Propriedades eletrônicas, estruturais e constantes elásticas do ZnO

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

Inhibitors of Clostridium histolyticum colagenase

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

AÇÃO do DICLOFENACO DE SÓDIO em ANASTOMOSES REALIZADAS NO INTESTINO DELGADO DE RATOS

Este trabalho avaliou a ação do Diclofenaco de Sódio (DS) na cicatrização de anastomoses realizados no íleo terminal de ratos, tendo sido analisados os seguintes parâmetros: evolução clínica, resistência mecânica, colágeno tecidual e alterações histopatológicas. Foram utilizados 519 ratos Wistar divididos em 4 grupos experimentais. O Grupo 1: Controle sem anastomose, 52 ratos tratados com solução fisiológica (SF)3 ml/kg de peso, administrada por via intra-muscular (IM) por 4 dias; Grupo 2: 110 ratos submetidos à anastomose no íleo terminal + SF; Grupo 3: 52 ratos tratados com DS na dose de 3 mg/kg de peso por dia, IM, por 4 dias e o Grupo 4: 295 ratos tratados com DS e submetidos à anastomose no íleo terminal, recebendo DS de maneira idêntica ao grupo anterior. Dez animais sem manipulação, foram utilizados para medidas da força de ruptura e dosagens bioquímicas, com obtenção de parâmetros caracterizados como MO. Os parâmetros foram analisados no 4o, 7o, 14o e 21o dia de pós-operatório. Os animais do Grupo 1 não apresentaram alterações clínicas durante o período de acompanhamento. No Grupo 3, 15,4% dos animais apresentaram diarréia. Neste grupo houve uma diminuição do colágeno tecidual e da força de ruptura quando comparados com o grupo 1. Entre os animais submetidos à anastomoses no íleo terminal, observou-se taxa de mortalidade maior nos animais que receberam DS, além de retardo na cicatrização, caracterizado por uma maior reação inflamatória polimorfonuclear, retardo na regeneração da mucosa, diminuição de macrófagos e do colágeno tecidual. Pelos resultados obtidos concluiu-se que o DS é deletério à evolução cicatricial de anastomoses realizadas no íleo terminal de ratos

RELATING THE QCD POMERON TO AN EFFECTIVE GLUON MASS

We construct the Pomeron as an exchange of two nonperturbative gluons, where the nonperturbative gluon propagator is described by an approximate solution of the Schwinger-Dyson equation which contains a dynamically generated gluon mass. We compute the total and elastic differential (dsigma/dt) cross sections for pp scattering, obtaining agreement with the experimental data for a gluon mass m = 370 MeV for LAMBDA(QCD) = 300 MeV. In particular, the Pomeron effectively behaves like a photon-exchange diagram with a coupling determined by the glucon mass.

THE ESSENTIAL ROLE OF ZINC IN GROWTH

Zinc is known to play a relevant role in growth and development. The basic mechanisms of action of this trace element are intimately linked to the structure and action of countless enzymes involved in many different metabolic processes. In this respect, when zinc specifically acts on cartilage growth it is involved in multiple enzymatic reactions which make this a multifactorial event. Thus, we may divide the actions of zinc into three distinct types: 1) action on taste and smell acuity, appetite regulation, and food consumption and regulation; 2) action on DNA and RNA synthesis stimulating a) cell replication and differentiation of chondrocytes, osteoblasts and fibroblasts; b) cell transcription culminating in the synthesis of somatomedin-C (liver), alkaline phosphatase, collagen and osteocalcin (bone), and c) protein, carbohydrate and lipid metabolism, that is intimately related to the mechanisms of smell, taste, appetite, and food consumption and utilization; 3) action on hormonal mediation by participating in a) GH synthesis and secretion in somatomammotroph cells, b) the action of GH on liver somatomedin-C production, and c) somatomedin-C activation in bone cartilage. In addition to these multiple functions, zinc also interacts with other hormones somehow related to bone growth such as testosterone, thyroid hormones, insulin, and vitamin D-3.On the basis of the above considerations, we conclude that the integration of these mechanisms contributes to the perfect physiological functioning of bone. Tn the presence of zinc deficiency, this homeostasis is impaired, causing the weight-height deficiency detected in several species studied, the human species in particular.

Nanomechanical properties of glass-ceramic films obtained by pressure impregnation of oxide powders on commercial float glass surfaces

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Características anatômicas de espinheira-santa (Maytenus ilicifolia Mart. ex Reissek e Maytenus aquifolia Mart.) e mata-olho (Sorocea bonplandii (Baill.) Burg. Lanj. & Boer.) para o controle de qualidade da matéria prima

Maytenus ilicifolia and Maytenus aquifolia (Celastraceae) both designated espinheira-santa have proven anti-ulcer activity. Morphologic similarities between leaves of espinheira-santa and mata-olho (Sorocea bonplandii), has motivated fakes in the market of phytotherapy. The present work consisted of the anatomical study, including stem and leaf, of the species M. ilicifolia, M. aquifolia and S. bomplandii. Samples of adult leaves and stem of plants located in the cities of Maringá and Marialva were collected. Both are located in the northwest region of Paraná State. The botanical material was prepared with using usual techniques of anatomy. The leaves of both Maytenus species presented great similarities, characterizing itself for the presence of epidermal cells with straight walls, biseriate palisade tissue, petiole vascular system represented by unique amphicribal bundle and sclereids, which were present in the stems of these two species. S. bomplandii leaves differed of Maytenus species for presenting epidermal cells with undulated walls, uniserite palisade tissue, petiole vascular system represented by many collateral bundles and gelatinous fibres. Non-glandular trichomes, glandular trichomes, and laticifer only occur in S. bomplandii.

Active flutter suppression in a 2-D airfoil using linear matrix inequalities techniques

Flutter is an in-flight vibration of flexible structures caused by energy in the airstream absorbed by the lifting surface. This aeroelastic phenomenon is a problem of considerable interest in the aeronautic industry, because flutter is a potentially destructive instability resulting from an interaction between aerodynamic, inertial, and elastic forces. To overcome this effect, it is possible to use passive or active methodologies, but passive control adds mass to the structure and it is, therefore, undesirable. Thus, in this paper, the goal is to use linear matrix inequalities (LMIs) techniques to design an active state-feedback control to suppress flutter. Due to unmeasurable aerodynamic-lag states, one needs to use a dynamic observer. So, LMIs also were applied to design a state-estimator. The simulated model, consists of a classical flat plate in a two-dimensional flow. Two regulators were designed, the first one is a non-robust design for parametric variation and the second one is a robust control design, both designed by using LMIs. The parametric uncertainties are modeled through polytopic uncertainties. The paper concludes with numerical simulations for each controller. The open-loop and closed-loop responses are also compared and the results show the flutter suppression. The perfomance for both controllers are compared and discussed. Copyright © 2006 by ABCM.

Comparative morphology of the ileum of three species of Cephalotes (formicidae, myrmicinae)

The histology (H.E.), histochemistry (carbohydrates, proteins, collagen, and calcium), enzyme profile (ATPase and Acid phosphatase), and ultramorphology of the ileum of Cephalotes atratus, C. clypeatus and C. pusillus were studied in order to obtain some information about the similarities of these species. The relationship among these three species, as well as the results obtained for the wall, and the contents of this portion of the digestive tract were discussed. In C. clypeatus the ileum is somewhat smaller than that of C. atratus, despite the similarities in body size. The ATPase results showed 2 different regions: the anterior region responsible for absorbing material from the haemolymph and the posterior region for absorbtion from the ileum lumen. Other histochemical analyses failed to show any differences.

Comparative morphology of the midgut of three species of Cephalotes (Hymenoptera, Formicidae, Myrmicinae)

Studies of histological nature, histochemistry and ultra-morphology of the midgut of three species of ants belonging to the genus Cephalotes (atratus, clypeatus and pusillus) were performed. In histology H-E was employed, and in histochemistry techniques for detection of carbohydrates, proteins in general and collagen and calcium fibers were used. The results obtained from this second technique made possible some discussion about the pH of the midgut of these insects. The species are identical in the characters under study. The digestive cells exhibited a secretion that is typical of ants, the apocrine type.

Osteologia craniana de Nyctibiidae (Aves, Caprimulgiformes)

The Potoos form an exclusively neotropical family of nocturnal birds distributed throughout Central and South America, except Chile, and reaching their highest diversity in the Amazon region. The seven currently recognized species are certainly among the most poorly known birds of this region. They are characterized by a distinctive mimicry of vegetal trunks, where they remain almost motionless during daytime. For this reason, their nocturnal and cryptic habits make them exceedingly difficult to study. Published accounts on behavior and natural history of the family are scarce and contributions regarding its anatomy are rare. Here we sample six of the seven currently recognized species of Nyctibiidae, including Nyctibius grandis, N. aethereus, N. griseus, N. jamaicensis, N. leucopterus and N. bracteatus, in order to conduct a detailed and illustrated description of the skull and jaw osteology. High interspecific variation in skull osteology was observed in the family. Species of this family possess a highly modified skull, adapted to their life habits, which shelters their well developed eyes and permits a large mouth opening. The bones that form the palate structure exhibit a dorsoventral flattening, particularly in the pterigoid and parasphenoid bones, with the palatine bone being a broadly developed, wing-shaped structure. In the maxilar region, near the jugal arch, there is a tooth-like projection, unique among birds, which may assist in the retention of prey upon capture. The vomer bone is highly variable within the family, showing varying numbers of rostral projections amongst species. The broad occipital region exhibits large spacing between the quadrate bones, which are vertically disposed and possess a reduced processus orbitalis. The mandible, which is flexible and elastic, has an extremely short symphyseal region and sindesmotic joints in both mandibular rami. As a family, potoos possess a highly specialized skull which provides insight into the relationship between the form of the structures and the feeding habits of the species. Furthermore, the large interspecific variation in skull morphology emphasizes the needs for taxonomic revision within the family, which at present is lumped into a single genus.

Ultrasonic material characterization using diffraction-free PVDF receivers

This work describes the use of a large aperture PVDF receiver in the measurement of density of liquids and elastic constants of composite materials. The density measurement of several liquids is obtained with the accuracy of less than 0.2% using a conventional NDT emitter transducer and a 70-mm diameter, 52-μm P(VDF-TrFE) membrane with gold electrodes. The determination of the elastic constants of composite materials is based in the measurement of phase velocity. It is shown that the diffraction can lead to errors around 1% in the velocity measurement when using a pair of ultrasonic transducers (1MHz and 19mm diameter) operating in transmission-reception mode separated by a distance of 100 mm. This effect is negligible when using a pair of 10-MHz transducers. On the other hand, the dispersion at 10 MHz can result in errors of about 0.5%, measuring the velocity in composite materials. The use of an 80-mm diameter, 52-μm thick PVDF membrane receiver allows measuring the phase velocity without the diffraction effects.

Prostatic stromal cells of old gerbils respond to steroidal blockades creating a microenvironment similar to reactive stroma

The present study examined the changes in prostatic stroma of old gerbils (18 months) submitted to orchiectomy associated or not with steroidal blockades. Animals were divided into six groups, all surgically castrated except the control group composed of intact animals. The other two controls were formed by castrated animals, one that received and one that did not receive the drug vehicle. In the experimental groups, doses of flutamide (10 mg/kg/day) and/or tamoxifen (1 mg/kg/48 h) were applied for 1, 3, 7 and 30 days post-castration. The methodologies involved were: morphological (HE, Gömöri reticulin, Picrosirius-hematoxylin), immunohistochemical (tenascin, type IV collagen) and ultrastructural analyses. Gradually, the epithelial compartment was significantly exceeded in volume by the stromal compartment, characterizing regression but not atrophy of the gland. The smooth muscle cell frequency increased significantly after 30 days and participated effectively in the stromal increase. Large collagen I and tenascin deposits in the subepithelial region were a hallmark of prostatic acini in the experimental groups up to 7 days, while in the 30-day group these elements practically disappear. Fibroblasts with reactive aspect, changes in basement membrane structure and maintenance and/or increase of blood vessels were also associated with treatments. These results showed, in part, the sensitivity of stromal components to suppressed hormones and favored the creation of a differentiated glandular microenvironment. Therefore, the data suggest the importance of considering aging when analyzing aspects of prostatic regression between rodents and humans after hormonal ablation. © 2011 Elsevier Masson SAS. All rights reserved.

Point vibration measurements for the detection of shallow-buried objects

A major UK initiative, entitled 'Mapping the Underworld', is seeking to address the serious social, environmental and economic consequences arising from an inability to locate accurately and comprehensively the buried utility service infrastructure without resorting to extensive excavations. Mapping the Underworld aims to develop and prove the efficacy of a multi-sensor device for accurate remote buried utility service detection, location and, where possible, identification. One of the technologies to be incorporated in the device is low-frequency vibro-acoustics, and application of this technique for detecting buried infrastructure is currently being investigated. Here, the potential for making a number of simple point vibration measurements in order to detect shallow-buried objects, in particular plastic pipes, is explored. Point measurements can be made relatively quickly without the need for arrays of surface sensors, which can be expensive, time-consuming to deploy, and sometimes impractical in congested areas. At low frequencies, the ground behaves as a simple single-degree-of-freedom (mass-spring) system with a well-defined resonance, the frequency of which will depend on the density and elastic properties of the soil locally. This resonance will be altered by the presence of a buried object whose properties differ from the surrounding soil. It is this behavior which can be exploited in order to detect the presence of a buried object, provided it is buried at a sufficiently shallow depth. The theoretical background is described and preliminary measurements are made both on a dedicated buried pipe rig and on the ground over a domestic waste pipe. Preliminary findings suggest that, for shallow-buried pipes, a measurement of this kind could be a quick and useful adjunct to more conventional methods of buried pipe detection. © 2012 Elsevier Ltd. All rights reserved.

Plasma-polymerized acetylene nanofilms modified by nitrogen ion implantation

Thin films were prepared by plasma enhanced chemical vapour deposition (PECVD) from a mixture of acetylene and argon, and post deposition-treated by plasma immersion ion implantation (PIII). The effect of PIII on the nanofilms properties was evaluated as a function of treatment time. The average thickness and roughness were diminished upon PIII. On the other hand, hardness (0.7-3.9 GPa) and elastic modulus (29-54 GPa) increased upon 60 min of ion bombardment. Such results are ascribed mainly to the densification of the film structure caused by the increment in the crosslinking degree with increasing the energy deposited in the films. Wettability of the samples, investigated by contact angle measurements, was reduced (from 64 to 21°) right after PIII. This result, attributed to the introduction of polar groups in the film structure, was not preserved as the sample was aged in atmosphere. After aging, contact angles were larger than 70° but still smaller than 90°. Although the wettability has decreased with aging, the hydrophilic character of the samples was preserved. For certain treatment times, nitrogen PIII turned the plasma-polymerized acetylene films smoother, denser, mechanically and tribologicaly more resistant than the as-deposited material. © 2013 Elsevier B.V.