全文获取类型
收费全文 | 104629篇 |
免费 | 6564篇 |
国内免费 | 781篇 |
专业分类
耳鼻咽喉 | 1507篇 |
儿科学 | 1855篇 |
妇产科学 | 1683篇 |
基础医学 | 16128篇 |
口腔科学 | 2601篇 |
临床医学 | 9617篇 |
内科学 | 20462篇 |
皮肤病学 | 2595篇 |
神经病学 | 8741篇 |
特种医学 | 5514篇 |
外国民族医学 | 6篇 |
外科学 | 14640篇 |
综合类 | 805篇 |
现状与发展 | 1篇 |
一般理论 | 57篇 |
预防医学 | 6724篇 |
眼科学 | 2429篇 |
药学 | 7901篇 |
中国医学 | 693篇 |
肿瘤学 | 8015篇 |
出版年
2023年 | 631篇 |
2022年 | 1665篇 |
2021年 | 2856篇 |
2020年 | 1595篇 |
2019年 | 2096篇 |
2018年 | 2611篇 |
2017年 | 2011篇 |
2016年 | 2669篇 |
2015年 | 3605篇 |
2014年 | 4516篇 |
2013年 | 5522篇 |
2012年 | 8398篇 |
2011年 | 8082篇 |
2010年 | 4659篇 |
2009年 | 4063篇 |
2008年 | 6454篇 |
2007年 | 6225篇 |
2006年 | 5748篇 |
2005年 | 5379篇 |
2004年 | 4859篇 |
2003年 | 4439篇 |
2002年 | 4087篇 |
2001年 | 1975篇 |
2000年 | 1827篇 |
1999年 | 1539篇 |
1998年 | 962篇 |
1997年 | 717篇 |
1996年 | 627篇 |
1995年 | 578篇 |
1994年 | 470篇 |
1993年 | 424篇 |
1992年 | 702篇 |
1991年 | 654篇 |
1990年 | 588篇 |
1989年 | 583篇 |
1988年 | 539篇 |
1987年 | 556篇 |
1986年 | 456篇 |
1985年 | 465篇 |
1984年 | 424篇 |
1983年 | 403篇 |
1982年 | 372篇 |
1981年 | 353篇 |
1980年 | 303篇 |
1979年 | 306篇 |
1978年 | 301篇 |
1977年 | 234篇 |
1976年 | 213篇 |
1975年 | 227篇 |
1974年 | 243篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
53.
Neetu Radhakrishnan M.D. Chong. H. Park M.D. Barry M. Kaplan M.D. F.A.C.C. Rajiv Jauhar M.D. F.A.C.C. 《The International journal of angiology》2006,15(1):37-42
A 65-year-old man developed acute limb ischemia, severe abdominal wall and lower limb livedo reticularis following a coronary
angiogram. The differential diagnoses of acute limb ischemia and multiple cholesterol emboli syndrome (MCES) are discussed.
This work was performed at Long Island Jewish Medical Center, 270-05, 76th Avenue, New Hyde Park, NY 11040. 相似文献
54.
55.
56.
Genomes of some parasites contain dozens of alternative and highly diverged surface antigens, of which only a single one is expressed in any cell. Individual cells occasionally change expression of their surface antigen, allowing them to escape immune surveillance. These switches appear to occur in a partly random way, creating a diverse set of antigenic variants. In spite of this diversity, the parasitemia develops as a series of outbreaks, in which each outbreak is dominated by relatively few antigenic types. Host-specific immunity eventually clears the dominant antigenic types, and a new outbreak follows from antigenic types that have apparently been present all along at low frequency. This pattern of sequential dominance by different antigenic types remains unexplained. We review the five most prominent theories, which have developed mainly from studies of the protozoans Trypanosoma and Plasmodium, and the bacterial spirochete Borrelia. The most promising theories depend on some combination of mechanisms to create favored connectivity pathways through the matrix of transitions between variants. Favored pathways may arise from biased switches at the molecular level of gene expression or from biases imposed by immune selection. We illustrate the concept of connectivity pathways by reanalysis of data on transitions between variants from Borrelia hermsii. 相似文献
57.
58.
Renal fibrosis and the origin of the renal fibroblast. 总被引:4,自引:0,他引:4
Many studies have determined that the extent of tubulointerstitialinvolvement, particularly fibrosis, correlates better with renalfunction than glomerular changes do, thus, the extent of tubulointerstitialdamage in any given renal biopsy has important implicationsfor the renal prognosis of the patient (summarized in [1]).Tubulointerstitial fibrosis is characterized by the accumulationof extracellular matrix components including collagen typesI, III, IV, proteoglycans and fibronectin. In recent years,much controversy has been created in the nephrology communityregarding the origin of matrix-producing cells in the kidney.Several possibilities exist, including activation of residentinterstitial fibroblasts, migrating haematopoietic or mesenchymalstem cells from the bone marrow, periadventitial cells and epithelialmesenchymaltransition (EMT) of tubular epithelial cells. This review summarizesrecent data indicating the possible origin of matrix-producingcells in the kidney, and illustrates from a clinical point of 相似文献
59.
Jin Hwan Ahn Joon Ho Wang Jae Chul Yoo Sung Kon Kim Jung Ho Park Jong Woong Park 《Knee surgery, sports traumatology, arthroscopy》2006,14(12):1288-1291
This article describes a modified suture technique designed for the vertical repair of the anterior horn of the meniscus after arthroscopic decompression of a large meniscal cyst. This procedure comprises of three steps: first, the meniscus was pierced vertically using a suture hook and a No. 0 PDS suture. Second, both ends of the No. 0 PDS on the femoral and tibial surfaces of the meniscus were pulled to the outside of the joint capsule using a spinal needle preloaded with suture material. Finally, a skin incision was made adjacent to the suture materials, and both ends were tied. We recommend this technique not only for the vertical repair of the anterior horn of the meniscus after decompression of large meniscal cyst, but also to repair a longitudinal tear of the meniscus. 相似文献
60.
Eun Sang Park Jung Im Na Seon Ok Kim Chang Hun Huh Sang Woong Youn Kyoung Chan Park 《Skin research and technology》2006,12(4):298-302
Background/purpose: Vitiligo and nevus depigmentosus (ND) present similar hypopigmented macules with significantly different prognoses. Although the distinction between the two diseases is important, differential diagnosis relies on medical history and physical examination, which is far from decisive in some cases. The Mexameter® is an objective skin color-measuring device, and has been reported to provide a reproducible and sensitive means of quantifying small skin color differences. In this study, we investigated the usefulness of a Mexameter® for discriminating these diseases.
Methods: A selection of 202 hypopigmented skin lesions (182 from vitiligo and 20 from ND) were the objects of this study. Using a Mexameter, MIs were obtained from lesions and symmetrically located control skin. RMIs, ratios of the MIs of lesional skins to control skins, were calculated.
Results: The mean MIs and RMIs were significantly different for vitiligo and ND. The mean RMI of ND lesions was 74±13, which was significantly higher than that of vitiligo lesions (50±24). No ND lesion had an RMI of <50%.
Conclusion: This study shows that the Mexameter® , an objective pigment-measuring device, can be used to achieve a more accurate diagnosis of hypopigmentary disorders, and that the relative melanin index (RMI), which represents the relative pigment levels, might be a more effective parameter than the melanin index (MI) itself for comparing pigmentation differences. 相似文献
Methods: A selection of 202 hypopigmented skin lesions (182 from vitiligo and 20 from ND) were the objects of this study. Using a Mexameter, MIs were obtained from lesions and symmetrically located control skin. RMIs, ratios of the MIs of lesional skins to control skins, were calculated.
Results: The mean MIs and RMIs were significantly different for vitiligo and ND. The mean RMI of ND lesions was 74±13, which was significantly higher than that of vitiligo lesions (50±24). No ND lesion had an RMI of <50%.
Conclusion: This study shows that the Mexameter