951 research outputs found
Atomistic origin of metal versus charge-density-wave phase separation in indium atomic wires on Si(111)
We investigate in atomic scale the electronic phase separation occurring in
the well known quasi 1D charge-density wave (CDW) phase of the In atomic wire
array on a Si(111) surface. The characteristic atomic scale defects, originated
from excess In atoms, are found to be actively involved in the formation of the
phase boundary between the metallic and the CDW phases by extensive analysis of
scanning tunneling microscopy images at various temperatures. These particular
defects flip the phase of the quasi 1D CDW to impose strong local constraints
in the CDW correlation. We show that such local constraints and the substantial
interwire CDW interaction induce local condensates of CDW and the phase
separation between the metallic and the CDW phases. This work unveils the
atomistic origin of the electronic phase separation, highlighting the
importance of atomic scale structures of defects and their collective
interaction in electronically inhomogeneous materials
Pseudogap and weak multifractality in disordered Mott charge-density-wave insulator
The competition, coexistence and cooperation of various orders in
low-dimensional materials like spin, charge, topological orders and
charge-density-wave has been one of the most intriguing issues in condensed
matter physics. In particular, layered transition metal dichalcogenides provide
an ideal platform for studying such an interplay with a notable case of
1-TaS featuring Mott-insulating ground state, charge-density-wave,
spin frustration and emerging superconductivity together. We investigated local
electronic states of Se-substituted 1-TaS by scanning tunneling
microscopy/spectroscopy (STM/STS), where superconductivity emerges from the
unique Mott-CDW state. Spatially resolved STS measurements reveal that an
apparent V-shape pseudogap forms at the Fermi Level (E), with the origin
of the electronic states splitting and transformation from the Mott states, and
the CDW gaps are largely preserved. The formation of the pseudogap has little
correlation to the variation of local Se concentration, but appears to be a
global characteristics. Furthermore, the correlation length of local density of
states (LDOS) diverges at the Fermi energy and decays rapidly at high energies.
The spatial correlation shows a power-law decay close to the Fermi energy. Our
statistics analysis of the LDOS indicates that our system exhibits weak
multifractal behavior of the wave functions. These findings strongly support a
correlated metallic state induced by disorder in our system, which provides an
new insight into the novel mechanism of emerging superconductivity in the
two-dimensional correlated electronic systems
Categorization of lower body shapes of abdominal obese men using a script-based 3D body measurement software
The objectives of this study are to identify the principal components that represent distinctive shapes from the silhouette and profile views of the lower body shapes of abdominal obese Korean men and to categorize their body types. Using 3D scans of 625 men aged 35–64 in the 6th SizeKorea dataset, 173 scans (27.7%) of men in abdominal obese category (BMI value of 25, waist girth to height ratio of 0.53, and waist girth to hip girth ratio of 0.9 or higher) were utilized. We developed a script to measure 38 items such as front/back crotch length and front/back depths and angles using the SNU-BM program, which is a script-based automated 3D body scan measurement software. The measurements used for principal component (PC) analysis were 31 drops, 2 heights, 2 lengths and 4 angles. Ten PCs representing distinctive silhouettes and profiles of lower body shapes were extracted. The PCs were interpreted as follows: abdomen prominence, thigh to knee profile, upper buttocks prominence, waist to hip drop, thigh to knee silhouette, lower body tilt angle, waist to crotch length, vertical height, abdomen to crotch height, and lower buttocks slope. The three body shape groups were categorized using a K means cluster analysis with ten PC scores. Group 1 had a flat abdomen but prominent buttocks. Group 2 had a developed abdomen and buttocks with vertical thighs. Group 3 had drooped buttocks with tilted thighs.This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government
(MSIP) (NRF-2017R1C1B5017733)
Translational repression of mouse mu opioid receptor expression via leaky scanning
Mu opioid receptor (MOR) expression is under temporal and spatial controls, but expression levels of the MOR gene are relatively low in vivo. In addition to transcriptional regulations, upstream AUGs (uAUGs) and open reading frames (uORFs) profoundly affect the translation of the primary ORF and thus the protein levels in several genes. The 5′-untranslated region (UTR) of mouse MOR mRNA contains three uORFs preceding the MOR main initiation codon. In MOR-fused EGFP or MOR promoter/luciferase reporter constructs, mutating each uAUG individually or in combinations increased MOR transient heterologous expression in neuroblastoma NMB and HEK293 cells significantly. Translation of such constructs increased up to 3-fold without altering the mRNA levels if either the third uAUG or both the second and third AUGs were mutated. Additionally, these uAUG-mediated translational inhibitions were independent of their peptide as confirmed by internal mutation analyses in each uORF. Translational studies indicated that protein syntheses were initiated at these uAUG initiation sites, with the third uAUG initiating the highest translation level. These results support the hypothesis that uORFs in mouse MOR mRNA act as negative regulators through a ribosome leaky scanning mechanism. Such leaky scanning resulted in the suppression of mouse MOR under normal conditions
Protects Porcine Intestinal Barrier from Deoxynivalenol via Improved Zonula Occludens-1 Expression
Intestinal epithelial cells (IECs) forming the barrier for the first-line of protection are interconnected by tight junction (TJ) proteins. TJ alteration results in impaired barrier function, which causes potentially excessive inflammation leading to intestinal disorders. It has been suggested that toll-like receptor (TLR) 2 ligands and some bacteria enhance epithelial barrier function in humans and mice. However, no such study has yet to be claimed in swine. The aim of the present study was to examine whether Bacillus subtilis could improve barrier integrity and protection against deoxynivalenol (DON)-induced barrier disruption in porcine intestinal epithelial cell line (IPEC-J2). We found that B. subtilis decreased permeability of TJ and improved the expression of zonula occludens (ZO)-1 and occludin during the process of forming TJ. In addition, ZO-1 expression of IPEC-J2 cells treated with B. subtilis was up-regulated against DON-induced damage. In conclusion, B. subtilis may have potential to enhance epithelial barrier function and to prevent the cells from DON-induced barrier dysfunction
Barrier protection via Toll-like receptor 2 signaling in porcine intestinal epithelial cells damaged by deoxynivalnol
Additional file 2. IPEC-J2 cells pretreated with TLR2 ligand maintained the expression of MCP-1, GM-CSF and TLR2 against DON exposure. IPEC-J2 cells pretreated with or without TLR2 ligand for 24 h were exposed to DON. (A) The bar graph showed the mRNA levels of porcine mcp-1, gm-csf measured using real time-PCR at 1 and 6 h after DON exposure (n = 3). (B) The mRNA levels of porcine tlr2 were measured using real-time quantitative PCR analysis at 6 h. NT represents no treatment. Expression of each mRNA was presented relative to the expression of housekeeping gene, gapdh (n = 3). *P < 0.05; **P < 0.01; ***P < 0.001, determined by one-way ANOVA with Tukey’s posttest
The effect of alpha lipoic acid in a porcine in-stent restenosis model
SummaryBackgroundThe aim of this study was to investigate the effect of alpha lipoic acid (α-LA) on a porcine in-stent restenosis (ISR) model.MethodsIn protocol 1, porcine vascular smooth muscle cells (PVSMC) were stimulated by granulocyte-colony stimulating factor (G-CSF) in the presence or absence of α-LA. MTT (3-[4,5-dimethylthiazole-2-yl] 2,5-diphenyl tetrazolium bromide) assay and western blotting were used to determine the cell growth inhibitory rate and anti-inflammatory effect associated with nuclear factor-κb (NF-κb) and extracellular signal-regulated kinase (ERK). In protocol 2, 28 days after balloon overdilation injuries, 24 bare metal stents were placed in coronary artery of 12 pigs. The pigs were randomly divided to receive control diet with or without α-LA (100mg/kg). In protocol 3, 8 control stents and 8 α-LA coated stents were randomly implanted in 2 coronary arteries of 8 pigs and follow-up coronary angiogram and histopathologic assessment were performed 4 weeks after stenting.ResultsProtocol 1. The proliferation of PVSMC was inhibited and protein expression of NF-κb and ERK were attenuated by α-LA pretreatment. Protocol 2. On histopathologic analysis, the neointimal area (4.0±1.0mm2 vs. 1.5±0.7mm2, p<0.001) and histopathologic area of stenosis (66.7±10.7% vs. 24.2±9.7%, p<0.001) were reduced in the α-LA feeding group compared to controls. Protocol 3. On histopathologic analysis, the neointimal area (3.9±0.8mm2 vs. 1.0±0.4mm2, p<0.001), and the histopathologic area of stenosis (67.1±8.8% vs. 17.4±10.0%, p<0.001) were reduced in the α-LA coated stent group compared to the control stent group.Conclusionsα-LA feeding and α-LA coated stents inhibit neointimal hyperplasia in porcine ISR, possibly through inhibiting the activation of NF-κb pathway and proliferation of PVSMC
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