Additional observations on the social perceptions of authoritarians and nonauthoritarians.

The perceptions of authoritarians (highs) by other authoritarians and nonauthoritarians (lows) by other nonauthoritarians are investigated by placing 12 pairs of highs and 12 pairs of lows in a social situation and instructing them to discuss the neutral topics of radio, television, and the movies. Each S had previously responded to the F scale along with some buffer MMPI items. After the discussion was completed, each S was again given the questionnaire, but was instructed to respond to it as he felt his partner would answer it. The combined data of this, and a previous study show that highs tend to estimate peers as having high attitudes, whether these peers are high or low. The estimates by lows of peers are less uniform than those of highs. The social perceptions of highs appear to be influenced by a "same-stereotype" while those of lows by an "other-stereotype." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Design of a Conformationally Rigid Hydrazide Organic Catalyst

Conformational control was utilized to design a hydrazide organocatalyst for asymmetric Diels–Alder reactions, thus introducing a new aspect to organocatalysis. Diastereoselectivities and enantioselectivities of up to 96 % were achieved by the application of the rigidified catalyst. The first crystal structure of a key iminium intermediate in an organocatalyzed process is also provided.     

Oxide films at the nanoscale: new structures, new functions, and new materials

We all make use of oxide ultrathin films, even if we are unaware of doing so. They are essential components of many common devices, such as mobile phones and laptops. The films in these ubiquitous electronics are composed of silicon dioxide, an unsurpassed material in the design of transistors. But oxide films at the nanoscale (typically just 10 nm or less in thickness) are integral to many other applications. In some cases, they form under normal reactive conditions and confer new properties to a material: one example is the corrosion protection of stainless steel, which is the result of a passive film. A new generation of devices for energy production and communications technology, such as ferroelectric ultrathin film capacitors, tunneling magnetoresistance sensors, solar energy materials, solid oxide fuel cells, and many others, are being specifically designed to exploit the unusual properties afforded by reduced oxide thickness. Oxide ultrathin films also have tremendous potential in chemistry, representing a rich new source of catalytic materials. About 20 years ago, researchers began to prepare model systems of truly heterogeneous catalysts based on thin oxide layers grown on single crystals of metal. Only recently, however, was it realized that these systems may behave quite differently from their corresponding bulk oxides. One of the phenomena uncovered is the occurrence of a spontaneous charge transfer from the metal support to an adsorbed species through the thin insulating layer (or vice versa). The importance of this property is clear: conceptually, the activation and bond breaking of adsorbed molecules begin with precisely the same process, electron transfer into an antibonding orbital. But electron transfer can also be harnessed to make a supported metal particle more chemically active, increase its adhesion energy, or change its shape. Most importantly, the basic principles underlying electron transfer and other phenomena (such as structural flexibility, electronic modifications, and nanoporosity) are now largely understood, thus paving the way for the rational design of new catalytic systems based on oxide ultrathin films. Many of the mechanisms involved (electron tunneling, work function changes, defects engineering, and so forth) are typical of semiconductor physics and allow a direct link between the two fields. A related conceptual framework, the "electronic theory of catalysis", was proposed a long time ago but has been largely neglected by the catalytic community. A renewed appreciation of this catalytic framework, together with spectacular advances in modeling and electronic structure methods, now makes it possible to combine theory with advanced experimental setups and meet the challenge of designing new materials with tailored properties. In this Account, we discuss some of the recent advances with nanoscale oxide films, highlighting contributions from our laboratory. Once mastered, ultrathin oxide films on metals will provide vast and unforeseen opportunities in heterogeneous catalysis as well as in other fields of science and technology.     

Hyperhomocysteinemia and polymorphisms of the methylenetetrahydrofolate gene in hemodialysis and peritoneal dialysis patients

Hyperhomocysteinemia has been documented in chronic renal failure (CRF). Premature as well as progressive occlusive vascular disease is common. Mutations or polymorphisms in the gene of the enzyme methylenetetrahydrofolate reductase (MTHFR), as C677T, A1298C and G1793A, are associated with hyperhomocysteinemia and possibly with elevated risk for vascular diseases. This study was conducted on 89 individuals with renal failure on dialysis to determine the allelic and genotypic frequencies of the mutations in the MTHFR gene and hyperhomocysteinemia. Blood samples were colleted for determination of homocysteine and DNA. The C677T, A1298C and G1793A mutations were detected. This study confirmed the high prevalence of hyperhomocysteinemia in patients on dialysis, which was diagnosed in 76 patients (85.39%) and high incidence of the C677T and A1298C mutation, 42 (47.19%) and 29 (32.58%) patients, respectively. Five patients (5.62%) presented the G1793A mutation and hyperhomocysteinemia. The authors concluded that there was no influence of the polymorphisms on homocysteine levels in these patients.     

Immunolocalization of S100-like protein in the brain of an emerging model organism: Nothobranchius furzeri

The S100 protein in nervous tissue appears to play important roles in regulating neuronal differentiation, glial proliferation, plasticity, development, axonal growth, and in neurogenetic processes. In fish, the adult neurogenic activity is much higher than in mammals. In this study, the localization of S100 protein was investigated in the brain of annual teleost fish, Nothobranchius furzeri, which is an emerging model organism for aging research. By immunohistochemical techniques, S100 immunoreactivity (IR) was detected in glial cells, small neurons, and fibers throughout all regions of central nervous system (CNS) with different pattern of distribution. In the telencephalon, S100 IR was seen in the olfactory bulbs and in different areas of the telencephalic hemispheres. In the diencephalon, S100 positivity was observed in the habenular nuclei of the epithalamus, in the cortical thalamic nucleus, in the dorsal, ventral and caudal portions, the latter with the posterior recessus nucleus, and in the diffuse inferior lobe of the hypothalamus, along the diencephalic ventricle and in the dorsal optic tract. In the mesencephalon, S100 IR was observed in the longitudinal tori, in the optic tectum, and along the mesencephalic ventricle. In the rhombencephalon, S100 IR was shown in valvula and body of the cerebellum, and in some nuclei of the medulla oblongata. The results suggest that S100 may play a key role in the maintenance of the CNS and in neurogenesis processes in the adulthood.     

Biogenic amines and microbial quality of sprouts

Changes in the biogenic amine content relative to microbial activities in mung bean, lentil and radish sprouts were investigated in prepacked and homegrown products. Biogenic amines were determined by ion-exchange chromatography. The major groups of micro-organisms were enumerated by aerobic plate count procedures, using universal and selective media. Putrescine, cadaverine, spermidine, agmatine and spermine were detected in different concentrations, depending on the type of sprouts. In prepacked retail products the total biogenic amine content was higher than in home-grown samples (mung bean 106 g/g compared to 87 g/g; lentil 316 g/g compared to 181 g/g; radish 1486 g/g compared to 252 g/g). It is concluded that sprouting time and storage conditions play a major part in the hygienic quality of legume sprouts.

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Gehalt an biogenen Aminen und mikrobiologische Qualität von Keimlingen

Zusammenfassung Der Gehalt an biogenen Aminen in Mungbohnen-, Linsen- und Rettichkeimlingen in Abhängigkeit von der mikrobiellen Belastung wurde an vorverpackten Produkten des Einzelhandels und hausgezogenen Keimlingen untersucht. Die biogenen Amine wurden mit Hilfe der Ionenaustauschchromatographie, die Mikroorganismen auf universellen und selektiven Medien bestimmt. Die Konzentrationen von Putrescin, Cadaverin, Spermidin, Agmatin und Spermin waren je nach Art der Keimlinge unterschiedlich hoch. In vorverpackten Produkten aus dem Einzelhandel war der Gesamtgehalt an biogenen Aminen höher als in hausgezogenen Keimlingen (Mungbohnen: 106 bzw. 87 g/g; Linsen: 316 bzw. 181 g/g; Rettich: 1486 bzw. 252 g/g). Keimdauer und Lagerungsbedingungen beeinflussen die hygienische Qualität von Keimlingen deutlich.

     

Determination of biogenic amines in leafy vegetables by amino acid analyser

An automated ion-exchange Chromatographic method is described for determination of biogenic amines in leafy vegetables using a cation-exchange resin column in potassium form and a three-buffer system. The following amines were separated and quantified for Chinese cabbage, endive, iceberg lettuce and radiocchio: putrescine, histamine, cadaverine, spermidine, agmatine, spermine, tyramine. Amines from vegetable samples were extracted with 10% trichloroacetic acid. The total concentration of these amines ranged from 14 to 20 g/g fresh weight. Spermidine was the major polyamine detected, present at concentrations of 7–15 g/g fresh weight.

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Bestimmung biogener Amine in Blattgemüse mit dem Aminosäureanalysator

Zusammenfassung Es wird eine Methode zur Bestimmung biogener Amine in Blattgemüse mittels automatisierter Ionenaustausch-Chromatographie beschrieben. Die Trennung erfolgte auf einer K⁺-Kationenaustauschersäule mit Hilfe eines Drei-Puffer-Systems. In Chinakohl, Endivie, Eisbergsalat und Radicchio sind folgende Amine bestimmt worden: Putrescin, Histamin, Cadaverin, Spermidin, Agmatin, Spermin und Tyramin. Die Extraktion erfolgte mit 10% Trichloressigsäure. Die Gesamtkonzentration biogener Amine betrug 14–20 g/ g Frischsubstanz. Von den nachgewiesenen Polyaminen war Spermidin mit einer Konzentration von 7–15 g Frischsubstanz am stärksten vertreten.

     

Mutations in the nucleotide-binding domain of putative sterol importers Aus1 and Pdr11 selectively affect utilization of exogenous sterol species in yeast

Sterol uptake in the yeast Saccharomyces cerevisiae is mediated by two plasma membrane ATP-binding cassette transporters, Aus1 and Pdr11. Their expression is regulated by oxygen and is triggered by anaerobic growth conditions. Under these conditions, internal ergosterol synthesis is arrested and utilization of exogenous sterol is vital for yeast cells. Here, we demonstrate that Aus1 is the major importer of non–yeast sterols, mammalian cholesterol, and plant sterols under anaerobic conditions. In contrast, uptake of yeast native sterol, ergosterol, is relatively low. This uptake could not be enhanced by overexpression of either of the transporters. Interestingly, overexpression of the minor importer Pdr11 resulted in a substantial import of non–yeast sterols. We show that mutation of the conserved residue in one of the ABC characteristic motifs—the H-loop in Aus1 and Pdr11—lowered their ATPase activity. The residual activity was sufficient to import exogenous sterols and to preserve cell viability. Importantly, the reduction of sterol import was dramatic for mammalian cholesterol and plant sterols, whereas import of yeast ergosterol was decreased only slightly indicating substrate selectivity of the sterol utilization process.     

Biocompatibility evaluation of a novel hydroxyapatite-polymer coating for medical implants (in vitro tests)

Nanocomposites consisting of hydroxyapatite (HA) and a sodium maleate copolymer (maleic polyelectrolyte), synthesized by hydrothermal method and deposited on titanium substrates by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique were tested for the biological properties. Coating bioanalysis was carried out by triple staining of actin, microtubules and nuclei followed by immunofluorescence microscopy. Within 24 h cells that occupied the biomaterial surface displayed the morphology and cytoskeleton pattern similar to the controls. Cells grown on nanocomposite coated surfaces had a higher proliferation rate than their counterparts grown on Ti coated with HA alone, indicating that maleic polyelectrolyte improved surface bio-adhesive characteristics. The capacity to induce cell attachment, spreading and proliferation demonstrated the potential of Ti coated with HA-polymer nanocomposites to be used as scaffolds in dental or orthopedic implantology.     

Assessment of wastewater reuse potential for irrigation in rural semi-arid areas: the case study of Punitaqui,Chile

Clean Technologies and Environmental Policy - Wastewater reuse in agriculture has been identified as an adaptive solution to climate change. This practice copes with two of the most limiting...