Effect of aging on the stability of ceramic foams prepared by thermostimulated sol-gel process

This work presents a new route of preparation of zirconium ceramic foams based on the thermostimulated sol-gel process. This method produces gelled bodies with up to 90% of porosity in the wet gel and can be used to make complex-shaped components. Unfortunately, the shrinkage during the drying step allows to a catastrophic reduction (50%) of the foam porosity. To improve the foam stability we carried out a systematic study of the effect of gel foam aging on the drying process. Samples were aged in closed vessel at 25 C during different time period (from 6 to 240 h). The shrinkage and the mass loss during drying at 50 C were measured in situ, using a non-contact technique performed with a special apparatus. The results show that the total linear shrinkage decreases from 46% to 8% as the aging period increase from 6 to 240 h. This behavior is followed by a small change of total mass loss, from 42 to 54%. It indicates that by aging the structural stiffness of the foams increases due to secondary condensation reactions. Thus, by controlling the aging period, the porosity can be increased from 67 to 75% and the average size of mesopores of dried foams can be screened from 0.3 to 0.9 mum. Finally, these results demonstrate that the thermostimulated sol-gel transition provides a potential route to ceramic foams manufacture.

Genetic and phenotypic trends for growth traits of buffaloes in Brazil

The objectives this paper were to estimate genetic parameters and genetic and phenotypic trends of birth weight (BWT) and weights adjusted to 205 (WT205), 365 (WT365) and 550 (P550) days of age of beef buffaloes born from 1985 to 2003 in Brazil. For BWT and WT205 the model included direct and maternal genetic and maternal environment as random effects and contemporary and genetic groups as fixed effects. For WT365 and WT550 the same model was used except without direct maternal and maternal environmental effects. The genetic and phenotypic trends were estimated by regression of means of dependent variables on birth year of animals Regressions were obtained by using two methodologies: 1) linear regression; and 2) non-parametric splined regression. The direct heritability estimates were 0.09, 0.45, 0.46 and 0.58 for BWT, WT205, WT365 and WT550, respectively. The direct genetic trends from linear regression were 0.01, 0.23, 0.58 and 1.40 kg per year for PN, WT205, VVT365 and WT550, respectively (P<0.001 for all). Phenotypic trends were strongly positive while genetic trends were consistently positive but small. Genetic parameters indicate potential for increased rate of genetic change with full implementation of genetic improvement programs.

The investigation of alpha -> beta phase transition in poly(vinylidene fluoride) (PVDF)

The phase transition from the non-polar a-phase to the polar beta-phase of poly(vinylidene fluoride) (PVDF) has been investigated using micro-Raman spectroscopy, which is advantageous for being a non-destructive technique. Films of alpha-PVDF were subjected to stretching under controlled rates and at 80 degrees C, the transition to beta-PVDF being monitored by the decrease in the Raman band at 794 cm(-1) characteristic of the a-phase, with the concomitant increase in the 839 cm(-1) band characteristic of the beta-phase. Poling with negative corona discharge was found to affect the alpha-PVDF morphology improving the Raman bands related to this crystalline phase. This effect is minimized for films stretched to higher ratios. Significantly, corona-induced effects could not be observed with the other experimental techniques, viz. X-ray diffraction and infrared spectroscopy.

One-year clinical performance of self-etch adhesives in posterior restorations

Purpose: To evaluate the 1-year clinical performance of three self-etching adhesives (Adper Prompt L-Pop, Clearfil S-3 Bond, iBond) in posterior composite restorations using one etch&rinse adhesive (One-Step Plus) as control. Methods: Upon approval by the Institutional Review Board, 121 restorations were inserted in 38 subjects. The adhesives were applied as per manufacturers' instructions. Preparations were restored with a nanofilled resin composite (Filtek Supreme) and evaluated at baseline, 6 months, and 1 year. Statistical analyses included the Chi-square distribution with the McNemar non-parametric test (P< 0.05). Results: At 1 year, 111 restorations in 35 subjects were evaluated using the USPHS modified criteria. No significant changes were observed for the etch&rinse adhesive One-Step Plus. At 1 year the number of Alfa ratings decreased significantly for Clearfil S-3 Bond and for iBond in the categories color match, marginal staining, and marginal adaptation. For Adper Prompt L-Pop, marginal adaptation at 1 year was significantly worse than at baseline. Postoperative sensitivity to air improved significantly for Adper Prompt L-Pop, Clearfil S-3 Bond, and iBond. When the evaluation criteria were paired at 1 year, iBond resulted in a significantly lower number of Alfa ratings than any of the other adhesives for color match, marginal staining, and marginal adaptation. One-Step Plus resulted in a greater number of Alfa ratings for marginal adaptation than either Adper Prompt L-Pop or Clearfil S-3 Bond. Marginal adaptation was significantly better for Clearfil S-3 Bond than for Adper Prompt L-Pop. The post-operative sensitivity measured at 1 year for Adper Prompt L-Pop was statistically better than that for One-Step Plus.

Univariate and bivariate distribution of growth traits in beef buffaloes from Brazil

The aim of this study was to analyze the weight at birth (BW) and adjusted at 205 (W205), 365 (W365) and 550 (W55O) days in beef buffaloes from Brazil, using two approaches: parametric, by normal distribution, and non-parametric, by kernel function, and thus estimating the genetic, environmental and phenotypic correlation among traits. Information of 5,169 animals at birth (BW), 3,792 at 205 days (W205), 3.883 at 365 days (W365) and 1,524 at 550 days of age (W550) were used. The birth weight distribution presented an evident discrepancy in relation to the normal distribution. However, W205, W365 and W550 presented normal distributions. The birth weight presented weak genetic, environmental, and phenotypic associations with the other weight measurements. on the other hand, the weight traits at 205, 365, 550 days of age showed a high genetic correlation.

A simple prescription for computing the stress-energy tensor

A non-variational technique for computing the stress-energy tensor is presented. The prescription is used, among other things, to obtain the correct field equations for Prasanna's highly nonlinear electrodynamics.

Comparing the efficacy of mandibular implant-retained overdentures and conventional dentures among elderly edentulous patients: satisfaction and quality of life

Objectives: the aim of this study was to compare the satisfaction and the quality of life in an elderly population using either mandibular conventional dentures or implant-retained overdentures.Materials and methods: A total of 34 patients were divided into two groups: group I-complete dentures users; group II - users of upper complete dentures opposed by implant-retained overdentures. The subjects were submitted to a questionnaire based on Oral Health impact Profile and oral health related quality of life to evaluate their satisfaction levels and quality of life with their prostheses. Data were evaluated using a non-parametric statistical analysis (Fischer test) with significant difference at alpha = 0.05.Results: There were no significant differences between the groups in relation to comfort, aesthetics, chewing ability, overall satisfaction, pain, functional, phonetic, social, and psychological limitations (p > 0.05). Comparing the stability of mandibular dentures, group II presented the better results (p < 0.05).Conclusion: Although the stability of the mandibular implant-retained overdenture was enhanced compared to a conventional denture, the quality of life and satisfaction levels were similar for both the groups.

Subclinical abnormalities of glucose metabolism in Brazilian women with a history of gestational diabetes mellitus

Background. To evaluate insulin release and insulin sensitivity in women with prior gestational diabetes mellitus (GDM) to gain a better understanding of type 2 diabetes pathogenesis.Methods. GDM women were individually matched for age, body mass index, and waist/hip ratio with those who were normal glucose tolerant in a previous pregnancy (NGT). All women presented with normal glucose tolerance. Twenty pairs were submitted to the oral glucose tolerance test (OGTT) with plasma glucose, insulin, and C-peptide determinations. of the 20 pairs, 18 participated in hyperglycemic (10.0 mmol/l) clamp experiments with frequent plasma glucose and insulin determinations, allowing us to calculate first- and second-phase insulin release and the insulin sensitivity index. GDM and NGT women were compared using Student's t-test, the Mann-Whitney U-test, Friedman's non-parametric test, and the two proportion test for independent groups.Results. GDM women showed higher glycosylated hemoglobin values; at OGTT, they showed late insulin peak with increased plasma insulin levels only during the second hour, and a similar plasma C-peptide response despite a higher plasma glucose curve; during hyperglycemic clamp procedures, they showed similar biphasic insulin release and insulin sensitivity index. Considering that a woman with previous GDM had a defect in insulin release and/or insulin sensitivity, if its magnitude was at least 25% lower than that of the matched NGT woman, 43.8% showed impairment of first-phase insulin release and 55.6% insulin resistance.Conclusions. GDM women showed some degree of glucose intolerance. It is therefore necessary to follow them for a longer time.

Effects of Antibacterial Agents on Dental Pulps of Monkeys Mechanically Exposed and Contaminated.

The purpose of this study was to compare the effectiveness of antibacterial agents and mineral trioxide aggregate in the healing of bacterial contaminated primate pulps. Study Design: The experiment required four adult male primates (Cebus opella) with 48 teeth prepared with buccal penetrartions into the pulpal tissues. The preparations (Cebus opella) with 48 teeth prepared with buccal penetrations into the exposed to cotton pellets soaked in a bacterial mixture consisting of microorganisms normally found in human pulpal abscesses obtained from the Endodontic Clinic of UNESP. Following bacterial inoculation (30 minute exposure), the pulpal tissue was immediately treated with either sterile saline, Cipro HC Otic solution (12), diluted Buckley formecresol solution (12) or Otosporin otic solution (12) for 5 minutes. After removal of the pellet, hemostasis was obtained and a ZOE base applied to the DFC treated pulps and the non-treated controls (12). After hemostasis, the other exposed pulps were covered with mineral trioxide aggregate (ProRoot). The pulpal bases were all covered with a RMGI (Fuji II LC). The tissue samples were collected at one day, two days, one week and over four weeks (34 days). Results: Following perfusion fixation, the samples were demineralized, sectioned, stained and histologically graded. After histologic analysis, presence of neutrophilic infiltrate and areas of hemorrhage with hyperemia were observed . The depth of the neutrophilic infiltrate depended on the agent or material used. The pupal tissue treated with Otic suspensions demonstrated significantly less inflammation (Kruskal Wallis non parametric analysis, H=9.595 with 1 degree of freedom; P=0.0223) than the formocresol and control groups. The hard tissue bridges formed over the exposure sites were more organized in the MTA treatment groups than in the control and ZOE groups (Kruskal Wallis non parametric analysis, H=18.291 with 1 degree of freedom; P=0.0004). Conclusions: Otic suspensions and MTA are effective in treating bacterial infected pulps and stimulate the production of a hard tissue bridge over the site of the exposure.

Neonatal meningitis according to the microbiological diagnosis: a decade of experience in a tertiary center

The aim of this study was to evaluate the incidence of and mortality due to meningitis and compare data according to microbiological diagnosis. This was a ten-year retrospective study conducted at a neonatal intensive care unit (NICU). Newborns with meningitis confirmed by positive CSF culture were included; those with congenital infection or malformations that made lumbar puncture impossible were excluded. The variables investigated were birth weight, gestational and postnatal age, procedures, hematological and CSF parameters, and complications. Parametric and non-parametric tests were used (statistical value p<0.05). The incidence of meningitis was 0.6% and mortality was 27%. of the 22 cases, 59% involved Gram-negative bacteria; 36% Gram-positive and 5% fungi. The groups did not differ in relation to birth weight, gestational and postnatal age, procedures or hematological and CSF parameters. Sepsis, convulsions and deaths were frequent in both groups, without statistical difference. Gram-negative cases showed abscesses and higher frequency of ventriculitis and hydrocephaly. Meningitis was infrequent, but presented high mortality and frequent complications.

Alterations in pulmonary structure by elastase administration in a model of emphysema in mice is associated with functional disturbances

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electromyographic analysis of the arm muscles in front support exercises

The electromyographic activity of the biceps brachii - BB (long head), triceps brachii - TB (long head) and deltoideus - DA (clavicular portion) muscles, during the going (G) and return (R) phases in front support exercise, as well the efficacy of this exercise for the development of these muscles strength were studied in 10 male volunteers. The values were normalized through maximum voluntary isometric contraction (MVIC = 100%) and statistically analyzed using the Friedman, DMS and Wilcoxon non-parametric test. A value of p≤0.05 indicated significance (Campos, 1983). All the muscles presented higher electromyographic activity in the return phase of the movement. The triceps brachii was the muscle which had higher activity in both phases of the movement. It was concluded that the front support exercise is efficient for strength development mainly in the triceps brachii muscle.

Intelligence functions disorders in patients with complex partial epilepsy

Objective: To compare the performance of patients with complex partial epilepsy with the normal controls in the subtests of an instrument used to assess intelligence function. Method: Fifty epileptic patients, whose ages ranged from 19 to 49 years and 20 normal controls without any neuropsychiatric disorders. The Wechsler-Bellevue adult intelligence test was applied in groups, epileptic patients and control subjects. This test is composed of several subtests that assess specific cognitive functions. A statistical analysis was performed using non-parametric tests. Results: All the Wechsler-Bellevue subtests revealed that the intelligence functions of the patients were significantly inferior to that of the controls (p<0.05). This performance was supported by the patient's complaints in relation to their cognitive performance. Conclusion: Patients with complex partial epilepsy presented poorer results in the intelligence test when compared with individuals without neuropsychiatric disorders.

Progression of liver fibrosis in blood donors infected with hepatitis C virus

Background/Aims. Chronic hepatitis by HCV is progressive towards cirrhosis, with variable rate. We evaluated the rate of fibrosis progression (RFP), risk factors associated with advanced fibrosis (F3 and F4), and estimated the evolution time to cirrhosis. Methods. We transversely selected 142 blood donors infected only with HCV, with a known route of infection, submitted to liver biopsy at admission. RFP= ratio between stage of fibrosis (METAVIR)/estimated duration of infection in years. Non-parametric tests and logistic regression analysis, with significance level of 5% were used. Results. Median RFP was 0.086 U/year (0.05 - 0.142). Ten patients had F4 and 25 had F3. Median RFP values were significantly different (p=0.001) from one age group at contamination to the others and ALT and AST levels. There were no differences in the expected evolution to cirrhosis between intermediate fibrosers (F2) and the rapid fibrosers (F3 and F4). The independent variables associated with advanced fibrosis were ALT (OR 7.2) and GGT (OR 6.4) and age at inclusion (OR 1.12). Conclusion. This study suggests that RFP is extremely variable, it is exponential with age, and mainly influenced by host characteristics, especially age at contamination and possibly ethnical group. These asymptomatic patients had high percentage of fibrosis F2, F3 and F4.

The investigation of α→β phase transition in poly(vinylidene fluoride) (PVDF)

The phase transition from the non-polar α-phase to the polar β-phase of poly(vinylidene fluoride) (PVDF) has been investigated using micro-Raman spectroscopy, which is advantageous for being a non-destructive technique. Films of α-PVDF were subjected to stretching under controlled rates and at 80°C, the transition to β-PVDF being monitored by the decrease in the Raman band at 794 cm-1 characteristic of the α-phase, with the concomitant increase in the 839 cm-1 band characteristic of the β-phase. Poling with negative corona discharge was found to affect the a-PVDF morphology improving the Raman bands related to this crystalline phase. This effect is minimized for films stretched to higher ratios. Significantly, corona-induced effects could not be observed with the other experimental techniques, viz. X-ray diffraction and infrared spectroscopy.