Mahidol University's Institutional Repository
คลังสารสนเทศสถาบันของมหาวิทยาลัยมหิดล
"Wisdom Repository You Discover"
To collect Mahidol University's academic publications and intellectual properties more than 39 faculties
To present over 50,000 items of information in digital formats
To make it easy to access to all information at anytime, anywhere
Communities in Mahidol IR
Select a community to browse its collections.
Recent Submissions
Electrical Impedance Tomography Monitoring During Extubation in Critically Ill Children
(2026-02-01) Kit-Anan W.; Vaewpanich J.; Anantasit N.; Kit-Anan W.; Mahidol University
Highlights: What are the main findings? Significant changes observed in key EIT parameters, including ΔEELI, tidal impedance, and global inhomogeneity, were consistently observed across the pre- and post-extubation time points in critically ill children. No extubation failure occurred in this study. Most respiratory and EIT parameters were similar in patients with abnormal compared to normal chest X-ray findings, with differences observed in TID and ODCL immediately after extubation. What are the implications of the main findings? EIT can detect dynamic changes in lung volume and ventilation distribution around extubation in pediatric patients; however, its ability to identify extubation failure could not be evaluated in the absence of failed extubation events. The high rate of prophylactic HFNC/NIV use may influence extubation physiology and should be considered when interpreting EIT trends or designing future pediatric extubation studies. Background: Extubation failure increases morbidity and mortality. Non-invasive ventilation (NIV), including high-flow nasal cannula (HFNC), can reduce reintubation rates. Current practice often involves prophylactic use of NIV post-extubation. Electrical Impedance Tomography (EIT) provides real-time monitoring of pulmonary distribution and ventilation. Recent adult studies suggest that EIT has potential in extubation failure prediction, but evidence in children is limited. Our objectives were to evaluate peri-extubation regional lung volume/distribution and to explore EIT-derived physiological changes and on post-extubation respiratory support patterns in critically ill children. Methods: A prospective observational study included intubated patients aged 1 month to 18 years in the PICU who were intubated for over 24 h. Vital signs and chest EIT were recorded pre-extubation (H0), immediately post-extubation (H1), at 30 min (H2), and at 4 h (H3). Patients were categorized by chest X-ray findings into abnormal or normal groups. Results: Among 209 ventilated patients, 54 were included. End-expiratory lung impedance (∆EELI), tidal impedance (TID), and the global inhomogeneity index (GI) demonstrated significant changes across predefined peri-extubation time points. Thirty-eight (70.4%) patients received HFNC or NIV immediately after extubation. No extubation failures occurred, precluding evaluation of extubation failure predictors. In the subgroup analyzed based on chest X-ray findings, differences in TID and ODCL were observed between patients with normal and abnormal chest X-rays immediately after extubation. Conclusions: The ∆EELI, TID, and GI demonstrated significant changes across predefined peri-extubation time points. In the absence of extubation failure events, the ability of EIT monitoring to evaluate extubation failure could not be assessed. The frequent use of prophylactic NIV support after extubation may have influenced post-extubation physiology.
Optical evaluation of antioxidant activity: a comparison between a spectrophotometer and a homebuilt photometer.
(2025-12-18) Luengviriya P.; Kiatsommart K.; Leelakanok C.; Patumorathai S.; Sibsiri K.; Wangkham T.; Luengviriya P.; Mahidol University
The antioxidant activity of an orange peel extract is determined using a DPPH (2,2-diphenyl-1-picrylhydrazyl) solution. Sample absorption is measured with both a commercial spectrophotometer and a homebuilt photometer equipped with a 525-nm LED. Small, dried pieces of orange peel are extracted using 95% ethanol. Seven DPPH solutions with concentrations ranging from 0.1 to 0.4 mM are measured to establish calibration equations. For the spectrophotometer, absorbance exhibits a linear increase with DPPH concentration at both 517 nm (absorbance peak) and 525 nm (matching the LED in the photometer). In the homebuilt photometer, three piecewise linear fittings for concentration 0.1– 0.4 mM provide a better representation of absorption data compared to a single overall fitting across 0.1–0.4 mM. Different volumes of orange peel extract are added into the DPPH solution (0.4 mM DPPH after mixing) and stored in darkness for 30 minutes before the measurement. In both spectrophotometer and photometer analyses, antioxidant activity increases with the extract volume. Using spectrophotometer measurements as reference, the photometer with piecewise fittings produces significantly lower errors compared to those obtained with overall fitting.
Environmental sustainability indicators in India: Evidence from ecological footprint, load capacity factor, nuclear energy, and human capital
(2026-06-01) Raihan A.; Rahman S.M.; Ridwan M.; Dhar B.K.; Martinho D.; Sarker T.; Raihan A.; Mahidol University
This study examines the challenge of measuring environmental sustainability in India using a multidimensional indicator framework that highlights the roles of nuclear energy and human capital in shaping long-term ecological outcomes. The analysis integrates three complementary indicators, carbon dioxide emissions, ecological footprint, and load capacity factor, which reflect emissions intensity, ecological demand, and regenerative capacity. Grounded in the Environmental Kuznets Curve and Load Capacity Curve hypotheses, the study uses annual data from 1969 to 2023 and applies the autoregressive distributed lag bounds testing approach together with robustness estimations using fully modified ordinary least squares, dynamic ordinary least squares, and canonical cointegration regression to assess both short run and long-run dynamics. The findings support the Environmental Kuznets Curve and Load Capacity Curve in India. Nuclear energy and human capital improve environmental performance, while economic growth and natural gas consumption increase ecological pressure. The study contributes by integrating carbon emissions, ecological footprint, and load capacity factor within a unified empirical framework for India, providing evidence to support energy reform, human capital investment, and sustainability oriented policy design.
Usnic Acid Derivatives as Inhibitors of Mycobacterium tuberculosis Uracil–DNA Glycosylase
(2026-02-01) Filimonov A.S.; Zateeva M.V.; Mechetin G.V.; Luzina O.A.; Eurtivong C.; Sari S.; Endutkin A.V.; Reynisson J.; Volcho K.P.; Salakhutdinov N.F.; Zharkov D.O.; Filimonov A.S.; Mahidol University
Tuberculosis (TB) remains a global health issue exacerbated by spreading drug resistance and lengthy treatment regimens. Targeting bacterial DNA-repair pathways, particularly those counteracting host-generated genotoxic stress, represents a promising strategy to sensitize Mycobacterium tuberculosis to existing antibiotics. Through structure-based virtual screening of a compound library, we identified novel small-molecule inhibitors of M. tuberculosis uracil–DNA glycosylase (MtbUng), an enzyme essential for the repair of DNA damage inflicted by macrophage-produced reactive nitrogen species. Experimental validation revealed that four derivatives of usnic acid, a lichen-derived metabolite, significantly inhibited MtbUng activity, with the most potent compound, OL10-88-1, exhibiting IC50 26 ± 7 µM. Molecular docking suggests that OL10-88-1 inhibits MtbUng by occupying both the active site and the DNA-binding groove, thereby disrupting multiple steps of uracil recognition. The compounds also showed variable inhibitory activity against uracil–DNA glycosylases from Escherichia coli, humans, and vaccinia virus. Our findings establish that the compound could potentially be used in combination therapies to enhance the efficacy of current anti-TB drugs by exploiting the vulnerability of DNA-repair-deficient mycobacteria.
Effects of proteolysis conditions on the chemical properties and peptides associated with hedonic perception in Pomacea canaliculata hydrolysates
(2026-01-01) Rosida D.F.; Priyanto A.D.; Kongpitchitchoke T.; Putra A.Y.T.; Havanapan P.O.; Rosida D.F.; Mahidol University
In this study, Pomacea canaliculata (PC) was hydrolyzed using bromelain and trypsin to generate peptides with desirable taste properties. Hydrolysates were prepared at enzyme-to-substrate (E/S) ratios of 1:10, 1:20, and 1:100 (w/v) for 3–18 h, and analyzed for degree of hydrolysis (DH), total peptide, and amino acid content. The optimal bromelain treatment (E/S 1:10, 15 h) yielded a DH of 48.58%, total peptide content of 8.62 mg/mL, and free amino group content of 85.03 mg/L. Similarly, trypsin hydrolysis (E/S 1:10, 15 h) resulted in a DH of 56.11%, total peptide content of 6.16 mg/mL, and free amino group content of 73.71 mg/L. Sensory evaluation using hedonic testing and principal component analysis (PCA) identified these two conditions as optimal, with peptides contributing to favorable taste attributes. Overall, PC hydrolysate exhibits promising potential as a natural flavor enhancer for food industry applications.