全文获取类型
收费全文 | 9223篇 |
免费 | 576篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 237篇 |
妇产科学 | 263篇 |
基础医学 | 1451篇 |
口腔科学 | 223篇 |
临床医学 | 774篇 |
内科学 | 2155篇 |
皮肤病学 | 216篇 |
神经病学 | 994篇 |
特种医学 | 317篇 |
外科学 | 810篇 |
综合类 | 42篇 |
一般理论 | 5篇 |
预防医学 | 741篇 |
眼科学 | 193篇 |
药学 | 608篇 |
中国医学 | 53篇 |
肿瘤学 | 743篇 |
出版年
2024年 | 10篇 |
2023年 | 103篇 |
2022年 | 231篇 |
2021年 | 340篇 |
2020年 | 226篇 |
2019年 | 269篇 |
2018年 | 314篇 |
2017年 | 236篇 |
2016年 | 280篇 |
2015年 | 325篇 |
2014年 | 408篇 |
2013年 | 473篇 |
2012年 | 774篇 |
2011年 | 791篇 |
2010年 | 403篇 |
2009年 | 396篇 |
2008年 | 570篇 |
2007年 | 622篇 |
2006年 | 560篇 |
2005年 | 566篇 |
2004年 | 487篇 |
2003年 | 400篇 |
2002年 | 358篇 |
2001年 | 49篇 |
2000年 | 48篇 |
1999年 | 63篇 |
1998年 | 80篇 |
1997年 | 67篇 |
1996年 | 52篇 |
1995年 | 57篇 |
1994年 | 31篇 |
1993年 | 49篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 23篇 |
1989年 | 12篇 |
1988年 | 17篇 |
1987年 | 15篇 |
1986年 | 13篇 |
1985年 | 13篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1976年 | 5篇 |
1974年 | 7篇 |
1972年 | 4篇 |
1969年 | 4篇 |
排序方式: 共有9874条查询结果,搜索用时 15 毫秒
131.
132.
133.
During a screening program for the identification of β-thalassemia (β-thal) carriers in Sardinia, Italy, we identified two subjects with increased hemoglobin (Hb) levels and an abnormal Hb variant. The same variant was detected in a family member. DNA sequencing revealed a TGT > TGG mutation at codon 93 of the β-globin gene. Structural analysis demonstrated that the cystine residue at position 93 of the β chain was substituted by tryptophan. Since this amino acid substitution had not yet been reported, we designated this variant Hb Santa Giusta Sardegna for the place of birth of the subjects. This amino acid substitution occurs at the tyrosine pocket of the β chain as well as at the α1β2/α2β1 contact of the quaternary structure of the molecule. The presence of this Hb in the hemolysate causes an increased oxygen affinity, a slightly reduced Bohr effect and a reduced heme-heme interaction (n(50), Hill's constant) in comparison with those of Hb A. 相似文献
134.
135.
Newly hatched chicks (Exp. 1) were exposed to an imprinting object of a certain shape (sphere/cylinder) on Day 1 (primary imprinting) and then to a different-shaped object (cylinder/sphere) on Day 2 (secondary imprinting). They were tested on Day 3 for preferences between primary and secondary imprinting objects in binocular and monocular conditions. Right-eyed males, but not females, showed relatively stronger preferences for the primary imprinting object than left-eyed males; however, the asymmetry was modulated by a spontaneous preference for the sphere. In Experiment 2, a more traditional imprinting paradigm was used: chicks were exposed to the same object for the first 2 days, and on Day 3 underwent a free-choice test between the imprinting object (sphere/cylinder) and a novel one (cylinder/sphere). Results showed that no asymmetries in the use of eyes were apparent, only a general preference for the sphere. In Experiment 3 chicks were exposed, as in Experiment 1, to a primary (Day 1) and a secondary (Day 2) imprinting object; on Day 3 they were exposed to both objects simultaneously; they were also tested for preferences for the two stimuli on Day 4. Left- and right-eyed chicks showed different choice, with the latter preferring the cylinder, thus showing that the eye-asymmetry was in some way peculiar to the secondary imprinting procedure. 相似文献
136.
Patrizia Dacci Stefano Amadio Simonetta Gerevini Lucia Moiola Ubaldo Del Carro Marta Radaelli Gianluca Figlia Vittorio Martinelli Giancarlo Comi Raffaella Fazio 《Neurological sciences》2013,34(3):393-396
Sciatic nerve traumatic damage very rarely occurs bilaterally. We describe the case of a 67-year-old woman who reported a bilateral traumatic lesion of the sciatic nerve during practice of yoga. Nerve conduction studies showed a bilateral sciatic nerve neuropathy, mostly affecting the peroneal component. Lumbar plexus MRI documented regular anatomical features of the main principal nerve roots with bilateral T2 signal alteration of roots L4, L5 and S1 that extended into the sciatic nerves showing both increase in size, probably related to chronic injury of nerves, and an alteration in diffusion signal that suggested a recent acute overlapped process. 相似文献
137.
138.
139.
Caroline E. Veltman Saskia L.M.A. Beeres Deborah N. Kalkman Tim P. Kelder Philippine Kiès Hubert W. Vliegen Mark G. Hazekamp Victoria Delgado Lucia J.M. Kroft Ernst E. van der Wall Adriana C. Gittenberger-de Groot Arthur J.H.A. Scholte Martin J. Schalij Monique R.M. Jongbloed 《The Annals of thoracic surgery》2013
140.