13 research outputs found
Use of the Subcutaneous Triptorelin Stimulation Test for Diagnosis of Central Precocious Puberty
Background: The gold standard gonadotropin-releasing hormone (GnRH) stimulation test uses the response to intravenously injected gonadorelin to diagnose central precocious puberty (CPP). However, gonadorelin is not always readily available. Objective: This study investigated the diagnostic efficacy of the subcutaneous triptorelin test and the optimal blood sampling time for diagnosis of CPP. Methods: This study retrospectively examined the medical records of 220 girls who had undergone either the triptorelin or gonadorelin test and compared their clinical characteristics. We retrospectively compared clinical parameters between girls diagnosed with CPP (n = 111) and idiopathic premature thelarche (IPT) (n = 109) using three different diagnostic methods: the gonadorelin, triptorelin 120 min, and triptorelin 180 min tests. The diagnostic ability of the stimulated luteinizing hormone (LH) concentration in the triptorelin test for CPP was evaluated using receiver operating characteristic (ROC) analysis. Results: The CPP group exhibited higher basal and peak gonadotropin levels, more advanced bone age, and a lower body mass index standard deviation score than the IPT group. In the gonadorelin test group, all girls with CPP exhibited a peak LH response 30â60 min after intravenous gonadorelin injection. In the triptorelin test group, most girls with CPP exhibited a peak LH response 60â180 min after subcutaneous triptorelin injection (n = 68). On the ROC curve, a peak LH concentration of â„ 4.52 IU/L at 120 min had the highest CPP diagnostic accuracy, with sensitivity and specificity of 100% and 95.83%, respectively
Exploring dopantâenhanced ionic conductivity of AgClâdoped Li<sub>7</sub>P<sub>3</sub>S<sub>11</sub> solid electrolytes:Integrating synchrotron Rietveld analysis, DFT, and ANNâbased molecular dynamics approaches
The effectiveness of dualâdoping as a method of improving the conductivity of sulfide solid electrolytes (SEs) is not in doubt; however, the atomicâlevel mechanisms underpinning these enhancements remain elusive. In this study, we investigate the atomic mechanisms associated with the high ionic conductivity of the Li7P3S11 (LPS) SE and its response to Ag/Cl dual dopants. Synthesis and electrochemical characterizations show that the 0.2 M AgClâdoped LPS (Li6.8P3Ag0.1S10.9Cl0.1) exhibited an over 80% improvement in ionic conductivity compared with the undoped LPS. The atomicâlevel structures responsible for the enhanced conductivity were generated by a set of experiment and simulation techniques: synchrotron Xâray diffractometry, Rietveld refinement, density functional theory, and artificial neural networkâbased molecular dynamics simulations. This thorough characterization highlights the role of dual dopants in altering the structure and ionic conductivity. We found that the PS4 and P2S7 structural motifs of LPS undergo transformation into various PSx substructures. These changes in the substructures, in conjunction with the paddleâwheel effect, enable rapid Li migration. The dopant atoms serve to enhance the flexibility of PS4âP2S7 polyhedral frameworks, consequently enhancing the ionic conductivity. Our study elucidates a clear structureâconductivity relationship for the dualâdoped LPS, providing a fundamental guideline for the development of sulfide SEs with superior conductivity
Exploring dopantâenhanced ionic conductivity of AgClâdoped Li<sub>7</sub>P<sub>3</sub>S<sub>11</sub> solid electrolytes:Integrating synchrotron Rietveld analysis, DFT, and ANNâbased molecular dynamics approaches
The effectiveness of dualâdoping as a method of improving the conductivity of sulfide solid electrolytes (SEs) is not in doubt; however, the atomicâlevel mechanisms underpinning these enhancements remain elusive. In this study, we investigate the atomic mechanisms associated with the high ionic conductivity of the Li7P3S11 (LPS) SE and its response to Ag/Cl dual dopants. Synthesis and electrochemical characterizations show that the 0.2 M AgClâdoped LPS (Li6.8P3Ag0.1S10.9Cl0.1) exhibited an over 80% improvement in ionic conductivity compared with the undoped LPS. The atomicâlevel structures responsible for the enhanced conductivity were generated by a set of experiment and simulation techniques: synchrotron Xâray diffractometry, Rietveld refinement, density functional theory, and artificial neural networkâbased molecular dynamics simulations. This thorough characterization highlights the role of dual dopants in altering the structure and ionic conductivity. We found that the PS4 and P2S7 structural motifs of LPS undergo transformation into various PSx substructures. These changes in the substructures, in conjunction with the paddleâwheel effect, enable rapid Li migration. The dopant atoms serve to enhance the flexibility of PS4âP2S7 polyhedral frameworks, consequently enhancing the ionic conductivity. Our study elucidates a clear structureâconductivity relationship for the dualâdoped LPS, providing a fundamental guideline for the development of sulfide SEs with superior conductivity
MODAL CHARACTERISTIC ANALYSIS OF THE APR1400 NUCLEAR REACTOR INTERNALS FOR SEISMIC ANALYSIS
Reactor internals are sensitive to dynamic loads such as earthquakes and flow induced vibration. Thus, it is essential to identify the dynamic characteristics to evaluate the seismic integrity of the structures. However, a full-sized system is too large to perform modal experiments, making it difficult to extract data on its modal characteristics. In this research, we constructed a finite element model of the APR1400 reactor internals to identify their modal characteristics. The commercial reactor was selected to reflect the actual boundary conditions. Our FE model was constructed based on scale-similarity analysis and fluid-structure interaction investigations using a fabricated scaled-down model
Is Hypovitaminosis D Associated with Stress Perception in the Elderly? A Nationwide Representative Study in Korea
Hypovitaminosis D and stress are common problems among the elderly. The aim of this cross-sectional nationally representative study was to evaluate the association between hypovitaminosis D and stress perception using large-scale nationally representative data from the Korea National Health and Nutrition Examination Survey (2012â2013). In our study, a total of 1393 elders (â„65 years old) were included to evaluate the association between hypovitaminosis D and stress perception. Serum 25-hydroxyvitamin D levels were determined using radioimmunoassay, and perceived stress status was assessed by a self-reporting questionnaire. The association between hypovitaminosis D and stress perception according to sex was examined using logistic regression analysis. After multivariate adjustment for sociodemographic and lifestyle factors and comorbidities, hypovitaminosis D was significantly associated with perceived stress (odds ratio, 2.73; 95% confidence interval, 1.10â6.77; p = 0.029) among women; however, this association was not significant among men. Hypovitaminosis D was a risk factor for higher stress perception in older Korean women. Even though the role of vitamin D in stress perception is still unclear, we suggest screening for hypovitaminosis D among the elderly
Effects of a new medical insurance payment system for hospice patients in palliative care programs in Korea
Abstract Background This study investigates the effects of a new medical insurance payment system for hospice patients in palliative care programs and analyzes length of survival (LoS) determinants. Method At the Pusan National University Hospital hospice center, between January 2015 and April 2016, 276 patients were hospitalized with several diagnosed types of terminal stage cancer. This study separated patients into two groups, âoldâ and ânew,â by admission date, considering the new system has been applied from July 15, 2015. The study subsequently compared LoS, total cost, and out-of-pocket expenses for the two groups. Results Overall, 142 patients applied to the new medical insurance payment system group, while the old medical insurance payment system included 134 patients. The results do not show a significantly negative difference in LoS for the new system group (pâ=â0.054). Total cost is higher within the new group (pâ<â 0.001); however, the new system registers lower patient out-of-pocket expenses (pâ<â 0.001). Conclusion The novelty of this study is proving that the new medical insurance payment system is not inferior to the classic one in terms of LoS. The total cost of the new system increased due to a multidisciplinary approach toward palliative care. However, out-of-pocket expenses for patients overall decreased, easing their financial burden
Evaluation of the cardiotoxicity potential of bisphenol analogues in human induced pluripotent stem cells derived cardiomyocytes
The importance of evaluating the cardiotoxicity potential of common chemicals as well as new drugs is increasing as a result of the development of animal alternative test methods using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Bisphenol A (BPA), which is used as a main material in plastics, is known as an endocrine-disrupting chemical, and recently reported to cause cardiotoxicity through inhibition of ion channels in CMs even with acute exposure. Accordingly, the need for the development of alternatives to BPA has been highlighted, and structural analogues including bisphenol AF, C, E, F, and S have been developed. However, cardiotoxicity data for analogues of bisphenol are not well known. In this study, in order to evaluate the cardiotoxicity potential of analogues, including BPA, a survival test of hiPSC-CMs and a dual-cardiotoxicity evaluation based on a multi-electrode array were performed. Acute exposure to all bisphenol analogues did not affect survival rate, but spike amplitude, beat period, and field potential duration were decreased in a dose-dependent manner in most of the bisphenols except bisphenol S. In addition, bisphenols, except for bisphenol S, reduced the contractile force of hiPSC-CMs and resulted in beating arrest at high doses. Taken together, it can be suggested that the developed bisphenol analogues could cause cardiotoxicity even with acute exposure, and it is considered that the application of the MEA-based dual-cardiotoxicity evaluation method can be an effective help in the development of safe alternatives