全文获取类型
收费全文 | 15779篇 |
免费 | 643篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 303篇 |
儿科学 | 1035篇 |
妇产科学 | 705篇 |
基础医学 | 1756篇 |
口腔科学 | 351篇 |
临床医学 | 1219篇 |
内科学 | 3455篇 |
皮肤病学 | 527篇 |
神经病学 | 970篇 |
特种医学 | 358篇 |
外科学 | 2408篇 |
综合类 | 329篇 |
一般理论 | 2篇 |
预防医学 | 1244篇 |
眼科学 | 324篇 |
药学 | 907篇 |
1篇 | |
中国医学 | 47篇 |
肿瘤学 | 534篇 |
出版年
2021年 | 114篇 |
2020年 | 76篇 |
2019年 | 123篇 |
2018年 | 140篇 |
2017年 | 133篇 |
2016年 | 121篇 |
2015年 | 200篇 |
2014年 | 250篇 |
2013年 | 326篇 |
2012年 | 444篇 |
2011年 | 485篇 |
2010年 | 306篇 |
2009年 | 316篇 |
2008年 | 487篇 |
2007年 | 544篇 |
2006年 | 566篇 |
2005年 | 504篇 |
2004年 | 444篇 |
2003年 | 404篇 |
2002年 | 439篇 |
2001年 | 376篇 |
2000年 | 388篇 |
1999年 | 344篇 |
1998年 | 236篇 |
1997年 | 251篇 |
1996年 | 276篇 |
1995年 | 224篇 |
1994年 | 214篇 |
1993年 | 216篇 |
1992年 | 259篇 |
1991年 | 249篇 |
1990年 | 218篇 |
1989年 | 203篇 |
1988年 | 189篇 |
1987年 | 203篇 |
1986年 | 149篇 |
1985年 | 125篇 |
1984年 | 108篇 |
1983年 | 88篇 |
1982年 | 75篇 |
1981年 | 86篇 |
1979年 | 61篇 |
1959年 | 345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10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
José Luis R Martin Víctor Pérez Montse Sacristán Fernando Rodríguez-Artalejo Cristóbal Martínez Enric Alvarez 《European psychiatry》2006,21(1):11-20
OBJECTIVE: To assess antipsychotic medication in the treatment of schizophrenia, based on trial drop-out rates. METHOD: The studies included were randomised controlled trials that compared any of the four clinically best-established atypical antipsychotics (quetiapine, olanzapine, risperidone or clozapine) against either of two typical antipsychotics regarded as the gold standard (haloperidol or chlorpromazine). RESULTS: Meta-analysis indicated less risk of all-cause patient withdrawal from atypical medication trials where dosage was flexible, in both the short, relative risk (RR) 0.70 (95% CI 0.64-0.76), P<0.00001, and long term, RR 0.72 (0.65-0.80), P<0.00001. Similar results were observed for withdrawal due to adverse events, RR: 0.54 (0.41-0.72), P<0.0001. Nevertheless, the favourable effects of atypical medication disappeared in trials relying on fixed dosage. CONCLUSIONS: We detected a significant positive effect in terms of the outcome of treatment discontinuation for atypical versus typical medication, though only where the use of flexible rather than fixed doses (closer to an experimental control situation) was possible. 相似文献
4.
5.
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
6.
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
7.
Computed tomographic (CT) scans of the brain in a child with Smith-Lemli-Opitz syndrome revealed enlargement of the ventricular system, hypoplasia of the cerebellum, and abnormal thickening of the gray matter, consistent with pachygyria. These findings have been previously noted in autopsies performed on patients with this disorder. We conclude that CT scanning is a valuable tool in the evaluation of children suspected of having the Smith-Lemli-Opitz syndrome. 相似文献
8.
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
9.
T López-Alburquerque A García Miguel J J Ruiz Ezquerro J de Portugal Alvarez 《Journal of neurology, neurosurgery, and psychiatry》1987,50(4):428-434
The nerve action potential at the elbow and somatosensory evoked potentials (SEPs) at the scalp were recorded over 30 minutes of tourniquet-induced limb ischaemia in 10 diabetic patients and 10 controls. According to the SEP changes, an increased resistance to nerve ischaemia in diabetic patients was observed. The pathways involved in SEP conduction are discussed. 相似文献
10.
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