全文获取类型
收费全文 | 978篇 |
免费 | 72篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 58篇 |
妇产科学 | 8篇 |
基础医学 | 86篇 |
口腔科学 | 30篇 |
临床医学 | 191篇 |
内科学 | 198篇 |
皮肤病学 | 13篇 |
神经病学 | 33篇 |
特种医学 | 246篇 |
外科学 | 50篇 |
综合类 | 21篇 |
预防医学 | 41篇 |
眼科学 | 7篇 |
药学 | 34篇 |
中国医学 | 5篇 |
肿瘤学 | 33篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 2篇 |
2021年 | 11篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 23篇 |
2017年 | 11篇 |
2016年 | 18篇 |
2015年 | 21篇 |
2014年 | 26篇 |
2013年 | 27篇 |
2012年 | 19篇 |
2011年 | 19篇 |
2010年 | 36篇 |
2009年 | 56篇 |
2008年 | 28篇 |
2007年 | 17篇 |
2006年 | 15篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 15篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 52篇 |
1997年 | 55篇 |
1996年 | 65篇 |
1995年 | 49篇 |
1994年 | 43篇 |
1993年 | 47篇 |
1992年 | 17篇 |
1991年 | 11篇 |
1990年 | 16篇 |
1989年 | 36篇 |
1988年 | 30篇 |
1987年 | 33篇 |
1986年 | 33篇 |
1985年 | 23篇 |
1984年 | 16篇 |
1983年 | 9篇 |
1982年 | 22篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 12篇 |
1976年 | 11篇 |
1975年 | 13篇 |
排序方式: 共有1057条查询结果,搜索用时 15 毫秒
101.
van Gils FC; van Teeffelen ME; Neelis KJ; Hendrikx J; Burger H; van Leen RW; Knol E; Wagemaker G; Wognum AW 《Blood》1995,86(2):592-597
To understand the hematopoietic and nonhematopoietic responses to interleukin-3 (IL-3), expression of cell-surface IL-3 receptors (IL-3R) was examined on bone marrow (BM) cells and peripheral blood (PB) cells of rhesus monkeys during the course of in vivo IL-3 treatment. Whereas IL-3R expression is low in untreated monkeys, IL-3 administration led to a gradual increase in both low- and high-affinity binding sites for IL-3. This increase reflected the total number of cells expressing IL- 3Rs, as detected by flow cytometry using biotinylated IL-3. Most of these IL-3R+ cells in both BM and PB could be characterized as basophilic granulocytes that contained high levels of histamine. In contrast to the effect on these differentiated cells, IL-3 administration did not significantly alter the low level IL-3R expression on immature, CD34+ cells. Further flow cytometric analysis using biotinylated growth factors showed that the IL-3R+ basophils also expressed receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF), but not for IL-6 or Kit ligand. These findings indicated that the IL-3R+ cells included neither monocytes, which express GM-CSFRs and IL-6Rs abundantly, nor mast cells, which express c- kit. By combining flow cytometric and Scatchard data, it was calculated that the basophils contain as many as 1 to 2 x 10(3) high-affinity IL- 3Rs and 15 to 30 x 10(3) low-affinity sites. The finding that in vivo IL-3 treatment leads to the production of large numbers of cells that express high levels of IL-3R and are capable of producing histamine provides an explanation for the often severe allergic reactions that occur during prolonged IL-3 administration. It also indicates that IL- 3, in addition to its direct effects on hematopoietic cells, may also stimulate hematopoiesis through the release of secondary mediators such as histamine by IL-3-responsive mature cells. 相似文献
102.
103.
Cytogenetic and histologic correlations in malignant lymphoma 总被引:9,自引:0,他引:9
Koduru PR; Filippa DA; Richardson ME; Jhanwar SC; Chaganti SR; Koziner B; Clarkson BD; Lieberman PH; Chaganti RS 《Blood》1987,69(1):97-102
Although a number of studies have indicated correlations between histologic subtypes of tumors and certain nonrandom chromosome changes, cytogenetic studies of lymphoma are in an early stage compared to those of leukemia. No comprehensive analysis of available data has so far been attempted in the literature either. Here we present an analysis of chromosome changes and their correlation with subtypes of lymphoma studied by conventional histology and cell surface markers, as observed in two sets of data: a group of 65 karyotypically abnormal tumors sequentially ascertained and studied by us during the period January 1, 1984 to April 30, 1985, and a larger data set derived by combining our data with those from two published series from the University of Minnesota that are comparable to our data. These combined data, which comprise the largest data set on the cytogenetics of lymphomas assembled so far, enabled a comprehensive analysis of correlation between chromosome change and tumor histology and the patterns of chromosome instability in these tumors. We found several significant associations, some previously described and others now recognized, between nonrandom chromosome gains, breaks, translocations, and deletions and histologic subtypes of tumors that characterize lymphomas. The data indicate that finding of chromosome breaks at certain sites (eg, 8q24, 14q32, 18q21) is of diagnostic value in dealing with cases of unusual lymphoma. Furthermore, nonrandom chromosome breakage exhibited three distinct patterns that reflected three levels of etiologically relevant genetic change. 相似文献
104.
Bruce Friedman PhD MPH Rachel L. Delavan MS Thomas H. Sheeran PhD ME MEd Martha L. Bruce PhD MPH 《Journal of the American Geriatrics Society》2009,57(4):669-675
OBJECTIVES: To examine the associations between major and minor depression and categories of Medicare home healthcare use.
DESIGN: Observational prospective study (1997–1999).
SETTING: Visiting nurse agency in suburban New York State.
PARTCIPANTS: Five hundred thirty-nine new Medicare admissions aged 65 and older (mean age 78.4), 65.1% female, and 15.0% nonwhite. Approximately 13.5% were diagnosed with major depression and another 10.8% with minor depression.
MEASUREMENTS: Consensus "best estimate" Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnoses for major and minor depression assessed using Structured Clinical Interviews for DSM-IV (SCID) plus medical charts.
RESULTS: Major and minor depression appear to have little association with probability and amount of use of the types of Medicare home health care (skilled nurse, home health aide, therapist (physical, occupational, and speech), and medical social services). Overall, patients with minor depression appear to have utilization similar to that of patients with major depression.
CONCLUSION: It seems likely that any potential incremental depression effect on utilization is being offset by the transitional medical state of the patients that entered Medicare home healthcare directly from a hospital, nursing home, or rehabilitation facility, and the overall severity of disability and chronic illness present in long-term home healthcare patients. Further research is required to determine whether similar findings occur in other home healthcare agencies and whether these are present under the current Medicare Prospective Payment System reimbursement mechanism. 相似文献
DESIGN: Observational prospective study (1997–1999).
SETTING: Visiting nurse agency in suburban New York State.
PARTCIPANTS: Five hundred thirty-nine new Medicare admissions aged 65 and older (mean age 78.4), 65.1% female, and 15.0% nonwhite. Approximately 13.5% were diagnosed with major depression and another 10.8% with minor depression.
MEASUREMENTS: Consensus "best estimate" Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnoses for major and minor depression assessed using Structured Clinical Interviews for DSM-IV (SCID) plus medical charts.
RESULTS: Major and minor depression appear to have little association with probability and amount of use of the types of Medicare home health care (skilled nurse, home health aide, therapist (physical, occupational, and speech), and medical social services). Overall, patients with minor depression appear to have utilization similar to that of patients with major depression.
CONCLUSION: It seems likely that any potential incremental depression effect on utilization is being offset by the transitional medical state of the patients that entered Medicare home healthcare directly from a hospital, nursing home, or rehabilitation facility, and the overall severity of disability and chronic illness present in long-term home healthcare patients. Further research is required to determine whether similar findings occur in other home healthcare agencies and whether these are present under the current Medicare Prospective Payment System reimbursement mechanism. 相似文献
105.
RABEH GHENIM M.D. JÉRÔME RONCALLI M.D. Ph.D. AMIR M. TIDJANE M.D. VANINA BONGARD M.D. Ph.D. ABDELKADER ZIANI M.D. NICOLAS BOUDOU M.D. NICOLAS DUMONTEIL M.D. BERTRAND MARCHEIX M.D. BERTRAND LÉOBON M.D. Ph.D. DIDIER CARRIÉ M.D. Ph.D. 《Journal of interventional cardiology》2009,22(6):520-526
Purpose: The present observational study compares in‐hospital and 12‐month clinical outcomes in elderly patients with unprotected left main coronary artery disease treated either with coronary artery bypass grafting or drug‐eluting stent. Methods: From January 2004 to December 2007, 211 patients (pts) with unprotected left main coronary artery (ULMCA) stenosis, aged 75 or older, underwent coronary revascularization either with coronary artery bypass graft (CABG) (106 pts) or drug‐eluting stent (DES) (105 pts). The decision to treat with CABG or percutaneous coronary intervention (PCI) was dependent on the patient's and the physician's choice. The occurrence of major adverse cardiac or cerebrovascular events (MACCE: death, nonfatal myocardial infarction, or stroke) and revascularizations was recorded after 1 year of follow‐up. A multivariate logistic regression analysis was performed using a propensity score method to take potential baseline differences between groups into account. Results: In‐hospital MACCE rates were 5.7% and 3.8% in the CABG and PCI groups, respectively (P = 0.748). After 1 year of follow‐up, these rates were, respectively, 13.9% and 14.9% (P = 0.841), and rates for target vessel revascularization at 12 months were 1.0% and 13.9% (P < 0.001). The PCI group was significantly associated with older age, dyslipidemia, history of cancer, high Euroscore, elevated creatininemia, single‐vessel disease, fewer chronic occlusions of the left anterior descending artery, and more LMCA stenosis ≥70%. The multivariate logistic regression analysis was adjusted for age, diabetes, left ventricular ejection fraction, Euroscore, and plasma creatininemia and stratified on the score of propensity to be treated with PCI. In the subgroup below median propensity score, the adjusted odds ratio for 1‐year MACCE was OR = 0.91 (95% confidence interval: 0.14 to 5.98; P = 0.924) whereas OR was 0.16 (0.04–0.69; P = 0.013) in the subgroup above median propensity score. Conclusions: In patients with a high probability of being treated with PCI (older age, high Euroscore, high creatininemia, single‐vessel disease, …), the 1‐year risk of MACCE was significantly lower in PCI‐ than in CABG‐treated subjects. No significant difference was found in other cases. 相似文献
106.
非酒精性脂肪性肝炎(non—alcoholicsteatohepatitis,NASH)现已成为肝移植愈来愈重要的基础肝病。鉴于晚期NASH患者常并存多种影响肝移植转归的临床问题,而至今尚无针对NASH患者进行肝移植的评估和治疗指南,为此英国移植学会(British Transplant Society,BTS)邀请相关专家制定了指南,以指导肝移植前后NASH患者的处理。 相似文献
107.
Ayako Kokubo ME Mitsuo Kuwabara PhD Naoko Tomitani BSc Shingo Yamashita ME Toshikazu Shiga PhD Kazuomi Kario MD PhD 《Journal of clinical hypertension (Greenwich, Conn.)》2023,25(4):388-392
Nocturnal blood pressure (BP) surge in seconds (sec-surge), which is characterized as acute transient BP elevation over several tens of seconds is induced by obstructive sleep apnea (OSA) and OSA-related sympathetic hyperactivity. The authors assessed the relationship between sec-surge and arterial stiffness in 34 nocturnal hypertensive patients with suspected OSA (mean age 63.9 ± 12.6 years, 32.4% female). During the night, they had beat-by-beat (BbB) BP and cuff-oscillometric BP measurements, and brachial-ankle pulse wave velocity (baPWV) was assessed as an arterial stiffness index. Multiple linear regression analysis revealed that the upward duration (UD) of sec-surge was significantly associated with baPWV independently of nocturnal oscillometric systolic BP variability (β = .365, p = .046). This study suggests that the UD of sec-surge, which can only be measured using a BbB BP monitoring device, may be worth monitoring in addition to nocturnal BP level. 相似文献
108.
Mauricio Pimentel Ana Paula Arbo Magalhes Camila Valvassori Novak Bruna Miers May Luiz Gustavo Bravosi da Rosa Leandro Ioschpe Zimerman 《Arquivos brasileiros de cardiologia》2021,117(5):1010
Background:The coronavirus disease 2019 (COVID-19) is associated with cardiovascular clinical manifestations, including cardiac arrhythmias.Objective:To assess the incidence of cardiac arrhythmias (atrial tachyarrhythmia, bradyarrhythmia, and sustained ventricular tachycardia) and cardiac arrest (CA) in a cohort of patients hospitalized with COVID-19 in a tertiary university-affiliated hospital.Methods:Cohort study with retrospective analysis of electronic medical records. For comparison between groups, a value of p <0.05 was considered statistically significantResults:We included 241 consecutive patients diagnosed with COVID-19 (mean age, 57.8 ± 15.0 years; 51.5% men; 80.5% white), 35.3% of whom received invasive mechanical ventilation (MV). The overall mortality was 26.6%, being 58.8% among those on MV. Cardiac arrhythmias were identified in 8.7% of the patients, the most common being atrial tachyarrhythmia (76.2%). Patients with arrhythmias had higher mortality (52.4% versus 24.1%, p = 0.005). On multivariate analysis, only the presence of heart failure (HF) was associated with a higher risk of arrhythmias (hazard ratio, 11.9; 95% CI: 3.6-39.5; p <0.001). During hospitalization, 3.3% of the patients experienced CA, with a predominance of non-shockable rhythms. All patients experiencing CA died during hospitalization.Conclusions:The incidence of cardiac arrhythmias in patients admitted with COVID-19 to a Brazilian tertiary hospital was 8.7%, and atrial tachyarrhythmia was the most common. Presence of HF was associated with an increased risk of arrhythmias. Patients with COVID-19 experiencing CA have high mortality. 相似文献
109.
Efficacy and safety of sodium‐glucose cotransporter‐2 inhibitors versus dipeptidyl peptidase‐4 inhibitors as monotherapy or add‐on to metformin in patients with type 2 diabetes mellitus: A systematic review and meta‐analysis 下载免费PDF全文
110.
A novel guidewire‐integrated embolic protection filter device with a handy‐folding system: In vitro and in vivo performance assessment 下载免费PDF全文