全文获取类型
收费全文 | 3461篇 |
免费 | 183篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 121篇 |
妇产科学 | 101篇 |
基础医学 | 274篇 |
口腔科学 | 50篇 |
临床医学 | 344篇 |
内科学 | 902篇 |
皮肤病学 | 37篇 |
神经病学 | 346篇 |
特种医学 | 108篇 |
外科学 | 625篇 |
综合类 | 83篇 |
一般理论 | 1篇 |
预防医学 | 143篇 |
眼科学 | 94篇 |
药学 | 207篇 |
中国医学 | 8篇 |
肿瘤学 | 173篇 |
出版年
2024年 | 4篇 |
2023年 | 21篇 |
2022年 | 60篇 |
2021年 | 113篇 |
2020年 | 81篇 |
2019年 | 114篇 |
2018年 | 133篇 |
2017年 | 87篇 |
2016年 | 99篇 |
2015年 | 118篇 |
2014年 | 162篇 |
2013年 | 190篇 |
2012年 | 278篇 |
2011年 | 310篇 |
2010年 | 151篇 |
2009年 | 149篇 |
2008年 | 231篇 |
2007年 | 243篇 |
2006年 | 206篇 |
2005年 | 235篇 |
2004年 | 186篇 |
2003年 | 189篇 |
2002年 | 146篇 |
2001年 | 18篇 |
2000年 | 14篇 |
1999年 | 17篇 |
1998年 | 17篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 5篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有3662条查询结果,搜索用时 15 毫秒
91.
We aimed to correlate the predisposing demographic and clinical factors for erectile dysfunction (ED) in young men and treatment response in these men with data from older men. The patients were divided into two groups: <40 years (group I, n = 58) and ≥40 years (group II, n = 73). ED was evaluated with the International Index of Erectile Function-5 (IIEF-5) questionnaire, and Beck's Depression Inventory (BDI) questionnaire was used to evaluate mood status. The number of patients with morning rigidity and normal libido was higher in group I (70.7% vs. 16.4%, p = .039 and 72% vs. 37%, p = .047). The increase in scores other than IIEF-Orgasmic Function and Sexual Desire domain scores after treatment was higher in the first group (p = .029, p = .035 and p < .001 respectively). In multivariate analysis, the factors predicting the low IIEF-Erectile Function domain score in young men were testosterone level and BDI score (p = .026 and p = .034). Although psychogenic factors contribute significantly to the aetiology of ED, hormone profile is more preserved in young men than in older men. 相似文献
92.
Tan Yi Han Teoh Siang Guan Muhammad Adnan Iqbal Rosenani A. Haque K. Sharmila Rajeswari Mohamed B. Khadeer Ahamed A. M. S. Abdul Majid 《Medicinal chemistry research》2014,23(5):2347-2359
Two ternary copper(II) complexes of dl-threonine and polypyridyl ligands with formula of [Cu(Thr)(Byp)Cl]·H2O (1) and [Cu(Thr)(Phen)H2O]Cl·2H2O (2) were synthesized. The complexes were characterized by spectral (NMR, FT-IR, and UV–Vis), CHN elemental analysis and have been structurally elucidated by X-ray crystallography. Both of the complexes formed slightly distorted square-pyramidal coordination geometry. The electronic absorption spectra of the complexes showed a very low intensity d–d electronic band in the range of 610–620 nm in Tris–HCl/NaCl (5:5 mM) pH 7.2 buffer solution. The DNA binding interaction with calf-thymus DNA (CT-DNA) was investigated by electronic absorption spectral titration and viscosity measurements. The results revealed that the phenanthroline complex (2) interact with CT-DNA through intercalation while bipyridyl complex (1) through the groove binding mode. The calculated intrinsic binding constant (K b) of (1) and (2) were 0.5 and 4.4 × 105 M?1, respectively. Both the complexes were found to promote efficient DNA cleavage activities at low concentration in the presence of H2O2. The results showed that (2) has the highest DNA binding and nuclease activity. Furthermore, both the complexes were tested against human colon cancer (HCT 116) and breast cancer (MCF-7) cell lines and showed a dose-dependent antiproliferation effect. 相似文献
93.
Irfan Sahin Ertugrul Okuyan Adnan Kaya Ilhan Ilker Avci Halil İbrahim Biter 《Scandinavian cardiovascular journal : SCJ》2014,48(5):278-283
Objectives. Vitamin D regulates calcium and bone homeostasis, and parathyroid hormone (PTH) secretion. Cross-sectional associations between lower vitamin D levels and cardiovascular diseases have been reported, but the relationship between vitamin D levels and collateral arteries in stable coronary artery disease (CAD) has not been reported before. Design. Two hundred and fourteen patients with above 95% stenosis in at least one epicardial coronary artery were consecutively recruited after coronary angiography (CAG) during the winter season. The coronary collateral circulation (CCC) was graded using Rentrop classification. Poor CCC group included patients with Rentrop Grade 0–1 CCC and control group included patients with Rentrop Grade 2–3 CCC. Vitamin D and PTH levels were measured on the day of CAG. Results. In the poor CCC group, vitamin D levels were lower (34 ± 25 pmol/L vs. 49 ± 33 pmol/L; p = 0.01) and the prevalence of vitamin D deficiency (< 37 pmol/L) was higher (67% vs. 43%; p = 0.01) compared to the controls. PTH levels, calcium, and phosphate levels were not significantly different between the groups. Female gender, lower HDL cholesterol, and lower vitamin D levels were independently correlated with poor CCC in the study population. Conclusion. Lower vitamin D levels may be associated with poor collateral development in patients with stable CAD. 相似文献
94.
Rokaya Abdelatty Adnan Khan Moinuddin Yusuf Abdullah Alashraf Rana Abdul Shakoor 《Materials》2021,14(8)
This research work aims at investigating the influence of a fixed content of silicon nitride (Si3N4) and varied contents of graphene nanoplatelets (GNPs) on the physical (density, structural, morphological) and mechanical properties (microhardness, nanoindentation) of Al-Si3N4-GNPs composites. The composites were fabricated by a microwave-assisted powder metallurgy route. The Si3N4 concentration was fixed at (5 wt.%) in Al-Si3N4-GNPs composites while the GNPs concentration was varied between (0 wt.%) to (1.5 wt.%) with an increment of (0.5 wt.%). The structural analysis indicates the formation of phase pure materials with high crystallinity. The microstructural analysis confirmed the presence of the Si3N4 and GNPs showing enhanced agglomeration with the increasing amount of GNPs. Moreover, the surface roughness of the synthesized composites increases with an increasing amount of GNPs reaching its maximum value (RMS = 65.32 nm) at 1.5 wt.% of GNPs. The Al-Si3N4-GNPs composites exhibit improved microhardness and promising load-indentation behavior during nanoindentation when compared to pure aluminum (Al). Moreover, Al-Si3N4-GNPs composites demonstrate higher values of compressive yield strength (CYS) and ultimate compressive strength (UCS) when compared to pure Al despite showing a declining trend with an increasing amount of GNPs in the matrix. Finally, a shear mode of fracture is prevalent in Al-Si3N4-GNPs composites under compression loading. 相似文献
95.
D. Scott Lim MD Robert L. Smith MD Firas Zahr MD Abhijeet Dhoble MD Roger Laham MD Mohamad Lazkani MD Susheel Kodali MD Chad Kliger MD James Hermiller MD Amit Vora MD Ian J. Sarembock MB ChB MD William Gray MD Samir Kapadia MD Adam Greenbaum MD Andrew Rassi MD David Lee MD Adnan Chhatriwalla MD Pinak Shah MD Josep Rodés-Cabau MD Homam Ibrahim MD Lowell Satler MD Howard C. Herrmann MD Paul Mahoney MD Charles Davidson MD George Petrossian MD Mayra Guerrero MD Konstantinos Koulogiannis MD Leo Marcoff MD Linda Gillam MD The CLASP IID Pivotal Trial Investigators 《Catheterization and cardiovascular interventions》2021,98(4):E637-E646
96.
Dacomitinib (DCB) is a second generation irreversible tyrosine kinase inhibitor (TKI) that is claimed to overcome the disadvantages of the resistance developed by the first line epidermal growth factor receptor (EGFR) TKIs. In the current study, metabolites of phase I for DCB were systematically explored. DCB reactive metabolites were also investigated in rat liver microsomes in presence of potassium cyanide or methoxylamine that were employed as capturing agents for iminium reactive intermediates and aldehyde, respectively, to form stable complexes which can be detected by LC-MS/MS. As a result, four in vitro phase I metabolites were observed with major pathway of piperidine ring hydroxylation. Additionally, two potentially reactive intermediates, one aldehyde and one iminium ions were characterized. Two different pathways of bioactivation were ultimately proposed.Dacomitinib (DCB) is a second generation irreversible tyrosine kinase inhibitor (TKI) that is claimed to overcome the disadvantages of the resistance developed by the first line epidermal growth factor receptor (EGFR) TKIs. 相似文献
97.
98.
Sayar A Metin M Solak O Turna A Alzafer S Ece T 《Asian cardiovascular & thoracic annals》2005,13(3):280-282
Reported is the successful treatment of a 24-year-old male with adenocystic carcinoma involving the tracheal carina, in which the tumor extended along the right main bronchus across the orifice of the right upper lobe. The patient underwent a carinal resection plus right upper lobectomy and reconstruction of the carina, resulting in neither anastomotic complication nor recurrence of disease during 28 months of follow-up. 相似文献
99.
Jens Wiebe Petra Hoppmann Salvatore Cassese Tobias Rheude Roisin Colleran Constantin Kuna Himanshu Rai Michael Valeskini Tareq Ibrahim Michael Joner Heribert Schunkert Karl-Ludwig Laugwitz Adnan Kastrati Robert A. Byrne 《Revista espa?ola de cardiología》2021,74(7):584-590
Introduction and objectivesLong-term outcomes of unselected patients treated with bioresorbable vascular scaffold (BVS) implantation are lacking, especially for the period after complete dissolution of the BVS. This study sought to evaluate 5-year outcomes in patients treated with BVS in routine practice.MethodsConsecutive patients who underwent implantation of everolimus-eluting BVS during routine clinical practice at 2 high-volume centres in Germany were studied. The patients were followed-up for up to 5 years. The primary endpoints of interest were the composite of death, myocardial infarction and target lesion revascularization, as well as definite scaffold thrombosis.ResultsA total of 419 patients (mean age 66.6 ± 10.9 years; 31.5% had diabetes) were included, of whom 38.9% presented with an acute coronary syndrome. Of the 527 lesions treated, 49.0% were classified as complex and 13.1% were bifurcation lesions. At 5 years, the composite clinical endpoint occurred in 33.1% of patients and definite scaffold thrombosis occurred in 4.7%. Most definite scaffold thrombosis occurred within 2 years after BVS implantation.ConclusionsIn patients treated with BVS implantation in routine clinical practice the rates of adverse clinical events at 5 years were high, including a considerable incidence of scaffold thrombosis. 相似文献
100.
Dibra A Ndrepepa G Mehilli J Dirschinger J Pache J Schühlen H Schömig A Kastrati A 《The American journal of cardiology》2005,95(10):1238-1240
We prospectively studied the inflammatory response to coronary stenting (calculated as the difference between the highest postprocedural C-reactive protein [CRP] and baseline CRP levels [DeltaCRP]) and restenosis in 301 patients who received a sirolimus-eluting stent (n = 149) or a bare stent (n = 152) in the setting of a randomized trial. Median values of DeltaCRP were 3.1 mg/L in the sirolimus-eluting stent group and 3.0 mg/L in the bare stent group (p = 0.71). In the sirolimus-eluting group, restenotic rates were 9.7% in the subgroup with DeltaCRP higher than the median and 11.5% in the subgroup with DeltaCRP no higher than the median (p = 0.37). In the bare stent group, restenotic rates were 28.6% in the subgroup with DeltaCRP higher than the median and 15.4% in the subgroup with DeltaCRP no higher than the median (p = 0.04). 相似文献