8,860 research outputs found
Exploring Team Growth and Fixed Mindsets in Work Teams at a Large Korean Corporation
We conducted a qualitative study to understand how team mindsets can be manifested in work teams. We interviewed 21 participants from seven departments in one of the big corporations in Korea
Realizing a Superconducting Square-Lattice Bismuth Monolayer
Interplay of crystal symmetry, strong spinorbit coupling (SOC), and
many-body interactions in low dimensional materials provides a fertile ground
for the discovery of unconventional electronic and magnetic properties and
versatile functionalities. Two-dimensional (2D) allotropes of group 15 elements
are appealing due to their structures and controllability over symmetries and
topology under strong SOC. Here, we report the heteroepitaxial growth of a
proximity-induced superconducting 2D square-lattice bismuth monolayer on
superconducting Pb films. The square lattice of monolayer bismuth films in a
symmetry together with a stripey moir\'e structure is clearly resolved by
our scanning tunneling microscopy and its atomic structure is revealed by
density functional theory (DFT) calculations. A Rashba-type spin-split Dirac
band is predicted by DFT calculations to exist at the Fermi level and becomes
superconducting through the proximity effect from the Pb substrate. We suggest
the possibility of a topological superconducting state in this system with
magnetic dopants/field. This work introduces an intriguing material platform
with 2D Dirac bands, strong SOC, topological superconductivity, and the moir\'e
superstructure.Comment: 21 pages, 4 figure
Time Dependent Gene Expression Changes in the Liver of Mice Treated with Benzene
Benzene is used as a general purpose solvent. Benzene metabolism starts from phenol and ends with p-benzoquinone and o-benzoquinone. Liver injury inducted by benzene still remains a toxicologic problem. Tumor related genes and immune responsive genes have been studied in patients suffering from benzene exposure. However, gene expression profiles and pathways related to its hepatotoxicity are not known. This study reports the results obtained in the liver of BALB/C mice (SLC, Inc., Japan) administered 0.05 ml/100 g body weight of 2% benzene for six days. Serum, ALT, AST and ALP were determined using automated analyzer (Fuji., Japan). Histopathological observations were made to support gene expression data. c-DNA microarray analyses were performed using Affymetrix Gene-chip system. After six days of benzene exposure, twenty five genes were down regulated whereas nineteen genes were up-regulated. These gene expression changes were found to be related to pathways of biotransformation, detoxification, apoptosis, oxidative stress and cell cycle. It has been shown for the first time that genes corresponding to circadian rhythms are affected by benzene. Results suggest that gene expression profile might serve as potential biomarkers of hepatotoxicity during benzene exposure
Analysis of Building Energy Savings Potential for Metal Panel Curtain Wall Building by Reducing Thermal Bridges at Joints Between Panels
AbstractTo achieve national greenhouse gas reduction in the building sector, heating and cooling energy in buildings should be reduced. The government has strengthened regulations on insulation performance for building energy savings. However, the building envelope has various thermal bridges. In particular, a metal panel curtain wall comprises a number of thermal bridges at joints between the panels and the fixing units, thus degrading the overall thermal performance. To reduce building energy, it is necessary to reduce thermal bridges in building envelopes. This study aims to analyze the energy saving potential achieved by reducing thermal bridges. For this, the insulation performance and building energy needs of the existing and alternative metal panel curtain wall were evaluated. The alternative metal panel curtain wall that uses plastic molds at joints between panels and the thermally-broken brackets was suggested to reduce heat loss through thermal bridges. As results, the effective U-value of the alternative metal panel curtain wall was reduced by 72% compared with the existing metal panel curtain wall. In addition, annual heating energy needs of the alternative metal panel curtain wall building was reduced by 26%, and annual total energy needs was reduced by 6% because annual cooling energy needs of it slightly increased compared with the existing metal panel curtain wall. In conclusion, the alternative metal panel curtain wall considerably influenced the savings in building energy needs by reducing thermal bridges
Ethanol Extract of the Flower Chrysanthemum morifolium Augments Pentobarbital-Induced Sleep Behaviors: Involvement of Cl− Channel Activation
Dried Chrysanthemum morifolium flowers have traditionally been used in Korea for the treatment
of insomnia. This study was performed to investigate whether the ethanol extract of Chrysanthemum
morifolium flowers (EFC) enhances pentobarbital-induced sleep behaviors. EFC prolonged sleep time
induced by pentobarbital similar to muscimol, a GABAA receptors agonist. EFC also increased sleep
rate and sleep time when administrated with pentobarbital at a subhypnotic dosage. Both EFC and
pentobarbital increased chloride (Cl−) influx in primary cultured cerebellar granule cells. EFC
increased glutamic acid decarboxylase (GAD) expression levels, but had no effect on the expression
of α1-, β2-, and γ2-subunits of the GABAA receptor in the hippocampus of a mouse brain. This is in
contrast to treatment with pentobarbital, which showed decreased α1-subunit expression and no
change in GAD expression. In conclusion, EFC augments pentobarbital-induced sleep behaviors;
these effects may result from Cl− channel activation
Inhibitory effect of a tyrosine-fructose Maillard reaction product, 2,4-bis(p-hydroxyphenyl)-2-butenal on amyloid-β generation and inflammatory reactions via inhibition of NF-κB and STAT3 activation in cultured astrocytes and microglial BV-2 cells
<p>Abstract</p> <p>Background</p> <p>Amyloidogenesis is linked to neuroinflammation. The tyrosine-fructose Maillard reaction product, 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal, possesses anti-inflammatory properties in cultured macrophages, and in an arthritis animal model. Because astrocytes and microglia are responsible for amyloidogenesis and inflammatory reactions in the brain, we investigated the anti-inflammatory and anti-amyloidogenic effects of 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal in lipopolysaccharide (LPS)-stimulated astrocytes and microglial BV-2 cells.</p> <p>Methods</p> <p>Cultured astrocytes and microglial BV-2 cells were treated with LPS (1 μg/ml) for 24 h, in the presence (1, 2, 5 μM) or absence of 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal, and harvested. We performed molecular biological analyses to determine the levels of inflammatory and amyloid-related proteins and molecules, cytokines, Aβ, and secretases activity. Nuclear factor-kappa B (NF-κB) DNA binding activity was determined using gel mobility shift assays.</p> <p>Results</p> <p>We found that 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal (1, 2, 5 μM) suppresses the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as the production of nitric oxide (NO), reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in LPS (1 μg/ml)-stimulated astrocytes and microglial BV-2 cells. Further, 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal inhibited the transcriptional and DNA binding activity of NF-κB--a transcription factor that regulates genes involved in neuroinflammation and amyloidogenesis via inhibition of IκB degradation as well as nuclear translocation of p50 and p65. Consistent with the inhibitory effect on inflammatory reactions, 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal inhibited LPS-elevated Aβ<sub>42 </sub>levels through attenuation of β- and γ-secretase activities. Moreover, studies using signal transducer and activator of transcription 3 (STAT3) siRNA and a pharmacological inhibitor showed that 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal inhibits LPS-induced activation of STAT3.</p> <p>Conclusions</p> <p>These results indicate that 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal inhibits neuroinflammatory reactions and amyloidogenesis through inhibition of NF-κB and STAT3 activation, and suggest that 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal may be useful for the treatment of neuroinflammatory diseases like Alzheimer's disease.</p
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