全文获取类型
收费全文 | 1833篇 |
免费 | 138篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 9篇 |
妇产科学 | 17篇 |
基础医学 | 375篇 |
口腔科学 | 19篇 |
临床医学 | 199篇 |
内科学 | 512篇 |
皮肤病学 | 30篇 |
神经病学 | 215篇 |
特种医学 | 23篇 |
外科学 | 172篇 |
综合类 | 3篇 |
预防医学 | 90篇 |
眼科学 | 25篇 |
药学 | 154篇 |
中国医学 | 2篇 |
肿瘤学 | 115篇 |
出版年
2024年 | 1篇 |
2023年 | 17篇 |
2022年 | 112篇 |
2021年 | 152篇 |
2020年 | 58篇 |
2019年 | 67篇 |
2018年 | 68篇 |
2017年 | 48篇 |
2016年 | 53篇 |
2015年 | 94篇 |
2014年 | 83篇 |
2013年 | 76篇 |
2012年 | 154篇 |
2011年 | 163篇 |
2010年 | 83篇 |
2009年 | 66篇 |
2008年 | 117篇 |
2007年 | 94篇 |
2006年 | 96篇 |
2005年 | 89篇 |
2004年 | 75篇 |
2003年 | 72篇 |
2002年 | 65篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 11篇 |
1997年 | 13篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
排序方式: 共有1976条查询结果,搜索用时 15 毫秒
1.
2.
Ketoconazole Impairs Early Pregnancy and the Decidual Cell Response via Alterations in Ovarian Function 总被引:1,自引:0,他引:1
Ketoconazole (KCZ) is an imidazole antifungal agent that alsoaffects P450 enzymes of the mammalian steroidogenic system.Several steps in the ovarian steroidogenesis pathway are knownto be inhibited by KCZ, but previous work has failed to addressthe ramifications of such inhibition with respect to early pregnancy.In initial studies, Holtzman rats (810/group) were administered10100 mg/kg KCZ during days 18 of pregnancy. Onday 9, evaluations revealed a reduction at both 75 and 100 mgKCZ/kg in the number of implantation sites and serum progesteronelevels as well as an increase in ovarian weight The decidualcell response (DCR) was blocked by KCZ in parallel with decreasedserum progesterone and increased ovarian weight, indicatingdirect interference with uterine function. KCZ had no effectwhen given to long-term-ovariectomized rats that were hormonesupplemented to permit the DCR, indicating that the ovary wasat least one site of KCZ action on early pregnancy. Measurementof ovarian progesterone production in vitro from ovaries removedfrom rats treated in vivo with KCZ indicated a decline in progesteroneproduction, suggesting a direct effect of KCZ on ovarian steroidogenesis.These data demonstrate that KCZ can compromise early pregnancyand appears to do so by inhibiting progesterone synthesis inthe ovary. 相似文献
3.
Clear cell ependymoma is a rare and diagnostically challenging subtype of ependymoma, whose genetic features are essentially unknown. We studied 13 clear cell ependymomas (five cases WHO grade II, eight cases WHO grade III) by comparative genomic hybridization (CGH). Chromosomal imbalances were found in 12/13 cases. The most common aberrations overall were +1q (38%), -9 (77%), -3 (31%), and -22q (23%). Clear cell ependymomas of WHO grade II were characterized by -9 (40%), whereas WHO grade III cases mainly showed +1q (63%), and +13q (25%), as well as -9 (100%), -3 (38%), and -22q (25%). In contrast to other ependymal tumors, clear cell ependymomas of WHO grade II showed fewer imbalances than WHO grade III samples (1.4 vs 3.5 per case). Although some of the implicated chromosomes have previously been shown to be involved in other ependymoma variants, the striking frequency of +1q, -9, and -3 suggests that aberrations differ between clear cell and other types of ependymomas, in particular, for loss of chromosome 9 which can be regarded as the molecular hallmark of clear cell ependymomas. 相似文献
4.
Lyudmila G. Yechevskaya Gennadii D. Bukatov Vladimir A. Zakharov Andrey V. Nosov 《Macromolecular chemistry and physics.》1987,188(11):2573-2583
The monomer composition and sequence distribution in ethylene-propylene copolymers (EPCs) obtained with supported titanium/magnesium (TMC) and vanadium/magnesium (VMC) catalysts as well as with titanium trichloride was studied by means of 13C NMR spectroscopy. Based on these data ethylene-propylene reactivity ratios were determined. The EPCs obtained on these catalysts are inhomogeneous in composition; the soluble fractions contain larger amounts of propylene. The microstructures of copolymers obtained on TMCs and TiCl3 are similar. For EPCs obtained on VMCs, propylene “head-to-head” or “tail-to-tail” inversions and a more homogeneous distribution of propylene are observed. 相似文献
5.
Pashov A Kenderov A Kyurkchiev S Kehayov I Hristova S Lacroix-Desmazes S Giltiay N Varamballi S Kazatchkine MD Kaveri SV 《International immunology》2002,14(5):453-461
The present study demonstrates the presence of natural autoantibodies of the IgG isotype directed against heat shock protein 90 (HSP90). The binding properties of affinity-purified anti-HSP antibodies were compared with those of natural antibodies specific for other self antigens, including anti-thyroglobulin and anti-myoglobin autoantibodies, by using semiquantitative immunoblotting, with solubilized proteins from normal liver tissue as antigens, and cross-blot analysis using purified self proteins. Affinity-purified anti-HSP90 antibodies were polyreactive and the non-HSP90-specific fraction of normal IgG was depleted in its natural autoantibody content. We further observed that self antigens including HSP, myosin, tubulin and aldolase with highly conserved structures show similar patterns of binding with natural antibodies, and form a well-defined cluster as demonstrated by cluster analysis of immunoreactivity data, whereas the less-conserved self and non-self antigens remained unclustered. The results favor the hypothesis that HSP90 belongs to a subset of highly conserved and immunodominant self antigens that are the primary target for natural autoantibodies in normal human IgG. 相似文献
6.
7.
Semenov SY Svenson RH Bulyshev AE Souvorov AE Nazarov AG Sizov YE Posukh VG Pavlovsky A Tatsis GP 《Annals of biomedical engineering》2000,28(1):55-60
The proposed dielectrical relaxation model of the myocardium in the microwave spectrum has been verified both on test solutions and on normal canine myocardium. Furthermore, the model was utilized to reconstruct the changes in tissue properties (including myocardial bulk resistance and water content) following myocardial acute ischemia and chronic infarction. It was shown that the reconstructed myocardial resistance and water content correlate dynamically with the process of the development of acute myocardial ischemic injury. In chronic cases the reconstructed resistance and water content of infarcted myocardium are significantly different from that of normal myocardium: the resistance is lower and water content is higher than in normal myocardium. © 2000 Biomedical Engineering Society.
PAC00: 8764-t, 8719Xx 相似文献
8.
Shebzukhov YV Koroleva EP Khlgatian SV Lagarkova MA Meshcheryakov AA Lichinitser MR Karbach J Jager E Kuprash DV Nedospasov SA 《Immunology letters》2005,100(1):88-93
Thymidylate synthase (TYMS), the critical enzyme for DNA synthesis and a target for chemotherapy, was recently characterized as an oncogene and a potential target for specific immunotherapy. Here we report TYMS-specific antibody response in a fraction of colon cancer patients. Humoral immune response to TYMS is induced by chemotherapy using TYMS inhibitors, such as 5-fluorouracil (5-FU), and may be associated with tumor burden. Therefore, TYMS may serve as a useful serological biomarker for monitoring the course of disease and treatment in cancer patients. 相似文献
9.
Nina L. Golitsina Andrey A. Bobkov Irina V. Dedova Dmitrii A. Pavlov Olga P. Nikolaeva Victor N. Orlov Dmitrii I. Levitsky 《Journal of muscle research and cell motility》1996,17(4):475-485
Summary The effects of various modifications of rabbit skeletal myosin subfragment 1 on thermal denaturation of subfragment 1 in ternary complexes with Mg-ADP and orthovanadate (Vi) or beryllium fluoride (BeFx) have been studied by differential scanning calorimetry. It has been shown that specific modifications of SH1 group of Cys-707 by different sulfhydryl reagents, trinitrophenylation of Lys-83, and reductive methylation of lysine residues promote the decomposition of the S1·ADP·Vi complex and change the character of structural transitions of the subfragment 1 molecule induced by the formation of this complex, but they have much less or no influence on subfragment 1 thermal stability in the S1·ADP·BeFx complex. Thus, the differential scanning calorimetric studies on modified subfragment 1 preparations reveal a significant difference between S1·ADP·Vi and S1·ADP·BeFx complexes. It is suggested that S1·ADP·Vi and S1·ADP·BeFx complexes represent structural analogues of different transition states of the ATPase cycle, namely the intermediate states S1**·ADP·Pi and S1*·ATP, respectively. It is also proposed that during formation of the S1·ADP·Vi complex the region containing both Cys-707 and Lys-83 plays an important role in the spread of conformational changes from the active site of subfragment 1 ATPase throughout the structure of the entire subfragment 1 molecule. In such a case, the effects of reductive methylation of lysine residues on the subfragment 1 structure in the S1·ADP·Vi complex are related to the modification of Lys-83. 相似文献
10.
Amadio Eliane Martins Marcos Rodrigo Labat Serra Andrey Jorge dos Santos Solange Almeida Caires Jheniphe Rocha Fernandes Guilherme Henrique Cardosos Leal-Junior Ernesto Cesar Ferrari João Carlos Correa de Tarso Camillo de Carvalho Paulo 《Lasers in medical science》2021,36(7):1427-1435
Lasers in Medical Science - Photobiomodulation therapy (PBMT) has been indicated for enforcement on healing skin wounds. This study evaluated the effects of PBMT on the healing of skin wounds... 相似文献