Journal of the Sri Lanka Association for the Advancement of Science

Molecular docking of potential antifungal compounds from Ulva fasciatamethanolic extract against Pseudopestalotiopsistheae

2025-06-25T04:56:17+00:00

Plant diseases caused by fungal pathogens significantly threaten global food security, accounting for nearly 40% of annual crop losses and incurring over US$220 billion in management costs worldwide. Among these, Pseudopestalotiopsistheae has emerged as notable phytopathogen in Sri Lanka, causing chlorosis in Solanum melongena. Its virulence is largely attributed to the secretion of pectinase enzymes, which degrade plant cell walls and facilitate host colonization. Excessive use of synthetic fungicides to manage such pathogens has led to environmental degradation, health risks, and the emergence of fungicide-resistant strains. Consequently, there is a growing interest in eco-friendly alternatives such as natural products derived from marine organisms. Marine macroalgae, particularly Ulva fasciata, commonly found in Thalpe reef, are known to produce a wide range of bioactive secondary metabolites with antifungal potential. In a previous study, methanolic extract of U. fasciata revealed numerous bioactive compounds with potential antifungal activity. The present studyaimed to evaluate the inhibitory potential of these compounds against the pectinase enzyme of P. theae using molecular docking, a powerful in silico approach for predicting interactions between small molecules and target proteins. The findings are expected to contribute to the development of sustainable, eco-friendly strategies for managing plant diseases, offering a cost-effective alternative to synthetic fungicides.This study highlights the potential of marine bioresources and computational tools in the discovery of novel antifungal agents targeting emerging phytopathogens.

Dosimetric Impact on IMRT Plans of Altering Per Control Point Statistical Uncertainty in Monaco TPS

2025-07-22T06:41:49+00:00

Intensity-Modulated Radiation Therapy (IMRT) uses computer-controlled linear accelerators to deliver precise radiation dose to a benign or malignant tumor or specific areas within the tumor while minimizing the radiation dose to healthy tissues and organs at risk. The purpose of this study is to evaluate the dosimetric impact on IMRT plans of altering the per control point Statistical Uncertainty (SU) from 1% to 6% at intervals of 1% using Monaco Treatment Planning System (TPS) for three different diagnoses. Such as Larynx, Oesophagus, and Prostate. Per control point SU is an important factor to decide dose calculation accuracy and calculation time. In this work, 54 IMRT plans were generated altering the per control point SU as 1%, 2%, 3%, 4%, 5%, and 6% using nine patients for Larynx, Oesophagus, and Prostate. Dosimetric indices; including Conformity Index, Heterogeneity Index, Target Dose (PTV) and Organ At Risk Doses, Dose Calculation Time, Treatment Delivery Results, and Dose Volume Histogram were used to evaluate the generated 54 IMRT plans. There are no significant differences observed in all the dosimetric indices and there is an exponential relationship observed between Dose Calculation Time and per Control Point SU. For IMRT plans, we can accept per Control Point SU from 3% to 4% with reduced and acceptable dose calculation time without compromising the plan quality and deliverability.

Keywords: Radiotherapy, IMRT, dosimetric impact, Per Control Point, Statistical Uncertainty

Development of a Solar-Powered, Automated Water Ionizer Using Graphite-Based Electrodes for Alkaline and Acidic Water Production

2025-07-27T09:20:36+00:00

This study presents the development and automation of a novel water ionizer, designed to produce ionized water with precisely controlled pH levels through an advanced electrolysis process. The primary objective is to generate both alkaline and acidic water for various applications, including sterilization, cleaning, and drinking. With the increasing demand for alkaline water due to its potential human health benefits in reducing oxidative stress caused by free radicals, this research introduces a cost-effective, eco-friendly system that integrates innovative graphite-based electrode materials, automated control mechanisms, and a PV solar power system. These electrodes contribute to cost reduction, while the automation system enables precise regulation of pH levels, significantly enhancing the reliability and user convenience of the ionizer. Additionally, the system is powered by a solar cell setup, optimizing the use of renewable energy and aligning with sustainability goals by reducing dependence on conventional power sources.

Keywords: Water Ionizer, Graphite-Based Electrodes, Electrolysis Automation