全文获取类型
收费全文 | 2474篇 |
免费 | 116篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 100篇 |
妇产科学 | 19篇 |
基础医学 | 468篇 |
口腔科学 | 115篇 |
临床医学 | 266篇 |
内科学 | 578篇 |
皮肤病学 | 120篇 |
神经病学 | 54篇 |
特种医学 | 274篇 |
外科学 | 228篇 |
综合类 | 51篇 |
预防医学 | 100篇 |
眼科学 | 27篇 |
药学 | 159篇 |
中国医学 | 3篇 |
肿瘤学 | 48篇 |
出版年
2018年 | 38篇 |
2016年 | 27篇 |
2015年 | 43篇 |
2014年 | 28篇 |
2013年 | 96篇 |
2012年 | 47篇 |
2011年 | 38篇 |
2010年 | 56篇 |
2009年 | 52篇 |
2008年 | 35篇 |
2007年 | 58篇 |
2006年 | 64篇 |
2005年 | 36篇 |
2004年 | 28篇 |
2003年 | 33篇 |
2002年 | 27篇 |
2001年 | 37篇 |
2000年 | 28篇 |
1999年 | 41篇 |
1998年 | 85篇 |
1997年 | 95篇 |
1996年 | 104篇 |
1995年 | 70篇 |
1994年 | 75篇 |
1993年 | 76篇 |
1992年 | 40篇 |
1991年 | 39篇 |
1990年 | 41篇 |
1989年 | 68篇 |
1988年 | 58篇 |
1987年 | 49篇 |
1986年 | 53篇 |
1985年 | 38篇 |
1984年 | 57篇 |
1983年 | 27篇 |
1982年 | 32篇 |
1981年 | 37篇 |
1980年 | 50篇 |
1978年 | 27篇 |
1977年 | 35篇 |
1976年 | 38篇 |
1975年 | 36篇 |
1972年 | 24篇 |
1970年 | 23篇 |
1965年 | 50篇 |
1964年 | 50篇 |
1963年 | 47篇 |
1962年 | 41篇 |
1961年 | 40篇 |
1960年 | 65篇 |
排序方式: 共有2620条查询结果,搜索用时 0 毫秒
31.
H B de Souza V Amato Neto L M Braz A A Moreira C K Takiguti R Campos L Matsubara 《Revista do Instituto de Medicina Tropical de S?o Paulo》1991,33(3):221-226
In order to simplify breeding of triatominae in the laboratory, for performing xenodiagnosis and other biologic studies, we tried to feed the insects "in vitro" with citrated or defibrinated blood from commercially abated chicken. Two types of efficacy observations were carried out with Triatoma infestans: a) analysis of the chaining of successive nymphal stages, viability of satisfactory matching, fertile oviposition and adequate reproduction; b) assessment of viability and infectivity of Trypanosoma cruzi in the insects. As a conclusion, it became evident that, despite operational easiness, the objectives were not achieved, since the classical procedure used as the control, was always superior. 相似文献
32.
Non-invasive detection of fecal protein kinase C betaII and zeta messenger RNA: putative biomarkers for colon cancer 总被引:2,自引:0,他引:2
Davidson LA; Aymond CM; Jiang YH; Turner ND; Lupton JR; Chapkin RS 《Carcinogenesis》1998,19(2):253-257
We have developed a non-invasive method utilizing feces, containing
sloughed colonocytes, as a sensitive technique for detecting diagnostic
colonic biomarkers. In this study, we used the rat colon carcinogenesis
model to determine if changes in fecal protein kinase C (PKC) expression
have predictive value in monitoring the neoplastic process. Weanling rats
were injected with saline or azoxymethane (AOM) and 36 weeks later fecal
samples and mucosa were collected, poly A+ RNA isolated, and quantitative
RT-PCR performed using primers to PKC betaII and zeta. Fecal PKC betaII and
zeta mRNA levels were altered by the presence of a tumor, with
tumor-bearing animals having a 3-fold higher (P < 0.05) PKC betaII
expression as compared with animals without tumors. In addition,
AOM-injection increased mucosal PKC betaII mRNA expression compared with
saline controls. No effect of tumor incidence on mucosal PKC betaII
expression was observed. In contrast, fecal PKC zeta expression was
2.5-fold lower (P < 0.05) in animals injected with azoxymethane versus
saline. Since tumor incidence exerts a reciprocal effect on fecal PKC
betaII and zeta mRNA expression, data were also expressed as the ratio
between PKC betaII and zeta. The isozyme ratio was strongly related to
tumor incidence, i.e. ratio for animals with tumors was 2.18 +/- 1.25,
animals without tumors was 0.50 +/- 0.16, P = 0.025. We demonstrate that
the expression of fecal PKC betaII and zeta may serve as a noninvasive
marker for development of colon tumors. A sensitive technique for the
detection of colon cancer is of importance since early diagnosis can
substantially reduce mortality.
相似文献
33.
Epilepsy surgery has emerged as an important option in the treatment of children with epilepsy that is refractory to antiepileptic drug management. The cornerstone of successful surgery is accurate localization of the brain region of seizure onset. Traditional techniques of seizure onset localization, e.g. surface electroencephalography (EEG) recording and magnetic resonance imaging (MRI), allow accurate localization in a significant number of patients. When the focus of seizure onset is not apparent from these non-invasive techniques, other methods of localization, e.g. intracranial EEG recording, may be needed before resection of the focus. Single-photon emission computed tomography (SPECT) is a nuclear medicine blood-flow technique that has been used to identify a region of epileptogenic brain associated with low blood flow in the resting state (interictal SPECT) or increased blood flow at the time of seizure activity (ictal SPECT). This report describes the validation and utility of a computer-assisted method of subtracting the interictal from the ictal SPECT scans and co-registering the difference image on the MRI. This method, called subtraction ictal SPECT co-registered on MRI (SISCOM), is used in guiding the location and the extent of intracranial electrode implantation, or in obviating the need for the implantation in some cases. 相似文献
34.
35.
36.
37.
38.
头皮糠疹是常见病是多发病,临床表现为头皮红斑和脱屑,提示皮损部位表皮结构和功能异常,头皮角质层代谢紊乱,最近对头皮糠疹病因和病理的研究证实马拉色菌,皮脂分泌和个体敏感性是形成上述皮损的3个关键因素,硫氧吡啶锌(PTZ或ZPT)可以有效地杀灭马拉色菌,PTZ的颗粒大小和形状对其在头皮的生物利用度有明显的影响。此外,PTZ的抗菌效果有赖于其分子结构的完整性,在外用制剂中加入附加的游离锌,可以有效防止PTZ解离,从而提高其疗效。 相似文献
39.
L R Troncone S Braz M A Benedito S Tufik 《Pharmacology, biochemistry, and behavior》1986,25(1):223-225
Beta adrenergic sites in rat brain are reduced after repeated treatment with antidepressant drugs, with REM sleep deprivation (REMSd) having the same effect. This paper reports the effects of REMSd in the production of 3H-cyclic AMP in frontal cortical slices by NE challenge. Data presented in this paper report a marked decrease in 3H-cyclic AMP synthesis after REMSd, which is in accordance with previous results showing adrenergic receptor down-regulation following REMSd. Results are discussed in view of possible interaction with dopaminergic systems and depression management. 相似文献
40.