MyMedR

Displaying all 8 publications

Abstract:

Sort:

Fulltext Seroprevalence and Distribution of Leptospiral Serovars in Livestock (cattle, Goats, and Sheep) in Flood-prone Kelantan, Malaysia

Sabri Abdul Rahman M, Khairani Bejo S, Zakaria Z, Hassan L, Azri Roslan M

J Vet Res, 2021 Mar;65(1):53-58.
PMID: 33817395 DOI: 10.2478/jvetres-2021-0003

Introduction: Leptospirosis is a bacterial disease that affects both humans and animals, the occurrence of which increases markedly during and after heavy rainfall and flooding. The aim of this study was to determine the serological prevalence of leptospiral infection in livestock after a voluminous flood in 10 districts of the Malaysian state of Kelantan.
Material and Methods: In December 2014, Kelantan was hit by an extensive flood. A total of 1,728 serum samples were collected from livestock from the state, comprised of 1,024 from cattle, 366 from goats and 338 from sheep, and they were tested using the microscopic agglutination test (MAT).
Results: Altogether, 203 (11.75%; 203/1728; 95% CI: 10.20%-13.30%) of the tested sera were found to be positive serologically. Cattle had the highest prevalence of 14.16% (145/1024), while goats and sheep had 11.20% (41/366) and 5.03% (17/338) respectively. The most frequent serovars detected were Hardjo-bovis (3.70%; 64/1728), Hebdomadis (2.08%; 36/1728) and Pomona (1.04%; 18/1728). There was a statistically significant association (P < 0.05) between livestock that were exposed to the flood and seropositivity.
Conclusion: This study showed that flood is a risk factor that can play a role in the epidemiology of leptospiral infection in livestock.
Fulltext Particle swarm optimization algorithm-based PI inverter controller for a grid-connected PV system

Roslan MF, Al-Shetwi AQ, Hannan MA, Ker PJ, Zuhdi AWM

PLoS One, 2020;15(12):e0243581.
PMID: 33362200 DOI: 10.1371/journal.pone.0243581

The lack of control in voltage overshoot, transient response, and steady state error are major issues that are frequently encountered in a grid-connected photovoltaic (PV) system, resulting in poor power quality performance and damages to the overall power system. This paper presents the performance of a control strategy for an inverter in a three-phase grid-connected PV system. The system consists of a PV panel, a boost converter, a DC link, an inverter, and a resistor-inductor (RL) filter and is connected to the utility grid through a voltage source inverter. The main objective of the proposed strategy is to improve the power quality performance of the three-phase grid-connected inverter system by optimising the proportional-integral (PI) controller. Such a strategy aims to reduce the DC link input voltage fluctuation, decrease the harmonics, and stabilise the output current, voltage, frequency, and power flow. The particle swarm optimisation (PSO) technique was implemented to tune the PI controller parameters by minimising the error of the voltage regulator and current controller schemes in the inverter system. The system model and control strategies were implemented using MATLAB/Simulink environment (Version 2020A) Simscape-Power system toolbox. Results show that the proposed strategy outperformed other reported research works with total harmonic distortion (THD) at a grid voltage and current of 0.29% and 2.72%, respectively, and a transient response time of 0.1853s. Compared to conventional systems, the PI controller with PSO-based optimization provides less voltage overshoot by 11.1% while reducing the time to reach equilibrium state by 32.6%. The consideration of additional input parameters and the optimization of input parameters were identified to be the two main factors that contribute to the significant improvements in power quality control. Therefore, the proposed strategy effectively enhances the power quality of the utility grid, and such an enhancement contributes to the efficient and smooth integration of the PV system.
Antibody Response against Severe Acute Respiratory Syndrome Coronavirus 2 Messenger Ribonucleic Acid Vaccines in Infected Individuals: A Systematic Review

Roslan M, Mohd Nisfu FR, Arzmi MH, Abdul Wahab R, Zainuddin N

Malays J Med Sci, 2023 Aug;30(4):8-24.
PMID: 37655145 DOI: 10.21315/mjms2023.30.4.2

Individuals with a history of coronavirus disease 2019 (COVID-19) exhibit memory immunity acquired during natural infection. However, a decline in immunity after infection renders these individuals vulnerable to re-infection, in addition to a higher risk of infection with new variants. This systematic review examined related studies to elucidate the antibody response in these infected individuals after messenger ribonucleic acid (mRNA) vaccination. Hence, the focus of this review was to ascertain differences in the concentration of binding and neutralising antibodies of previously infected individuals in comparison to those of infection-naïve individuals after administration of two doses of mRNA vaccination through available case-control and cohort studies. Positive reverse transcriptase-polymerase chain reaction (RT-PCR) test or detectable anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies at the baseline in included studies showed categorisation of infected and uninfected individuals. This review utilised three online databases: PubMed, Scopus and Cochrane with the following keywords: (COVID-19 OR 'Coronavirus Disease 2019' OR SARS-CoV-2) AND Immun* AND (Pfizer OR BioNTech OR BNT162b2 OR Comirnaty OR Moderna OR mRNA-1273) from January 2019 to July 2021. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol (PRISMA-P) 2020 guidelines and assessment based on the Crowe Critical Appraisal Tool (CCAT), we included 13 related qualified papers of observational studies discerning the binding and neutralising antibody concentrations of infected and uninfected individuals after administration of mRNA vaccines, such as the BNT162b2 and mRNA-1273 vaccine. The mRNA vaccines induced robust binding and neutralising antibody responses in both groups. However, infected individuals showed induction of higher antibody responses in a shorter time compared to uninfected individuals. Hence, a single dose of mRNA vaccination for infected individuals may be sufficient to reach the same level of antibody concentration as that observed in uninfected individuals after receiving two doses of vaccination.
A comparison study of HER2 protein overexpression and its gene status in breast cancer

Md Pauzi SH, Saari HN, Roslan MR, Syed Khair Azman Jamalulil SNS, Tauan IS, Mohd Rusli FA, et al.

Malays J Pathol, 2019 Aug;41(2):133-138.
PMID: 31427548

INTRODUCTION: Evaluation of HER2 status in breast cancer using immunohistochemistry (IHC) and in-situ-hybridisation (ISH) study is important to establish prognosis and to select patient for targeted therapy.
OBJECTIVE: The study aims to determine the concordance between HER2 protein IHC score and its gene status by dual-colour dual-hapten in-situ-hybridization (DDISH) study.
MATERIALS AND METHODS: Retrospective study was performed on 767 referred breast cancer cases over a period of five years. The HER2 IHC score (the initial and repeat test score) and the results of HER2 gene status by DDISH were retrieved from the histopathological reports. The agreement between initial IHC score with repeat test score was measured using Cohen Kappa. Chi square test analyzed the association between HER2 IHC score with its gene status by DDISH.
RESULTS: The concordance of HER2 IHC score between the initial and repeat test were 52.7% and 89.4% for IHC score 2+ and 3+ respectively. There was moderate agreement of HER2 IHC score between the initial and repeat test score (ϰ = 0.526, p<0.001). A significant association noted between HER2 IHC score with its gene status by DDISH (p<0.001). Only 56 out of 207 cases (27.1%) with 2+ IHC score showed HER2 gene amplification while the majority of cases with 3+ IHC score were gene-amplified (446 out of 451, 98.9%).
CONCLUSION: ISH study should be done in all IHC-equivocal cases (2+) to select patient for targeted therapy. Gene amplification must also be confirmed in IHC-positive cases (3+) to prevent from giving non-effective treatment with possible adverse effects to patient with non-amplified HER2 gene.
Fulltext Sound HIV knowledge and common misconceptions about HIV among university students

Normala I, Zubaidah JO, Nik Shaliza H, Hamidin A, Noorjan KON, Siti Irma Fadhilah I, et al.

Malaysian Journal of Medicine and Health Sciences, 2013;9(1):29-34.
MyJurnal

The objective of the study was to determine the proportion of sound HIV knowledge and common misconceptions about HIV among university students. A set of pre tested and validated questionnaire assessing sound HIV knowledge and common misconceptions about HIV was used in this cross sectional study. HIV knowledge was defined as sound when one was able to identify correctly two ways of preventing the sexual transmission of HIV and reject three major misconceptions about HIV. Out of 300 respondents, 298 completed the questionnaire giving a response rate of 99.3%. A total of 40.9% of university students have sound HIV knowledge. The majority of those who lacked sound HIV knowledge were young (60.2%) and female (60.4%). A significant proportion still believed that HIV can be transmitted via social contact (13.8%), by sneezing or coughing (11.4%) and mosquito bites (10.1%). About 6.7% were believed wrongly that HIV can be treated by vaccine and healthy-looking people cannot have HIV.
Study site: Universiti Putra Malaysia (UPM), Malaysia
Seroprevalence of Leptospirosis in Working Dogs

Lau SF, Wong JY, Khor KH, Roslan MA, Abdul Rahman MS, Bejo SK, et al.

Top Companion Anim Med, 2017 Dec;32(4):121-125.
PMID: 29525230 DOI: 10.1053/j.tcam.2017.12.001

Working dogs are canine animals that have been trained to assist human beings in carrying out various tasks. They help in guarding property, performing rescues, assisting the visually impaired or physically handicapped, searching for drugs, explosives, and others. Leptospirosis is one of the most widespread zoonotic diseases in the world and a commonly occurring disease of the tropics and subtropics. In Malaysia, all working dogs are normally vaccinated with serovars, Pomona, Icterohaemorrhagiae, Canicola, and Grippotyphosa based on protocols recommended from other countries. The duration of immunity in vaccinated dogs for Leptospira can last up to 13 months; however, there is no full crossprotection between the different serovars. Five representative canine units from different government agencies in Malaysia (n = 96 dogs) were recruited in this study. For detection, the microscopic agglutination test was performed by incubating the serum from dogs with various serovars of leptospires, namely, Icterohaemorrhagiae, Canicola, Pomona, Grippotyphosa, Australis, Bataviae, Javanica, Tarassovi, Hebdomadis, Lai, and Pyrogenes. The plasma obtained was used for polymerase chain reaction (PCR) analysis, for the detection of 16S rRNA, and lipL 32 genes of Leptospira. Out of the 96 dogs sampled, only 3 dogs were positive toward serovars, Australis, Bataviae, and Javanica, based on the cutoff point at 1:80. The seroprevalence of canine leptospirosis in this population was 3.1% (n = 3/96). However, all 96 blood samples of working dogs tested negative for both pathogenic and nonpathogenic Leptospira genes. The results revealed that, by vaccination alone, working dogs were not fully protected against leptospirosis and could pose a risk to dog handlers. A preventative and control protocol for leptospirosis is warranted, and its implementation should be monitored and improved accordingly from time to time, in order to maintain a healthy condition in both working dogs and their handlers.
Differentiation of lard from other animal fats based on n-Alkane profiles using chemometric analysis

Ain Syaqirah Sapian N, Aidilfitri Mohamad Roslan M, Mohd Hashim A, Nasir Mohd Desa M, Halim M, Noorzianna Abdul Manaf Y, et al.

Food Res Int, 2023 Feb;164:112332.
PMID: 36737925 DOI: 10.1016/j.foodres.2022.112332

Adulteration of lard with other fats and oils in food production affects many areas including economics, religion, and health. Previous studies discriminated lard based on major components of fats, i.e. triglycerides and fatty acids. This study aimed to differentiate lard and other animal fats (beef, chicken and mutton fat) based on n-alkane profiles established by gas chromatography-mass spectrometry (GC-MS). Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA) were able to initiate clustering of lard and other animal fats. Good result was obtained using Random Forest (RF) and Partial Least Squares-Discriminant Analysis (PLS-DA). Statistical models propose tetracosane (C24) as a potential n-alkane marker and it was found that C24 was the major alkane with composition of 15.72% (GC-MS) of total alkanes identified. Based on this finding, more interesting study may potentially be explored for the interest of various fats and oils consumers in vast applications especially using chemometrics analysis.
Investigation of structural, electronic and optical properties of two-dimensional MoS2-doped-V2O5 composites for photocatalytic application: a density functional theory study

Jameel MH, Sufi Bin Roslan M, Bin Mayzan MZH, Agam MAB, Zaki ZI, Fallatah AM

R Soc Open Sci, 2023 Jul;10(7):230503.
PMID: 37476508 DOI: 10.1098/rsos.230503

In the present research, the structural, electronic and optical properties of transition metal dichalcogenide-doped transition metal oxides MoS2-doped-V2O5 with various doping concentrations (x = 1-3%) of MoS2 atoms are studied by using first principles calculation. The generalized gradient approximation Perdew-Burke-Ernzerhof simulation approach is used to investigate the energy bandgap (Eg) of orthorhombic structures. We examined the energy bandgap (Eg) decrement from 2.76 to 1.30 eV with various doping (x = 1-3%) of molybdenum disulfide (MoS2) atoms. The bandgap nature shows that the material is a well-known direct bandgap semiconductor. MoS2 doping (x = 1-3%) atoms in pentoxide (V2O5) creates the extra gamma active states which contribute to the formation of conduction and valance bands. MoS2-doped-V2O5 composite is a proficient photocatalyst, has a large surface area for absorption of light, decreases the electron-hole pairs recombination rate and increases the charge transport. A comprehensive study of optical conductivity reveals that strong peaks of MoS2-doped-V2O5 increase in ultraviolet spectrum region with small shifts at larger energy bands through increment doping x = 1-3% atoms of MoS2. A significant decrement was found in the reflectivity due to the decrement in the bandgap with doping. The optical properties significantly increased by the decrement of bandgap (Eg). Two-dimensional MoS2-doped-V2O5 composite has high energy absorption, optical conductivity and refractive index, and is an appropriate material for photocatalytic applications.