In vitro ion chelating, antioxidative mechanism of extracts from fruits and barks of tetrapleura tetraptera and their protective effects against fenton mediated toxicity of metal ions on liver homogenates

The aim of the present study was to investigate the antioxidant activity and protective potential of T. tetraptera extracts against ion toxicity. The antioxidant activity of the extracts was investigated spectrophotometrically against several radicals (1,1-diphenyl-2-picrylhydrazyl (DPPH•), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS•), hydroxyl radical (HO•), and nitric oxide (NO•)), followed by the ferric reducing power, total phenols, flavonoid, and flavonol contents. The effects of the extracts on catalase (CAT), superoxide dismutase (SOD), and peroxidase activities were also determined using the standard methods as well as the polyphenol profile using HPLC. The results showed that the hydroethanolic extract of T. tetraptera (CFH) has the lowest ICvalue with the DPPH, ABTS, OH, and NO radicals. The same extract also exhibited the significantly higher level of total phenols (37.24 ± 2.00 CAE/g dried extract); flavonoids (11.36 ± 1.88 QE/g dried extract); and flavonols contents (3.95 ± 0.39 QE/g dried extract). The HPLC profile of T. tetraptera revealed that eugenol (958.81 ± 00 mg/g DW), quercetin (353.78 ± 00 mg/g DW), and rutin (210.54 ± 00 mg/g DW) were higher in the fruit than the bark extracts. In conclusion, extracts from T. tetraptera may act as a protector against oxidative mediated ion toxicity. © 2015 Bruno Moukette Moukette et al

Optical Diagnostics of Switching Arcs Near Current-zero: Speckle Imaging and Interferometry

Optical diagnostics can be used to obtain spatially resolved measurements of the density, temperature, conductivity, and electron density of circuit breaker arcs embedded in transonic flows; these can be used to validate the results of simulations, the accuracy of which can currently be assessed in only a limited way. We compare speckle imaging and an interferometric approach. Both use a pulsed nanosecond laser. The speckle imaging setup does not require a reference beam, but only yields information about the gradient of the refractive index. Its accuracy is sensitive to the alignment of the optical components. Interferometry directly yields high resolution images of the index of refraction, from which the density can be calculated using the Gladstone-Dale relation. By using two laser beams, interferometry provides spatially resolved information about the electron density. Such measurements are a significant step towards more accurate CFD models

Numerical Investigation, Including Experimental Validation, of an Axially Blown, Stable Arc in Argon

In this work we present the outcome of a numerical validation study conducted with an arc model developed within a computational fluid dynamics (CFD) tool. The numerical investigations were aimed at reproducing the spatially resolved temperature data obtained with an experiment in which an axially symmetric argon arc was established in the observation region. The full absorption spectrum has been computed for argon and then compressed with minimum loss of information to a relatively small set of bands. The latter has been used for solving the radiative transfer equation in a computationally affordable, yet accurate way. The comparison between the arc temperature simulated with the reduced absorption data and the measured one is presented

Resolution and enhancement in nanoantenna-based fluorescence microscopy

Single gold nanoparticles can act as nanoantennas for enhancing the fluorescence of emitters in their near-fields. Here we present experimental and theoretical studies of scanning antenna-based fluorescence microscopy as a function of the diameter of the gold nanoparticle. We examine the interplay between fluorescence enhancement and spatial resolution and discuss the requirements for deciphering single molecules in a dense sample. Resolutions better than 20 nm and fluorescence enhancement up to 30 times are demonstrated experimentally. By accounting for the tip shaft and the sample interface in finite-difference time-domain calculations, we explain why the measured fluorescence enhancements are higher in the presence of an interface than the values predicted for a homogeneous environment.Comment: 10 pages, 3 figures. accepted for publication in Nano Letter

Relativistic Calculation of two-Electron one-Photon and Hypersatellite Transition Energies for 12≤Z≤3012\leq Z\leq30 Elements

Energies of two-electron one-photon transitions from initial double K-hole states were computed using the Dirac-Fock model. The transition energies of competing processes, the K$\alpha$ hypersatellites, were also computed. The results are compared to experiment and to other theoretical calculations.Comment: accepted versio

Nanoparticle Tracking Analysis for the Enumeration and Characterization of Mineralo-Organic Nanoparticles in Feline Urine

Urinary stone disease, particularly calcium oxalate, is common in both humans and cats. Calcifying nanoparticles (CNP) are spherical nanocrystallite material, and are composed of proteins (fetuin, albumin) and inorganic minerals. CNP are suggested to play a role in a wide array of pathologic mineralization syndromes including urolithiasis. We documented the development of a clinically relevant protocol to assess urinary CNP in 9 healthy cats consuming the same diet in a controlled environment using Nanoparticle Tracking Analysis (NTA®). NTA® is a novel method that allows for characterization of the CNP in an efficient, accurate method that can differentiate these particles from other urinary submicron particulates. The predominant nanoscale particles in feline urine are characteristic of CNP in terms of their size, their ability to spontaneously form under suitable conditions, and the presence of an outer layer that is rich in calcium and capable of binding to hydroxyapatite binders such as alendronate and osteopontin. The expansion of this particle population can be suppressed by the addition of citrate to urine samples. Further, compounds targeting exosomal surfaces do not label these particulates. As CNP have been associated with a number of significant urologic maladies, the method described herein may prove to be a useful adjunct in evaluating lithogenesis risk in mammals

An Ethnographer Lured into Darkness

No matter the combination of methods ethnographers bring to their research design and to participant observation, our pursuit to log, interpret, analyse and present the lives of those we meet is never an entirely intellectual or objective one. Ethnographic fieldwork is intimately sensory (Pink, Doing sensory ethnography, Sage, London, 2015), invokes our imagination (Sparkes, Qualitative research in sport and exercise, 1:21–35, 2009) and requires us to actively navigate social landscapes (Hammersley and Atkinson, Field relations. Ethnography: Principles in practice, Routledge, Stoodleigh, 2007). There is a tendency for these elements to fade in terms of visibility and immediacy within the research process. For those in accord with (Davies, Reflexive ethnography: A guide to researching selves and others, Routledge, New York, 2008), continuous reflexive labour becomes a core praxis to monitor the ways we observe and participate in this textured environment. Without this, we are left in the dark and are less able to see how we can (or should) respond to the nitty–gritty qualitative nature of ethnography. In this Chapter, two of methodological vignettes will act as entry points to unpack a set of tensions that commanded my attention during an eighteen months ethnography in Higher Education. ‘You Look Like an Ivory Tower Student’, for example, begins to troubleshoot ethnographic participation within educational environments. ‘Going Dark’, on the other hand, problematises the prioritisation of visual observations that are implicit in ethnographic tradition. Throughout these discussions a metaphor of being lured into darkness is offered as a productive orientation for ethnography

The protease‐activated receptor 4 Ala120Thr variant alters platelet responsiveness to low‐dose thrombin and protease‐activated receptor 4 desensitization, and is blocked by non‐competitive P2Y12 inhibition

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146616/1/jth14318_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146616/2/jth14318.pd

The influence of transition metal solutes on dislocation core structure and values of Peierls stress and barrier in tungsten

Several transition metals were examined to evaluate their potential for improving the ductility of tungsten. The dislocation core structure and Peierls stress and barrier of $1/2$ screw dislocations in binary tungsten-transition metal alloys (W$_{1-x}$TM$_{x}$) were investigated using first principles electronic structure calculations. The periodic quadrupole approach was applied to model the structure of $1/2$ dislocation. Alloying with transition metals was modeled using the virtual crystal approximation and the applicability of this approach was assessed by calculating the equilibrium lattice parameter and elastic constants of the tungsten alloys. Reasonable agreement was obtained with experimental data and with results obtained from the conventional supercell approach. Increasing the concentration of a transition metal from the VIIIA group, i.e. the elements in columns headed by Fe, Co and Ni, leads to reduction of the $C^\prime$ elastic constant and increase of elastic anisotropy A=$C_{44}/C^\prime$. Alloying W with a group VIIIA transition metal changes the structure of the dislocation core from symmetric to asymmetric, similar to results obtained for W$_{1-x}$Re$_{x}$ alloys in the earlier work of Romaner {\it et al} (Phys. Rev. Lett. 104, 195503 (2010))\comments{\cite{WRECORE}}. In addition to a change in the core symmetry, the values of the Peierls stress and barrier are reduced. The latter effect could lead to increased ductility in a tungsten-based alloy\comments{\cite{WRECORE}}. Our results demonstrate that alloying with any of the transition metals from the VIIIA group should have similar effect as alloying with Re.Comment: 12 pages, 8 figures, 3 table

Masculine femininities/feminine masculinities: power, identities and gender

This paper is basically about terminology. In it I discuss the terms 'masculinity' and 'femininity' and how they relate to being male and being female. My theme arises from an increasing difficulty that I am finding in understanding how individual identities relate to dominant constructions of masculinity and femininity. Christine Skelton and Becky Francis argue that we should not be afraid to name certain behaviours as masculine even when they are performed by girls. After a discussion of the problems of defining both 'masculinity' and 'femininity', and a consideration of the power relations between these terms, I go on to consider the concept of 'female masculinity' (Halberstam). I argue that this formulation is problematic, due to its dependence on a main term whose definition is unclear. Finally, I argue that we need to distinguish 'masculinity' and 'femininity' from 'masculinities' and 'femininities'