Industrial and simulation analysis of the nitrogen trichloride decomposition process in electrolytic chlorine production.

This work presents the dynamic simulation of the thermal decomposition of nitrogen trichloride (NCl(3)) during electrolytic chlorine (Cl(2)) production, using an industrial plant as a case study. NCl(3) is an extremely unstable and explosive compound and the decomposition process has the following main problems: changeability of the reactor temperature and loss of solvent. The results of this work will be used to establish a more efficient and safe control strategy and to analyze the loss of solvent during the dynamic period.

Self-assembly in a catanionic mixture with an aminoacid-derived surfactant: from mixed micelles to spontaneous vesicles.

The aqueous self-assembly of a novel lysine-derived surfactant with a gemini-like architecture, designated here as 12-Lys-12, has been experimentally investigated for the amphiphile alone in water and in a mixture with dodecyltrimethylammonium bromide (DTAB). The neat surfactant forms interesting micrometer-sized rigid tubules in the dilute region, resulting in very viscous solutions. For the catanionic mixture with DTAB, various single and multiphase regions were identified (up to a total surfactant concentration of 1.

Is saliva as reliable as urine for detection of cytomegalovirus DNA for neonatal screening of congenital CMV infection?

Background: There are no studies on the detection of cytomegalovirus (CMV) DNA by molecular methods in the saliva of newborn infants in large scale screening programs.

Objectives: To evaluate the usefulness of saliva as a sample for the neonatal screening of congenital CMV infection as compared to urine when processed by a PCR.

Study Design: Saliva and urine samples were obtained during the first week of life.

Fluctuation-induced casimir forces in granular fluids.

We numerically investigate the behavior of driven noncohesive granular media and find that two fixed large intruder particles, immersed in a sea of small particles, experience, in addition to a short-range depletion force, a long-range repulsive force. The observed long-range interaction is fluctuation-induced and we propose a mechanism similar to the Casimir effect that generates it: The hydrodynamic fluctuations are geometrically confined between the intruders, producing an unbalanced renormalized pressure. An estimation based on computing the possible Fourier modes explains the repulsive force and is in qualitative agreement with the simulations.

Genetic characterization of a new set of recombinant inbred lines (LGXSM) formed from the inter-cross of SM/J and LG/J inbred mouse strains.

A new set of LGXSM recombinant inbred (RI) strains is presented. The RI strain panel consists of 18 remaining strains of the original 55 founding strains. Strain characterization is based on 506 polymorphic microsatellites and 4,289 single nucleotide polymorphisms (SNPs) distributed across the genome.

Surgical management of intracranial complications of otogenic infection.

We conducted a prospective study of 24 patients to evaluate the evolution of intracranial complications resulting from otogenic infection and to correlate the course of the disease with surgical treatment. Almost half of the patients were younger than 18 years, and most were male. The most common intracranial complication was brain abscess, followed by meningitis, lateral sinus thrombosis, and extradural abscess.

Conformation study of HA(306-318) antigenic peptide of the haemagglutinin influenza virus protein.

Several HLA-DR alleles present the immunodominant HA(306-318) peptide of haemagglutinin of the influenza virus to T cells. NMR data of the peptide in various water solutions exclude any alpha-helix or turn conformations. Circular dichroism and Fourier transform infrared spectroscopies indicate an estimated beta-extended structure in water of 31% and 28%, respectively, with spectra shape similar to the ones observed for beta-sheet containing proteins.

Generalized Green-Kubo formulas for fluids with impulsive, dissipative, stochastic, and conservative interactions.

We present a generalization of the Green-Kubo expressions for thermal transport coefficients mu in complex fluids of the generic form [equation see text], i.e., a sum of an instantaneous transport coefficient muinfinity, and a time integral over a time correlation function in a state of thermal equilibrium between a current J and its conjugate current Jepsilon.

The evolution of genetic architecture. I. Diversification of genetic backgrounds by genetic drift.

The genetic architecture of a phenotype plays a critical role in determining phenotypic evolution through its effects on patterns of genetic variation. Genetic architecture is often considered to be constant in evolutionary quantitative genetic models. However, genetic architecture may be variable and itself evolve when there are dominance and epistatic interactions among alleles at the same and different loci, respectively.

Enthalpic and entropic contributions mediate the role of disulfide bonds on the conformational stability of interleukin-4.

The role of disulfide bridges in the structure, stability, and folding pathways of proteins has been the subject of wide interest in the fields of protein design and engineering. However, the relative importance of entropic and enthalpic contributions for the stabilization of proteins provided by disulfides is not always clear. Here, we perform a detailed analysis of the role of disulfides in the conformational stability of human Interleukin-4 (IL4), a four-helix bundle protein.

Towards data warehousing and mining of protein unfolding simulation data.

Objectives: The prediction of protein structure and the precise understanding of protein folding and unfolding processes remains one of the greatest challenges in structural biology and bioinformatics. Computer simulations based on molecular dynamics (MD) are at the forefront of the effort to gain a deeper understanding of these complex processes. Currently, these MD simulations are usually on the order of tens of nanoseconds, generate a large amount of conformational data and are computationally expensive.

A structural model of an amyloid protofilament of transthyretin.

A docking-and-alignment protocol was devised in order to build amyloid protofilaments of Transthyretin (TTR), starting from partially disrupted TTR monomeric subunits and based on experimentally available information. The docking approach is driven by a combination of shape complementarity and energetic criteria, and uses constraints derived from experimental data obtained for the fibrillar state. The dimeric structures obtained were then subjected to an alignment scheme followed by clustering analysis, producing a collection of protofilaments with distinct geometric properties.

Thermotropic phase behavior of triple-chained catanionic surfactants with varying headgroup chemistry.

Catanionic surfactants result from the pairing of oppositely charged amphiphilic molecules, forming a new class of surfactant molecules with various interesting lyotropic and thermotropic properties. With the aim of probing the role of both headgroup chemical nature/structure and molecular shape, a series of catanionic surfactants were synthesized. The cationic portion of the molecule is kept constant, being the dioctadecyldimethylammonium double chain.

A horizontal Brazil-nut effect and its reverse.

Transport effects in a monolayer consisting of a binary granular mixture, confined in a horizontally vibrating circular dish, are studied experimentally and compared with a reduced theoretical model. Depending on the ratio of the particles' material density and size, migration of the larger particles occurs either towards the boundary or to the center of the circular container. These directed motions show similarities to the Brazil-nut effect and its reverse form.

Neat DODAB vesicles: Effect of sonication time on the phase transition thermodynamic parameters and its relation with incomplete chain freezing.

Vesicle solutions formed by the cationic lipid dioctadecyldimethylammonium bromide have been extensively used in the past 20 years as model membrane systems. Often, discrepancies are found in the literature for the thermodynamic parameters of the gel-to-liquid crystal (gel-lc) phase transition of these vesicles. In this work we present a systematic DSC investigation on the influence of the sonication method on the main temperature and enthalpy of the transition for DODAB vesicles, prepared both in normal and deuterated water.

[Concept analysis and critical thinking: a complementary relationship in nursing].

The purpose of this paper is to demonstrate the relationship between the concept analysis process and critical thinking skills in nursing. Utilizing a discursive essay approach, it is argued that the concept analysis technique enhances critical thinking. The steps of the concept analysis are analyzed as to the inherent cognitive operations that represent critical reasoning processes.

Analysis of the MMP-9 (C-1562 T) and TIMP-2 (G-418C) gene promoter polymorphisms in patients with chronic periodontitis.

Background: Matrix metalloproteinases (MMP)-9 is an important member of the matrix metalloproteinase family. A functional polymorphism has been described in the promoter region of the human MMP-9 gene. A C-to-T base exchange at -1562 creates two different alleles, and the C/T and T/T genotypes promote high activity of the MMP-9 gene promoter, increasing the risk for inflammatory diseases.

Factorial effects of salinity, dietary carbohydrate and moult cycle on digestive carbohydrases and hexokinases in Litopenaeus vannamei (Boone, 1931).

Litopenaeus vannamei were reared in close cycle over seven generations and tested for their capacity to digest starch and to metabolise glucose at different stages of the moulting cycle. After acclimation with 42.3% of carbohydrates (HCBH) or 2.

Simultaneous analysis of cytoskeletal patterns and chromosome positioning in human fertilization failures.

Objective: To sequentially and reliably apply both tubulin immunocytochemistry (ICC) and fluorescence in situ hybridization (FISH) to human fertilization failures, thus providing a tool for a multiple analysis of arrest.

Design: Analysis of human fertilization failures at several stages of arrest.

Setting: Academic and clinical institutions.

Gunshot wounds to the facial nerve.

Objective: This paper presents our experience with gunshot wounds to the temporal bone and discusses facial nerve lesions, surgical indication, surgical timing, and other findings.

Study Design: We performed a retrospective review of patients treated for facial nerve lesion after gunshot injury to the temporal bone.

Setting: The study was performed in the Otolaryngology Department of the University of Sao Paulo Medical School, Sao Paulo, Brazil.

[Asthma in schoolchildren from Recife, Brazil. Prevalence comparison: 1994-95 and 2002].

Objectives: To describe the prevalence of asthma and asthma variants in schoolchildren from Recife in 2002, and to compare these data with data from 1994-95; to analyze the relationship between maternal schooling and the presence of asthma or worsening asthma; and to evaluate the diagnostic accuracy of the yearly prevalence of wheezing as an asthma indicator.

Methods: Cross-sectional study. A probabilistic sample of 3,086 and 2,774 13- and 14-year-old students answered a written questionnaire in 1994-95 and 2002, as part of the International Study of Asthma and Allergies in Childhood.

Protein folding and unfolding simulations: a new challenge for data mining.

One of the unsolved paradigms in molecular biology is the protein folding problem. In recent years, with the identification of several diseases as protein folding disorders and with the explosion of genome information and the need for efficient ways to predict protein structure, protein folding became a central issue in molecular sciences research. Using molecular dynamics unfolding simulations of an amyloidogenic protein--transthyretin--as an example, we put forward a series of ideas on how simulations of this type may be used to infer rules and unfolding behavior in amyloidogenic proteins, and to extrapolate rules for protein folding in different structural classes of proteins.

Stress-induced expression in wheat of the Arabidopsis thaliana DREB1A gene delays water stress symptoms under greenhouse conditions.

One of the major environmental factors limiting plant productivity is lack of water. This is especially true for the major cereals maize, rice, and wheat, which demonstrate a range of susceptibility to moisture deficit. Although conventional breeding and marker-assisted selection are being used to develop varieties more tolerant to water stress, these methods are time and resource consuming and germplasm dependent.

Epistasis affecting litter size in mice.

Litter size is an important reproductive trait as it makes a major contribution to fitness. Generally, traits closely related to fitness show low heritability perhaps because of the corrosive effects of directional natural selection on the additive genetic variance. Nonetheless, low heritability does not imply, necessarily, a complete absence of genetic variation because genetic interactions (epistasis and dominance) contribute to variation in traits displaying strong heterosis in crosses, such as litter size.

Interleukin 10 gene promoter polymorphisms are associated with chronic periodontitis.

Background: Chronic periodontitis (CP) is characterized by an inflammation in the supporting tissues of the teeth caused primarily by bacterial infection. Interleukin 10 (IL10) is an anti-inflammatory cytokine whose genetic polymorphisms may influence the expression of the protein.

Objective: In this study we investigated the hypothesis that single-nucleotide polymorphisms (SNPs) in the promoter of IL10 gene might be related to CP.