207 research outputs found
Simultaneous morphological transformation of metal salt and conformations of DNA in a bio-based ionic liquid
The extraordinary left handed conformation of DNA known as Z-DNA has attracted the attention of structural biologists due to its characteristic features such as its possible role in regulation of gene expression and genetic instability. There are number of physical parameters which can induce the conformational transformation of double helical B-DNA to Z-DNA. Among the various physical conditions, right-handed B-DNA can be transformed into left-handed Z-DNA in vitro at high salt concentrations or in vivo under physiological conditions. Herein DNA solubilized in a choline based ionic liquid namely choline formate was found to reduce Ag(I) salt into silver nanoparticles (AgNPs) with the size distribution of 10-20 nm. During the process, the interaction of DNA with the ionic liquid induces alteration in secondary structure of DNA (B-Z transition). The formation of the NPs was confirmed by UV-Vis spectrophotometer and Transmission Electron Microscopic (TEM) measurements, while the formation of Z-DNA was confirmed by circular dichroism (CD) spectroscopic measurements. Upon molecular docking studies, choline-formate was found to present different binding sites for its cation and anion and they promote torsions on DNA structure leading to possible changes in DNA three dimensional structures (B-Z transition).publishe
The influence of extrinsic motivating factors on employees’ work performance at banking sectors in Malaysia: The mediating effect of psychological ownership
This study investigates the influences of extrinsic motivating factors on employees' work performance in banking sectors in Malaysia when the psychological ownership act as mediating effect existed. Generally, this study analyses three independent variables, categorized as extrinsic (working condition, job security, and company policy) motivating factors on the dependent variable of employees' work performance when psychological ownership acts as a mediating effect in banking sectors in Malaysia. This study was conducted to determine employee work performance issues, namely, poor service quality, poor communication, high employee turnover, and work-related stress in Malaysian banking sectors. The research tools used in this study were personal distribution and online mail questionnaires. A total of 3700 frontline employees were selected for the questionnaire, but only 370 respondents are fit for further analysis. The survey data was gathered within a one-month duration. The findings revealed that work conditions and company policy have a significant favourable influence on psychological ownership. The following results show that psychological ownership positively mediates the relationship between company policy and work conditions with work performance. A theoretical framework has been constructed based on Herzberg's Theory of hygiene factors used in this research. The outcome of this study would help bank management introduce practical strategies for improving the employees' work performance which leads to business growth
Charge density wave origin of cuprate checkerboard visualized by scanning tunneling microscopy
One of the main challenges in understanding high TC superconductivity is to
disentangle the rich variety of states of matter that may coexist, cooperate,
or compete with d-wave superconductivity. At center stage is the pseudogap
phase, which occupies a large portion of the cuprate phase diagram surrounding
the superconducting dome [1]. Using scanning tunneling microscopy, we find that
a static, non-dispersive, "checkerboard"-like electronic modulation exists in a
broad regime of the cuprate phase diagram and exhibits strong doping
dependence. The continuous increase of checkerboard periodicity with hole
density strongly suggests that the checkerboard originates from charge density
wave formation in the anti-nodal region of the cuprate Fermi surface. These
results reveal a coherent picture for static electronic orderings in the
cuprates and shed important new light on the nature of the pseudogap phase.Comment: 5 pages, 4 figure
Collimated hot electron generation from sub-wavelength grating target irradiated by a femtosecond laser pulse of relativistic intensity
We investigate the production of hot electrons from the interaction of
relativistically intense () ultra-short (25 fs) laser
pulses with sub-wavelength grating target. We measure the hot electron angular
distribution and energy spectra for grating target and compare them with those
from a planar mirror target. We observe that hot electrons are emitted in a
collimated beam along the specular direction of the grating target. From the
measured electron energy spectra we see electron temperature for grating is
higher than the mirror, suggesting a higher electron yield and hence a stronger
coupling with the laser. We performed numerical simulations which are in good
agreement with experimental results, offer insights into the acceleration
mechanism by resulting electric and magnetic fields. Such collimated fast
electron beams have a wide range of applications in applied and fundamental
science.Comment: 6 figure
Oxidative stress and inflammatory markers are associated with depression and nicotine dependence
AbstractTo determine if oxidative stress and inflammation are linked with major depressive disorder, nicotine dependence and both disorders combined. This study comprised 150 smokers and 191 never smokers. The instruments were: a socio-demographic questionnaire, diagnoses of mood disorder and nicotine dependence according to DSM-IV, (SCID-IV), and the Alcohol, Smoking and Substance Involvement Screening Test. Laboratory assessments included: nitric oxide metabolites (NOx), lipid hydroperoxides, malondialdehyde (MDA), total reactive antioxidant potential (TRAP), advanced oxidation protein products (AOPP), fibrinogen concentrations, homocysteine, erythrocytes sedimentation rate (ESR) and high-sensitivity C-reactive protein (hs-CRP) were assayed from blood specimens. Statistically significant differences were found among depressed smokers who had more severe depressive symptoms, a higher risk of alcohol consumption, more suicide attempts, and more disability for work than non-depressed never smokers. Depressed smokers had significantly higher levels of NOx, fibrinogen, hs-CRP, AOPP, ESR and lower levels of TRAP compared to non-depressed never smokers. Depressed smokers had significant levels of oxidative stress and inflammatory biomarkers after adjusting for gender, age, years of education, disability for work, and laboratory measures. The levels of NOx, lipid hydroperoxides, AOPP, and fibrinogen were substantially higher, whereas levels of TRAP were lower in depressed smokers compared to non-depressed never smokers. (1) Depressed smokers exhibited altered concentrations of NOx, lipid hydroperoxides, AOPP, TRAP, and fibrinogen. (2) Depressed smokers were more unable to work, showed more severe depressive symptoms and attempted suicide more frequently
Imaging the Two Gaps of the High-TC Superconductor Pb-Bi2Sr2CuO6+x
The nature of the pseudogap state, observed above the superconducting
transition temperature TC in many high temperature superconductors, is the
center of much debate. Recently, this discussion has focused on the number of
energy gaps in these materials. Some experiments indicate a single energy gap,
implying that the pseudogap is a precursor state. Others indicate two,
suggesting that it is a competing or coexisting phase. Here we report on
temperature dependent scanning tunneling spectroscopy of Pb-Bi2Sr2CuO6+x. We
have found a new, narrow, homogeneous gap that vanishes near TC, superimposed
on the typically observed, inhomogeneous, broad gap, which is only weakly
temperature dependent. These results not only support the two gap picture, but
also explain previously troubling differences between scanning tunneling
microscopy and other experimental measurements.Comment: 6 page
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