全文获取类型
收费全文 | 77522篇 |
免费 | 4811篇 |
国内免费 | 2038篇 |
专业分类
耳鼻咽喉 | 441篇 |
儿科学 | 1155篇 |
妇产科学 | 751篇 |
基础医学 | 8578篇 |
口腔科学 | 1158篇 |
临床医学 | 7353篇 |
内科学 | 11512篇 |
皮肤病学 | 415篇 |
神经病学 | 9189篇 |
特种医学 | 2333篇 |
外国民族医学 | 2篇 |
外科学 | 5931篇 |
综合类 | 11428篇 |
现状与发展 | 6篇 |
预防医学 | 10626篇 |
眼科学 | 711篇 |
药学 | 8103篇 |
110篇 | |
中国医学 | 2433篇 |
肿瘤学 | 2136篇 |
出版年
2024年 | 136篇 |
2023年 | 1184篇 |
2022年 | 1860篇 |
2021年 | 3286篇 |
2020年 | 2884篇 |
2019年 | 2561篇 |
2018年 | 2590篇 |
2017年 | 2326篇 |
2016年 | 2422篇 |
2015年 | 2434篇 |
2014年 | 5179篇 |
2013年 | 5454篇 |
2012年 | 4584篇 |
2011年 | 5074篇 |
2010年 | 3923篇 |
2009年 | 3813篇 |
2008年 | 3966篇 |
2007年 | 3638篇 |
2006年 | 3250篇 |
2005年 | 2797篇 |
2004年 | 2301篇 |
2003年 | 2012篇 |
2002年 | 1597篇 |
2001年 | 1381篇 |
2000年 | 1150篇 |
1999年 | 972篇 |
1998年 | 935篇 |
1997年 | 922篇 |
1996年 | 772篇 |
1995年 | 731篇 |
1994年 | 716篇 |
1993年 | 624篇 |
1992年 | 583篇 |
1991年 | 560篇 |
1990年 | 467篇 |
1989年 | 424篇 |
1988年 | 434篇 |
1987年 | 400篇 |
1986年 | 371篇 |
1985年 | 541篇 |
1984年 | 521篇 |
1983年 | 362篇 |
1982年 | 360篇 |
1981年 | 366篇 |
1980年 | 309篇 |
1979年 | 243篇 |
1978年 | 224篇 |
1977年 | 195篇 |
1976年 | 165篇 |
1975年 | 111篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Lesley A. Inker Morgan E. Grams Andrew S. Levey Josef Coresh Massimo Cirillo John F. Collins Ron T. Gansevoort Orlando M. Gutierrez Takayuki Hamano Gunnar H. Heine Shizukiyo Ishikawa Sun Ha Jee Florian Kronenberg Martin J. Landray Katsuyuki Miura Girish N. Nadkarni Carmen A. Peralta Dietrich Rothenbacher Mark Woodward 《American journal of kidney diseases》2019,73(2):206-217
72.
Rotary ventricular assist devices (VADs) are less sensitive to preload than the healthy heart, resulting in inadequate flow regulation in response to changes in patient cardiac demand. Starling‐like physiological controllers (SLCs) have been developed to automatically regulate VAD flow based on ventricular preload. An SLC consists of a cardiac response curve (CRC) which imposes a nonlinear relationship between VAD flow and ventricular preload, and a venous return line (VRL) which determines the return path of the controller. This study investigates the importance of a physiological VRL in SLC of dual rotary blood pumps for biventricular support. Two experiments were conducted on a physical mock circulation loop (MCL); the first compared an SLC with an angled physiological VRL (SLC‐P) against an SLC with a vertical VRL (SLC‐V). The second experiment quantified the benefit of a dynamic VRL, represented by a series of specific VRLs, which could adapt to different circulatory states including changes in pulmonary (PVR) and systemic (SVR) vascular resistance versus a fixed physiological VRL which was calculated at rest. In both sets of experiments, the transient controller responses were evaluated through reductions in preload caused by the removal of fluid from the MCL. The SLC‐P produced no overshoot or oscillations following step changes in preload, whereas SLC‐V produced 0.4 L/min (12.5%) overshoot for both left and right VADs. Additionally, the SLC‐V had increased settling time and reduced controller stability as evidenced by transient controller oscillations. The transient results comparing the specific and standard VRLs demonstrated that specific VRL rise times were improved by between 1.2 and 4.7 s ( = 3.05 s), while specific VRL settling times were improved by between 2.8 and 16.1 seconds ( = 8.38 s) over the standard VRL. This suggests only a minor improvement in controller response time from a dynamic VRL compared to the fixed VRL. These results indicate that the use of a fixed physiologically representative VRL is adequate over a wide variety of physiological conditions. 相似文献
73.
A. Guerrero Gómez N. González Jaramillo J.A. Castro Pérez 《Revista espa?ola de anestesiología y reanimación》2019,66(1):10-17
Introduction
The fast track / ultra-fast-track protocols are techniques used to optimise the patient care process and a quick recovery after cardiac surgery. They are one of the mainstays of efficient practice. With their use, the length of hospital and intensive care unit (ICU) stays are reduced, with a direct impact on costs and the quality of the health service.Objective
To compare the length of stay in the ICU, length of hospital stay, and post-operative mortality in ultra-fast-track extubated (uFTE) patients and those with conventional extubation (CE) after cardiac surgery.Methods
Longitudinal, analytical, retrospective study was conducted, with the period between the time of surgery and discharge being included as the study period.Results
A total of 396 patients older than 18 years who required cardiac surgery were included, of whom 207 patients had (uFTE) and 189 had CE. Although the groups were not comparable due to the statistical differences found, when performing the multivariate adjustment, uFTE maintained its statistical independence and was associated with lower cardiovascular morbidity, such as myocardial ischaemia (95% CI: 0.37-0.86; P = .01) and lower post-surgical vasopressor requirement (95% CI: 0.18-0.49; P < .01). No significant differences were found in the length of hospital stay, ICU stay, or post-operative mortality in the ICU.Conclusion
Implementing the uFTE strategy, decreases cardiovascular morbidity and vasopressor requirement. The change to uFTE should be accompanied by changes in models and practices in patient recovery to standardised protocols. This study shows that uFTE did not reduce the length of ICU stay, hospital stay, or mortality. 相似文献74.
《Journal of pharmaceutical sciences》2019,108(10):3425-3433
This study aimed at evaluating how encapsulation in a regular nanocarrier (NC) (providing extended circulation time) or in a brain-targeting NC (providing prolonged circulation time and increased brain uptake) may influence the therapeutic index compared with the unformulated drug and to explore the key parameters affecting therapeutic performance using a model-based approach. Pharmacokinetic (PK) models were built with chosen PK parameters. For a scenario where central effect depends on area under the unbound brain concentration curve and peripheral toxicity relates to peak unbound plasma concentration, dose-effect and drug-side effect curves were constructed, and the therapeutic index was evaluated. Regular NC improved the therapeutic index compared with the unformulated drug due to reduced peripheral toxicity, while brain-targeting NC enhanced the therapeutic index by lowering peripheral toxicity and increasing central effect. Decreasing drug release rate or systemic clearance of NC with drug still encapsulated could increase the therapeutic index. Also, a drug with shorter half-life would therapeutically benefit more from a NC encapsulation. This work provides insights into how a NC for brain delivery should be optimized to maximize the therapeutic performance and is helpful to predict if and to what extent a drug with certain PK properties would obtain therapeutic benefit from nanoencapsulation. 相似文献
75.
Renal Denervation for Treatment of Cardiac Arrhythmias: State of the Art and Future Directions 下载免费PDF全文
JEDRZEJ KOSIUK M.D. SEBASTIAN HILBERT M.D. EVGENY POKUSHALOV M.D. GERHARD HINDRICKS M.D. Ph.D. JONATHAN S. STEINBERG M.D. ANDREAS BOLLMANN M.D. Ph.D. 《Journal of cardiovascular electrophysiology》2015,26(2):233-238
Renal Denervation for Treatment of Cardiac Arrhythmias . It has now been more than a quarter of a century since modulation of the sympathetic nervous system was proposed for the treatment of cardiac arrhythmias of different origins. But it has also been some time since some of the early surgical attempts have been abandoned. With the development of ablation techniques, however, new approaches and targets have been recently introduced that have revolutionized our way of thinking about sympathetic modulation. Renal nerve ablation technology is now being successfully used for the treatment of resistant hypertension, but the indication spectrum might broaden and new therapeutic options might arise in the near future. This review focuses on the possible impact of renal sympathetic system modulation on cardiac arrhythmias, the current evidence supporting this approach, and the ongoing trials of this method in electrophysiological laboratories. We will discuss the potential roles that sympathetic modulation may play in the future. 相似文献
76.
Carlos Robles-Medranda Manuel Valero Miguel Puga-Tejada Roberto Oleas Jorge Baquerizo-Burgos Miguel Soria-Alc var Haydee Alvarado-Escobar Hannah Pitanga-Lukashok 《World journal of gastrointestinal endoscopy》2020,12(1):23-32
BACKGROUND Accurate detection of gastric infection by Helicobacter pylori(H.pylori) and premalignant lesions are important for effective provision of treatment,preventing the development of gastric neoplasia.Optical enhancement systems with optical magnification improved the identification of mucosal superficial and vascular patterns in patients with dyspepsia.AIM To evaluate an optical enhancement system with high-definition magnification,for diagnosis of normal gastric mucosa,H.pylori-associated gastritis,and gastric atrophy.METHODS A cross-sectional,nonrandomized study from November 2015 to April 2016 performed in a single-tertiary academic center from Ecuador.Seventy-two consecutive patients with functional dyspepsia according to the Rome III criteria,were tested for H.pylori using a stool antigen test and were assigned to an Hp+group or an Hp-control group.Esophagogastroduodenoscopy with highdefinition optical magnification and digital chromoendoscopy was performed,and patients were classified into 4 groups,in accordance to the microvasculararchitecture pattern of the mucosa.Interobserver and intraobserver agreement among operators were calculated.RESULTS Of the 72 participants,35 were Hp+ and 37 were Hp-.Among 10 patients with normal mucosal histology in biopsy samples,90% had a Type I pattern of microvascular architecture by endoscopy.Among participants with type IIa and type IIb patterns,significantly more were Hp+ than Hp-(32 vs 8),and most(31 out of 40) had histological diagnoses of chronic active gastritis.Two of the three participants with a histological diagnosis of atrophy had a type III microvascular pattern.The type I pattern predicted normal mucosa,type IIa–IIb predicted H.pylori infection,and type III predicted atrophy with sensitivities of 90.0%,91.4%,and 66.7%,respectively.The intraobserver and interobserver agreements had kappa values of 0.91 and 0.89,respectively.CONCLUSION High-definition optical magnification with digital chromoendoscopy is useful for diagnosis of normal gastric mucosa and H.pylori-associated gastritis with high accuracy,but further studies are needed to determine whether endoscopic diagnosis of gastric atrophy is feasible. 相似文献
77.
通过探讨DRG支付方式改革下医院财务管理的应对策略,可以有效地降低医疗支付方式改革对医院财务管理的负面影响,促使医院财务管理在"危"与"机"的转换中抢抓机遇,促进医院财务管理提质增效。 相似文献
78.
79.
ObjectiveGrowing evidence demonstrates that perceived discrimination and racism are significant contributing factors to psychological distress, low-grade chronic inflammation, and cardiovascular health disparities among minorities, particularly among Black women. Despite this evidence, there are no evidence-based complementary therapy interventions available to ameliorate chronic stress associated with racism and discrimination. The purpose of this study was to examine the feasibility and effectiveness of a novel, 8-week, group-based stress reduction program, Resilience, Stress and Ethnicity (RiSE), designed to help Black women at risk for cardiovascular disease (CVD) develop effective coping skills for dealing with chronic stress uniquely associated with being a minority.MethodsWe conducted two semi-structured focus groups with Black women (N = 22) following their participation in the 8-week RiSE program. We analyzed the data using constant comparative qualitative methods.ResultsAttrition rate was low (13%) with all participants attending at least 6 of the 8 classes. Participants reported high levels of satisfaction with the program and the majority (81%) reported practicing the skills that they learned in real-life stressful situations. In describing the participants’ response to the program, four key categories emerged from the data: (1) Increasing awareness of stressors associated with perceived discrimination and racism; (2) Coping with race-based stressors; (3) Coping with other sources of stress; and (4) Increasing sense of empowerment and emotion regulation.ConclusionsFindings suggest that RiSE is feasible and effective in helping Black women at risk for CVD cope with chronic stress associated with being a minority. Given evidence that perceived discrimination and racism are underlying factors in many inflammatory-based chronic diseases, this research may have broader implications for reducing health disparities across a wide-spectrum of chronic illnesses in which women minorities are disproportionately affected. 相似文献
80.