1,563 research outputs found
Origin, criterion, and mechanism of vortex-core reversals in soft magnetic nanodisks under perpendicular bias fields
We studied dynamics of vortex-core reversals driven by circular rotating fields along with static perpendicular magnetic fields of different direction and strength. We found that the application of perpendicular fields H p modifies the starting ground state of vortex magnetizations, thereby instigating the development of a magnetization dip mz,dip in the vicinity of the original core up to its threshold value, m z,dip cri ???-p, which is necessary for vortex-core reversals, where p is the initial core polarization. We found the relationship of the dynamic evolutions of the mz,dip and the out-of-plane gyrofields hz, which was induced, in this case, by vortex-core motion of velocity ??, thereby their critical value relation ??crihz cri. The simulation results indicated that the variation of the critical core velocity ??cri with Hp can be expressed explicitly as ??cri / ?? cri 0 = (??/ ??0) | -p- m z,dip g |, with the core size ?? and the starting ground-state magnetization dip m z,dip g variable with H p, and for the values of ?? cri 0 and ??0 at H p =0. This work offers deeper and/or new insights into the origin, criterion and mechanism of vortex-core reversals under application of static perpendicular bias fields.open7
Transcultural validation of the return-to-work self-efficacy scale in Korean patients with work-related injuries
Background
This study aimed to develop a Korean version of the Return-to-Work Self-Efficacy (RTWSE)-19 Scale using forward- and backward-translation and investigate the validity of the RTWSE Scale specifically for Korean workers with work-related injuries.
Methods
Participants were 202 injured workers who had filed a claim accepted by the workers compensation system and had received medical rehabilitation at workers compensation hospitals following a work-related musculoskeletal injury. Among these participants, 88.1% were male, 54.5% were over 45 years, 45.5% were manufacturing employees, and 54.5% were craft or machine operator and assemblers. The 19 item RTWSE-19 scale was developed by Shaw et al. and have three underlying subscales: (i) meeting job demands, (ii) modifying job tasks, and (iii) communicating needs to others. Statistical analysis included exploratory factor analysis (maximum likelihood estimation with oblique quartimin rotation), internal consistency reliability using Cronbachs alpha, and correlations with related measures: pain intensity; fear-avoidance beliefs; general health; depression; and general self-efficacy.
Results
Using exploratory factor analysis, three factors with 17 items were identified: meeting job demands, modifying job tasks, and communicating needs to others. The removal of two items in the modifying job tasks domain resulted in an increased reliability. The Korean version of the RTWSE-17 showed reasonable model fit (CFI = .963; TLI = .943; RMSEA = .068; SRMR = 0.029), satisfactory reliability (r = 0.925), no floor and ceiling effect, and construct validity.
Conclusions
The Korean RTWSE-17 scale was found to possess good psychometric properties and could address different injury types ranging from fractures to amputations involved in sub-acute and rehabilitation phases in the Korean context. This studys findings provide insights for practitioners and researchers to return to work after rehabilitation in a Korean clinical and workplace setting.This work was funded by Korea Workers Compensation and Welfare Service (grant number 0720185002 and 0720205002). The funder played no role in the conception, methodology, and interpretation of data or reporting of this stud
Serial I-123-FP-CIT SPECT Image Findings of Parkinson's Disease Patients With Levodopa-Induced Dyskinesia
Background: Levodopa-induced dyskinesia (LID) is a major complication of dopamine replacement drug usage in Parkinson's disease (PD) patients. Since the mechanism of LID is yet unclear, we analyzed serial [I-123] N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) nortropane (I-123 FP-CIT) single photon emission computed tomography (SPECT) images. We investigated the changes of dopaminergic innervation during the progression of PD in relation to the development of LID.Methods: Data were obtained from the Parkinson's Progression Markers Initiative (PPMI) database. Two hundred and ninety PD dopamine replacement drug-naïve patients (age 61.0 ± 9.7, M: F = 195: 95) were enrolled. I-123 FP-CIT SPECT images from baseline, 12, 24, and 48 months were analyzed among with clinical factors. specific binding ratios (SBRs) of the striatal regions from I-123 FP-CIT SPECT images were analyzed. We used independent tests and logistic regression for analysis of LID risk association.Results: Among 290 patients, 36 patients developed LID after 48 months follow-up. Baseline MDS-UPDRS Part II and III scores were significantly higher in the PD patients with LID, compared with the PD patients without LID. Striatal SBRs were significantly lower in the PD patients with LID at baseline, 24 and 48 months (p < 0.001). Multivariate analysis revealed MDS-UPDRS Part II and putaminal SBRs at baseline and 24 months to be significantly associated with the development of LID (p < 0.001). Also, patients who developed LID at 48 months had a higher decrease rate of putaminal SBR at the 24 months (p < 0.05), and 48 months (p < 0.01) period.Conclusion: In this study, we demonstrated the serial changes of the nigrostriatal dopaminergic innervation in relationship to LID development for the first time. The deterioration rate of dopaminergic innervation was significantly higher in the PD patients who developed LID, compared with the PD patients who did not develop LID. Serial follow up I-123 FP-CIT SPECT acquisition during the course of PD could be helpful in predicting the development of LID
Superparamagnetic Iron Oxide Nanoparticles Coated with Galactose-Carrying Polymer for Hepatocyte Targeting
Our goal is to develop the functionalized superparamagnetic
iron oxide nanoparticles (SPIONs) demonstrating the capacities
to be delivered in liver specifically and to be dispersed in
physiological environment stably. For this purpose, SPIONs
were coated with polyvinylbenzyl-O-β-D-galactopyranosyl-D-gluconamide (PVLA) having
galactose moieties to be recognized by asialoglycoprotein
receptors (ASGP-R) on hepatocytes. For use as a control, we also
prepared SPIONs coordinated with 2-pyrrolidone. The sizes, size
distribution, structure, and coating of the nanoparticles were
characterized by transmission electron microscopy (TEM),
electrophoretic light scattering spectrophotometer (ELS), X-ray
diffractometer (XRD), and Fourier transform infrared (FT-IR),
respectively. Intracellular uptake of the PVLA-coated SPIONs was
visualized by confocal laser scanning microscopy, and their
hepatocyte-specific delivery was also investigated through
magnetic resonance (MR) images of rat liver. MRI experimental
results indicated that the PVLA-coated SPIONs possess the more
specific accumulation property in liver compared with control,
which suggests their potential utility as liver-targeting MRI
contrast agent
Potential role and mechanism of IFN-gamma inducible protein-10 on receptor activator of nuclear factor kappa-B ligand (RANKL) expression in rheumatoid arthritis
Introduction
IFN-gamma inducible protein-10 (CXCL10), a member of the CXC chemokine family, and its receptor CXCR3 contribute to the recruitment of T cells from the blood stream into the inflamed joints and have a crucial role in perpetuating inflammation in rheumatoid arthritis (RA) synovial joints. Recently we showed the role of CXCL10 on receptor activator of nuclear factor kappa-B ligand (RANKL) expression in an animal model of RA and suggested the contribution to osteoclastogenesis. We tested the effects of CXCL10 on the expression of RANKL in RA synoviocytes and T cells, and we investigated which subunit of CXCR3 contributes to RANKL expression by CXCL10.
Methods
Synoviocytes derived from RA patients were kept in culture for 24 hours in the presence or absence of TNF-α. CXCL10 expression was measured by reverse transcriptase polymerase chain reaction (RT-PCR) of cultured synoviocytes. Expression of RANKL was measured by RT-PCR and western blot in cultured synoviocytes with or without CXCL10 and also measured in Jurkat/Hut 78 T cells and CD4+ T cells in the presence of CXCL10 or dexamethasone. CXCL10 induced RANKL expression in Jurkat T cells was tested upon the pertussis toxin (PTX), an inhibitor of Gi subunit of G protein coupled receptor (GPCR). The synthetic siRNA for Gαi2 was used to knock down gene expression of respective proteins.
Results
CXCL10 expression in RA synoviocytes was increased by TNF-α. CXCL10 slightly increased RANKL expression in RA synoviocytes, but markedly increased RANKL expression in Jurkat/Hut 78 T cell or CD4+ T cell. CXCL10 augmented the expression of RANKL by 62.6%, and PTX inhibited both basal level of RANKL (from 37.4 ± 16.0 to 18.9 ± 13.0%) and CXCL10-induced RANKL expression in Jurkat T cells (from 100% to 48.6 ± 27.3%). Knock down of Gαi2 by siRNA transfection, which suppressed the basal level of RANKL (from 61.8 ± 17.9% to 31.1 ± 15.9%) and CXCL10-induced RANKL expression (from 100% to 53.1 ± 27.1%) in Jurkat T cells, is consistent with PTX, which inhibited RANKL expression.
Conclusions
CXCL10 increased RANKL expression in CD4+ T cells and it was mediated by Gαi subunits of CXCR3. These results indicate that CXCL10 may have a potential role in osteoclastogenesis of RA synovial tissue and subsequent joint erosion
factor 1α in precancerous nodules with telomere
Increased expression of stathmin and elongatio
Precessing Jet and Large Dust Grains in the V380 Ori NE Star-forming Region
The V380 Ori NE bipolar outflow was imaged in the SiO and CO J = 1 - 0 lines,
and dense cores in L1641 were observed in the 2.0-0.89 mm continuum. The highly
collimated SiO jet shows point-symmetric oscillation patterns in both position
and velocity, which suggests that the jet axis is precessing and the driving
source may belong to a non-coplanar binary system. By considering the position
and velocity variabilities together, accurate jet parameters were derived. The
protostellar system is viewed nearly edge-on, and the jet has a flow speed of
35 km/s and a precession period of 1600 years. The CO outflow length gives a
dynamical timescale of 6300 years, and the protostar must be extremely young.
The inferred binary separation of 6-70 au implies that this protobinary system
may have been formed through the disk instability process. The continuum
spectra of L1641 dense cores indicate that the emission comes from dust, and
the fits with modified blackbody functions give emissivity power indices of
beta = 0.3-2.2. The emissivity index shows a positive correlation with the
molecular line width, but no strong correlation with bolometric luminosity or
temperature. V380 Ori NE has a particularly low value of beta = 0.3, which
tentatively suggests the presence of millimeter-sized dust grains. Because the
dust growth takes millions of years, much longer than the protostellar age,
this core may have produced large grains in the starless core stage. HH 34 MMS
and HH 147 MMS also have low emissivity indices.Comment: To appear in the Astrophysical Journal Supplement Serie
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