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1.
Context  Following percutaneous coronary intervention (PCI), short-term clopidogrel therapy in addition to aspirin leads to greater protection from thrombotic complications than aspirin alone. However, the optimal duration of combination oral antiplatelet therapy is unknown. Also, although current clinical data suggest a benefit for beginning therapy with a clopidogrel loading dose prior to PCI, the practical application of this therapy has not been prospectively studied. Objectives  To evaluate the benefit of long-term (12-month) treatment with clopidogrel after PCI and to determine the benefit of initiating clopidogrel with a preprocedure loading dose, both in addition to aspirin therapy. Design, Setting, and Participants  The Clopidogrel for the Reduction of Events During Observation (CREDO) trial, a randomized, double-blind, placebo-controlled trial conducted among 2116 patients who were to undergo elective PCI or were deemed at high likelihood of undergoing PCI, enrolled at 99 centers in North America from June 1999 through April 2001. Interventions  Patients were randomly assigned to receive a 300-mg clopidogrel loading dose (n = 1053) or placebo (n = 1063) 3 to 24 hours before PCI. Thereafter, all patients received clopidogrel, 75 mg/d, through day 28. From day 29 through 12 months, patients in the loading-dose group received clopidogrel, 75 mg/d, and those in the control group received placebo. Both groups received aspirin throughout the study. Main Outcome Measures  One-year incidence of the composite of death, myocardial infarction (MI), or stroke in the intent-to-treat population; 28-day incidence of the composite of death, MI, or urgent target vessel revascularization in the per-protocol population. Results  At 1 year, long-term clopidogrel therapy was associated with a 26.9% relative reduction in the combined risk of death, MI, or stroke (95% confidence interval [CI], 3.9%-44.4%; P = .02; absolute reduction, 3%). Clopidogrel pretreatment did not significantly reduce the combined risk of death, MI, or urgent target vessel revascularization at 28 days (reduction, 18.5%; 95% CI, -14.2% to 41.8%; P = .23). However, in a prespecified subgroup analysis, patients who received clopidogrel at least 6 hours before PCI experienced a relative risk reduction of 38.6% (95% CI, -1.6% to 62.9%; P = .051) for this end point compared with no reduction with treatment less than 6 hours before PCI. Risk of major bleeding at 1 year increased, but not significantly (8.8% with clopidogrel vs 6.7% with placebo; P = .07). Conclusions  Following PCI, long-term (1-year) clopidogrel therapy significantly reduced the risk of adverse ischemic events. A loading dose of clopidogrel given at least 3 hours before the procedure did not reduce events at 28 days, but subgroup analyses suggest that longer intervals between the loading dose and PCI may reduce events.   相似文献
2.
Context  Patients with serum thyroid-stimulating hormone (TSH) levels outside the reference range and levels of free thyroxine (FT4) and triiodothyronine (T3) within the reference range are common in clinical practice. The necessity for further evaluation, possible treatment, and the urgency of treatment have not been clearly established. Objectives  To define subclinical thyroid disease, review its epidemiology, recommend an appropriate evaluation, explore the risks and benefits of treatment and consequences of nontreatment, and determine whether population-based screening is warranted. Data Sources  MEDLINE, EMBASE, Biosis, the Agency for Healthcare Research and Quality, National Guideline Clearing House, the Cochrane Database of Systematic Reviews and Controlled Trials Register, and several National Health Services (UK) databases were searched for articles on subclinical thyroid disease published between 1995 and 2002. Articles published before 1995 were recommended by expert consultants. Study Selection and Data Extraction  A total of 195 English-language or translated papers were reviewed. Editorials, individual case studies, studies enrolling fewer than 10 patients, and nonsystematic reviews were excluded. Information related to authorship, year of publication, number of subjects, study design, and results were extracted and formed the basis for an evidence report, consisting of tables and summaries of each subject area. Data Synthesis  The strength of the evidence that untreated subclinical thyroid disease is associated with clinical symptoms and adverse clinical outcomes was assessed and recommendations for clinical practice developed. Data relating the progression of subclinical to overt hypothyroidism were rated as good, but data relating treatment to prevention of progression were inadequate to determine a treatment benefit. Data relating a serum TSH level higher than 10 mIU/L to elevations in serum cholesterol were rated as fair but data relating to benefits of treatment were rated as insufficient. All other associations of symptoms and benefit of treatment were rated as insufficient or absent. Data relating a serum TSH concentration lower than 0.1 mIU/L to the presence of atrial fibrillation and progression to overt hyperthyroidism were rated as good, but no data supported treatment to prevent these outcomes. Data relating restoration of the TSH level to within the reference range with improvements in bone mineral density were rated as fair. Data addressing all other associations of subclinical hyperthyroid disease and adverse clinical outcomes or treatment benefits were rated as insufficient or absent. Subclinical hypothyroid disease in pregnancy is a special case and aggressive case finding and treatment in pregnant women can be justified. Conclusions  Data supporting associations of subclinical thyroid disease with symptoms or adverse clinical outcomes or benefits of treatment are few. The consequences of subclinical thyroid disease (serum TSH 0.1-0.45 mIU/L or 4.5-10.0 mIU/L) are minimal and we recommend against routine treatment of patients with TSH levels in these ranges. There is insufficient evidence to support population-based screening. Aggressive case finding is appropriate in pregnant women, women older than 60 years, and others at high risk for thyroid dysfunction.   相似文献
3.
Obstructive sleep apnea: implications for cardiac and vascular disease   总被引:55,自引:0,他引:55  
Context  Obstructive sleep apnea (OSA) has been increasingly implicated in the initiation and progression of cardiovascular diseases. Objective  To systematically review the interactions of OSA with cardiovascular pathophysiology and diseases. Data Sources and Study Selection  The MEDLINE database from January 1966 to March 2003 was searched using the Medical Subject Headings sleep, sleep apnea, obesity, hypertension, heart failure, cardiac arrhythmia, coronary artery disease, stroke, sympathetic activity, endothelium, inflammation, and continuous positive airway pressure (CPAP) to identify peer-reviewed studies of OSA. Priority was given to large prospective cohort studies and to randomized controlled trials. Data Extraction  We identified 154 original investigations and reviews of sleep-related breathing disorders. Data from these studies were examined for relevance and extracted by one of the authors. Data Synthesis  Approximately 1 in 5 adults has at least mild OSA (apnea-hypopnea index [ie, the number of apneic and hypopneic events per hour], 5-15), and 1 in 15 adults has at least moderate OSA (apnea-hypopnea index, 15-30). Repetitive apneic events disrupt the normal physiologic interactions between sleep and the cardiovascular system. Such sleep fragmentation, as well as abnormalities evident in patients with OSA (eg, increased sympathetic activation, vascular endothelial dysfunction, increased oxidative stress, inflammation, increased platelet aggregability, metabolic dysregulation), may be implicated in the initiation and progression of cardiac and vascular disease. Persuasive data implicate OSA in the development of hypertension, and OSA also may contribute to cardiac ischemia, congestive heart failure, cardiac arrhythmias, and perhaps also to cerebrovascular disease and stroke. Conclusions  Obstructive sleep apnea is common, readily diagnosed, and usually treatable. It frequently coexists undiagnosed in patients with cardiovascular disease, activates disease mechanisms known to elicit cardiac and vascular damage, and may be implicated in progression of cardiovascular disease and resistance to conventional therapeutic strategies. In the absence of definitive evidence from large-scale trials and a better understanding of potential cost-effectiveness, the likely benefits of diagnosis and treatment of OSA are presently best appraised on an individualized patient basis.   相似文献
4.
Context  Progressive heart failure is the most common mechanism of death among patients with advanced heart failure. Cardiac resynchronization, a pacemaker-based therapy for heart failure, enhances cardiac performance and quality of life, but its effect on mortality is uncertain. Objective  To determine whether cardiac resynchronization reduces mortality from progressive heart failure. Data Sources  MEDLINE (1966-2002), EMBASE (1980-2002), the Cochrane Controlled Trials Register (Second Quarter, 2002), The National Institutes of Health ClinicalTrials.gov database, the US Food and Drug Administration Web site, and reports presented at scientific meetings (1994-2002). Search terms included pacemaker, pacing, heart failure, dual-site, multisite, biventricular, resynchronization, and left ventricular preexcitation. Study Selection  Eligible studies were randomized controlled trials of cardiac resynchronization for the treatment of chronic symptomatic left ventricular dysfunction. Eligible studies reported death, hospitalization for heart failure, or ventricular arrhythmia as outcomes. Of the 6883 potentially relevant reports initially identified, 11 reports of 4 randomized trials with 1634 total patients were included in the meta-analysis. Data Extraction  Trial reports were reviewed independently by 2 investigators in an unblinded standardized manner. Data Synthesis  Follow-up in the included trials ranged from 3 to 6 months. Pooled data from the 4 selected studies showed that cardiac resynchronization reduced death from progressive heart failure by 51% relative to controls (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.25-0.93). Progressive heart failure mortality was 1.7% for cardiac resynchronization patients and 3.5% for controls. Cardiac resynchronization also reduced heart failure hospitalization by 29% (OR, 0.71; 95% CI, 0.53-0.96) and showed a trend toward reducing all-cause mortality (OR, 0.77; 95% CI, 0.51-1.18). Cardiac resynchronization was not associated with a statistically significant effect on non–heart failure mortality (OR, 1.15; 95% CI, 0.65-2.02). Among patients with implantable cardioverter defibrillators, cardiac resynchronization had no clear impact on ventricular tachycardia or ventricular fibrillation (OR, 0.92; 95% CI, 0.67-1.27). Conclusions  Cardiac resynchronization reduces mortality from progressive heart failure in patients with symptomatic left ventricular dysfunction. This finding suggests that cardiac resynchronization may have a substantial impact on the most common mechanism of death among patients with advanced heart failure. Cardiac resynchronization also reduces heart failure hospitalization and shows a trend toward reducing all-cause mortality.   相似文献
5.
CONTEXT: Approximately half of patients with overt congestive heart failure (CHF) have diastolic dysfunction without reduced ejection fraction (EF). Yet, the prevalence of diastolic dysfunction and its relation to systolic dysfunction and CHF in the community remain undefined. OBJECTIVES: To determine the prevalence of CHF and preclinical diastolic dysfunction and systolic dysfunction in the community and determine if diastolic dysfunction is predictive of all-cause mortality. DESIGN, SETTING, PARTICIPANTS: Cross-sectional survey of 2042 randomly selected residents of Olmsted County, Minnesota, aged 45 years or older from June 1997 through September 2000. MAIN OUTCOME MEASURES: Doppler echocardiographic assessment of systolic and diastolic function. Presence of CHF diagnosis by review of medical records with designation as validated CHF if Framingham criteria are satisfied. Subjects without a CHF diagnosis but with diastolic or systolic dysfunction were considered as having either preclinical diastolic or preclinical systolic dysfunction. RESULTS: The prevalence of validated CHF was 2.2% (95% confidence interval [CI], 1.6%-2.8%) with 44% having an EF higher than 50%. Overall, 20.8% (95% CI, 19.0%-22.7%) of the population had mild diastolic dysfunction, 6.6% (95% CI, 5.5%-7.8%) had moderate diastolic dysfunction, and 0.7% (95% CI, 0.3%-1.1%) had severe diastolic dysfunction with 5.6% (95% CI, 4.5%-6.7%) of the population having moderate or severe diastolic dysfunction with normal EF. The prevalence of any systolic dysfunction (EF < or =50%) was 6.0% (95% CI, 5.0%-7.1%) with moderate or severe systolic dysfunction (EF < or =40%) being present in 2.0% (95% CI, 1.4%-2.5%). CHF was much more common among those with systolic or diastolic dysfunction than in those with normal ventricular function. However, even among those with moderate or severe diastolic or systolic dysfunction, less than half had recognized CHF. In multivariate analysis, controlling for age, sex, and EF, mild diastolic dysfunction (hazard ratio, 8.31 [95% CI, 3.00-23.1], P<.001) and moderate or severe diastolic dysfunction (hazard ratio, 10.17 [95% CI, 3.28-31.0], P<.001) were predictive of all-cause mortality. CONCLUSIONS: In the community, systolic dysfunction is frequently present in individuals without recognized CHF. Furthermore, diastolic dysfunction as rigorously defined by comprehensive Doppler techniques is common, often not accompanied by recognized CHF, and associated with marked increases in all-cause mortality.  相似文献
6.
Context  Contrast-induced nephropathy remains a common complication of radiographic procedures. Pretreatment with sodium bicarbonate is more protective than sodium chloride in animal models of acute ischemic renal failure. Acute renal failure from both ischemia and contrast are postulated to occur from free-radical injury. However, no studies in humans or animals have evaluated the efficacy of sodium bicarbonate for prophylaxis against contrast-induced nephropathy. Objective  To examine the efficacy of sodium bicarbonate compared with sodium chloride for preventive hydration before and after radiographic contrast. Design, Setting, and Patients  A prospective, single-center, randomized trial conducted from September 16, 2002, to June 17, 2003, of 119 patients with stable serum creatinine levels of at least 1.1 mg/dL (=" BORDER="0">97.2 µmol/L) who were randomized to receive a 154-mEq/L infusion of either sodium chloride (n = 59) or sodium bicarbonate (n = 60) before and after iopamidol administration (370 mg iodine/mL). Serum creatinine levels were measured at baseline and 1 and 2 days after contrast. Interventions  Patients received 154 mEq/L of either sodium chloride or sodium bicarbonate, as a bolus of 3 mL/kg per hour for 1 hour before iopamidol contrast, followed by an infusion of 1 mL/kg per hour for 6 hours after the procedure. Main Outcome Measure  Contrast-induced nephropathy, defined as an increase of 25% or more in serum creatinine within 2 days of contrast. Results  There were no significant group differences in age, sex, incidence of diabetes mellitus, ethnicity, or contrast volume. Baseline serum creatinine was slightly higher but not statistically different in patients receiving sodium bicarbonate treatment (mean [SD], 1.71 [0.42] mg/dL [151.2 {37.1} µmol/L] for sodium chloride and 1.89 [0.69] mg/dL [167.1 {61.0} µmol/L] for sodium bicarbonate; P = .09). The primary end point of contrast-induced nephropathy occurred in 8 patients (13.6%) infused with sodium chloride but in only 1 (1.7%) of those receiving sodium bicarbonate(mean difference, 11.9%; 95% confidence interval [CI], 2.6%-21.2%; P = .02). A follow-up registry of 191 consecutive patients receiving prophylactic sodium bicarbonate and meeting the same inclusion criteria as the study resulted in 3 cases of contrast-induced nephropathy (1.6%; 95% CI, 0%-3.4%). Conclusion  Hydration with sodium bicarbonate before contrast exposure is more effective than hydration with sodium chloride for prophylaxis of contrast-induced renal failure.   相似文献
7.
8.
Context  Memantine is a low- to moderate-affinity, uncompetitive N-methyl-D-aspartate receptor antagonist. Controlled trials have demonstrated the safety and efficacy of memantine monotherapy for patients with moderate to severe Alzheimer disease (AD) but no controlled trials of memantine in patients receiving a cholinesterase inhibitor have been performed. Objective  To compare the efficacy and safety of memantine vs placebo in patients with moderate to severe AD already receiving stable treatment with donepezil. Design, Setting, and Participants  A randomized, double-blind, placebo-controlled clinical trial of 404 patients with moderate to severe AD and Mini-Mental State Examination scores of 5 to 14, who received stable doses of donepezil, conducted at 37 US sites between June 11, 2001, and June 3, 2002. A total of 322 patients (80%) completed the trial. Interventions  Participants were randomized to receive memantine (starting dose 5 mg/d, increased to 20 mg/d, n = 203) or placebo (n = 201) for 24 weeks. Main Outcome Measures  Change from baseline on the Severe Impairment Battery (SIB), a measure of cognition, and on a modified 19-item AD Cooperative Study–Activities of Daily Living Inventory (ADCS-ADL19). Secondary outcomes included a Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-Plus), the Neuropsychiatric Inventory, and the Behavioral Rating Scale for Geriatric Patients (BGP Care Dependency Subscale). Results  The change in total mean (SE) scores favored memantine vs placebo treatment for SIB (possible score range, 0-100), 0.9 (0.67) vs –2.5 (0.69), respectively (P<.001); ADCS-ADL19 (possible score range, 0-54), –2.0 (0.50) vs –3.4 (0.51), respectively (P = .03); and the CIBIC-Plus (possible score range, 1-7), 4.41 (0.074) vs 4.66 (0.075), respectively (P = .03). All other secondary measures showed significant benefits of memantine treatment. Treatment discontinuations because of adverse events for memantine vs placebo were 15 (7.4%) vs 25 (12.4%), respectively. Conclusions  In patients with moderate to severe AD receiving stable doses of donepezil, memantine resulted in significantly better outcomes than placebo on measures of cognition, activities of daily living, global outcome, and behavior and was well tolerated. These results, together with previous studies, suggest that memantine represents a new approach for the treatment of patients with moderate to severe AD.   相似文献
9.
Context  Laparoscopic-assisted colectomy (LAC) has emerged as the preferred minimally invasive surgical strategy for diseases of the colon. The safety and efficacy of LAC for colon cancer are unknown, and the nature and magnitude of any quality-of-life (QOL) benefit resulting from LAC for colon cancer is also unknown. Objective  To compare short-term QOL outcomes after LAC vs open colectomy for colon cancer. Design, Setting, and Participants  Multicenter, randomized controlled trial (Clinical Outcomes of Surgical Therapy [COST]). Between September 1994 and February 1999, 37 of 48 centers provided data for the QOL component of the trial for 449 consecutive patients with clinically resectable colon cancer. Main Outcome Measures  Scores on the Symptoms Distress Scale (SDS), Quality of Life Index, and a single-item global rating scale at 2 days, 2 weeks, and 2 months postoperative; duration of postoperative in-hospital analgesic use; and length of stay. Results  Of 449 patients, 428 provided QOL data. In an intention-to-treat analysis comparing SDS pain intensity, SDS summary, QOL Index summary, and global rating scale scores at each time point, the only statistically significant difference observed between groups was the global rating scale score for 2 weeks postsurgery. The mean (median) global rating scale scores for 2 weeks postsurgery were 76.9 (80) for LAC vs 74.4 (75) for open colectomy (P = .009). While in the hospital, patients assigned to LAC required fewer days of both parenteral analgesics compared with patients assigned to open colectomy (mean [median], 3.2 [3] vs 4.0 [4] days; P<.001) and oral analgesics (mean [median], 1.9 [1] vs 2.2 [2] days; P = .03). Conclusion  Only minimal short-term QOL benefits were found with LAC for colon cancer compared with standard open colectomy. Until ongoing trials establish that LAC is as effective as open colectomy in preventing recurrence and death from colon cancer, this procedure should not be offered to patients with colon cancer.   相似文献
10.
Sunitinib in patients with metastatic renal cell carcinoma   总被引:34,自引:0,他引:34  
Context  Current treatment options for metastatic renal cell carcinoma (RCC) are limited and there is a need to identify novel and effective therapies. Sunitinib malate is an oral multitargeted tyrosine kinase inhibitor, which has shown activity in an initial study of cytokine-refractory metastatic RCC patients. Objective  To confirm the antitumor efficacy of sunitinib as second-line treatment in patients with metastatic clear-cell RCC, the predominant cell type of this malignancy. Design, Setting, and Patients  Open-label, single-arm, multicenter clinical trial. Patients were enrolled between February and November 2004, with follow-up continuing until disease progression, unacceptable toxicity, or withdrawal of consent. The reported data apply through August 2005. Patients (N = 106) had metastatic clear-cell RCC, which had progressed despite previous cytokine therapy. Intervention  Repeated 6-week cycles of sunitinib, 50 mg per day given orally for 4 consecutive weeks followed by 2 weeks off per treatment cycle. Main Outcome Measures  Assessment of clinical response, degree of tumor regression on imaging studies using the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines. Primary end point was overall objective response rate (complete plus partial). Secondary end points were progression-free survival and safety. Response was evaluated by independent third-party core imaging laboratory and by treating physicians (investigator assessment). Results  All 106 patients received sunitinib and were included in the intent-to-treat population for safety analyses. Of these, 105 patients were evaluable for efficacy analyses. The objective response rate according to an independent third-party assessment resulted in 36 patients with partial response (34%; 95% confidence interval, 25%-44%), and a median progression-free survival of 8.3 months (95% confidence interval, 7.8-14.5 months). The most common adverse events experienced by patients were fatigue in 30 (28%) and diarrhea 21 (20%). Neutropenia, elevation of lipase, and anemia were the most common laboratory abnormalities observed in 45 (42%), 30 (28%), and 27 (26%) patients, respectively. Conclusion  The results of this trial demonstrate the efficacy and manageable adverse-event profile of sunitinib as a single agent in second-line therapy for patients with cytokine-refractory metastatic clear-cell RCC. Trial Registration  clinicaltrials.gov Identifier: NCT00077974   相似文献
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