全文获取类型
收费全文 | 7917篇 |
免费 | 575篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 76篇 |
儿科学 | 238篇 |
妇产科学 | 235篇 |
基础医学 | 1181篇 |
口腔科学 | 140篇 |
临床医学 | 857篇 |
内科学 | 1613篇 |
皮肤病学 | 206篇 |
神经病学 | 762篇 |
特种医学 | 165篇 |
外科学 | 692篇 |
综合类 | 73篇 |
一般理论 | 9篇 |
预防医学 | 934篇 |
眼科学 | 119篇 |
药学 | 644篇 |
中国医学 | 19篇 |
肿瘤学 | 565篇 |
出版年
2024年 | 12篇 |
2023年 | 85篇 |
2022年 | 158篇 |
2021年 | 310篇 |
2020年 | 190篇 |
2019年 | 262篇 |
2018年 | 290篇 |
2017年 | 186篇 |
2016年 | 241篇 |
2015年 | 265篇 |
2014年 | 332篇 |
2013年 | 417篇 |
2012年 | 679篇 |
2011年 | 684篇 |
2010年 | 396篇 |
2009年 | 308篇 |
2008年 | 529篇 |
2007年 | 509篇 |
2006年 | 498篇 |
2005年 | 444篇 |
2004年 | 371篇 |
2003年 | 354篇 |
2002年 | 318篇 |
2001年 | 33篇 |
2000年 | 32篇 |
1999年 | 36篇 |
1998年 | 61篇 |
1997年 | 51篇 |
1996年 | 33篇 |
1995年 | 36篇 |
1994年 | 31篇 |
1993年 | 19篇 |
1992年 | 16篇 |
1991年 | 24篇 |
1990年 | 13篇 |
1989年 | 8篇 |
1988年 | 13篇 |
1987年 | 16篇 |
1986年 | 16篇 |
1985年 | 29篇 |
1984年 | 16篇 |
1983年 | 14篇 |
1982年 | 17篇 |
1981年 | 20篇 |
1980年 | 21篇 |
1979年 | 12篇 |
1977年 | 8篇 |
1974年 | 9篇 |
1973年 | 12篇 |
1928年 | 13篇 |
排序方式: 共有8528条查询结果,搜索用时 15 毫秒
171.
Miriam C. Boesch Oliver Wendt Anu Subramanian Ning Hsu 《Research in autism spectrum disorders》2013,7(3):480-493
An experimental, single-subject research study investigated the comparative efficacy of the Picture Exchange Communication System (PECS) versus a speech-generating device (SGD) in developing requesting skills for three elementary-age children with severe autism and little to no functional speech. Results demonstrated increases in requesting behavior for all participants across intervention phases with both augmentative and alternative communication (AAC) intervention strategies; however, difficulties were observed with picture discrimination. The Wilcoxon signed pair test did not reveal significant differences between PECS and the SGD for any participant. Findings suggest PECS and SGD are equally appropriate for developing initial requesting skills. Based on the current findings, successful implementation of either AAC strategy is achievable when appropriate instructional strategies are used. 相似文献
172.
Miriam Coelho Molck Társis Paiva Vieira Ilária Cristina Sgardioli Milena Simioni Ana Paula dos Santos Josiane Souza Fabíola Paoli Monteiro Vera Lúcia Gil-da-Silva-Lopes 《European journal of medical genetics》2013,56(9):515-520
The 22q11.2 Deletion Syndrome (22q11.2DS) is the most common microdeletion syndrome in humans, with a highly variable phenotype. This chromosomal region contains low copy repeat (LCR) sequences that mediate non-allelic homologous recombination which predispose to copy number abnormalities at this locus. This article describes three patients investigated for suspicion of 22q11.2DS presenting atypical copy number abnormalities overlapping or not with the common ~3 Mb deletion. They were investigated by G-banding karyotype, Multiplex-ligation dependent probe amplification (MLPA) and array Genomic Hibridization (aGH). Clinical and molecular data were compared with literature, in order to contribute to genotype–phenotype correlation. Atypical chromosomal abnormalities were detected: 3.6 Mb deletion at 22q11.21-q11.23 between LCRs B–F in patient 1 and approximately 1.5 Mb deletion at 22q11.21-q11.22 between LCRs D–E in patients 2 and 3. The breakpoints detected in patient 1 have not been previously described. These findings exemplify the complexity and genetic heterogeneity observed in 22q11.2 region and corroborates the idea that genetic modifiers contribute to the phenotypic variability observed in proximal and distal 22q11.2 deletion syndromes. 相似文献
173.
Helga V. Toriello Miriam Erick Jean‐Luc Alessandri Diana Bailey Nicola Brunetti‐Pierri Helen Cox Alan Fryer Denise Marty Charles McCurdy John B. Mulliken Helen Murphy Joseph Omlor Richard M. Pauli Judith D. Ranells Amarillis Sanchez‐Valle Ana Tobiasz Lionel Van Maldergem Angela E. Lin 《American journal of medical genetics. Part A》2013,161(3):417-429
Chondrodysplasia punctata (CDP) is an etiologically heterogeneous disorder characterized by the radiographic finding of stippled epiphyses (punctate calcifications). It is often accompanied by a characteristic facial appearance, known as the Binder phenotype, which is attributed to hypoplasia of the nasal cartilages; abnormal distal phalanges (brachytelephalangy) are a common component manifestation as well. We report eight patients with a Binder phenotype with or without CDP who all shared a known or suspected maternal deficiency of vitamin K. We suspect that this phenotype is probably under recognized, and we hope to increase awareness about the maternal risk factors, especially hyperemesis gravidarum, which lead to nutritional deficiency. © 2013 Wiley Periodicals, Inc. 相似文献
174.
175.
176.
177.
178.
Mycobacterium tuberculosis is an important pathogen that infects approximately one-third of the world's population and kills almost two million people annually. An important aspect of M.?tuberculosis physiology and pathogenesis is its ability to export proteins into and across the thick mycobacterial cell envelope, where they are ideally positioned to interact with the host. In addition to the specific proteins that are exported by M.?tuberculosis, the systems through which these proteins are exported represent potential targets for future drug development. M.?tuberculosis possesses two well-known and conserved export systems: the housekeeping Sec pathway and the Tat pathway. In addition, M.?tuberculosis possesses specialized export systems including the accessory SecA2 pathway and five ESX pathways. Here we review the current understanding of each of these export systems, with a focus on M.?tuberculosis, and discuss the contribution of each system to disease and physiology. 相似文献
179.
Alejandro J Garcia Colton Tom Miriam Guemes Gloria Polanco Maria E Mayorga Korinna Wend Gustavo A Miranda‐Carboni Susan A Krum 《Journal of bone and mineral research》2013,28(2):283-290
The benefits of estrogens on bone health are well established; how estrogens signal to regulate bone formation and resorption is less well understood. We show here that 17β‐estradiol (E2)‐induced apoptosis of bone‐resorbing osteoclasts is mediated by cleavage and solubilization of osteoblast‐expressed Fas ligand (FasL). U2OS‐ERα osteoblast‐like cells expressing an EGFP‐tagged FasL at the C‐terminus showed decreased fluorescence after E2 treatment, indicative of a cleavage event. Treatment of U2OS‐ERα cultures with a specific MMP3 inhibitor in the presence of E2 blocked FasL cleavage and showed an increase in the number of EGFP‐FasL+ cells. siRNA experiments successfully knocked down MMP3 expression and restored full‐length FasL to basal levels. E2 treatment of both human and murine primary osteoblasts showed upregulation of MMP3 mRNA expression, and calvarial organ cultures showed increased expression of MMP3 protein and colocalization with the osteoblast‐specific RUNX2 after E2 treatment. In addition, osteoblast cell cultures derived from ERαKO mice showed decreased expression of MMP3 but not MMP7 and ADAM10, two known FasL proteases, demonstrating that ERα signaling regulates MMP3. Also, conditioned media of E2‐treated calvarial osteoblasts showed an approximate sixfold increase in the concentration of soluble FasL, indicating extensive cleavage, and soluble FasL concentrations were reduced in the presence of a specific MMP3 inhibitor. Finally, to show the role of soluble FasL in osteoclast apoptosis, human osteoclasts were cocultured with MC3T3 osteoblasts. Both a specific MMP3 inhibitor and an MMP inhibitor cocktail preserved osteoclast differentiation and survival in the presence of E2 and demonstrate the necessity of MMP3 for E2‐induced osteoclast apoptosis. These experiments further define the molecular mechanism of estrogen's bone‐protective effects by inducing osteoclast apoptosis through upregulation of MMP3 and FasL cleavage. © 2013 American Society for Bone and Mineral Research 相似文献
180.
Asaf Vivante Michal Mark-Danieli Miriam Davidovits Orit Harari-Steinberg Dorit Omer Yehudit Gnatek Roxana Cleper Daniel Landau Yael Kovalski Irit Weissman Israel Eisenstein Michalle Soudack Haike Reznik Wolf Naomi Issler Danny Lotan Yair Anikster Benjamin Dekel 《Journal of the American Society of Nephrology : JASN》2013,24(4):550-558