4,273 research outputs found
Enhanced spin density wave in LaOFeSb
We predict atomic, electronic, and magnetic structures of a hypothetical
compound LaOFeSb by first-principles density-functional calculations. It is
shown that LaOFeSb prefers a stripe-type antiferromagnetic phase (i.e., spin
density wave (SDW) phase) to the non-magnetic (NM) phase, with a larger Fe spin
moment and greater SDW-NM energy difference than those of LaOFeAs. The SDW
phase is found to favor the orthorhombic structure while the tetragonal
structure is more stable in the NM phase. In the NM-phase LaOFeSb, the
electronic bandwidth near the Fermi energy is reduced compared with LaOFeAs,
indicating smaller orbital overlap between Fe states and subsequently
enhanced intra-atomic exchange coupling. The calculated Fermi surface in the NM
phase consists of three hole and two electron sheets, and shows increased
nesting between two hole and two electron sheets compared with LaOFeAs.
Monotonous changes found in our calculated material properties of LaOFePn
(Pn=P, As, and Sb), along with reported superconducting properties of doped
LaOFeP and LaOFeAs, suggest that doped LaOFeSb may have a higher
superconducting transition temperature.Comment: 5 pages with 3 figures and 1 table, double colum
KINEMATIC COMPARISONS OF KETTLEBELL TWO-ARM SWINGS BETWEEN EXPERTS AND BEGINNERS
The purpose of this study was to investigate kinematic comparisons of kettlebell two-arm swings between experts and beginners in order to find out biomechanical key points for preventing sports injuries and enhancing kettlebell performance. Four experts and three beginners performed kettlebell two-arm swings fifteen times with a 16 kg kettlebell. Experts demonstrated larger ranges of motions (ROM) of pelvic segment and hip joint than beginners, while beginners revealed larger ROM of shoulder joint than experts. Magnitudes and sequential orders of peak angular velocities of major joints were significantly different between two groups. Conclusively, the mobility of pelvic segment and hip joint are required, while the stability of the other joint are needed to produce appropriate kettlebell two-arm swings. The activation and strength of gluteus muscles would be key contributors
Emergence of robust 2D skyrmions in SrRuO3 ultrathin film without the capping layer
Magnetic skyrmions have fast evolved from a novelty, as a realization of
topologically protected structure with particle-like character, into a
promising platform for new types of magnetic storage. Significant engineering
progress was achieved with the synthesis of compounds hosting room-temperature
skyrmions in magnetic heterostructures, with the interfacial
Dzyaloshinskii-Moriya interactions (DMI) conducive to the skyrmion formation.
Here we report findings of ultrathin skyrmion formation in a few layers of
SrRuO3 grown on SrTiO3 substrate without the heavy-metal capping layer.
Measurement of the topological Hall effect (THE) reveals a robust stability of
skyrmions in this platform, judging from the high value of the critical field
1.57 Tesla (T) at low temperature. THE survives as the field is tilted by as
much as 85 degrees at 10 Kelvin, with the in-plane magnetic field reaching up
to 6.5 T. Coherent Bragg Rod Analysis, or COBRA for short, on the same film
proves the rumpling of the Ru-O plane to be the source of inversion symmetry
breaking and DMI. First-principles calculations based on the structure obtained
from COBRA find significant magnetic anisotropy in the SrRuO3 film to be the
main source of skyrmion robustness. These features promise a few-layer SRO to
be an important new platform for skyrmionics, without the necessity of
introducing the capping layer to boost the spin-orbit coupling strength
artificially.Comment: Supplementary Information available upon reques
Emergence of robust 2D skyrmions in SrRuO3 ultrathin film without the capping layer
Magnetic skyrmions have fast evolved from a novelty, as a realization of
topologically protected structure with particle-like character, into a
promising platform for new types of magnetic storage. Significant engineering
progress was achieved with the synthesis of compounds hosting room-temperature
skyrmions in magnetic heterostructures, with the interfacial
Dzyaloshinskii-Moriya interactions (DMI) conducive to the skyrmion formation.
Here we report findings of ultrathin skyrmion formation in a few layers of
SrRuO3 grown on SrTiO3 substrate without the heavy-metal capping layer.
Measurement of the topological Hall effect (THE) reveals a robust stability of
skyrmions in this platform, judging from the high value of the critical field
1.57 Tesla (T) at low temperature. THE survives as the field is tilted by as
much as 85 degrees at 10 Kelvin, with the in-plane magnetic field reaching up
to 6.5 T. Coherent Bragg Rod Analysis, or COBRA for short, on the same film
proves the rumpling of the Ru-O plane to be the source of inversion symmetry
breaking and DMI. First-principles calculations based on the structure obtained
from COBRA find significant magnetic anisotropy in the SrRuO3 film to be the
main source of skyrmion robustness. These features promise a few-layer SRO to
be an important new platform for skyrmionics, without the necessity of
introducing the capping layer to boost the spin-orbit coupling strength
artificially.Comment: Supplementary Information available upon reques
Cephalometric predictors of long-term stability in the early treatment of class III malocclusion
The aim of this study was to examine the differences in the early craniofacial morphology
of Class III malocclusions. Lateral cephalograms of 45 subjects with a Class III malocclusion
and an anterior crossbite in the deciduous or mixed dentition were examined before treatment,
after treatment, and during the long-term retention stage. The anterior crossbites of all
patients were corrected after a series of orthodontic treatments. After a mean follow-up period of
5.7 years, all the subjects were reevaluated and divided into three groups according to the final
occlusal status: good, fair, and poor occlusal stability. Twenty cephalometric variables on the
pretreatment lateral cephalograms were analyzed by one-way analysis of variance and discriminant
analysis to identify the key determinants for discriminating among the three groups. Among
the 20 variables, 11 showed statistical significance. Generally, the subjects with a smaller gonial
angle and a more hypodivergent skeletal pattern had good prognosis after the early treatment of
Class III malocclusion. When the AB to mandibular plane angle and N-perpendicular to point A
were selected in discriminant analysis, the AB to mandibular plane angle was the most significant
variable. Discriminant analysis showed a relatively high degree of correct classifications of the
patients with early Class III malocclusion. In particular, discriminant analysis showed the highest
accuracy (93.3%) when predicting a poor prognosis.This study was supported by a grant from the Korea Health 21
R&D Project, Ministry of Health & Welfare, Republic of Korea (03-
PJ1-PG1-CH09-0001)
Contact holes in vertical electrode structures analyzed by voltage contrast-SEM and conducting AFM
Soaring demands of multi-stacked memory devices request urgent development of
backside contact electrode technologies, such as high aspect ratio etching,
metallization, and inspection methods. Especially the complex metal contact
process should be monitored for each manufacturing step to filter the defective
samples and to maintain the high yield of production. Among the inspection
methods for detecting the electrical connections, there is voltage contrast
(VC)-SEM and conducting AFM (C-AFM). In this report, we investigated the two
inspection methods for testing designed samples with different contact hole
states. The VC-SEM data shows the contrast variation at the contact holes, from
which one may discern the contact status with an optimum voltage. The C-AFM
results clearly demonstrate a finite electrical current in the connected
contact, while a negligible current in the disconnected one. Finally, we
discuss insights of using the two methods for analyzing the contact hole
technologies with high aspect ratios.Comment: 17 pages, 4 figure
Functional elements demarcated by histone modifications in breast cancer cells
AbstractHistone modifications are regarded as one of markers to identify regulatory elements which are DNA segments modulating gene transcription. Aberrant changes of histone modification levels are frequently observed in cancer. We have employed ChIP-Seq to identify regulatory elements in human breast cancer cell line, MCF-7 by comparing histone modification patterns of H3K4me1, H3K4me3, and H3K9/14ac to those in normal mammary epithelial cell line, MCF-10A. The genome-wide analysis shows that H3K4me3 and H3K9/14ac are highly enriched at promoter regions and H3K4me1 has a relatively broad distribution over proximity of TSSs as well as other genomic regions. We identified that many differentially expressed genes in MCF-7 have divergent histone modification patterns. To understand the functional roles of distinctively histone-modified regions, we selected 35 genomic regions marked by at least one histone modification and located from 3 to 10kb upstream of TSS in both MCF-7 and MCF-10A and assessed their transcriptional activities. About 66% and 60% of selected regions in MCF-7 and MCF-10A, respectively, enhanced the transcriptional activity. Interestingly, most regions marked by H3K4me1 exhibited an enhancer activity. Regions with two or more kinds of histone modifications did show varying activities. In conclusion, our data reflects that comprehensive analysis of histone modification profiles under cell type-specific chromatin environment should provide a better chance for defining functional regulatory elements in the genome
Inhibition of c-Jun NH(2)-terminal kinase or extracellular signal-regulated kinase improves lung injury
BACKGROUND: Although in vitro studies have determined that the activation of mitogen-activated protein (MAP) kinases is crucial to the activation of transcription factors and regulation of the production of proinflammatory mediators, the roles of c-Jun NH(2)-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) in acute lung injury have not been elucidated. METHODS: Saline or lipopolysaccharide (LPS, 6 mg/kg of body weight) was administered intratracheally with a 1-hour pretreatment with SP600125 (a JNK inhibitor; 30 mg/kg, IO), or PD98059 (an MEK/ERK inhibitor; 30 mg/kg, IO). Rats were sacrificed 4 hours after LPS treatment. RESULTS: SP600125 or PD98059 inhibited LPS-induced phosphorylation of JNK and ERK, total protein and LDH activity in BAL fluid, and neutrophil influx into the lungs. In addition, these MAP kinase inhibitors substantially reduced LPS-induced production of inflammatory mediators, such as CINC, MMP-9, and nitric oxide. Inhibition of JNK correlated with suppression of NF-κB activation through downregulation of phosphorylation and degradation of IκB-α, while ERK inhibition only slightly influenced the NF-κB pathway. CONCLUSION: JNK and ERK play pivotal roles in LPS-induced acute lung injury. Therefore, inhibition of JNK or ERK activity has potential as an effective therapeutic strategy in interventions of inflammatory cascade-associated lung injury
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