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We report from ab initiocalculations that the band-gap sensitive side-wall functionalization of a carbon nanotube is feasible with the fluorine molecule (F2), which can provide a route to the extraction of semiconducting nanotubes by etching away metallic ones. In the small diameter cases like (11, 0) and (12, 0), the nanotubes are easily functionalized with F2regardless of their electronic properties. As the diameter becomes larger, however, the fluorination is favoured on metallic CNTs with smaller activation barriers than those of semiconducting ones. Our results suggest that low-temperature exposure to F2molecules in the gas phase can make a dominant portion of fluorinated metallic nanotubes and unfluorinated semiconducting ones. This is consistent with recent experimental reports. [ABSTRACT FROM AUTHOR]

Abstract

Working memory (WM) deficit is a cardinal cognitive symptom of schizophrenia, but the differences among the tasks and measures used to assess WM make it difficult to compare across studies. The authors conducted a meta-analytic review to address 3 major questions: (a) Do patients with schizophrenia show WM deficits across diverse methodology; (b) Is WM deficit supramodal; and (c) Does the WM deficit worsen with longer delays? The results indicate that significant WM deficit was present in schizophrenia patients in all modalities examined. Increasing delay beyond 1 s did not influence the performance difference between schizophrenia patients and healthy control participants in WM. These results suggest that WM deficit in schizophrenia is modality independent and that encoding and/or early part of maintenance may be problematic. [ABSTRACT FROM AUTHOR]

Objective: The authors examined gender differences in d-amphetamine-induced displacements of [18F]fallypride in the striatal and extrastriatal brain regions and the correlations of these displacements with cognition and sensation seeking. Method: Six women and seven men underwent positron emission tomography (PET) with [18F]fallypride before and after an oral dose of d-amphetamine. Percent displacements were calculated using regions of interest and parametric images of dopamine 2 (D2) receptor binding potential. Results: Parametric images of dopamine release suggest that the female subjects had greater dopamine release than the male subjects in the right globus pallidus and right inferior frontal gyrus. Gender differences were observed in correlations of changes in cognition and sensation seeking with regional dopamine release. Conclusion: Findings revealed a greater dopamine release in women as well as gender differences in the relationship between regional dopamine release and sensation seeking and cognition. [ABSTRACT FROM AUTHOR]

Background/Aims Data on real-life patterns of biologic use for inflammatory bowel disease (IBD) are scarce. We examined the patterns of biologic use and the factors associated with non-persistence and switching of biologics in Korean IBD patients. Methods Using National Health Insurance claims, we collected data on patients who were diagnosed with IBD and exposed to biologics between 2010 and 2016. Results Among 1,838 patients with Crohn's disease (CD), 1,237 and 601 started with infliximab and adalimumab, respectively. Among 1,125 patients with ulcerative colitis (UC), 774, 294, and 57 initiated infliximab, adalimumab, and golimumab, respectively. Rates of non-persistence and switching were higher in UC than in CD. One- and 3-year non-persistence rates were 14.2% and 26.5% in CD and 35.4% and 53.4% in UC, respectively. Oneand 3-year switching rates were3.7% and 10.1% in CD and 15.6% and 22.0% in UC, respectively. In both CD and UC, infliximab and adalimumab initiators showed similar persistence rates, whereas adalimumab initiators had a higher risk of switching than infliximab initiators. In UC, golimumab initiators had a higher risk of non-persistence and switching than infliximab initiators. Steroid use at biologic initiation was associated with an increased risk of non-persistence and switching in both CD and UC. UC patients who started biologic treatment at tertiary hospitals were more likely to continue treatment than those who started at general hospitals/community hospitals/clinics. Conclusions In real-world clinical practice settings, discontinuation of biologics occurred frequently in IBD patients, and switching of biologics was common in UC patients. [ABSTRACT FROM AUTHOR]

Definition: The Barnett critique states that there is an internal inconsistency between the theory that is implied by simple sum monetary aggregation (perfect substitutability among components) and the economic theory that produces the models within which those aggregates are used. That inconsistency causes the appearance of unstable demand and supply for money. The incorrect inference of unstable money demand has caused serious harm to the field of monetary economics. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the equivalence of the ICON® electrical cardiometry (EC) haemodynamic monitor to measure cardiac output (CO) relative to transthoracic Doppler echocardiography (TTE) in paediatric patients with repaired coarctation of the aorta (CoA). Approach: A group of n  =  28 CoA patients and n  =  27 matched controls were enrolled. EC and TTE were performed synchronously on each participant and CO measurements compared using linear regression and Bland–Altman analysis. The CoA group was further subdivided into two groups, with n  =  10 and without n  =  18 increased left ventricular outflow tract velocity (iLVOTv) for comparison. Main results: CO measurements from EC and TTE in controls showed a strong correlation (R  =  0.80, p  <  0.001) and an acceptable percentage error (PE) of 28.1%. However, combining CoA and control groups revealed a moderate correlation (R  =  0.57, p  <  0.001) and a poor PE (44.2%). We suspected that the CO in a subset of CoA participants with iLVOTv was overestimated by TTE. Excluding the iLVOTv CoA participants improved the correlation (R  =  0.77, p  <  0.001) and resulted in an acceptable PE of 31.2%. Significance: CO measurements in paediatric CoA patients in the absence of iLVOTv are clinically equivalent between EC and TTE. The presence of iLVOTv may impact the accuracy of CO measurement by TTE, but not EC. [ABSTRACT FROM AUTHOR]

Background: Recent data suggests the inoculum effect ofmethicillin-susceptible Staphylococcus aureus (MSSA) against beta-lactam antibiotics and their association with functionality or genotypic variation of agr locus. Methods: MSSA blood isolates were collected at a tertiary care hospital in Korea from June 2014 to December 2017. The functionality of the agr operon was measured by 5-hemolysin assays. Multiplex PCRwas performed to determine the agr genotype. The cefazolin minimum inhibitory concentrations (MICs) at a high inoculum concentration (-5 x 107 CFU/ml) were compared to the MICs at a standard inoculum concentration (-5 x 105 CFU/ml) to identify strains with the cefazolin inoculum effect (CIE). The DNA sequencing of blaZ gene was performed to classify the blaZ genotype. R e su lts Among the 195 MSSA blood isolates, agr genotype I was most common (68.2%), followed by type III (16.4%), type IV (9.2%), and type II (6.2%). Sixty-seven (34.3%) MSSA isolates had dysfunctional agr, but neither CIE nor blaZ genotype was associated with dysfunctional agr. The MSSA with agr type III genotype exhibited significantly higher CIE positivity (agrIII 43.8% vs. non -a g rlll 5.5%, P<0.01) and erythromycin/clindamycin resistance. In the subgroup analysis of type A blaZ possessing MSSA, almost all of the agr III MSSA isolates exhibited CIE, while only 20% of not\-agr\W isolates had CIE (P <0.01). Conclusion In MSSA blood isolates, CIE might be associated with agr genotype rather than with dysfunctional agr. [ABSTRACT FROM AUTHOR]

We argue that autism and psychosis spectrum disorders cannot be conceptualized as polar extremes of mentalizing ability. We raise two main objections: (1) the autistic-psychotic continuum, as conceptualized by the authors, excludes defining features of schizophrenia spectrum: negative symptoms, which correlate more strongly with mentalizing impairments; and (2) little evidence exists for a relationship between mentalizing ability and positive symptoms. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The escalating burden of cardiovascular disease (CVD) is a critical public health issue worldwide. CVD, especially acute myocardial infarction (AMI) and stroke, is the leading contributor to morbidity and mortality in Korea. We aimed to develop algorithms for identifying AMI and stroke events from the National Health Insurance Service (NHIS) database and validate these algorithms through medical record review. METHODS: We first established a concept and definition of "hospitalization episode," taking into account the unique features of health claims-based NHIS database. We then developed first and recurrent event identification algorithms, separately for AMI and stroke, to determine whether each hospitalization episode represents a true incident case of AMI or stroke. Finally, we assessed our algorithms' accuracy by calculating their positive predictive values (PPVs) based on medical records of algorithm-identified events. RESULTS: We developed identification algorithms for both AMI and stroke. To validate them, we conducted retrospective review of medical records for 3,140 algorithm-identified events (1,399 AMI and 1,741 stroke events) across 24 hospitals throughout Korea. The overall PPVs for the first and recurrent AMI events were around 92% and 78%, respectively, while those for the first and recurrent stroke events were around 88% and 81%, respectively. CONCLUSIONS: We successfully developed algorithms for identifying AMI and stroke events. The algorithms demonstrated high accuracy, with PPVs of approximately 90% for first events and 80% for recurrent events. These findings indicate that our algorithms hold promise as an instrumental tool for the consistent and reliable production of national CVD statistics in Korea. [ABSTRACT FROM AUTHOR]

Histone methyltransferase (HMT) enzymes that methylate the lysine of histones are involved in chromatin-mediated gene expression. Previously, we reported that a novel polymorphism of SUV39H2, the HMT that is required for the methylation of H3-K9, was associated with an increased risk of lung cancer in Koreans. The retinoblastoma protein-interacting zinc finger gene RIZ (PRDM2) is also a member of a histone/protein-methyltransferase superfamily, and the inactivation of RIZ in many cancers was detected as frameshift mutations, hypermethylation and missense mutations. In this study, we show the association of RIZ polymorphisms with the risk of lung cancer. In a hospital-based study of 335 lung cancer patients and 335 age- and gender-matched healthy controls, 120 polymorphisms of RIZ were screened. Of the 120 genotyped single nucleotide polymorphisms (SNPs), 42 SNPs were selected for the statistical analysis based on their frequency (>5%) and linkage disequilibrium [LD; only a representative SNP was analyzed if there were absolute LDs (r2 = 1)]; this resulted in three LD blocks. The +92337G>A and +95701C>A polymorphisms showed a statistically significant association with the reduced risk of lung adenocarcinomas after correcting the P values for multiple testing [for carrying one variant allele versus none, adjusted odds ratio (aOR) = 0.55 (95% CI = 0.38–0.78), corrected P = 0.04; aOR = 0.54 (95% CI = 0.38–0.77), corrected P = 0.02, respectively]. One haplotype (Ht5) in LD block 3 of RIZ was significantly associated with the reduced risk of lung adenocarcinomas (aOR = 0.28, 95% CI = 0.13–0.58) as well as overall lung cancer (aOR = 0.50, 95% CI = 0.30–0.82). This study suggested that RIZ polymorphisms may be important predictive markers for lung cancer susceptibility. [ABSTRACT FROM AUTHOR]

Schizophrenia is often accompanied by a range of visual perception deficits, with many involving impairments in motion perception. The presence of perceptual abnormalities may impair neural processes that depend on normal visual analysis, which in turn may affect overall functioning in dynamic visual environments. Here, we examine the integrity of suppressive center-surround mechanisms in motion perception of schizophrenic patients. Center-surround suppression has been implicated in a range of visual functions, including figure- ground segregation and pursuit eye movements, visual functions that are impaired in schizophrenia. In control subjects, evidence of center-surround suppression is found in a reduced ability to perceive motion of a high-contrast stimulus as its size increases. This counterintuitive finding is likely a perceptual correlate of center-surround mechanisms in cortical area MT. We now show that schizophrenic patients exhibit abnormally weak center-surround suppression in motion, an abnormality that is most pronounced in patients with severe negative symptoms. Interestingly, patients with the weakest surround suppression outperformed control subjects in motion discriminations of large high-contrast stimuli. This enhanced motion perception of large high-contrast stimuli is consistent with an MT abnormality in schizophrenia and has a potential to disrupt smooth pursuit eye movements and other visual functions that depend on unimpaired center-surround interactions in motion. [ABSTRACT FROM AUTHOR]

Purpose High breast cancer incidence and dense breast prevalence among women in forties are specific to Asian. This study examined the natural history of breast cancer among Korean women. Materials and Methods We applied a three-state Markov model (i.e., healthy, preclinical, and clinical state) to fit the natural history of breast cancer to data in the Korean National Cancer Screening Program. Breast cancer was ascertained by linkage to the Korean Central Cancer Registry. Disease-progression rates (i.e., transition rates between three states), mean sojourn time (MST) and mammographic sensitivity were estimated across 10-year age groups and levels of breast density determined by the Breast Imaging, Reporting and Data System. Results Overall prevalence of dense breast was 53.9%. Transition rate from healthy to preclinical state, indicating the preclinical incidence of breast cancer, was higher among women in forties (0.0019; 95% confidence interval [CI], 0.0017 to 0.0021) and fifties (0.0020; 95% CI, 0.0017 to 0.0022), than women in sixties (0.0014; 95% CI, 0.0012 to 0.0017). The MSTs, in which the tumor is asymptomatic but detectable by screening, were also fastest among younger age groups, estimated as 1.98 years (95% CI, 1.67 to 2.33), 2.49 years (95% CI, 1.92 to 3.22), and 3.07 years (95% CI, 2.11 to 4.46) for women in forties, fifties, and sixties, respectively. Having dense breasts increased the likelihood of the preclinical cancer risk (1.96 to 2.35 times) and decreased the duration of MST (1.53 to 2.02 times). Conclusion This study estimated Korean-specific natural history parameters of breast cancer that would be utilized for establishing optimal screening strategies in countries with higher dense breast prevalence. [ABSTRACT FROM AUTHOR]

Background/Aims: Little is known about the national colonoscopy volume in Asian countries. This study aimed to assess the national colonoscopy volume in Korea over a 12- year period on the basis of a nationwide population-based database. Methods: We conducted a population-based study for colonoscopy claims (14,511,158 colonoscopies performed on 13,219,781 patients) on the basis of the Korean National Health Insurance Service database from 2002 to 2013. The 12-year national colonoscopy burden was analyzed according to patient age, patient sex, and healthcare facility type. Results: The overall volume of colonoscopy increased 8-fold over the 12-year period. The annual colonoscopic polypectomy rate significantly increased in all patient sex and age groups over the 12-years period (all p<0.001). The yearly colonoscopic polypectomy rate for men was significantly increased compared with that for women (2.3% vs 1.7%, p<0.001) and for the screening-age group compared with that for the young-age group (2.0% vs 1.6%, p<0.001). The yearly colonoscopic polypectomy rate relative to the total colonoscopy volume significantly increased in primary, secondary, and tertiary facilities by 2.4%, 1.9%, and 1.4% during the 12-year period (all p<0.001). In addition, the annual colonoscopy volume covered by high-volume facilities significantly increased by 1.8% in primary healthcare facilities over the 12-year period (p<0.001). Conclusions: Healthcare resources should be prioritized to allow adequate colonoscopic capacity, especially for men, individuals in the screeningage group, and at primary healthcare facilities. Cost-effective strategies to improve the quality of colonoscopy may focus on primary healthcare facilities and high-volume facilities in Korea. [ABSTRACT FROM AUTHOR]

Purpose Considering the health impact of obesity and cancer, it is important to estimate the burden of cancer attributable to high body mass index (BMI). Therefore, the present study attempts to measure the health burden of cancer attributable to excess BMI, according to cancer sites. Materials and Methods The present study used nationwide medical check-up sample cohort data (2002-2015). The study subjects were 496,390 individuals (268,944 men and 227,446 women). We first calculated hazard ratio (HR) in order to evaluate the effect of excess BMI on cancer incidence and mortality. Then, the adjusted HR values and the prevalence of excess BMI were used to calculate the population attributable risk. This study also used the Global Burden of Disease method, to examine the health burden of obesity-related cancers attributable to obesity. Results The highest disability-adjusted life year (DALY) values attributable to overweight and obesity in men were shown in liver cancer, colorectal cancer, and gallbladder cancer. Among women, colorectal, ovarian, and breast (postmenopausal) cancers had the highest DALYs values attributable to overweight and obesity. Approximately 8.0% and 12.5% of cancer health burden (as measured by DALY values) among obesity-related cancers in men and women, respectively, can be prevented. Conclusion Obesity has added to the health burden of cancer. By measuring the proportion of cancer burden attributable to excess BMI, the current findings provide support for the importance of properly allocating healthcare resources and for developing cancer prevention strategies to reduce the future burden of cancer. [ABSTRACT FROM AUTHOR]

Objectives: While the prevalence of obesity in Asian women has remained stagnant, studies of socioeconomic inequalities in obesity among Asian women are scarce. This study aimed to examine the recent prevalence of obesity in Korean women aged between 19 years and 79 years and to analyze socioeconomic inequalities in obesity.Methods: Data were derived from the 2016 Korean Study of Women's Health-Related Issues. The chi-square test and logistic regression analysis were used to analyze the associations between socioeconomic factors and obesity using Asian standard body mass index (BMI) categories: low (<18.5 kg/m2 ), normal (18.5-22.9 kg/m2 ), overweight (23.0-24.9 kg/m2 ), and obese (≥25.0 kg/ m2 ). As inequality-specific indicators, the slope index of inequality (SII) and relative index of inequality (RII) were calculated, with adjustment for age and self-reported health status.Results: Korean women were classified into the following BMI categories: underweight (5.3%), normal weight (59.1%), overweight (21.2%), and obese (14.4%). The SII and RII revealed substantial inequalities in obesity in favor of more urbanized women (SII, 4.5; RII, 1.4) and against of women who were highly educated (SII, -16.7; RII, 0.3). Subgroup analysis revealed inequalities in obesity according to household income among younger women and according to urbanization among women aged 65-79 years.Conclusions: Clear educational inequalities in obesity existed in Korean women. Reverse inequalities in urbanization were also apparent in older women. Developing strategies to address the multiple observed inequalities in obesity among Korean women may prove essential for effectively reducing the burden of this disease. [ABSTRACT FROM AUTHOR]