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Fulltext Length-weight and Length-length Relationship of Longsnouted Catfish, Plicofollis argyropleuron (Valenciennes, 1840) in the Northern Part of Peninsular Malaysia

Rosli NA, Isa MM

Trop Life Sci Res, 2012 Dec;23(2):59-65.
PMID: 24575234 MyJurnal

Scanty information exists pertaining to the length-weight relationship (LWR) and length-length relationship (LLR) parameters of longsnouted catfish, Plicofollis argyropleuron in lotic systems throughout the northern part of Peninsular Malaysia. It is vital to reveal these biological properties of P. argyropleuron in Kuala Muda and Merbok estuary for future management and to increase knowledge about this fish stocks. The fish samples were randomly collected in the estuary area of Kuala Muda and Merbok, Kedah for 10 months from March 2009 to December 2009. The values of the exponent b in the LWR equations (W = aL(b) ) were approximately 3, indicating an isometric growth with high correlation coefficient (r(2)). The value of LLR (r(2)>0.9) indicated that they are highly significant and highly correlated. These parameters are essential for evaluating the relative condition of fish and species managements as well as their fisheries and stock assessment.
Fulltext Current approaches for the exploration of antimicrobial activities of nanoparticles

Rosli NA, Teow YH, Mahmoudi E

Sci Technol Adv Mater, 2021;22(1):885-907.
PMID: 34675754 DOI: 10.1080/14686996.2021.1978801

Infectious diseases of bacterial and viral origins contribute to substantial mortality worldwide. Collaborative efforts have been underway between academia and the industry to develop technologies for a more effective treatment for such diseases. Due to their utility in various industrial applications, nanoparticles (NPs) offer promising potential as antimicrobial agents against bacterial and viral infections. NPs have been established to possess potent antimicrobial activities against various types of pathogens due to their unique characteristics and cell-damaging ability through several mechanisms. The recently accepted antimicrobial mechanisms possessed by NPs include metal ion release, oxidative stress induction, and non-oxidative mechanisms. Another merit of NPs lies in the low likelihood of the development of microbial tolerance towards NPs, given the multiple simultaneous mechanisms of action against the pathogens targeting numerous gene mutations in these pathogens. Moreover, NPs provide a fascinating opportunity to curb microbial growth before infections: this outstanding feature has led to their utilization as active antimicrobial agents in different industrial applications, e.g. the coating of medical devices, incorporation in food packaging, promoting wound healing and encapsulation with other potential materials for wastewater treatment. This review discusses the progress and achievements in the antimicrobial applications of NPs, factors contributing to their actions, mechanisms underlying their efficiency, and risks of their applications, including the antimicrobial action of metal nanoclusters (NCs). The review concludes with a discussion of the restrictions on present studies and future prospects of nanotechnology-based NPs development.
Fulltext Editorial: Integrated omics approaches in the understanding of host-pathogen interactions

Al-Maleki AR, Braima K, Rosli NA

Front Cell Infect Microbiol, 2023;13:1215104.
PMID: 37305425 DOI: 10.3389/fcimb.2023.1215104
Fulltext Influence of amorphous cellulose on mechanical, thermal, and hydrolytic degradation of poly(lactic acid) biocomposites

Wan Ishak WH, Rosli NA, Ahmad I

Sci Rep, 2020 Jul 09;10(1):11342.
PMID: 32647369 DOI: 10.1038/s41598-020-68274-x

Eco-friendly materials such as poly(lactic acid) (PLA) and cellulose are gaining considerable interest as suitable substitutes for petroleum-based plastics. Therefore, amorphous cellulose (AC) was fabricated as a new reinforcing material for PLA biocomposites by modifying a microcrystalline cellulose (MCC) structure via milling. In this study, the mechanical properties, thermal properties, and degradability of PLA were analysed to compare the effects of both MCC and AC on PLA. The tensile and impact properties improved at an optimum value with AC at 8 wt% and 4 wt% fibre loading, respectively. Notably, a scanning electron micrograph analysis revealed improved AC fibre-matrix adhesion, compared with MCC fibre-matrix adhesion, as well as excellent interaction between AC and PLA. Both MCC and AC improved the hydrolytic degradation of PLA. Moreover, the biocomposites with AC exhibited superior degradation when the incorporation of AC improved the water absorption efficiency of PLA. These findings can expand AC applications and improve sustainability.
Hydrophobic modification of cellulose isolated from Agave angustifolia fibre by graft copolymerisation using methyl methacrylate

Rosli NA, Ahmad I, Abdullah I, Anuar FH, Mohamed F

Carbohydr Polym, 2015 Jul 10;125:69-75.
PMID: 25857961 DOI: 10.1016/j.carbpol.2015.03.002

Graft copolymerisation of methyl methacrylate (MMA) onto Agave angustifolia was conducted with ceric ammonium nitrate (CAN) as the redox initiator. The maximum grafting efficiency was observed at CAN and MMA concentrations of 0.91 × 10(-3) and 5.63 × 10(-2)M, respectively, at 45°C for 3h reaction time. Four characteristic peaks at 2995, 1738, 1440, and 845 cm(-1), attributed to PMMA, were found in the IR spectrum of grafted cellulose. The crystallinity index dropped from 0.74 to 0.46, while the thermal stability improved upon grafting. The water contact angle increased with grafting yield, indicating increased hydrophobicity of cellulose. SEM images showed the grafted cellulose to be enlarged and rougher. The changes in the physical nature of PMMA-grafted cellulose can be attributed to the PMMA grafting in the amorphous regions of cellulose, causing it to expand at the expense of the crystalline component.
A mixture of sewage sludge and red gypsum as an alternative material for temporary landfill cover

Rosli NA, Aziz HA, Selamat MR, Lim LLP

J Environ Manage, 2020 Jun 01;263:110420.
PMID: 32883483 DOI: 10.1016/j.jenvman.2020.110420

This study proposed the recycling of sewage sludge (SS) and red gypsum (RG) as potential temporary landfill cover materials. Mixtures with different SS and RG compositions were prepared and tested in determining the most suitable design mix based on the resulting physical, mechanical, and geotechnical properties, namely the hydraulic conductivity, compressive strength, and plasticity. A maximum compressive strength of 524 kPa was achieved for the optimum SS:RG composition of 1:1, corresponding to Ca:Si composition of 2.5:1, which was appropriate to form the calcium silicate hydrate (CSH) gel. The SS and RG compositions did not affect the hydraulic conductivity, which was in the order 10-5 cm/s for all mixtures. Mixtures with RG greater than SS in composition exhibited plastic behaviour due to the Fe content in the RG, which helped minimize the risk of cracking. The optimum mixture had compressive strength greater than the specified minimum of 345 kPa, medium hydraulic conductivity, and moderate plasticity, thus appropriate for application as an alternative material for the temporary landfill cover in the tropics.
Application of polymethylmethacrylate-grafted cellulose as reinforcement for compatibilised polylactic acid/natural rubber blends

Rosli NA, Ahmad I, Anuar FH, Abdullah I

Carbohydr Polym, 2019 Jun 01;213:50-58.
PMID: 30879689 DOI: 10.1016/j.carbpol.2019.02.074

In this study, modified agave cellulose fibre combined by graft copolymerisation with methylmethacrylate was tested as a potential reinforcement for polylactic acid (PLA)-natural rubber/liquid natural rubber blends. Mechanical, morphological, thermal, wetting, and biodegradation characterisations were performed to assess the influence of cellulose-graft-polymethylmethacrylate (cell-g-PMMA) content on the properties of biocomposites. The addition of cell-g-PMMA improved the mechanical properties of the composites because of the chemical interaction between PLA and PMMA. Thermal stability decreased slightly upon cell-g-PMMA addition because of the low thermal stability of PMMA. A soil burial test revealed that the degradation of composites decreased with an increase in the cell-g-PMMA content. However, the weight loss after burial, which directly affected the water absorption capacity, was still higher for the cell-g-PMMA composites than for the polymer alone.
Fulltext Congenital Adrenal Hyperplasia: Diagnostic Pitfalls in Prolonged Neonatal Jaundice

Rosli NA, Mazapuspavina MY, Mohd Nor NS

Clin Pract, 2021 Nov 17;11(4):870-877.
PMID: 34842633 DOI: 10.3390/clinpract11040102

Congenital Adrenal Hyperplasia (CAH) is a genetic disorder that leads to cortisol deficiency. However, prolonged neonatal jaundice is a rare presentation of CAH. The pathophysiology of hyperbilirubinemia in CAH is still ill-defined. Plausible causes are related to the synthesis of bile, maturity of the liver and adrenal function. This case reported a neonate who presented with severe prolonged jaundice that lasted for more than a month. A short Synacthen test confirmed diagnosis of CAH. He was started on steroid replacement. He had regular follow-up under paediatric endocrinologist and primary care physician for long-term monitoring and overall health care. This case demonstrates the importance of recognizing the clinical and biochemical features of CAH for early detection and referral. Long-term follow-up and monitoring is necessary due to the risk of complications and side effects of medications. This is the first case of CAH presented with persistent hyperbilirubinemia to be reported from Malaysia. The case describes the difficult workup that has been encountered in the patient's care and management.
Comprehensive exploration of natural degradation of poly(lactic acid) blends in various degradation media: A review

Rosli NA, Karamanlioglu M, Kargarzadeh H, Ahmad I

Int J Biol Macromol, 2021 Sep 30;187:732-741.
PMID: 34358596 DOI: 10.1016/j.ijbiomac.2021.07.196

Poly(lactic acid) (PLA), a bio-based polyester, has been extensively investigated in the recent past owing to its excellent mechanical properties. Several studies have been conducted on PLA blends, with a focus on improving the brittleness of PLA to ensure its suitability for various applications. However, the increasing use of PLA has increased the contamination of PLA-based products in the environment because PLA remains intact even after three years at sea or in soil. This review focuses on analyzing studies that have worked on improving the degradation properties of PLA blends and studies how other additives affect degradation by considering different degradation media. Factors affecting the degradation properties, such as surface morphology, water uptake, and crystallinity of PLA blends, are highlighted. In natural, biotic, and abiotic media, water uptake plays a crucial role in determining biodegradation rates. Immiscible blends of PLA with other polymer matrices cause phase separation, increasing the water absorption. The susceptibility of PLA to hydrolytic and enzymatic degradation is high in the amorphous region because it can be easily penetrated by water. It is essential to study the morphology, water absorption, and structural properties of PLA blends to predict the biodegradation properties of PLA in the blends.
Fulltext A Feasible Compatibilization Processing Technique for Improving the Mechanical and Thermal Performance of Rubbery Biopolymer/Graphene Nanocomposites

Shahdan D, Rosli NA, Chen RS, Ahmad S

Polymers (Basel), 2022 Nov 18;14(22).
PMID: 36433138 DOI: 10.3390/polym14225009

Over the last few decades, processing and compatibility have become challenging and interesting investigation areas of polymer matrix nanocomposites. This study investigated the addition of maleic anhydride (MAH) at different ratios with graphene nanoplatelets (GnPs) in poly(lactic acid)/modified natural rubber/polyaniline/GnP (PLA/m-NR/PANI/GnP) nanocomposites via two processing methods: a two-step technique and a one-pot technique. The former technique involved first preparing a master batch of PLA grafted with MAH, followed by a second step involving the melt blending of the nanocomposite (T1) using MAH-g-PLA. On the other hand, the one-pot technique involved the direct mixing of MAH during the melt-blending process (T2). The mechanical, morphological and thermal properties of the prepared nanocomposites were investigated. The findings showed that adding MAH significantly improved the tensile strength and elongation at break by about 25% for PLA/m-NR/PANi/GnP nanocomposites, with an optimal ratio of 1:1 of MAH-g-PLA to GnP loading using the T1 technique. FTIR analysis confirmed the chemical interaction between MAH and PLA for T1 nanocomposites, which exhibited improved phase morphology with smoother surfaces. MAH-compatibilized nanocomposites had enhanced thermal stabilities when compared to the sample without a compatibilizer. The findings show that the compatibilized PLA nanocomposite is potentially suitable for bio-inspired materials.
Strategies for strengthening toughened poly(lactic acid) blend via natural reinforcement with enhanced biodegradability: A review

Shahdan D, Rosli NA, Chen RS, Ahmad S, Gan S

Int J Biol Macromol, 2023 Aug 11;251:126214.
PMID: 37572810 DOI: 10.1016/j.ijbiomac.2023.126214

The growing popularity of poly(lactic acid) (PLA) can be attributed to its favorable attributes, such as excellent compostability and robust mechanical properties. Two notable limitations of PLA are its high brittleness and slow biodegradation rate. Both of blending and copolymerization strategies work well to improve PLA's toughness while sacrificing the good tensile strength and modulus properties of PLA. One of the most effective and economical approaches to address this challenge is to incorporate natural reinforcing agents into the toughened PLA system, thereby simultaneously promoting the biodegradation rate of PLA. Nevertheless, the enhancement of tensile strength and modulus is accompanied by a notable decrease in elongation. Therefore, this review provides comprehensive information on the literature works related to the tensile strength, modulus, elongation at break and impact strength of the toughened PLA and its natural fiber reinforced composites. The impact of natural reinforcing agent on the tensile fracture mechanism as well as the synergistic effect on strengthening and toughening performance will be discussed. This review also focuses on the factors boosting the biodegradability of toughened PLA blend by using natural reinforcing fiber. Review presents potential future insights into the development of biodegradable and balanced strengthened-toughened PLA based advanced materials.
Self-preference music for gagging patient: Effect on physiology and oral health-related quality of life during dental impression

Mustafa NWNA, Ishak NH, Mohd Rosli NA, Nik Zulkifeli NR, Rajali A

Complement Ther Clin Pract, 2021 May;43:101392.
PMID: 33862351 DOI: 10.1016/j.ctcp.2021.101392

BACKGROUND: Gagging condition is among factors contributing to avoidance behavior to seek the dental treatment, and rigorous management is still under investigation. This study aims to explore the effect of listening to the self-preference music in reducing the gagging condition during dental impression procedure towards gagging patient. Physiology and psychological impact to the procedure with and without musical intervention are investigated.
METHOD AND MATERIAL: A group of twenty-five patients that will undergo impression procedure was randomly selected. Self-reported Gagging Problem Assessment (GPA-pa-SF) questionnaires was then administered to determine the severity of gagging. Maxillary impression was taken twice within the same patient in two different time intervals (1st without any intervention and 2nd with musical intervention). During both procedures, the pulse rate/minutes (BPM) and arterial oxygen saturation of haemoglobin (SpO2%) were recorded and psychometric assessment was evaluated through the Oral Health Impact Profile (OHIP-14).
RESULT: Mean value of BPM was significantly reduced with music (p
Polymorphism of virulence genes and biofilm associated with in vitro induced resistance to clarithromycin in Helicobacter pylori

Rosli NA, Al-Maleki AR, Loke MF, Chua EG, Alhoot MA, Vadivelu J

Gut Pathog, 2023 Oct 28;15(1):52.
PMID: 37898785 DOI: 10.1186/s13099-023-00579-4

BACKGROUND: Clarithromycin-containing triple therapy is commonly used to treat Helicobacter pylori infections. Clarithromycin resistance is the leading cause of H. pylori treatment failure. Understanding the specific mutations that occur in H. pylori strains that have evolved antibiotic resistance can help create a more effective and individualised antibiotic treatment plan. However, little is understood about the genetic reprogramming linked to clarithromycin exposure and the emergence of antibiotic resistance in H. pylori. Therefore, this study aims to identify compensatory mutations and biofilm formation associated with the development of clarithromycin resistance in H. pylori. Clarithromycin-sensitive H. pylori clinical isolates were induced to develop clarithromycin resistance through in vitro exposure to incrementally increasing concentration of the antibiotic. The genomes of the origin sensitive isolates (S), isogenic breakpoint (B), and resistant isolates (R) were sequenced. Single nucleotide variations (SNVs), and insertions or deletions (InDels) associated with the development of clarithromycin resistance were identified. Growth and biofilm production were also assessed.
RESULTS: The S isolates with A2143G mutation in the 23S rRNA gene were successfully induced to be resistant. According to the data, antibiotic exposure may alter the expression of certain genes, including those that code for the Cag4/Cag protein, the vacuolating cytotoxin domain-containing protein, the sel1 repeat family protein, and the rsmh gene, which may increase the risk of developing and enhances virulence in H. pylori. Enhanced biofilm formation was detected among R isolates compared to B and S isolates. Furthermore, high polymorphism was also detected among the genes associated with biofilm production.
CONCLUSIONS: Therefore, this study suggests that H. pylori may acquire virulence factors while also developing antibiotic resistance due to clarithromycin exposure.
Fulltext Synthesis and Swelling Behavior of pH-Sensitive Semi-IPN Superabsorbent Hydrogels Based on Poly(acrylic acid) Reinforced with Cellulose Nanocrystals

Lim LS, Rosli NA, Ahmad I, Mat Lazim A, Mohd Amin MCI

Nanomaterials (Basel), 2017 Nov 20;7(11).
PMID: 29156613 DOI: 10.3390/nano7110399

pH-sensitive poly(acrylic acid) (PAA) hydrogel reinforced with cellulose nanocrystals (CNC) was prepared. Acrylic acid (AA) was subjected to chemical cross-linking using the cross-linking agent MBA (N,N-methylenebisacrylamide) with CNC entrapped in the PAA matrix. The quantity of CNC was varied between 0, 5, 10, 15, 20, and 25 wt %. X-ray diffraction (XRD) data showed an increase in crystallinity with the addition of CNC, while rheology tests demonstrated a significant increase in the storage modulus of the hydrogel with an increase in CNC content. It was found that the hydrogel reached maximum swelling at pH 7. The potential of the resulting hydrogels to act as drug carriers was then evaluated by means of the drug encapsulation efficiency test using theophylline as a model drug. It was observed that 15% CNC/PAA hydrogel showed the potential to be used as drug carrier system.
Fulltext Density Functional Theory Studies of the Electronic Structure and Muon Hyperfine Interaction in [Au25(SR)18]0 and [Au25(SeR)18]0 Nanoclusters

Ahmad SN, Zaharim WN, Sulaiman S, Hasan Baseri DF, Mohd Rosli NA, Ang LS, et al.

ACS Omega, 2020 Dec 29;5(51):33253-33261.
PMID: 33403287 DOI: 10.1021/acsomega.0c04937

Density functional theory computational investigation was performed to study the electronic structures, muon sites, and the associated hyperfine interactions in [Au25(SR)18]0 and [Au25(SeR)18]0 where R is phenylethane. The calculated electronic structures show inhomogeneous spin density distribution and are also affected by different ligands. The two most stable muon sites near Au atoms in the thiolated system are MAu11 and MAu6. When the thiolate ligands were replaced by selenolate ligands, the lowest energy positions of muons moved to MAu6 and MAu5. Muons prefer to stop inside the Au12 icosahedral shell, away from the central Au and the staple motifs region. Muonium states at phenyl ring and S/Se atoms in the ligand were found to be stable and the Fermi contact fields are much larger as compared to the field experienced by muons near Au atoms.
Fulltext Exposure of Helicobacter pylori to clarithromycin in vitro resulting in the development of resistance and triggers metabolic reprogramming associated with virulence and pathogenicity

Rosli NA, Al-Maleki AR, Loke MF, Tay ST, Rofiee MS, Teh LK, et al.

PLoS One, 2024;19(3):e0298434.
PMID: 38446753 DOI: 10.1371/journal.pone.0298434

In H. pylori infection, antibiotic-resistance is one of the most common causes of treatment failure. Bacterial metabolic activities, such as energy production, bacterial growth, cell wall construction, and cell-cell communication, all play important roles in antimicrobial resistance mechanisms. Identification of microbial metabolites may result in the discovery of novel antimicrobial therapeutic targets and treatments. The purpose of this work is to assess H. pylori metabolomic reprogramming in order to reveal the underlying mechanisms associated with the development of clarithromycin resistance. Previously, four H. pylori isolates were induced to become resistant to clarithromycin in vitro by incrementally increasing the concentrations of clarithromycin. Bacterial metabolites were extracted using the Bligh and Dyer technique and analyzed using metabolomic fingerprinting based on Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry (LC-Q-ToF-MS). The data was processed and analyzed using the MassHunter Qualitative Analysis and Mass Profiler Professional software. In parental sensitivity (S), breakpoint isolates (B), and induced resistance isolates (R) H. pylori isolates, 982 metabolites were found. Furthermore, based on accurate mass, isotope ratios, abundances, and spacing, 292 metabolites matched the metabolites in the Agilent METLIN precise Mass-Personal Metabolite Database and Library (AM-PCDL). Several metabolites associated with bacterial virulence, pathogenicity, survival, and proliferation (L-leucine, Pyridoxone [Vitamine B6], D-Mannitol, Sphingolipids, Indoleacrylic acid, Dulcitol, and D-Proline) were found to be elevated in generated resistant H. pylori isolates when compared to parental sensitive isolates. The elevated metabolites could be part of antibiotics resistance mechanisms. Understanding the fundamental metabolome changes in the course of progressing from clarithromycin-sensitive to breakpoint to resistant in H. pylori clinical isolates may be a promising strategy for discovering novel alternatives therapeutic targets.
Gender disparity in the prescription of secondary prevention medications in a Malaysian primary care clinic

Baharudin N, Ahmad Roslan AM, Mohamed Yassin MS, Ramli AS, Zainal Abidin ANI, Sahar NH, et al.

Malays Fam Physician, 2021 Jul 22;16(2):37-44.
PMID: 34386162 DOI: 10.51866/oa1080

Introduction: Cardiovascular disease is the leading cause of death worldwide. Despite the proven benefit of secondary prevention medications (SPMs), their utilisation remains suboptimal in many countries. This study aimed to assess the use of SPMs in a Malaysian primary care clinic and factors associated with it.
Methods: A retrospective review of electronic medical records was conducted to assess the prescription of SPMs among patients with coronary artery disease who attended the clinic between 1st January 2018 and 31st December 2018. Prescriptions of SPMs were documented in numbers and percentages. Multiple logistic regressions were used to analyse factors associated with the prescription of SPMs.
Results: Of the 662 patients included in the study, 99.1% were prescribed statins, 97% antiplatelets, 81.7% angiotensin-converting enzyme (ACE)-inhibitors or angiotensin II receptor blockers (ARBs), and 78.7% beta-blockers. Male patients were more likely to be prescribed statins (OR = 8.584, 95% CI: 1.431 - 51.510) and antiplatelets (OR = 6.818, 95% CI: 2.294 - 20.257). Another significant factor for antiplatelets prescription was having diabetes (OR = 3.318, 95% CI: 1.148 - 9.590). Having hypertension was associated with ACE-inhibitors or ARBs prescription (OR = 4.008, 95% CI: 2.522 - 6.370).
Conclusion: Although the majority of patients received SPMs, there were significant disparities for some SPMs prescriptions among female patients. As these medications are widely available in the Malaysian primary care setting, steps should be taken to ensure that these medications are prescribed equally for all eligible patients.
Fulltext Density Functional Theory Study of 12mer Single-Strand Guanine Oligomer and Associated Muon Hyperfine Interaction

Zaharim WN, Ahmad SNA, Sulaiman S, Rozak H, Hasan Baseri DF, Mohamad Rosli NA, et al.

ACS Omega, 2021 Nov 09;6(44):29641-29650.
PMID: 34778635 DOI: 10.1021/acsomega.1c03956

Density functional theory method at the B3LYP/6-31G level was used to determine the structure of 12mer single-strand guanine oligomers. The length and width of the optimized structure are 38.7 and 18.2 Å, respectively, and the observed high-resolution transmission electron microscopy image of the 12mer single-strand guanine sample shows similar oligomer dimensions with the calculated ones. Both HOMO and LUMO are significantly delocalized, and the calculated HOMO-LUMO gap is 3.31 eV. A total of 96 muonium trapping sites at C2, C4, C5, C6, C8, N3, N7, and O6 were investigated. All 12 C8 sites have lower energy than the other 84 sites and are clustered in the energy-muon hyperfine coupling constant scatter plot. The calculated muon hyperfine coupling constant at C8 sites range from 384.6 to 481.1 MHz, and the corresponding estimated ALC-μSR resonance for |ΔM| = 1 range from 1.419 to 1.775 T.

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