3,738 research outputs found

    Explicit computations of low lying eigenfunctions for the quantum trigonometric Calogero-Sutherland model related to the exceptional algebra E7

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    In the previous paper math-ph/0507015 we have studied the characters and Clebsch-Gordan series for the exceptional Lie algebra E7 by relating them to the quantum trigonometric Calogero-Sutherland Hamiltonian with coupling constant K=1. Now we extend that approach to the case of general K

    Generating functions and multiplicity formulas: the case of rank two simple Lie algebras

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    A procedure is described that makes use of the generating function of characters to obtain a new generating function HH giving the multiplicities of each weight in all the representations of a simple Lie algebra. The way to extract from HH explicit multiplicity formulas for particular weights is explained and the results corresponding to rank two simple Lie algebras shown

    Fabrication and Characterization of Multiband Solar Cells Based on Highly Mismatched Alloys

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    Multiband solar cells are one type of third generation photovoltaic devices in which an increase of the power conversion efficiency is achieved through the absorption of low energy photons while preserving a large band gap that determines the open circuit voltage. The ability to absorb photons from different parts of the solar spectrum originates from the presence of an intermediate energy band located within the band gap of the material. This intermediate band, acting as a stepping stone allows the absorption of low energy photons to transfer electrons from the valence band to the conduction band by a sequential two photons absorption process. It has been demonstrated that highly mismatched alloys offer a potential to be used as a model material system for practical realization of multiband solar cells. Dilute nitride GaAs1-xNx highly mismatched alloy with low mole fraction of N is a prototypical multiband semiconductor with a well-defined intermediate band. Currently, we are using chemical beam epitaxy to synthesize dilute nitride highly mismatched alloys. The materials are characterized by a variety of structural and optical methods to optimize their properties for multiband photovoltaic devices

    Antimicrobial resistance characteristics and fitness of Gram-negative fecal bacteria from volunteers treated with minocycline or amoxicillin.

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    A yearlong study was performed to examine the effect of antibiotic administration on the bacterial gut flora. Gram-negative facultative anaerobic bacteria were recovered from the feces of healthy adult volunteers administered amoxicillin, minocycline or placebo, and changes determined in antimicrobial resistance (AMR) gene carriage. Seventy percent of the 1039 facultative anaerobic isolates recovered were identified by MALDI-TOF as Escherichia coli. A microarray used to determine virulence and resistance gene carriage demonstrated that AMR genes were widespread in all administration groups, with the most common resistance genes being bla TEM, dfr, strB, tet(A), and tet(B). Following amoxicillin administration, an increase in the proportion of amoxicillin resistant E. coli and a three-fold increase in the levels of bla TEM gene carriage was observed, an effect not observed in the other two treatment groups. Detection of virulence genes, including stx1A, indicated not all E. coli were innocuous commensals. Approximately 150 E. coli collected from 6 participants were selected for pulse field gel electrophoresis (PFGE), and a subset used for characterisation of plasmids and Phenotypic Microarrays (PM). PFGE indicated some E. coli clones had persisted in volunteers for up to 1 year, while others were transient. Although there were no unique characteristics associated with plasmids from persistent or transient isolates, PM assays showed transient isolates had greater adaptability to a range of antiseptic biocides and tetracycline; characteristics which were lost in some, but not all persistent isolates. This study indicates healthy individuals carry bacteria harboring resistance to a variety of antibiotics and biocides in their intestinal tract. Antibiotic administration can have a temporary effect of selecting bacteria, showing co-resistance to multiple antibiotics, some of which can persist within the gut for up to 1 year

    <em>Theobroma genus</em>: Exploring the therapeutic potential of <em>T. grandiflorum</em> and <em>T. bicolor</em> in biomedicine

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    \ua9 2024 The Authors. The Amazon rainforest hosts a plethora of fruit-bearing plants, yet many remain untapped for commercial purposes. Among these, Theobroma genus stands out for its unique characteristics deeply rooted in culinary and traditional medicinal practices, significantly contributing to Amazonian biodiversity and cultural heritage. Particularly, T. cacao, the most renowned species, exhibits versatile applications owing to its health benefits, with distinct groups influencing cocoa quality. Similarly, T. bicolor, thriving in humid regions, has undergone domestication to yield pulp and seeds valuable in food and cosmetic industries. Meanwhile, T. grandiflorum, found across tropical regions of Central and South America, presents unique sensory profiles and fruit characteristics, making it a significant player in Amazonian agriculture. This review primarily aims to offer insights into the therapeutic potential of T. grandiflorum and T. bicolor, with comparisons to T. cacao, revealing a notable increase in publications concerning the physico-chemical and biological properties of these species in recent years. Specifically, the review examines their chemical composition, bioactive compounds, and methodologies for determination, with a focus on biological evaluations encompassing enzymatic, cellular, and animal tests, thereby shedding light on the medicinal properties of these species. Finally, future research perspectives, emphasising the utilisation of waste biomass and further exploration of these invaluable Amazonian resources, have been discussed

    Multifunctional Eu-doped NaGd(MoO4)(2) nanoparticles functionalized with poly(L-lysine) for optical and MRI imaging

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    A method for the synthesis of non-aggregated and highly uniform Eu3+ doped NaGd(MoO4)(2) nanoparticles is reported for the first time. The obtained particles present tetragonal structure, ellipsoidal shape and their size can be varied by adjusting the experimental synthesis parameters. These nanoparticles, which were coated with citrate anions and functionalised with PLL, have also been developed in order to improve their colloidal stability in physiological medium (2-(N-morpholino) ethanesulfonic acid, MES). A study of the luminescent dynamics of the samples as a function of the Eu doping level has been conducted in order to find the optimum nanophosphors, whose magnetic relaxivity and cell viability have also been evaluated for the first time for this system, in order to assess their suitability as multifunctional probes for optical (in vitro) and magnetic bioimaging applications

    Muscle transcriptome analysis reveals molecular pathways related to oxidative phosphorylation, antioxidant defense, fatness and growth in Mangalitsa and Moravka pigs

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    This work was aimed at evaluating loin transcriptome and metabolic pathway differences between the two main Serbian local pig breeds with divergent characteristics regarding muscle growth and fatness, as well as exploring nutrigenomic effects of tannin supplementation in Mangalitsa (MA) pigs. The study comprised 24 Mangalitsa and 10 Moravka (MO) males, which were kept under identical management conditions. Mangalitsa animals were divided in two nutritional groups (n = 12) receiving a standard (control) or tannin–supplemented diet (1.5%; MAT). Moravka pigs were fed the standard mixture. All animals were slaughtered at a similar age; 120 kg of average live weight (LW) and loin tissue was used for RNA‐seq analysis. Results showed 306 differentially expressed genes (DEGs) according to breed, enriched in genes involved in growth, lipid metabolism, protein metabolism and muscle development, such as PDK4, FABP4, MYOD1 and STAT3, as well as a relevant number of genes involved in mitochondrial respiratory activity (MT‐NDs, NDUFAs among others). Oxidative phosphorylation was the most significantly affected pathway, activated in Mangalitsa muscle, revealing the basis of a different muscle metabolism. Also, many other relevant pathways were affected by breed and involved in oxidative stress response, fat accumulation and development of skeletal muscle. Results also allowed the identification of potential regulators and causal networks such as those controlled by FLCN, PPARGC1A or PRKAB1 with relevant regulatory roles on DEGs involved in mitochondrial and lipid metabolism, or IL3 and TRAF2 potentially controlling DEGs involved in muscle development. The Tannin effect on transcriptome was small, with only 23 DEGs, but included interesting ones involved in lipid deposition such as PPARGC1B. The results indicate a significant effect of the breed on muscle tissue gene expression, affecting relevant biological pathways and allowing the identification of strong regulatory candidate genes to underlie the gene expression and phenotypic differences between the compared groups

    Replication, Pathogenesis and Transmission of Pandemic (H1N1) 2009 Virus in Non-Immune Pigs

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    The declaration of the human influenza A pandemic (H1N1) 2009 (H1N1/09) raised important questions, including origin and host range [1,2]. Two of the three pandemics in the last century resulted in the spread of virus to pigs (H1N1, 1918; H3N2, 1968) with subsequent independent establishment and evolution within swine worldwide [3]. A key public and veterinary health consideration in the context of the evolving pandemic is whether the H1N1/09 virus could become established in pig populations [4]. We performed an infection and transmission study in pigs with A/California/07/09. In combination, clinical, pathological, modified influenza A matrix gene real time RT-PCR and viral genomic analyses have shown that infection results in the induction of clinical signs, viral pathogenesis restricted to the respiratory tract, infection dynamics consistent with endemic strains of influenza A in pigs, virus transmissibility between pigs and virus-host adaptation events. Our results demonstrate that extant H1N1/09 is fully capable of becoming established in global pig populations. We also show the roles of viral receptor specificity in both transmission and tissue tropism. Remarkably, following direct inoculation of pigs with virus quasispecies differing by amino acid substitutions in the haemagglutinin receptor-binding site, only virus with aspartic acid at position 225 (225D) was detected in nasal secretions of contact infected pigs. In contrast, in lower respiratory tract samples from directly inoculated pigs, with clearly demonstrable pulmonary pathology, there was apparent selection of a virus variant with glycine (225G). These findings provide potential clues to the existence and biological significance of viral receptor-binding variants with 225D and 225G during the 1918 pandemic [5]

    A selective metasurface absorber with an amorphous carbon interlayer for solar thermal applications

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordData availability: Data shown in this paper is accessible via the University of Bristol data repository: 10.5523/bris.11twobtdyxfs1ib2fxhlvn107This paper presents fabrication, measurement and modelling results for a metal-dielectric-metal metasurface absorber for solar thermal applications. The structure uses amorphous carbon as an inter-layer between thin gold films with the upper film patterned with a 2D periodic array using focused ion beam etching. The patterned has been optimised to give high absorptance from 400-1200nm and low absorptance above this wavelength range to minimise thermal radiation and hence obtain higher temperature performance. Wide angle absorptance results are shown and detailed modelling of a realistic nanostructured upper layer results in excellent agreement between measured and modelled results. The use of gold in this paper is a first step towards a high temperature metasurface where gold can be replaced by other refractory metals such as tungsten or chrome.Engineering and Physical Sciences Research Council (EPSRC
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