全文获取类型
收费全文 | 11221篇 |
免费 | 578篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 223篇 |
儿科学 | 853篇 |
妇产科学 | 427篇 |
基础医学 | 1143篇 |
口腔科学 | 319篇 |
临床医学 | 1092篇 |
内科学 | 2164篇 |
皮肤病学 | 445篇 |
神经病学 | 591篇 |
特种医学 | 305篇 |
外科学 | 1551篇 |
综合类 | 451篇 |
一般理论 | 3篇 |
预防医学 | 1036篇 |
眼科学 | 242篇 |
药学 | 653篇 |
1篇 | |
中国医学 | 15篇 |
肿瘤学 | 330篇 |
出版年
2021年 | 118篇 |
2019年 | 82篇 |
2018年 | 100篇 |
2017年 | 102篇 |
2016年 | 85篇 |
2015年 | 111篇 |
2014年 | 131篇 |
2013年 | 204篇 |
2012年 | 266篇 |
2011年 | 242篇 |
2010年 | 189篇 |
2009年 | 215篇 |
2008年 | 209篇 |
2007年 | 222篇 |
2006年 | 214篇 |
2005年 | 189篇 |
2004年 | 123篇 |
2003年 | 126篇 |
2002年 | 129篇 |
2001年 | 132篇 |
2000年 | 117篇 |
1999年 | 153篇 |
1998年 | 183篇 |
1997年 | 210篇 |
1996年 | 244篇 |
1995年 | 194篇 |
1994年 | 189篇 |
1993年 | 188篇 |
1992年 | 145篇 |
1991年 | 159篇 |
1990年 | 162篇 |
1989年 | 161篇 |
1988年 | 146篇 |
1987年 | 139篇 |
1986年 | 129篇 |
1985年 | 94篇 |
1984年 | 104篇 |
1983年 | 81篇 |
1982年 | 68篇 |
1981年 | 70篇 |
1980年 | 67篇 |
1979年 | 67篇 |
1959年 | 347篇 |
1958年 | 760篇 |
1957年 | 870篇 |
1956年 | 773篇 |
1955年 | 807篇 |
1954年 | 788篇 |
1949年 | 184篇 |
1948年 | 125篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Restriction fragment length polymorphism of human mitochondrial DNA in a sample population from Apulia (Southern Italy) 总被引:8,自引:1,他引:7
Restriction fragment length polymorphism (RFLP) of human mitochondrial DNA was analysed in a sample of 87 subjects from Apulia (South Italy) by the restriction enzymes Hpa I, Bam HI, Hae II, Msp I, Ava II, and Hinc II using total blood cell DNA probed by human mtDNA from placenta. Five BamHI morphs were observed, two of which are new ( Bam HI-4 and -5), as well as one new Ava II morph ( Ava II-28). The association Bam HI-4/ Ava II-28 enables us to demonstrate for the first time two polymorphic Bam HI sites present together in the same mtDNA molecule. In agreement with historical data the Apulian sample has been shown to be the most heterogeneous Italian population so far tested. 相似文献
4.
GIUSEPPE PERSEO MAURO GIGLI ROBERTO DE CASTIGLIONE 《Chemical biology & drug design》1987,29(4):478-485
The synthesis of TPH-13 (Glp-Glu-Lys-Pro-Tyr-Trp-Pro-Pro-Pro-Ile-Tyr-Pro-Met-OH), a tridecapeptide isolated from the skin of the South American frog Phyllomedusa rohdei, is described and alternative approaches are discussed. 相似文献
5.
Intratemporal vascular tumors: detection with CT and MR imaging 总被引:1,自引:0,他引:1
Lo WW; Shelton C; Waluch V; Solti-Bohman LG; Carberry JN; Brackmann DE; Wade CT 《Radiology》1989,171(2):445-448
The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion. 相似文献
6.
Guerard W. Byrne Johannes M. Schirmer David N. Fass Sumeet S. Teotia Walter K. Kremers Hui Xu Bashoo Naziruddin Henry D. Tazelaar John S. Logan Christopher G. A. McGregor 《American journal of transplantation》2005,5(5):1011-1020
Microvascular thrombosis is a prominent feature in cardiac delayed xenograft rejection (DXR). We investigated the impact of warfarin or low-molecular-weight heparin (LMWH) anti-coagulation on xenograft function using a heterotopic pig-to-primate model. Donor hearts were from CD46 transgenic pigs and baboon immunosuppression included tacrolimus, sirolimus, anti-CD20 and TPC, an alpha-galactosyl-polyethylene glycol conjugate. Three groups of animals were studied. Group 1 (n = 9) was treated with warfarin, Group 2 (n = 13) with LMWH and Group 3, received no anti-coagulant drugs. The median duration of xenograft function was 20 days (range 3-62 days), 18 days (range 5-109 days) and 15 days (range 4-53 days) in Groups 1 to 3 respectively. Anti-coagulation achieved the targeted international normalized prothrombin ratio (INR) and anti-factor Xa levels consistent with effective in vivo therapy yet, no significant impact on median xenograft function was observed. At rejection, a similar histology of thrombosis and ischemia was apparent in each group and the levels of fibrin deposition and platelet thrombi in rejected tissue was the same. Anti-coagulation with warfarin or LMWH did not have a significant impact on the onset of DXR and microvascular thrombosis. However, a role for specific anti-coagulant strategies to achieve long-term xenograft function cannot be excluded. 相似文献
7.
L. TIMMER-DE MIK M.D. D.M. BROEKHUIJSEN-VAN HENTEN M.D. † J.M. OLDHOFF M.D. PH.D. D.B. DE GEER M.D. ‡ V. SIGURDSSON M.D. PH.D. S.G.M.A. PASMANS M.D. PH.D. 《Pediatric dermatology》2009,26(3):358-360
Abstract: In Sweet's syndrome, the essential features are the characteristic morphology of the lesions, their histologic appearance, the dramatic response to corticosteroids and the absence of scarring. We report an 8-month-old infant in whom Sweet's syndrome was diagnosed and who developed acquired cutis laxa in the skin lesions. 相似文献
8.
9.
10.