全文获取类型
收费全文 | 1967篇 |
免费 | 111篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 52篇 |
妇产科学 | 56篇 |
基础医学 | 319篇 |
口腔科学 | 38篇 |
临床医学 | 150篇 |
内科学 | 437篇 |
皮肤病学 | 105篇 |
神经病学 | 197篇 |
特种医学 | 65篇 |
外科学 | 162篇 |
综合类 | 16篇 |
预防医学 | 199篇 |
眼科学 | 38篇 |
药学 | 113篇 |
中国医学 | 7篇 |
肿瘤学 | 128篇 |
出版年
2023年 | 20篇 |
2022年 | 47篇 |
2021年 | 86篇 |
2020年 | 41篇 |
2019年 | 60篇 |
2018年 | 70篇 |
2017年 | 46篇 |
2016年 | 52篇 |
2015年 | 43篇 |
2014年 | 91篇 |
2013年 | 105篇 |
2012年 | 135篇 |
2011年 | 161篇 |
2010年 | 80篇 |
2009年 | 98篇 |
2008年 | 120篇 |
2007年 | 130篇 |
2006年 | 120篇 |
2005年 | 112篇 |
2004年 | 86篇 |
2003年 | 96篇 |
2002年 | 90篇 |
2001年 | 16篇 |
2000年 | 17篇 |
1999年 | 19篇 |
1998年 | 19篇 |
1997年 | 19篇 |
1996年 | 16篇 |
1995年 | 16篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1980年 | 4篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1948年 | 1篇 |
1947年 | 1篇 |
1943年 | 1篇 |
1934年 | 1篇 |
1913年 | 2篇 |
1912年 | 3篇 |
排序方式: 共有2088条查询结果,搜索用时 15 毫秒
51.
52.
53.
Tania Pereira Jose Muguruza Virtu Mária Ester Vilaprinyo Albert Sorribas Elvira Fernandez Jose Manuel Fernandez-Armenteros Juan Antonio Baena Ferran Rius Angels Betriu Francesc Solsona Rui Alves 《Ultrasound in medicine & biology》2018,44(12):2780-2792
Adventitial vasa vasorum are physiologic microvessels that nourish artery walls. In the presence of cardiovascular risk factors, these microvessels proliferate abnormally. Studies have reported that they are the first stage of atheromatous disease. Contrast-enhanced ultrasound (CEUS) of the carotid allows direct, quantitative and non-invasive visualization of the adventitial vasa vasorum. Hence, the development of computer-assisted methods that speed image analysis and eliminate user subjectivity is important. We developed methods for automatic analyses and quantification of vasa vasorum neovascularization in CEUS and tested these methods in a cohort of 186 individuals, 63 of whom were healthy volunteers. We implemented alternative automatic strategies for using the images to stratify patients according to their risk group and compare the strategies with respect to diagnostic performance. An automatic single-parameter strategy performs less effectively than the corresponding Arcidiacono method based on manual interpretation of the images (68 < area under the receiver operating characteristic curve [AUROC] for the manual Arcidiacono method < 82; 60 < AUROC for the automatic single-parameter strategy < 63). However, by use of additional image parameters, an automatic multiparameter strategy has significantly improved performance with respect to the manual Arcidiacono method (78 < AUROC < 90). The automatic multiparameter strategy is a valuable alternative to the manual Arcidiacono method, improving both diagnostic speed and diagnostic accuracy. 相似文献
54.
55.
The hemolysin-producer coelomocytes in Holothuria polii 总被引:1,自引:0,他引:1
Calogero Canicatti Donatella Ciulla Elvira Farinalipari 《Developmental and comparative immunology》1988,12(4):729-736
Using sodium metrizoate discontinuous gradients, two hemolysin-producer amebocyte populations have been separated from total circulating Holothuria polii coelomocytes. The amebocytes of population 1 are responsible for the production of the calcium-dependent and temperature-labile hemolysin, whereas those of population 2 produce the calcium-independent and temperature-stable one. The intracytoplasmic hemolysins were evidenced also by immunofluorescence. Petaloid and filipodial amebocytes were the only positive cell types. 相似文献
56.
Verdaguer E Jordà EG Canudas AM Jiménez A Folch J Rimbau V Pallàs M Camins A 《Brain research》2004,1030(2):297-302
Kainic acid (KA) treatment induced neuronal death and apoptosis in murine cerebellar granule cells (CGNs) cultures from both wild-type and knockout p21(-/-) mice. There was not statistically significant difference in the percentage of neuronal apoptosis among strains. KA-induced neurotoxicity was prevented in the presence of NBQX (20 microM) and GYKI 52446 (20 microM), but not by z-VAD-fmk, suggesting that caspases are not involved in the apoptotic process. Data suggest that p21(WAF/Cip) was unable to modulate KA-induced apoptosis in murine CGNs. 相似文献
57.
Virginia Andreoli Elvira Valeria De Marco Francesca Trecroci Rita Cittadella Gemma Di Palma Antonio Gambardella 《Journal of neural transmission (Vienna, Austria : 1996)》2014,121(5):533-542
Increasing evidence links dysregulation of NR2B-containing N-methyl-d-aspartate receptor remodelling and trafficking to Alzheimer’s disease (AD). This theme offers the possibility that the GRIN2B gene, encoding this selective NR2B subunit, represents a potential molecular modulating factor for this disease. Based on this hypothesis, we carried out a mutation scanning of exons and flanking regions of GRIN2B in a well-characterized cohort of AD patients, recruited from Southern Italy. A “de novo” p.K1293R mutation, affecting a highly conserved residue of the protein in the C-terminal domain, was observed for the first time in a woman with familial AD, as the only genetic alteration of relevance. Moreover, an association study between the other detected sequence variants and AD was performed. In particular, the study was focused on five identified single nucleotide polymorphisms: rs7301328, rs1805482, rs3026160, rs1806191 and rs1806201, highlighting a significant contribution from the GRIN2B rs1806201 T allele towards disease susceptibility [adjusted odds ratio (OR) = 1.92, 95% confidence interval (CI) 1.40–2.63, p < 0.001, after correction for sex, age, and APOE ε4 genotype]. This was confirmed by haplotype analysis that identified a specific haplotype, carrying the rs1806201 T allele (CCCTC), over-represented in patients versus controls (adjusted OR = 6.03; p < 0.0001). Although the pathogenic role of the GRIN2B-K1293R mutation in AD is not clear, our data advocate that genetic variability in the GRIN2B gene, involved in synaptic functioning, might provide valuable insights into disease pathogenesis, continuing to attract significant attention in biomedical research on its genetic and functional role. 相似文献
58.
J. L. Carpintero A. Rodriguez Diez M. J. Ruiz Elvira J. A. Benitez A. Perez Rielo 《Intensive care medicine》1980,6(4):217-221
We have treated 30 patients with flail chest, with priority given to associated factors (pain, secretions retention, hemo-/pneumothorax and underlying pulmonary contusion). When this treatment was insufficient IMV+PEEP was instituted; in this group there was a 58.8% incidence of pneumonia, 47.5% of sepsis and 11.7 days average stay in the ICU. These were significantly different when compared to the patients controlled without mechanical ventilatory support (7.7% pneumonia, 0% sepsis, 3.2 days).Surgical fixation was limited to 4 patients who presented with multiple and greatly displaced rib fractures, which made fixation by mechanical ventilation unpredictable. 相似文献
59.
60.
Elvira T Mambetisaeva William Andrews Laura Camurri Adelaide Annan Vasi Sundaresan 《Developmental dynamics》2005,233(1):41-51
The ventral midline of the central nervous system is an important intermediate target where growing commissural axons either cross and project contralaterally or remain on the same side of the body. New studies on mice and humans show that this decision by commissural axons is largely dependent on Slits, extracellular matrix proteins that are widely expressed in the midline of the nervous system, and their receptors, Robos (Long et al. [2004] Neuron 42:213-223; Sabatier et al. [2004] Cell 117:157-169; Jen et al. [2004] Science 304:1509-1513). Here, we show that the Robo family proteins Robo1 and Rig-1 exhibit differential expression patterns on commissural axons as they approach, cross, and leave the midline of the developing mouse spinal cord and demonstrate that Robo1 and Robo2 bind Slit1 and Slit2, but Rig-1 does not. In addition, we show that cultured chick commissural axons are repelled by a source of Slit protein, and the soluble Robo-Fc proteins are capable of neutralizing this repulsion. Finally, we exploit the large size and accessibility of the early chick embryo to analyze the function of Slit/Robo signaling in midline commissural axon guidance, and we demonstrate that the in vivo perturbation of Robo-Slit interaction at the floor plate causes consistent guidance defects of commissural axons during midline crossing. These findings demonstrate the evolutionarily conserved role for Robo-Slit interaction in the control of midline crossing axons in vertebrates. 相似文献