Displaying publications 1 - 20 of 166 in total

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  1. Borhan MN, Ibrahim ANH, Aziz A, Yazid MRM
    Accid Anal Prev, 2018 Dec;121:94-100.
    PMID: 30237047 DOI: 10.1016/j.aap.2018.09.004
    In the context of road safety, risk-taking is undoubtedly one of the main contributory factors in road accidents. The actual forces which influence individuals to take such risks, nevertheless, are still not fully understood. To address this, this study was therefore conducted to investigate the relationship of the demographic, personal, and social factors of motorcyclists, with a specific focus on their risk-taking behavior at signalized intersections in Malaysia. This study adopted the quantitative method using cross-sectional questionnaire surveys and involved 251 respondents. The demographic factors were analyzed using the t-test and an ANOVA Scheffe Post-Hoc test, while the motorcyclists' personal and social characteristics were analyzed with multiple linear regression. The findings indicate that the individuals who were greater risk takers at signalized intersections were teenage motorcyclists (16-25 years old) who had finished their education before taking their high school diploma, and who also received a lower than average monthly income from private sector firms. The actual experience of accidents was also shown to be positively related to this risk-taking behavior. In addition, in term of personal and social factors, results showed that, for these individuals, there was a significant difference between the strength of peer influence and that of parental and spouse guidance. However, there was no significant difference in the risk-taking behavior of Malaysian motorcyclists riding at signalized intersections for the following factors: between genders, in terms of accident involvement, in terms of enforcement of traffic regulations, and prevention steps and confidence level after being involved in an accident.
  2. Abdul Aziz, A, Ahmad, S.F., Muslim, Y.R
    Ann Dent, 2006;13(1):34-38.
    MyJurnal
    This clinical case report details the clinical sequence of a 78-year-old male receiving prosthetic rehabilitation using an implant-supported screwretained fixed partial denture. Despite the limitations imposed, the aesthetic and functional demands of the patient were fulfilled by this prosthetic rehabilitation. The importance of detailed prosthetic planning and evaluation prior to implant surgery is essential, therefore ideally, it should be done by the same operator or a team of operators working together. Problems can arise when the construction of the prosthesis is performed by other people who are not involved in the planning stage.
  3. Abdul Aziz, A., Abu Kasim, N.H., Ramasindarum, C., Mohamad Yusof, M.Y.P., Paiizi, M., Ahmad, R.
    Ann Dent, 2011;18(1):1-7.
    MyJurnal
    The aim of this study was to assess the wear of tungsten carbide burs and round rotary diamond instruments through measurements of rake angle and visual observations respectively under a field emission scanning electron microscope. Sixty short and long head pear-shaped tungsten carbide burs and 18 round rotary diamond instruments that had been used to complete < 5, > 5 and > 10 cavity preparations (n=10/group) were selected from the 3rd and 4th year dental students, Faculty of Dentistry, University of Malaya. There were two control groups consisting of long and short tungsten carbide burs of ten each. Two-way ANOVA was used to analyse the rake angle data. The data from the two control groups were collectively analysed following multiple paired t-test (p>.05) which showed no significant difference between the two types of tungsten carbide bur (short and long head). The mean rake angle of the control group was significantly higher (p < .05) compared to the < 5, > 5 and > 10 cavity preparation groups. The rake angle of the > 10 cavity preparation group was significantly lower than the other two test groups (p < .05). Round rotary diamond instruments in the < 5 cavity preparation group showed intact diamond particles with distinct cutting facets comparable to the control group. However, diamonds instruments in the > 5 and > 10 cavity preparation groups showed blunt diamond particles. In conclusion, wear of tungsten carbide burs and round rotary diamond instruments were evident after repeated use. Wear was more pronounced when instruments were used to prepare more than ten cavities.
  4. Shakeel S, Muneswarao J, Abdul Aziz A, Yeong Le H, Abd Halim FS, Rehman AU, et al.
    Antibiotics (Basel), 2021 Dec 04;10(12).
    PMID: 34943702 DOI: 10.3390/antibiotics10121490
    The evaluation of disease progression and onsite therapeutic care choices for community-acquired pneumonia (CAP) patients is vital for their well-being and the optimum utilization of healthcare resources. The current study was conducted to assess physicians' adherence to clinical practice standards and antibiotic prescribing behavior for the treatment of CAP in older people. A prospective study that included 121 consecutive patients admitted for CAP was conducted at Kulim Hospital, Kedah, from March 2020 to August 2020. Medical records including demographic data, comorbidity, physical examination, laboratory or radiologic findings, and drugs used for the treatment of CAP were accessed from bed head tickets (BHT). The mean age for patients was 73.5 ± 6.2 years, 73 (60.3%) and 48 (39.6%) were males and females, respectively. Amoxicillin/clavulanate (19.8%) was the most prescribed antibiotic for non-severe pneumonia followed by ampicillin sodium/sulbactam sodium (6.6%), while in patients with severe CAP beta-lactam + beta lactamase inhibitors (BLIs) with a combination of macrolide were the most common antibiotics prescribed either in patients with (21.4%) or without co-morbidities (8.2%). The average length of stay in the hospital with severe pneumonia was 6-7 days for 23.9% of patients and < 5 days for 21.4% of patients. The duration of intravenous antibiotics in patients with severe pneumonia was 6-7 days for 32.2% of patients. The present findings revealed the adherence of antibiotic prescribing practices to the Malaysian National Antimicrobial Guideline 2019 for CAP therapy among geriatric patients and adherence to the CAP criteria for hospital admissions.
  5. Jusoh M, Loh SH, Aziz A, Cha TS
    Appl Biochem Biotechnol, 2019 Jun;188(2):450-459.
    PMID: 30536033 DOI: 10.1007/s12010-018-02937-4
    Microalgae lipids and oils are potential candidates for renewable biofuels and nutritional inventions. Recent studies from our lab have shown that two plant hormones, auxin and jasmonic acid, influence microalgae growth and fatty acid accumulation. Therefore, in this study, a high oil-producing strain Chlorella vulgaris UMT-M1 was selected for hormonal study using gibberellin (GA). Exogenous GA3 was applied to early stationary culture of C. vulgaris UMT-M1. Results showed that GA3 gradually increases the cell density of C. vulgaris to up to 42% on days after treatment (DAT)-8 and also capable of delaying the algal senescence. However, the increment in cell density did not enhance the total oil production albeit transient modification of fatty acid compositions was observed for saturated (SFA) and polyunsaturated (PUFA) fatty acids. This illustrates that GA3 only promotes cell division and growth but not the oil accumulation. In addition, application of GA3 in culture medium was shown to promote transient increment of palmitic (C16:0) and stearic (C18:0) acids from DAT-4 to DAT-6 and these changes are correlated with the expression of β-ketoacyl ACP synthase I (KAS I) gene.
  6. Anne-Marie K, Yee W, Loh SH, Aziz A, Cha TS
    Appl Biochem Biotechnol, 2020 Apr;190(4):1438-1456.
    PMID: 31782088 DOI: 10.1007/s12010-019-03182-z
    In this study, the effects of limited and excess phosphate on biomass content, oil content, fatty acid profile and the expression of three fatty acid desaturases in Messastrum gracile SE-MC4 were determined. It was found that total biomass (0.67-0.83 g L-1), oil content (30.99-38.08%) and the duration for cells to reach stationary phase (25-27 days) were not considerably affected by phosphate limitation. However, excess phosphate slightly reduced total biomass and oil content to 0.50 g L-1 and 25.36% respectively. The dominant fatty acids in M. gracile, pamitic acid (C16:0) and oleic acid (C18:1) which constitute more than 81% of the total fatty acids remained relatively high and constant across all phosphate concentrations. Reduction of phosphate concentration to 25% and below significantly increased total MUFA, whereas increasing phosphate concentration to ≥ 50% and ≥ 100% significantly increased total SFA and PUFA content respectively. The expression of omega-3 fatty acid desaturase (ω-3 FADi1, ω-3 FADi2) and omega-6 fatty acid desaturase (ω-6 FAD) was increased under phosphate limitation, especially at ≤ 12.5% phosphate, whereas levels of streoyl-ACP desaturase (SAD) transcripts were relatively unchanged across all phosphate concentrations. The first isoform of ω-3 FAD (ω-3 FADi) displayed a binary upregulation under limited (≤ 12.5%) and excess (200%) phosphate. The expression of ω-6 FAD, ω-3 FAD and SAD were inconsistent with the accumulation of oleic acid (C18:1), linoleic acid (C18:2) and alpha-linolenic acid (C18:3), suggesting that these genes may be regulated indirectly by phosphate availability via post-transcriptional or post-translational mechanisms.
  7. Norlina R, Norashikin MN, Loh SH, Aziz A, Cha TS
    Appl Biochem Biotechnol, 2020 Aug;191(4):1653-1669.
    PMID: 32198601 DOI: 10.1007/s12010-020-03312-y
    Abscisic acid (ABA) has been known to exist in a microalgal system and serves as one of the chemical stimuli in various biological pathways. Nonetheless, the involvement of ABA in fatty acid biosynthesis, particularly at the transcription level in microalgae is poorly understood. The objective of this study was to determine the effects of exogenous ABA on growth, total oil content, fatty acid composition, and the expression level of beta ketoacyl-ACP synthase I (KAS I) and omega-3 fatty acid desaturase (ω-3 FAD) genes in Chlorella vulgaris UMT-M1. ABA was applied to early stationary C. vulgaris cultures at concentrations of 0, 10, 20, and 80 μM for 48 h. The results showed that ABA significantly increased biomass production and total oil content. The increment of palmitic (C16:0) and stearic (C18:0) acids was coupled by decrement in linoleic (C18:2) and α-linolenic (C18:3n3) acids. Both KAS I and ω-3 FAD gene expression were downregulated, which was negatively correlated to saturated fatty acid (SFAs), but positively correlated to polyunsaturated fatty acid (PUFA) accumulations. Further analysis of both KAS I and ω-3 FAD promoters revealed the presence of multiple ABA-responsive elements (ABREs) in addition to other phytohormone-responsive elements. However, the role of these phytohormone-responsive elements in regulating KAS I and ω-3 FAD gene expression still remains elusive. This revelation might suggest that phytohormone-responsive gene regulation in C. vulgaris and microalgae as a whole might diverge from higher plants which deserve further scientific research to elucidate its functional roles.
  8. Iffa ED, Aziz AR, Malik AS
    Appl Opt, 2011 Feb 10;50(5):618-25.
    PMID: 21343981 DOI: 10.1364/AO.50.000618
    This paper utilizes the background oriented schlieren (BOS) technique to measure the velocity field of a variable density round jet. The density field of the jet is computed based on the light deflection created during the passage of light through the understudy jet. The deflection vector estimation was carried out using phase-based optical flow algorithms. The density field is further exploited to extract the axial and radial velocity vectors with the aid of continuity and energy equations. The experiment is conducted at six different jet-exit temperature values. Additional turbulence parameters, such as velocity variance and power spectral density of the vector field, are also computed. Finally, the measured velocity parameters are compared with the hot wire anemometer measurements and their correlation is displayed.
  9. Kamal N, Nizam S, Abdul Aziz A
    Appl Radiat Isot, 2024 Jan;203:111085.
    PMID: 37924626 DOI: 10.1016/j.apradiso.2023.111085
    In this study, the theoretical cross sections of 209Bi(α,2n)211At, 65Cu(α,n)68Ga, 100Ru(α,n)103Pd, and 121Sb(α,n)124I are calculated using TALYS 1.96, incorporating the effects of the alpha optical model potential and nuclear level density models. The validation process involves comparing the calculated cross sections with experimental data and utilizing statistical deviation factors. This comparison allows us to determine the optimal combination of nuclear model parameters for each reaction. The result shows that theoretical calculations which utilized semi microscopic level density models and alpha OMP managed to describe the excitation functions close to the experimental data. The comparison of nuclear model calculations with experimental data plays a crucial role in ensuring the reliability of the data, making it an essential aspect of modern evaluation procedures.
  10. Hasnul MA, Ab Aziz NA, Abd Aziz A
    Arab J Sci Eng, 2023 Jan 11.
    PMID: 36685996 DOI: 10.1007/s13369-022-07585-9
    A physiological-based emotion recognition system (ERS) with a unimodal approach such as an electrocardiogram (ECG) is not as popular compared to a multimodal approach. However, a single modality has the advantage of lower development and computational cost. Therefore, this study focuses on a unimodal ECG-based ERS. The ECG-based ERS has the potential to become the next mass-adopted consumer application due to the wide availability of wearable and mobile ECG devices in the market. Currently, ECG-inclusive affective datasets are limited, and many of the existing datasets have small sample sizes. Hence, ECG-based ERS studies are stunted by the lack of quality data. A novel multi-filtering augmentation technique is proposed here to increase the sample size of the ECG data. This technique augments the ECG signals by cleaning the data in different ways. Three small ECG datasets labelled according to emotion state are used in this study. The benefit of the proposed augmentation techniques is measured using the classification accuracy of five machine learning algorithms; k-nearest neighbours (KNN), support vector machine, decision tree, random forest and multilayer perceptron. The results show that with the proposed technique, there is a significant improvement in performance for all the datasets and classifiers. KNN classifier improved the most with the augmented data and the reported classification accuracies of over 90%.
  11. Kono Y, Yusnita Y, Mohd Ali AR, Maizan M, Sharifah SH, Fauzia O, et al.
    Arch Virol, 2002 Aug;147(8):1623-30.
    PMID: 12181680
    A virus, named Oya virus, was isolated in Vero cell cultures from the lungs of a pig suspected of Nipah virus infection. The virus was revealed as a spherical enveloped RNA virus with a diameter of 79 nm. For identification of Oya virus, RT-PCR was performed. A common primer set for S-RNA of the Simbu serogroup of the genus Bunyavirus was able to amplify a cDNA from Oya virus RNA. The sequence data of the product revealed that the partial gene of Oya virus S-RNA segment had 65-70% homology with published cDNA sequences of Simbu serogroup viruses. The phylogenetic analysis of the data showed that the Oya virus is grouped in Simbu serogroup, but is genetically distinct from the serogroup viruses that have been analyzed molecularly. Serological surveys revealed that the virus distributed widely and densely in Malaysia.
  12. Makhadmeh GN, Abdul Aziz A, Abdul Razak K
    Artif Cells Nanomed Biotechnol, 2016 May;44(3):1018-22.
    PMID: 25707443 DOI: 10.3109/21691401.2015.1008511
    This study analyzed the physical effects of methylene blue (MB) encapsulated within silica nanoparticles (SiNPs) in photodynamic therapy.
  13. Makhadmeh GN, Abdul Aziz A, Abdul Razak K
    Artif Cells Nanomed Biotechnol, 2016 Aug;44(5):1285-9.
    PMID: 25811998 DOI: 10.3109/21691401.2015.1024843
    The synthesis of methylene blue (MB) encapsulated in silica nanoparticles (SiNPs) as an application for photodynamic therapy is reported in this study. Semi-rigid tissues with optical properties similar to that of human tissues were used as sample materials to determine the applicability of MB encapsulated in SiNPs.
  14. Makhadmeh GN, Abdul Aziz A
    Artif Cells Nanomed Biotechnol, 2018;46(sup3):S1043-S1046.
    PMID: 30449196 DOI: 10.1080/21691401.2018.1528982
    BACKGROUND: Achieved Silica Nanoparticles (SiNPs) to encapsulate the photosensitizer [Protoporphyrin IX (PpIX)] in photodynamic therapy (PDT) application was reported in this research.

    MATERIALS AND METHODS: Cytotoxicity for five different concentrations of encapsulated and naked PpIX was measured. Optimum concentration and optimum exposure time of encapsulated and naked PpIX that needed to destroy the cells (Osteosarcoma cells) was measured.

    RESULTS: The results showed that the encapsulated PpIX has more efficacy compared to the naked PpIX and the applicability of the encapsulated PpIX-SiNPs was proved on osteosarcoma cells.

    CONCLUSION: The results established the important in-vitro photodynamic effectiveness of PpIX-SiNP, which may open a new application for PpIX in its clinical and in-vitro studies.

  15. Ho C, Samwil SNM, Kahairudin Z, Jamhuri N, Abd Aziz A
    Asian J Surg, 2023 Sep;46(9):3716-3721.
    PMID: 36931924 DOI: 10.1016/j.asjsur.2023.03.026
    BACKGROUND: Bariatric surgery is considered as an effective therapy for those with morbid obesity. Preoperative weight loss with a very low-calorie diet is commonly used to ease the bariatric surgery. Pre-habilitation increases functional and physiological capacity. The study demonstrated the changes of body composition and functional status following short term pre-habilitation before bariatric surgery.

    METHOD: This prospective study targeted those admitted for bariatric surgery. Participants underwent the biweekly pre-habilitation program included an individualized high whey-based protein very low-calorie (VLCHP) enteral regime (600-900 kcal/day) and moderate intensive exercise before bariatric surgery. Body composition and waist circumference were assessed after fortnight. Participants were segregated into morbid obese (MOG) (BMI <49 kg/m2) and super morbid obese group (SMOG) (BMI ≥50 kg/m2) for analysis.

    RESULT: Majority of participants were female (71%) with median age 36.0 years old (MOG) and 34.3 years old (SMOG) respectively. SMOG achieved significant greater loss in weight (-7.4 kg vs -4.0 kg), fat percentage (-4.4% vs -1.7%) and fat mass (-9.9 kg vs -3.8 kg); but MOG had a significant increment in muscle mass (3.2 kg vs 2.8 kg) as compared to SOG (p 

  16. Razali N, Mat Junit S, Ariffin A, Ramli NS, Abdul Aziz A
    PMID: 26683054 DOI: 10.1186/s12906-015-0963-2
    Tamarindus indica L. (T. indica) or locally known as "asam jawa" belongs to the family Leguminosae. T. indica seeds as by-products from the fruits were previously reported to contain high polyphenolic content. However, identification of their bioactive polyphenols using recent technologies is less well researched but nonetheless important. Hence, it was the aim of this study to provide further information on the polyphenolic content and antioxidant activities as well as to identify and quantify its bioactive polyphenols.
  17. Abrahim NN, Kanthimathi MS, Abdul-Aziz A
    BMC Complement Altern Med, 2012 Nov 15;12:220.
    PMID: 23153283 DOI: 10.1186/1472-6882-12-220
    BACKGROUND: Breast cancer is the most common form of cancer and the focus on finding chemotherapeutic agents have recently shifted to natural products. Piper betle is a medicinal plant with various biological activities. However, not much data is available on the anti-cancer effects of P. betle on breast cancer. Due to the current interest in the potential effects of antioxidants from natural products in breast cancer treatment, we investigated the antioxidant activities of the leaves of P. betle and its inhibitory effect on the proliferation of the breast cancer cell line, MCF-7.

    METHODS: The leaves of P. betle were extracted with solvents of varying polarities (water, methanol, ethyl acetate and hexane) and their phenolic and flavonoid content were determined using colorimetric assays. Phenolic composition was characterized using HPLC. Antioxidant activities were measured using FRAP, DPPH, superoxide anion, nitric oxide and hyroxyl radical scavenging assays. Biological activities of the extracts were analysed using MTT assay and antioxidant enzyme (catalase, superoxide dismutase, glutathione peroxidase) assays in MCF-7 cells.

    RESULTS: Overall, the ethyl acetate extract showed the highest ferric reducing activity and radical scavenging activities against DPPH, superoxide anion and nitric oxide radicals. This extract also contained the highest phenolic content implying the potential contribution of phenolics towards the antioxidant activities. HPLC analyses revealed the presence of catechin, morin and quercetin in the leaves. The ethyl acetate extract also showed the highest inhibitory effect against the proliferation of MCF-7 cells (IC50=65 μg/ml). Treatment of MCF-7 cells with the plant extract increased activities of catalase and superoxide dismutase.

    CONCLUSIONS: Ethyl acetate is the optimal solvent for the extraction of compounds with antioxidant and anti-proliferative activities. The increased activities of catalase and superoxide dismutase in the treated cells could alter the antioxidant defense system, potentially contributing towards the anti-proliferative effect. There is great potential for the ethyl acetate extract of P. betle leaf as a source of natural antioxidants and to be developed as therapeutics in cancer treatment.

  18. Chew KS, Kueh YC, Abdul Aziz A
    BMC Med Educ, 2017 Mar 21;17(1):58.
    PMID: 28320367 DOI: 10.1186/s12909-017-0897-0
    BACKGROUND: Despite their importance on diagnostic accuracy, there is a paucity of literature on questionnaire tools to assess clinicians' awareness toward cognitive errors. A validation study was conducted to develop a questionnaire tool to evaluate the Clinician's Awareness Towards Cognitive Errors (CATChES) in clinical decision making.

    METHODS: This questionnaire is divided into two parts. Part A is to evaluate the clinicians' awareness towards cognitive errors in clinical decision making while Part B is to evaluate their perception towards specific cognitive errors. Content validation for both parts was first determined followed by construct validation for Part A. Construct validation for Part B was not determined as the responses were set in a dichotomous format.

    RESULTS: For content validation, all items in both Part A and Part B were rated as "excellent" in terms of their relevance in clinical settings. For construct validation using exploratory factor analysis (EFA) for Part A, a two-factor model with total variance extraction of 60% was determined. Two items were deleted. Then, the EFA was repeated showing that all factor loadings are above the cut-off value of >0.5. The Cronbach's alpha for both factors are above 0.6.

    CONCLUSION: The CATChES questionnaire tool is a valid questionnaire tool aimed to evaluate the awareness among clinicians toward cognitive errors in clinical decision making.

  19. Chong UR, Abdul-Rahman PS, Abdul-Aziz A, Hashim OH, Mat-Junit S
    Biomed Res Int, 2013;2013:459017.
    PMID: 24455694 DOI: 10.1155/2013/459017
    The fruit pulp extract of Tamarindus indica has been reported for its antioxidant and hypolipidemic properties. In this study, the methanol extract of T. indica fruit pulp was investigated for its effects on the abundance of HepG2 cell lysate proteins. Cell lysate was extracted from HepG2 cells grown in the absence and presence of the methanol extract of T. indica fruit pulp. Approximately 2500 spots were resolved using two-dimensional gel electrophoresis and the abundance of 20 cellular proteins was found to be significantly reduced. Among the proteins of reduced abundance, fourteen, including six proteins involved in metabolism (including ethanolamine phosphate cytidylyltransferase), four mitochondrial proteins (including prohibitin and respiratory chain proteins), and four proteins involved in translation and splicing, were positively identified by mass spectrometry and database search. The identified HepG2 altered abundance proteins, when taken together and analyzed by Ingenuity Pathways Analysis (IPA) software, are suggestive of the effects of T. indica fruit pulp extract on metabolism and inflammation, which are modulated by LXR/RXR. In conclusion, the methanol fruit pulp extract of T. indica was shown to cause reduced abundance of HepG2 mitochondrial, metabolic, and regulatory proteins involved in oxidative phosphorylation, protein synthesis, and cellular metabolism.
  20. Abioye OP, Agamuthu P, Abdul Aziz AR
    Biodegradation, 2012 Apr;23(2):277-86.
    PMID: 21870160 DOI: 10.1007/s10532-011-9506-9
    Soil contamination by hydrocarbons, especially by used lubricating oil, is a growing problem in developing countries, which poses a serious threat to the environment. Phytoremediation of these contaminated soils offers environmental friendly and a cost effective method for their remediation. Hibiscus cannabinus was studied for the remediation of soil contaminated with 2.5 and 1% used lubricating oil and treated with organic wastes [banana skin (BS), brewery spent grain (BSG) and spent mushroom compost (SMC)] for a period of 90 days under natural conditions. Loss of 86.4 and 91.8% used lubricating oil was recorded in soil contaminated with 2.5 and 1% oil and treated with organic wastes respectively at the end of 90 days. However, 52.5 and 58.9% oil loss was recorded in unamended soil contaminated with 2.5 and 1% oil, respectively. The plant did not accumulate hydrocarbon from the soil but shows appreciable accumulation of Fe and Zn in the root and stem of H. cannabinus at the end of the experiment. The first order kinetic rate of uptake of Fe and Zn in H. cannabinus was higher in organic wastes amendment treatments compared to the unamended treatments, which are extremely low. The results of this study suggest that H. cannabinus has a high potential for remediation of hydrocarbon and heavy metal contaminated soil.
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