993 resultados para indirizzo :: 908 :: Processi e materiali


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Three compounds have been synthesized with formulae [3-MeRad][Ni(dmit)2] (1), [4-MeRad][Ni(dmit)2] (2) and [4-PrRad][Ni(dmit)2] (3) where [Ni(dmit)2]- is an anionic pi-radical (dmit = 1,3-dithiol-2-thione-4,5-dithiolate) and [3-MeRad]+ is 3-N-methylpyridinium alpha-nitronyl nitroxide, [4-MeRad]+ is 4-N-methylpyridinium alpha-nitronyl nitroxide and [4-PrRad]+ is 4-N-propylpyridinium alpha-nitronyl nitroxide. The temperature-dependent magnetic susceptibility of 1 revealed that an antiferromagnetic interaction operates between the 3-MeRad+ radical cations with exchange coupling constants of J1 = - 1.72 cm-1 and antiferromagnetism assigned to the spin ladder chains of the Ni(dmit)2 radical anions. Compound 1 exhibits semiconducting behavior and 3 presents capacitor behavior in the temperature range studied (4 - 300 K).

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The antioxidant activity of sugarcane (Saccharum officinarum L.) juice towards DPPH reagent was determined (EC50) and the main compounds with radical scavenging activity in juice and leaves extracts were identified by HPLC-UV/PAD analysis combined with HPLC microfractionation monitored by TLC using β-carotene and DPPH as the detection reagents. In sugarcane leaves, luteolin-8-C-(rhamnosylglucoside) (1) was the most important compound with radical scavenging activity; in sugarcane juice, the flavones diosmetin-8-C-glucoside (2), vitexin (3) schaftoside (9), isoschaftoside (10) and 4',5'-dimethyl-luteolin-8-C-glucoside (11) were the most relevant compounds. The content of juice flavonoids (0.241 ± 0.001 mg total flavonoids/mL juice), comparable to other food sources of flavonoids, suggest the potential of sugarcane as a dietary source of natural antioxidants. However, the low antioxidant ability of sugarcane juice (EC50 = 100.2 ± 2.6 g L-1) also points to the need for further studies about the dietary intake of sugarcane flavonoids and its effects on human health.

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The effect of genetic and non-genetic factors for carcass, breast meat and leg weights, and yields of a commercial broiler line were investigated using the restricted maximum likelihood method, considering four different animal models, including or excluding maternal genetic effect with covariance between direct and maternal genetic effects, and maternal permanent environmental effect. The likelihood ratio test was used to determine the most adequate model for each trait. For carcass, breast, and leg weight, and for carcass and breast yield, maternal genetic and permanent environmental effects as well as the covariance between direct and maternal genetic effects were significant. The estimates of direct and maternal heritability were 0.17 and 0.04 for carcass weight, 0.26 and 0.06 for breast weight, 0.22 and 0.02 for leg weight, 0.32 and 0.02 for carcass yield, and 0.52 and 0.04 for breast yield, respectively. For leg yield, maternal permanent environmental effect was important, in addition to direct genetic effects. For that trait, direct heritability and maternal permanent environmental variance as a proportion of the phenotypic variance were 0.43 and 0.02, respectively. The results indicate that ignoring maternal effects in the models, even though they were of small magnitude (0.02 to 0.06), tended to overestimate direct genetic variance and heritability for all traits.

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Aims. We present a dynamical analysis of the galaxy cluster Abell 1942 based on a set of 128 velocities obtained at the European Southern Observatory. Methods. Data on individual galaxies are presented and the accuracy of the determined velocities as some properties of the cluster are discussed. We have also made use of publicly available Chandra X-ray data. Results. We obtained an improved mean redshift value z = 0.22513 +/- 0.0008 and velocity dispersion sigma = 908(139)(+147) km s(-1). Our analysis indicates that inside a radius of similar to 1.5 h(70)(-1) Mpc (similar to 7 arcmin) the cluster is well relaxed, without any remarkable features and the X-ray emission traces the galaxy distribution fairly well. Two possible optical substructures are seen at similar to 5 arcmin from the centre in the northwest and the southwest directions, but are not confirmed by the velocity field. These clumps are, however, kinematically bound to the main structure of Abell 1942. X-ray spectroscopic analysis of Chandra data resulted in a temperature kT = 5.5+/-0.5 keV and metal abundance Z = 0.33 +/- 0.15 Z(circle dot). The velocity dispersion corresponding to this temperature using the T(X-sigma) scaling relation is in good agreement with the measured galaxy velocities. Our photometric redshift analysis suggests that the weak lensing signal observed to the south of the cluster and previously attributed to a ""dark clump"" is produced by background sources, possibly distributed as a filamentary structure.

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Moniliophthora perniciosa is a hemibiotrophic fungus that causes witches` broom disease (WBD) in cacao. Marked dimorphism characterizes this fungus, showing a monokaryotic or biotrophic phase that causes disease symptoms and a later dikaryotic or saprotrophic phase. A combined strategy of DNA microarray, expressed sequence tag, and real-time reverse-transcriptase polymerase chain reaction analyses was employed to analyze differences between these two fungal stages in vitro. In all, 1,131 putative genes were hybridized with cDNA from different phases, resulting in 189 differentially expressed genes, and 4,595 reads were clusterized, producing 1,534 unigenes. The analysis of these genes, which represent approximately 21% of the total genes, indicates that the biotrophic-like phase undergoes carbon and nitrogen catabollite repression that correlates to the expression of phytopathogenicity genes. Moreover, downregulation of mitochondrial oxidative phosphorylation and the presence of a putative ngr1 of Saccharomyces cerevisiae could help explain its lower growth rate. In contrast, the saprotrophic mycelium expresses genes related to the metabolism of hexoses, ammonia, and oxidative phosphorylation, which could explain its faster growth. Antifungal toxins were upregulated and could prevent the colonization by competing fungi. This work significantly contributes to our understanding of the molecular mechanisms of WBD and, to our knowledge, is the first to analyze differential gene expression of the different phases of a hemibiotrophic fungus.

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Background: Zidovudine is a thymidine nucleoside reverse transcriptase inhibitor with activity against HIV type 1. Some (similar to 8) generic formulations of zidovudine are available in Brazil; however, based on a literature search, information concerning their bioavailability and pharmacokinetic properties in the Brazilian population has not been reported. Objective: The aim of this study was to compare the bioavailability and pharmacokinetic properties of 2 capsule formulations of zidovudine 100 mg in healthy Brazilian volunteers. Methods: This open-label, randomized, 2-way crossover study utilized a 1-week washout period between doses. Blood samples were collected for 8 hours after a single dose of zidovudine 100-mg test (Zidovudina, Fundaqdo para o Remedio Popular, Sao Paulo, Brazil) or reference formulation (Retrovir (R), GlaxoSmithKline, Philadelphia, Pennsylvania). Plasma zidovudine concentrations were determined using a validated high-performance liquid chromatography method with ultraviolet detection at 265 nm. C-max, T-max, AUC(0-t), AUC(0-infinity), t(1/2), and the elimination constant (k(e)) were determined using noncompartmental analysis. The formulations were considered bioequivalent if the 90% CIS for C-max, AUC(0-t), and AUC(0-infinity) fell within the interval of 80 % to 125 %, the regulatory definition set by the US Food and Drug Administration (FDA). Results: Twenty-four healthy volunteers (12 males, 12 females; mean age, 27 years; weight, 60 kg; height, 167 cm) were enrolled and completed the study. The 90% CIs of the treatment ratios for the logarithmic-transformed values of C-max, AUC(0-t), and AUC(0-infinity) were 80.0% to 113.6%, 93.9% to 109.7%, and 93.6% to 110.1 %, respectively. The values for the test and reference formulations were within the FDA bioequivalence definition intervals of 80% to 125%. Conclusions: In this small study in healthy subjects, no statistically significant differences in C-max, AUC(0-t), and AUC(0-)infinity were found between the test and reference formulations of zidovudine 100-mg capsules. The 90% CIs for the mean ratio values for the test and reference formulations of AUC(0-t), AUC(0-infinity), and C-max indicated that the reported data were entirely within the bioequivalence acceptance range proposed by the FDA of 80% to 125% (using log-transformed data).

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Phospholipase A(2) (PLA(2), EC 3.1.1.4), a major component of snake venoms, specifically catalyzes the hydrolysis of fatty acid ester bonds at position 2 of 1,2-diacyl-sn-3-phosphoglycerides in the presence of calcium. This article reports the purification and biochemical/functional characterization of BmooTX-I, a new myotoxic acidic phospholipase A(2) from Bothrops moojeni snake venom. The purification of the enzyme was carried out through three chromatographic steps (ion-exchange on DEAE-Sepharose, molecular exclusion on Sephadex G-75 and hydrophobic chromatography on Phenyl-Sepharose). BmooTX-I was found to be a single-chain protein of 15,000 Da and pI 4.2. The N-terminal sequence revealed a high homology with other acidic Asp49 PLA(2)S from Bothrops snake venoms. It displayed a high phospholipase activity and platelet aggregation inhibition induced by collagen or ADP. Edema and myotoxicity in vivo were also induced by BmooTX-I. Analysis of myotoxic activity was carried out by optical and ultrastructural microscopy, demonstrating high levels of leukocytary infiltrate. Previous treatment of BmooTX-1 with BPB reduced its enzymatic and myotoxic activities, as well as the effect on platelet aggregation. Acidic myotoxic PLA(2)S from Bothrops snake venoms have been little explored and the knowledge of its structural and functional features will be able to contribute for a better understanding of their action mechanism regarding enzymatic and toxic activities. (C) 2008 Elsevier Ltd. All rights reserved.

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Snake Venom L-amino acid oxidases (LAAOs E.C. 1.4.3.2) are flavoenzymes broadly found in various snake venom compositions. LAAOs have become an attractive subject for molecular biology, biochemistry, physiology and medicine due to their actions on various cells and biological effects on platelets, apoptosis, hemorrhage and others. In this review we try to summarize some of these reports, with special emphasis on apoptosis, anti-protozoa, bactericidal and anti-viral activities.

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Two experiments were conducted to investigate the effect of a threatening stimulus in human adults in a temporal bisection task. In Experiment I. for two anchor duration conditions (400/800 vs. 800/1600 ms), the participants completed trials in which the probe duration was followed by an aversive stimulus or a nonaversive stimulus. The results showed that the duration was judged longer when the participants expected an aversive rather than a nonaversive stimulus. In Experiment 2, the effect of the temporal localization of the aversive stimulus was also tested, with the aversive stimulus being presented at the beginning or at the end of the probe duration. The results revealed a temporal overestimation in each condition compared to the trials in which no aversive stimulus was presented. Furthermore, the temporal overestimation was greater when the expectation for the forthcoming threatening stimulus was longer. This temporal overestimation is explained in terms of a speeding-up of the neural timing system in response to the increase in the arousal level produced by the expectation of a threatening stimulus.

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Two N-based isomeric copper(II) complexes of the macrocycle trans-6,13-dimethyl-6,13-bis(dimethylamino)1,4,8,11-tetraazacyclotetradecane (L(3)) have been synthesized and characterised spectroscopically and structurally: alpha-[CuL(3)(OH2)(2)]Cl-2, monoclinic, space group C2/m, a = 12.908(4), b = 12.433(2), c = 7.330(2) Angstrom, beta = 105.87(2)degrees, Z = 2; beta-[CuL(3)(OClO3)(2)]. 2H(2)O, monoclinic, space group P2(1)/c, a = 9.708(3), b = 9.686(3), c = 14.202(4) Angstrom, beta = 106.17(1)degrees, Z = 2. The two isomers exhibit very similar co-ordination spheres but significantly different visible electronic maxima. This difference is attributed to an intramolecular N ... H contact between the pendant dimethylamino group and an adjacent secondary amine H atom.

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OBJECTIVE To determine the prevalence of erectile dysfunction (ED) in a large cohort of Brazilian men who were screened for prostate cancer, and to determine risk factors in this population, as there are large cultural differences among countries in reporting the frequency of ED, and it is likely that the prevalence of ED among men screened for prostate cancer cannot be generally applied across countries. SUBJECTS AND METHODS The analysis focused on the baseline characteristics of 1008 consecutive South American men from Brazil with no known prostate disease who had routine screening for prostate cancer by urologists. The variables analysed were patient age, urinary symptoms, patient health-related quality of life (HRQL), prostate-specific antigen (PSA) levels, prostate volume and erectile function. To assess lower urinary tract symptoms (LUTS) and HRQL, we used the American Urological Association symptom score and its appended eighth question, respectively. Benign prostatic hyperplasia was defined as a prostate volume of > 30 g. Sexual function was assessed using the five-item version of the International Index of Erectile Function questionnaire. Thus, ED was considered to absent for scores of 22-25, mild for 17-21, mild to moderate for 12-16, moderate for 8-11, or severe for 5-7. Obesity was defined by calculating the body mass index (BMI), and categorized as underweight (< 18.5 kg/m908 patients. ED was considered to be absent, mild, mild to moderate, moderate and severe in 169 (18.6%), 210 (23.1%), 169 (18.6%), 138 (15.2%) and 222 (24.5%) patients, respectively. The ED was severe in 18.4%, 25.7% and 43.4% of patients with mild, moderate and severe LUTS, respectively (P < 0.001). The answer to the HRQL question was also significantly associated with ED; ED was severe in 16.5% of patients feeling delighted/pleased and in 35.8% of patients feeling unhappy/terrible (P < 0.001). The prostate volume was significantly related to ED. The BMI category showed that normal weight, overweight and obese patients had similar rates of ED (P = 0.415); ED was severe in about a quarter of the patients in each of these categories, and 50% and 24% of patients in the underweight and greater BMI groups had severe ED, respectively. CONCLUSIONS Of men screened for prostate cancer in Brazil, approximate to 40% have moderate or severe ED. Severe LUTS, higher HRQL scores, a large prostate volume, a low BMI and higher PSA levels might be associated with higher rates of ED. These variables should be considered when analysing the erectile function of patients screened for prostate cancer.

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Background: Posterior reconstruction (PR) of the rhabdosphincter has been previously described during retropubic radical prostatectomy, and shorter times to return of urinary continence were reported using this technical modification. This technique has also been applied during robot-assisted radical prostatectomy (RARP); however, contradictory results have been reported. Objective: We describe here a modified technique for PR of the rhabdosphincter during RARP and report its impact on early recovery of urinary continence and on cystographic leakage rates. Design, setting, and participants: We analyzed 803 consecutive patients who underwent RARP by a single surgeon over a 12-mo period: 330 without performing PR and 473 with PR. Surgical procedure: The reconstruction was performed using two 6-in 3-0 Poliglecaprone sutures tied together. The free edge of the remaining Denonvillier`s fascia was identified after prostatectomy and approximated to the posterior aspect of the rhabdosphincter and the posterior median raphe using one arm of the continuous suture. The second layer of the reconstruction was then performed with the other arm of the suture, approximating the posterior lip of the bladder neck and vesicoprostatic muscle to the posterior urethral edge. Measurements: Continence rates were assessed with a self-administrated, validated questionnaire (Expanded Prostate Cancer Index Composite) at 1, 4, 12, and 24 wk after catheter removal. Continence was defined as the use of ""no absorbent pads."" Cystogram was performed in all patients on postoperative day 4 or 5 before catheter removal. Results and limitations: There was no significant difference between the groups with respect to patient age, body mass index, prostate-specific antigen levels, prostate weight, American Urological Association symptom score, estimated blood loss, operative time, number of nerve-sparing procedures, and days with catheter. In the PR group, the continence rates at 1, 4, 12, and 24 wk postoperatively were 22.7%, 42.7%, 91.8%, and 96.3%, respectively; in the non-PR group, the continence rates were 28.7%, 51.6%, 91.1%, and 97%, respectively. The modified PR technique resulted in significantly higher continence rates at 1 and 4 wk after catheter removal (p = 0.048 and 0.016, respectively), although the continence rates at 12 and 24 wk were not significantly affected (p = 0.908 and p = 0.741, respectively). The median interval to recovery of continence was also statistically significantly shorter in the PR group (median: 4 wk; 95% confidence interval [CI]: 3.39-4.61) when compared to the non-PR group (median: 6 wk; 95% CI: 5.18-6.82; log-rank test, p = 0.037). Finally, the incidence of cystographic leaks was lower in the PR group (0.4% vs 2.1%; p = 0.036). Although the patients` baseline characteristics were similar between the groups, the patients were not preoperatively randomized and unknown confounding factors may have influenced the results. Conclusions: Our modified PR combines the benefits of early recovery of continence reported with the original PR technique with a reinforced watertight closure of the posterior anastomotic wall. Shorter interval to recovery of continence and lower incidence of cystographic leaks were demonstrated with our PR technique when compared to RARP with no reconstruction. (C) 2010 European Association of Urology. Published by Elsevier B.V. All rights reserved.

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Alagille syndrome is a rare developmental disorder combining bile duct paucity, congenital cardiopathy, facial dysmorphy, vertebrae defects, and ocular abnormalities; and frequent renal abnormalities. It does not usually predispose to malignancies. Nephroblastoma has been observed in many developmental disorders, but never in Alagille syndrome. We report two original cases of nephroblastoma associated to Alagille syndrome. We identified a new V136G JAG1 missense mutation in one patient and a constitutional deletion of 20p12 in the other. In one nephroblastoma an additional somatic 1p36 deletion was present. The link between Alagille syndrome, JAG1 alterations and nephroblastoma is discussed.

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Purpose To compare the process of myelination in the developing optic nerve (ON) of anaemic rats with the subsequent recovery after being fed an iron-recovery diet. Methods In this study, the morphometrical parameters in the ON were assessed by electron microscopy in Wistar rats that were on an iron-deficient diet for 32 days or for 21 days followed by 10 days on an iron-recovery diet. Qualitative and quantitative analyses were performed using representative electron ultramicrographs. Data were analysed by one-way analysis of variance (ANOVA). When differences were detected, comparisons were made using Tukey`s post hoc test (P<0.05 was considered to be significant). Results Qualitative analysis of the ONs in anaemic and recovered animals showed a higher rate of deformed axons and increased lamellar separation in the myelin sheath when compared with the respective control group. The ON of the anaemic group showed a reduced mean density of myelinated fibres when compared with the control group. The fibre area ratio, axon area ratio, and myelin area ratio of large axons/small axons in the ONs of the control group showed the highest values for the myelin areas, axon areas, and total fibre areas. The control group showed a significantly higher myelin sheath thickness when compared with the anaemic and recovered groups. Conclusions Our data indicate that iron is necessary for maintenance of the ON cell structure, and that morphological damage from iron deficiency is not easily reverted by iron repletion. Eye (2010) 24, 901-908; doi:10.1038/eye.2009.205; published online 14 August 2009

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Objective: To evaluate infection control practices among dentists in private and public practice. Design: Survey and cross-sectional analysis. Setting: Sertaozinho city, Brazil. Participants: All dentists who were currently working at the study city, and agreed to participate, resulting in a study population of 135 dentists. Methods: Participants were personally interviewed and variables were submitted to X(2) or Fisher`s exact test. Results: Hand washing before and after each patient was reported by 86.7% of dentists, but private practitioners used liquid soap and paper towels more often than their public colleagues (p<0.001). Most of the study population (97.8%) used gloves routinely during clinical sessions, but 8.2% reused them. Dry-heat was the main method employed for sterilisation of heat-stable devices by 80.0% of dentists, but adequate temperature and time of exposure was accomplished by only 32.1% of public and 70.0% of private professionals (p<0.001). Heat-sensitive devices were disinfected with an adequate substance by 60.0% of both affiliation dentists (p=0.908). Conclusions: There is a large gap between infection control recommendations and practices observed among the study population, and the situation is worse in public services. To reverse that situation, infection control issues must be openly debated by professional associations, dental schools and health authorities.