全文获取类型
收费全文 | 5438篇 |
免费 | 420篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 107篇 |
儿科学 | 172篇 |
妇产科学 | 102篇 |
基础医学 | 715篇 |
口腔科学 | 211篇 |
临床医学 | 520篇 |
内科学 | 1252篇 |
皮肤病学 | 100篇 |
神经病学 | 536篇 |
特种医学 | 182篇 |
外科学 | 737篇 |
综合类 | 65篇 |
一般理论 | 2篇 |
预防医学 | 343篇 |
眼科学 | 49篇 |
药学 | 250篇 |
中国医学 | 8篇 |
肿瘤学 | 534篇 |
出版年
2023年 | 44篇 |
2022年 | 69篇 |
2021年 | 173篇 |
2020年 | 108篇 |
2019年 | 144篇 |
2018年 | 176篇 |
2017年 | 110篇 |
2016年 | 160篇 |
2015年 | 142篇 |
2014年 | 200篇 |
2013年 | 229篇 |
2012年 | 372篇 |
2011年 | 364篇 |
2010年 | 201篇 |
2009年 | 198篇 |
2008年 | 309篇 |
2007年 | 289篇 |
2006年 | 283篇 |
2005年 | 256篇 |
2004年 | 255篇 |
2003年 | 235篇 |
2002年 | 216篇 |
2001年 | 78篇 |
2000年 | 90篇 |
1999年 | 80篇 |
1998年 | 39篇 |
1997年 | 38篇 |
1996年 | 44篇 |
1995年 | 38篇 |
1994年 | 38篇 |
1993年 | 32篇 |
1992年 | 51篇 |
1991年 | 53篇 |
1990年 | 59篇 |
1989年 | 48篇 |
1988年 | 50篇 |
1987年 | 51篇 |
1986年 | 48篇 |
1985年 | 39篇 |
1984年 | 35篇 |
1983年 | 30篇 |
1982年 | 33篇 |
1981年 | 36篇 |
1980年 | 26篇 |
1979年 | 34篇 |
1978年 | 24篇 |
1977年 | 23篇 |
1975年 | 28篇 |
1974年 | 23篇 |
1972年 | 28篇 |
排序方式: 共有5885条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Raphael Mohr Robert Schierwagen Carolynne Schwarze-Zander Christoph Boesecke Jan-Christian Wasmuth Jonel Trebicka Jürgen Kurt Rockstroh 《Medicine》2015,94(50)
Liver-related death in human immunodeficiency virus (HIV)-infected individuals is about 10 times higher compared with the general population, and the prevalence of significant liver fibrosis in those with HIV approaches 15%. The present study aimed to assess risk factors for development of hepatic fibrosis in HIV patients receiving a modern combination anti-retroviral therapy (cART).This cross-sectional prospective study included 432 HIV patients, of which 68 (16%) patients were anti-hepatitis C virus (HCV) positive and 23 (5%) were HBsAg positive.Health trajectory including clinical characteristics and liver fibrosis stage assessed by transient elastography were collected at inclusion. Liver stiffness values >7.1 kPa were considered as significant fibrosis, while values >12.5 kPa were defined as severe fibrosis. Logistic regression and Cox regression uni- and multivariate analyses were performed to identify independent factors associated with liver fibrosis.Significant liver fibrosis was detected in 10% of HIV mono-infected, in 37% of HCV co-infected patients, and in 18% of hepatitis B virus co-infected patients. The presence of diabetes mellitus (odds ratio [OR] = 4.6) and FIB4 score (OR = 2.4) were independently associated with presence of significant fibrosis in the whole cohort. Similarly, diabetes mellitus (OR = 5.4), adiposity (OR = 4.6), and the FIB4 score (OR = 3.3) were independently associated with significant fibrosis in HIV mono-infected patients. Importantly, cumulative cART duration protected, whereas persistent HIV viral replication promoted the development of significant liver fibrosis along the duration of HIV infection.Our findings strongly indicate that besides known risk factors like metabolic disorders, HIV may also have a direct effect on fibrogenesis. Successful cART leading to complete suppression of HIV replication might protect from development of liver fibrosis. 相似文献
5.
F Lofaso F Nicot M Lejaille L Falaize A Louis A Clement J-C Raphael D Orlikowski B Fauroux 《The European respiratory journal》2006,27(5):980-982
Sniff nasal inspiratory pressure (SNIP) measurement is a volitional noninvasive assessment of inspiratory muscle strength. A maximum of 10 sniffs is generally used. The purpose of the present study was to investigate whether the maximum SNIP improved after the tenth sniff. In total, 20 healthy volunteers and 305 patients with various neuromuscular and lung diseases were encouraged to perform 40 and 20 sniffs, respectively. The best SNIP among the first 10 sniffs was lower than the best SNIP among the next 10 sniffs in the healthy volunteers and patients. The SNIP improvement after the twentieth sniff was marginal. In conclusion, a learning effect persists after the tenth sniff. The current authors suggest using 10 additional sniffs when the best result of the first 10 sniffs is slightly below normal, or when sniff nasal inspiratory pressure is used to monitor a progressive decline in inspiratory muscle strength. 相似文献
6.
Neil H Pliskin Alia N Ammar Joseph W Fink S Kristian Hill Aaron C Malina Alona Ramati Kathleen M Kelley Raphael C Lee 《Journal of the International Neuropsychological Society》2006,12(1):17-23
The clinical presentation of electrical injury commonly involves physical, cognitive, and emotional complaints. Neuropsychological studies, including case reports, have indicated that electrical injury (EI) survivors may experience a broad range of impaired neuropsychological functions, although this has not been clarified through controlled investigation. In this study, we describe the neuropsychological test findings in a series of 29 EI patients carefully screened and matched to a group of 29 demographically similar healthy electricians. Participants were matched by their estimated premorbid intellectual ability. Multivariate analysis of variance was used to assess group differences in the following neuropsychological domains: attention and mental speed, working memory, verbal memory, visual memory, and motor skills. EI patients performed significantly worse on composite measures of attention/mental speed and motor skills, which could not be explained by demographic differences, injury parameters, litigation status, or mood disturbance. Results suggest that cognitive changes do occur in patients suffering from electrical injury. 相似文献
7.
8.
9.
In a study of aerobically perfused rat hearts, the in situ photoactivation (530-590 nm) of rose bengal (a process that leads to the production of singlet oxygen and superoxide) has been shown to lead to the rapid development of electrocardiographic abnormalities and arrhythmias. With rose bengal concentrations of 1,000, 500, 250, 100, and 50 nmol/l (n = 6/group), photoactivation (3,600 lx) led to electrocardiographic changes (inversion of the T wave, Q-T prolongation, or both) after 3.8 +/- 0.9, 4.5 +/- 0.7, 11.8 +/- 2.1, 24.8 +/- 3.9, and 65.3 +/- 6.0 seconds), respectively; ventricular premature beats occurred in 100% of hearts after 0.5 +/- 0.2, 1.1 +/- 0.3, 2.2 +/- 0.7, 4.4 +/- 0.8, and 6.6 +/- 1.2 minutes, respectively. Ventricular tachycardia occurred in 83%, 83%, 83%, 67%, and 50% of hearts after 2.1 +/- 0.2, 2.1 +/- 0.4, 2.8 +/- 0.7, 5.7 +/- 2.0, and 11.2 +/- 1.9 minutes, respectively, and complete atrioventricular block in 100%, 100%, 100%, 100%, and 67% of hearts after 3.8 +/- 0.7, 6.5 +/- 1.0, 5.5 +/- 0.9, 13.8 +/- 1.0, and 14.1 +/- 0.9 minutes, respectively. With a fixed concentration (250 nmol/l) of rose bengal, similar light-response relations were observed. Photoactivation of rose bengal had no effect on heart rate but caused a transient (0-4 minutes) vasodilation followed by a progressive vasoconstriction. In further studies in which rose bengal was washed out for 10 minutes before photoactivation, several arrhythmias still developed, indicating that rose bengal binds strongly to tissue and acts as a cellular level rather than in the vascular compartment. To assess the reversibility of rose bengal-induced effects, hearts (n = 6/group) were perfused with rose bengal (250 nmol/l) for 1, 2, 4, 6, and 20 minutes followed by perfusion in the dark for 19, 18, 16, 14, and 0 minutes, respectively. During dark perfusion, the incidence of arrhythmias declined and any decrease in coronary flow was reversed. However, analysis of contents of adenosine triphosphate, creatine phosphate, lactate, and creatine kinase leakage indicated the occurrence of severe injury that did not abate on termination of photoactivation. Finally, although many arrhythmias developed before the onset of vasoconstriction, the reduction in flow with consequent ischemia was shown to exacerbate vulnerability to arrhythmias. In conclusion, short-lived reactive oxygen intermediates such as singlet oxygen and superoxide, which are produced during the photoactivation of rose bengal, can cause rapid and major damage to the heart and its function. 相似文献
10.
1. The oxygen consumption of blood of normal individuals, when the hemoglobin is saturated with oxygen, is practically zero within the limits of experimental error of the microspirometer used. 2. The oxygen consumed in a microspirometer by the blood of patients with chronic myelogenous leucemia with a high white blood cell count, and of one with leucocytosis from sepsis, was proportional to the number of adult polymorphonuclear neutrophils in the blood. 3. No correlation could be made between the rate of oxygen absorption and the total number of white blood cells in the blood, or the total number of immature cells, or the number of red blood cells, or the amount of oxyhemoglobin. 4. The blood of patients with chronic myelogenous leucemia continued to use oxygen in the microspirometer longer than that of normal individuals, and the hemoglobin, in the leucemic bloods, became desaturated even though exposed to air. 5. In blood in which the bulk. of the cells were immature and the mature cells few, the oxygen consumption was lower than in blood in which the mature cells predominated. The rate of oxygen consumption of the immature cells was relatively low as compared to the mature. 6. The slower rate of oxygen absorption by the immature leucocytes in chronic myelogenous leucemia as compared to the mature cells, places them, in accord with Warburg''s reports, in the class of the malignant tissues in this respect rather than in the group of young or embryonic cells. 相似文献