全文获取类型
收费全文 | 2492篇 |
免费 | 184篇 |
国内免费 | 115篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 99篇 |
妇产科学 | 62篇 |
基础医学 | 295篇 |
口腔科学 | 47篇 |
临床医学 | 300篇 |
内科学 | 549篇 |
皮肤病学 | 44篇 |
神经病学 | 179篇 |
特种医学 | 407篇 |
外国民族医学 | 1篇 |
外科学 | 163篇 |
综合类 | 73篇 |
一般理论 | 2篇 |
预防医学 | 187篇 |
眼科学 | 41篇 |
药学 | 174篇 |
中国医学 | 1篇 |
肿瘤学 | 118篇 |
出版年
2022年 | 11篇 |
2021年 | 26篇 |
2020年 | 15篇 |
2019年 | 24篇 |
2018年 | 40篇 |
2017年 | 17篇 |
2016年 | 35篇 |
2015年 | 41篇 |
2014年 | 39篇 |
2013年 | 67篇 |
2012年 | 52篇 |
2011年 | 92篇 |
2010年 | 75篇 |
2009年 | 74篇 |
2008年 | 70篇 |
2007年 | 124篇 |
2006年 | 69篇 |
2005年 | 107篇 |
2004年 | 65篇 |
2003年 | 60篇 |
2002年 | 53篇 |
2001年 | 63篇 |
2000年 | 62篇 |
1999年 | 67篇 |
1998年 | 117篇 |
1997年 | 112篇 |
1996年 | 117篇 |
1995年 | 82篇 |
1994年 | 79篇 |
1993年 | 74篇 |
1992年 | 32篇 |
1991年 | 59篇 |
1990年 | 45篇 |
1989年 | 80篇 |
1988年 | 66篇 |
1987年 | 72篇 |
1986年 | 45篇 |
1985年 | 64篇 |
1984年 | 39篇 |
1983年 | 31篇 |
1982年 | 35篇 |
1981年 | 26篇 |
1980年 | 33篇 |
1979年 | 18篇 |
1978年 | 18篇 |
1977年 | 21篇 |
1976年 | 39篇 |
1975年 | 22篇 |
1974年 | 12篇 |
1973年 | 12篇 |
排序方式: 共有2791条查询结果,搜索用时 15 毫秒
1.
Letitia Lancaster 《European Journal of Oncology Nursing》2004,8(1):30-39
Despite advances in brachytherapy techniques in recent years, patients still experience a variety of treatment-related complications. Vaginal stenosis is a recognised toxicity of brachytherapy for the treatment of gynaecological cancer. It can result in long-term sexual dysfunction and painful vaginal examinations; however, it is generally accepted that it may be prevented by regular sexual intercourse or the use of vaginal dilators. The incidence of vaginal stenosis is variably reported in the literature, while preventative strategies and compliance are infrequently described and rarely evaluated. A telephone survey of radiation oncology centres in Australia was undertaken as a quality improvement activity to determine best practice for the use of vaginal dilators for the prevention of vaginal stenosis, by way of identifying similarities of practice. The results revealed a lack of consistency for all variables, including which patients are advised to use vaginal dilators, the time to initiate use, frequency of use, insertion time and duration of use. These findings suggest that current methods for preventing radiation-induced vaginal stenosis warrant formal evaluation in order to establish an evidence base for practice. 相似文献
2.
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
3.
4.
5.
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
6.
Lofepramine is a tricyclic antidepressant that is structurally similar to imipramine and is extensively metabolised to desipramine. In the absence of other major pharmacological effects it appears that its antidepressant activity stems from the facilitation of noradrenergic neurotransmission by uptake inhibition, and possibly by the additional facilitation of serotoninergic neurotransmission. The overall therapeutic efficacy of lofepramine is comparable to that of imipramine, amitriptyline, clomipramine, maprotiline and mianserin in patients with depression of varying severity, and coexisting anxiety. Dry mouth is the most commonly reported side effect of usual therapeutic doses of lofepramine, but the incidence of this and other anticholinergic side effects is less among patients treated with lofepramine than with imipramine. Lofepramine has not been associated with adverse effects on cardiac function even in cases of attempted suicide by overdose. Thus, providing its apparent favourable side effect profile is confirmed in practice, lofepramine may be a valuable alternative for treatment of the depressed patient where a tricyclic is indicated. 相似文献
7.
8.
9.
Effectiveness of training health professionals to provide smoking cessation interventions: systematic review of randomised controlled trials.
下载免费PDF全文
![点击此处可从《Quality in health care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
OBJECTIVE--To assess the effectiveness of interventions that train healthcare professionals in methods for improving the quality of care delivered to patients who smoke. DESIGN--Systematic literature review. SETTING--Primary care medical and dental practices in the United States and Canada. Patients were recruited opportunistically. SUBJECTS--878 healthcare professionals and 11,228 patients who smoked and were identified in eight randomised controlled trials. In each of these trials healthcare professionals received formal training in smoking cessation, and their performance was compared with that of a control group. MAIN MEASURES--Point prevalence rates of abstinence from smoking at six or 12 months in patients who were smokers at baseline. Rates of performance of tasks of smoking cessation by healthcare professionals, including offering counselling, setting dates to stop smoking, giving follow up appointments, distributing self help materials, and recommending nicotine gum. METHODS--Trials were identified by multiple methods. Data were abstracted according to predetermined criteria by two observers. When possible, meta-analysis was performed using a fixed effects model and the results were subjected to sensitivity analysis. RESULTS--Healthcare professionals who had received training were significantly more likely to perform tasks of smoking cessation than untrained controls. There was a modest increase in the odds of stopping smoking for smokers attending health professionals who had received training compared with patients attending control practitioners (odds ratio 1.35 (95% confidence interval 1.09 to 1.68)). This result was not robust to sensitivity analysis. The effects of training were increased if prompts and reminders were used. There was no definite benefit found for more intensive forms of counselling compared with minimal contact strategies. CONCLUSIONS--Training health professionals to provide smoking cessation interventions had a measurable impact on professional performance. A modest, but non-robust, effect on patient outcome was also found, suggesting that training alone is unlikely to be an effective strategy for improving quality of care, unless organisational and other factors are also considered. 相似文献
10.
Drinking patterns of male and female Long-Evans rats were compared during a 15-day drinking period. All animals were tested for preference for alcohol for 24 h during which food, water, and beer containing 5% ethanol were freely available. Animals drinking 50 ml or more of beer were chosen for the experiments. On days 1-5, animals were offered food, water, and beer containing 5% ethanol (v/v). On days 6-15, the concentration of ethanol in the beer was doubled to 10% (v/v). Preference ratios (beer/total fluid) were higher for females than males, and females consumed more grams of alcohol per unit of body weight. When alcohol concentration was doubled, females increased alcohol intake (g/kg), while males tended to titrate alcohol intake to levels consumed at 5% concentration. Female patterns of drinking differed from male patterns of drinking. 相似文献