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Very few population-based studies have examined the epidemiology of Wilson’s disease (WD). We investigated the epidemiology of WD using the National Health Insurance Service (NHIS) database in South Korea. We analyzed not only the statistical variables of WD, but also those of WD-related diseases. WD patients were identified with the relevant International Classification of Diseases-10 code out of 50.5 million people. We used the NHIS database from 2009 to 2016 and analyzed the incidence rate, prevalence, and clinical symptoms of WD. A total of 1,333 patients were identified. The average annual incidence rate was 3.8 per million person-years. The prevalence was 38.7 per million people. The mean diagnostic age was 26.1 ± 17.2 with earlier diagnosis in men (P = 0.0003). Among the patients, 988 (74.1%) had hepatic symptoms, 510 (38.3%) had neurologic symptoms, and 601 (45.1%) had psychiatric symptoms. Before the diagnosis of WD, 350 (26.3%) had neurologic symptoms, and 427 (32%) had psychiatric symptoms. The annual mortality rate was 0.7%. Age, liver cirrhosis, and liver failure correlated with a fatal prognosis (P

BACKGROUND: Mechanical thrombectomy (MT) of ischemic stroke was demonstrated to be effective in clinical trials and was reported to have favorable outcomes in real clinical settings since 2015. We aimed to determine the national trends of MT and compare the outcomes between the different levels of treating hospital. METHODS: We obtained data from the nationwide database from 2008 to 2017. Patients with ischemic stroke who received MT were identified using the International Classification of Disease Codes. Good outcome was defined as discharge to home, and a poor outcome was defined as cerebral hemorrhage, physical disability, or death. The study period was divided into three (off-label MT, transitional, MT period). Hospital groups where MT was performed were divided into tertiary and non-tertiary hospitals. RESULTS: In MT period, 47.0% of the MT procedures were performed in non-tertiary hospitals compared with 36.1% in off-label MT period. Comparison of the 3-month mortality between patients who were treated in tertiary vs. non-tertiary hospitals revealed significant lower mortality in tertiary hospital through all period. The incidence of cerebral hemorrhage and physical disability did not differ between hospital groups. However, the percentage of patients discharged home was 41.4% for tertiary hospitals and 42.4% for non-tertiary hospitals, which was not statistically different in MT period (P=0.4671). CONCLUSIONS: Analysis of the nationwide data confirmed that the extent of increase in MT was higher in non-tertiary hospitals than tertiary hospitals. In addition, no significant difference was revealed in the number of favorable clinical outcome between the hospital groups during MT period.

Idiopathic pulmonary fibrosis (IPF) is an independent risk factor for lung cancer (LC) development; however, there are currently no clinical guidelines for LC surveillance in IPF. This study aimed to investigate the cumulative incidence and survival outcomes of LC in IPF. Using the National Health Insurance Service database, including medical information on people aged ≥ 40 years between 2011 and 2016, we identified IPF patients and confirmed the presence of comorbid LC. Patients diagnosed with IPF in 2011 were washed out, and mortality data were analyzed from 2012 to 2018. A total of 7277 newly diagnosed IPF patients were identified among Korean citizens aged ≥ 40 years (about 50 million people) between 2011 and 2016. Their average age was 71.5 years and 72.8% of them were male. The prevalence of LC in the IPF cases was 6.4%. The cumulative incidence rates of LC in IPF patients who did not have LC at the time of IPF diagnosis were 1.7%, 4.7%, and 7.0%, at 1, 3, and 5 years, respectively. The median time from IPF diagnosis to LC development was 16.3 (Interquartile range, 8.2–28.8) months. The survival rate was significantly lower in the IPF with LC group than the IPF without LC group (P

INTRODUCTION: Clinical studies have produced conflicting results on the effects of metformin on gastrointestinal cancer development. We aimed to investigate the association between metformin use and stomach, colon, liver, and pancreatic cancer development among patients with newly diagnosed, drug-naïve type 2 diabetes. METHODS: This retrospective study evaluated propensity score-matched patients with newly diagnosed type 2 diabetes from the Korean National Health Insurance Service database. Metformin users were categorized into tertiles according to the cumulative dose or duration of metformin treatment, and the risks of gastrointestinal cancers were compared. RESULTS: Metformin users had reduced risks of developing stomach cancer (hazard ratio [HR]: 0.841, 95% confidence interval [CI]: 0.797–0.887), colon cancer (HR: 0.865, 95% CI: 0.822–0.91), and liver cancer (HR: 0.709, 95% CI: 0.675–0.746; P < 0.001). However, metformin users did not have a reduced overall risk of pancreatic cancer (HR: 1.335, 95% CI: 1.209–1.475; P < 0.001). The risks tended to decrease at higher cumulative doses and durations of metformin use, with significantly reduced risks of all 4 cancers at the highest cumulative dose (≥1,200,000 mg) and the longest duration (≥2,000 days) of metformin use. DISCUSSION: This population-based data suggest that metformin could be associated with reductions in the risks of stomach, colon, and liver cancers, as well a reduced risk of pancreatic cancer in some subgroups. Metformin has benefit as a first-line treatment for type 2 diabetes mellitus. A further role in cancer risk reduction could be studied in controlled trials.

Background The prevalence and incidence of sarcoidosis, a granulomatous disorder involving multiple organ systems, varies among geographical regions and ethnicities. This study evaluated the incidence, prevalence, and mortality of sarcoidosis in a large nationwide population-based cohort in Korea. Methods We used data of the National Health Insurance Service database, which is an extensive health-related database including most Korean residents. Adults with a primary diagnosis of sarcoidosis, as determined by International Classification of Disease-Tenth Revision coding (D86), were identified between 2003 and 2015. The incidence, prevalence, and mortality of sarcoidosis were analysed by sex and age. Results A total of 6376 individuals had a primary diagnosis of sarcoidosis. Their mean age was 48.8 years, and 58.6% were women. The age-adjusted incidence and prevalence of sarcoidosis were 1.3 and 3.4 per 100,000 population respectively; both tended to increase between 2003 and 2015. The all-cause mortality rate was 13.1 per 1000 sarcoidosis patients. The standardised mortality ratio of sarcoidosis patients to the general population was 1.7 (95% confidence interval, 1.5 to 1.8). Conclusions This is the largest epidemiologic study of sarcoidosis in an Asian population to date. In Korea, the annual incidence and prevalence of sarcoidosis were relatively low but tended to increase over the 13 years of the study period. Importantly, the overall mortality rate of patients with sarcoidosis was higher than that of the general population.

Metformin, the most widely used drug for type 2 diabetes, has recently attracted attention with regard to its antitumor activity. However, clinical studies have yielded conflicting results regarding the association between metformin and thyroid cancer development, despite its antitumor effect in preclinical studies.This is a retrospective cohort study using the Korean National Health Insurance claim database. Matched populations of 128,453 metformin users and 128,453 non-users were analyzed for thyroid cancer incidence. Metformin users were categorized into lowest, middle, and highest tertiles according to cumulative dose or duration of metformin therapy.Thyroid cancer developed in 340 (0.26%) metformin users and 487 (0.38%) non-users during a mean follow-up of 7.2 years (hazard ratio = 0.69 [confidence interval 0.60-0.79]; p 0.001). The incidence of thyroid cancer per 10Metformin appears to be associated with a preventive effect on thyroid cancer development in a nationwide population-based study, but is not effective in the early phase of treatment. Considering the increasing prevalence of obesity and the role of insulin resistance in the development of cancer, metformin might be the preferred treatment for its dual anti-diabetic and antitumor effects.

A Nd:YAG linearly polarized nanosecond laser emitting at a wavelength of 355 nm was used to irradiate amorphous-Si thin film (50 nm thickness) on a glass substrate at a repetition rate of 14 kHz and a pulse duration of 5.5 ns. By scanning the laser beam with an asymmetric Gaussian shape in the lateral and vertical directions with various scan pitches at maximum fluences of 55 mJ/cm2 and 90 mJ/cm2, uniform surface textures were obtained when the laser was scanned in the vertical direction at a scan pitch of ∼35–40 μm along the long beam axis. The surface textures were composed of nanoparticle arrays embedded in the Si layer, whose height gradually increased up to 100–150 nm as the number of pulses increased. However, when over-irradiated, the nanoparticles with a rounded shape were transformed to an irregular shape, and the surface roughness also increased. These results would enable application of a 355-nm nanosecond laser to achieve uniform surfaces as a result of the laser crystallization process for organic light-emitting diode displays or photovoltaic devices.

IntroductionTo examine how the risk of cardiovascular disease changes according to degree of change in body mass index (BMI) and low-density lipoprotein (LDL)-cholesterol in patients with diabetes using the health medical examination cohort database of the National Health Insurance Service in Korea. In comparison, the pattern in a non-diabetic control group was also examined.Research design and methodsThe study samples were 13 800 patients with type 2 diabetes and 185 898 non-diabetic controls, and their baseline characteristics and repeatedly measured BMI and LDL-cholesterol until occurrence of cardiovascular disease were collected in longitudinal data. We used the variability model that is joint of mixed effects and regression model, then estimated parameters about variability by Bayesian methods.ResultsThe risk of cardiovascular disease was increased significantly with high average real variability (ARV) of BMI in the patients with diabetes, but the risk of cardiovascular disease was not increased according to degree of ARV in non-diabetic controls. The Bayesian variability model was used to analyze the effects of BMI and LDL-cholesterol change pattern on development of cardiovascular disease in diabetics, showing that variability did not have a statistically significant effect on cardiovascular disease. This shows the danger of the former simple method when interpreting only the mean of the absolute value of the variation.ConclusionsThe approach of simple SD in previous studies for estimation of individual variability does not consider the order of observation. However, the Bayesian method used in this study allows for flexible modeling by superimposing volatility assessments on multistage models.

Background Epidemiologic characteristics of nontuberculous mycobacterial (NTM) disease remain largely unknown. The objective of this study was to evaluate incidence, prevalence, and mortality of NTM infection in a large nationwide population-based cohort in Korea. Methods Data of the National Health Insurance Service database, an extensive health-related database including most Korean residents, were used. Adults with a primary diagnosis of NTM as determined by International Classification of Disease-Tenth Revision coding (A31) were identified between 2003 and 2016. Incidence, prevalence, and mortality of NTM infection were analyzed. Results A total of 46,194 individuals had a primary diagnosis of NTM infection. Their mean age was 55.8 years. Of these subjects, 61.1% were females. Annual age-adjusted incidence and prevalence of NTM infection tended to increase rapidly from 2003 to 2016. Age-adjusted incidence and prevalence was 17.9 and 33.3 per 100,000 population in 2016. The incidence and prevalence were higher in females and the elderly. The 5-year mortality rate in the population with NTM infection was 17.8%. The standardized mortality ratio of patients with NTM infection to the general population was 2.16 (95% confidence interval: 2.10 to 2.22). Conclusions This large population-based study showed that the incidence and prevalence of NTM infection in Korea increased rapidly from 2003 to 2016. They were higher in women and the elderly. The mortality rate in the population with NTM infection was higher than that in the general population.

Background To determine the effect of missing teeth on the risk of dementia onset among individuals who received tooth extractions and those who did not, based on the number of missing teeth. Methods We selected individuals who had not been diagnosed or treated for dementia between 2002 to 2011 from the National Health Insurance Service-Elderly Cohort Database (NHIS-ECD). We divided participants into two cohorts, a tooth extraction and non-extraction cohort, based on tooth loss from 2002 to 2011. After propensity score matching, there were 104,903 individuals in each cohort, and we included a total of 209,806 individuals in this study. Each cohort was grouped by sex, age, residential area, health insurance eligibility, income level, history of dental caries, history of periodontal treatment, and number of extracted teeth. We analyzed the relationship between dementia onset and these variables using logistic regression analysis. Results Individuals with tooth loss had a higher risk for dementia than those without tooth loss (odds ratio [OR] = 1.18; 95% confidence interval [CI]: 1.146–1.215). Regarding the incidence of dementia, the OR increased as the number of missing teeth and age increased, and the OR was higher for women (OR = 1.33; 95% CI: 1.286–1.367) than for men, and this difference was statistically significant (P

Laser-crystallization processes to convert amorphous-Si to poly-crystalline-Si are attracted considerable attention owing to their industrial applications, such as in active matrix organic light-emitting diode displays (AMOLEDs) and photovoltaic devices and general scientific interest. Multiple irradiation sequences were conducted with a 355 nm UV laser on amorphous-Si (40, 50, and 60 nm)/oxide(300 nm) layers on glass substrates. The resultant periodic surface textures on Si thin layers were characterized by resonance peaks in the transmittance spectra, depending on the polarization of the normal-incident light. By modeling the periodic textures as 1D linear gratings, the variations in peak intensities and positions were analyzed with respect to Si-layer thickness using the guided-mode resonance theory. In the case of transverse electric polarization, the electric field generated at resonance was entirely concentrated in the Si layer, leading to a red-shift with an increase in Si-layer thickness. Meanwhile, with transverse magnetic polarization, the magnetic field generated at resonance was mainly localized within the Si layer, but was partially distributed in the lower oxide layer when the Si-layer thickness was less than 45 nm and highly concentrated in the Si layer at Si-layer thicknesses greater than 45 nm. These results were consistent with the measured ripple positions and intensities. Thus, we propose that the observed resonance peaks can be used to characterize the surface ripples generated by laser crystallization, for e.g., in optical sensor devices on flexible substrates.

The laser crystallization process that converts amorphous-Si to poly-crystalline-Si has attracted considerable attention owing to its wide industrial applications, such as active matrix organic light-emitting diode displays and photovoltaic devices. Herein, for thin-layer configurations of amorphous-Si/oxide/nitride deposited on a glass substrate, periodic surface ripples on Si induced by irradiation with a solid-state laser at an ultraviolet wavelength of 355 nm were examined using a guided-mode resonance theory. Modeling the periodic textures as one-dimensional gratings demonstrated several resonance peaks in the transmittance spectra, which were similar to the measured spectra. Furthermore, by varying the thickness of oxide (0–300 nm) and nitride (60–120 nm) sublayers, two resonance modes with separations of a few tens of nanometers were predicted for the transverse electric and transverse magnetic polarizations, respectively. The two-dimensional mode plots and electric and magnetic fields at the resonance wavelengths indicated that the mode couplings were mainly owing to the guided modes propagating in the Si and nitride layers. Because the peak positions and intensity of the resonance modes represent the figure-of-merit of the laser crystallization process, the resonance modes may be employed for the evaluation of the laser crystallization process; this will enable a more efficient evaluation compared to the current manual inspection of diffraction images by human eyes.

The process of inducing crystallization on the surface of a 50-nm-thick amorphous Si (a-Si) thin film was analyzed by applying a Nd:YAG (λ = 355 nm) nanosecond laser with an asymmetric Gaussian shape at a pulse repetition rate of 14 kHz and pulse duration of 5.5 ns. Single-laser-pulse irradiation with a peak fluence of 124 mJ/cm2 resulted in the formation of circular Si nanoparticles on the surface, which was observed to have multiple domains with varying degrees of surface roughness and crystallinity. Additionally, the light absorption significantly increased at the center of irradiation, where the density of the nanoparticles was maximized. Specifically, at the ultraviolet wavelength of 380 nm, the absorption was 85%, which is approximately twice that for the non-laser-treated a-Si (i.e., 42%). These results are attributable to the anti-reflection effect of the Si nanoparticles, and have been validated by numerical simulations. Although the intensity and absorption were observed to be heterogeneous, it is suggested that uniform crystallinity can be achieved by optimizing the scan pitch and laser fluence; these conditions would enable application of a 355-nm nanosecond laser to the laser crystallization process for organic light-emitting diode displays or photovoltaic devices.

A Nd:YAG (λ = 355 nm) nanosecond laser is used to anneal a 45-nm-thick amorphous-Si (a-Si) thin film on a glass substrate. Via scanning with a laser beam having a Gaussian shape at a repetition rate of 14 kHz, the surface of the a-Si film is crystallized, and laser-induced periodic surface structures (LIPSSs) are formed within the fluence range of 30–35 mJ/cm2. The formation energy of surface ripples is significantly lower than the typical fluence of a few 100 mJ/cm2. Confocal Raman spectroscopy and atomic force microscopy reveal that the a-Si film is only crystallized near the top surface and that the surface ripples are aligned to the perpendicular direction of laser polarization, in accordance with the LIPSS model. For a laser fluence of >35 mJ/cm2, the surface texture loses its periodicity but forms randomly distributed Si grains with a surface roughness of >40 nm. The laser processing on an a-Si film achieved by scanning up to 20 × 20 mm2 shows uniform periodic surface textures, which can be employed in the display or photovoltaic applications.

Coriolus versicolor, is one of the most popular medicinal mushrooms due its various biologically active components. This study was conducted to obtain basic information regarding the mycelial culture conditions of C. versicolor. Based on the culture, and MCM media were suitable for the mycelial growth of the mushroom. The optimum carbon and nitrogen sources were dextrin and yeast extract, respectively, and the optimum C/N ratio was 10 to 2 when 2% glucose was used. Other minor components required for optimal growth included thiamine-HCl and biotin as vitamins, succinic acid, lactic acid and citric acid as organic acids, as well as MgSO4·7H2O as mineral salts.