全文获取类型
收费全文 | 162720篇 |
免费 | 15024篇 |
国内免费 | 4758篇 |
专业分类
耳鼻咽喉 | 1233篇 |
儿科学 | 2103篇 |
妇产科学 | 1540篇 |
基础医学 | 18988篇 |
口腔科学 | 4689篇 |
临床医学 | 16593篇 |
内科学 | 16171篇 |
皮肤病学 | 1627篇 |
神经病学 | 15277篇 |
特种医学 | 5303篇 |
外国民族医学 | 13篇 |
外科学 | 11471篇 |
综合类 | 24998篇 |
现状与发展 | 14篇 |
一般理论 | 3篇 |
预防医学 | 25429篇 |
眼科学 | 1806篇 |
药学 | 20670篇 |
203篇 | |
中国医学 | 7920篇 |
肿瘤学 | 6451篇 |
出版年
2024年 | 231篇 |
2023年 | 2701篇 |
2022年 | 4028篇 |
2021年 | 6887篇 |
2020年 | 7110篇 |
2019年 | 5970篇 |
2018年 | 5555篇 |
2017年 | 5894篇 |
2016年 | 6138篇 |
2015年 | 6021篇 |
2014年 | 11151篇 |
2013年 | 12165篇 |
2012年 | 10731篇 |
2011年 | 11421篇 |
2010年 | 8749篇 |
2009年 | 8246篇 |
2008年 | 8116篇 |
2007年 | 7890篇 |
2006年 | 6895篇 |
2005年 | 5946篇 |
2004年 | 4957篇 |
2003年 | 4448篇 |
2002年 | 3494篇 |
2001年 | 3189篇 |
2000年 | 2552篇 |
1999年 | 2135篇 |
1998年 | 1909篇 |
1997年 | 1763篇 |
1996年 | 1487篇 |
1995年 | 1570篇 |
1994年 | 1517篇 |
1993年 | 1226篇 |
1992年 | 1164篇 |
1991年 | 1059篇 |
1990年 | 887篇 |
1989年 | 856篇 |
1988年 | 804篇 |
1987年 | 733篇 |
1986年 | 625篇 |
1985年 | 837篇 |
1984年 | 685篇 |
1983年 | 416篇 |
1982年 | 466篇 |
1981年 | 392篇 |
1980年 | 378篇 |
1979年 | 259篇 |
1978年 | 210篇 |
1977年 | 171篇 |
1976年 | 157篇 |
1974年 | 85篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Saudi Pharmaceutical Journal》2022,30(6):669-678
BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction. 相似文献
2.
3.
《Dental materials》2022,38(1):204-213
ObjectiveTo investigate the fatigue behavior of restored teeth, in particular the mechanisms of longitudinal dentinal cracking under cyclic mechanical loading, using finite element analysis (FEA) and the stress-life (S-N) approach.MethodsTen root-filled premolars restored with resin composites were subjected to step-stress cyclic loading to produce longitudinal cracks. Fracture loads and number of cycles completed at each load level were recorded. FEA was used to predict the stress amplitude of each component under the global cyclic load. Both intact and debonded conditions were considered for the dentin-composite interface in the FEA. The predicted stress concentrations were compared with the fracture patterns to help elucidate the failure mechanisms. The S-N approach was further used to predict the lifetimes of the different components in the restored teeth. Cumulative fatigue damage was represented by the sum of the fractions of life spent under the different stress amplitudes.ResultsLongitudinal cracks were seen in ~50% of the samples with a mean fracture load of 770 ± 45 N and a mean number of cycles to failure of 32,297 ± 12,624. The longitudinal dentinal cracks seemed to start near the line angle of the cavity, and propagated longitudinally towards the root. The sum of fractions of life spent for the dentin-composite interface exceeded 1 after ~7000 cycles when that for dentin was much lower than 1, indicating that interfacial debonding would occur prior to dentin fracture. This was supported by micro-CT images showing widened interfacial space in the cracked samples. In the debonded tooth, FEA showed dentinal stress concentrations at the gingival wall of the cavity, which coincided with the longitudinal cracks found in the cyclic loading test. The sum of fractions of life spent for dentin was close to 1 at ~30,000 cycles, similar to the experimental value.SignificanceDebonding of the dentin-composite interface may occur prior to longitudinal cracking of dentin in root-filled teeth under cyclic loading. The approximate time of occurrence for these events could be estimated using fatigue analysis with stresses provided by FEA. This methodology can therefore be used to evaluate the longevity of restoration designs for root-filled teeth. 相似文献
4.
5.
《The British journal of oral & maxillofacial surgery》2022,60(5):610-616
In patients treated by orbital wall decompression for endocrine orbitopathy (EO) there is limited evidence on the effect of orbital wall resections. Thus, the aim of this study was to evaluate the effect of one, two, and three-wall resections on orbital parameters to determine if any such correlations exist. Preoperative and postoperative data from all patients at a tertiary care centre who underwent decompression surgery from 2010 - 2020 were digitally analysed. The effect of the number and area of resected walls on orbital area, orbital volume, and Hertel value, and the effect of lateral rim advancement (LARA) were determined. A total of 131 orbital areas showed an increase from a mean (SD) preoperative area of 42.0 (4.6) cm2 to 47.3 (6.1) cm2 postoperatively (p<0.001). In total, the mean (SD) area of osseous wall removed in all patients was 6.2 (1.7) cm2 at the lateral orbit (n = 129), 6.7 (2.3) cm2 at the orbital floor (n = 123), and 5.8 (1.8) cm2 at the medial orbital wall (n =30). The mean (SD) orbital volume increased by 6.0 (3.0) cm3 after decompression. There was also a significant reduction in exophthalmos of 7.3 (3.2) mm (from 25.2 (3.9) to 17.9 (3.5), p<0.001). LARA was performed in 50 patients. Changes in volume and area, and reduction in exophthalmos were not significantly different with or without LARA. The postoperative effects of orbital wall resection are predictable and exhibit a relation with six units of change. Two-wall resection is the most common intervention. 相似文献
6.
《台湾医志》2022,121(9):1864-1871
7.
《Transfusion Clinique et Biologique》2022,29(3):269-272
A delayed haemolytic transfusion reaction (DHTR) encompasses a positive direct antiglobulin test (DAT) developed anytime between 24 hours to 28 days after cessation of transfusion, a positive eluate or a newly identified alloantibody in the plasma or serum along with features of haemolysis in the patient. Routinely, it is expected that with the transfusion of one unit of packed red cells in a patient of average height and weight, the haemoglobin level and hematocrit increase by 1 g/dL and 3% respectively. However, in a patient with DHTR, an inadequate rise of post-transfusion haemoglobin (< 1 g/dL) or rapid fall in haemoglobin back to pre-transfusion levels is observed. Kidd antibodies are particularly known to cause DHTR, maybe alone or in unison with other antibodies. Detection of these alloantibodies is consequential in providing good transfusion support to these patients. These events may be difficult to detect as they may present as varied clinical features or immunological nuisances. In this case series, we have presented three cases of DHTR with special emphasis on their clinical presentations, immunohaematological evaluations, laboratory parameters and the role of proper transfusion support in these patients to avoid further complications. 相似文献
8.
9.
《Nutrition, metabolism, and cardiovascular diseases : NMCD》2022,32(5):1165-1174
Background and aimsThe extent to which dietary patterns influence the risk of abnormal blood lipids throughout young adulthood remains unclear. The aim was to investigate whether early young adulthood dietary patterns predict the risk of abnormal blood lipids during later young adulthood.Methods and resultsWe used data from a long running birth cohort study in Australia. Western dietary pattern rich in meats, processed foods and high-fat dairy products and prudent pattern rich in fruit, vegetables, fish, nuts, whole grains and low-fat dairy products were derived using principal component analysis at the 21-year follow-up from dietary data obtained using a food frequency questionnaire. After 9-years, fasting blood samples of all participants were collected and their total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterols and triglyceride (TG) levels were measured. Abnormal blood lipids were based on clinical cut-offs for total, LDL and HDL cholesterols, and TG and relative distributions for total:HDL and TG:HDL cholesterols ratios. Log-binomial models were used to estimate risk of each outcome in relation to dietary patterns. Greater adherence to the Western pattern predicted increased risks of high LDL (RR: 1.47; 95%CI: 1.06, 2.03) and TG (1.90; 1.25, 2.86), and high ratios of total:HDL (1.48; 1.00, 2.19) and TG:HDL (1.78; 1.18, 2.70) cholesterols in fully adjusted models. Conversely, a prudent pattern predicted reduced risks of low HDL (0.58; 0.42, 0.78) and high TG (0.66; 0.47, 0.92) and high total:HDL (0.71; 0.51, 0.98) and TG:HDL (0.61; 0.45, 0.84) cholesterols ratios.ConclusionThis is the first prospective study to show greater adherence to unhealthy Western diet predicted increased risks of abnormal blood lipids, whereas healthy prudent diet predicted lower such risks in young adults. Addressing diets in early course may improve cardiovascular health of young adults. 相似文献
10.
目的:通过小范围的临床实践,使用数据包络分析(data envelopment analysis,DEA)方法对基于全程化抗栓药学服务模式的华法林抗凝管理工作效率进行评价。方法:选取2021年7-12月南京大学医学院附属鼓楼医院心胸外科瓣膜置换术后使用华法林抗凝的患者。将患者分为实验组和对照组,实验组由临床药师利用基于分级管理的全程化抗栓药学服务模式进行抗凝管理和药学监护,对照组由临床药师按照无差别监护模式进行抗凝管理和监护,记录2种模式下药师工作内容和工作成效,通过DEA方法分析比较2种抗凝管理模式的效率。结果:研究最终纳入服用华法林的患者233人(实验组116人,对照组117人),实验组的单位患者管理时间显著减少[(27.8±9.7)min vs.(34.8±11.4)min]。经模型计算后,实验组的总体效率值为1,说明其投入和产出最优,且效率高于对照组。结论:全程化抗栓药学服务模式下药师管理单位抗凝患者需要的时间更少,管理效率更高。 相似文献