全文获取类型
收费全文 | 169924篇 |
免费 | 12479篇 |
国内免费 | 523篇 |
专业分类
耳鼻咽喉 | 2218篇 |
儿科学 | 4506篇 |
妇产科学 | 3355篇 |
基础医学 | 22569篇 |
口腔科学 | 3604篇 |
临床医学 | 18169篇 |
内科学 | 34219篇 |
皮肤病学 | 2488篇 |
神经病学 | 15587篇 |
特种医学 | 6274篇 |
外国民族医学 | 5篇 |
外科学 | 23832篇 |
综合类 | 2728篇 |
现状与发展 | 1篇 |
一般理论 | 189篇 |
预防医学 | 16214篇 |
眼科学 | 3941篇 |
药学 | 12131篇 |
4篇 | |
中国医学 | 227篇 |
肿瘤学 | 10665篇 |
出版年
2022年 | 1085篇 |
2021年 | 2686篇 |
2020年 | 1568篇 |
2019年 | 2627篇 |
2018年 | 3023篇 |
2017年 | 2385篇 |
2016年 | 2529篇 |
2015年 | 3080篇 |
2014年 | 4321篇 |
2013年 | 6730篇 |
2012年 | 9786篇 |
2011年 | 10371篇 |
2010年 | 5811篇 |
2009年 | 5437篇 |
2008年 | 9713篇 |
2007年 | 10394篇 |
2006年 | 10227篇 |
2005年 | 10495篇 |
2004年 | 9891篇 |
2003年 | 9556篇 |
2002年 | 9152篇 |
2001年 | 2764篇 |
2000年 | 2627篇 |
1999年 | 2648篇 |
1998年 | 2287篇 |
1997年 | 1901篇 |
1996年 | 1644篇 |
1995年 | 1640篇 |
1994年 | 1353篇 |
1993年 | 1383篇 |
1992年 | 1996篇 |
1991年 | 1860篇 |
1990年 | 1808篇 |
1989年 | 1684篇 |
1988年 | 1550篇 |
1987年 | 1525篇 |
1986年 | 1449篇 |
1985年 | 1562篇 |
1984年 | 1533篇 |
1983年 | 1446篇 |
1982年 | 1592篇 |
1981年 | 1430篇 |
1980年 | 1334篇 |
1979年 | 1115篇 |
1978年 | 1091篇 |
1977年 | 951篇 |
1976年 | 842篇 |
1975年 | 775篇 |
1974年 | 814篇 |
1973年 | 736篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments. 相似文献
4.
In cystic fibrosis (CF), perturbations of total daily energy expenditure (TDEE) may be a major determinant of altered nutrition and growth. Measurement of TDEE is problematic, though the flex-heart rate method (FHRM) provides a close estimation of TDEE, as compared to the cost-prohibitive, gold standard, the double-labeled water method, and permits estimates of the energy cost of daily activities (ECA) above resting energy expenditure (REE). We hypothesize that alterations in ECA affects TDEE in CF. PURPOSE: To measure components of TDEE in adolescents with CF and normal lung function compared with controls, and to determine whether ECA can be improved by diet and exercise. METHODS: Clinically stable CF subjects (aged 9-13, n=12) and age- and gender-matched controls (n=13) had repeated measurements of TDEE by FHRM, REE, and maximal cardiopulmonary exercise testing (CPET) during a 6-week exercise and diet program. RESULTS: While the mean REE was similar in both groups, ECA was significantly lower in CF adolescents as compared to controls (p=0.02). During CPET, maximal exercise in CF was characterized by hyperventilation, which was unrelated to ventilation-perfusion mismatching. There were no changes in REE after dietary intervention. CONCLUSION: ECA in CF adolescents with normal lung function is lower when compared to healthy controls. These findings support the hypothesis that clinically stable patients with CF have inefficient energy metabolism or alternatively conserve energy during activities of daily living. 相似文献
5.
6.
Epistaxis is a common ear, nose and throat emergency. A variety of nasal packs are available to control the bleeding by tamponade. Training of junior doctors to insert nasal packs is difficult when dealing with a bleeding patient. We discovered a readily available and simple model to enable trainees to learn the method of nasal packing. 相似文献
7.
8.
9.
Previously, we have demonstrated that chronic-alcohol exposure alters insulin-like growth factor 1 (IGF1) signaling in adult rat heart cells. This report examines the effects of alcohol in vitro on the expression of protein kinase C (PKC) alpha, delta, and epsilon using the embryonic heart cell line, H9c2, and how this may be linked to changes in IGF1 signal transduction. Western blot analyses of H9c2 protein preparations demonstrate that there are significant increases in the total protein levels of PKC delta and epsilon after 4 days exposure to alcohol, and similar increases were found after 2 and 6 days exposure. In addition, there was a significant increase in PKC delta and epsilon in the membranal fractions and a decrease in the cytosolic fractions. No change was found in the expression or activity levels for PKC alpha. Chronic-alcohol exposure (100 mM, 4 days) increased the basal tyrosine kinase activity of the IGF1 receptor (IGF1R), and altered its rate of activation. Chronic-alcohol exposure also reduced the rate of Erk1/Erk2 activation by IGF1. Chronic alcohol blocked the proliferative effects of IGF1 on cell growth and reduced cell viability both in the presence and absence of IGF1, and this alcohol-induced reduction in cell viability was blocked using siRNA to inhibit PKC delta. In addition, a reduction in the amount of myosin light chain 2 was found in the alcohol-exposed cells. In conclusion, chronic alcohol alters PKC delta and epsilon expression and activity, and suppresses the IGF1 signaling pathway in embryonic heart cell culture. Blockage of PKC delta expression using siRNA inhibits the suppressive effects of alcohol on cell viability. 相似文献
10.
Severe persistent asthma can have a substantial impact on a patient's health-related quality of life (HRQL), both as a result of symptoms and from side effects of treatment. The HRQL impact of two doses (400 and 800 microg twice daily) of mometasone furoate dry powder inhaler (MF DPI) was compared with placebo in patients with severe persistent asthma previously maintained on oral steroids as a component of a previously published randomized, 12-week, double-blind, placebo-controlled, multicenter trial. A 9-month open-label extension (OLE), with all patients treated with MF DPI, followed. Patients 12 years of age or older completed a generic HRQL measure, the Medical Outcomes Trust Short Form-36 (SF-36), and an asthma-specific measure, the Marks Asthma Quality of Life Questionnaire (AQLQ-M), at baseline, at endpoint (last evaluable visit) of the double-blind phase (EODBP), and after the first 3 months of the OLE. Of 132 patients enrolled in the study, 128 provided HRQL data at baseline and at EODBP. Mean SF-36 scores at baseline showed significant HRQL impairment compared with U.S. general population norms. With treatment, the reduction in oral corticosteroid (OCS) requirements of the MF-DPI-treated groups was accompanied by significant (p < 0.05) improvement over placebo in the physical domain of HRQL (SF-36 physical component summary score and the physical function subscale) at EODBP. MF-DPI-treated patients also showed significant improvements at EODBP in each of the four subscales of the AQLQ-M (p<0.05). From EODBP to the OLE 3-month endpoint, patients treated with MF DPI twice daily maintained, or improved, SF-36 scores in most domains. Symptomatic improvement and reduction in OCS use with MF DPI were accompanied by significant improvement in HRQL in patients with severe persistent asthma. These improvements were maintained during the 3-month period of the OLE in which HRQL was evaluated. 相似文献