全文获取类型
收费全文 | 5631篇 |
免费 | 269篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 184篇 |
儿科学 | 257篇 |
妇产科学 | 220篇 |
基础医学 | 858篇 |
口腔科学 | 52篇 |
临床医学 | 350篇 |
内科学 | 1305篇 |
皮肤病学 | 85篇 |
神经病学 | 509篇 |
特种医学 | 114篇 |
外科学 | 418篇 |
综合类 | 36篇 |
一般理论 | 1篇 |
预防医学 | 443篇 |
眼科学 | 94篇 |
药学 | 702篇 |
中国医学 | 13篇 |
肿瘤学 | 281篇 |
出版年
2024年 | 8篇 |
2023年 | 51篇 |
2022年 | 250篇 |
2021年 | 382篇 |
2020年 | 145篇 |
2019年 | 182篇 |
2018年 | 260篇 |
2017年 | 180篇 |
2016年 | 199篇 |
2015年 | 220篇 |
2014年 | 299篇 |
2013年 | 383篇 |
2012年 | 518篇 |
2011年 | 580篇 |
2010年 | 262篇 |
2009年 | 165篇 |
2008年 | 270篇 |
2007年 | 303篇 |
2006年 | 281篇 |
2005年 | 268篇 |
2004年 | 254篇 |
2003年 | 213篇 |
2002年 | 136篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 13篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1970年 | 2篇 |
1938年 | 1篇 |
1930年 | 2篇 |
1900年 | 1篇 |
1898年 | 1篇 |
排序方式: 共有5922条查询结果,搜索用时 78 毫秒
1.
Bień Agnieszka Rzońca Ewa Zarajczyk Marta Wilkosz Katarzyna Wdowiak Artur Iwanowicz-Palus Grażyna 《Quality of life research》2020,29(10):2669-2677
Quality of Life Research - The aim of the study was to assess QoL and identify and analyse its determinants in women with endometriosis. The study was performed in 2019 in health centres in Lublin... 相似文献
2.
3.
4.
5.
Marcela Hernández Hoyos Piotr Orłowski Ewa Piątkowska-Janko Piotr Bogorodzki Maciej Orkisz 《International journal of computer assisted radiology and surgery》2006,1(1):51-61
The accuracy of 2D phase contrast (PC) magnetic resonance angiography (MRA) depends on the alignment between the vessels and
the imaging plane. PC MRA imaging of blood flow is challenging when the flow in several vessels is to be evaluated with one
acquisition. For this purpose, semi-automatic determination of the plane most perpendicular to several vessels is proposed
based on centerlines extracted from 3D MRA. Arterial centerlines are extracted from 3D MRA based on iterative estimation-prediction,
multi-scale analysis of image moments, and a second-order shape model. The optimal plane is determined by minimizing misalignment
between its normal vector and the centerlines’ tangent vectors. The method was evaluated on a phantom and on 35 patients,
by seeking the optimal plane for cerebral blood flow quantification simultaneously in internal carotids and vertebral arteries.
In the phantom, difference of orientation and of height between known and calculated planes was 1.2° and 2.5 mm, respectively.
In the patients, all but one centerline were correctly extracted and the misalignment of the plane was within 12° per artery.
Semi-automatic centerline extraction simplifies and automates determination of the plane orthogonal to one vessel, thereby
permitting automatic simultaneous minimization of the misalignment with several vessels in PC MRA. 相似文献
6.
Edward Malec Katarzyna Januszewska Jacek Kolcz Tomasz Mroczek 《European journal of cardio-thoracic surgery》2003,23(5):728-33; discussion 733-4
OBJECTIVE: The aim of this study was to assess changes in early and late haemodynamic status after the Norwood procedure (NP), caused by the implementation of right ventricle-to-pulmonary artery shunt (RV-PA). METHODS: A consecutive series of 68 children with hypoplastic left heart syndrome underwent NP: Group 1 (n=31) with the application of a modified Blalock-Taussig shunt and Group 2 (n=37) with RV-PA. Haemodynamic data from the early postoperative period (72 h after the operation) and cardiac catheterisation data, as well as blood tests before the hemi-Fontan procedure (HF) were analysed. Univariate (chi(2) test, Mann-Whitney's and Student's t-tests) and multiple regression analysis were carried out. RESULTS: In Group 1, circulatory collapse requiring resuscitation occurred in 15 (48.4%) children, within 72 h after the procedure. The resuscitation was unsuccessful in nine (29%) cases. The operative mortality (30 days) was 35%. In Group 2, two (5%) children died within the early and two (5%) within the late postoperative period. The postoperative course in the remaining children from Group 2 was uneventful. In Group 2 there was a significantly higher mean diastolic pressure after NP (P<0.05). The arterial pulse pressure after NP was significantly lower in Group 2 (P<0.05). Before HF, the application of RV-PA was associated with a lower Qp:Qs ratio (P=0.020), lower aortic pulse pressure (P=0.004) and lower aortic oxygen saturation (P=0.039). CONCLUSIONS: A stable haemodynamic status due to independent coronary perfusion, higher diastolic and lower pulse pressure is the most advantageous effect of RV-PA, resulting in a lower mortality and morbidity after NP. A lower Qp:Qs ratio eliminates the danger of the ventricular volume overload and ensures good conditions for the development of the pulmonary circulation before HF. 相似文献
7.
Mazur G Bogunia-Kubik K Wróbel T Karabon L Polak M Kuliczkowski K Lange A 《Immunology letters》2005,96(2):241-246
Multiple myeloma (MM) is a plasma cell malignancy characterised by bone marrow infiltration and the presence of a monoclonal protein in serum and/or urine. Interleukin-6 (IL-6) has been identified as one of the most important cytokines that contributes to myeloma cell survival and proliferation. Recent investigations suggest involvement of another cytokine, IL-10, in the activation of MM cells. The present study aimed to determine whether there is an association between the polymorphic features located within the promoter regions of IL-6 and IL-10 genes and progression the disease. IL-6 (-174 G/C) and IL-10 (-1082 A/G, -819 C/T, -592 A/C) promoter single nucleotide polymorphisms (SNPs) were determined by PCR-SSP technique using commercial primers. Our single centre results were compared with the data from literature and combined in cumulative analysis employing the Mantel-Haenszel method. In univariate analysis, only IL-10 ACC genotype tended to prevail in our (Polish) group of patients. None of IL-6 genotypes or IL-10 (-1082) alleles was found to associate with MM disease either in our single centre or in cumulative study. Among patients who died within 36 months of diagnosis, a significant prevalence (P < 0.05) of IL-6 heterozygous cases as opposed to IL-6 homozygotes was observed. IL-6 and IL-10 promoter gene polymorphisms were not found to associate with the susceptibility to the development of MM. However, the IL-6 polymorphic features appeared as factors that might affect the survival of MM patients. The latter observation warrants further study. 相似文献
8.
M. Parczewski J. Kordek E. Janczewska A. Pisula W. Łojewski Ł. Socha M. Wawrzynowicz-Syczewska M. Bociąga-Jasik A. Szymczak I. Cielniak E. Siwak E. Mularska B. Aksak-Wąs A. Urbańska N. Lübke 《Clinical microbiology and infection》2019,21(4):513.e1-513.e6
Objectives
The aim of the study was to characterize the differences in the frequencies of NS3 and NS5A resistance-associated variants (RAVs) among Polish therapy-naive genotype 1 (G1) hepatitis C virus (HCV)-monoinfected and human immunodeficiency virus (HIV)/HCV-coinfected patients including clustering patterns and association of RAV frequency with liver fibrosis.Methods
NS3/NS5A RAVs were identified by population sequencing in 387 directly acting antiviral treatment-naive G1-infected individuals (54 with genotype 1a (G1a) and 333 with genotype 1b (G1b)). Liver fibrosis was assessed based on histopathology or ultrasound elastography. Phylogenetic clusters were identified using maximum likelihood models. For statistics, chi-squared or two-sided Fisher's exact tests and multivariate logistic regression models were used, as appropriate.Results
NS3 RAVs were found in 33.33% (18/54) for G1a and 2.62% (8/297) for G1b whereas NS5A variants were present in 5.55% (3/54) G1a and 9.31% (31/333) G1b sequences. Variations in NS5A 31 and 93 codon positions were found only in G1b (4.2% (14/333) for L31I/F/M and 5.39% (17/333) for Y93H). NS5A RAVs were more frequent among patients with advanced liver fibrosis (17.17% (17/99) for F3–F4 versus 6.94% (17/245) for F0–F2; p 0.004) or liver cirrhosis (20.34% (12/59) for F4 versus 7.72% (22/285) for F0–F3; p 0.003). Liver cirrhosis (F4) was associated with higher odds ratio of the NS5A RAVs among HCV-infected patients (odds ratio 2.34, 95% CI 1.004–5.291; p 0.049). NS5A RAVs were less frequent among sequences forming clusters and pairs (5.16% (8/155) versus 11.21% (26/232); p 0.039).Conclusions
Presence of NS5A RAVs correlated with progression of liver fibrosis and represents de novo selection of variants rather than transmission of drug resistance. Hence, the presence of NS5A RAVs may be a predictor for a long-lasting HCV infection. 相似文献9.
Differential effects of estradiol, raloxifene and tamoxifen on estrogen receptor expression in cultured human skin fibroblasts 总被引:2,自引:0,他引:2
10.
CTLA-4 (CD152) gene polymorphism at position 49 in exon 1 in Graves' disease in a Polish population of the Lower Silesian region 总被引:2,自引:0,他引:2
Frydecka I Daroszewski J Suwalska K Zołedziowska M Tutak A Słowik M Potoczek S Dobosz T 《Archivum immunologiae et therapiae experimentalis》2004,52(5):369-374
INTRODUCTION: Graves' disease ((GD)is an autoimmune disease believed to be caused by a combination of environmental and genetic factors. The gene encoding cytotoxic T lymphocyte-associated antigen-4 (CTLA-4)is one of the candidate genes for conferring susceptibility to thyroid autoimmunity. he aim of the study was to investigate the association between the exon 1 CTLA-4 gene polymorphism A(49)G and susceptibility to GD and Graves ' ophthalmopathy (GO)as well as its severity in a Polish population of the Lower Silesia region. MATERIALS AND METHODS: We analyzed the A(49)G exon 1 CTLA-4 gene polymorphism in 99 unrelated Polish patients with GD, of whom 50 had clinically evident GO (NOSPECS class III and higher), and 154 matched healthy subjects from the Lower Silesia region. Genomic DNA was isolated from whole frozen blood using the NucleoSpin Blood kit. A/G transition was genotyped by polymerase chain reaction followed by labeling with the SnaPshot kit of PE Applied Biosystems and detected using an ABI PRISM 310 capillary genetic analyzer. RESULTS: The distribution of CTLA-4 exon 1 A(49)G enotype, allele, and phenotypic frequencies did not differ between patients with GD and healthy subjects. There was a significantly lower frequency of the AA genotype in the group of patients with clinically evident GO than in patients without severe GO (22% vs. 43%; p=0.02, OR=2.6). CONCLUSIONS: Our results showed that the AA genotype in patients with GD is associated with a lower risk of GO severity. 相似文献