全文获取类型
收费全文 | 330823篇 |
免费 | 15580篇 |
国内免费 | 10258篇 |
专业分类
耳鼻咽喉 | 2699篇 |
儿科学 | 8725篇 |
妇产科学 | 4259篇 |
基础医学 | 31351篇 |
口腔科学 | 4199篇 |
临床医学 | 30442篇 |
内科学 | 52667篇 |
皮肤病学 | 2382篇 |
神经病学 | 23765篇 |
特种医学 | 15149篇 |
外国民族医学 | 41篇 |
外科学 | 45771篇 |
综合类 | 33703篇 |
现状与发展 | 38篇 |
一般理论 | 14篇 |
预防医学 | 30975篇 |
眼科学 | 5928篇 |
药学 | 25526篇 |
171篇 | |
中国医学 | 11143篇 |
肿瘤学 | 27713篇 |
出版年
2024年 | 886篇 |
2023年 | 2124篇 |
2022年 | 5401篇 |
2021年 | 7246篇 |
2020年 | 5662篇 |
2019年 | 4598篇 |
2018年 | 26250篇 |
2017年 | 21868篇 |
2016年 | 23748篇 |
2015年 | 7802篇 |
2014年 | 9669篇 |
2013年 | 9739篇 |
2012年 | 19876篇 |
2011年 | 34931篇 |
2010年 | 29413篇 |
2009年 | 20591篇 |
2008年 | 29894篇 |
2007年 | 31878篇 |
2006年 | 9883篇 |
2005年 | 10482篇 |
2004年 | 9558篇 |
2003年 | 10111篇 |
2002年 | 7416篇 |
2001年 | 3600篇 |
2000年 | 3044篇 |
1999年 | 2081篇 |
1998年 | 1383篇 |
1997年 | 1479篇 |
1996年 | 928篇 |
1995年 | 873篇 |
1994年 | 747篇 |
1993年 | 479篇 |
1992年 | 419篇 |
1991年 | 398篇 |
1990年 | 361篇 |
1989年 | 287篇 |
1988年 | 231篇 |
1987年 | 189篇 |
1986年 | 144篇 |
1985年 | 116篇 |
1984年 | 80篇 |
1983年 | 53篇 |
1982年 | 57篇 |
1981年 | 29篇 |
1980年 | 65篇 |
1974年 | 31篇 |
1938年 | 62篇 |
1934年 | 30篇 |
1932年 | 57篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
1.
2.
Tian-Yuan Xiong Fang-Yang Huang Qi Liu Yong Peng Yuan-Ning Xu Jia-Fu Wei 《Annals of medicine》2020,52(7):361-366
Abstract
Background
Comorbidities are commonly seen in patients with coronavirus disease 2019 (COVID-19), but the clinical implication is not yet well-delineated. We aim to characterize the prevalence and clinical implications of comorbidities in patients with COVID-19. 相似文献3.
Kazunori Aizawa Takeshi Hanaoka Hiroki Kasai Kaoru Kogashi Setsuo Kumazaki Jun Koyama Hiroshi Tsutsui Yoshikazu Yazaki Noboru Watanabe Osamu Kinoshita Uichi Ikeda 《Hypertension research》2006,29(2):123-128
The phosphodiesterase-5 (PDE-5) inhibitor, sildenafil, has been reported to produce sustained pulmonary vasodilatation in patients with pulmonary hypertension (PH). Recently, vardenafil, a more potent and selective PDE-5 inhibitor than sildenafil, has been approved for the treatment of erectile dysfunction. However, the long-term effects of oral vardenafil in patients with PH are unknown. We studied five consecutive patients with PH; one with primary pulmonary hypertension, two with chronic pulmonary thromboembolism, one with Eisenmenger syndrome (ventricular septal defect) and one with secondary pulmonary hypertension after a ventricular septal defect closure operation. In an acute hemodynamic trial, vardenafil (5 mg) significantly decreased both the pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) with an increase in cardiac output. In a chronic hemodynamic trial, the maintenance dose of vardenafil (10 to 15 mg) for 3 months significantly decreased the PVR, but not the SVR, with a 20.7% reduction of the PVR/ SVR ratio. Plasma brain natriuretic peptide (BNP) levels were also significantly decreased after 3 months. This pilot study demonstrates that long-term oral vardenafil therapy may be a safe and effective treatment for patients with PH. 相似文献
4.
Jun Agata Nobuyuki Ura Hideaki Yoshida Yasuyuki Shinshi Haruki Sasaki Masaya Hyakkoku Shinya Taniguchi Kazuaki Shimamoto 《Hypertension research》2006,29(11):865-874
Angiotensin II receptor blockers (ARBs) are widely used for the treatment of hypertension. It is believed that treatment with an ARB increases the level of plasma angiotensin II (Ang II) because of a lack of negative feedback on renin activity. However, Ichikawa (Hypertens Res 2001; 24: 641-646) reported that long-term treatment of hypertensive patients with olmesartan resulted in a reduction in plasma Ang II level, though the mechanism was not determined. It has been reported that angiotensin 1-7 (Ang-(1-7)) potentiates the effect of bradykinin and acts as an angiotensin-converting enzyme (ACE) inhibitor. It is known that ACE2, which was discovered as a novel ACE-related carboxypeptidase in 2000, hydrolyzes Ang I to Ang-(1-9) and also Ang II to Ang-(1-7). It has recently been reported that olmesartan increases plasma Ang-(1-7) through an increase in ACE2 expression in rats with myocardial infarction. We hypothesized that over-expression of ACE2 may be related to a reduction in Ang II level and the cardioprotective effect of olmesartan. Administration of 0.5 mg/kg/day of olmesartan for 4 weeks to 12-week-old stroke-prone spontaneously hypertensive rats (SHRSP) significantly reduced blood pressure and left ventricular weight compared to those in SHRSP given a vehicle. Co-administration of olmesartan and (D-Ala7)-Ang-(1-7), a selective Ang-(1-7) antagonist, partially inhibited the effect of olmesartan on blood pressure and left ventricular weight. Interestingly, co-administration of (D-Ala7)-Ang-(1-7) with olmesartan significantly increased the plasma Ang II level (453.2+/-113.8 pg/ml) compared to olmesartan alone (144.9+/-27.0 pg/ml, p<0.05). Moreover, olmesartan significantly increased the cardiac ACE2 expression level compared to that in Wistar Kyoto rats and SHRSP treated with a vehicle. Olmesartan significantly improved cardiovascular remodeling and cardiac nitrite/ nitrate content, but co-administration of olmesartan and (D-Ala7)-Ang-(1-7) partially reversed this anti-remodeling effect and the increase in nitrite/nitrate. These findings suggest that olmesartan may exhibit an ACE inhibitory action in addition to an Ang II receptor blocking action, prevent an increase in Ang II level, and protect cardiovascular remodeling through an increase in cardiac nitric oxide production and endogenous Ang-(1-7) via over-expression of ACE2. 相似文献
5.
6.
7.
8.
9.
10.
Debra L. Roter Richard M. Frankel Judith A. Hall David Sluyter 《Journal of general internal medicine》2006,21(1):28-34
Relationship-centered care reflects both knowing and feeling: the knowledge that physician and patient bring from their respective domains of expertise, and the physician’s and patient’s experience, expression, and perception of emotions during the medical encounter. These processes are conveyed and reciprocated in the care process through verbal and nonverbal communication. We suggest that the emotional context of care is especially related to nonverbal communication and that emotion-related communication skills, including sending and receiving nonverbal messages and emotional self-awareness, are critical elements of high-quality care. Although nonverbal behavior has received far less study than other care processes, the current review argues that it holds significance for the therapeutic relationship and influences important outcomes including satisfaction, adherence, and clinical outcomes of care. 相似文献