全文获取类型
收费全文 | 78634篇 |
免费 | 4414篇 |
国内免费 | 182篇 |
专业分类
耳鼻咽喉 | 1015篇 |
儿科学 | 1811篇 |
妇产科学 | 1531篇 |
基础医学 | 10584篇 |
口腔科学 | 2971篇 |
临床医学 | 5979篇 |
内科学 | 19281篇 |
皮肤病学 | 1846篇 |
神经病学 | 7028篇 |
特种医学 | 1836篇 |
外国民族医学 | 2篇 |
外科学 | 10637篇 |
综合类 | 323篇 |
一般理论 | 28篇 |
预防医学 | 6959篇 |
眼科学 | 1520篇 |
药学 | 5219篇 |
中国医学 | 292篇 |
肿瘤学 | 4368篇 |
出版年
2023年 | 514篇 |
2022年 | 266篇 |
2021年 | 1254篇 |
2020年 | 768篇 |
2019年 | 1320篇 |
2018年 | 2466篇 |
2017年 | 1485篇 |
2016年 | 1569篇 |
2015年 | 2253篇 |
2014年 | 2313篇 |
2013年 | 3391篇 |
2012年 | 6765篇 |
2011年 | 6821篇 |
2010年 | 3046篇 |
2009年 | 2231篇 |
2008年 | 5841篇 |
2007年 | 5972篇 |
2006年 | 6092篇 |
2005年 | 5812篇 |
2004年 | 5286篇 |
2003年 | 4769篇 |
2002年 | 4561篇 |
2001年 | 1690篇 |
2000年 | 2202篇 |
1999年 | 1116篇 |
1998年 | 253篇 |
1997年 | 179篇 |
1996年 | 177篇 |
1995年 | 162篇 |
1994年 | 123篇 |
1993年 | 124篇 |
1992年 | 203篇 |
1991年 | 186篇 |
1990年 | 147篇 |
1989年 | 132篇 |
1988年 | 95篇 |
1987年 | 96篇 |
1986年 | 111篇 |
1985年 | 112篇 |
1984年 | 131篇 |
1983年 | 93篇 |
1982年 | 101篇 |
1981年 | 80篇 |
1980年 | 88篇 |
1979年 | 65篇 |
1978年 | 61篇 |
1977年 | 48篇 |
1976年 | 60篇 |
1974年 | 49篇 |
1973年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 32 毫秒
991.
992.
José A Larrauri Lisalynn D Kelley Mason R Jenkins Eric C Westman Nestor A Schmajuk M Zachary Rosenthal Edward D Levin 《Neuropsychopharmacology》2014,39(3):651-659
Histamine H1 receptor systems have been shown in animal studies to have important roles in the reversal of sensorimotor gating deficits, as measured by prepulse inhibition (PPI). H1-antagonist treatment attenuates the PPI impairments caused by either blockade of NMDA glutamate receptors or facilitation of dopamine transmission. The current experiment brought the investigation of H1 effects on sensorimotor gating to human studies. The effects of the histamine H1 antagonist meclizine on the startle response and PPI were investigated in healthy male subjects with high baseline startle responses and low PPI levels. Meclizine was administered to participants (n=24) using a within-subjects design with each participant receiving 0, 12.5, and 25 mg of meclizine in a counterbalanced order. Startle response, PPI, heart rate response, galvanic skin response, and changes in self-report ratings of alertness levels and affective states (arousal and valence) were assessed. When compared with the control (placebo) condition, the two doses of meclizine analyzed (12.5 and 25 mg) produced significant increases in PPI without affecting the magnitude of the startle response or other physiological variables. Meclizine also caused a significant increase in overall self-reported arousal levels, which was not correlated with the observed increase in PPI. These results are in agreement with previous reports in the animal literature and suggest that H1 antagonists may have beneficial effects in the treatment of subjects with compromised sensorimotor gating and enhanced motor responses to sensory stimuli. 相似文献
993.
José Robson Neves Cavalcanti Filho Tiago Fonseca Silva Woah Queiroz Nobre Larissa Isabela Oliveira de Souza Cristiane Santos Silva e Silva Figueiredo Regina Celia Bressan Queiroz de Figueiredo 《Pharmaceutical biology》2017,55(1):1521-1527
Context: Buchenavia tetraphylla (Aubl.) RA Howard (Combretaceae: Combretoideae) is an ethnomedicinal plant with reported antifungal action.Objective: This study evaluates the antimicrobial activity of B. tetraphylla leaf extracts against clinical isolates of Candida albicans. The morphological alterations, combinatory effects with fluconazole and the cytotoxicity of the active extract were analyzed.Materials and methods: Extracts were obtained using different solvents (hexane: BTHE; chloroform: BTCE; ethyl acetate: BTEE; and methanol: BTME). Antimicrobial activity was determined by the broth microdilution method using nine strains of C. albicans isolated from vaginal secretions and one standard strain (UFPEDA 1007).Results: All extracts showed anti-C. albicans activity, including against the azole-resistant strains. The MIC values ranged from 156 to 2500?μg/mL for the BTHE; 156 to 1250?μg/mL for the BTCE; 625 to 1250?μg/mL for the BTME and 625?μg/mL to 2500?μg/mL for the BTEE. BTME showed the best anti-C. albicans activity. This extract demonstrated additive/synergistic interactions with fluconazole. Scanning electron microscopy analysis suggested that the BTME interferes with the cell division and development of C. albicans. BTME showed IC50 values of 981 and 3935?μg/mL, against J774 macrophages and human erythrocytes, respectively. This extract also enhanced the production of nitric oxide by J774 macrophages.Discussion and conclusion: Buchenavia tetraphylla methanolic extract (BTME) is a great source of antimicrobial compounds that are able to enhance the action of fluconazole against different C. albicans strains; this action seems related to inhibition of cell division. 相似文献
994.
995.
Zsuzsanna Némethné Gyurcsik Anita András Nóra Bodnár Zoltán Szekanecz Sándor Szántó 《Rheumatology international》2012,32(12):3931-3936
Physical therapy in ankylosing spondylitis (AS) is important for maintaining or improving mobility, fitness, functioning, and global health. It also plays a role in the prevention and management of structural deformities. In this study we assessed the functional status of AS patients in relation to disease duration and activity. Furthermore, in volunteering patients we analyzed the efficacy of a controlled, individualized physiotherapeutic program. Altogether, clinical data of 75 AS patients were retrospectively analyzed. Anthropometrical data, duration since diagnosis and disease activity, pain intensity, tender points, sacroiliac joint involvement determined by X-ray, functional condition, and physical activity level were recorded. Subjective, functional, and physical tests were performed. Out of the 75 patients, 10 volunteered to undergo a complex physical exercise program twice a week for 3?months. The program included 1.5?h of general posture reeducation, manual mobilization of the spine, and pelvic-, upper-, and lower-extremity exercises, stretching with joint prevention strategies and functional exercises. In AS, pain intensity recorded on a 10-cm visual analog scale (VAS), BASFI, BASDAI, modified Schober index, chest expansion and occiput-to-wall distance values showed significant correlation with disease activity. The 3-month physical therapy improved several subjective and functional parameters, and markedly reduced pain intensity and spine stiffness. A complex, individualized physical therapy program may be useful and should be introduced to AS patients in order to maintain and increase spine mobility, preserve functional capacity, decrease the pain and stiffness. 相似文献
996.
Indoor fungal diversity in primary schools may differently influence allergic sensitization and asthma in children
下载免费PDF全文
![点击此处可从《Pediatric allergy and immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
997.
998.
999.
A haplotype block downstream of plasminogen is associated with chronic and aggressive periodontitis
下载免费PDF全文
![点击此处可从《Journal of clinical periodontology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yvonne Jockel‐Schneider Knut Adam Per Hoffman Klaus Berger Thomas Kocher Jörg Meyle Peter Eickholz Christof Doerfer Matthias Laudes André Uitterlinden Wolfgang Lieb Andre Franke Stefan Schreiber Steven Offenbacher Kimon Divaris Corinna Bruckmann Bruno G. Loos Søeren Jepsen Henrik Dommisch Arne S. Schäefer 《Journal of clinical periodontology》2017,44(10):962-970
1000.
Melatonin enhances neural stem cell differentiation and engraftment by increasing mitochondrial function
下载免费PDF全文
![点击此处可从《Journal of pineal research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Miguel Mendivil‐Perez Viviana Soto‐Mercado Ana Guerra‐Librero Beatriz I. Fernandez‐Gil Javier Florido Ying‐Qiang Shen Miguel A. Tejada Vivian Capilla‐Gonzalez Iryna Rusanova José M. Garcia‐Verdugo Darío Acuña‐Castroviejo Luis Carlos López Carlos Velez‐Pardo Marlene Jimenez‐Del‐Rio José M. Ferrer Germaine Escames 《Journal of pineal research》2017,63(2)
Neural stem cells (NSCs) are regarded as a promising therapeutic approach to protecting and restoring damaged neurons in neurodegenerative diseases (NDs) such as Parkinson's disease and Alzheimer's disease (PD and AD, respectively). However, new research suggests that NSC differentiation is required to make this strategy effective. Several studies have demonstrated that melatonin increases mature neuronal markers, which reflects NSC differentiation into neurons. Nevertheless, the possible involvement of mitochondria in the effects of melatonin during NSC differentiation has not yet been fully established. We therefore tested the impact of melatonin on NSC proliferation and differentiation in an attempt to determine whether these actions depend on modulating mitochondrial activity. We measured proliferation and differentiation markers, mitochondrial structural and functional parameters as well as oxidative stress indicators and also evaluated cell transplant engraftment. This enabled us to show that melatonin (25 μM) induces NSC differentiation into oligodendrocytes and neurons. These effects depend on increased mitochondrial mass/DNA/complexes, mitochondrial respiration, and membrane potential as well as ATP synthesis in NSCs. It is also interesting to note that melatonin prevented oxidative stress caused by high levels of mitochondrial activity. Finally, we found that melatonin enriches NSC engraftment in the ND mouse model following transplantation. We concluded that a combined therapy involving transplantation of NSCs pretreated with pharmacological doses of melatonin could efficiently restore neuronal cell populations in PD and AD mouse models depending on mitochondrial activity promotion. 相似文献