Displaying publications 1 - 20 of 35 in total

Abstract:
Sort:
  1. Bacterial mediated silver nanoparticles and their efficacy against MRSA
    Saleem S, Iqbal A, Hasnain S
    Trop Biomed, 2020 Jun 01;37(2):482-488.
    PMID: 33612817
    Bacterial mediated Silver nanoparticles is considered as an emerging Ecofriendly approach to eradicate human pathogens. This paper aims to provide the biological approach for the synthesis of silver nanoparticles from indigenously isolated bacteria. This study will be beneficial to control the nosocomial infections triggered by MRSA (Methicillin-resistant Staphylococcus aureus). The current study is the extracellular synthesis of silver nanoparticles by using the cell free filtrate of bacterial strains isolated from the soil. The optimization study was also carried out to obtain the maximum production of silver nanoparticles. Nanoparticles were confirmed and characterized by UV-Vis spectroscopy and Transmission Electron Microscopy (TEM) having the plasmon resonance peak between 420-450nm with 10-60nm in size range and most were spherical in shape. Synthesized silver nanoparticles showed a potential antibacterial activity against MRSA (Methicillin Resistant Staphylococcus aureus) in-vitro study. This is the green approach for the production of AgNPs, as there was no previous work done on the synthesis of silver nanoparticles by bacteria in this region of Southern Punjab, Pakistan and these nanoparticles can be used to treat nosocomial infection. These silver nanoparticles can be used in effective disease management as antimicrobial agent.
  2. Effect of Cu doping on the photocatalytic activity of InVO4 for hazardous dye photodegradation under LED light and its mechanism
    Faisal M, Iqbal A, Adam F, Jothiramalingam R
    Water Sci Technol, 2021 Aug;84(3):576-595.
    PMID: 34388120 DOI: 10.2166/wst.2021.244
    Cu doped InVO4 (xCu-InVO4 (x = 0.06-0.15 wt %) was synthesized by a facile one-pot hydrothermal method for the removal of methylene blue (MB) under LED light irradiation. The X-ray photoelectron spectroscopy (XPS) analysis indicated the coexistence of V5+ and V4+ species due to the O-deficient nature of the xCu-InVO4. The synthesized photocatalysts displayed a morphology of spherical and square shaped particles (20-40 nm) and micro-sized rectangle rods with a length range of 100-200 μm. The xCu-InVO4 exhibited superior adsorption and photodegradation efficiency compared to pristine InVO4 and TiO2 due to the presence of O2 vacancies, V4+/V5+ species, and Cu dopant. The optimum reaction conditions were found to be 5 mg L-1 (MB concentration), pH 6, and 100 mg of photocatalyst mass with a removal efficiency and mineralization degree of 100% and 96.67%, respectively. The main active species responsible for the degradation of MB were •OH radicals and h+. Reusability studies indicated that the 0.13Cu-InVO4 was deactivated after a single cycle of photocatalytic reaction due to significant leaching of V4+ and Cu2+ species.
  3. Fulltext The Asia Pacific Pediatric Association (APPA) position statement on the MAFLD definition of fatty liver disease
    Memon IA, Parkash A, Sadiq K, Kamal NM, El-Shabrawi MHF
    Ther Adv Chronic Dis, 2023;14:20406223231164523.
    PMID: 37051073 DOI: 10.1177/20406223231164523
  4. Fulltext High diversity of Cryptosporidium subgenotypes identified in Malaysian HIV/AIDS individuals targeting gp60 gene
    Iqbal A, Lim YA, Surin J, Sim BL
    PLoS One, 2012;7(2):e31139.
    PMID: 22347442 DOI: 10.1371/journal.pone.0031139
    Currently, there is a lack of vital information in the genetic makeup of Cryptosporidium especially in developing countries. The present study aimed at determining the genotypes and subgenotypes of Cryptosporidium in hospitalized Malaysian human immunodeficiency virus (HIV) positive patients.
  5. Fulltext FEM Analysis of Sezawa Mode SAW Sensor for VOC Based on CMOS Compatible AlN/SiO₂/Si Multilayer Structure
    Aslam MZ, Jeoti V, Karuppanan S, Malik AF, Iqbal A
    Sensors (Basel), 2018 May 24;18(6).
    PMID: 29882929 DOI: 10.3390/s18061687
    A Finite Element Method (FEM) simulation study is conducted, aiming to scrutinize the sensitivity of Sezawa wave mode in a multilayer AlN/SiO₂/Si Surface Acoustic Wave (SAW) sensor to low concentrations of Volatile Organic Compounds (VOCs), that is, trichloromethane, trichloroethylene, carbon tetrachloride and tetrachloroethene. A Complimentary Metal-Oxide Semiconductor (CMOS) compatible AlN/SiO₂/Si based multilayer SAW resonator structure is taken into account for this purpose. In this study, first, the influence of AlN and SiO₂ layers’ thicknesses over phase velocities and electromechanical coupling coefficients (k²) of two SAW modes (i.e., Rayleigh and Sezawa) is analyzed and the optimal thicknesses of AlN and SiO₂ layers are opted for best propagation characteristics. Next, the study is further extended to analyze the mass loading effect on resonance frequencies of SAW modes by coating a thin Polyisobutylene (PIB) polymer film over the AlN surface. Finally, the sensitivity of the two SAW modes is examined for VOCs. This study concluded that the sensitivity of Sezawa wave mode for 1 ppm of selected volatile organic gases is twice that of the Rayleigh wave mode.
  6. Fulltext A Compact UWB Antenna with Independently Controllable Notch Bands
    Iqbal A, Smida A, Mallat NK, Islam MT, Kim S
    Sensors (Basel), 2019 Mar 22;19(6).
    PMID: 30909414 DOI: 10.3390/s19061411
    A minimally-sized, triple-notched band ultra-wideband (UWB) antenna, useful for many applications, is designed, analyzed, and experimentally validated in this paper. A modified maple leaf-shaped main radiating element with partial ground is used in the proposed design. An E-shaped resonator, meandered slot, and U-shaped slot are implemented in the proposed design to block the co-existing bands. The E-shaped resonator stops frequencies ranging from 1.8⁻2.3 GHz (Advanced Wireless System (AWS1⁻AWS2) band), while the meandered slot blocks frequencies from 3.2⁻3.8 GHz (WiMAX band). The co-existing band ranging from 5.6⁻6.1 GHz (IEEE 802.11/HIPERLANband) is blocked by utilizing the U-shaped section in the feeding network. The notched bands can be independently controlled over a wide range of frequencies using specific parameters. The proposed antenna is suitable for many applications because of its flat gain, good radiation characteristics at both principal planes, uniform group delay, and non-varying transfer function ( S 21 ) for the entire UWB frequency range.
  7. Fulltext Comparison of the Surface Properties of Hydrothermally Synthesised Fe3O4@C Nanocomposites at Variable Reaction Times
    Sani S, Adnan R, Oh WD, Iqbal A
    Nanomaterials (Basel), 2021 Oct 16;11(10).
    PMID: 34685183 DOI: 10.3390/nano11102742
    The influence of variable reaction time (tr) on surface/textural properties (surface area, total pore volume, and pore diameter) of carbon-encapsulated magnetite (Fe3O4@C) nanocomposites fabricated by a hydrothermal process at 190 °C for 3, 4, and 5 h was studied. The properties were calculated using the Brunauer-Emmett-Teller (BET) isotherms data. The nanocomposites were characterised using Fourier transform infrared spectroscopy, X-ray diffraction analysis, thermogravimetry, and scanning and transmission electron microscopies. Analysis of variance shows tr has the largest effect on pore volume (F value = 1117.6, p value < 0.0001), followed by the surface area (F value = 54.8, p value < 0.0001) and pore diameter (F value = 10.4, p value < 0.001) with R2-adjusted values of 99.5%, 88.5% and 63.1%, respectively. Tukey and Fisher tests confirmed tr rise to have caused increased variations in mean particle sizes (11-91 nm), crystallite sizes (5-21 nm), pore diameters (9-16 nm), pore volume (0.017-0.089 cm3 g-1) and surface area (7.6-22.4 m2 g-1) of the nanocomposites with individual and simultaneous confidence limits of 97.9 and 84.4 (p-adj < 0.05). The nanocomposites' retained Fe-O vibrations at octahedral (436 cm-1) and tetrahedral (570 cm-1) cubic ferrite sites, modest thermal stability (37-60 % weight loss), and large volume-specific surface area with potential for catalytic application in advanced oxidation processes.
  8. Pneumocystis jirovecii pneumonia 13 years post renal transplant following a recurrent cytomegalovirus infection
    Muhammad Iqbal AH, Lim SK, Ng KP, Tan LP, Chong YB, Keng TC
    Transpl Infect Dis, 2012 Aug;14(4):E23-6.
    PMID: 22551151 DOI: 10.1111/j.1399-3062.2012.00738.x
    Pneumocystis jirovecii (formerly Pneumocystis carinii) pneumonia (PCP) is a rare but serious infection that usually occurs within a year after solid organ transplantation. PCP may occur after 1 year post transplantation, but the rate is reported to be very low. Studies have shown an association between cytomegalovirus (CMV) infection in solid organ transplant patients and an increased risk of opportunistic infection. This increased risk is thought to be a result of the immunomodulatory effects of the CMV infection. We present a case of PCP infection occurring 13 years after a renal transplantation. This occurred following a recurrent CMV infection while the patient was on low-dose immunosuppressants.
  9. Perceptions of nurses on inter-shift handover: A descriptive study in Hospital Kuala Lumpur, Malaysia
    Chong DWQ, Iqbal AR, Kaur Jaj B, Zainab A, Nordin A, Abd Majid ND, et al.
    Med J Malaysia, 2020 11;75(6):691-697.
    PMID: 33219179
    INTRODUCTION: The quality of information and efficiency in the practice and care environments are important aspects of nursing care. The use of a reliable and valid scale can monitor the quality of handover and provide information for continuous improvement of practice. This study aims to describe the perception of nurses, on the domains of quality of information, efficiency, interaction and support and patient involvement.

    METHOD: A cross-sectional descriptive study was conducted among 450 nurses from 37 wards in Hospital Kuala Lumpur. Nurses on shift duty were recruited by convenience sampling from the Medical, Surgery, Obstetrics & Gynaecology, Orthopaedic and Paediatric wards. Using a validated questionnaire (Handover Evaluation Scale), nurses self-rated their perceptions using a 7-point scale and provided open-ended responses to the strengths and challenges that they faced. Descriptive and inferential analyses were done while open-ended questions were summarised based on key themes.

    RESULTS: A total of 414 nurses completed the survey (92.0% response rate). Nurses had an overall mean (SD) perception score of 5.01 (SD 0.56). They perceived good interaction and support during handover and on the quality of information that they received, with mean scores of 5.54 (SD 0.79) and 5.19 (SD 0.69), respectively. There was an association between the departments where the nurses worked and their overall perceptions on nursing handover (p<0.001). Interruptions being the most common theme emerged from the open-ended section.

    CONCLUSION: Despite having substantial interaction and support amongst nurses, opportunities for improvements were noted. Improvements in the quality of handover information and reducing interruptions should be the main emphases as these were perceived to be essential in the current handover practices by nurses.

  10. Fulltext Multimode HMSIW-Based Bandpass Filter with Improved Selectivity for Fifth-Generation (5G) RF Front-Ends
    Iqbal A, Jiat Tiang J, Kin Wong S, Alibakhshikenari M, Falcone F, Limiti E
    Sensors (Basel), 2020 Dec 19;20(24).
    PMID: 33352800 DOI: 10.3390/s20247320
    This article presents the detailed theoretical, simulation, and experimental analysis of a half-mode substrate integrated waveguide (HMSIW)-based multimode wideband filter. A third-order, semicircular HMSIW filter is developed in this paper. A semicircular HMSIW cavity resonator is adopted to achieve wide band characteristics. A U-shaped slot (acts as a λ/4 stub) in the center of a semicircular HMSIW cavity resonator and L-shaped open-circuited stubs are used to improve the out-of-band response by generating multiple transmission zeros (TZs) in the stop-band region of the filter. The TZs on either side of the passband can be controlled by adjusting dimensions of a U-shaped slot and L-shaped open-circuited stubs. The proposed filter covers a wide fractional bandwidth, has a lower insertion loss value, and has multiple TZs (which improves the selectivity). The simulated response of filter agrees well with the measured data. The proposed HMSIW bandpass filter can be integrated with any planar wideband communication system circuit, thanks to its planar structure.
  11. Fulltext Author Correction: Artocarpus altilis extracts as a food-borne pathogen and oxidation inhibitors: RSM, COSMO RS, and molecular docking approaches
    Ahmad MN, Karim NU, Normaya E, Piah BM, Iqbal A, Bulat KHK
    Sci Rep, 2020 Nov 05;10(1):19573.
    PMID: 33154550 DOI: 10.1038/s41598-020-76567-4
    An amendment to this paper has been published and can be accessed via a link at the top of the paper.
  12. Fulltext Synthesis of lignin based composites of TiO2 for potential application as radical scavengers in sunscreen formulation
    Ibrahim MNM, Iqbal A, Shen CC, Bhawani SA, Adam F
    BMC Chem, 2019 Dec;13(1):17.
    PMID: 31384766 DOI: 10.1186/s13065-019-0537-3
    Titanium dioxide (TiO2) is added in sunscreens due to its ability to absorb ultraviolet (UV) light. However, upon irradiation of UV light, reactive oxygen species particularly hydroxyl radical which can damage human skin will be generated. In this study, lignin/TiO2 composites were employed to quench the hydroxyl radicals generated by the TiO2. The lignin was extracted from oil palm empty fruit bunch (OPEFB) via kraft and soda pulping processes. The kraft lignin composite was labelled as KL/TiO2 whereas the soda lignin composite was labelled as SL/TiO2. The lignins and the composites were characterized by FTIR, UV spectroscopy, 13C NMR, SEM, EDX, and XRD. The relative hydroxyl radical production of composites and TiO2 were compared through photo-oxidation of coumarin to 7-hydroxycoumarin as a test medium. The effect of types and amounts of lignin used were studied. The KL/TiO2 composite showed the least radical production due to higher phenolic hydroxyl content of kraft lignin. The activity of the hydroxyl radicals will be quenched when it abstract hydrogen atoms from the phenolic hydroxyl groups.
  13. Fulltext Floating ZnO QDs-Modified TiO2/LLDPE Hybrid Polymer Film for the Effective Photodegradation of Tetracycline under Fluorescent Light Irradiation: Synthesis and Characterisation
    Iqbal A, Saidu U, Adam F, Sreekantan S, Yahaya N, Ahmad MN, et al.
    Molecules, 2021 Apr 25;26(9).
    PMID: 33923041 DOI: 10.3390/molecules26092509
    In this work, mesoporous TiO2-modified ZnO quantum dots (QDs) were immobilised on a linear low-density polyethylene (LLDPE) polymer using a solution casting method for the photodegradation of tetracycline (TC) antibiotics under fluorescent light irradiation. Various spectroscopic and microscopic techniques were used to investigate the physicochemical properties of the floating hybrid polymer film catalyst (8%-ZT@LLDPE). The highest removal (89.5%) of TC (40 mg/L) was achieved within 90 min at pH 9 due to enhanced water uptake by the LDDPE film and the surface roughness of the hybrid film. The formation of heterojunctions increased the separation of photogenerated electron-hole pairs. The QDs size-dependent quantum confinement effect leads to the displacement of the conduction band potential of ZnO QDs to more negative energy values than TiO2. The displacement generates more reactive species with higher oxidation ability. The highly stable film photocatalyst can be separated easily and can be repeatedly used up to 8 cycles without significant loss in the photocatalytic ability. The scavenging test indicates that the main species responsible for the photodegradation was O2●-. The proposed photodegradation mechanism of TC was demonstrated in further detail based on the intermediates detected by LC-time-of-flight/mass spectrometry (LC/TOF-MS).
  14. Fulltext Artocarpus altilis extracts as a food-borne pathogen and oxidation inhibitors: RSM, COSMO RS, and molecular docking approaches
    Ahmad MN, Karim NU, Normaya E, Mat Piah B, Iqbal A, Ku Bulat KH
    Sci Rep, 2020 06 12;10(1):9566.
    PMID: 32533034 DOI: 10.1038/s41598-020-66488-7
    Lipid oxidation and microbial contamination are the major factors contributing to food deterioration. Food additives like antioxidants and antibacterials can prevent food spoilage by delaying oxidation and preventing the growth of bacteria. Artocarpus altilis leaves exhibited biological properties that suggested its use as a new source of natural antioxidant and antimicrobial. Supercritical fluid extraction (SFE) was used to optimize the extraction of bioactive compounds from the leaves using response surface methodology (yield and antioxidant activity). The optimum SFE conditions were 50.5 °C temperature, 3784 psi pressure and 52 min extraction time. Verification test results (Tukey's test) showed that no significant difference between the expected and experimental DPPH activity and yield value (99%) were found. Gas-chromatography -mass spectrometry (GC-MS) analysis revealed three major bioactive compounds existed in A. altilis extract. The extract demonstrated antioxidant and antibacterial properties with 2,3-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing ability of plasma (FRAP), hydroxyl radical scavenging activity, tyrosinase mushrrom inhibition of 41.5%, 8.15 ± 1.31 (µg of ascorbic acid equivalents), 32%, 37% and inhibition zone diameter of 0.766 ± 0.06 cm (B. cereus) and 1.27 ± 0.12 cm (E. coli). Conductor like screening model for real solvents (COSMO RS) was performed to explain the extraction mechanism of the major bioactive compounds during SFE. Molecular electrostatic potential (MEP) shows the probability site of nucleophilic and electrophilic attack during bacterial inhibition. Based on molecular docking study, non-covalent interactions are the main interaction occurring between the major bioactive compounds and bacteria (antibacterial inhibition).
  15. The applicability of using a protease extracted from cashew fruits (Anacardium occidentale), as possible meat tenderizer: An experimental design approach
    Ahmad MN, Shuhaimen MS, Normaya E, Omar MN, Iqbal A, Ku Bulat KH
    J Texture Stud, 2020 10;51(5):810-829.
    PMID: 32401337 DOI: 10.1111/jtxs.12529
    Meat tenderness is one of the most important organoleptic properties in determining consumer acceptance in meat product marketability. Therefore, an effective meat tenderization method is sought after by exploring plant-derived proteolytic enzymes as meat tenderizer. In this study, a novel protease from Cashew was identified as a new alternative halal meat tenderizer. The extraction of cashew protease was optimized using response surface methodology (R2 = 0.9803) by varying pH, CaCl2 concentration, mixing time, and mass. pH 6.34, 7.92 mM CaCl2 concentration, 5.51 min mixing time, and 19.24 g sample mass were the optimal extraction conditions. There was no significant difference (n = 3; p 
  16. Development and characterization novel bio-adhesive for wood using kenaf core (Hibiscus cannabinus) lignin and glyoxal
    Hazwan Hussin M, Aziz AA, Iqbal A, Ibrahim MNM, Latif NHA
    Int J Biol Macromol, 2019 Feb 01;122:713-722.
    PMID: 30399384 DOI: 10.1016/j.ijbiomac.2018.11.009
    The recent study focused on lignin-phenol-glyoxal (LPG) as an alternative way to replace toxic formaldehyde used in commercially available wood adhesives. The concern of the uses of carcinogenic formaldehyde in wood adhesive industry has become major problem over human health, environmental and economy issues. In this study, lignin isolated from Kenaf (Hibiscus cannabinus) via soda and Kraft pulping were modified into SLPG (soda lignin-phenol-glyoxal) and KLPG (Kraft lignin-phenol-glyoxal) adhesives and were compared to phenol-formaldehyde (PF). Complementary analyses such as Fourier Transform Infrared (FTIR) spectroscopy, 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopy, thermal stability; Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) were utilized to characterize all isolated lignin samples. The physical properties of the resins were further characterized in term of viscosity, gel time and total solid content. It was found that soda lignin comprised higher phenolic OH content and greater molecular weight compared to Kraft lignin. Various molar ratio of adhesives were applied on plywood and were mechanically tested. The 30% (w/w) SLPG has shown to have higher tensile strength and internal bonding stress at 72.08 MPa and 53.83 N mm-2 respectively to that of PF.
  17. Fulltext Cylindrical Dielectric Resonator Antenna-Based Sensors for Liquid Chemical Detection
    Iqbal A, Smida A, Saraereh OA, Alsafasfeh QH, Mallat NK, Lee BM
    Sensors (Basel), 2019 Mar 08;19(5).
    PMID: 30857265 DOI: 10.3390/s19051200
    A compact, cylindrical dielectric resonator antenna (CDRA), using radio frequency signals to identify different liquids is proposed in this paper. The proposed CDRA sensor is excited by a rectangular slot through a 3-mm-wide microstrip line. The rectangular slot has been used to excite the CDRA for H E M 11 mode at 5.25 GHz. Circuit model values (capacitance, inductance, resistance and transformer ratios) of the proposed CDRA are derived to show the true behaviour of the system. The proposed CDRA acts as a sensor due to the fact that different liquids have different dielectric permittivities and, hence, will be having different resonance frequencies. Two different types of CDRA sensors are designed and experimentally validated with four different liquids (Isopropyl, ethanol, methanol and water).
  18. Two-Dimensional Infrared Correlation Spectroscopy, Conductor-like Screening Model for Real Solvents, and Density Functional Theory Study on the Adsorption Mechanism of Polyvinylpolypyrrolidone for Effective Phenol Removal in an Aqueous Medium
    Mohammad Alwi MA, Normaya E, Ismail H, Iqbal A, Mat Piah B, Abu Samah MA, et al.
    ACS Omega, 2021 Oct 05;6(39):25179-25192.
    PMID: 34632177 DOI: 10.1021/acsomega.1c02699
    The discharge of industrial effluents, such as phenol, into aquatic and soil environments is a global problem due to its serious negative impacts on human health and aquatic ecosystems. In this study, the ability of polyvinylpolypyrrolidone (PVPP) to remove phenol from an aqueous medium was investigated. The results showed that a significant proportion of phenol (up to 74.91%) was removed using PVPP at pH 6.5. Isotherm adsorption experiments of phenol on PVPP indicated that the best-fit adsorption was obtained using Langmuir models. The response peaks of the hydroxyl groups of phenol (OH) and the carboxyl groups (i.e., C=O) of PVPP were altered, indicating the formation of a hydrogen bond between the PVPP and phenol during phenol removal, as characterized using 1D and 2D IR spectroscopy. The resulting complexes were successfully characterized based on their thermodynamic properties, Mulliken charge, and electronic transition using the DFT approach. To clarify the types of interactions taking place in the complex systems, quantum theory of atoms in molecules (QTAIM) analysis, reduced density gradient noncovalent interaction (RDG-NCI) approach, and conductor-like screening model for real solvents (COSMO-RS) approach were also successfully calculated. The results showed that the interactions that occurred in the process of removing phenol by PVPP were through hydrogen bonding (based on RDG-NCI and COSMO-RS), which was identified as an intermediate type (∇2ρ(r) > 0 and H < 0, QTAIM). To gain a deeper understanding of how these interactions occurred, further characterization was performed based on adsorption mechanisms using molecular electrostatic potential, global reactivity, and local reactivity descriptors. The results showed that during hydrogen bond formation, PVPP acts as a nucleophile, whereas phenol acts as an electrophile and the O9 atom (i.e., donor electron) reacts with the H22 atom (i.e., acceptor electron).
  19. Electrospun PAN/PEG Nanofibrous Membrane Embedded with a MgO/gC3N4 Nanocomposite for Effective Bone Regeneration
    Danagody B, Bose N, Rajappan K, Iqbal A, Ramanujam GM, Anilkumar AK
    ACS Biomater Sci Eng, 2024 Jan 08;10(1):468-481.
    PMID: 38078836 DOI: 10.1021/acsbiomaterials.3c00892
    Developing biomaterial scaffolds using tissue engineering with physical and chemical surface modification processes can improve the bioactivity and biocompatibility of the materials. The appropriate substrate and site for cell attachment are crucial in cell behavior and biological activities. Therefore, the study aims to develop a conventional electrospun nanofibrous biomaterial using reproducible surface topography, which offers beneficial effects on the cell activities of bone cells. The bioactive MgO/gC3N4 was incorporated on PAN/PEG and fabricated into a nanofibrous membrane using electrospinning. The nanocomposite uniformly distributed on the PAN/PEG nanofiber helps to increase the number of induced pores and reduce the hydrophobicity of PAN. The physiochemical characterization of prepared nanoparticles and nanofibers was carried out using FTIR, X-ray diffraction (XRD), thermogravimetry analysis (TGA), X-ray photoelectron spectroscopy (XPS), and water contact angle measurements. SEM and TEM analyses examined the nanofibrous morphology and the structure of MgO/gC3N4. In vitro studies such as on ALP activity demonstrated the membrane's ability to regenerate new bone and healing capacity. Furthermore, alizarin red staining showed the increasing ability of the cell-cell interaction and calcium content for tissue regeneration. The cytotoxicity of the prepared membrane was about 97.09% of live THP-1 cells on the surface of the MgO/gC3N4@PAN/PEG membrane evaluated using MTT dye staining. The soil burial degradation analysis exhibited that the maximum degradation occurs on the 45th day because of microbial activity. In vitro PBS degradation was observed on the 15th day after the bulk hydrolysis mechanism. Hence, on the basis of the study outcomes, we affirm that the MgO/gC3N4@PAN/PEG nanofibrous membrane can act as a potential bone regenerative substrate.
  20. Methyl 4-pyridyl ketone thiosemicarbazone (4-PT) as an effective and safe inhibitor of mushroom tyrosinase and antibrowning agent
    Hassanuddin NA, Normaya E, Ismail H, Iqbal A, Piah MBM, Abd Hamid S, et al.
    Int J Biol Macromol, 2024 Jan;255:128229.
    PMID: 37981274 DOI: 10.1016/j.ijbiomac.2023.128229
    Enzymatic browning is of concern as it can affect food safety and quality. In this study, an effective and safe tyrosinase inhibitor and anti-browning agent, methyl 4-pyridyl ketone thiosemicarbazone (4-PT), was synthesised and characterised using Fourier-transform infrared (FTIR) spectroscopy, CHNS elemental analysis, and proton (1H) and carbon-13 (13C) nuclear magnetic resonance (NMR) spectroscopy. The vibrational frequencies of 4-PT were studied theoretically using vibrational energy distribution analysis (VEDA). Density functional theory (DFT) was applied to elucidate its chemical properties, including the Mulliken atomic charges, molecular electrostatic potential (MEP), quantum theory of atoms in molecules (QTAIM) and reduced density gradient non-covalent interactions (RDG-NCIs). Moreover, 4-PT was compared with kojic acid in terms of its effectiveness as a tyrosinase inhibitor and anti-browning agent. The toxicity and physicochemical properties of 4-PT were predicted via ADME evaluation, which proved that 4-PT is safer than kojic acid. Experimentally, 4-PT (IC50 = 5.82 μM, browning index (10 days) = 0.292 ± 0.002) was proven to be an effective tyrosinase inhibitor and anti-browning agent compared to kojic acid (IC50 = 128.17 μM, browning index (10 days) = 0.332 ± 0.002). Furthermore, kinetic analyses indicated that the type of tyrosinase inhibition is a mixed inhibition, with Km and Vmax values of 0.85 mM and 2.78 E-09 μM/s, respectively. Finally, the mechanism of 4-PT for tyrosinase inhibition was proven by 1D, second derivative and 2D IR spectroscopy, molecular docking and molecular dynamic simulation approaches.
Related Terms
    Try searching for something
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links