for detection of transitional cell carcinoma. 相似文献
34.
Soluble CD14 but not interleukin-6 is a new marker for clinical activity in atopic dermatitis 总被引:4,自引:0,他引:4
Summary Levels of soluble IL-2 receptors, IL-6, soluble CD23, soluble CD14 and ECP (eosinophilic cationic protein) were measured as markers of T-cell, B-cell, monocyte and eosinophilic leucocyte activation in 26 patients with atopic dermatitis (AD) on admission to (A) and at discharge from (D) the Department of Dermatology in Zurich. The serum levels of sIL-2R, IL-6, sCD23, sCD14 and ECP were significantly elevated in AD patients in comparison with the normal values of healthy donors. A significant decrease in sIL-2R (p=0.0093) and in sCD14 (p=0.0134) levels was demonstrated between A and D, correlating with the improvement in the skin intensity score (SIS). In addition, a significant correlation of the sCD14 levels and the SIS at A was demonstrated (p=0.0415). These results also incriminate monocytes in the pathogenesis of AD, indicating that, besides sIL-2R and ECP, SCD14 could also be a possible marker for the disease activity. 相似文献
35.
36.
Corinna S. Bowser Jean Kaye Rauno O. Joks Cascy-Arnoux Charlot H. Jack Moallem 《Pediatric allergy and immunology》2007,18(4):298-303
Elevated serum immunoglobulin E (IgE) and increased prevalence of atopy is reported in patients infected with human immunodeficiency virus (HIV). The elevated serum IgE may be attributed to polyclonal stimulation of B cells or IgE production against allergens, viruses, fungi and bacteria. This study investigates the prevalence of atopy in perinatally HIV-infected children, and the relationships between serum IgE (and other serum immunoglobulins) with atopy, CD4+ cell count and HIV-disease stage. Serum immunoglobulin levels, epicutaneous skin test for common aeroallergens, clinical Centers for Disease Control and Prevention (CDC) classification, CD4+ cell counts and allergy history were extracted from the charts of perinatally HIV-infected children on highly active antiretroviral therapy. The prevalence of atopy (52%) and the pattern of aeroallergen sensitivity were comparable with the US pediatric population. Serum IgE levels did not correlate with clinical disease stage. However, in non-atopic patients, serum IgE levels increased with disease progression (p = 0.02). There was an inverse relationship between the prevalence of elevated serum IgE levels and atopy with progression of disease (p = 0.019). Serum IgE did not correlate with atopy, CD4+ cell count, or duration of HIV infection or levels of serum immunoglobulins. This is the first study to show no increased prevalence of atopy in perinatally HIV-infected children compared with the general population. In advanced stages of HIV, elevated serum IgE may be specific for antigens other than those known as allergens. 相似文献
37.
M. STEWARD R. BISHOP N.H. PIGGOTT I.D. MILTON B. ANGUS C.H.W. HORNE 《Histopathology》1997,30(1):16-22
Phenotypic analysis of lymphoproliferative disorders is now considered mandatory for accurate classification which is the basis for optimum patient management. This is presently carried out in most cases using a range of antibodies recognizing B and T-cell antigens effective in paraffin sections, and an antibody to CD3 is currently a key member of such panels, indicating T-cell phenotype. Current antibodies to CD3 are polyclonal with the inherent disadvantages of this type of reagent compared to monoclonal antibodies. In this study, we have used a recombinant fusion protein representing part of the epsilon subunit of the CD3 molecule to generate a novel monoclonal antibody (NCL-CD3-PS1) effective in paraffin sections. The antibody has been characterized biochemically and by immunohistochemistry using a wide range of normal and pathological tissues. Lineage and phenotype specificity have been supported in our study and results from other laboratories are awaited with interest. 相似文献
38.
39.
40.