Displaying publications 61 - 80 of 164 in total

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  1. Nguan H, Ahmadi S, Hashim R
    Phys Chem Chem Phys, 2014 Jan 7;16(1):324-34.
    PMID: 24257208 DOI: 10.1039/c3cp52385c
    Through atomistic molecular dynamic simulations using a GROMOS53a6 force field for the carbohydrate, we studied the lyotropic reverse hexagonal phase HII from a glycolipid, namely the Guerbet branched-chain β-d-glucoside, at 14% and 22% water concentrations. Our simulations showed that at low water concentration (14%) the sugar head group overlapped extensively and protruded into the water channel. In contrast, in the 22% concentration system a water column free from the sugar headgroup ('free' water) was formed as expected for the system close to the limit of maximum hydration. In both concentrations, we found anomalous water diffusion in the xy-plane, i.e. the two-dimensional space confined by the surface of the cylinder. On the other hand, along the z-axis, the water diffusion obeyed the Einstein relation for the 22% system, while for the 14% system it was slightly anomalous. For the 22% system, the diffusion along the z-axis of the 'free' water obeyed the Einstein relation, while that of the 'bound' water is slightly anomalous. The xy-plane displacement of the 'bound' water was higher than that for the 'free' water at times longer than 200 ps, as a consequence of the exchange of water molecules between the two regions. Based on our findings, we proposed an alternative explanation to the observed spatial heterogeneity in the HII phase from probe diffusion by Penaloza et al. (Phys. Chem. Chem. Phys., 2012, 14(15), 5247-5250). We found the extent of contact with water was different at different oxygen atoms within the sugar ring. Generally, a higher probability of hydrogen bonding but a shorter lifetime was found in 22% water compared to the case of 14% water. Finally, we examined the extension and compression of the alkyl chain of a columnar.
  2. Nguan H, Ahmadi S, Hashim R
    J Mol Model, 2012 Dec;18(12):5041-50.
    PMID: 22752540 DOI: 10.1007/s00894-012-1497-x
    A theoretical study of a series of five glucose based glycolipid crown ethers and their complexes with Na(+) and K(+) was performed using the density functional theory with B3LYP/6-31 G* to obtain the optimized geometrical structures and electronic properties. The local nucleophilicity of the five molecules was investigated using Fukui function, while the global nucleophilicity was calculated from the ionization potential and electron affinity. The structures and coordination of the complexes were studied to identify the best match of the glycolipid crown ethers with cations. In general, it was found that the oxygen atoms pairs O2 and O3 (or O4 and O6) on the sugar ring are constrained from moving toward the cation, which results in a weaker O-cation coordination strength for the oxygen pair compared to the other oxygen atoms in the crown ether ring. The thermodynamic properties of the binding of the complexes and the exchange reaction in gas phase were evaluated. The cation selectivity pattern among the five molecules was in good agreement with the experiment.
  3. Ng CYB, Gan WC, Velayutham TS, Goh BT, Hashim R
    Phys Chem Chem Phys, 2020 Jan 29;22(4):2414-2423.
    PMID: 31939468 DOI: 10.1039/c9cp01556f
    The effects of solvents and temperature on the crystal formation were investigated for vinylidene fluoride/trifluoroethylene copolymer P(VDF-TrFE). Highly crystalline P(VDF-TrFE) thin films were fabricated by spin-casting using various polar solvents such as diethyl carbonate (DEC), methyl ethyl ketone (MEK), N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Ferroelectric polarisation reversal of the P(VDF-TrFE) was evidenced by a displacement (D)-electric field (E) hysteresis loop measurement and supported by the presence of pyroelectric activity. The samples which were annealed above 100 °C gave elongated rod-like crystalline structures and the highest crystallinity, Xc of 83% was formed at 120 °C. Consequently, remnant polarisation (85 mC m-2) and the pyroelectric coefficient (30 μC m-2 K-1) were enhanced. Thus, annealing plays a substantial role in controlling the crystalline structure of P(VDF-TrFE) films regardless of the choice of solvent. Although, the crystalline structure control is almost independent of the solvent's polarity, the choice of solvent is essential in preparing a smoother film surface. Molecular dynamics of P(VDF-TrFE) are discussed from the observation of two dielectric relaxation processes, β and γ related to the segmental micro-Brownian and local modes, respectively. The complete ferroelectric polarization reversal caused a reduction in the dielectric polarization and reduced the lattice spacing of the 110/200 planes.
  4. Nathir I, Abd Aziz F, Hashim R
    Cureus, 2023 Dec;15(12):e49854.
    PMID: 38169767 DOI: 10.7759/cureus.49854
    The predictive value of apolipoprotein B (apo B) has been proven in the development of coronary artery disease (CAD) among normotensives only, but it has not been directly studied in hypertensive patients. The objective of this study is to explore the association between apo B and CAD among patients with hypertension. Search strategies were conducted on September 24, 2022, and involved the databases PubMed, Web of Science, and Scopus. The current systematic review included observational case-control and cohort study design involving adult humans, both hypertensives and normotensives. The selected studies were restricted to those written in the English language and published after 2000. Reviews, interventional, animal, and overlapping studies, grey literature, and articles without full text were excluded from the current study. The modified Newcastle-Ottawa Scale was used to assess the risk of bias for the screened studies after data extraction. Out of 3644 publications, only five studies were included in the review, including 5222 participants. Of those, 2335 were hypertensive, 733 of them developed CAD, and 296 normotensive subjects developed CAD. The average apo B was 1.09 g/l and 1.07 g/l for hypertensives and normotensives, respectively. The risk of developing CAD is higher in patients with hypertension, or those with higher apo B. Moreover, the risk of CAD was exacerbated in hypertensive participants with elevated apo B. This systematic review highlights the independent power of apo B on the development of CAD among both hypertensive and normotensive subjects.
  5. Nainggolan I, Radiman S, Hamzah AS, Hashim R
    Colloids Surf B Biointerfaces, 2009 Oct 1;73(1):84-91.
    PMID: 19540095 DOI: 10.1016/j.colsurfb.2009.05.021
    Two novel glycolipids have been synthesized and their phase behaviour studied. They have been characterized using FT-IR, FAB and 13C NMR and 1H NMR to ensure the purity of novel glycolipids. The two glycolipids are distinguished based on the head group of glycolipids (monosaccharide/glucose and disaccharide/maltose). These two novel glycolipids have been used as surfactant to perform two phase diagrams. Phase behaviours that have been investigated are 2-hexyldecyl-beta-D-glucopyranoside (2-HDG)/n-octane/water ternary system and 2-hexyldecyl-beta-D-maltoside (2-HDM)/n-octane/water ternary system. SAXS and polarizing optical microscope have been used to study the phase behaviours of these two surfactants in ternary phase diagram. Study of effect of the head group on branched-alkyl chain surfactants in ternary system is a strategy to derive the structure-property relationship. For comparison, 2-HDM and 2-HDG have been used as surfactant in the same ternary system. The phase diagram of 2-hexyldecyl-beta-D-maltoside/n-octane/water ternary system exhibited a Lalpha phase at a higher concentration regime, followed with two phases and a micellar solution region in a lower concentration regime. The phase diagram of 2-HDG/water/n-octane ternary system shows hexagonal phase, cubic phase, rectangular ribbon phase, lamellar phase, cubic phase as the surfactant concentration increase.
  6. Murugaiah H, Teh CL, Loh KC, Mohamad Yahya AR, Md Noh NA, Abu Bakar NHH, et al.
    Molecules, 2021 Oct 24;26(21).
    PMID: 34770823 DOI: 10.3390/molecules26216414
    Here, we report the extracellular biosynthesis of silver nanoparticles (AgNPs) and determination of their antibacterial and anticancer properties. We also explore the efficacy of bioAgNPs incorporated in cellulose nanocrystals (CNCs) and alginate (Alg) for the formation of an antibacterial hydrogel film. Streptomyces sp. PBD-311B was used for the biosynthesis of AgNPs. The synthesized bioAgNPs were characterized using UV-Vis spectroscopy, TEM, XRD, and FTIR analysis. Then, the bioAgNPs' antibacterial and anticancer properties were determined using TEMA and cytotoxicity analysis. To form the antibacterial hydrogel film, bioAgNPs were mixed with a CNC and Alg solution and further characterized using FTIR analysis and a disc diffusion test. The average size of the synthesized bioAgNPs is around 69 ± 2 nm with a spherical shape. XRD analysis confirmed the formation of silver nanocrystals. FTIR analysis showed the presence of protein capping at the bioAgNP surface and could be attributed to the extracellular protein binding to bioAgNPs. The MIC value of bioAgNPs against P. aeruginosa USM-AR2 and MRSA was 6.25 mg/mL and 3.13 mg/mL, respectively. In addition, the bioAgNPs displayed cytotoxicity effects against cancer cells (DBTRG-0.5MG and MCF-7) and showed minimal effects against normal cells (SVG-p12 and MCF-10A), conferring selective toxicity. Interestingly, the bioAgNPs still exhibited inhibition activity when incorporated into CNC/Alg, which implies that the hydrogel film has antibacterial properties. It was also found that bioAgNP-CNC/Alg displayed a minimal or slow release of bioAgNPs owing to the intermolecular interaction and the hydrogel's properties. Overall, bioAgNP-CNC/Alg is a promising antibacterial hydrogel film that showed inhibition against the pathogenic bacteria P. aeruginosa and MRSA and its application can be further evaluated for the inhibition of cancer cells. It showed benefits for surgical resection of a tumor to avoid post-operative wound infection and tumor recurrence at the surgical site.
  7. Muntohar, A.S., Rahman, M.E., Hashim, R., Islam, M.S.
    MyJurnal
    The importance of numerical analysis in investigation of piled embankment over soft soil has been developed since 1990. Several investigators have extended the numerical analysis to model ground improvement using soil-column to support embankment or structures. This paper presents a numerical analysis of the Pulverized Fuel Ash (PFA) column-treated peat and compared with field static-loading test results. Back analysis was performed to determine the material parameters and soil stiffness surrounding soil & soil-column. Two geometrical models were used in this analysis: (a) block (Model A), and (b) column group (Model B). This situation was analyzed using commercially available finite element package PLAXIS 2D ver. 8.2. It is found that both models are reliable to simulate the field static-loading test for column-treated peat. Model B shows a higher stability to failure if compared to Model A.
  8. Munir MB, Hashim R, Abdul Manaf MS, Nor SA
    Trop Life Sci Res, 2016 Aug;27(2):111-25.
    PMID: 27688855 MyJurnal DOI: 10.21315/tlsr2016.27.2.9
    This study used a two-phase feeding trial to determine the influence of selected dietary prebiotics and probiotics on growth performance, feed utilisation, and morphological changes in snakehead (Channa striata) fingerlings as well as the duration of these effects over a post-experimental period without supplementation. Triplicate groups of fish (22.46 ±0.17 g) were raised on six different treatment diets: three prebiotics (0.2% β-glucan, 1% galacto-oligosaccharides [GOS], 0.5% mannan-oligosaccharides [MOS]), two probiotics (1% live yeast [Saccharomyces cerevisiae] and 0.01% Lactobacillus acidophilus [LBA] powder) and a control (unsupplemented) diet; there were three replicates for each treatment. All diets contained 40% crude protein and 12% crude lipid. Fish were fed to satiation three times daily. No mortalities were recorded during Phase 1; however, 14% mortality was documented in the control and prebiotic-amended fish during Phase 2. At the end of Phase 1, growth performance and feed utilisation were significantly higher (p<0.05) in the LBA-treated fish, followed by live yeast treatment, compared with all other diets tested. The performance of fish on the three prebiotic diets were not significantly different from one another but was significantly higher than the control diet. During Phase 2 (the post-feeding phase), fish growth continued until the 6th week for the probiotic-based diets but levelled off after four weeks for the fish fed the prebiotic diets. The feed conversion ratio (FCR) was higher in all treatments during the post-feeding period. The hepatosomatic index (HSI) did not differ significantly among the tested diets. The visceral somatic index (VSI) and intraperitoneal fat (IPF) were highest in the LBA-based diet and the control diet, respectively. The body indices were significantly different (p<0.05) between Phases 1 and 2. This study demonstrates that probiotic-based diets have a more positive influence on the growth, feed utilisation, and survival of C. striata fingerlings compared with supplementation with prebiotics.
  9. Munir MB, Hashim R, Nor SAM, Marsh TL
    Fish Shellfish Immunol, 2018 Apr;75:99-108.
    PMID: 29407616 DOI: 10.1016/j.fsi.2018.02.005
    This study examined the effect of dietary prebiotics and probiotics after 16 weeks, followed by 8 weeks of post feeding trial with the control unsupplemented diet on haematological and immune response against Aeromonas hydrophila infection in Channa striata fingerlings. Fish were raised on a 40% protein and 12% lipid feed containing three commercial prebiotics (β-glucan, GOS or galacto-oligosaccharide, MOS or mannan-oligosaccharide); and two probiotics- (Saccharomyces cerevisiae, Lactobacillus acidophilus), respectively and a control. Throughout the study, supplementation with dietary prebiotics and probiotics led to significant (P 
  10. Motamedi S, Hashim R, Zakaria R, Song KI, Sofawi B
    ScientificWorldJournal, 2014;2014:953830.
    PMID: 25097894 DOI: 10.1155/2014/953830
    Wave energy and storm surges threaten coastal ecology and nearshore infrastructures. Although coastal structures are conventionally constructed to dampen the wave energy, they introduce tremendous damage to the ecology of the coast. To minimize environmental impact, ecofriendly coastal protection schemes should be introduced. In this paper, we discuss an example of an innovative mangrove rehabilitation attempt to restore the endangered mangroves on Carey Island, Malaysia. A submerged detached breakwater system was constructed to dampen the energy of wave and trap the sediments behind the structure. Further, a large number of mangrove seedlings were planted using different techniques. Further, we assess the possibility of success for a future mangrove rehabilitation project at the site in the context of sedimentology, bathymetry, and hydrogeochemistry. The assessment showed an increase in the amount of silt and clay, and the seabed was noticeably elevated. The nutrient concentration, the pH value, and the salinity index demonstrate that the site is conducive in establishing mangrove seedlings. As a result, we conclude that the site is now ready for attempts to rehabilitate the lost mangrove forest.
  11. Motamedi S, Roy C, Shamshirband S, Hashim R, Petković D, Song KI
    Ultrasonics, 2015 Aug;61:103-13.
    PMID: 25957464 DOI: 10.1016/j.ultras.2015.04.002
    Ultrasonic pulse velocity is affected by defects in material structure. This study applied soft computing techniques to predict the ultrasonic pulse velocity for various peats and cement content mixtures for several curing periods. First, this investigation constructed a process to simulate the ultrasonic pulse velocity with adaptive neuro-fuzzy inference system. Then, an ANFIS network with neurons was developed. The input and output layers consisted of four and one neurons, respectively. The four inputs were cement, peat, sand content (%) and curing period (days). The simulation results showed efficient performance of the proposed system. The ANFIS and experimental results were compared through the coefficient of determination and root-mean-square error. In conclusion, use of ANFIS network enhances prediction and generation of strength. The simulation results confirmed the effectiveness of the suggested strategies.
  12. Mosapour Kotena Z, Behjatmanesh-Ardakani R, Hashim R, Manickam Achari V
    J Mol Model, 2013 Feb;19(2):589-99.
    PMID: 22972691 DOI: 10.1007/s00894-012-1576-z
    Density functional theory calculations on two glycosides, namely, n-octyl-β-D-glucopyranoside (C(8)O-β-Glc) and n-octyl-β-D-galactopyranoside (C(8)O-β-Gal) were performed for geometry optimization at the B3LYP/6-31G level. Both molecules are stereoisomers (epimers) differing only in the orientation of the hydroxyl group at the C4 position. Thus it is interesting to investigate electronically the effect of the direction (axial/equatorial) of the hydroxyl group at the C4 position. The structure parameters of X-H∙∙∙Y intramolecular hydrogen bonds were analyzed, while the nature of these bonds and the intramolecular interactions were considered using the atoms in molecules (AIM) approach. Natural bond orbital analysis (NBO) was used to determine bond orders, charge and lone pair electrons on each atom and effective non-bonding interactions. We have also reported electronic energy and dipole moment in gas and solution phases. Further, the electronic properties such as the highest occupied molecular orbital, lowest unoccupied molecular orbital, ionization energy, electron affinity, electronic chemical potential, chemical hardness, softness and electrophilicity index, are also presented here for both C(8)O-β-Glc and C(8)O-β-Gal. These results show that, while C(8)O-β-Glc possess- only one hydrogen bond, C(8)O-β-Gal has two intramolecular hydrogen bonds, which further confirms the anomalous stability of the latter in self-assembly phenomena.
  13. Mohd Tap R, Sabaratnam P, Ramli NY, Hashim R, Mohd Fuat AR, Ng PP, et al.
    Mycopathologia, 2016 Apr;181(3-4):285-90.
    PMID: 26493614 DOI: 10.1007/s11046-015-9958-2
    Trichosporon species are opportunistic yeasts which can cause infections, especially in immunocompromised patients. This is a report of Trichosporon ovoides that caused subcutaneous infection in a patient with underlying ischemic heart disease. The identification of fungal isolate was confirmed by PCR sequencing of ITS and large subunit regions in rRNA gene. In vitro susceptibility study showed that the isolate was susceptible to amphotericin B, fluconazole and voriconazole, and resistant to caspofungin, anidulafungin and itraconazole. The lesion improved after treatment with oral fluconazole and topical miconazole.
  14. Mohd Tap R, Sabaratnam P, Ahmad NA, Abd Razak MF, Hashim R, Ahmad N
    Mycopathologia, 2015 Aug;180(1-2):137-41.
    PMID: 25894509 DOI: 10.1007/s11046-015-9890-5
    An 11-year-old girl presented with multiple blisters on her the right foot complicated with cellulitis. The conventional and molecular identification were performed on the culture. The internal transcribed spacer (ITS) region in rRNA gene of the isolate was amplified by PCR. The sequence of the amplified ITS region matched 99 % with that of Chaetomium globosum in the GenBank. This is the first report describing C. globosum causing cutaneous infection in Malaysia.
  15. Mohd Khalid MKN, Ahmad N, Hii SYF, Abd Wahab MA, Hashim R, Liow YL
    J Med Microbiol, 2019 Jan;68(1):105-110.
    PMID: 30465638 DOI: 10.1099/jmm.0.000881
    Sporadic diphtheria cases in Malaysia have remained low in number since the 1990s. However, in 2016 a total of 31 cases were reported nationwide and to investigate this we performed molecular characterization of 30 Corynebacterium diphtheriae isolates collected from 1981 to 2016 using multilocus sequence typing (MLST). C. diphtheriae isolates were identified and biotyped using the API Coryne kit, while the toxigenicity was determined by PCR and the Elek test. All of the 2016 isolates belonged to biotype mitis, caused respiratory diphtheria and were toxigenic strains. MLST analysis identified 17 sequence types (STs), including 11 new ones. ST453 was the most common clone (7/30, 23.3 %), followed by ST141 (5/30, 16.7 %), ST451 (3/30, 10.0 %) and ST248 (2/30, 6.7 %). The clones identified in 2016 had not been detected in previous isolations and they were phylogenetically distinct. Our results suggest that the diphtheria cases in 2016 were caused by the emergence and spread of new clones in Malaysia.
  16. Mohd Hajiri M, Shaharuddin S, Long CM, Hashim R, Zulkifly HH, Kasim SS, et al.
    Value Health, 2015 Nov;18(7):A378.
    PMID: 26532133 DOI: 10.1016/j.jval.2015.09.795
    Conference abstract:
    Objectives: Warfarin has been used for more than 50 years as stroke prophylaxis in patients with atrial fibrillation. New oral anticoagulant, Dabigatran, was developed and shown to be safer and more efficacious compared to Warfarin due to its lower tendency of bleeding and in reducing stroke incidences. This study aims to compare the pattern of anticoagulants used and to assess their safety and efficacy by evaluating bleeding and stroke occurrences in both groups.
    Methods: This is a retrospective study carried out at a hospital with hematology clinic in the state of Selangor, Malaysia. The samples of the study were patients with atrial fibrillation, prescribed with warfarin or dabigatran. Data collected includes patients’ demographics, co-morbidities, and stroke and haemorrhage events.
    Results: A total of 71 patients were recruited in this study with 21, 21 and 29 patients were on Warfarin, Dabigatran 110 mg and Dabigatran 150 mg respectively. Out of 50 Dabigatran users, 36 of them are warfarin-experienced. 1 out of 21 patients on warfarin experienced stroke while none in both 110 and 150mg dabigatran group. A total of 11 (52.4%) of warfarin patients experienced bleeding with 2 of them having major bleeding whereas, only 4 (8%) out of 50 dabigatran patients experienced minor bleeding, 1 in patient who were on Dabigatran 150mg and 3 patients who were on Dabigatran 110mg.
    Conclusions: The pattern of anticoagulant used for stroke prophylaxis in atrial fibrillation is slowly changing from Warfarin to Dabigatran. Evaluation of safety and efficacy profile of Warfarin shows that Warfarin requires more extensive management and monitoring in order to achieve therapeutic goals with fewer side effects. Comparison between both anticoagulants show that Dabigatran is safer and more effective compared to warfarin
    Study site: Haematology clinic, hospital, Selangor, Malaysia
  17. Mohan A, Munusamy C, Tan YC, Muthuvelu S, Hashim R, Chien SL, et al.
    BMC Infect Dis, 2019 Apr 18;19(1):330.
    PMID: 30999894 DOI: 10.1186/s12879-019-3963-x
    BACKGROUND: Invasive Salmonella infections result in significant morbidity and mortality in developing countries. In Asia, typhoid and paratyphoid fever are reported to be the major invasive Salmonella infections, while invasive non-typhoidal Salmonella (iNTS) infections are believed to be uncommon. Data from Sarawak, in Malaysian Borneo, are limited.

    METHODS: A retrospective study identifying all children aged

  18. Mohamed Zahidi J, Bee Yong T, Hashim R, Mohd Noor A, Hamzah SH, Ahmad N
    Diagn Microbiol Infect Dis, 2015 Apr;81(4):227-33.
    PMID: 25641125 DOI: 10.1016/j.diagmicrobio.2014.12.012
    Molecular approaches have been investigated to overcome difficulties in identification and differentiation of Brucella spp. using conventional phenotypic methods. In this study, high-resolution melt (HRM) analysis was used for rapid identification and differentiation of members of Brucella genus. A total of 41 Brucella spp. isolates from human brucellosis were subjected to HRM analysis using 4 sets of primers, which identified 40 isolates as Brucella melitensis and 1 as Brucella canis. The technique utilized low DNA concentration and was highly reproducible. The assay is shown to be a useful diagnostic tool, which can rapidly differentiate Brucella up to species level.
  19. Mohamed Zahidi J, Ahmad N, Tay BY, Hashim R, Khoo E, Ahmad N, et al.
    Genome Announc, 2017 Aug 03;5(31).
    PMID: 28774972 DOI: 10.1128/genomeA.00689-17
    Human brucellosis is a neglected zoonotic disease and has widespread geographical distribution. Brucella melitensis has caused outbreaks and sporadic cases in Malaysia. Here, we present the whole-genome sequences of four B. melitensis strains isolated from brucellosis patients in Malaysia.
  20. Miyagi I, Toma T, Okazawa T, Mogi M, Hashim R
    J Am Mosq Control Assoc, 2005 Dec;21(4):466-8.
    PMID: 16506575
    During a mosquito survey in Ulu Gombak, Selangor, Peninsular Malaysia, October 2-16, 2003, we observed a peculiar oviposition habit of Armigeres flavus. This strange behavior is described and illustrated with photographs; although it is well known, no detailed description has been made previously.
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