The trafficking pathway of a wheat storage protein in transgenic rice endosperm

Background and Aims The trafficking of proteins in the endoplasmic reticulum (ER) of plant cells is a topic of considerable interest since this organelle serves as an entry point for proteins destined for other organelles, as well as for the ER itself. In the current work, transgenic rice was used to study the pattern and pathway of deposition of the wheat high molecular weight (HMW) glutenin sub-unit (GS) 1Dx5 within the rice endosperm using specific antibodies to determine whether it is deposited in the same or different protein bodies from the rice storage proteins, and whether it is located in the same or separate phases within these. Methods The protein distribution and the expression pattern of HMW sub-unit 1Dx5 in transgenic rice endosperm at different stages of development were determined using light and electron microscopy after labelling with antibodies. Key results The use of HMW-GS-specific antibodies showed that sub-unit 1Dx5 was expressed mainly in the sub-aleurone cells of the endosperm and that it was deposited in both types of protein body present in the rice endosperm: derived from the ER and containing prolamins, and derived from the vacuole and containing glutelins. In addition, new types of protein bodies were also formed within the endosperm cells. Conclusions The results suggest that the HMW 1Dx5 protein could be trafficked by either the ER or vacuolar pathway, possibly depending on the stage of development, and that its accumulation in the rice endosperm could compromise the structural integrity of protein bodies and their segregation into two distinct populations in the mature endosperm.

Compósitos poliméricos a base de fibras de licuri: efeitos da hibridização e do envelhecimento ambiental acelerado

The gradual replacement of conventional materials by the ones called composite materials is becoming a concern about the response of these composites against adverse environmental conditions, such as ultraviolet radiation, high temperature and moist. Also the search for new composite using natural fibers or a blend of it with synthetic fibers as reinforcement has been studied. In this sense, this research begins with a thorough study of microstructural characterization of licuri fiber, as a proposal of alternative reinforcement to polymeric composites. Thus, a study about the development of two composite laminates was done. The first one, involving only the fiber of licuri and the second comprising a hybrid composite based of fiber glass E and the fiber of licuri, in order to know the performance of the fiber when of fiber across the hybridization process. The laminates were made in the form of plates using the tereftálica ortho-polyester resin as matrix. The composite laminate made only by licuri fiber had two reinforcing fabric layers of unidirectional licuri and the hybrid composite had two reinforcing layers of unidirectional licuri fabric and three layers of fiber short glass-E mat. Finally, both laminates was exposed to aging acceleration in order to study the influence of environmental degradation involving the mechanical properties and fracture characteristics thereof. Regarding the mechanical properties of composites, these were determined through uniaxial tensile tests, uniaxial compression and three bending points for both laminates in original state, and uniaxial tensile tests and three bending points after accelerated aging. As regards the study of structural degradation due to aging of the laminates, it was carried out based on microscopic analysis and microstructure, as well as measuring weight loss. The characteristics of the fracture was performed by macroscopic and microscopic (optical and SEM) analysis. In general, the laminated composites based on fiber licuri showed some advantages in their responses to environmental aging. These advantages are observed in the behavior related to stiffness as well as the microstructural degradation and photo-oxidation processes. However, the structural integrity of this laminate was more affected in case the action of uniaxial tensile loads, where it was noted a lower rate of withholding his last resistance property

Avaliação por pig de perfilagem de danos superfciais nos materiais das paredes de dutos de petróleo

The modern technology of materials and structural integrity of pipelines requests the use of inspection tools named inspection pigs to detect, localize and measure the length, width and depth dimensions of the thickness losses of walls of buried and underwater pipelines in service. These tools run them internally, performing and recording measurements, with performance that varies according to the pig s technology. It has been developed recently an instrumented pig technology, called feller pig. This work aims to indicate factors that influence the feller pig technology performance in the detection and in the accuracy of measurement of the length, width and depth dimensions of the thickness losses on the internal surface of an oil pipeline wall under normal conditions of oil pipe inspection with pig. In this work, is made a collection of factors and an analyses of the technology based on the available literature, as well as an experiment to observe the technology and the factors operating. In the experiment, a feeler pig is used in a pipeline built in carbon steel and in operation that flows petroleum, in witch are observed areas with internal thickness losses occurred naturally. Some of these areas and their dimensions taken by automated ultra-sound scanner are compared with the ones indicated by the feller pig. Based on the data collection, on the analysis and on the experiment, the influence of factors object of this research is discussed. It is concluded that, among these, there are factors related to pipe fabrication tolerances, to wear of pig components, to internal adhesive wear of pipeline, to other pipeline damages and to technology characteristics. Finally, actions are suggested to know better, improve and define the applicability of this technology

Análise topológica experimental por perfilometria cíclica indutiva de superficies de paredes estruturais

To enhance the maintenance practices, Oil and Gas Pipelines are inspected from the inside by automated systems called PIG (Pipeline Inspection Gauge). The inspection and mapping of defects, as dents and holes, in the internal wall of these pipelines are increasingly put into service toward an overall Structural Integrity Policy. The residual life of these structures must be determined such that minimize its probability of failure. For this reason, the investigation on the detection limits of some basic topological features constituted by peaks or valleys disposed along a smooth surface is of great value for determining the sensitivity of the measurements of defects from some combinations of circumferential, axial and radial extent. In this investigation, it was analyzed an inductive profilometric sensor to scan three races, radius r1, r2, r3, in a circular surface of low carbon steel, equipped with eight consecutive defects simulated by bulges and holes by orbit, equally spaced at p/4 rad. A test rig and a methodology for testing in laboratory were developed to evaluate the sensor response and identify their dead zones and jumps due to fluctuations as a function of topological features and scanning velocity, four speeds different. The results are presented, analyzed and suggestions are made toward a new conception of sensor topologies, more sensible to detect these type of damage morphologies

Impacto da ingestão de cálcio sobre a mineralização óssea em adolescentes

A puberdade destaca-se como período fundamental para a aquisição de massa óssea. Durante essa fase da vida, a mineralização encontra-se aumentada com taxas de formação óssea superior às de reabsorção. Nesse sentido, o objetivo desta revisão foi investigar a inter-relação da ingestão dietética de cálcio com a mineralização óssea, durante a puberdade. Entre os fatores influenciadores nutricionais, merecem destaque o fosfato e o magnésio, que, juntamente com o cálcio, mantêm a integridade estrutural do esqueleto. A revisão de literatura indicou que os excessos de proteína e de refrigerantes, na alimentação dos jovens, acarretam comprometimento na mineralização óssea, embora os dados sejam ainda contraditórios. Conclui-se que, durante o período da puberdade, é indicado manter o aporte de cálcio em níveis adequados, na perspectiva de maximizar o pico da massa óssea.

Colonization of rocky and leaf pack substrates by benthic macroinvertebrates in a stream in southeast Brazil.

A comparative analysis was conducted of the colonization by benthic macroinvertebrates of rocky and leaf pack substrates, both natural and artificial. This colonization was evaluated by season, with the objective of ascertaining the influence of rainfall on the rate of colonization. The total density of macroinvertebrates after 21 days of colonization was significantly greater in the dry than in the wet season. When the substrate types were compared, artificial leaf pack substrate presented the smallest density for both seasons. In the wet season, Chironomidae, Leptohyphidae, Hydropsychidae, Elmidae, immature stages of Trichoptera, and Hydroptilidae showed a more representative density. In the dry season, Chironomidae, Baetidae and Oligochaeta were the most abundant taxa. The artificial rocky substrate used in this experiment was the most appropriate, due to its resemblance with natural substrate conditions in terms of the maintenance of the structural integrity of the substrate throughout the experimental period. Successional and seasonal effects were of great relevance, playing an important role in the colonization process.

The effect of chilling on the photosynthetic activity in coffee (Coffea arabica L.) seedlings. The protective action of chloroplastid pigments

Coffea arabica is considered to be sensitive to low temperatures, being affected throughout its entire life cycle. Injury caused by chilling (low temperatures above zero degree centigrade) is characterized primarily by inhibition of the photosynthetic process. The objective of this work was to evaluate the role of photosynthetic pigments in the tolerance of coffee (C. arabica L.) seedlings to chilling. The evaluation the photosynthetic activity was made by emission of Chl a fluorescence at room temperature (25°C) in vivo and in situ, using a portable fluorometer. The pigment content was obtained by extraction with 80% acetone, while estimation of membrane lipid peroxidation was determined by measuring the MDA content in leaf tissue extracts. The results indicated a generalized reduction in the quantum yield of PSII when the seedlings were maintained in the dark. The reduction occurred in the seedlings submitted to chilling treatment as well as in the control ones. This demonstrates that not only chilling acts to cause an alteration in PSII. It is possible that the tissue storage reserves had been totally exhausted, with the respiratory rate exceeding the photosynthetic rate; the later was nil, since the seedlings were kept in the dark. The efficiency in the capture, transfer and utilization of light energy in PS11 photochemical reactions requires a sequence of photochemical, biochemical and biophysical events which depend on the structural integrity of the photosynthetic apparatus. However, this efficiency was found to be related to the protective action of chloroplastid pigments, rather than to the concentration of these pigments.

In vivo preservation of the hybrid layer by chlorhexidine

Host-derived proteases have been reported to degrade the collagen matrix of incompletely-resin-infiltrated dentin. This study tested the hypothesis that interfacial degradation of resin-dentin bonds may be prevented or delayed by the application of chlorhexidine (CHX), a matrix metalloproteinase inhibitor, to dentin after phosphoric acid-etching. Contralateral pairs of resin-bonded Class I restorations in non-carious third molars were kept under intra-oral function for 14 months. Preservation of resin-dentin bonds was assessed by microtensile bond strength tests and TEM examination. In vivo bond strength remained stable in the CHX-treated specimens, while bond strength decreased significantly in control teeth. Resin-infiltrated dentin in CHX-treated specimens exhibited normal structural integrity of the collagen network. Conversely, progressive disintegration of the fibrillar network was identified in control specimens. Auto-degradation of collagen matrices can occur in resin-infiltrated dentin, but may be prevented by the application of a synthetic protease inhibitor, such as chlorhexidine.

Cimetidine-induced vascular cell apoptosis impairs testicular microvasculature in adult rats

Cimetidine, an H2 receptor antagonist used for treatment of gastric ulcers, exerts antiandrogenic and antiangiogenic effects. In the testes cimetidine impairs spermatogenesis, Sertoli cells and peritubular tissue, inducing apoptosis in the myoid cells. Regarding the importance of histamine and androgens for vascular maintenance, the effect of cimetidine on the structural integrity of the testicular vasculature was evaluated. Adult male rats received cimetidine (CMTG) and saline (CG) for 50 days. The testes were fixed in buffered 4% formaldehyde and embedded in historesin and paraffin. In the PAS-stained sections, the microvascular density (MVD) and the vascular luminal area (VLA) were obtained. TUNEL method was performed for detection of cell death. Testicular fragments embedded in Araldite were analyzed under transmission electron microscopy. A significant decrease in the MVD and VLA and a high number of collapsed blood vessel profiles were observed in CMTG. Endothelial cells and vascular muscle cells were TUNEL-positive and showed ultrastructural features of apoptosis. These results indicate that cimetidine induces apoptosis in vascular cells, leading to testicular vascular atrophy. A possible antagonist effect of cimetidine on the H2 receptors and/or androgen receptors in the vascular cells may be responsible for the impairment of the testicular microvasculature.

Estudo do efeito do extrato hidroglicólico de Bidens pilosa na expressão de genes relacionados à intergridade da pele

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Imunimarcação de subpopulações de linfócitos CD3+, CD4+ e CD8 associada à expressão de metaloproteinases -2 e -9 em cerebelos de cães infectados naturalmente com vírus da cinomose canina

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

Esterelização de esmalte bovino por meio de irradiação por microondas: efeito sobre a microdureza superficial e resistência à desmineralização

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fabrication of Zinc Oxide Nanowires/Polymer Composites by Two-Photon Polymerization

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

Evaluation of Cracks Caused by Mechanical Vibrations in Buildings

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Leakage detection in water pipe networks using electromechanical impedance (EMI) based technique

The electromechanical impedance (EMI) technique has been successfully used in structural health monitoring (SHM) systems on a wide variety of structures. The basic concept of this technique is to monitor the structural integrity by exciting and sensing a piezoelectric transducer, usually a lead zirconate titanate (PZT) wafer bonded to the structure to be monitored and excited in a suitable frequency range. Because of the piezoelectric effect, there is a relationship between the mechanical impedance of the host structure, which is directly related to its integrity, and the electrical impedance of the PZT transducer, obtained by a ratio between the excitation and the sensing signals.This work presents a study on damage (leaks) detection using EMI based method. Tests were carried out in a rig water system built in a Hydraulic Laboratory for different leaks conditions in a metallic pipeline. Also, it was evaluated the influence of the PZT position bonded to the pipeline. The results show that leaks can effectively be detected using common metrics for damage detection such as RMSD and CCDM. Further, it was observed that the position of the PZT bonded to the pipes is an important variable and has to be controlled.