Silver halide sensitized gelatin process effects in holographic lenses recorded on Slavich PFG-01 plates

In this work we study the feasibility of using silver halide sensitized gelatin based on PFG-01 (Slavich) emulsions to construct uniaxial compound lenses. This processing is able to introduce variations in the thickness and refractive index of the emulsion. We prove that these changes are not sufficient to provide the observed variations in Bragg conditions in the reconstruction and that a shear-type effect must exist to explain the performance of processed emulsions. We study the characteristics of a compound lens, obtaining acceptable image quality, good resolution, and the typical field limitation of volume holographic elements.     

Molecular and microbiological analysis of caecal microbiota in rats fed with diets supplemented either with prebiotics or probiotics

The potential health-improving effects of both a prebiotic and a probiotic infant formula have been evaluated in a rat model. Two groups of 10 rats were fed with either prebiotics containing fructo-oligosaccharides or probiotics containing viable Bifidobacterium lactis and Streptococcus thermophilus. The composition of their caecal microbiota was analyzed both by classical plate count of the main bacterial groups and by PCR amplification of a V3 fragment of 16S rRNA genes and denaturing gradient gel electrophoresis (DGGE). Both diets induced a significant reduction of clostridia and Bacteroides spp. compared to a control diet, whereas prebiotics were also able to reduce the number of coliforms and to increase the presence of bifidobacteria. DGGE analysis showed a significant increase of 16S rRNA gene fragments in rats fed with either probotics or prebiotics. Nineteen bands were sequenced and most of them showed similarity to cultured bacteria. Detection of Bifidobacterium spp. by this technique using genus-specific primers only permitted these bacteria to be detected in prebiotics-fed rats, whereas the use of Lactobacillus group-specific primers gave similar results in rats fed with any diet, in agreement with the plate count results.     

Characterization of Lactobacillus strains and monitoring by RAPD-PCR in controlled fermentations of "Almagro" eggplants

The characterization of 23 Lactobacillus strains was performed. The strains were assayed for biogenic amine-forming capacity, hydrogen peroxide production, pectin esterase, cellulase and polygalacturonase production, growth rate, acidifying capacity and salt tolerance. Three strains were selected which belonged to the species, Lactobacillus brevis, Lactobacillus plantarum and Lactobacillus fermentum. Different starter cultures prepared as combinations of these three strains were assayed in pilot scale fermentations and Randomly Amplified Polymorphic DNA (RAPD) analysis, using a previously selected random primer, was applied for monitoring the inoculated strains. The course of fermentations was similar in all batches but sensorial analysis of eggplants fermented using a mixed culture of the three strains displayed the best results, and no differences were obtained when compared with commercial eggplants.     

Resveratrol as an anti-inflammatory and anti-aging agent: mechanisms and clinical implications

Resveratrol is a phytoalexin polyphenolic compound found in various plants, including grapes, berries, and peanuts. Multiple lines of compelling evidence indicate its beneficial effects on neurological, hepatic, and cardiovascular systems. Also one of the most striking biological activities of resveratrol soundly investigated during the late years has been its cancer-chemopreventive potential. In fact, recently it has been demonstrated that this stilbene blocks the multistep process of carcinogenesis at various stages: tumor initiation, promotion, and progression. One of the possible mechanisms for its biological activities involves downregulation of the inflammatory response through inhibition of synthesis and release of pro-inflammatory mediators, modification of eicosanoid synthesis, inhibition of activated immune cells, or inhibiting such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) via its inhibitory effects on nuclear factor (kappa)B (NF-(kappa)B) or the activator protein-1 (AP-1). More recent data provide interesting insights into the effect of this compound on the lifespan of yeast and flies, implicating the potential of resveratrol as an anti-aging agent in treating age-related human diseases. It is worthy to note that the phenolic compound possesses a low bioavailability and rapid clearance from the plasma. As the positive effects of resveratrol on inflammatory response regulation may comprise relevant clinical implications, the purpose of this article is to review its strong anti-inflammatory activity and the plausible mechanisms of these effects. Also, this review is intended to provide the reader an up-date of the bioavailability and pharmacokinetics of resveratrol and its impact on lifespan.     

Preservation of the endogenous antioxidant system of fish muscle by grape polyphenols during frozen storage

The capacity of a phenolic extract, OW, obtained from grape (Vitis vinifera) by-products, and of a purified fraction of procyanidins from OW, fraction IV, for preservation of endogenous antioxidants of fatty fish was investigated during frozen storage. They were used in muscle concentrations of 0.01% (w/w). Grape polyphenols were compared with propyl gallate, a synthetic antioxidant. The exogenous compounds were added to minced mackerel (Scomber scombrus) muscle and horse mackerel (Trauchurus trauchurus) fillets, before freezing at –10 °C. The results demonstrated that grape polyphenols and propyl gallate inhibit the depletion of endogenous -tocopherol, ubiquinone-10 and total glutathione. Grape polyphenols and propyl gallate showed similar efficiency for preservation of ubiquinone, in both minced and filleted muscle, and total glutathione, in minced muscle. Total glutathione in the fillets was better maintained by propyl gallate than grape polyphenols. The endogenous antioxidant more efficiently preserved by grape polyphenols and propyl gallate was -tocopherol. Its loss elapsed faster in the order control> OW>fraction IV>propyl gallate. The depletion of -tocopherol was highly correlated with the evolution of lipid oxidation. The development of lipid oxidation was repressed, while the concentration of -tocopherol was not reduced up to critical levels.     

Temperature Measurement: Christiansen Wavelength and Blackbody Reference

The aim of this paper is to propose simple and reliable methods to measure temperatures exceeding 1500°C by pyrometry on dielectric heteropolar compounds. By adopting a spectroscopic approach based on a knowledge of the material (chemical composition, texture, size), it is suggested first to work at the Christiansen wavelength that is nearly independent of temperature, the texture, and the shape. Second, recent developments concerning plate blackbodies that are operable up to 1600 K are presented. Such compact systems are suitable to be installed in industrial heating devices in order to easily calibrate the pyrometer. Paper presented at the Seventh International Workshop on Subsecond Thermophysics, October 6–8, 2004, Orléans, France.     

Treatment of severe malnourished children with WHO protocol: experience of a referral center in São Paulo, Brazil

Mortality rate, anthropometric development and nutritional therapy with the use of World Health Organization guidelines (WHO) were assessed. In a cross-sectional retrospective study 191 hospitalized malnourished children were assessed. To classify and evaluate nutritional rehabilitation Z-score was used: weight-for-age (ZW), height-for-age(ZH) and weight-for-height(ZWH). The children were divided in three groups (G): GI (primary malnutrition--30,9%), GII (secondary malnutrition--51,7%) and GIII (children who were admitted as GI but during internation had an identified chronic disease--12%). Nutritional therapy used was based on WHO guidelines, with slight modifications. The formulas chosen were all industrialized: lactose-free polymeric formula (PLF) for children with diarrhea, low lactose polymeric formula (PLL) for children without diarrhea and cow's milk hydrolysate (H) for sepsis or chronic diarrhea. In the rehabilitation phase, all the children used PLL formula. Statistical analysis: Student's, chi-square tests, simple linear regression. The median age and mortality rate were 10,3 months and 4,2%, respectively. The GI and GII children were older than GIII (11vs12vs7months,p=0,02) and had shorter length of stay (20vs22vs37days,p=0,010). Mortality risks in GIII were twice as frequent as in GI+GII. Pneumonia, diarrhea and poor weight gain were the main diagnosis at admission. Tubes were used more frequently in GII+GIII than GI (p=0,004). Parenteral nutrition was indicated in 5,7% of children, more often in GIII than GI+GII (p=0,037). Tolerance of the initial formula wasn't satisfactory in 20% of the children. An improvement of 87% ZWH, 74,1% ZW and 22% was observed. ZW in GI and ZWH in GIII were the indices that showed the most effective gain during hospital stay. The modified WHO guidelines were effective in the multiprofessional treatment of malnourished children, resulting in good nutritional rehabilitation with low mortality rates. A high percentage of children admitted as primary malnutrition who had a chronic disease diagnosed was observed. The late diagnosis may be responsible for the high length of stay, formula intolerance and mortality risk.     

Moisture induced degradation of multilayer ceramic capacitors

When both precious metal electrode and base metal electrode (BME) capacitors were subjected to autoclave (121 °C/100% RH) testing for 500 h, it was found that the precious metal capacitors aged according to a well known aging mechanism (average capacitance degraded less than 3% from their starting values), but the BME capacitors degraded to below the −30% specification limit. One hypothesis for this new failure mechanism was that there could be oxidation or corrosion of the nickel plates. Another hypothesis was that the loss of capacitance was due to chemical changes in the barium titanate.This paper presents the evaluation of the two hypotheses and the physics of the degradation mechanism. It is concluded that there are chemical changes in the barium titanate resulting from the interaction of residual point defects from BME manufacturing and humidity in the field. The continuous reduction in capacitor size makes the newer base metal electrode capacitors more vulnerable to moisture degradation than the older generation precious metal capacitors. In addition, standard humidity life testing, such as JESD-22 THB and HAST, will likely not uncover this problem. Therefore, poor reliability due to degradation of base metal electrode multilayer ceramic capacitors may catch manufacturers and consumers by surprise.     

Performance enhancement of DS-CDMA system using overlapping sectors with interference avoidance

A cellular system with overlapping sectors is proposed to enhance system performance through interference avoidance. Due to the overlapping effect, each user is allowed to select one sector out of many for operation. It is shown that the mutual interference among users in different regions within a cell can be minimized by choosing a good sector combination. The potential benefits of the proposed technique are investigated in two scenarios: orthogonal and nonorthogonal code division multiple access systems. In the former case, it is shown that when compared with the traditional nonoverlapping sectors system, one is able to reduce the number of spreading codes required to support all users by using appropriate code allocation in the proposed system. A theoretical framework based on combinatorial enumeration is developed to assess the performance of the proposed system. For the latter case, the enhancement takes the form of multiple access interference reduction. Simulation results show that its improvement is significant and can be further enhanced by increasing the number of overlapping sectors.