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This study examined height inequality as an indicator of income inequality during the colonial period (1910–1945) in Korea. Data were taken from a sample of 1796 male prisoners from a wide range of geographical locations and with varied socioeconomic backgrounds. Height inequality was measured using the coefficient of variation of height (CV) for each birth decade. The results indicated that height inequality, as measured by the CV, increased slightly from 3.32 to 3.35 for the birth decades 1890–99 and 1900–09, then jumped to 3.50 for the birth decade 1910–19. Considering the Kuznets curve, the presented results have socioeconomic implications for Japan’s impact in Korea, at least during the early colonial period.
Our aim was to examine the prevalence, correlates, and association of depressive and anxiety disorders with quality of life (QoL) and such other outcomes as the need for psychosocial services in cancer patients.
A total of 400 patients participated in a multicenter survey involving five cancer centers located throughout Korea. The Short-Form Health Survey, the MD Anderson Symptom Inventory, the Mini-Mental Adjustment to Cancer (MINI-MAC), and Mini-International Neuropsychiatric Interview were administered.
The prevalence rates for depressive and anxiety disorders were 16 and 17.1%, respectively. Younger age and poor Eastern Cooperative Oncology Group performance status, and all physical symptoms, as well as helplessness/hopelessness, anxious preoccupation (AP), and cognitive avoidance (CA) on the MINI-MAC were found to be significantly related to depressive disorder (DD) in a univariate logistic regression analysis. Metastases, the symptoms of disturbed sleep, dry mouth, and numbness or tingling, as well as AP and CA were significantly correlated with anxiety disorder (AD) in the univariate analysis. In the multivariate analyses, only AP was significant for AD (odds ratio = 2.94, p < 0.001), while none reached statistical significance for DD. Psychiatric comorbidity status had a detrimental effect on various dimensions of QoL. Patients with DD or AD reported a significantly higher need for professional psychosocial services.
Significance of results:
Given the substantial prevalence and pervasive impact of DD and AD on various aspects of QoL, its assessment and care should be integrated as a regular part of oncological care throughout the cancer continuum.
Personality may predispose family caregivers to experience caregiving differently in similar situations and influence the outcomes of caregiving. A limited body of research has examined the role of some personality traits for health-related quality of life (HRQoL) among family caregivers of persons with dementia (PWD) in relation to burden and depression.
Data from a large clinic-based national study in South Korea, the Caregivers of Alzheimer's Disease Research (CARE), were analyzed (N = 476). Path analysis was performed to explore the association between family caregivers’ personality traits and HRQoL. With depression and burden as mediating factors, direct and indirect associations between five personality traits and HRQoL of family caregivers were examined.
Results demonstrated the mediating role of caregiver burden and depression in linking two personality traits (neuroticism and extraversion) and HRQoL. Neuroticism and extraversion directly and indirectly influenced the mental HRQoL of caregivers. Neuroticism and extraversion only indirectly influenced their physical HRQoL. Neuroticism increased the caregiver's depression, whereas extraversion decreased it. Neuroticism only was mediated by burden to influence depression and mental and physical HRQoL.
Personality traits can influence caregiving outcomes and be viewed as an individual resource of the caregiver. A family caregiver's personality characteristics need to be assessed for tailoring support programs to get the optimal benefits from caregiver interventions.
This study evaluated the impacts of earlier traumatic events on the mental health of older adults, in terms of mental disorders and mental well-being, according to sociodemographic variables, trauma-related characteristics, and personality traits in a nationally representative sample of older Koreans.
A total of 1,621 subjects aged 60 to 74 years from a Korean national epidemiological survey of mental disorders responded face-to-face interviews. The Korean Composite International Diagnostic Interview was used to investigate lifetime trauma exposure (LTE) and psychiatric diagnoses. The EuroQol health classification system and life satisfaction scale were used to assess quality of life (QoL), and the Big Five Inventory-10 (BFI-10) to measure personality traits.
Five-hundred and seventy-seven subjects (35.6%) reported a history of LTE (mean age at trauma, 30.8 years old). Current mental disorders were more prevalent in elderly people with LTE, while better current QoL was more frequent in those without LTE. Among older people with LTE, lower extraversion and higher neuroticism increased the risk of current mood or anxiety disorders, whereas higher extraversion increased the probability of experiencing mental well-being after adjusting for sociodemographic and trauma-related variables.
Personality traits, especially extraversion, and neuroticism, may be useful for predicting the mental health outcomes of LTE in older adults. Further longitudinal studies investigating the relationship between traumatic events and mental health outcomes are needed.
Removing residual moisture in lithium-ion battery electrodes is essential for
desired electrochemical performance. In this manuscript, the residual moisture
in LiNi0.5Mn0.3Co0.2O2 cathodes
produced by conventional solvent-based and aqueous processing is characterized
and compared. The electrochemical performance has also been investigated for
various residual moisture contents. It has been demonstrated that the residual
moisture lowers the first cycle coulombic efficiency, but its effect on short
term cycle life is insignificant.
Cerebral white matter hyperintensities (WMH) are prevalent incident findings on brain MRI scans among elderly people and have been consistently implicated in cognitive dysfunction. However, differential roles of WMH by region in cognitive function are still unclear. The aim of this study was to ascertain the differential role of regional WMH in predicting progression from mild cognitive impairment (MCI) to different subtypes of dementia.
Participants were recruited from the Clinical Research Center for Dementia of South Korea (CREDOS) study. A total of 622 participants with MCI diagnoses at baseline and follow-up evaluations were included for the analysis. Initial MRI scans were rated for WMH on a visual rating scale developed for the CREDOS. Differential effects of regional WMH in predicting incident dementia were evaluated using the Cox proportional hazards model.
Of the 622 participants with MCI at baseline, 139 patients (22.3%) converted to all-cause dementia over a median of 14.3 (range 6.0–36.5) months. Severe periventricular WMH (PWMH) predicted incident all-cause dementia (Hazard ratio (HR) 2.22; 95% confidence interval (CI) 1.43–3.43) and Alzheimer's disease (AD) (HR 1.86; 95% CI 1.12–3.07). Subcortical vascular dementia (SVD) was predicted by both PWMH (HR 16.14; 95% CI 1.97–132.06) and DWMH (HR 8.77; 95% CI 1.77–43.49) in more severe form (≥ 10 mm).
WMH differentially predict dementia by region and severity. Our findings suggest that PWMH may play an independent role in the pathogenesis of dementia, especially in AD.
We report on the formation of highly flexible and transparent TiO2/Ag/ITO multilayer films deposited on polyethylene terephthalate substrates. The optical and electrical properties of the multilayer films were investigated as a function of oxide thickness. The transmission window gradually shifted toward lower energies with increasing oxide thickness. The TiO2 (40 nm)/Ag (18 nm)/ITO (40 nm) films gave the transmittance of 93.1% at 560 nm. The relationship between transmittance and oxide thickness was simulated using the scattering matrix method to understand high transmittance. As the oxide thickness increased from 20 to 50 nm, the carrier concentration gradually decreased from 1.08 × 1022 to 6.66 × 1021 cm−3, while the sheet resistance varied from 5.8 to 6.1 Ω/sq. Haacke's figure of merit reached a maximum at 40 nm and then decreased with increasing oxide thickness. The change in resistance for the 60 nm-thick ITO single film rapidly increased with increasing bending cycles, while that of the TiO2/Ag/ITO (40 nm/18 nm/40 nm) film remained virtually unchanged during the bending test.
There is increasing evidence of a relationship between underweight or obesity and dementia risk. Several studies have investigated the relationship between body weight and brain atrophy, a pathological change preceding dementia, but their results are inconsistent. Therefore, we aimed to evaluate the relationship between body mass index (BMI) and cortical atrophy among cognitively normal participants.
We recruited cognitively normal participants (n = 1,111) who underwent medical checkups and detailed neurologic screening, including magnetic resonance imaging (MRI) in the health screening visits between September 2008 and December 2011. The main outcome was cortical thickness measured using MRI. The number of subjects with five BMI groups in men/women was 9/9, 148/258, 185/128, 149/111, and 64/50 in underweight, normal, overweight, mild obesity, and moderate to severe obesity, respectively. Linear and non-linear relationships between BMI and cortical thickness were examined using multiple linear regression analysis and generalized additive models after adjustment for potential confounders.
Among men, underweight participants showed significant cortical thinning in the frontal and temporal regions compared to normal weight participants, while overweight and mildly obese participants had greater cortical thicknesses in the frontal region and the frontal, temporal, and occipital regions, respectively. However, cortical thickness in each brain region was not significantly different in normal weight and moderate to severe obesity groups. Among women, the association between BMI and cortical thickness was not statistically significant.
Our findings suggested that underweight might be an important risk factor for pathological changes in the brain, while overweight or mild obesity may be inversely associated with cortical atrophy in cognitively normal elderly males.
The flow in an axisymmetric contraction fitted to a fully developed pipe flow is experimentally and numerically studied. The reduction in turbulence intensity in the core region of the flow is discussed on the basis of the budgets for the various turbulent stresses as they develop downstream. The contraction generates a corresponding increase in energy in the near-wall region, where the sources for energy production are quite different and of opposite sign compared to the core region, where these effects are caused primarily by vortex stretching. The vortices in the pipe become aligned with the flow as the stretching develops through the contraction. Vortices which originally have a spanwise component in the pipe are stretched into pairs of counter-rotating vortices which become disconnected and aligned with the mean flow. The structures originating in the pipe which are inclined at an angle with respect to the wall are rotated towards the local mean streamlines. In the very near-wall region and the central part of the contraction the flow tends towards two-component turbulence, but these structures are different. The streamwise and azimuthal stresses are dominant in the near-wall region, while the lateral components dominate in the central part of the flow. The two regions are separated by a rather thin region where the flow is almost isotropic.
The bonding between two dissimilar materials has been a problem, partiularly in coating metals with non-metallic protective layer. In this work, it is demonstrated that a strong bonding between ceramics/metal can be achieved by mixing the atoms at the interface by ion-beam. Specifically, SiC coating on Hastelloy X was studied for a high temperature corrosion protection. Auger elemental mapping across the interface shows a far broader mixed region than the region expected by SRIM calculation, which is thought to be due to the thermal spike liquid state diffusion. The results showed that, although the thermal expansion coefficient of Hastelloy X is about three times higher than that of SiC, the film did not peel-off at above 900 oC confirming excellent adhesion. Instead, the SiC film was cracked along the grain boundary of the substrate above 700 oC. At above 900 oC, the film was crystallized forming islands on the substrate so that a considerable part of the substrate surface could be exposed to the corrosive environment. To cover the exposed area, it is suggested that the coating/IBM process should be repeated multiply.
When a drop is deposited on a superhydrophilic micropillar array, the upper part of the drop (referred to as the bulk) collapses while the bottom part penetrates into the gaps of the array, forming a fringe film. Here we quantify the early stage dynamics of this process using a combination of experiment and theory. We show that the circular front of the fringe film spreads like t1/2, t being time, when coupled to the bulk flow. However, the film is found to advance like t1/3 through faceted zippering in the absence of the bulk. We then show that the spreading of the bulk and the entire drop footprint follows a power law (t1/4) that is different from Washburn's law. This work can be a starting point to completely understand the spreading of liquids on superhydrophilic surfaces and opens questions specific to superwetting behaviour including the criteria to determine whether the fringe film will expand through lateral zipping or advance radially outwards.
SrTiO3:Pr,Ga phosphor using Li2CO3 as a flux has been investigated as a red phosphor for the application to fluorescent displays operated at low voltage. In SrTiO3:Pr,Ga system, Pr3+can substitute for Sr2+ because the ionic radius of Pr3+almost coincides with that of Sr2+. Previous work, it was found by XRF analysis of SrTiO3:Pr,Ga single crystal that only a small fraction of Pr ions are incorporated in the SrTiO3 lattice. In the present study, the effect of Li addition into SrTiO3:Pr,Ga on the cathodoluminescence (CL) properties was examined at low acceleration voltage. Especially, thanks to the liquid phase of Li2CO3 during the sintering process, doped Li ions act as a lubricant for the efficient incorporation of Pr ions into SrTiO3:Pr,Ga lattice. Furthermore, it is found that the Li addition could enhance the generation of the characteristic emission of Pr-activated SrTiO3phosphors.
We have studied a CW laser crystallization (CLC) of various-shaped a-Si patterns on glass with changing scanning speed and laser power. The crystallized region inside the patterns showed 3 distinct regions, which is distinguished by their grain size; fine grains of several tens of nanometers near the edge of the pattern, very large grains over a few micrometers at the center of the pattern, so called Sequential Lateral Crystallization region and large grains about a micrometer or less between SLC and fine grain regions. This phenomenon is due to the formation of 2-D temperature gradient inside the pattern. One is the temperature gradient between the edge and center; the temperature of outer region is lower than that of inner region during or right after a CW laser scanning. The other is the temperature gradient along the scan direction; the temperature of starting region of a CW laser scanned area is lower than that of ending region. The former contributes mainly to make molten silicon area inside a pattern, and the latter induces lateral growth along the scan direction to make long grains in SLC region.
We investigated the temperature dependent characteristics of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFT's) at temperatures down to 20 K. With decreasing temperature, the threshold voltage increased, the field effect mobility and the on-current decreased. The measured on-currents versus inverse temperature above 80 K are represented as the sum of two exponentially varied currents. It is concluded that on-current is nearest-neighbour hopping between 120 K and 80 K. Below this temperature, the temperature dependence of on-current is explained by variable range hopping and below about 30 K on-current becomes nearly independent of temperature. At very low temperature hopping probability may be governed not by temperature but by temperature independent tunneling, depending on the overlap of the wave function. The explanation of threshold voltage increase at low temperature is given.
We presents a new model for the series resistance of an amorphous silicon (a-Si) thin film transistor (TFT) with an inverted-staggered configuration, considering the current spreading under the source and the drain contacts as well as the space charge limited current. The calculated results of our model have been in good agreements with the measured data over a wide range of applied voltage, gate-to-source and gate-to-drain overlap length, channel length, and operating temperature. Our model shows that the relative contribution of the series resistances to the current-voltage (I-V) characteristics of the a-Si TFT in the linear regime is more significant at low drain and high gate voltages, for short channel and small overlap length, and at low operating temperature, which has been verified successfully by the experimental measurements.
The experimental results regarding to the effects of ultraviolet (UV) light illumination on the characteristics of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFT's) have been presented. The device parameters of a-Si:H TFT, such as threshold voltage, field-effect mobility, and subthreshold slope, have been degraded by electrical stress and visible light illumination, but substantially improved by UV radiation. This may be attributed to an annealing effect on the dangling-bond defects, involving a number of phonons generated by absorption of high energy UV photons in the a-Si:H TFT channel. It has been also observed that the off-current of a-Si:H TFT decreases remarkably while the on-current changes very little. From the experimental results, we report that the improved on/off current ratio of a-Si:H TFT may be achieved by UV radiation.
We have studied the growth of undoped and n+ μc-Si:H (:CI) films by Remote Plasma CVD using SiH4/SiH2Cl2/H2/He mixtures. It was found that the μc-Si film can be fabricated by increasing flow rate of SiH2Cl2 and/or H2. The deposited undoped μc-Si film exhibited a maximum crystalline volume fraction of 85 %, obtained from Raman spectroscopy. The n-type μc-Si film, deposited with SiH4/SiH2Cl2/H2/PH3/He mixtures, shows a room temperature conductivity of 2 S/cm, conductivity activation energy of 29.8 meV and optical band gap of-2.0 eV. The optical band gap of n-type μc-S1 deposited using SiH2Cl2 is much higher compared to conventional μc-Si film.
We have studied the structural properties of hydrogenated carbon films deposited by plasma enhanced chemical vapor deposition (PECVD). The substrate holder in reaction chamber could be biased and be heated. The Raman peak intensity at 1350 cm−1 was increased by reducing CH4 flow rate. The film structure changed from soft a-C:H to hard carbon with decreasing CH4 flow rate, resulted from increased self-bias. The 1520 cm−1 peak shifts to higher frequency by reducing the CH4flow rate, probably resulted from the increased internal stress.