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Climate change poses a major threat to marine ecosystems, with its effects felt worldwide. A major effect of climate change on marine ecosystems is the rise in water temperature, leading to a northward expansion of habitats for marine organisms. Herdmania momus, a species of ascidians (sea squirts), originally found in tropical and subtropical regions, was introduced to the Korean Peninsula. In this study, we examined the habitat of H. momus along the southeastern coast of the Korean Peninsula between 2016 and 2022. We found that H. momus settlements were observed across the entire survey area, with confirmed habitation in Busan in 2016, Ulsan in 2021, and Gyeongju (the northernmost location) in 2022. The observed habitation trend indicates a rapid geographical expansion, occurring approximately 79 years earlier than previously predicted. These observations demonstrate that marine organisms are undergoing a more rapid geographical expansion than previously projected. These unexpected findings should inform government policies related to proactive measures and strategies for managing the impact of climate change on marine ecosystems.
Although people who attempted suicide tend to repeat suicide attempts, there is a lack of evidence on the association between psychiatric service factors and suicide reattempt among them.
Methods:
We used a nationwide, population-based medical record database of South Korea to investigate the use of psychiatric services before and after the index suicide attempt and the association between psychiatric service factors after the index suicide attempt with the risk of suicide reattempt.
Results:
Among 5,874 people who had attempted suicide, the all-cause mortality within 3 months after the suicide attempt was 11.6%. Among all subjects who attempted suicide, 30.6% of them had used psychiatric services within 6 months before the suicide attempt; 43.7% of them had used psychiatric services within 3 months after the suicide attempt. Among individuals who had visited clinics following attempted suicide, the cumulative incidence of suicide reattempt over a mean follow-up period of 5.1 years was 3.4%. About half of suicide reattempts occurred within 1 year after the index suicide attempt. Referral to psychiatric services within 7 days was associated with a decreased risk of suicide reattempt (adjusted hazard ratio, 0.51; 95% confidence intervals, 0.29-0.89).
Conclusion:
An early psychiatric referral within 1 week after a suicide attempt was associated with a decreased risk of suicide reattempt.
Depression is a risk factor for dementia and weight change can appear as a symptom of depression. However, the association between weight change after the diagnosis of depression and the risk of dementia is poorly established. This study aimed to investigate the association between weight change before and after a diagnosis of depression with the subsequent risk of dementia.
Methods
The National Health Insurance Sharing Service database was used. 1 308 730 patients aged ⩾40 years diagnosed with depression were identified to be eligible. Weight changes after their depression diagnosis were categorized and subsequent incidence of dementia was followed up.
Results
During an average follow-up period of 5.2 years (s.d., 2.0 years), 69 373 subjects were newly diagnosed with all-cause dementia (56 351 were Alzheimer's disease and 6877 were vascular dementia). Regarding all outcomes, compared to those with a minimal weight change (−5 to 5%), all groups with weight gain or loss showed increased risks of dementia after adjusting potential risk factors for dementia, in all analysis models with a dose–response relationship, showing a U-shaped association.
Conclusions
Weight change as a symptom of depression could be a predictor for the future development of dementia.
Waterproofing treatment is important for the preservation of smectite-rich rocks because of their shrinking and swelling properties. The effects of water repellents on the smectite structure and the water sorption of untreated and treated smectites were studied using X-ray diffraction. The hydrophobic Wacker BS 290 (around 100% silane/siloxane) does not prevent water from sorbing on the interlayer surface of smectite because the hydrophobic silane/siloxane is not intercalated into the interlayer space, but adsorbed onto the external surface of smectite. However, the hydrophilic Wacker BS 1001 (water-soluble emulsified silane/siloxane) prevents water from sorbing onto the interlayer surface beyond 33.3 wt.% because the hydrophobic part of the intercalated surfactant has a poor affinity for water. These results imply that water repellent containing a surfactant is suitable for smectite-rich rocks, but the expansion of smectite by intercalation of the surfactant is likely to influence volume change in smectite-rich rocks. This study notes that smectite within a rock can be one of the most important factors influencing the effectiveness of waterproof treatment. This study proposes that an intensive preliminary examination should be performed before applying water repellents to rocks, and furthermore, encourages development of new chemical reagents suitable for protecting smectite-rich rocks from moisture.
The immobilization of antimicrobial drugs can be used to expand the application of antibacterial properties to consumer products. The purpose of this study was to stabilize an antimicrobial agent, levofloxacin (LVX), for sustained antibacterial activity by immobilizing the drug molecules in a layered double hydroxide (LDH) and embedded in a polyurethane substrate. As-prepared MgAl-LDH was calcined at 400°C and reconstructed with LVX for intercalation. The X-ray diffraction patterns and cross-sectional transmission electron microscopy images showed lattice expansion along the crystallographic c axis upon LVX intercalation, suggesting successful loading of the drug. Fourier-transform infrared spectra revealed that the structure of LVX was well preserved between LDH layers. Elemental analysis indicated that the loading capacity of LVX in the hybrid was 41.7%. Bacterial-colony forming inhibitory assay on Bacillus subtilis exhibited ~100% antibacterial activity of both LVX alone and LVX-LDH hybrid (LL). To determine sustainability of antibacterial activity by the hybrid, either LVX alone or LL hybrid was loaded in the polyurethane (PU) substrate for which antibacterial activity was evaluated before and after immersion in a phosphate-buffered saline for 3 days. The LVX-composited PU showed a dramatic decrease in antibacterial activity, down to 0% after buffer treatment; LL-composited PU still contained antibacterial activity (~34% of colony suppression) after phosphate-buffered saline immersion.
South Korea has introduced conditionality to coverage decisions for certain difficult or high-risk procedures. The transcatheter aortic valve implantation (TAVI) was included in the coverage with evidence development (CED) in 2014. This study reviewed the results of reassessment for the TAVI using real world data (RWD) and suggested its implications.
Methods
Healthcare providers authorized to use the promising technologies are required to collect the RWD for suitability evaluation, safety monitoring, and cost-effectiveness, differing from the general reassessment process. In 2021, 45 healthcare providers collected clinical information for TAVI patients. Their registries were linked with the national health insurance claims, which provided data on 19 items to assess safety and effectiveness such as overall mortality, reoperation rates, hospital readmission rates, and degree of functional improvement.
Results
According to the Society of Thoracic Surgeons’ predicted risk of mortality (STS), 988 TAVI patients were classified into three groups; high (STS >8 percent, n=347), intermediate (STS 4-8 percent, n=272), and low (STS <4 percent, n=369); We compared main outcomes and estimated survival probabilities between subgroups. Within 30 days, the overall mortality rates were 4.9 percent (high), 2.6 percent (intermediate), and 1.4 percent (low); major bleeding rates were 7.6 percent (high), 6.2 percent (intermediate),and 1.4 percent (low); incidence of new atrial fibrillation were 6.8 percent (high), 4.2 percent (intermediate), and 3.2 percent (low). Based on the quantitative results using RWD and systematic review for the safety and effectiveness, TAVI is reported to have essential benefits for high-risk group and elderly patients (>80 years). Whereas, intermediate and low-risk groups have out-of-pocket payment rates of 50 percent and 80 percent, respectively.
Conclusions
The reassessment system through RWD accumulation enabled the evidence-based evaluation for the TAVI. Based on the transition to CED for essential benefits, a systematic framework such as RWD collection from treatment commencement should be introduced to broaden RWD use for benefit management of medical technologies with uncertain levels of evidence. Therefore, this ensures overall quality of care and effective coverage in health.
In this article, we explore whether hierarchy and linearity conspire to affect agreement. The data come from an experimental study of honorific agreement between verbal si and coordinate subjects in Korean. We focus on computing the mismatch driven by honorifically mixed conjuncts. Unlike South Slavic gender agreement, Korean has neither Resolved Agreement nor First Conjunct Agreement. Only Last Conjunct Agreement is attested in Korean honorification. We show that honorific agreement within coordinate subjects is triggered only when the honorific verbal si appears, which is substantially different from the case with the honorific nominal nim. We also show that acceptability significantly decreases when the last conjunct of coordinate subjects is incongruous with an honorific verb. We thus argue that verbal honorific agreement with Korean coordinate subjects is sensitive to linear order, mimicking South Slavic gender agreement.
We report VLBI monitoring observations of the 22 GHz H2O masers toward the Mira variable BX Cam. Data from 37 epochs spanning ∼3 stellar pulsation periods were obtained between May 2018 and June 2021 with a time interval of 3–4 weeks. In particular, the VERA dual-beam system was used to measure the kinematics and parallaxes of the H2O maser features. The obtained parallax, 1.79±0.08 mas, is consistent with Gaia EDR3 and previous VLBI measurements. The position of the central star was estimated relied on Gaia EDR3 data and the center position of the 43 GHz SiO maser ring imaged with KVN. Analysis of the 3D maser kinematics revealed an expanding circumstellar envelope with a velocity of 13±4 km s−1 and significant spatial and velocity asymmetries. The H2O maser animation achieved by our dense monitoring program manifests the propagation of shock waves in the circumstellar envelope of BX Cam.
Nosocomial transmission of COVID-19 among immunocompromised hosts can have a serious impact on COVID-19 severity, underlying disease progression and SARS-CoV-2 transmission to other patients and healthcare workers within hospitals. We experienced a nosocomial outbreak of COVID-19 in the setting of a daycare unit for paediatric and young adult cancer patients. Between 9 and 18 November 2020, 473 individuals (181 patients, 247 caregivers/siblings and 45 staff members) were exposed to the index case, who was a nursing staff. Among them, three patients and four caregivers were infected. Two 5-year-old cancer patients with COVID-19 were not severely ill, but a 25-year-old cancer patient showed prolonged shedding of SARS-CoV-2 RNA for at least 12 weeks, which probably infected his mother at home approximately 7–8 weeks after the initial diagnosis. Except for this case, no secondary transmission was observed from the confirmed cases in either the hospital or the community. To conclude, in the day care setting of immunocompromised children and young adults, the rate of in-hospital transmission of SARS-CoV-2 was 1.6% when applying the stringent policy of infection prevention and control, including universal mask application and rapid and extensive contact investigation. Severely immunocompromised children/young adults with COVID-19 would have to be carefully managed after the mandatory isolation period while keeping the possibility of prolonged shedding of live virus in mind.
There are growing concerns about the impact of the COVID-19 pandemic on the mental health of older adults. We examined the effect of the pandemic on the risk of depression in older adults.
Methods
We analyzed data from the prospective cohort study of Korean older adults, which has been followed every 2 years. Among the 2308 participants who completed both the third and the fourth follow-up assessments, 58.4% completed their fourth follow-up before the outbreak of COVID-19 and the rest completed it during the pandemic. We conducted face-to-face diagnostic interviews using Mini International Neuropsychiatric Interview and used Geriatric Depression Scale. We performed generalized estimating equations and logistic regression analyses.
Results
The COVID-19 pandemic was associated with increased depressive symptoms in older adults [b (standard error) = 0.42 (0.20), p = 0.040] and a doubling of the risk for incident depressive disorder even in euthymic older adults without a history of depression (odds ratio = 2.44, 95% confidence interval 1.18–5.02, p = 0.016). Less social activities, which was associated with the risk of depressive disorder before the pandemic, was not associated with the risk of depressive disorder during the pandemic. However, less family gatherings, which was not associated with the risk of depressive disorder before the pandemic, was associated with the doubled risk of depressive disorder during the pandemic.
Conclusions
The COVID-19 pandemic significantly influences the risk of late-life depression in the community. Older adults with a lack of family gatherings may be particularly vulnerable.
Accurate prognostication is important for patients and their families to prepare for the end of life. Objective Prognostic Score (OPS) is an easy-to-use tool that does not require the clinicians’ prediction of survival (CPS), whereas Palliative Prognostic Score (PaP) needs CPS. Thus, inexperienced clinicians may hesitate to use PaP. We aimed to evaluate the accuracy of OPS compared with PaP in inpatients in palliative care units (PCUs) in three East Asian countries.
Method
This study was a secondary analysis of a cross-cultural, multicenter cohort study. We enrolled inpatients with far-advanced cancer in PCUs in Japan, Korea, and Taiwan from 2017 to 2018. We calculated the area under the receiver operating characteristics (AUROC) curve to compare the accuracy of OPS and PaP.
Results
A total of 1,628 inpatients in 33 PCUs in Japan and Korea were analyzed. OPS and PaP were calculated in 71.7% of the Japanese patients and 80.0% of the Korean patients. In Taiwan, PaP was calculated for 81.6% of the patients. The AUROC for 3-week survival was 0.74 for OPS in Japan, 0.68 for OPS in Korea, 0.80 for PaP in Japan, and 0.73 for PaP in Korea. The AUROC for 30-day survival was 0.70 for OPS in Japan, 0.71 for OPS in Korea, 0.79 for PaP in Japan, and 0.74 for PaP in Korea.
Significance of results
Both OPS and PaP showed good performance in Japan and Korea. Compared with PaP, OPS could be more useful for inexperienced physicians who hesitate to estimate CPS.
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.
Methods
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.
Results
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.
Conclusion
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.
A suboptimal diet and nutritional deficiencies can have important influences on health with significant impact among older adults. This study aims to assess the presence of suboptimal dietary intake among older Americans and identify risk and protective factors influencing diet quality.
Design:
Cross-sectional secondary analysis.
Setting:
USA.
Participants:
A nationally representative sample of 5614 community-dwelling older adults over age 54 in the Health and Retirement Study – Health Care and Nutrition Survey.
Results:
Overall, only 10·7 % of respondents had a good quality diet (Healthy Eating Index score 81 and above); the majority had diets considered poor or needing improvement. Less than 50 % of respondents met dietary guidelines and nutritional goals for most individual food groups and nutrients. Respondents with low socio-economic status, fewer psychosocial resources and those who had limited access to healthy food outlets were more likely to have a diet of suboptimal quality.
Conclusions:
Efforts to remove identified barriers that put older adults at risk for poor nutrition and to provide resources that increase access to healthy food should be made to encourage healthy eating and enhance diet quality.
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.
We calculated the human resources required for an antimicrobial stewardship program (ASP) in Korean hospitals.
Design:
Multicenter retrospective study.
Setting:
Eight Korean hospitals ranging in size from 295 to 1,337 beds.
Methods:
The time required for performing ASP activities for all hospitalized patients under antibiotic therapy was estimated and converted into hours per week. The actual time spent on patient reviews of each ASP activity was measured with a small number of cases, then the total time was estimated by applying the determined times to a larger number of cases. Full-time equivalents (FTEs) were measured according to labor laws in Korea (52 hours per week).
Results:
In total, 225 cases were reviewed to measure time spent on patient reviews. The median time spent per patient review for ASP activities ranged from 10 to 16 minutes. The total time spent on the review for all hospitalized patients was estimated using the observed number of ASP activities for 1,534 patients who underwent antibiotic therapy on surveillance days. The most commonly observed ASP activity was ‘review of surgical prophylactic antibiotics’ (32.7%), followed by ‘appropriate antibiotics recommendations for patients with suspected infection without a proven site of infection but without causative pathogens’ (28.6%). The personnel requirement was calculated as 1.20 FTEs (interquartile range [IQR], 1.02–1.38) per 100 beds and 2.28 FTEs (IQR, 1.93–2.62) per 100 patients who underwent antibiotic therapy, respectively.
Conclusion:
The estimated time required for human resources performing extensive ASP activities on all hospitalized patients undergoing antibiotic therapy in Korean hospitals was ~1.20 FTEs (IQR, 1.02–1.38) per 100 beds.
The 14C peak in AD 775 (M12) has been measured and confirmed globally in several studies since it was first measured in annual tree rings by Miyake et al. (2012). However, M12 data measurements in early- and latewood are limited. This paper presents the Δ14C values in early- and latewood from AD 762–776 Zelkova serrata tree rings from Bangu-dong, Ulsan, South Korea (35°33′N, 129°20′E). The results indicate no early rise in Δ14C values in the latewood of AD 774 in this sample located at mid-latitude. A comparison of the results of this and previous studies suggests latitude dependence (Büntgen et al. 2018); that is, the early rise of Δ14C in AD 774 was not observed at mid-latitudes in South Korea but was observed at high latitudes in Finland. The half-oxidation time of 14C was estimated from a detailed analysis of a small bomb peak in AD 1962. Based on the half-oxidation time, the Δ14C rise in the latewood, but not in the earlywood, of AD 774 in Finland, and the absence of a Δ14C rise in both the early- and latewood of AD 774 in South Korea, the 14C spike was estimated to have been produced from late April to mid-June in AD 774.
We recently reported an association between TAAR6 (trace amine associated receptor 6 gene) variations and schizophrenia (SZ). We now report an association of a set of TAAR6 variations and clinical presentation and outcome in a sample of 240 SZ Korean patients. Patients were selected by a Structured Clinical Interview, DSM-IV Axis I disorders – Clinical Version (SCID-CV). Other psychiatric or neurologic disorders, as well as medical diseases, were exclusion criteria. To assess symptom severity, patients were administered the CGI scale and the PANSS at baseline and at the moment of discharge, 1 month later on average. TAAR6 variations rs6903874, rs7452939, rs8192625 and rs4305745 were investigated; rs6903874, rs7452939 and rs8192625 entered the statistical investigation after LD analysis. Rs8192625 G/G homozygosis was found to be significantly associated both with a worse clinical presentation at PANSS total and positive scores and with a shorter period of illness before hospitalization. No haplotype significant findings were found. The present study stands for a role of the TAAR6 in the clinical presentation of SZ. Moreover, our results show that this genetic effect may be counteracted by a correct treatment. Haplotype analysis was not informative in our sample, probably also because of the incomplete SNPs' coverage of the gene we performed. Further studies in this direction are warranted.
The mobile screening test system for screening mild cognitive impairment (mSTS-MCI) was developed for clinical use. However, the clinical usefulness of mSTS-MCI to detect elderly with MCI from those who are cognitively healthy has yet to be validated. Moreover, the comparability between this system and traditional screening tests for MCI has not been evaluated.
Objective:
The purpose of this study was to examine the validity and reliability of the mSTS-MCI and confirm the cut-off scores to detect MCI.
Method:
The data were collected from 107 healthy elderly people and 74 elderly people with MCI. Concurrent validity was examined using the Korean version of Montreal Cognitive Assessment (MoCA-K) as a gold standard test, and test–retest reliability was investigated using 30 of the study participants at four-week intervals. The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were confirmed through Receiver Operating Characteristic (ROC) analysis, and the cut-off scores for elderly people with MCI were identified.
Results:
Concurrent validity showed statistically significant correlations between the mSTS-MCI and MoCA-K and test–rests reliability indicated high correlation. As a result of screening predictability, the mSTS-MCI had a higher NPV than the MoCA-K.
Conclusions:
The mSTS-MCI was identified as a system with a high degree of validity and reliability. In addition, the mSTS-MCI showed high screening predictability, indicating it can be used in the clinical field as a screening test system for mild cognitive impairment.
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.
Method:
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.
Results:
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.