全文获取类型
收费全文 | 1728篇 |
免费 | 93篇 |
国内免费 | 114篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 97篇 |
妇产科学 | 16篇 |
基础医学 | 185篇 |
口腔科学 | 33篇 |
临床医学 | 186篇 |
内科学 | 387篇 |
皮肤病学 | 47篇 |
神经病学 | 176篇 |
特种医学 | 369篇 |
外国民族医学 | 1篇 |
外科学 | 112篇 |
综合类 | 40篇 |
预防医学 | 85篇 |
眼科学 | 18篇 |
药学 | 96篇 |
中国医学 | 1篇 |
肿瘤学 | 84篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 11篇 |
2018年 | 19篇 |
2017年 | 3篇 |
2016年 | 19篇 |
2015年 | 21篇 |
2014年 | 19篇 |
2013年 | 38篇 |
2012年 | 27篇 |
2011年 | 43篇 |
2010年 | 51篇 |
2009年 | 59篇 |
2008年 | 37篇 |
2007年 | 76篇 |
2006年 | 61篇 |
2005年 | 77篇 |
2004年 | 37篇 |
2003年 | 32篇 |
2002年 | 30篇 |
2001年 | 33篇 |
2000年 | 43篇 |
1999年 | 35篇 |
1998年 | 98篇 |
1997年 | 103篇 |
1996年 | 112篇 |
1995年 | 70篇 |
1994年 | 68篇 |
1993年 | 70篇 |
1992年 | 23篇 |
1991年 | 42篇 |
1990年 | 43篇 |
1989年 | 66篇 |
1988年 | 48篇 |
1987年 | 67篇 |
1986年 | 42篇 |
1985年 | 60篇 |
1984年 | 29篇 |
1983年 | 29篇 |
1982年 | 31篇 |
1981年 | 25篇 |
1980年 | 32篇 |
1979年 | 11篇 |
1978年 | 14篇 |
1977年 | 17篇 |
1976年 | 27篇 |
1975年 | 15篇 |
1970年 | 2篇 |
排序方式: 共有1935条查询结果,搜索用时 93 毫秒
1.
Summary— To investigate if the functional alterations observed in resistance arteries of spontaneously hypertensive rats (SHRs) were also present at the coronary level, in vitro experiments were performed in mesenteric resistance arteries (MRA) and in right (RIC) and left interventricular coronary (LIC) arteries taken from 15–25-week-old SHR and age-matched Wistar Kyoto rats WKYs. Using a passive extension protocol, internal diameters corresponding to 100 mmHg intraluminal pressure (D100) were determined and vessels were set up to a normalized internal diameter (0.9 D100). SHR mesenteric resistance arteries had a significantly smaller diameter compared to WKY arteries, whereas both types of SHR coronary arteries had a greater diameter compared to those of WKY rats. In arteries in the absence of contracting agonist, nitro-L-arginine (NOLA, 100 μM) induced a progressive rise in basal tone, which could be reversed by subsequent addition of L-arginine (100 μM) but not D-arginine (100 μM). When expressed as percent of maximal contractions induced by agonists (noradrenaline, NA [10 μM] in MRA; serotonin, 5-HT [10 μM], in RIC and LIC), these contractions were significantly stronger in WKY compared to SHR coronary and mesenteric resistance arteries. In NA-precontracted MRA and 5HT-precontracted coronary arteries in the presence of indomethacin (10 μM), the magnitude of acetylcholine-induced maximal relaxations (expressed as percent of maximal contractions induced by agonists) was greater in WKY compared to SHR arteries. After a 30-min incubation period, NOLA (100 μM) completely inhibited relaxations induced by acetylcholine (0.01–10 μM) in all types of precontracted arteries. Subsequent additions of sodium nitroprusside, (SNP, 10 μM) induced complete relaxations in all preparations. These results show that a basal release of NO or NO-like compound by endothelial cells is present in isolated mesenteric resistance and coronary arteries of WKY rats and SHRs. The contribution of endothelium-derived relaxing factor-nitric oxide (EDRF-NO) to arterial tone was lower in MRA compared to coronary arteries in both strains and in SHR compared to WKY arteries. In the SHR preparations, the impaired relaxation induced by acetylcholine appeared to be due to a functional alteration of the endothelium in the presence of normal reactivity of the smooth muscle cells. 相似文献
2.
3.
4.
表小檗碱对α受体的作用 总被引:2,自引:0,他引:2
表小檗碱(epiberberine,EB)是从湖北产黄连(Coptis chinensis Franch)中提取的一种生物碱,属苯喹嗪类原小檗碱,对其药理作用的研究资料甚少,未见其对α肾上腺素体作用的报道。资料表明,许多原小檗碱类化合物有α受体阻滞作用,为从该类化合物中选择 相似文献
5.
6.
Rianne P Reijs Saskia G M van Mil Mariette H J A van Hall Johan B A M Arends Jacobiene W Weber Willy O Renier Albert P Aldenkamp 《Seizure》2007,16(5):438-444
INTRODUCTION: One-third of children with epilepsy are classified as having a cryptogenic localization related epilepsy (CLRE). In cohort studies CLRE is often grouped together with either symptomatic localization related epilepsy (SLRE) or idiopathic generalized epilepsy (IGE). Therefore, this categorization is not specific enough and will not lead to prognostic or treatment information. We objectified the classification differences between these categories. METHODS: A total of 114 children admitted to our epilepsy centre underwent a standardized clinical analysis, which yielded age at onset, duration of the epilepsy, seizure frequency, seizure type, percentage of interictal epileptiform activity on EEG (IEA), type of treatment, and full scale IQ. These variables are regarded the characteristics of the epilepsy, and used in a discriminant function analysis. RESULTS: IEA was found to be the only variable to distinguish between groups of epilepsy. SLRE could easily be distinguished significantly from IGE and CLRE, while the latter two did not differ significantly. Discriminant function analysis combined the variables into two functions, applicable to classify the children. By applying this statistical analysis method, the groups clinically classified as SLRE and IGE were mostly classified as SLRE (71.4%) and IGE (57.9%). However, CLRE appeared difficult to classify (49.2%), and most children were classified as either SLRE (19%) or IGE (31.7%). CONCLUSION: The current opinion that CLRE is 'probably symptomatic' cannot be confirmed in all cases in this study. It is most likely that the current CLRE population consists of both children with eventually SLRE, as well as yet to be described syndromes to be classified as idiopathic epilepsies. We emphasize the need for separate studies regarding children with 'probably symptomatic' (cryptogenic) localization related epilepsy, as this will maximally help children, caretakers and treating physicians to achieve the best possible outcome. 相似文献
7.
8.
A A Gabre?ls-Festen F J Gabre?ls E M Joosten H M Vingerhoets W O Renier 《Neuropediatrics》1992,23(3):138-143
Four children, index cases of families in which autosomal dominant neuropathy with liability to pressure palsies (HNPP) was diagnosed, are presented. Only one child was admitted for evaluation of an acute peroneal palsy, three presented with other symptoms. Polyneuropathy was diagnosed in all four children, in one of their parents and in some sibs. On inquiry, one child and several members of the four families had experienced transient palsies before. Morphological studies of the sural nerves showed frequently large tomacula and a neuropathic process of segmental de- and remyelination, and axonal degeneration. Attention is drawn to the atypical presentation without pressure palsies of HNPP. 相似文献
9.
10.
M F Beersma J M Galama H A Van Druten W O Renier C J Lucas J G Kapsenberg 《International journal of epidemiology》1992,21(3):583-588
Since 1976, when general immunization against measles was introduced in the Netherlands, all new cases of subacute sclerosing panencephalitis (SSPE) were registered and detailed data about immunization, epidemiology and disease progression were collected on them. Up to 1991, 99 new patients have been registered of which 81 were born in this country and 18 elsewhere. From 1981 onwards, the incidence of SSPE among those born in the Netherlands decreased gradually from 13 cases per year to one case per year. This decrease is attributed to the large scale of immunization against measles. Three SSPE patients had been immunized against measles, all of them without a history of clinical measles. Epidemiology and risk factors of SSPE did not differ from those reported in other countries. An exceptional cluster of four patients in one town, who had measles in the same year, is reported. Progression of SSPE appeared to be age related. A total of 28 patients was treated with Inosiplex; no significant effect on survival in stage 3 of the disease was found. 相似文献