全文获取类型
收费全文 | 64903篇 |
免费 | 4398篇 |
国内免费 | 313篇 |
专业分类
耳鼻咽喉 | 590篇 |
儿科学 | 2380篇 |
妇产科学 | 1651篇 |
基础医学 | 9751篇 |
口腔科学 | 1007篇 |
临床医学 | 6443篇 |
内科学 | 14482篇 |
皮肤病学 | 1398篇 |
神经病学 | 6989篇 |
特种医学 | 1399篇 |
外科学 | 5474篇 |
综合类 | 373篇 |
现状与发展 | 1篇 |
一般理论 | 51篇 |
预防医学 | 6006篇 |
眼科学 | 1083篇 |
药学 | 4863篇 |
中国医学 | 178篇 |
肿瘤学 | 5495篇 |
出版年
2024年 | 95篇 |
2023年 | 760篇 |
2022年 | 1623篇 |
2021年 | 2747篇 |
2020年 | 1595篇 |
2019年 | 2083篇 |
2018年 | 2315篇 |
2017年 | 1811篇 |
2016年 | 2012篇 |
2015年 | 2243篇 |
2014年 | 2908篇 |
2013年 | 3741篇 |
2012年 | 5461篇 |
2011年 | 5513篇 |
2010年 | 2926篇 |
2009年 | 2512篇 |
2008年 | 4185篇 |
2007年 | 4225篇 |
2006年 | 3845篇 |
2005年 | 3531篇 |
2004年 | 3252篇 |
2003年 | 2946篇 |
2002年 | 2668篇 |
2001年 | 305篇 |
2000年 | 234篇 |
1999年 | 334篇 |
1998年 | 448篇 |
1997年 | 382篇 |
1996年 | 259篇 |
1995年 | 251篇 |
1994年 | 241篇 |
1993年 | 186篇 |
1992年 | 138篇 |
1991年 | 119篇 |
1990年 | 87篇 |
1989年 | 101篇 |
1988年 | 104篇 |
1987年 | 84篇 |
1986年 | 87篇 |
1985年 | 83篇 |
1984年 | 115篇 |
1983年 | 104篇 |
1982年 | 117篇 |
1981年 | 106篇 |
1980年 | 94篇 |
1979年 | 52篇 |
1978年 | 53篇 |
1977年 | 46篇 |
1976年 | 36篇 |
1975年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Alexander S. Goldfarb‐Rumyantzev Gurprataap S. Sandhu Anna Barenbaum Bradley C. Baird Bhanu K. Patibandla Akshita Narra James K. Koford Lev Barenbaum 《Clinical transplantation》2012,26(6):891-899
In this study, we hypothesized that higher level of education might be associated with reduced racial disparities in renal transplantation outcomes. We used data from the United States Renal Data System (September 1, 1990–September 1, 2007) (n = 79 223) and analyzed two outcomes, graft loss and recipient mortality, using Cox models. Compared with whites, African Americans had increased risk of graft failure (HR, 1.48; p < 0.001) and recipient mortality (HR, 1.06; p = 0.004). Compared with recipients who graduated from college, all other education groups had inferior graft survival. Specifically, compared with college‐graduated individuals, African Americans who never finished high school had the highest risk of graft failure (HR, 1.45; p < 0.001), followed by high school graduates (HR, 1.27; p < 0.001) and those with some college education (HR, 1.18; p < 0.001). A similar trend was observed in whites. In African Americans (compared with whites), the highest risk of graft failure was associated with individuals who did not complete high school (HR, 1.96; p < 0.001) followed by high school graduates (HR, 1.47; p < 0.001), individuals with some college education (HR, 1.45; p < 0.001), and college graduates (HR, 1.39; p < 0.001). A similar trend was observed with recipient mortality. In sum, higher education was associated with reduced racial disparities in graft and recipient survival. 相似文献
992.
Emerging evidence is fueling a new appreciation of oligodendrocyte diversity that is overturning the tradi-tional view that oligodendrocytes are a homogenous cell population. Oligodendrocytes of distinct origins, maturational stages, and regional locations may differ in their functional capacity or susceptibility to injury. One of the most unique qualities of the oligodendrocyte is its ability to produce myelin. Myelin abnormali-ties have been ascribed to a remarkable array of perinatal brain injuries, with concomitant oligodendrocyte dysregulation. Within this review, we discuss new insights into the diversity of the oligodendrocyte lineage and highlight their relevance in paradigms of perinatal brain injury. Future therapeutic development will be informed by comprehensive knowledge of oligodendrocyte pathophysiology that considers the particular facets of heterogeneity that this lineage exhibits. 相似文献
993.
Kara J. Walters PharmD Anna Meador PharmD BCACP John A. Galdo PharmD BCPS CGP Katharine Ciarrocca DMD MSEd 《Special care in dentistry》2017,37(2):62-70
Coagulation disorders account for a high incidence of death in the U.S. due to stroke, myocardial infarction, and venous thromboembolism. In the past few years, numerous agents have been brought to market for the treatment of thromboembolism or prevention of thromboembolism. Similar to warfarin, these agents can cause bleeding disorders, which may exacerbate dental care treatment plans. This literature review examines the newer agents for the treatment of thromboembolism disorders, common side effects and drug interactions, the specific medical conditions each agent treats, and the dental perspective on how to medically management patients prescribed these medications. 相似文献
994.
European Child & Adolescent Psychiatry - Weight-related teasing is a widespread phenomenon in childhood, and might foster the internalization of weight bias. The goal of this study was to... 相似文献
995.
Roberta Rea Francesco Maria Di Matteo Margareth Martino Monica Pandolfi Paola Saccomandi Carla Rabitti Anna Crescenzi Guido Costamagna 《Lasers in medical science》2017,32(6):1411-1415
Adequate biliary drainage with endoscopic or percutaneous placement of self-expandable metal stents represents the goal of palliation in patients with inoperable malignant obstruction of the biliary tree. As an adjunct to stenting, various tissue ablation treatments have been proposed with conflicting results. The aim of this study was to test the effect on biliary tissue of a new ablation technique based on Nd:YAG laser light delivery. The study was conducted on ex vivo specimens of 18 healthy farm pigs, using cystic ducts that are the simplest biliary structures to isolate and cannulate ex vivo. A 22G cannula was positioned into the cystic duct and a quartz optical fibre, with a prototypal cooling system, was inserted into the cannula. Nd:YAG laser output powers of 10, 12, and 15 W were tested, with a total delivered energy of 1000 J in continuous mode in each case. After laser treatment, histological analysis was performed. At macroscopical examination, no lesions of the external wall of the cystic ducts were detected. At histopathological examination, a coagulative necrosis involving the entire mucosa up to the muscolaris propria without significant changes of periductal tissues was observed in all specimens. This study shows the possibility of using Nd:YAG laser on ex vivo porcine biliary ducts with the effect of obtaining a coagulative necrosis involving the whole mucosa. 相似文献
996.
L. J. Lubaki G. Ghanem P. Vereecken E. Fouty L. Benammar J. Vadoud-Seyedi M. L. Dell’Anna S. Briganti M. Picardo M. Heenen 《Archives of dermatological research》2010,302(2):131-137
New topical immunomodulators have been reported to cause repigmentation of vitiligo lesions. However, time-kinetics of such repigmentation in different anatomic locations is not well known. We performed a randomized double-blind placebo control study with tacrolimus versus the vehicle and a nonrandomized control study with pimecrolimus to evaluate the time to reach significant pigmentation, its duration and extent in treated areas. Antioxidant status of serum was also assessed. Twenty patients, in the tacrolimus study, had one pair of lesions on different localizations, and 20 on face and/or upper limbs for pimecrolimus. The extent of repigmentation was evaluated by slides and mapmakings at baseline and every 4 weeks during 7 months. Adverse events were recorded. The derivatives of oxygen metabolites, the ferric reducing ability of serum and vitamin E were assessed. Three groups of patients were identified with the tacrolimus study. Eight had no significant change in response characterized by a parallel increase of repigmentation or none in treated and control areas. Nine had a better repigmentation to tacrolimus at fifth month of treatment. Three had a marked repigmentation in control areas at the end of treatment. Repigmentation was significant on the face compared to upper-limbs with pimecrolimus from fourth to seventh month. A significant reduction of oxidative stress and an increase in antioxidant capacity in serum of patients treated with topical tacrolimus was observed, while those treated with pimecrolimus did not show any significant changes but an increase in vitamin E. Our work defines three periods in repigmentation, triggering during the first 4 months, increase in pigmentation with tacrolimus and a plateau or a sustained repigmentation. The continuity of the treatment seems necessary to ensure a prolonged repigmenting effect and even an enhanced one, such as the one we observed on the face with pimecrolimus. The extent of repigmentation was more significant on the face compared to other locations probably due to differences in melanocyte density. Furthermore, we did not find any relationship between repigmentation and the duration of vitiligo. Tacrolimus was able to reduce the systemic oxidative stress independently from its repigmenting capacity. Both drugs were well tolerated. 相似文献
997.
To attend successfully, a specification of what is currently relevant is necessary, but not sufficient. Irrelevant stimuli that are also present in the environment must be recognized as such and filtered out at the same time. Using functional magnetic resonance imaging, we showed that posterior brain regions in parietal, occipital and temporal cortex are recruited in order to ignore distracting visual stimuli, while the specification and selection of relevant stimuli is associated with differential activity in frontal cortex and hippocampal areas instead. The results thus suggest that the selection of relevant objects can be anatomically dissociated from the handling of competing irrelevant objects. The dissociation between the increased involvement of parietal and occipital cortex in handling distraction on one hand, and that of frontal cortex in target specification on the other provides neurophysiological support for models of attention that make this functional distinction. 相似文献
998.
999.
Federico Ibba Stefania Vinci Saturnino Spiga Alessandra T. Peana Anna R. Assaretti Liliana Spina Rosanna Longoni Elio Acquas 《Alcoholism, clinical and experimental research》2009,33(5):858-867
Background: Addictive drugs activate extracellular signal regulated kinase (ERK) in brain regions critically involved in their affective and motivational properties. The aim of this study was to demonstrate the ethanol-induced activation of ERK in the nucleus accumbens (Acb) and in the extended amygdala [bed nucleus of the stria terminalis lateralis (BSTL) and central nucleus of the amygdala (CeA)] and to highlight the role of dopamine (DA) D1 receptors in these effects.
Methods: Ethanol (0.5, 1, and 2 g/kg) was administered by gavage and ERK phosphorylation was determined in the nucleus Acb (shell and core), BSTL, and CeA by immunohistochemistry. The DA D1 receptor antagonist, SCH 39166 (SCH) (50 μg/kg), was administered 10 minutes before ethanol (1 g/kg).
Results: Quantitative microscopic examination showed that ethanol, dose-dependently increased phospho-ERK immunoreactivity (optical and neuronal densities) in the shell and core of nucleus Acb, BSTL, and CeA. Pretreatment with SCH fully prevented the increases elicited by ethanol (1 g/kg) in all brain regions studied.
Conclusions: The results of this study indicate that ethanol, similar to other addictive drugs, activates ERK in nucleus Acb and extended amygdala via a DA D1 receptor-mediated mechanism. Overall, these results suggest that the D1 receptors/ERK pathway may play a critical role in the motivational properties of ethanol. 相似文献
Methods: Ethanol (0.5, 1, and 2 g/kg) was administered by gavage and ERK phosphorylation was determined in the nucleus Acb (shell and core), BSTL, and CeA by immunohistochemistry. The DA D
Results: Quantitative microscopic examination showed that ethanol, dose-dependently increased phospho-ERK immunoreactivity (optical and neuronal densities) in the shell and core of nucleus Acb, BSTL, and CeA. Pretreatment with SCH fully prevented the increases elicited by ethanol (1 g/kg) in all brain regions studied.
Conclusions: The results of this study indicate that ethanol, similar to other addictive drugs, activates ERK in nucleus Acb and extended amygdala via a DA D
1000.
Joanna Leszczyńska Anna Diowksz Agata ??cka Ma?gorzata Bryszewska Katarzyna Wolska Wojciech Ambroziak 《Food and Agricultural Immunology》2009,20(2):139-145
Results of the research on the lowering of allergenicity of wheat flour fermented using homo- and heterofermentative lactic acid bacteria and mixed cultures with yeast were discussed. The gliadins’ immunoreactivity was measured using the indirect non-competitive enzyme-linked immunosorbent assay method. The biggest decrease of the immunoreactivity of gliadin fraction was observed in the case of fermentation performed with the use of mixed cultures of lactic acid bacteria and yeast. This way of wheat flour modification seems to be promising, because fermentation is a natural process causing not only lowering of the allergenicity, but also improving organoleptic and nutritional values of obtained products. 相似文献