全文获取类型
收费全文 | 37089篇 |
免费 | 3384篇 |
国内免费 | 471篇 |
专业分类
耳鼻咽喉 | 202篇 |
儿科学 | 1892篇 |
妇产科学 | 873篇 |
基础医学 | 3276篇 |
口腔科学 | 280篇 |
临床医学 | 3977篇 |
内科学 | 10988篇 |
皮肤病学 | 675篇 |
神经病学 | 2914篇 |
特种医学 | 500篇 |
外科学 | 4319篇 |
综合类 | 1620篇 |
现状与发展 | 1篇 |
一般理论 | 9篇 |
预防医学 | 3299篇 |
眼科学 | 1555篇 |
药学 | 1668篇 |
3篇 | |
中国医学 | 235篇 |
肿瘤学 | 2658篇 |
出版年
2024年 | 67篇 |
2023年 | 541篇 |
2022年 | 366篇 |
2021年 | 626篇 |
2020年 | 588篇 |
2019年 | 245篇 |
2018年 | 941篇 |
2017年 | 946篇 |
2016年 | 1061篇 |
2015年 | 1014篇 |
2014年 | 910篇 |
2013年 | 1304篇 |
2012年 | 2617篇 |
2011年 | 2977篇 |
2010年 | 1349篇 |
2009年 | 1274篇 |
2008年 | 2933篇 |
2007年 | 2811篇 |
2006年 | 2406篇 |
2005年 | 2591篇 |
2004年 | 2979篇 |
2003年 | 2863篇 |
2002年 | 2262篇 |
2001年 | 1770篇 |
2000年 | 528篇 |
1999年 | 404篇 |
1998年 | 473篇 |
1997年 | 364篇 |
1996年 | 196篇 |
1995年 | 137篇 |
1994年 | 138篇 |
1993年 | 127篇 |
1992年 | 125篇 |
1991年 | 81篇 |
1990年 | 88篇 |
1989年 | 87篇 |
1988年 | 82篇 |
1987年 | 77篇 |
1986年 | 63篇 |
1985年 | 42篇 |
1984年 | 43篇 |
1983年 | 29篇 |
1982年 | 33篇 |
1981年 | 37篇 |
1980年 | 25篇 |
1977年 | 15篇 |
1975年 | 16篇 |
1974年 | 22篇 |
1970年 | 16篇 |
1968年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Genes encoding the common gonadotrophin subunit and folliclestimulating hormone (FSH)-specific ß subunit wereisolated from a DNA library derived from human fetal liver cells,and inserted into separate expression vectors containing a selectable/amplifiablegene. These vectors were inserted into the genome of the Chinesehamster ovary cell line, resulting in expression of large amountsof biologically active human (h)FSH. This cell line was culturedon microcarrier beads in a large-scale bioreactor. hFSH in thecell culture supernatant was purified to homogeneity by a multistepprocess. The mature ß subunit had seven fewer aminoacid residues than reported in the literature and three otherdifferences were found in the sequence. Similar oligosaccharidestructures were present on recombinant (r)-hFSH and a purifiedurinary (u)-hFSH preparation. In-vitro and in-vivo, the biologicalactivities of u- and r-hFSH were indistinguishable, r-hFSH wasformulated in ampoules containing 75 IU FSH activity ( 7.5 µgFSH), which accounts for >99% of the protein content of thepreparation. Studies in non-human primates and human volunteersshowed the pharmacokinetics of u- and r-hFSH to be similar.In healthy volunteers, r-hFSH stimulated follicular developmentand induced significant increases in serum oestradiol and inhibin.Clinical experience with r-hFSH has shown it is more effectiveat stimulating ovarian follicle growth than urinary gonadotrophins.It is also effective at initiating spermatogenesis when giventogether with human chorionic gonadotrophin. 相似文献
52.
Siddharth K. Prakash Soniely Lugo‐Ruiz Michelle Rivera‐Dávila Nunilo Rubio Jr. Avni N. Shah Rebecca C. Knickmeyer Cindy Scurlock Melissa Crenshaw Shanlee M. Davis Gary A. Lorigan Aaron T. Dorfman Karen Rubin Cheryl Maslen Vaneeta Bamba Paul Kruszka Michael Silberbach Scientific Advisory Board of the TSRR 《American journal of medical genetics. Part C, Seminars in medical genetics》2019,181(1):7-12
To address knowledge gaps about Turner syndrome (TS) associated disease mechanisms, the Turner Syndrome Society of the United States created the Turner Syndrome Research Registry (TSRR), a patient‐powered registry for girls and women with TS. More than 600 participants, parents or guardians completed a 33‐item foundational survey that included questions about demographics, medical conditions, psychological conditions, sexuality, hormonal therapy, patient and provider knowledge about TS, and patient satisfaction. The TSRR platform is engineered to allow individuals living with rare conditions and investigators to work side‐by‐side. The purpose of this article is to introduce the concept, architecture, and currently available content of the TSRR, in anticipation of inviting proposals to utilize registry resources. 相似文献
53.
54.
BACKGROUND: The clinical efficacy and safety of a six-grass pollen allergoid has been studied. The advent of more exacting clinical guidelines and a better appreciation of the possible mechanisms of treatment prompted this reappraisal. METHODS: A 2-year double-blind multicentre placebo-controlled phase 3 clinical trial was undertaken in 154 patients suffering symptoms of rhinoconjunctivitis with or without asthma (GINA I or II). Therapy comprised two consecutive preseasonal short-courses of subcutaneous injections using a grass pollen allergoid adsorbed to aluminium hydroxide. RESULTS: A combined symptom and medication score (SMS) was used as the primary end-point for clinical efficacy. SMS from the first year showed a significant difference of 26.6% between the two study groups (P=0.026) and this was improved after the second year when there was a 48.4% difference in SMS between active and placebo treatment in favour of the allergoid (P = 0.018). Highly significant increases in grass pollen allergen-specific IgG1 and IgG4 antibody concentrations were measured in association with active treatment. Allergen tolerance was increased as judged by a conjunctival provocation test and significant improvements in quality of life were documented using a standardized questionnaire. The allergoid was well tolerated. CONCLUSIONS: The grass pollen allergoid was shown to be safe and clinically efficacious in the management of hay fever with or without asthma (GINA I or II). 相似文献
55.
Kristiansen OP Karlsen AE Larsen ZM Johannesen J Pociot F Mandrup-Poulsen T;Danish IDDM Epidemiology Genetics Group Danish Study Group of IDDM in Childhood 《Scandinavian journal of immunology》2004,59(6):582-591
CD4 is a candidate gene in autoimmune diseases, including Type 1 diabetes mellitus (T1DM), because the CD4 receptor is crucial for appropriate antigen responses of CD4(+) T cells. We previously found linkage between a CD4-1188(TTTTC)(5-14) promoter polymorphism and T1DM. In the present study, we screened the human CD4 promoter for mutations and identified three frequent single nucleotide polymorphisms (SNPs): CD4-181C/G, CD4-521C/G and CD4-1050T/C. The SNPs are in strong linkage disequilibrium (LD) and association with the CD4-1188(TTTTC)(5-14) alleles, and we observed nine CD4 promoter haplotypes, of which four are frequent. We genotyped the SNPs in 253 Danish T1DM families (1129 individuals) and found evidence for linkage and association of a CD4 (A4(-1188)T(-1050)G(-521)C(-181)) haplotype to T1DM. In reporter studies, we show that (1) the T1DM-associated CD4 haplotype encodes high constitutive promoter activity and (2) the CD4-181G variant encodes higher stimulated promoter activity than the CD4-181C variant. This difference is in part neutralized in the frequently occurring CD4 promoter haplotypes by the more upstream genetic variants. Thus, we report functional impact of a novel CD4-181C/G SNP on stimulated CD4 promoter activity and the identification of a novel CD4 haplotype with high constitutive promoter activity that is linked and associated with T1DM. 相似文献
56.
Amir?R?RazaviEmail author Hans?Gill Olle?St?l Marie?Sundquist Sten?Thorstenson Hans??hlfeldt Nosrat?Shahsavar the South-East Swedish Breast Cancer Study Group 《BMC medical informatics and decision making》2005,5(1):29
Background
A common approach in exploring register data is to find relationships between outcomes and predictors by using multiple regression analysis (MRA). If there is more than one outcome variable, the analysis must then be repeated, and the results combined in some arbitrary fashion. In contrast, Canonical Correlation Analysis (CCA) has the ability to analyze multiple outcomes at the same time. 相似文献57.
58.
Oral Anticoagulation Monitoring Study Group 《American journal of clinical pathology》2001,115(2):288-296
We enrolled 386 subjects in a multicenter study of a point-of-care (POC) prothrombin time (PT) testing device. POC tests were performed by health care professionals using venous and finger-stick specimens and by patients using finger-stick specimens. Venous blood also was analyzed in the local hospital laboratory and a national reference laboratory. Accurate POC results were obtained by professionals using both types of specimens. Patients' results were equivalent to those of professionals. The identification of the patient's therapeutic status based on the International Normalized Ratio (INR) was equivalent for POC and local hospital laboratory PT results; 75% of local laboratory results and 77% of POC results were within 0.4 INR of reference laboratory results, while 93% of either system (POC or local laboratory) were within 0.7 INR. Patients overwhelmingly reported satisfaction with the self-test, including the finger stick and device operation. The INR from the POC device is clinically equivalent to the laboratory INR for assessment of anticoagulation status and management decisions in professional and self-testing environments. Patients can learn to perform accurate PT testing, and POC PT testing is feasible in patients' homes. 相似文献
59.