全文获取类型
收费全文 | 4473篇 |
免费 | 262篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 81篇 |
儿科学 | 183篇 |
妇产科学 | 125篇 |
基础医学 | 628篇 |
口腔科学 | 63篇 |
临床医学 | 358篇 |
内科学 | 1482篇 |
皮肤病学 | 85篇 |
神经病学 | 233篇 |
特种医学 | 94篇 |
外科学 | 538篇 |
综合类 | 46篇 |
一般理论 | 1篇 |
预防医学 | 173篇 |
眼科学 | 95篇 |
药学 | 372篇 |
中国医学 | 19篇 |
肿瘤学 | 174篇 |
出版年
2023年 | 18篇 |
2022年 | 66篇 |
2021年 | 193篇 |
2020年 | 74篇 |
2019年 | 82篇 |
2018年 | 106篇 |
2017年 | 91篇 |
2016年 | 86篇 |
2015年 | 89篇 |
2014年 | 135篇 |
2013年 | 161篇 |
2012年 | 282篇 |
2011年 | 280篇 |
2010年 | 181篇 |
2009年 | 122篇 |
2008年 | 242篇 |
2007年 | 276篇 |
2006年 | 220篇 |
2005年 | 225篇 |
2004年 | 225篇 |
2003年 | 202篇 |
2002年 | 175篇 |
2001年 | 99篇 |
2000年 | 112篇 |
1999年 | 79篇 |
1998年 | 34篇 |
1997年 | 31篇 |
1996年 | 27篇 |
1995年 | 28篇 |
1994年 | 19篇 |
1993年 | 22篇 |
1992年 | 66篇 |
1991年 | 52篇 |
1990年 | 45篇 |
1989年 | 53篇 |
1988年 | 44篇 |
1987年 | 45篇 |
1986年 | 43篇 |
1985年 | 58篇 |
1984年 | 43篇 |
1983年 | 27篇 |
1981年 | 17篇 |
1980年 | 13篇 |
1979年 | 22篇 |
1978年 | 11篇 |
1975年 | 11篇 |
1974年 | 15篇 |
1973年 | 13篇 |
1971年 | 13篇 |
1968年 | 11篇 |
排序方式: 共有4750条查询结果,搜索用时 187 毫秒
1.
Bień Agnieszka Rzońca Ewa Zarajczyk Marta Wilkosz Katarzyna Wdowiak Artur Iwanowicz-Palus Grażyna 《Quality of life research》2020,29(10):2669-2677
Quality of Life Research - The aim of the study was to assess QoL and identify and analyse its determinants in women with endometriosis. The study was performed in 2019 in health centres in Lublin... 相似文献
2.
3.
Marcin Wojnar Dariusz Wasilewski Halina Matsumoto Artur Cedro 《Alcoholism, clinical and experimental research》1997,21(8):1351-1355
A retrospective study compared the course of alcohol withdrawal, including delirium tremens, in women and men hospitalized in the Nowowiejski Hospital in Warsaw from 1973 to 1987. Medical records pertaining to 1179 patients were analyzed; 13.8% of these patients were women and 86.2% were men. The study showed that women began intensive alcohol drinking later than men ( p < 0.0001), but the period between the onset of alcohol abuse and the first occurrence of alcohol withdrawal was shorter in women than in men ( p < 0.0001). In the period of heavy drinking before hospitalization, women consumed significantly less alcohol then men ( p < 0.0001); moreover, women drank nonbeverage alcohol less frequently than men ( p < 0.05). Women were hospitalized substantially longer than men ( p < 0.0001), whereas the duration of alcohol withdrawal symptoms at the time of hospitalization was comparable in both groups. Withdrawal seizures were significantly more frequent among men than among women ( p < 0.001). Significant differences in the patients'somatic conditions were not noted between the groups, with the exception of anemia and decreased potassium concentration, which were more frequently observed in women (both p < 0.0001), and of increased concentration of ALT and hypoproteinemia, which were more frequent in men (respectively, p < 0.05 and p < 0.01). Co-existing personality disorders, depressive disorders, and anxiety disorders—as well as abuse of benzodiazepines and barbiturates—were more frequently observed in women ( p < 0.0001). The period between the first hospitalization due to alcohol withdrawal and the time of death was significantly shorter in men than in women ( p < 0.05). The results point to differences in the conditions and the course of alcohol dependence and alcohol withdrawal between women and men. 相似文献
4.
5.
D. Le Elizabeth Eric R. Powers Jian-Ping Bin Howard Leong-Poi N. Craig Goodman Sanjiv Kaul 《Journal of nuclear cardiology》2007,14(2):207-214
Background The mechanism by which transmyocardial revascularization (TMR) offers clinical benefit is controversial. We hypothesized that
TMR ameliorates ischemia by reversing paradoxical catecholamine-induced vasoconstriction.
Methods and Results Chronic ischemic cardiomyopathy was created in 11 dogs by placing ameroid constrictors on the proximal coronary arteries and
their major branches. Six weeks later, 35 channels were created percutaneously in the left circumflex artery region, with
the left anterior descending artery region serving as control. At rest, wall thickening and myocardial blood flow did not
change in the treated region, whereas they deteriorated in the control bed. Contractile and myocardial blood flow reserve
increased in the treated region but deteriorated in the control region. There was diminished iodine 123 metaiodobenzylguanidine
uptake and a significant reduction in noradrenergic nerves in the treated region compared with the control region, with a
corresponding reduction in tissue tyrosine hydroxylase activity.
Conclusions We conclude that the absence of a catecholamine-induced reduction in MBF reserve and contractile reserve in the TMR-treated
region with associated evidence of neuronal injury indicates that the relief of exercise-induced ischemia after TMR most likely
results from reversal of paradoxical catecholamine-induced vasoconstriction. These findings may have implications in selecting
patients who would benefit from TMR.
Supported in part by grants from the National Institutes of Health (R01-HL66034 and K-08-HL074290-01). Bethesda. Md. The radio-labeled
microspheres were provided by DuPont Pharmaceuticals, North Billerica. Mass, and the ultrasound equipment was supplied by
Philips. Andover, Mass. Dr Leong-Poi was the recipient of a Fellowship Training Grant from the Canadian Institute of Health
Research and the Heart and Stroke Foundation of Canada. 相似文献
6.
We compared the antihypertensive effects and tolerability of a new calcium channel antagonist felodipine with nifedipine in an open randomised parallel group study in 49 patients with moderate hypertension (diastolic blood pressure 105-120 mm Hg). After two weeks run in period felodipine 5 mg and 10 mg once daily was compared with nifedipine 10 mg tid for an active treatment period of 4 weeks. Twenty three patients (mean age 42 +/- 10 years) received felodipine 5 mg once daily for first 2 weeks and 10 mg once daily for subsequent 2 weeks. Twenty six patients (mean age 45 +/- 9 years) received nifedipine 10 mg tid for 4 weeks. The mean reduction in supine diastolic blood pressure in two groups was 17 +/- 6 mm Hg (nifedipine) and 19 +/- 8 mm Hg (felodipine) (p = NS). The goal diastolic blood pressure of less than or equal to 90 mm Hg was achieved in 31 percent (nifedipine group) and 43.5 percent (felodipine group) of patients (p = NS). Side effects were common with both drugs; however, the tolerability was better with felodipine than with nifedipine. In conclusion felodipine was as effective as nifedipine and had the advantage of once a day dosage. 相似文献
7.
Francisco Airton Castro da Rocha Artur José de Brum-Fernandes 《Journal of bone and mineral research》2002,17(3):434-442
Peroxynitrite (PN), a nitric oxide (NO*)-derived anion, has been associated with NO* damage in various cell types. We examined the effects of adding PN to cultured human osteoblast-like (hOB) cells obtained after hip arthroplasty. Exposure to PN (0.1-0.4 mM) decreased both hOB proliferation and differentiation, measured by [3H]thymidine uptake and alkaline phosphatase production, respectively. Incubation with 3-morpholinosydnonimine (SIN-1; 0.25-1 mM), an NO* and O2- donor that leads to PN release, also reduced both hOB proliferation and differentiation. Coincubation with both superoxide dismutase (SOD; 100 U/ml) and catalase (CAT; 50 U/ml), rendering SIN-1 a pure NO* donor, reversed its effects on hOB proliferation and differentiation. However, SIN-1-induced NO* production, measured by nitrite release to the hOB medium, was not altered by cotreatment with SOD and CAT. Expression of nitrotyrosine by hOB, a marker of PN action, was significantly increased after SIN-1 addition, as compared with untreated cells, as revealed by Western blot analysis. Interleukin-1alpha (IL-1alpha) and interferon gamma (IFN-gamma) but not tumor necrosis factor alpha (TNF-alpha) also significantly increased nitrotyrosine expression in these cells. These data show that PN is at least partially responsible for osteoblast derangement by NO* and that cytokines released during inflammatory arthropathies can induce PN production in hOB cells. 相似文献
8.
9.
Trauma is the third most common cause of death in the West. In the US, approximately 90,000 deaths annually are traumatic
in nature and over 75% of casualties from blunt trauma are due to chest injuries. Cardiac injuries from rib fractures following
blunt trauma are extremely rare. We report the unusual case of a patient who fell from a height and presented with haemopericardium
and haemothorax as a result of left ventricular and lingular lacerations and was sucessfully operated upon. 相似文献
10.
目的:探讨小容积动物线圈3.0T临床磁共振扫描仪体外示踪磁标记间充质干细胞的可行性。方法:用GFP转染法将含有不同剂量铁(56ug/ml和560ug/m1)的超顺磁氧化铁(SPIO)标记间充质干细胞。细胞内铁的含量利用原子吸收谱来测量。磁共振扫描和显微镜可以观察培养试管中的磁标记间充质干细胞。 相似文献