synthesis-triazole-tetrazole-functionalized-zr-based-metal-organic

Synthesis of Triazole and Tetrazole-Functionalized Zr-Based Metal-Organic Frameworks Through Post-Synthetic Ligand Exchange

Metal-organic frameworks (MOFs) are a class of porous materials that are formed through coordination bonds between metal clusters and organic ligands. ...

Seoul National University

The purpose of this study was to evaluate the associations between weight status and mental disorders, including depressive disorder, anxiety disorder and alcohol use disorder. A total of nationally representative 6,510 subjects aged 18-64 yr was interviewed in face-to-face household survey. Response rate was 81.7%. Mental disorders were diagnosed using the Korean version of the Composite International Diagnostic Interview (K-CIDI). The subjects reported their heights and weights. After adjusting for age and gender, the lifetime diagnosis of depressive disorder had a significant association with only the underweight group (odds ratio [OR], 1.68, 95% confidence interval [CI], 1.19-2.38). The association between underweight and depressive disorder was the strongest for subjects with a high education level (OR, 1.75, 95% CI, 1.2-2.56), subjects with a married/cohabiting status (OR, 1.94, 95% CI, 1.17-3.22) and smokers (OR, 2.58, 95% CI, 1.33-4.98). There was no significant association between obesity and depressive disorder in Korea. But there was a significant association between the underweight group and depressive disorder. The relationship between obesity and mental disorder in a Korean population was different from that in a Western population. These results suggest that the differences of traditional cultures and races might have an important effect on the associations between the weight status and mental disorders.

Relationships of mental disorders and weight status in the Korean adult population.

The present study represents the first attempt at examining variation across Korean cohorts with respect to lifetime risk of DSM-IV psychiatric disorders.

Lifetime risk and age of onset distributions of psychiatric disorders: analysis of national sample survey in South Korea.

The aim of this study was to estimate the prevalence of the DSM-IV major mental disorders in the Korean population using the Korean version of Composite International Diagnostic Interview (K-CIDI).

Prevalence of DSM-IV major mental disorders among Korean adults: A 2006 National Epidemiologic Survey (KECA-R).

Corrigendum to "Prevalence of DSM-IV major mental disorders among Korean adults: A 2006 National Epidemiologic Survey (KECA-R)" [Asian Journal of Psychiatry 3 (2010) 26-30].

Kinetic-quantum-sieving-assisted H :D separation in flexible porous materials is more effective than the currently used energy-intensive cryogenic distillation and girdle-sulfide processes for isotope separation. It is believed that material flexibility results in a pore-breathing phenomenon under the influence of external stimuli, which helps in adjusting the pore size and gives rise to the optimum quantum-sieving phenomenon at each stage of gas separation. However, only a few studies have investigated kinetic-quantum-sieving-assisted isotope separation using flexible porous materials. In addition, no reports are available on the microscopic observation of isotopic molecular transportation during the separation process under dynamic transition. Here, the experimental observation of a significantly faster diffusion of deuterium than hydrogen in a flexible pore structure, even at high temperatures, through quasi-elastic neutron scattering, is reported. Unlike rigid structures, the extracted diffusion dynamics of hydrogen isotopes within flexible frameworks show that the diffusion difference between the isotopes increases with an increase in temperature. Owing to this unique inverse trend, a new strategy is suggested for achieving higher operating temperatures for efficient isotope separation utilizing a flexible metal-organic framework system.

Elucidation of Diffusivity of Hydrogen Isotopes in Flexible MOFs by Quasi-Elastic Neutron Scattering.

A covalent connection between two orthogonal functional groups (-NH and -OH) in metal-organic frameworks (MOFs) has been developed. This post-synthetic ligand cyclization (PSLC) was successfully demonstrated to synthesize a benzoxazole-functionalized MOF from a Zr-based UiO-66-2,3-(NH)(OH) under microwave irradiation. In contrast, the regioisomeric UiO-66-2,5-(NH)(OH) only produces a non-cyclized formamide-functionalized MOF.

Post-synthetic ligand cyclization in metal-organic frameworks through functional group connection with regioisomerism.

Since flexible devices are being used in various states of charge (SoCs), it is important to investigate SoCs that are durable against external mechanical deformations. In this study, the effects of a mechanical fatigue test under various initial SoCs of batteries were investigated. More specifically, ultrathin pouch-type Li-ion polymer batteries with different initial SoCs were subjected to repeated torsional stress and then galvanostatically cycled 200 times. The cycle performance of the cells after the mechanical test was compared to investigate the effect of the initial SoCs. Electrochemical impedance spectroscopy was employed to analyze the interfacial resistance changes of the anode and cathode in the cycled cells. When the initial SoC was at 70% before mechanical deformation, both electrodes well maintained their initial state during the mechanical fatigue test and the cell capacity was well retained during the cycling test. This indicates that the cells could well endure mechanical fatigue stress when both electrodes had moderate lithiation states. With initial SoCs at 0% and 100%, the batteries subjected to the mechanical test exhibited relatively drastic capacity fading. This indicates that the cells are vulnerable to mechanical fatigue stress when both electrodes have high lithiation states. Furthermore, it is noted that the stress accumulated inside the batteries caused by mechanical fatigue can act as an accelerated degradation factor during cycling.

Jin Yeong Kim

Department of Chemistry Education

Seoul National University

Synthesis of Triazole and Tetrazole-Functionalized Zr-Based Metal-Organic Frameworks Through Post-Synthetic Ligand Exchange

Jin Yeong Kim

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Chemistry Education

Seoul National University

Synthesis of Triazole and Tetrazole-Functionalized Zr-Based Metal-Organic Frameworks Through Post-Synthetic Ligand Exchange

Department of Chemistry Education