全文获取类型
收费全文 | 8108篇 |
免费 | 618篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 131篇 |
儿科学 | 252篇 |
妇产科学 | 238篇 |
基础医学 | 1170篇 |
口腔科学 | 112篇 |
临床医学 | 850篇 |
内科学 | 1770篇 |
皮肤病学 | 111篇 |
神经病学 | 749篇 |
特种医学 | 192篇 |
外科学 | 915篇 |
综合类 | 135篇 |
一般理论 | 9篇 |
预防医学 | 820篇 |
眼科学 | 66篇 |
药学 | 523篇 |
中国医学 | 12篇 |
肿瘤学 | 684篇 |
出版年
2023年 | 66篇 |
2022年 | 101篇 |
2021年 | 200篇 |
2020年 | 116篇 |
2019年 | 212篇 |
2018年 | 248篇 |
2017年 | 157篇 |
2016年 | 178篇 |
2015年 | 212篇 |
2014年 | 270篇 |
2013年 | 399篇 |
2012年 | 574篇 |
2011年 | 574篇 |
2010年 | 314篇 |
2009年 | 249篇 |
2008年 | 416篇 |
2007年 | 423篇 |
2006年 | 405篇 |
2005年 | 359篇 |
2004年 | 336篇 |
2003年 | 308篇 |
2002年 | 300篇 |
2001年 | 176篇 |
2000年 | 174篇 |
1999年 | 155篇 |
1998年 | 75篇 |
1997年 | 53篇 |
1996年 | 54篇 |
1995年 | 52篇 |
1994年 | 60篇 |
1993年 | 42篇 |
1992年 | 117篇 |
1991年 | 122篇 |
1990年 | 94篇 |
1989年 | 101篇 |
1988年 | 103篇 |
1987年 | 93篇 |
1986年 | 93篇 |
1985年 | 75篇 |
1984年 | 51篇 |
1983年 | 48篇 |
1982年 | 34篇 |
1981年 | 30篇 |
1980年 | 32篇 |
1979年 | 66篇 |
1978年 | 50篇 |
1976年 | 34篇 |
1974年 | 32篇 |
1970年 | 26篇 |
1966年 | 26篇 |
排序方式: 共有8739条查询结果,搜索用时 15 毫秒
61.
Hanisah Sharif Swati Acharya Gopal Krishna R. Dhondalay Gilda Varricchi Shoshanna Krasner-Macleod Wannada Laisuan Amy Switzer Madison Lenormand Elena Kashe Rebecca V. Parkin Yi Yi Merve Koc Oleksandra Fedina Gemma Vilà-Nadal Gianni Marone Aarif Eifan Guy W. Scadding David J. Fear Mohamed H. Shamji 《The Journal of allergy and clinical immunology》2021,147(2):663-676
- Download : Download high-res image (285KB)
- Download : Download full-size image
62.
We are reporting on a 4-generation family in which 6 individuals had frontonasal dysplasia with variable extracranial abnormalities. All affected persons had hypertelorism, bifid or broad nose, and highly arched palate. Associated abnormalities included cleft lip and palate (1/6), webbed neck (2/6), Sprengel anomaly (2/6), pseudoarthrosis of the clavicle (2/6), pectus excavatum (3/6), narrow, sloping shoulders (3/6), diaphragmatic hernia (2/6), broad first toe (4/6), brachydactyly (3/6), fifth finger clinodactyly (5/6), longitudinal grooves of nails (5/6), shawl scrotum (2/3 males), first degree hypospadias (1/3), and mild mental retardation (1/6). Only one affected female had brachycephaly and right coronal synostosis. Four other affected relatives had varying degrees of facial asymmetry, but normal skull contour. No male to male transmission is observed, and both daughters of an affected male were affected. Based on the phenotype of the 3 affected females, craniofrontonasal syndrome (CFNS) is the likely diagnosis. However, there are 3 affected males in this kindred, and 2 of the 3 had significant anomalies. Affected males also had genital abnormalities and pectus deformity of the chest, not previously reported in this condition. Two of the 3 males have posterolateral diaphragmatic hernia. This family expands the phenotype of affected males. 相似文献
63.
Clinical comparison of the Isolator 1.5 microbial tube and the BACTEC radiometric system for detection of bacteremia in children. 总被引:2,自引:16,他引:2
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)
R B Carey 《Journal of clinical microbiology》1984,19(5):634-638
The Isolator 1.5 microbial tube (E. I. du Pont de Nemours & Co., Inc., Wilmington , Del.) was compared with the BACTEC radiometric detection system (Johnston Laboratories, Inc., Cockeysville, Md.) for the detection of bacteremia in children. The Isolator 1.5 is a blood culture system designed for small volumes of blood (0.5 to 1.5 ml). The method involves lysis of the cells of the patient and the direct plating of the entire blood lysate on agar media appropriate for the growth of fastidious microorganisms. Of 1,500 paired samples inoculated into the two systems, 68 were positive for 73 clinically significant organisms. The Isolator 1.5 recovered 81% of the positive cultures compared with 84% recovered by the BACTEC system. When paired blood samples with disproportionate volumes were excluded, the Isolator 1.5 detected 3% more positive cultures. More isolates of Streptococcus pneumoniae and Neisseria meningitidis were recovered by the Isolator 1.5, whereas Haemophilus influenzae was recovered most often in the BACTEC bottles (P greater than 0.1). The contamination rates were 8.7 and 3.1% for the Isolator 1.5 and the BACTEC system, respectively. In cultures positive by both systems, the mean time to detection was 4.1 h faster with the Isolator 1.5. The mean time to obtain isolated colonies was 26.6 h faster with the Isolator 1.5. These data indicate the potential value of the Isolator 1.5 microbial tube as a simple, rapid, and sensitive method for the detection of bacteremia in children. 相似文献
64.
F E Kocka A L Chittom L Sanders L Hernandez E Soriano N Jacobs R B Carey 《Journal of clinical microbiology》1987,25(4):736-737
A nutritionally variant Streptococcus pyogenes strain was isolated from a periorbital abscess. The organism was identified with the use of three rapid biochemical test kits, and the group A antigen was detected by conventional serology as well as direct antigen detection tests. 相似文献
65.
Our objective was to develop data-based algorithms for definition of immunologic response to AIDS therapies in pediatric patients, taking account of T-cell subset measurement errors. The study design involved cross-protocol analysis of 2,148 enrollees in six completed Pediatric AIDS Clinical Trials Group trials. We used standard quantitation of T-cell subsets; linear modeling with mean-dependent measurement error variance was used to develop 95% tolerance limits for change in CD4%. For individuals with a CD4% of approximately 25%, the measurement error-based 95% tolerance interval ranges from 15% to 35%, whereas for individuals with a CD4% of approximately 5%, the tolerance interval ranges from 3% to 7%. When pairs of CD4% measures taken within a time interval of less than 30 days are averaged to estimate steady-state CD4%, tolerance interval width decreases by approximately 30%. A simple graphical tool that provides a data-based criterion for immunologic response over and above variation ascribable to T-cell measurement error is provided. Variability in CD4% due to measurement error is substantial, increases with level of CD4%, and complicates assessment of immunologic response to therapy. Replicates of CD4% measures could be used to improve precision of interpretation of CD4% measures. 相似文献
66.
Considerable differences have been found in two-dimensional polyacrylamide gel electrophoresis fingerprints of complete ribonuclease T1 digestion products of the RNAs of representative members of the entero-, cardio-, and foot-and-mouth disease virus subgroups of the picornavirus family. Individual members of the different subgroups, serotypes of a virus, and even subtypes within a serotype can be distinguished by the use of this technique. The method has also facilitated the identification of homopolymeric regions within the different picornavirus genomes, and the presence of a poly(C) tract in the cardio- and foot-and-mouth disease virus subgroups has been confirmed. A poly(A)-rich tract of approx 40–100 nucleotides has been detected in all the picornaviruses studied. Oligonucleotide fragments possibly specific to the enterovirus subgroup were also detected and partially characterised. 相似文献
67.
The IBD6 Crohn's disease locus demonstrates complex interactions with CARD15 and IBD5 disease-associated variants 总被引:2,自引:0,他引:2
van Heel DA Dechairo BM Dawson G McGovern DP Negoro K Carey AH Cardon LR Mackay I Jewell DP Lench NJ 《Human molecular genetics》2003,12(20):2569-2575
Genetic studies in inflammatory bowel disease have identified multiple susceptibility loci, whose relevance depends critically on verification in independent cohorts. Genetic variants associated with Crohn's disease have now been identified on chromosomes 5 (IBD5/5q31 risk haplotype) and 16 (IBD1 locus, CARD15/NOD2 mutations). Stratification of genome-wide linkage analyses by disease associated variants is now possible, offering both increased power for identification of other loci and improved understanding of genetic mechanisms. We performed a genome-wide scan of 137 Crohn's disease affected relative pairs from 112 families. Multipoint non-parametric linkage analyses were performed, with further stratification of affection status by common CARD15 mutations and the IBD5 haplotype. We verified linkage of Crohn's disease to regions on chromosome 3 (P=0.0009) and X (P=0.001) in our cohort. Linkage to chromosome 16 (IBD1) was observed in Crohn's disease pairs not possessing common CARD15 mutations (P=0.0007), approximately 25 cM q telomeric of CARD15. Evidence for linkage to chromosome 19 (IBD6) was observed in Crohn's disease pairs not possessing CARD15 mutations (P=0.0001), and in pairs possessing one or two copies of the IBD5 risk haplotype (P=0.0005), with significant evidence for genetic heterogeneity and epistasis, respectively. These analyses demonstrate the complex genetic basis to Crohn's disease, and show that the discovery of disease-causing variants may be used to aid identification of further susceptibility loci in complex disease. 相似文献
68.
69.
Alcohol use disorders in persons with co-occurring psychiatric disorders are associated with high rates of psy-chosocial instability and poorer treatment outcomes. Thus, assessment of alcohol use and abuse should become an integral part of psychiatric care. Because setf-report-based measures are frequently used, issues of reliability and validity in this population should be critically examined. The purpose of this article is to review and critique the existing empirical literature that has evaluated the psychometric integrity of self- report-based measures in psychiatric settings, and to outline a research agenda that promises to enhance the accuracy of alcohol assessment by persons receiving psychiatric treatment. 相似文献
70.
T cell epitope spreading to myelin oligodendrocyte glycoprotein in HLA-DR4 transgenic mice during experimental autoimmune encephalomyelitis 总被引:2,自引:0,他引:2
Klehmet J Shive C Guardia-Wolff R Petersen I Spack EG Boehm BO Weissert R Forsthuber TG 《Clinical immunology (Orlando, Fla.)》2004,111(1):53-60
Epitope spreading has been implicated in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and human multiple sclerosis (MS). T cell epitope spreading has been demonstrated in rodents for myelin basic protein (MBP) and proteolipid protein (PLP) determinants, but not for myelin oligodendrocyte glycoprotein (MOG), another important myelin antigen. Moreover, the role of human autoimmunity-associated MHC molecules in epitope spreading, including HLA-DR2 and DR4, has not been formally examined. To address these questions, we investigated epitope spreading to MOG determinants in HLA-DR4 (DRB1*0401) transgenic mice during EAE. The data show that upon induction of EAE in HLA-DR4 transgenic mice with the immunodominant HLA-DR4-restricted MOG peptide 97-108 (MOG(97-108); TCFFRDHSYQEE), the T cell response diversifies over time to MOG(181-200) (core: MOG(183-191); FVIVPVLGP) and MBP. The spreading epitope MOG(181-200) binds with high affinity to HLA-DRB1*0401 and is presented by human HLA-DRB1*0401+antigen presenting cells. Moreover, this epitope is encephalitogenic in HLA-DRB1*0401 transgenic mice. This study demonstrates intra- and intermolecular epitope spreading to MOG and MBP in "humanized" HLA-DR4 transgenic mice. 相似文献