Structural Investigation of BaIrO3_3 by Neutron Diffraction

We report a temperature-dependent neutron diffraction (ND) study on polycrystalline monoclinic BaIrO$_3$ which is famous for charge density wave (CDW) and weak ferromagnetic phase transitions at T$_C$$\sim$180 K simultaneously. A Rietveld analysis on the ND patterns reveals that even though there is no symmetry breaking in crystal structure, a noticeable change in the four kinds of IrO$_{6}$ octahedra is isolated as the temperature approaches to T$_C$. Based on the structure analysis results, we calculated the $d$-orbital energy level splittings by crystal electric field for each type of the IrO$_6$ octahedra. By taking into account the strong spin-orbit coupling in Ir 5$d$ orbitals and the lattice distortions obtained from the ND analysis, we propose an electronic configuration model to understand the phase transition of the system, where an effective $J_{\rm eff, 1/2}$ Mott insulating phase and a charge gap phase induced by bonding states between the $J_{\rm eff,1/2}$ states compete each other.Comment: To appear in Journal of the Korean Physical Societ

Dissociating stable nitrogen molecules under mild conditions by cyclic strain engineering

All quiet on the nitrogen front. The dissociation of stable diatomic nitrogen molecules (N-2) is one of the most challenging tasks in the scientific community and currently requires both high pressure and high temperature. Here, we demonstrate that N-2 can be dissociated under mild conditions by cyclic strain engineering. The method can be performed at a critical reaction pressure of less than 1 bar, and the temperature of the reaction container is only 40 degrees C. When graphite was used as a dissociated N* receptor, the normalized loading of N to C reached as high as 16.3 at/at %. Such efficient nitrogen dissociation is induced by the cyclic loading and unloading mechanical strain, which has the effect of altering the binding energy of N, facilitating adsorption in the strain-free stage and desorption in the compressive strain stage. Our finding may lead to opportunities for the direct synthesis of N-containing compounds from N-2

Magnetic resonance imaging analysis of rotator cuff tear after shoulder dislocation in a patient older than 40 years

Background This study was designed to evaluate characters of the rotator cuff tear (RCT) recognized after primary shoulder dislocation in patients older than 40. Methods From 2008 to 2019, patients who visited two hospitals after dislocation were retrospectively reviewed. Inclusion criteria were patients over 40 who had dislocation, with magnetic resonance imaging (MRI) undergone. Exclusion criteria were patients who lost to follow-up, combined with any proximal humerus fracture, brachial plexus injury, and previous operation or dislocation history in the ipsilateral shoulder. Also patients who had only bankart or bony bakart lesion in MRI were excluded. We evaluated RCTs that were recognized by MRI after the primary shoulder dislocation with regard to tear size, degree, involved tendons, fatty degeneration, the age when the first dislocation occurred, and the duration until the MRI was evaluated after the dislocation. Results Fifty-five RCTs were included. According to age groups, the tear size was increased in coronal and sagittal direction, the number of involved tendons was increased, and the degree of fatty degeneration was advanced in infraspinatus muscle. Thirty-two cases (58.2%) conducted MRI after 3 weeks from the first shoulder dislocation event. This group showed that the retraction size of the coronal plane was increased significantly and the fatty accumulation of the supraspinatus muscle had progressed significantly. Conclusions Age is also a strong factor to affect the feature of RCT after the shoulder dislocation in patients over 40. And the delay of the MRI may deteriorate the degree of tear size and fatty degeneration

Core-Level X-Ray Photoemission Satellites in Ruthenates: A New Mechanism Revealing the Mott Transition

Ru 3d core-level x-ray photoemission spectra of various ruthenates are examined. They show in general two-peak structures, which can be assigned as the screened and unscreened peaks. The screened peak is absent in a Mott insulator, but develops into a main peak in the metallic regime. This spectral behavior is well explained by the dynamical mean-field theory calculation for the single-band Hubbard model with on-site core-hole potential using the exact diagonalization method. The new mechanism of the core-level photoemission satellite can be utilized to reveal the Mott transition phenomenon in various strongly correlated electron systems, especially in nano-scale devices and phase-separated materials.Comment: 4 pages, 5 figures, submitted to PR

Effects of Mental Health Support on the Grief of Bereaved People Caused by Sewol Ferry Accident

Few studies have assessed the overall effects of multi-centered, complicated mental health support on the grief process. This study investigated the broader influence of mental health support provided practically to the bereaved family on the severity of complicated grief. Ninety-three bereaved family members of the Sewol ferry accident were recruited. Severity of complicated grief, post-traumatic stress disorder (PTSD) and depressive disorder was assessed through self-reporting questionnaire, inventory of complicated grief (ICG), PTSD Check List-5 (PCL-5) and Patient Health Questionnaire-9 (PHQ-9). We also included demographic, socioeconomic, health-related variables, and Functional Social Support Questionnaire (FSSQ), which affect the ICG score. Participants were divided into 4 groups based on the experience of psychotherapy or psychiatry clinic service before the accident and mental health support after the disaster. In univariate analysis, these 4 groups showed a significant difference in the mean ICG score (P=0.020). Participants who received mental health support only after the Sewol ferry accident (group 2) showed a lower mean ICG score than those who received neither psychotherapy or psychiatry clinic service before the disaster nor mental health support after the accident (group 4). There was no significant correlation between the ICG score and other variables except for subjective health status measured 1 month after the disaster (P=0.005). There was no significant difference in PCL-5 (P=0.140) and PHQ-9 scores (P=0.603) among groups, respectively. In conclusion, mental health support significantly reduced the severity of grief only in those participants who had not received any psychotherapy or psychiatry clinic service before the accident

Two levels above and one level below pedicle screw fixation for the treatment of unstable thoracolumbar fracture with partial or intact neurology

<p>Abstract</p> <p>Background</p> <p>Treatment of unstable thoracolumbar fractures is controversial regarding short or long segment pedicle screw fixation. Although long level fixation is better, it can decrease one motion segment distally, thus increasing load to lower discs.</p> <p>Methods</p> <p>We retrospectively analyzed 31 unstable thoracolumbar fractures with partial or intact neurology. All patients were operated with posterior approach using pedicle screws fixed two levels above and one level below the fracture vertebra. No laminectomy, discectomy or decompression procedure was done. Posterior fusion was achieved in all. Post operative and at final follow-up radiological evaluation was done by measuring the correction and maintenance of kyphotic angle at thoracolumbar junction. Complications were also reported including implant failure.</p> <p>Results</p> <p>Average follow-up was 34 months. All patients had full recovery at final follow-up. Average kyphosis was improved from 26.7° to 4.1° postoperatively and to 6.3° at final follow-up. And mean pain scale was improved from 7.5 to 3.9 postoperatively and to 1.6 at final follow-up, All patients resumed their activity within six months. Only 4 (12%) complications were noted including only one hardware failure.</p> <p>Conclusion</p> <p>Two levels above and one level below pedicle screw fixation in unstable thoracolumbar burst fracture is useful to prevent progressive kyphosis and preserves one motion segment distally.</p

Arthroscopic Treatment of Septic Arthritis of Acromioclavicular Joint

Septic arthritis requires an early diagnosis and proper treatment to prevent the destruction of articular cartilage and joint contracture. This paper presents a rare case of septic arthritis of the acromioclavicular joint that was treated with arthroscopic debridement and resection of the distal clavicle

Association between blood pressure and the risk of chronic kidney disease in treatment-naïve hypertensive patients

Background Although hypertension is a well-known risk factor for chronic kidney disease (CKD), the blood pressure (BP) at which antihypertensive interventions should be initiated remains to be determined. Therefore, we investigated the association between BP and CKD in treatment-naïve individuals. Methods This prospective cohort study considered 7,343 individuals in the Korean Genome and Epidemiology Study who were not taking antihypertensive medications. Subjects were categorized into six groups according to their systolic BP (SBP) and five groups according to their diastolic BP (DBP). The primary outcome was incident CKD, which was defined as an estimated glomerular filtration rate of <60 mL/min/1.73 m2 or the development of proteinuria. The secondary outcome was incident cardiovascular disease (CVD). Results In the time-varying Cox models, the hazard ratios (95% confidence interval [CI]) for CKD were 1.39 (1.10–1.77) with SBP 130–139 mmHg, 1.79 (1.40–2.28) with SBP 140–159 mmHg, and 3.22 (2.35–4.40) with SBP ≥ 160 mmHg, compared with SBP 100–119 mmHg. In addition, the hazard ratios (95% CI) for CKD were 1.88 (1.48–2.37) with DBP 90–99 mmHg and 4.30 (3.20–5.76) with DBP ≥ 100 mmHg, compared with DBP 70–79 mmHg. A significantly increased CVD risk was also observed in subjects with SBP ≥ 130 mmHg or DBP ≥ 90 mmHg. Conclusion Our findings indicate that SBP ≥ 130 mmHg and DBP ≥ 90 mmHg are associated with an increased risk of CKD. Therefore, BP-lowering strategies should be considered starting at those thresholds to prevent CKD development