Displaying publications 1 - 20 of 79 in total

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  1. Abdullah A, Ramly R, Mohammad Ridzwan MS, Sudirwan F, Abas A, Ahmad K, et al.
    J Fish Dis, 2018 Sep;41(9):1459-1462.
    PMID: 30027657 DOI: 10.1111/jfd.12843
  2. Abdullahi A, Ahmad K, Ismail IS, Asib N, Ahmed OH, Abubakar AI, et al.
    Plant Pathol J, 2020 Dec 01;36(6):515-535.
    PMID: 33312089 DOI: 10.5423/PPJ.RW.05.2020.0077
    Essential oils (EOs) have gained a renewed interest in many disciplines such as plant disease control and medicine. This review discusses the components of ginger EOs, their mode of action, and their potential nanotechnology applications in controlling tropical plant diseases. Gas chromatography-mass spectroscopy (GC-MS), high-performance liquid chromatography, and headspace procedures are commonly used to detect and profile their chemical compositions EOs in ginger. The ginger EOs are composed of monoterpenes (transcaryophyllene, camphene, geranial, eucalyptol, and neral) and sesquiterpene hydrocarbons (α-zingiberene, ar-curcumene, β-bisabolene, and β-sesquiphellandrene). GC-MS analysis of the EOs revealed many compounds but few compounds were revealed using the headspace approach. The EOs have a wide range of activities against many phytopathogens. EOs mode of action affects both the pathogen cell's external envelope and internal structures. The problems associated with solubility and stability of EOs had prompted the use nanotechnology such as nanoemulsions. The use of nanoemulsion to increase efficiency and supply of EOs to control plant diseases control was discussed in this present paper. The findings of this review paper may accelerate the effective use of ginger EOs in controlling tropical plant diseases.
  3. Adamu A, Ahmad K, Siddiqui Y, Ismail IS, Asib N, Bashir Kutawa A, et al.
    Molecules, 2021 Jun 25;26(13).
    PMID: 34202405 DOI: 10.3390/molecules26133902
    The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious rice diseases, causing huge yield losses worldwide. Several technologies and approaches have been opted to reduce the damage; however, these have had limited success. Recently, scientists have been focusing their efforts on developing efficient and environmentally friendly nanobactericides for controlling bacterial diseases in rice fields. In the present study, a scanning electron microscope (SEM), transmission electron microscope (TEM), and a confocal laser scanning microscope (CLSM) were utilized to investigate the mode of actions of ginger EOs on the cell structure of Xoo. The ginger EOs caused the cells to grow abnormally, resulting in an irregular form with hollow layers, whereas the dimethylsulfoxide (DMSO) treatment showed a typical rod shape for the Xoo cell. Ginger EOs restricted the growth and production of biofilms by reducing the number of biofilms generated as indicated by CLSM. Due to the instability, poor solubility, and durability of ginger EOs, a nanoemulsions approach was used, and a glasshouse trial was performed to assess their efficacy on BLB disease control. The in vitro antibacterial activity of the developed nanobactericides was promising at different concentration (50-125 µL/mL) tested. The efficacy was concentration-dependent. There was significant antibacterial activity recorded at higher concentrations. A glasshouse trial revealed that developed nanobactericides managed to suppress BLB disease severity effectively. Treatment at a concentration of 125 μL/mL was the best based on the suppression of disease severity index, AUDPC value, disease reduction (DR), and protection index (PI). Furthermore, findings on plant growth, physiological features, and yield parameters were significantly enhanced compared to the positive control treatment. In conclusion, the results indicated that ginger essential oils loaded-nanoemulsions are a promising alternative to synthetic antibiotics in suppressing Xoo growth, regulating the BLB disease, and enhancing rice yield under a glasshouse trial.
  4. Adamu Ahmad K, Sabo Mohammed A, Abas F
    Molecules, 2016 Mar 14;21(3):256.
    PMID: 26985885 DOI: 10.3390/molecules21030256
    The use of chitosan as a delivery carrier has attracted much attention in recent years. In this study, chitosan nanoparticles (CS-NP) and chitosan-ΦKAZ14 bacteriophage-loaded nanoparticles (C-ΦKAZ14 NP) were prepared by a simple coercavation method and characterized. The objective was to achieve an effective protection of bacteriophage from gastric acids and enzymes in the chicken gastrointestinal tract. The average particle sizes for CS-NP and C-ΦKAZ14 NP were 188 ± 7.4 and 176 ± 3.2 nm, respectively. The zeta potentials for CS-NP and C-ΦKAZ14 NP were 50 and 60 mV, respectively. Differential scanning calorimetry (DSC) of C-ΦKAZ14 NP gave an onset temperature of -17.17 °C with a peak at 17.32 °C and final end set of 17.41 °C, while blank chitosan NP had an onset of -20.00 °C with a peak at -19.78 °C and final end set at -20.47. FT-IR spectroscopy data of both CS-NP and C-ΦKAZ14 NP were the same. Chitosan nanoparticles showed considerable protection of ΦKAZ14 bacteriophage against degradation by enzymes as evidenced in gel electrophoresis, whereby ΦKAZ14 bacteriophage encapsulated in chitosan nanoparticles were protected whereas the naked ΦKAZ14 bacteriophage were degraded. C-ΦKAZ14 NP was non-toxic as shown by a chorioallantoic membrane (CAM) toxicity assay. It was concluded that chitosan nanoparticles could be a potent carrier of ΦKAZ14 bacteriophage for oral therapy against colibacillosis in poultry.
  5. Aftab SM, Mohd Rafie AS, Razak NA, Ahmad KA
    PLoS One, 2016;11(4):e0153755.
    PMID: 27104354 DOI: 10.1371/journal.pone.0153755
    One of the major flow phenomena associated with low Reynolds number flow is the formation of separation bubbles on an airfoil's surface. NACA4415 airfoil is commonly used in wind turbines and UAV applications. The stall characteristics are gradual compared to thin airfoils. The primary criterion set for this work is the capture of laminar separation bubble. Flow is simulated for a Reynolds number of 120,000. The numerical analysis carried out shows the advantages and disadvantages of a few turbulence models. The turbulence models tested were: one equation Spallart Allmars (S-A), two equation SST K-ω, three equation Intermittency (γ) SST, k-kl-ω and finally, the four equation transition γ-Reθ SST. However, the variation in flow physics differs between these turbulence models. Procedure to establish the accuracy of the simulation, in accord with previous experimental results, has been discussed in detail.
  6. Aftab SMA, Ahmad KA
    PLoS One, 2017;12(8):e0183456.
    PMID: 28850622 DOI: 10.1371/journal.pone.0183456
    The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE) effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD) study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The tubercle designs implemented on the airfoil are sinusoidal and spherical. A parametric study is also carried out considering three amplitudes (0.025c, 0.05c and 0.075c), the wavelength (0.25c) is fixed. Structured mesh is utilized to generate grid and Transition SST turbulence model is used to capture the flow physics. Results clearly show spherical tubercles outperform sinusoidal tubercles. Furthermore experimental study considering spherical TLE is carried out at Reynolds number 200,000. The experimental results show that spherical TLE improve performance compared to clean airfoil.
  7. Ahmad K, Yan Y, Bless D
    J Voice, 2012 Nov;26(6):751-9.
    PMID: 22633334 DOI: 10.1016/j.jvoice.2011.12.002
    A high proportion of the geriatric population suffers from presbylaryngis and presbyphonia; however, our knowledge of vibratory patterns in this population is almost nonexistent. In this study, we investigate the vocal fold vibratory patterns of healthy elderly females to determine which features or combination of them could best describe the geriatric voices.
  8. Ahmad K, Aziz Z
    J Ethnopharmacol, 2012 May 7;141(1):446-50.
    PMID: 22440259 DOI: 10.1016/j.jep.2012.03.009
    ETHNOPHARMACOLOGICAL RELEVANCE:
    The consumption of Mitragyna speciosa (MS) for its psychoactive effects is widely reported amongst people in the villages in Thailand and Malaysia even though its use is illegal.
    AIM OF THE STUDY: This study examined the pattern of MS use, its reported effects and explored its potential to cause dependence.
    MATERIALS AND METHODS: We used both convenience and snowball-sampling methods to recruit participants in a border town between two northern states in Malaysia. Face-to-face interviews were conducted with the use of a structured questionnaire on 562 respondents who gave oral consent to participate in the study.
    RESULTS: The response rate was 91%. The majority of the respondents (88%) reported daily use of MS. The main mode of using MS was by drinking the MS extract as tea (90%). The mean age of starting MS use was 28.3 (SD=8.1) years. A variety of reasons were given for using MS including for social and recreational needs, stamina and physical endurance, pain relief and improved sexual performance. Despite its reported usefulness in weaning off opiate addiction, 460 (87%) admitted they were not able to stop using MS. Only education level had a statistically significant association with the ability to stop or not stop the use of MS (χ(2)=31.0, df=1, p<0.001). Significantly higher proportions of those with a lower education level (38%) were able to stop using MS compared to respondents with a higher education level.
    CONCLUSIONS: Our study provides important information on the pattern of MS use, its effects and its potential to cause addiction, as there has been growing interest in MS as evidenced by the number of advertisements for its sale on the Internet. Future study is required to explore its psychological and social impact on users.
  9. Ahmad K, Yan Y, Bless DM
    J Voice, 2012 Mar;26(2):239-53.
    PMID: 21621975 DOI: 10.1016/j.jvoice.2011.02.001
    The purpose of the study was to investigate relationships between vocal fold vibrations and voice quality. Laryngeal images obtained from high-speed digital imaging (HSDI) were examined for their open-closed timing characteristics and perturbation values. A customized software delineated the glottal edges and used the Hilbert transform-based method of analysis to provide objective quantification of glottal perturbation. Overlay tracings of the transformed glottal cycles provided visual patterns on the overall vibratory dynamics. In this paper, we described the use of this method in looking at vibratory characteristics of a group of young female speakers (N=23). We found that, females with no voice complaints and who had been perceived to have normal voices were not a homogeneous group in terms of their glottal vibratory patterns during phonation. Their vibratory patterns showed characteristics similar to exemplar voices targeted to be clear (50%), pressed (27%), breathy (15%), or a mixed quality (8%). Perturbation range in terms of cycle-to-cycle frequency and amplitude was small and did not discriminate patterns. All these patterns yielded perceptually normal voices suggesting that in normal young speakers, the level of perturbation may be more important to the judgment than the actual pattern of closure.
  10. Ahmad K
    Int J Speech Lang Pathol, 2010 Aug;12(4):317-9; discussion 329-32.
    PMID: 20590514 DOI: 10.3109/17549507.2010.483017
    Speech-language pathologists (SLPs) practising in Malaysia face similar dilemmas as their counterparts in more developed countries when it comes to deciding on discharge/termination of services for their patients. Furthermore, discharge dilemmas appear to be a frequent and inevitable part of their everyday practice. In an interview conducted for the purpose of this paper, it was clear that many SLPs found it difficult to articulate or justify the process they took to reach a decision on whether or not to terminate their services or discharge their patients. Much of the difficulty is anchored on the need to be realistic and function within the confines of limited resources. Malaysian SLPs were aware of the ideals that had to be abandoned along the way but had not allowed guilt to dissuade or discourage them from providing what they perceived as the next best available service. The not-so ideal decisions made by these SLPs may be frowned upon by international standards but must be examined within the local historical perspective of the development of the SLP profession in Malaysia. The dilemma will continue until the country produces SLPs in sufficient numbers but the profession is reminded that less-than-ideal practices may perpetuate over time into unhealthy traditions that will require major efforts to be undone.
  11. Ahmad K, Thomas NF, Nafiah MA, Awang K, Ng SW
    PMID: 21583151 DOI: 10.1107/S1600536809017401
    In the title compound, C(17)H(17)NO(2), the phenyl-ene rings are bent with respect to the carbon-carbon double bond [dihedral angle between rings = 39.6 (1)°]. The acetamido group is twisted out of the plane of the aromatic ring [dihedral angle = 44.2 (1)°] in order to form an N-H⋯O hydrogen bond to the acetamido group of an adjacent mol-ecule, generating a zigzag chain running along the c axis.
  12. Ahmad K, Thomas NF, Din MF, Awang K, Ng SW
    PMID: 21583150 DOI: 10.1107/S1600536809017395
    In the title compound, C(17)H(17)NO(2), the phenyl-ene rings are nearly coplanar [dihedral angle 7.3 (1)°]. The acetamido group is twisted out of the plane of the aromatic ring in order to form an N-H⋯O hydrogen bond to the acetamido group of an adjacent mol-ecule, generating a helical chain running along the b axis.
  13. Ahmad K, Ibrahim H, Othman BF, Vong E
    Int J Speech Lang Pathol, 2013 Feb;15(1):37-41.
    PMID: 23323816 DOI: 10.3109/17549507.2012.757709
    The current paper is a response to the Wiley, McAllister, Davidson, and Marshall lead article regarding the application of the World Report on Disability (WRD) to people with communication disorders. The current paper directly addresses recommendation 5 (improvement of human resource capacity) and indirectly addresses recommendations 7, 8, and 9 (related to improving local knowledge and data on communicative disabilities) indirectly. The paper describes Malaysia's initiatives in the early 1990s, in developing its local professional capacity to provide services for people with communication disorders (PWCD). It charts the history of development of a local undergraduate entry-level degree program for speech-language pathology (SLP) from the point of conceptualization to full execution. The article provides glimpses to the processes and challenges faced by Universiti Kebangsaan Malaysia as the pioneer university in the South East Asia region to undertake the training and education of the SLP profession and highlights relevant issues faced by newly introduced professions in a country where resources and practice traditions were previously unavailable. It underscores the important role played by government institutions and an international professional network in driving forward-looking policies to implement and sustain the program.
  14. Ahmad K, Thomas NF, Hadi AH, Mukhtar MR, Mohamad K, Nafiah MA, et al.
    Chem Pharm Bull (Tokyo), 2010 Aug;58(8):1085-7.
    PMID: 20686264
    A phytochemical study on the bark of Neisosperma oppositifolia (Apocynaceae) yielded two new beta-carboline indole alkaloids, oppositinines A (1) and B (2), together with five known alkaloids, isoreserpiline, isocarapanaubine, vobasine, 10-methoxydihydrocorynantheol-N-oxide, and ochropposinine oxindole. Structural elucidation of 1 and 2 was performed using 2D NMR methods. Oppositinines A (1) and B (2) showed potent vasorelaxant effects on the rat aorta.
  15. Ahmad K, Win T, Jaffri JM, Edueng K, Taher M
    AAPS PharmSciTech, 2018 Jan;19(1):371-383.
    PMID: 28744617 DOI: 10.1208/s12249-017-0843-9
    This study aims to investigate the use of palm olein as the oil phase for betamethasone 17-valerate (BV) emulsions. The physicochemical properties of the formulations were characterized. In vitro drug release study was performed with the Hanson Vertical Diffusion Cell System; the samples were quantified with HPLC and the results were compared with commercial products. Optimized emulsion formulations were subjected to stability studies for 3 months at temperatures of 4, 25, and 40°C; the betamethasone 17-valerate content was analyzed using HPLC. The formulations produced mean particle size of 2-4 μm, viscosities of 50-250 mPa.s, and zeta potential between -45 and -68 mV. The rheological analyses showed that the emulsions exhibited pseudoplastic and viscoelastic behavior. The in vitro release of BV from palm olein emulsion through cellulose acetate was 4.5 times higher than that of commercial products and more BV molecules deposited in rat skin. Less than 4% of the drug was degraded in the formulations during the 3-month period when they were subjected to the three different temperatures. These findings indicate that palm olein-in-water emulsion can be an alternative vehicle for topical drug delivery system with superior permeability.
  16. Ahmad K, Ariffin MFM, Deraman F, Ariffin S, Abdullah M, Razzak MMA, et al.
    J Relig Health, 2018 Oct;57(5):1649-1663.
    PMID: 29075949 DOI: 10.1007/s10943-017-0507-9
    This study was conducted to identify and describe the patients' perceptions of Islamic medicine based on gender, age, marital, educational level and working status among the Malaysian Muslim population. A nationwide interviewer-administered questionnaire survey was conducted in 2013. An open-ended questionnaire pertaining to Islamic medicine was used to increase the probability of capturing maximum data. This survey implemented a multistage design, stratified by state, proportionate to the size of the state population and was representative of the Malaysian population. Post-survey classification of results was performed accordingly. Complex data analysis was carried out using SPSS 16.0. The discussion was identified and categorised into various sections. The paper concludes that Islamic medicine has a major influence in the Malaysian Muslim community compared to other alternatives. Further, its potential for growth and importance especially for treating spiritual ailments cannot be denied. The respondents indicated that two factors motivate Islamic medicine in Malaysia: (1) the Muslim community opts for alternative healing because of their dissatisfaction with conventional methods; (2) Islamic medicine focuses only on healing spiritual-related problems. The average perception of respondents is that the function of Islamic medicine in healing physical diseases is undervalued and that it is not suitable to replace the functions of modern health institutions.
  17. Ahmad K, Anchah L, Ting CY, Lim SE
    Contemp Clin Trials Commun, 2024 Apr;38:101280.
    PMID: 38435429 DOI: 10.1016/j.conctc.2024.101280
    AIMS: This study presents a protocol for the Pharmacy Integrated Community Care (PICC) program, meticulously designed to enhance Hemoglobin A1c (HbA1c) levels and augment knowledge about diabetes mellitus (DM) among individuals diagnosed with Type 2 Diabetes Mellitus (T2DM) in the Sarawak State of Malaysia.

    METHODS: From 1 May to December 31, 2023, a prospective, multicenter, parallel-design randomised controlled trial will be conducted with two groups, each consisting of 47 participants. The intervention group will receive a structured, four-session group-based program guided by experienced pharmacists, focusing on medication adherence and diabetes management. The control group will follow the standard Diabetes Mellitus Adherence Clinic program. The primary outcomes of this study encompass enhancements in knowledge regarding diabetes medication management and adherence, followed by subsequent changes in HbA1c levels.

    CONCLUSIONS: The successful implementation of the PICC program holds promise for enhancing health outcomes in the T2DM population, potentially leading to more effective diabetes management initiatives and better health practices in the community.

    TRIAL REGISTRATION CLINICALTRIALSGOV IDENTIFIER: NCT05106231.

  18. Ahmadi P, Muharam FM, Ahmad K, Mansor S, Abu Seman I
    Plant Dis, 2017 Jun;101(6):1009-1016.
    PMID: 30682927 DOI: 10.1094/PDIS-12-16-1699-RE
    Ganoderma boninense is a causal agent of basal stem rot (BSR) and is responsible for a significant portion of oil palm (Elaeis guineensis) losses, which can reach US$500 million a year in Southeast Asia. At the early stage of this disease, infected palms are symptomless, which imposes difficulties in detecting the disease. In spite of the availability of tissue and DNA sampling techniques, there is a particular need for replacing costly field data collection methods for detecting Ganoderma in its early stage with a technique derived from spectroscopic and imagery data. Therefore, this study was carried out to apply the artificial neural network (ANN) analysis technique for discriminating and classifying fungal infections in oil palm trees at an early stage using raw, first, and second derivative spectroradiometer datasets. These were acquired from 1,016 spectral signatures of foliar samples in four disease levels (T1: healthy, T2: mildly-infected, T3: moderately infected, and T4: severely infected). Most of the satisfactory results occurred in the visible range, especially in the green wavelength. The healthy oil palms and those which were infected by Ganoderma at an early stage (T2) were classified satisfactorily with an accuracy of 83.3%, and 100.0% in 540 to 550 nm, respectively, by ANN using first derivative spectral data. The results further indicated that the sensitive frond number modeled by ANN provided the highest accuracy of 100.0% for frond number 9 compared with frond 17. This study showed evidence that employment of ANN can predict the early infection of BSR disease on oil palm with a high degree of accuracy.
  19. Ahmadu T, Ahmad K, Ismail SI, Rashed O, Asib N, Omar D
    Braz J Biol, 2020 11 12;81(4):1007-1022.
    PMID: 33175006 DOI: 10.1590/1519-6984.233173
    Drawbacks associated with the use of chemical fungicides to control plant pathogenic fungi such as Botrytis cinerea stimulate the need for alternatives. Therefore, the present study was carried out to determine the antifungal potentials of Moringa oleifera extracts against B. cinerea. Phytochemical analysis using qualitative chemical tests revealed the presence of huge amount of crucial phytochemicals compounds like phenolic compounds, alkaloids and saponins in the M. oleifera leaf extract. Antifungal bioassay of the crude extracts indicated better mycelial growth inhibition by methanol leaf extract (99%). The minimum inhibitory concentration (MIC) was 5 mg/ml with 100% spore germination inhibition and minimum fungicidal concentration (MFC) was 10 mg/ml with 98.10% mycelial growth inhibition using broth micro dilution and poisoned food techniques. Gas chromatography-mass spectrometry (GC-MS) analysis led to the identification of 67 volatile chemical compounds in the leaf extract with 6-decenoic acid (Z)- (19.87%) was the predominant compound. Further chemical elucidation of the crude extracts performed by liquid chromatography with tandem mass spectrometry (LC-MS/MS) showed the presence of non-volatile chemical compounds, mostly flavones, flavonoids and phenolic acids (i.e. quercetin and kaempferol). Scanning electron microscopy and transmission electron microscopy analysis showed positive effect of M. oleifera leaf extract on the treated conidia and mycelium of B. cinerea. Findings revealed that irreversible surface and ultra-structural changes with severe detrimental effects on conidia and mycelium morphology compared to control treatment. Overall findings suggested that M. oleifera leaf extract is a promising candidate for biological control of fungal pathogens, thus limiting overdependence on chemical fungicides.
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