全文获取类型
收费全文 | 6665篇 |
免费 | 474篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 149篇 |
妇产科学 | 100篇 |
基础医学 | 946篇 |
口腔科学 | 190篇 |
临床医学 | 638篇 |
内科学 | 1552篇 |
皮肤病学 | 85篇 |
神经病学 | 668篇 |
特种医学 | 285篇 |
外科学 | 1025篇 |
综合类 | 59篇 |
一般理论 | 5篇 |
预防医学 | 367篇 |
眼科学 | 131篇 |
药学 | 334篇 |
中国医学 | 8篇 |
肿瘤学 | 535篇 |
出版年
2023年 | 60篇 |
2022年 | 104篇 |
2021年 | 188篇 |
2020年 | 134篇 |
2019年 | 168篇 |
2018年 | 206篇 |
2017年 | 150篇 |
2016年 | 170篇 |
2015年 | 200篇 |
2014年 | 265篇 |
2013年 | 337篇 |
2012年 | 525篇 |
2011年 | 504篇 |
2010年 | 326篇 |
2009年 | 260篇 |
2008年 | 469篇 |
2007年 | 446篇 |
2006年 | 392篇 |
2005年 | 384篇 |
2004年 | 317篇 |
2003年 | 311篇 |
2002年 | 276篇 |
2001年 | 61篇 |
2000年 | 42篇 |
1999年 | 65篇 |
1998年 | 50篇 |
1997年 | 37篇 |
1996年 | 40篇 |
1995年 | 45篇 |
1994年 | 30篇 |
1993年 | 41篇 |
1992年 | 32篇 |
1991年 | 32篇 |
1990年 | 29篇 |
1989年 | 32篇 |
1988年 | 39篇 |
1987年 | 34篇 |
1986年 | 25篇 |
1985年 | 22篇 |
1984年 | 28篇 |
1983年 | 27篇 |
1982年 | 28篇 |
1981年 | 26篇 |
1980年 | 13篇 |
1979年 | 21篇 |
1978年 | 16篇 |
1975年 | 12篇 |
1974年 | 17篇 |
1973年 | 13篇 |
1972年 | 13篇 |
排序方式: 共有7163条查询结果,搜索用时 15 毫秒
81.
Jeph Herrin Ph.D. Justin St. Andre M.A. Kevin Kenward Ph.D. Maulik S. Joshi Dr.P.H. Anne‐Marie J. Audet M.D. M.Sc. Stephen C. Hines Ph.D. 《Health services research》2015,50(1):20-39
Objective
To examine the relationship between community factors and hospital readmission rates.Data Sources/Study Setting
We examined all hospitals with publicly reported 30-day readmission rates for patients discharged during July 1, 2007, to June 30, 2010, with acute myocardial infarction (AMI), heart failure (HF), or pneumonia (PN). We linked these to publicly available county data from the Area Resource File, the Census, Nursing Home Compare, and the Neilsen PopFacts datasets.Study Design
We used hierarchical linear models to assess the effect of county demographic, access to care, and nursing home quality characteristics on the pooled 30-day risk-standardized readmission rate.Data Collection/Extraction Methods
Not applicable.Principal Findings
The study sample included 4,073 hospitals. Fifty-eight percent of national variation in hospital readmission rates was explained by the county in which the hospital was located. In multivariable analysis, a number of county characteristics were found to be independently associated with higher readmission rates, the strongest associations being for measures of access to care. These county characteristics explained almost half of the total variation across counties.Conclusions
Community factors, as measured by county characteristics, explain a substantial amount of variation in hospital readmission rates. 相似文献82.
Treatment of heterotopic caesarean scar pregnancy complicated with post termination increase in size of residual mass and morbidly adherent placenta 下载免费PDF全文
Andre Hadyme Miyague MD PhD Adriano Pienaro Chrisostomo MD Sergio Luis Costa MD Edson Tetsuya Nakatani MD William Kondo MD Claudio Corrêa Gomes MD 《Journal of clinical ultrasound : JCU》2018,46(3):227-230
We report a case of a secundipara with heterotopic cesarean scar pregnancy (HCSP) treated with potassium chloride injection into the ectopic embryo followed by sac aspiration. The remaining “mass” increased in size threefold and was surrounded by a rich vascular network. An arteriovenous malformation was suspected; however, appropriate treatment was precluded because of the viability of the ectopic gestation. Sonographic examination revealed a morbidly adherent placenta, and attempt to resect the mass laparoscopically was complicated by bleeding that required hysterectomy. This case illustrates a complication of the intervention performed to preserve the intrauterine gestation in case of HCSP. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46 :227–230, 2018 相似文献
83.
84.
Increased plasma levels of soluble TNF receptors 1 and 2 in bipolar depression and impact of lithium treatment 下载免费PDF全文
85.
86.
Kir6.2 is required for adaptation to stress 总被引:28,自引:0,他引:28
Zingman LV Hodgson DM Bast PH Kane GC Perez-Terzic C Gumina RJ Pucar D Bienengraeber M Dzeja PP Miki T Seino S Alekseev AE Terzic A 《Proceedings of the National Academy of Sciences of the United States of America》2002,99(20):13278-13283
Reaction to stress requires feedback adaptation of cellular functions to secure a response without distress, but the molecular order of this process is only partially understood. Here, we report a previously unrecognized regulatory element in the general adaptation syndrome. Kir6.2, the ion-conducting subunit of the metabolically responsive ATP-sensitive potassium (K(ATP)) channel, was mandatory for optimal adaptation capacity under stress. Genetic deletion of Kir6.2 disrupted K(ATP) channel-dependent adjustment of membrane excitability and calcium handling, compromising the enhancement of cardiac performance driven by sympathetic stimulation, a key mediator of the adaptation response. In the absence of Kir6.2, vigorous sympathetic challenge caused arrhythmia and sudden death, preventable by calcium-channel blockade. Thus, this vital function identifies a physiological role for K(ATP) channels in the heart. 相似文献
87.
Dr. Andre van Gossum MD PhD Philippe Closset MD Etienne Noel MD Michel Cremer MD PhD Jean Neve PhD 《Digestive diseases and sciences》1996,41(6):1225-1231
Free radicals have been suspected to play a role in the pathogenicity of alcohol-related chronic pancreatitis. The aim of this study was to determine the status of several antioxidant parameters in these patients and examine the factors that are likely to influence them. Thirty-five subjects (23 males and 12 females, mean age 48±8 years) with disease proven by endoscopic pancreatography and 14 healthy controls (6 males and 8 females, mean age 44±7 years) were included in the study. Biochemical antioxidant parameters included: selenium, zinc, and copper levels in plasma; glutathione peroxidase in plasma and erythrocytes; plasma malondialdehyde concentrations assessed by thiobarbituric acid reactants; and serum vitamin E and A levels. Selenium and vitamin E oral intake was assessed by a five-day diet analysis. Hemoglobin (130±16 vs 143±15 g/liter), vitamin E (8±5 vs 16±9 mg/liter), vitamin A (30±11 vs 49±12µg/dl), selenium (54±20 vs 87±11µg/liter), and plasma glutathione peroxidase (903±313 vs 1326±168 units/liter) were significantly lower in patients than in controls (P<0.05). In contrast, white blood cell count, C-reactive protein, and plasma copper levels were significantly higher in patients than in controls. Cholesterol, triglycerides, iron, ferritin, total proteins, zinc, and malondialdehyde were not different. Vitamin E was lower in patients with steatorrhea, while vitamin A was lower in patients with concomitant diabetes mellitus. Dietary intakes were not different between patients and controls. In conclusion, patients with alcohol-related chronic pancreatitis have low blood levels in many antioxidant factors. Dietary intakes of some of them (selenium and vitamin E) are adequate, however. Such deficiencies are secondary to pancreatic insufficiency and probably to increased requirements related to enhanced oxidative stress. 相似文献
88.
89.
Craig A. Friesen Zhiyue Lin Robert Garola Linda Andre Nancy Burchell 《Digestive diseases and sciences》2000,45(6):1245-1256
Abstract List
Abstracts of Eighth International Workshop on Electrogastrography 相似文献90.
The mannitol-lactulose intestinal permeability test was evaluated in 100 healthy controls and 47 patients with Crohn's disease. These patients were further separated into three subgroups of increased activity (Harvey-Bradshaw index) and in two subgroups, with elective colonic lesions and associated ileal and colonic lesions. Results were given as percentages of urinary recoveries for mannitol (M), lactulose (L), and L/M ratio. As a whole, patients with Crohn's disease have lower mean M and higher mean L and mean L/M ratios than controls. The magnitude of alterations in M, L, and L/M increased with activity. The sensitivity of the test, however, reached interesting figures (67%:L and 86%:L/M) only in subgroup III which was composed of relapsing patients. Mean M was lower in patients with associated ileal lesion but, whatever the criterion (M, L, or L/M), the test does not provide any clue for the detection of a possible infraclinical associated ileal localisation. 相似文献