Periapical Tissue Response After Use of Intermediate Restorative Material, Gutta-Percha, Reinforced Zinc Oxide Cement, and Mineral Trioxide Aggregate as Retrograde Root-End Filling Materials: A Histologic Study in Dogs

Purpose: To investigate the periapical tissue response of 4 different retrograde root-filling materials, ie, intermediate restorative material, thermoplasticized gutta-percha, reinforced zinc oxide cement (Super-EBA), and mineral trioxide aggregate (MTA), in conjunction with an ultrasonic root-end preparation technique in an animal model. Materials and Methods: Vital roots of the third and fourth right mandibular premolars in 6 healthy mongrel dogs were apicectomized and sealed with 1 of the materials using a standardized surgical procedure. After 120 days, the animals were sacrificed and the specimens were analyzed radiologically, histologically, and scanning electron microscopically. The Fisher exact test was performed on the 2 outcome values. Results: Twenty-three sections were analyzed histologically. Evaluation showed better re-establishment of the periapical tissues and generally lower inflammatory infiltration in the sections from teeth treated with the intermediate restorative material and the MTA. New root cement on the resected dentin surfaces was seen on all sections regardless of the used material. New hard tissue formation, directly on the surface of the material, was seen only in the MTA sections. There was no statistical difference in outcome among the tested materials. Conclusions: The results from this dog model favor the intermediate restorative material and MTA as retrograde fillings when evaluating the bone defect regeneration. MTA has the most favorable periapical tissue response when comparing the biocompatibility of the materials tested. (C) 2012 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 70:2041-2047, 2012

Monitoring internal load parameters during simulated and official basketball matches

Moreira, A, McGuigan, MR, Arruda, AFS, Freitas, CG, and Aoki, MS. Monitoring internal load parameters during simulated and official basketball matches. J Strength Cond Res 26(3): 861-866, 2012-The purpose of this study was to compare the internal load responses (session rating of perceived exertion [RPE] and salivary cortisol) between simulated and official matches (SM and OM). Ten professional basketball players participated in 2 OMs and 2 SMs during the competition season. Subjects provided saliva samples 30 minutes before the prematch warm-up (PRE) and 10 minutes after the end of the match. Session RPE (CR-10 scale) was assessed 30 minutes after each match. The results from the 2-way analysis of variance showed significant differences for post-OM salivary cortisol as compared with pre-OM values (p < 0.05). No changes were observed for cortisol during the SM. Before the OM, a significant difference in salivary cortisol was observed as compared with pre-SM values (p < 0.05). Moreover, the OM session RPE was significantly greater than that of SM. There was a significant correlation between session RPE and cortisol changes (r = 0.75). In summary, the results of this study showed a greater magnitude of cortisol and session RPE responses after OM as compared with that after SM confirming the hypothesis that a real competition generates a greater stress response than a simulated condition does. The anticipatory effect was also observed in the OM. In addition, the results indicate that session RPE seems to be a viable tool in monitoring internal loads, and the results are useful in providing a better understanding of internal loads imposed by basketball training and competitions. The precise monitoring of these responses might help the coaches to plan appropriate loads maximizing recovery and performance.

Positive effects of zinc supplementation on growth, GH, IGF1, and IGFBP3 in eutrophic children

Zinc is an essential micronutrient for growth and development. Its deficiency causes growth retardation in children and adolescents. The present study analyzes the effect of zinc on growth hormone (GH) secretion, insulin-like growth factor 1 (IGF1), and insulin-like growth factor-binding protein 3 (IGFBP3) in normal children before puberty. Thirty normal children were studied, 15 boys and 15 girls, aged 6-9 years. They were orally supplemented with 5 mg Zn/day for 3 months and 0.06537 mg Zn/kg body weight was injected before and after oral supplementation. Dietary intake and anthropometric measurements were assessed at baseline and end of study. Plasma GH levels increased during intravenous zinc administration and IGF1 and IGFBP3 increased after oral zinc supplementation. There was a positive correlation between the areas under the curves of GH and zinc after oral supplementation. Zinc supplementation was possibly effective in improving the body zinc status of the children, secretory levels of IGF1 and IGFBP3, GH potentialization, and height.

Urea-Based Synthesis of Zinc Oxide Nanostructures at Low Temperature

The preparation of nanometer-sized structures of zinc oxide (ZnO) from zinc acetate and urea as raw materials was performed using conventional water bath heating and a microwave hydrothermal (MH) method in an aqueous solution. The oxide formation is controlled by decomposition of the added urea in the sealed autoclave. The influence of urea and the synthesis method on the final product formation are discussed. Broadband photoluminescence (PL) behavior in visible-range spectra was observed with a maximum peak centered in the green region which was attributed to different defects and the structural changes involved with ZnO crystals which were produced during the nucleation process.

Effects of catalyst load in Pt and Pb-based catalysts using formic acid oxidation as a model

In this paper, we discuss the effects of catalyst load with respect to carbon powder for several Pt and Pb-based catalysts, using formic acid as a model molecule. The discussion is based on electrochemical tests, a complete morphological investigation and theoretical calculations. We show that the Pt and Pb-based catalysts presented activity in formic acid oxidation at very low catalyst loads (e.g., 0.5% in respect to the carbon content). Physical characterisations demonstrate that the electrodes are composed of separated phases of Pt and lead distributed in Pt nanometric-sized islands that are heterogeneously dispersed on the carbon support and Pb ultra-small particles homogeneously distributed throughout the entire carbon surface, as demonstrated by the microscopy studies. At high catalyst loads, very large clusters of Pb(x)O(y) could be observed. Electrochemical tests indicated an increase in the apparent resistance of the system (by a factor of 19.7 Omega) when the catalyst load was increased. The effect of lead in the materials was also studied by theoretical calculations (OFT). The main conclusion is that the presence of Pb atoms in the catalyst can improve the adsorption of formic acid in the catalytic system compared with a pure Pt-based catalyst. (C) 2011 Elsevier B.V. All rights reserved.

Is there a relationship between the total volume of load lifted in bench press exercise and the rating of perceived exertion?

Aim. The purpose of the study was to investigate the relationship between the total volume of load lifted (TVLL) and the rating of perceived exertion (RPE) measures during different resistance training (RT) schemes using the bench press exercise. Methods. The present study was divided into two experiments. In the first experiment, 18 healthy men performed three different RT schemes: a strength oriented scheme (SS), a muscular endurance oriented scheme (ES) and a hypertrophy oriented scheme (HS). TVLL was calculated for each scheme. Mean-RPE and session-RPE were assessed. In the second experiment, 23 men performed two resistance exercise bouts at different intensities (50 %-1RM and 75%-1RM) with matched TVLL. Mean-RPE and session-RPE were also assessed. Results. SS and HS showed higher TVLL and greater RPE scores as compared to ES (P<0.05). No significant difference was observed between SS and HS. It was verified significant positive correlations between TVLL and session-RPE (SS r=0.63, HS r=0.64, ES r=0.56; P<0.05), and between mean-RPE and TVLL (SS r=0.55, HS r=0.52, ES r=0.47; P<0.05) for all schemes. No differences were observed for mean-RPE, session-RPE and TVLL between the 50%-1RM and 75%1RM. Significant positive relationships between TVLL and session-RPE (50 %-1RM r=0.61, 75 %-1RM r=0.66; p<0.05) and between TVLL and mean-RPE (50 %-1RM r=0.51, 75%1RM r=0.49; P<0.05) were observed. Conclusion. The results of this study have shown that the TVLL in RT influences RPE measures. These findings corroborates the existence of a relationship between total work performed (external training load) and perception of effort (internal training load).

MRKAd5 HIV-1 Gag/Pol/Nef Vaccine-Induced T-Cell Responses Inadequately Predict Distance of Breakthrough HIV-1 Sequences to the Vaccine or Viral Load

Background: The sieve analysis for the Step trial found evidence that breakthrough HIV-1 sequences for MRKAd5/HIV-1 Gag/Pol/Nef vaccine recipients were more divergent from the vaccine insert than placebo sequences in regions with predicted epitopes. We linked the viral sequence data with immune response and acute viral load data to explore mechanisms for and consequences of the observed sieve effect. Methods: Ninety-one male participants (37 placebo and 54 vaccine recipients) were included; viral sequences were obtained at the time of HIV-1 diagnosis. T-cell responses were measured 4 weeks post-second vaccination and at the first or second week post-diagnosis. Acute viral load was obtained at RNA-positive and antibody-negative visits. Findings: Vaccine recipients had a greater magnitude of post-infection CD8+ T cell response than placebo recipients (median 1.68% vs 1.18%; p = 0.04) and greater breadth of post-infection response (median 4.5 vs 2; p = 0.06). Viral sequences for vaccine recipients were marginally more divergent from the insert than placebo sequences in regions of Nef targeted by pre-infection immune responses (p = 0.04; Pol p = 0.13; Gag p = 0.89). Magnitude and breadth of pre-infection responses did not correlate with distance of the viral sequence to the insert (p. 0.50). Acute log viral load trended lower in vaccine versus placebo recipients (estimated mean 4.7 vs 5.1) but the difference was not significant (p = 0.27). Neither was acute viral load associated with distance of the viral sequence to the insert (p>0.30). Interpretation: Despite evidence of anamnestic responses, the sieve effect was not well explained by available measures of T-cell immunogenicity. Sequence divergence from the vaccine was not significantly associated with acute viral load. While point estimates suggested weak vaccine suppression of viral load, the result was not significant and more viral load data would be needed to detect suppression.

Mechanism and Efficiency of Cell Death of Type II Photosensitizers: Effect of Zinc Chelation

A series of meso-substituted tetra-cationic porphyrins, which have methyl and octyl substituents, was studied in order to understand the effect of zinc chelation and photosensitizer subcellular localization in the mechanism of cell death. Zinc chelation does not change the photophysical properties of the photosensitizers (all molecules studied are type II photosensitizers) but affects considerably the interaction of the porphyrins with membranes, reducing mitochondrial accumulation. The total amount of intracellular reactive species induced by treating cells with photosensitizer and light is similar for zinc-chelated and free-base porphyrins that have the same alkyl substituent. Zinc-chelated porphyrins, which are poorly accumulated in mitochondria, show higher efficiency of cell death with features of apoptosis (higher MTT response compared with trypan blue staining, specific acridine orange/ethidium bromide staining, loss of mitochondrial transmembrane potential, stronger cytochrome c release and larger sub-G1 cell population), whereas nonchelated porphyrins, which are considerably more concentrated in mitochondria, triggered mainly necrotic cell death. We hypothesized that zinc-chelation protects the photoinduced properties of the porphyrins in the mitochondrial environment.

Band structure calculations of InP wurtzite/zinc-blende quantum wells

Semiconductor nanowhiskers (NWs) made of III-V compounds exhibit great potential for technological applications. Controlling the growth conditions, such as temperature and diameter, it is possible to alternate between zinc-blende (ZB) and wurtzite (WZ) crystalline phases, giving origin to the so called polytypism. This effect has great influence in the electronic and optical properties of the system, generating new forms of confinement to the carriers. A theoretical model capable to accurately describe electronic and optical properties in these polytypical nanostructures can be used to study and develop new kinds of nanodevices. In this study, we present the development of a wurtzite/zinc-blende polytypical model to calculate the electronic band structure of nanowhiskers based on group theory concepts and the k.p method. Although the interest is in polytypical superlattices, the proposed model was applied to a single quantum well of InP to study the physics of the wurtzite/zinc-blende polytypism. By the analysis of our results, some trends can be predicted: spatial carriers' separation, predominance of perpendicular polarization (xy plane) in the luminescence spectra, and interband transition blueshifts with strain. Also, a possible range of values for the wurtzite InP spontaneous polarization is suggested. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4767511]

Mechanistic Implications of Zinc(II) Ions on the Degradation of Phenol by the Fenton Reaction

A study of the interference of Zn2+ ions on phenol degradation by Fenton reaction (Fe2+/Fe3(+) + H2O2) is reported. One of the first intermediates formed in the reaction, catechol, can reduce Fe3+ to Fe2+ and, in the presence of H2O2 initiates an efficient catalytic redox cycle. In the initial stages of the reaction, this catechol-mediated cycle becomes the principal route of thermal degradation of phenol and its oxidation products. The Zn2+ ion addition enhances the persistence time of catechol, probably by stabilization of the corresponding semiquinone radical via complexation.

Coffee is highly tolerant to cadmium, nickel and zinc: Plant and soil nutritional status, metal distribution and bean yield

Sewage sludge has been used to fertilize coffee, increasing the risk of metal contamination in this crop. The aim of this work was to study the effects of Cd, Zn and Ni in adult coffee plants growing under field conditions. Seven-year-old coffee plants growing in the field received one of three;loses of Cd, Zn or Ni: 15,45 and 90 g Cd plant(-1); 35, 105 and 210 g Ni plant(-1); and 100, 300 and 600 g Zn plant(-1), with all three metals in the form of sulphate salts. After three months, we noticed good penetration of the three metals into the soil, especially in the first 50 cm, which is the region where most coffee plant roots are concentrated. Leaf concentrations of K, Ca, Mg, S, B, Cu, Fe and Mn were nor affected. N levels did not change with the application of Ni or Zn but were reduced with either 45 or 90 g Cd plant(-1). Foliar P concentrations decreased with the addition of 45 and 90 g Cd plant(-1) and 600 g Zn plant(-1). Zn levels in leaves were not affected by the application of Cd or Ni. The highest concentrations. of Zn were found in branches (30-230 mg kg(-1)), leaves (7-35 mg kg(-1)) and beam (4-6.5 mg kg(-1)); Ni was found in leaves (4-45 mg kg(-1)), branches (3-18 mg kg(-1)) and beans (1-5 mg kg(-1)); and Cd was found in branches (0-6.2 mg kg(-1)) and beans (0-1.5 mg kg(-1)) but was absent in leaves. The mean yield of two harvests was not affected by Ni, but it decreased at the highest dose of Zn (600 g plant(-1)) and the two higher doses of Cd (45 and 90 g plant(-1)). Plants died when treated with the highest dose of Cd and showed symptoms of toxicity with the highest dose of Zn. Nevertheless, based on the amounts of metal used and the results obtained, we conclude that coffee plants are highly tolerant to the three metals tested. Moreover, even at high doses, there was very little transport to the beans, which is the part consumed by humans. (C) 2011 Elsevier B.V. All rights reserved.

Lack of evidence to support the association of a single IL28B genotype SNP rs12979860 with the HTLV-1 clinical outcomes and proviral load

Background: The Interleukin 28B (IL28B) rs12979860 polymorphisms was recently reported to be associated with the human T-cell leukemia virus type 1 (HTLV-1) proviral load (PvL) and the development of the HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Methods: In an attempt to examine this hypothesis, we assessed the association of the rs12979860 genotypes with HTLV-1 PvL levels and clinical status in 112 unrelated Brazilian subjects (81 HTLV-1 asymptomatic carriers, 24 individuals with HAM/TSP and 7 with Adult T cell Leukemia/Lymphoma (ATLL)). Results: All 112 samples were successfully genotyped and their PvLs compared. Neither the homozygote TT nor the heterozygote CT mutations nor the combination genotypes (TT/CT) were associated with a greater PvL. We also observed no significant difference in allele distribution between asymptomatic carriers and patients with HTLV-1 associated HAM/TSP. Conclusions: Our study failed to support the previously reported positive association between the IL28B rs12979860 polymorphisms and an increased risk of developing HAM/TSP in the Brazilian population.

Describing fatigue crack growth and load ratio effects in Al 2524 T3 alloy with an enhanced exponential model

The fatigue crack behavior in metals and alloys under constant amplitude test conditions is usually described by relationships between the crack growth rate da/dN and the stress intensity factor range Delta K. In the present work, an enhanced two-parameter exponential equation of fatigue crack growth was introduced in order to describe sub-critical crack propagation behavior of Al 2524-T3 alloy, commonly used in aircraft engineering applications. It was demonstrated that besides adequately correlating the load ratio effects, the exponential model also accounts for the slight deviations from linearity shown by the experimental curves. A comparison with Elber, Kujawski and "Unified Approach" models allowed for verifying the better performance, when confronted to the other tested models, presented by the exponential model. (C) 2012 Elsevier Ltd. All rights reserved.

Is zinc-alpha 2-glycoprotein a cardiovascular protective factor for patients undergoing hemodialysis?

Background: Zinc-alpha 2-glycoprotein (ZAG) is a lipid mobilizing factor. Its anti-inflammatory action and expression pattern suggest that ZAG could act by protecting against the obesity-associated disorders. In hemodialysis (HD) patients, ZAG levels were described to be elevated but its effects on markers of inflammation and LDL oxidation are still unclear. We investigated the relationship between ZAG and markers of systemic inflammation and LDL atherogenic modification profile in HD patients. Methods: Forty-three patients regularly on HD were studied and compared to 20 healthy subjects. Plasma ZAG, adiponectin, electronegative LDL [LDL(-)], an atherosclerotic negatively charged LDL subtraction, and anti-LDL(-) autoantibodies levels were measured by ELISA. Markers of inflammation and atherogenic cell recruitment (TNF-alpha, interleukin-6, VCAM-1, ICAM-1, MCP-1 and PAI-1) were also determined. Results: Inflammatory markers and atherogenic cell recruitment were higher in HD patients when compared to healthy subjects. ZAG levels were also higher in HD patients (151.5 +/- 50.1 mg/l vs 54.6 +/- 23.0 mg/l; p<0.0001) and its levels were negatively correlated with TNF-alpha (r= -0.39; p = 0.001) and VCAM-1 (r= -0.52; p<0.0001) and, positively correlated with anti-LDL(-) autoantibodies (r = 038; p = 0.016). On multivariate analyses, plasma ZAG levels were independently associated with VCAM-1 (p = 0.01). Conclusion: ZAG is inversely associated with markers of pro-atherogenic factors linked to systemic inflammation and oxidative stress. Thus, this adipokine may constitute a novel marker of a favorable metabolic profile regarding cardiovascular risk factors in HD population. (C) 2011 Elsevier B.V. All rights reserved.

CHEMICAL CHANGES AND ZINC PHYTOAVAILABILITY IN SEWAGE SLUDGE-AMENDED SOIL ESTIMATED BY THE ISOTOPIC METHOD

CHEMICAL CHANGES AND ZINC PHYTOAVAILABILITY IN SEWAGE SLUDGE-AMENDED SOIL ESTIMATED BY THE ISOTOPIC METHOD. Zn availability in Red Latossol (Rhodic Ferralsol) of different pH amended with different rates of sewage sludge was studied by the isotopic Zn-65 L value method. Soil chemical properties were found to be altered by SS addition. Zn concentration and Zn derived from SS (ZnpfSS) in plant, and Zn phytoavailability (L value), were increased with increasing SS rates. The linear correlation coefficient of plant Zn with SS rates and with L value was significant at 1% probability. The L value proved an efficient method for predicting Zn phytoavailability in sewage sludge-amended soil with different pH under the soil conditions studied.