全文获取类型
收费全文 | 2177286篇 |
免费 | 152978篇 |
国内免费 | 3194篇 |
专业分类
耳鼻咽喉 | 31181篇 |
儿科学 | 71479篇 |
妇产科学 | 61990篇 |
基础医学 | 313498篇 |
口腔科学 | 61323篇 |
临床医学 | 189032篇 |
内科学 | 419141篇 |
皮肤病学 | 47232篇 |
神经病学 | 167660篇 |
特种医学 | 85962篇 |
外国民族医学 | 564篇 |
外科学 | 334576篇 |
综合类 | 45127篇 |
现状与发展 | 2篇 |
一般理论 | 544篇 |
预防医学 | 156212篇 |
眼科学 | 49889篇 |
药学 | 170177篇 |
8篇 | |
中国医学 | 4901篇 |
肿瘤学 | 122960篇 |
出版年
2018年 | 21343篇 |
2016年 | 18534篇 |
2015年 | 21048篇 |
2014年 | 28802篇 |
2013年 | 43168篇 |
2012年 | 59211篇 |
2011年 | 63172篇 |
2010年 | 37357篇 |
2009年 | 35072篇 |
2008年 | 60172篇 |
2007年 | 64881篇 |
2006年 | 65891篇 |
2005年 | 63816篇 |
2004年 | 61298篇 |
2003年 | 59359篇 |
2002年 | 57939篇 |
2001年 | 107107篇 |
2000年 | 109938篇 |
1999年 | 92497篇 |
1998年 | 24725篇 |
1997年 | 21963篇 |
1996年 | 22091篇 |
1995年 | 20869篇 |
1994年 | 19402篇 |
1993年 | 18099篇 |
1992年 | 72328篇 |
1991年 | 70391篇 |
1990年 | 69427篇 |
1989年 | 67133篇 |
1988年 | 61750篇 |
1987年 | 60347篇 |
1986年 | 57311篇 |
1985年 | 54263篇 |
1984年 | 39992篇 |
1983年 | 34331篇 |
1982年 | 19682篇 |
1981年 | 17380篇 |
1979年 | 36999篇 |
1978年 | 25494篇 |
1977年 | 22382篇 |
1976年 | 20369篇 |
1975年 | 22734篇 |
1974年 | 26632篇 |
1973年 | 25738篇 |
1972年 | 24580篇 |
1971年 | 22943篇 |
1970年 | 21201篇 |
1969年 | 20544篇 |
1968年 | 18837篇 |
1967年 | 16685篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
We developed a novel method which enables bloodless exposure of the levator veli palatini muscle in rat in order to investigate the physiological properties of this muscle. The levator veli palatini muscle which is innervated by a branch of the glossopharyngeal nerve showed rhythmic spontaneous movement in rats. Cutting the branch supplying LVP of the glossopharyngeal nerve caused cessation of the spontaneous movement of the levator veli palatini muscle. The spontaneous discharges of the glossopharyngeal nerve were synchronized with those of the phrenic nerve. A mixture of 95% oxygen and 5% room air influenced the efferent discharges from the branch of the glossopharyngeal nerve supplying the levator veli palatini muscle. These findings indicate that the motor nerve supply to the levator veli palatini muscle is the glossopharyngeal nerve, and the levator veli palatini muscle is related to the respiratory system, in particular with inspiration in rats. 相似文献
992.
993.
994.
P G Crosignani A M Mattei C Scarduelli V Cavioni P Boracchi 《Human reproduction (Oxford, England)》1989,4(8):910-912
This paper reports the changes in prolactin levels after 12 spontaneous and 52 induced pregnancies in 54 women with unambiguous hyperprolactinaemia (median plasma prolactin levels 67.5 ng/ml, range 40-400). Twenty-three of the patients showed radiological evidence of prolactinoma. The pregnancies were induced in 37 patients by bromocriptine, in nine by metergoline, in two by lisuride and in four by other treatments. Of the 64 pregnancies, 16 ended in spontaneous abortion, while 48 went to term. Follow-up was continued for at least 6 months after delivery or until the end of lactation. In a control group of 32 hyperprolactinaemic women (median prolactin 70 ng/ml, range 40-400) not wishing to become pregnant, prolactin changes were similarly registered over a mean period of 15 months without any treatment (range 6-38 months). After pregnancy, a significant downward trend of plasma prolactin was observed in the puerperal women with a 'normalization' rate of 17%. No changes were observed in the 32 controls who did not become pregnant. 相似文献
995.
A family with two members (two generations) exhibiting Turner syndrome is described. Cytogenetic studies on these individuals showed the presence of multiple X chromosome changes. Evidence is presented to show that the maternally inherited X chromosome is the chromosome involved in the structural alterations observed. The effect of a tendency of the maternal X chromosome to break at specific sites on the development of the Turner phenotype and abnormal karyology is discussed. 相似文献
996.
G K Freeman 《The British journal of general practice》1989,39(321):145-147
The influence of receptionists on continuity of care in four group practices was examined. Twenty two receptionists were observed making 543 appointments and afterwards were interviewed about their personal priority for continuity of care. One of the practices ran a personal list system. It was found that the personal list practice attracted more requests for a specific doctor and time which were then more difficult to satisfy. Most receptionists thought it was important that patients should see the same doctor but their influence seemed to be small compared with that of the doctor as expressed in practice policies. Marked variation in demand for individual doctors was seen in two of the practices without a personal list system. 相似文献
997.
Human subjects maintained isometric plantar or dorsal flexions of the ankle in a matching task. H-reflexes of different sizes were superimposed on the steady activity. The peak-to-peak amplitude of the reflexes was measured on the electromyogram (EMG) of the soleus muscle. The size of the corresponding muscle contractions was determined on the isometric torque signal in relation to the maintained flexion force. The EMG-torque relation which was defined as the reflex muscle contraction as a function of the EMG reflex signal approximated a square root function for a given steady contraction level. It was not modulated by steady dorsal flexions, but it decreased continuously with stronger plantar steady torques. This dependence was caused by the silent period following the reflex discharge. Since the reflex discharge and the silent period were near in time to the duration of the contraction, the silent period had a direct effect on the reflex contraction amplitude. 相似文献
998.
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
999.
1000.