Type-4 spinors: transmuting from Elko to single-helicity spinors

In this communication we briefly report an unexpected theoretical discovery which emerge from the mapping of Elko mass-dimension-one spinors into single helicity spinors. Such procedure unveils a class of spinor which is classified as type-4 spinor field within Lounesto classification. In this paper we explore the underlying physical and mathematical contents of the type-4 spinor.Comment: 9 pages, 0 figure

A family of thermostable fungal cellulases created by structure-guided recombination

SCHEMA structure-guided recombination of 3 fungal class II cellobiohydrolases (CBH II cellulases) has yielded a collection of highly thermostable CBH II chimeras. Twenty-three of 48 genes sampled from the 6,561 possible chimeric sequences were secreted by the Saccharomyces cerevisiae heterologous host in catalytically active form. Five of these chimeras have half-lives of thermal inactivation at 63°C that are greater than the most stable parent, CBH II enzyme from the thermophilic fungus Humicola insolens, which suggests that this chimera collection contains hundreds of highly stable cellulases. Twenty-five new sequences were designed based on mathematical modeling of the thermostabilities for the first set of chimeras. Ten of these sequences were expressed in active form; all 10 retained more activity than H. insolens CBH II after incubation at 63°C. The total of 15 validated thermostable CBH II enzymes have high sequence diversity, differing from their closest natural homologs at up to 63 amino acid positions. Selected purified thermostable chimeras hydrolyzed phosphoric acid swollen cellulose at temperatures 7 to 15°C higher than the parent enzymes. These chimeras also hydrolyzed as much or more cellulose than the parent CBH II enzymes in long-time cellulose hydrolysis assays and had pH/activity profiles as broad, or broader than, the parent enzymes. Generating this group of diverse, thermostable fungal CBH II chimeras is the first step in building an inventory of stable cellulases from which optimized enzyme mixtures for biomass conversion can be formulated

Phenotypic and molecular characterization of Phaseolus vulgaris plants from non-cryopreserved and cryopreserved seeds

The objective of this work was to evaluate if cryostorage of Phaseolus vulgaris L. seeds induced variations in regenerated plants at the phenotypic and molecular levels. A series of agricultural traits was measured on plants grown from control, non-cryopreserved and cryopreserved seeds, and the genetic stability of plants of the second generation was analysed at selected microsatellite loci. The phenotype of the second generation plants was evaluated as well. No statistically significant phenotypic differences were observed for the parameters measured, neither in the first nor in the second generations. Averaging both treatments, about 76% of the seeds had germinated 10 days after sowing. At harvest we recorded plants with about 73 cm in height, 13 stem internodes, 25 fruits, 103 grains and 4 grains per fruit. One hundred seeds weighted about 26 g. The genetic analyses performed on the second generation plants using six nuclear Simple Sequences Repeats (SSR) markers revealed no changes in microsatellite length between control and cryopreserved samples, implying that there was no effect of seed liquid nitrogen exposure on genome integrity. The phenotypic and molecular results reported here confirm that cryostorage is an efficient and reliable technique to conserve P. vulgaris seeds and regenerate true-to-type plants

New-generation biocompatible Ti-based metallic glass ribbons for flexible implants

We introduce five new biocompatible Ti-based metallic glass (MG) compositions with different metalloid and soft metal content for a synergistic improvement in corrosion properties. Without any potentially harmful elements such as Cu, Ni or Be, these novel alloys can eliminate the risk of inflammatory reaction when utilized for permanent medical implants. Excluding Cu, Ni or Be, which are essential for Ti-based bulk MG production, on the other hand, confines the glass-forming ability of novel alloys to a moderate level. In this study, toxic-element free MG alloys with significant metalloid (Si–Ge–B, 15–18 at.%) and minor soft element (Sn, 2–5 at.%) additions are produced in ribbon form using conventional single-roller melt spinning technique. Their glass-forming abilities and their structural and thermal properties are comparatively investigated using X-ray diffraction (XRD), synchrotron XRD and differential scanning calorimetry. Their corrosion resistance is ascertained in a biological solution to analyze their biocorrosion properties and compare them with other Ti-based bulk MGs along with energy dispersive X-ray. Ti60Zr20Si8Ge7B3Sn2 and Ti50Zr30Si8Ge7B3Sn2 MG ribbons present a higher pitting potential and passivation domain compared with other Ti-based MG alloys tested in similar conditions. Human mesenchymal stem cell metabolic activity and cytocompatibility tests confirm their outstanding cytocompatibility, outperforming Ti-Al6-V4

Xenoestrogens released from lacquer coatings in food cans

We present data showing that some foods preserved in lacquer-coated cans and the liquid in them may acquire estrogenic activity. Hormonal activity was measured using the E-screen bioassay. The biological activity of vegetables packed in cans was a result of plastic monomers used in manufacturing the containers. The plastic monomer bisphenol-A, identified by mass spectrometry, was found as a contaminant not only in the liquid of the preserved vegetables but also in water autoclaved in the cans. The amount of bisphenol-A in the extracts accounted for all the hormonal activity measured. Although the presence of other xenoestrogens cannot be ruled out, it is apparent that all estrogenic activity in these cans was due to bisphenol-A leached from the lacquer coating. The use of plastic in food-packaging materials may require closer scrutiny to determine whether epoxy resins and polycarbonates contribute to human exposure to xenoestrogens.This work was supported by grant 94/1551 from the Fondo de Investigaciones Sanitarias (FIS), Spanish Ministry of Health

Evaluation of the contribution of D9S1120 to anthropological studies in Native American populations

The D9S1120 locus exhibits a population-specific allele of 9 repeats (9RA) in all Native American and two Siberian populations currently studied, but it is absent in other worldwide populations. Although this feature has been used in anthropological genetic studies, its impact on the evaluation of the structure and genetic relations among Native American populations has been scarcely assessed. Consequently, the aim of this study was to evaluate the anthropological impact of D9S1120 when it was added to STR population datasets in Mexican Native American groups. We analyzed D9S1120 by PCR and capillary electrophoresis (CE) in 1117 unrelated individuals from 13 native groups from the north and west of Mexico. Additional worldwide populations previously studied with D9S1120 and/or 15 autosomal STRs (Identifier kit) were included for interpopulation analyses. We report statistical results of forensic importance for D9S1120. On average, the modal alleles were the Native American-specific allele 9RA (0.3254) and 16 (0.3362). Genetic distances between Native American and worldwide populations were estimated. When D9S1120 was included in the 15 STR population dataset, we observed improvements for admixture estimation in Mestizo populations and for representing congruent genetic relationships in dendrograms. Analysis of molecular variance (AMOVA) based on D9S1120 confirms that most of the genetic variability in the Mexican population is attributable to their Native American backgrounds, and allows the detection of significant intercontinental differentiation attributed to the exclusive presence of 9RA in America. Our findings demonstrate the contribution of D9S1120 to a better understanding of the genetic relationships and structure among Mexican Native groups.CONACYT (Consejo Nacional de Ciencia y Tecnología) (México)Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEinpres

CB6 87. Sustitución valvular aórtica en octogenarios

IntroducciónEn las últimas décadas, la población mayor de 80 años que requiere una cirugía por estenosis aórtica degenerativa ha aumentado sustancialmente.Material y métodosSe compararon los resultados a corto y medio plazo de la sustitución valvular aórtica convencional (SVAo) en estenosis aórtica degenerativa en pacientes mayores y menores de 80 años intervenidos en nuestro centro entre abril de 2004 y diciembre de 2008. Los predictores de mortalidad y eventos adversos mayores cardio y cerebrovasculares (MACCE) en el postoperatorio y el seguimiento se determinaron por análisis multivariante.ResultadosCuatrocientos cincuenta y un pacientes fueron incluidos; 94 (20,8%) eran mayores de 80 años. La cirugía cardíaca previa (odds ratio [OR]: 4,08; p=0,047), la insuficiencia renal (OR: 6,75; p < 0,001), la cirugía coronaria concomitante (OR: 2,57; p=0,034), el sexo femenino (OR: 2,49; p=0,047) y la hipertensión pulmonar grave (OR: 3,68; p=0,024) fueron predictores independientes de mortalidad hospitalaria. En el seguimiento, la edad (hazard ratio [HR]: 2,24; p=0,02), la vasculopatía periférica (HR: 5,1; p < 0,001) e hipertensión arterial (HTA) (HR: 5,2; p=0,025) fueron predictores independientes de mortalidad tardía. Sólo la vasculopatía periférica (HR: 3,55; p=0,014) e HTA (HR: 8,24; p=0,04) fueron predictores independientes de mortalidad cardíaca tardía. La insuficiencia renal (OR: 2,57; p=0,005), hipertensión pulmonar grave (OR: 3,49; p=0,005) y cirugía coronaria asociada (OR: 2,49; p=0,002) fueron predictores independientes de MACCE postoperatorios. Diabetes mellitus (HR: 2,03; p=0,033) y vasculopatía periférica (HR: 2,3; p=0,041) predijeron una mayor incidencia de MACCE en el seguimiento.ConclusionesLa edad mayor de 80 años no empeora el pronóstico a corto y medio plazo tras la SVAo por estenosis aórtica grave degenerativa