Evaluation of Atmospheric and Vacuum Residues Using Molecular Distillation and Optimization

The term atmospheric residue describes the material at the bottom of the atmospheric distillation tower having a lower boiling point limit of about 340°C; the term vacuum residue (heavy petroleum fractions) refers to the bottom of the vacuum distillation, which has an atmospheric equivalent boiling point (AEBP) above 540°C. In this work, the objective is to evaluate the behavior of different kinds of Brazilian atmospheric and vacuum residues using molecular distillation. The Falling Film Molecular Distillator was used. For the results obtained through this process, a significant range of temperature can be explored avoiding the thermal decomposition of the material. So these results are very important to the refinery decisions and improvements. The Experimental Factorial Design results showed that the temperature has more influence on the process than the feed flow rate, when a higher percentage of distillate is required.     

Role of Perceived Importance in Intergroup Contact.

Furthering G. W. Allport's (1954) contentions for optimal contact, the authors introduce a new construct: the perceived importance of contact. They propose that perceived importance is the best proximal predictor of contact's reduction of prejudice. If individuals have opportunities for contact at work or in the neighborhood, their chances to have intergroup acquaintances and friends increase. Intergroup contact among acquaintances and friends can be perceived as more or less important, which in turn determines intergroup evaluations. A 1st study shows that the new measure of perceived importance is indeed distinct from established quantity and quality indicators. The results are cross-validated in a 2nd study that also sheds light on the meaning of importance. In 3rd and 4th studies, structural equation analyses and a meta-analysis support the hypotheses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Embedded is the new paradigm(s)

Embedded computing moved beyond toasters quite some time ago, but there are still misconceptions about what embedded computers do. Some of those misconceptions come from an old-fashioned view of what a computer is.     

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine as a substrate of cytochrome P450 2D6: allosteric effects of NADPH-cytochrome P450 reductase

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a neurotoxin that produces Parkinsonism symptoms in man, has been examined as a substrate of recombinant human cytochrome P450 2D6. When cumene hydroperoxide is used as an oxygen and electron donor, a single product is formed, identified as 4-phenyl-1,2,3,6-tetrahydropyridine. The K(m) for formation of this product (130 microM) is in agreement with the dissociation constants for MPTP binding to the enzyme determined by optical and nuclear magnetic resonance (NMR) spectroscopy. When the reaction is carried out with nicotinamide adenine dinucleotide phosphate (reduced) (NADPH) and recombinant human NADPH-cytochrome P450 reductase, a second product, identified as 1-methyl-4-(4'-hydroxyphenyl)-1,2,3,6-tetrahydropyridine, is formed in addition to 4-phenyl-1,2,3,6-tetrahydropyridine. The K(m) values for formation of these two products are 19 microM and 120 microM, respectively. Paramagnetic relaxation experiments have been used to measure distances between the protons of bound MPTP and the heme iron, and these have been used to construct models for the position and orientation of MPTP in the active site. For the cytochrome alone, a single mode of binding was observed, with the N-methyl close to the heme iron in a position appropriate for the observed N-demethylation reaction. In the presence of the reductase, the data were not consistent with a single mode of binding but could be explained by the existence of two alternative orientations of MPTP in the active site. One of these, characterized by a dissociation constant of 150 microM, is essentially identical to that observed in the absence of the reductase. In the second, which has a K(d) of 25 microM, the MPTP is oriented so that the aromatic ring is close to the heme iron, in a position appropriate for p-hydroxylation leading to the formation of the product seen only in the presence of the reductase. In the case of codeine, another substrate for cytochrome P450 2D6, the addition of reductase had no effect on the nature of the product formed, the dissociation constant, or the orientation in the binding site. These observations show that NADPH-cytochrome P450 reductase has an allosteric effect on the active site of cytochrome P450 2D6 that affects the binding of some substrates but not others.     

Selection of serum deproteinization methods

Dentists are often called upon to perform painful procedures on children. This may present a management problem for the practitioner who is unfamiliar with accepted behavioural management techniques or prescribing analgesics for paediatric patients. This article will review techniques that may be used to guide a child patient's behaviour through painful procedures as well as addressing the need for post-operative analgesics in the paediatric population.     

The number and biodiversity of the parasites from small mammals in the evacuation area of the Chernobyl Nuclear Power Station

The study of the micromammalian parasite complexes in the Belorussian part of the evacuation zone of the Chernobyl nuclear station revealed 13 species of Coccidia and 30 species of ectoparasitic Arthropoda. Total increase of abundance and biodiversity of both parasites and their hosts was observed. The part of ectoparasites being epidemically hazardous was significantly increased. An analysis of a long-term dynamics of parasite abundance reveals their adaptation to new conditions in the Belorussia.     

The patterns of oxygen metabolism in the early posthemorrhagic period]

Investigated all links of oxygen homeostasis of patients in early period afterwards surgical stoppage gastro-intestinal bleeding and urgent intravascular volume replacement. Macrodelivery of oxygen (DO2) was reduced in two and more time in comparison with norm predominant in connection with anemia. In spite of the infringement of transport of oxygen through alveolar-capillary membrane (especially in patients with complications and death in early postoperative period), little affected of degree of hemoglobin saturation by oxygen. Despite decrease of erythrocyte zeta-potential, largely expressed in cases of lethal outcome, considerable infringement of passage through microcirculation vessels is fixed was not. The increase of degree of morbidity and anaerobic metabolism in early postoperative period was accompanied of hyperdynamic hemodynamic reaction. The increase of degree of morbidity was accompanied of increase oxygen deficit owing to infringement of oxidoreduction in fabries also.     

Enhancing effect of natural killer cell stimulatory factor (NKSF/interleukin-12) on cell-mediated cytotoxicity against tumor-derived and virus-infected cells

Natural killer cell stimulatory factor (NKSF) or interleukin-12 (IL-12) is a heterodimeric cytokine with pleiomorphic effects on T and NK cells, including induction of lymphokine production, mitogenesis, and enhancement of spontaneous cytotoxic activity. Similarly to IL-2, NKSF/IL-12 enhances NK cell-mediated cytotoxicity within a few hours and independently from induced proliferation. This effect is independent from other induced cytokines, because it is not prevented by antibodies neutralizing interferon (IFN)-alpha, IFN-beta, IFN-gamma, IL-2 or tumor necrosis factor (TNF)-alpha and, unlike the induction of IFN-gamma production by peripheral blood lymphocytes, it does not require HLA class II-positive accessory cells. Enhanced cytotoxicity is accompanied by morphologic changes in NK cells, including a significant increase in the number of cytoplasmic granules. In addition to the previously described ability to enhance the cytotoxic activity of NK cells against tumor-derived target cells, NKSF/IL-12 is also a potent stimulator of cytotoxicity against virus-infected cells, either fibroblasts acutely infected with herpes viruses or T cell lines chronically infected with human immunodeficiency virus-1. NK cell-mediated antibody-dependent cytotoxicity or anti-CD16 antibody-redirected lysis is not significantly enhanced by NKSF/IL-12. However, the ability of resting peripheral blood T cells to mediate anti-CD3 antibody-redirected lysis is enhanced by 18-h incubation with NKSF/IL-12, indicating that this lymphokine can modulate the cytotoxic capability of both NK and T cells.