To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Substantial evidence indicates structural abnormalities in the cerebral cortex of patients with schizophrenia (SCZ), although their clinical implications remain unclear. Previous case-control studies have investigated group-level differences in structural abnormalities, although the study design cannot account for interindividual differences. Recent research has focused on the association between the heterogeneity of the cerebral cortex morphometric features and clinical heterogeneity.
We used neuroimaging data from 420 healthy controls and 695 patients with SCZ from seven studies. Four cerebral cortex measures were obtained: surface area, gray matter volume, thickness, and local gyrification index. We calculated the coefficient of variation (CV) and person-based similarity index (PBSI) scores and performed group comparisons. Associations between the PBSI scores and cognitive functions were evaluated using Spearman's rho test and normative modeling.
Patients with SCZ had a greater CV of surface area and cortical thickness than those of healthy controls. All PBSI scores across cortical measures were lower in patients with SCZ than in HCs. In the patient group, the PBSI scores for gray matter volume and all cortical measures taken together positively correlated with the full-scale IQ scores. Patients with deviant PBSI scores for gray matter volume and all cortical measures taken together had lower full-scale IQ scores than those of other patients.
The cerebral cortex in patients with SCZ showed greater regional and global structural variability than that in healthy controls. Patients with deviant similarity of cortical structural profiles exhibited a lower general intelligence than those exhibited by the other patients.
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.
Progenitors of Type Ib and Ic supernovae (SNe) are stripped envelope stars and provide important clues on the mass-loss history of massive stars. Direct observations of the progenitors before the supernova explosion would provide strong constraints on the exact nature of SN Ib/Ic progenitors. Given that stripped envelope massive stars can have an optically thick wind as in the case of Wolf-Rayet stars, the influence of the wind on the observational properties needs to be properly considered to correctly infer progenitor properties from pre-SN observations. Non-LTE stellar atmosphere models indicate that the optical brightness could be greatly enhanced with an optically thick wind because of lifting-up of the photosphere from the stellar surface to the wind matter, and line and free-free emissions. So far, only a limited number of SN Ib/Ic progenitor candidates have been reported, including iPTF13bvn, SN 2017ein and SN 2019yvr. We argue that these three candidates are a biased sample, being unusually bright in the optical compared to what is expected from typical SN Ib/Ic progenitors, and that mass-loss enhancement during the final evolutionary stage can explain their optical properties.
To investigate the impacts of depression screening, diagnosis and treatment on major adverse cardiac events (MACEs) in acute coronary syndrome (ACS).
Prospective cohort study including a nested 24-week randomised clinical trial for treating depression was performed with 5–12 years after the index ACS. A total of 1152 patients recently hospitalised with ACS were recruited from 2006 to 2012, and were divided by depression screening and diagnosis at baseline and 24-week treatment allocation into five groups: 651 screening negative (N), 55 screening positive but no depressive disorder (S), 149 depressive disorder randomised to escitalopram (E), 151 depressive disorder randomised to placebo (P) and 146 depressive disorder receiving medical treatment only (M).
Cumulative MACE incidences over a median 8.4-year follow-up period were 29.6% in N, 43.6% in S, 40.9% in E, 53.6% in P and 59.6% in M. Compared to N, screening positive was associated with higher incidence of MACE [adjusted hazards ratio 2.15 (95% confidence interval 1.63–2.83)]. No differences were found between screening positive with and without a formal depressive disorder diagnosis. Of those screening positive, E was associated with a lower incidence of MACE than P and M. M had the worst outcomes even compared to P, despite significantly milder depressive symptoms at baseline.
Routine depression screening in patients with recent ACS and subsequent appropriate treatment of depression could improve long-term cardiac outcomes.
Our aim was to examine the prevalence, correlates, and association of depressive and anxiety disorders with quality of life (QoL) and such other outcomes as the need for psychosocial services in cancer patients.
A total of 400 patients participated in a multicenter survey involving five cancer centers located throughout Korea. The Short-Form Health Survey, the MD Anderson Symptom Inventory, the Mini-Mental Adjustment to Cancer (MINI-MAC), and Mini-International Neuropsychiatric Interview were administered.
The prevalence rates for depressive and anxiety disorders were 16 and 17.1%, respectively. Younger age and poor Eastern Cooperative Oncology Group performance status, and all physical symptoms, as well as helplessness/hopelessness, anxious preoccupation (AP), and cognitive avoidance (CA) on the MINI-MAC were found to be significantly related to depressive disorder (DD) in a univariate logistic regression analysis. Metastases, the symptoms of disturbed sleep, dry mouth, and numbness or tingling, as well as AP and CA were significantly correlated with anxiety disorder (AD) in the univariate analysis. In the multivariate analyses, only AP was significant for AD (odds ratio = 2.94, p < 0.001), while none reached statistical significance for DD. Psychiatric comorbidity status had a detrimental effect on various dimensions of QoL. Patients with DD or AD reported a significantly higher need for professional psychosocial services.
Significance of results:
Given the substantial prevalence and pervasive impact of DD and AD on various aspects of QoL, its assessment and care should be integrated as a regular part of oncological care throughout the cancer continuum.
The National Institute of Neurological Disease and Stroke-Canadian Stroke Network (NINDS-CSN) 5-minute neuropsychology protocol consists of only verbal tasks, and is proposed as a brief screening method for vascular cognitive impairment. We evaluated its feasibility within two weeks after stroke and ability to predict the development of post-stroke dementia (PSD) at 3 months after stroke.
We prospectively enrolled subjects with ischemic stroke within seven days of symptom onset who were consecutively admitted to 12 university hospitals. Neuropsychological assessments using the NINDS-CSN 5-minute and 60-minute neuropsychology protocols were administered within two weeks and at 3 months after stroke onset, respectively. PSD was diagnosed with reference to the American Heart Association/American Stroke Association statement, requiring deficits in at least two cognitive domains.
Of 620 patients, 512 (82.6%) were feasible for the NINDS-CSN 5-minute protocol within two weeks after stroke. The incidence of PSD was 16.2% in 308 subjects who had completed follow-up at 3 months after stroke onset. The total score of the NINDS-CSN 5-minute protocol differed significantly between those with and without PSD (4.0 ± 2.7, 7.4 ± 2.7, respectively; p < 0.01). A cut-off value of 6/7 showed reasonable discriminative power (sensitivity 0.82, specificity 0.67, AUC 0.74). The NINDS-CSN 5-minute protocol score was a significant predictor for PSD (adjusted odds ratio 6.32, 95% CI 2.65–15.05).
The NINDS-CSN 5-minute protocol is feasible to evaluate cognitive functions in patients with acute ischemic stroke. It might be a useful screening method for early identification of high-risk groups for PSD.
Devastating disasters around the world directly contribute to significant increases in human mortality and economic costs. The objective of this study was to examine the current state of the Korea Disaster Relief Team that participated in an international training module.
The whole training period was videotaped in order to observe and evaluate the respondents. The survey was carried out after completion of the 3-day training, and the scores were reported by use of a 5-point Likert scale.
A total of 43 respondents were interviewed for the survey, and the results showed that the overall preparedness score for international disasters was 3.4±1.6 (mean±SD). The awareness of the Incident Command System for international disasters was shown to be low (3.5±1.1). Higher scores were given to personnel who took on leadership roles in the team and who answered “I knew my duty” (4.4±0.6) in the survey, as well as to the training participants who answered “I clearly knew my duty” (4.5±0.5).
The preparedness level of the Korea Disaster Relief Team was shown to be insufficient, whereas understanding of the roles of leaders and training participants in the rescue team was found to be high. It is assumed that the preparedness level for disaster relief must be improved through continued training. (Disaster Med Public Health Preparedness. 2016;1–5)
It is controversial whether Borna disease virus (BDV) infects humans and causes psychiatric disorders.
The relationship between BDV infection and schizophrenia with deficit syndrome was investigated.
Using the Schedule for the Deficit Syndrome, 62 schizophrenic in-patients were selected from three psychiatric hospitals. RNA was extracted from peripheral blood mononuclear cells and analyzed using nested reverse transcriptase-polymerase chain reaction with primers to detect BDV p24 and p40.
Results and conclusions:
BDV transcripts were not detected in samples from any of the 62 schizophrenic patients. These data do not support an etiologic association between BDV infection and the deficit form of schizophrenia.
The liquid phase plasma reduction method has been applied to prepare silver nanoparticles from a solution of silver nitrate (AgNO3) using a bipolar pulsed electrical discharge system. The excited states of atomic silver, hydrogen and oxygen as well as the molecular bands of hydroxyl radicals were detected in the emission spectra. As the discharge duration increased up to 10 min, silver particle peaks produced by surface plasmon absorption were observed around 430 nm. Both the particle size and the particle numbers were observed to increase with the length of the plasma treatment time and with the initial AgNO3 concentration. Spherical nanoparticles of about 5–20 nm in size were obtained with the discharging time of 5 min, whereas aggregates of nanoparticles of about 10–50 nm in size were mainly produced with the discharging time of 20 min. The cationic surfactant of cetyltrimethylammonium bromide (CTAB) added with the CTAB/AgNO3 molar ratio of 30% was shown to inhibit nanoparticle aggregation.
Pathological gambling (PG) is a severe and persistent pattern of problem gambling that has been aligned with obsessive-compulsive disorder (OCD). However, no study has compared the neurocognitive profiles of individuals with PG and OCD.
We compared neurocognitive functioning, including executive function, verbal learning and memory, and visual–spatial organization and memory among 16 pathological gamblers, 31 drug-naïve OCD subjects, and 52 healthy controls.
The only neurocognitive marker common to both groups was increased fragmentation errors on the Rey–Osterrieth Complex Figure Test (ROCF). The PG subjects showed increased nonperseverative error on the Wisconsin Card Sorting Test and organization difficulties in the ROCF, whereas the OCD subjects revealed longer response times on the Stroop test and retention difficulties on the immediate recall scale of the ROCF.
A more careful approach is required in considering whether PG is a part of the OCD spectrum, as little evidence of neurocognitive overlap between PG and OCD has been reported.
Oxidative stress may be affected by lead exposure as well as antioxidants, yet little is known about the interaction between dietary antioxidants and blood lead levels (BLL) on oxidative stress level. We investigated the interaction between dietary antioxidants and BLL on oxidative stress level. As part of the Biomarker Monitoring for Environmental Health conducted in Seoul and Incheon, Korea, between April and December 2005, we analysed data from 683 adults (female = 47·4 %, mean age 51·4 (sd 8·4) years) who had complete measures on BLL, dietary intakes and oxidative stress marker (urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG)). Dietary intakes were assessed by a validated semi-quantitative FFQ, BLL was measured using atomic absorption spectrophotometry, and 8-OHdG by ELISA. Multivariate linear regression analyses were used to evaluate the influence of BLL on the association between dietary antioxidants and 8-OHdG. Geometric means of BLL and 8-OHdG concentrations were 4·1 (sd 1·5) μg/dl and 5·4 (sd 1·9) μg/g creatinine, respectively. Increases of vitamins C and E were significantly associated with the decrease of log10 8-OHdG in the adults from the lowest quartile of the BLL group ( ≤ 3·18 μg/dl, geometric mean = 2·36 μg/dl) than those of the highest quartile BLL group (>5·36 μg/dl, geometric mean = 6·78 μg/dl). Regarding antioxidant-related foods, vegetables excluding kimchi showed a higher inverse relationship with 8-OHdG in the lowest quartile BLL group than the highest group. These findings suggest a rationale for lowering the BLL and increasing the intake of dietary antioxidants in the urban population in Korea.
The purpose of this study was to investigate whether there is any association between preeclampsia and eNOS, DDAH, and VEGF gene polymorphisms, and also to search for a possible association between haplotypes in eNOS, DDHA, and VEGF genes and the risk for preeclampsia. DNA was extracted from whole blood of 223 preeclampsia patients and 237 healthy pregnant women. The genotypes were analyzed by a single base primer extension assay using a SNaPShot assay kit. Results were analyzed with the Student's t-test, Chi-square test, and Logistic regression analysis. Haplotype analyses were performed using Haploview 3.2 version. There were no significant differences in genotype or allele frequencies of eNOS, DDAH, and VEGF gene polymorphisms between preeclampsia patients and controls. No increase in the risk of preeclampsia for those genes was observed under any model of inheritance and there were no statistically significant associations between any haplotypes and preeclampsia risk. Polymorphisms in eNOS, DDAH, and VEGF gene do not seem to be risk factors for preeclampsia.
Background: The influences of demographics, culture, language, and environmental changes on Mini-Mental State Examination (MMSE) scores are considerable.
Methods: Using a sample of 7452 healthy, community-dwelling elderly Koreans, aged 55 to 94 years, who participated in the four ongoing geriatric cohorts in Korea, we investigated demographic influences on MMSE scores and derived normative data for this population. Geropsychiatrists strictly excluded subjects with cognitive disorders according to the protocol of the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K) Clinical Assessment Battery (CERAD-K-C).
Results: Education (standardized β = 0.463), age (standardized β = −0.303), and gender (standardized β = −0.057) had significant effects on MMSE scores (p < 0.001). The score of MMSE increase 0.379 point per 1-year education, decrease 0.188 per 1-year older, and decrease 0.491 in women compared to men. Education explained 30.4% of the scores’ total variance, which was much larger than the variances explained by age (8.4%) or gender (0.3%). Accordingly, we present normative data for the MMSE stratified by education (0, 1–3, 4–6, 7–9, 10–12, and ≥ 13 years), age (60–69, 70–79, and 80–89 years), and gender.
Conclusions: We provide contemporary education-, age-, and gender-stratified norms for the MMSE, derived from a large, community-dwelling elderly Korean population sample, which could be useful in evaluating individual MMSE scores.
Both luminous efficiency and lifetime in blue fluorescence organic light
emitting devices (OLEDs) have been improved by modified HTMs with higher
LUMO energy levels. The LUMO energy levels of HTM were increased by
modifying substituent in HTM molecules. Two HTMs containing ortho and meta
biphenyl substituent and one HTM containing thiophene substituent were
synthesized via palladium catalyzed amine coupling reactions to compare with
a para biphenyl substituent HTM-1 as a standard molecule. According to TDDFT
calculations, these three modified HTMs showed 0.05-0.15 eV higher LUMO
energy levels compared to the para biphenyl substituent HTM-1. The luminous
efficiency and the lifetime (LT90) of OLEDs using HTM-2 at 500
cd/m2 have been enhanced up to 20 % and 52 %, respectively,
compared to the standard device using HTM-1.
To enhance the lifetime of large-sized active matrix organic light emitting
diodes (AMOLEDs), we developed a liquid desiccant for encapsulation. The
liquid desiccant was prepared by mixing nano-sized calcium oxide (CaO)
powders and silicone binder including polyalkylalkenylsiloxane,
polyalkylhydrogensiloxane and platinum compound. It was confirmed that
liquid desiccant had an effect on absorption of penetrated moisture and
oxygen through calcium tests. Also, the test cells encapsulated with only
epoxy sealant dispensed at the edge of the cell developed dark spots within
100 hrs, which grew larger with time at 85 oC and 85 % R.H. On the other hand, the test cell sealed with epoxy
sealant and liquid desiccant showed no dark spots and retained 97% of its
initial luminance even after being stored for 800 hrs at 85 oC and 85 % R.H. Furthermore, the accelerating storage lifetimes of
31-inch bottom-emitting AMOLEDs with epoxy sealant and liquid desiccant
showed about 1000 hrs. These results suggest that the liquid desiccant can
be applied to encapsulation of large-sized AMOLEDs.
Pure CdSe and Mg-doped CdSe nanocrystal quantum dots were synthesized into the zinc-blende structure at a low temperature by the inverse micelle technique using paraffin oil and oleic acid as surface capping agents. The ripening behavior of the nanocrystals was monitored using the red shift in ultraviolet (UV)-visible light absorption peaks, and their size variation was estimated using the so-called, quantum confinement theory. The Lifshitz–Slyozov–Wagner (LSW) kinetics analyses were performed based on the variation in size according to the ripening temperature and time period. The activation energy (Q) and reaction rate constant (Ko) were determined for the ripening reaction using Arrhenius-type plots. The kinetics analyses reveal that the volume diffusion through the liquid-phase solution is the governing mechanism for the ripening of both nanocrystals. The Mg-doped CdSe nanocrystals showed enhanced ripening kinetics due to the low activation energy for the volume diffusion.
MgO thin films are widely used in plasma display panels (PDPs) to protect the dielectric layer, which is composed of PbO2, B2O3, and SiO2 compound, against ion bombardment during discharge. To improve the electrical properties of the MgO thin films, (Ba,Sr,Ca)CO3 or LaB6, which has a lower work function than that of MgO, added to the MgO films. The effects of (Ba,Sr,Ca)CO3 or LaB6 addition on the electrical properties, microstructure, and electronic band structure were investigated. In the case where (Ba,Sr,Ca)CO3 was added, the firing voltage, which is the voltage when the panel is ignited the first time during increasing input voltage, was about 18.4 V lower than that of the conventional MgO films. In the case where LaB6 was added, the firing voltage was also reduced by about 24 V. The luminance and luminous efficiency were also increased. Of particular interest was the valence band spectra changed after adding (Ba,Sr,Ca)CO3 or LaB6. The valence band edge, which is the top of the valence band, was shifted to lower binding states and the width of the valence band was increased. Moreover, the band gap was slightly reduced. Considering the emission mechanism of MgO films in plasma display panels, these results mean that the secondary electrons can be ejected more easily and the ejected electrons have more energy. Therefore, the addition of (Ba,Sr,Ca)CO3 or LaB6 might improve the electrical properties.
A bistable effects of Au nano-crystals embedded in poly(N-vinylcarbazole) (PVK) were observed. Subsequently we investigated dependency of the nonvolatile memory behavior on curing temperature for the Au nano-crystals embedded in the PVK. For the study, in the devices of different curing temperatures we measured current-voltage characteristics for the devices and investigated the formation of the Au nano-crystals using cross sectional transmission electron microscopy (TEM). The nonvolatile memory behavior depends on the curing temperature, which is attributed to the suitable formation of the Au nano-crystal.