Displaying publications 61 - 80 of 152 in total

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  1. Lew MH, Noordin R, Monsur Alam Khan M, Tye GJ
    Pathog Glob Health, 2018 10;112(7):387-394.
    PMID: 30332344 DOI: 10.1080/20477724.2018.1536854
    Toxoplasmosis, a parasitic disease in human and animals, is caused by Toxoplasma gondii. Our previous study has led to the discovery of a novel RAP domain binding protein antigen (TgRA15), an apparent in-vivo induced antigen recognised by antibodies in acutely infected individuals. This study is aimed to evaluate the humoral response and cytokine release elicited by recombinant TgRA15 protein in C57BL/6 mice, demonstrating its potential as a candidate vaccine for Toxoplasma gondii infection. In this study, the recombinant TgRA15 protein was expressed in Escherichia coli, purified and refolded into soluble form. C57BL/6 mice were immunised intradermally with the antigen and CASAC (Combined Adjuvant for Synergistic Activation of Cellular immunity). Antigen-specific humoral and cell-mediated responses were evaluated using Western blot and ELISA. The total IgG, IgG1 and IgG2a antibodies specific to the antigen were significantly increased in treatment group compare to control group. A higher level of interferon gamma (IFN-γ) secretion was demonstrated in the mice group receiving booster doses of rTgRA15 protein, suggesting a potential Th1-mediated response. In conclusion, the rTgRA15 protein has the potential to generate specific antibody response and elicit cellular response, thus potentially serve as a vaccine candidate against T. gondii infection.
  2. Lajis NH, Abdullah AS, Salim SJ, Bremner JB, Khan MN
    Steroids, 1993 Aug;58(8):387-9.
    PMID: 8212090
    Spectroscopic examination of purified extracts of the rumen content of sheep intoxicated by Brachiaria decumbens revealed the presence of two spirostanes, identified as epi-sarsasapogenin and epi-smilagenin. Sarsasapogenone was obtained by the oxidation of sarsasapogenin. The reduction of sarsasapogenone using lithium aluminum hydride yielded isomeric products, sarsasapogenin (20%) and epi-sarsasapogenin (80%).
  3. Lajis NH, Noor HM, Khan MN
    J Pharm Sci, 1995 Jan;84(1):126-30.
    PMID: 7714735
    The hydroxide ion-catalyzed hydrolysis of securinine involves the ring opening of the lactone moiety. The rate of hydrolysis is insensitive to the ionic strength. The observed pseudo-first-order rate constants reveal a decrease of approximately 4-fold due to the increase in the MeCN content from 4 to 50% (v/v) in mixed aqueous solvent. The temperature dependence of the rate of hydrolysis follows the Eyring equation, which yields delta H* and delta S* as 11.0 kcal mol-1 and -34.5 cal deg-1 mol-1, respectively. The hydroxyl carboxylate product of the alkaline hydrolysis of securinine is shown to undergo cyclization in acidic medium to yield securinine. The observed pseudo-first-order rate constants for cyclization increase linearly with an increase in [H+]. The change in the content of MeCN from 3.8 to 47.2% (v/v) in mixed aqueous solvents does not show an effect on the rate of the cyclization reaction. The most plausible mechanisms for alkaline hydrolysis and acid cyclization reactions are also discussed.
  4. Kumar SSA, Mohammed NB, Alduhaish O, Ramesh K, Ramesh S, Khan M, et al.
    Polymers (Basel), 2023 May 23;15(11).
    PMID: 37299227 DOI: 10.3390/polym15112428
    Globally, researchers have devoted consistent efforts to producing excellent coating properties since coating plays an essential role in enhancing electrochemical performance and surface quality. In this study, TiO2 nanoparticles in varying concentrations of 0.5, 1, 2, and 3 wt.% were added into the acrylic-epoxy polymeric matrix with 90:10 wt.% (90A:10E) ratio incorporated with 1 wt.% graphene, to fabricate graphene/TiO2 -based nanocomposite coating systems. Furthermore, the properties of the graphene/TiO2 composites were investigated by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), ultraviolet-visible (UV-Vis) spectroscopy, water contact angle (WCA) measurements, and cross-hatch test (CHT), respectively. Moreover, the field emission scanning electron microscope (FESEM) and the electrochemical impedance spectroscopy (EIS) tests were conducted to investigate the dispersibility and anticorrosion mechanism of the coatings. The EIS was observed by determining the breakpoint frequencies over a period of 90 days. The results revealed that the TiO2 nanoparticles were successfully decorated on the graphene surface by chemical bonds, which resulted in the graphene/TiO2 nanocomposite coatings exhibiting better dispersibility within the polymeric matrix. The WCA of the graphene/TiO2 coating increased along with the ratio of TiO2 to graphene, achieving the highest CA of 120.85° for 3 wt.% of TiO2. Excellent dispersion and uniform distribution of the TiO2 nanoparticles within the polymer matrix were shown up to 2 wt.% of TiO2 inclusion. Among the coating systems, throughout the immersion time, the graphene/TiO2 (1:1) coating system exhibited the best dispersibility and high impedance modulus values (Z0.01 Hz), exceeding 1010 Ω cm2.
  5. Konto M, Fufa GI, Zakaria A, Tukur SM, Watanabe M, Ola-Fadunsin SD, et al.
    Vet World, 2015 Oct;8(10):1167-71.
    PMID: 27047012 DOI: 10.14202/vetworld.2015.1167-1171
    The red jungle fowl is generally considered as one of the endangered Asian wild Galleopheasants due to man-made encroachment of their habitats, coupled with the effect of disease and disease causing organisms like ticks and tick-borne infections. This study aimed to determine the tick fauna of the red jungle fowl and their predilection sites based on developmental stages.
  6. Khan S, Ali Khan M, Zafar A, Javed MF, Aslam F, Musarat MA, et al.
    Materials (Basel), 2021 Dec 22;15(1).
    PMID: 35009186 DOI: 10.3390/ma15010039
    The object of this research is concrete-filled steel tubes (CFST). The article aimed to develop a prediction Multiphysics model for the circular CFST column by using the Artificial Neural Network (ANN), the Adaptive Neuro-Fuzzy Inference System (ANFIS) and the Gene Expression Program (GEP). The database for this study contains 1667 datapoints in which 702 are short CFST columns and 965 are long CFST columns. The input parameters are the geometric dimensions of the structural elements of the column and the mechanical properties of materials. The target parameters are the bearing capacity of columns, which determines their life cycle. A Multiphysics model was developed, and various statistical checks were applied using the three artificial intelligence techniques mentioned above. Parametric and sensitivity analyses were also performed on both short and long GEP models. The overall performance of the GEP model was better than the ANN and ANFIS models, and the prediction values of the GEP model were near actual values. The PI of the predicted Nst by GEP, ANN and ANFIS for training are 0.0416, 0.1423, and 0.1016, respectively, and for Nlg these values are 0.1169, 0.2990 and 0.1542, respectively. Corresponding OF values are 0.2300, 0.1200, and 0.090 for Nst, and 0.1000, 0.2700, and 0.1500 for Nlg. The superiority of the GEP method to the other techniques can be seen from the fact that the GEP technique provides suitable connections based on practical experimental work and does not rely on prior solutions. It is concluded that the GEP model can be used to predict the bearing capacity of circular CFST columns to avoid any laborious and time-consuming experimental work. It is also recommended that further research should be performed on the data to develop a prediction equation using other techniques such as Random Forest Regression and Multi Expression Program.
  7. Khan RU, Khan M, Sohail A, Ullah R, Iqbal A, Ahmad B, et al.
    Trop Biomed, 2022 Dec 01;39(4):511-517.
    PMID: 36602209 DOI: 10.47665/tb.39.4.003
    The present study compares the in vitro effects of nanoparticles loaded pentamidine drug and conventional pentamidine on Leishmania tropica. Herein, pentamidine-loaded chitosan nanoparticles (PTN-CNPs) have been synthesized through an ionic gelation method with sodium tripolyphosphate (TPP). Next, the physical characteristics of PTN-CNPs were determined through the surface texture, zeta potential, in vitro drug release, drug loading content (DLC), and encapsulation efficacy (EE) and compared its efficacy with free pentamidine (PTN) drug against promastigotes and axenic amastigotes forms of L. tropica in vitro. The PTN-CNPs displayed a spherical shape having a size of 88 nm, an almost negative surface charge (-3.09 mV), EE for PTN entrapment of 86%, and in vitro drug release of 92% after 36 h. In vitro antileishmanial activity of PTN-CNPs and free PTN was performed against Leishmania tropica KWH23 promastigote and axenic amastigote using 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyletetrazolium bromide (MTT) assay. It was observed that the effect of PTN-CNPs and free PTN on both forms of the parasite was dose and time dependent. Free PTN presented low efficacy even at higher dose (40 µg/ml) with 25.6 ± 1.3 and 26.5 ±1.4 mean viability rate of the promastigotes and axenic amastigotes, respectively after 72 hrs incubation. While PTN-CNPs showed strong antileishmanial effects on both forms of parasite with 16 ± 0.4 and 19 ± 0.7 mean viability rate at the same higher concentration (40 µg/ml) after 72 hrs incubation. Half maximal inhibitory concentration (IC50) values of PTN-CNPs toward promastigotes and amastigotes were obtained as 0.1375 µg/ml and 0.1910 µg/ml, respectively. In conclusion, PTN-CNPs effectively inhibited both forms of the L. tropica; however, its effect was more salient on promastigotes. This data indicates that the PTN-CNPs act as a target drug delivery system. However, further research is needed to support its efficacy in animal and human CL.
  8. Khan MS, Ibrahim SM, Adamu AA, Rahman MBA, Bakar MZA, Noordin MM, et al.
    Cryobiology, 2020 02 01;92:26-33.
    PMID: 31580830 DOI: 10.1016/j.cryobiol.2019.09.012
    A number of living creatures in the Antarctic region have developed characteristic adaptation of cold weather by producing antifreeze proteins (AFP). Antifreeze peptide (Afp1m) fragment have been designed in the sequence of strings from native proteins. The objectives of this study were to assess the properties of Afp1m to cryopreserve skin graft at the temperature of -10 °C and -20 °C and to assess sub-zero injuries in Afp1m cryopreserved skin graft using light microscopic techniques. In the present study, a process was developed to cryopreserve Sprague-Dawley (SD) rat skin grafts with antifreeze peptide, Afp1m, α-helix peptide fragment derived from Glaciozyma antractica yeast. Its viability assessed by different microscopic techniques. This study also described the damages caused by subzero temperatures (-10 and -20 °C) on tissue cryopreserved in different concentrations of Afp1m (0.5, 1, 2, 5 and 10 mg/mL) for 72 h. Histological scores of epidermis, dermis and hypodermis of cryopreserved skin grafts showed highly significant difference (p 
  9. Khan MN, Sim YL, Ariffin A
    ScientificWorldJournal, 2014;2014:592691.
    PMID: 24574900 DOI: 10.1155/2014/592691
    The values of pseudo-first-order rate constants (k(obs)) for alkaline hydrolysis of 1, obtained at 1.0 mM NaOH and within [C(m)E(n)]T (total concentration of C(m)E(n)) range of 3.0-5.0 mM for C(12)E(23) and 10-20 mM for C(18)E(20), fail to obey pseudophase micellar (PM) model. The values of the fraction of near irreversible C m E n micellar trapped 1 molecules (F(IT1)) vary in the range ~0-0.75 for C(12)E(23) and ~0-0.83 for C(18)E(20) under such conditions. The values of F(IT1) become 1.0 at ≥ 10 mM C(12)E(23) and 50 mM C(18)E(20). Kinetic analysis of the observed data at ≥ 10 mM C(12)E(23) shows near irreversible micellar entrapment of 1 molecules under such conditions.
  10. Khan MN
    Adv Colloid Interface Sci, 2010 Sep 15;159(2):160-79.
    PMID: 20673861 DOI: 10.1016/j.cis.2010.06.005
    A new method, based upon semi-empirical kinetic approach, for the determination of ion exchange constant for ion exchange processes occurring between counterions at the cationic micellar surface is described in this review article. Basically, the method involves a reaction kinetic probe which gives observed pseudo-first-order rate constants (k(obs)) for a nucleophilic substitution reaction between the nonionic and anionic reactants (R and S) in the presence of a constant concentration of both reactants as well as cationic micelles and varying concentrations of an inert inorganic or organic salt (MX). The observed data (k(obs), versus [MX]) fit satisfactorily (in terms of residual errors) to an empirical equation which could be derived from an equation explaining the mechanism of the reaction of the kinetic probe in terms of pseudophase micellar (PM) model coupled with another empirical equation. This (another) empirical equation explains the effect of [MX] on cationic micellar binding constant (K(S)) of the anionic reactant (say S) and gives an empirical constant, K(X/S). The magnitude of K(X/S) is the measure of the ability of X(-) to expel S(-) from a cationic micellar pseudophase to the bulk aqueous phase through ion exchange X(-)/S(-). The values of K(X/S) and K(Y/S) (where Y(-) is another inert counterion) give the ion exchange constant, K(X)(Y) (=K(X)/K(Y) where K(X) and K(Y) represent cationic micellar binding constants of X(-) and Y(-), respectively). The suitability of this method is demonstrated by the use of three different reaction kinetic probes and various MX.
  11. Khan MN, Azri MH
    J Phys Chem B, 2010 Jun 24;114(24):8089-99.
    PMID: 20509705 DOI: 10.1021/jp102109q
    Pseudofirst-order rate constants for aqueous cleavage of N-(2'-hydroxyphenyl)phthalimide (1), obtained at 0.001 M NaOH, 2 x 10(-4) M 1, 2% v/v CH(3)CN, and 30 degrees C, show a nonmonotonic decrease with the increase in the total concentration of cetyltrimethylammonium bromide ([CTABr](T)) within its range >/=9 x 10(-5)-M. Similar observations have been obtained in the presence of the constant concentration of NaBr at M. The values of k(obs) become independent of [CTABr](T) at >or=0.04 M CTABr and within a [NaBr] range of 0.0-0.005 M. These observations, in view of the pseudophase (PP) model of the micelle, reveal the presence of presumably spherical micelles at M CTABr in the presence of a constant concentration of NaBr within its range of 0.0-0.01 M. The average value of the CTABr micellar binding constant (K(S)) of ionized 1 (i.e., 1(-)), under these conditions, is (1.88 +/- 0.62) x 10(3) M(-1). The increase in [CTABr](T) at >or=4 x 10(-4) M causes a micellar structural transition from most likely spherical to cylindrical, which is evident from the increase in K(S) values from 3.46 x 10(3) to 11.4 x 10(3) M(-1) with the increase in [CTABr](T) from 4 x 10(-4) to approximately 1 x 10(-3) M in the absence of NaBr. The values of k(obs) at different [NaBr] and at a constant [CTABr](T) follow a kinetic relationship derived from an empirical equation coupled with a PP model of micelle. This relationship gives the value of a kinetic parameter, F(X/S), which represents the fraction of micellized S(-) (S(-) = 1(-)) transferred to the aqueous phase by the limiting concentration of X(-) (X(-) = Br(-)) through ion exchange X(-)/S(-). The value of F(Br/1) is 0.65 +/- 0.12.
  12. Khan MN, Ismail E
    J Phys Chem A, 2009 Jun 11;113(23):6484-8.
    PMID: 19449852 DOI: 10.1021/jp902886z
    A kinetic probe, which involves the determination of pseudo-first-order rate constants (k(obs)) for the nucleophilic reaction of piperidine (Pip) with ionized phenyl salicylate (S(-)) at constant [Pip](T) (= 0.1 M), [S(-)](T) (= 2 x 10(-4) M), [CTABr](T), < or = 0.10 M NaOH and varying concentration of MX (= 3-ClC(6)H(4)CO(2)Na and C(6)H(5)CH=CHCO(2)Na), gives the following information. The nonlinear plots of k(obs) versus [MX] reveal indirectly the occurrence of more than one independent ion-exchange processes at the CTABr micellar surface. These observed data fit to a kinetic relationship derived from an empirical equation coupled with pseudophase micellar (PM) model. This relationship gives an empirical constant (K(X/S)) that is used to determine the usual ion-exchange constant (K(X)(Y)). The values of K(X)(Br) (Y = Br) have been calculated for X = 3-ClC(6)H(4)CO(2)(-) and C(6)H(5)CH=CHCO(2)(-). More than 12-fold larger value of K(X)(Br) for X = 3-ClC(6)H(4)CO(2)(-) than that for X = 2-ClC(6)H(4)CO(2)(-) is attributed to the presence and absence of viscoelasticity in the respective presence of 3-ClC(6)H(4)CO(2)(-) and 2-ClC(6)H(4)CO(2)(-).
  13. Khan MN, Ismail E
    J Colloid Interface Sci, 2001 Aug 15;240(2):636-639.
    PMID: 11482975
    Pseudo-first-order rate constants (k(obs)) for alkaline hydrolysis of 4-nitrophthalimide show a monotonic decrease with increase in [C(12)E(23)](T) (total concentration of Brij 35) at constant [CH(3)CN] and [NaOH]. This micellar effect is explained in terms of a pseudophase micelle model. The rate of hydrolysis becomes too slow to monitor at [C(12)E(23)](T)>/=0.03 M in the absence of cetyltrimethylammonium bromide (CTABr) and at [C(12)E(23)](T)>/=0.04 M in the presence of 0.006-0.02 M CTABr at 0.01 M NaOH. The plots of k(obs) versus [C(12)E(23)](T) show minima at 0.006 and 0.01 M CTABr, while such a minimum is not visible at 0.02 M CTABr. Copyright 2001 Academic Press.
  14. Khan MN, Ariffin A
    Org Biomol Chem, 2003 Apr 21;1(8):1404-8.
    PMID: 12929671
    The rate of formation and disappearance of phthalic anhydride (PAn) intermediate in the aqueous cleavage of N-methoxyphthalamic acid (NMPA) under acidic pH was studied spectrophotometrically in mixed CH3CN-H2O solvents. The rate of formation of PAn from NMPA is almost independent of the change in acetonitrile content from 20 to 70% v/v in mixed aqueous solvents. The rate constants for the formation of PAn from NMPA are approximately 10-fold smaller than the corresponding rate constants for the formation of PAn from o-carboxybenzohydroxamic acid (OCBA). These observations are ascribed to the consequence of the occurrence of slightly different mechanisms in these reactions.
  15. Khan MN
    J Org Chem, 1996 Nov 15;61(23):8063-8068.
    PMID: 11667789
    A slight modification of the Gabriel synthesis of primary amines is suggested on the basis of the observed and reported values of rate constants for the alkaline and acid hydrolyses of phthalimide, phthalamic acid, benzamide, and their N-substituted derivatives. The suggested procedure requires shorter reactions time and milder acid-base reaction conditions compared with the conventional acid-base hydrolysis in the Gabriel synthesis. A slight modification in the Ing-Manske procedure is also suggested. Pseudo-first-order rate constants, k(obs), for hydrolysis of N-phthaloylglycine, NPG, decrease from 24.1 x 10(-3) to 7.72 x 10(-3) and 6.12 x 10(-3) s(-1) with increasing acetonitrile and 1,4-dioxan contents, respectively, from 2 to 50% v/v (all the percentages given in the paper are vol %), while increasing the organic cosolvents content from 50 to 80% increases k(obs) from 7.72 x 10(-3) to 19.7 x 10(-3) s(-1) for acetonitrile and from 6.12 x 10(-3) to 52.8 x 10(-3) s(-1) for 1,4-dioxan, in aqueous organic solvents containing 0.004 M NaOH at 35 degrees C. The rate constants for NPG hydrolysis decrease from 2.11 x 10(-2) to 1.19 x 10(-4) s(-1) with increasing MeOH content from 2 to 84%, in aqueous organic solvents containing 2% MeCN and 0.004 M NaOH at 35 degrees C.
  16. Khan MN
    J Org Chem, 1997 May 16;62(10):3190-3193.
    PMID: 11671702
    Pseudo-first-order rate constants obtained for methanolysis of ionized phenyl salicylate (PS(-)) at constant [MeOH], [MeCN], [NaOH] or [KOH], and [KBr] and at 35 degrees C show a decrease with the increase in [CTABr] (where CTABr represents cetyltrimethylammonium bromide) from 0.0-0.01 M. These observed data obey a pseudophase model of the micelle. The micellar binding constants (K(S)) of PS(-), pseudo-first-order rate constants (k(M)) for methanolysis of PS(-) in the micellar pseudophase and cmc are almost unchanged with the change in [NaOH] from 0.005-0.050 M. The increase in [KBr] from 0.0 to 0.3 M at 0.01 M KOH decreases K(S) from 5140 to 653 M(-)(1) and cmc from 1.9 x 10(-)(4) to 0.2 x 10(-)(4) M. Pseudo-first-order rate constants, k(M), are almost independent of [KBr] at 0.01 M KOH.
  17. Khan MF, Ghazal TM, Said RA, Fatima A, Abbas S, Khan MA, et al.
    Comput Intell Neurosci, 2021;2021:2487759.
    PMID: 34868288 DOI: 10.1155/2021/2487759
    The Internet of Medical Things (IoMT) enables digital devices to gather, infer, and broadcast health data via the cloud platform. The phenomenal growth of the IoMT is fueled by many factors, including the widespread and growing availability of wearables and the ever-decreasing cost of sensor-based technology. The cost of related healthcare will rise as the global population of elderly people grows in parallel with an overall life expectancy that demands affordable healthcare services, solutions, and developments. IoMT may bring revolution in the medical sciences in terms of the quality of healthcare of elderly people while entangled with machine learning (ML) algorithms. The effectiveness of the smart healthcare (SHC) model to monitor elderly people was observed by performing tests on IoMT datasets. For evaluation, the precision, recall, fscore, accuracy, and ROC values are computed. The authors also compare the results of the SHC model with different conventional popular ML techniques, e.g., support vector machine (SVM), K-nearest neighbor (KNN), and decision tree (DT), to analyze the effectiveness of the result.
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