Influence of cassava starch content and sintering temperature on the alumina consolidation technique

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Improvements for ZCS-PWM commutation cell in high-power-factor preregulator application

A Summary of different topological arrangements concerning a ZCS-PWM cell is presented, based on the analysis of its application in boost rectifying preregulators, controlled by the technique of instantaneous average values of input current, with the purpose of obtaining high-input-power-factor rectifier and high efficiency in single-phase applications in telecommunication systems. The main characteristics of each switching cell are described, providing conditions to establish a qualitative comparison among the structures. In addition, experimental results are presented for a prototype of the latest version of the ZCS-PWM boost rectifier, implemented for processing normal values of 1200 W output power and 400 V output average voltage, at 220 V Input RMS voltage and 50 kHz switching frequency.

High-Volume Peritoneal Dialysis in Acute Kidney Injury: Indications and Limitations

Background and objectives Peritoneal dialysis is still used for AKI in developing countries despite concerns about its limitations. The objective of this study was to explore the role of high-volume peritoneal dialysis in AM patients in relation to metabolic and fluid control, outcome, and risk factors associated with death.Design, setting, participants, & measurements A prospective study was performed on 204 AKI patients who were assigned to high-volume peritoneal dialysis (prescribed Kt/V=0.60/session) by flexible catheter and cycler; 150 patients (80.2%) were included in the final analysis.Results Mean age was 63.8 +/- 15.8 years, 70% of patients were in the intensive care unit, and sepsis was the main etiology of AKI (54.7%). BUN and creatinine levels stabilized after four sessions at around 50 and 4 mg/dl, respectively. Fluid removal and nitrogen balance increased progressively and stabilized around 1200 ml and -1 g/d after four sessions, respectively. Weekly delivered Kt/V was 3.5 +/- 0.68. Regarding AKI outcome, 23% of patients presented renal function recovery, 6.6% of patients remained on dialysis after 30 days, and 57.3% of patients died. Age and sepsis were identified as risk factors for death. In urine output, increase of 1 g in nitrogen balance and increase of 500 ml in ultrafiltration after three sessions were identified as protective factors.Conclusions High-volume peritoneal dialysis is effective for a selected AKI patient group, allowing adequate metabolic and fluid control. Age, sepsis, and urine output as well as nitrogen balance and ultrafiltration after three high-volume peritoneal dialysis sessions were associated significantly with death. Clin J Am Soc Nephrol 7: 887-894, 2012. doi: 10.2215/CJN.11131111

Propriedades magnéticas de ortoferritas de lantânio dopadas com estrôncio

Samples of lanthanum Ortoferrites doped with strontium were synthesized in a single phase by the sol-gel method. Two samples were prepared, one by varying the concentration of strontium in lanthanum ortoferrites La1−xSrxFeO3−δ with (0 ≤ x ≤ 0.5), and another batch of samples of type, La1/3Sr2/3FeO3−δ, now varying only the temperature of calcination. Our samples were obtained by Pechini method and sintered in air and oxygen atmospheric. Their crystal structures were determined by x-ray diraction (XRD), scanning electron microscopy (SEM), where we observed that the samples (0 ≤ x ≤ 0.3) have orthorhombic symmetry and the volume of the single cell decreases with the increasing of concentration of strontium. For x = 0.5 it is only observed the simple phase when that is sintered in O2 atmospheric. Their magnetic characteristics were obtained by the Mössbauer spectroscopy and magnetic measurements. The magnetization measurements for samples La1−xSrxFeO3−δ with (0 ≤ x ≤ 0.5) revealed that the magnetization decreases with increasing concentration of strontium, but for the sample x = 0.4 the magnetization shows a high coercive field and a ferrimagnetic behavior, which is attributed to a small amount of strontium hexaferrite. As for the samples La1/3Sr2/3FeO3−δ calcined between 800 oC e 1200 oC. The hysteresis curves revealed two distinct behaviors: an declined antiferromagnetic behavior (Canted) for samples calcined between 800 oC and 1000 oC and a paramagnetic behavior for the samples calcined at 1100 oC e 1200 o C. Thermal hysteresis and sharp peaks around the Néel temperature (TN), over the curves of specific heat as a function of temperature was only observed in calcined samples with 1100 oC and 1200 oC. This eect is attributed to the charge ordering. These results indicate that the charge ordering occurs only in the samples without oxygen deficiency. Magnetic measurements as a function of temperature are also in agreement with this interpretation

Dinâmica do uso e ocupação do solo no litoral de Macau-RN no período de 1978 a 2008

This study was developed in the northern coast of the city of Macau, a total area of 88,52 km², located in the State of Rio Grande do Norte. It presents relatively plain surface, with interlaced of streams and gamboas, characterized by contributions of oceanic water, flooding areas of swamps. Altogether, the climatic and topographical conditions provide an ideal environment for the development of saline activity. Inserted in the geologic context of the Potiguar Basin, the region presents favorable conditions for the production of hydro-carbons. It still presents natural conditions for shrimp breeding and artisanal fishing. This work analyzes the transformations occurred in the land use, using air photographs of 1978, Landsat 5 ETM Images of 1988, 1998 and 2008. A secular analyzes was carried through the dynamics of the use of the territory and the transformations occurred in the landscape due to the increment of the productive activities. In the survey of the data for study of the area, it was verified that little alteration occurred in the 30 years. The saline activity that was present since the year of 1978 having an increase of about 5% in thirty years; the shrimp breeding activity that had its presence in the decade of 1990, presented a high growth in the land use, therefore in 1998 it presented 0.45% and currently it presents 6.59%. In the field it was observed that great areas used previously for the saline activity, today it is prepared for shrimp breeding and that the areas of petroleum exploration occupy salt mines, beaches and trays. In 1988 it presented a percentage of 0, 07% and currently it occupies 0.46%, having grown 50% in the last 10 years. Although the variation of the occupation of the area has been little expressive, shrimp breeding showed a growth of 1,200% in only 10 years. In regards to petroleum activity, there wasn t any demonstration of an increasing impact in the land use in the area of study in 26 years of exploration

Bioestimulação da atividade reprodutiva de coelhas lactantes em regime de monta natural

Esta pesquisa avaliou o efeito da separação mãe-ninhada sobre o desempenho reprodutivo de coelhas lactantes e ponderal das ninhadas até aos 70 dias de idade. Examinaram-se 415 exposições ao macho de 157 fêmeas lactantes distribuídas em dois grupos: controle, com livre acesso ao ninho, e tratado, cujo acesso bloqueou-se entre o sétimo e o nono dias pós-parto, durante as 39 horas que precederam a cobrição. Das 415 exposições ao macho, 387 resultaram em cobrições e 264 em partos. As fêmeas tratadas, de quinta lactação em diante, apresentaram receptividade e taxa de parição, respectivamente, 6,7% e 10,8% maiores em comparação às fêmeas do grupo controle. Não se constatou efeito da interação tratamento x ordem de lactação, ou do tratamento, com respeito ao número de láparos/ninhada à desmama e nos 70 dias de idade. em ninhadas de primíparas, a taxa de mortalidade da separação até 70 dias de idade foi maior no grupo tratado, em relação ao controle (0,248±0,047 vs. 0,120±0,047). O peso total da ninhada à desmama foi inferior no grupo tratado, do que no controle (5.753±93 g vs. 6.222±89 g) em todas as ordens. Todavia, não se observou diferença no peso total ou médio da ninhada nos 70 dias de idade. O tratamento também reduziu o peso individual à desmama (912,4±4,9 g vs. 962,7±4,5 g) em todas as ordens de lactação, entretanto, elevou o ganho de peso médio diário pós-desmama (32,25±0,19 g/d vs. 31,44±0,17 g/d), proporcionando a ocorrência de ganho compensatório neste período. Pode-se recomendar a separação temporária mãe-ninhada para melhorar o desempenho reprodutivo de coelhas lactantes multíparas; mas deve ser evitada para as primíparas, devido à elevação da taxa de mortalidade das ninhadas.

Avaliação do desempenho e de parâmetros gastrintestinais de frangos de corte alimentados com dietas formuladas com sorgo alto tanino e baixo tanino

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

Effect of sodium gluconate on performance, carcass characteristics, and intestinal morphometry of broilers from 22 to 42 days of age

O presente estudo teve por objetivo avaliar o efeito da utilização de níveis crescentes do gluconato de sódio sobre o desempenho, o rendimento de carcaça e de partes e a morfometria da mucosa intestinal de frangos de corte de 22 a 42 dias de idade. Foram utilizados 1200 frangos de corte da linhagem Cobb, distribuídos em um delineamento inteiramente casualizado, envolvendo cinco tratamentos (0,00; 0,10; 0,20; 0,30 e 0,40% de gluconato de sódio) com oito repetições de 30 aves cada parcela. As variáveis foram submetidas à análise de variância e em caso de significância estatística foram realizadas análises de regressão pelos modelos polinomial e quadrático. A inclusão do gluconato de sódio não afetou o desempenho e o rendimento de carcaça e de partes. Entretanto, exerceu efeito benéfico sobre a morfometria da mucosa intestinal do duodeno e do jejuno.

Plasma progesterone concentration in beef heifers receiving exogenous glucose, insulin, or bovine somatotropin

Three experiments were conducted to evaluate plasma concentrations of glucose, insulin, IGF-I, and progesterone (P4) in pubertal beef heifers receiving exogenous glucose, insulin, or sometribove zinc. All heifers used had no luteal P4 synthesis but received a controlled internal drug-releasing device containing 1.38 g of P4 to estimate treatment effects on hepatic P4 degradation. In Exp. 1, 8 pubertal, nulliparous Angus x Hereford heifers (initial BW = 442 +/- 14 kg; initial age = 656 +/- 7 d) were randomly assigned to receive, in a crossover design containing 2 periods of 10 h, intravenous (i.v.) infusions (10 mL) of insulin (1 mu g/kg of BW; INS) or saline (0.9%; SAL). Treatments were administered via jugular venipuncture in 7 applications (0.15 mu g insulin/kg BW per application) 45 min apart (from 0 to 270 min). Blood samples were collected immediately before each infusion as well as at -120, -60, 330, 390, and 450 min relative to the first infusion. Heifers receiving INS had greater (P < 0.01) plasma insulin, reduced (P <= 0.04) plasma glucose and IGF-I, and similar (P = 0.62) plasma P4 concentrations compared with SAL heifers. In Exp. 2, the same heifers were assigned to receive, in a similar experimental design as Exp. 1, i.v. infusions (10 mL) of 1) insulin (1 mu g/kg BW) and glucose (0.5 g/kg BW; INS+G) or 2) SAL. Heifers receiving INS+G had greater (P <= 0.02) plasma insulin, glucose, and P4 but reduced (P = 0.01) plasma IGF-I concentrations compared with SAL heifers. In Exp. 3, the same heifers were assigned to receive, in a crossover design containing 2 periods of 14 d, subcutaneous (s.c.) injections of 1) 250 mg of sometribove zinc (BST) or 2) SAL. Blood samples were collected 3 h apart (0900, 1200, 1500, and 1800 h) from heifers on d 6, 8, and 10 relative to treatment administration (d 1). Heifers receiving BST had greater (P < 0.01) plasma glucose and IGF-I and similar (P >= 0.67) plasma insulin and P4 concentrations compared with SAL heifers. Results from this series of experiments suggested that concurrent increases in glucose and insulin are required to reduce hepatic catabolism and increase plasma concentrations of P4 in bovine females.

Effects of body weight loss on serum progesterone concentrations of non-lactating dairy cows

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

Análise da influência do ultrassom de baixa intensidade na região de reparo ósseo em ratos sob ausência de carga

Há evidências de que o ultrassom (US) de baixa intensidade pode acelerar a regeneração óssea. Este trabalho objetivou verificar a ação do US no defeito ósseo, criado experimentalmente em tíbias de ratos sob ausência de carga. Vinte Rattus novergicus albinus, Wistar adultos, divididos em: G1 (n=10), grupo experimental de 15 dias sem suspensão, e G2 (n=10), grupo experimental de 15 dias suspenso pela cauda, foram submetidos à osteotomia em ambas as tíbias e à aplicação do US, frequência de 1,5 MHz, ciclo de trabalho 1:4, 30 mW/cm², nas tíbias direitas por 12 sessões de 20 minutos. Após o sacrifício, as tíbias foram submetidas à análise da Densidade Mineral Óssea (DMO). Os resultados demonstraram DMO de 0,139±0,018 g/cm² para tíbia tratada; 0,131±0,009 g/cm² para tíbia controle no G1; e no G2 registrou-se 0,120±0,009 g/cm² para tíbia tratada e 0,106±0,017 g/cm² para tíbia controle. Houve diferença significante entre os grupos nos quais o G2 apresentou menor DMO, o que demonstra que a suspensão prejudica a manutenção das propriedades ósseas, e entre as tíbias tratadas e controles do G2, demonstrando que o US acelerou o processo de reparo, concluindo que a impossibilidade do estímulo mecânico causada pela não deambulação em um processo de reparo ósseo pode ser minimizada pela ação do US. No G1, a aplicação do US não teve influência significante no aumento da DMO, talvez pelo fato dos animais já terem estímulo mecânico suficiente à formação óssea.

Histological analyses of thermal effect caused by 1.2 W diode laser irradiation at rat periodontal pockets

The aim of this in vivo study was to evaluate the thermal effects caused by 810 nm 1.2 W diode laser irradiation of periodontal tissues. Despite all data available concerning the laser application for periodontal treatment, one of the most relevant challenges is to prevent the harmful tissue heating induced by different clinical protocols. Periodontal pockets were induced at molars in 96 rats. Several irradiation powers under CW mode were investigated: 0, 400, 600, 800, 1000, 1200 mW. The pockets were irradiated using a 300 A mu m frontal illumination fiber. The animals were killed at 4 or 10 days after irradiation. The mandible was surgically removed and histologically processed. The histological sections stained with H/E demonstrated that irradiation parameters up to 1000 mW were thermally safe for the periodontal tissues. The sections stained with Brown & Brenn technique evidenced bacteria in the periodontal tissues. Consequently, the diode laser irradiation as a unique treatment was not capable to eliminate bacteria of the biofilm present in the pockets. According to the methodology used here, it was concluded that the thermal variation promoted by a diode laser can cause damage to periodontal tissues depending on the energy density used. The 1.2 W diode laser irradiation itself does not control the bacteria present in the biofilm of the periodontal pockets without mechanical action. The knowledge of proper high intensity laser parameters and methods of irradiation for periodontal protocols may prevent any undesirable thermal damage to the tissues.

Differential pulse voltammetric determination of nitrite with gold ultramicroelectrode

The application of disk shaped gold ultramicroelectrode for nitrite determination with and without addition of supporting electrolyte was studied using the differential pulse voltammetric method. The well-defined peak for nitrite oxidation near 0.8V (vs. Ag/AgCl reference electrode) was used to obtain analytical plots in the concentration range from 0.1 to 0.6 mmol L-1 and from 10.0 to 50.0 mu mol.L-1. The calculated detection limit was 0.65 mu mol.L-1 in purified water, in the absence of supporting electrolyte, with relative standard deviation of 1.36% (n=6) for analyzing 10.0 mu mol L-1 nitrite solutions, and accuracy of 100.9 %, based on recovery studies. The application of this analytical method to mineral and river water samples of natural pH also showed improved sensitivity when compared with the linear sweep voltammetric method previously reported.

Bathymetric distribution of the shrimp Rimapenaeus constrictus (Stimpson, 1874) (Decapoda, Penaeidae) in two locations off the southeastern Brazilian coast

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