首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1882篇
  免费   101篇
  国内免费   45篇
耳鼻咽喉   9篇
儿科学   6篇
妇产科学   2篇
基础医学   48篇
口腔科学   111篇
临床医学   139篇
内科学   940篇
皮肤病学   2篇
神经病学   109篇
特种医学   86篇
外科学   342篇
综合类   163篇
现状与发展   1篇
预防医学   19篇
眼科学   1篇
药学   34篇
  1篇
中国医学   13篇
肿瘤学   2篇
  2024年   2篇
  2023年   45篇
  2022年   73篇
  2021年   114篇
  2020年   130篇
  2019年   98篇
  2018年   128篇
  2017年   47篇
  2016年   61篇
  2015年   81篇
  2014年   123篇
  2013年   135篇
  2012年   76篇
  2011年   86篇
  2010年   65篇
  2009年   71篇
  2008年   76篇
  2007年   76篇
  2006年   53篇
  2005年   43篇
  2004年   57篇
  2003年   47篇
  2002年   46篇
  2001年   45篇
  2000年   37篇
  1999年   28篇
  1998年   30篇
  1997年   30篇
  1996年   14篇
  1995年   10篇
  1994年   6篇
  1993年   10篇
  1992年   12篇
  1991年   15篇
  1990年   9篇
  1989年   2篇
  1988年   8篇
  1987年   5篇
  1986年   3篇
  1985年   6篇
  1984年   5篇
  1983年   4篇
  1982年   6篇
  1981年   8篇
  1977年   1篇
  1976年   1篇
排序方式: 共有2028条查询结果,搜索用时 46 毫秒
61.
62.
Brief commentary about implications of the Pilot Study of Mechanical Thrombectomy in the Public Healthcare System of Chile.  相似文献   
63.
目的观察iRoot BP Plus在根管内血运重建术中的治疗效果。方法选取接受治疗的80例年轻恒牙牙髓坏死患者为研究对象,随机分为观察组(n=40)与对照组(n=40)。2组均行根管内血运重建术,对照组采用矿物三氧化聚合体(MTA)封闭根管上段,观察组采用iRoot BP Plus封闭根管上段。观察2组患者6个月后的治疗总有效率,比较6、12个月牙本质表面牙骨质样组织沉积率。结果治疗6个月后,观察组治愈20例,好转13例,无效7例,总有效率为82.5%。对照组治疗6个月后治愈17例,好转11例,无效12例,总有效率为70.0%。观察组总有效率高于对照组,差异有统计学意义(P<0.05)。治疗后6、12个月,观察组牙本质表面牙骨质样组织沉积率均高于对照组,差异有统计学意义(P<0.05)。结论iRoot BP Plus应用于根管内血运重建术治疗年轻恒牙牙髓坏死可获得更好的治疗效果,可作为治疗年轻恒牙的牙髓坏死的新选择。  相似文献   
64.
To describe the morphology of the proximal femoral epiphysis in a rabbit model from the ischemic insult to the end of the revascularization process. Ischemia of the femoral head was induced in 32 rabbits at the 8th day of life, by sectioning the joint capsule and the ligamentum teres and dislocating the femoral head. Rabbits were sacrificed at 4, 8, 12, 18, 21, 26, 34, and 48 days after surgery and femoral heads were observed histologically. During the first days following the ischemic injury, large areas underwent necrotic changes. Both epiphyseal and physeal cartilage were thicker than normal and less trabecular bone formation was evident. Bone marrow was also diffusely necrotic within the secondary center of ossification. After day 12th, reparative process started with formation of extensive areas of fibrocartilage and several secondary centers of ossifications. At that stage femoral head deformity was already evident. In the following days the secondary centers of ossification cohalesced and epiphyseal and physeal cartilage resumed a normal appearance, but the femur showed a permanent deformity. In newborn rabbits, the ischemic injury to the femoral head blocked the ossification of the epiphyseal and physeal cartilage associated to necrotic bone marrow within the secondary center of ossification of the femoral head as well as to extensive areas of necrosis of epiphyseal and physeal cartilage. Extensive areas of fibrocartilage and small newly formed ossification centers within the femoral epiphysis were the results of the revascularization process, and femoral head deformity became stable afterward. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:535–541, 2015.  相似文献   
65.
《Indian heart journal》2019,71(6):481-487
BackgroundFrontal QRS-T angle (FQRST) has previously been correlated with mortality in patients with stable coronary artery disease, but its role as survival predictor after ST-elevation myocardial infarction (STEMI) remains unknown.MethodsWe evaluated 267 consecutive patients with STEMI undergoing reperfusion or coronary artery bypass grafting. Data assessed included demographics, clinical presentation, electrocardiograms, medical therapy, and one-year mortality.ResultsOf 267 patients, 187 (70%) were males and most (49.4%) patients were Caucasian. All-cause mortality was significantly higher among patients with the highest (101–180°) FQRST [28% vs. 15%, p = 0.02]. Patients with FQRST 1–50° had higher survival (85.6%) compared with FQRST = 51–100° (72.3%) and FQRST = 101–180° (67.9%), [log rank, p = 0.01]. Adjusting for significant variables identified during univariate analysis, FQRST (OR = 2.04 [95% CI: 1.31–13.50]) remained an independent predictor of one-year mortality. FQRST-based risk score (1–50° = 0 points, 51–100° = 2 points, 101–180° = 5 points) had excellent discriminatory ability for one-year mortality when combined with Mayo Clinic Risk Score (C statistic = 0.875 [95%CI: 0.813–0.937]. A high (>4 points) FQRST risk score was associated with greater mortality (32% vs. 19%, p = 0.02) and longer length of stay (6 vs. 2 days, p < 0.001).ConclusionFQRST represents a novel independent predictor of one-year mortality in patients with STEMI undergoing reperfusion. A high FQRST-based risk score was associated with greater mortality and longer length of stay and, after combining with Mayo Clinic Risk Score, improved discriminatory ability for one-year mortality.  相似文献   
66.
  • Coronary stents are commonly deployed using high pressure. However, the duration time of balloon inflation during deployment is still to be determined.
  • Vallurupalli and coworkers, in this issue of CCI, show that the stent system takes an average of 33 sec to “accommodate” its pressure during in vitro deployment. In patients, the mean stent inflation time to achieve pressure stability was 104 seconds, ranging from 30 to 380 sec.
  • These results challenge a rapid inflation/deflation approach for stent deployment. It is suggested that the duration of the inflation might be individualized, in a case‐by‐case approach.
  • However, the findings must be interpreted with caution, as they cannot be directly extrapolated to more diverse clinical, angiographic, and interventional scenarios.
  相似文献   
67.
ObjectivesThis study sought to determine the relationship between the severity of reduced quantitative perfusion parameters and mortality with and without revascularization.BackgroundThe physiological mechanisms for differential mortality risk of coronary flow reserve (CFR) and coronary flow capacity (CFC) before and after revascularization are unknown.MethodsGlobal and regional rest-stress (ml/min/g), CFR, their regional per-pixel combination as CFC, and relative stress in ml/min/g were measured as percent of LV in all serial routine 5,274 diagnostic PET scans with systematic follow-up over 10 years (mean 4.2 ± 2.5 years) for all-cause mortality with and without revascularization.ResultsSeverely reduced CFR of 1.0 to 1.5 and stress perfusion ≤1.0 cc/min/g incurred increasing size-dependent risks that were additive because regional severely reduced CFC (CFCsevere) was associated with the highest major adverse cardiac event rate of 80% (p < 0.0001 vs. either alone) and a mortality risk of 14% (vs. 2.3% for no CFCsevere; p = 0.001). Small regions of CFCsevere ≤0.5% predicted high risk (p < 0.0001 vs. no CFCsevere) related to a wave front of border zones at risk around the small most severe center. By receiver-operating characteristic analysis, relative stress topogram maps of stress (ml/min/g) as a fraction of LV defined these border zones at risk or for mildly reduced CFC (area under the curve [AUC]: 0.69) with a reduced relative tomographic subendocardial-to-subepicardial ratio. CFCsevere incurred the highest mortality risk that was reduced by revascularization (p = 0.005 vs. no revascularization) for artery-specific stenosis not defined by global CFR or stress perfusion alone.ConclusionsCFC is associated with the size-dependent highest mortality risk resulting from the additive risk of CFR and stress (ml/min/g) that is significantly reduced after revascularization, a finding not seen for global CFR. Small regions of CFCsevere ≤0.5% of LV also carry a high risk because of the surrounding border zones at risk defined by relative stress perfusion and a reduced relative subendocardial-to-subepicardial ratio.  相似文献   
68.

Objectives

The aim of this study was to assess the safety and effectiveness of a next-generation low-dose drug-coated balloon (DCB) designed to optimize the amount of drug transferred into the vessel wall and to maximize the amount of time the drug resides in the vessel wall.

Background

Several randomized controlled studies evaluating various DCBs have demonstrated a significantly higher patency rate compared with noncoated percutaneous transluminal angioplasty balloons at 1 year. However, the data are limited and vary by DCB at longer follow-up time points. An earlier generation low-dose DCB failed to demonstrate significant treatment effect at 2 years, raising questions regarding the durability of low-dose DCBs.

Methods

In this prospective, multicenter trial, 294 patients were randomized (3:1) to treatment with a DCB or an uncoated percutaneous transluminal angioplasty balloon. Assessments at 2 years included primary patency with duplex ultrasonography, clinically driven target lesion revascularization, and functional outcomes.

Results

Primary patency at 2 years was significantly higher in the DCB cohort (75.9% vs. 61.0%; p = 0.025), and the rate of clinically driven target lesion revascularization was significantly lower (12.1% vs. 30.5%; p < 0.001). There were no major limb amputations in either group. The rates of all-cause (6.5% vs. 5.1%; p = 1.00) and cardiovascular-related (1.6% vs. 1.7%; p = 1.00) mortality were similar between groups. Functional improvements over baseline were sustained in both groups, with 60% fewer reinterventions in the DCB group.

Conclusions

A sustained treatment effect is achievable with a low-dose DCB with an optimized coating formulation. This trial demonstrated for the first time a statistically significantly higher primary patency rate for a low-dose DCB versus PTA at 2 years. (CVI Drug Coated Balloon European Randomized Clinical Trial; NCT01858363)  相似文献   
69.

Objectives

The authors sought to investigate the impact of diabetes mellitus (DM) on outcomes following contemporary drug-eluting stent (DES) implantation in the BIONICS (BioNIR Ridaforolimus Eluting Coronary Stent System in Coronary Stenosis) trial.

Background

Patients with DM are at increased risk for adverse events following percutaneous coronary intervention (PCI).

Methods

A prospective, multicenter, 1:1 randomized trial was conducted to evaluate in a noninferiority design the safety and efficacy of ridaforolimus-eluting stents versus zotarolimus-eluting stents among 1,919 patients undergoing PCI. Randomization was stratified to the presence of medically treated DM, and a pre-specified analysis compared outcomes according to the presence or absence of DM up to 2 years.

Results

The overall prevalence of DM was 29.1% (559 of 1,919). DM patients had higher body mass index, greater prevalence of hyperlipidemia and hypertension, and smaller reference vessel diameter. One-year target lesion failure (cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization) was significantly higher among diabetic patients (7.8% vs. 4.2%; p = 0.002), mainly due to higher target lesion revascularization (4.5% vs. 2.0%; p = 0.002). Rates of cardiac death, myocardial infarction, and stent thrombosis did not statistically vary. Among 158 patients undergoing 13-month angiographic follow-up, restenosis rates were 3 times higher in diabetic patients compared with nondiabetic patients (15.2% vs. 4.7%; p = 0.01). Clinical and angiographic outcomes were similar between ridaforolimus-eluting stent– and zotarolimus-eluting stent–treated patients.

Conclusions

Despite advances in interventional therapies, and the implementation of new-generation DES, diabetic patients still have worse angiographic and clinical outcomes compared with nondiabetic patients undergoing PCI.  相似文献   
70.
Immature avulsed teeth are not usually treated with pulp revascularization because of the possibility of complications. However, this therapy has shown success in the treatment of immature teeth with periapical lesions. This report describes the case of an immature replanted tooth that was successfully treated by pulp revascularization. An 8‐year‐old boy suffered avulsion on his maxillary left lateral incisor. The tooth showed incomplete root development and was replanted after 30 minutes. After diagnosis, revascularization therapy was performed by irrigating the root canal and applying a calcium hydroxide paste and 2% chlorhexidine gel for 21 days. In the second session, the intracanal dressing was removed and a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate was placed as a cervical barrier at the entrance of the root canal and the crown was restored. During the follow‐up period, periapical repair, apical closure and calcification in the apical 4 mm of the root canal was observed. An avulsed immature tooth replanted after a brief extra‐alveolar period and maintained in a viable storage medium may be treated with revascularization.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号