全文获取类型
收费全文 | 319662篇 |
免费 | 28591篇 |
国内免费 | 12925篇 |
专业分类
耳鼻咽喉 | 1974篇 |
儿科学 | 8893篇 |
妇产科学 | 5778篇 |
基础医学 | 50894篇 |
口腔科学 | 6610篇 |
临床医学 | 24243篇 |
内科学 | 55530篇 |
皮肤病学 | 4962篇 |
神经病学 | 24571篇 |
特种医学 | 6044篇 |
外国民族医学 | 84篇 |
外科学 | 23702篇 |
综合类 | 43990篇 |
现状与发展 | 51篇 |
预防医学 | 19977篇 |
眼科学 | 5285篇 |
药学 | 37265篇 |
60篇 | |
中国医学 | 11185篇 |
肿瘤学 | 30080篇 |
出版年
2024年 | 843篇 |
2023年 | 4548篇 |
2022年 | 9510篇 |
2021年 | 12174篇 |
2020年 | 10461篇 |
2019年 | 11187篇 |
2018年 | 10775篇 |
2017年 | 11194篇 |
2016年 | 11313篇 |
2015年 | 12760篇 |
2014年 | 18958篇 |
2013年 | 21954篇 |
2012年 | 19361篇 |
2011年 | 22466篇 |
2010年 | 18944篇 |
2009年 | 18075篇 |
2008年 | 17793篇 |
2007年 | 16786篇 |
2006年 | 15126篇 |
2005年 | 13150篇 |
2004年 | 11403篇 |
2003年 | 9832篇 |
2002年 | 7867篇 |
2001年 | 6842篇 |
2000年 | 5779篇 |
1999年 | 5097篇 |
1998年 | 4365篇 |
1997年 | 3974篇 |
1996年 | 3457篇 |
1995年 | 3001篇 |
1994年 | 2594篇 |
1993年 | 2183篇 |
1992年 | 1889篇 |
1991年 | 1628篇 |
1990年 | 1432篇 |
1989年 | 1177篇 |
1988年 | 976篇 |
1987年 | 847篇 |
1986年 | 803篇 |
1985年 | 1328篇 |
1984年 | 1274篇 |
1983年 | 867篇 |
1982年 | 1047篇 |
1981年 | 804篇 |
1980年 | 709篇 |
1979年 | 583篇 |
1978年 | 457篇 |
1977年 | 374篇 |
1976年 | 344篇 |
1975年 | 229篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Effects of two antiandrogen treatments on hirsutism and insulin sensitivity in women with polycystic ovary syndrome 总被引:7,自引:7,他引:7
Dahlgren E.; Landin K.; Krotkiewski M.; Holm G.; Janson P.O. 《Human reproduction (Oxford, England)》1998,13(10):2706-2711
Thirty-two women with polycystic ovary syndrome (PCOS) wereallocated to two antiandrogen treatment regimens; 28 women completedthe trial. Twenty women were treated with ethinyloestradioland cyproterone acetate (EO-CA) cyclically for 6 months andeight women were treated with the gonadotrophin releasing hormone(GnRH) analogue, goserelin for 6 months. Effects on hirsutism,insulin sensitivity (estimated by glucose clamp technique),blood lipids and hormones were measured. Women treated withEO-CA showed a reduction in hirsutism (P <0.05), and decreasedserum androgen concentrations (P <0.001) as well as reducedinsulin sensitivity (P <0.05). In women treated with goserelin,serum androgen concentrations also decreased (P <0.001),but there was no significant reduction of hirsutism. This group,however, showed an improved insulin sensitivity (P <0.05)despite an unchanged body mass index. Bone mineral density wasunaltered in both treatment groups. The reduction in androgenconcentrations caused by EO-CA was not paralleled by increasedinsulin sensitivity, most probably due to the effect of ethinyloestradiolper se. In contrast, the reduction in androgen concentrationsby goserelin was accompanied by an improved insulin sensitivity. 相似文献
992.
Abstract: Recently, an independent association between tumor necrosis factor (TNF) gene polymorphism and ceiiac disease was observed in the Irish population. We tested this association in Finnish patients with celiac disease. The TNF microsatellite alleles a2 and b3 were strongly associated (Pcorr <0.0001 for both) with celiac disease when the patients were compared to the random population. However, when the comparison was made with the DQ2-matched controls, no association could be found. We therefore conclude that in Finland the TNFa2 and b3 alleles are associated with DQ2-positive haplotypes rather than celiac disease. 相似文献
993.
Kazuhiko Yasuml Rong-Jun Guo Hiroyuki Hanai Hajime Arai Eizo Kaneko Hiroyuki Konno Selichi Takenoshita Koichi Hagiwara Haruhiko Sugimura 《Pathology international》1998,48(2):134-137
A new mutation in the serine-threonine klnase domain of the transforming growth factor β type II receptor (TGFpRII) was found in a case of diffuse, B cell non-Hodgkin's lymphoma of the stomach. A mfssense mutation (ACA to GCA, Thr to Ala) was detected In exon 5, and a wild type allele was also present. This Is the first naturally occurring mutation in the klnase domain of this gene identified in human primary lymphoma. The replication error at three loci was negative, and the poly A tract of exon 3, which is frequently a target of mismatch repair genes, was intact. Malignant lymphoma of B cell origin in the stomach Is an addition to an expanding catalogue of tumors with TGFβRII alterations, and the biological sequelae of the change in the functional domain and the clinical characteristics of the patient in this study are intriguing. 相似文献
994.
Monocyte cytokine secretion induced by chemically-defined derivatives of Klebsiella pneumoniae. 下载免费PDF全文
Z Hmama G Lina C Vincent J Wijdenes G Normier H Binz J P Revillard 《Clinical and experimental immunology》1992,89(1):104-109
The capacity of a K. pneumoniae membrane proteoglycan (Kp-MPG) and four of its chemically defined derivatives to activate human monocytes was studied by measuring immunoreactive IL-1 beta, IL-6 and tumour necrosis factor-alpha (TNF-alpha) in culture supernatants. Monocyte culture supernatants were also tested for their comitogenic activity on concanavalin A-stimulated thymocytes and for their cytotoxic activity on the mouse fibroblastic L929 cell line. The four Kp-MPG derivatives were: (i) an acylpoly(1-3)galactoside (APG); (ii) an APG preparation submitted to acid hydrolysis which removed all fatty acids but left intact the galactose chain of APG (GC-APG); (iii) a preparation obtained by mild alkaline hydrolysis, containing additional ester-linked C14 and C16 fatty acids bound to the APG molecule (EFA-APG); and (iv) a polymer of the latter compound (APG pol). Kp-MPG induced the synthesis of IL-1 beta, IL-6 and TNF-alpha with dose-responses and kinetics similar to those of Salmonella minnesota lipopolysaccharide (Sm-Re-LPS). APG pol and EFA-APG induced the secretion of the three cytokines with lower potency than Kp-MPG or Sm-Re-LPS. APG did not trigger any detectable cytokine production and GC-APG induced only borderline and inconsistent responses. Our data demonstrate the critical role of ester-linked C14 and C16 fatty acids in the triggering of monocyte response to Kp-MPG derivatives. 相似文献
995.
Purnomo Suryantoro Yasuhiro Takeshima Alimsardjono Haryanto Masafumi Matsuo 《Journal of human genetics》1995,40(2):195-201
Summary Hemoglobin (Hb) M-Saskatoon, a variant of methemoglobin, is characterized by mild hemolysis. It is caused by the substitution of a histidine by a tyrosine at the 63rd amino acid residue of the -globin chain. Amplification and sequence analysis of genomic -globin DNA from an Indonesian boy diagnosed as having the more severe disease thalasemia demonstrated the presence of a C to T transition at nucleotide 473 in one of the two -blogin genes resulting in a histidine to tyrosine substitution at 63rd residue. This amino acid change matched with that reported in Hb M-Saskatoon. This nucleotide change abolished a recognition site for the restriction endonucleaseNlaIII.NalIII digestion of the corresponding -globin DNA amplified from the patient's parents indicated that the mutation was inherited through from his mother. This result shows that the world-wide distribution of Hb M-Saskatoon extends to Indonesia, where it was not previously identified. Possible causes of the unusually severe symptoms observed in the case are discussed. 相似文献
996.
Nakamura Tetsuya; Sekar M. Chandra; Kubagawa Hiromi; Cooper Max D. 《International immunology》1993,5(10):1309-1315
Ig and Igß heterodimers are non-covalently associatedwith Ig to compose the antigen receptor complexes on B cells.The demonstration that different sets of tyrosine kinases bindto the cytoplasmic tails of Ig and Igß suggests thatIg and Igß may activate distinct second messengerpathways. In this study, we examined the effects of mAbs againstan exposed epitope of human Igß on pre-B and B celltriggering. Cross-linkage of Igß on B cells leadsto activation of tyrosine kinases, hydrolysis of phosphatidylinositides,and elevation of intracellular Ca2+, effects qualitatively identicalto those of anti-µ mAbs. Our observations thus indicatethat cross-linking of Igß does not segregate signaltransduction pathways connected with the cytoplasmic talls ofIg and Igß. Ig ligation has been reported to be moreeffective in triggering pre-B than B cells, whereas our resultsindicated that Igß ligation is more efficient in triggeringB than pre-B cells. In addition to their activation properties,the anti-Igß mAbs effectively modulated B cell receptorcomplexes and blocked terminal differentiation of all plasmacell isotypes. The findings support the idea that anti-Igßcould serve as a universal B cell immunosuppressant. 相似文献
997.
Raymond G. Goodwin Wenie S. Din Terri Davis-Smith Dirk M. Anderson Steven D. Gimpel Timothy A. Sato Charles R. Maliszewski Camilynn I. Brannan Neal G. Copeland Nancy A. Jenkins Terry Farrah Richard J. Armitage William C. Fanslow Craig A. Smith 《European journal of immunology》1993,23(10):2631-2641
4-1BB is an inducible T cell antigen that shows sequence homology to members of an emerging family of cytokine receptors, including those for tumor necrosis factor and nerve growth factor. To aid in the analysis of the function of 4-1BB we have utilized a soluble form of the molecule as a probe to identify and clone the gene which encodes its ligand. The ligand for 4-1BB is a type II membrane glycoprotein that has homology to tumor necrosis factor, lymphotoxin, and the ligands for CD40 and CD27, all of which are themselves ligands to receptors in this superfamily. The gene for 4-IBB is on mouse chromosome 4 and maps close to the p80 form of the tumor necrosis factor receptor as well as the gene for CD30. The gene for 4-IBB ligand maps to mouse chromosome 17, but considerably distal to the tumor necrosis factor and lymphotoxin genes. Interaction of 4-1BB with its ligand induces the proliferation of activated thymocytes and splenic T cells, a response which is mimicked on similar cell populations stimulated with an antibody to 4-1BB. 相似文献
998.
Objective and design: Myeloperoxidase (MPO) and proinflammatory cytokines play an important role in the development of inflammation. These markers
are generally measured using tedious ELISA procedures. In this study, a novel technique utilizing antibody conjugated quantum
dot nanoparticles was developed to detect Myeloperoxidase, Interleukin-1α (IL-1α) and Tumor Necrosis Factor-α (TNF-α) in vivo in the dextran sodium sulfate (DSS) model of experimental colitis.
Materials and methods: Colitis was induced in animals (n = 8 animals/group) by feeding 4% DSS solution ad libitum for seven to eight days. Quantum Dots (QDs) exhibiting fluorescence at various wavelengths were conjugated to MPO, IL-1α
and TNF-α polyclonal antibodies and tested in vivo at various stages of colitis. Tissue sections obtained were imaged with confocal microscope. The image intensity obtained
from the tissue specimen was correlated with clinical activity measured as Disease Activity Index (DAI).
Results: Myeloperoxidase, IL-1α and TNF-α were visualized with quantum dots on various days of disease. The intensity of quantum dots
increased with the increase in inflammation. The increase in intensity showed an excellent correlation with the DAI based
on the clinical parameters.
Conclusion: The study demonstrated that multiple biomarkers can be detected simultaneously and their quantitative expression correlated
well with clinical disease severity. This novel technology should facilitate design of a novel optical platform for imaging
various biomarkers of inflammation, early detection of acute and chronic disease markers and inflammation-mediated cancer
markers. This detection may also facilitate determination of therapeutic success.
Received 14 March 2007; returned for revision 8 May 2007; accepted by M. Parnham 27 June 2007 相似文献
999.
1000.
Seeliger F Drögemüller C Tegtmeier P Baumgärtner W Distl O Leeb T 《Journal of comparative pathology》2005,132(4):346-349
A 2-year-old German Holstein bull was identified as a carrier of a mutation within the X-chromosomal ED1 gene, which encodes a TNF-related signalling molecule mainly involved in ectodermal development. The clinicopathological appearance was associated with hypotrichosis, hypodontia, and a reduced number of eccrine glands, in addition to chronic rhinotracheitis and partial squamous metaplasia. Furthermore, for the first time in an ED1-deficient animal, a complete lack of respiratory mucous glands was observed. This suggests that the ED1 gene plays a role in the development of mucous glands, the absence of which resembles a feature of X-linked anhidrotic ectodermal dysplasia (ED1) in human patients. 相似文献