Superconducting state in a mesoscopic segment ring

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alterations in the intestinal wall due to protein malnutrition in rats. Evaluation of the rupture strength and the tissue's collagen

OBJETIVO: Avaliar o efeito da desnutrição protéica na parede intestinal do rato através da medida de força de ruptura e dosagem do colágeno tecidual no íleo e cólon distal. MÉTODOS: Foram utilizados 120 ratos, pesando em média 100g, que receberam durante 07 dias uma dieta padrão, contendo 20% de caseína para adaptação dos animais as condições do biotério. Após esse período os animais foram divididos em dois grupos de 60, o controle denominado grupo um que recebeu a dieta padrão, e o grupo teste denominado grupo dois, que recebeu dieta hipoprotéica contendo 2% de caseína. Os dois grupos receberam suas respectivas dietas por um período de 21 dias. Após esse período iniciou-se o sacrifício seqüencial dos animais em ambos os grupos, em número de 12 animais em cada momento, correspondendo ao dia Zero (MO), 4º dia (M1), 7º dia (M2), 14º dia (M3), e 21º dia (M4) sendo mantida a mesma dieta até o final do sacrifício. em cada momento foram avaliados o peso corpóreo, albumina sanguínea, hidroxiprolina tecidual, relação hidroxiprolina/proteína tecidual e a força de ruptura no segmento ileal e cólico dos animais. RESULTADOS: Observou-se que a força de ruptura do segmento ileal e do cólon distal foi menor nos animais desnutridos (Grupo 2). A perda da resistência mecânica foi maior no segmento do cólon distal do que no segmento ileal, provavelmente pela menor concentração do colágeno tecidual no cólon distal. CONCLUSÃO: A desnutrição protéica induz a diminuição da resistência mecânica no íleo e no cólon distal associado a diminuição do colágeno tecidual na parede intestinal.

Cytogenetic characterization of a supernumerary chromosome segment and of B-chromosomes in Astyanax scabripinnis (Teleostei, Characidae)

The chromosome complement of a local population of Astyanax scabripinnis in Brazil was investigated with emphasis on the study of the heterochromatin attached to the A-chromosomes and present in the macro B-chromosome. Analysis after C-banding, silver and CMA(3) staining, incorporation of 5-bromo-2'-deoxyuridine and chromosome digestion with nine restriction endonucleases revealed that the heterochromatin in the B-chromosomes was different from that found in the A-chromosomes. A polymorphism due to the presence of a supernumerary heterochromatic chromosome segment was observed in the population investigated. Some aspects related to the origin of the heterochromatin polymorphism in Astyanax scabripinnis are discussed.

Higgsing M2 to D2 with gravity: N=6 chiral supergravity from topologically gauged ABJM theory

We present the higgsing of three-dimensional N = 6 superconformal ABJM type theories coupled to conformal supergravity, so called topologically gauged ABJM theory, thus providing a gravitational extension of previous work on the relation between N M2 and N D2-branes. The resulting N = 6 supergravity theory appears at a chiral point similar to that of three-dimensional chiral gravity introduced recently by Li, Song and Strominger, but with the opposite sign for the Ricci scalar term in the lagrangian. We identify the supersymmetry in the broken phase as a particular linear combination of the supersymmetry and special conformal supersymmetry in the original topologically gauged ABJM theory. We also discuss the higgsing procedure in detail paying special attention to the role played by the U(1) factors in the original ABJM model and the U(1) introduced in the topological gauging.

A and B mode ultrasonography in preoperative evaluation of lens and posterior segment of dogs eyes with cataract

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

IDENTIFICATION OF A PUTATIVE MEMBRANE-INSERTED SEGMENT IN THE ALPHA-TOXIN OF STAPHYLOCOCCUS-AUREUS

To gain a fuller understanding of the regions of the Staphylococcus aureus alpha-toxin important in pore formation, we have used Forster dipole-dipole energy transfer to demonstrate that a central glycine-rich region of alpha-toxin (the so-called ''hinge'' region) inserts deeply into the bilayer on association of toxin with liposomes. Mutant alpha-toxins with unique cysteine (C) residues at positions 69 and 130 [Palmer, M., et al. (1993) J. Biol. Chem. 268, 11959) were reacted with the C-specific fluorophore acrylodan, which acted as an energy donor. The chosen acceptor was N-(7-nitrobenz-2-oxa-13-diazol-4-yl)-1,2-bis(hexadecanoyl) -sn-glycero-3-phosphoethanolamine (NBD-PE). Measurement of the degree of donor quenching with increasing NBD-PE in the inner bilayer leaflet enables the distance of closest approach between donor and acceptor to be estimated. For toxin labeled with acrylodan at position 130 (in the hinge region), this distance is approximately 5 +/- 2 Angstrom, showing that the probe is close to the inner surface of the liposomes. A second probe labeled at position 69 (in the N-terminal domain) shows negligible energy transfer, indicating a distance of closest approach >40 Angstrom. This implies that this N-terminal region remains ''outside'' the liposome. We propose a model in which the central region of the alpha-toxin inserts into the membrane and possibly participates in forming the wall of the pore.

A procedure to estimate parameters of a line segment taking into account its representation through pi circuits: Theoretical development

The objective of this paper is to show an alternative methodology to estimate per unit length parameters of a line segment of a transmission line. With this methodology the line segment parameters can be obtained starting from the phase currents and -voltages in receiving and sending end of the line segment. If the line segment is represented as being one or more pi circuits whose frequency dependent parameters are considered lumped, its impedance and admittance can be easily expressed as functions of the currents and voltages at the sending and receiving end. Because we are supposing that voltages and currents at the sending and receiving end of the tine segment (in frequency domain) are known, it is possible to obtains its impedance and admittance and consequently its per unit length longitudinal and transversal parameters. The procedure will be applied to estimate the longitudinal and transversal parameters of a small segment of a single-phase line that is already built.

Structural characteristics of the superior venae cavae wall at the intrapericardium segment in adults and aging individuals

The authors admit that the conjunctive-muscular constitution of the walls of the superior venae cavae throughout the length of the intrapericardium segment and the debouchement in the right atrium, associated with the presence of a myocardium sheath can be made up of a functional device of sphincter form able to act on the control of the blood flow to the interior of the arterial chamber as well as stopping blood flow during the arterial systole. The fixation of the venous wall to the deep chamber of the serous pericardium, contributes to growth in resistance during the elevation of venous pressure, making possible the preservation of integrity of the superior venae cavae. The expansion of fasciculi of nodal fibers in the right wall of the superior venae cavae permits that the unlocked impulse in the S-A node also reaches the vascular wall contributing to the shortening and diminution in caliber of the vein.

Differences in the number of sensilla coeloconica and sensilla ampullacea of segment 10 of the antennae of Africanized and Caucasian bees and of their F1 hybrids

The numbers of sensilla coeloconica and sensilla ampullacea of segment 10 of the antennae of Caucasian and Africanized worker bees and of their hybrids were counted with the aid of a scanning electron microscope. Africanized bees have fewer sensilla than Caucasian bees and the continuous distribution obtained from the F1 values suggests polygenic inheritance for the control of this trait. There are also indications that the hybrid Brazilian Apis mellifera studied here are close to typical African bees (Apis mellifera scutellata) in terms of number of sensilla.

Road segment delineation using active testing principle and an edge-based post-processing strategy

This paper presents a semi-automated method for extracting road segments from medium-resolution images based on active testing and edge analysis. The method is based on two sequential and independent stages. Firstly, an active testing method is used to extract an approximated road centreline which is based on a sequential and local exploitation of the image. Secondly, an iterative strategy based on edge analysis and the approximated centreline is used to measure precisely the road centreline. Based on the results obtained using medium-resolution test images, the method seems to be very promising. In general, the method proved to be very accurate whenever the roads are characterized by two well-defined anti-parallel edges and robust even in the presence of larger obstacles such as trees and shadows.

A procedure to estimate parameters of a line segment taking into account its representation through π circuits: Theoretical development

The objective of this paper is to show an alternative methodology to estimate per unit length parameters of a line segment of a transmission line. With this methodology the line segment parameters can be obtained starting from the phase currents and voltages in receiving and sending end of the line segment. If the line segment is represented as being one or more π circuits whose frequency dependent parameters are considered lumped, its impedance and admittance can be easily expressed as functions of the currents and voltages at the sending and receiving end. Because we are supposing that voltages and currents at the sending and receiving end of the line segment (in frequency domain) are known, it is possible to obtains its impedance and admittance and consequently its per unit length longitudinal and transversal parameters. The procedure will be applied to estimate the longitudinal and transversal parameters of a small segment of a single-phase line that is already built. © 2006 IEEE.

Comparison between polyurethanes containing castor oil (Soft Segment) and cancellous bone autograft in the treatment of segmental bone defect induced in rabbits

The aim of this study is to compare polyurethanes containing castor oil (soft segment) in granular form compared to cancellous bone autograft applied to a segmental bone defect. Norfolk adult female rabbits - approximately 13 months of age with a mean body weight of 4.5 kg - are used. In both radial diaphyses, 1 cm osteoperiosteal segmental defects are created. The defect in the left radius is filled with the castor-oil-based polyurethane, and the right one, filled with cancellous bone autograft, collected from the left proximal humerus. The rabbits are euthanazed at 15, 30, 60, and 120 days postsurgery (5 animals/ period), for histological analyses. By radiographic analyses, at these time points, the bone regeneration is more evident and accelerated in the bone defects treated with the cancellous bone autograft. At 120 days postsurgery, the segmental bone defects treated with the cancellous bone autograft are totally reconstituted and remodeled, while the bone defects treated with polyurethane polymer have bone formation of 79%. Histological study shows that the polyurethane acts as a space filler, minimizing the local production of fibrous tissue. No granule degradation, resorption or any inflammatory reaction is detected. Thus, it is possible to conclude that the castor-oil-plant-based polyurethane - in the granule presentation - is biocompatible and osteointegrated, but does not show the same bone regeneration capacity as the cancellous bone autograft. © 2007 SAGE Publications.

La technique de l’arc segmenté. Contrôle de l’ancrage et modification significative du profil facial : une étude de cas

This article evaluates space closure mechanics efficiency in an extraction case where maximum anchorage was a requirement. The Segmented Arch Technique (SAT) was utilized as an anchorage control strategy to obtain maximum anterior retraction and, in consequence, significant facial profile change. A 20-year-10-month old woman needed severe labial and profile changes. The patient had four premolars extracted and SAT with type A mechanics [1] (Marcotte [2] activation protocol) was applied. The results showed significant reduction in labial protrusion and incisal angulation with effective anchorage control. The results were compared to others available in the literature derived from different techniques, where anterior retraction was also accomplished with maximum anchorage [3-7]. In conclusion, the SAT with type A mechanics has been shown to be another treatment option when significant changes in the soft-tissue profile are needed in extraction cases. © 2008. CEO. Published by Elsevier Masson SAS. All rights reserved.

Biocompatibility of Ferrara intracorneal ring segment with and without chondroitin sulfate coating: Clinical and histopathological evaluation in rabbits

PURPOSE: To investigate and compare the biocompatibility of two types of Ferrara intracorneal ring segment: with and without chondroitin sulfate coating by clinical and histopathological evaluation. METHODS: A randomized experimental study was carried out on thirty right-eye corneas from 30 Norfolk albino rabbits allocated into two experimental groups: Group G1 - implanted with Ferrara intracorneal ring segment without coating (FICRS) and Group G2 - implanted with Ferrara intracorneal ring segment with chondroitin sulfate coating (FICRS-CS). Left eyes formed the control group. Clinical parameters analyzed were: presence of edema, vascularization, infection and ring extrusion one, 30, and 60 days after surgery. Histopathological parameters analyzed were: number of corneal epithelial layers over and adjacent to the ring, presence of spongiosis, hydropic degeneration, basement membrane thinning, inflammatory cells, neovascularization and pseudocapsule formation. RESULTS: At clinical examination 60 days after implant, edema, vascularization and extrusion were observed respectively in 20%, 26.7%, 6.7% of FICRS corneas and in 6.7%, 6.7%, and 0% of FICRS-CS corneas. Histopathological evaluation showed epithelial-layer reduction from 5 (5;6) to 3 (3;3) with FICRS and from 5 (5;5) to 4 (3;5) with FICRS-CS in the region over the ring. Epithelial spongiosis, hydropic degeneration, and basement membrane thinning were present in 69.2%, 53.8%, and 69.2% of FICRS and in 73.3%, 73.3%, and 46.7% with FICRS-CS, respectively. Vascularization was present in 38.5% of FICRS and 13.3% with FICRS-CS, inflammatory cells in 75% of FICRS and 33.3% with FICRS-CS, and pseudocapsule in 66.7% of FICRS and 93.3% with FICRS-CS. Giant cells occurred only in the FICRS-CS group (20%). CONCLUSION: Ferrara intracorneal rings coated with chondroitin sulfate (FICRS-CS) caused lower frequency of clinical and histopathological alterations than Ferrara intracorneal rings without the coating (FICRS), demonstrating higher biocompatibility of the FICRS-CS.