全文获取类型
收费全文 | 9132篇 |
免费 | 488篇 |
国内免费 | 73篇 |
专业分类
耳鼻咽喉 | 111篇 |
儿科学 | 197篇 |
妇产科学 | 57篇 |
基础医学 | 1059篇 |
口腔科学 | 264篇 |
临床医学 | 624篇 |
内科学 | 2332篇 |
皮肤病学 | 192篇 |
神经病学 | 629篇 |
特种医学 | 333篇 |
外科学 | 1441篇 |
综合类 | 39篇 |
预防医学 | 268篇 |
眼科学 | 281篇 |
药学 | 781篇 |
中国医学 | 17篇 |
肿瘤学 | 1068篇 |
出版年
2023年 | 62篇 |
2022年 | 134篇 |
2021年 | 227篇 |
2020年 | 145篇 |
2019年 | 170篇 |
2018年 | 237篇 |
2017年 | 169篇 |
2016年 | 226篇 |
2015年 | 233篇 |
2014年 | 280篇 |
2013年 | 344篇 |
2012年 | 570篇 |
2011年 | 610篇 |
2010年 | 368篇 |
2009年 | 302篇 |
2008年 | 571篇 |
2007年 | 572篇 |
2006年 | 583篇 |
2005年 | 532篇 |
2004年 | 489篇 |
2003年 | 451篇 |
2002年 | 460篇 |
2001年 | 155篇 |
2000年 | 143篇 |
1999年 | 154篇 |
1998年 | 97篇 |
1997年 | 88篇 |
1996年 | 90篇 |
1995年 | 74篇 |
1994年 | 58篇 |
1993年 | 60篇 |
1992年 | 95篇 |
1991年 | 70篇 |
1990年 | 66篇 |
1989年 | 82篇 |
1988年 | 61篇 |
1987年 | 62篇 |
1986年 | 64篇 |
1985年 | 68篇 |
1984年 | 55篇 |
1983年 | 42篇 |
1982年 | 31篇 |
1981年 | 36篇 |
1980年 | 30篇 |
1979年 | 37篇 |
1978年 | 29篇 |
1977年 | 31篇 |
1975年 | 20篇 |
1969年 | 19篇 |
1968年 | 20篇 |
排序方式: 共有9693条查询结果,搜索用时 15 毫秒
1.
Vasundhara Sridharan Yuichi Shoda Jaimee L. Heffner Jonathan Bricker 《Substance use & misuse》2019,54(7):1086-1095
Background: Lay belief systems about the malleability of human attributes have been shown to impact behavior change in multiple domains. Addiction mindset—i.e., beliefs about the permanence (vs. malleability) of addiction — may affect cigarette smokers’ ability to quit, but this has never been examined. Objectives: The aims of the present research were to develop a measure of addiction mindset (study 1) and examine its associations with various psychological aspects of quitting smoking (study 2). Methods: In Study 1, using factor analysis of current smokers’ and nonsmokers’ (n?=?600) responses to 22 items designed to measure addiction mindset, we developed a reliable six-item Addiction Mindset Scale (AMS). In Study 2, adult smokers (n?=?200) completed the AMS, and measures of a number of psychological processes related to smoking. Results: Higher scores on the AMS, indicative of the belief that addiction is malleable (referred to as a growth mindset), were positively and significantly associated with greater motivation to quit, greater commitment to quitting, greater self-efficacy to abstain, less attribution of failure to lack of ability to change addiction, and fewer self-reported barriers to cessation (all p’s < .05). Conclusions: The results of this study show a relationship between the beliefs about the permanence of addiction and psychological processes relevant to quitting smoking. The findings underscore the potential of future research exploring how addiction mindsets relate to successful smoking cessation as well as other types of addictive behavior and how they can be applied to change people’s behavior. 相似文献
2.
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.
We examined stochastic resonance with a differential coding scheme using a multilayer feedforward neural network which is composed of intra-layer connections. We show that the network, with random synaptic connections in each layer, encodes an input signal into a spike coherence that represents temporal differences among the inputs. We also demonstrate that both internal and external noise enhance the detection of weak signals. Finally, we discuss how the feedforward network with intra-layer random connections is similar to a membrane in its sensitivity to and amplification of a change in stimulus and suggest that the intensity of internal noise may be tuned in a real brain. 相似文献
5.
Nobuaki Yanagisawa Shinichi Abe Hiroko Agematsu Koji Sakiyama Akinobu Usami Yuichi Tamatsu Yoshinobu Ide 《Annals of anatomy》2006,188(4):329-336
To elucidate the effects of teeth on muscle fibers in the tongue during the developmental process, we examined the expression of muscle contractile proteins and the genes for those proteins in normal mice and microphthalmic (mi/mi) mice with impaired tooth eruption. The mice were observed during the growth period, including weaning, which is when feeding movements undergo major changes. Expression of the myosin heavy chain (MyHC)-2a protein, whose contraction speed is relatively slow, disappeared after weaning in normal mice, while it remained in high concentrations even after weaning in mi/mi mice. The presence of MyHC-2a after weaning in mice with no tooth eruption was attributed to a compensation for lack of proper masticatory function and sucking-like movements, as MyHC-2a is necessary for these movements. 相似文献
6.
7.
8.
Yuhei Okubo Junji Yonese Satoru Kawakami Sinya Yamamoto Yoshinobu Komai Hideki Takeshita Yuichi Ishikawa Iwao Fukui 《International journal of urology》2007,14(9):854-855
Renal cell carcinoma (RCC) causes many kinds of symptoms such as hypercalcemia, hypertension, polycythemia and fever. Here we describe a rare case of RCC presenting with a persistent cough. After radical nephrectomy, the obstinate cough disappeared. When the tumor recurred locally, the cough also recurred. Furthermore, the cough disappeared completely again after the removal of the recurrent tumor. Although all the clinical findings suggested that the RCC caused the cough, we could not identify a specific humoral substance responsible for the cough. 相似文献
9.
10.