Unusual transport characteristics of nitrogen-doped single-walled carbon nanotubes

Electrical transport characteristics of nitrogen-doped single-walled carbon nanotubes (N-SWCNTs), in which the nitrogen dopant is believed to form a pyridinelike bonding configuration, are studied with the field effect transistor operations. Contrary to the expectation that the nitrogen atoms may induce a n -type doping, the electrical transports through our N-SWCNTs are either ambipolar in vacuum or p -type in air. Through the first-principles electronic structure calculations, we show that the nitrogen dopant indeed favors the pyridinelike configuration and the Fermi level of the pyridinelike N-SWCNT is almost at the intrinsic level.open01

Association between thyroid hormones and the components of metabolic syndrome

BACKGROUND: Thyroid hormones are known to have direct and indirect effects on metabolism. Individuals with metabolic syndrome, a disease that is growing in incidence at a rapid rate, are at higher risk for cardiovascular disease, diabetes, and cancer. The aim of this study was to identify whether significant correlations exist between thyroid hormone levels and components of the metabolic syndrome in the general population of Korea. METHODS: The data were collected from the sixth Korea National Health and Nutrition Examination Surveys from 2013 to 2015. A total of 1423 participants were tested for thyroid function. The analysis of variance and multiple linear regression were performed to analyze the relationship between thyroid hormone level and components of the metabolic syndrome. RESULTS: A positive association between free thyroxine and fasting glucose level was observed in patients with high free thyroxine levels (≥1.70 ng/dL, β = 15.992, p = < 0.0001), when compared with patients with normal-middle free thyroxine levels. Moreover, a negative association was observed between free thyroxine and triglyceride levels in patients with normal-high free thyroxine levels (β = - 21.145, p = 0.0054) and those with high free thyroxine levels (β = - 49.713, p = 0.0404). CONCLUSION: Free thyroxine shows a partially positive association with fasting glucose and a partially negative association with triglycerides in the Korean population. In patients with abnormal thyroid function, follow up tests for glucose levels and lipid profiling during treatment for thyroid dysfunction would be beneficial in terms of overlooking metabolic syndrome and to prevent related diseases

Safety and tissue yield for percutaneous native kidney biopsy according to practitioner and ultrasound technique

BACKGROUND: Although percutaneous renal biopsy remains an essential tool in the diagnosis and treatment of renal diseases, in recent times the traditional procedure of nephrologists has been performed by non-nephrologists rather than nephrologists at many institutions. The present study assessed the safety and adequacy of tissue yield during percutaneous renal biopsy according to practitioners and techniques based on ultrasound. METHODS: This study included 658 native renal biopsies performed from 2005 to 2010 at a single centre. The biopsies were performed by nephrologists or expert ultrasound radiologists using the ultrasound-marked blind or real-time ultrasound-guided techniques. RESULTS: A total of 271 ultrasound-marked blind biopsies were performed by nephrologists, 170 real-time ultrasound-guided biopsies were performed by nephrologists, and 217 real-time ultrasound-guided biopsies were performed by radiologists during the study period. No differences in post-biopsy complications such as haematoma, need for transfusion and intervention, gross haematuria, pain, or infection were observed among groups. Glomerular numbers of renal specimens from biopsies performed by nephrologists without reference to any technique were higher than those obtained from real-time ultrasound-guided biopsies performed by expert ultrasound radiologists. CONCLUSIONS: Percutaneous renal biopsy performed by nephrologists was not inferior to that performed by expert ultrasound radiologists as related to specimen yield and post-biopsy complications

Prediction of abundance of arthropods according to climate change scenario RCP 4.5 and 8.5 in South Korea

AbstractAbundance and diversity of arthropods were projected according to climate warming in South Korea. The taxa highly linked with temperature were selected for the projection. The values of abundance and richness were estimated using the mean values of abundance and richness in each temperature range. Temperature changes were based on the RCP (Representative Concentration Pathway) 4.5 and RCP 8.5, and the abundance and richness during two periods (2011 -2015, 2056 -2065) were projected. From these projected results, change of other common taxa (> 1% occurrence) were qualitatively predicted (i.e., decrease or increase). The projections showed that 45 of a total of 73 taxa will increase, 6 will change a little and 24 will decrease: the number of taxa that were expected to increase was two times more than the number of taxa that were expected to decrease. However, the overall abundance and diversity of arthropods were expected to decline as the temperature rises

Structure and spectral features of H+(H2O)(7): Eigen versus Zundel forms

The two dimensional (2D) to three dimensional (3D) transition for the protonated water cluster has been controversial, in particular, for H+(H2O)(7). For H+(H2O)(7) the 3D structure is predicted to be lower in energy than the 2D structure at most levels of theory without zero-point energy (ZPE) correction. On the other hand, with ZPE correction it is predicted to be either 2D or 3D depending on the calculational levels. Although the ZPE correction favors the 3D structure at the level of coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)] using the aug-cc-pVDZ basis set, the result based on the anharmonic zero-point vibrational energy correction favors the 2D structure. Therefore, the authors investigated the energies based on the complete basis set limit scheme (which we devised in an unbiased way) at the resolution of the identity approximation Moller-Plesset second order perturbation theory and CCSD(T) levels, and found that the 2D structure has the lowest energy for H+(H2O)(7) [though nearly isoenergetic to the 3D structure for D+(D2O)(7)]. This structure has the Zundel-type configuration, but it shows the quantum probabilistic distribution including some of the Eigen-type configuration. The vibrational spectra of MP2/aug-cc-pVDZ calculations and Car-Parrinello molecular dynamics simulations, taking into account the thermal and dynamic effects, show that the 2D Zundel-type form is in good agreement with experiments. (c) 2006 American Institute of Physics.open353

Trends in Cancer Screening Rates among Korean Men and Women: Results from the Korean National Cancer Screening Survey (KNCSS), 2004-2010

PURPOSE: The Korean National Cancer Screening Survey (KNCSS) is a continuous nationwide survey implemented by the National Cancer Center in Korea since 2004. The purpose of the present study was to report trends in cancer screening rates for the five major cancers (stomach, liver, colorectal, breast, and cervix uteri) in Korean men and women. MATERIALS AND METHODS: The study used KNCSS data collected between 2004 and 2010. The survey was conducted on Korean men aged 40-74 years and Korean women aged 30-74 years with no history of cancer diagnosis. The annual percentage change and corresponding 95% confidence intervals were used to examine changes in annual screening rates. RESULTS: Screening rates with recommendation increased by 4.4% annually for stomach cancer, 1.5% for liver cancer, 2.8% per year for colorectal cancer, 4.5% for breast cancer, and 1.2% for cervix uteri cancer. The increasing trend in cancer screening rates, with the exception of liver cancer, was significant. CONCLUSION: Cancer screening rates have increased consistently from 2004 to 2010 among Korean men and women. Stomach and breast cancer screening rates in particular have increased markedly.ope

Effect of regional medical disparities on complications in patients with hypertension: Cox’s proportional hazard models

ObjectiveComplications associated with hypertension can be alleviated by providing necessary medical services. However, there may be disparities in their provision depending on regional differences. Thus, this study aimed to examine the effects of regional healthcare disparities on complications in patients with hypertension in South Korea.MethodsData from the National Health Insurance Service National Sample Cohort (2004–2019) were analyzed. The position value for the relative composite index was used to identify medically vulnerable regions. The diagnosis of hypertension within the region was also considered. The risk of complications associated with hypertension included cardiovascular, cerebrovascular, and kidney diseases. Cox proportional hazards models were used for statistical analysis.ResultsA total of 246,490 patients were included in this study. Patients who lived in medically vulnerable regions and were diagnosed outside their residential area had a higher risk of complications than those living in non-vulnerable regions and were diagnosed outside the residential area (hazard ratio: 1.156, 95% confidence interval: 1.119–1.195).ConclusionPatients living in medically vulnerable regions who were diagnosed outside their residential areas were more likely to have hypertension complications regardless of the type of complication. Necessary policies should be implemented to reduce regional healthcare disparities

Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2008

PURPOSE: This paper overviews the nationwide cancer statistics including incidence, mortality, survival and prevalence, and their trends in Korea based on the year 2008 cancer incidence data. MATERIALS AND METHODS: Incidence data from 1993 to 2008 were obtained from the Korea National Cancer Incidence Database, and the vital status was followed through December 31, 2009. Mortality data from 1983 to 2008 were obtained from the Korea National Statistics Office. Crude rates and age-standardized rates for incidence, mortality, prevalence and relative survival were calculated. RESULTS: There were 178,816 cancer cases and 68,912 cancer deaths observed during year 2008 and 724,663 10-year cancer prevalent cases as of January 1, 2009 in Korea. The incidence rate for all cancer combined showed an annual increase of 3.1% from 1999 to 2008. CONCLUSION: With significantly increasing cancer incidence, Korea faces a large cancer burden and efficient cancer control programs are essential.ope