Myocardial contractile dysfunction contributes to the development of heart failure in rats with aortic stenosis

Objectives: To analyze the potential contribution of contractility state and ventricular geometry to the development of heart failure in rats with aortic stenosis.Methods: Rats were divided into three groups: compensated aortic stenosis (AS, n = 11), heart failure AS (n = 12) and control rats (C, n = 13).Results: After 21 weeks, failing AS rats presented higher systolic (C = 36.6 +/- 3.1, AS-78.6 +/- 4.8*, failing AS = 104.6 +/- 7.8*) and diastolic meridian stress (C = 6.9 +/- 0.4, AS = 20.1 +/- 1.1*, failing AS = 43.2 +/- 3.2*(dagger)), hydroxyproline (C = 3.6 +/- 0.7 mg/g, AS = 6.6 +/- 0.6* mg/g, failing AS = 9.2 +/- 1.4*(dagger) mg/g) and cross-sectional area (C = 338 +/- 25 mu m(2), AS = 451 +/- 32* mu m(2), failing AS = 508 +/- 36*(dagger) mu m(2)), in comparison with control and compensated AS animals (*p < 0.05 vs. control, (dagger)p < 0.05 vs. AS). In the isometric contraction study, considering the time from peak tension to 50% relaxation (RT50), the relative variation responses, following post-rest contraction and increase in Ca2+ concentration, were higher in failing AS than compensated AS animals. In contrast, following post-rest contraction, compensated AS group presented higher values of the peak developed tension (DT) than failing AS group. Following beta-adrenergic stimulation, control animals presented higher values of +dT/dt and -dT/dt than AS animals. In addition, failing AS animals presented higher TPT values than compensated AS animals.Conclusion: Myocardial contractile dysfunction contributes to the development of heart failure in rats with aortic stenosis. (c) 2006 Elsevier B.V.. All rights reserved.

Increase of temperature of an ideal nondegenerate quantum gas in a suddenly expanding box due to energy quantization

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Application of Factorial Design Experiments to the Development of a Disposable Amperometric DNA Biosensor

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Analysis of floristic composition and structure as an aid to monitoring protected areas of dense rain forest in southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A Biophysical Evaluation of a MSW-to-energy System

A biophysical understanding of the MSW-to-energy facility located at the Sao Joao landfill in São Paulo is performed using emergy synthesis. The implementation of a plan for environmental compensation in fulfillment of State's requirements was also assessed. Emergy based indices are calculated to assess the environmental pressure and sustainability status of the biogas project. The study was conducted by combining the study of emergy indicators and the net emergy yield ratio to determine long-term sustainability and measure global environmental stress. The Emergy investment to the use of biogas is relatively low and profitable. The implementation of the project for environmental compensation does not change the Emergy investment significantly, but the energy recovery is high. The conclusions justify the effort invested in developing MSW-to-energy plants and are applicable for policy makers in a highly sensitive sector to achieve sustainability goals - recovery of energy.

Paper-based diffusive gradients in thin films technique coupled to energy dispersive X-ray fluorescence spectrometry for the determination of labile Mn, Co, Ni, Cu, Zn and Pb in river water

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Enhanced frequency upconversion in Er3+ doped fluoroindate glass due to energy transfer from Tm3+

Energy transfer processes between Er3+ and Tm3+ were investigated examining the frequency upconversion emissions in a fluoroindate glass pumped at 790 nm. A 60-fold enhancement in the emission at ≈670 nm originating from Er3+ was observed when Tm3+ at concentration of 2% was introduced in a sample containing 2% of Er3+. The results are explained considering the influence of cross-relaxation processes between the active ions. © 2002 Elsevier Science B.V. All rights reserved.

Caribbean tourism and agriculture: linking to enhance development and competitiveness

Includes bibliography

Sociodemographic vulnerability in the Caribbean: an examination of the social and demographic impediments to equitable development with participatory citizenship in the Caribbean at the dawn of the twenty-first century

Includes bibliography

From technological dependence to technological development: the case of the USIMINAS steel plant in Brazil

Includes bibliography

The housing problem in Latin America in relation to structural development factors

Includes bibliography