全文获取类型
收费全文 | 8603篇 |
免费 | 529篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 265篇 |
妇产科学 | 268篇 |
基础医学 | 885篇 |
口腔科学 | 139篇 |
临床医学 | 781篇 |
内科学 | 2226篇 |
皮肤病学 | 84篇 |
神经病学 | 834篇 |
特种医学 | 337篇 |
外科学 | 951篇 |
综合类 | 93篇 |
一般理论 | 6篇 |
预防医学 | 995篇 |
眼科学 | 157篇 |
药学 | 591篇 |
中国医学 | 2篇 |
肿瘤学 | 418篇 |
出版年
2023年 | 32篇 |
2022年 | 45篇 |
2021年 | 176篇 |
2020年 | 83篇 |
2019年 | 169篇 |
2018年 | 194篇 |
2017年 | 160篇 |
2016年 | 149篇 |
2015年 | 171篇 |
2014年 | 280篇 |
2013年 | 396篇 |
2012年 | 642篇 |
2011年 | 707篇 |
2010年 | 377篇 |
2009年 | 377篇 |
2008年 | 576篇 |
2007年 | 691篇 |
2006年 | 642篇 |
2005年 | 615篇 |
2004年 | 578篇 |
2003年 | 527篇 |
2002年 | 467篇 |
2001年 | 98篇 |
2000年 | 65篇 |
1999年 | 81篇 |
1998年 | 103篇 |
1997年 | 75篇 |
1996年 | 59篇 |
1995年 | 69篇 |
1994年 | 50篇 |
1993年 | 49篇 |
1992年 | 48篇 |
1991年 | 29篇 |
1990年 | 36篇 |
1989年 | 60篇 |
1988年 | 35篇 |
1987年 | 23篇 |
1986年 | 21篇 |
1985年 | 17篇 |
1984年 | 30篇 |
1983年 | 20篇 |
1982年 | 23篇 |
1981年 | 18篇 |
1980年 | 16篇 |
1979年 | 7篇 |
1978年 | 14篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1974年 | 6篇 |
1971年 | 6篇 |
排序方式: 共有9158条查询结果,搜索用时 15 毫秒
991.
Dalm S Enthoven L Meijer OC van der Mark MH Karssen AM de Kloet ER Oitzl MS 《Neuroendocrinology》2005,81(6):372-380
As there is little known about age-related changes in the hypothalamic-pituitary-adrenal (HPA) axis of mice, we determined the daily patterns of corticosterone secretion every 2 h, together with adrenocorticotropic hormone (ACTH) release and central HPA axis markers in the morning and evening of 3-, 9- and 16-month-old male C57BL/6J mice. We observed that: (i) corticosterone secretion showed a distinct age-related circadian pattern. During the light period this was expressed by relative hypercorticism in 9-month-old mice and relative hypocorticism in 16-month-old mice. ACTH was elevated at 16 months of age; (ii) mineralocorticoid (MR) and glucocorticoid receptor (GR) mRNA expression in the hippocampus was significantly decreased in 9-month-old mice, whereas in 16-month-old mice, expression was similar to young animals. Circadian variation was modest in all age groups; (iii) the parvocellular hypothalamic paraventricular nucleus (PVN) expressed very high vasopressin mRNA, which was subject to circadian variation in 3- and 9-month-old mice. Furthermore, significant levels of MR mRNA were expressed in the PVN. In conclusion, basal HPA axis activity and expression of its central regulatory markers are age-dependent in mice. This suggests that the capacity to adjust to environmental demands is either a function of age, or depends on different dynamics of the HPA axis. 相似文献
992.
993.
Isabelle Labont�� Michel Laviolette Ron Olivenstein Jamila Chakir Louis-Philippe Boulet Qutayba Hamid 《Canadian respiratory journal》2008,15(8):431-435
BACKGROUND:
Bronchial biopsies are widely used for histopathological, primary cell culture and genetic studies, but very few reports have evaluated their quality.OBJECTIVES AND METHODS:
The present project evaluated the quality (using a scoring system) and the general morphology of a pool of six bronchial biopsy specimens taken from three different sampling sites (the lobar, segmental and subsegmental carinae) in 27 subjects (13 asthmatic subjects and 14 healthy controls). The present study also assessed quantitative measurements of structural changes related to asthma.RESULTS:
In total, 94.4% of the biopsy attempts had enough tissue to be processed. From these, 61.7% were scored with a good to excellent quality, while 76.5% presented smooth muscle bundles and 40.5% had an intact epithelium wall. The data also confirmed the structural changes observed in asthma, such as increased apparent thickening of the basement membrane, reduced amounts of smooth muscle for healthy controls and decreased percentage of intact epithelium for asthmatic subjects.CONCLUSION:
A pool of six bronchial biopsy specimens can provide tissue of excellent quality in both asthmatic and healthy subjects and, consequently, a valuable sample for morphological analysis of mucosal structures. 相似文献994.
995.
Rha SW Kuchulakanti PK Pakala R Cheneau E Pinnow E Torguson R Pichard AD Satler LF Suddath WO Kent KM Lindsay J Waksman R 《The American journal of cardiology》2005,96(1):67-70
Bivalirudin (Angiomax) is increasingly used as a substitute for heparin in a variety of percutaneous coronary interventions, and data on its usage in saphenous vein graft interventions are limited. This retrospective, observational study evaluated the efficacy and safety of bivalirudin compared with heparin as an antithrombotic regimen in patients who underwent saphenous vein graft intervention with distal protection devices. We found that bivalirudin use is clinically safe and feasible, with fewer vascular and ischemic complications compared with heparin. 相似文献
996.
Yaka R Thornton C Vagts AJ Phamluong K Bonci A Ron D 《Proceedings of the National Academy of Sciences of the United States of America》2002,99(8):5710-5715
Phosphorylation regulates the function of ligand-gated ion channels such as the N-methyl d-aspartate (NMDA) receptor. Here we report a mechanism for modulation of the phosphorylation state and function of the NMDA receptor via an inhibitory scaffolding protein, RACK1. We found that RACK1 binds both the NR2B subunit of the NMDA receptor and the nonreceptor protein tyrosine kinase, Fyn. RACK1 inhibits Fyn phosphorylation of NR2B and decreases NMDA receptor-mediated currents in CA1 hippocampal slices. Peptides that disrupt the interactions between RACK1, NR2B, and Fyn induce phosphorylation and potentiate NMDA receptor-mediated currents. Therefore, RACK1 is a regulator of NMDA receptor function and may play a role in synaptic plasticity, addiction, learning, and memory. 相似文献
997.
Rebecca Anhang Price Marc N. Elliott Paul D. Cleary Alan M. Zaslavsky Ron D. Hays 《Journal of general internal medicine》2015,30(2):253-256
Measures of patients’ care experiences are increasingly used as quality measures in accountability initiatives. As the prominence and financial impact of patient experience measures have increased, so too have concerns about the relevance and fairness of including them as indicators of health care quality. Using evidence from the Consumer Assessment of Healthcare Providers and Systems (CAHPS®) surveys, the most widely used patient experience measures in the United States, we address seven common critiques of patient experience measures: (1) consumers do not have the expertise needed to evaluate care quality; (2) patient “satisfaction” is subjective and thus not valid or actionable; (3) increasing emphasis on improving patient experiences encourages health care providers and plans to fulfill patient desires, leading to care that is inappropriate, ineffective, and/or inefficient; (4) there is a trade-off between providing good patient experiences and providing high-quality clinical care; (5) patient scores cannot be fairly compared across health care providers or plans due to factors beyond providers’ control; (6) response rates to patient experience surveys are low, or responses reflect only patients with extreme experiences; and (7) there are faster, cheaper, and more customized ways to survey patients than the standardized approaches mandated by federal accountability initiatives.KEY WORDS: patient satisfaction, performance measurement, quality assessment, patient-centered care 相似文献
998.
Predictors and clinical implications of atrial fibrillation in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation
下载免费PDF全文
![点击此处可从《Catheterization and cardiovascular interventions》网站下载免费的PDF全文](/ch/ext_images/free.gif)
999.
Oleg Butovsky PhD Mark P. Jedrychowski PhD Ron Cialic PhD MD Susanne Krasemann PhD Gopal Murugaiyan PhD Zain Fanek BSc David J. Greco BSc Pauline M. Wu BSc Camille E. Doykan BSc Olga Kiner MSc Robert J. Lawson BSc Matthew P. Frosch MD Nathalie Pochet PhD Rachid El Fatimy PhD Anna M. Krichevsky PhD Steven P. Gygi PhD Hans Lassmann MD James Berry MD Merit E. Cudkowicz MD Howard L. Weiner MD 《Annals of neurology》2015,77(1):75-99
1000.
Pascal Buijs Stefan van Nieuwkoop Vincent Vaes Ron Fouchier Casper van Eijck Bernadette van den Hoogen 《Viruses》2015,7(6):2980-2998
Oncolytic Newcastle disease virus (NDV) might be a promising new therapeutic agent for the treatment of pancreatic cancer. We evaluated recombinant NDVs (rNDVs) expressing interferon (rNDV-hIFNβ-F0) or an IFN antagonistic protein (rNDV-NS1-F0), as well as rNDV with increased virulence (rNDV-F3aa) for oncolytic efficacy in human pancreatic adenocarcinoma cells. Expression of additional proteins did not hamper virus replication or cytotoxic effects on itself. However, expression of interferon, but not NS1, resulted in loss of multicycle replication. Conversely, increasing the virulence (rNDV-F3aa) resulted in enhanced replication of the virus. Type I interferon was produced in high amounts by all tumor cells inoculated with rNDV-hIFNβ-F0, while inoculation with rNDV-NS1-F0 resulted in a complete block of interferon production in most cells. Inoculation of human pancreatic adenocarcinoma cells with rNDV-F3aa caused markedly more cytotoxicity compared to rNDV-F0, while inoculation with rNDV-hIFNβ-F0 and rNDV-NS1-F0 induced cytotoxic effects comparable to those induced by the parental rNDV-F0. Evaluation in vivo using mice bearing subcutaneous pancreatic cancer xenografts revealed that only intratumoral injection with rNDV-F3aa resulted in regression of tumors. We conclude that although lentogenic rNDVs harboring proteins that modulate the type I interferon pathway proteins do have an oncolytic effect, a more virulent mesogenic rNDV might be needed to improve oncolytic efficacy. 相似文献