全文获取类型
收费全文 | 3744篇 |
免费 | 367篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 48篇 |
妇产科学 | 64篇 |
基础医学 | 576篇 |
口腔科学 | 40篇 |
临床医学 | 440篇 |
内科学 | 1008篇 |
皮肤病学 | 73篇 |
神经病学 | 344篇 |
特种医学 | 120篇 |
外科学 | 504篇 |
综合类 | 81篇 |
一般理论 | 3篇 |
预防医学 | 229篇 |
眼科学 | 32篇 |
药学 | 133篇 |
中国医学 | 4篇 |
肿瘤学 | 399篇 |
出版年
2023年 | 22篇 |
2022年 | 24篇 |
2021年 | 98篇 |
2020年 | 45篇 |
2019年 | 69篇 |
2018年 | 98篇 |
2017年 | 59篇 |
2016年 | 78篇 |
2015年 | 108篇 |
2014年 | 139篇 |
2013年 | 175篇 |
2012年 | 223篇 |
2011年 | 216篇 |
2010年 | 125篇 |
2009年 | 139篇 |
2008年 | 207篇 |
2007年 | 229篇 |
2006年 | 203篇 |
2005年 | 214篇 |
2004年 | 187篇 |
2003年 | 159篇 |
2002年 | 131篇 |
2001年 | 120篇 |
2000年 | 85篇 |
1999年 | 73篇 |
1998年 | 31篇 |
1997年 | 29篇 |
1996年 | 35篇 |
1995年 | 24篇 |
1994年 | 30篇 |
1993年 | 14篇 |
1992年 | 55篇 |
1991年 | 51篇 |
1990年 | 51篇 |
1989年 | 45篇 |
1988年 | 34篇 |
1987年 | 38篇 |
1986年 | 35篇 |
1985年 | 42篇 |
1984年 | 27篇 |
1983年 | 33篇 |
1982年 | 26篇 |
1981年 | 28篇 |
1980年 | 20篇 |
1979年 | 27篇 |
1978年 | 15篇 |
1976年 | 14篇 |
1972年 | 16篇 |
1937年 | 41篇 |
1936年 | 38篇 |
排序方式: 共有4142条查询结果,搜索用时 350 毫秒
111.
Ji-Hyun Park Yoshihiko Nakamura Wenlu Li Gen Hamanaka Ken Arai Eng H Lo Kazuhide Hayakawa 《Journal of cerebral blood flow and metabolism》2021,41(7):1523
Mitochondria may be transferred from cell to cell in the central nervous system and this process may help defend neurons against injury and disease. But how mitochondria maintain their functionality during the process of release into extracellular space remains unknown. Here, we report that mitochondrial protein O-GlcNAcylation is a critical process to support extracellular mitochondrial functionality. Activation of CD38-cADPR signaling in astrocytes robustly induced protein O-GlcNAcylation in mitochondria, while oxygen-glucose deprivation and reoxygenation showed transient and mild protein modification. Blocking the endoplasmic reticulum – Golgi trafficking with Brefeldin A or slc35B4 siRNA reduced O-GlcNAcylation, and resulted in the secretion of mitochondria with decreased membrane potential and mtDNA. Finally, loss-of-function studies verified that O-GlcNAc-modified mitochondria demonstrated higher levels of neuroprotection after astrocyte-to-neuron mitochondrial transfer. Collectively, these findings suggest that post-translational modification by O-GlcNAc may be required for supporting the functionality and neuroprotective properties of mitochondria released from astrocytes. 相似文献
112.
Noor H. A. Suaini Evelyn Xiu-Ling Loo Rachel L. Peters Gaik Chin Yap Katrina J. Allen Hugo Van Bever David J. Martino Anne Eng Neo Goh Shyamali C. Dharmage Marjorelee T. Colega Mary Foong Fong Chong Anne-Louise Ponsonby Kok Hian Tan Mimi L. K. Tang Keith M. Godfrey Bee Wah Lee Lynette Pei-Chi Shek Jennifer J. Koplin Elizabeth Huiwen Tham 《Allergy》2021,76(10):3171-3182
113.
Lauren Desrosiers Sarah Scollon Rebecca Littlejohn Kimberly Nugent Rebecca Althaus Jessica Corredor Emily Berenson Rachel Wyatt Timothy Griffin Kelly Vallance Jonathan Gill Gail Tomlinson Juan Carlos Bernini Angshumoy Roy George Miles Jacquelyn Reuther Shashikant Kulkarni Christine Eng Sharon Plon 《Molecular genetics and metabolism》2021
114.
Martin H. Berryer Fadi F. Hamdan Laura L. Klitten Rikke S. Møller Lionel Carmant Jeremy Schwartzentruber Lysanne Patry Sylvia Dobrzeniecka Daniel Rochefort Mathilde Neugnot‐Cerioli Jean‐Claude Lacaille Zhiyv Niu Christine M. Eng Yaping Yang Sylvain Palardy Céline Belhumeur Guy A. Rouleau Niels Tommerup LaDonna Immken Miriam H. Beauchamp Gayle Simpson Patel Jacek Majewski Mark A. Tarnopolsky Klaus Scheffzek Helle Hjalgrim Jacques L. Michaud Graziella Di Cristo 《Human mutation》2013,34(2):385-394
De novo mutations in SYNGAP1, which codes for a RAS/RAP GTP‐activating protein, cause nonsyndromic intellectual disability (NSID). All disease‐causing point mutations identified until now in SYNGAP1 are truncating, raising the possibility of an association between this type of mutations and NSID. Here, we report the identification of the first pathogenic missense mutations (c.1084T>C [p.W362R], c.1685C>T [p.P562L]) and three novel truncating mutations (c.283dupC [p.H95PfsX5], c.2212_2213del [p.S738X], and (c.2184del [p.N729TfsX31]) in SYNGAP1 in patients with NSID. A subset of these patients also showed ataxia, autism, and a specific form of generalized epilepsy that can be refractory to treatment. All of these mutations occurred de novo, except c.283dupC, which was inherited from a father who is a mosaic. Biolistic transfection of wild‐type SYNGAP1 in pyramidal cells from cortical organotypic cultures significantly reduced activity‐dependent phosphorylated extracellular signal‐regulated kinase (pERK) levels. In contrast, constructs expressing p.W362R, p.P562L, or the previously described p.R579X had no significant effect on pERK levels. These experiments suggest that the de novo missense mutations, p.R579X, and possibly all the other truncating mutations in SYNGAP1 result in a loss of its function. Moreover, our study confirms the involvement of SYNGAP1 in autism while providing novel insight into the epileptic manifestations associated with its disruption. 相似文献
115.
Klapholz M Thomas I Eng C Iteld BJ Ponce GA Niederman AL Bilsker M Heywood JT Synhorst D 《The American journal of cardiology》2001,88(6):657-661
Omapatrilat, a novel vasopeptidase inhibitor, is a highly potent and selective inhibitor of neutral endopeptidase and angiotensin-converting enzyme; its therapeutic potential is being investigated for treatment of hypertension and heart failure. In the present study, the safety, tolerability, and hemodynamic effects of single oral doses of omapatrilat (1 to 50 mg) are compared with placebo in patients with heart failure. Patients with heart failure (New York Heart Association functional class II to IV) and a resting left ventricular ejection fraction < or = 40% were enrolled in a double-blind, placebo-controlled, sequential-panel study of single doses of omapatrilat of 1, 2.5, 5, 10, 25, or 50 mg, followed by hemodynamic assessment for 24 hours. At 4 to 6 hours after dosing, the 25- and 50-mg doses of omapatrilat, compared with placebo, reduced mean pulmonary capillary wedge pressure by approximately 6 mm Hg from 20 and 23 mm Hg at baseline to 14 and 16 mm Hg. The 50-mg omapatrilat dose maintained this effect compared with placebo with an approximately 2.5-mm Hg reduction in mean pulmonary capillary wedge pressure at 24 hours. Omapatrilat improved additional hemodynamic parameters, including cardiac index, systemic vascular resistance, stroke volume index, and mean arterial pressure. Additionally, by 2 hours after dosing with omapatrilat 25 and 50 mg, a trend in peak increases from baseline in plasma atrial natriuretic peptide (twofold) and cyclic guanosine monophosphate (nearly twofold) was observed. Moreover, omapatrilat was well tolerated. Thus, omapatrilat administered orally to patients with heart failure was safe and well tolerated and resulted in improved hemodynamic performance. 相似文献
116.
Plasma radioiron kinetics in man: explanation for the effect of plasma iron concentration.
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
K Skarberg M Eng H Huebers G Marsaglia C Finch 《Proceedings of the National Academy of Sciences of the United States of America》1978,75(3):1559-1561
The plasma iron turnover was measured in 19 normal subjects. A correlation was found between plasma iron concentration and plasma iron turnover. In addition to the turnover of 55Fe at normal plasma iron concentration (predominantly monoferric transferrin), a second turnover in which the labeled plasma was saturated with iron (to produce predominantly diferric transferrin) was studied with 50Fe. It was demonstrated that diferric transferrin had a greater rate of iron turnover but that the distribution between erythroid and non-erythroid tissues was unchanged. It was concluded that plasma iron turnover is dependent on the monoferric/diferric transferrin ratio in the plasma but that the internal distribution of iron is unaffected. 相似文献
117.
Sanja Percac-Lima Lydia E. Pace Kevin H. Nguyen Charis N. Crofton Katharine A. Normandin Sara J. Singer Meredith B. Rosenthal Alyna T. Chien 《Journal of general internal medicine》2018,33(4):415-422
Background
Rectal bleeding is a common, frequently benign problem that can also be an early sign of colorectal cancer. Diagnostic evaluation for rectal bleeding is complex, and clinical practice may deviate from available guidelines.Objective
To assess the degree to which primary care physicians document risk factors for colorectal cancer among patients with rectal bleeding and order colonoscopies when indicated, and the likelihood of physicians ordering and patients receiving recommended colonoscopies based on demographic characteristics, visit patterns, and clinical presentations.Design
Cross-sectional study using explicit chart abstraction methods.Participants
Three hundred adults, 40–80 years of age, presenting with rectal bleeding to 15 academically affiliated primary care practices between 2012 and 2016.Main Measures
1) The frequency at which colorectal cancer risk factors were documented in patients’ charts, 2) the frequency at which physicians ordered colonoscopies and patients received them, and 3) the odds of ordering and patients receiving recommended colonoscopies based on patient demographic characteristics, visit patterns, and clinical presentations.Key Results
Risk factors for colorectal cancer were documented between 9% and 66% of the time. Most patients (89%) with rectal bleeding needed a colonoscopy according to a clinical guideline. Physicians placed colonoscopy orders for 74% of these patients, and 56% completed the colonoscopy within a year (36% within 60 days). The odds of physicians ordering recommended colonoscopies were significantly higher in patients aged 50–64 years of age than in those aged 40–50 years (OR?=?2.23, 95% CI: 1.04, 4.80), and for patients whose most recent colonoscopy was 5 or more years ago (OR?=?4.04, 95% CI: 1.50, 10.83). The odds of physicians ordering and patients receiving recommended colonoscopies were significantly lower for each primary care visit unrelated to rectal bleeding (OR?=?0.85, 95% CI: 0.75, 0.96).Conclusions
Diagnostic evaluation of patients presenting to primary care with rectal bleeding may be suboptimal because of inadequate risk factor assessment and prioritization of patients’ other concurrent medical problems.118.
ANEES THAJUDEEN M.D. WARREN M. JACKMAN M.D. BRIAN STEWART M.S. IVAN COKIC M.D. HIROSHI NAKAGAWA M.D. Ph.D. MICHAEL SHEHATA M.D. ALLEN M. AMORN M.D. AVINASH KALI M.S. EZH LIU M.D. DORON HARLEV M.Sc. NATHAN BENNETT M.Eng. ROHAN DHARMAKUMAR Ph.D. SUMEET S. CHUGH M.D. XUNZHANG WANG M.D. 《Pacing and clinical electrophysiology : PACE》2015,38(6):663-674
119.
Choe J. H. Overman M. J. Fournier K. F. Royal R. E. Ohinata A. Rafeeq S. Beaty K. Phillips J. K. Wolff R. A. Mansfield P. F. Eng C. 《Annals of surgical oncology》2015,22(8):2578-2584
Annals of Surgical Oncology - Currently, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy are accepted treatments for surgically resectable appendiceal epithelial neoplasms.... 相似文献
120.