Malaysian Journal of Science 2022-10-31T12:11:59+08:00 Prof. Dr. Wan Haliza binti Abd Majid Open Journal Systems <p style="text-align: justify;">Malaysian Journal of Science (MJS) is the official peer-reviewed open access journal of the <a href="">Faculty of Science, University of Malaya</a>. Effective from year 2020 onwards, the frequency of regular issues publication is three times a year. MJS is indexed in Scopus, EMBASE, Compendex, GEOBASE, EMBiology, Elsevier BIOBASE, FLUIDEX ,World Textiles, CAB Abstracts, Chemical Abstracts Service Database and ASEAN Citation Index (ACI).</p> <p style="text-align: justify;">MJS is a reputable journal with a growing number of audience, which focuses on current developments in all disciplines of science. The journal publishes original articles, review articles, short communications and case reports that are of importance to the scientific community. </p> <p style="text-align: justify;"><strong>eISSN : 2600-8688<br /></strong><strong><strong>Print ISSN : 1394-3065<br /></strong></strong><strong><strong>Publisher : Faculty of Science, University of Malaya</strong></strong> </p> BIOAUTOGRAPHY, COMBINATION EFFECTS AND PHOTO-ACTIVATED ENZYMATIC RESTRICTION INHIBITORY ACTIVITY OF ANTIMICROBIAL ALKALOIDS FROM GLYCOSMIS PENTAPHYLLA (RETZ.) DC. 2021-08-04T10:48:42+08:00 Nurhaya Md Taib Norazian Mohd Hassan Laina Zarisa Mohd Kamal May Khin Soe <p><em>Glycosmis pentaphylla</em> (Retz.) DC., locally known as nerapan, has long been used in Asian countries as a traditional remedy for ailments attributed to microbial infections. This study aims to isolate antimicrobial alkaloids from <em>G. pentaphylla</em>, to determine their combination effects with selected antimicrobial agents and to screen for their photoactivated enzymatic restriction inhibitory activity. Bioautography-guided isolation of antimicrobial alkaloids was performed by using column chromatography with <em>Staphylococcus aureus</em>, <em>Escherichia coli</em>, and <em>Candida albicans</em> as the indicator microbes. The antimicrobial effects of the alkaloids combined with selected antimicrobial agents, namely, ciprofloxacin, erythromycin, vancomycin, and ketoconazole, were determined by using a checkerboard assay. Photoactivated enzymatic restriction inhibitory activity was assessed by using agarose gel electrophoresis. Two antimicrobial active alkaloids were isolated and identified as arborinine and arborine. The antimicrobial activity of arborinine and arborine was determined to be in the range of 250 µg/ml and 1000 µg/ml. Partial synergy was observed for all arborine-antibiotics and arborinine-ketoconazole interactions against <em>S. aureus</em> and <em>C. albicans</em>, respectively. Arborine was relatively the strongest photoactivated enzymatic restriction inhibitor, particularly against EcoRI, PstI, and SalI. The results obtained are promising and encourage further research on alkaloids as potential antimicrobial-enhancing agents.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science GASTROINTESTINAL PARASITES IN Macaca fascicularis LIVING IN TWO URBAN AREAS OF MALAYSIA 2022-02-25T08:51:09+08:00 Sharifah Aminah Tuan Said Jaya Vejayan Nur A’fiefah Mohd Zulkeffli Hani Kartini Agustar <p><em>Macaca fascicularis</em> or commonly known as long-tailed macaques, are nonhuman primates that are increasingly vulnerable in becoming natural reservoirs for many microorganisms including gastrointestinal (GI) parasites, largely due to anthropogenic activities. This study was conducted to detect and compare GI parasites in <em>M. fascicularis</em> found in densely urbanized settings. The fecal samples of the long-tailed macaques were collected at a public university campus (Universiti Kebangsaan Malaysia, Bangi) and a tourist site (Bukit Melawati, Kuala Selangor). A total of 80 fecal samples were collected: 50 at the university campus, and the remaining samples from the tourist site. The fecal samples were processed by flotation techniques to include the GI parasites and then were subjected to morphological analysis to identify important taxonomy keys under microscopic magnification. A total of 139 parasites were identified from both locations and classified into 5 phylums and 17 families. Among the 139 parasites, 33 parasites were grouped into 6 genus of GI parasites. Among the gastrointestinal parasites that were identified from both study sites, three parasites were zoonotic namely <em>Strongyloids</em> spp., <em>Trichostrongylus</em> spp. and <em>Trichuris</em> spp. Results showed that the diversity index of GI parasites was higher at the university campus compared to the tourist site with Simpson’s Index values of 0.953 and 0.880, respectively, while the Shannon’s Index values were 3.282 and 2.399, respectively. This research revealed that there are more parasite infections in the long-tailed macaques in the campus surroundings compared to those found in the tourist site. Therefore, it is highly suggested that authority intervention by translocating the long-tailed macaques elsewhere is necessary to avoid prolonged contact and possible parasite transmission to humans, and if any parasitic infections occur, appropriate medication such as anthelmintic drugs should be readily available at the university campus clinics.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science ESTIMATION OF THERMODYNAMIC PARAMETERS OF Ni-Si BASE ALLOYS USING THE SEMI-EMPIRICAL MIEDEMA MODEL 2022-02-14T12:48:29+08:00 Ali Kadhim Alsaedi Faiz Salih Abbas Azhar S. Alaboodi Ali Abid Abojassim <p>In this paper, we present a calculation method for evaluating the possibility of enhancing the thermal stability of nickel silicide by alloying with metals, which consists in determining the formation enthalpy (∆H) of nickel silicide using the Miedema model. Changes in formation enthalpy (∆H) were observed for nickel silicides that were alloyed with Mo, Pt, Pd, W, and Zr. The MAAT (Materials Analysis Applying Thermodynamics) software was used to calculate and plot the formation enthalpy of binary and ternary systems. Based on our calculations, we found that in binary systems, the optimum values to expand the formation enthalpy were 51.28 and 49.57 kJ/mol for nickel silicide alloys. For the ternary system, the results showed that adding Zr could increase monosilicide phase stability.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science PHOTOPROTECTIVE EFFECTS OF CARRAGEENANS AGAINST ULTRAVIOLETB-INDUCED EXTRACELLULAR MATRIX (ECM) DAMAGE IN KERATINOCYTES 2022-01-07T14:23:16+08:00 Haema Thevanayagam Shar Mariam Mohamed Wan Loy Chu Zolkapli Eshak <p>Carrageenans, the polysaccharide from red seaweeds is widely used in food, medicine and as an excipient in cosmetics and skincare products. Carrageenans have shown prospective photoprotective effect against ultraviolet B (UVB) irradiation on immortalised normal human keratinocyte (HaCaT) cells. The aim of this research was to evaluate the photoprotective effect of iota (ι), kappa (κ)-carrageenans and their combination with vitamin E against UVB-induced extracellular matrix (ECM) damage in HaCaT cells. The study also assessed the superoxide dismutase (SOD) and catalase (CAT) antioxidant enzymes in UVB exposed pre-treated and non-pre-treated cells. The parameters assessed were biological mediators important for the structural integrity of ECM, comprising of epidermal growth factor receptor (EGFR), mitogen-activated protein kinase (MAPK), activating protein- (AP-1) and matrix metalloproteinases (MMPs), liberated by the UVB exposed cells. Enzyme linked immunosorbent assay was used to evaluate the release of these mediators. Carrageenans enhanced the activities of the antioxidant enzymes SOD and CAT which acts as a defence mechanism against oxidative stress. The levels of the biological mediators were also reduced in cells pre-treated with carrageenans, suggesting that the polysaccharide has potential in maintaining the skin’s integrity by reducing the damage to ECM upon UVB exposure. Taken together, the results suggest that carrageenans do possess photoprotective effects against UVB-induced ECM damage and stimulates antioxidant enzymes.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science A WAITING TIME-BASED BULLY ALGORITHM FOR LEADER NODE SELECTION IN DISTRIBUTED SYSTEMS 2021-04-06T08:52:33+08:00 Md. Navid Bin Anwar Afroza Nahar Nashid Kamal Md. Mehedi Hasan Shuvo <p>In distributed systems, a single node (referred to as a leader) coordinates all other nodes to ensure synchronization. If this node fails, another node in the system must adopt the role of leader. The classic bully algorithm suffers from some significant drawbacks, such as excessive message passing, a redundant number of election calls, and uncertainties over message delivery. The enhanced bully algorithm is one of the most recent improvements of this algorithm. However, this algorithm performs poorly in average- and worst-case scenarios. In this paper, a novel waiting time-based algorithm is proposed to improve the enhanced bully algorithm for electing a new leader during such critical scenarios. In this algorithm, if a single or multiple number of nodes discover that the leader has failed, it does not broadcast instantly. Rather, it waits for a certain period, and this waiting time is assigned to the nodes according to their load. After the timeout, the node sends its message and starts the election process. Moreover, it restricts nodes from unnecessary message passing and stops any redundant election calls. Accordingly, this algorithm detects the failure of the leader node more precisely and elects a new leader more quickly.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science MORTALITY PREDICTION OF SURGICAL INTENSIVE CARE UNIT PATIENTS USING DEEP LEARNING-BASED SURVIVAL MODELS 2022-01-10T11:24:44+08:00 Lintu M.K. S.N.S. Acharya Asha Kamath David Raj Micheal <p>Mortality prediction in surgical intensive care units (SICUs) is considered to be among the most critical steps in enforcing efficient treatment policies. This study aims to evaluate the performance of various deep learning models in predicting the mortality of patients admitted to SICUs. The survival of 2,225 adult patients admitted to SICUs was modeled using five salient deep learning-based survival models, namely, Cox-CC, Cox-Time, DeepSurv, DeepHit, and N-MTLR. The data were extracted from the Medical Information Mart for Intensive Care II (MIMIC-II) database. The performance of the models was compared using the time-dependent concordance index (C<sup>td</sup>-index) and integrated Brier score (IBS). From among the five models, DeepSurv achieved the most accurate prediction, while Cox-Time demonstrated the least optimal predictive ability. For DeepSurv, Cox-CC, DeepHit, N-MTLR, and Cox-Time, the mean C<sup>td</sup> -index was 0.773, 0.767, 0.765, 0.732, and 0.659, and the mean IBS was 0.181, 0.192, 0.195, 0.212, and 0.225, respectively. DeepSurv, Cox-CC, and DeepHit yielded comparable performance. Deep learning models are free from the stringent assumptions inherent in standard survival models. Hence, these models are considered flexible alternatives to the standard approaches in scalable, real-world survival problems.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science RELIABILITY ANALYSIS OF ACTIVE REDUNDANT SYSTEM USING GEOMETRIC DISTRIBUTION 2022-03-24T16:02:36+08:00 Pankaj Jasdev Bhatti Mohit Kumar kakkar <p>The present paper is an initiative taken towards study and analysis of industries concerning different maintenance strategies towards their products on behalf of their working and maintenance level. The objective of presenting the concept of the dual nature of repair for units having extra or major failures in addition to regular ones is well explained. The stochastic analysis of reliability characteristics using regenerative techniques for the system consisting of two parallel units following the active-standby redundancy and having different repair time distributions was also studied using geometric distribution. The numerical equations and results are being evaluated for reliability parameters like mean time to system failure, availability of the system in operative form, down period of the system following repair mechanism using regenerative techniques, and geometric distribution. The graphical analysis has also been presented for-profit function with respect to repair and failure rate.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science ARDUINO BASED SMART SOLAR PHOTOVOLTAIC REMOTE MONITORING SYSTEM 2022-02-15T09:13:42+08:00 Vinoth Kumar V Sasikala G <p>The continuous monitoring system of the photo voltaic solar based energy model is currently highly crucial to monitor the overall performance and other related characteristics of energy solar energy systems from remote locations. For this, data loggers also play a vital role. These technologies are highly important to identify any malfunctions inherent in PV based solar energy systems. The proposed IoT based system is useful to obtain real time data from PV based solar energy systems from remote areas. An Arduino ATMEGA16 microcontroller was used to acquire real time data from the system, which is incorporated with the blynk app to transmit real time data to the destination through a webpage. The proposed system consists of a PV based solar system, Arduino controller board Wi-Fi module and the blynk app, in order obtain and transmit data from any remote location. We have developed a cost effective IoT based Smart monitoring system for PV based solar energy applications to monitor the various characteristics and performance of the system, as well as to carry out preventive maintenance and fault detection.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science THE MOLECULAR BEHAVIORS OF CALIXARENES AT THE AIR-WATER INTERFACE: DENSITY FUNCTIONAL THEORY, SURFACE PRESSURE, POTENTIAL, AND EFFECTIVE DIPOLE MOMENT 2022-06-23T13:33:46+08:00 Faridah Lisa Supian Yeong Yi Wong Nur Farah Nadia Abd Karim Afiq Radzwan Darvina Choo Kheng Lim Abdullah Faisal Al Naim <p>This study examined the behaviors of Langmuir-Blodgett ultrathin calixarene films at the air-water interface. The Langmuir trough was used to estimate the surface pressure, surface potential, and effective dipole moment of two calixarenes, namely, calix[4]arene (THC4) and calix[8]arene (THC8). The band gap was determined using the density functional theory (DFT). The DFT simulation gave a band gap of 2.28 eV for THC4, confirming that THC4 was an insulator. The surface pressure isotherms of THC4 and THC8 yielded the expected molecular behavior from the gaseous to the solid phases. THC4 and THC8 showed a perpendicular and a parallel orientation in the air-water subphase, respectively. The ∆Vmax values of TCH4 and THC 8 were 205 mV and 141mV, respectively, and their µ﬩max values were 0.147 D and 0.088 D, respectively.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science SYSTEMATIC LITERATURE REVIEW ON 3D PRINTING PERSONALISED FOOD FOR THE ELDERLY 2021-09-13T12:46:11+08:00 Muhammad Salahuddin Haris Nur Fatin Adlin Kamarudin Khairul Auni Adli Mohamed Aini Harith Juwaidi Abdul Rais Shaiqah Mohd Rus Sakinah Harith <p>Three-dimensional (3D) printing is currently a new technology being developed in the food industry due to its ability to design, customize, and fabricate a product with good precision and accuracy. Therefore, with regard to the mastication problems frequently faced by elderly people, this technology is utilized to design foods that can be consumed by them. Since there was limited published literature on the subject, the present study aimed to systematically review 3D printing personalized food for the elderly. The study used PRISMA as a guideline for report writing while integrating multiple research designs. This paper employed three databases to select the articles: Science Direct, Scopus, and Google Scholar. The study included five analyzed themes: 1) hardness; 2) moisture; 3) viscosity; 4) elasticity; and 5) printability. The study significantly contributed to several practical purposes and the body of knowledge. The findings provided the factors affecting the 3D printing of food, its mechanisms, and its significance.</p> 2022-10-31T00:00:00+08:00 Copyright (c) 2022 Malaysian Journal of Science