Left Atrial Strain Insights in Atrial Fibrillation and the Interplay with Metabolic Syndrome.

INTRODUCTION: Understanding the interplay between metabolic syndrome and left atrial (LA) function is crucial, especially in patients newly diagnosed with atrial fibrillation (AF). We evaluated the association between subclinical atrial function and metabolic syndrome in patients diagnosed with new-onset AF. METHODS: A retrospective analysis was conducted on 220 patients, aged between 20 and 100 years, who were newly diagnosed with AF. These patients were divided into two groups based on the presence or absence of metabolic syndrome. LA reservoir strain, a measure of LA function, was assessed using transthoracic echocardiography. Statistical methods, including receiver operating characteristic (ROC) curve and logistic regression analyses, were employed to evaluate the association between LA strain and metabolic syndrome. RESULTS: Among the 220 patients, 108 had metabolic syndrome and displayed more adverse clinical characteristics. The LA reservoir strain was significantly lower in this group (9.7% ± 5.2% vs. 12.0% ± 5.8%, p = 0.003). ROC curve analysis identified 9.3% as the optimal cutoff value for predicting metabolic syndrome, with a sensitivity of 50.9% and specificity of 70.5%. Further, multivariate analysis confirmed that an LA reservoir strain below 9.3% was independently linked to metabolic syndrome (odds ratio 4.261, 95% confidence interval 1.134-16.009, p = 0.032). CONCLUSIONS: The findings reveal a significant association between lower LA reservoir strain values and the presence of metabolic syndrome in patients newly diagnosed with AF. An LA strain value below 9.3% serves as a critical diagnostic and prognostic indicator, highlighting its clinical importance in managing patients with AF.

Development and effects of a non-face-to-face forest therapy program for nurses during the COVID-19 pandemic.

AIM: In this study, we developed a non-face-to-face forest therapy program using videos and applied it to nurses working in hospitals during the prolonged COVID-19 situation to confirm the effect on their mental health. METHOD: This study was a randomized control group pretest-posttest, and 27 clinical nurses in the experimental group and 28 clinical nurses in the control group participated. The program developed forest therapy videos and three city videos each. The experimental group watched the forest therapy video and the control group watched the city video and stress and happiness were measured through pre-test and post-test. RESULTS: The stress level of clinical nurses who applied the non-face-to-face forest therapy program had a significant reduction effect compared to the control group on day 2 (t = -2.239 P = .026) and day 3 (t = -3.188, P = .003). On the other hand, there was no significant effect in happiness in both groups. In addition, repeated measures analysis of variance statistical analysis confirmed that the stress level of the experimental group significantly decreased over time (F = 10.578, P < .001). CONCLUSION: The non-face-to-face forest therapy program is significant in that it had a positive effect on relieving stress by conducting a randomized controlled study targeting clinical nurses working in various hospitals.

Sex differences in effect of patients-centered intervention on blood pressure in patients with hypertension.

Hypertension exhibits sex-related differences in its causes, symptoms, and complications. In this study, we aimed to confirm the efficacy of hypertension intervention by applying a patient-centered approach based on sex differences. We enrolled 95 hypertensive patients in this prospective quasi-experimental pretest-posttest study. The patient-centered lifestyle intervention included penalized nutrition and exercise education in 30-min one-on-one sessions. Before the intervention, we conducted a pretest to evaluate physical examination, behavioral status, quality of life (QoL), blood pressure (BP) measurements, and routine blood tests. The same evaluations were conducted again in a posttest after 3 months. After 3 months of patient-centered intervention, all patients showed a decrease in systolic BP by 2.87 mmHg and diastolic BP by 1.04 mmHg. However, there was no significant difference in BP between men and women after the 3-month follow-up. There were differences in lipid profiles based on sex, with total cholesterol and low-density lipoprotein cholesterol levels decreasing in men and increasing in women. Behavioral and QoL scores improved after the intervention; however, there was no significant difference based on sex. A patient-centered lifestyle intervention for hypertensive patients can effectively lower BP, and sex-specific risk factors affecting its efficacy have been identified.

First report of konjac mosaic virus in Spuriopimpinella brachycarpa in Korea.

Spuriopimpinella brachycarpa Nakai (Common name, Chamnamul; family Apiaceae) is a plant whose leaves are consumed as a vegetable and used as a folk medicine in Korea (Kim et al., 2020). In February 2020, seven samples of S. brachycarpa leaf showing virus symptoms including yellowing, vein chlorosis, chlorotic lesions, and severe mottling were collected from a greenhouse in Busan, South Korea, to diagnose the potential disease (Fig. S1a, b). The disease incidence rate in the greenhouse was >10% (2,970 m2). To identify the causal virus, we analyzed leaf dip preparation and thin sections of the symptomatic leaves by transmission electron microscopy. Filamentous virus particles and pinwheel structures were observed, indicating the presence of a potyvirus (Fig. S1c, d). To confirm these results, the symptomatic leaf samples were further analyzed by reverse-transcription polymerase chain reaction (RT-PCR) using potyvirus universal primers (Table S2) and direct sequencing of the PCR products. All samples were positive for konjac mosaic virus (KoMV). To exclude the possibility of infection by multiple viruses, we performed high-throughput sequencing (HTS) on an Illumina NovaSeq 6000 system (Macrogen Inc., Seoul, South Korea). There were two contigs (9,267 and 2,851 nt) mapping to KoMV sequences. A large contig (9,267 nt; 705,967 mapped reads; mean read coverage of 11,351.4x) showed about 80% identity (93% coverage) with KoMV-F (GenBank accession no. NC_007913) isolated from Amorphophallus konjac in Japan (Nishiguchi et al., 2006). To isolate KoMV from S. brachycarpa, we mechanically inoculated leaf extracts from symptomatic samples onto Chenopodium quinoa as an assay host via three single-lesion passages, followed by propagation in Nicotiana benthamiana. In a bioassay of the KoMV isolate (KoMV-BS), we mechanically inoculated sap from infected N. benthamiana onto 31 indicator plants including Cryptotaenia japonica (Apiaceae), which is similar to S. brachycarpa (Table S3). KoMV-BS systemically induced vein chlorosis and/or leaf mottling in four Nicotiana species and C. japonica, and chlorotic local lesions in upper leaves of C. quinoa; no symptoms were observed in 25 other indicator plants. These results were confirmed by RT-PCR. Next, we obtained the complete genome sequence of KoMV-BS using HTS and 5' and 3' rapid amplification of cDNA ends, with newly designed primers (Table S2). The assembled full-length KoMV-BS genome sequence was 9,392 nt in length, excluding the poly(A) tail, and encoded a polyprotein composed of 3,060 amino acids. The sequence was deposited in GenBank (accession no. OR001914). BLAST analysis showed 84~88% and 90~98% identities at CP nucleotide and amino acid levels, respectively with the reported KoMV isolates, confirming the virus to be an isolate of KoMV (synonym; Japanese hornwort mosaic virus, zantedeschia mosaic virus) (Adams et al., 2005; Nishiguchi et al., 2006). KoMV infection was first reported in A. konjac from Japan (Shimoyama et al. 1992) and has been spread worldwide as one of the major causal agents of viral diseases in calla lily (Liao et al., 2020). To the best of our knowledge, this is the first report of KoMV infection in S. brachycarpa. To date, cucumber mosaic virus and tobacco mosaic virus have been reported to infect S. brachycarpa in Korea (Yoon et al., 2016; 2017). Our findings will be helpful for developing virus-management strategies to prevent yield and quality loss in S. brachycarpa.

First report of beet western yellows virus in radish in Korea.

Radish (Raphanus sativus L.) is an important root vegetable widely consumed in kimchi in Korea. In October 2021, radish leaves with virus-like symptoms of mosaic and yellowing were collected in three fields around Naju, Korea (Fig. S1). A pooled sample (n = 24) was screened for causal viruses by high-throughput sequencing (HTS), with detection confirmed by reverse transcription (RT) PCR. Total RNA was extracted from symptomatic leaves using the Plant RNA Prep kit (Biocube System, Korea), and a cDNA library was constructed and sequenced on an Illumina NovaSeq 6000 system (Macrogen, Korea). De novo transcriptome assembly yielded 63,708 contigs, which were analyzed against the viral reference genome database in GenBank by BLASTn and BLASTx searches. Two large contigs were clearly of viral origin. BLASTn analysis showed that a 9,842-bp contig (4,481,600 mapped reads, mean read coverage 68,758.6×) had 99% identity (99% coverage) with isolate CCLB of turnip mosaic virus (TuMV) from radish in China (KR153038). A second contig of 5,711 bp (7,185 mapped reads, mean read coverage 189.9×) had 97% identity (99% coverage) with isolate SDJN16 of beet western yellows virus (BWYV) from Capsicum annuum in China (MK307779). To confirm the presence of these viruses, total RNA extracted from 24 leaf samples was subjected to RT-PCR using primers specific for TuMV (N60_5'-ACATTGAAAAGCGTAACCA-3' and C30_5'-TCCCATAAGCGAGAATACTAACGA-3', amplicon 356 bp) and BWYV (95F_5'-CGAATCTTGAACACAGCAGAG-3' and 784R_5'-TGTGGG ATCTTGAAGGATAGG-3', amplicon 690 bp) for virus detection. Of the 24 samples, 22 were positive for TuMV and 7 were co-infected with BWYV. Single infection of BWYV was not detected. Infection with TuMV, the predominant virus in radish in Korea, was previously reported (Choi and Choi, 1992; Chung et al., 2015). To determine the complete genomic sequence of the BWYV isolate (BWYV-NJ22) from radish, RT-PCR was conducted using eight overlapping primer pairs designed according to the alignment of previously reported BWYV sequences (Table S2). Terminal sequences of the viral genome were analyzed by 5' and 3' rapid amplification of cDNA ends (RACE; Thermo Fisher Scientific Corp.). The assembled complete genome sequence of BWYV-NJ22 was 5,694 nt long and was deposited in GenBank (accession no. OQ625515). The Sanger sequences shared 96% nt identity with the HTS-derived sequence. BLASTn analysis showed that BWYV-NJ22 had high nucleotide identity (98%) at the complete genome level with a BWYV isolate (OL449448) from C. annuum in Korea. BWYV (genus Polerovirus, family Solemoviridae), is an aphid-borne virus with a host range that includes > 150 plant species and is one of the most important viruses causing yellowing and stunting of vegetable crops (Brunt et al., 1996; Duffus 1973). In Korea, BWYV was first reported to infect paprika, followed by pepper, motherwort, and figwort (Jeon et al., 2021; Kwon et al., 2016; 2018; Park et al., 2018). During fall and winter 2021, 675 radish plants with virus-like symptoms of mosaic, yellowing, and chlorosis were collected from 129 farms in major cultivation areas in Korea and analyzed by RT-PCR using the BWYV detection primers. The incidence of BWYV in radish plants was 4.7%, and all infections were mixed infections with TuMV. To our knowledge, this is the first report of BWYV infecting radish in Korea. The symptoms of single BWYV infection are unclear, as radish is a new host plant of BWYV in Korea. Further research on the pathogenicity and impact of this virus in radish is therefore needed.

Expression Patterns of PAK4 and PHF8 Are Associated with the Survival of Gallbladder Carcinoma Patients.

BACKGROUND: PAK4 and PHF8 are involved in cancer progression and are under evaluation as targets for cancer therapy. However, despite extensive studies in human cancers, there are limited reports on the roles of PAK4 and PHF8 in gallbladder cancers. METHODS: Immunohistochemical expression of PAK4 and PHF8 and their prognostic significance were evaluated in 148 human gallbladder carcinomas. RESULTS: PAK4 expression was significantly associated with PHF8 expression in gallbladder carcinomas. Positive expression of nuclear PAK4, cytoplasmic PAK4, nuclear PHF8, and cytoplasmic PHF8 were significantly associated with shorter overall survival and relapse-free survival in univariate analysis. Multivariate analysis showed that nuclear PAK4 expression and nuclear PHF8 expression were independent predictors of overall survival and relapse-free survival in gallbladder carcinomas. Furthermore, coexpression of nuclear PAK4 and nuclear PHF8 predicted shorter overall survival (p < 0.001) and relapse-free survival (p < 0.001) of gallbladder carcinoma in multivariate analysis. CONCLUSIONS: This study suggests that the individual and coexpression patterns of PAK4 and PHF8 as the prognostic indicators for gallbladder carcinoma patients.

Mechanistic Investigation of WWOX Function in NF-kB-Induced Skin Inflammation in Psoriasis.

Psoriasis is a chronic inflammatory skin disease characterized by epidermal hyperproliferation, aberrant differentiation of keratinocytes, and dysregulated immune responses. WW domain-containing oxidoreductase (WWOX) is a non-classical tumor suppressor gene that regulates multiple cellular processes, including proliferation, apoptosis, and migration. This study aimed to explore the possible role of WWOX in the pathogenesis of psoriasis. Immunohistochemical analysis showed that the expression of WWOX was increased in epidermal keratinocytes of both human psoriatic lesions and imiquimod-induced mice psoriatic model. Immortalized human epidermal keratinocytes were transduced with a recombinant adenovirus expressing microRNA specific for WWOX to downregulate its expression. Inflammatory responses were detected using Western blotting, real-time quantitative reverse transcription polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay. In human epidermal keratinocytes, WWOX knockdown reduced nuclear factor-kappa B signaling and levels of proinflammatory cytokines induced by polyinosinic: polycytidylic acid [(poly(I:C)] in vitro. Furthermore, calcium chelator and protein kinase C (PKC) inhibitors significantly reduced poly(I:C)-induced inflammatory reactions. WWOX plays a role in the inflammatory reaction of epidermal keratinocytes by regulating calcium and PKC signaling. Targeting WWOX could be a novel therapeutic approach for psoriasis in the future.

Effects of Forest-Based Interventions on Mental Health: A Meta-Analysis of Randomized Controlled Trials.

Forest-based interventions are a promising alternative therapy for enhancing mental health. The current study investigated the effects of forest therapy on anxiety, depression, and negative and positive mental condition through a meta-analysis of recent randomized controlled trials, using the PRISMA guideline. Of 825 articles retrieved from databases including PubMed, EMBASE, CINAHL, Cochrane, and PsycINFO, 6 met the inclusion criteria. The results of this study showed that forest-based interventions improved the mental health of participants in the intervention groups when compared to those in the control groups. Thirty-four outcome variables were analyzed from six studies. The overall effect size of the forest therapy programs was 1.25 (95% CI = 0.93−1.57, p < 0.001), which was large and statistically significant. These findings imply that forest-based interventions can improve mental health as a nonpharmacological intervention. This study is significant in that it is a meta-analysis of mental health that included only high-quality domestic and international RCTs. In future studies, more RCTs related to various forest interventions and studies involving many participants should be undertaken, which will complement heterogeneity in future meta-analysis studies.

Peroxiredoxin I participates in the protection of reactive oxygen species-mediated cellular senescence.

Peroxiredoxin I (Prx I) plays an important role as a reactive oxygen species (ROS) scavenger in protecting and maintaining cellular homeostasis; however, the underlying mechanisms are not well understood. Here, we identified a critical role of Prx I in protecting cells against ROS-mediated cellular senescence by suppression of p16INK4a expression. Compared to wild-type mouse embryonic fibroblasts (WT-MEFs), Prx I-/- MEFs exhibited senescence-associated phenotypes. Moreover, the aged Prx I-/- mice showed an increased number of cells with senescence associated-ß-galactosidase (SA-ß-gal) activity in a variety of tissues. Increased ROS levels and SA-ß-gal activity, and reduction of chemical antioxidant further in Prx I-/- MEF supported an essential role of Prx I peroxidase activity in cellular senescence that is mediated by oxidative stress. The up-regulation of p16INK4a expression in Prx I-/- and suppression by overexpression of Prx I indicate that Prx I possibly modulate cellular senescence through ROS/p16INK4a pathway. [BMB Reports 2017; 50(10): 528-533].

Right ventricular strain as predictor of pulmonary complications in patients with femur fracture.

BACKGROUND: Following femur fracture, medullary fat enters the systemic circulation and altered pulmonary haemodynamics may contribute to pulmonary complications. This study evaluated the association between right ventricular (RV) function and pulmonary complications in patients with femur fracture. METHODS: Patients with a femur fracture who had undergone pre-operative echocardiography that included RV peak global longitudinal strain (RV GLS) were evaluated retrospectively between March 2015 and February 2016. Pulmonary complications were defined as the development of pneumonia or pulmonary thromboembolism during the first postoperative month. RESULTS: Among 78 patients, pulmonary complications developed in eight (10.3%). The RV GLS value of all patients was lower than the normal range. In addition, the RV GLS value of patients with pulmonary complications was significantly lower than that of patients without pulmonary complications. Multivariate regression analyses found that worse RV GLS values independently predicted pulmonary complications [odds ratio (OR) 2.09, 95% confidence interval (CI) 1.047-4.151, p = 0.037]. Receiver operating characteristic curve analysis found that a RV GLS value of -14.85% was the best cut-off value to predict pulmonary complications; sensitivity: 75.0%; specificity: 62.9%. Moreover, patients with RV GLS values > -14.85% had significantly lower pulmonary complication-free survival. CONCLUSIONS: In patients with femur fracture, RV GLS values could help predict pulmonary complications. Therefore, patients with RV GLS values > -14.85 should be monitored closely before and after surgery for femur fracture.

The Effect of Patient-centered CPR Education for Family Caregivers of Patients with Cardiovascular Diseases.

PURPOSE: For cardiovascular patients, family caregivers play a vital role in daily nursing and cardiac emergencies. This study aimed to evaluate the effect of patient-centered CPR education (PCE) for family caregivers of patients with cardiovascular diseases. METHODS: Fifty-four participants were randomly assigned to the PCE or control group. The PCE group received tailored counseling on overall cardiovascular disease information and CPR followed by interactive instructor-guided CPR training and re-education follow-up by telephone 2 weeks later. The control group received only video-based CPR self-education and booklets. Cardiovascular disease and CPR knowledge and self-efficacy were measured before (pre-test), immediately after (post-test 1), and 4 weeks after the PCE (post-test 2). CPR skills and performance were measured pre-test and at post-test1. RESULTS: The PCE group demonstrated significant improvements in knowledge (F=91.09, p<.001), self-efficacy (F=15.19, p<.001) and CPR skills and performance (F=8.10, p=.008), as well as significant differences over time (knowledge: F=364.25, p<.001; self-efficacy: F=1162.28, p<.001; CPR skills and performance: F=1798.81, p<.001). There were significant group-by-time interactions for knowledge (F=8.10, p=.001), self-efficacy (F=4.30, p=.019) and CPR skills and performance (F=4.81, p=.036) by repeated measures ANOVA. CONCLUSION: This is the first study to demonstrate the effects of a patient-centered intervention with CPR education tailored for patients' and family caregivers' preferences, needs, and lifestyles. The results of this study encourage the use of tailored, patient-centered interventions in cardiovascular nursing practice.

Prx I suppresses K-ras-driven lung tumorigenesis by opposing redox-sensitive ERK/cyclin D1 pathway.

AIMS: Coupled responses of mutated K-ras and oxidative stress are often an important etiological factor in non-small-cell lung cancer (NSCLC). However, relatively few studies have examined the control mechanism of oxidative stress in oncogenic K-ras-driven NSCLC progression. Here, we studied whether the redox signaling pathway governed by peroxiredoxin I (Prx I) is involved in K-ras(G12D)-mediated lung adenocarcinogenesis. RESULTS: Using human-lung adenocarcinoma tissues and lung-specific K-ras(G12D)-transgenic mice, we found that Prx I was significantly up-regulated in the tumor regions via activation of nuclear erythroid 2-related factor 2 (Nrf2) transcription. Interestingly, the increased reactive oxygen species (ROS) by null mutation of Prx I greatly promoted K-ras(G12D)-driven lung tumorigenesis in number and size, which appeared to require the activation of the ROS-dependent extracellular signal-regulated kinase (ERK)/cyclin D1 pathway. INNOVATION: Taken together, these results suggest that Prx I functions as an Nrf2-dependently inducible tumor suppressant in K-ras-driven lung adenocarcinogenesis by opposing ROS/ERK/cyclin D1 pathway activation. CONCLUSION: These findings provide a better understanding of oxidative stress-mediated lung tumorigenesis.

Relationship between mortality and fine particles during Asian dust, smog-Asian dust, and smog days in Korea.

This study examined the association between all-cause/cardiovascular mortality and PM(2.5) as related to Asian dust (AD), smog-AD, smog, and nonevent days and evaluated the differential risks according to specific events for mortality. The daily records of all-cause/cardiovascular mortality and PM(2.5) from March to May 2003-2006 in Seoul, Korea, were used as independent and dependent variables. Differences in the event effects were assessed using a time-series analysis. Both all-cause and cardiovascular mortalities were significantly associated with PM(2.5) during smog-AD and AD days only. Differences in chemical composition emerging during long-range transport to Korea may explain these observations, especially as regards secondary aerosol, metal-sulfate/or nitrate, and metallic components. These results suggest that exposure to PM(2.5) during specific events is differentially associated with human mortality and that changes in the chemical composition of PM(2.5), occurring during long-range transport, represent important factors in such differential effects on health.

Electrical control of terahertz nano antennas on VO2 thin film.

We demonstrate an active metamaterial device that allows to electrically control terahertz transmission over more than one order of magnitude. Our device consists of a lithographically defined gold nano antenna array fabricated on a thin film of vanadium dioxide (VO(2)), a material that possesses an insulator to metal transition. The nano antennas let terahertz (THz) radiation funnel through when the VO(2) film is in the insulating state. By applying a dc-bias voltage through our device, the VO(2) becomes metallic. This electrically shorts the antennas and therefore switches off the transmission in two distinct regimes: reversible and irreversible switching.

KR33426, [2-(2,5-dichlorophenyl)-5-methyloxazol-4yl]carbonylguanidine, is a novel compound to be effective on mouse systemic lupus erythematosus.

B cell-activating factor (BAFF) is a key regulator of B lymphocyte development. Signals from BAFF are transmitted through binding to a specific BAFF receptor (BAFF-R). Here, we established screening method to find a specific inhibitor for the interference of BAFF-BAFF-R interactions. We screened oxazole-4-carbonylguanidine derivatives and selected KR33426, [2-(2,5-dichlorophenyl)-5-methyloxazol-4yl]carbonylguanidine, as a candidate to interfere BAFF-BAFF-R interactions. KR33426 inhibited BAFF-mediated anti-apoptotic effect on splenocytes as judged by hypodiploid cell formation. KR33426 also increased the degradation of procaspase-3 that was inhibited by BAFF protein. In addition, we examined whether KR33426 was effective on the treatment of systemic lupus erythematosus-like symptom in MRL(lpr/lpr) mouse. When 5 or 10mg/kg KR33426 was intraperitoneally administered to MRL(lpr/lpr) mice for 4 weeks, histopathological changes were ameliorated in the narrowed space between renal glomerulus and glomerulus capsule. KR33426 reduced B220(+) B cell population and B cell mitogen, lipopolysaccharide-stimulated lymphocyte proliferation in splenocytes. KR33426 attenuated an increase in CD43(-)IgM(+) immature pro-B and a decrease in CD21(+) IgM(+) T2-B and IgD(+) IgM(-)recirculating-B cells on B cell development. Data show that KR33426 inhibits BAFF-BAFF-R interactions and it is effective on the treatment of systemic lupus erythematosus-like symptom in MRL(lpr/lpr) mice. Thus, it suggests that KR33426 is a novel candidate to develop anti-autoimmune therapeutics by the interference of BAFF-BAFF-R interactions, specifically.

Giant nonlinear response of terahertz nanoresonators on VO2 thin film.

We report on an order of magnitude enhanced nonlinear response of vanadium dioxide thin film patterned with nanoresonators--nano slot antennas fabricated on the gold film. Transmission of terahertz radiation, little affected by an optical pumping for the case of bulk thin film, can now be completely switched-off: DeltaT/T approximately -0.9999 by the same optical pumping power. This unprecedentedly large optical pump-terahertz probe nonlinearity originates from the insulator-to-metal phase transition drastically reducing the antenna cross sections of the nanoresonators. Our scheme enables nanoscale-thin film technology to be used for all-optical switching of long wavelength light.

Active terahertz nanoantennas based on VO2 phase transition.

Unusual performances of metamaterials such as negative index of refraction, memory effect, and cloaking originate from the resonance features of the metallic composite atom(1-6). Indeed, control of metamaterial properties by changing dielectric environments of thin films below the metallic resonators has been demonstrated(7-11). However, the dynamic control ranges are still limited to less than a factor of 10,(7-11) with the applicable bandwidth defined by the sharp resonance features. Here, we present ultra-broad-band metamaterial thin film with colossal dynamic control range, fulfilling present day research demands. Hybridized with thin VO(2) (vanadium dioxide) (12-18) films, nanoresonator supercell arrays designed for one decade of spectral width in terahertz frequency region show an unprecedented extinction ratio of over 10000 when the underlying thin film experiences a phase transition. Our nanoresonator approach realizes the full potential of the thin film technology for long wavelength applications.

Early initiation of alcohol drinking, cigarette smoking, and sexual intercourse linked to suicidal ideation and attempts: findings from the 2006 Korean Youth Risk Behavior Survey.

PURPOSE: This study examined the association between early initiation of problem behaviors (alcohol drinking, cigarette smoking, and sexual intercourse) and suicidal behaviors (suicidal ideation and suicide attempts), and explored the effect of concurrent participation in these problem behaviors on suicidal behaviors among Korean adolescent males and females. MATERIALS AND METHODS: Data were obtained from the 2006 Korean Youth Risk Behavior Survey, a nationally representative sample of middle and high school students (32,417 males and 31,467 females) in grades seven through twelve. Bivariate and multivariate logistic analyses were conducted. Several important covariates, such as age, family living structure, household economic status, academic performance, current alcohol drinking, current cigarette smoking, current butane gas or glue sniffing, perceived body weight, unhealthy weight control behaviors, subjective sleep evaluation, and depressed mood were included in the analyses. RESULTS: Both male and female preteen initiators of each problem behavior were at greater risk for suicidal behaviors than non-initiators, even after controlling for covariates. More numerous concurrent problematic behaviors were correlated with greater likelihood of seriously considering or attempting suicide among both males and females. This pattern was more clearly observed in preteen than in teen initiators although the former and latter were engaged in the same frequency of problem behavior. CONCLUSION: Early initiation of alcohol drinking, cigarette smoking, and sexual intercourse, particularly among preteens, represented an important predictor of later suicidal ideation and suicide attempts in both genders. Thus, early preventive intervention programs should be developed and may reduce the potential risks for subsequent suicidal behaviors.

Body-image dissatisfaction as a predictor of suicidal ideation among Korean boys and girls in different stages of adolescence: a two-year longitudinal study.

PURPOSE: To descriptively examine trends in body dissatisfaction and suicidal ideation during adolescence, and to investigate whether body dissatisfaction at an early stage (Time 1) predicts suicidal ideation at a later stage (Time 2) among boys and girls in different stages of adolescence (early and midadolescence), controlling for Time 1 of relevant variables, including suicidal ideation, depressed mood, and self-esteem. METHODS: Data were obtained from Korea Youth Panel Survey data sets for early adolescents (1380 boys and 1209 girls, Time 1 mean age 10 years) and midadolescents (1429 boys and 1437 girls, Time 1 mean age 15 years) and from follow-up surveys of the same individuals after 2 years. Multivariate logistic analyses were carried out to assess the relationship of Time 1 body dissatisfaction to Time 2 suicidal ideation. RESULTS: For both genders, body dissatisfaction and suicidal ideation progressively increased until peaking at midadolescence and slightly decreasing thereafter. After controlling for psychological problems and other possible variables, body dissatisfaction prospectively predicted the risk of suicidal ideation in early-adolescent girls and midadolescent boys, but not in early-adolescent boys or midadolescent girls. CONCLUSIONS: The results underscore that programs aimed at adolescents with body dissatisfaction should contain different material according to their gender and stage of adolescence. Such differential interventions may reduce suicide risk in adolescents.

Methane emission estimation from landfills in Korea (1978-2004): quantitative assessment of a new approach.

Quantifying methane emission from landfills is important to evaluating measures for reduction of greenhouse gas (GHG) emissions. To quantify GHG emissions and identify sensitive parameters for their measurement, a new assessment approach consisting of six different scenarios was developed using Tier 1 (mass balance method) and Tier 2 (the first-order decay method) methodologies for GHG estimation from landfills, suggested by the Intergovernmental Panel on Climate Change (IPCC). Methane emissions using Tier 1 correspond to trends in disposed waste amount, whereas emissions from Tier 2 gradually increase as disposed waste decomposes over time. The results indicate that the amount of disposed waste and the decay rate for anaerobic decomposition were decisive parameters for emission estimation using Tier 1 and Tier 2. As for the different scenarios, methane emissions were highest under Scope 1 (scenarios I and II), in which all landfills in Korea were regarded as one landfill. Methane emissions under scenarios III, IV, and V, which separated the dissimilated fraction of degradable organic carbon (DOC(F)) by waste type and/or revised the methane correction factor (MCF) by waste layer, were underestimated compared with scenarios II and III. This indicates that the methodology of scenario I, which has been used in most previous studies, may lead to an overestimation of methane emissions. Additionally, separate DOC(F) and revised MCF were shown to be important parameters for methane emission estimation from landfills, and revised MCF by waste layer played an important role in emission variations. Therefore, more precise information on each landfill and careful determination of parameter values and characteristics of disposed waste in Korea should be used to accurately estimate methane emissions from landfills.