Synaptomenal complex analysis of four breeds of Bos taurus taurus x B. taurus indicus hybrids

The synaptonemal complex (SC) was analyzed in four F1 hybrids of Bos taurus taurus and B. taurus indicus including Gyr-Simmental (G-S), Nelore Simmental (N-S), Gyr-Holstein-Friesian (G-H) and Nelore-Piemontese (N-P). We analysed the frequency of various types of SC abnormalities and the frequency of cells with SC abnormalities. The results were compared with similar observations made on purebred animals. All the animals studied possessed 29 autosomal and one sex bivalent. The frequency of cells with abnormalities in the hybrids were 28.0% in the N-P, 29.1% in the G-S, 33.3% in the N-S and 40.0% in the G-H. The frequency of cells with abnormalities in the four hybrids was 31.5%; 57.9% of these abnormalities occurred in zygotene and 42.0% occurred in pachytene. The comparisons among the hybrids and among the hybrids and their parental breeds showed that the only significant difference was between Gyr and Gyr-Holstein-Friesian animals. Some aspects of the relationship between the frequency of cells with anomalies and the fertility of hybrids are discussed.

Anomalias e números fermiônicos induzidos em grafeno com deformações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Indicadores de qualidade assistencial e Nursing Activities Score análise correlacional em um Hospital Especializado

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pressure-induced electrical and structural anomalies in Pb1-xCaxTiO3 thin films grown at various oxygen pressures by chemical solution route

Lead calcium titanate (Pb1-xCaxTiO3 or PCT) thin films have been thermally treated under different oxygen pressures, 10, 40 and 80 bar, by using the so-called chemical solution deposition method. The structural, morphological, dielectric and ferroelectric properties were characterized by x-ray diffraction, FT-infrared and Raman spectroscopy, atomic force microscopy and polarization-electric-field hysteresis loop measurements. By annealing at a controlled pressure of around 10 and 40 bar, well-crystallized PCT thin films were successfully prepared. For the sample submitted to 80 bar, the x-ray diffraction, Fourier transformed-infrared and Raman data indicated deviation from the tetragonal symmetry. The most interesting feature in the Raman spectra is the occurrence of intense vibrational modes at frequencies of around 747 and 820 cm(-1), whose presence depends strongly on the amount of the pyrochlore phase. In addition, the Raman spectrum indicates the presence of symmetry-breaking disorder, which would be expected for an amorphous (disorder) and mixed pyrochlore-perovskite phase. During the high-pressure annealing process, the crystallinity and the grain size of the annealed film decreased. This process effectively suppressed both the dielectric and ferroelectric behaviour. Ferroelectric hysteresis loop measurements performed on these PCT films exhibited a clear decrease in the remanent polarization with increasing oxygen pressure.

Electrical and Optical Properties of Conductive and Transparent ITO@PMMA Nanocomposites

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

Conductive hearing loss in children with bronchopulmonary dysplasia: A longitudinal follow-up study in children aged between 6 and 24 months

Aims: To determine the occurrence of isolated and recurrent episodes of conductive hearing loss (CHL) during the first two years of life in very low birth weight (VLBW) infants with and without bronchopulmonary dysplasia (BPD).Study design, subjects and outcome measures: In a longitudinal clinical study. 187 children were evaluated at 6, 9, 12,15 18 and 24 months of age by visual reinforcement audiometry, tympanometry and auditory brain response system.Results: of the children with BPD, 54.5% presented with episodes of CHL, as opposed to 34.7% of the children without BPD. This difference was found to be statistically significant. The recurrent or persistent episodes were more frequent among children with BPD (25.7%) than among those without BPD (8.3%). The independent variables that contributed to this finding were small for gestational age and a 5 min Apgar score.Conclusions: Recurrent CHL episodes are more frequent among VLBW infants with BPD than among VLBW infants without BPD. (C) 2010 Elsevier B.V. All rights reserved.

The association between prune belly syndrome and dental anomalies: a case report

Background: Prune belly syndrome is a rare condition produced by an early mesodermal defect that causes abdominal abnormalities. However, the literature indicates that disturbances related to ectodermal development may also be present. This is the first case report in the literature to suggest that dental abnormalities are part of the broad spectrum of clinical features of prune belly syndrome. Because the syndrome causes many serious medical problems, early diagnosis of abnormalities involving the primary and permanent dentitions are encouraged.Case presentation: The authors report the clinical case of a 4-year-old Caucasian boy with prune belly syndrome. In addition to the triad of abdominal muscle deficiency, abnormalities of the gastrointestinal and urinary tracts, and cryptorchidism, a geminated mandibular right central incisor, agenesis of a mandibular permanent left incisor, and congenitally missing primary teeth (namely, the mandibular right and left lateral incisors) were noted.Conclusion: This original case report about prune belly syndrome highlights the possibility that dental abnormalities are a part of the broad spectrum of clinical features of the syndrome. Therefore, an accurate intra-oral clinical examination and radiographic evaluation are required for patients with this syndrome in order to provide an early diagnosis of abnormalities involving the primary and permanent dentitions.

Detection of numerical chromosome anomalies in interphase cells of benign and malignant thyroid lesions using fluorescence in situ hybridization

Benign and malignant thyroid tumors constitute a wide range of neoplasias showing recurrent chromosome abnormalities. In an attempt to characterize specific numerical chromosome abnormalities in thyroid tissues, We present here the findings from a study of archival samples depicted by 10 malignant tumors, 30 benign lesions, and 10 normal thyroid tissues. Fluorescence in situ hybridization was performed on noncultured samples using biotinylated centromere-specific probes for chromosomes 7, 10, and 17. Trisomy or tetrasomy 7 were present in 19 benign and in 7 malignant tumors. Trisomy 10 or 17 were observed in 18 adenomas or goiters and in 9 carcinomas, and monosomy 17 was seen in 2 carcinomas. Our findings suggest that such abnormalities are an in vivo phenomenon and may be important in the neoplastic proliferation of thyroid gland. (C) Elsevier B.V., 2000. All rights reserved.

Hydrochemistry and weathering rates on Corumbatai River basin, São Paulo State, Brazil

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

Mechanical and electrical driving field induced high-frequency dielectric anomalies in ferroelectric systems

Polycrystalline or single-crystal ferroelectric materials present dielectric dispersion in the frequency range 100 MHz-1 GHz that has been attributed to a dispersive ( relaxation-like) mechanism as well as a resonant mechanism. Particularly in 'normal' ferroelectric materials, a dielectric response that is indistinguishable from dispersion or a resonance has been reported. Nevertheless, the reported results are not conclusive enough to distinguish each mechanism clearly. A detailed study of the dielectric dispersion phenomenon has been carried out in PbTiO3-based ferroelectric ceramics, with the composition Pb1-xLaxTiO3 (x = 0.15), over a wide range of temperatures and frequencies, including microwave frequencies. The dielectric response of La-modified lead titanate ferroelectric ceramics, in 'virgin' and poled states, has been investigated in the temperature and frequency ranges 300-450 K and 1 kHz-2 GHz, respectively. The results revealed that the frequency dependence of the dielectric anomalies, depending on the measuring direction with respect to the orientation of the macroscopic polarization, may be described as a general mechanism related to an 'over-damped' resonant process. Applying either a uniaxial stress along the measurement field direction or a poling electric field parallel and/or perpendicular to the measuring direction, a resonant response of the real and imaginary components of the dielectric constant is observed, in contrast to the dispersion behavior obtained in the absence of the stress, for the 'virgin' samples. Both results, resonance and/or dispersion, can be explained by considering a common mechanism involving a resonant response (damped and/or over-damped) which is strongly affected by a ferroelastic-ferroelectric coupling, contributing to the low-field dielectric constant.

Conductive composites of natural rubber and carbon black for pressure sensors

Composites of natural rubber and carbon black have attracted great interest due to their technological applications. In this work natural rubber (NR) and carbon black (CB) were compounded, aiming the development of composites with good mechanical properties, processability and electrical conductivity for use as pressure sensors. The electrical conductivity changes from 10(-11) to 10(-2) S.cm(-1) depending on the percentage of CB in the composite. It was also observed that the conductivity varies reversibly and linearly with the applied pressure. The latter demonstrates that this material can be used as pressure sensors.

Transparent and conductive ZnO : Al thin films prepared by sol-gel dip-coating

Aluminum doped zinc oxide polycrystalline thin films (AZO) were prepared by sol-gel dip-coating process. The sol was prepared from an ethanolic solution of zinc acetate using lithium hydroxide or succinic acid as hydrolytic catalyst. The quantity of aluminum in the sol was varied from 1 to 10 mol%. The structural characteristics studied by X-ray diffractometry were complemented by resistivity measurements and UV-Vis-NIR spectroscopy. The films are transparent from the near ultraviolet to the near infrared, presenting an absorption cut-off at almost 290 nm, irrespective of the nature of the catalyst and doping level. The best conductors were obtained for the AZO films containing 3 mol% of aluminum, prepared under acidic and basic catalysis and sintered at 450 degreesC. Their optical band-gap of 4.4 eV calculated from the absorption cut-off is larger than the values for band-gap widening predicted by the standard model for polar semiconductors. These polycrystalline films are textured with preferential orientation of grains along the wurtzite c-axis or the (100) direction. (C) 2003 Elsevier Ltd. All rights reserved.

Anderson localization and Brewster anomalies in photonic disordered quasiperiodic lattices

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hydrochemistry on a waste disposal area of sand mining activities at Analandia, Sao Paulo State, Brazil, and their implications on the mobilization of uranium

Groundwaters and surface waters from an area of treatment of sand for industrial purposes at Analandia municipality, nearly in the center of Sao Paulo State, Brazil, were chemically and isotopically analyzed with two aims: to evaluate if the anthropogenic activities that has taken place for the last 6 years is affecting the quality of the hydrological resources and to relate the hydrogeochemical behaviour of the uranium isotopes 234U and 238U with the pattern of circulation of groundwaters.