Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury

Background. Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury. Method. A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n=7) or 15 min (group 2; n=7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview®; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated. Results. Injection of contrast material significantly increased the apparent volume of lung tissue by 83 ± 57 ml in group 1 and 102 ± 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 ± 52 ml and 31 ± 18 ml. Conclusion. Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications.

The role of coarse intermetallics in the localized corrosion behaviour of AA 2024-T3 in low concentrated chloride media

Aluminium alloy (AA) 2024-T3 is an important engineering material due to its widespread use in the aerospace industry. However, it is very prone to localized corrosion attack in chloride containing media, which has been mainly associated to the presence of coarse intermetallics (IMs). In this work the corrosion behaviour of aluminium alloy 2024-T3 in low concentrated chloride media was investigated using microscopy and electrochemical methods. SEM observations have shown that intermetallics with the same nominal composition present heterogeneous reaction rates, and that both types of coarse IMs normally found in the AA 2024-T3 microstructure corrode. Moreover, EDS analyses have shown important compositional changes in the corroded IMs, evidencing the selective corrosion of their more active constituents and the onset of an intense oxygen peak, irrespective to the IM nature. TEM/EDS observations on non-corroded samples have evidenced the heterogeneous composition within the IMs. On the other hand, the results of the electrochemical investigations, in accordance with the SEM/EDS observations, have evidenced that IMs corrosion dominates the electrochemical response of the alloy during the first hours of immersion in the test electrolyte. © 2009 by NACE International.

Cytotoxic effects of white-MTA and MTA-Bio cements on odontoblast-like cells (MDPC-23)

This study evaluated the cytotoxic effects of 2 mineral trioxide aggregate (MTA) cements - White-MTA-Angelus and a new formulation, MTA-Bio - on odontoblast-like cell (MDPC-23) cultures. Twenty-four disc-shaped (2 mm diameter x 2 mm thick) specimens were fabricated from each material and immersed individually in wells containing 1 mL of DMEM culture medium for either 24 h or 7 days to obtain extracts, giving rise to 4 groups of 12 specimens each: G1 - White-MTA/24 h; G2 - White-MTA/7 days; G3 - MTA-Bio/24 h; and G4 - MTA-Bio/7 days. Plain culture medium (DMEM) was used as a negative control (G5). Cells at 30,000 cells/cm 2 concentration were seeded in the wells of 24-well plates and incubated in a humidified incubator with 5% CO 2 and 95% air at 37°C for 72 h. After this period, the culture medium of each well was replaced by 1 mL of extract (or plain DMEM in the control group) and the cells were incubated for additional 2 h. Cell metabolism was evaluated by the MTT assay and the data were analyzed statistically by ANOVA and Tukey's test (α=0.05). Cell morphology and the surface of representative MTA specimens of each group were examined by scanning electron microscopy. There was no statistically significant difference (p>0.05) between G1 and G2 or between G3 and G4. No significant difference (p>0.05) was found between the experimental and control groups either. Similar cell organization and morphology were observed in all groups, regardless of the storage periods. However, the number of cells observed in the experimental groups decreased compared to the control group. MTA-Bio presented irregular surface with more porosities than White-MTA. In conclusion, White-MTA and MTA-Bio presented low cytotoxic effects on odontoblast-like cell (MDPC-23) cultures.

Antimicrobial effects of ozonated water on the sanitization of dental instruments contaminated with E. coli, S. aureus, C. albicans, or the spores of B. atrophaeus

Objectives: Ozone has been used as an alternative method for the decontamination of water, food, equipment and instruments. The objective of this study was to evaluate the antimicrobial effects of ozonated water on the sanitization of dental instruments that were contaminated by Escherichia coli, Staphylococcus aureus, Candida albicans and the spores of Bacillus atrophaeus. Methods: A total of one hundred and twenty standardized samples of diamond dental burs were experimentally contaminated with E. coli (ATCC 25922), S. aureus (ATCC 6538) and C. albicans (ATCC 18804) and the spores of B. atrophaeus (ATCC 6633) for 30min. After the contamination, the samples were exposed to ozonated water (10mg/L O3) for 10 or 30min. The control group was composed of samples that were exposed to distilled water for 30min. After the exposure to the ozonated water, 0.1mL aliquots were seeded onto BHI agar to count the colony-forming units per milliliter (CFU/mL) of E. coli, S. aureus, and B. atrophaeus. Sabouraud dextrose agar was used to count the CFU/mL of C. albicans. The results were subjected to an analysis of variance and the Tukey test. Results: For all of the microorganisms studied, the ozonated water reduced the number of CFU/mL after 10 and 30. min of sanitization, and this microbial reduction was dependent on the duration of the exposure to the ozonated water. E. coli exhibited the greatest reduction in CFU/mL (2.72-3.78. log) followed by S. aureus (2.14-3.19. log), C. albicans (1.44-2.14. log) and the spores of B. atrophaeus (1.01-1.98. log). Conclusion: The ozonated water was effective in reducing the CFU of E. coli, S. aureus, C. albicans and B. atrophaeus spores, suggesting that ozonated water can be used for the sanitization of dental instruments. © 2012 King Saud Bin Abdulaziz University for Health Sciences.

Effects of ascorbic acid on in vitro culture of bovine preantral follicles

The objective of this study was to evaluate the effects of adding ascorbic acid to the media for in vitro culture of cattle ovarian fragments and to determine their effects on growth activation and viability of early-stage follicles. The ovarian cortex was divided into small fragments; one fragment was immediately fixed (control) and the other fragments were cultured in minimum essential medium (MEM) supplemented or not with various doses of ascorbic acid. Ovarian tissue was processed for histology, transmission electron microscopy (TEM) and immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA). Compared with control fragments, the percentage of primordial follicles was reduced (p < 0.05) and the percentage of growing follicles had increased (p < 0.05) in cultured cortical fragments, independent of the tested medium or incubation time. Furthermore, compared with control tissue, culture of ovarian cortex for 8 days reduced the percentages of healthy, viable follicles (p < 0.05), but not when cultures were supplemented with 25, 50 or 100 μg/ml of ascorbic acid. Ultrastructural and immunohistochemical analysis of 8 day cultured ovarian cortical fragments, however, showed the integrity and viability of follicles only when fragments were cultured in presence of 50 μg/ml of ascorbic acid. In conclusion, this study demonstrated that addition of ascorbic acid to MEM at a concentration of 50 μg/ml not only stimulates the activation of 8 day in vitro cultured cattle primordial follicles and subsequent growth of activated follicles, but also safeguards the viability of these early-stage follicles. © 2012 Copyright Cambridge University Press.

Effects of treatment of the fat body trophocytes of Melipona quadrifasciata anthidioides nurse workers and virgin queens in culture by juvenile hormone III and ecdysterone (20-HE)

The fat body (FB) consists of two types of cells: throphocytes and oenocytes. Throphocytes are related to intermediary metabolism storing lipids, carbohydrates, and proteins while oenocytes play role in the lipids and lipoproteins production. The vitellogenin is the precursor of egg yolk (vitelline) and is synthesized on FB. The aim of this work was to analyze the effects of hormones acting in bee reproduction, as juvenile hormone (JH) and ecdisteroids (20 HE) on FB cells, where vitellogenin is synthesized. For the study were chose nurse workers that in Melipona quadrifasciata anthidioides present activated ovaries and produce eggs, and virgin queens whose ovaries are not yet activated, presenting only previtellogenic follicles. FB trophocytes from these classes of bees were cultivated in media containing different amounts of JH and 20-HE. The effects on trophocytes cytoplasm reserves of lipids, proteins, and activity of acid phosphatase were compared by observing preparations from cultured FB, treated and control, by transmission electron microscopy (TEM). The results showed that the hormones effects are related to the bee's caste and functional ovary stage. The role of acid phosphatase on mobilization of the trophocyte reserves was also determined. © 2012 Wiley Periodicals, Inc.

Evaluation of the effects of nicorandil and its molecular precursor (without radical NO) on proliferation and apoptosis of 786-cell

Nicorandil is a nitric oxide (NO) donor used in the treatment of angina symptoms. It has also been reported to protect cells and affect the proliferation and death of cells in some tissues. The molecules that interfere with these processes can cause dysfunction in healthy tissues but can also assist in the therapy of some disorders. In this study we examined the effect of nicorandil and of the molecular precursor that does not have the NO radical (N-(beta-hydroxyethyl) nicotinamide) on the cell proliferation and death of human renal carcinoma cells (786-O) under normal oxygenation conditions. The molecular precursor was used in order to analyze the effects independents of NO. In the cytotoxicity test, nicorandil was shown to be cytotoxic at very high concentrations and it was more cytotoxic than its precursor (cytotoxic at concentrations of 2,000 and 3,000 μg/mL, respectively). We propose that the lower cytotoxicity of the precursor is due to the absence of the NO radical. In this study, the cells exposed to nicorandil showed neither statistically significant changes in cell proliferation nor increases in apoptosis or genotoxicity. The precursor generated similar results to those of nicorandil. We conclude that nicorandil causes no changes in the proliferation or apoptosis of the cell 786-O in normal oxygenation conditions. Moreover, the lack of NO radical in the precursor molecule did not show a different result, except in the cell cytotoxicity. © 2013 Springer Science+Business Media Dordrecht.

Reservoir design and operation: Effects on aquatic biota-a case study of planktonic copepods

Copepod assemblages from two cascade reservoirs were analyzed during two consecutive years. The upstream reservoir (Chavantes) is a storage system with a high water retention time (WRT of 400 days), and the downstream one (Salto Grande) is a run-of-river system with only 1. 5 days WRT. Copepod composition, richness, abundance, and diversity were correlated with the limnological variables and the hydrological and morphometric features. Standard methods were employed for zooplankton sampling and analysis (vertical 50-μm net hauls and counting under a stereomicroscope). Two hypotheses were postulated and confirmed through the data obtained: (1) compartmentalization is more pronounced in the storage reservoir and determines the differences in the copepod assemblage structure; and (2) the assemblages are more homogeneous in the run-of-river reservoir, where the abundance decreases because of the predominance of washout effects. For both reservoirs, the upstream zone is more distinctive. In addition, in the smaller reservoir the influence of the input from tributaries is stronger (turbid waters). Richness did not differ significantly among seasons, but abundance was higher in the run-of-river reservoir during summer. © 2012 Springer Science+Business Media Dordrecht.

Effects of sublethal dose of fipronil on neuron metabolic activity of africanized honeybees

Fipronil is a neurotoxic insecticide that inhibits the gamma-aminobutyric acid receptor and can affect gustative perception, olfactory learning, and motor activity of the honeybee Apis mellifera. This study determined the lethal dose (LD50) and the lethal concentration (LC50) for Africanized honeybee and evaluated the toxicity of a sublethal dose of fipronil on neuron metabolic activity by way of histochemical analysis using cytochrome oxidase detection in brains from worker bees of different ages. In addition, the present study investigated the recovery mechanism by discontinuing the oral exposure to fipronil. The results showed that mushroom bodies of aged Africanized honeybees are affected by fipronil, which causes changes in metabolism by increasing the respiratory activity of mitochondria. In antennal lobes, the sublethal dose of fipronil did not cause an increase in metabolic activity. The recovery experiments showed that discontinued exposure to a diet contaminated with fipronil did not lead to recovery of neural activity. Our results show that even at very low concentrations, fipronil is harmful to honeybees and can induce several types of injuries to honeybee physiology. © 2012 Springer Science+Business Media New York.

The effects of pinning on critical currents of superconducting films

Using molecular dynamics simulations, we analyze the effects of artificial periodic arrays of pinning sites on the critical current of superconducting thin films as a function of vortex density. We analyze two types of periodic pinning array: hexagonal and Kagomé. For the Kagome pinning network we make calculations using two directions of transport current: along and perpendicular to the main axis of the lattice. Our results show that the hexagonal pinning array presents higher critical currents than the Kagomé and random pinning configuration for all vortex densities. In addition, the Kagomé networks show anisotropy in their transport properties. © 2012 Springer Science+Business Media, LLC.

Effects of local and regional factors on the fish assemblage structure in Meridional Amazonian streams

The aim of this study was to evaluate the effects of local, regional and temporal factors structuring fish assemblages in Meridional Amazonian streams during the months of May (rainy season) and August (dry season) of 2008. To accomplish this task, 14 streams located in Serra do Expedito (Aripuanã River basin) were sampled along 30-m stretches. A total of 3,212 specimens distributed among five orders, 18 families, and 55 species were recorded. The fish assemblage structure in the streams presented variation among types of riparian vegetation (local factor) and watersheds (regional factor), but did not present variation between seasons (temporal factor) and stream order (regional factor). Larger streams with margins covered with pasture presented higher species richness and abundance than smaller streams with margins covered with forest. © 2012 Springer Science+Business Media B.V.

Effects of a single nucleotide polymorphism in the leptin gene on the productive traits of dairy buffaloes (Bubalus bubalis)

The gene responsible for coding the leptin hormone has been associated with productive and reproductive traits in cattle. In dairy cattle, different polymorphisms found in the leptin gene have been associated with several traits of economic interest, such as energy balance, milk yield and composition, live weight, fertility and dry matter consumption. The aim of this study was to detect genetic variability in the leptin gene of buffaloes and to test possible associations with milk yield, fat and protein percentages, age at first calving and first calving interval. Three genotypes (AA, AG and GG) were identified by polymerase chain reaction-restriction fragment length polymorphism, which presented genotypic frequencies of 0.30, 0.54 and 0.16, respectively. The allele frequencies were 0.57 for the A allele and 0.43 for the G allele. No significant effects were found in the present study, but there is an indicative that leptin gene affects lipid metabolism. © 2013 Springer Science+Business Media Dordrecht.

Transdução e realidade híbrida em Avatar: uma experiência media assemblage

Pós-graduação em Comunicação - FAAC

3D raytracing through homogeneous anisotropic media with smooth interfaces

O raio conectando dois pontos em um meio anisotrópico, homogêneo por partes e com variação lateral, é calculado utilizando-se técnicas de continuação em 3D. Se combinado com algoritmos para solução do problema de valor inicial, o método pode ser estendido para o cálculo de eventos qS₁ e qS₂. O algoritmo apresenta a mesma eficiência e robustez que implementações de técnicas de continuação em meios isotrópicos. Rotinas baseadas neste algoritmo têm várias aplicações de interesse. Primeiramente, na modelagem e inversão de parâmetros elásticos na presença de anisotropia. Em segundo lugar, as iterações de Newton-Raphson produzem atributos da frente de onda como vetor vagarosidade e a matrix hessiana do tempo de trânsito, quantidades que permitem determinar o espalhamento geométrico e aproximações de segunda ordem para o tempo de trânsito. Estes atributos permitem calcular as amplitudes ao longo do raio e investigar os efeitos da anisotropia no empilhamento CRS em modelos de velocidade simples.

Effects of calcium salts of soybean oil on factors that influence pregnancy establishment in Bos indicus beef cows

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