523 research outputs found
A virtual reality game to promote the role of a healthy diet in male reproduction
This paper presents gaming as an alternative way of transmitting information compared to traditional academic methods. New technologies provide an opportunity, and in particular,
virtual reality gaming allows users to have an immersive, personifying, intuitive, and engaging experience useful in visualizing complex concepts. Questionnaires were administered
to secondary school students to extrapolate relevant information regarding the role of diet on sperm quality following the experience of the virtual reality game “Oxistress.” This game allows participants to understand in a playful and recreational way how the presence of reactive oxygen species can damage spermatozoa and how adequate diet choices provide ammunition in the form of antioxidants and omega-3 fatty acids to protect and repair spermatozoa. The results suggest that virtual reality (VR) may represent an important way to improve knowledge of scientific topics. Further studies will be necessary, involving larger popula
tions with different basic knowledge as well as checks on whether the information acquired remains in memory after months
A Virtual Reality Game to Promote the Role of a Healthy Diet in Male Reproduction
This paper presents gaming as an alternative way of transmitting information compared to traditional academic methods. New technologies provide an opportunity, and in particular, virtual reality gaming allows users to have an immersive, personifying, intuitive, and engaging experience useful in visualizing complex concepts. Questionnaires were administered to secondary school students to extrapolate relevant information regarding the role of diet on sperm quality following the experience of the virtual reality game “Oxistress.” This game allows participants to understand in a playful and recreational way how the presence of reactive oxygen species can damage spermatozoa and how adequate diet choices provide ammunition in the form of antioxidants and omega-3 fatty acids to protect and repair spermatozoa. The results suggest that virtual reality (VR) may represent an important way to improve knowledge of scientific topics. Further studies will be necessary, involving larger populations with different basic knowledge as well as checks on whether the information acquired remains in memory after months
Selecting soluble/foldable protein domains through single-gene or genomic ORF filtering: structure of the head domain of Burkholderia pseudomallei antigen BPSL2063
The 1.8\u2005\uc5 resolution crystal structure of a conserved domain of the potential Burkholderia pseudomallei antigen and trimeric autotransporter BPSL2063 is presented as a structural vaccinology target for melioidosis vaccine development. Since BPSL2063 (1090 amino acids) hosts only one conserved domain, and the expression/purification of the full-length protein proved to be problematic, a domain-filtering library was generated using \u3b2-lactamase as a reporter gene to select further BPSL2063 domains. As a result, two domains (D1 and D2) were identified and produced in soluble form in Escherichia coli. Furthermore, as a general tool, a genomic open reading frame-filtering library from the B. pseudomallei genome was also constructed to facilitate the selection of domain boundaries from the entire ORFeome. Such an approach allowed the selection of three potential protein antigens that were also produced in soluble form. The results imply the further development of ORF-filtering methods as a tool in protein-based research to improve the selection and production of soluble proteins or domains for downstream applications such as X-ray crystallography
Boson-boson scattering and Higgs production at the LHC from a six fermion point of view: four jets + l processes at \O(\alpha_{em}^6)
Boson-boson scattering and Higgs production in boson-boson fusion hold the
key to electroweak symmetry breaking. In order to analyze these essential
features of the Standard Model we have performed a partonic level study of all
processes at the LHC using the exact matrix
elements at \O(\alpha_{em}^6) provided by \Phase, a new MC generator. These
processes include also three boson production and the purely electroweak
contribution to \toptop production as well as all irreducible backgrounds.
Kinematical cuts have been studied in order to enhance the VV scattering signal
over background. \Phase has been compared with different Monte Carlo's showing
that a complete calculation is necessary for a correct description of the
process.Comment: 26 pages, 19 figure
Glycosylation tunes neuroserpin physiological and pathological properties
Neuroserpin (NS) is a member of the serine protease inhibitors superfamily. Specific point
mutations are responsible for its accumulation in the endoplasmic reticulum of neurons that leads to
a pathological condition named familial encephalopathy with neuroserpin inclusion bodies (FENIB).
Wild-type NS presents two N-glycosylation chains and does not form polymers in vivo, while
non-glycosylated NS causes aberrant polymer accumulation in cell models. To date, all in vitro
studies have been conducted on bacterially expressed NS, de facto neglecting the role of glycosylation
in the biochemical properties of NS. Here, we report the expression and purification of human
glycosylated NS (gNS) using a novel eukaryotic expression system, LEXSY. Our results confirm the
correct N-glycosylation of wild-type gNS. The fold and stability of gNS are not altered compared
to bacterially expressed NS, as demonstrated by the circular dichroism and intrinsic tryptophan
fluorescence assays. Intriguingly, gNS displays a remarkably reduced polymerisation propensity
compared to non-glycosylated NS, in keeping with what was previously observed for wild-type NS
in vivo and in cell models. Thus, our results support the relevance of gNS as a new in vitro tool to
study the molecular bases of FENIB
A systematic study of the valence electronic structure of cyclo(Gly–Phe), cyclo(Trp–Tyr) and cyclo(Trp–Trp) dipeptides in the gas phase
The electronic energy levels of cyclo(glycine–phenylalanine), cyclo(tryptophan–tyrosine) and cyclo(tryptophan–tryptophan) dipeptides are investigated with a joint experimental and theoretical approach. Experimentally, valence photoelectron spectra in the gas phase are measured using VUV radiation. Theoretically, we first obtain low-energy conformers through an automated conformer–rotamer ensemble sampling scheme based on tight-binding simulations. Then, different first principles computational schemes are considered to simulate the spectra: Hartree–Fock (HF), density functional theory (DFT) within the B3LYP approximation, the quasi-particle GW correction, and the quantumchemistry CCSD method. Theory allows assignment of the main features of the spectra. A discussion on the role of electronic correlation is provided, by comparing computationally cheaper DFT scheme (and GW) results with the accurate CCSD method
Embelin binds to human neuroserpin and impairs its polymerisation
Neuroserpin (NS) is a serpin inhibitor of tissue plasminogen activator (tPA) in the brain. The polymerisation of NS pathologic mutants is responsible for a genetic dementia known as familial encephalopathy with neuroserpin inclusion bodies (FENIB). So far, a pharmacological treatment of FENIB, i.e. an inhibitor of NS polymerisation, remains an unmet challenge. Here, we present a biophysical characterisation of the effects caused by embelin (EMB a small natural compound) on NS conformers and NS polymerisation. EMB destabilises all known NS conformers, specifically binding to NS molecules with a 1:1 NS:EMB molar ratio without unfolding the NS fold. In particular, NS polymers disaggregate in the presence of EMB, and their formation is prevented. The NS/EMB complex does not inhibit tPA proteolytic activity. Both effects are pharmacologically relevant: firstly by inhibiting the NS polymerisation associated to FENIB, and secondly by potentially antagonizing metastatic processes facilitated by NS activity in the brain
Structural insights into the DNA recognition mechanism by the bacterial transcription factor PdxR
Specificity in protein-DNA recognition arises from the synergy of several factors that stem from the structural and chemical signatures encoded within the targeted DNA molecule. Here, we deciphered the nature of the interactions driving DNA recognition and binding by the bacterial transcription factor PdxR, a member of the MocR family responsible for the regulation of pyridoxal 5 & PRIME;-phosphate (PLP) biosynthesis. Single particle cryo-EM performed on the PLP-PdxR bound to its target DNA enabled the isolation of three conformers of the complex, which may be considered as snapshots of the binding process. Moreover, the resolution of an apo-PdxR crystallographic structure provided a detailed description of the transition of the effector domain to the holo-PdxR form triggered by the binding of the PLP effector molecule. Binding analyses of mutated DNA sequences using both wild type and PdxR variants revealed a central role of electrostatic interactions and of the intrinsic asymmetric bending of the DNA in allosterically guiding the holo-PdxR-DNA recognition process, from the first encounter through the fully bound state. Our results detail the structure and dynamics of the PdxR-DNA complex, clarifying the mechanism governing the DNA-binding mode of the holo-PdxR and the regulation features of the MocR family of transcription factors
Epitaxial multilayers of alkanes on two-dimensional black phosphorus as passivating and electrically insulating nanostructures
© The Royal Society of Chemistry. Mechanically exfoliated two-dimensional (2D) black phosphorus (bP) is epitaxially terminated by monolayers and multilayers of tetracosane, a linear alkane, to form a weakly interacting van der Waals heterostructure. Atomic force microscopy (AFM) and computational modelling show that epitaxial domains of alkane chains are ordered in parallel lamellae along the principal crystalline axis of bP, and this order is extended over a few layers above the interface. Epitaxial alkane multilayers delay the oxidation of 2D bP in air by 18 hours, in comparison to 1 hour for bare 2D bP, and act as an electrical insulator, as demonstrated using electrostatic force microscopy. The presented heterostructure is a technologically relevant insulator-semiconductor model system that can open the way to the use of 2D bP in micro-and nanoelectronic, optoelectronic and photonic applications
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