全文获取类型
收费全文 | 1713310篇 |
免费 | 124446篇 |
国内免费 | 4033篇 |
专业分类
耳鼻咽喉 | 22131篇 |
儿科学 | 55837篇 |
妇产科学 | 46464篇 |
基础医学 | 244135篇 |
口腔科学 | 49046篇 |
临床医学 | 152775篇 |
内科学 | 336965篇 |
皮肤病学 | 39522篇 |
神经病学 | 132281篇 |
特种医学 | 65123篇 |
外国民族医学 | 242篇 |
外科学 | 259470篇 |
综合类 | 38995篇 |
现状与发展 | 4篇 |
一般理论 | 539篇 |
预防医学 | 124761篇 |
眼科学 | 40583篇 |
药学 | 125417篇 |
7篇 | |
中国医学 | 4749篇 |
肿瘤学 | 102743篇 |
出版年
2021年 | 13596篇 |
2019年 | 14059篇 |
2018年 | 20574篇 |
2017年 | 15749篇 |
2016年 | 17413篇 |
2015年 | 20078篇 |
2014年 | 27447篇 |
2013年 | 39265篇 |
2012年 | 54644篇 |
2011年 | 57192篇 |
2010年 | 33873篇 |
2009年 | 31522篇 |
2008年 | 52598篇 |
2007年 | 55742篇 |
2006年 | 56113篇 |
2005年 | 53270篇 |
2004年 | 51256篇 |
2003年 | 48607篇 |
2002年 | 46720篇 |
2001年 | 91837篇 |
2000年 | 93649篇 |
1999年 | 77003篇 |
1998年 | 19766篇 |
1997年 | 17298篇 |
1996年 | 17408篇 |
1995年 | 16757篇 |
1994年 | 15309篇 |
1993年 | 14087篇 |
1992年 | 57391篇 |
1991年 | 55286篇 |
1990年 | 52981篇 |
1989年 | 50761篇 |
1988年 | 46142篇 |
1987年 | 44949篇 |
1986年 | 42237篇 |
1985年 | 39992篇 |
1984年 | 29364篇 |
1983年 | 24909篇 |
1982年 | 13902篇 |
1979年 | 25538篇 |
1978年 | 17577篇 |
1977年 | 14908篇 |
1976年 | 13876篇 |
1975年 | 14564篇 |
1974年 | 17634篇 |
1973年 | 16946篇 |
1972年 | 15676篇 |
1971年 | 14454篇 |
1970年 | 13431篇 |
1969年 | 12518篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
81.
82.
83.
Clinical usefulness of intraductal ultrasonography for the management of acute biliary pancreatitis 下载免费PDF全文
84.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery. 相似文献
85.
Ann S. O’Malley Kevin Draper Rebecca Gourevitch Dori A. Cross Sarah Hudson Scholle 《J Am Med Inform Assoc》2015,22(2):426-434
Objective Consensus that enhanced teamwork is necessary for efficient and effective primary care delivery is growing. We sought to identify how electronic health records (EHRs) facilitate and pose challenges to primary care teams as well as how practices are overcoming these challenges.Methods Practices in this qualitative study were selected from those recognized as patient-centered medical homes via the National Committee for Quality Assurance 2011 tool, which included a section on practice teamwork. We interviewed 63 respondents, ranging from physicians to front-desk staff, from 27 primary care practices ranging in size, type, geography, and population size.Results EHRs were found to facilitate communication and task delegation in primary care teams through instant messaging, task management software, and the ability to create evidence-based templates for symptom-specific data collection from patients by medical assistants and nurses (which can offload work from physicians). Areas where respondents felt that electronic medical record EHR functionalities were weakest and posed challenges to teamwork included the lack of integrated care manager software and care plans in EHRs, poor practice registry functionality and interoperability, and inadequate ease of tracking patient data in the EHR over time.Discussion Practices developed solutions for some of the challenges they faced when attempting to use EHRs to support teamwork but wanted more permanent vendor and policy solutions for other challenges.Conclusions EHR vendors in the United States need to work alongside practicing primary care teams to create more clinically useful EHRs that support dynamic care plans, integrated care management software, more functional and interoperable practice registries, and greater ease of data tracking over time. 相似文献
86.
87.
88.
Objective:To study the effect of oral administration of dimethyl dimethoxy biphenyl dicarboxylate(DDB) on adjusting angiogeneic/inflammatory mediators and ameliorating the pathology of bones in rats with collagen-induced arthritis(CIA).Methods:Wistar rat model of CIA was set up using bovine collagen type Ⅱ.Fifty rats were divided into five groups randomly:normal,CIA model,DDB treatment,methotrexate(MTX) treatment,and combined DDB+MTX treatment.Ankle joints of rats were imaged with digital X-ray machine to show the destruction of joints.Fore and hind paw and knee joints were removed above the ankle joint then processed for haematoxylin and eosin staining.Plasma levels of vascular endothelial growth factor(VEGF),platelet derived growth factor,interleukin-8(IL-8),IL-4,tumor necrosis factor α(TNF-α),and cyclooxygenase-2(COX-2) were quantified by enzyme-linked immunosorbent assay.Nitric oxide levels were detected by Griess reagent.Results:Compared with the CIA model group,a remarkable reduction in various angiogenic(VEGF and IL-8) and inflammatory mediators(TNF-α,IL-4 and COX-2) after treatment with DDB either alone or combined with MTX(P0.05 or P0.01).Histopathological and X-ray findings were confirmatory to the observed DDB anti-arthritic effect.The DDB-treated group showed amelioration in signs of arthritis which appeared essentially similar to normal.Conclusion:Our data shed light on the therapeutic efficacy of DDB in experimental rheumatoid arthritis(RA) compared with a choice drug(MTX) and it may be offered as a second-line drug in the treatment of RA. 相似文献
89.
90.
Wilbert S Aronow 《Expert opinion on pharmacotherapy》2016,17(2):205-215
Introduction: It is important to know how to treat hypertension in patients with coronary artery disease (CAD). The reason for the review was to update this treatment and to discuss the 2015 American Heart Association/American College of Cardiology/American Society of Hypertension 2015 guidelines of treatment of hypertension in patients with CAD.Areas covered: Studies between 1968 and 2015 were reviewed on treatment of hypertension in patients with CAD using a Medline search, and studies between 1977 and 2015 were reported. Hypertension should be treated with beta blockers and ACE inhibitors or angiotensin receptor blockers (ARBs). Long-acting nitrates are effective antianginal and anti-ischemic drugs. Calcium-channel blockers (CCBs) may be added if angina persists despite beta blockers and long-acting nitrates. The 2015 guidelines recommend that the blood pressure should be < 140/90 mm Hg in patients aged ≤ 80 years and the systolic blood pressure < 150 mm Hg if they are ≥ 80 years.Expert opinion: Hypertension in patients with CAD should be treated with beta blockers and ACE inhibitors or ARBs. Long-acting nitrates are effective antianginal and anti-ischemic drugs. CCBs may be added if angina persists despite beta blockers and long-acting nitrates. The blood pressure should be < 140/90 mm Hg in patients aged < 80 years and the systolic blood pressure < 150 mm Hg if they are ≥ 80 years. 相似文献