Electron spin dynamics and electron spin resonance in graphene

A theory of spin relaxation in graphene including intrinsic, Bychkov-Rashba, and ripple spin-orbit coupling is presented. We find from spin relaxation data by Tombros et al. [Nature 448, 571 (2007).] that intrinsic spin-orbit coupling dominates over other contributions with a coupling constant of 3.7 meV. Although it is 1-3 orders of magnitude larger than those obtained from first principles, we show that comparable values are found for other honeycomb systems, MgB2 and LiC6; the latter is studied herein by electron spin resonance (ESR). We predict that spin coherence is longer preserved for spins perpendicular to the graphene plane, which is beneficial for spintronics. We identify experimental conditions when bulk ESR is realizable on graphene

Analysis of Invasion Proteins MMP2, MMP9, ADAM12, and ADAM17 in Glioblastoma U87MG Cells treated with anti-cancer compound 3,4-dimethoxybenzaldehyde

This research tested the effectiveness of novel compound 3,4-dimethoxybenzaldehyde, demonstrated to have anti-cancer properties. U87MG Glioblastoma cells were exposed to the compound at its LC50 concentration, then processed to collect proteins from the cells. Proteins were analyzed via Western blotting for specific protein levels of matrix metalloproteinase 2 and 9 (MMP) and disintegrin and metalloprotease 12 and 17 (ADAM). Previous research indicates these proteins are involved in the invasive properties of glioblastoma cells. Westerns were quantified with ImageJ and compared using a one-way ANOVA. Results indicate the compound has minimal effect upon the expression of MMP2, MMP9, ADAM12, ADAM17 proteins

Super-resolution microscopy reveals specific recruitment of HIV-1 envelope proteins to viral assembly sites dependent on the envelope C-terminal tail

The inner structural Gag proteins and the envelope (Env) glycoproteins of human immunodeficiency virus (HIV-1) traffic independently to the plasma membrane, where they assemble the nascent virion. HIV-1 carries a relatively low number of glycoproteins in its membrane, and the mechanism of Env recruitment and virus incorporation is incompletely understood. We employed dual-color super-resolution microscopy visualizing Gag assembly sites and HIV-1 Env proteins in virus-producing and in Env expressing cells. Distinctive HIV-1 Gag assembly sites were readily detected and were associated with Env clusters that always extended beyond the actual Gag assembly site and often showed enrichment at the periphery and surrounding the assembly site. Formation of these Env clusters depended on the presence of other HIV-1 proteins and on the long cytoplasmic tail (CT) of Env. CT deletion, a matrix mutation affecting Env incorporation or Env expression in the absence of other HIV-1 proteins led to much smaller Env clusters, which were not enriched at viral assembly sites. These results show that Env is recruited to HIV-1 assembly sites in a CT-dependent manner, while Env(ΔCT) appears to be randomly incorporated. The observed Env accumulation surrounding Gag assemblies, with a lower density on the actual bud, could facilitate viral spread . Keeping Env molecules on the nascent virus low may be important for escape from the humoral immune response, while cell-cell contacts mediated by surrounding Env molecules could promote HIV-1 transmission through the virological synapse

Antimicrobial, starch based barrier coatings prepared using mixed silver/sodium exchanged bentonite

The effect of silver nitrate concentration, pre-washed bentonite (to remove extraneous salt) and back-exchange procedures have been explored to assess the type of silver species formed and their behaviour upon exposure to further salts. X-ray fluorescence was used to quantify the amount of silver present and whether in cation exchange sites, whereas X-ray diffraction and transmission electron microscopy identified the silver compounds present. A further objective was to assess the antimicrobial, barrier and dispersion properties of the silver/sodium bentonites when incorporated into a starch-plasticiser-clay coating used for packaging. The silver/sodium bentonites demonstrated very strong antimicrobial activity towards Escherichia coli, Kocuria rhizophila and Aspergillus niger. Incorporating just 0.03 wt% of silver/sodium bentonite in the coating (0.2 μmol/m2 Ag in dried coating with thickness of 14 μm) produced a > 4.4 log reduction against an initial loading of 2.1 × 105 CFU/object for E. coli. Water vapour barrier properties of coatings prepared on paper and containing the mixed silver/sodium bentonite were unaffected since water vapour transmission rate values of ~20–40 g/m2.day (23°C, 50% relative humidity) were maintained. Also the presence of silver did not adversely affect the clay dispersion. The Ag+ release profile from mixed silver/sodium clay upon addition of HNO3 and NaNO3 is discussed

A radikalizmus szociális reprezentációja fiatalok körében

A tanulmányban egy nemzetközi kutatás (Myplace) adatait felhasználva, politikai szocializációs szempontból lényegesen eltérő két városban (Ózd és Sopron) élő 15–26 éves fiatalok radikalizmus értelmezését a szociális reprezentáció elmélet alapján vizsgáltuk. Az elméletre épülő egyik empirikus módszernek megfelelően, a 2012-ben lebonyolított kérdőíves adatfelvétel során asszociációs válaszok kvantifikálásával a radikalizmus reprezentációjának strukturális és tartalmi jellemzését követően a fiatalokra jellemző nacionalizmus és a demokratikus alapelvekhez való viszony, valamint a radikalizmus reprezentációjának kapcsolatát elemeztük

Study of led lamp power supply

В данной статье исследуется источник питания светодиодного светильника с высокимкоэффициентом мощности. Использована микросхема корректора коэффициента мощности компании STMicroelectronics L6561 в обратноходовой топологии. С помощью этой микросхемы упрощается построение источника питания, учитывая стандарты энергосбережения и требования к уровню вносимых в питающую сеть искажений.In this article, we investigate the LED lamp power supply with a high power factor. To implement this, the power factor corrector of STMicroelectronics L6561 is used in the fly-back topology. With the help of this IC simplifies the construction of the power supply, considering energy-efficiency standards and requirements for the level introduced into the mains distortion.Fir filter design using frequency sampling method