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   1508篇
  免费   83篇
  国内免费   7篇
耳鼻咽喉   19篇
儿科学   42篇
妇产科学   24篇
基础医学   136篇
口腔科学   7篇
临床医学   173篇
内科学   331篇
皮肤病学   7篇
神经病学   194篇
特种医学   54篇
外科学   260篇
综合类   13篇
预防医学   146篇
眼科学   13篇
药学   64篇
中国医学   2篇
肿瘤学   113篇
  2023年   10篇
  2022年   17篇
  2021年   15篇
  2020年   12篇
  2019年   35篇
  2018年   35篇
  2017年   28篇
  2016年   30篇
  2015年   26篇
  2014年   56篇
  2013年   65篇
  2012年   90篇
  2011年   131篇
  2010年   71篇
  2009年   61篇
  2008年   116篇
  2007年   85篇
  2006年   105篇
  2005年   106篇
  2004年   75篇
  2003年   85篇
  2002年   78篇
  2001年   32篇
  2000年   29篇
  1999年   30篇
  1998年   24篇
  1997年   14篇
  1996年   12篇
  1995年   9篇
  1994年   2篇
  1993年   7篇
  1992年   5篇
  1991年   3篇
  1990年   7篇
  1989年   5篇
  1988年   9篇
  1987年   9篇
  1986年   11篇
  1985年   13篇
  1984年   5篇
  1983年   6篇
  1982年   7篇
  1981年   4篇
  1980年   3篇
  1978年   2篇
  1975年   2篇
  1973年   2篇
  1972年   2篇
  1969年   4篇
  1961年   1篇
排序方式: 共有1598条查询结果,搜索用时 0 毫秒
151.
Elevated plasma levels of inflammatory markers, such as C-reactive protein (CRP), have been associated with adverse outcome in selected patients with coronary artery disease (CAD) treated with coronary angioplasty or stenting. The aim of this study was to evaluate the predictive value of preprocedural interleukin-1 receptor antagonist (IL-1Ra) plasma levels for long-term major adverse cardiac events (MACE) in a series of unselected patients with symptomatic CAD treated with percutaneous coronary intervention (PCI). Seventy-three consecutive patients (62 men, aged 62 +/- 9 years) undergoing PCI were enrolled in a prospective follow-up study. IL-1Ra and CRP plasma levels were measured before the procedure; 36 patients (49%) had unstable angina pectoris on admission, 37 (51%) had chronic stable angina pectoris, and 30 (41%) had multivessel CAD, 15 of whom underwent multivessel PCI. Success was achieved in all 73 patients, with coronary stenting performed in 63 (86%). Follow-up clinical assessment included occurrence of MACE at 3, 6, 12, and 18 months. Logistic regression analysis, performed to determine independent predictors of MACE, identified IL-1Ra levels in the upper quartile as the only independent predictive factor of MACE at 18 months (19% in the fourth quartile vs 0% in the first quartile; p = 0.032). Patients with high preprocedural CRP levels (fourth quartile) had a nonsignificant increased risk of MACE (p = 0.09). Thus, preprocedural IL-1Ra plasma levels appear to be a valuable independent predictive factor of MACE in unselected patients undergoing PCI.  相似文献   
152.
153.

Objectives

This study sought to evaluate the feasibility, safety, and efficacy of intracardiac echocardiography (ICE)–guided versus transesophageal echocardiography (TEE)–guided left atrial appendage occlusion (LAAO) by the use of Amplatzer Cardiac Plug or Amulet devices included in a large Italian registry.

Background

TEE is widely used for LAAO procedure guidance. ICE may be a potential alternative imaging modality in LAAO.

Methods

Data from 604 LAAO procedures performed in 16 Italian centers were reviewed. ICE-guided LAAO was performed in 187 patients, whereas TEE was used in 417 patients. Procedural success was defined as LAAO without occurrence of pericardial tamponade, stroke, systemic embolism with end organ damage, major bleeding, and device embolization. Stroke, transient ischemic attack, major bleeding, overall and cardiovascular death were analyzed.

Results

CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65 to 74 years, sex category) and HAS-BLED (hypertension, abnormal renal and liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol) scores were similar between the ICE and TEE groups. TEE implied lower procedural (delta 12 min) and fluoroscopy time (delta 5 min) when compared with ICE. Procedural success was similarly high (≥94%) between the TEE and ICE groups with a complication rate of 6.5% for TEE versus 4.2% for ICE (odds ratio: 1.468; 95% confidence interval: 0.681 to 3.166; p = 0.327). At median follow-up of 451 days (interquartile range: 162 to 899 days), the rate of cerebral ischemic events was similar between TEE-guided and ICE-guided procedures.

Conclusions

ICE-guided LAAO by means of Amplatzer devices may represent a second alternative imaging modality after an appropriate learning curve and bearing in mind that pre-procedural computed tomography imaging is mandatory. When comparing ICE with TEE, TEE remains the gold standard.  相似文献   
154.
Allopurinol is a first line agent in treating gout, but it also carries the risk of severe side effects. Stevens-Johnson syndrome (SJS) is one of the life threatening severe cutaneous adverse reactions caused by allopurinol. The severity of the severe cutaneous adverse reactions can be categorized based upon the area of skin involvement: (1) erythema multiforme major limited to 1-2 % of the body surface area (BSA); (2) SJS involving <10% of the BSA, (3) SJS and toxic epidermal necrolysis overlap involving 10-30% of the BSA and (4) toxic epidermal necrolysis syndrome involving >30% of the BSA. SJS can be caused by drugs and viruses, the former being more frequent. We report a case of an 85-year-old Han-Chinese female who developed SJS after ingestion of allopurinol 8 days prior to the hospitalization. The patient also had concomitant acute viral illness, which complicated the clinical scenario causing acute renal failure and hemodynamic compromise.  相似文献   
155.
Esophageal diverticula are rare. The association of cancer and diverticula has been described. Some authors adopt a conservative non‐surgical approach in selected patients with diverticula whereas others treat the symptoms by diverticulopexy or myotomy only, leaving the diverticulum in situ. However, the risk of malignant degeneration should be may be taken in account if the diverticulum is not resected. The correct evaluation of the possible risk factors for malignancy may help in the decision making process. We performed a literature review of esophageal diverticula and cancer. The incidence of cancer in a diverticulum is 0.3–7, 1.8, and 0.6% for pharyngoesophageal, midesophageal, and epiphrenic diverticula, respectively. Symptoms may mimic those of the diverticulum or underlying motor disorder. Progressive dysphagia, unintentional weight loss, the presence of blood in the regurgitated material, regurgitation of peaces of the tumor, odynophagia, melena, hemathemesis, and hemoptysis are key symptoms. Risk factors for malignancy are old age, male gender, long‐standing history, and larger diverticula. A carcinoma may develop in treated diverticula, even after resection. Outcomes are usually quoted as dismal because of a delayed diagnosis but several cases of superficial carcinoma have been described. The treatment follows the same principals as the therapy for esophageal cancer; however, diverticulectomy is enough in cases of superficial carcinomas. Patients must be carefully evaluated before therapy and a long‐term follow‐up is advisable.  相似文献   
156.
We report a case of spontaneous familial pneumothorax in fraternal twin boys. The twins' family history is remarkable for reactive airway disease and a female sibling also born with spontaneous pneumothorax. The family had no history of connective tissue disorders, renal cancer, or dermatologic diseases. Analysis of the twins' α(1)-antitrypsin (AAT) genotype, phenotype, and serum concentration revealed that both were compound heterozygous for rare SERPINA1 alleles. These findings suggest a role for AAT deficiency in spontaneous pneumothorax of the newborn. To our knowledge, these are the first genetic data to support etiology of neonatal spontaneous familial pneumothorax.  相似文献   
157.
158.
Bivalirudin, a direct thrombin inhibitor, is as effective as unfractionated heparin (UFH), with decreased bleeding in patients with acute coronary syndromes who undergo percutaneous coronary intervention (PCI). The aim of this study was to evaluate the effectiveness of bivalirudin versus UFH in selected PCI patients at high bleeding risk. Four hundred one consecutive patients who underwent PCI fulfilling ≥ 1 enrollment criterion (age >75 years, chronic renal failure, and diabetes mellitus) were randomized to bivalirudin (bolus 0.75 mg/kg followed by infusion during the procedure; n = 198) or UFH (75 IU/kg; n = 203). In the overall population, 39% were aged >75 years, 22% had renal failure, 63% had diabetes, and 29% had acute coronary syndromes. The primary efficacy end point was the 30-day incidence of major adverse cardiac events (cardiac death, myocardial infarction, stent thrombosis, or target vessel revascularization). The primary safety end point was the occurrence of any bleeding or entry-site complications after PCI. All patients were preloaded with clopidogrel 600 mg. Glycoprotein IIb/IIIa inhibitors were used at the operators' discretion. Thirty-day major adverse cardiac event rates were 11.1% in the bivalirudin group and 8.9% in the UFH group (p = 0.56); the primary efficacy end point was reached mainly because of periprocedural myocardial infarction; 1 patient in the bivalirudin group had stent thrombosis. Occurrence of the primary safety end point was 1.5% in the bivalirudin group and 9.9% in the UFH group (p = 0.0001); this benefit was essentially driven by the prevention of entry-site hematomas >10 cm (0.5% vs 6.9%, p = 0.002). In conclusion, Anti-Thrombotic Strategy for Reduction of Myocardial Damage During Angioplasty-Bivalirudin vs Heparin (ARMYDA-7 BIVALVE) indicates that bivalirudin, compared with UFH, causes significantly lower bleeding and has a similar incidence of major adverse cardiac events in patients with older age, diabetes mellitus, or chronic renal failure who undergo PCI.  相似文献   
159.
160.
Summary To compare the effects of dietary cholesterol supplementation in insulin-dependent diabetic (IDDM) patients and normal subjects, 10 male IDDM patients in good glycaemic control (HbA1 c 7.3 ± 0.9 %) (mean ± SD) and normal plasma lipid levels, and 11 control male subjects of similar age, body mass index and lipid plasma levels underwent a double blind, cross-over, sequential study. Cholesterol supplementation of 800 mg/day or placebo were given for consecutive periods of 3 weeks. The concentration of plasma total cholesterol increased significantly with the dietary cholesterol supplementation compared to placebo in IDDM patients by 6 % (p < 0.05) and in control subjects by 9 % (p < 0.05). No changes were observed in the concentration of plasma triglycerides in either group. The LDL cholesterol level increased by 12 % (p < 0.01) in patients and by 7 % (p < 0.05) in control subjects. In patients plasma HDL cholesterol concentration remained the same, while in control subjects it tended to increase after cholesterol supplementation (from 1.14 ± 0.26 to 1.23 ± 0.27 mmol/l, p = 0.06). During the cholesterol intake period the mean concentration of LDL1, LDL2 and LDL3 subclasses in patients showed a significant increase by 21.0 (p < 0.05), 20.4 (p < 0.001) and 11.1 % (p < 0.05), respectively, resulting in an 18.0 % increase in mean total LDL mass (p < 0.001) without major changes in LDL composition. In the control subjects the changes in the concentrations of LDL subclasses during cholesterol intake were less and not significant. In the IDDM patients the cholesterol intake did not affect the concentration or composition of HDL subclasses or total HDL mass. In contrast, in control subjects cholesterol intake increased the mean concentration of HDL2 a by 12.2.% (p < 0.05) and this increase was significantly different if compared to changes obtained in the patients. In conclusion, compared to normal subjects, in IDDM patients, dietary cholesterol intake increased the LDL particle mass significantly and had no positive effect on HDL. [Diabetologia (1998) 41: 193–200] Received: 4 July 1997 and in revised form: 12 September 1997  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