Displaying publications 1 - 20 of 164 in total

Abstract:
Sort:
  1. Yehye WA, Ariffin A, Rahman NA, Ng SW
    PMID: 21577527 DOI: 10.1107/S1600536809030645
    The title compound, C(25)H(34)N(2)O(3)S, is a derivative of N'-benzyl-ideneacetohydrazide having substituents on the acetyl and benzylidenyl parts, and displays a planar C(carbon-yl)-NH-NC(anis-yl) fragment [torsion angle = 174.9 (3)°]. The -NH- unit forms an N-H⋯O hydrogen bond with the carbonyl O atom of an inversion-related mol-ecule.
  2. Mansor S, Yehye WA, Ariffin A, Rahman NA, Ng SW
    PMID: 21201758 DOI: 10.1107/S1600536808026056
    Two mol-ecules of the title compound, C(21)H(27)NO(3)S, are disposed about a center of inversion, generating an O-H⋯O hydrogen-bonded dimer.
  3. Yehye WA, Ariffin A, Rahman NA, Ng SW
    Acta Crystallogr Sect E Struct Rep Online, 2010 Mar 20;66(Pt 4):o878.
    PMID: 21580697 DOI: 10.1107/S1600536810009621
    In the title mol-ecule, C(24)H(20)N(2)O(4), the five-membered oxadiazole ring is nearly planar (r.m.s. deviation = 0.053 Å) and the phenyl ring of the biphenyl unit attached to it forms a dihedral angle of 73.2 (1)°; the other phenyl ring is close to coplanar with the oxadiazole ring [dihedral angle = 6.2 (2)°].
  4. Yaeghoobi M, Rahman NA, Ng SW
    PMID: 21583886 DOI: 10.1107/S1600536809013348
    In the title Schiff base, C(16)H(16)ClNO(2), the 2-(4-methoxy-phen-yl)ethyl (CH(3)OC(6)H(4)CH(2)CH(2)-; r.m.s. deviation = 0.10 Å) and 4-chloro-2-(imino-meth-yl)phenol (N=CHC(6)H(3)ClOH; r.m.s. deviation = 0.01 Å) portions are both essentially planar, the two parts being inclined at an angle of 61.8 (1)°. The hydroxy group forms a hydrogen bond to the imino N atom.
  5. Abd Rahman NA, Noor SK, Ibrahim IM, Yasin MNM, Ismail AM, Osman MN, et al.
    Micromachines (Basel), 2023 Apr 13;14(4).
    PMID: 37421074 DOI: 10.3390/mi14040841
    This paper presents the generation of orbital angular momentum (OAM) vortex waves with mode +1 using dielectric resonator antenna (DRA) array. The proposed antenna was designed and fabricated using FR-4 substrate to generate OAM mode +1 at 3.56 GHz (5G new radio band). The proposed antenna consists of 2 × 2 rectangular DRA array, a feeding network, and four cross slots etched on the ground plane. The proposed antenna succeeded in generating OAM waves; this was confirmed by the measured radiation pattern (2D polar form), simulated phase distribution, and intensity distribution. Moreover, mode purity analysis was carried out to verify the generation of OAM mode +1, and the purity obtained was 53.87%. The antenna operates from 3.2 to 3.66 GHz with a maximum gain of 7.3 dBi. Compared with previous designs, this proposed antenna is low-profile and easy to fabricate. In addition, the proposed antenna has a compact structure, wide bandwidth, high gain, and low losses, thus meeting the requirements of 5G NR applications.
  6. Abd Rahman NA, Mohd Yasin MN, Ibrahim IM, Jusoh M, Noor SK, Ekscalin Emalda Mary MR, et al.
    Micromachines (Basel), 2022 Dec 08;13(12).
    PMID: 36557477 DOI: 10.3390/mi13122178
    A comprehensive review on recent developments and applications of circularly polarized (CP) dielectric resonator antennas (DRAs) is proposed in this paper. DRAs have received more considerations in various applications due to their advantages such as wide bandwidth, high gain, high efficiency, low losses, and low profile. A broad justification for circular polarization and DRAs is stated at the beginning of the review. Various techniques such as single feed, dual, or multiple feeds used by different researchers for generating circular polarization in DRAs are briefly studied in this paper. Multiple-input-multiple-output (MIMO) CP DRAs, which can increase channel capacity, link reliability, and data rate, have also been analyzed. Additionally, innovative design solutions for broadening the circular polarization bandwidth and reducing mutual coupling are studied. Several applications of DRA are also discussed comprehensively. This paper finishes with concluding remarks.
  7. Pasupuleti VR, Arigela CS, Gan SH, Salam SKN, Krishnan KT, Rahman NA, et al.
    Oxid Med Cell Longev, 2020;2020:8878172.
    PMID: 33299532 DOI: 10.1155/2020/8878172
    Despite the availability of various antidiabetic drugs, diabetes mellitus (DM) remains one of the world's most prevalent chronic diseases and is a global burden. Hyperglycaemia, a characteristic of type 2 diabetes mellitus (T2DM), substantially leads to the generation of reactive oxygen species (ROS), triggering oxidative stress as well as numerous cellular and molecular modifications such as mitochondrial dysfunction affecting normal physiological functions in the body. In mitochondrial-mediated processes, oxidative pathways play an important role, although the responsible molecular mechanisms remain unclear. The impaired mitochondrial function is evidenced by insulin insensitivity in various cell types. In addition, the roles of master antioxidant pathway nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)/antioxidant response elements (ARE) are being deciphered to explain various molecular pathways involved in diabetes. Dietary factors are known to influence diabetes, and many natural dietary factors have been studied to improve diabetes. Honey is primarily rich in carbohydrates and is also abundant in flavonoids and phenolic acids; thus, it is a promising therapeutic antioxidant for various disorders. Various research has indicated that honey has strong wound-healing properties and has antibacterial, anti-inflammatory, antifungal, and antiviral effects; thus, it is a promising antidiabetic agent. The potential antidiabetic mechanisms of honey were proposed based on its major constituents. This review focuses on the various prospects of using honey as an antidiabetic agent and the potential insights.
  8. Rothan HA, Bahrani H, Mohamed Z, Teoh TC, Shankar EM, Rahman NA, et al.
    PLoS One, 2015;10(5):e0126360.
    PMID: 25970853 DOI: 10.1371/journal.pone.0126360
    Lack of vaccine and effective antiviral drugs against chikungunya virus (CHIKV) outbreaks have led to significant impact on health care in the developing world. Here, we evaluated the antiviral effects of tetracycline (TETRA) derivatives and other common antiviral agents against CHIKV. Our results showed that within the TETRA derivatives group, Doxycycline (DOXY) exhibited the highest inhibitory effect against CHIKV replication in Vero cells. On the other hand, in the antiviral group Ribavirin (RIBA) showed higher inhibitory effects against CHIKV replication compared to Aciclovir (ACIC). Interestingly, RIBA inhibitory effects were also higher than all but DOXY within the TETRA derivatives group. Docking studies of DOXY to viral cysteine protease and E2 envelope protein showed non-competitive interaction with docking energy of -6.6±0.1 and -6.4±0.1 kcal/mol respectively. The 50% effective concentration (EC50) of DOXY and RIBA was determined to be 10.95±2.12 μM and 15.51±1.62 μM respectively, while DOXY+RIBA (1:1 combination) showed an EC50 of 4.52±1.42 μM. When compared, DOXY showed higher inhibition of viral infectivity and entry than RIBA. In contrast however, RIBA showed higher inhibition against viral replication in target cells compared to DOXY. Assays using mice as animal models revealed that DOXY+RIBA effectively inhibited CHIKV replication and attenuated its infectivity in vivo. Further experimental and clinical studies are warranted to investigate their potential application for clinical intervention of CHIKV disease.
  9. Ramli R, Rahman NA, Rahman RA, Hussaini HM, Hamid AL
    Dent Traumatol, 2011 Apr;27(2):122-6.
    PMID: 21281443 DOI: 10.1111/j.1600-9657.2010.00968.x
    Aetiology of oral and maxillofacial injuries in this country includes motorvehicle accident (MVA), fall, industrial accidents and others. Among these causes, MVA accident is the predominant cause of injury in Malaysia.
  10. Rasul RM, Tamilarasi Muniandy M, Zakaria Z, Shah K, Chee CF, Dabbagh A, et al.
    Carbohydr Polym, 2020 Dec 15;250:116800.
    PMID: 33049807 DOI: 10.1016/j.carbpol.2020.116800
    Chitosan, as a biodegradable and biocompatible polymer, is characterized by anti-microbial and anti-cancer properties. It lately has received a widespread interest for use as the pulmonary particulate backbone materials of drug carrier for the treatment of infectious disease and cancer. The success of chitosan as pulmonary particulate drug carrier is a critical interplay of their mucoadhesive, permeation enhancement and site/cell-specific attributes. In the case of nanocarriers, various microencapsulation and micro-nano blending systems have been devised to equip them with an appropriate aerodynamic character to enable efficient pulmonary aerosolization and inhalation. The late COVID-19 infection is met with acute respiratory distress syndrome and cancer. Chitosan and its derivatives are found useful in combating HCoV and cancer as a function of their molecular weight, substituent type and its degree of substitution. The interest in chitosan is expected to rise in the next decade from the perspectives of drug delivery in combination with its therapeutic performance.
  11. Ahmad R, Nik Abdul Rahman NH, Mohd Noh AY, Nik Abdul Rahman NA, Mohamad N, Baharudin KA
    Malays J Med Sci, 2010 Jan;17(1):38-43.
    PMID: 22135524 MyJurnal
    The observation ward (OW) allows patients to be reassessed and monitored before deciding either to admit or to discharge them. This is a six-month descriptive cross-sectional study conducted in the observation ward of the Emergency Department (ED) of Hospital Universiti Sains Malaysia, Kelantan. The objective of this study was to examine the demographic characteristics and clinical profiles of adult observed patients and to determine the effectiveness of OW management.
  12. Ikram NK, Durrant JD, Muchtaridi M, Zalaludin AS, Purwitasari N, Mohamed N, et al.
    J Chem Inf Model, 2015 Feb 23;55(2):308-16.
    PMID: 25555059 DOI: 10.1021/ci500405g
    Recent outbreaks of highly pathogenic and occasional drug-resistant influenza strains have highlighted the need to develop novel anti-influenza therapeutics. Here, we report computational and experimental efforts to identify influenza neuraminidase inhibitors from among the 3000 natural compounds in the Malaysian-Plants Natural-Product (NADI) database. These 3000 compounds were first docked into the neuraminidase active site. The five plants with the largest number of top predicted ligands were selected for experimental evaluation. Twelve specific compounds isolated from these five plants were shown to inhibit neuraminidase, including two compounds with IC50 values less than 92 μM. Furthermore, four of the 12 isolated compounds had also been identified in the top 100 compounds from the virtual screen. Together, these results suggest an effective new approach for identifying bioactive plant species that will further the identification of new pharmacologically active compounds from diverse natural-product resources.
  13. Baharuddin IH, Arifin WN, Kueh YC, Rahman NA
    Malays J Med Sci, 2018 May;25(3):111-119.
    PMID: 30899192 DOI: 10.21315/mjms2018.25.3.11
    Background: Many questionnaires have been developed to measure dental anxiety and fear. Among them is the Index of Dental Anxiety and Fear Scale (IDAF-4C+), which consists of a dental anxiety and fear module (IDAF-4C), a phobia module (IDAF-P) and a stimulus module (IDAF-S). The objective of this research was to report the adaptation and validation of the IDAF-4C+ for Malaysian secondary school children.

    Methods: This was a cross-sectional validation study. The original English version of the IDAF-4C+ was translated into Malay, back-translated, and then sent for content validation via an expert validation and face validation by the target student population. Three hundred and seventy questionnaires were then distributed among 16-year-old school children. Confirmatory factor analysis (CFA) was conducted for the IDAF-4C module using a bootstrapped maximum likelihood estimator. Spearman's rank correlation was used to assess the relationship between the IDAF-S and IDAF-4C modules. Intraclass correlation (ICC) was used to determine the stability of the IDAF-S and IDAF-4C modules, while kappa values were used for the IDAF-P module.

    Results: The response rate was 86.5% for CFA and 76.9% for stability. CFA showed the existence of only one factor with a reliability estimate of 0.921, obtained via Raykov's procedure. All items in the IDAF-S module were significantly correlated with the IDAF-4C module (P < 0.001). The IDAF-S and IDAF-4C modules were stable, as determined via a two-way mixed model with absolute agreement, a single measure and a Case 3 ICC (A, 1). The IDAF-P module showed satisfactory stability, as assessed via kappa values.

    Conclusion: The Malay version of the IDAF-4C+ is valid and reliable in measuring dental anxiety and fear among Malaysian secondary school children.

  14. Othman S, Rahman NA, Yusof R
    Trans R Soc Trop Med Hyg, 2010 Dec;104(12):806-8.
    PMID: 20800252 DOI: 10.1016/j.trstmh.2010.07.004
    In contrast to many viruses that escape the host's immune responses by suppressing the major histocompatibility complex (MHC) class I pathway, flaviviruses have been shown to up-regulate the cell surface expression of MHC class I complex. The mechanism by which dengue virus (DV) achieves this up-regulation remains unclear. Our investigation on the HLA-A2 gene in human liver cells demonstrated that all four serotypes of dengue virus, DV1 to DV4, resulted in variable degrees of promoter induction. This illustrates the importance of MHC class I transcription regulation in primary infections by different DV serotypes that may have even greater impact in secondary infections, associated with increased disease severity.
  15. Mokhtar KS, Rahman NA, Haron MS, Rahman NHA
    J Infect Dev Ctries, 2020 04 30;14(4):349-359.
    PMID: 32379711 DOI: 10.3855/jidc.11583
    INTRODUCTION: The prevalence of tuberculosis (TB) remains alarmingly high in developing countries, including Malaysia. Recognised as the leading global infectious disease, untreated TB can be fatal. TB is easily spread through the air, and any close contact with a TB patient can put others at risk. This study therefore aimed to investigate the level of awareness of TB among TB patients and how their attitudes affect self-preventive healthcare.

    METHODOLOGY: This cross-sectional study was conducted using a validated self-administered questionnaire at 18 hospitals in six states of Malaysia, namely, Selangor, Kuala Lumpur, Penang, Kelantan, Sabah, and Sarawak in 2015. The study sample comprised 1600 TB patients who were randomly selected using data obtained from the Disease Control Division, Ministry of Health Malaysia. A total of 1368 of the completed questionnaires were considered usable and included in the statistical analysis.

    RESULTS: Overall, the level of TB awareness was found to be high, and the respondents possessed positive attitudes towards TB and health-seeking behaviours. Self-preventive care among the TB patients was determined as being at a moderate level. With regard to contact with others, the patients were more comfortable around their families than their friends and neighbours.

    CONCLUSIONS: More health education programmes are recommended to cultivate positive attitudes towards TB, to encourage communities to have a better understanding of TB, and to create awareness among patients of the proper ways to practice self-preventive care.

  16. Sukumaran SD, Nasir SB, Tee JT, Buckle MJC, Othman R, Rahman NA, et al.
    J Enzyme Inhib Med Chem, 2021 Dec;36(1):130-137.
    PMID: 33243025 DOI: 10.1080/14756366.2020.1847100
    A series of C4-substituted tertiary nitrogen-bearing 2'-hydroxychalcones were designed and synthesised based on a previous mixed type acetylcholinesterase inhibitor. Majority of the 2'-hydroxychalcone analogues displayed a better inhibition against acetylcholinesterase (AChE) than butyrylcholinesterase (BuChE). Among them, compound 4c was identified as the most potent AChE inhibitor (IC50: 3.3 µM) and showed the highest selectivity for AChE over BuChE (ratio >30:1). Molecular docking studies suggested that compound 4c interacts with both the peripheral anionic site (PAS) and catalytic anionic site (CAS) regions of AChE. ADMET analysis confirmed the therapeutic potential of compound 4c based on its blood-brain barrier penetrating. Overall, the results suggest that this 2'-hydroxychalcone deserves further investigation into the therapeutic lead for Alzheimer's disease (AD).
  17. Othman R, Wahab HA, Yusof R, Rahman NA
    In Silico Biol. (Gedrukt), 2007;7(2):215-24.
    PMID: 17688447
    Multiple sequence alignment was performed against eight proteases from the Flaviviridae family using ClustalW to illustrate conserved domains. Two sets of prediction approaches were applied and the results compared. Firstly, secondary structure prediction was performed using available structure prediction servers. The second approach made use of the information on the secondary structures extracted from structure prediction servers, threading techniques and DSSP database of some of the templates used in the threading techniques. Consensus on the one-dimensional secondary structure of Den2 protease was obtained from each approach and evaluated against data from the recently crystallised Den2 NS2B/NS3 obtained from the Protein Data Bank (PDB). Results indicated the second approach to show higher accuracy compared to the use of prediction servers only. Thus, it is plausible that this approach is applicable to the initial stage of structural studies of proteins with low amino acid sequence homology against other available proteins in the PDB.
  18. Bukhari SN, Lauro G, Jantan I, Fei Chee C, Amjad MW, Bifulco G, et al.
    Future Med Chem, 2016 Oct;8(16):1953-1967.
    PMID: 27654499
    In present study, the anti-inflammatory activities of a new series of benzimidazole derivatives were studied, investigating their inhibition of secretory phospholipase A2, lipoxygenase, COXs and lipopolysaccharide-induced secretion of TNF-α and IL-6 in mouse RAW264.7 macrophages.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links