全文获取类型
收费全文 | 1159篇 |
免费 | 83篇 |
国内免费 | 99篇 |
专业分类
儿科学 | 1篇 |
妇产科学 | 10篇 |
基础医学 | 80篇 |
口腔科学 | 175篇 |
临床医学 | 170篇 |
内科学 | 315篇 |
皮肤病学 | 18篇 |
神经病学 | 66篇 |
特种医学 | 107篇 |
外科学 | 54篇 |
综合类 | 184篇 |
预防医学 | 40篇 |
眼科学 | 5篇 |
药学 | 77篇 |
中国医学 | 30篇 |
肿瘤学 | 9篇 |
出版年
2023年 | 12篇 |
2022年 | 41篇 |
2021年 | 52篇 |
2020年 | 49篇 |
2019年 | 40篇 |
2018年 | 43篇 |
2017年 | 57篇 |
2016年 | 54篇 |
2015年 | 55篇 |
2014年 | 103篇 |
2013年 | 91篇 |
2012年 | 75篇 |
2011年 | 91篇 |
2010年 | 49篇 |
2009年 | 73篇 |
2008年 | 53篇 |
2007年 | 54篇 |
2006年 | 66篇 |
2005年 | 47篇 |
2004年 | 35篇 |
2003年 | 32篇 |
2002年 | 16篇 |
2001年 | 13篇 |
2000年 | 12篇 |
1999年 | 10篇 |
1998年 | 14篇 |
1997年 | 10篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 6篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有1341条查询结果,搜索用时 0 毫秒
31.
目的:研究PPARγ基因表达与ApoE-/-小鼠主动脉斑块成份的相互关系。方法:以20和40周龄ApoE-/-小鼠(n=10/组)为研究对象,相同基因背景和周龄C57BL/6 J小鼠设为对照。采用RT-PCR和免疫印迹技术检测各组小鼠主动脉PPARγ基因和蛋白表达变化;Movat 5色套染法和油红O染色检测ApoE-/-小鼠主动脉斑块成份;免疫组织化学技术检测斑块内PPARγ、SM-actin、MOMA-2抗原表达。结合免疫荧光技术分析PPARγ基因在主动脉斑块巨噬细胞、平滑肌细胞的表达及与脂质、弹性纤维、胶原和蛋白聚糖的相互关系。结果:20和40周龄C57BL/6 J小鼠主动脉壁有少量PPARγ表达,以20周龄组明显。ApoE-/-小鼠主动脉壁和斑块内PPARγ表达增多,以斑块内表达明显(P<0.05);与20周龄组比较,40周龄组表达最显著;且斑块脂质含量丰富;弹性纤维、胶原和蛋白聚糖含量减少,血管正性重塑明显;MOMA-2表达增加,SM-actin表达降低(P<0.05)。PPARγ在斑块内巨噬细胞、血管中膜平滑肌细胞和斑块内平滑肌细胞都有表达,但以脂质含量丰富处PPARγ表达最明显。结论:PPARγ在C57BL/6 J小鼠动脉壁表达随增龄而减少;在ApoE-/-小鼠主动脉壁和斑块内PPARγ表达随AS病变进程而增加。推测ApoE-/-小鼠主动脉斑块PPARγ表达上调可能是机体一种代偿行为和自我保护机制。 相似文献
32.
不同含漱液控制菌斑和消除牙龈炎症效果的比较 总被引:3,自引:1,他引:3
目的:研究护齿含漱剂、口泰含漱液、万宝林牙齿、口腔清洁液在控制菌斑和牙龈炎的作用.方法:选择203例牙龈炎患者,随机分为护齿含漱剂组、口泰含漱液组、万宝林牙齿、口腔清洁液组、多贝尔氏液组和蒸馏水组,用药前后检查牙龈指数(GI)、牙龈出血指数(SBI)、菌斑指数(PLI).结果:用药后护齿含漱剂、口泰含漱液、万宝林牙齿、口腔清洁液组的GI、SBI、PLE均比用药前有明显降低(p<0.01),且优于多贝尔氏液和蒸馏水组.结论:护齿含漱剂、口泰含漱液、万宝林牙齿、口腔清洁液能有效控制菌斑及牙龈炎 相似文献
33.
目的观察Listerine漱口水对固定矫治患者牙周及牙菌斑的影响。方法选择30例固定矫治患者,年龄12~25岁,随机分成实验组和对照组,实验组使用Listerine漱口水漱口,对照组不使用漱口水。分别测量治疗初,3个月,6个月时的菌斑指数(PLI),牙龈指数(GI),出血指数(BI)。应用SPSS10.0统计软件,采用Student-newman-Keuls比较不同时间各指数间的差异。采用t检验比较同一时间同一指数实验组和对照组间的差异。以P≤0.05为有统计学意义。结果实验组在3个月,6个月时BI,PLI,GI升高缓慢,无统计学意义。实验组在3个月和6个月时的PLI,GI,BI值明显低于对照组,且有统计学差异,PLI:(P〈0.01),GI:(P〈0.01),BI:(P〈0.001)。6个月时对照组同实验组间的PLI,GI,BI也有明显的统计学差异(P〈0.001)。结论使用Listerine漱口水可以明显减少固定矫治患者的牙菌斑及牙龈炎的发生发展,有利于患者保持口腔卫生。 相似文献
34.
冠状动脉轻中度狭窄病变的血管内超声特征 总被引:5,自引:2,他引:5
通过分析病变的结构特点 ,探讨轻中度狭窄病变斑块不稳定的机制。对冠状动脉造影显示轻中度狭窄(直径狭窄率 2 0 %~ 6 0 % ) 6 2例及重度狭窄 2 6例冠心病患者行血管内超声显像检查 ,分析粥样硬化斑块性质及其狭窄程度。结果发现 ,轻中度狭窄患者中软斑块 (6 8.2 %比 15 .4 % ,P <0 .0 1)、薄纤维帽 (6 5 .9%比 7.7% ,P <0 .0 1)显著多于重度狭窄患者 ,并且斑块破裂 (2 8.2 %比 7.7% ,P <0 .0 1)及正性重构 (5 1.8%比 0 % ,P <0 .0 1)也显著多于重度狭窄患者。轻中度狭窄患者偏心斑块检出率显著多于重度狭窄者 (84 .7%比 30 .1% ,P <0 .0 1) ,但钙化少见 (16 .5 %比 84 .6 % ,P <0 .0 1)。结果提示 ,冠状动脉造影轻中度狭窄患者多数具有不稳定性斑块的结构特点 ,这些特点导致轻中度狭窄者容易发生急性冠状动脉综合征。 相似文献
35.
《Journal of Cardiovascular Computed Tomography》2019,13(5):254-260
Invasive coronary plaque imaging such as intravascular ultrasound and optical coherence tomography has been widely used to observe culprit or non-culprit coronary atherosclerosis, as well as optimize stent sizing, apposition and deployment. Coronary computed tomographic angiography (CTA) is non-invasively available to assess coronary artery disease (CAD) and has become an appropriate strategy to evaluate patients with suspected CAD. Given recent technologies, semi-automated plaque software is available to identify coronary plaque stenosis, volume and characteristics and potentially allows to be used for the assessment of more details of plaque information, progression and future risk as a surrogate tool of the invasive imaging modalities. This review article aims to focus on various evidence in coronary plaque imaging by coronary CTA and describes how accurate coronary CTA can classify coronary atherosclerosis. 相似文献
36.
《Journal of Cardiovascular Computed Tomography》2018,12(5):436-443
BackgroundCoronary computed tomography angiography (CCTA) not only provides information regarding luminal stenoses but also allows for visualization of mural atheromatous changes (coronary plaques).ObjectiveWe sought to elucidate whether plaques seen on CCTA enable prediction of 2-year outcomes in patients with suspected and known coronary artery disease (CAD).MethodsOf 3015 patients who underwent CCTA, the images and 2-year clinical courses of 2802 patients were independently analyzed. The primary endpoint was the composite of all-cause death and acute coronary syndrome.ResultsDuring the 2-year observation period, 49 (1.7%) patients developed the primary outcome. The 2-year rates of the primary outcome in the normal (n = 515, no mural lesions), calcium (n = 654, calcified lesion alone), and plaque groups (n = 1633, presence of noncalcified or partially calcified plaques) were 0.2%, 2.0%, and 2.1%, respectively (P = 0.0028). Adverse plaque features such as low attenuation, positive remodeling, spotty calcification, and the napkin-ring sign (low-attenuation core with a higher-attenuation rim) were assessed by an independent core laboratory. Stepwise multivariate Cox proportional hazard analysis showed that a plaque with two or more characteristics (adjusted hazard ratio, 1.98; 95% confidence interval, 1.09–3.60; P = 0.0254), age of ≥67 years (mean), statin treatment after CCTA, and obstructive stenosis remained independent predictors of the primary outcome.ConclusionsPlaque imaging in CCTA has predictive value for the 2-year outcome and is a useful identifier for high-risk patients among those with known and suspected CAD. 相似文献
37.
S. Rozie T. T. de Weert C. de Monyé P. J. Homburg H. L. J. Tanghe D. W. J. Dippel A. van der Lugt 《European radiology》2009,19(9):2294-2301
The purpose of this study was to examine the volume and the composition of atherosclerotic plaque in symptomatic carotid arteries
and to investigate the relationship between these plaque features and the severity of stenosis and the presence of cardiovascular
risk factors. One hundred patients with cerebrovascular symptoms underwent CT angiography. We measured plaque volume (PV)
and the relative contribution of plaque components (calcifications, fibrous tissue, and lipid) in the symptomatic artery.
The contribution of different components was measured as the number of voxels within defined ranges of HU values (calcification
>130 HU, fibrous tissue 60–130 HU, lipid core <60 HU). Fifty-seven patients had atherosclerotic plaque in the symptomatic
carotid artery. The severity of stenosis and PV were moderately correlated. Age and smoking were independently related to
PV. Patients with hypercholesterolemia had significantly less lipid and more calcium in their plaques than patients without
hypercholesterolemia. Other cardiovascular risk factors were not significantly related to PV or plaque composition. Luminal
stenosis of the carotid artery partly reflects the amount of atherosclerotic carotid disease. Plaque volume and plaque composition
are associated with cardiovascular risk factors. 相似文献
38.
Hui Gu Yang Gao Haiping Wang Zhennan Li Liang Xu Bo Xu Ximing Wang Bin Lu 《Journal of Cardiovascular Computed Tomography》2017,11(2):105-110
Background
To compare the difference of coronary diameter stenosis by quantitative analysis of CT angiography (QCT) in the systolic (QCT-S) and diastolic phase (QCT-D) of the cardiac cycle, with invasive catheter angiography (QCA) as reference standard.Methods
A total of 109 patients (57.5 ± 10.6 years, 78.9% male) with suspected coronary artery disease (CAD) who underwent both CT angiography and invasive catheter angiography were retrospectively included in this study. Coronary diameter stenoses in systolic and diastolic coronary CTA reconstructions were compared with QCA.Results
Mean time interval between CT angiography and invasive angiography was 17.4 ± 4.4 days. QCT-D overestimated coronary diameter stenosis by 5.7%–8.5% while QCT-S overestimated coronary diameter stenosis by 9.4%–11.9% (p < 0.05). In calcified lesions, QCT-D overestimated coronary diameter stenosis by 13.2 ± 4.3%, while QCT-S overestimated by stenosis by 16.6 ± 4.3% (p < 0.05).Conclusions
Coronary diameter stenosis was overestimated by QCT-D as well as QCT-S, respectively, when compared with QCA. Overestimation was more pronounced in calcified lesions. 相似文献39.
《Journal of Cardiovascular Computed Tomography》2023,17(3):177-184
BackgroundThe various plaque components have been associated with ischemia and outcomes in patients with coronary artery disease (CAD). The main goal of this analysis was to test the hypothesis that, at patient level, the fraction of non-calcified plaque volume (PV) of total PV is associated with ischemia and outcomes in patients with CAD. This ratio could be a simple and clinically useful parameter, if predicting outcomes.MethodsConsecutive patients with suspected CAD undergoing coronary computed tomography angiography with selective positron emission tomography perfusion imaging were selected. Plaque components were quantitatively analyzed at patient level. The fraction of various plaque components were expressed as percentage of total PV and examined among patients with non-obstructive CAD, suspected stenosis with normal perfusion, and those with reduced myocardial perfusion. Clinical outcomes included all-cause mortality and myocardial infarction.ResultsIn total, 494 patients (age 63 ± 9 years, 55% male) were included. Total PV and all plaque components were significantly larger in patients with reduced myocardial perfusion compared to patients with normal perfusion and those with non-obstructive CAD. During follow-up 35 events occurred. Patients with any plaque component ≥ median showed worse outcomes (log-rank p < 0.001 for all). In addition, low-attenuation plaque ≥ median was associated with worse outcomes independent of total PV (adjusted HR: 2.754, 95% CI: 1.022–7.0419, p = 0.045). The fractions of the various plaque components were not associated with outcomes.ConclusionLarger total PV or any plaque component at patient level are associated with abnormal myocardial perfusion and adverse events. The various plaque components as fraction of total PV lack additional prognostic value. 相似文献
40.
目的探讨血管性痴呆患者检测颈动脉粥样硬化的临床意义。方法经临床确诊的血管性痴呆患者30例,年龄等人口学指标匹配的健康体检者30例作为对照组。利用高频超声探测颈动脉内-中膜厚度(IMT)及粥样硬化斑块形成情况。结果血管性痴呆组的IMT增厚、粥样硬化斑块发生率明显高于对照组(P〈0.05);血管性痴呆组中软斑检出率高于硬斑及混合斑(P〈0.05)。血管性痴呆组患者的IMT及粥样硬化斑块形成率明显高于对照组,血管性痴呆组检出斑块中软斑占优势。结论高频超声是检测血管性痴呆患者颈动脉粥样硬化的简便而有效的方法,具有重要的临床价值。 相似文献