Displaying publications 81 - 100 of 198 in total

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  1. Jamshed W, Eid MR, Safdar R, Pasha AA, Mohamed Isa SSP, Adil M, et al.
    Sci Rep, 2022 Jul 07;12(1):11484.
    PMID: 35798787 DOI: 10.1038/s41598-022-15685-7
    In solar heating, ventilation, and air conditioning (HVAC), communications are designed to create new 3D mathematical models that address the flow of rotating Sutterby hybrid nanofluids exposed to slippery and expandable seats. The heat transmission investigation included effects such as copper and graphene oxide nanoparticles, as well as thermal radiative fluxing. The activation energy effect was used to investigate mass transfer with fluid concentration. The boundary constraints utilized were Maxwell speed and Smoluchowksi temperature slippage. With the utilization of fitting changes, partial differential equations (PDEs) for impetus, energy, and concentricity can be decreased to ordinary differential equations (ODEs). To address dimensionless ODEs, MATLAB's Keller box numerical technique was employed. Graphene oxide Copper/engine oil (GO-Cu/EO) is taken into consideration to address the performance analysis of the current study. Physical attributes, for example, surface drag coefficient, heat move, and mass exchange are mathematically processed and shown as tables and figures when numerous diverse factors are varied. The temperature field is enhanced by an increase in the volume fraction of copper and graphene oxide nanoparticles, while the mass fraction field is enhanced by an increase in activation energy.
  2. Redouane F, Jamshed W, Devi SSU, Prakash M, Nasir NAAM, Hammouch Z, et al.
    Sci Rep, 2022 Feb 10;12(1):2302.
    PMID: 35145142 DOI: 10.1038/s41598-022-06134-6
    MHD Natural convection, which is one of the principal types of convective heat transfer in numerous research of heat exchangers and geothermal energy systems, as well as nanofluids and hybrid nanofluids. This work focuses on the investigation of Natural convective heat transfer evaluation inside a porous triangular cavity filled with silver-magnesium oxide/water hybrid nanofluid [H2O/Ag-MgO]hnf under a consistent magnetic field. The laminar and incompressible nanofluid flow is taken to account while Darcy-Forchheimer model takes account of the advection inertia effect in the porous sheet. Controlled equations of the work have been approached nondimensional and resolved by Galerkin finite element technique. The numerical analyses were carried out by varying the Darcy, Hartmann, and Rayleigh numbers, porosity, and characteristics of solid volume fraction and flow fields. Further, the findings are reported in streamlines, isotherms and Nusselt numbers. For this work, the parametric impact may be categorized into two groups. One of them has an effect on the structural factors such as triangular form and scale on the physical characteristics of the important outputs such as fluidity and thermal transfer rates. The significant findings are the parameters like Rayleigh and slightly supported by Hartmann along with Darcy number, minimally assists by solid-particle size and rotating factor as clockwise assists the cooler flow at the center and anticlockwise direction assists the warmer flow. Clear raise in heat transporting rate can be obtained for increasing solid-particle size.
  3. Jamshed W, Nasir NAAM, Isa SSPM, Safdar R, Shahzad F, Nisar KS, et al.
    Sci Rep, 2021 Sep 21;11(1):18704.
    PMID: 34548554 DOI: 10.1038/s41598-021-98103-8
    Nowadays, with the advantages of nanotechnology and solar radiation, the research of Solar Water Pump (SWP) production has become a trend. In this article, Prandtl-Eyring hybrid nanofluid (P-EHNF) is chosen as a working fluid in the SWP model for the production of SWP in a parabolic trough surface collector (PTSC) is investigated for the case of numerous viscous dissipation, heat radiations, heat source, and the entropy generation analysis. By using a well-established numerical scheme the group of equations in terms of energy and momentum have been handled that is called the Keller-box method. The velocity, temperature, and shear stress are briefly explained and displayed in tables and figures. Nusselt number and surface drag coefficient are also being taken into reflection for illustrating the numerical results. The first finding is the improvement in SWP production is generated by amplification in thermal radiation and thermal conductivity variables. A single nanofluid and hybrid nanofluid is very crucial to provide us the efficient heat energy sources. Further, the thermal efficiency of MoS2-Cu/EO than Cu-EO is between 3.3 and 4.4% The second finding is the addition of entropy is due to the increasing level of radiative flow, nanoparticles size, and Prandtl-Eyring variable.
  4. Hussain SM, Shahzad F, Katbar NM, Jamshed W, Eid MR, Kamel A, et al.
    Heliyon, 2023 Jul;9(7):e17668.
    PMID: 37483748 DOI: 10.1016/j.heliyon.2023.e17668
    The goal of this research is to investigate the effects of Ohmic heating, heat generation, and viscous dissipative flow on magneto (MHD) boundary-layer heat transmission flowing of Jeffrey nanofluid across a stretchable surface using the Koo-Kleinstreuer-Li (KKL) model. Engine oil serves as the primary fluid and is suspended with copper oxide nanomolecules. The governing equations that regulate the flowing and heat transmission fields are partial-differential equations (PDEs) that are then converted to a model of non-linear ordinary differential equations (ODEs) via similarity transformation. The resultant ODEs are numerically resolved using a Keller box technique via MATLAB software that is suggested. Diagrams and tables are used to express the effects of various normal liquids, nanomolecule sizes, magneto parameters, Prandtl, Deborah, and Eckert numbers on the velocity field and temperature field. The outcomes display that the copper oxide-engine oil nanofluid has a lower velocity, drag force, and Nusselt number than the plain liquid, although the introduction of nanoparticles raises the heat. The heat transference rate is reduced by Eckert number, size of nanomolecules, and magneto parameter rising. Whilst, Deborah number is shown to enhance both the drag-force factor and the heat transfer rate. Furthermore, the discoveries reported are advantageous to upgrading incandescent lighting bulbs, heating, and cooling equipment, filament-generating light, energy generation, multiple heating devices, and other similar devices.
  5. Jamshed W, Prakash M, Devi SSU, Ibrahim RW, Shahzad F, Nisar KS, et al.
    Sci Rep, 2021 Dec 15;11(1):24032.
    PMID: 34912014 DOI: 10.1038/s41598-021-03392-8
    A novel hybrid nanofluid was explored in order to find an efficient heat-transmitting fluid to replace standard fluids and revolutionary nanofluids. By using tangent hyperbolic hybrid combination nanoliquid with non-Newtonian ethylene glycol (EG) as a basis fluid and a copper (Cu) and titanium dioxide (TiO2) mixture, this work aims to investigate the viscoelastic elements of the thermal transferring process. Flow and thermal facts, such as a slippery extended surface with magnetohydrodynamic (MHD), suction/injection, form factor, Joule heating, and thermal radiation effects, including changing thermal conductivity, were also integrated. The Keller-Box method was used to perform collective numerical computations of parametric analysis using governing equivalences. In the form of graphs and tables, the results of TiO2-Cu/EG hybrid nanofluid were compared to those of standard Cu/EG nanofluid in important critical physical circumstances. The entropy generation study was used to examine energy balance and usefulness for important physically impacting parameters. Detailed scrutiny on entropy development get assisted with Weissenberg number, magnetic parameter, fractional volumes, injection parameter, thermal radiation, variable thermal conductivity, Biot number, shape variation parameter, Reynolds and Brinkman number. Whereas the entropy gets resisted for slip and suction parameter. In this case, spotted entropy buildup with important parametric ranges could aid future optimization.
  6. Al-Gheethi AA, Radin Mohamed RM, Efaq AN, Amir Hashim MK
    J Water Health, 2016 Jun;14(3):379-98.
    PMID: 27280605 DOI: 10.2166/wh.2015.220
    Greywater is one of the most important alternative sources for irrigation in arid and semi-arid countries. However, the health risk associated with the microbial contents of these waters limits their utilization. Many techniques have been developed and used to generate a high microbiological quality of greywater. The main problem in the treatment of greywater lies in the nature of pathogenic bacteria in terms of their ability to survive during/after the treatment process. The present review focused on the health risk associated with the presence of pathogenic bacteria in greywater and the treatment technologies used for the disinfection processes.
  7. Mohamed R, Ng CJ, Tong WT, Abidin SZ, Wong LP, Low WY
    BMC Public Health, 2012;12:601.
    PMID: 22856889 DOI: 10.1186/1471-2458-12-601
    BACKGROUND: Hepatitis B (HBV) is the leading cause of cirrhosis and hepatocellular carcinoma worldwide. This study assessed the knowledge, attitudes and practices of people with chronic HBV and the associated factors.
    METHODS: This cross-sectional study was conducted at an outpatient adult hepatology clinic at a tertiary hospital in Kuala Lumpur. A self-administered questionnaire was administered on a one-to-one basis to assess knowledge, attitudes, and lifestyle practices of people with chronic HBV.
    RESULTS: The response rate was 89% (n = 483/543). Participants had a mean age of 46.3 (±14.7) years and the mean duration of HBV from time of diagnosis was 12.2 (±8.8) years. The mean knowledge score was 12.57/20 (standard deviation: ±4.4, range: 0-19). Participants aged 30-39 years, with higher educational attainment, employed in professional jobs, longer duration of diagnosis and those without cirrhosis had significantly higher knowledge scores. Age, education level and duration of diagnosis were significant predictors of the knowledge score on standard multiple regression analysis. More than half of the participants were worried of spreading HBV infection to family and friends and worried since the diagnosis. A third of the participants (33.5%) were embarrassed to reveal their diagnosis to the public but most of them (93.6%) would inform their family. Those who reported feeling worried since their diagnosis were more likely to be middle-aged, of Malay ethnicity, have shorter duration of diagnosis of less than 10 years and have received therapy. About half of the participants (50.6%) did not share dining utensils and the majority (93.2%) believed that HBV can be transmitted by sharing of eating and drinking utensils. Older patients were significantly less likely to share utensils. Those who felt worried since diagnosis had significant higher knowledge of HBV.
    CONCLUSION: The findings highlight the stigma and misconceptions that still exist among the HBV patients. More patient and public education about HBV and its prevention are essential to increase awareness and to demystify the disease.
    Study site: Hepatology clinic, University of Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
  8. Rampal S, Mahadeva S, Guallar E, Bulgiba A, Mohamed R, Rahmat R, et al.
    PLoS One, 2012;7(9):e46365.
    PMID: 23029497 DOI: 10.1371/journal.pone.0046365
    The prevalence of metabolic syndrome is increasing disproportionately among the different ethnicities in Asia compared to the rest of the world. This study aims to determine the differences in the prevalence of metabolic syndrome across ethnicities in Malaysia, a multi-ethnic country.
  9. Loh KB, Bux SI, Abdullah BJ, Raja Mokhtar RA, Mohamed R
    Korean J Radiol, 2012 Sep-Oct;13(5):643-7.
    PMID: 22977334 DOI: 10.3348/kjr.2012.13.5.643
    Local treatment for hepatocellular carcinoma (HCC) has been widely used in clinical practice due to its minimal invasiveness and high rate of cure. Percutaneous radiofrequency ablation (RFA) is widely used because its treatment effectiveness. However, some serious complications can arise from percutaneous RFA. We present here a rare case of hemorrhagic cardiac tamponade secondary to an anterior cardiac vein (right marginal vein) injury during RFA for treatment of HCC.
  10. Ng CJ, Low WY, Wong LP, Sudin MR, Mohamed R
    Asia Pac J Public Health, 2013 Jan;25(1):32-40.
    PMID: 21807630 DOI: 10.1177/1010539511413258
    Patients with hepatitis B face uncertainty at diagnosis. Information and support they receive at the early stage of the disease determine their adherence to follow up and treatment. This study aimed to explore the experiences and needs of patients with hepatitis B at diagnosis. A qualitative methodology was used. Nine focus groups (n = 44) were conducted to explore patients' feelings and reaction to the diagnosis, encounters with health care professionals, and their needs. The transcribed data were analyzed using a thematic approach. Most patients were not prepared for the diagnosis and many felt anxious and distressed. This was attributed to poor patients' knowledge, doctor's emphasis on disease complications, and associated stigma. Information about the disease was lacking and patients wanted to know more about the mode of transmission, natural progression of the disease, complications, and treatment options. There was a feeling of "passivity" among patients because there was often no active treatment available at diagnosis. This resulted in patients defaulting surveillance visits and missing the opportunity to start antiviral treatment. Therefore, there is an urgent need to provide sufficient information and education about hepatitis B to newly diagnosed patients, break "bad news" to patients with sensitivity, address their emotional needs, and emphasize on the rationale and importance of surveillance and treatment. This may entail public awareness campaign, implementation of pretest and posttest counseling, and educating doctors on how to communicate the diagnosis and management to patients accurately and sensitively.
  11. Balasubramaniam VR, Hassan SS, Omar AR, Mohamed M, Noor SM, Mohamed R, et al.
    Virol J, 2011;8:196.
    PMID: 21529348 DOI: 10.1186/1743-422X-8-196
    Highly pathogenic Avian Influenza (HPAI) virus is able to infect many hosts and the virus replicates in high levels in the respiratory tract inducing severe lung lesions. The pathogenesis of the disease is actually the outcome of the infection as determined by complex host-virus interactions involving the functional kinetics of large numbers of participating genes. Understanding the genes and proteins involved in host cellular responses are therefore, critical for the elucidation of the mechanisms of infection.
  12. Shee YG, Mahdi MA, Al-Mansoori MH, Yaakob S, Mohamed R, Zamzuri AK, et al.
    Opt Lett, 2010 May 1;35(9):1461-3.
    PMID: 20436603 DOI: 10.1364/OL.35.001461
    An all-optical generation of a microwave carrier at 21 GHz that incorporates a double-Brillouin frequency shifter is presented. The frequency shift of approximately 21 GHz is achieved by generating the second-order Brillouin Stokes signal from the Brillouin pump. This is accomplished through the circulation and isolation of its first-order Stokes signal in the optical fiber. The Brillouin pump signal is heterodyned with its second-order Brillouin Stokes signal at a high-speed photodetector, and the output beating frequency is equal to the offset between these two signals. The generated microwave carrier is measured at 21.3968 GHz, and the carrier phase noise as low as -58.67 dBc/Hz is achieved.
  13. Chook JB, Ngeow YF, Yap SF, Tan TC, Mohamed R
    J Med Virol, 2011 Apr;83(4):594-601.
    PMID: 21328372 DOI: 10.1002/jmv.22016
    Hepatitis B virus (HBV) and high liver iron deposits have both been associated with the development of cirrhosis. Among HBV factors, genotype and mutations in the basal core promoter (BCP) and precore regions have been most frequently studied but the evidence for a positive association with cirrhosis has been inconsistent. In this study, sera from persons with chronic HBV infection with and without cirrhosis were used for whole HBV genome analysis and for the estimation of serum iron marker (serum iron or ferritin) levels. Single codon analysis showed that the precore wild-type, TGG (nt 1,895-1,897), gave the highest accuracy (77.5%) for the identification of cirrhosis compared to other codons. When TGG was analyzed together with the precore start codon wild-type, ATG (nt 1,814-1,816), the accuracy was improved to 80.0% (odds ratio=35.29; 95% confidence interval=3.87-321.93; Phi=0.629; P<0.001). When the serum iron marker was included for analysis, it was clear that a combination of a precore wild-type and high serum iron marker gave a better accuracy (90.0%) (odds ratio=107.67; 95% confidence interval=10.21-1,135.59; Phi=0.804; P<0.001) for the identification of cirrhosis than either biomarker alone. It appeared that a combined use of both these biomarkers might help to predict the development of cirrhosis in a person with chronic HBV infection, but longitudinal studies are required to test this hypothesis.
  14. Mohamed R, Hanafiah A, Rose IM, Manaf MR, Abdullah SA, Sagap I, et al.
    Eur J Clin Microbiol Infect Dis, 2009 Jul;28(7):865-9.
    PMID: 19247698 DOI: 10.1007/s10096-009-0712-x
    We have defined DNA repeat variability in the 3'-terminus of the cagA gene of Helicobacter pylori strains from Malaysian patients of different ethnicities. We identified different alleles based on the EPIYA repeats. cagA types A-B-D and A-B-B-D are more similar to the sequence of Japanese strains, whereas cagA types A-B-C, A-B-C-C, A-B and A-C displayed similarity to strain 26695 sequences. A significant association was found between cagA genotypes and patients' ethnicity, with cagA type A-B-D being predominantly isolated from Chinese patients and cagA type A-B-C from Malays and Indians. Our data further corroborate the possibility that variant biological activity of CagA may affect the host specificity and/or pathogenicity of H. pylori.
  15. Lee SH, Chong CE, Lim BS, Chai SJ, Sam KK, Mohamed R, et al.
    Diagn Microbiol Infect Dis, 2007 Jul;58(3):263-70.
    PMID: 17350202
    Burkholderia pseudomallei is a Gram-negative saprophytic soil bacterium, which is the etiologic agent of melioidosis, a severe and fatal infectious disease occurring in human and animals. Distinct clinical and animal isolates have been shown to exhibit differences in phenotypic trait such as growth rate, colony morphology, antimicrobial resistance, and virulence. This study was carried out to gain insight into the intrinsic differences between 4 clinical and 6 animal B. pseudomallei isolates from Malaysia. The 16S rRNA-encoding genes from these 10 isolates of B. pseudomallei were sequenced to confirm the identity of these isolates along with the avirulent Burkholderia thailandensis. The nucleotide sequences indicated that the 16S rRNA-encoding genes among the 10 B. pseudomallei isolates were identical to each other. However, the nucleotide sequence differences in the 16S rRNA-encoding genes appeared to be B. pseudomallei and B. thailandensis specific. The growth rate of all B. pseudomallei isolates was determined by generating growth curves at 37 degrees C for 72 h. The isolates were found to differ in growth rates with doubling time varying from 1.5 to 2.3 h. In addition, the B. pseudomallei isolates exhibited considerable variation in colony morphology when grown on Ashdown media, brain-heart infusion agar, and Luria-Bertani agar over 9 days of observation. Antimicrobial susceptibility tests indicated that 80% of the isolates examined were Amp(R) Cb(R) Kn(R) Gm(R) Chl(S) Te(S). Virulence of the B. pseudomallei clinical and animal isolates was evaluated in B. pseudomallei-susceptible BALB/c mice. Most of the clinical isolates were highly virulent. However, virulence did not correlate with isolate origin since 2 of the animal isolates were also highly virulent.
  16. Ling KH, Loo SS, Rosli R, Shamsudin MN, Mohamed R, Wan KL
    In Silico Biol. (Gedrukt), 2007;7(1):115-21.
    PMID: 17688436
    Phosphatidylinositol 4-phosphate 5-kinases (PIP5Ks) play diverse roles in the cellular biology of many organisms, including signal transduction, secretion and vesicular trafficking, and regulation of cytoskeleton assembly. Discovery of the PIP5K gene in Eimeria tenella may shed light on its role in the biology of this avian protozoan, and afford further understanding of the cell-host interaction, particularly during the invasion process. In this study, we report the identification of the PIP5K coding region in the genome sequence of Eimeria tenella using in silico gene prediction approaches. Prediction of the PIP5K coding sequence was confirmed by mapping the full-length cDNA sequence, generated via the Rapid Amplification of cDNA Ends (RACE) method, to the genomic sequence. The putative PIP5K gene of Eimeria tenella is located on the complementary strand of the E1080B12.b1 contig, and comprises 12 exons. Further analysis showed that the coding region spans from exon 1 to exon 7, with all exons obeying the adopted 'gt...ag' splicing rule of intronic sequences. Consensus of the hexameric 5' donor-splice site was deduced as GTRDBB... and the consensus for the 3' acceptor-splice sites as ...BHDYAG. The gene encodes a 252-amino acid residue protein. Domain search and protein fold recognition analyses provide compelling evidences that the deduced protein is a PIP5K.
  17. Zain SM, Mohamed Z, Mahadeva S, Rampal S, Basu RC, Cheah PL, et al.
    PLoS One, 2013;8(3):e58538.
    PMID: 23484035 DOI: 10.1371/journal.pone.0058538
    Angiotensin II type 1 receptor (AGTR1) has been reported to play a fibrogenic role in non-alcoholic fatty liver disease (NAFLD). In this study, five variants of the AGTR1 gene (rs3772622, rs3772627, rs3772630, rs3772633, and rs2276736) were examined for their association with susceptibility to NAFLD. Subjects made up of 144 biopsy-proven NAFLD patients and 198 controls were genotyped using TaqMan assays. The liver biopsy specimens were histologically graded and scored according to the method of Brunt. Single locus analysis in pooled subjects revealed no association between each of the five variants with susceptibility to NAFLD. In the Indian ethnic group, the rs2276736, rs3772630 and rs3772627 appear to be protective against NAFLD (p = 0.010, p = 0.016 and p = 0.026, respectively). Haplotype ACGCA is shown to be protective against NAFLD for the Indian ethnic subgroup (p = 0.03). Gene-gene interaction between the AGTR1 gene and the patatin-like phospholipase domain-containing 3 (PNPLA3) gene, which we previously reported as associated with NAFLD in this sample, showed a strong interaction between AGTR1 (rs3772627), AGTRI (rs3772630) and PNPLA3 (rs738409) polymorphisms on NAFLD susceptibility (p = 0.007). Further analysis of the NAFLD patients revealed that the G allele of the AGTR1 rs3772622 is associated with increased fibrosis score (p = 0.003). This is the first study that replicates an association between AGTR1 polymorphism and NAFLD, with further details in histological features of NAFLD. There is lack of evidence to suggest an association between any of the five variants of the AGTR1 gene and NAFLD in the Malays and Chinese. In the Indians, the rs2276736, rs3772630 and rs3772627 appear to protect against NAFLD. We report novel findings of an association between the G allele of the rs3772622 with occurrence of fibrosis and of the gene-gene interaction between AGTR1gene and the much-studied PNPLA3 gene.
  18. Khoo JS, Chai SF, Mohamed R, Nathan S, Firdaus-Raih M
    BMC Genomics, 2012;13 Suppl 7:S13.
    PMID: 23282220 DOI: 10.1186/1471-2164-13-S7-S13
    The sRNAs of bacterial pathogens are known to be involved in various cellular roles including environmental adaptation as well as regulation of virulence and pathogenicity. It is expected that sRNAs may also have similar functions for Burkholderia pseudomallei, a soil bacterium that can adapt to diverse environmental conditions, which causes the disease melioidosis and is also able to infect a wide variety of hosts.
  19. Chook JB, Ngeow YF, Khang TF, Ng KP, Tiang YP, Mohamed R
    J Med Virol, 2013 Mar;85(3):419-24.
    PMID: 23297244 DOI: 10.1002/jmv.23500
    Infection with the hepatitis B virus (HBV) may lead to an acute or chronic infection. It is generally accepted that the clinical outcome of infection depends on the balance between host immunity and viral survival strategies. In order to persist, the virus needs to have a high rate of replication and some immune-escape capabilities. Hence, HBVs lacking these properties are likely to be eliminated more rapidly by the host, leading to a lower rate of chronicity. To test this hypothesis, 177 HBV genomes from acute non-fulminant cases and 1,149 from chronic cases were retrieved from GenBank for comparative analysis. Selection of candidate nucleotides associated with the disease state was done using random guess cut-off and the Bonferroni correction. Five significant nucleotides were detected using this filtering step. Their predictive values were assessed using the support vector machine classification with five-fold cross-validation. The average prediction accuracy was 61% ± 1%, with a sensitivity of 24% ± 1%, specificity of 98% ± 1%, positive predictive value of 92% ± 4% and negative predictive value of 56% ± 1%. BCP/X, enhancer I and surface/polymerase variants were found to be associated almost exclusively with acute hepatitis. These HBV variants are novel potential markers for non-progression to chronic hepatitis.
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