Dithieno[3,2‐b:2′,3′‐d]pyrrole and Benzothiadiazole‐Based Semicrystalline Copolymer for Photovoltaic Devices with Indene‐C60 Bisadduct

A semicrystalline low‐bandgap polymer (PDTPBT) based on alternating dithienopyrrole and benzothiadiazole moieties as a pair of the indene‐C₆₀ bisadduct (ICBA) for polymeric solar cells is reported. The lowest unoccupied molecular orbital (LUMO) level of PDTPBT is measured to be ?3.47 eV, ensuring sufficient energy offset for photoinduced charge transfer to ICBA. Photovoltaic cells are fabricated with ICBA and [6,6]‐phenyl‐C₇₁‐butyric acid methyl ester (PC₇₁BM) as an acceptor. By replacing PC₇₁BM with ICBA, the open‐circuit voltage is increased by 0.23 V and the resulting power conversion efficiency is improved from 1.17% to 1.71%. To optimize the ICBA‐based devices, crystalline low‐bandgap structures should be designed carefully as a pair of ICBA by considering the energy‐level offset for charge separation and crystalline interchain ordering, for minimizing the intercalated ICBAs inside the polymer domain.

     

Estimation of risk parameters from both indoor and outdoor sources in apartment houses

The aim of this study was to evaluate the indoor/outdoor levels of volatile organic carbons (VOCs) using prediction for 26 apartment houses that are less than 4 years old (ALT4) and/or more than 4 years old (AMT4) in three different cities. The mass balance equation and linear regression analysis were employed to estimate source strength factor and decay constant simultaneously to identify characteristics of indoor air quality of VOCs. We failed to build prediction models for benzene and/orm-xylene compounds because benzene andm-xylene were below the detection limits in the indoor air. The estimation by linear regression for toluene showed a more appropriate fit (R²=0.707) with the Asan data than other two fits for Seoul and Daegu.     

DRD1 associations with smoking abstinence across slow and normal nicotine metabolizers

Nicotine metabolism and genetic variation have an impact on nicotine addiction and smoking abstinence; however, further research is required. The nicotine metabolite ratio (NMR) is a robust biomarker of nicotine metabolism used to categorize slow and normal nicotine metabolizers (lower 25th quartile cut off). In two randomized clinical trials of smoking abstinence treatments, we conducted NMR-stratified analyses on smoking abstinence across 13 regions coding for nicotinic acetylcholine receptors and proteins involved in the dopamine reward system. Gene×NMR interaction P-values were adjusted for multiple correlated tests, and we used a Bonferroni-corrected α-level of 0.004 to determine system-wide significance. Three single-nucleotide polymorphisms in DRD1 (rs11746641, rs2168631, and rs11749035) had significant interactions (0.001 ≤ adjusted P-values ≤ 0.004) with increased odds of abstinence within slow metabolizers (odds ratios=3.1-3.5, 95% confidence interval 1.7-6.7). Our findings support the role of DRD1 in nicotine dependence, and identify genetic and nicotine metabolism profiles that may interact to impact nicotine dependence.     

Respiratory health effects among schoolchildren and their relationship to air pollutants in Korea

The objective of this study is to investigate the relationship between five air pollutants (PM₁₀, SO₂, NO₂, O₃, CO) measured on the daily basis, and adverse health symptoms using epidemiological surveillance data. The generalized estimated equation (GEE) model, a logistic regression analysis model, was used to estimate the effects of air pollution on children's daily health symptoms, focusing on the morbidity including both respiratory and allergic symptoms in four different cities. Analysis of the effects of each pollutant on children's respiratory and allergic symptoms demonstrated that CO affected all symptoms in all the study areas. When the concentration of SO₂ and NO₂ was elevated, upper respiratory symptoms increased significantly. In contrast, when the concentration of O₃ rose, the symptoms decreased significantly. The relationship between measured concentrations and health symptoms was site-dependent for each pollutant.     

Incidence of Cholangiocarcinoma with or without Previous Resection of Liver for Hepatolithiasis

Background/Aims

To investigate the incidence of cholangiocarcinoma in patients with hepatolithiasis with or without previous resection of liver.

Methods

From 2002 to 2009, we retrospectively reviewed 117 patients who were diagnosed and treated for hepatolithiasis in Korea University Guro Hospital. Among the 117 patients, 55 patients who were lost during follow-up were excluded, and 62 patients were eligible for analysis. The hepatic resection group (n=25) included patients who underwent left hemihepatectomy (n=2); left lateral segmentectomy (n=10); left lobectomy (n=9); right lobectomy (n=3); or wedge resection (n=1). The nonhepatic resection group (n=37) included transhepatic cholangiographic lithotomy and endoscopic retrograde cholangiopancreatography-treated patients. The mean follow-up period was 47 months.

Results

The incidence of cholangiocarcinoma while patients were followed for hepatolithiasis was 12.9% (8/62) (hepatic resection group, three cases [12%] vs nonhepatic resection group, five cases [13.5%]; p=1.000). The mean follow-up period was 53 months (47±11 months) until the diagnosis of cholangiocarcinoma.

Conclusions

There was no difference in the incidence of cholangiocarcinoma according to previous liver resections. Patients with hepatolithiasis should be carefully followed up for detection of cholangiocarcinoma even after a previous liver resection.     

Urinary concentrations of bisphenol A and triclosan and associations with demographic factors in the Korean population

Bisphenol A (BPA) and triclosan are synthetic phenolic compounds to which the general public can be extensively exposed via consumer products and environmental contamination.In this study, we assessed exposure to BPA and triclosan in the Korean adult population aged 18–69 based on the Korean National Human Biomonitoring Survey conducted in 2009. Relying on data from 1870 representative Koreans, we found that the geometric mean urinary concentrations of BPA and triclosan were 1.90 ng/ml [95% confidence interval (CI): 1.81–1.99] and 1.68 ng/ml (95% CI: 1.48–1.90), respectively. The creatinine-adjusted geometric means of BPA and triclosan were 1.79 μg/g creatinine (95% CI: 1.70–1.90) and 1.58 μg/g creatinine (95% CI: 1.39–1.81), respectively. About 99.8% of the Korean adult population had urinary concentrations of BPA and about 92.6% of the Korean adult population had urinary concentrations of triclosan above the level of 0.05 ng/ml (limit of detection, LOD). Urinary BPA concentrations were higher in residents of rural areas, whereas urinary triclosan concentrations were significantly associated with cigarette smoking. These findings suggested that most Koreans had detectable levels of BPA and triclosan in their urine and that the body burden of BPA and triclosan varied according to demographic and geographic factors.     

Influence of Statin Therapy on Aneurysm Sac Regression after Endovascular Aortic Repair

Purpose

To determine whether statin therapy is associated with abdominal aortic aneurysm (AAA) sac regression after endovascular aneurysm repair (EVAR).

Nonalcoholic fatty liver disease is associated with coronary artery disease in Koreans

AIM:To investigate whether nonalcoholic fatty liver disease(NAFLD)affects coronary artery disease(CAD)and identify candidate mediators.METHODS:Patients who underwent coronary angiography were consecutively recruited.The patients were classified into four groups by coronary artery stenosis:A,insignificant;B,one-vessel disease;C,two-vessel disease;and D,three-vessel disease.Abdominal ultrasonography was performed to determine the presence of a fatty liver and categorize by grade:0,no evidence;1,mild;2,moderate;and 3,severe.We measured not only known CAD risk factors,but also serum insulin,HOMA-index,adiponectin,interleukin-6,tumor necrosis factor-αand high-sensitivity C-reactive protein levels.RESULTS:Of the 134 patients who met the inclusion criteria,82(61.2%)had ultrasonographically diagnosed NAFLD.Among the 46 patients with CAD,37(80.4%)had evidence of a fatty liver.The two groups(A vs B-D)were significantly different in terms of age,total cholesterol,triglycerides,low-density lipoprotein levels and fatty liver.Coronary artery stenosis was strongly associated with fatty liver in a grade-dependent manner(P=0.025).In binary logistic regression,NAFLD was a significant independent predictor of CAD(P=0.03,OR=1.685;95%CI:1.051-2.702).Among the candidate mediators,the serum adiponectin level showed a trend toward lowering based on CAD progression(P=0.071).CONCLUSION:NAFLD is an independent risk factor for CAD in a grade-dependent manner.Moreover,adiponectin might be related to the pathogenesis of NAFLD.