Oxidative stress in asthmatic and non-asthmatic adolescent swimmers - a breathomics approach

We hypothesize that oxidative stress induced by trichloramine exposure during swimming could be related to etiopathogenesis of asthma among elite swimmers. Aim: To investigate the effect of a swimming training session on oxidative stress markers of asthmatic compared to non‐asthmatic elite swimmers using exhaled breath (EB) metabolomics. Methods: Elite swimmers annually screened in our department (n=27) were invited and those who agreed to participate (n=20, of which 9 with asthma) had EB collected (Tedlar® bags) before and after a swimming training session. SPME fiber (DVB/CAR/PDMS) was used to extract EB metabolites followed by a multidimensional gas chromatography analysis (GC×GC‐ToFMS). Dataset comprises eight metabolites end products of lipid peroxidation: five aliphatic alkanes (nonane, 2,2,4,6,6‐pentamethylheptane, decane, dodecane, and tetradecane) and three aldehydes (nonanal, decanal, and dodecanal). To assess exercise impact on lipid peroxidation markers, data were analyzed using principle component analysis (PCA), which was run on the original data set and on the data set constructed using differences in the metabolite total areas before and after exercise session. Results: Heatmap representation revealed that metabolites content decreased after exercise, both for control and asthma groups; however, the greater decrease was observed for controls. Asthmatics and controls did not form separated clusters; however, control swimmers demonstrated a more varied response to the exercise being dispersed along all score plot. Conclusion: In well‐trained athletes, swimming is associated with a decrease in oxidative stress markers independently of the presence of asthma, although a more pronounced decrease was seen in controls.European Regional Development Fund FEDER through the Competitive Factors Thematic Operational Programme (COMPETE) and FCT, Portugal, under projects PEST-C/QUI/UI0062/2013 (Research Unit 62/94 QOPNA) and PTDC/QUI-QUI/117803/2010

Experimental and process modelling investigation of the hydrogen generation from formic acid decomposition using a pd/zn catalyst

The use of hydrogen as a renewable fuel has attracted great attention in recent years. The decomposition of formic acid under mild conditions was investigated using a 2%Pd6Zn4 catalyst in a batch reactor. The results showed that the conversion of formic acid increases with reaction temperature and with the formic acid concentration. A process-simulation model was developed to predict the decomposition of formic acid using 2%Pd6Zn4 in a batch reactor. The model demonstrated very good validation with the experimental work. Further comparisons between the 2%Pd6Zn4 catalyst and a commercial Pd/C catalyst were carried out. It was found that the 2%Pd6Zn4 demonstrated significantly higher conversions when compared with the commercial catalyst

Automated data analysis to rapidly derive and communicate ecological insights from satellite-tag data: A case study of reintroduced red kites

Analysis of satellite-telemetry data mostly occurs long after it has been collected, due to the time and effort needed to collate and interpret such material. Such delayed reporting does reduce the usefulness of such data for nature conservation when timely information about animal movements is required. To counter this problem we present a novel approach which combines automated analysis of satellite-telemetry data with rapid communication of insights derived from such data. A relatively simple algorithm (comprising speed of movement and turning angle calculated from fixes), allowed instantaneous detection of excursions away from settlement areas and automated calculation of home ranges on the remaining data Automating the detection of both excursions and home range calculations enabled us to disseminate ecological insights from satellite-tag data instantaneously through a dedicated web portal to inform conservationists and wider audiences. We recommend automated analysis, interpretation and communication of satellite tag and other ecological data to advance nature conservation research and practice

Facile Synthesis of High Quality Graphene Nanoribbons

Graphene nanoribbons have attracted attention for their novel electronic and spin transport properties1-6, and because nanoribbons less than 10 nm wide have a band gap that can be used to make field effect transistors. However, producing nanoribbons of very high quality, or in high volumes, remains a challenge. Here, we show that pristine few-layer nanoribbons can be produced by unzipping mildly gas-phase oxidized multiwalled carbon nanotube using mechanical sonication in an organic solvent. The nanoribbons exhibit very high quality, with smooth edges (as seen by high-resolution transmission electron microscopy), low ratios of disorder to graphitic Raman bands, and the highest electrical conductance and mobility reported to date (up to 5e2/h and 1500 cm2/Vs for ribbons 10-20 nm in width). Further, at low temperature, the nanoribbons exhibit phase coherent transport and Fabry-Perot interference, suggesting minimal defects and edge roughness. The yield of nanoribbons was ~2% of the starting raw nanotube soot material, which was significantly higher than previous methods capable of producing high quality narrow nanoribbons1. The relatively high yield synthesis of pristine graphene nanoribbons will make these materials easily accessible for a wide range of fundamental and practical applications.Comment: Nature Nanotechnology in pres

Typing of Salmonella Typhi strains isolated from Egypt by RAPD PCR

PCR-based fingerprinting using random amplified polymorphic DNA (RAPD) has been used widely for genome identification. In this study, 13 Salmonella Typhi strains were isolated from typhoid patients from Aswan, Cairo, Fayoum, and Monofya Governorates of Egypt. The isolates, along with three reference strains, i.e., O901, H901, and Ty2 were subjected to whole genome typing by RAPD PCR. Three RAPD-PCR 10-mer primers generated a total of 85 RAPD bands (81 polymorphic bands), 12 distinct PCR profiles, and proved to be useful for discriminating the isolates and strains studied. Interestingly, the B1 and C1 PCR profile were found only in Cairo and Monofya, respectively; and some PCR types appeared only in certain Governorates of Egypt. By combining the profiles obtained with the primer trio used in this study, an excellent discrimination index (D) of 0.942 was reached. Pairwise comparisons of Jaccard’s similarity coefficients calculated among the 12 PCR types identified three major clusters; i.e., O901 branch and Ty2 and H901 sub-branches. Principal component analysis adequately resolved each of these three major clusters. Three principal components accounted for about 72% of the variation, with the first two components accounting for about 62% of the total variance among the genotypes studied. Biclustering improved the display of groups of RAPD amplicons (markers) that cluster similarly across the genomes and could delineate features pertaining to genome structure. In conclusion, RAPD PCR provided a fast method with high potentials in surveillance and epidemiological investigations of Salmonella Typhi infections

Information content and reward processing in the human striatum during performance of a declarative memory task

Negative feedback can signal poor performance, but it also provides information that can help learners reach the goal of task mastery. The primary aim of this study was to test the hypothesis that the amount of information provided by negative feedback during a paired-associate learning task influences feedback-related processing in the caudate nucleus. To do this, we manipulated the number of response options: With two options, positive and negative feedback provide equal amounts of information, whereas with four options, positive feedback provides more information than does negative feedback. We found that positive and negative feedback activated the caudate similarly when there were two response options. With four options, the caudate’s response to negative feedback was reduced. A secondary goal was to investigate the link between brain-based measures of feedback-related processing and behavioral indices of learning. Analysis of the posttest measures showed that trials with positive feedback were associated with higher posttest confidence ratings. Additionally, when positive feedback was delivered, caudate activity was greater for trials with high than with low posttest confidence. This experiment demonstrated the context sensitivity of feedback processing and provided evidence that feedback processing in the striatum can contribute to the strengthening of the representations available within declarative memory

VIP Enhances Phagocytosis of Fibrillar Beta-Amyloid by Microglia and Attenuates Amyloid Deposition in the Brain of APP/PS1 Mice

Vasoactive intestinal peptide (VIP) is a multifunctional neuropeptide with demonstrated immunosuppressive and neuroprotective activities. It has been shown to inhibit Amyloid beta (Aβ)-induced neurodegeneration by indirectly suppressing the production and release of a variety of inflammatory and neurotoxic factors by activated microglia. We demonstrated that VIP markedly increased microglial phagocytosis of fibrillar Aβ42 and that this enhanced phagocytotic activity depended on activation of the Protein kinase C (PKC) signaling pathway. In addition, VIP suppressed the release of tumor necrosis factor alpha (TNF-α) and nitric oxide(NO) from microglia activated by combined treatment with fibrillar Aβ42 and low dose interferon-γ (IFN-γ). We utilized an adenovirus-mediated gene delivery method to overexpress VIP constitutively in the hippocampus of APPswPS1 transgenic mice. The Aβ load was significantly reduced in the hippocampus of this animal model of Alzheimer's disease, possibly due to the accumulation and activation of cd11b-immunoactive microglial cells. The modulation of microglial activation, phagocytosis, and secretion by VIP is a promising therapeutic option for the treatment of Alzheimer's disease(AD)

The many faces of nitric oxide: cytotoxic, cytoprotective or both

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74882/1/j.1365-2982.2007.00958.x.pd