Displaying publications 1 - 20 of 110 in total

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  1. Aan GJ, Hairi HA, Makpol S, Rahman MA, Karsani SA
    Electrophoresis, 2013 Aug;34(15):2209-17.
    PMID: 23712505 DOI: 10.1002/elps.201300086
    Replicative senescence and stress-induced premature senescence (SIPS) cells are known to share certain traits. However, whether these cells are different at the protein level is unclear. Thus, this study has utilized proteomics to identify differences in the proteomes of replicative senescence and SIPS cells compared to normal cells. Replicative senescence was induced by serial passage of normal cells in culture. SIPS was established by exposure to H2 O2 at a subcytotoxic concentration of 20 μM for two weeks. Following 2DE, protein profiles were compared and protein spots that changed in abundance were identified by MALDI-TOF MS. Quantitative real-time RT-PCR was then performed to evaluate the transcript expression of selected altered proteins. A total of 24 and 10 proteins were found to have changed in abundance in replicative senescence and SIPS cells, respectively, when compared to young cells. Quantitative RT-PCR revealed that nine genes showed the same direction of change as observed in the proteomics analysis. Very little overlap was observed between proteins that changed in replicative senescence and SIPS cells, suggesting that although both SIPS and replicative senescence cells share hallmarks of cellular senescence, they were different in terms of proteins that changed in abundance.
  2. Ab Rahman NI, Yunos NM, Atan R, Mariapun J, Ab Rahman MA, Ismail AJ, et al.
    Front Med (Lausanne), 2022;9:1086288.
    PMID: 36698832 DOI: 10.3389/fmed.2022.1086288
    BACKGROUND: Coronavirus disease 2019 (COVID-19) emerged with a wide range of clinical presentations; Malaysia was not spared from its impact. This study describes the clinical characteristics of COVID-19 patients admitted to intensive care unit, their clinical course, management, and hospital outcomes.

    METHODS: COVIDICU-MY is a retrospective analysis of COVID-19 patients from 19 intensive care units (ICU) across Malaysia from 1 March 2020 to 31 May 2020. We collected epidemiological history, demographics, clinical comorbidities, laboratory investigations, respiratory and hemodynamic values, management, length of stay and survival status. We compared these variables between survival and non-survival groups.

    RESULTS: A total of 170 critically ill patients were included, with 77% above 50 years of age [median age 60, IQR (51-66)] and 75.3% male. Hypertension, diabetes mellitus, hyperlipidemia, chronic cardiac disease, and chronic kidney disease were most common among patients. A high Simplified Acute Physiology Score (SAPS) II score [median 45, IQR (34-49)] and Sequential Organ Failure Assessment (SOFA) score [median 8, IQR (6-11)] were associated with mortality. Patients were profoundly hypoxic with a median lowest PaO2/FiO2 ratio of 150 (IQR 99-220) at admission. 91 patients (53.5%) required intubation on their first day of admission, out of which 38 died (73.1% of the hospital non-survivors). Our sample had more patients with moderate Acute Respiratory Distress Syndrome (ARDS), 58 patients (43.9%), compared to severe ARDS, 33 patients (25%); with both ARDS classification groups contributing to 25 patients (54.4%) and 11 patients (23.9%) of the non-survival group, respectively. Cumulative fluid balance over 24 h was higher in the non-survival group with significant differences on Day 3 (1,953 vs. 622 ml, p < 0.05) and Day 7 of ICU (3,485 vs. 830 ml, p < 0.05). Patients with high serum creatinine, urea, lactate dehydrogenase, aspartate aminotransferase and d-dimer, and low lymphocyte count throughout the stay also had a higher risk of mortality. The hospital mortality rate was 30.6% in our sample.

    CONCLUSION: We report high mortality amongst critically ill patients in intensive care units in Malaysia, at 30.6%, during the March to May 2020 period. High admission SAPS II and SOFA, and severe hypoxemia and high cumulative fluid balance were associated with mortality. Higher creatinine, urea, lactate dehydrogenase, aspartate aminotransferase and d-dimer, and lymphopenia were observed in the non-survival group.

  3. Abir T, Kalimullah NA, Osuagwu UL, Nur-A Yazdani DM, Husain T, Goson PC, et al.
    Ann Glob Health, 2021 04 26;87(1):43.
    PMID: 33981590 DOI: 10.5334/aogh.3269
    Background: Feelings of isolation, insecurity, and instability triggered by COVID-19 could have a long-term impact on the mental health status of individuals.

    Objectives: The aim of this study was to examine the prevalence of mental health symptoms (anxiety, depression, and stress) in Bangladesh and the factors associated with these symptoms during the COVID-19 pandemic.

    Methods: From 1 to 30 April 2020, we used a validated self-administered questionnaire to conduct a cross-sectional study on 10,609 participants through an online survey platform. We assessed mental health status using the Depression, Anxiety, and Stress Scale (DASS-21). The total depression, anxiety, and stress subscale scores were divided into normal, mild, moderate, severe, and multinomial logistic regression was used to examine associated factors.

    Findings: The prevalence of depressive symptoms was 15%, 34%, and 15% for mild, moderate, and severe depressive symptoms, respectively. The prevalence of anxiety symptoms was 59% for severe anxiety symptoms, 14% for moderate anxiety symptoms, and 14% for mild anxiety symptoms, while the prevalence for stress levels were 16% for severe stress level, 22% for moderate stress level, and 13% for mild stress level. Multivariate analyses revealed that the most consistent factors associated with mild, moderate, and severe of the three mental health subscales (depression, anxiety, and stress) were respondents who lived in Dhaka and Rangpur division, females, those who self-quarantined in the previous seven days before the survey, and those respondents who experienced chills, breathing difficulty, dizziness, and sore throat.

    Conclusion: Our results showed that about 64%, 87%, and 61% of the respondents in Bangladesh reported high levels of depression, anxiety, and stress, respectively. There is a need for mental health support targeting women and those who self-quarantined or lived in Dhaka and Rangpur during the pandemic.

  4. Abir T, Osuagwu UL, Kalimullah NA, Yazdani DMN, Husain T, Basak P, et al.
    Health Secur, 2021 08 03;19(5):468-478.
    PMID: 34348050 DOI: 10.1089/hs.2020.0205
    The COVID-19 pandemic has generated fear, panic, distress, anxiety, and depression among many people in Bangladesh. In this cross-sectional study, we examined factors associated with different levels of psychological impact as a result of COVID-19 in Bangladesh. From April 1 to 30, 2020, we used a self-administered online questionnaire to collect data from 10,609 respondents. Using the Impact of Event Scale-Revised to assess the psychological impact of the COVID-19 pandemic on respondents, we categorized the levels of impact as normal, mild, moderate, or severe. Ordinal logistic regression was used to examine the associated factors. The prevalence of mild, moderate, and severe psychological impact was 10.2%, 4.8%, and 45.5%, respectively. Multivariate analysis revealed that the odds of reporting normal vs mild, moderate, or severe psychological impact were 5.9 times higher for people living in the Chittagong Division, 1.7 times higher for women with lower education levels, 3.0 times higher among those who were divorced or separated, 1.8 times higher for those working full time, and 2.4 times higher for those living in shared apartments. The odds of reporting a psychological impact were also higher among people who did not enforce protective measures inside the home, those in self-quarantine, those who did not wear face masks, and those who did not comply with World Health Organization precautionary measures. Increased psychological health risks due to COVID-19 were significantly higher among people who experienced chills, headache, cough, breathing difficulties, dizziness, and sore throat before data collection. Our results showed that 1 in 2 respondents experienced a significant psychological impact as a result of the COVID-19 pandemic. Public health researchers should consider these factors when targeting interventions that would have a protective effect on the individual's psychological health during a pandemic or future disease outbreak.
  5. Adam MR, Salleh NM, Othman MHD, Matsuura T, Ali MH, Puteh MH, et al.
    J Environ Manage, 2018 Oct 15;224:252-262.
    PMID: 30055458 DOI: 10.1016/j.jenvman.2018.07.043
    Adsorption is one of the most efficient ways to remove heavy metal from wastewater. In this study, the adsorptive removal of hexavalent chromium, Cr (VI) from aqueous solution was investigated using natural zeolite, clinoptilolite, in the form of hollow fibre ceramic membrane (HFCM). The HFCM sample was prepared using phase inversion-based extrusion technique and followed by sintering process at different sintering temperatures in the range of 900-1050 °C. The fabricated HFCM was characterised using scanning electron microscopy (SEM), contact angle, water permeability, and mechanical strength for all HFCMs sintered at different temperatures. The adsorption and filtration test of Cr (VI) were performed using an in-house water permeation set up with a dead-end cross-flow permeation test. An asymmetric structure with sponge- and finger-like structures across the cross-section of HFCM was observed using SEM. Based on the characterisation data, 1050 °C was chosen to be the best sintering temperature as the water permeability and mechanical strength of this HFCM were 29.14 L/m2∙h and 50.92 MPa, respectively. The performance of the HFCM in adsorption/filtration was 44% of Cr (VI) removal at the Cr (VI) concentration of 40 mg/L and pH 4. In addition, the mathematical model was also performed in simulating the experimental data obtained from this study. All in all, the natural zeolite-based HFCM has a potential as a single-step Cr (VI) removal by membrane adsorption for the wastewater treatment.
  6. Adibah Yusof NA, Abdul Karim MK, Asikin NM, Paiman S, Awang Kechik MM, Abdul Rahman MA, et al.
    Curr Med Imaging, 2023;19(10):1105-1113.
    PMID: 35975862 DOI: 10.2174/1573405618666220816160544
    BACKGROUND: For almost three decades, computed tomography (CT) has been extensively used in medical diagnosis, which led researchers to conduct linking of CT dose exposure with image quality.

    METHODS: In this study, a systematic review and a meta-analysis study were conducted on CT phantom for resolution study especially based on the low contrast detectability (LCD). Furthermore, the association between the CT parameter such as tube voltage and the type of reconstruction algorithm, the amount of phantom scanning affecting the image quality and the exposure dose were also investigated in this study. We utilize PubMed, ScienceDirect, Google Scholar and Scopus databases to search related published articles from the year 2011 until 2020. The notable keywords comprise "computed tomography", "CT phantom", and "low contrast detectability". Of 52 articles, 20 articles are within the inclusion criteria in this systematic review.

    RESULTS: The dichotomous outcomes were chosen to represent the results in terms of risk ratio as per meta-analysis study. Notably, the noise in iterative reconstruction (IR) reduced by 24%, 33% and 36% with the use of smooth, medium and sharp filters, respectively. Furthermore, adaptive iterative dose reduction (AIDR 3D) improved image quality and the visibility of smaller less dense objects compared to filtered back-projection. Most of the researchers used 120 kVp tube voltage to scan phantom for quality assurance study.

    CONCLUSION: Hence, optimizing primary factors such as tube potential reduces the dose exposure significantly, and the optimized IR technique could substantially reduce the radiation dose while maintaining the image quality.

  7. Afroz S, Fairuz S, Joty JA, Uddin MN, Rahman MA
    J Food Biochem, 2021 12;45(12):e13961.
    PMID: 34676581 DOI: 10.1111/jfbc.13961
    COVID-19 has become the focal point since 2019 after the outbreak of coronavirus disease. Many drugs are being tested and used to treat coronavirus infections; different kinds of vaccines are also introduced as preventive measure. Alternative therapeutics are as well incorporated into the health guidelines of some countries. This research aimed to look into the underlying mechanisms of functional foods and how they may improve the long-term post COVID-19 cardiovascular, diabetic, and respiratory complications through their bioactive compounds. The potentiality of nine functional foods for post COVID-19 complications was investigated through computational approaches. A total of 266 bioactive compounds of these foods were searched via extensive literature reviewing. Three highly associated targets namely troponin I interacting kinase (TNNI3K), dipeptidyl peptidase 4 (DPP-4), and transforming growth factor beta 1 (TGF-β1) were selected for cardiovascular, diabetes, and respiratory disorders, respectively, after COVID-19 infections. Best docked compounds were further analyzed by network pharmacological tools to explore their interactions with complication-related genes (MAPK1 and HSP90AA1 for cardiovascular, PPARG and TNF-alpha for diabetes, and AKT-1 for respiratory disorders). Seventy-one suggested compounds out of one-hundred and thirty-nine (139) docked compounds in network pharmacology recommended 169 Gene Ontology (GO) items and 99 Kyoto Encyclopedia of Genes and Genomes signaling pathways preferably AKT signaling pathway, MAPK signaling pathway, ACE2 receptor signaling pathway, insulin signaling pathway, and PPAR signaling pathway. Among the chosen functional foods, black cumin, fenugreek, garlic, ginger, turmeric, bitter melon, and Indian pennywort were found to modulate the actions. Results demonstrate that aforesaid functional foods have attenuating roles to manage post COVID-19 complications. PRACTICAL APPLICATIONS: Functional foods have been approaching a greater interest due to their medicinal uses other than gastronomic pleasure. Nine functional food resources have been used in this research for their traditional and ethnopharmacological uses, but their directive-role in modulating the genes involved in the management of post COVID-19 complications is inadequately studied and reported. Therefore, the foods types used in this research may be prioritized to be used as functional foods for ameliorating the major post COVID-19 complications through appropriate science.
  8. Akomolafe O, Owolabi TO, Abd Rahman MA, Awang Kechik MM, Yasin MNM, Souiyah M
    Materials (Basel), 2021 Aug 16;14(16).
    PMID: 34443126 DOI: 10.3390/ma14164604
    Structural transformation and magnetic ordering interplays for emergence as well as suppression of superconductivity in 122-iron-based superconducting materials. Electron and hole doping play a vital role in structural transition and magnetism suppression and ultimately enhance the room pressure superconducting critical temperature of the compound. This work models the superconducting critical temperature of 122-iron-based superconductor using tetragonal to orthorhombic lattice (LAT) structural transformation during low-temperature cooling and ionic radii of the dopants as descriptors through hybridization of support vector regression (SVR) intelligent algorithm with particle swarm (PS) parameter optimization method. The developed PS-SVR-RAD model, which utilizes ionic radii (RAD) and the concentrations of dopants as descriptors, shows better performance over the developed PS-SVR-LAT model that employs lattice parameters emanated from structural transformation as descriptors. Using the root mean square error (RMSE), coefficient of correlation (CC) and mean absolute error as performance measuring criteria, the developed PS-SVR-RAD model performs better than the PS-SVR-LAT model with performance improvement of 15.28, 7.62 and 72.12%, on the basis of RMSE, CC and Mean Absolute Error (MAE), respectively. Among the merits of the developed PS-SVR-RAD model over the PS-SVR-LAT model is the possibility of electrons and holes doping from four different dopants, better performance and ease of model development at relatively low cost since the descriptors are easily fetched ionic radii. The developed intelligent models in this work would definitely facilitate quick and precise determination of critical transition temperature of 122-iron-based superconductor for desired applications at low cost with experimental stress circumvention.
  9. Alade IO, Abd Rahman MA, Bagudu A, Abbas Z, Yaakob Y, Saleh TA
    Heliyon, 2019 Jun;5(6):e01882.
    PMID: 31304407 DOI: 10.1016/j.heliyon.2019.e01882
    The specific heat capacity of nanofluids ( C P n f ) is a fundamental thermophysical property that measures the heat storage capacity of the nanofluids. C P n f is usually determined through experimental measurement. As it is known, experimental procedures are characterised with some complexities, which include, the challenge of preparing stable nanofluids and relatively long periods to conduct experiments. So far, two correlations have been developed to estimate the C P n f . The accuracies of these models are still subject to further improvement for many nanofluid compositions. This study presents a four-input support vector regression (SVR) model hybridized with a Bayesian algorithm to predict the specific heat capacity of metallic oxides/ethylene glycol-based nanofluids. The bayesian algorithm was used to obtain the optimum SVR hyperparameters. 189 experimental data collected from published literature was used for the model development. The proposed model exhibits low average absolute relative deviation (AARD) and a high correlation coefficient (r) of 0.40 and 99.53 %, respectively. In addition, we analysed the accuracies of the existing analytical models on the considered nanofluid compositions. The model based on the thermal equilibrium between the nanoparticles and base fluid (model II) show good agreement with experimental results while the model based on simple mixing rule (model I) overestimated the specific heat capacity of the nanofluids. To further validate the superiority of the proposed technique over the existing analytical models, we compared various statistical errors for the three models. The AARD for the BSVR, model II, and model I are 0.40, 0.82 and 4.97, respectively. This clearly shows that the model developed has much better prediction accuracy than existing models in predicting the specific heat capacity of metallic oxides/ethylene glycol-based nanofluids. We believe the presented model will be important in the design of nanofluid-based applications due to its improved accuracy.
  10. Alhodieb FS, Rahman MA, Barkat MA, Alanezi AA, Barkat HA, Hadi HA, et al.
    Nanomedicine (Lond), 2023 Mar 20.
    PMID: 36938800 DOI: 10.2217/nnm-2022-0108
    Drug-loaded, brain-targeted nanocarriers could be a promising tool in overcoming the challenges associated with Alzheimer's disease therapy. These nanocargoes are enormously flexible to functionalize and facilitate the delivery of drugs to brain cells by bridging the blood-brain barrier and into brain cells. To date, modifications have included nanoparticles (NPs) coating with tunable surfactants/phospholipids, covalently attaching polyethylene glycol chains (PEGylation), and tethering different targeting ligands to cell-penetrating peptides in a manner that facilitates their entry across the BBB and downregulates various pathological hallmarks as well as intra- and extracellular signaling pathways. This review provides a brief update on drug-loaded, multifunctional nanocarriers and the therapeutic intervention of autophagy and stem cells in the management of Alzheimer's disease.
  11. Ali Reza ASM, Nasrin MS, Hossen MA, Rahman MA, Jantan I, Haque MA, et al.
    Crit Rev Food Sci Nutr, 2023;63(22):5546-5576.
    PMID: 34955042 DOI: 10.1080/10408398.2021.2021138
    Medicinally important plant-foods offer a balanced immune function, which is essential for protecting the body against antigenic invasion, mainly by microorganisms. Immunomodulators play pivotal roles in supporting immune function either suppressing or stimulating the immune system's response to invading pathogens. Among different immunomodulators, plant-based secondary metabolites have emerged as high potential not only for immune defense but also for cellular immunoresponsiveness. These natural immunomodulators can be developed into safer alternatives to the clinically used immunosuppressants and immunostimulant cytotoxic drugs which possess serious side effects. Many plants of different species have been reported to possess strong immunomodulating properties. The immunomodulatory effects of plant extracts and their bioactive metabolites have been suggested due to their diverse mechanisms of modulation of the complex immune system and their multifarious molecular targets. Phytochemicals such as alkaloids, flavonoids, terpenoids, carbohydrates and polyphenols have been reported as responsible for the immunomodulatory effects of several medicinal plants. This review illustrates the potent immunomodulatory effects of 65 plant secondary metabolites, including dietary compounds and their underlying mechanisms of action on cellular and humoral immune functions in in vitro and in vivo studies. The clinical potential of some of the compounds to be used for various immune-related disorders is highlighted.
  12. Alias NH, Jaafar J, Samitsu S, Yusof N, Othman MHD, Rahman MA, et al.
    Chemosphere, 2018 Aug;204:79-86.
    PMID: 29653325 DOI: 10.1016/j.chemosphere.2018.04.033
    Separation and purification of oilfield produced water (OPW) is a major environmental challenge due to the co-production of the OPW during petroleum exploration and production operations. Effective capture of oil contaminant and its in-situ photodegradation is one of the promising methods to purify the OPW. Based on the photocatalytic capability of graphitic carbon nitride (GCN) which was recently rediscovered, photodegradation capability of GCN for OPW was investigated in this study. GCN was synthesized by calcination of urea and further exfoliated into nanosheets. The GCNs were incorporated into polyacrylonitrile nanofibers using electrospinning, which gave a liquid-permeable self-supporting photocatalytic nanofiber mat that can be handled by hand. The photocatalytic nanofiber demonstrated 85.4% degradation of OPW under visible light irradiation, and improved the degradation to 96.6% under UV light. Effective photodegradation of the photocatalytic nanofiber for OPW originates from synergetic effects of oil adsorption by PAN nanofibers and oil photodegradation by GCNs. This study provides an insight for industrial application on purification of OPW through photocatalytic degradation under solar irradiation.
  13. Alyan E, Saad NM, Kamel N, Yusoff MZ, Zakariya MA, Rahman MA, et al.
    Sensors (Basel), 2021 Mar 11;21(6).
    PMID: 33799722 DOI: 10.3390/s21061968
    This study aims to investigate the effects of workplace noise on neural activity and alpha asymmetries of the prefrontal cortex (PFC) during mental stress conditions. Workplace noise exposure is a pervasive environmental pollutant and is negatively linked to cognitive effects and selective attention. Generally, the stress theory is assumed to underlie the impact of noise on health. Evidence for the impacts of workplace noise on mental stress is lacking. Fifteen healthy volunteer subjects performed the Montreal imaging stress task in quiet and noisy workplaces while their brain activity was recorded using electroencephalography. The salivary alpha-amylase (sAA) was measured before and immediately after each tested workplace to evaluate the stress level. The results showed a decrease in alpha rhythms, or an increase in cortical activity, of the PFC for all participants at the noisy workplace. Further analysis of alpha asymmetry revealed a greater significant relative right frontal activation of the noisy workplace group at electrode pairs F4-F3 but not F8-F7. Furthermore, a significant increase in sAA activity was observed in all participants at the noisy workplace, demonstrating the presence of stress. The findings provide critical information on the effects of workplace noise-related stress that might be neglected during mental stress evaluations.
  14. Alyan E, Saad NM, Kamel N, Rahman MA
    Appl Ergon, 2021 Oct;96:103497.
    PMID: 34139374 DOI: 10.1016/j.apergo.2021.103497
    This study aims to evaluate the effect of workstation type on the neural and vascular networks of the prefrontal cortex (PFC) underlying the cognitive activity involved during mental stress. Workstation design has been reported to affect the physical and mental health of employees. However, while the functional effects of ergonomic workstations have been documented, there is little research on the influence of workstation design on the executive function of the brain. In this study, 23 healthy volunteers in ergonomic and non-ergonomic workstations completed the Montreal imaging stress task, while their brain activity was recorded using the synchronized measurement of electroencephalography and functional near-infrared spectroscopy. The results revealed desynchronization in alpha rhythms and oxygenated hemoglobin, as well as decreased functional connectivity in the PFC networks at the non-ergonomic workstations. Additionally, a significant increase in salivary alpha-amylase activity was observed in all participants at the non-ergonomic workstations, confirming the presence of induced stress. These findings suggest that workstation design can significantly impact cognitive functioning and human capabilities at work. Therefore, the use of functional neuroimaging in workplace design can provide critical information on the causes of workplace-related stress.
  15. Bahar Moni AS, Abdullah S, Bin Abdullah MFIL, Kabir MS, Alif SM, Sultana F, et al.
    PLoS One, 2021;16(9):e0257304.
    PMID: 34506576 DOI: 10.1371/journal.pone.0257304
    INTRODUCTION: The COVID-19 pandemic has enormously affected the psychological well-being, social and working life of millions of people across the world. This study aimed to investigate the psychological distress, fear and coping strategies as a result of the COVID-19 pandemic and its associated factors among Malaysian residents.

    METHODS: Participants were invited to an online cross-sectional survey from Aug-Sep 2020. The study assessed psychological distress using the Kessler Psychological Distress Scale, level of fear using the Fear of COVID-19 Scale, and coping strategies using the Brief Resilient Coping Scale. Univariate and multivariate logistic regression analyses were conducted to adjust for potential confounders.

    RESULTS: The mean age (±SD) of the participants (N = 720) was 31.7 (±11.5) years, and most of them were females (67.1%). Half of the participants had an income source, while 216 (30%) identified themselves as frontline health or essential service workers. People whose financial situation was impacted due to COVID-19 (AOR 2.16, 95% CIs 1.54-3.03), people who drank alcohol in the last four weeks (3.43, 1.45-8.10), people who were a patient (2.02, 1.39-2.93), and had higher levels of fear of COVID-19 (2.55, 1.70-3.80) were more likely to have higher levels of psychological distress. Participants who self-isolated due to exposure to COVID-19 (3.12, 1.04-9.32) and who had moderate to very high levels of psychological distress (2.56, 1.71-3.83) had higher levels of fear. Participants who provided care to a family member/patient with a suspected case of COVID-19 were more likely to be moderately to highly resilient compared to those who did not.

    CONCLUSION: Vulnerable groups of individuals such as patients and those impacted financially during COVID-19 should be supported for their mental wellbeing. Behavioural interventions should be targeted to reduce the impact of alcohol drinking during such crisis period.

  16. Biswas K, Nazir A, Rahman MT, Khandaker MU, Idris AM, Islam J, et al.
    PLoS One, 2022;17(1):e0261427.
    PMID: 35085239 DOI: 10.1371/journal.pone.0261427
    Cost and safety are critical factors in the oil and gas industry for optimizing wellbore trajectory, which is a constrained and nonlinear optimization problem. In this work, the wellbore trajectory is optimized using the true measured depth, well profile energy, and torque. Numerous metaheuristic algorithms were employed to optimize these objectives by tuning 17 constrained variables, with notable drawbacks including decreased exploitation/exploration capability, local optima trapping, non-uniform distribution of non-dominated solutions, and inability to track isolated minima. The purpose of this work is to propose a modified multi-objective cellular spotted hyena algorithm (MOCSHOPSO) for optimizing true measured depth, well profile energy, and torque. To overcome the aforementioned difficulties, the modification incorporates cellular automata (CA) and particle swarm optimization (PSO). By adding CA, the SHO's exploration phase is enhanced, and the SHO's hunting mechanisms are modified with PSO's velocity update property. Several geophysical and operational constraints have been utilized during trajectory optimization and data has been collected from the Gulf of Suez oil field. The proposed algorithm was compared with the standard methods (MOCPSO, MOSHO, MOCGWO) and observed significant improvements in terms of better distribution of non-dominated solutions, better-searching capability, a minimum number of isolated minima, and better Pareto optimal front. These significant improvements were validated by analysing the algorithms in terms of some statistical analysis, such as IGD, MS, SP, and ER. The proposed algorithm has obtained the lowest values in IGD, SP and ER, on the other side highest values in MS. Finally, an adaptive neighbourhood mechanism has been proposed which showed better performance than the fixed neighbourhood topology such as L5, L9, C9, C13, C21, and C25. Hopefully, this newly proposed modified algorithm will pave the way for better wellbore trajectory optimization.
  17. Chandraseharan P, Sockalingam SNM, Shafiei Z, Zakaria ASI, Mahyuddin A, Rahman MA
    J Contemp Dent Pract, 2023 Oct 01;24(10):779-786.
    PMID: 38152911 DOI: 10.5005/jp-journals-10024-3581
    AIMS AND BACKGROUND: This study evaluates the antimicrobial activities of commercially available 5% apple cider vinegar (ACV) against Enterococcus faecalis, Streptococcus mutans, and Lactobacillus casei. Materials and methods: Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were conducted using the broth microdilution method. Sodium hypochlorite (NaOCl) of 5.25% was used as a positive control, and comparisons were also made with acetic acid (AA) as the main ingredient in ACV. The three test bacteria treated with the most effective ACV dilution were visualized under a transmission electron microscope (TEM) for structural changes.

    RESULTS: Minimal inhibitory concentration was determined at 0.625% of the concentration of ACV against S. mutans and E. faecalis and 1.25% of the concentration of ACV against L. casei with two-fold serial dilutions. A concentration of 5 × 10-1% with 10-fold serial dilutions was found to be the MIC value for all three bacteria. No significant differences were found when compared with the positive control (NaOCl) (p = 0.182, p = 0.171, and p = 0.234), respectively, for two-fold serial dilutions and (p = 1.000, p = 0.658, and p = 0.110), respectively for 10-fold serial dilutions. MBC was observed to be 5% ACV for both E. faecalis and S. mutans. However, positive microbial growth was observed on the agar plate when cultured with L. casei. An independent sample t-test showed no significant differences (p > 0.05) in the antimicrobial activities between 5% ACV and 5% pure AA. TEM revealed cell wall and cytoplasmic membrane disruptions on all three bacteria at MIC value.

    CONCLUSION: Apple cider vinegar has antimicrobial activities against Enterococcus faecalis, Streptococcus mutans, and Lactobacillus casei at their respective MIC values.

    CLINICAL SIGNIFICANCE: Apple cider vinegar can be an alternative antimicrobial dental pulp disinfectant to sodium hypochlorite. Apple cider vinegar can be used safely, especially in children's dental pulp therapy and deep caries management, when adequate tooth isolation is not readily achievable. Thus, adverse reactions commonly associated with other frequently used chemical disinfectants can be avoided.

  18. Chang HY, Hor SY, Lim KP, Zain RB, Cheong SC, Rahman MA, et al.
    Electrophoresis, 2013 Aug;34(15):2199-208.
    PMID: 23712713 DOI: 10.1002/elps.201300126
    This study aims to identify cancer-associated proteins in the secretome of oral cancer cell lines. We have successfully established four primary cell cultures of normal cells with a limited lifespan without human telomerase reverse transcriptase (hTERT) immortalization. The secretome of these primary cell cultures were compared with that of oral cancer cell lines using 2DE. Thirty five protein spots were found to have changed in abundance. Unambiguous identification of these proteins was achieved by MALDI TOF/TOF. In silico analysis predicted that 24 of these proteins were secreted via classical or nonclassical mechanisms. The mRNA expression of six genes was found to correlate with the corresponding protein abundance. Ingenuity Pathway Analysis (IPA) core analysis revealed that the identified proteins were relevant in, and related to, cancer development with likely involvements in tumor growth, metastasis, hyperproliferation, tumorigenesis, neoplasia, hyperplasia, and cell transformation. In conclusion, we have demonstrated that a comparative study of the secretome of cancer versus normal cell lines can be used to identify cancer-associated proteins.
  19. Chua VL, Smith BT, Burner RC, Rahman MA, Lakim M, Prawiradilaga DM, et al.
    Mol Phylogenet Evol, 2017 Aug;113:139-149.
    PMID: 28545973 DOI: 10.1016/j.ympev.2017.05.016
    The mountains of Borneo are well known for their high endemicity and historical role in preserving Southeast Asian rainforest biodiversity, but the diversification of populations inhabiting these mountains is poorly studied. Here we examine the genetic structure of 12 Bornean montane passerines by comparing complete mtDNA ND2 gene sequences of populations spanning the island. Maximum likelihood and Bayesian phylogenetic trees and haplotype networks are examined for common patterns that might signal important historical events or boundaries to dispersal. Morphological and ecological characteristics of each species are also examined using phylogenetic generalized least-squares (PGLS) for correlation with population structure. Populations in only four of the 12 species are subdivided into distinct clades or haplotype groups. Although this subdivision occurred at about the same time in each species (ca. 0.6-0.7Ma), the spatial positioning of the genetic break differs among the species. In two species, northeastern populations are genetically divergent from populations elsewhere on the island. In the other two species, populations in the main Bornean mountain chain, including the northeast, are distinct from those on two isolated peaks in northwestern Borneo. We suggest different historical forces played a role in shaping these two distributions, despite commonality in timing. PGLS analysis showed that only a single characteristic-hand-wing index-is correlated with population structure. Birds with longer wings, and hence potentially more dispersal power, have less population structure. To understand historical forces influencing montane population structure on Borneo, future studies must compare populations across the entirety of Sundaland.
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