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"Jung, Yujung"
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Thermodynamic Feasibility Evaluation of Alkaline Thermal Treatment Process for Hydrogen Production and Carbon Capture from Biomass by Process Modeling
2024
Hydrogen is attracting attention as a low-carbon fuel. In particular, economical hydrogen production technologies without carbon emissions are gaining increasing attention. Recently, alkaline thermal treatment (ATT) has been proposed to reduce carbon emissions by capturing carbon in its solid phase during hydrogen production. By adding an alkali catalyst to the conventional thermochemical hydrogen production reaction, ATT enables carbon capture through the reaction of an alkali catalyst and carbon. In this study, a thermodynamic feasibility evaluation was carried out, and the effects of the process conditions for ATT with wheat straw grass (WSG) as biomass were investigated using Aspen Plus software V12.1. First, an ATT process model was developed, and basic thermodynamic equilibrium compositions were obtained in various conditions. Then, the effects of the process parameters of the reactor temperature and the mass ratio of NaOH/WSG (alkali/biomass, A/B value) were analyzed. Finally, the product gas compositions, process efficiency, and amount of carbon capture were evaluated. The results showed that the ATT process could be an efficient hydrogen production process with carbon capture, and the optimal process conditions were a reactor temperature of 800 °C, an A/B value of three, and a flow rate of steam of 6.9 × 10−5 L/min. Under these conditions, the maximum efficiency and the amount of carbon dioxide captured were 56.9% and 28.41 mmol/g WSG, respectively.
Journal Article
Identification of Eupatilin from Artemisia argyi as a Selective PPARα Agonist Using Affinity Selection Ultrafiltration LC-MS
by
Kim, Su-Nam
,
Choi, Yongsoo
,
Jung, Yujung
in
Artemisia - chemistry
,
Artemisia argyi
,
Cell Line
2015
Peroxisome proliferator-activated receptors (PPARs) are key nuclear receptors and therapeutic targets for the treatment of metabolic diseases through the regulation of insulin resistance, diabetes, and dyslipidemia. Although a few drugs that target PPARs have been approved, more diverse and novel PPAR ligands are necessary to improve the safety and efficacy of available drugs. To expedite the search for new natural agonists of PPARs, we developed a screening assay based on ultrafiltration liquid chromatography-mass spectrometry (LC-MS) that is compatible with complex samples such as dietary foods or botanical extracts. The known PPARα and/or PPARγ ligands resveratrol and rosiglitazone were used as positive controls to validate the developed method. When applied to the screening of an Artemisia argyi extract, eupatilin was identified as a selective PPARα ligand. A PPAR competitive binding assay based on FRET detection also confirmed eupatilin as a selective PPARα agonist exhibiting a binding affinity of 1.18 μM (IC50). Furthermore, eupatilin activation of the transcriptional activity of PPARα was confirmed using a cell-based transactivation assay. Thus, ultrafiltration LC-MS is a suitable assay for the identification of PPAR ligands in complex matrixes such as extracts of dietary foods and botanicals.
Journal Article
Development and Validation of an Improved HPLC-MS/MS Method for Quantifying Total and Unbound Lenalidomide in Human Plasma
2024
Background/Objectives: This study aimed to develop a fully validated HPLC-MS/MS method for quantifying total and unbound lenalidomide concentrations in human plasma. Methods: Unbound concentrations were measured using plasma ultrafiltrate prepared with Amicon® Centrifugal Filters. Lenalidomide and lenalidomide-d5 (internal standard) were extracted from 50 μL of human plasma using liquid–liquid extraction. Chromatography was conducted with a Halo® C18 column using 0.1% formic acid and methanol (20:80, v/v) as the mobile phase. The mass spectrometer was operated in a positive ion mode with an electrospray ionization interface and multiple reaction monitoring modes. Results: Calibration curves were linear over the range of 5 to 1000 ng/mL (r2 > 0.996) for both the total and unbound lenalidomide. For total lenalidomide concentrations, between-run precision (coefficients of variation) and accuracy were 1.70–7.65% and 94.45–101.10%, respectively. For unbound concentrations, inter-day precision and accuracy were 1.98–10.55% and 93.95–98.48%, respectively. Conclusions: We developed a highly reproducible, sensitive, and efficient bioanalytical method using a smaller volume of plasma sample (50 μL) with a relatively short run time (2.5 min). The proposed analytical method was successfully applied to measure total and unbound lenalidomide concentrations at various time points in multiple myeloma patients with renal impairment.
Journal Article
COVID-19 mRNA Vaccines May Cause False Reactivity in Some Serologic Laboratory Tests, Including Rapid Plasma Reagin Tests
by
Jung, Yujung
,
Wheeler, Bradley
,
Korentzelos, Dimitrios
in
Antiphospholipid syndrome
,
Brief Report
,
Coronaviruses
2022
Abstract
Objectives
Acute viral infections and some vaccines have been shown to increase false positivity in serologic assays. We assessed if the messenger RNA coronavirus disease 2019 (COVID-19) vaccines could cause false reactivity in common serologic assays in a pilot longitudinal cohort.
Methods
Thirty-eight participants with sera available prevaccination, 2 weeks after each vaccine dose, and monthly thereafter for up to 5 months were tested for common infectious disease serologies and antiphospholipid syndrome (APS) serology markers on the BioPlex 2200, Sure-Vue rapid plasma reagin (RPR), and Macro-Vue RPR. Twenty-two participants received the Moderna vaccine and 16 received the Pfizer vaccine.
Results
Most assays had no change in reactivity over the course of the sample draws, including APS markers. Epstein-Barr virus immunoglobulin G (IgG), measles IgG, and rubella immunoglobulin M all had possible false reactivity in one to two participants. RPR tests demonstrated false reactivity, with baseline nonreactive participant samples becoming reactive following vaccination. There were more false reactive participants (7/38) in the BioPlex RPR than in the Sure-Vue (2/38) and Macro-Vue (1/38) tests. All falsely reactive RPR tests were in participants who received the Moderna vaccine.
Conclusions
Serologic assays with results that do not fit the clinical picture following COVID-19 vaccination should be repeated. Effects of false reactivity can last more than 5 months in some assays. In particular, RPR is susceptible to false reactivity, and there is variability among assays. Larger longitudinal studies are needed to determine the incidence and window of false reactivity.
Journal Article
Performance of High Throughput SARS-CoV-2 Antigen Testing Compared to Nucleic Acid Testing
by
Ghumman, Shmyle
,
Hasskamp, Joanne H
,
Wheeler, Sarah E
in
Agreements
,
Antigens
,
Comparative analysis
2023
Abstract
Objective
Independent assessment of SARS-CoV-2 antigen (COV2Ag) tests remains important as varying performance between assays is common. We assessed the performance of a new high-throughput COV2Ag test compared to SARS-CoV-2 nucleic acid amplification tests (NAAT).
Methods
A total of 347 nasopharyngeal samples collected from January to October 2021 were assessed by NAAT as part of standard-of-care testing (CDC LDT or GeneXpert System, Cepheid) and COV2Ag using the ADVIA Centaur CoV2Ag assay (Siemens Healthineers).
Results
Among NAAT positive specimens we found 82.4% agreement and in NAAT negative specimens we found 97.3% agreement (overall agreement 85.6%). In symptomatic persons, COV2Ag agreed with NAAT 90.0% (n = 291), and in asymptomatic persons, 62.5% (n = 56). Agreement between positive NAAT and COV2Ag increased at lower cycle threshold (Ct) values.
Conclusion
The COV2Ag assay exceeded the World Health Organization minimum performance requirements of ≥ 80% sensitivity and ≥ 97% specificity. The COV2Ag assay is helpful for large scale screening efforts due to high-throughput and reduced wait times.
Journal Article
Identification of Eupatilin from Artemisia argyi as a Selective PPARalpha Agonist Using Affinity Selection Ultrafiltration LC-MS
2015
Peroxisome proliferator-activated receptors (PPARs) are key nuclear receptors and therapeutic targets for the treatment of metabolic diseases through the regulation of insulin resistance, diabetes, and dyslipidemia. Although a few drugs that target PPARs have been approved, more diverse and novel PPAR ligands are necessary to improve the safety and efficacy of available drugs. To expedite the search for new natural agonists of PPARs, we developed a screening assay based on ultrafiltration liquid chromatography-mass spectrometry (LC-MS) that is compatible with complex samples such as dietary foods or botanical extracts. The known PPARα and/or PPARγ ligands resveratrol and rosiglitazone were used as positive controls to validate the developed method. When applied to the screening of an Artemisia argyi extract, eupatilin was identified as a selective PPARα ligand. A PPAR competitive binding assay based on FRET detection also confirmed eupatilin as a selective PPARα agonist exhibiting a binding affinity of 1.18 μM (IC50). Furthermore, eupatilin activation of the transcriptional activity of PPARα was confirmed using a cell-based transactivation assay. Thus, ultrafiltration LC-MS is a suitable assay for the identification of PPAR ligands in complex matrixes such as extracts of dietary foods and botanicals.
Journal Article
Trajectories of health-related quality of life in breast cancer patients
2020
Purpose
The purpose of this study was to explore the trajectory of health-related quality of life (HRQoL) and its predictors in breast cancer patients.
Methods
A total of 126 women with newly diagnosed breast cancer provided baseline sociodemographic and medical characteristics and then completed an HRQoL questionnaire along with self-report measures of anxiety, depression, and cancer-related fatigue prior to their first cycle of chemotherapy (baseline), after chemotherapy completion, and at 6, and 12 months after chemotherapy completion. Group-based trajectory models were constructed to identify HRQoL trajectories over time. Logistic regression analysis was used to evaluate predictors of HRQoL in distinct patient groups.
Results
Group-based trajectory modeling classified two patient groups: participants with consistently medium overall HRQoL trajectories (41.1%) and participants with consistently low overall HRQoL trajectories (58.9%). Older age, perceived severe economic burden, and higher depression predicted consistently low overall HRQoL through 12 months after chemotherapy.
Conclusions
Less than half of the total number of patients maintained a medium level of overall HRQoL after diagnosis and treatment of breast cancer, and nearly 60% continued to have lower overall HRQoL even after the treatment was complete. Older participants with more severe economic burden and higher depression experienced lower and more persistent overall HRQoL; thus, these patients should be monitored and provided supportive care as a part of survivorship care.
Journal Article
Temporal trends in the causes of in-hospital cardiac arrest: a retrospective observational cohort study on the limitations of the current alert system at a tertiary hospital in Korea
2025
ObjectivesIn-hospital cardiac arrest (IHCA) is associated with high mortality and serious neurological sequelae. Although medical alert systems have evolved, the ability of these systems to influence changes in IHCA incidence and aetiology remains limited.DesignsRetrospective observational cohort study.SettingsA single tertiary hospital in South Korea, covering tertiary care levels.ParticipantsA total of 1994 adult patients (≥18 years) who experienced 2121 episodes of IHCA between January 2011 and December 2019. Patients with out-of-hospital cardiac arrest, those aged ≤18 years and those with do-not-resuscitate orders were excluded. The mean age of patients was 63.0 years (SD, 14.6); 64.1% were male.InterventionsNot applicable.Main outcome measuresThe incidence and temporal trends of IHCA were stratified by aetiology (cardiac vs non-cardiac). Additional analyses examined changes in arrhythmic versus non-arrhythmic causes over time using Poisson regression.ResultsCardiac arrhythmia was the most common cause of IHCA (314 of 2121, 14.8%; incidence: 0.42/1000 admissions), including ventricular tachycardia (n=86), ventricular fibrillation (n=87) and Torsades de Pointes (n=79). Respiratory failure was the second most common cause (266 of 2121, 12.5%; incidence: 0.36/1000 admissions). The incidence of IHCA due to respiratory failure in 2011 was 0.63/1000 admissions, which decreased to 0.20/1000 admissions by 2019 (β=0.883, 95% CI 0.842 to 0.926, p for trend 0.007; Poisson p<0.001). In contrast, the incidence of IHCA due to arrhythmia in 2011 was 0.49/1000 admissions and remained similar over time (0.29/1000 admissions in 2019, β=0.972, 95% CI 0.932 to 1.015, p for trend 0.194; Poisson p=0.198).ConclusionIHCA causes have shown significant temporal shifts. Arrhythmia has become the leading cause of IHCA, with incidences remaining stable, whereas a marked decrease has been observed in respiratory-related IHCA. Therefore, enhanced in-hospital cardiac monitoring systems are required for early detection.
Journal Article
Impact of hospitalization duration before medical emergency team activation: A retrospective cohort study
by
Choi, Eunjoo
,
Choi, Sunhui
,
Hong, Sang-Bum
in
Biology and Life Sciences
,
Cohort analysis
,
Critical care
2021
The rapid response system has been implemented in many hospitals worldwide and, reportedly, the timing of medical emergency team (MET) attendance in relation to the duration of hospitalization is associated with the mortality of MET patients. We evaluated the relationship between duration of hospitalization before MET activation and patient mortality. We compared cases of MET activation for early, intermediate, and late deterioration to patient characteristics, activation characteristics, and patient outcomes. We also aimed to determine the relationship, after adjusting for confounders, between the duration of hospitalization before MET activation and patient mortality.
We retrospectively evaluated patients who triggered MET activation in general wards from March 2009 to February 2015 at the Asan Medical Center in Seoul. Patients were categorized as those with early deterioration (less than 2 days after admission), intermediate deterioration (2-7 days after admission), and late deterioration (more than 7 days after admission) and compared them to patient characteristics, activation characteristics, and patient outcomes.
Overall, 7114 patients were included. Of these, 1793 (25.2%) showed early deterioration, 2113 (29.7%) showed intermediate deterioration, and 3208 (45.1%) showed late deterioration. Etiologies of MET activation were similar among these groups. The clinical outcomes significantly differed among the groups (intensive care unit transfer: 34.1%, 35.6%, and 40.4%; p < 0.001 and mortality: 26.3%, 31.5%, and 41.2%; p < 0.001 for early, intermediate, and late deterioration, respectively). Compared with early deterioration and adjusted for confounders, the odds ratio of mortality for late deterioration was 1.68 (1.46-1.93).
Nearly 50% of the acute clinically-deteriorating patients who activated the MET had been hospitalized for more than 7 days. Furthermore, they presented with higher rates of mortality and ICU transfer than patients admitted for less than 7 days before MET activation and had mortality as an independent risk factor.
Journal Article
Electrospinning and Partial Etching Behaviors of Core–Shell Nanofibers Directly Electrospun on Mesh Substrates for Application in a Cover-Free Compact Air Filter
2024
The exposure of workers to propylene glycol monomethyl ether acetate (PGMEA) in manufacturing environments can result in potential health risks. Therefore, systems for PGMEA removal are required for indoor air quality control. In this study, core–shell zeolite socony mobil-5 (ZSM-5)/polyvinylpyrrolidone–polyvinylidene fluoride nanofibers were directly electrospun and partially wet-etched on a mesh substrate to develop a cover-free compact PGMEA air filter. The electrospinning behaviors of the core–shell nanofibers were investigated to optimize the electrospinning time and humidity and to enable the manufacture of thin and light air-filter layers. The partial wet etching of the nanofibers was undertaken using different etching solvents and times to ensure the exposure of the active sites of ZSM-5. The performances of the ZSM-5/PVDF nanofiber air filters were assessed by measuring five consecutive PGMEA adsorption–desorption cycles at different desorption temperatures. The synthesized material remained stable upon repeated adsorption–desorption cycles and could be regenerated at a low desorption temperature (80 °C), demonstrating a consistent adsorption performance upon prolonged adsorption–desorption cycling and low energy consumption during regeneration. The results of this study provide new insights into the design of industrial air filters using functional ceramic/polymer nanofibers and the application of these filters.
Journal Article