Development of a Novel Nanoarchitecture of the Robust Photosystem I from a Volcanic Microalga Cyanidioschyzon merolae on Single Layer Graphene for Improved Photocurrent Generation

Here, we report the development of a novel photoactive biomolecular nanoarchitecture based on the genetically engineered extremophilic photosystem I (PSI) biophotocatalyst interfaced with a single layer graphene via pyrene-nitrilotriacetic acid self-assembled monolayer (SAM). For the oriented and stable immobilization of the PSI biophotocatalyst, an His₆-tag was genetically engineered at the N-terminus of the stromal PsaD subunit of PSI, allowing for the preferential binding of this photoactive complex with its reducing side towards the graphene monolayer. This approach yielded a novel robust and ordered nanoarchitecture designed to generate an efficient direct electron transfer pathway between graphene, the metal redox center in the organic SAM and the photo-oxidized PSI biocatalyst. The nanosystem yielded an overall current output of 16.5 µA·cm⁻² for the nickel- and 17.3 µA·cm⁻² for the cobalt-based nanoassemblies, and was stable for at least 1 h of continuous standard illumination. The novel green nanosystem described in this work carries the high potential for future applications due to its robustness, highly ordered and simple architecture characterized by the high biophotocatalyst loading as well as simplicity of manufacturing.     

Binding capacity of brown pigments present in special Spanish sweet wines

Some special Spanish sweet wines are obtained by addition of a sweetening and coloring agent called grape syrup, which is obtained by heating must to give a dark and highly caramelised liquid, with similar consistency than other syrups. The aim of this work was to establish the influence of the addition of boiled must or “grape syrup” on the aroma and colour of sweet wines focussing specially on the possible binding effect on volatile compounds. The influence of must polyphenols was also studied, so, a wine sweetened with a “grape syrup” free of polyphenols was also elaborated. As it was expected, the addition of grape syrups gave an increase in the levels of furfural related compounds, and sweet wines showed lower concentrations of terpenes, ethyl esters, organic acids and acetates of alcohols than the control wine. The capacity of brown polymers present in grape syrups to bind these volatile compounds is discussed. Furthermore, colour parameters were also studied and significant differences were found for all of them between sweet wines and control wine.     

Hexabromocyclododecanes in indoor dust from Canada, the United Kingdom, and the United States

alpha-, beta-, and gamma-hexabromocyclododecane diastereomers (HBCDs) were measured in house dust from Birmingham, U.K. (n=31, median concentration=730 ng sigmaHBCDs g(-1)); Amarillo/Austin, TX (n=13, 390 ng g(-1)); and Toronto, Canada (n=8, 640 ng g(-1)). Concentrations in dust (n=6, 650 ng g(-1)) from U.K. offices were within the range for UK homes. Concentrations from each country were statistically indistinguishable. In one UK house dust sample, 110,000 ng g(-1) was recorded-the highest recorded in indoor dust to date. While upper bound average U.K. dietary exposures for adults and toddlers, respectively, are 413 and 240 ng sigmaHBCDs day(-1), U.K. adults and toddlers daily ingesting, respectively, 50 and 200 mg of dust contaminated at the 95th percentile concentration are exposed, respectively, to 1100 and 4400 ng sigmaHBCDs day(-1). Normalized to body weight, this high-end exposure scenario estimate for toddlers is within the range reported elsewhere for occupationally exposed adults. While in commercial formulations gamma-HBCD predominates (>80%), alpha-HBCD in dust constitutes 14-67% of sigmaHBCDs (average 32%). Hence the predominance of the alpha-diastereomer in humans may arise partly from dust ingestion, and not solely to in vivo metabolism (when alpha-HBCD is formed from bioisomerization of other diastereomers), or dietary exposure (where alpha-HBCD predominates in most foodstuffs).     

Detection and identification of Lactobacillus helveticus bacteriophages by PCR

A PCR protocol for detection of Lactobacillus helveticus bacteriophages was optimized. PCR was designed taking into account the sequence of the lys gene of temperate bacteriophage Phi-0303 and optimized to obtain a fragment of 222 bp using different Lb. helveticus phages from our collection. PCR was applied to total phage DNA extracted from 53 natural whey starters used for the production of Grana cheese and all gave the expected fragment. The presence of actively growing phages in the cultures was verified by traditional tests. Several PCR products of the lys gene were sequenced and aligned. The resulting sequences showed variable heterogeneity between the phages.     

Characterisation of lactic acid bacteria isolated from the Georgian,yoghurt‐like Matsoni

Matsoni is a traditional Caucasian fermented milk product, characterised by a lactic acid bacteria (LAB) microbiota. Objectives of the present study were to isolate and identify the LAB of Matsoni samples collected from various Georgian areas and to study their technological characteristics. About 300 LAB from 71 samples of Matsoni were isolated and characterised. The species most representatives were Lactobacillus delbrueckii, Streptococcus thermophilus and Lactobacillus rhamnosus. This study highlighted a high degree of biodiversity and a specific geographical distribution of the dominant LAB present in artisanal Matsoni. Some strains showed technological features useful to design a multistrain starter culture for Matsoni.     

Selection of Streptococcus thermophilus strains able to produce exopolysaccharides in milk

A collection of 139 Streptococcus thermophilus strains was genetically screened by PCR targeting some genes involved in exopolysaccharide (EPS) biosynthesis. Twenty‐nine strains were found to be PCR positive and were grown in skim milk to highlight their ropy character, that is the ability to efficiently thicken the milk cultures and minimise syneresis. Three strains producing a skim milk culture with apparent viscosities of 275 ± 14, 340 ± 21 and 510 ± 42 mPa.s, significantly higher than the average value (135 ± 87.3 mPa.s), were selected. EPS from milk cultures of these three strains was extracted and quantified from 84.4 to 209.2 mg/L.     

Determination of Over 350 Multiclass Pesticides in Jams by Ultra-High Performance Liquid Chromatography Time-of-Flight Mass Spectrometry (UHPLC-TOFMS)

In this study, a screening method was developed using ultra-high performance liquid chromatography time-of-flight mass spectrometry (UHPLC-TOFMS) for multiclass pesticide analysis in jam samples. The method was based on an experimental database with retention time/accurate mass data for the 353 selected analytes. Compound identification was based on retention time and the accurate mass measurements of the protonated molecules. The limits of detection were below 10 μg kg^?1 for 90 % of the studied compounds. The proposed method was successfully applied to evaluate the presence and concentration levels of over 350 multiclass pesticides in a total of 54 jam market samples collected in Spain from different companies. Results found were in compliance with the current regulations with the exception of a sample, which contained monocrotophos. Forty-one percent of the samples were found free of pesticides; 26 % of the samples contained only one pesticide while 33 % contained at least two or more pesticides.     

Patterns of adolescents' participation in organized activities: Are sports best when combined with other activities?

Although many adolescents participate in sports and other types of organized activities, little extant research explores how youth development outcomes may vary for youth involved in different combinations of activities. The present study uses the Child Development Supplement of the Panel Study of Income Dynamics, a large, nationally representative sample, to compare activity patterns of adolescents ages 10–18 years (n = 1,711). A cluster analytic technique revealed 5 activity clusters: sports-focused, sports plus other activities, primarily school-based activities, primarily religious youth groups, and low activity involvement. Activity patterns were examined in conjunction with 5 categories of youth development outcomes, including competence (e.g., academic ability), confidence (e.g., self-concept of ability), connections (e.g., talking with friends), character (e.g., externalizing behavior problems), and caring (e.g., prosocial behavior). Results showed that those who participated only in sports had more positive outcomes compared with those who had little or no involvement in organized activities, but less positive outcomes compared with those who participated in sports plus other activities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aquaporin-4 Mediates Permanent Brain Alterations in a Mouse Model of Hypoxia-Aged Hydrocephalus

Aquaporin-4 (AQP4) is the principal water channel in the brain being expressed in astrocytes and ependymal cells. AQP4 plays an important role in cerebrospinal fluid (CSF) homeostasis, and alterations in its expression have been associated with hydrocephalus. AQP4 contributes to the development of hydrocephalus by hypoxia in aged mice, reproducing such principal characteristics of the disease. Here, we explore whether these alterations associated with the hydrocephalic state are permanent or can be reverted by reexposure to normoxia. Alterations such as ventriculomegaly, elevated intracranial pressure, and cognitive deficits were reversed, whereas deficits in CSF outflow and ventricular distensibility were not recovered, remaining impaired even one month after reestablishment of normoxia. Interestingly, in AQP4^−/− mice, the impairment in CSF drainage and ventricular distensibility was completely reverted by re-normoxia, indicating that AQP4 has a structural role in the chronification of those alterations. Finally, we show that aged mice subjected to two hypoxic episodes experience permanent ventriculomegaly. These data reveal that repetitive hypoxic events in aged cerebral tissue promote the permanent alterations involved in hydrocephalic pathophysiology, which are dependent on AQP4 expression.