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Fulltext Application of Metabolomics in the Study of Starvation-Induced Autophagy in Saccharomyces cerevisiae: A Scoping Review

Nasaruddin ML, Tajul Arifin K

J Fungi (Basel), 2021 Nov 19;7(11).
PMID: 34829274 DOI: 10.3390/jof7110987

This scoping review is aimed at the application of the metabolomics platform to dissect key metabolites and their intermediates to observe the regulatory mechanisms of starvation-induced autophagy in Saccharomyces cerevisiae. Four research papers were shortlisted in this review following the inclusion and exclusion criteria. We observed a commonly shared pathway undertaken by S. cerevisiae under nutritional stress. Targeted and untargeted metabolomics was applied in either of these studies using varying platforms resulting in the annotation of several different observable metabolites. We saw a commonly shared pathway undertaken by S. cerevisiae under nutritional stress. Following nitrogen starvation, the concentration of cellular nucleosides was altered as a result of autophagic RNA degradation. Additionally, it is also found that autophagy replenishes amino acid pools to sustain macromolecule synthesis. Furthermore, in glucose starvation, nucleosides were broken down into carbonaceous metabolites that are being funneled into the non-oxidative pentose phosphate pathway. The ribose salvage allows for the survival of starved yeast. Moreover, acute glucose starvation showed autophagy to be involved in maintaining ATP/energy levels. We highlighted the practicality of metabolomics as a tool to better understand the underlying mechanisms involved to maintain homeostasis by recycling degradative products to ensure the survival of S. cerevisiae under starvation. The application of metabolomics has extended the scope of autophagy and provided newer intervention targets against cancer as well as neurodegenerative diseases in which autophagy is implicated.
A DFT analyses for molecular structure, electronic state and spectroscopic property of a dithiolene tungsten carbonyl complex

Arifin K, Daud WR, Kassim MB

Spectrochim Acta A Mol Biomol Spectrosc, 2014 Apr 24;124:375-82.
PMID: 24508875 DOI: 10.1016/j.saa.2013.12.107

Bis(dithiolene) tungsten carbonyl complex, W(S2C2Ph2)2(CO)2 was successfully synthesized and the structure, frontier molecular orbital and optical properties of the complex were investigated theoretically using density functional theory calculations. The investigation started with a molecular structure construction, followed by an optimization of the structural geometry using generalized-gradient approximation (GGA) in a double numeric plus polarization (DNP) basis set at three different functional calculation approaches. Vibrational frequency analysis was used to confirm the optimized geometry of two possible conformations of [W(S2C2Ph2)2(CO)2], which showed distorted octahedral geometry. Electronic structure and optical characterization were done on the ground states. Metal to ligand and ligand to metal charge transfer were dominant in this system.
Fulltext Response surface optimisation of high antioxidant jelly from Musa paradisiaca and Trigona sp. honey using central composite design as a convenient functional food

Mohd Nur Nasyriq, A., Muhammad, I., Badr Eddin, K.,, Nur Aizura, M. A., Ainin Azwani, A. R., Norazlanshah, H, et al.

International Food Research Journal, 2019;26(4):1201-1209.
MyJurnal

The optimum combination of Musa paradisiaca (MP) and Trigona sp. Honey (TH) in formulating high antioxidant jelly was analysed for total carbohydrate content (CHO), antioxidant capacity (AC), and acceptability via the Response Surface Methodology. Central composite design was employed to optimise the combination effect of two independent variables; namely MP (X1: 20-100%) and TH (X2: 20-100%) on the recovery of three responses; total carbohydrate content (Y1), antioxidant capacity (Y2), and acceptability (Y3). A polynomial model generated a satisfactory fitting of the experimental data with regards to total carbohydrate content (R2
= 0.8974, p < 0.0024), total antioxidant capacity (R2 = 0.9702, p < 0.0001), and acceptability (R2 = 0.9136, p < 0.0001). The optimum combination for maximum recovery of CHO, AC and acceptability were 20% of MP and 20% of TBH, with a predicted CHO of 33 Kcal/5 g, AC of
0.34 nm and acceptability score of 6.16 (< 5: not accepted; > 5: accepted).
Fulltext Characterization of the functional domain of β2-microglobulin from the Asian seabass, Lates calcarifer

Mohd-Padil H, Tajul-Arifin K, Mohd-Adnan A

PLoS One, 2010;5(10):e13159.
PMID: 20949082 DOI: 10.1371/journal.pone.0013159

β2-Microglobulin (β(2)M) is the light chain of major histocompatibility class I (MHC I) that binds non-covalently with the α heavy chain. Both proteins attach to the antigen peptide, presenting a complex to the T cell to be destroyed via the immune mechanism.
Synthesis, structure and theoretical investigation into a homoleptic tris(dithiolene) tungsten

Arifin K, Minggu LJ, Daud WR, Yamin BM, Daik R, Kassim MB

Spectrochim Acta A Mol Biomol Spectrosc, 2014;120:208-15.
PMID: 24184623 DOI: 10.1016/j.saa.2013.09.069

A new homoleptic dithiolene tungsten complex, tris-{1,2-bis(3,5-dimethoxyphenyl)-1,2-ethylenodithiolene-S,S'}tungsten, was successfully synthesized via a reaction of the thiophosphate ester and sodium tungstate. The thiophosphate ester was prepared from 3,5-dimethoxybenzaldehyde via benzoin condensation to produce the intermediate 1,2-bis-(3,5-dimethoxyphenyl)-2-hydroxy-ethanone compound, followed by a reaction of the intermediate with phosphorus pentasulfide. FTIR, UV-Vis spectroscopy, 1H NMR and 13C NMR and elemental analysis confirmed the product as tris{1,2-bis-(3,5-dimethoxyphenyl)-1,2-ethylenodithiolene-S,S'}tungsten with the molecular formula of C54H54O12S6W. Crystals of the product adopted a monoclinic system with space group of P2(1)/n, where a=12.756(2) Å, b=21.560(3) Å, c=24.980(4) Å and β=103.998(3)°. Three thioester ligands were attached to the tungsten as bidentate chelates to form a distorted octahedral geometry. Density functional theory calculations were performed to investigate the molecular properties in a generalized-gradient approximation framework system using Perdew-Burke-Ernzerhof functions and a double numeric plus polarization basis set. The HOMO was concentrated on the phenyl ligands, while the LUMO was found along the W(S2C2)3 rings. The theoretical optical properties showed a slight blue shift in several low dielectric solvents. The solvatochromism effect was insignificant for high polar solvents.
Targeting genes in insulin-associated signalling pathway, DNA damage, cell proliferation and cell differentiation pathways by tocotrienol-rich fraction in preventing cellular senescence of human diploid fibroblasts

Durani LW, Jaafar F, Tan JK, Tajul Arifin K, Mohd Yusof YA, Wan Ngah WZ, et al.

Clin Ter, 2016;166(6):e365-73.
PMID: 26794818 DOI: 10.7417/T.2015.1902

Tocotrienols have been known for their antioxidant properties besides their roles in cellular signalling, gene expression, immune response and apoptosis. This study aimed to determine the molecular mechanism of tocotrienol-rich fraction (TRF) in preventing cellular senescence of human diploid fibroblasts (HDFs) by targeting the genes in senescence-associated signalling pathways.
Fulltext Data for the subsurface characterization of Pahang River Basin with the application of Transient Electromagnetic geophysical surveys

Arifin H, Kayode J, Arifin K, Zahir Z, Abdullah M, Azmi A

Data Brief, 2020 Jun;30:105491.
PMID: 32373680 DOI: 10.1016/j.dib.2020.105491

The Transient Electro-Magnetic (TEM) geophysical technique was deployed to map and characterized the subsurface of Pahang River Basin along the East Coast Peninsula Malaysia. The data aimed at differentiating between the massive zones and the weak zones within the region, to also assess and differentiate the subsurface structures and comes up with recommendations for policy decision, formulation and plans on the flooding impact, surface water and groundwater managements, in addition to other environmental related issues ravaging the area. The data presented in this paper, showed the properties of the subsurface rocks underlain the region as beneficial to the Agriculturists; Climatologists; Engineers; Environmentalists; Geoscientists, Hydrologists and Policy formulation officers. The TEM data collection utilized a 100 m x 100 m single loop coil for both the Transmitter (Tx) loop and the Receiver (Rx) loop to produce a total surface area coverage of 10,000 m2 per survey line along a single profile. The total area covered in the data extended across an average area of 30 km x 40 km in parts of Maran, Temerloh and Jerantut districts, within the State of Pahang, East Coast, Peninsula Malaysia. The conductivity data recorded varied from -20 mS/m to about 440 mS/m at a maximum depth of about 375 m. On the other hand, the resistivity data recorded varied from 0 Oh-m to about 1000 Oh-m. The information derived from the data are intended for potential abstraction by the Malaysian Groundwater Management Board; the Department of Mineral and Geoscience; Department of Irrigation and Drainage; the Pahang State Water Board, and the Department of Agriculture.
Occupational safety and health management in the construction industry: a review

Jaafar MH, Arifin K, Aiyub K, Razman MR, Ishak MIS, Samsurijan MS

Int J Occup Saf Ergon, 2018 Dec;24(4):493-506.
PMID: 28849991 DOI: 10.1080/10803548.2017.1366129

The construction industry plays a significant role in contributing to the economy and development globally. During the process of construction, various hazards coupled with the unique nature of the industry contribute to high fatality rates. This review refers to previous published studies and related Malaysian legislation documents. Four main elements consisting of human, worksite, management and external elements which cause occupational accidents and illnesses were identified. External and management elements are the underlying causes contributing to occupational safety and health (OSH), while human and worksite elements are more apparent causes of occupational accidents and illnesses. An effective OSH management approach is required to contain all hazards at construction sites. An approach to OSH management constructed by elements of policy, process, personnel and incentive developed in previous work is explored. Changes to the sub-elements according to previous studies and the related Malaysian legislation are also covered in this review.
Fulltext Elevation of tumour markers TGF-β, M2-PK, OV-6 and AFP in hepatocellular carcinoma (HCC)-induced rats and their suppression by microalgae Chlorella vulgaris

Tajul Arifin K, Sulaiman S, Md Saad S, Ahmad Damanhuri H, Wan Ngah WZ, Mohd Yusof YA

BMC Cancer, 2017 12 21;17(1):879.
PMID: 29268718 DOI: 10.1186/s12885-017-3883-3

BACKGROUND: Chlorella vulgaris (ChV), a unicellular green algae has been reported to have anticancer and antioxidant effects. The aim of this study was to determine the chemopreventive effect of ChV on liver cancer induced rats by determining the level and expression of several liver tumour markers.
METHODS: Male Wistar rats (200-250 g) were divided into 4 groups according to the diet given: control group (normal diet), ChV group with three different doses (50, 150 and 300 mg/kg body weight), liver cancer- induced group (choline deficient diet + 0.1% ethionine in drinking water or CDE group), and the treatment group (CDE group treated with three different doses of ChV). Rats were killed at 0, 4, 8 and 12 weeks of experiment and blood and tissue samples were taken from all groups for the determination of tumour markers expression alpha-fetoprotein (AFP), transforming growth factor-β (TGF-β), M2-pyruvate kinase (M2-PK) and specific antigen for oval cells (OV-6).
RESULTS: Serum level of TGF-β increased significantly (p < 0.05) in CDE rats. However, ChV at all doses managed to decrease (p < 0.05) its levels to control values. Expressions of liver tumour markers AFP, TGF-β, M2-PK and OV-6 were significantly higher (p < 0.05) in tissues of CDE rats when compared to control showing an increased number of cancer cells during hepatocarcinogenesis. ChV at all doses reduced their expressions significantly (p < 0.05).
CONCLUSIONS: Chlorella vulgaris has chemopreventive effect by downregulating the expression of tumour markers M2-PK, OV-6, AFP and TGF-β, in HCC-induced rats.
TiO2 Nanotubes Decorated with Mo2C for Enhanced Photoelectrochemical Water-Splitting Properties

Moridon SNF, Arifin K, Mohamed MA, Minggu LJ, Mohamad Yunus R, Kassim MB

Materials (Basel), 2023 Sep 18;16(18).
PMID: 37763538 DOI: 10.3390/ma16186261

The presence of Ti3+ in the structure of TiO2 nanotube arrays (NTs) has been shown to enhance the photoelectrochemical (PEC) water-splitting performance of these NTs, leading to improved results compared to pristine anatase TiO2 NTs. To further improve the properties related to PEC performance, we successfully produced TiO2 NTs using a two-step electrochemical anodization technique, followed by annealing at a temperature of 450 °C. Subsequently, Mo2C was decorated onto the NTs by dip coating them with precursors at varying concentrations and times. The presence of anatase TiO2 and Ti3O5 phases within the TiO2 NTs was confirmed through X-ray diffraction (XRD) analysis. The TiO2 NTs that were decorated with Mo2C demonstrated a photocurrent density of approximately 1.4 mA cm-2, a value that is approximately five times greater than the photocurrent density exhibited by the bare TiO2 NTs, which was approximately 0.21 mA cm-2. The observed increase in photocurrent density can be ascribed to the incorporation of Mo2C as a cocatalyst, which significantly enhances the photocatalytic characteristics of the TiO2 NTs. The successful deposition of Mo2C onto the TiO2 NTs was further corroborated by the characterization techniques utilized. The utilization of field emission scanning electron microscopy (FESEM) allowed for the observation of Mo2C particles on the surface of TiO2 NTs. To validate the composition and optical characteristics of the decorated NTs, X-ray photoelectron spectroscopy (XPS) and UV absorbance analysis were performed. This study introduces a potentially effective method for developing efficient photoelectrodes based on TiO2 for environmentally sustainable hydrogen production through the use of photoelectrochemical water-splitting devices. The utilization of Mo2C as a cocatalyst on TiO2 NTs presents opportunities for the advancement of effective and environmentally friendly photoelectrochemical (PEC) systems.
The influence of hazard control and prevention toward safety behaviors and safety outcomes in coal-fired power plants using PLS-SEM

Arifin K, Ali MXM, Abas A, Ahmad MA, Ahamad MA, Sahimi AS

J Safety Res, 2023 Sep;86:376-389.
PMID: 37718065 DOI: 10.1016/j.jsr.2023.07.017

INTRODUCTION: The electrical utility industry, which plays a vital role in sustaining other sectors, contributes to high occupational accident rates in the utility industries. The high accident rate shows that there has been insufficient effort made to control unsafe actions and conditions in the workplace. This study aims to examine the influence of hazard control and prevention as leading indicators of safety behaviors and outcomes in coal-fired power plants in Malaysia.
METHODS: This quantitative research was conducted by distributing survey questionnaires randomly to five coal-fired power plants in Peninsular Malaysia. A total of 340 respondents were involved in this research. Partial least squares structural equation modeling (PLS-SEM) analysis was performed using SmartPLS to validate and examine the relationship of the proposed model.
RESULTS: The results validate the construct of hazard control and prevention consisting of planning, action, managing, and verifying, while the safety outcomes construct consists of occupational accidents, fatal accidents, near misses, and lost time injuries. The results indicate that hazard control and prevention significantly relate to safety compliance, safety participation, safety motivation, and safety knowledge. Moreover, safety outcomes were influenced negatively by hazard control and prevention through safety compliance.
CONCLUSION: The model provides a better understanding of the influence of hazard control and prevention on safety behavior and outcomes.
PRACTICAL APPLICATIONS: The model can be used as guidance for practitioners and researchers in planning and implementing hazard control and prevention to improve health and safety in the workplace.
Vertical MoS2on SiO2/Si and Graphene: Effect of Surface Morphology on Photoelectrochemical Properties

Rosman NN, Mohamad Yunus R, Jeffery Minggu L, Arifin K, B Kassim M, Mohamed MA

Nanotechnology, 2020 Oct 06.
PMID: 33022666 DOI: 10.1088/1361-6528/abbea9

Two-dimensional materials have attracted intensive attention recently due to their unique optical and electronic properties and their promising applications in water splitting and solar cells. As a representative layer-structured of transition metal dichalcogenides, MoS2has attracted considerable devotion owing to its exceptional photo and electro properties. Here, we show that the chemical vapour deposition (CVD) growth of MoS2on Si photocathode and graphene/Si photocathode can be used to prepare photoelectrocatalysts for water splitting. We explore a bottom-up method to grow vertical heterostructures of MoS2and graphene by using the two-step CVD. Graphene is first grown through ambient-pressure CVD on a Cu substrate and then transferred onto SiO2/Si substrate by using the chemical wet transfer followed by the second CVD method to grow MoS2over the graphene/SiO2/Si. The effect of the growth temperatures of MoS2is studied, and the optimum temperature is 800 °C. The MoS2produced at 800 °C has the highest photocurrent density at -0.23 mA cm-2in 0.5 M Na2SO4and -0.51 mA cm-2in 0.5 M H2SO4at -0.8 V vs. Ag/AgCl. The linear sweep voltammetry shows that MoS2in 0.5 M H2SO4has about 55% higher photocurrent density than MoS2in Na2SO4due to the higher protons (H+) in the H2SO4electrolyte solution, which are sufficiently charged to reduce to H2and, therefore hydrogen evolves more rapidly where the photocurrent density and hydrogen generation can be enhanced. MoS2/graphene/SiO2/Si (MGS) has -0.07 mA cm-2at -0.8 V vs. Ag/AgCl of photocurrent density, which is 70% lower than that of bare MoS2because MGS is thicker compared with MoS2. Thus, MoS2has potential as a photocatalyst in photoelectrochemical water splitting. The structure and the morphology of MoS2play an important role in determining the photocurrent performance.
Fulltext Bioinformatics in Malaysia: hope, initiative, effort, reality, and challenges

Zeti AM, Shamsir MS, Tajul-Arifin K, Merican AF, Mohamed R, Nathan S, et al.

PLoS Comput Biol, 2009 Aug;5(8):e1000457.
PMID: 19714208 DOI: 10.1371/journal.pcbi.1000457
Fulltext CD64 and Group II Secretory Phospholipase A2 (sPLA2-IIA) as Biomarkers for Distinguishing Adult Sepsis and Bacterial Infections in the Emergency Department

Tan TL, Ahmad NS, Nasuruddin DN, Ithnin A, Tajul Arifin K, Zaini IZ, et al.

PLoS One, 2016;11(3):e0152065.
PMID: 27003588 DOI: 10.1371/journal.pone.0152065

INTRODUCTION: Early diagnosis of sepsis and bacterial infection is imperative as treatment relies on early antibiotic administration. There is a need to develop new biomarkers to detect patients with sepsis and bacterial infection as early as possible, thereby enabling prompt antibiotic treatment and improving the survival rate.
METHODS: Fifty-one adult patients with suspected bacterial sepsis on admission to the Emergency Department (ED) of a teaching hospital were included into the study. All relevant cultures and serology tests were performed. Serum levels for Group II Secretory Phospholipase A2 (sPLA2-IIA) and CD64 were subsequently analyzed.
RESULTS AND DISCUSSION: Sepsis was confirmed in 42 patients from a total of 51 recruited subjects. Twenty-one patients had culture-confirmed bacterial infections. Both biomarkers were shown to be good in distinguishing sepsis from non-sepsis groups. CD64 and sPLA2-IIA also demonstrated a strong correlation with early sepsis diagnosis in adults. The area under the curve (AUC) of both Receiver Operating Characteristic curves showed that sPLA2-IIA was better than CD64 (AUC = 0.93, 95% confidence interval (CI) = 0.83-0.97 and AUC = 0.88, 95% CI = 0.82-0.99, respectively). The optimum cutoff value was 2.13μg/l for sPLA2-IIA (sensitivity = 91%, specificity = 78%) and 45 antigen bound cell (abc) for CD64 (sensitivity = 81%, specificity = 89%). In diagnosing bacterial infections, sPLA2-IIA showed superiority over CD64 (AUC = 0.97, 95% CI = 0.85-0.96, and AUC = 0.95, 95% CI = 0.93-1.00, respectively). The optimum cutoff value for bacterial infection was 5.63μg/l for sPLA2-IIA (sensitivity = 94%, specificity = 94%) and 46abc for CD64 (sensitivity = 94%, specificity = 83%).
CONCLUSIONS: sPLA2-IIA showed superior performance in sepsis and bacterial infection diagnosis compared to CD64. sPLA2-IIA appears to be an excellent biomarker for sepsis screening and for diagnosing bacterial infections, whereas CD64 could be used for screening bacterial infections. Both biomarkers either alone or in combination with other markers may assist in decision making for early antimicrobial administration. We recommend incorporating sPLA2-IIA and CD64 into the diagnostic algorithm of sepsis in ED.
Fulltext Comparison of sPLA2IIA performance with high-sensitive CRP neutrophil percentage PCT and lactate to identify bacterial infection

Tan TL, Kang CW, Ooi KS, Tan ST, Ahmad NS, Nasuruddin DN, et al.

Sci Rep, 2021 05 31;11(1):11369.
PMID: 34059757 DOI: 10.1038/s41598-021-90894-0

Early bacterial infection (BI) identification in resource-limiting Emergency Departments (ED) is challenging, especially in low- and middle-income counties (LMIC). Misdiagnosis predisposes to antibiotic overuse and propagates antimicrobial resistance. This study evaluates new emerging biomarkers, secretory phospholipase A2 group IIA (sPLA2-IIA) and compares with other biomarkers on their performance characteristic of BI detection in Malaysia, an LMIC. A prospective cohort study was conducted involving 151 consecutive patients admitted to the ED. A single measurement was taken upon patient arrival in ED and was analysed for serum levels of sPLA2-IIA, high-sensitive C-reactive protein (CRP), procalcitonin (PCT), neutrophil percentage (N%), and lactate. All biomarkers' performance was compared for the outcomes using area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity. The performance of sPLA2-IIA (AUROC 0.93 [95% CI: 0.89-0.97]; Sn 80% [95% CI: 72-87]; Sp 94% [95% CI: 81-89]) was the highest among all. It was comparable with high-sensitive CRP (AUROC 0.93 [95% CI: 0.88-0.97]; Sn 75% [95% CI: 66-83]; Sp 91 [95% CI: 77-98]) but had a higher Sn and Sp. The sPLA2-IIA was also found superior to N%, PCT, and lactate. This finding suggested sPLA2-IIA was recommended biomarkers for BI detection in LMIC.

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