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Network approach has been applied to a wide variety of psychiatric disorders. The aim of the present study was to identify network structures of remitters and non-remitters in patients with first-episode psychosis (FEP) at baseline and the 6-month follow-up.
Participants (n = 252) from the Korean Early Psychosis Study (KEPS) were enrolled. They were classified as remitters or non-remitters using Andreasen's criteria. We estimated network structure with 10 symptoms (three symptoms from the Positive and Negative Syndrome Scale, one depressive symptom, and six symptoms related to schema and rumination) as nodes using a Gaussian graphical model. Global and local network metrics were compared within and between the networks over time.
Global network metrics did not differ between the remitters and non-remitters at baseline or 6 months. However, the network structure and nodal strengths associated with positive-self and positive-others scores changed significantly in the remitters over time. Unique central symptoms for remitters and non-remitters were cognitive brooding and negative-self, respectively. The correlation stability coefficients for nodal strength were within the acceptable range.
Our findings indicate that network structure and some nodal strengths were more flexible in remitters. Negative-self could be an important target for therapeutic intervention.
In South Korea, the law concerning automated external defibrillators (AEDs) states that they should be installed in specific places including apartment complexes. This study was conducted to investigate the current status and effectiveness of installation and usage of AEDs in South Korea.
Installation and usage of AEDs in South Korea is registered in the National Emergency Medical Center (NEMC) database. Compared were the installed number, usage, and annual rate of AED use according to places of installation. All data were obtained from the NEMC database.
After excluding AEDs installed in ambulances or fire engines (n = 2,003), 36,498 AEDs were registered in South Korea from 1998 through 2018. A higher number of AEDs were installed in places required by the law compared with those not required by the law (20,678 [56.7%] vs. 15,820 [43.3%]; P <.001). Among them, 11,318 (31.0%) AEDs were installed in apartment complexes. The overall annual rate of AED use was 0.38% (95% CI, 0.33-0.44). The annual rate of AED use was significantly higher in places not required by the law (0.62% [95% CI, 0.52-0.72] versus 0.21% [95% CI, 0.16-0.25]; P <.001). The annual rate of AED use in apartment complexes was 0.13% (95% CI, 0.08-0.17).
There were significant mismatches between the number of installed AEDs and the annual rate of AED use among places. To optimize the benefit of AEDs in South Korea, changes in the policy for selecting AED placement are needed.
To determine the level of vitamin D and to identify the association between vitamin D and depressive symptoms in apparently healthy Korean male adults.
A retrospective study design. Among 43 513 participants between 1 March and 30 November 2018, after eliminating participants with a history of depression or vitamin D deficiency, 9058 were included. To determine the level of vitamin D, serum 25-hydroxyvitamin D [25(OH)D] was measured. To assess the level of depression, the Korean version of the Center for Epidemiologic Studies Depression Scale (CES-D) was used.
Male adults who underwent routine health check-ups.
The average vitamin D level was 22·31 ± 7·09 ng/ml as 25(OH)D, while the number of subjects in the vitamin D insufficiency group with a finding of <20 ng/ml was 3783 (41·8 %). The mean CES-D score in all subjects was 8·31 ± 5·97 points, and the proportion of the depressive symptoms group with a score of ≥16 was 8·71 %. The OR of patients in the depressive symptoms group also being in the insufficiency group was found to be 1·49 (95 % CI 1·12, 2·00).
A total of 41·8 % of apparently healthy male adults had vitamin D levels <20 ng/ml. We identified an association between vitamin D insufficiency and depressive symptoms in apparently healthy Korean male adults.
The aims of this study were to identify the unmet care needs and to examine the mediating effect of unmet supportive care needs in the relationship between functional status and quality of life (QOL) in Korean patients with amyotrophic lateral sclerosis (ALS).
This was a cross-sectional study conducted among 186 patients with ALS recruited from a tertiary hospital in Seoul, South Korea. ALS patients' functional status, unmet supportive care needs, and QOL were assessed by Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised, the Amyotrophic Lateral Sclerosis Supportive Care Needs Instrument, and the Amyotrophic Lateral Sclerosis Specific Quality of Life – Revised Instrument, respectively. Mediation analysis was tested using Baron and Kenny's regression analysis and a Sobel test.
The mean score for functional status was 33.35 ± 8.89; for unmet supportive care needs it was 2.40 ± 0.66; and for QOL it was 4.95 ± 1.29. Functional status was significantly correlated with unmet care needs and QOL. Unmet care needs satisfaction demonstrated a complete mediating effect on the relationship between functional status and QOL of the patients with ALS (β = –0.53, p < 0.001) and the effect was significant (Sobel test; Z = 5.48, p < 0.001).
Significance of results
Although QOL was negatively affected by the functional status in our sample, the relationship was fully mediated via unmet supportive care needs. Because there is no cure for ALS, and the condition is rapidly progressive with a lethal outcome, providing care by meeting patients’ needs is a critical aspect of caring for these patients. Early assessment of supportive care needs, providing services, and referring ALS patients to appropriate resources could enhance their QOL.
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.
While normative data on neuropsychological performance provide baseline metrics for the assessment and diagnosis of mild cognitive impairment and dementia, a lack of comparative normative data in non-Caucasian populations makes it difficult to conduct similar evaluations and studies in individuals from diverse backgrounds. The current paper aims to provide normative data on a range of cognitive measures in a Korean general population sample and investigate various demographic and health variables associated with cognitive performance in this representative population.
The study population was 1,528 stroke and dementia-free individuals who participated in the Korean Genome and Epidemiology study (KoGES) (mean age 60.43 ± 7.30, 52.42% female). All participants underwent a comprehensive neuropsychological test battery that included verbal and visual memory, language, attention, and executive function measures. A health examination and a questionnaire-based interview were also administered.
The majority of cognitive test results were associated with age, education, and gender. In general, higher education and younger age was associated with better cognitive performance. Explained variance increased modestly in models that included measures of general health and depressive symptoms.
Normative data of cognitive performance in a community based Korean population are presented. These norms provide reference values in a non-Caucasian middle to older aged sample.
Following ovulation, oocytes undergo a time-dependent deterioration in quality referred to as post-ovulatory ageing. Although various factors influence the post-ovulatory ageing of oocytes, oxidative stress is a key factor involved in deterioration of oocyte quality. Artemisia asiatica Nakai ex Pamp. has been widely used in East Asia as a food ingredient and traditional medicine for the treatment of inflammation, cancer, and microbial infections. Recent studies have shown that A. asiatica exhibits antioxidative effects. In this study, we investigated whether A. asiatica has the potential to attenuate deterioration in oocyte quality during post-ovulatory ageing. Freshly ovulated mouse oocytes were cultured with 0, 50, 100 or 200 μg/ml ethanol extracts of A. asiatica Nakai ex Pamp. After culture for up to 24 h, various ageing-induced oocyte abnormalities, including morphological changes, reactive oxygen species (ROS) accumulation, apoptosis, chromosome and spindle defects, and mitochondrial aggregation were determined. Treatment of oocytes with A. asiatica extracts reduced ageing-induced morphological changes. Moreover, A. asiatica extracts decreased ROS generation and the onset of apoptosis by preventing elevation of the Bax/Bcl-2 expression ratio during post-ovulatory ageing. Furthermore, A. asiatica extracts attenuated the ageing-induced abnormalities including spindle defects, chromosome misalignment and mitochondrial aggregation. Our results demonstrate that A. asiatica can relieve deterioration in oocyte quality and delay the onset of apoptosis during post-ovulatory ageing.
Whether an association exists between cerebral microbleeds (CMBs) and functional recovery after ischemic stroke is unclear. We aimed to evaluate the association between CMBs and functional outcome after acute ischemic stroke.
Consecutive patients with acute stroke were enrolled, and all patients were stratified into good and poor functional outcome groups at discharge and 6 months after ischemic stroke by using a modified Rankin Scale score. Cardiovascular risk factors, CMBs, and white matter hyperintensities were compared between these two outcome groups. Logistic regression analysis was used to estimate the risk of poor functional outcomes.
A total of 225 patients were enrolled, 121 of whom were classified as having a good functional outcome at discharge and 142 as having a good 6-month functional outcome. The presence of CMBs was associated with a poor functional outcome at discharge [CMBs (+) patients in poor vs. good functional group; 48.1% vs. 30.6%; p=0.007] and 6 months [53.0% vs. 30.3%; p=0.001]. After adjustment for confounding factors, only the presence of infratentorial CMBs was associated with a poor functional outcome at discharge and 6 months. The poor functional outcome group had more CMBs than the good outcome group at 6 months.
Infratentorial cerebral microbleeds were significantly associated with worse functional outcomes not only in the early phase of ischemic stroke but also in the chronic phase. These findings suggest that the presence of infratentorial CMBs can predict poor functional outcome after acute ischemic stroke.
Suicide among older people is one of the most rapidly emerging healthcare issues. The objective of this study was to identify the factors associated with suicide ideation in the aged population in South Korea.
The study recruited 684 subjects older than 65 years old (males = 147, females = 537, mean age = 78.20±7.02 years), and trained interviewers performed the interviews. The study was performed as part of a community mental health suicide prevention program. The subjects’ socio-demographic data, physical health, alcohol problems, social relationships, psychological well-being, and depression severity were all considered. The Korean version of the Beck Scale for Suicide Ideation (K-BSI) was used to evaluate the intensity of suicide ideation. Correlation and hierarchical multiple regression analyses were performed to identify the factors associated with the K-BSI. The study results were tested using a path analysis.
Depression severity was positively correlated with suicide ideation, and economic status, psychological well-being, and social relationships were negatively correlated with suicide ideation. Depression severity had the largest direct impact, and economic status and social relationships had indirect impacts on suicide ideation. Psychological well-being exerted both direct and indirect influences.
Depression severity was the most important predictor of suicide ideation among older people. Other direct and indirect factors played secondary roles. Effective suicide prevention strategies should focus on early detection and active intervention for depression. Socio-economic programs may also indirectly reduce suicide ideation among the aged population.
A K-band microstrip delay line based on parasitic reduced left-handed transmission line (LHTL) with interdigital capacitors and shunt inductors is demonstrated with the aid of printed circuit board technology. The proposed delay line has ground slots under the interdigital capacitors to reduce the parasitic capacitance. The time delay of the proposed LHTLs is approximately 2.6 times larger than that of the conventional LHTLs. The input return loss of the proposed LHTL at 24 GHz is −16.9 dB and less than −10 dB from 20.5 to 26.1 GHz.
Electron tomography (ET) has recently afforded new insights into neuronal architecture. However, the tedious process of sample preparation, image acquisition, alignment, back projection, and additional segmentation process of ET repels beginners. We have tried Hitachi's commercial packages integrated with a Hitachi H-7650 TEM to examine the potential of using an automated fiducial-less approach for our own neuroscience research. Semi-thick sections (200–300 nm) were cut from blocks of fixed mouse (C57BL) cerebellum and prepared for ET. Sets of images were collected automatically as each section was tilted by 2° increments (±60°). “Virtual” image volumes were computationally reconstructed in three dimension (3D) with the EMIP software using either the commonly used “weighted back-projection” (WBP) method or “topography-based reconstruction” (TBR) algorithm for comparison. Computed tomograms using the TBR were more precisely reconstructed compared with the WBP method. Following reconstruction, the image volumes were imported into the 3D editing software A-View and segmented according to synaptic organization. The detailed synaptic components were revealed by very thin virtual image slices; 3D models of synapse structure could be constructed efficiently. Overall, this simplified system provided us with a graspable tool for pursuing ET studies in neuroscience.
In this study, we fabricated blue OLEDs with quantum well structure (QWS) using four different blue emissive materials such as DPVBi, ADN and DPASN, and BAlq as QWS material. Conventional QWS blue OLEDs used to be composed of emissive layer and charge blocking layer with lower HOMO-LUMO energy level, but we designed triple emitting layer for more significant hole-electron recombination in EML and a wider region of exciton generation as forming QWS spontaneously. The structure of triple emitting layered blue OLED is ITO / NPB(700 Å) / X(100 Å) / BAlq(100 Å) /X (100 Å) / Bphen(300 Å) / Liq(20 Å) / Al(1200 Å) (X= DPVBi, ADN, DPASN). HOMO-LUMO energy levels of DPVBi, ADN, DPASN and BAlq were 2.8-5.9, 2.6-5.6, 2.3-5.2 and 2.9-5.9 eV, respectively. The maximum luminous efficiency was 5.32 cd/A at 3.5 V in a blue OLED with DPASN / BAlq / DPASN QWS.
A transverse (d33) mode piezoelectric cantilever was fabricated for energy harvesting. Various dimensions of interdigital electrodes (IDE) were deposited on a piezoelectric layer to examine the effects of electrode design on the performance of energy harvesters. Modeling was performed to calculate the output power of the devices. The estimation was based on Roundy’s analytical modeling derived for a d31 mode piezoelectric energy harvester (PEH). In order to apply the Roundy’s model to d33 mode PEH, the IDE configuration was converted to the area of top and bottom electrodes (TBE). The power conversion in d33 mode PEH was commonly estimated by the product of piezoelectric layer’s thickness and finger electrode’s length. In addition, the spacing between fingers was regarded as gap between top and bottom electrodes. However, the output power in a transverse mode PEH increases continuously with the increase of finger spacing, which does not correspond to experimental results. In this research, the dimension of IDE was converted to that of TBE using conformal mapping, and variation of power of PEH was remodeled. The modified model suggests that the maximum power in a transverse mode PEH is obtained when the finger spacing is identical with effective finger spacing. The output power then decreases when finger spacing is larger than effective finger spacing. The decrease of efficiency may result from insufficient degree of poling and increased charged defect with increasing finger spacing.
Assessment of frontal lobe impairment in amyotrophic lateral sclerosis (ALS) is a matter of great importance, since it often causes ALS patients to decrease medication and nursing compliance, thus shortening their survival time.
The frontal assessment battery (FAB) is a short and rapid method for assessing frontal executive functions. We investigated the applicability of the FAB as a screening method for assessing cognitive impairments in 61 ALS patients. Depending on the results of the FAB, we classified patients into two subgroups: FAB-normal and FAB-abnormal. We then performed additional evaluations of cognitive function using the Korean version of the mini-mental state examination (K-MMSE), a verbal fluency test (COWAT), and a neuropsychiatric inventory (NPI). Results of these tests were compared between the two groups using Mann-Whitney U-tests, and Spearman correlation analyses were used to investigate the relationships between FAB score and disease duration and severity.
Of the 61 sporadic ALS patients included in this study, 14 were classified as FAB-abnormal and 47 were classified as FAB-normal. The FAB-normal and FAB-abnormal patients performed significantly differently in all domains of the COWAT. There was no difference in behavioral disturbance, as assessed by the NPI, between the two groups. The FAB scores were found to significantly correlate with both disease duration and severity.
The FAB shows promise as a method of screening for frontal lobe dysfunction in ALS, as it is not only quick and easy, but also reliable. Additional studies should examine how FAB performance changes as ALS progresses.
Motor deficits associated with Parkinson's disease (PD) have been well described, yet little attention has been paid to non-motor symptoms, especially cortical visual dysfunction. We investigated stereopsis, as well as the relationship between stereopsis and other cognitive function, in a sample of PD patients.
We used Titmus stereotest plates for assessing stereopsis. Fifty-nine subjects (29 PD patients and 30 normal controls) were included in this study. The included patients underwent a neurological examination, clinical rating scale and neuropsychological tests.
Drug naïve PD patients showed decreased stereopsis on the Titmus fly stereopsis test (Pearson χ2=23.80, p<0.001) compared to PD patients with normal stereopsis. The Hoehn-Yahr stages and Unified Parkinson's Disease Rating Scale motor scores were significantly higher in patients with PD with abnormal stereopsis than in patients with PD with normal stereopsis (p=0.026; p=0.046). The frequency of abnormal visual perception/constructive function was greater in patients with PD with abnormal stereopsis compared to patients with PD with normal stereopsis (Pearson χ2=5.11, p=0.024).
These findings suggest that stereopsis deficits and visual perception/constructive dysfunction are common in de novo PD patients.
We evaluate Vickers hardness and true instrumented indentation test (IIT) hardness of 24 metals over a wide range of mechanical properties using just IIT parameters by taking into account the real contact morphology beneath the Vickers indenter. Correlating the conventional Vickers hardness, indentation contact morphology, and IIT parameters for the 24 metals reveals relationships between contact depths and apparent material properties. We report the conventional Vickers and true IIT hardnesses measured only from IIT contact depths; these agree well with directly measured hardnesses within ±6% for Vickers hardness and ±10% for true IIT hardness.