Ordinary kriging approach to predicting long-term particulate matter concentrations in seven major Korean cities

Objectives Cohort studies of associations between air pollution and health have used exposure prediction approaches to estimate individual-level concentrations. A common prediction method used in Korean cohort studies is ordinary kriging. In this study, performance of ordinary kriging models for long-term particulate matter less than or equal to 10 μm in diameter (PM10) concentrations in seven major Korean cities was investigated with a focus on spatial prediction ability. Methods We obtained hourly PM10 data for 2010 at 226 urban-ambient monitoring sites in South Korea and computed annual average PM10 concentrations at each site. Given the annual averages, we developed ordinary kriging prediction models for each of the seven major cities and for the entire country by using an exponential covariance reference model and a maximum likelihood estimation method. For model evaluation, cross-validation was performed and mean square error and R-squared (R2) statistics were computed. Results Mean annual average PM10 concentrations in the seven major cities ranged between 45.5 and 66.0 μg/m3 (standard deviation=2.40 and 9.51 μg/m3, respectively). Cross-validated R2 values in Seoul and Busan were 0.31 and 0.23, respectively, whereas the other five cities had R2 values of zero. The national model produced a higher crossvalidated R2 (0.36) than those for the city-specific models. Conclusions In general, the ordinary kriging models performed poorly for the seven major cities and the entire country of South Korea, but the model performance was better in the national model. To improve model performance, future studies should examine different prediction approaches that incorporate PM10 source characteristics

Blockade of Airway Inflammation by Kaempferol via Disturbing Tyk-STAT Signaling in Airway Epithelial Cells and in Asthmatic Mice

Asthma is characterized by bronchial inflammation causing increased airway hyperresponsiveness and eosinophilia. The interaction between airway epithelium and inflammatory mediators plays a key role in the asthmatic pathogenesis. The in vitro study elucidated inhibitory effects of kaempferol, a flavonoid found in apples and many berries, on inflammation in human airway epithelial BEAS-2B cells. Nontoxic kaempferol at ≤20 μM suppressed the LPS-induced IL-8 production through the TLR4 activation, inhibiting eotaxin-1 induction. The in vivo study explored the demoting effects of kaempferol on asthmatic inflammation in BALB/c mice sensitized with ovalbumin (OVA). Mouse macrophage inflammatory protein-2 production and CXCR2 expression were upregulated in OVA-challenged mice, which was attenuated by oral administration of ≥10 mg/kg kaempferol. Kaempferol allayed the airway tissue levels of eotaxin-1 and eotaxin receptor CCR3 enhanced by OVA challenge. This study further explored the blockade of Tyk-STAT signaling by kaempferol in both LPS-stimulated BEAS-2B cells and OVA-challenged mice. LPS activated Tyk2 responsible for eotaxin-1 induction, while kaempferol dose-dependently inhibited LPS- or IL-8-inflamed Tyk2 activation. Similar inhibition of Tyk2 activation by kaempferol was observed in OVA-induced mice. Additionally, LPS stimulated the activation of STAT1/3 signaling concomitant with downregulated expression of Tyk-inhibiting SOCS3. In contrast, kaempferol encumbered STAT1/3 signaling with restoration of SOCS3 expression. Consistently, oral administration of kaempferol blocked STAT3 transactivation elevated by OVA challenge. These results demonstrate that kaempferol alleviated airway inflammation through modulating Tyk2-STAT1/3 signaling responsive to IL-8 in endotoxin-exposed airway epithelium and in asthmatic mice. Therefore, kaempferol may be a therapeutic agent targeting asthmatic diseases

Negative Life Events and Problematic Internet Use as Factors Associated With Psychotic-Like Experiences in Adolescents

Objectives: Psychotic-like experiences (PLEs) and problematic internet use (PIU) are common in adolescents. However, little is known about the association between PLEs and PIU among adolescents. The present study examined the associations between PLEs and PIU and negative life events among adolescents.Methods: In total, 1,678 adolescents attending high school were recruited for a cross-sectional survey. They completed self-reported assessments of PLEs using the Prodromal Questionnaire-16 (PQ-16) and measures of depression, anxiety, self-esteem, internet use, and negative life events using the Center for Epidemiological Studies Depression Scale (CES-D), the State-Trait Anxiety Inventory (STAI), the Rosenberg Self-Esteem Scale (RSES), the Korean Scale for Internet Addiction (K-scale), and the Lifetime Incidence of Traumatic Events for Children (LITE-C), including cybersexual harassment and school violence.Results: A total of 1,239 subjects (73.8%) scored at least 1 on the PQ-16. The mean total and distress PQ-16 scores were significantly higher in students who used mental health services. The total and distress prodromal questionnaire-16 (PQ-16) scores were positively correlated with the CES-D, STAI-S, STAI-T, LITE-C, and K-scale scores but negatively correlated with the RSES score. Hierarchical linear regression analysis revealed that PLEs were significantly associated with a high K-scale score and the incidence of negative life events, such as LITE-C, cybersexual harassment, and bully–victims.Conclusion: Our results demonstrate that PIU and negative life experiences were significantly associated with PLEs in adolescents. Assessment and therapeutic intervention with regard to internet use as a coping strategy for stress are needed to prevent the development of clinical psychotic symptoms

Comparison of CPR quality and rescuer fatigue between standard 30:2 CPR and chest compression-only CPR: a randomized crossover manikin trial

Objective We aimed to compare rescuer fatigue and cardiopulmonary resuscitation (CPR) quality between standard 30:2 CPR (ST-CPR) and chest compression only CPR (CO-CPR) performed for 8 minutes on a realistic manikin by following the 2010 CPR guidelines. Methods All 36 volunteers (laypersons; 18 men and 18 women) were randomized to ST-CPR or CO-CPR at first, and then each CPR technique was performed for 8 minutes with a 3-hour rest interval. We measured the mean blood pressure (MBP) of the volunteers before and after performing each CPR technique, and continuously monitored the heart rate (HR) of the volunteers during each CPR technique using the MRx monitor. CPR quality measures included the depth of chest compression (CC) and the number of adequate CCs per minute. Results The adequate CC rate significantly differed between the 2 groups after 2 minutes, with it being higher in the ST-CPR group than in the CO-CPR group. Additionally, the adequate CC rate significantly differed between the 2 groups during 8 minutes for male volunteers (p =0.012). The number of adequate CCs was higher in the ST-CPR group than in the CO-CPR group after 3 minutes (p =0.001). The change in MBP before and after performing CPR did not differ between the 2 groups. However, the change in HR during 8 minutes of CPR was higher in the CO-CPR group than in the ST-CPR group (p =0.007). Conclusions The rate and number of adequate CCs were significantly lower with the CO-CPR than with the ST-CPR after 2 and 6 minutes, respectively, and performer fatigue was higher with the CO-CPR than with the ST-CPR during 8 minutes of CPR.OAIID:RECH_ACHV_DSTSH_NO:220142014020983001RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A080158CITE_RATE:2.025FILENAME:comparison of cpr quality and rescuer fatigue between st-cpr and cc-only cpr_a randomized crossover manikin trial_scand j trauma resusc emerg med_2014.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:YFILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/d98e73fe-13a9-4bea-b265-cb96af10284f/linkCONFIRM: