The elevated aldosterone in primary aldosteronism (PA) is associated with increased insulin resistance and prevalence of diabetes mellitus (DM). Both aldosterone excess and DM lead to left ...ventricular (LV) pathological remodeling. In this study, we investigated the impact of DM on LV non-hemodynamic remodeling in patients with PA. We enrolled 665 PA patients, of whom 112 had DM and 553 did not. Clinical, biochemical, and echocardiographic data were analyzed at baseline and 1 year after adrenalectomy. LV non-hemodynamic remodeling was represented by inappropriate excess left ventricular mass index (ieLVMI), which was defined as the difference between left ventricular mass index (LVMI) and predicted left ventricular mass index (pLVMI). Propensity score matching (PSM) was used with age, sex, systolic, and diastolic blood pressure to adjust for baseline variables. After PSM, the patient characteristics were balanced between the DM and non-DM groups, except for fasting glucose, HbA1c, and lipid profile. A total of 111 DM and 419 non-DM patients were selected for further analysis. Compared to the non-DM group, the DM group had significantly higher ieLVMI and LVMI. After multivariable linear regression analysis, the presence of DM remained a significant predictor of increased ieLVMI. After adrenalectomy, ieLVMI decreased significantly in the non-DM group but not in DM group. The presence of DM in PA patients was associated with more prominent non-hemodynamic LV remodeling and less recovery after adrenalectomy.
Proton accelerators in the energy range of approximately 200MeV have become increasingly popular for cancer treatment in recent years. These proton therapy facilities usually involve bulky concrete ...or iron in their shielding design or accelerator structure. Simple shielding data, such as source terms or attenuation lengths for various proton energies and materials are useful in designing accelerator shielding. Understanding the appropriateness or uncertainties associated with these data, which are largely generated from Monte Carlo simulations, is critical to the quality of a shielding design. This study demonstrated and investigated the problems of deep-penetration calculations on the estimation of shielding parameters through an extensive comparison between the FLUKA and MCNPX calculations for shielding against a 200-MeV proton beam hitting an iron target. Simulations of double-differential neutron production from proton bombardment were validated by comparison with experimental data. For the concrete shielding, the FLUKA calculated depth–dose distributions were consistent with the MCNPX results, except for some discrepancies in backward directions. However, for the iron shielding, if FLUKA is used inappropriately then overestimation of neutron attenuation can be expected as shown by this work because of the multigroup treatment for low-energy neutrons in FLUKA. Two neutron energy group structures, three degrees of self-shielding correction, and two iron compositions were considered in this study. Significant variation of the resulting attenuation lengths indicated the importance of problem-dependent multigroup cross sections and proper modeling of iron composition in deep-penetration calculations.
Objective: Cardiac remodeling is a critical pathological manifestation in primary aldosteronism (PA) attributed to excessive aldosterone secretion. The plasma aldosterone concentration (PAC) ...following the captopril suppression test (CCT) may serve as an indicator of unregulated aldosterone and could potentially offer improved predictive value for cardiovascular outcomes. This study aimed to explore the association between nadir aldosterone levels post-CCT and left ventricular remodeling as well as diastolic dysfunction. Design and method: We conducted a retrospective analysis of PA patients within the TAIPAI (Taiwan Primary Aldosteronism Investigation) cohort with complete baseline and post-CCT plasma renin activity (PRA), PAC, aldosterone-to-renin ratio (ARR), and echocardiography data for further investigation. Results: A total of 540 patients were included in the study. Among baseline and post-CCT PRA, PAC, and ARR, post-CCT PAC exhibited the strongest correlation with left ventricular mass index (LVMI) and diastolic dysfunction (E/e’). In multivariable regression analysis, post-CCT PAC emerged as an independent predictor of LVMI (beta: 24.6, 95% CI: 9.6 to 39.5, P=0.001) and diastolic dysfunction (beta: 1.9, 95% CI: 0.5 to 3.3, P=0.006). Restricted cubic spline analysis revealed significant correlations between both baseline and post-CCT PAC with LVMI, whereas only post-CCT PAC exhibited a significant correlation with diastolic function. Conclusions: Plasma aldosterone concentration following CCT, reflective of unregulated aldosterone excess, is significantly associated with left ventricular hypertrophy and diastolic dysfunction. PA patients with elevated post-CCT PAC may face increased cardiovascular risks, underscoring the importance of timely and appropriate management.
This work aims to measure different components of natural background radiation on a train. A radiation measurement system consisting of four types of radiation detectors, namely, a Berkeley Lab ...cosmic-ray detector, moderated (3)He detector, high-pressure ionisation chamber and NaI(Tl) spectrometer, associated with a global positioning system unit was established for this purpose. For the commissioning of the system, a test measurement on a train along the railway around the northern Taiwan coast from Hsinchu to Hualien with a distance of ∼ 275 km was carried out. No significant variation of the intensities of the different components of natural background radiation was observed, except when the train went underground or in the tunnels. The average external dose rate received by the crew of the train was estimated to be 62 nSv h(-1).
Intravascular brachytherapy (IVBT) has been recognised as a treatment modality for reducing coronary restenosis after angioplasty and stent-implantation procedures. For the treatment of in-stent ...restenosis using beta-emitter 188Re, delivering adequate doses to the entire vessel wall is not possible without the potential of overdosing tissues. A method to measure the dose distribution, perturbation and percentage depth dose using plane-parallel and cylindrical tissue-equivalent phantoms has been developed. Good agreement was found between experimental results and Monte Carlo simulation performed using MCNP4C code. The dose given to the affected area in the vascular region for intravascular radiation treatment was 15–30 Gy. Dose inhomogeneity beyond the stent surface decreased significantly with increasing radial distance. In the region close to the stent outer surface (>0.5-mm radial distance), a dose reduction of 11–17% due to the stent was observed. However, the dose perturbations due to the physical properties of metallic stents were found to be significant in IVBT for in-stent restenosis by using measured dose profiles in phantoms. The method can provide accuracy in beta isotope in vivo dosimetry results for treatments involving short-range dose distributions and provide a relatively high-level spatial resolution for detection.
The National Radiation Standard Laboratory of the Institute of Nuclear Energy Research (INER) designed and constructed an improved Attix style free-air ionisation chamber (FAC) for low-energy X-ray ...measurements. Clinically, X rays in this energy range are used in mammography radiology. This chamber is also used to perform air-kerma measurements. The original Attix two-sectional design was redesigned by INER using the piston design. The correction factors were determined experimentally for volume estimation, ion recombination and air attenuation. The aperture transmission, wall transmission, electron loss and photon scatter correction factors were determined using Monte Carlo calculations. INER established the Bureau International des Poids et Mesures (BIPM) X-ray beam code and performed a comparison of secondary standard air-kerma calibration factors for 10–50 kV low- energy X rays to verify the experimental accuracy and measurement consistency of the improved chamber. The INER–NMIJ/National Institute of Advanced Industrial Science and Technology (AIST) experimental results comparison using a transfer chamber yielded a difference <1.0% at the 95% confidence level in calibration factors. The overall uncertainty for the X-ray measurement in terms of air kerma was <0.6% at the 95% confidence level. These results indicated that the improved FAC is capable of serving as a primary standard as well as a trace standard in low-energy X-ray calibration services in Taiwan and even forming a basis for the future mammography X-ray air-kerma primary standard.
Cloud computing has become one of the most significant issues in recent years. Those associative applications and services based on cloud computing are dramatically emerging. However, in order to ...enjoy the widely utilization of cloud computing through wired/wireless networking, providing sufficient assurance of information security such as confidentiality, authentication, non-repudiation, and integrity is the critical factor of success promotion. In this paper, a dynamic intrusion detection system for strengthening the security application of cloud computing is proposed. In the proposed mechanism, numbers of intrusion detectors are dispatched on the whole topology of the networking system through multi-layers and multi-stages deployment. Those information security issues related with the application and service of cloud computing will be experimented and discussed. The experiments include the equipment security of the client side termination, the threats of web site and webpage, the detection and diagnosis and surveillance of intrusion, the access and security of database in the cloud side, the detection of system leakage and the monitor of real-time repairing process, the management of server system, the management of mobile e-commerce processing, and the integrated analysis of associated security information and issues. The goal of the proposed mechanism is not only focused on find out some solutions, but also focused on develop some feasible information security techniques or products for the application and service of cloud computing. Experimental results demonstrate that the proposed mechanism does provide good performance for intrusion detection.
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