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Over the past two decades, early detection and early intervention in psychosis have become essential goals of psychiatry. However, clinical impressions are insufficient for predicting psychosis outcomes in clinical high-risk (CHR) individuals; a more rigorous and objective model is needed. This study aims to develop and internally validate a model for predicting the transition to psychosis within 10 years.
Two hundred and eight help-seeking individuals who fulfilled the CHR criteria were enrolled from the prospective, naturalistic cohort program for CHR at the Seoul Youth Clinic (SYC). The least absolute shrinkage and selection operator (LASSO)-penalized Cox regression was used to develop a predictive model for a psychotic transition. We performed k-means clustering and survival analysis to stratify the risk of psychosis.
The predictive model, which includes clinical and cognitive variables, identified the following six baseline variables as important predictors: 1-year percentage decrease in the Global Assessment of Functioning score, IQ, California Verbal Learning Test score, Strange Stories test score, and scores in two domains of the Social Functioning Scale. The predictive model showed a cross-validated Harrell's C-index of 0.78 and identified three subclusters with significantly different risk levels.
Overall, our predictive model showed a predictive ability and could facilitate a personalized therapeutic approach to different risks in high-risk individuals.
We report our experience with an emergency room (ER) shutdown related to an accidental exposure to a patient with coronavirus disease 2019 (COVID-19) who had not been isolated.
A 635-bed, tertiary-care hospital in Daegu, South Korea.
To prevent nosocomial transmission of the disease, we subsequently isolated patients with suspected symptoms, relevant radiographic findings, or epidemiology. Severe acute respiratory coronavirus 2 (SARS-CoV-2) reverse-transcriptase polymerase chain reaction assays (RT-PCR) were performed for most patients requiring hospitalization. A universal mask policy and comprehensive use of personal protective equipment (PPE) were implemented. We analyzed effects of these interventions.
From the pre-shutdown period (February 10–25, 2020) to the post-shutdown period (February 28 to March 16, 2020), the mean hourly turnaround time decreased from 23:31 ±6:43 hours to 9:27 ±3:41 hours (P < .001). As a result, the proportion of the patients tested increased from 5.8% (N=1,037) to 64.6% (N=690) (P < .001) and the average number of tests per day increased from 3.8±4.3 to 24.7±5.0 (P < .001). All 23 patients with COVID-19 in the post-shutdown period were isolated in the ER without any problematic accidental exposure or nosocomial transmission. After the shutdown, several metrics increased. The median duration of stay in the ER among hospitalized patients increased from 4:30 hours (interquartile range [IQR], 2:17–9:48) to 14:33 hours (IQR, 6:55–24:50) (P < .001). Rates of intensive care unit admissions increased from 1.4% to 2.9% (P = .023), and mortality increased from 0.9% to 3.0% (P = .001).
Problematic accidental exposure and nosocomial transmission of COVID-19 can be successfully prevented through active isolation and surveillance policies and comprehensive PPE use despite longer ER stays and the presence of more severely ill patients during a severe COVID-19 outbreak.
This study compares the investigated water vapor diffusion coefficient in the neat polyurethane (PU) membrane, the silica–PU nanocomposite membrane, and two surface-modified silica–PU nanocomposite membranes. The silane first surface modifier is with an amine functional group known as N-[3-(trimethoxysilyl)propyl]ethylenediamine, while the second one is with an aniline functional group known as N-[3-(trimethoxysilyl)propyl]aniline. The enhancement of water vapor diffusivity values through the polymer nanocomposite is desirable for the membrane air dehumidification application. The diffusivities were calculated via molecular dynamics simulations at the temperature of 298.15 K. The Einstein's relationship known as the mean square displacement method was used to obtain the diffusivity for the membranes. The results showed a significant effect on the diffusivity of water vapor for the surface-modified silica–PU nanocomposite membrane as compared with the neat PU and the unmodified silica–PU nanocomposite membranes. For the amine-modified silica, the diffusion coefficient increased by 80.3% compared with the unmodified silica–PU nanocomposite membrane. On the other hand, the aniline-modified silica outperformed the amine-modified one in terms of the diffusion coefficient by 22.4%.
Obsession and delusion are theoretically distinct from each other in terms of reality testing. Despite such phenomenological distinction, no extant studies have examined the identification of common and distinct neural correlates of obsession and delusion by employing biologically grounded methods. Here, we investigated dimensional effects of obsession and delusion spanning across the traditional diagnostic boundaries reflected upon the resting-state functional connectivity (RSFC) using connectome-wide association studies (CWAS).
Our study sample comprised of 96 patients with obsessive–compulsive disorder, 75 patients with schizophrenia, and 65 healthy controls. A connectome-wide analysis was conducted to examine the relationship between obsession and delusion severity and RFSC using multivariate distance-based matrix regression.
Obsession was associated with the supplementary motor area, precentral gyrus, and superior parietal lobule, while delusion was associated with the precuneus. Follow-up seed-based RSFC and modularity analyses revealed that obsession was related to aberrant inter-network connectivity strength. Additional inter-network analyses demonstrated the association between obsession severity and inter-network connectivity between the frontoparietal control network and the dorsal attention network.
Our CWAS study based on the Research Domain Criteria (RDoC) provides novel evidence for the circuit-level functional dysconnectivity associated with obsession and delusion severity across diagnostic boundaries. Further refinement and accumulation of biomarkers from studies embedded within the RDoC framework would provide useful information in treating individuals who have some obsession or delusion symptoms but cannot be identified by the category of clinical symptoms alone.
We have investigated interfacial thermal resistance (ITR) between single-layer graphene and Cu substrate by using both experimental and numerical methods. For experiments, the micropipette sensing technique was utilized to measure the thermal conductivity of suspended graphene and temperature profile of supported graphene on Cu film subjected to heating with a point source continuous wave laser. The thermal conductivity of suspended single-layer graphene was measured to be 3492 ± 453 W/m°C from measurements of temperature profile on the suspended graphene. This intrinsic graphene thermal conductivity and the finite element method integrated with a multi-parameter fitting technique were used to estimate ITR between graphene and Cu film. In the multi-parameter fitting technique, the simulated temperature profile is compared with experimentally measured temperature profile on the supported graphene surface and the best-fitted parameters including thermal interface resistance was obtained. The estimated interface thermal resistance between single graphene and Cu substrate is 2.3 × 10−7 m2 K/W and the difference between experiment and simulation result during multi-parameter fitting is 6.9%.
Given its diverse disease courses and symptom presentations, multiple phenotype dimensions with different biological underpinnings are expected with bipolar disorders (BPs). In this study, we aimed to identify lifetime BP psychopathology dimensions. We also explored the differing associations with bipolar I (BP-I) and bipolar II (BP-II) disorders.
We included a total of 307 subjects with BPs in the analysis. For the factor analysis, we chose six variables related to clinical courses, 29 indicators covering lifetime symptoms of mood episodes, and 6 specific comorbid conditions. To determine the relationships among the identified phenotypic dimensions and their effects on differentiating BP subtypes, we applied structural equation modeling.
We selected a six-factor solution through scree plot, Velicer's minimum average partial test, and face validity evaluations; the six factors were cyclicity, depression, atypical vegetative symptoms, elation, psychotic/irritable mania, and comorbidity. In the path analysis, five factors excluding atypical vegetative symptoms were associated with one another. Cyclicity, depression, and comorbidity had positive associations, and they correlated negatively with psychotic/irritable mania; elation showed positive correlations with cyclicity and psychotic/irritable mania. Depression, cyclicity, and comorbidity were stronger in BP-II than in BP-I, and they contributed significantly to the distinction between the two disorders.
We identified six phenotype dimensions; in addition to symptom features of manic and depressive episodes, various comorbidities and high cyclicity constructed separate dimensions. Except for atypical vegetative symptoms, all factors showed a complex interdependency and played roles in discriminating BP-II from BP-I.
We examined whether hypotension in very low birth weight infants aged⩽1 week was associated with hospital morbidities and overall mortality. Further, we studied whether hypotension was associated with poor neurodevelopmental outcomes in these patients at the corrected age of 18 months. A total of 166 very low birth weight infants were studied during this period. Hospital outcomes and neurodevelopmental outcomes at the corrected age of 18 months were evaluated. Among the 166 very low birth weight infants, 95 patients (57.2%) experienced hypotension at⩽1 week and were associated with an increased incidence of morbidities and mortality. At the corrected age of 18 months, hypotension of the⩽1 week group had significantly lower scores in all three – cognitive, language, and motor – composites of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) screening tests. In addition, a multivariable logistic regression analysis showed that longer mechanical ventilation and periventricular leukomalacia were additionally associated with worse cognitive and language neurodevelopmental outcomes. Hypotension in very low birth weight infants within 1 week of life was associated with increased morbidities and overall mortality. It was also associated with an increased risk of cognitive and language outcomes.
The submarine channel-fill system of the Cambrian Spurs Formation exhibits unique metre-scale cycles of breccia and diamictite. The studied sections, Eureka Spurs, are located at the Mariner Glacier in the central-eastern part of northern Victoria Land, Antarctica. A facies analysis of the channel-fill deposit has led to the recognition of four main lithofacies: breccia, diamictite, thin-bedded sandstone and mudstone. The channel-fill deposit consists of two architectural elements: hollow-fill (HF) and sheet-like (SL) elements. The SL has wide convex-up geometry and consists solely of a very thick bed of diamictite, and is interpreted as a submarine channel lobe. The HF has a concave-up erosional base and flat upper surface. The HF consists of nine cyclic alternations of underlying breccia (cohesionless debris flow) and overlying diamictite (cohesive debris flow). The deposition of breccia is interpreted to have been controlled by repeated allogenic processes such as earthquakes. In contrast, the abrupt vertical transition from breccia to diamictite in each cycle is interpreted to have resulted from an autogenic, slope instability-related process. The interaction of the allogenic and autogenic factors recorded in the metre-scale unique cyclic deposits provides new criteria to interpret cycles of submarine debris flow.
Despite their importance in the formation and evolution of stellar clusters and galaxies, the formation of high-mass stars remains poorly understood. We recently started a systematic observational study of the 22 GHz water and 44 GHz class I methanol masers in high-mass star-forming regions as a four-year KaVA large program. Our sample consists of 87 high-mass young stellar objects (HM-YSOs) in various evolutionary phases, many of which are associated with two or more different maser species. The primary scientific goals are to measure the spatial distributions and 3-dimensional velocity fields of multiple maser species, and understand the dynamical evolution of HM-YSOs and their circumstellar structures, in conjunction with follow-up observations with JVN/EAVN (6.7 GHz class II methanol masers), VERA, and ALMA. In this paper we present details of our KaVA large program, including the first-year results and observing/data analysis plans for the second year and beyond.
We present the results of the linear polarisation observations of methanol masers at 44 and 95 GHz towards 39 massive star forming regions (Kang et al. 2016). These two lines are observed simultaneously with the 21-m Korean VLBI Network (KVN) telescope in single dish mode. About 60% of the observed showed fractional polarisation of a few percents at least at one of the two transition lines. We note that the linear polarisation of the 44 GHz methanol maser is first detected in this study including single dish and interferometer observations. We find the polarisation properties of these two lines are similar as expected, since they trace similar regions. As a follow-up study, we have carried out the VLBI polarisation observations toward some 44 GHz maser targets using the KVN telescope. We present preliminary VLBI polarisation results of G10.34-0.14, which show consistent polarisation properties in multiple epoch observations.
Technologies for detecting and analyzing a single molecule help us understand and engineer numerous phenomena observed in nature. Carbon nanotubes (CNTs) are highly efficient molecular conduits due to their atomically smooth surface. Because of their small diameters, comparable to the size of a single molecule, even a single blocking molecule can obstruct CNT fluidic channels. Analyzing these pore-blocking events in CNTs therefore enables single-molecule studies. The high-aspect ratios of CNT channels, which extend the time scale of transport, allow for studying molecular transport that is too fast to record in other systems. Both theoretical studies and ensemble experimental measurements have verified the enhanced flow of various ions and molecular species in CNTs. Experimental measurements of a single-CNT fluidic channel, however, have only recently begun, demonstrating the detection of individual DNA, polymer, and alkali-metal ions. This article reviews recent advances in single-nanotube fluidic channels with a focus on experimental measurements.
Two challenges exist in laser-assisted atom probe tomography (APT). First, a drastic decline in mass-resolving power is caused, not only by laser-induced thermal effects on the APT tips of bulk oxide materials, but also the associated asymmetric evaporation behavior; second, the field evaporation mechanisms of bulk oxide tips under laser illumination are still unclear due to the complex relations between laser pulse and oxide materials. In this study, both phenomena were investigated by depositing Ni- and Co-capping layers onto the bulk LaAlO3 tips, and using stepwise APT analysis with transmission electron microscopy (TEM) observation of the tip shapes. By employing the metallic capping, the heating at the surface of the oxide tips during APT analysis became more symmetrical, thereby enabling a high mass-resolving power in the mass spectrum. In addition, the stepwise microscopy technique visualized tip shape evolution during APT analysis, thereby accounting for evaporation sequences at the tip surface. The combination of “capping” and “stepwise APT with TEM,” is applicable to any nonconductors; it provides a direct observation of tip shape evolution, allows determination of the field evaporation strength of oxides, and facilitates understanding of the effects of ultrafast laser illumination on an oxide tip.
This study aimed to investigate the relationship between the unemployment experience and depressive symptoms among mid-aged (ages 45–59) and elderly (ages 60 or above) persons and to examine further the effects of unemployment insurance, industrial accident compensation insurance (IACI) and national pension on the stated relationship. Data were used from the Korean Longitudinal Study of Aging (KLoSA) between 2006 and 2012. A total of 1,536 individuals employed at the 2006 baseline were followed. The association between employment status change during 2006 to 2008, 2008 to 2010 or 2010 to 2012 and depressive symptoms in years 2008, 2010 or 2012 were analysed using a generalised estimating equation model. Depressive symptoms were measured with the Center for Epidemiological Studies Depression Scale (CES-D 10) scale. The results showed that the ‘employed to unemployed’ group had statistically significant increases in depression scores in the mid-aged (β = 0.4884, p = 0.0038) and elderly (β = 0.8275, p ⩽ 0.0001) categories, compared to the ‘employed to employed’ group. Findings were maintained in groups without a social safety net. Contrastingly, the ‘employed to unemployed’ groups with unemployment insurance and IACI did not show statistically significant increases in depression scores. The ‘employed to unemployed’ category of individuals enrolled in the national pension system exhibited a lower increase of depression. Therefore, an enhanced focus on the mental health of unemployed individuals is required, in addition to the provision of a reliable social safety net.
Background: Patients diagnosed with Parkinson’s disease (PD) on clinics who subsequently turn out to have normal dopamine transporter images have been referred to as scans without evidence of dopaminergic deficits (SWEDDs) patients. Cardiovascular autonomic dysfunction has frequently been reported in PD. In this study, we determined the similarities and differences in cardiac autonomic dysfunction between SWEDDs and PD patients. This study investigated whether 24-hour ambulatory blood pressure monitoring (24-hour ABPM) can help identify possible cases with SWEDDs. Methods: We enrolled 28 SWEDDs patients, 46 patients with PD, and 30 healthy controls. To evaluate cardiac autonomic function, 24-hour ABPM was performed on all subjects. Cardiac metaiodobenzylguanidine (MIBG) scintigraphy was performed on the SWEDDs and PD subjects. Results: The percentage nocturnal decline in blood pressure differed significantly among SWEDDs patients, PD patients, and controls (p<0.05). In addition to the abnormal nocturnal BP, regulation (nondipping and reverse dipping) was significantly higher in SWEDDs and PD subjects than in the control subjects (p<0.05). There was no significant correlation between the % nocturnal blood pressure reduction and parameters of cardiac MIBG uptake ratio. However, orthostatic hypotension was significant correlated with the nocturnal blood pressure dip (%), nocturnal blood pressure patterns, and the cardiac MIBG uptake ratio (early and late) in combined SWEDDs and PD subjects. Conclusions: Pathologic nocturnal blood pressure regulation and nocturnal hypertension, known characteristics of PD, are also present in SWEDDs. Moreover, cardiac sympathetic denervation should not be attributed to cardiac autonomic dysfunction in SWEDDs patients. As with PD patients, the SWEDDs patients studied here tended to have cardiac autonomic dysfunction.
Steel coils coated with Zn–Mg alloy containing high Mg content develop dark rust when exposed to an extremely limited amount of aqueous environment. To understand the nature of the dark rust and its formation mechanism, the steel is evaluated by the immersion test and high temperature–humidity test followed by critical evaluation with transmission electron microscopy for cross-sectional observation, field-emission scanning electron microscopy for surface morphology observation, Auger electron spectroscopy and glow discharge spectroscopy for identification of chemical composition as a function of depth. The results indicate that the dark rust is formed by precipitation of Mg-based corrosion product on the outermost surface when the steel is exposed to aqueous environment at high temperature. This is due mainly to preferential dissolution of Mg phases by the galvanic action with MgZn2 and Mg2Zn11 composed of the coating layer, and easy precipitation of Mg2+ ion in a form of Mg(OH)2 in a limited volume of the condensed water film on the surface.
The diagnostic relevance of subjective memory complaints (SMCs) in mild cognitive impairment (MCI) remains to be unresolved. The aim of this study is to determine clinical correlates of SMCs in MCI. Furthermore, we examined whether there are the differences due to different aspects of complaints (i.e. prospective memory (PM) versus retrospective memory (RM) complaints).
We examined the cross-sectional associations between SMCs and depressive symptoms, instrumental activities of daily living (IADL), and cognitive measures in sixty-six individuals with MCI (mean age: 65.7 ± 8.01 years). The criteria for MCI included SMCs, objective cognitive impairment, normal general cognitive function, largely intact functional activities, and absence of dementia. SMCs were assessed using the Prospective and Retrospective Memory Questionnaire (PRMQ), which contains 16 items describing everyday memory failure of both PM and RM.
SMC severity (i.e. PRMQ total score) was associated with stronger depressive symptoms and worse IADL performance. SMCs were not related to cognitive measures. For PM and RM subscores, both depressive symptoms and IADL were related to the PRMQ-PM and -RM scores. The main contributors to these PM and RM scores were depressive symptoms and IADL impairment, respectively.
This study suggests that SMCs are more associated with depressive symptoms and IADL problems than with cognitive performance in individuals with MCI. Furthermore, while PM and RM complaints are related to both depressive symptoms and IADL, the differences between these main contributors suggest that RM complaints based on IADL could be more associated with the organically driven pathological features of MCI.