全文获取类型
收费全文 | 58171篇 |
免费 | 3180篇 |
国内免费 | 1497篇 |
专业分类
耳鼻咽喉 | 359篇 |
儿科学 | 921篇 |
妇产科学 | 812篇 |
基础医学 | 4079篇 |
口腔科学 | 309篇 |
临床医学 | 7696篇 |
内科学 | 14514篇 |
皮肤病学 | 104篇 |
神经病学 | 3479篇 |
特种医学 | 5136篇 |
外国民族医学 | 3篇 |
外科学 | 9128篇 |
综合类 | 9153篇 |
现状与发展 | 3篇 |
预防医学 | 1350篇 |
眼科学 | 489篇 |
药学 | 3417篇 |
27篇 | |
中国医学 | 1215篇 |
肿瘤学 | 654篇 |
出版年
2024年 | 73篇 |
2023年 | 803篇 |
2022年 | 1297篇 |
2021年 | 2198篇 |
2020年 | 1976篇 |
2019年 | 1786篇 |
2018年 | 1834篇 |
2017年 | 1636篇 |
2016年 | 1706篇 |
2015年 | 1856篇 |
2014年 | 3970篇 |
2013年 | 3800篇 |
2012年 | 3230篇 |
2011年 | 3604篇 |
2010年 | 3097篇 |
2009年 | 3094篇 |
2008年 | 3148篇 |
2007年 | 3197篇 |
2006年 | 2917篇 |
2005年 | 2420篇 |
2004年 | 1922篇 |
2003年 | 1661篇 |
2002年 | 1357篇 |
2001年 | 1314篇 |
2000年 | 993篇 |
1999年 | 907篇 |
1998年 | 906篇 |
1997年 | 842篇 |
1996年 | 639篇 |
1995年 | 638篇 |
1994年 | 524篇 |
1993年 | 479篇 |
1992年 | 423篇 |
1991年 | 339篇 |
1990年 | 291篇 |
1989年 | 260篇 |
1988年 | 243篇 |
1987年 | 213篇 |
1986年 | 174篇 |
1985年 | 209篇 |
1984年 | 170篇 |
1983年 | 89篇 |
1982年 | 139篇 |
1981年 | 100篇 |
1980年 | 85篇 |
1979年 | 82篇 |
1978年 | 63篇 |
1977年 | 48篇 |
1976年 | 42篇 |
1975年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
33.
34.
患者男,22岁,无明显诱因咳嗽、痰中带血1周,起初干咳,后咳痰并痰中带血,偶咯出少量暗红色血液;无发热、盗汗、乏力,无胸闷、胸痛及呼吸困难,平素体健,无家族病史。查体:双肺呼吸音稍粗,右肺下叶闻及细湿啰音。胸部增强CT:右肺下叶基底段见片状磨玻璃影,内见直径约8mm粗大供血动脉自腹腔干发出;支气管树分支及肺发育正常,未见隔离肺(图1A^1C)。肺动脉CTA示右下肺基底段动脉部分缺如(图1D),考虑为右下肺异常体动脉供血并周围肺组织肺泡出血可能。 相似文献
35.
Changes in Right Ventricular Shape and Deformation Following Coronary Artery Bypass Surgery—Insights from Echocardiography with Strain Rate and Magnetic Resonance Imaging 下载免费PDF全文
36.
37.
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
38.
Roberto V.P. Ribeiro Mitesh V. Badiwala Danny Ramzy Laura C. Tumiati Vivek Rao 《The Journal of thoracic and cardiovascular surgery》2019,157(2):615-625.e1
Objective
Hypertonic saline (HTS) has potent immune and vascular effects. We assessed recipient pretreatment with HTS on allograft function in a porcine model of heart transplantation and hypothesized that HTS infusion would limit endothelial and left ventricular (LV) dysfunction following transplantation.Methods
Heart transplants were performed after 6 hours of cold ischemic storage. Recipient pigs were randomized to treatment with or without HTS (7.5% NaCl) before cardiopulmonary bypass (CPB). Using a myograft apparatus, coronary artery endothelial-dependent (Edep) and -independent (Eind) relaxation was assessed. LV performance was determined using pressure-volume loop analysis. Pulmonary interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α expression was measured.Results
Weaning from CPB and LV performance after transplantation were improved in HTS-treated animals. Successful weaning from CPB was greater in the HTS-treated hearts (8 of 8 vs 2 of 8; P < .05). Mean LV functional recovery was improved in the HTS-treated animals, as assessed by preload recruitable stroke work (65 ± 10% vs 27 ± 10%; P < .001) and end-systolic elastance (55 ± 7% vs 37 ± 4%; P < .001). Treatment with HTS resulted in improved Edep (mean maximum elastance [Emax], 56 ± 5% vs 37 ± 7%; P < .001) and Eind (mean Emax%, 77 ± 6% vs 52 ± 4%; P < .001) vasorelaxation compared with control. Pulmonary expression of IL-2, IL-6, and TNF-α increased following transplantation, whereas HTS therapy attenuated IL production (P < .001). Transplantation increased plasma TNF-α levels and LV TNF-α expression, whereas HTS prevented this up-regulation (P < .001).Conclusions
Recipient HTS pretreatment preserves allograft vasomotor and LV function, and HTS therapy limits CPB-induced injury. HTS may be a novel recipient intervention to prevent graft dysfunction. 相似文献39.
J.A. Hannam S.J. Mitchell D. Cumin C. Frampton A.F. Merry M.R. Moore C.J. Kruger 《British journal of anaesthesia》2019,122(2):198-205
Background
Etomidate is frequently selected over propofol for induction of anaesthesia because of a putatively favourable haemodynamic profile, but data confirming this perception are limited.Methods
Patients undergoing cardiac surgery were randomised to induction of anaesthesia with propofol or etomidate. Phase I (n=75) was conducted as open-label, whereas Phase II (n=75) was double blind. Mean arterial blood pressure (MAP) and boluses of vasopressor administered after induction were recorded. The primary endpoint was the area under the curve below baseline MAP (MAP-time integral) during the 10 min after induction. Secondary endpoints were the use of vasopressors over the same period, and the effect of blinding on the aforementioned endpoints. Groups were compared using regression models with phase and anaesthetist as factors.Results
The mean difference between etomidate and propofol in the MAP-time integral below baseline was 2244 mm Hg s (95% confidence interval, 581–3906; P=0.009), representing a 34% greater reduction with propofol. Overall, vasopressors were used in 10/75 patients in the etomidate group vs 21/75 in the propofol group (P=0.38), and in 20/74 patients during the blinded phase vs 11/76 during the open-label phase (P=0.31). The interaction between randomisation and phase (open-labelled or blinded) was not significant for either primary (P=0.73) or secondary endpoints (P=0.90).Conclusions
Propofol caused a 34% greater reduction in MAP-time integral from baseline after induction of anaesthesia than etomidate, despite more frequent use of vasopressors with propofol, confirming the superior haemodynamic profile of etomidate in this context. The proportion of patients receiving vasopressors increased slightly, albeit not significantly, in both groups in the blinded phase.Clinical trial registration
Australian and New Zealand Clinical Trials Registry, ACTRN12614000717651. 相似文献40.
Ewelina Kazimierczyk Andrzej Eljaszewicz Paula Zembko Ewa Tarasiuk Malgorzata Rusak Agnieszka Kulczynska-Przybik Marta Lukaszewicz-Zajac Karol Kaminski Barbara Mroczko Maciej Szmitkowski Milena Dabrowska Bozena Sobkowicz Marcin Moniuszko Agnieszka Tycinska 《Pharmacological reports : PR》2019,71(1):73-81