872 resultados para VALVE-REPLACEMENT


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Human health and environmental concerns are not usually considered at the same time. Tin-lead solders are still widely used in several countries, including Brazil, by manufacturers of electronic assemblies. One of the options to reduce or eliminate lead from the manufacturing environment is its replacement with lead-free alloys. This paper applies emergy synthesis and the DALY indicator (Disability Adjusted Life Years) to assess the impact of manufacturing soft solder using tin, lead and other metals on the environment and on human health. The results are presented together with the company's financial results and the results calculated from the Brazilian statistical value of life. The calculation of emergy per unit showed that more resources are used to produce one ton of lead-free solders than to produce one ton of tin-lead solders, with and without the use of consumer waste recovered through a reverse logistics system. The assessment of air emissions during solder production shows that the benefits of the lead-free solution are limited to the stages of manufacturing and assembling. The tin-lead solder appears as the best option in terms of resource use efficiency and with respect to emissions into the atmosphere when the mining stage is included. A discussion on the influence of the system's boundaries on the decision-making process for materials substitution is presented. (C) 2012 Elsevier Ltd. All rights reserved.

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Herein is reported the case of a patient who presented initially with aortic insufficiency and a fistula between the sinus of Valsalva and right atrium when aged 31 years. Closure of the fistula and replacement of the aortic valve with a Starr-Edwards A-9 caged-ball prosthesis was performed in 1972, since when the valve has survived for 40 years without dysfunction. This is one of the longest follow ups of the Starr-Edwards prosthesis reported, and highlights the possibility of acceptable valve performance over long periods of time.

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

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This clinical report describes an adult patient referred for orthodontic treatment with mini-implants as anchorage to correct the root angulation of maxillary lateral incisors. The purpose of this report was to demonstrate the versatility of mini-implants placed in a vertical direction in esthetic areas. During orthodontic treatment, some aspects must be observed to preserve the interim restoration against the occlusal loads to avoid screw fracture. A fixed appliance was placed to correct the position of the maxillary anterior teeth and to complete the treatment. Acceptable esthetics and function were achieved.

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

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The Cashew Nut Shell Liquid (CNSL) can be considered as a versatile raw material with wide applications in the form of surface coatings, paints and varnishes, as well as the production of polymers. Within this context, the chemical constituents of CNSL (anarcadic acid, cardanol, 2-cardol and methylcardol) become promising in the development of new materials components. Once separated, CNSL can be used in the research and development of additives, surfactants, pharmaceuticals, pesticides, polymers, resins and others. Being a byproduct, CNSL used in the preparation of new materials is characterized as a truly technological innovation.

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

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In the present work is proposed the experimental study of hydrodynamic behaviour of membrane neurological valve, applied in treatment of hydrocephalus, a pathophisiology that affects both adults and children, caused due to the excess of cerebrospinal fluid in brain ventricles.

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Calcific aortic valve disease (CAVD) is a chronic disorder characterized by an abnormal mineralization of the leaflets, which is accelerated in bicuspid aortic valve (BAV). It is suspected that mechanical strain may promote/enhance mineralization of the aortic valve. However, the effect of mechanical strain and the involved pathways during mineralization of the aortic valve remains largely unknown. Valve interstitial cells (VICs) were isolated and studied under strain conditions. Human bicuspid aortic valves were examined as a model relevant to increase mechanical strain. Cyclic strain increased mineralization of VICs by several-fold. Scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analyses revealed that mechanical strain promoted the formation of mineralized spheroid microparticles, which coalesced into larger structure at the surface of apoptotic VICs. Apoptosis and mineralization were closely associated with expression of ENPP1. Inhibition of ENPP1 greatly reduced mineralization of VIC cultures. Through several lines of evidence we showed that mechanical strain promoted the export of ENPP1-containing vesicles to the plasma membrane through a RhoA/ROCK pathway. Studies conducted in human BAV revealed the presence of spheroid mineralized structures along with the expression of ENPP1 in areas of high mechanical strain. Mechanical strain promotes the production and accumulation of spheroid mineralized microparticles by VICs, which may represent one important underlying mechanism involved in aortic valve mineralization. RhoA/ROCK-mediated export of ENPP1 to the plasma membrane promotes strain-induced mineralization of VICs.

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Prolonged intermittent renal replacement therapy (PIRRT) has emerged as an alternative to continuous renal replacement therapy in the management of acute kidney injury (AKI) patients. This trial aimed to compare the dialysis complications occurring during different durations of PIRRT sessions in critically ill AKI patients. We included patients older than 18 years with AKI associated with sepsis admitted to the intensive care unit and using noradrenaline doses ranging from 0.3 to 0.7 mu g/kg/min. Patients were divided into two groups randomly: in G1, 6-h sessions were performed, and in G2, 10-h sessions were performed. Seventy-five patients were treated with 195 PIRRT sessions for 18 consecutive months. The prevalence of hypotension, filter clotting, hypokalemia, and hypophosphatemia was 82.6, 25.3, 20, and 10.6%, respectively. G1 was composed of 38 patients treated with 100 sessions, whereas G2 consisted of 37 patients treated with 95 sessions. G1 and G2 were similar in male predominance (65.7 vs. 75.6%, P=0.34), age (63.6 +/- 14 vs. 59.9 +/- 15.5 years, P=0.28) and Sequential Organ Failure Assessment score (SOFA; 13.1 +/- 2.4 vs. 14.2 +/- 3.0, P=0.2). There was no significant difference between the two groups in hypotension (81.5 vs. 83.7%, P=0.8), filter clotting (23.6 vs. 27%, P=0.73), hypokalemia (13.1 vs. 8.1%, P=0.71), and hypophosphatemia (18.4 vs. 21.6%, P=0.72). However, the group treated with sessions of 10h were refractory to clinical measures for hypotension, and dialysis sessions were interrupted more often (9.5 vs. 30.1%, P=0.03). Metabolic control and fluid balance were similar between G1 and G2 (blood urea nitrogen [BUN]: 81 +/- 30 vs. 73 +/- 33mg/dL, P=1.0; delivered Kt/V: 1.09 +/- 0.24 vs. 1.26 +/- 0.26, P=0.09; actual ultrafiltration: 1731 +/- 818 vs. 2332 +/- 947mL, P=0.13) and fluid balance (-731 +/- 125 vs. -652 +/- 141mL, respectively) . In conclusion, intradialysis hypotension was common in AKI patients treated with PIRRT. There was no difference in the prevalence of dialysis complications in patients undergoing different durations of PIRRT.

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

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Background and aims Estrogen deficiency results in increased bone turnover and can lead to osteoporosis. Hormone replacement therapy (HRT) seems to be the most effective means of reducing bone loss and fractures. However, the effects of the period of HRT onset on bone tissue require further elucidation. This study aimed to evaluate the effects of different periods of HRT onset on the trabecular bone of ovariectomized rats.Methods Seventy-five ovariectomized Wistar rats were divided into five groups according to the onset of treatment. Each group was subdivided into experimental (E; n = 10) and control (C; n = 5), according to treatment with 17-beta-estradiol or vehicle alone (soybean oil), respectively, administered subcutaneously. The first group received treatment immediately post-surgery, while treatment in the remaining groups was initiated 1, 2, 3 and 4 weeks post-surgery. Euthanasia occurred at 9 weeks post-surgery. The left tibias were removed and prepared for histomorphometric analyses. The histomorphometric results were statistically analyzed by the Student's t test (p < 0.05).Results The percentage of trabecular bone was significantly greater in the first (p = 0.002) and second (p = 0.039) experimental subgroups compared with the control for the same period. In the experimental subgroups, the percentage of trabecular bone decreased according to the delay in HRT onset and was statistically significant (t = 3.367; p = 0.0023).Conclusion These findings indicate an increase in trabecular bone loss in tibia at 9 weeks post-ovariectomy. The period of HRT/E onset is important for preventing bone loss; however, despite its preventive effects, HRT/E does not restore lost bone.