全文获取类型
收费全文 | 4242篇 |
免费 | 276篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 101篇 |
妇产科学 | 92篇 |
基础医学 | 695篇 |
口腔科学 | 68篇 |
临床医学 | 397篇 |
内科学 | 819篇 |
皮肤病学 | 66篇 |
神经病学 | 626篇 |
特种医学 | 177篇 |
外科学 | 540篇 |
综合类 | 10篇 |
一般理论 | 1篇 |
预防医学 | 99篇 |
眼科学 | 131篇 |
药学 | 356篇 |
中国医学 | 12篇 |
肿瘤学 | 299篇 |
出版年
2023年 | 26篇 |
2022年 | 20篇 |
2021年 | 148篇 |
2020年 | 82篇 |
2019年 | 107篇 |
2018年 | 122篇 |
2017年 | 83篇 |
2016年 | 123篇 |
2015年 | 139篇 |
2014年 | 157篇 |
2013年 | 200篇 |
2012年 | 286篇 |
2011年 | 302篇 |
2010年 | 182篇 |
2009年 | 155篇 |
2008年 | 247篇 |
2007年 | 284篇 |
2006年 | 249篇 |
2005年 | 244篇 |
2004年 | 216篇 |
2003年 | 194篇 |
2002年 | 206篇 |
2001年 | 37篇 |
2000年 | 30篇 |
1999年 | 26篇 |
1998年 | 30篇 |
1997年 | 18篇 |
1996年 | 13篇 |
1995年 | 16篇 |
1994年 | 14篇 |
1992年 | 13篇 |
1989年 | 10篇 |
1936年 | 10篇 |
1934年 | 9篇 |
1933年 | 14篇 |
1932年 | 12篇 |
1931年 | 13篇 |
1930年 | 15篇 |
1929年 | 15篇 |
1928年 | 19篇 |
1927年 | 18篇 |
1926年 | 16篇 |
1925年 | 22篇 |
1924年 | 24篇 |
1923年 | 16篇 |
1922年 | 16篇 |
1921年 | 10篇 |
1911年 | 11篇 |
1908年 | 9篇 |
1905年 | 9篇 |
排序方式: 共有4534条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
Introduction: Perivascular epithelioid cell tumor (PEComa) is a family of rare mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells (PECs). These tumors have been described at multiple anatomic sites. PEComas presenting in bone are especially rare and they have been reported to be either primary or metastatic lesions. None of them is located at the level of the foot.Patient: We report on a case of primary bone PEComa of the talus, the first one to be published to the best of our knowledge.Treatment and result: Limb sparing surgical treatment has been done using intralesional tumor removal, burring and application of argon beam at the tumor walls and primary filling of the tumor cavity by bone cement with so far absence of any tumor recurrence documented by multiple histological sections at second look operation nine months after primary surgery, where cement has been replaced by autologous bone graft, and by subsequent follow-up.Conclusions: PEComa is a very rare tumor, and its presence in bone is especially rare. The here reported case of PEComa presenting at the level of the talus is, to the best of our knowledge, the first case to be reported in the literature. 相似文献
6.
Capsulomas comprise a category of very rare benign tumors derived from the renal capsule, the most encountered being myxomas and leiomyomas. To get more information on the histogenetic origin of these tumors, a comprehensive ultrastructural investigation on the human renal capsule has been done on kidney biopsy samples performed for nephropathologic diagnosis. The human renal capsule ultrastructure is similar to that of the mammalian renal capsule. There are two cellular layers: an inner layer made up of particular (immature) smooth muscle cells, and a second outer layer consisting of fibroblasts, collagen fibers, extracellular matrix, and telocyte-like cells. Two cases of leiomyomas of microscopic dimensions, situated beneath the capsule have been described. Data from the literature presenting the ultrastructure and perirenal location of myxomas support the affiliation of these capsulomas with the resident renal capsular cells. Based on ultrastructural studies, the authors demonstrate the presence of telocyte-like cells in the outer layer of the human renal capsule and propose distinct histogeneses for leiomyomas and for capsular myxomas as derived from the inner and outer capsular layers, respectively. 相似文献
7.
Sonia Mercurio Sara Petrillo Deborah Chiabrando Zuni Irma Bassi Dafne Gays Annalisa Camporeale Andrei Vacaru Barbara Miniscalco Giulio Valperga Lorenzo Silengo Fiorella Altruda Margaret H. Baron Massimo Mattia Santoro Emanuela Tolosano 《Haematologica》2015,100(6):720-729
Feline leukemia virus subgroup C receptor 1 (Flvcr1) encodes two heme exporters: FLVCR1a, which localizes to the plasma membrane, and FLVCR1b, which localizes to mitochondria. Here, we investigated the role of the two Flvcr1 isoforms during erythropoiesis. We showed that, in mice and zebrafish, Flvcr1a is required for the expansion of committed erythroid progenitors but cannot drive their terminal differentiation, while Flvcr1b contributes to the expansion phase and is required for differentiation. FLVCR1a-down-regulated K562 cells have defective proliferation, enhanced differentiation, and heme loading in the cytosol, while FLVCR1a/1b-deficient K562 cells show impairment in both proliferation and differentiation, and accumulate heme in mitochondria. These data support a model in which the coordinated expression of Flvcr1a and Flvcr1b contributes to control the size of the cytosolic heme pool required to sustain metabolic activity during the expansion of erythroid progenitors and to allow hemoglobinization during their terminal maturation. Consistently, reduction or increase of the cytosolic heme rescued the erythroid defects in zebrafish deficient in Flvcr1a or Flvcr1b, respectively. Thus, heme export represents a tightly regulated process that controls erythropoiesis. 相似文献
8.
Alexander Imbault Yue Wang Peter Kruse Evgheni Strelcov Elisabetta Comini Giorgio Sberveglieri Andrei Kolmakov 《Materials》2015,8(10):6677-6684
Conductometric gas sensors made of gas permeable metal oxide ultrathin membranes can combine the functions of a selective filter, preconcentrator, and sensing element and thus can be particularly promising for the active sampling of diluted analytes. Here we report a case study of the electron transport and gas sensing properties of such a membrane made of nanoporous Ta2O5. These membranes demonstrated a noticeable chemical sensitivity toward ammonia, ethanol, and acetone at high temperatures above 400 °C. Different from traditional thin films, such gas permeable, ultrathin gas sensing elements can be made suspended enabling advanced architectures of ultrasensitive analytical systems operating at high temperatures and in harsh environments. 相似文献
9.
10.