On the development of an unstructured grid solver for inert and reactive high speed flow simulations

An unstructured grid Euler solver for reactive compressible flow applications is presented. The method is implemented in a cell centered, finite volume context for unstructured triangular grids. Three different schemes for spatial discretization are implemented and analyzed. Time march is implemented in a time-split fashion with independent integrators for the flow and chemistry equations. The capability implemented is tested for inert flows in a hypersonic inlet and for inert and reactive supersonic flows over a 2-D wedge. The results of the different schemes are compared with each other and with independent calculations using a structured grid code. The strengths and the possible weaknesses of the proposed methods are discussed.

Response of Grilage-Like Structures by the Mobility Approach

This work presents an application of the Mobility Approach to the analysis of the power flow through grillage-like structures. Such structures are usually found in offshore platforms, supporting large and heavy machines. Different wave kinds (longitudinal, flexural and torsional) were initially considered in the power flow analysis between two beams joined in L. Beams excited by an in-plane point force showed strong coupling between longitudinal-flexural waves, while that for out-of-plane point force excitation, flexural-torsional waves coupling represents the most important mechanism of energy transmission. The response determination of grillages by the mobility approach requires the structure to be separated into simple beam-like structural components. Equations for rotations and displacements at the joints of all beams are written for as mobility functions, and moments and forces acting at the joints. A system of equations relating all such internal forces and moments is obtained. This approach was applied to simple grillages. Response results showed good agreement when compared to those provided by Finite Elements.

Active search for leprosy cases in Midwestern Brazil: a serological evaluation of asymptomatic household contacts before and after prophylaxis with bacillus Calmette-Guérin

Leprosy is a disease caused by Mycobacterium leprae that carries a high risk of disability, making early diagnosis mandatory. This study aimed to determine the applicability of anti-PGL-1 IgM antibody detection, using the ML FLOW technique, as an assistant tool for the detection of leprosy infection in asymptomatic household contacts (AHHC) of multibacillary leprosy index cases from Midwest Brazil. Serological changes induced by the prophylaxis of these household contacts with Bacillus Calmette-Guérin (BCG) were also verified. A total of 91 AHHC were assessed, among which, 18.68% (n = 17) presented both positive bacilloscopy and positive anti-PGL-1 IgM serology. Positivity concordance between these two laboratorial exams (Kappa Index = 1; p < 0.001) was indicated, however, one case did not demonstrate concordance between the semiquantitative assessment of anti-PGL-1 IgM and the bacilloscopy index (Kappa Index = 0.96; p < 0.001). Among the 17 AHHC with positive bacilloscopy, eight were reassessed after prophylaxis with BCG and two of them presented negative anti-PGL-1 IgM serology, being these patients who had presented a bacilloscopy index of < 2[+] in the initial assessment. This study shows that anti-PGL-1 IgM detection may be used as a tool to determine the bacillary load in AHHC and to detect immune changes related to prophylaxis by nonspecific vaccination.

Use of the paired samples (cerebrospinal fluid and serum) in immunodiagnostic of active and inactive human neurocysticercosis

Paired samples of cerebrospinal fluid (CSF) and serum of 30 patients - 10 with active, 10 with inactive neurocysticercosis (NCC), and 10 control subjects - were evaluated by enzyme-linked immunosorbent assay (ELISA) using two Taenia crassiceps metacestode extracts as antigen in order to detect IgG antibodies. In active NCC, high levels of IgG were detected (p < 0.05). The CSF samples showed 80% (CI 72-88) of reactivity in the saline extract (S) and 90% (CI 84-95) in sodium dodecyl sulphate (SDS) and the serum samples were reactive in 90% (CI 84-95) and 100% (CI 98-100) in the S and SDS antigenic extracts, respectively. The use of the paired samples of CSF and serum in active NCC showed equivalent results suggesting that the serum samples could be used as a screening in those patients whose CSF puncture is counter-indicated.

Optimal use of SSR markers for varietal identification of upland cotton

Abstract: The objective of this work was to identify polymorphic simple sequence repeat (SSR) markers for varietal identification of cotton and evaluation of the genetic distance among the varieties. Initially, 92 SSR markers were genotyped in 20 Brazilian cotton cultivars. Of this total, 38 loci were polymorphic, two of which were amplified by one primer pair; the mean number of alleles per locus was 2.2. The values of polymorphic information content (PIC) and discrimination power (DP) were, on average, 0.374 and 0.433, respectively. The mean genetic distance was 0.397 (minimum of 0.092 and maximum of 0.641). A panel of 96 varieties originating from different regions of the world was assessed by 21 polymorphic loci derived from 17 selected primer pairs. Among these varieties, the mean genetic distance was 0.387 (minimum of 0 and maximum of 0.786). The dendrograms generated by the unweighted pair group method with arithmetic average (UPGMA) did not reflect the regions of Brazil (20 genotypes) or around the world (96 genotypes), where the varieties or lines were selected. Bootstrap resampling shows that genotype identification is viable with 19 loci. The polymorphic markers evaluated are useful to perform varietal identification in a large panel of cotton varieties and may be applied in studies of the species diversity.

Role of Doppler ultrasonography evaluation of superior mesenteric artery flow volume in the assessment of Crohn's disease activity

Objective To investigate superior mesenteric artery flow measurement by Doppler ultrasonography as a means of characterizing inflammatory activity in Crohn's disease. Materials and Methods Forty patients were examined and divided into two groups – disease activity and remission – according to their Crohn's disease activity index score. Mean superior mesenteric artery flow volume was calculated for each group and correlated with Crohn's disease activity index score. Results The mean superior mesenteric artery flow volume was significantly greater in the patients with active disease (626 ml/min ± 236 × 376 ml/min ± 190; p = 0.001). As a cut off corresponding to 500 ml/min was utilized, the superior mesenteric artery flow volume demonstrated sensitivity of 83% and specificity of 82% for the diagnosis of Crohn's disease activity. Conclusion The present results suggest that patients with active Crohn's disease have increased superior mesenteric artery flow volume as compared with patients in remission. Superior mesenteric artery flow measurement had a good performance in the assessment of disease activity in this study sample.

Determination of sulfate in the wet-process of phosphoric acid by reverse flow injection

An improved method based on reverse flow injection is proposed for determining sulfate concentration in the wet-process of phosphoric acid (WPA). The effect of reagent composition, flow rate, temperature, acid concentration, length of the reaction coil, and linear response range on the flow system is discussed in detail. Optimal conditions are established for determining sulfate in the WPA samples. Baseline drift is avoided by a periodic washing step with EDTA in an alkaline medium. A linear response is observed within a range of 20 - 360 mg L-1, given by the equation A = 0.0020C (mg L-1) + 0.0300, R² = 0.9991. The detection limit of the proposed method for sulfate analysis is 3 mg L-1, and the relative standard deviation (n = 12) of sulfate absorbance peak is less than 1.60%. This method has a rate of up to 29 samples per hour, and the results compare well with those obtained with gravimetric method.

Software for calculation of reservoir active capacity with the sequent-peak algorithm

It is presented a software developed with Delphi programming language to compute the reservoir's annual regulated active storage, based on the sequent-peak algorithm. Mathematical models used for that purpose generally require extended hydrological series. Usually, the analysis of those series is performed with spreadsheets or graphical representations. Based on that, it was developed a software for calculation of reservoir active capacity. An example calculation is shown by 30-years (from 1977 to 2009) monthly mean flow historical data, from Corrente River, located at São Francisco River Basin, Brazil. As an additional tool, an interface was developed to manage water resources, helping to manipulate data and to point out information that it would be of interest to the user. Moreover, with that interface irrigation districts where water consumption is higher can be analyzed as a function of specific seasonal water demands situations. From a practical application, it is possible to conclude that the program provides the calculation originally proposed. It was designed to keep information organized and retrievable at any time, and to show simulation on seasonal water demands throughout the year, contributing with the elements of study concerning reservoir projects. This program, with its functionality, is an important tool for decision making in the water resources management.

Do blood components affect the production of reactive oxygen species (ROS) by equine synovial cells in vitro?

Blood-derived products are commonly administered to horses and humans to treat many musculoskeletal diseases, due to their potential antioxidant and anti-inflammatory effects. Nevertheless, antioxidant effects have never been shown upon horse synovial fluid cells in vitro. If proved, this could give a new perspective to justify the clinical application of blood-derived products. The aim of the present study was to investigate the antioxidant effects of two blood-derived products - plasma (unconditioned blood product - UBP) and a commercial blood preparation (conditioned blood product - CBP)¹ - upon stimulated equine synovial fluid cells. Healthy tarsocrural joints (60) were tapped to obtain synovial fluid cells; these cells were pooled, processed, stimulated with lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA), and evaluated by flow cytometry for the production of reactive oxygen species (ROS). Upon addition of any blood-derived product here used - UBP and CBP - there was a significant decrease in the oxidative burst of synovial fluid cells (P<0.05). There was no difference between UBP and CBP effects. In conclusion, treatment of stimulated equine synovial cells with either UBP or CBP efficiently restored their redox equilibrium.

Numerical study on mixed convection in a horizontal flow past a square porous cavity using UNIFAES scheme

Mixed convection on the flow past a heated length and past a porous cavity located in a horizontal wall bounding a saturated porous medium is numerically simulated. The cavity is heated from below. The steady-state regime is studied for several intensities of the buoyancy effects due to temperature variations. The influences of Péclet and Rayleigh numbers on the flow pattern and the temperature distributions are examined. Local and global Nusselt numbers are reported for the heated surface. The convective-diffusive fluxes at the volume boundaries are represented using the UNIFAES, Unified Finite Approach Exponential-type Scheme, with the Power-Law approximation to reduce the computing time. The conditions established by Rivas for the quadratic order of accuracy of the central differencing to be maintained in irregular grids are shown to be extensible to other quadratic schemes, including UNIFAES, so that accuracy estimates could be obtained.

Involvement of glutamate and reactive oxygen species in methylmercury neurotoxicity

This review addresses the mechanisms of methylmercury (MeHg)-induced neurotoxicity, specifically examining the role of oxidative stress in mediating neuronal damage. A number of critical findings point to a central role for astrocytes in mediating MeHg-induced neurotoxicity as evidenced by the following observations: a) MeHg preferentially accumulates in astrocytes; b) MeHg specifically inhibits glutamate uptake in astrocytes; c) neuronal dysfunction is secondary to disturbances in astrocytes. The generation of reactive oxygen species (ROS) by MeHg has been observed in various experimental paradigms. For example, MeHg enhances ROS formation both in vivo (rodent cerebellum) and in vitro (isolated rat brain synaptosomes), as well as in neuronal and mixed reaggregating cell cultures. Antioxidants, including selenocompounds, can rescue astrocytes from MeHg-induced cytotoxicity by reducing ROS formation. We emphasize that oxidative stress plays a significant role in mediating MeHg-induced neurotoxic damage with active involvement of the mitochondria in this process. Furthermore, we provide a mechanistic overview on oxidative stress induced by MeHg that is triggered by a series of molecular events such as activation of various kinases, stress proteins and other immediate early genes culminating in cell damage.

Expression and purification of the immunogenically active fragment B of the Park Williams 8 Corynebacterium diphtheriae strain toxin

The construction of a hexahistidine-tagged version of the B fragment of diphtheria toxin (DTB) represents an important step in the study of the biological properties of DTB because it will permit the production of pure recombinant DTB (rDTB) in less time and with higher yields than currently available. In the present study, the genomic DNA of the Corynebacterium diphtheriae Park Williams 8 (PW8) vaccine strain was used as a template for PCR amplification of the dtb gene. After amplification, the dtb gene was cloned and expressed in competent Escherichia coli M15™ cells using the expression vector pQE-30™. The lysate obtained from transformed E. coli cells containing the rDTB PW8 was clarified by centrifugation and purified by affinity chromatography. The homogeneity of the purified rDTB PW8 was confirmed by immunoblotting using mouse polyclonal anti-diphtheria toxoid antibodies and the immune response induced in animals with rDTB PW8 was evaluated by ELISA and dermonecrotic neutralization assays. The main result of the present study was an alternative and accessible method for the expression and purification of immunogenically reactive rDTB PW8 using commercially available systems. Data also provided preliminary evidence that rabbits immunized with rDTB PW8 are able to mount a neutralizing response against the challenge with toxigenic C. diphtheriae.

Human monocytes tolerant to LPS retain the ability to phagocytose bacteria and generate reactive oxygen species

Tolerance to lipopolysaccharide (LPS) occurs when animals or cells exposed to LPS become hyporesponsive to a subsequent challenge with LPS. This mechanism is believed to be involved in the down-regulation of cellular responses observed in septic patients. The aim of this investigation was to evaluate LPS-induced monocyte tolerance of healthy volunteers using whole blood. The detection of intracellular IL-6, bacterial phagocytosis and reactive oxygen species (ROS) was determined by flow cytometry, using anti-IL-6-PE, heat-killed Staphylococcus aureus stained with propidium iodide and 2',7'-dichlorofluorescein diacetate, respectively. Monocytes were gated in whole blood by combining FSC and SSC parameters and CD14-positive staining. The exposure to increasing LPS concentrations resulted in lower intracellular concentration of IL-6 in monocytes after challenge. A similar effect was observed with challenge with MALP-2 (a Toll-like receptor (TLR)2/6 agonist) and killed Pseudomonas aeruginosa and S. aureus, but not with flagellin (a TLR5 agonist). LPS conditioning with 15 ng/mL resulted in a 40% reduction of IL-6 in monocytes. In contrast, phagocytosis of P. aeruginosa and S. aureus and induced ROS generation were preserved or increased in tolerant cells. The phenomenon of tolerance involves a complex regulation in which the production of IL-6 was diminished, whereas the bacterial phagocytosis and production of ROS was preserved. Decreased production of proinflammatory cytokines and preserved or increased production of ROS may be an adaptation to control the deleterious effects of inflammation while preserving antimicrobial activity.

An in vitro analysis of the total phenolic content, antioxidant power, physical, physicochemical, and chemical composition of Terminalia Catappa Linn fruits

This study assessed the antioxidant, total phenolic, and physicochemical properties of in vitro Terminalia Catappa Linn (locally called castanhola) using the DPPH assay. The castanhola fruits had an average weight of 19.60 ± 0.00 g, combining shell, pulp, and seed weight, and a soluble solids content of 8 °Brix. The chemical composition was determined with predominance of carbohydrates (76,88 ± 0,58%).The titration method was used to determine Vitamin C content using 2,6-dichlorophenolindophenol (DCFI), known as reactive Tillmans resulting in no significant levels. Aqueous extracts of castanhola pulp showed a higher concentration of phenolics, 244.33 ± 18.86 GAE.g-1 of fruit, and alcoholic extracts, 142.84 ± 2.09 GAE.g-1 of fruit. EC50 values of the aqueous extract showed a greater ability to scavenge free radicals than the alcoholic extracts. The fruit had a significant content of phenolic compounds and high antioxidant capacity.