Displaying publications 1 - 20 of 198 in total

  1. Ahmed A. Ahmed Al-Dulaimi, Shahrir Hashim, Mohammed Ilyas Khan
    Polyaniline (PANI) and polyaniline composites with aluminium oxide (Al2O3) were prepared using the in situ polymerization method. The composites were then blended with acrylic paint and applied to carbon steel panels. The coated steel panels were evaluated for corrosion using the immersion test technique. The results revealed that the steel panels coated with polyaniline composites and with Al2O3 containing coatings had small corrosion as compared to the bare sample and the samples coated with polyaniline and paint alone. The samples were characterized by Fourier transform infrared (FTIR) and X-ray diffraction(XRD). In addition, the morphology of the finished samples was observed using the scanning electron microscopy (SEM). This novel composite was used as a paint pigment for enhancing the barrier properties and the paint protectable against aggressive ions. Meanwhile, corrosion was evaluated through visual monitoring using a digital camera after 60 days of fully immersion test in 5% NaCl. The weight loss method was also used to evaluate corrosion.
  2. Husham, M., Hassan, Z., Ahmed A. Al-Dulaimi
    Science Letters, 2016;11(2):11-14.
    Nanocrystalline lead sulfide (PbS) thin films have been successfully grown on glass substrate using the chemical bath deposition technique. Microwave oven was used as a heating source to facilitate the growth process of the thin films. Aqueous solutions of lead nitrate Pb(NO3) and thiourea [SC(NH2)2] were used as lead and sulfur ion sources, respectively. Structural, morphological and optical analyses revealed good quality growth of nanocrystalline PbS thin films. This study introduced a facile and low cost method to prepare high quality nanocrystalline PbS thin films in a relatively short growth time for optoelectronic applications.
  3. Ahmed, M., Huq, M.S., Ibrahim, B.S.K.K., Ahmed, A.
    Movement Health & Exercise, 2018;7(1):211-223.
    Functional Electrical Stimulation (FES) can be used to revive movement
    functions of the human body to a certain degree which was lost due to
    occurrences of the nervous system disorders resulting from accidents or
    diseases. It can also be employed for gait rehabilitation as well as therapy.
    Control systems could be employed to improve on the FES-induced motion,
    and the closed-loop was targeted due to its advantages. Based on the papers
    reviewed, studies have shown that the linear control schemes are popular for
    movement restoration in the lower limb, but mostly for continuous standing
    contributing to mainly the stance phase. Therefore, a myriad of limitations
    was observed which include: the need for using improved sensors, re-tuning
    for every subject, tests conducted using patient with more straightforward
    ailments, complexity in implementation and most importantly is the issue of
    stability. The swing phase of gait movement and the full walking motion have
    more complex dynamics and coupled with the nature of the plant (human with
    nervous system disorder and the neuromuscular structure) could render the
    linear control method obsolete or unsuitable. Hence, there is a need to
    investigate other techniques such as the nonlinear and intelligent control
  4. Al-Dulaimi AA, Shahrir Hashim, Khan M
    Sains Malaysiana, 2011;40:1179-1186.
    Two inorganic pigments (TiO2 and SiO2) were used to prepare composites with polyaniline (PANI) by situ polymerization method. PANI and PANI composites with SiO2 and TiO2 were characterized using Fourier transform infrared spectroscopy and X-ray diffraction. The morphology of the synthesized pigments (PANI , PANI-SiO2 and PANI-TiO2) was examined using scanning electron microscopy. Samples were then used as pigments through blending them with acrylic paint and applied on the surface of carbon steel panels. Corrosion was evaluated for coating of carbon steel panels through full immersion test up to standard ASTMG 31. Mass loss was calculated after they have been exposed in acidic media. A digital camera was also used for monitoring corrosion visually on the surface of carbon steel specimens. The results revealed that acrylic paint pigmented by PANI-SiO2 composite was more efficient in corrosion protection for carbon steel compared with the other synthesized pigments.
  5. Abdul KareemMeera Mohaideen, Riaz Ahmed A., Hasnan Jaafar, Murali
    Introduction: In Malaysia, about 800 children are diagnosed with cancer, a globally a dreadful disease, each year, and osteosarcoma accounts for approximately 3% of such cancer. The early detection of the type and extent of bone cancer is important for effective management through surgery. But, the presence of soft tissue edema around a neoplasm can interfere with accurate local tumor staging and subsequent surgical planning. However very scanty research is done on this; none of the past studies focused specifically on the incidence and quantity of extraosseous edema and its impact. Our interdisciplinary retrospective study with objectives to study the presence of soft tissue edema adjacent to the tumors in the extremities, characterize their pattern and distribution involved 82 patients of wide range of age attending the Hospital Universiti Sains Malaysia with a histologically proven tumor or tumor-like lesion of bone. Methods: This paper emphasizes avoiding misinterpretation of such edema and subsequent over-staging of musculoskeletal tumor. We exclusively used 1T-Magnetic Resonance Imaging due to its excellent resolution. All cases were imaged (T1W, T2W, T1W fat suppressed Gadolinium enhanced, and STIR images) by using 1.5 Tesla MRI unit. STIR images permit study of larger volume of abnormal tissue than spin echo images. Results: Peritumoral edema in 5 cases, Paratumoral edema in 11 patients and mixed type in 45 cases were found including 10 benign tumors. Overall, 5 malignant lesions did not show any sift tissue edema! All the data were analyzed and interpretation and charecterisation of the edema was done by an experienced radiologist. The findings were correlated with histopathology examination results. Conclusion: In conclusion, accurate definition of the local extent of a bone tumor and exploration of soft tissue edema is required to maximize the success of diagnostic work-up and staging prior to biopsy and subsequent interventions while minimizing the amount of tissue removed.
  6. Ahmed A. Hussien, Mohd Z. Abdullah, Mohd A. Al-Nimr, Yusop, N.M., Nuntadusit, C., Elnaggar, M.H.
    One of the best ways to enhance heat transfer coefficient is by improving thermal properties of the
    working fluid. Gold/water nanofluid flow through horizontal minitube with very low Reynolds number
    was simulated by using Thermal Lattice Boltzmann Method (TLBM) under uniform heat flux boundary
    condition. The effect of different volume fraction of nanoparticles on the heat transfer coefficient was
    studied and compared with the base fluid (water). The results were verified using Finite Volume Method
    (FVM). The results showed enhancement of heat transfer coefficient when using gold/water nanofluid
    and this enhancement depends on the volume concentration of Gold nanoparticles. The maximum
    enhancement was 18% with 0.03 volume concentration.
  7. Mirghani, M.E.S., Mohammedelnour, Ahmed A., Kabbashi, Nasser A., Alam, Md Z., Musa, Khalid H., Abdullah, Aminah.
    Acacia polyacantha gum (APG) is a dried exudate which obtained from the stems and branches of Acacia polyacantha trees. APG is rich in soluble dietary fibers as well as organic compounds. In this study quantitation of the levels of total phenolics content (TPC) and antioxidant activities were conducted using ABTS and CUPRAC assays for APG extraction using pure solvents (methanol, ethanol, acetone) and their aqueous mixtures at 50% and 100%. The antioxidant levels were evaluated by 2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) radical cation deculturization and cupric iron reducing capacity in the presence of neocuproine (CUPRAC) for the evaluation of reducing power, and (TPC) was evaluated by the Folin-Ciocalteu method. The solvent Methanol (50%) gave the best extraction ratio for APG presented by highest (TPC 60.78 mg GAE/100g of DW, CUPRAC 34.65 mg TE/100g DW, and, ABTS about 37.65 mg TE/100g DW respectively), followed by ethanol 50% extract. On the other hand, pure methanol showed the lowest TPC 5.33 mg GAE/100g of DW, ABTS 10.9 mg TE/100g DW, and CUPRAC 7.80 mg TE/100g DW, values respectively. Therefore, the variation in the antioxidant capacity of extracts was possibly due to the difference of polarity, immiscibility and the nature of the APG compounds extracted using various solvents. The higher content of antioxidant activity in APG shall be useful to human health if it is properly utilized.
  8. Al-Amiery AA, Kadhum AA, Obayes HR, Mohamad AB
    Bioinorg Chem Appl, 2013;2013:354982.
    PMID: 24170994 DOI: 10.1155/2013/354982
    The novel curcumin derivative (1E,4Z,6E)-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (5-chlorocurcumin) was prepared from natural curcumin. The newly synthesised compound was characterised by spectral studies (IR, 1H NMR, and 13C NMR). The free radical scavenging activity of 5-chlorocurcumin has been determined by measuring interaction with the stable free radical DPPH, and 5-chlorocurcumin has shown encouraging antioxidant activities. Theory calculations of the synthesised 5-chlorocurcumin were performed using molecular structures with optimised geometries. Molecular orbital calculations provided a detailed description of the orbitals, including spatial characteristics, nodal patterns, and the contributions of individual atoms.
  9. Al-Amiery AA, Kadhum AA, Mohamad AB
    Molecules, 2012;17(5):5713-23.
    PMID: 22628043 DOI: 10.3390/molecules17055713
    Newly synthesized coumarins 4-((5-mercapto-4-phenyl-4H-1,2,4-triazol-3-yl)-methoxy)-2H-chromen-2-one and 4-((5-(phenylamino)-1,3,4-thiadiazol-2-yl)-methoxy)-2H-chromen-2-one were tested against selected types of fungi and showed significant activities. DFT calculations of the synthesized coumarins were performed using molecular structures with optimized geometries. Molecular orbital calculations provide a detailed description of the orbitals, including spatial characteristics, nodal patterns, and the contributions of individual atoms.
  10. Al-Amiery AA, Kadhum AA, Mohamad AB
    Bioinorg Chem Appl, 2012;2012:795812.
    PMID: 22400016 DOI: 10.1155/2012/795812
    Metal complexes of (Z)-2-(pyrrolidin-2-ylidene)hydrazinecarbothioamide (L) with Cu(II), Co(II), and Ni(II) chlorides were tested against selected types of fungi and were found to have significant antifungal activities. The free-radical-scavenging ability of the metal complexes was determined by their interaction with the stable free radical 2,2''-diphenyl-1-picrylhydrazyl, and all the compounds showed encouraging antioxidant activities. DFT calculations of the Cu complex were performed using molecular structures with optimized geometries. Molecular orbital calculations provide a detailed description of the orbitals, including spatial characteristics, nodal patterns, and the contributions of individual atoms.
  11. Kadhum AA, Al-Amiery AA, Musa AY, Mohamad AB
    Int J Mol Sci, 2011;12(9):5747-61.
    PMID: 22016624 DOI: 10.3390/ijms12095747
    The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N'-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2-6 are proposed on the basis of spectroscopic evidence.
  12. Al-Amiery AA, Musa AY, Kadhum AA, Mohamad AB
    Molecules, 2011 Aug 10;16(8):6833-43.
    PMID: 21832973 DOI: 10.3390/molecules16086833
    New coumarin derivatives, namely 7-[(5-amino-1,3,4-thiadiazol-2-yl)methoxy]-2H-chromen-2-one, 5-[(2-oxo-2H-chromen-7-yloxy)methyl]-1,3,4-thiadiazol-2(3H)-one, 2-[2-(2-oxo-2H-chromen-7-yloxy)acetyl]-N-phenylhydrazinecarbothioamide, 7-[(5-(phenylamino)-1,3,4-thiadiazol-2-yl)methoxy]-2H-chromen-2-one and 7-[(5-mercapto-4-phenyl-4H-1,2,4-triazol-3-yl)methoxy]-2H-chromen-2-one were prepared starting from the natural compound umbelliferone. The newly synthesized compounds were characterized by elemental analysis and spectral studies (IR, ¹H-NMR and ¹³C-NMR).
  13. Abu Kasim NH, Madfa AA, Hamdi M, Rahbari GR
    Dent Mater J, 2011;30(6):869-80.
    PMID: 22123011 DOI: 10.4012/dmj.2010-161
    This study aimed to compare the biomechanical behaviour of functionally graded structured posts (FGSPs) and homogenous-type posts in simulated models of a maxillary central incisor. Two models of FGSPs consisting of a multilayer xTi-yHA composite design, where zirconia and alumina was added as the first layer for models A and B respectively were compared to homogenous zirconia post (model C) and a titanium post (model D). The amount of Ti and HA in the FGSP models was varied in gradations. 3D-FEA was performed on all models and stress distributions were investigated along the dental post. In addition, interface stresses between the posts and their surrounding structures were investigated under vertical, oblique, and horizontal loadings. Strain distribution along the post-dentine interface was also investigated. The results showed that FGSPs models, A and B demonstrated better stress distribution than models C and D, indicating that dental posts with multilayered structure dissipate localized and interfacial stress and strain more efficiently than homogenous-type posts.
  14. Kadhum AA, Mohamad AB, Al-Amiery AA, Takriff MS
    Molecules, 2011 Aug 15;16(8):6969-84.
    PMID: 21844844 DOI: 10.3390/molecules16086969
    3-Aminocoumarin (L) has been synthesized and used as a ligand for the formation of Cr(III), Ni(II), and Cu(II) complexes. The chemical structures were characterized using different spectroscopic methods. The elemental analyses revealed that the complexes where M=Ni(II) and Cu(II) have the general formulae [ML(2)Cl(2)], while the Cr(III) complex has the formula [CrL(2)Cl(2)]Cl. The molar conductance data reveal that all the metal chelates, except the Cr(III) one, are non-electrolytes. From the magnetic and UV-Visible spectra, it is found that these complexes have octahedral structures. The stability for the prepared complexes was studied theoretically using Density Function Theory. The total energy for the complexes was calculated and it was shown that the copper complex is the most stable one. Complexes were tested against selected types of microbial organisms and showed significant activities. The free radical scavenging activity of metal complexes have been determined by measuring their interaction with the stable free radical DPPH and all the compounds have shown encouraging antioxidant activities.
  15. Baradaran S, Basirun WJ, Zalnezhad E, Hamdi M, Sarhan AA, Alias Y
    J Mech Behav Biomed Mater, 2013 Apr;20:272-82.
    PMID: 23453827 DOI: 10.1016/j.jmbbm.2013.01.020
    In this study, titanium thin films were deposited on alumina substrates by radio frequency (RF) magnetron sputtering. The mechanical properties of the Ti coatings were evaluated in terms of adhesion strength at various RF powers, temperatures, and substrate bias voltages. The coating conditions of 400W of RF power, 250°C, and a 75V substrate bias voltage produced the strongest coating adhesion, as obtained by the Taguchi optimisation method. TiO2 nanotube arrays were grown as a second layer on the Ti substrates using electrochemical anodisation at a constant potential of 20V and anodisation times of 15min, 45min, and 75min in a NH4F electrolyte solution (75 ethylene glycol: 25 water). The anodised titanium was annealed at 450°C and 650°C in a N2 gas furnace to obtain different phases of titania, anatase and rutile, respectively. The mechanical properties of the anodised layer were investigated by nanoindentation. The results indicate that Young's modulus and hardness increased with annealing temperature to 650°C.
  16. Al-Amiery AA, Kadhum AAH, Mohamad AB, Junaedi S
    Materials (Basel), 2013 Apr 02;6(4):1420-1431.
    PMID: 28809218 DOI: 10.3390/ma6041420
    2-(1-methyl-4-((E)-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene)-hydrazineecarbothioamide (HCB) was synthesized as a corrosion inhibitor from the reaction of 4-aminoantipyrine, thiosemicarbazide and 2-methylbenzaldehyde. The corrosion inhibitory effects of HCB on mild steel in 1.0 M HCl were investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The results showed that HCB inhibited mild steel corrosion in acidic solution and inhibition efficiency increased with an increase in the concentration of the inhibitor. The inhibition efficiency was up to 96.5% at 5.0 mM. Changes in the impedance parameters suggested that HCB adsorbed on the surface of mild steel, leading to the formation of a protective film. The novel corrosion inhibitor synthesized in the present study was characterized using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectral data.
  17. Abdulsalam M Q AM, Mohammed A K M, Ahmed A A, Fong MY
    Trop Biomed, 2010 Dec;27(3):551-8.
    PMID: 21399597 MyJurnal
    Malaria remains a major public health problem causing mortality and morbidity in tropical and subtropical countries. A cross-sectional study was carried out to determine malaria prevalence and its clinical pattern during malaria season in Yemen. Blood samples were collected from 511 patients with fever who voluntary participated in this study, of them 268 were males and 242 females. Malaria was screened using Giemsa-stained thick and thin blood films. Clinical profile was recorded through physical and laboratory examinations and biodata were collected by pre-tested standard questionnaire. The overall prevalence was 15.3%. Three malaria species (Plasmodium falciparum, Plasmodium vivax and Plasmodium malarae) were detected with the predominance of P. falciparum (83.33%). People living in the rural areas had higher infection rate compared to urban areas (p < 0.005). Children were at higher risk of developing severe malaria compared to adults (p < 0.05). Severe anaemia, respiratory distress, jaundice, convulsion and bleeding were more apparent among younger age groups of malaria cases compared to older children. The study indicates that malaria is still a public health problem with children being at high risk of developing severe malaria which may lead to death.
  18. Daddiouaissa D, Amid A, Abdullah Sani MS, Elnour AAM
    J Ethnopharmacol, 2021 Apr 24;270:113813.
    PMID: 33444719 DOI: 10.1016/j.jep.2021.113813
    ETHNOPHARMACOLOGICAL RELEVANCE: Medicinal plants have been used by indigenous people across the world for centuries to help individuals preserve their wellbeing and cure diseases. Annona muricata L. (Graviola) which is belonging to the Annonaceae family has been traditionally used due to its medicinal abilities including antimicrobial, anti-inflammatory, antioxidant and cancer cell growth inhibition. Graviola is claimed to be a potential antitumor due to its selective cytotoxicity against several cancer cell lines. However, the metabolic mechanism information underlying the anticancer activity remains limited.

    AIM OF THE STUDY: This study aimed to investigate the effect of ionic liquid-Graviola fruit pulp extract (IL-GPE) on the metabolomics behavior of colon cancer (HT29) by using an untargeted GC-TOFMS-based metabolic profiling.

    MATERIALS AND METHODS: Multivariate data analysis was used to determine the metabolic profiling, and the ingenuity pathway analysis (IPA) was used to predict the altered canonical pathways after treating the HT29 cells with crude IL-GPE and Taxol (positive control).

    RESULTS: The principal components analysis (PCA) identified 44 metabolites with the most reliable factor loading, and the cluster analysis (CA) separated three groups of metabolites: metabolites specific to the non-treated HT29 cells, metabolites specific to the treated HT29 cells with the crude IL-GPE and metabolites specific to Taxol treatment. Pathway analysis of metabolomic profiles revealed an alteration of many metabolic pathways, including amino acid metabolism, aerobic glycolysis, urea cycle and ketone bodies metabolism that contribute to energy metabolism and cancer cell proliferation.

    CONCLUSION: The crude IL-GPE can be one of the promising anticancer agents due to its selective inhibition of energy metabolism and cancer cell proliferation.

  19. Alavi J, Ewees AA, Ansari S, Shahid S, Yaseen ZM
    PMID: 34741267 DOI: 10.1007/s11356-021-17190-2
    Accurate prediction of inlet chemical oxygen demand (COD) is vital for better planning and management of wastewater treatment plants. The COD values at the inlet follow a complex nonstationary pattern, making its prediction challenging. This study compared the performance of several novel machine learning models developed through hybridizing kernel-based extreme learning machines (KELMs) with intelligent optimization algorithms for the reliable prediction of real-time COD values. The combined time-series learning method and consumer behaviours, estimated from water-use data (hour/day), were used as the supplementary inputs of the hybrid KELM models. Comparison of model performances for different input combinations revealed the best performance using up to 2-day lag values of COD with the other wastewater properties. The results also showed the best performance of the KELM-salp swarm algorithm (SSA) model among all the hybrid models with a minimum root mean square error of 0.058 and mean absolute error of 0.044.
  20. Ahmed A, Abdo A, Salim N
    ScientificWorldJournal, 2012;2012:410914.
    PMID: 22623895 DOI: 10.1100/2012/410914
    Many of the similarity-based virtual screening approaches assume that molecular fragments that are not related to the biological activity carry the same weight as the important ones. This was the reason that led to the use of Bayesian networks as an alternative to existing tools for similarity-based virtual screening. In our recent work, the retrieval performance of the Bayesian inference network (BIN) was observed to improve significantly when molecular fragments were reweighted using the relevance feedback information. In this paper, a set of active reference structures were used to reweight the fragments in the reference structure. In this approach, higher weights were assigned to those fragments that occur more frequently in the set of active reference structures while others were penalized. Simulated virtual screening experiments with MDL Drug Data Report datasets showed that the proposed approach significantly improved the retrieval effectiveness of ligand-based virtual screening, especially when the active molecules being sought had a high degree of structural heterogeneity.
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