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Background/Objectives:Decades of research have investigated the association between body mass index (BMI) and depression. Although it has been suggested that obesity lowers the risk of depression in elderly adults, the association of overweight and obesity with depression across age groups remains controversial. Thus, we aimed to investigate how the odds of depression vary between BMI groups in the general population.Subjects/Methods:In this study, data were collected from the sixth Korea National Health and Nutrition Examination Survey of 2014 (KNHANES VI; n=7550), and 4932 adults were included in the study sample. We investigated the adjusted association between depression, which was measured by the Patient Health Questionnaire 9 (PHQ-9), and BMI groups (underweight, normal weight, overweight, obese class I, obese classes II and III).Results:In all adults, after adjusting for sex, age, income and presence of chronic illnesses, overweight had lower odds of depression than normal weight (OR, 0.811; 95% CI, 0.661–0.995), whereas underweight had higher odds of depression than normal-weight subjects (OR, 1.776; 95% CI, 1.241–2.540). Overweight elderly adults had lower odds of depression than normal-weight elderly adults (OR, 0.522, 95% CI, 0.367–0.743), and obese class I elderly adults also had lower odds of depression than normal-weight elderly adults in both men (OR, 0.482, 95% CI, 0.251–0.924) and women (OR, 0.637, 95% CI, 0.418–0.970). Furthermore, in the normal-weight-to-obese class I elderly adults group, we found that an increase of 1?kg?m-2BMI was significantly associated with a decreased prevalence of depression in both men (OR, 0.898, 95% CI, 0.808–0.997) and women (OR, 0.911, 95% CI, 0.844–0.982).Conclusions:We found that overweight and mild obesity significantly lowered the risk of depression in elderly adults. These findings suggest that mild increases in BMI beyond the normal range may be a protective factor for depression in elderly Korean adults.

In this study, β-SiC powder was prepared using a pyrolysed spherical precursor derived from the hydrolysis mixture of phenyltrimethoxysilane and tetraethyl orthosilicate. Before the pyrolysed experiment, an alkoxide precursor was characterised using 29Si solid nuclear magnetic resonance, Fourier transform infrared spectroscopy and thermogravimetric analysis. The alkoxide precursor was heated at 1800°C for 4 h under an Ar atmosphere. To examine the pyrolysed residue after heat treatment, the sample was collected and analysed with X-ray diffraction. The X-ray diffraction results for the sample show diffraction peaks at ∼35, 60 and 73°, which correspond to the β-SiC phase. According to the results of chemical analysis, the SiC content of the powder that was prepared at 1800°C was determined to be 99·4%. The sintering behaviour of the prepared β-SiC powder was examined using B4C and C as sintering additives in the temperature range of 1900–2200°C.

This study describes the preparation of hydroxyapatite microspheres for local drugs delivery. The formation of the hydroxyapatite microspheres was initiated by enzymatic decomposition of urea and accomplished by emulsification process (water-in-oil). The microspheres obtained were sintered at 500°C. Scanning electron microscope (SEM) indicated that the microspheres have various porous with random size, which maximizes the surface area. Cytotoxicity was not observed after sintering. Osteoporosis drugs, alendronate and BMP-2, were loaded into HAp microspheres and the releases of both molecules showed sustained releasing profiles.

We investigated characteristics of high performance GaN-based laser diodes grown on LEO-GaN/sapphire and free-standing GaN substrates. The maximum output power was 300 mW under cw operation. The operation current and voltage were 53 mA and 4.67 V, respectively, for 30 mW-output power. Thermal simulation and junction temperature measurement of laser diodes showed that epi-down bonding was essential for the use of sapphire substrate. It was proposed that Mg diffusion into active layers was responsible for the degradation mechanism of GaN-based laser diodes. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Coke formation on KVO3−B2O3/SA5203 catalysts during naphtha pyrolysis in a fixed-bed reactor was studied. As the KVO3 loading increased, the amount of coke deposited on KVO3−B2O3/SA5203 decreased, but CO2 formation increased, indicating that KVO3 plays a key role in retarding coke accumulation but not in enhancing the product yields. The coke layers formed on the support and KVO3−B2O3/SA5203 were different in their properties. The coke layer formed on KVO3−B2O3/ SA5203 was free of soluble coke, which dissolves in the CH2Cl2 solution, and consisted of mainly insoluble coke; in contrast, the coke layer formed on the support consisted of both soluble and insoluble coke. The coke layer on KVO3−B2O3/SA5203 catalyst was porous, whereas that on SA5203 was nonporous. KVO3 on the catalyst apparently plays a key role in catalyzing the gasification of soluble coke to CO2.

The catalytic pyrolysis of naphtha has been carried out with 5 mm KVO3-impregnated α-Al2O3. The yields of ethylene and propylene exhibit about 10% and 5% higher values compared to the thermal pyrolysis in a vacant tube at the same operation condition. This increase in the olefin yield comes from the thermal effect through the better heat transfer. The amount of coke accumulated on the catalyst during the pyrolysis increases with an increase in the reaction temperature and the axial length of the reactor. The role of KVO3 is to suppress the coke deposition on the catalyst surface. The addition of B2O3 to the KVO3/α-Al2O3 system causes a strong interaction between KVO3 and α-Al2O3. The results of temperature-programmed reduction and X-ray photoelectron spectroscopy suggest that KVO3 may be reduced to KVO1.5 during the pyrolysis reaction. The weight loss of K and V in the catalyst occurs during the pyrolysis.

Sleep deprivation can affect the waking EEG that may reflect information processing of the brain. We examined the effect of total sleep deprivation (TSD) on nonlinear dynamics of the waking EEG.