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Firefighters are routinely exposed to various traumatic events and often experience a range of trauma-related symptoms. Although these repeated traumatic exposures rarely progress to the development of post-traumatic stress disorder, firefighters are still considered to be a vulnerable population with regard to trauma.
To investigate how the human brain responds to or compensates for the repeated experience of traumatic stress.
We included 98 healthy firefighters with repeated traumatic experiences but without any diagnosis of mental illness and 98 non-firefighter healthy individuals without any history of trauma. Functional connectivity within the fear circuitry, which consists of the dorsal anterior cingulate cortex, insula, amygdala, hippocampus and ventromedial prefrontal cortex (vmPFC), was examined using resting-state functional magnetic resonance imaging. Trauma-related symptoms were evaluated using the Impact of Event Scale – Revised.
The firefighter group had greater functional connectivity between the insula and several regions of the fear circuitry including the bilateral amygdalae, bilateral hippocampi and vmPFC as compared with healthy individuals. In the firefighter group, stronger insula–amygdala connectivity was associated with greater severity of trauma-related symptoms (β = 0.36, P = 0.005), whereas higher insula–vmPFC connectivity was related to milder symptoms in response to repeated trauma (β = −0.28, P = 0.01).
The current findings suggest an active involvement of insular functional connectivity in response to repeated traumatic stress. Functional connectivity of the insula in relation to the amygdala and vmPFC may be potential pathways that underlie the risk for and resilience to repeated traumatic stress, respectively.
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.
Existing literature suggests that mental health literacy is positively associated with mental health services utilization. Despite an aging population that faces significant mental health concerns in Korea, the role of mental health literacy on mental health services utilization is not known among older adults in Korea. This study aimed to (1) identify whether mental health literacy mediates the association between population characteristics and mental health services utilization and (2) identify an optimal path model for mental health services utilization among Korean older adults.
Using a cross-sectional survey with a quota sampling strategy, we collected and analyzed responses from 596 community-dwelling individuals ages 65 years and older. We used structural equation modeling (SEM) to estimate the effect of mental health literacy as a mediator.
When controlling for other relevant covariates in the optimal path model, mental health literacy mediated the relationships between three socio-demographic factors (education, general literacy, and health status) and mental health services utilization. The model fit index shows that the SEM fits very well (CFI = 0.92, NFI = 0.90, RMSEA = 0.07).
Efforts to improve mental health literacy through community-based education programs may need to particularly target Korean older adults with the relevant socio-demographic characteristics to enhance their utilization of appropriate mental health services.
Among domesticated traits, pre-harvest sprouting (PHS) caused by the early breakage of dormancy leads to severe economic losses. Therefore, regulating PHS is important for cereal crop improvement against changes in climate. In this study, we surveyed naturally occurring variations in seed germination in diverse rice germplasm for the available resources of this trait, and investigated the changes of abscisic acid (ABA) levels during grain development by the distinguished PHS-resistant groups. We discovered wide variations in germination among the 205 rice accessions examined and found that 90 accessions are resistant (germination <20%) to PHS. Tropical and subtropical accessions, which are subjected to long wet periods, are more resistant to PHS than the other accessions. We detected an increase in germination of detached seeds from the panicle compared with intact seeds in panicle at harvesting time. This might be attributed to a weakening of the mechanical barrier that prevents water imbibition and radical emergence. ABA levels were maximal at 10 d after flowering and decreased thereafter. Interestingly, PHS-susceptible accessions maintained higher or similar ABA levels compared with PHS-resistant accessions, suggesting that the key factors for seed dormancy and its breakage are ABA perception and signal transduction rather than total ABA content. The diversity of germination ability detected in this study could be sustainably used for crop improvement and to help unveil the genetic and physiological basis of this quantitative trait.
During the past decade, carbapenemase-producing Enterobacteriaceae (CPE) has emerged and spread across the world.1 The major carbapenemase enzymes currently being reported are KPC, NDM-1, VIM, IMP, and OXA.2 Because carbapenemase can be effectively transmitted via mobile genetic elements, and current therapeutic options for CPE infections are extremely limited, CPE may be one of the most serious contemporary threats to public health. However, very little is known about the characteristics of CPE carriage during hospitalization. The aims of this study were to investigate the clearance rate of CPE carriage and determine the number of consecutive negative cultures required to confirm CPE clearance. We also examined CPE transmission among hospitalized patients.
Infect. Control Hosp. Epidemiol. 2015;36(11):1361–1362
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.
We present a novel method to build a coarse-grained (CG) model based on the Mori-Zwanzig (MZ) formalism that reproduces kinetics. Our approach leads to the computation of a generalized Langevin equation (GLE), which includes the memory kernel and the fluctuation that are consistent with brute force molecular dynamics (MD) simulations. Our CG model based on the MZ formalism successfully reproduces kinetics, i.e. the distribution of first passage times (FPT) and velocity autocorrelation functions (VACF), for alanine dipeptide. In addition, we show that the memory part of the CG model of GLE is essential to reproduce kinetics. In other words, the Markovian model fails to reproduce brute force MD results, whereas the GLE model succeeds.
The modified TiO2 nanoparticles were incorporated into the Bulk heterojunction system of P3HT:PCBM to improve the performance of P3HT:PCBM bulk heterojunction organic solar cells. The organically-modified TiO2 nanoparticle compounds were synthesized in aqueous media at room temperature. These TiO2 compounds in various solution concentrations were deposited on the top of the P3HT:PCBM active layer by spin coating. The performance of organic solar cells was carefully investigated in the respect of the scattering and the localized surface plasmon resonance (LSPR) that couple strongly to the incident light. In addition to the device, P3HT:PCBM solar cells with the use of the TiO2 nanoparticles, enhanced Fill Factor (FF) due mainly to improved shunt resistance (Rsh). The TiO2 plays a critical role in improving the interface between P3HT:PCBM active layer and Al electrode.
Visual hallucination (VH) is a common psychotic symptom in patients with Parkinson's disease (PD) and may be a significant predictor of cognitive impairment (CI) in such patients.
This study aimed to investigate the pattern of glucose metabolism of VH and the relationship between VH and CI in PD.
We studied 28 PD patients, including 15 with VH (PD-VH) and 13 without VH (PD-NVH). Of the 15 PD-VH patients, 8 patients had cognitive impairment (PD-VHCI) whereas 7 did not (PD-VHNCI). All patients underwent [18F] fluorodeoxyglucose positron emission tomography ([18F] FDG PET) followed by statistical parametric mapping (SPM) analyses.
Compared to the patients with PDNVH, PD-VHNCI patients showed glucose hypometabolism in the inferior and middle temporal cortices, fusiform gyri, and frontal areas, suggesting the involvement of the ventral visual pathway. Compared to the patients with PDNVH, PD-VHCI patients showed glucose hypometabolism in the temporoparietal association cortices with scattered frontal areas.
Dysfunction of ventral visual pathway involving the temporal lobe may play a key role in VH development in PD patients. The evolving distribution from the ventral visual pathway to more extensive posterior cortices in PD-VHCI patients suggests that VH may be a prodromal symptom occurring prior to CI in PD patients.
Cataract, defined as opacity of the lens in one or both eyes, is a major cause of blindness throughout the world, and not uncommon, particularly in the elderly population. However, congenital cataracts are rare and occur with a frequency of 30 cases in 100,000 births. About one-third of the cases fall into the group inherited without systemic abnormality. Importantly, congenital cataracts produce deprivation amblyopia, refractive amblyopia, and retinal detachment, leading to lifelong visual impairment. Successful management is dependent on early diagnosis and referral for surgery when indicated. Here we present a case of hereditary bilateral cataracts in a dizygotic twin detected on prenatal ultrasound examinations and postnatally confirmed as congenital cataracts associated with posterior lenticonus.
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.
Two studies are reported using the theory of planned behaviour (TPB) to examine Koreans' intentions and self-reported behaviour of joining and not joining alcohol-related social gatherings with work colleagues after work hours. Study 1 showed that group-related attitudes and perceived behavioural control of the TPB components regarding joining were significantly associated with intentions to join. Study 2 examined TPB components regarding not joining and intentions to not join. Study 2 found that although none of the TPB components was directly related to intentions, subjective norms from work colleagues moderated the effect of group-related attitudes on intentions to not join. The TPB components and intentions were not significantly related to self-reported behaviour of joining. The findings indicate that the relationships between the TPB components and intentions can be different for engaging and not engaging in a behaviour.
Alternative assessment in education is becoming widely implemented around the Pacific region. This study conducted a multilevel analysis of communication climate and beliefs about the effectiveness of alternative assessment. Participants were 662 teachers from 75 elementary schools in Korea. The findings showed that teachers' beliefs about the effectiveness of alternative assessment were positively influenced by their perception of communication climate at their schools and their perception of support from principals, peer teachers, students and parents. The effect of teachers' endorsement of textbook-based learning was moderated by school-level communication climate. The findings indicated that an open communication climate at schools is a key for the successful implementation of alternative assessment.
Tin oxide has been proposed as a promising alternative anode material for microbatteries. It has been reported that its theoretical volumetric capacity is four times larger than that of carbon-based materials, while its gravimetric capacity is twice as large. In this experiment, optimal Si and Bi doped SnO2 films were prepared with e-beam evaporation to improve both the cycle performance and the reversible capacity. The films with addition of Si only exhibited reductions in aggregation of tin particles and formation of micro-cracks. However, there still remained cracks, which induce capacity loss during cycling. To improve capacity retention, Bi was added with Si to SnO2 films, which exhibited the highest reversible capacity of 200µAh/cm2-µm at 200th cycle. The films doped with Bi and Si were found to be ill-defined and featureless without noticeable particle aggregation and cracks. However, the films that underwent cycling tests showed again aggregated tin particles and formation of cracks, which would induce cell failure during cycling. We believe that some types of Li-Bi phases as mixed-conductor matrices have improved the cycle life.
Extent of Mn diffusion to the plasma-oxidized AlOx tunnel barrier of magnetic tunnel junction was examined using Auger Electron Spectroscopy (AES) and X-Ray Photoelectron Spectroscopy (XPS). A magnetic film stack consisting of Ta/AlOx/CoFe/IrMn/NiFe/Ta was deposited with the AlOx layer treated under different plasma oxidation durations. AES depth profiles showed that Mn diffusion to the AlOx/CoFe interface increased with increasing oxidation after annealing at 300°C. XPS analysis indicated that Mn found at the CoFe/AlOx interface in the over-oxidized electrode was in the form of MnO2. Our research suggests that Mn diffusion was accelerated by preferential oxidation of Mn at the CoFe/AlOx interface.
We have proposed nitrous oxide (N2O) plasma pre-treatment in order to reduce the oxide charge densities as well as to increase the breakdown field of silicon dioxide film for flexible display. Our experimental results show that the proposed treatment improved both the flat-band voltage from –3V to –1.8V and the breakdown voltage of gate oxide from 7MV/cm to 9.5MV/cm, respectively. The proposed treatment also improved poly-Si TFT characteristics such as low sub-threshold swing of 0.43V/dec.
RF MEMS(Micro-Electro-Mechanical-System) switch technology is one of powerful solution for future RF systems. This technology provides low insertion loss, High linearity and broad bandwidth. Wide driving membrane used MEMS switch can reduce driving voltage but it is easy to bend because of the stress gradient. In order to solve this problem we fabricated Au cantilever in various sputtering condition and various substrate materials. As a result of this experiment, we fabricated cantilever which was bent within 1 um, with 2 um thickness and 340 um length. We applied this condition to RF MEMS switch and we fabricated switch membrane within 1 um bend, under 10MPa stress gradient.
AlxGa1-xN sample with x=0.36 was epitaxially grown on sapphire by MOCVD. SAW velocity of 5420 m/s and TCF (temperature coefficient of frequency) of -51.20 ppm/°C were measured from the SAW devices fabricated on the AlxGa1-xN sample, when kh value was 0.078, at temperatures between –30 °C and 60 °C Electromechanical coupling coefficient was ranged from 1.26 % to 2.22 %. The fabricated SAW filter have shown a good device performance with insertion loss of -33.853 dB and side lobe attenuation of 20 dB.
Porous low dielectric films containing nano pores (∼20Å) with low dielectric constant (<2.2), have been prepared by using various kinds of cyclodextrin derivatives as porogenic materials. The pore structure such as pore size and interconnectivity can be controlled by changing functional groups of the cyclodextrin derivatives. We found that mechanical properties of porous low-k thin film prepared with mCSSQ (modified cyclic silsesquioxane) precursor and cyclodextrin derivatives were correlated with the pore interconnection length. The longer the interconnection length of nanopores in the thin film, the worse the mechanical properties of the thin film (such as hardness and modulus) even though the pore diameter of the films were microporous (∼2nm).