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Radiation hardness tests were conducted on a silicon detector and preamplifier to develop a reactor coolant leakage monitoring system, which detects high-energy beta particles from 16N in the primary reactor coolant of nuclear power plants. Monte Carlo simulations were used to calculate the doses that would be absorbed on components over a 60-year design lifetime. The components were exposed to a 60Co gamma source with an activity of 2.4 kCi for 54 hours. The absorbed doses accumulated during the test were determined to be 0.99 kGy for the detector and 1.37 kGy for the preamplifier. During the test, the alpha count from a check source in the high-channel range disappeared in a high-dose-rate environment, and the gross gamma count decreased as the accumulated dose increased. The performance degradation of the detector and preamplifier was evaluated by comparing the alpha signals and background noise before and after irradiation. The energy resolution of the alpha signals in the high-channel range exhibited slight changes, whereas the electronic noise in the low-channel range increased by approximately 773 % for the irradiated detector and 17 % for the irradiated pre-amp. A method employing various low-level discriminator channels is proposed to miti-gate noise effects in the monitoring system.

We investigated the effect of differential blood pressure (BP) levels on future end-stage renal disease (ESRD) in patients with type 2 diabetes mellitus (T2DM) and established coronary artery disease with a previous record of percutaneous coronary intervention (PCI). Using health check-up data from the Korean National Health Insurance Service (2015–2016), we analyzed 80,187 T2DM patients with a history of PCI. Patients were categorized by BP levels measured: systolic BP < 120, 120–129 (reference), 130–139, 140–149, and ≥150 mmHg; diastolic BP < 70, 70–79 (reference), 80–89, and ≥90 mmHg. Incident ESRD, defined by disease codes and renal replacement therapy initiation, was the primary outcome. Multivariate Cox proportional hazard regression assessed adjusted hazard ratios (HRs) (95% confidence intervals) by BP group. Mean age was 67.7 years; 80.9% used antihypertensives. ESRD incidence was 1.70% (1,362 patients) over 4.7 years. After adjustment for confounding factors, the HR of ESRD patients significantly and sequentially increased in the higher BP groups. Similar trends were seen with pulse pressure (PP). Subgroup analysis showed stronger BP-ESRD association in < 65-year-olds compared to those aged ≥65 years. ESRD risk linearly increased with systolic BP and had a J-shaped association with diastolic BP, with the lowest risk at 68 mmHg. Elevated BP, including PP, correlated with ESRD risk in a dose‒response manner among T2DM patients with a previous record of PCI. Strict BP control is crucial for preventing ESRD in these high-risk patients. [ABSTRACT FROM AUTHOR]

Background: Intermediate lesions (ILs) present challenges in making therapeutic decisions. This study aimed to determine the practical coronary angiographic predictors for revascularization in patients with ILs who underwent repeated angiograms. Methods: This study was a retrospective single-center study. The study subjects were divided into two groups according to their target lesion revascularization (TLR) during the follow-up period: the TLR (+) group (n = 135, 30.9%) and the TLR (−) group (n = 302, 69.1%). We evaluated the angiographic characteristics of ILs such as the presence of branches, luminal irregularity, tortuosity, ulcer/erosion, haziness, and calcification in the ILs, with an average follow-up of 34.2 ± 32.0 months. Results: The TLR (+) group had higher percentage of diameter stenoses (47.3 ± 13.5% vs. 44.2 ± 12.2%, p = 0.006) than the TLR (−) group, whereas the lesion length of the ILs showed no significant differences between the two groups. The prevalence of branches (79.0% vs. 69.1%, p = 0.018) and haziness (4.3% vs. 2.6%, p < 0.001) was higher in the ILs of the TLR (+) group than those of the TLR (−) group. Therefore, the angiographic predictors for the TLR of ILs were haziness (hazard ratio = 2.126, 95% confidence interval = 1.240–3.644, p = 0.006) and % diameter stenosis (DS) ≥ 60% (hazard ratio = 1.025, 95% confidence interval = 1.013–1.037, p < 0.001). Conclusions: Angiographic haziness and % DS > 60% were the independent angiographic predictors for TLR in patients with ILs. Our study is the first to present the angiographic findings of vulnerable plaques of ILs. Further studies such as intravascular imaging or physiologic studies should be strongly considered before making treatment decisions in ILs when such angiographic features are observed. [ABSTRACT FROM AUTHOR]

Background/Objectives: To date, population pharmacokinetic (PK) studies of vancomycin on healthy Korean adults have not been conducted. This study aimed to investigate the PK properties of vancomycin in healthy volunteers and to identify optimal dosing regimens based on the area under the concentration–time curve (AUC) in adult patients with normal renal function. Methods: We conducted a prospective clinical study, analysing PK samples from 12 healthy participants using noncompartmental analysis and non-linear mixed-effects modelling. The population PK parameters derived were employed in Monte Carlo simulations to evaluate the adequacy of the current dosing regimen and to formulate dosing recommendations. Results: The PK profiles were optimally described by a two-compartment model, with body weight and age as significant covariates affecting total clearance. The simulations indicated that to achieve a therapeutic target—defined as an AUC at steady-state over 24 h of 400–600 mg·h/L—daily doses ranging from 60 to 70 mg/kg are necessary in adults with normal renal function. Conclusions: This study underscores the need to actively adjust dosage and administration based on a vancomycin PK model that adequately reflects the demographic characteristics of patients to meet both safety and efficacy standards. [ABSTRACT FROM AUTHOR]