Microwave-induced fast decalcification of rat bone for electron microscopic analysis: An ultrastructural and cytochemical study

Bone decalcification is a time-consuming process. It takes weeks and preservation of the tissue structure depends on the quality and velocity of the demineralization process. In the present study, a decalcification methodology was adapted using microwaving to accelerate the decalcification of rat bone for electron microscopic analysis. The ultrastructure of the bone decalcified by microwave energy was observed. Wistar rats were perfused with paraformaldehyde and maxillary segments were removed and fixed in glutaraldehyde. Half of specimens were decalcified by conventional treatment with immersion in Warshawsky solution at 4oC during 45 days, and the other half of specimens were placed into the beaker with 20 mL of the Warshawsky solution in ice bath and thereafter submitted to irradiation in a domestic microwave oven (700 maximum power) during 20 s/350 W/±37°C. In the first day, the specimens were irradiated 9 times and stored at 40°C overnight. In the second day, the specimens were irradiated 20 times changing the solution and the ice after each bath. After decalcification, some specimens were postfixed in osmium tetroxide and others in osmium tetroxide and potassium pyroantimonate. The specimens were observed under transmission electron microscopy. The results showed an increase in the decalcification rate in the specimens activated by microwaving and a reduction of total experiment time from 45 days in the conventional method to 48 hours in the microwave-aided method.

Efeito do sabor azedo e da temperatura fria na fase oral da deglutição no acidente vascular encefálico

Pós-graduação em Bases Gerais da Cirurgia - FMB

O efeito do sabor azedo e da temperatura fria no tempo de trânsito faríngeo da deglutição em indivíduos após acidente vascular encefálico hemisférico isquêmico

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

Formas inorgânicas e orgânicas de minerais e temperatura ambiente sobre o desempenho,imunidade e parâmetros sanguíneos em frangos de corte

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Respostas respiratórias à hipóxia e hipercapnia de frangos de corte provenientes de ovos incubados em diferentes temperaturas

Pós-graduação em Zootecnia - FCAV

A influência dos estímulos azedo e frio sobre o tempo da trânsito faríngeo da deglutição no acidente vascular encefálico isquêmico

Pós-graduação em Bases Gerais da Cirurgia - FMB

Controle de doenças fúngicas e de danos por frio em pós-colheita de lima ácida Tahiti

The Tahiti lime appears very susceptible to attack by post-harvest diseases, primarily by the fungi Penicillium and Phomopsis, and also because of its high sensitivity to storage at low temperatures. In order to reduce such damage, the present study aimed to verify the efficiency of heat treatment and disinfection of pathogens in the prevention of post-harvest chilling injury of this cultivar and to compare this treatment with other products using the conventional fungicides. The heat treatments were studied with hot-water temperatures ranging between 48 and 56° C. Water at room temperature was used as a control treatment. After treatment, the fruits were kept under cold temperature at 10° C and RH 90% for about 45 days. For comparison, three other treatments were carried out simultaneously, one using imazalil, one with baking soda, and a third with sodium carbonate, these three products being applied by baths in cold water. Two groups of fruit were evaluated, one treated by immersion considering pathogens coming from the field and another by inoculation with spores of the previously isolated pathogens. For the evaluation of physical and chemical parameters of fruits, determinations were made of the skin color, texture, weight loss, size, juice yield, soluble solids, total acidity and vitamin C content. The determination of the sensitivity of the fruit to cold was made by their exposure at temperatures inducing cold damage. The design was a randomized block design with nine treatments, analyzed by the Statgraphics statistical package. Heat treatments, especially at 52° C, were shown to be more promising in the control of pathogenic fungi and cold damage, surpassing the conventional fungicides. No changes were found in the intrinsic and extrinsic parameters in relation to the application of the different treatments.

Uma aplicação do planejamento de experimentos e carta de controle em uma indústria de cosmésticos: ciclo DMAIC

Pós-graduação em Engenharia de Produção - FEB

Risco climático, vulnerabilidade socioespacial e eventos climáticos extremos relacionados ao calor e ao frio no estado do Rio Grande do Sul- Brasil

Pós-graduação em Geografia - FCT

Parâmetros hemetológicos da tilápia-do-Nilo: efeito da dieta suplementada com levedura e zinco e do estímulo pelo frio

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

Características pós-colheita em frutos de pitaya orgânica submetida a diferentes doses de irradiação

The objective was to evaluate the influence of different irradiation doses in post-harvest characteristics of pitaya organic species Hylocereus undatus grown in the municipality of Itajobi - SP. The experiment was conducted at the Fruit and Vegetable Department of Agribusiness Management and Technology - FCA / UNESP - Botucatu - SP from December 2008 to January 2009. The radiation process was conducted at the Institute for Energy and Nuclear Research (IPEN) located in Sao Paulo. The design was randomized blocks with six treatments and three replications. The fruits were harvested on the third day after onset of color, selected, cleaned, packed in polystyrene trays covered with PVC film, pre - cooled (8 ° C for 24 hours) and subjected to different doses of gamma irradiation (0.0; 0.2, 0.4, 0.6, 0.8 and 1.0 kGy of cobalt-60) and subsequently stored in cold temperature of 8 degrees C, with relative humidity of about 85 ± 5%. The fruits were evaluated at twenty days after irradiation for pH, soluble solids (SS), Titratable Acidity (TA), ratio (SS / TA) and percentage loss of mass (weight). Data were subjected to analysis of variance and means compared by Tukey test at 5% probability. There were no statistically significant differences (p <0.05) for pH (4.82), soluble solids (11.33) Titratable acidity (0.12) and ratio (79.42) compared to non-irradiated fruit. Regarding the percentage of loss of mass (weight), the highest among the patients treated irradiated with 0.8 kGy (12.12%), whereas for treatment at a dose of 0.0 kGy (irradiated) showed a lower loss weight (11.59%), a result that differs significantly (P <0.05) from the remaining doses of irradiation. The loss of mass (weight) of fruit irradiated with other doses was not statistically significant (P> 0.05).

Effects of acute cold exposure on rectal temperature, blood glucose and plasma free fatty acids in alloxan-diabetic rats

These experiments were carried out to study the effects of acute cold exposure (0-2°C/4 hr) on rectal temperature, blood glucose and plasma free fatty acids (FFA) in alloxan-diabetic rats. Male Wistar rats weighing 170-190 g were used and diabetes was induced by i.v. alloxan injection (40 mg/kg body wt). Cold exposure produced severe hypothermia in diabetic rats. After 4 hr of cold, blood glucose of diabetic rats was reduced from 296±16 to 86t±12 mg/dl (P<0.01), and FFA increased slightly, but was not statistically different (P>0.05) from the initial value. As expected, interscapular brown adipose tissue (IBAT) and retroperitoneal and epididymal white adipose tissues were significantly lower in diabetic than in control rats. Cold exposure reduced total IBAT lipids in control but not in diabetic animals. The results of this experiment suggest that diabetic rats were unable to maintain body temperature in the cold, probably because of a failure to generate an adequate amount of heat by nonshivering thermogenesis in brown adipose tissue.

Thermogenesis, vocalization, and temperature preference of 1-day-old chicken hatchlings after cold-exposure in late embryogenesis

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

Heat or cold chronic stress affects organ weights and Hsp70 levels in chicken embryos

This study was carried out with the objective of evaluating the effect of heat (38.8 degreesC) or cold (35.8 degreesC) stress on chicken embryo development and tissues Hsp70 levels, after the 13th day of incubation. Embryo weight (percent egg weight), organ weight (percent embryo weight) and Hsp70 levels (ng Hsp70 mug(-1) total protein) in different tissues (liver, breast muscle, heart, lungs, brain and kidney) were studied at the end of incubation. Cold stress induced a lower embryo weight and lower kidney and lungs weights, whereas heart and liver were lighter in heat-stressed embryos. An interaction between temperature and age was obtained only for Hsp70 levels in kidney and heart. Cold-stressed embryos showed higher Hsp70 levels in the brain, lungs and liver; a decrease in brain and breast muscle Hsp70 levels was seen from the 19th to 20th days in control embryos. Hsp70 levels increased with age in kidneys of control embryos and in heart of heat- and cold-stressed embryos. In conclusion, this study showed that chicken embryo organ weights are affected by incubation temperature, and that Hsp70 expression is tissue dependent (higher levels being seen in the brain) being cold-stress more effective in increasing Hsp70 levels in most studied tissues.

Expression of MyoD, myogenin, myostatin and Hsp70 transcripts in chicken embryos submitted to mild cold or heat

The expression of the MyoD, myogenin, myostatin and Hsp70 genes was estimated in chicken embryos submitted to mild cold (36 +/- 0.5degreesC) or heat (44 +/- 0.5degreesC) for 1 h. 2. Marked decreases in MyoD, myogenin and myostatin transcript levels were observed in embryos exposed to high temperature, contrasting to the higher expression of the Hsp70 mRNA detected in heat-stressed embryos. 3. The exposure of chicken embryos to low temperature significantly affected only the abundance of myogenin mRNA. 4. These findings suggest that myogenic proliferation and differentiation events are compromised by variations in environmental temperature during avian embryogenesis. (C) 2003 Elsevier B.V. Ltd. All rights reserved.