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Depressive symptoms are common in bereaved caregivers; however, there have been few prospective studies using a structured interview. This study investigated the prevalence and preloss predictors of major depressive disorder (MDD) in bereaved caregivers of patients in a palliative care unit.
This prospective cohort study collected caregiver sociodemographic and psychological data before the death of a palliative care unit patient, including MDD, care-burden, coping style, and hopeful attitude. Postloss MDD was assessed 6 and 13 months after death, and a multivariate logistic regression analysis was conducted to identify its predictors.
Of 305 caregivers contacted, 92 participated in this study. The prevalence of preloss MDD was 21.8%; the prevalences of postloss MDD were 34.8% and 24.7% at 6 and 13 months, respectively. Preloss MDD predicted postloss MDD at 6 months (odds ratio [OR] = 5.38, 95% confidence interval [CI95%] = 1.29, 22.43); preloss nonhopeful attitude and unemployment status of caregivers predicted postloss MDD at 13 months (OR = 8.77, CI95% = 1.87, 41.13 and OR = 7.10, CI95% = 1.28, 39.36, respectively).
Significance of results
Approximately 35% of caregivers suffered from MDD at 6 months postloss, but the prevalence of MDD decreased to about 25% at 13 months. Preloss MDD significantly predicted postloss MDD at 6 months, whereas hopeful attitude and unemployment at baseline were significantly associated with postloss MDD at 13 months.
To secure the reliability of flexible electronics, the effect of multicomponent stress on the device properties during complex mechanical deformation needs to be thoroughly understood. The electrical resistances of metal interconnects are investigated by in situ monitoring at different twisting angles and with different pattern positions. As the twisting angle increased, the electrical resistance increased earlier. Furthermore, in the line pattern located far from the central axis, severe electrical degradation and fatigue damage formation were observed. Multicomponent stress evolution during twisting was analyzed by the finite-element simulation method. For easy practical application for estimating the representative twisting strain, an analytic solution of twisting deformation was formulated and compared with the simulation. Using the equivalent strain, the fatigue lifetime was fitted, and the exponents were obtained for lifetime expectation. This systematic study provides the guidelines for highly reliable flexible devices and the tools for determining the expected fatigue lifetime.
We trace Sn nanoparticles (NPs) produced from SnO2 nanotubes (NTs) during lithiation initialized by high energy e-beam irradiation. The growth dynamics of Sn NPs is visualized in liquid electrolytes by graphene liquid cell transmission electron microscopy. The observation reveals that Sn NPs grow on the surface of SnO2 NTs via coalescence and the final shape of agglomerated NPs is governed by surface energy of the Sn NPs and the interfacial energy between Sn NPs and SnO2 NTs. Our result will likely benefit more rational material design of the ideal interface for facile ion insertion.
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.
The Sewol ferry disaster is one of the most tragic events in Korea’s modern history. Among the 476 people on board, which included Danwon High School students (324) and teachers (14), 304 passengers died in the disaster (295 recovered corpses and 9 missing) and 172 survived. Of the rescued survivors, 72 were attending Danwon High School, located in Ansan City, and residing in a residence nearby. Because the students were young, emotionally susceptible adolescents, both the government and the parents requested the students be grouped together at a single hospital capable of appropriate psychiatric care. Korea University Ansan Hospital was the logical choice, as the only third-tier university-grade hospital with the necessary faculty and facilities within the residential area of the families of the students. We report the experiences and the lessons learned from the processes of preparing for and managing the surviving young students as a community-based hospital. (Disaster Med Public Health Preparedness. 2017;11:389–393)
According to most prospective studies, being underweight (BMI<18·5 kg/m2) is associated with significantly higher mortality than being of normal weight, especially among smokers. We aimed to explore in a generally lean population whether being underweight is significantly associated with increased all-cause mortality.
Prospective cohort study.
Korea Medical Insurance Corporation study with 14 years of follow-up.
After excluding deaths within the first 5 years of follow-up (1993–1997) to minimize reverse causation and excluding participants without information about smoking and health status, 94 133 men and 48 496 women aged 35–59 years in 1990 were included.
We documented 5411 (5·7 %) deaths in men and 762 (1·6 %) in women. Among never smokers, hazard ratios (HR) for underweight individuals were not significantly higher than those for normal-weight individuals (BMI=18·5–22·9 kg/m2): HR=0·87 (95 % CI 0·41, 1·84, P=0·72) for underweight men and HR=1·12 (95 % CI 0·76, 1·65, P=0·58) for underweight women. Among ex-smokers, HR=0·86 (95 % CI 0·38, 1·93, P=0·72) for underweight men and HR=3·77 (95 % CI 0·42, 32·29, P=0·24) for underweight women. Among current smokers, HR=1·60 (95 % CI 1·28, 2·01, P<0·001) for underweight men and HR=2·07 (95 % CI 0·43, 9·94, P=0·36) for underweight women.
The present study does not support that being underweight per se is associated with increased all-cause mortality in Korean men and women.
To determine the influence of caregiver personality and other factors on the burden of family caregivers of terminally ill cancer patients.
We investigated a wide range of factors related to the patient–family caregiver dyad in a palliative care setting using a cross-sectional design. Caregiver burden was assessed using the seven-item short version of the Zarit Burden Interview (ZBI–7). Caregiver personality was assessed using the 10-item short version of the Big Five Inventory (BFI–10), which measures the following five personality dimensions: extroversion, agreeableness, conscientiousness, neuroticism, and openness. Patient- and caregiver-related sociodemographic and psychological factors were included in the analysis because of their potential association with caregiver burden. Clinical patient data were obtained from medical charts or by using other measures. Multivariate linear regression analysis was performed to identify the independent factors associated with caregiver burden.
We analyzed 227 patient–family caregiver dyads. The multivariate analysis revealed that caregiver extroversion was protective against caregiver burden, whereas depressive symptoms in caregivers were related to increased burden. Neuroticism was positively correlated with caregiver burden, but this relationship was nonsignificant following adjustment for depressive symptoms. Patient-related factors were not significantly associated with caregiver burden.
Significance of Results:
Evaluating caregiver personality traits could facilitate identification of individuals at greater risk of high burden. Furthermore, depression screening and treatment programs for caregivers in palliative care settings are required to decrease caregiver burden.
The thickness dependence of the electrical stability under monotonic and cyclic tensile loading is investigated for Cu films on polymer substrates. As for monotonic tensile deformation, thicker films show better stability than thinner films due to their higher ductility and the larger capability of strain accommodation. For the fatigue resistance, however, a more complex behavior was observed depending on the amount of the applied strain. For low strain amplitude in the high cycle fatigue (HCF) regime, thinner films exhibit longer fatigue life because the larger strength of thinner films suppresses dislocation movement and damage nucleation. However, for high strain amplitudes in the low cycle fatigue (LCF) regime, the fatigue life for thinner films is drastically reduced compared to thicker films. It is shown that fatigue coefficients in the LCF regime can be obtained when applying the Coffin–Manson relationship.
Cancer is a leading cause of death, and the dietary pattern in Korea is changing rapidly from a traditional Korean diet to a Westernised diet. In the present study, we investigated the effects of dietary factors on cancer risk with a prospective cohort study. Among 26 815 individuals who participated in cancer screening examinations from September 2004 to December 2008, 8024 subjects who completed a self-administered questionnaire concerning demographic and lifestyle factors, and a 3 d food record were selected. As of September 2013, 387 cancer cases were identified from the National Cancer Registry System, and the remaining individuals were included in the control group. The hazard ratio (HR) of cancer for the subjects older than or equal to 50 years of age was higher (HR 1·80, 95 % CI 1·41, 2·31; P< 0·0001) than that for the other subjects. Red meat consumption, Na intake and obesity (BMI ≥ 25 kg/m2) were positively associated with overall cancer incidence in men (HR 1·41, 95 % CI 1·02, 1·94; P= 0·0382), gastric cancer (HR 2·34, 95 % CI 1·06, 5·19; P= 0·0365) and thyroid cancer (HR 1·56, 95 % CI 1·05, 2·31; P= 0·0270), respectively. Participants who had at least three dietary risk factors among the high intakes of red meat and Na, low intakes of vegetables and fruits, and obesity suggested by the World Cancer Research Fund/American Institute for Cancer Research at baseline tended to have a higher risk of cancer than the others (HR 1·26, 95 % CI 0·99, 1·60; P= 0·0653). In summary, high intakes of red meat and Na were significant risk factors of cancer among Koreans.
Background: Highly educated participants with normal cognition show lower incidence of Alzheimer's disease (AD) than poorly educated participants, whereas longitudinal studies involving AD have reported that higher education is associated with more rapid cognitive decline. We aimed to evaluate whether highly educated amnestic mild cognitive impairment (aMCI) participants show more rapid cognitive decline than those with lower levels of education.
Methods: A total of 249 aMCI patients enrolled from 31 memory clinics using the standard assessment and diagnostic processes were followed with neuropsychological evaluation (duration 17.2 ± 8.8 months). According to baseline performances on memory tests, participants were divided into early-stage aMCI (−1.5 to −1.0 standard deviation (SD)) and late-stage aMCI (below −1.5 SD) groups. Risk of AD conversion and changes in neuropsychological performances according to the level of education were evaluated.
Results: Sixty-two patients converted to AD over a mean follow-up of 1.43 years. The risk of AD conversion was higher in late-stage aMCI than early-stage aMCI. Cox proportional hazard models showed that aMCI participants, and late-stage aMCI participants in particular, with higher levels of education had a higher risk of AD conversion than those with lower levels of education. Late-stage aMCI participants with higher education showed faster cognitive decline in language, memory, and Clinical Dementia Rating Sum of Boxes (CDR-SOB) scores. On the contrary, early-stage aMCI participants with higher education showed slower cognitive decline in MMSE and CDR-SOB scores.
Conclusions: Our findings suggest that the protective effects of education against cognitive decline remain in early-stage aMCI and disappear in late-stage aMCI.
Highly mesoporous TiO2 nanoparticles (NPs) were synthesized by an aero-sol-gel process in this approach. By varying the mass fraction of inorganic templates, the formation of mesoporous TiO2 NPs with optimized surface area and pore volume distributions was examined. Then, the photovoltaic properties of the resulting mesoporous TiO2 NPs were systematically investigated by applying them into the photoanode of dye-sensitized solar cells (DSSCs). The mesoporous TiO2 NP-based DSSCs fabricated in this study showed an improved short circuit current density and power conversion efficiency compared with solid TiO2 NP-based DSSCs due to the increase of the amount of inorganic dye (N719) adsorption in the mesoporous TiO2 NPs. These mesoporous TiO2 NPs fabricated have a strong potential as an effective dye supporting and electron transfer medium to improve the photovoltaic performance of DSSCs.
The diatoms are an ecologically important group of algae that have been extensively studied by ecologists and taxonomists. However, the large-scale patterns of diatom distribution and the factors underlying this distribution are largely unknown. The aims of this study were to identify the large-scale spatial patterns of benthic diatom assemblages in Korean streams and rivers, and to assess the importance of numerous environmental factors on diatom distribution. We classified 720 study sites based on diatom flora. Benthic diatoms, water chemistry, altitude, and riparian land cover and use were characterized by multivariate analyses, Monte Carlo permutation tests, and indicator species analysis. In total, we identified 531 diatom taxa. Diatom assemblages were mostly dominated by species of the genera Achnanthes, Navicula, Nitzschia, Cocconeis, Fragilaria (Synedra included), Cymbella, Gomphonema, and Melosira. Cluster analysis partitioned all 720 sites into eight groups based on diatom species composition. Canonical correspondence analysis indicated that altitude, land cover and use, current velocity, electrical conductivity, and nutrient levels explained a significant amount of the variation in the composition of assemblages of benthic diatoms. At the national scale, a downstream ecological gradient was apparent, from fast-flowing, mostly oligotrophic highland streams to slow-flowing, mostly eutrophic lowland rivers. Our data suggest that spatial factors explain some of the variation in diatom distribution. The present investigation of the spatial patterns of benthic diatoms, the ecological determinants of diatom occurrence, and the identification of diatom indicator species contributes to development of a program for assessing the biological integrity of lotic ecosystems in Korea.
Current optical data storage is challenging to increase its memory capacity and data transfer rate for realizing high-quality image and rapid service in the coming digital, multimedia and network era. To actualize more effective and simple data storage, a novel parallel near-field optical system has been proposed using vertical cavity surface emitting laser (VCSEL) microprobe arrays. The new parallel optical system is based a multibeam recording head consisting of a VCSEL array with apertures of nanometer size as a near-field wave exit. We have developed some candidates for the parallel recording head, including the direct aperture formation on the VCSEL emitting surface and the preparation of microprobe arrays with flat-tip structure. The new flat-tip microprobe array has advantages for improving the optical efficiency and stabilizing the contact head system with optical media since it is prepared from semiconductor materials of high refractive index. Silicon nano-aperture probe array has been prepared successfully with the aperture size of 150 to 500nm using micro-fabrication techniques. We have also investigated the integrated microprobe array by the direct fabrication of flat-tip probes on the substrate of bottom emitting VCSEL arrays. Finally the reading mechanism has been studied theoretically using a finite difference time domain (FDTD) simulation and an optical feedback effect of semiconductor lasers for the integrated microprobe VCSEL array. We believe this nano-aperture VCSEL probe array is sufficiently effective to be applied to the parallel recording head for the near-field optical data storage of a high data capacity and fast transfer rate.