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In this study, we developed a neutron time-of-flight (nTOF) measurement system for a 1.7-MV tandem proton accelerator with a target covered with 300-nm-thick lithium (Li) layer. With implementation of beam chopping module after its ion source, the accelerator is configured to operate in pulsed-beam mode with a pulse width

This article presents time-resolved analysis of SF6 arc plasma generated in a laboratory-scale model chamber prepared for studying the characteristics of a circuit breaker. During the arc discharge, the optical emission spectra are measured by a high-speed spectrometer under various operating conditions. The time-resolved electron temperature and density values are determined using the well-known Boltzmann plot and Stark broadening methods, respectively, for the measured Cu I, S II, and F I emission lines. Moreover, the temporal evolution of the electrical conductivity of the arc plasma is deduced from the measured electron temperature and density values, depending on the operating conditions. In our experimental conditions, it is revealed that the electrical conductivity of arc plasmas is mainly determined by Coulomb (electron–ion) collisions as opposed to electron–neutral collisions due to the much higher Coulomb collision frequency compared to the electron–neutral collision frequency. Both the electron temperature and density were found to increase when the discharge current is increased at a fixed gas pressure, resulting in an increase of the electrical conductivity. When the gas pressure inside the model chamber is increased, the electron density is increased as well, but the electrical conductivity does not change significantly due to the slight change in the electron temperature. The present study will be helpful for investigating the performance capabilities of circuit breakers because the electrical conductivity, the most important parameter to guarantee successful circuit breaking at points near the current-zero, is determined by the temperature and density of the electrons.

This paper presents the experimental results of neutron spectra measurements with organic scintillators at the copper beam dump of the 100-MeV proton linear accelerator in the Korea Multi-Purpose Accelerator Complex (KOMAC). For the measurement of the fast neutrons generated by the proton-copper nuclear reaction, two organic scintillators made of a stilbene crystal and liquid EJ-309 combined with photomultipliers and fast digitizers were utilized. Both detectors were installed inside radiation shielding structures facing the conical-shaped 100-MeV proton beam dump. The neutron transport was calculated using two Monte-Carlo codes, MCNP6 and GEANT4, with a proper physical model and a nuclear data library, along with the appropriate consideration of the detailed geometrical factors in the vicinity of the beam-dump and the neutron detectors. Each pulse signal measured in the detectors was analyzed to identify whether it was induced by a neutron or a gamma-ray in a mixed radiation field by using pulse shape discrimination technique. For operation of beam current of 5 mA and duty of 0.2%, the neutron yield was measured to be approximately 9.0E+10 n/s, which was 23% smaller than the numerically estimated value. In addition, both the measured and the estimated neutron energy spectra were compared.

Purpose The association between tobacco smoking and thyroid cancer remains uncertain. We evaluated the associations of active and passive smokingwith the risk of papillary thyroid cancer (PTC), the most common type of thyroid cancer, and with the BRAFV600E mutation, the most common oncogenic mutation in PTC related to poor prognosis. Materials and methods We conducted this study with newly diagnosed PTC patients (n=2,142) and community controls (n=21,420) individually matched to cases for age and sex. Information on active and passive smoking and potential confounders were obtained from structured questionnaires, anthropometric measurements, and medical records. BRAFV600E mutation status was assessed in PTC patients. We evaluated the associations of active and passive smoking with PTC and BRAFV600E mutation risk using conditional and unconditional logistic regression models, respectively. Results We did not find associations between exposure indices of active and passive smoking and PTC risk in both men and women, except for the association between current smoking and lower PTC risk. Cumulative smoking ≥ 20 pack-years was associated with lower BRAFV600E mutation risk in male PTC patients (odds ratio [OR], 0.55; 95% confidence interval [CI], 0.30 to 1.00). The CI for the association was wider in female PTC patients (OR, 0.23; 95% CI, 0.02 to 2.62), possibly owing to a smaller sample size in this stratum. Conclusion We did not find consistent associations between active and passive smoking and PTC risk. Cumulative smoking ≥ 20 pack-years was associated with lower BRAFV600E mutation risk in male PTC patients.

A Thomson scattering diagnostic system was developed and successfully measured electron temperature and density of core plasma (R = 0.35 m) in Versatile Experiment Spherical Torus (VEST). However, the current system is able to measure only a single time point in a shot. Therefore, upgrade of the Thomson scattering system has been prepared and is in progress to obtain the time evolution. The upgrade is focused on three parts. First, the laser injection system is improved by introducing a burst mode laser with the energy of 2 J and repetition rate of 1 kHz for 10 ms. Furthermore, the laser injection optics is improved to minimize the optical loss. Second, minimum etendue limit of the collection optics is increased by employing a fiber bundle of three single-core fibers. Finally, a data acquisition system is prepared to record the burst laser signals for high sampling rate. Oscilloscope envelope mode is adopted and tested for measuring ten burst laser signal with 1.25 GS/s. Through the upgrade, the time evolution of electron temperature and density is expected to be measured in a single shot with enhanced signal-to-noise ratio.

Purpose - Few studies investigated roles of body mass index (BMI) on gastric cancer (GC) risk according to Helicobacter pylori infection status. This study was conducted to evaluate associations between BMI and GC risk with consideration of H. pylori infection information. Materials and Methods - We performed a case-cohort study (n=2,458) that consists of a subcohort, (n=2,193 including 67 GC incident cases) randomly selected from the Korean Multicenter Cancer Cohort (KMCC) and 265 incident GC cases outside of the subcohort. H. pylori infection was assessed using an immunoblot assay. GC risk according to BMI was evaluated by calculating hazard ratios (HRs) and their 95% confidence intervals (95% CIs) using weighted Cox hazard regression model. Results - Increased GC risk in lower BMI group (< 23 kg/m2) with marginal significance, (HR, 1.32; 95% CI, 0.98 to 1.77) compared to the reference group (BMI of 23-24.9 kg/m2) was observed. In the H. pylori non-infection, both lower (< 23 kg/m2) and higher BMI (≥ 25 kg/m2) showed non-significantly increased GC risk (HR, 10.82; 95% CI, 1.25 to 93.60 and HR, 11.33; 95% CI, 1.13 to 113.66, respectively). However, these U-shaped associations between BMI and GC risk were not observed in the group who had ever been infected by H. pylori. Conclusion - This study suggests the U-shaped associations between BMI and GC risk, especially in subjects who had never been infected by H. pylori.

A Thomson scattering (TS) system has been developed on Versatile Experiment Spherical Torus (VEST) to measure the electron temperature and the density. In VEST, it is quite challenging to measure TS signals because the energy of the utilized pulsed laser and the target electron density are low, 0.85 J and ∼5 × 1018 m−3, respectively. Furthermore, the difficulties caused by filter specifications have to be resolved because of the use of commercial interference filters with broad bandwidth and poor blocking at the laser wavelength. Therefore, we especially optimize the placement order of the filter sets based on the evaluation of the relative errors to overcome the poor spectral resolution. In addition, the amount of the stray light that penetrating filters is reduced by vacuum components such as baffles, louvres, and a viewing dump. With the careful installation and the optimization of the system, we can develop an efficient Thomson scattering system. Recently, TS signals have been successfully measured from the ohmic plasmas, and the electron temperature and the density are determined by analyzing the signals with the Bayesian method.

Background and Aims Calcimimetic therapy, including oral cinacalcet and intravenous (IV) etelcalcetide, is often used to control parathyroid hormone (PTH) levels in hemodialysis (HD) patients. In a head-to-head clinical trial, etelcalcetide was superior to cinacalcet on PTH reduction. Given that oral administration of cinacalcet is susceptible to challenges of self-management and adherence, etelcalcetide may be even more effective in the real-world setting. To limit confounding by indication, we used a facility calcimimetic preference approach to investigate the comparative effectiveness of etelcalcetide vs. cinacalcet by estimating effects on PTH and other mineral and bone disorder (MBD) markers in a cohort of US HD patients. Method We used data from the US Dialysis Outcomes and Practice Patterns Study (US-DOPPS), a prospective cohort study of in-center HD patients. During a 6-month run-in period from March to August 2019, we evaluated facility calcimimetic preference by calculating the proportion of calcimimetic users in each facility who were prescribed etelcalcetide (vs. cinacalcet). Among patients with any prescription for a calcimimetic during the 6-month run-in period, we evaluated MBD marker outcomes (PTH, albumin-corrected serum calcium [Ca], serum phosphorus [P]), averaged over the subsequent 6 months, from September 2019 to February 2020. We compared HD facilities that treated >75% of calcimimetic users with etelcalcetide (“Etel-first”) vs. those that treated >75% of calcimimetic users with cinacalcet (“Cina-first”). Linear regression was used to model each continuous outcome. Modified Poisson regression was used to estimate the prevalence ratio (PR) of each MBD marker being out of target (PTH >600 pg/mL, Ca 5.5 mg/dL). All models were adjusted for patient-level and facility-level confounders and accounted for facility clustering using GEE. Results We excluded 38 HD facilities with little-to-no calcimimetic use (600 was lower (PR=0.75; 95% CI: 0.60, 0.94) in adjusted models. The adjusted mean levels of serum Ca and serum P (secondary outcomes) were slightly lower in Etel-first (vs. Cina-first) facilities [Table 1]. Conclusion To our knowledge, this is the first large-scale comparison of IV etelcalcetide with oral cinacalcet in the real-world setting. Our unique approach resembles a natural experiment by leveraging practice variation across the US and isolating HD facilities with a clear preference for one calcimimetic. Thus, the prescribed calcimimetic type for included patients was more likely determined by facility preference than biased by patient indication. Our results indicate better PTH control (mean levels ∼100 pg/mL lower) in US HD facilities using etelcalcetide (vs. cinacalcet) as the primary calcimimetic therapy. Further research is needed to investigate the degree to which the greater real-world effectiveness of IV etelcalcetide (vs. oral cinacalcet) may be driven by adherence to the prescribed therapy, and how clinical outcomes may be affected.

This study examines how terrorist attacks and CEO confidence levels impact CEO compensation structures. Terrorist attacks in the United States from 1999 to 2018 are examined as negative exogenous shocks affecting CEO compensation. The findings indicate that overconfident CEOs of affected firms are likely to receive higher equity compensation than overconfident CEOs of firms located far from attacks, while non-overconfident CEOs of affected firms receive higher cash compensation than CEOs located far from attacks. This study contributes to the literature by examining how CEO compensation levels and structures vary according to nonfinancial shocks and CEO confidence levels.

This study aimed to investigate the association between adolescent overweight and obesity and PTC risk in adulthood. We conducted a case-control study in the Republic of Korea with 1,549 PTC patients and 15,490 controls individually matched for age and sex. We estimated body mass index (BMI) at age 18 years from self-reported weight at this age. Compared with BMI BRAFV600E mutation. Adolescent overweight and obesity was associated with higher risk of PTC in adulthood. Our results emphasise the importance of weight management in adolescence to decrease the PTC risk.

BackgroundReal-world evidence of low-density lipoprotein cholesterol (LDL-C) goal attainment rates for Asian patients is deficient. The objective of this study was to assess the status of dyslipidemia management, especially in high-risk patients with cardiovascular disease (CVD) including stroke and acute coronary syndrome (ACS).MethodsThis was a retrospective cohort study of 514,866 subjects from the National Health Insurance Service-National Health Screening Cohort database in Korea. Participants were followed up from 2002 to 2015. Subjects with a high-risk of CVD prior to LDL-C measurement and subjects who were newly-diagnosed for high-risk of CVD following LDL-C measurement were defined as known high-risk patients (n = 224,837) and newly defined high-risk patients (n = 127,559), respectively. Data were analyzed by disease status: stroke, ACS, coronary heart disease (CHD), peripheral artery disease (PAD), diabetes mellitus (DM) and atherosclerotic artery disease (AAD).ResultsOverall, less than 50% of patients in each disease category achieved LDL-C goals (LDL-C ConclusionsLDL-C goal attainment rates in high-risk patients with CVD and DM in Korea demonstrate unmet medical needs. Proactive management is necessary to bridge the gap between the recommendations of clinical guidelines and actual clinical practice.

This paper presents the electrical conductivity data of copper along the gas branch of the binodal curve in the warm dense matter (WDM) regime as a function of mass density and temperature. All data are obtained using the underwater wire explosion technique, in which vaporized copper cools along the gas branch of the binodal curve during the period of current dwell after the wire explodes. Mass density and temperature are measured by fast imaging and optical spectroscopy, respectively. Combining these data with electrical measurements of the wire resistance, we obtain the conductivities of copper along the binodal curve in the WDM regime. The electrical conductivity data measured here are expected to be helpful for developing a more accurate and reliable theory of transport properties in the WDM regime.

A new method of calculating the beam energy fraction using multiple linear regression (MLR) to ion dump calorimetric data is proposed in Korea Superconducting Tokamak Advanced Research (KSTAR). MLR was applied by collecting the cooling water temperature data from an ion dump calorimeter, where the beam energy fraction directly affects. Through the MLR method, the power delivered to the ion dump can be separated by the beam energy and the beamline A, B, and C, respectively. This power can be converted to the ratio of full, half, and one-third energy particles. By considering the neutralization efficiency, the energy fraction of the source ions and the neutrals can be finally calculated. The beam energy fraction results of the 2019 and 2020 campaign were obtained through this method. For the 2019 campaign, the results were compared with the beam energy fraction obtained using the Doppler shift spectroscopy (DSS) measurement. A notable difference in the first beam energy fraction exists between 2019 and 2020, where A decreases and C increases. This difference in the neutral particle fraction has been understood by the exchange between A and C’s ion buckets.

PURPOSE This study was performed to investigate the effectiveness of gastric cancer (GC) screening methods in a community-based prospective cohort of the Korean Multi-center Cancer Cohort (KMCC) with over a 10-year follow-up. MATERIALS AND METHODS A total 10,909 and 4,773 subjects from the KMCC with information on gastroendoscopy (GE) and upper gastrointestinal series (UGIS) were included in this study. Cox proportional hazard model adjusted for age, sex, Helicobacter pylori infection, cigarette smoking, and alcohol drinking was used to estimate the hazard ratios (HRs) and 95% confidence interval (CI). RESULTS The GE screened subjects had almost half the risk of GC-specific death than that of unscreened subjects (HR, 0.58; 95% CI, 0.36 to 0.94). Among the GC patients, GE screenees had a 2.24-fold higher survival rate than that of the non-screenees (95% CI, 1.61 to 3.11). In particular, GE screenees who underwent two or more screening episodes had a higher survival rate than that of the non-screenees (HR, 13.11; 95% CI, 7.38 to 23.30). The effectiveness of GE screening on reduced GC mortality and increased survival rate of GC patients was better in elderly subjects (≥ 65 years old) (HR, 0.47; 95% CI, 0.24 to 0.95 and HR, 8.84; 95% CI, 3.63 to 21.57, respectively) than that in younger subjects (< 65 years old) (HR, 0.66; 95% CI, 0.34 to 1.29 and HR, 1.83; 95% CI, 1.24 to 2.68, respectively). In contrast, UGIS screening had no significant relation to GC mortality and survival. CONCLUSION The findings of this study suggest that a decreased GC-specific mortality and improved survival rate in GC patients can be achieved through GE screening.

Background Iodine excess has been suggested as an exogenous risk factor of papillary thyroid cancer (PTC). We performed a systematic review and meta-analysis to assess the relationship between iodine exposure measured in various forms and PTC prevalence. Methods We searched MEDLINE, Embase, and the Cochrane Library for case-control studies on iodine and PTC published up to December 2015. Exposure to iodine was compared between PTC and control groups. Results From the 16 selected studies, the odds ratio (OR) for the overall effect size between high iodine exposure and PTC risk was 1.418 (95% confidence interval [CI] 1.054-1.909). Based on 7 studies conducted in high iodinated regions, a positive association between iodine exposure and PTC was observed (OR 2.200; 95% CI 1.389-3.483). Conclusion This study demonstrated a higher exposure to iodine in patients with PTC compared with controls, especially for patients from high iodinated regions.

Objectives We conducted a systematic review and meta-analysis to summarize current evidence regarding the association of parity and duration of breastfeeding with the risk of epithelial ovarian cancer (EOC). Methods A systematic search of relevant studies published by December 31, 2015 was performed in PubMed and EMBASE. A random-effect model was used to obtain the summary relative risks (RRs) and 95% confidence intervals (CIs). Results Thirty-two studies had parity categories of 1, 2, and ≥3. The summary RRs for EOC were 0.72 (95% CI, 0.65 to 0.79), 0.57 (95% CI, 0.49 to 0.65), and 0.46 (95% CI, 0.41 to 0.52), respectively. Small to moderate heterogeneity was observed for one birth (p13 months. The summary RRs were 0.79 (95% CI, 0.72 to 0.87), 0.72 (95% CI, 0.64 to 0.81), and 0.67 (95% CI, 0.56 to 0.79), respectively. Only small heterogeneity was observed for

Purpose: Smartphone use has dramatically increased in recent years. Smartphones may have adverse health effects, particularly on the eyes, because users stare at the screen for a much longer time than they do with ordinary mobile phones. The objective of this study was to elucidate the relationship between smartphone use and ocular symptoms among adolescents. Methods: Information on smartphone use and ocular symptoms (blurring, redness, visual disturbance, secretion, inflammation, lacrimation and dryness) related to eye fatigue and strain from 715 adolescent subjects from three cities in Korea was obtained using a structured questionnaire. Ocular health was scored using number of ocular symptoms. Odds ratios (ORs), 95% confidence intervals (95% CIs) and p-values for ocular symptoms were calculated with binomial and multinomial logistic regression models. Results: Higher prevalence rates for ocular symptoms were observed in groups with greater exposure to smartphones (p < 0.05). Longer daily smartphone use was associated with a higher likelihood of having multiple ocular symptoms (5–7 symptoms out of 7 symptoms; p = 0.005). Excessive/intermittent use (>2 hours daily and ≤2 hours continuously) and excessive/persistent use (>2 hours daily and >2 hours continuously) compared to shorter use (p = 0.001). Conclusion: Increasing exposure to smartphones can have a negative impact on ocular health in adolescents.

The importance of adherence to antihypertensive treatments for the prevention of cardiovascular disease has not been well elucidated. This study evaluated the effect of antihypertensive medication adherence on specific cardiovascular disease mortality (ischemic heart disease [IHD], cerebral hemorrhage, and cerebral infarction). Our study used data from a 3% sample cohort that was randomly extracted from enrollees of Korean National Health Insurance. Study subjects were aged ≥20 years, were diagnosed with hypertension, and started newly prescribed antihypertensive medication in 2003 to 2004. Adherence to antihypertensive medication was estimated as the cumulative medication adherence. Subjects were divided into good (cumulative medication adherence, ≥80%), intermediate (cumulative medication adherence, 50%–80%), and poor (cumulative medication adherence, P for trend=0.005), cerebral hemorrhage (hazard ratio, 2.19; 95% confidence interval, 1.28–3.77; P for trend=0.004), and cerebral infarction (hazard ratio, 1.92; 95% confidence interval, 1.25–2.96; P for trend=0.003) than those with good adherence. The estimated hazard ratios of hospitalization for cardiovascular disease were consistent with the mortality end point. Poor medication adherence was associated with higher mortality and a greater risk of hospitalization for specific cardiovascular diseases, emphasizing the importance of a monitoring system and strategies to improve medication adherence in clinical practice.

During the early campaigns of the KSTAR project, feedback control of plasma density has been successfully commissioned at the very first attempt by using a transfer function analysis. In order to minimize a chance of any risk happening, a stable and robust Ohmic discharge was chosen as a test-bed of 300 kA ( I p ) circular limited plasma in 2.0 T ( B t ). Pre-programmed fueling modulation was carried out first by puffing the deuterium gas via a piezoelectric valve. Line-averaged plasma density was measured in real-time by a 280 GHz interferometer system. From those modulations, both the density decay time ( τ i * ) and the external fueling efficiency ( f ex ) were approximated in windows: 3.0–5.0 s and 10–20% respectively. By using the results, a simple plant model has been established based on a global particle balance equation. Then several transient responses such as rising time, settling time and overshoot ratio were estimated in a certain range depending on the windows of τ i * and f ex . It is found that τ i * has little effect on those response characteristics while f ex plays primary role together with magnitude of the proportional gain G P . This is due to predominance of valve response whose characteristic time τ v was approximately 60 ms, which is much shorter than τ i * . Considering the responses, G P for closed-loop control were set initially very low i.e. 2.5 being concerned on excessive fueling. It was followed by several stepwise increments to reduce steady-state error instead of using any integral gain G I to avoid any chance of instability and uncertainty. Similarly, the target density was also initially low and gradually growing. In this way the very first density feedback control was successfully completed although some of the transient responses were different from the anticipated results while the predicted steady-state error was in good agreement with the experimental undershoot. By investigating an arbitrary time delay τ a , it is found that the digital-low-pass filter embedded in the plasma control system (PCS) of 50 ms also plays crucial role together with the τ v . In such way, settling time τ s and low overshoot case were well agreed but rising time t r and strong overshoot were not able to be found with those time delays. Considering well predicted steady-state error, with settling time t s , the transfer function analysis with the simple particle balance model is appropriate for relatively slow responses but not applicable for the faster responses and strong overshoot, which may not be linear-time-invariant (LTI) system anymore. More comprehensive physics-basis modeling will be necessary for more accurate prediction including fast responses and strong overshoot of feedback control of the density.

Background Previous studies have reported an association between dietary sodium intake and overweight/central obesity. However, dietary survey methods were prone to underestimate sodium intake. Therefore, this study investigated the associations of calculated 24-h urinary sodium excretion, an index of dietary sodium intake, with various obesity parameters including body mass index (BMI) and waist circumference (WC) in a population with a relatively high sodium intake. Methods A total of 16,250 adults (aged ≥19 years) and 1476 adolescents (aged 10-18 years), with available information on spot urine sodium levels and anthropometric measurements from the Korea National Health and Nutrition Examination Survey (KNHANES) were included in this study. We calculated 24-h urine sodium excretion levels from spot urine sodium levels using the Tanaka formula. Results In adults, those with high sodium excretion levels (≥ 3200 mg) showed increased odds of overweight and central obesity compared to those with low urinary sodium excretion level (

Measurement on surface temperature of a copper wire exploded in water by current pulse has been carried out using optical pyrometry technique. The pyrometer system consists of a volume phase holographic grating (VPHG), a fast-framing camera (1.5 Mfps in the 128x8 pixel images), light collecting optical fiber, and three lenses. The measured continuous spectra in the visible range are fitted to the Planck's radiation curve in order to estimate surface temperature of the exploding copper wire under the assumption of constant spectral emissivity. In this paper, we present the details of the optical pyrometry system and the temporal evolution of surface temperature during the current dwell period of the exploding copper wire. We also discuss the prospect of the present technique for investigating electric conductivity of metals in the regime of metal-nonmetal transition by comparing the experimental results with the numerical simulation [1].

In this paper, we propose a new technique to improve an energy efficiency in development of strong shock wave by using underwater pulsed spark discharges. By preconditioning a water-gap via water electrolysis, hydrogen microbubbles are produced at a cathode, and drift towards the anode during the preconditioning phase. A negatively enhanced electrode pair is adopted to initiate the negative (anode-directed) streamer in the presence of microbubbles near the cathode tip. When a high-voltage pulse is applied to the water-gap just after the end of the preconditioning phase, the overall pre-breakdown process is observed to be remarkably accelerated. Since the reaction rate of the electrolysis depends on the experimental conditions such as water conductivity, hydrostatic pressure, structure of water-gap, and amplitude of preconditioning pulse, it is found that there is an optimum preconditioning duration in terms of energy efficiency for the shock wave generation. More interestingly, it is experimentally demonstrated that the morphology of the underwater streamer significantly influences on the development of shock waves. In particular, the tree-like structure of the negative subsonic streamers is much more advantageous than the volcano-like structure of the conventional positive (cathode-directed) subsonic streamers. That is, it is clearly shown that this technique overcomes the biggest drawback of negative subsonic discharges, i.e. the slow vapor bubble formation due to screening effect, and thus provides a new way to improve the efficiency of shock wave generation by pulsed spark discharges in water. Here, we elucidate the working principle of this technique, and discuss some engineering issues associated with the environmental factors.

Purpose The Health and Prevention Enhancement (H-PEACE) study was designed to investigate the association of diagnostic imaging results, biomarkers and the predisease stage of non-communicable diseases (NCDs), such as malignancies and metabolic diseases, in an average-risk population in Korea. Participants This study enrolled a large-scale retrospective cohort at the Healthcare System Gangnam Center, Seoul National University Hospital, from October 2003 to December 2014. Findings to date The baseline and follow-up information collected in the predisease stage of NCDs allows for evaluation of an individual’s potential NCD risk, which is necessary for establishing personalised prevention strategies. A total of 91 336 health examinees were included in the cohort, and we repeatedly measured and collected information for 50.9% (n=46 484) of the cohort members. All participants completed structured questionnaires (lifestyle, medical history, mini-dietary assessment index, sex-specific variables and psychiatric assessment), doctors’ physical examinations, laboratory blood and urine tests and digital chest X-ray imaging. For participants with available data, we also obtained information on specific diagnostic variables using advanced diagnostic tests, including coronary CT for coronary calcium scores, colonoscopy and brain MRI. Furthermore, 17 455 of the participants who provided informed consent and donated blood samples were enrolled into the Gene-environmental interaction and phenotype study, a subcohort of the H-PEACE, from October 2013, and we analysed genome-wide single-nucleotide polymorphism array data for 6579 of these blood samples. Future plans The data obtained from this cohort will be used to facilitate advanced and accurate diagnostic techniques related to NCDs while considering various phenotypes. Potential collaborators can access the dataset after receiving approval from our institutional review board. Applications can be submitted on the study homepage (http://en-healthcare.snuh.org/HPEACEstudy).

Background The ongoing Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) aims to observe the natural course of papillary thyroid microcarcinoma (PTMC), develop a protocol for active surveillance (AS), and compare the long-term prognosis, quality of life, and medical costs between the AS and immediate surgery groups. Methods This multicenter prospective cohort study of PTMC started in June 2016. The inclusion criteria were suspicious of malignancy or malignancy based on fine needle aspiration or core needle biopsy, age of ≥18 years, and a maximum diameter of ≤1 cm. If there was no major organ involvement, no lymph node/distant metastasis, and no variants with poor prognosis, the patients were explained of the pros and cons of immediate surgery and AS before selecting AS or immediate surgery. Follow-up visits (physical examination, ultrasonography, thyroid function, and questionnaires) are scheduled every 6 months during the first 2 years, and then every 1 year thereafter. Progression was defined as a maximum diameter increase of ≥3, ≥2 mm in two dimensions, suspected organ involvement, or lymph node/distant metastasis. Results Among 439 enrolled patients, 290 patients (66.1%) chose AS and 149 patients (33.9%) chose immediate surgery. The median follow-up was 6.7 months (range, 0.2 to 11.9). The immediate surgery group had a larger maximum tumor diameter, compared to the AS group (7.1±1.9 mm vs. 6.6±2.0 mm, respectively; P=0.014). Conclusion The results will be useful for developing an appropriate PTMC treatment policy based on its natural course and risk factors for progression.

Previous observational studies have suggested that metformin in diabetes patients may reduce breast cancer risk more than the reductions from other anti-diabetes medications. This randomized, double-blind, placebo-controlled trial was performed to evaluate the efficacy of metformin for controlling physical and metabolic profiles related to prognosis and adverse events in non-diabetic breast cancer patients. Female breast cancer patients (N = 105), at least 6 months post-mastectomy, with obesity (≥25 kg/m(2)) and/or pre-diabetes (fasting blood sugar levels ≥100 mg/dL), were randomly assigned to three groups (placebo, metformin 500 mg, and metformin 1000 mg) stratified by tamoxifen use. A linear mixed model for repeated measurements among three groups and ANOVA for profile differences during 6 months of treatment were used for the intention-to-treat analysis. The metformin 1000 mg group had a significantly greater decline in glucose and HbA1c levels between treatment weeks 0 and 6 month (p = 0.008 and 0.009, respectively), and the declines increased with an increase in body mass index (BMI) level (p interaction with BMI = 0.007 and 0.067, respectively). A marginally significant different effect from the metformin 1000 mg treatment was detected for glucose and HbA1c levels (p interaction = 0.084 and 0.063, respectively) in the intention-to-treat analysis. Metformin 1000 mg treatment had a favorable effect on controlling glucose and HbA1C levels in obese non-diabetic breast cancer patients, indicating prognostic importance. Further trials are needed to elucidate the risk-benefit ratio of long-term use of metformin.

Transition of thermodynamic behavior for the electrons in a magnetically expanding collisionless plasma is experimentally observed by local measurement using an axially movable cylindrical Langmuir probe. The polytropic indexes which are deduced from the correlations among the plasma potential, effective electron temperature, and electron density seem to have a quite different value of $3 \pm 0.2$ and $1.17 \pm 0.03$ near the nozzle throat and far from the nozzle, respectively. The transition of polytropic index can be explained by a theoretical calculation of effective polytropic index depending on the double-adiabatic laws and the thermal energies for magnetized anisotropic plasmas1. The results show that the significant electron cooling near the nozzle throat is caused by nearly one-dimensional adiabatic expansion along almost parallel strong magnetic field. With increasing the distance from the nozzle throat, the magnetic field strength decreases and the electron cooling rate is also decreased. The present study demonstrates that a sufficiently high and nearly longitudinal magnetic field configuration can enhance the electron cooling near the nozzle throat significantly. It also means that the ion acceleration can be enhanced through high potential drop generated by high electron cooling rate. Ion demagnetization is correlated with the change in the thermodynamic property of electrons along the distance from the magnetic nozzle.

Aim. The incidence of thyroid cancer is increasing worldwide. The prevalence of type 2 diabetes mellitus (T2DM) is also increasing. Therefore, we aimed to analyze the effect of T2DM on thyroid cancer. Methods. A case-control study was performed. A total of 415 healthy controls with thyroid ultrasound screening and physician consultation were selected from the Thyroid Cancer Longitudinal Study (T-CALOS). Among patients with thyroid cancer who were enrolled in T-CALOS, 415 patients were matched to the control group according to age and sex. We assessed the effects of T2DM, T2DM duration, and T2DM medication on thyroid cancer. Results. Women with T2DM had lower odds of thyroid cancer than women without T2DM (odds ratio [OR]: 0.40, 95% confidence interval [CI]: 0.20–0.81). Individuals receiving T2DM medication had higher odds of thyroid cancer compared to those without T2DM medication (OR: 5.21, 95% CI: 1.58–17.15). Individuals with T2DM duration Conclusions. Individuals with early T2DM are presumed to have a low incidence of thyroid cancer, and this effect seems to last up to 6 years after diagnosis of T2DM.

스크린 공막힘에 의하여 채수량이 감소된 지하수 관정은 여러 방법을 통하여 재생시켜주면 지하수 채수량을 개선시켜 관정의 수명을 연장할 수 있다. 본 논문에서는 화약이나 압축 유체를 사용하는 기존의 공막힘 재생기술을 대신할 수 있는 고전압 펄스 방전에 의한 지하수 관정 스크린 공막힘의 재생법에 대하여 연구하였다. 본 기술은 수중에 삽입된 전극에 순간적으로 고전압의 전기에너지를 주입하여 이 때 전극 사이에서 발생하는 고온, 고압의 플라즈마의 팽창력에 의하여 발생하는 수중 충격파를 이용하는 기술로, 기존 기술 대비 취급이 용이하며 구조가 간단하고 충격압의 크기 조절이 용이하다는 장점을 갖는다. 본 연구에서는 축전기 방전형 펄스 발생장치를 사용하여 약 200 J의 전기에너지를 수중에 삽입된 전극에 순간적으로 주입함으로써 전극으로부터 6cm 떨어진 곳에서 약 10.7 MPa의 수중 충격압을 얻었다. 이 충격압의 크기는 축전기의 충전 전압을 바꿔줌으로써 손쉽게 조절이 가능하였으며, 다양한 전압에서의 실험을 통하여 방전 전류의 첨두치와 선형적인 관계를 갖고 있음을 알았다. 또한 지하수 관정에 사용되는스크린과 유사한 시료에 대한 모의실험을 통하여 이 기술을 이용한 지하수 관정의 세척 가능성을 확인하였다.주요어 : 지하수 재생, 스크린 공막힘, 수중 충격압, 펄스 방전The application of appropriate rehabilitation methods can improve the efficiency of clogged wells and extend their life.In this paper, we study the feasibility of well cleaning using high-voltage pulsed discharge, in which electrical energy isused to produce impulsive pressure in water, in contrast to conventional methods that employ chemical or pneumaticenergy sources. This technique utilizes the compressive shock wave generated by the expansive force of hot, dense plasmathat is produced during a pulsed discharge in the gap between electrodes immersed in water. Compared with conventionaltechniques, this method is simple, and easy to handle and control. Using a capacitive pulsed power system with an elec-trical energy of 200 J, an impulsive pressure of 10.7 MPa is achieved at the position 6 cm away from the discharge gap.The amplitude of the impulsive pressure was easily controlled by adjusting the charging voltage of the capacitor and wasalmost linearly proportional to peak discharge current. The technique achieved good results in cleaning feasibility testswith mock-up specimens similar to clogged well screens.

Sir,Mortazavi and co-authors have given two insightful comments on our paper “Association between Exposure to Smartphones and Ocular Health in Adolescents,” which we examined thoroughly. We appreci...

A time-transient simulation code for analyzing underwater wire explosion driven by a pulsed capacitive discharge is developed. It solves a circuit equation coupled with one-dimensional magneto-hydrodynamic equations with the help of appropriate wide-range equation of state (EOS) and electrical conductivity for copper. A modified quotidian EOS model1 is further improved to include the liquid-vapor phase transition which is critical for the generation of shock waves by wire explosion. For the electrical conductivity of copper, a semi-empirical set of equations covering from solid to strongly coupled, partially ionized plasma state2 is utilized. With an appropriate tuning of coefficients appeared in the equation set, an excellent agreement with the experimental results is obtained in terms of temporal motions of a plasma channel boundary and a shock front as well as current and voltage waveforms. It is found that the strength of shock wave generated by wire explosion is greatly influenced by a diameter of the wire and the peak pressure is proportional to the current value at the time of voltage peak irrespective of operating conditions. The numerical model presented in this paper will be utilized not only to optimize the wire explosion system for generating strong shock waves, but also to investigate thermophysical and transport properties of non-ideal plasmas.

Supplemental Digital Content is available in the text, We conducted a heterogeneous risk assessment of breast cancer based on the hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) calculating the risks and population-based attributable fractions (PAFs) for modifiable and nonmodifiable factors. Using matched case–control study design from the Seoul Breast Cancer Study and the national prevalence of exposure, the risks and PAFs for modifiable and nonmodifiable factors were estimated for total breast cancers and subtypes. The attribution to modifiable factors was different for each subtype (luminal A, PAF = 61.4% [95% confidence interval, CI = 54.3%–69.8%]; luminal B, 21.4% [95% CI = 18.6–24.9%]; HER2-overexpression, 59.4% [95% CI = 47.8%–74.3%], and triple negative tumors [TNs], 27.1% [95% CI = 22.9%–32.4%)], and the attribution to the modifiable factors for the luminal A and HER2-overexpression subtypes was higher than that of the luminal B and TN subtypes (P heterogeneity ≤ 0.001). The contribution of modifiable reproductive factors to luminal A type in premenopausal women was higher than that of the other subtypes (18.2% for luminal A; 3.1%, 8.1%, and −3.1% for luminal B, HER2-overexpression, and TN subtypes, respectively; P heterogeneity ≤ 0.001). Physical activity had the highest impact preventing 32.6% of luminal A, 14.5% of luminal B, 38.0% of HER2-overexpression, and 26.9% of TN subtypes (P heterogeneity = 0.014). Total reproductive factors were also heterogeneously attributed to each breast cancer subtype (luminal A, 65.4%; luminal B, 24.1%; HER2-overexpression, 57.9%, and TN subtypes, −3.1%; P heterogeneity ≤ 0.001). Each pathological subtype of breast cancer by HRs and HER2 status may be associated with heterogeneous risk factors and their attributable risk, suggesting a different etiology. The luminal B and TN subtypes seemed to be less preventable despite intervention for alleged risk factors, even though physical activity had a high preventable potential against breast cancer.

Supplemental Digital Content is available in the text, We evaluated the association between weight change in middle-aged adults and papillary thyroid cancer (PTC) based on a large-scale case-control study. Our study included data from 1551 PTC patients (19.3% men and 80.7% women) who underwent thyroidectomy at the 3 general hospitals in Korea and 15,510 individually matched control subjects. The subjects’ weight history, epidemiologic information, and tumor characteristics confirmed after thyroidectomy were analyzed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined for the annual average changes in weight and obesity indicators (body mass index (BMI), body surface area, and body fat percentage (BF%) in subjects since the age of 35 years. Subjects with a total weight gain ≥10 kg after age 35 years were more likely to have PTC (men, OR, 5.39, 95% CI, 3.88–7.49; women, OR, 3.36, 95% CI, 2.87–3.93) compared with subjects with a stable weight (loss or gain

Source: doi: 10.1371/journal.pone.0151562 Background: This study evaluated the effects of acute high-dose and chronic lifetime exposure to alcohol and exposure patterns on the development of differentiated thyroid cancer (DTC). Methods: The Thyroid Cancer Longitudinal Study (T-CALOS) included 2,258 DTC patients (449 men and 1,809 women) and 22,580 healthy participants (4,490 men and 18,090 women) who were individually matched by age, gender, and enrollment year. In-person interviews were conducted with a structured questionnaire to obtain epidemiologic data. Clinicopathologic features of the patients were obtained by chart reviews. Odds ratios (ORs) and 95% confidence intervals (95%CI) were estimated using conditional regression models. Results: While light or moderate drinking behavior was related to a reduced risk of DTC, acute heavy alcohol consumption (151 g or more per event or on a single occasion) was associated with increased risks in men (OR = 2.22, 95%CI = 1.27–3.87) and women (OR = 3.61, 95%CI = 1.52–8.58) compared with never-drinkers. The consumption of alcohol for 31 or more years was a significant risk factor for DTC for both men (31–40 years: OR = 1.58, 95%CI = 1.10– 2.28; 41+ years: OR = 3.46, 95%CI = 2.06–5.80) and women (31–40 years: OR = 2.18, 95%CI = 1.62–2.92; 41+ years: OR = 2.71, 95%CI = 1.36–5.05) compared with never-drinkers. The consumption of a large amount of alcohol on a single occasion was also a significant risk factor, even after restricting DTC outcomes to tumor size, lymph node metastasis, extrathyroidal extension and TNM stage. Conclusion: The findings of this study suggest that the threshold effects of acute high-dose alcohol consumption and long-term alcohol consumption are linked to an increased risk of DTC.

A D–D neutron generator was developed with an intensity of 108 n/s. A helicon plasma ion source was used to produce a large current deuteron beam, and neutrons were generated by irradiating the deuteron beam on a titanium drive-in target made of commercial pure titanium. The neutron generator was test-run for several hundred hours, and the performances were investigated. The available range of the deuteron beam current was 0.8–8 mA and the beam could be accelerated up to 97.5 keV. The maximum neutron generation rate in the test-runs was 1.9 × 108 n/s, which was achieved by irradiating a 7.6 mA deuteron beam at 94.0 keV on a 0.5 mm-thick target. The operation of the neutron generator was fairly stable, such that the neutron generation rate was not altered by high voltage breakdowns during the test-runs. Neutron generation efficiency was rated as low as 10% when compared to an ideal case of irradiating a 100% monatomic deuteron beam on a perfect TiD2 target. Factors causing the low efficiency were suggested and discussed.

Context: Previous studies on the extent to which radioactive iodine (RAI) therapy for thyroid cancer increases the risk of subsequently developing breast cancer have given conflicting results. Objective: This study aimed to evaluate the effect of RAI treatment on breast cancer development and recurrence among female patients with primary thyroid cancer. Design: This was a retrospective cohort study. The risk of subsequent breast cancer associated with RAI and its dose in hazard ratios (HRs) with 95% confidential intervals (CIs) were calculated using time-dependent Cox proportional hazard models. Patients: A total of 6150 patients with thyroid cancer enrolled between 1973 and 2009 were followed until December 2012. Of these, 3631 (59.0%) received RAI therapy. During the follow-up period, 99 primary breast cancers were diagnosed. Main Outcome Measure: Risk of breast cancer development according to RAI therapy and RAI dose during treatment for primary thyroid cancer. Results: RAI therapy did not significantly increase the incidence of subsequent breast cancer among female patients (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.22–1.06) when a 2-year latency period was accounted for. High-dose RAI (≥120 mCi) was associated with a reduced incidence of subsequent breast cancer (HR, 0.17; 95% CI, 0.05–0.62) in the cohort with a 2-year latency period. Conclusions: The long-term follow-up results of this study suggest that RAI treatment for patients with thyroid cancer may not increase the risk or recurrence of breast cancer.