全文获取类型
收费全文 | 9171篇 |
免费 | 340篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 227篇 |
儿科学 | 744篇 |
妇产科学 | 387篇 |
基础医学 | 971篇 |
口腔科学 | 244篇 |
临床医学 | 802篇 |
内科学 | 1775篇 |
皮肤病学 | 401篇 |
神经病学 | 407篇 |
特种医学 | 231篇 |
外科学 | 1312篇 |
综合类 | 321篇 |
一般理论 | 2篇 |
预防医学 | 778篇 |
眼科学 | 242篇 |
药学 | 462篇 |
1篇 | |
中国医学 | 15篇 |
肿瘤学 | 231篇 |
出版年
2017年 | 52篇 |
2016年 | 42篇 |
2015年 | 72篇 |
2014年 | 79篇 |
2013年 | 130篇 |
2012年 | 139篇 |
2011年 | 176篇 |
2010年 | 143篇 |
2009年 | 169篇 |
2008年 | 121篇 |
2007年 | 134篇 |
2006年 | 164篇 |
2005年 | 105篇 |
2004年 | 52篇 |
2003年 | 56篇 |
2002年 | 63篇 |
2001年 | 73篇 |
2000年 | 65篇 |
1999年 | 103篇 |
1998年 | 163篇 |
1997年 | 188篇 |
1996年 | 213篇 |
1995年 | 165篇 |
1994年 | 166篇 |
1993年 | 163篇 |
1992年 | 115篇 |
1991年 | 115篇 |
1990年 | 112篇 |
1989年 | 127篇 |
1988年 | 108篇 |
1987年 | 119篇 |
1986年 | 93篇 |
1985年 | 78篇 |
1984年 | 83篇 |
1983年 | 64篇 |
1982年 | 58篇 |
1981年 | 69篇 |
1980年 | 54篇 |
1979年 | 54篇 |
1978年 | 46篇 |
1977年 | 51篇 |
1976年 | 49篇 |
1959年 | 343篇 |
1958年 | 759篇 |
1957年 | 868篇 |
1956年 | 771篇 |
1955年 | 803篇 |
1954年 | 780篇 |
1949年 | 182篇 |
1948年 | 125篇 |
排序方式: 共有9553条查询结果,搜索用时 15 毫秒
1.
2.
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
3.
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
4.
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
5.
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
6.
7.
The association of circulating endotoxin with the development of the adult respiratory distress syndrome 总被引:6,自引:0,他引:6
P E Parsons G S Worthen E E Moore R M Tate P M Henson 《The American review of respiratory disease》1989,140(2):294-301
Despite extensive investigation, the pathogenesis of the adult respiratory distress syndrome (ARDS) remains uncertain. As yet, there is no clear explanation of why some patients at risk for ARDS develop the syndrome, whereas others do not. Neutrophils and complement fragments have been implicated in the acute lung injury, but it is clear from published data that evidence of complement activation alone predicts neither the development nor the severity of ARDS. We investigated whether the combination of endotoxin, a leukocyte-priming agent, and complement fragments, leukocyte-stimulating agents, was associated with the development of ARDS. Ninety-eight patients were identified as being either at risk for the development of ARDS or having ARDS, and serial blood samples were obtained. There was no correlation between C5 fragments and the development of ARDS. C3 fragment levels were increased in 89% of the patients with ARDS, but they were also increased in 62% of patients at risk. Endotoxin was detected in 74% of the plasma samples obtained from patients at risk who subsequent developed ARDS and in 64% of the plasma samples obtained from the patients with ARDS. In contrast, only 22% of the plasma samples obtained from the patients at risk who did not develop ARDS had measurable endotoxin. We suggest that the combination of endotoxin and complement fragments may be one mechanism involved in the development of ARDS. 相似文献
8.
9.
10.