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1.
The aging process is accompanied by significant changes in body composition characterized by decreased fat free mass and increased and redistributed fat mass. Muscle loss results from the atrophy of muscle fibers and decreased synthesis of muscle proteins. Increased number of adipocytes and fat accumulation in non-adipose tissue leads to adiposity. These changes can impose functional limitations and increase morbidity. In men, declining testosterone levels that occur with aging can be a contributing factor to these changes. Studies in hypogonadal men have shown that testosterone replacement is effective in increasing muscle mass and strength and decreasing fat mass. The molecular mechanisms of testosterone's influence on muscle and adipose are not fully elucidated. However, testosterone appears to stimulate IGF-1 expression directly and indirectly leading to increased muscle protein synthesis and growth. It may also counter the inhibitory effects of myostatin, cytokines, and glucocorticoids. The predominant effects of testosterone on fat mass are increased lipolysis and decreased adipogenesis. Current evidence suggests that testosterone replacement may be effective in reversing age-dependent body composition changes and associated morbidity. However, hypogonadism must be diagnosed carefully, and therapy should be monitored regularly in order to avoid the adverse effects associated with testosterone supplementation.  相似文献   
2.
Accurate determination of left ventricular (LV) volume has important therapeutic and prognostic implications in patients with cardiac disease. Volume estimations by two-dimensional techniques are not very accurate due to geometric assumptions. OBJECTIVES: To validate LV volume determinations by a new transesophageal three-dimensional echocardiographic technique. We performed three-dimensional reconstruction of the LV using an echo-computed tomographic (CT) technique based on serial pullback parallel slice imaging technique in both in vitro and in vivo settings. Fourteen latex balloons with various sizes (30-235 mL) and shapes (conical, pear shaped, round, elliptical, and aneurysms in various locations) filled with known volumes of water were imaged in a water bath. From the static three-dimensional image, the LV long axis was defined and the LV was sectioned perpendicular to this axis into 2-mm slices. The volume of each slice was calculated with the observer blinded to the actual volume as the product of the slice thickness and the manually traced perimeter of the slice and the LV volume as the sum of the volumes of the slices (Simpson's method). The calculated LV volume closely correlated with the actual volume (r = 0.99, P < 0.0001, calculated volume = 1.06x - 11.3, Deltavolume = -5.7 +/- 10.0 cc). Using the same system, transesophageal echocardiographic (TEE) images of the LV were obtained in 15 patients gated to respiration and ECG. Satisfactory dynamic three-dimensional reconstruction of the LV was possible in ten patients. The three-dimensional LV volumes (systolic and diastolic) using Simpson's method correlated well with those obtained from biplane or multiplane TEE images using the area length method (r = 0.89, p < 0.0001, y = 12.7 + 0.84x, Deltavolume = 1.3 +/- 18.1 cc). The LV major-axis diameters by the two methods showed very close correlations as well (r = 0.86, P < 0.0001, y = 19 + 0.74x, Deltadiameter = 1.0 +/- 7.2 mm). We conclude that three-dimensional LV volume calculation by the echo-CT technique is intrinsically sound, is independent of LV geometry, and with some limitations, is applicable in vivo. (ECHOCARDIOGRAPHY, Volume 13, November 1996)  相似文献   
3.
A patient with eroded tricuspid and pulmonic valves, who eventually developed elevated right atrial and systemic venous pressure that led to hepatic cirrhosis and recurrent pleural effusion, is presented. The complex issues involved over a long period in this patient, who ultimately required combined heart and liver transplant, are discussed.  相似文献   
4.
PURPOSE OF REVIEW: Echocardiographic assessment plays a major role in the evaluation of aortic stenosis (AS). Because of its proven accuracy, ease of applicability, and safety, it is replacing cardiac catheterization for the assessment of AS in many centers. RECENT FINDINGS: In this review, we discuss the basic principles of echocardiographic assessment of AS and clinically challenging scenarios including AS with low cardiac output state or other structural heart disease. Dobutamine stress echocardiography is a useful tool for assessing low cardiac output AS. The role of transesophageal echocardiography in the evaluation of AS is also reviewed. SUMMARY: Echocardiographic techniques provide critical information in the assessment of patients with known or suspected AS and guide decision-making regarding the appropriateness of valve replacement.  相似文献   
5.
Speckle-tracking echocardiography (STE) is an advanced echocardiographic technique that allows a novel approach to the assessment of cardiac physiology through the study of myocardial mechanics. In its three-dimensional (3D) modality, it overcomes the drawbacks inherent to other echocardiographic techniques, namely two-dimensional echocardiography and tissue Doppler imaging. Several research studies and software improvements have led 3D-STE to become a promising tool for accurate evaluation of global and regional cardiac function. This article addresses the image acquisition, analytical methods, and parameters of myocardial mechanics that could be derived from 3D-STE. This systematic guidance may help to establish its usefulness in the global and regional evaluation of cardiac function, and to facilitate its clinical application.  相似文献   
6.
BACKGROUND AND AIM OF THE STUDY: Two-dimensional echocardiography (2DE) performed to evaluate mitral valve anatomy during valve repair has certain limitations and pitfalls. The study aim was to assess the feasibility, accuracy and incremental value of three-dimensional echocardiography (3DE), coupled with 2DE in evaluating mitral valve structure, before and after repair and pericardial posterior annuloplasty. METHODS: The site and extent of mitral valve prolapse, systolic and diastolic changes of mitral annular area were evaluated using 2D and 3D transesophageal echocardiography (TEE), both pre- and postoperatively in 34 patients before and after mitral valve repair and pericardial posterior annuloplasty. RESULTS: Concordance between 2DE and surgery in evaluating prolapsing mitral valve scallops was 76% for the anterior leaflet and 75% for the posterior leaflet; for 3DE and surgery, concordance was 87% and 93% respectively. There was a significant reduction in maximal and minimal annular area after surgery, with a statistically significant difference between systolic-diastolic changes. CONCLUSION: 3DE, coupled with 2DE, is feasible and accurate in delineating the extent and location of prolapsing scallops of the mitral valve. The combined approach is also valuable in planning mitral valve surgery and evaluating the mitral valve annulus in vivo.  相似文献   
7.
Background: We hypothesized that degenerative calcific aortic stenosis (DCAS) is a syndrome influenced by factors beyond aortic valve stenosis (AS). The aim of this study was to assess how frequently DCAS is complicated by increased vascular load, systolic and/or diastolic left ventricular (LV) dysfunction, and comorbid disorders. Methods: In 215 consecutive patients > 60 years of age with severe and moderate AS, we analyzed systemic arterial compliance, global hemodynamic load, LV ejection fraction (EF), the presence of diastolic dysfunction, and other valvular or systemic disorders. Results: A total of 164 patients had severe AS and 51 had moderate AS. In patients with severe AS, the prevalence of increased vascular load was 42%; LV systolic and diastolic dysfunction was present in 27% and 42%; other valve diseases in 23%; and comorbid disorders in 82%. In the moderate AS group, abnormal vascular load was found in 52%; LV systolic and diastolic dysfunction was prevalent in 26% and 31%; other valve diseases in 17%; and comorbid disorders in 78% patients. More than half the patients in both groups had symptoms. In both severe and moderate AS groups, the prevalence of increased vascular load and systolic dysfunction was higher in the symptomatic group. Conclusion: Considerable number of patients with DCAS have abnormal vascular load, abnormal LV function, and significant coexisting disorders. These could influence the total pathophysiologic burden on the heart and symptom expression. Thus, DCAS should not be considered just as valvular stenosis, but a syndrome of DCAS because of the diagnostic, prognostic, and therapeutic implications of various factors associated with it.  相似文献   
8.
The relationship between left ventricular shape and QT interval dispersion   总被引:4,自引:0,他引:4  
Left ventricular geometry is suspected to affect heterogeneity of myocardial repolarization; therefore, it is plausible but unproven that increased sphericity of the left ventricle is associated with greater QT interval dispersion. In 60 patients with dilated cardiomyopathy with left ventricular ejection fraction < or = 30%, we found that spherical distortion of the left ventricle was associated with increased QT dispersion, implying increased heterogeneity of myocardial repolarization.  相似文献   
9.
Postoperative cardiac tamponade in the modern surgical era   总被引:2,自引:0,他引:2  
BACKGROUND: Pericardial effusions resulting in cardiac tamponade (CT) are uncommon after open heart surgery (OHS) and are associated with significant morbidity and mortality. Characteristics and outcomes of patients who develop postoperative CT are poorly defined. Our objective was to further analyze the population at risk for developing postoperative CT, identify potential perioperative and surgical risk factors, and evaluate the impact of CT on patient outcomes. METHODS: A retrospective analysis of 4,561 consecutive patients undergoing OHS at our institution was performed. Patients with clinical suspicion of pericardial effusion following surgery were evaluated by transthoracic or transesophageal echocardiography, and clinical parameters were analyzed. RESULTS: Forty-eight (1%) of the 4,561 patients were found to have echocardiographic evidence of a moderate or large pericardial effusion, of whom 36 (74%) had evidence of CT. The mean age of the patients with CT was 61 years. Coronary artery bypass grafting (CABG) had been performed in 24% of these patients, valve +/- CABG in 73%, and other OHS procedures in 3%. The incidence of CT following CABG alone was 0.2%, whereas it was 0.6% after valve +/- CABG. Females had a higher risk for developing CT, and this occurred earlier in the postoperative period when compared with men. Aspirin, heparin, or warfarin were given to 84% of patients within 3 days of surgery. Mean time to diagnosis of CT was 10 +/- 1 days after OHS. Prior to diagnosis of CT, the maximum international normalized ratio (INR) and partial thromboplastin time (PTT) were 2.7 +/- 0.3 and 68 +/- 5 seconds, respectively. Forty-nine percent of pericardial effusions were posterior and 46% were circumferential; one-third of the effusions were considered large by echocardiography. There was one in-hospital cardiovascular death. CONCLUSIONS: CT after OHS is more common following valve surgery than CABG alone and may be related to the preoperative use of anticoagulants. Females appear to be at higher risk for developing early postoperative CT. When diagnosed and treated promptly, postoperative CT should not significantly increase mortality.  相似文献   
10.
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