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South Korea experienced Middle East Respiratory Syndrome (MERS) outbreak in 2015. To mitigate the threat posed by MERS, the Ministry of Health and Center for Disease Control designated hospitals to be responsible for managing any suspected or confirmed infectious patient. These hospitals receive mandatory training in managing infectious patients, but many of the trainings lack practical skills practice and pandemic preparedness exercise.
To develop and evaluate a training course designed to train healthcare providers from designated hospitals to enhance their competencies in managing emerging infectious diseases and potential outbreaks.
A two-day course was developed by the Center for Disaster Relief, Training, and Research in collaboration with the Korea Health Promotion Institute using Kern’s 6-step approach. The course consisted of didactic lectures, technical skills training, tabletop simulation, and scenario-based simulation. Table-top simulation exercises consisted of cases involving a single infectious patient detected in the outpatient clinic and outbreak in the emergency department. Scenario-based simulation exercises involved managing a critically ill infectious patient in an isolated ward. A post-survey questionnaire was used to evaluate the course and assess the perception changes of the participants. All pre-to-post differences within subjects were analyzed with paired t-tests.
A total of 121 healthcare providers participated in three separate courses. The competencies for pandemic preparedness knowledge, skills, and attitude improved from pre- to post-course. The differences were all statistically significant (p<0.05). Overall course satisfaction in average for expectation, time, delivery method, and contents were 9.5, 9.2, 9.4, and 9.2, respectively.
There needs to be tests and exercises to recognize gaps of systems in place for pandemic preparedness. Simulation exercises are ideal tools for this purpose. Although this was only a two-day intensive course, this increased familiarity with workflows, tested the coordination of workflows between different disciplines and allowed the identification of gaps.
Recent hospital fire incidents in South Korea have heightened the importance of patient evacuation. Moving patients from an intensive care unit (ICU) or emergency department (ED) setting is a challenge due to the complexity of moving acutely unwell patients who are reliant on invasive monitoring and organ support. Despite the importance of patient evacuation, the readiness of ICU and ED for urgent evacuation has not been assessed.
To enhance the readiness and competencies of workers from ICU and ED in the evacuation of patients during a simulated tabletop fire exercise.
A tabletop simulation exercise was developed by the Center for Disaster Relief, Training, and Research referencing the fire evacuation manual developed by the hospital’s ICU and ED. The scenario consisted of evacuating patients horizontally and vertically from each department. The participants’ actions were assessed using a checklist. A debriefing was completed after the exercise to discuss the gaps observed. A post-survey questionnaire was used to evaluate the exercise and assess the perception changes of the participants. All pre-to-post differences within subjects were analyzed with paired t-tests.
A total of 22 and 29 people participated in the exercise from ICU and ED, respectively. Knowledge and confidence improved post-exercise for both ICU and ED scenarios (p<0.05). Course satisfaction was 7.9 and 8.7, respectively for ICU and ED exercise. Correct performance rates for ICU and ED were 59% and 58%, respectively. Common gaps noted for both ICU and ED were wearing protective masks, patient hand-over communication, and preparation for resources.
There need to be exercises to recognize system gaps in place for hospital fire evacuation preparedness. Tabletop simulation exercises are ideal tools for this purpose. Although this was a short 90-minute exercise, this increased familiarity with the evacuation plan, tested the plan, and allowed for identification of gaps.
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.
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.
The present study was performed to investigate whether breast-feeding is associated with early pubertal development among children 7–9 years old in Korea.
Children were divided into those who did and did not receive breast-feeding for 6 months or longer in accordance with the recommendations of the WHO. Pubertal status was determined by clinical examination using Tanner staging.
Prospective observational study.
We conducted a follow-up study of children aged 7–9 years in 2011 who had taken part in the Ewha Birth & Growth Cohort study.
Fifty (22·8 %) of the total of 219 children were in early puberty, with the proportion being slightly higher for girls (24·1 %) than boys (21·4 %). Children who had entered early puberty were taller, weighed more and had a higher concentration of insulin-like growth factor 1. Moreover, the change in weight Z-score from birth to follow-up was significantly lower in children who were breast-fed than in those who were not (weight Z-score change: 0·32 (sd 1·59) v. 0·77 (sd 1·61), respectively, P=0·04). Comparison of breast-feeding by puberty status indicated a preventive association with early puberty in children who were breast-fed for 6 months or longer (OR=0·37; 95 % CI 0·18, 0·74). This association remained significant after adjustment for relevant covariates.
These results demonstrate a beneficial association between breast-feeding and early pubertal development, especially in those breast-fed for 6 months or longer. The study suggests that interventions would need to start early in life to prevent early pubertal development.
The crystallization of amorphous silicon thin films by electron beam exposure was studied. Amorphous silicon and silicon dioxide layers were deposited on glass substrate by PECVD at 360 °C. The optimization to crystallize 300 nm thick amorphous silicon film was carried out at a RF power of 300 W, DC voltage of 1500 V, Argon gas flow rate of 3 sccm and a distance between electron beam mesh and sample of 40 mm. High quality nano-crystalline silicon films with an activation energy of 0.47 eV from conductivity, a grain size of 15–45 nm from SEM and Raman crystalline volume fraction of 93.1% were fabricated. We expect that e-beam exposure will be applied to crystallization of amorphous silicon films.
To compare the characteristics and risk factors for surgical site infections (SSIs) after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in a nationwide survey, using shared case detection and recording systems.
Retrospective cohort study.
Twenty-six hospitals participating in the Korean Nosocomial Infections Surveillance System (KONIS).
From 2006 to 2009, all patients undergoing THA and TKA in KONIS were enrolled.
SSI occurred in 161 (2.35%) of 6,848 cases (3,422 THAs and 3,426 TKAs). Pooled mean SSI rates were 1.69% and 2.82% for THA and TKA, respectively. Of the cases we examined, 42 (26%) were superficial-incisional SSIs and 119 (74%) were “severe” SSIs; of the latter, 24 (15%) were deep-incisional SSIs and 95 (59%) were organ/space SSIs. In multivariate analysis, a duration of preoperative hospital stay of greater than 3 days was a risk factor for total SSI after both THA and TKA. Diabetes mellitus, revision surgery, prolonged duration of surgery (above the 75th percentile), and the need for surgery due to trauma were independent risk factors for total and severe SSI after THA, while male sex and an operating room without artificial ventilation were independent risk factors for total and severe SSI after TKA. A large volume of surgeries (more than 10 procedures per month) protected against total and severe SSI, but only in patients who underwent TKA.
Risk factors for SSI after arthroplasty differ according to the site of the arthroplasty. Therefore, clinicians should take into account the site of arthroplasty in the analysis of SSI and the development of strategies for reducing SSI.
To evaluate the risk factors for surgical site infection (SSI) after gastric surgery in patients in Korea.
A nationwide prospective multicenter study.
Twenty university-affiliated hospitals in Korea.
The Korean Nosocomial Infections Surveillance System (KONIS), a Web-based system, was developed. Patients in 20 Korean hospitals from 2007 to 2009 were prospectively monitored for SSI for up to 30 days after gastric surgery. Demographic data, hospital characteristics, and potential perioperative risk factors were collected and analyzed, using multivariate logistic regression models.
Of the 4,238 case patients monitored, 64.9% (2,752) were male, and mean age (±SD) was 58.8 (±12.3) years. The SSI rates were 2.92, 6.45, and 10.87 per 100 operations for the National Nosocomial Infections Surveillance system risk index categories of 0, 1, and 2 or 3, respectively. The majority (69.4%) of the SSIs observed were organ or space SSIs. The most frequently isolated microorganisms were Staphylococcus aureus and Klebsiella pneumoniae. Male sex (odds ratio [OR], 1.67 [95% confidence interval (CI), 1.09–2.58]), increased operation time (1.20 [1.07–1.34] per 1-hour increase), reoperation (7.27 [3.68–14.38]), combined multiple procedures (1.79 [1.13–2.83]), prophylactic administration of the first antibiotic dose after skin incision (3.00 [1.09–8.23]), and prolonged duration (≥7 days) of surgical antibiotic prophylaxis (SAP; 2.70 [1.26–5.64]) were independently associated with increased risk of SSI.
Male sex, inappropriate SAP, and operation-related variables are independent risk factors for SSI after gastric surgery.
The present study was carried out to evaluate the microstructures and mechanical properties of severely deformed Ni-30Cr alloy. Cross-roll rolling (CRR) as severe plastic deformation (SPD) process was introduced and Ni-30Cr alloy sheets were cold rolled to a 90% thickness reduction and subsequently annealed at 700 °C for 30 min so as to obtain the recrystallized microstructure. For the analysis of grain boundary character distributions (GBCDs), electron back-scattered diffraction (EBSD) technique was introduced. CRR on Ni-30Cr alloy was effective to enhance the grain refinement through heat treatment; consequently, average grain size was significantly reduced from 33 μm in initial material to 0.6 μm in CRR processed material. This grain refinement directly affected the mechanical properties improvement, in which yield and tensile strengths were significantly increased than those of initial material. In this study, we systematically discussed the grain refinement, accompanying with increase in mechanical properties, in terms of the effective strain imposed by CRR, comparing with conventional rolling (CR).
We investigated microstructures, compositional distributions, and electrical properties of dielectric CaCu3Ti4O12 (CCTO) thin films deposited on Pt/TiO2/SiO2/Si substrates from 700 to 800 °C by pulsed laser deposition. With increasing the deposition temperature from 700 to 750 °C, the dielectric constants (εr) of CCTO films were greatly enhanced from ∼300 to ∼2000 at 10 kHz, respectively. However, the εr values of CCTO films were gradually decreased above 750 °C, which was surely attributable to the formation of a TiO2-rich dead layer at the interface between CCTO and Pt electrode. Compositional analyses by Auger electron spectroscopy, energy dispersive spectroscopy, and electron energy loss spectroscopy revealed that the TiO2-rich dead layer became thicker because of severe Cu diffusion from CCTO films to Pt electrode. The leakage current behaviors of CCTO films are in good agreement with Poole–Frenkel conduction mechanism, where both the TiO2-rich dead layer and rutile TiO2 nanocrystalline particles are considered to play a role of charge trapping centers.
The effects of tannic acid (TA) supplementation (0·02 %, wt/wt) were compared with the effects of clofibrate (CF) supplementation (0·02 %, wt/wt) in apo E-deficient (apo E− / −) mice fed a AIN-76 semi-synthetic diet (normal diet) over 20 weeks. The mice were monitored for the modulation of hepatic mRNA expression and the activities of lipid-regulating enzymes. Both TA and CF supplementation lowered hepatic 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) activity and prevented atherosclerotic lesion formation in comparison with the control group. Hepatic carnitine palmitoyl transferase and β-oxidation activities were significantly higher in the TA and CF groups than in the control group. Both CF and TA supplementation resulted in significant decreases in hepatic HMGR mRNA levels in association with its enzyme activity. However, in contrast to CF supplementation, TA supplementation seemed to decrease the accumulation of hepatic lipids in the apo E− / − mice without increasing liver weight. These results suggest that the overall effect of TA is more desirable than CF for the alleviation of hepatic lipogenesis and atherogenesis in apo E− / − mice.
Intra-uterine growth retardation has been linked to the development of type 2 diabetes in later life. Mitochondrial changes have been suggested as a link between fetal malnutrition and adult insulin resistance. Taurine has been implicated in this process. We investigated whether protein malnutrition in early life alters mitochondria of the pancreatic islets in adulthood, and whether taurine supplementation restores these changes. Male offspring of rats fed a control diet, a low-protein diet or a low-protein diet supplemented with taurine during pregnancy and lactation were weaned onto the control diet. In each group, at 20 weeks of age, intravenous glucose tolerance tests, euglycaemic–hyperinsulinaemic clamp studies, morphometric analysis of the pancreatic islets and ultra-structural analysis of the mitochondria of the β-cells were performed. The expressions of cytochrome c oxidase (COX) I and mitochondrial respiratory chain complex II were also measured. Fetal protein-malnourished rats showed decreased pancreatic islet mass and reduced insulin-secretory responses to a glucose load. These rats also showed reduced mitochondrial DNA-encoded COX I gene expression in the islets. Electron microscopic examination showed abnormal mitochondrial shapes in the β-cells of fetal protein-malnourished rats. Taurine supplementation to the low-protein diet restored all these changes. Our findings indicate that a maternal protein-restriction diet causes long-lasting mitochondrial changes that may contribute to the development of type 2 diabetes later in life. The lack of taurine may be a key causative factor for these dysfunctional mitochondrial changes.
Light soaking gives rise to the increase of active acceptors as well as to the creation of dangling bonds in boron doped hydrogenated amorphous silicon. The annealing out of the metastable active dopants is slow compared with that of the created dangling bonds, results in higher conductivity than annealed value during heating the sample upon light soaking. The activation energy of the relaxation time for the metastable active dopants is ˜0.1 eV higher than that for the annealing of the created dangling bonds. We ropose a new model to explain our results.
Polycrystalline ZnO thin films were deposited on SiO2/Si(100) substrate using RF magnetron sputtering. The film deposition performed in this work was composed of following two procedures; the 1st-deposition for 30 min without oxygen at 100 W and the 2nd-deposition with oxygen in the range O2/(Ar+O2) = 10∼50 %. Deposited ZnO films revealed a strongly c-axis preferred-orientation (the corresponding texture coefficient ∼ 100 %) as well as a high resistivity (> 107 Ωcm). It was also observed that the crystallite size of ZnO was noticeably increased by thermal-annealing.
Nanocrystalline silicon (nc-Si) films were deposited by inductively coupled plasma chemical vapor deposition (ICP-CVD) at 150°C. ICP power was 400W. The process gas was SiH4 diluted with He as well as H2. The flow rate of He, H2 and He/H2 mixture was varied from 20sccm to 60sccm and that of SiH4 was 3sccm. X-ray diffraction (XRD) patterns of the nc-Si films were measured. From the XRD results of nc-Si films deposited by ICP-CVD, the properties of Si film deposited under each condition were studied. As the dilution ratio increases and He/H2 mixture was used as a dilution gas, intensities of <111>and<220> peaks were increased and the incubation layer was thin. These results were explained in the point of role of H2 plasma and He plasma in the nc-Si deposition process. Our experimental results show that nc-Si film deposited by ICP-CVD may be suitable for an active layer of nc-Si TFTs.
The MEMS (micro-electro-mechanical systems) microphone enables the manufacturing of small mechanical components on the surface of a silicon wafer. The MEMS microphones are less susceptible to vibration because of the smaller diaphragm mass and an excellent candidate for chip-scale packaging. In this paper, we present a piezoelectric MEMS microphone based on (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) single crystal diaphragm. The PMN-PT materials exhibit extremely high piezoelectric coefficients and other desirable properties for an acoustic sensor. The piezoelectric-based microphone can offer the ability to passively sense without the power requirements. In particular, this paper introduces the design of a PMN-PT single crystal diaphragm with interdigitated electrode. We were able to fabricate miniaturized PMN-PT single crystal diaphragms. The fabricated sensor exhibits the sensitivity of 1.5mV/Pa. This implies that the PMN-PT thin film microphone has a potential of excellent acoustic characteristics.