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Fulltext Microstructural Characterization of Fibric Peat Stabilized with Portland Cement and Silica Fume

Ahmad A, Sutanto MH, Ahmad NR, Mohamad ME, Bujang M

Materials (Basel), 2022 Dec 20;16(1).
PMID: 36614356 DOI: 10.3390/ma16010018

Peat is a renowned problematic soil and needs stabilization to enhance its engineering properties. Silica fume (SF) and Ordinary Portland Cement (OPC) were extensively adopted to increase the mechanical properties of peat; however, their microstructural analysis is lacking. Investigated herein is the microstructural evolution caused by the OPC and SF implementation in peat soil stabilization. Initially, the compositional analysis (elements and oxides) of peat and binders was carried out via energy-dispersive X-ray (EDX) and X-ray fluorescence (XRF). Subsequently, the microstructural changes that occurred in the stabilized peat were examined through a series of microstructural analyses. The analysis includes scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), and thermogravimetric analysis (TGA) for morphological, mineralogical, functional group analysis, and bond thermal analysis, respectively. The SEM micrographs evidence the transformation of loosely packed with large micropores of untreated peat into a compact dense peat matrix. This transformation is due to the formation of newly developed minerals, i.e., calcium hydrates (CH), calcium silicate hydrates (C-S-H), calcium aluminate hydrate (CAH), ettringite (Aft) caused by the pozzolanic reaction of binders as recorded by the XRD. Similarly, different molecular functional groups were found in the FTIR analysis with the incorporation of SF and OPC. Finally, the percentage of mass loss was assessed through TGA analysis revealing the decomposition of stabilized in the second and third stages.
Application of rotten rice as a substrate for bacterial species to generate energy and the removal of toxic metals from wastewater through microbial fuel cells

Daud NNM, Ahmad A, Yaqoob AA, Ibrahim MNM

Environ Sci Pollut Res Int, 2021 Nov;28(44):62816-62827.
PMID: 34215989 DOI: 10.1007/s11356-021-15104-w

Microbial fuel cells (MFCs) are the efficient and sustainable approach for the removal of toxic metals and generate energy concurrently. This article highlighted the effective use of rotten rice as an organic source for bacterial species to generate electricity and decrease the metal concentrations from wastewater. The obtained results were corresponding to the unique MFCs operation where the 510 mV voltage was produced within 14-day operation with 1000 Ω external resistance. The maximum power density and current density were found to be 2.9 mW/m2 and 168.42 mA/m2 with 363.6 Ω internal resistance. Similarly, the maximum metal removal efficiency was found to be 82.2% (Cd), 95.71% (Pb), 96.13% (Cr), 89.50% (Ni), 89.82 (Co), 99.50% (Ag), and 99.88% (Cu). In the biological test, it was found that Lysinibacillus strains, Chryseobacterium strains, Escherichia strains, Bacillus strains are responsible for energy generation and metal removal. Furthermore, a multiparameter optimization revealed that MFCs are the best approach for a natural environment with no special requirements. Lastly, the working mechanism of MFCs and future recommendations are enclosed.
Fulltext Rapid determination of kappa-carrageenan using a biosensor from immobilized Pseudomonas carrageenovora cells

Hassan RA, Heng LY, Ahmad A, Tan LL

PLoS One, 2019;14(4):e0214580.
PMID: 30990847 DOI: 10.1371/journal.pone.0214580

A potentiometric whole cell biosensor based on immobilized marine bacterium, Pseudomonas carrageenovora producing κ-carrageenase and glycosulfatase enzymes for specific and direct determination of κ-carrageenan, is described. The bacterial cells were immobilized on the self-plasticized hydrogen ion (H+)-selective acrylic membrane electrode surface to form a catalytic layer. Hydrogen ionophore I was incorporated in the poly(n-butyl acrylate) [poly(nBA)] as a pH ionophore. Catalytic decomposition of κ-carrageenan by the bienzymatic cascade reaction produced neoagarobiose, an inorganic sulfate ion and a proton. The latter was detectable by H+ ion transducer for indirect potentiometric quantification of κ-carrageenan concentration. The use of a disposable screen-printed Ag/AgCl electrode (SPE) provided no cleaning requirement and enabled κ-carrageenan detection to be carried out conveniently without cross contamination in a complex food sample. The SPE-based microbial biosensor response was found to be reproducible with high reproducibility and relative standard deviation (RSD) at 2.6% (n = 3). The whole cell biosensor demonstrated a broad dynamic linear response range to κ-carrageenan from 0.2-100 ppm in 20 mM phosphate buffer saline (PBS) at pH 7.5 with a detection limit at 0.05 ppm and a Nernstian sensitivity of 58.78±0.87 mV/decade (R2 = 0.995). The biosensor showed excellent selectivity towards κ-carrageenan compared to other types of carrageenans tested e.g. ι-carrageenan and λ-carrageenan. No pretreatment to the food sample was necessary when the developed whole cell biosensor was employed for direct assay of κ-carrageenan in dairy product.
Fulltext Effect of diet-induced weight loss on iron status and its markers among young women with overweight/obesity and iron deficiency anemia: a randomized controlled trial

Alshwaiyat NM, Ahmad A, Al-Jamal HAN

Front Nutr, 2023;10:1155947.
PMID: 37284649 DOI: 10.3389/fnut.2023.1155947

INTRODUCTION: Obesity and iron deficiency are prevalent health problems that affect billions of people all over the world. Obesity is postulated to relate to iron deficiency via reduced intestinal iron absorption due to increased serum hepcidin level, which is mediated by chronic inflammation. Weight loss in individuals with overweight or obesity and iron deficiency anemia is believed to be associated with an improvement in iron status however the evidence from clinical trials is scarce. This study was conducted to evaluate the effect of diet-induced weight loss on iron status and its markers among young women with overweight/obesity and iron deficiency anemia.
METHODS: The study design was a single-blinded, randomized controlled trial with two parallel arms (weight loss intervention vs control). Study participants were recruited using the convenience sampling method through public advertisements posted and disseminated through social media. Interested and potential participants were asked to visit the Diet Clinic for eligibility screening. A total of 62 women were recruited and randomized into weight loss intervention and control group. The intervention duration was three months. The intervention group received individual consultation sessions with the dietitian and tailored energy-restricted diets. Physical activity levels, dietary intake, anthropometric measurements and clinical markers were measured at baseline and end of the trial.
RESULTS: There was a significant decrease (p < 0.001) in body weight of the intervention group (-7.4 ± 2.7 kg) that was associated with significant improvements in iron status and its markers (p < 0.01). The intervention group experienced a significant increase in hemoglobin (0.5 ± 0.6 g/dL), serum ferritin (5.6 ± 5.8 ng/mL), and serum iron (13.0 ± 16.2 µg/dL), and a significant decrease in high-sensitivity C-reactive protein (-5.2 ± 5.6 mg/L), and serum hepcidin level (-1.9 ± 2.2 ng/mL) at the end of the trial.
CONCLUSION: Our findings indicate that diet-induced weight loss among participants was associated with an improvement in iron status and its related clinical markers.
CLINICAL TRIAL REGISTRATION: [https://www.thaiclinicaltrials.org/show/TCTR20221009001], identifier [TCTR20221009001].
Current Trends of Analytical Techniques for Total Alkalinity Measurement in Water Samples: A Review

Ahmad M, Ahmad A, Omar TFT, Mohammad R

Crit Rev Anal Chem, 2023 Apr 13.
PMID: 37052389 DOI: 10.1080/10408347.2023.2199432

Increasing acidity of seawater caused by increasing anthropogenic carbon dioxide absorbed into the seawater attracted the interest of researchers due to increased concern on the deterioration of marine systems and food supply to humans. Total alkalinity (TA) is one of the important parameters in determining carbonate chemistry and is described as the capacity of the sample to neutralize acids. Over the last two decades, many analytical techniques have been developed to determine TA. This article presents a review of different analytical techniques including titration, colorimetric, spectrophotometric, and potentiometric analyses in measuring TA. Among these analytical techniques, potentiometry analysis, which utilizes electrode systems such as glass electrode and ion-selective electrode used as indicator electrodes, is the most used technique. Important features such as principle, limitations, and challenges of the involved technique are discussed in detail.
Fulltext Outcome of a newborn hearing screening program in a tertiary hospital in Malaysia: the first five years

Ahmad A, Mohamad I, Mansor S, Daud MK, Sidek D

Ann Saudi Med, 2011 Jan-Feb;31(1):24-8.
PMID: 21245595 DOI: 10.4103/0256-4947.75774

Universal newborn hearing screening (UNHS) was started in the Hospital Universiti Sains Malaysia (HUSM) in January 2003. To comply with international standards, we determined the outcome of the newborn hearing screening program for the first 5 years of its implementation, from January 2003 to December 2007.
Molecular prevalence of Anaplasma marginale in ruminants and Rhipicephalus ticks in northern Pakistan

Ali S, Hasan M, Ahmad AS, Ashraf K, Khan JA, Rashid MI

Trop Biomed, 2023 Mar 01;40(1):7-13.
PMID: 37355998 DOI: 10.47665/tb.40.1.005

Anaplasma marginale is the most prevalent tick-borne haemoparasite of cattle and causes huge economic losses to the dairy industry worldwide. This study aimed to determine the occurrence of A. marginale infection in blood and tick samples collected from livestock animals in the districts located in Khyber Pakhtunkhwa (KPK), Pakistan. A total of 184 blood and 370 tick samples were included in this study. It has never been reported that sheep, goats, and cattle in Tank, Ghulam Khan, Birmil and Miran Shah areas were infected with A. marginale. All samples of blood and ticks were collected through random sampling from March 2021 to January 2022 from cattle, sheep and goats and screened through PCR for anaplasmosis by using primer pairs of Anaplasma spp. Three hundred and seventy ticks were collected from infested hosts (120/184, 64.21%). Among the four morphologically identified tick species, the highest occurrence was recorded for Rhipicephalus sanguineus (n=138, 37.29%), followed by Rhipicephalus microplus (n=131, 35.4%), Rhipicephalus annulatus (n=40, 10.81%), Hyalomma anatolicum (n=31, 8.37%), and Hyalomma marginatum (n=30, 8.1%). The occurrence of female tick was highest (n=160, 43.24%), followed by nymphs (n=140, 37.38%) and males ticks (n=70, 18.9%). Among these ticks, A. marginale was detected in female ticks of R. microplus, and R. sanguineus. Molecular identification of A. marginale was confirmed in 120 out of 184 blood samples and 6 out of 74 tick samples. Overall, occurrence of A. marginale in blood and tick samples was found to be 65.21% and 8.1% respectively. Species-wise occurrence in blood samples of goats were 71.11% followed by sheep 68.31% and cattle 50%. Specie-wise occurrence of A. marginale in tick samples of cattle were 12.5% followed by goats 6.89%. The obtained sequence showed similarity with A. marginale reported from Kenya and USA. We report the first PCR based detection of A. marginale infection in blood samples and in R. sanguineus ticks of goats simultaneously.
Fulltext The Effects of 12 Weeks Colostrum Milk Supplementation on the Expression Levels of Pro-Inflammatory Mediators and Metabolic Changes among Older Adults: Findings from the Biomarkers and Untargeted Metabolomic Analysis

Ooi TC, Ahmad A, Rajab NF, Sharif R

Nutrients, 2023 Jul 18;15(14).
PMID: 37513601 DOI: 10.3390/nu15143184

Senescence is a normal biological process that is accompanied with a series of deteriorations in physiological function. This study aimed to investigate the effects of bovine colostrum milk supplementation on metabolic changes and the expression of various biomarkers on inflammation, antioxidant and oxidative damage, nutrient metabolism, and genomic stability among older adults. Older adults (50-69 years old) who participated in the 12-week randomized, double-blinded, placebo-controlled trial were instructed to consume the IgCo bovine colostrum-enriched skim milk or regular skim milk (placebo) twice daily. Following 12 weeks of intervention, participants in the intervention group had lower expression levels in pro-inflammatory mediators (CRP, IL-6, and TNF-α), with significant (p < 0.05) interaction effects of the group and time observed. However, no significant interaction effect was observed in the vitamin D, telomerase, 8-OHdG, MDA, and SOD activities. UPLC-MS-based untargeted metabolomics analysis revealed that 22 metabolites were upregulated and 11 were downregulated in the intervention group compared to the placebo group. Glycerophospholipid metabolism, along with cysteine and methionine metabolism were identified as the potential metabolic pathways that are associated with bovine colostrum milk consumption. In conclusion, consuming bovine colostrum milk may induce metabolic changes and reduce the expression of various pro-inflammatory mediators, thus improving the immune function in older adults.
Fulltext Biocompatible and Biodegradable Surfactants from Orange Peel for Oil Spill Remediation

Wang PS, Ahmad A, Nazar M, Rahmah AU, Moniruzzaman M

Molecules, 2023 Aug 01;28(15).
PMID: 37570764 DOI: 10.3390/molecules28155794

Oil spill remediation plays a vital role in mitigating the environmental impacts caused by oil spills. The chemical method is one of the widely recognized approaches in chemical surfactants. However, the most commonly used chemical surfactants are toxic and non-biodegradable. Herein, two biocompatible and biodegradable surfactants were synthesized from orange peel using the ionic liquid 1-butyl-3-methylimidazolium chloride (BMIMCl) and organic solvent dimethylacetamide (CH3CN(CH3)2) as reaction media. The acronyms SOPIL and SOPOS refer to the surfactants prepared with BMIMCl and dimethylacetamide, respectively. The surface tension, dispersant effectiveness, optical microscopy, and emulsion stability test were conducted to examine the comparative performance of the synthesized surfactants. The Baffled flask test (BFT) was carried out to determine the dispersion effectiveness. The toxicity test was performed against zebrafish (Danio rerio), whereas the closed bottle test (CBT) evaluated biodegradability. The results revealed that the critical micelle concentration (CMC) value of SOPIL was lower (8.57 mg/L) than that of SOPOS (9.42 mg/L). The dispersion effectiveness values for SOPIL and SOPOS were 69.78% and 40.30%, respectively. The acute toxicity test demonstrated that SOPIL was 'practically non-toxic' with a median lethal concentration of more than 1000 mg/L after 96 h. The biodegradation rate was recorded as higher than 60% for both surfactants within 28 days, demonstrating their readily biodegradable nature. Considering these attributes, biocompatible and biodegradable surfactants derived from orange peel emerge as a promising and sustainable alternative for oil spill remediation.
Fulltext Probiotic potentials of Lactobacillus plantarum isolated from fermented durian (Tempoyak), a Malaysian traditional condiment

Ahmad A, Yap WB, Kofli NT, Ghazali AR

Food Sci Nutr, 2018 Sep;6(6):1370-1377.
PMID: 30258578 DOI: 10.1002/fsn3.672

Lactic acid bacterium isolated from fermented durian (tempoyak) was investigated for its potentials as a probiotic strain. Bacterial tolerance toward gastrointestinal environment, adhesion, and cytotoxic activity in human colon adenocarcinoma cell line HT-29 was evaluated. 16S rRNA sequencing identified the lactic acid bacterium as Lactobacillus plantarum. The bacterium demonstrated good tolerance toward gastrointestinal pH 2.0 and 0.3% bile salts. It showed strong adhesive capacity in human intestinal cell line, HT-29, with an adhesion index of 159 ± 10. Cytotoxicity of L. plantarum was investigated using both live bacterial cells (BC) and cell-free supernatant (CFS). Findings showed that both BC and CFS of L. plantarum reduced proliferation of HT-29 colon adenocarcinoma cells using MTT assay. The results imply potential probiotic properties of L. plantarum isolated from tempoyak.
Fulltext Harnessing the power of AI: Advanced deep learning models optimization for accurate SARS-CoV-2 forecasting

Tariq MU, Ismail SB, Babar M, Ahmad A

PLoS One, 2023;18(7):e0287755.
PMID: 37471397 DOI: 10.1371/journal.pone.0287755

The pandemic has significantly affected many countries including the USA, UK, Asia, the Middle East and Africa region, and many other countries. Similarly, it has substantially affected Malaysia, making it crucial to develop efficient and precise forecasting tools for guiding public health policies and approaches. Our study is based on advanced deep-learning models to predict the SARS-CoV-2 cases. We evaluate the performance of Long Short-Term Memory (LSTM), Bi-directional LSTM, Convolutional Neural Networks (CNN), CNN-LSTM, Multilayer Perceptron, Gated Recurrent Unit (GRU), and Recurrent Neural Networks (RNN). We trained these models and assessed them using a detailed dataset of confirmed cases, demographic data, and pertinent socio-economic factors. Our research aims to determine the most reliable and accurate model for forecasting SARS-CoV-2 cases in the region. We were able to test and optimize deep learning models to predict cases, with each model displaying diverse levels of accuracy and precision. A comprehensive evaluation of the models' performance discloses the most appropriate architecture for Malaysia's specific situation. This study supports ongoing efforts to combat the pandemic by offering valuable insights into the application of sophisticated deep-learning models for precise and timely SARS-CoV-2 case predictions. The findings hold considerable implications for public health decision-making, empowering authorities to create targeted and data-driven interventions to limit the virus's spread and minimize its effects on Malaysia's population.
Identification of copy neutral loss of heterozygosity on chromosomes 1p, 1q, and 6p among nonsyndromic cleft lip and/or without cleft palate with hypodontia

Ghazali N, Rahman NA, Kannan TP, Ahmad A, Sulong S

BMC Oral Health, 2023 Nov 29;23(1):945.
PMID: 38031027 DOI: 10.1186/s12903-023-03464-3

BACKGROUND: Nonsyndromic cleft lip and/or without cleft palate (NSCL/P) with or without hypodontia is a common developmental aberration in humans and animals. This study aimed to identify the loss of heterozygosity (LOH) involved in hypodontia and NSCL/P pathogenesis.
METHODS: This is a cross-sectional study that conducted genome-wide copy number analysis using CytoScan 750K array on salivary samples from Malay subjects with NSCL/P with or without hypodontia aged 7-13 years. To confirm the significant results, simple logistic regression was employed to conduct statistical data analysis using SPSS software.
RESULTS: The results indicated the most common recurrent copy neutral LOH (cnLOH) observed at 1p33-1p32.3, 1q32.2-1q42.13 and 6p12.1-6p11.1 loci in 8 (13%), 4 (7%), and 3 (5%) of the NSCL/P subjects, respectively. The cnLOHs at 1p33-1p32.3 (D1S197), 1q32.2-1q42.13 (D1S160), and 6p12.1-6p11.1 (D1S1661) were identified observed in NSCL/P and noncleft children using microsatellite analysis markers as a validation analysis. The regions affected by the cnLOHs at 1p33-1p32.3, 1q32.2-1q42.13, and 6p12.1-6p11.1 loci contained selected genes, namely FAF1, WNT3A and BMP5, respectively. There was a significant association between the D1S197 (1p33-32.3) markers containing the FAF1 gene among NSCL/P subjects with or without hypodontia compared with the noncleft subjects (p-value = 0.023).
CONCLUSION: The results supported the finding that the genetic aberration on 1p33-32.3 significantly contributed to the development of NSCL/P with or without hypodontia. These results have an exciting prospect in the promising field of individualized preventive oral health care.
Fulltext Conjectured the Behaviour of a Recycled Metal Matrix Composite (MMC⁻AlR) Developed through Hot Press Forging by Means of 3D FEM Simulation

Ahmad A, Lajis MA, Shamsudin S, Yusuf NK

Materials (Basel), 2018 Jun 06;11(6).
PMID: 29882752 DOI: 10.3390/ma11060958

Melting aluminium waste to produce a secondary bulk material is such an energy-intensive recycling technique that it also indirectly threatens the environment. Hot press forging is introduced as an alternative. Mixing the waste with another substance is a proven practice that enhances the material integrity. To cope with the technology revolution, a finite element is utilised to predict the behaviour without a practical trial. Utilising commercial software, DEFORM 3D, the conjectures were demonstrated scientifically. The flow stress of the material was modified to suit the material used in the actual experiment. It is acknowledged that the stress⁻strain had gradually increased in each step. Due to the confined forming space, the temperature decreased by ~0.5% because the heat could not simply vacate the area. A reduction of ~10% of the flesh observed in the simulation is roughly the same as in the actual experiment. Above all, the simulation abides by the standards and follows what has been done previously. Through the finite element utilisation, this study forecasted the performance of the recycled composite. The results presented may facilitate improvement of the recycling issue and conserve the environment for a better future.
Fulltext A simplification of intricate multifocal electroretinogram understanding: A mini-review

Chen AH, Rafiuddin MSM, Ahmad A, Rosli SA

Oman J Ophthalmol, 2024;17(1):11-18.
PMID: 38524335 DOI: 10.4103/ojo.ojo_48_23

Variation of multifocal electroretinogram (mfERG) data presentation in existing scientific publications is a challenge for eye care practitioners to apply the scientific information for evidence-based practice in patient management. This review offers an overview of the mfERG data presentation types. Eight types of data presentation in the form of a table, scatter plot, line graph, bar graph/box plot, single waveform/a group of waveforms, trace array topography, three-dimensional topography, and two-dimensional topography are identified. The table format is used to provide the exact values. Line graphs, scatter, and box plots offer information about the relationship of mfERG values. Waveforms are helpful for comparison between groups or conditions. Topographies outline the retinal, especially the specific localized retinal abnormalities. An infographic of fundamental mfERG electrical response with definitions and clinical indications is provided to bridge the gap between researchers and clinicians to facilitate efficient clinical application.
Fulltext A comparison of enoxaparin with unfractionated heparins in patients with coronary heart disease in an emergency department in rural South Indian tertiary care teaching hospital

Ahmad A, Patel I, Asani H, Jagadeesan M, Parimalakrishnan S, Selvamuthukumaran S

Indian J Pharmacol, 2015 Jan-Feb;47(1):90-4.
PMID: 25821318 DOI: 10.4103/0253-7613.150360

Antithrombotic therapy with heparin plus antiplatelets reduces the rate of ischemic events in patients with coronary heart disease. Low molecular weight heparin has a more predictable anticoagulant effect than standard unfractionated heparin, is easier to administer, does not require monitoring and is associated with less ADRs. The purpose of the present study was to evaluate and compare the clinical and cost outcomes of Enoxaparin with a standard unfractionated heparin in patients with coronary heart disease.
Preliminary study of a new online and equipment-free vision screening alternative for remote and isolated community

Chen AH, Rosli SA, Ahmad A, Moore BD

Med J Malaysia, 2024 Mar;79(Suppl 1):140-147.
PMID: 38555899

INTRODUCTION: Vision screening has been initiated to detect potential vision problems, paving referral pathways towards a full eye examination. Time-cost-labour practicality challenges of equipment-based vision screening have lingered for decades. Going for the highest sensitivity and specificity or opting for a pragmatic and affordable vision screening program remains a dilemma in public eye health. We aimed to report the development of a new online and equipment-free vision screening called Eye: Questionnairebased Vision Screening (EyeQVS). We also analysed the visual profile of Orang Bateq resided in a remote locality, using findings from EyeQVS, single test vision screening and full eye examination.
MATERIALS AND METHODS: Multi-perspective development strategies were employed in designing EyeQVS. The questionnaire items were constructed using the working backward technique, compiling common vision disorders from the literature and face validation using expert panels. Face validation and usability assessment were performed on EyeQVS. The vision screening was carried out using EyeQVS and single test visual acuity screening method. The full eye examination included visual acuity, refraction, binocular vision and ocular health assessment. The visual profile of indigenous people (Orang Bateq) at Kampung Bengoi and Kampung Atok, Jerantut, Pahang was analysed using EyeQVS, single test visual acuity screening method and full eye examination.
RESULTS: The performance of EyeQVS was affirmative in both face validation and usability. About 95% of Orang Bateq failed full eye examination, while 55% failed EyeQVS screening. None of them failed single test vision screening. Binocular disorders and dry eye problems were commonly found in Orang Bateq. EyeQVS unearthed more various vision problems compared to the single test vision screening (visual acuity alone) as a screening tool in a remote location.
CONCLUSION: EyeQVS can screen for binocular disorders and dry eyes problem commonly found among indigenous people, which might be missed using a single-test visual acuity screening approach. EyeQVS is a practical alternative for vision screening in places where financial or location hinders eye healthcare access.
Fulltext Microencapsulated Aliivibrio fischeri in alginate microspheres for monitoring heavy metal toxicity in environmental waters

Futra D, Heng LY, Surif S, Ahmad A, Ling TL

Sensors (Basel), 2014 Dec 05;14(12):23248-68.
PMID: 25490588 DOI: 10.3390/s141223248

In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri) encapsulated in alginate microspheres is described. Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(II) were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD) range of 2.4-5.7% (n = 8). The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD) for Cu(II) (6.40 μg/L), Cd(II) (1.56 μg/L), Pb(II) (47 μg/L), Ag(I) (18 μg/L) than Zn(II) (320 μg/L), Cr(VI) (1,000 μg/L), Co(II) (1700 μg/L), Ni(II) (2800 μg/L), and Fe(III) (3100 μg/L). Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The A. fischeri bacteria microencapsulated in alginate biopolymer could maintain their metabolic activity for a prolonged period of up to six weeks without any noticeable changes in the bioluminescence response. The bioluminescent biosensor could also be used for the determination of antagonistic toxicity levels for toxicant mixtures. A comparison of the results obtained by atomic absorption spectroscopy (AAS) and using the proposed luminescent A. fischeri-based biosensor suggests that the optical toxicity biosensor can be used for quantitative microdetermination of heavy metal toxicity in environmental water samples.
Fulltext Validation of the Enterococci indicator for bacteriological quality monitoring of beaches in Malaysia using a multivariate approach

Ahmad A, Dada AC, Usup G, Heng LY

Springerplus, 2013;2:425.
PMID: 24052928 DOI: 10.1186/2193-1801-2-425

There is currently no established bacteriological beach quality monitoring (BQM) program in place in Malaysia. To initiate cost-effective, sustainable bacteriological BQM schemes for the ultimate goal of protecting public health, policy decision makers need to be provided robust, indigenous empirical findings that validate appropriate water quality parameters for inclusion in such monitoring programs. This is the first study that assesses the validity of enterococci as an ideal indicator for bacteriological BQM in Malaysia using a multivariate approach. Beach water and sand samples from 7 beach locations were analyzed for a total of twenty-one microbial and non-microbial water quality parameters. A multivariate approach incorporating cluster analyses (CA), principal component analyses (PCA), and factor analysis (FA) was also adopted. Apart from the weak correlations of Staphylococcus aureus with concentrations of Vibro species (r = 0.302, p = 0.037) and total coliforms (r = 0.392, p = 0.006) in seawater, no correlation existed between S. aureus concentration and other parameters. Faecal coliforms failed to correlate with any of the tested parameters. Enterococci also correlated with more quality parameters than faecal coliforms or any other indicator. Multiple linear regressions highlighted a significant, best fit model that could predict enterococci concentrations in relation to other parameters with a maximum predictive success of 69.64%. PCA/FA clearly delineated enterococci and faecal coliforms as parameters that weighed strongly for BQM while Staphylococcus aureus, faecal coliforms and enterococci weighed strongly for beach sand quality monitoring. On the whole, higher correlations of enterococci levels with other parameters than was observed for faecal coliforms suggest that the former be considered a preferred parameter of choice for BQM in Malaysia. Our findings provide meaningful evidence particularly as it relates to the correlation of Enterococci with pathogens and other non-microbial parameters. It also provides empirical data to validate the applicability of the enterococci indicator paradigm for bacteriological beach quality monitoring in Malaysia. The current study thus provides policy decision makers evidenced based approach to parameter streamlining for optimized beach sampling and sustainable bacteriological quality monitoring.
Binary mixture of ionic liquid and span 80 for oil spill remediation: Synthesis and performance evaluation

Nazar M, Ahmad A, Hussain SMS, Moniruzzaman M

Mar Pollut Bull, 2024 Apr 02;202:116311.
PMID: 38574502 DOI: 10.1016/j.marpolbul.2024.116311

The synthesis of new surfactants helps to mitigate the environmental and financial effects of oil spills by providing efficient cleanup options. Herein, this study provides the development of a binary mixture of Span 80 and Choline myristate [Cho][Mys], a surface-active ionic liquid (SAIL) as green dispersant for oil spill remediation. The synergistic interaction at a 60:40 (w/w) ratio significantly lowered the critical micelle concentration (cmc) to 0.029 mM. Dispersion efficiency tests with Arab crude oil showed optimal performance at a 60:40 ratio of Span 80 and [Cho][Mys] (1:25 dispersant to oil ratio, v/v), achieving 81.16 % dispersion effectiveness in the baffled flask test. The binary mixture demonstrated superior emulsion stability (6 h) and the lowest interfacial tension (1.12 mN/m). Acute toxicity experiments revealed the dispersant's practical non-toxicity with an LC50 value of 600 mg/L. Overall, this environmentally benign surfactant combination shows promise as a safe and effective oil spill dispersant.
Fulltext Profound swim stress-induced analgesia with ketamine

Ahmad AH, Ismail Z, Than M, Ahmad A

Malays J Med Sci, 2008 Jan;15(1):13-22.
PMID: 22589610 MyJurnal

The potential of ketamine, an N-methyl D-aspartate (NMDA) receptor antagonist, in preventing central sensitization has led to numerous studies. Ketamine is increasingly used in the clinical setting to provide analgesia and prevent the development of central sensitization at subanaesthetic doses. However, few studies have looked into the potential of ketamine in combination with stress-induced analgesia. This study looks at the effects of swim stress, which is mediated by opioid receptor, on ketamine analgesia using formalin test. Morphine is used as the standard analgesic for comparison. Adult male Sprague-Dawley rats were assigned to 6 groups: 3 groups (stressed groups) were given saline 1ml/kg intraperitoneally (ip), morphine 10mg/kg ip or ketamine 5mg/kg ip and subjected to swim stress; 3 more groups (non-stressed groups) were given the same drugs without swim stress. Formalin test, which involved formalin injection as the pain stimulus and the pain score recorded over time, was performed on all rats ten minutes after cessation of swimming or 30 minutes after injection of drugs. Combination of swim stress and ketamine resulted in complete analgesia in the formalin test which was significantly different from ketamine alone (p<0.05) and saline with stress (p<0.01). There is no significant difference between ketamine stressed and morphine stressed. These results indicate that ketamine and swim stress act synergistically to produce profound analgesia in the formalin test. This suggests that in the clinical setting, under stressful situations such as operative stress, ketamine is capable of producing profound analgesia at a subanaesthetic dose.

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