全文获取类型
收费全文 | 12364篇 |
免费 | 1229篇 |
国内免费 | 302篇 |
专业分类
耳鼻咽喉 | 144篇 |
儿科学 | 163篇 |
妇产科学 | 114篇 |
基础医学 | 1066篇 |
口腔科学 | 248篇 |
临床医学 | 1535篇 |
内科学 | 1702篇 |
皮肤病学 | 84篇 |
神经病学 | 972篇 |
特种医学 | 1624篇 |
外国民族医学 | 4篇 |
外科学 | 1422篇 |
综合类 | 1742篇 |
现状与发展 | 2篇 |
预防医学 | 498篇 |
眼科学 | 125篇 |
药学 | 697篇 |
3篇 | |
中国医学 | 134篇 |
肿瘤学 | 1616篇 |
出版年
2024年 | 37篇 |
2023年 | 328篇 |
2022年 | 713篇 |
2021年 | 1014篇 |
2020年 | 824篇 |
2019年 | 733篇 |
2018年 | 749篇 |
2017年 | 737篇 |
2016年 | 797篇 |
2015年 | 789篇 |
2014年 | 981篇 |
2013年 | 930篇 |
2012年 | 699篇 |
2011年 | 664篇 |
2010年 | 520篇 |
2009年 | 508篇 |
2008年 | 472篇 |
2007年 | 378篇 |
2006年 | 346篇 |
2005年 | 287篇 |
2004年 | 258篇 |
2003年 | 188篇 |
2002年 | 141篇 |
2001年 | 163篇 |
2000年 | 109篇 |
1999年 | 71篇 |
1998年 | 62篇 |
1997年 | 60篇 |
1996年 | 62篇 |
1995年 | 77篇 |
1994年 | 39篇 |
1993年 | 32篇 |
1992年 | 30篇 |
1991年 | 23篇 |
1990年 | 14篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 6篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
71.
Rita Noumeir 《Journal of digital imaging》2005,18(4):260-269
A few years ago, the Digital Imaging and Communications in Medicine standard introduced a network transaction that is initiated
by modality equipment, mainly at the beginning and at the end of the acquisition. This transaction, the Modality Performed
Procedure Step (MPPS), is sent to the Picture Archiving and Communication System and/or to the Radiology Information System.
It carries information about what really has been performed by the modality equipment during acquisition. In this paper, we
present MPPS and discuss its benefits. We show how MPPS enables efficient radiology workflow and how it ensures accuracy and
completeness of imaging information. We think our paper helps bridge the gap between MPPS implementation and deployment. By
understanding all the MPPS benefits, the end user becomes aware of the great enhancement in patient care that this transaction
provides. 相似文献
72.
73.
Stefanie Kreutmair Susanne Unger Nicolás Gonzalo Núñez Florian Ingelfinger Chiara Alberti Donatella De Feo Sinduya Krishnarajah Manuel Kauffmann Ekaterina Friebel Sepideh Babaei Benjamin Gaborit Mirjam Lutz Nicole Puertas Jurado Nisar P. Malek Siri Goepel Peter Rosenberger Helene A. Häberle Ikram Ayoub Burkhard Becher 《Immunity》2021,54(7):1578-1593.e5
- Download : Download high-res image (233KB)
- Download : Download full-size image
74.
The modulation transfer function for an elliptical tomographic scan is derived. Its imaging characteristics are compared with
those of linear and circular scans
Zusammenfassung Die Modulationsaustauschfunktion einer elliptischen tomographischen Abastung wird abgeleitet. Ihre Abbildungsmerkmale werden mit denen von linearen und runden Abtastungen verglichen.
Sommaire La fonction de transfert de modulation d'un balayage tomographique elliptique est dérivée dans cet article. Ses caratéristiques d'image sont comparées avec celles des balayages circulaires et linéaires.相似文献
75.
B. Shannon Danes Paula De Angelis Frank Traganos Ulrik Ringborg Lars Holme Nielsen Myron R. Melamed 《Clinical genetics》1990,37(3):188-193
The anatomical location of the squamous cell carcinoma (SCCA) within the oral cavity and oropharynx influenced the association of SCCA with the biomarker in vitro hyperdiploidy in human dermal fibroblast cultures (IVH). There was a strong association of IVH with the occurrence of SCCA in the anterior 2/3 of the tongue, floor of the mouth and lower alveolar ridge of the oral cavity and in the base of the tongue and pharyngeal wall of the oropharynx. There was a lower association of SCCA with IVH in the tonsillar region of the oropharynx. IVH showed no association with SCCA located in other anatomical parts of the oral region. The patient group whose diagnosis of SCCA in the anterior 2/3 of the tongue occurred prior to the age of 50 years were invariably IVH-, whereas those diagnosed after the age of 50 years were IVH+, providing evidence for heterogeneity. There was no such correlation of biomarker subgrouping with age of diagnosis demonstrated for SCCA at any other anatomical location within the oral cavity or oropharynx. 相似文献
76.
《The Journal of allergy and clinical immunology》2019,143(6):2254-2262.e5
- Download : Download high-res image (240KB)
- Download : Download full-size image
77.
Small studies in human populations have suggested a correlation between the frequency of errors in antigen receptor gene assembly and lymphoid malignancy risk. In particular, agricultural workers exposed to pesticides have both an increased risk for lymphoma and an increased frequency of errors in antigen receptor gene assembly. In order to further investigate the potential of such errors to serve as a mechanistically based biomarker of lymphoid cancer risk, we have developed a sensitive PCR assay for quantifying errors of V(D)J recombination in the thymocytes of mice. This assay measures interlocus rearrangements between two T-cell receptor loci, V-gamma and J-beta, located on chromosomes 13 and 6, respectively. The baseline frequency in four strains of mice was determined at several ages (2-8 weeks of age) and was found to be stable at approximately 1.5 x 10(-5) per thymocyte. Strain AKR, which has a high susceptibility to T-cell lymphomas, did not show an elevated frequency of aberrant V(D)J events. We used this assay to examine the effects of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on the frequency of these events. Female B6C3F1 mice, 27 days of age, were exposed to 2,4-D by gavage at doses of 0, 3, 10, 30, and 100 mg/kg/day for 4 successive days and sacrificed on day 5. Thymus DNA was isolated and examined for illegitimate V(D)J recombination-mediated gene rearrangements. In addition, pregnant mice were exposed to 2,4-D and thymocytes from the offspring examined at 2 weeks of age. No significant increase in aberrant V(D)J rearrangements was found, indicating that under these conditions 2,4-D does not appear to effect this important mechanism of carcinogenesis. 相似文献
78.
Independent Component Analysis (ICA) is a promising tool for the analysis of functional magnetic resonance imaging (fMRI) time series. In these studies, mostly assumed is a spatially independent component map of fMRI data (spatial ICA). In this paper, we assume that the temporal courses of the signal and noises are independent within a Tiny spatial domain (temporal ICA). Then with fast-ICA algorithm, spatially neighboring fMRI data were blindly separated into several temporal courses and were preassumed to be formed by a signal time course and several noise time courses where the signal has the largest correlation coefficient with the reference signal. The final functional imaging was completed for the signals obtained from each voxel. Simulations showed that compared with the spatial ICA method, the new temporal ICA method is more effective than the spatial ICA in detecting weak signal in a fMRI dataset. As background noise, the simulations include simulated Gaussian noise and fMRI data without stimulation. Finally, vivo fMRI tests showed that the excited areas evoked by a visual stimuli are mainly in the region of the primary visual cortex and that evoked by auditory stimuli are mainly in the region of the primary temporal cortex. 相似文献
79.
80.
目的 采用非靶向代谢组学技术探究麸炒苍术多糖与麸炒苍术正丁醇部位对脾虚大鼠血浆代谢产物的影响,进而阐明二者健脾作用机制。方法 将40只雄性SD大鼠随机分为空白组、模型组、多糖组(0.075 6 g·mL-1)和正丁醇部位组(0.012 1 g·mL-1),每组10只。除空白组外,其余3组采用过度劳倦、饮食失节加苦寒泻下的复合因素造模方法复制脾虚大鼠模型,造模结束后多糖组和正丁醇部位组分别给予相应药液灌胃治疗7 d,空白组和模型组给予等体积生理盐水。采用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法(UHPLC-Q-Orbitrap-MS)分析空白组、模型组、多糖组与正丁醇部位组大鼠血浆样品,并采用多元统计分析筛选差异代谢产物;采用京都基因与基因组百科全书(KEGG)数据库结合MetaboAnalyst 5.0软件对筛选出的差异代谢物进行代谢通路分析。结果 多元统计分析结果显示,模型组与空白组、多糖组、正丁醇部位组间代谢产物均存在明显差异。空白组与模型组间共有380个差异代谢物,麸炒苍术多糖与麸炒苍术正丁醇部位分别回调了其中78个和57个差异代谢物。代谢通路富集结果显示,麸炒苍术正丁醇部位主要影响了甘氨酸、丝氨酸和苏氨酸代谢,丙氨酸、天冬氨酸和谷氨酸代谢及D-精氨酸、D-鸟氨酸代谢;麸炒苍术多糖主要影响了甘氨酸、丝氨酸和苏氨酸代谢,丙氨酸、天冬氨酸和谷氨酸代谢,生物素代谢,硫胺素代谢及三羧酸循环。结论 麸炒苍术多糖与正丁醇部位均对脾虚大鼠的代谢异常有明显调节作用,其中正丁醇部位主要涉及氨基酸代谢,多糖除影响氨基酸代谢外,还参与调节能量代谢与辅因子和维生素代谢。 相似文献