全文获取类型
收费全文 | 10191篇 |
免费 | 379篇 |
国内免费 | 42篇 |
学科分类
医药卫生 | 10612篇 |
出版年
2019年 | 49篇 |
2018年 | 50篇 |
2017年 | 73篇 |
2016年 | 75篇 |
2015年 | 93篇 |
2014年 | 114篇 |
2013年 | 182篇 |
2012年 | 222篇 |
2011年 | 256篇 |
2010年 | 185篇 |
2009年 | 228篇 |
2008年 | 170篇 |
2007年 | 173篇 |
2006年 | 184篇 |
2005年 | 165篇 |
2004年 | 114篇 |
2003年 | 84篇 |
2002年 | 92篇 |
2001年 | 96篇 |
2000年 | 85篇 |
1999年 | 124篇 |
1998年 | 168篇 |
1997年 | 215篇 |
1996年 | 205篇 |
1995年 | 177篇 |
1994年 | 179篇 |
1993年 | 182篇 |
1992年 | 127篇 |
1991年 | 138篇 |
1990年 | 126篇 |
1989年 | 147篇 |
1988年 | 121篇 |
1987年 | 141篇 |
1986年 | 104篇 |
1985年 | 101篇 |
1984年 | 87篇 |
1983年 | 69篇 |
1982年 | 68篇 |
1981年 | 65篇 |
1980年 | 57篇 |
1977年 | 53篇 |
1976年 | 53篇 |
1959年 | 344篇 |
1958年 | 761篇 |
1957年 | 869篇 |
1956年 | 772篇 |
1955年 | 803篇 |
1954年 | 780篇 |
1949年 | 182篇 |
1948年 | 126篇 |
排序方式: 共有10000条查询结果,搜索用时 475 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.
Phonological disorders in children: changes in phonological process use during treatment 总被引:2,自引:0,他引:2
Unintelligible speech in childhood is often characterised by the use of unusual or deviant (i.e. non-developmental) phonological processes, e.g. initial consonant deletion. These processes are reported to appear at speech onset and to undergo little spontaneous change during the preschool years. The study reported here documents the changes that occurred in the phonological systems of seven phonologically disordered children during remediation that targeted unusual phonological processes. Qualitative changes in phonological process use were observed for all children. Six of the children made quantitative improvement in terms of the percentage consonants produced correctly in spontaneous speech. Individual differences in phonological learning strategy use are described. 相似文献
8.
9.
10.