Displaying publications 1 - 20 of 35 in total

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  1. 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).
  2. Shahzad F, Jamshed W, Eid MR, Safdar R, Putri Mohamed Isa SS, El Din SM, et al.
    Sci Rep, 2022 Nov 17;12(1):19817.
    PMID: 36396776 DOI: 10.1038/s41598-022-24294-3
    Solar radiation, which is emitted by the sun, is required to properly operate photovoltaic cells and solar water pumps (SWP). A parabolic trough surface collector (PTSC) installation model was created to investigate the efficacy of SWP. The thermal transfer performance in SWP is evaluated thru the presence of warmth radiation and heat cause besides viscid dissipation. This evaluation is performed by measuring the thermal transmission proportion of the selected warmth transmission liquid in the PTSC, known as a hybrid nano-fluid. Entropy analysis of Oldroyd-B hybrid nano-fluid via modified Buongiorno's model was also tested. The functions of regulating parameters are quantitatively observed by using the Keller-box approach in MATLAB coding. Short terms define various parameters for tables in velocity, shear pressure and temperature, gravity, and Nusselt numbers. In the condition of thermal radiation and thermal conductivity at room temperature, the competence of SWP is proven to be enhanced. Unlike basic nano-fluids, hybrid nano-fluids are an excellent source of heat transfer. Additionally, with at least 22.56% and 35.01% magnitude, the thermal efficiency of AA7075-Ti-6Al-4 V/EO is higher than AA7075-EO.
  3. 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 
  4. 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.
  5. Ang SP, Chia JE, Jaiswal V, Bandyopadhyay D, Iglesias J, Mohan GVK, et al.
    Curr Probl Cardiol, 2023 Aug;48(8):101719.
    PMID: 36967069 DOI: 10.1016/j.cpcardiol.2023.101719
    While subclinical hypothyroidism (SCH) was reportedly associated with an increased risk of cardiovascular mortality, the relationship between SCH and clinical outcomes of patients undergoing percutaneous coronary intervention (PCI) is uncertain. The aim of this study was to assess the association of SCH and cardiovascular outcomes in patients undergoing PCI. We searched PubMed, Embase, Scopus, and CENTRAL databases from its inception until April 1, 2022 for studies comparing the outcomes between SCH and euthyroid patients undergoing PCI. Outcomes of interest include cardiovascular mortality, all-cause mortality, myocardial infarction (MI), major adverse cardiovascular and cerebrovascular events (MACCE), repeat revascularization and heart failure. Outcomes were pooled using the DerSimonian and Laird random-effects model and reported as risk ratios (RR) and 95% confidence intervals (CI). A total of 7 studies involving 1132 patients with SCH and 11,753 euthyroid patients were included in the analysis. Compared with euthyroid patients, patients with SCH had significantly higher risk of cardiovascular mortality (RR 2.16, 95% CI: 1.38-3.38, P < 0.001), all-cause mortality (RR 1.68, 95% CI: 1.23-2.29, P = 0.001) and repeat revascularization (RR 1.96, 95% CI: 1.08-3.58, P = 0.03). However, there were no differences between both groups in terms of incidence of MI (RR 1.81, 95% CI: 0.97-3.37, P = 0.06), MACCE (RR 2.24, 95% CI: 0.55-9.08, P = 0.26) and heart failure (RR 5.38, 95% CI: 0.28-102.35, P = 0.26). Our analysis suggests among patients undergoing PCI, SCH was associated with increased risk of cardiovascular mortality, all-cause mortality and repeat revascularization compared to euthyroid patients.
  6. 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.
  7. 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.

  8. Ebadi M, Asikin-Mijan N, Md Jamil MS, Iqbal A, Yousif E, Md Zain AR, et al.
    Polymers (Basel), 2023 Jan 01;15(1).
    PMID: 36616581 DOI: 10.3390/polym15010232
    Although metallic nanocatalysts such as palladium nanoparticles (Pd NPs) are known to possess higher catalytic activity due to their large surface-to-volume ratio, however, in nanosize greatly reducing their activity due to aggregation. To overcome this challenge, superparamagnetic chitosan-coated manganese ferrite was successfully prepared and used as a support for the immobilization of palladium nanoparticles to overcome the above-mentioned challenge. The Pd-Chit@MnFe2O4 catalyst exhibited high catalytic activity in 4-nitrophenol and 4-nitroaniline reductions, with respective turnover frequencies of 357.1 min-1 and 571.4 min-1, respectively. The catalyst can also be recovered easily by magnetic separation after each reaction. Additionally, the Pd-Chit@MnFe2O4 catalyst performed well in the reductive deprotection of allyl carbamate. Coating the catalyst with chitosan reduced the Pd leaching and its cytotoxicity. Therefore, the catalytic activity of Pd-Chit@MnFe2O4 was proven to be unrestricted in biology conditions.
  9. Iqbal A, Rutter V, Gülpınar G, Halai M, Awele B, Elshenawy RA, et al.
    J Pharm Policy Pract, 2021 Dec 27;14(1):112.
    PMID: 34961548 DOI: 10.1186/s40545-021-00396-7
    BACKGROUND: The Commonwealth Pharmacists Association (CPA) is a charity representing pharmacists across the Commonwealth, with the vision of empowering and collaboratively develop the profession and fully utilise the potential of pharmacists to strengthen health systems through supporting better access to, quality and use of medicines and related services. Commonwealth comprises predominantly of low- and middle-income countries, where limited data often exists in pharmacy practice. There is a recognised need across the Commonwealth to focus on developing, implementing and fully utilising pharmacy professional services to progress universal health coverage and achieve the sustainable development goals, particularly in low and middle-income countries; however, currently a knowledge gap exists in understanding the national priorities in Commonwealth nations. CPA is ideally positioned to access to these nations. The aim of this study was thus to explore the priorities and focus areas of NPAs across the Commonwealth and create evidence for a needs-based approach to inform the support that the Commonwealth pharmacists association can collaboratively and strategically provide to its members to progress towards shared goals.

    METHODS: Data were collected virtually on Zoom by conducting interviews using a semi-structured interview guide developed for this study with CPA councillors representing NPAs or their equivalents if no official body existed. An inductive, reflexive, thematic analysis was performed for data analysis.

    RESULTS: In total, 30 councillors were interviewed from 30 low- and medium-income countries. The three main overarching priority areas identified across respective Commonwealth nations developing extended pharmacy services, improving pharmacy education, and developing and redefining the role of NPAs.

    CONCLUSIONS: This novel study highlights the collective priorities for the pharmacy profession across the low and middle-income countries of the Commonwealth and the urgent need for supporting NPAs around the three identified overarching priority areas. The mapped-out priorities will inform an evidence-based approach for the CPA to better support NPAs in their mission through advocacy and practitioner development, to fully harness pharmacists' unique skill set and maximise their contribution to progressing universal health coverage.

  10. 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. 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.
  12. Amin M, Shah HH, Naveed AB, Iqbal A, Gamil Y, Najeh T
    Front Chem, 2024;12:1374739.
    PMID: 38601886 DOI: 10.3389/fchem.2024.1374739
    The iron-based biomass-supported catalyst has been used for Fischer-Tropsch synthesis (FTS). However, there is no study regarding the life cycle assessment (LCA) of biomass-supported iron catalysts published in the literature. This study discusses a biomass-supported iron catalyst's LCA for the conversion of syngas into a liquid fuel product. The waste biomass is one of the source of activated carbon (AC), and it has been used as a support for the catalyst. The FTS reactions are carried out in the fixed-bed reactor at low or high temperatures. The use of promoters in the preparation of catalysts usually enhances C5+ production. In this study, the collection of precise data from on-site laboratory conditions is of utmost importance to ensure the credibility and validity of the study's outcomes. The environmental impact assessment modeling was carried out using the OpenLCA 1.10.3 software. The LCA results reveals that the synthesis process of iron-based biomass supported catalyst yields a total impact score in terms of global warming potential (GWP) of 1.235E + 01 kg CO2 equivalent. Within this process, the AC stage contributes 52% to the overall GWP, while the preparation stage for the catalyst precursor contributes 48%. The comprehensive evaluation of the iron-based biomass supported catalyst's impact score in terms of human toxicity reveals a total score of 1.98E-02 kg 1,4-dichlorobenzene (1,4-DB) equivalent.
  13. Shittu FB, Iqbal A, Ahmad MN, Yusop MR, Ibrahim MNM, Sabar S, et al.
    RSC Adv, 2022 Mar 31;12(17):10409-10423.
    PMID: 35424996 DOI: 10.1039/d2ra00995a
    Oxygen doped mesoporous carbon nitride (O-MCN) was successfully synthesized through one-step thermal polymerization of urea and glucose utilizing nanodisc silica (NDS) from rice husk ash as a hard template. The CO2 gas, NH3 and water vapor produced during the thermal process reshaped the morphology and textural properties of the of O-MCN compared to pristine mesoporous carbon nitride (MCN). Highest bisphenol A (BPA) removal achieved under visible light irradiation was 97%, with 60% mineralization ([BPA] = 10 mg L-1: catalyst dosage = 40 mg L-1; pH = 10; 180 min). In addition to mesoporosity, the sub-gap impurity states created from the oxygen doping reduced recombination rate of photogenerated carriers. Holes (h+) and superoxide (O2˙-) were identified as the predominant active species responsible for the photodegradation process. The photodegradation route was proposed based on the intermediates detected by LC-time-of-flight/mass spectrometry (LC/TOF-MS). The Density of States (DOS) showed that oxygen doping resulted in a higher photoactivity due to the stronger localization and delocalization of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). The adsorption pathway of the BPA on the O-MCN and MCN was successfully predicted using the DFT calculations, namely molecular electrostatic potential (MEP), global and local descriptors.
  14. Ali I, Wei DQ, Khan A, Feng Y, Waseem M, Hussain Z, et al.
    Biotechnol Appl Biochem, 2024 Apr;71(2):402-413.
    PMID: 38287712 DOI: 10.1002/bab.2548
    Malonyl-CoA serves as the main building block for the biosynthesis of many important polyketides, as well as fatty acid-derived compounds, such as biofuel. Escherichia coli, Corynebacterium gultamicum, and Saccharomyces cerevisiae have recently been engineered for the biosynthesis of such compounds. However, the developed processes and strains often have insufficient productivity. In the current study, we used enzyme-engineering approach to improve the binding of acetyl-CoA with ACC. We generated different mutations, and the impact was calculated, which reported that three mutations, that is, S343A, T347W, and S350W, significantly improve the substrate binding. Molecular docking investigation revealed an altered binding network compared to the wild type. In mutants, additional interactions stabilize the binding of the inner tail of acetyl-CoA. Using molecular simulation, the stability, compactness, hydrogen bonding, and protein motions were estimated, revealing different dynamic properties owned by the mutants only but not by the wild type. The findings were further validated by using the binding-free energy (BFE) method, which revealed these mutations as favorable substitutions. The total BFE was reported to be -52.66 ± 0.11 kcal/mol for the wild type, -55.87 ± 0.16 kcal/mol for the S343A mutant, -60.52 ± 0.25 kcal/mol for T347W mutant, and -59.64 ± 0.25 kcal/mol for the S350W mutant. This shows that the binding of the substrate is increased due to the induced mutations and strongly corroborates with the docking results. In sum, this study provides information regarding the essential hotspot residues for the substrate binding and can be used for application in industrial processes.
  15. Shrestha S, Iqbal A, Teoh SL, Khanal S, Gan SH, Lee SWH, et al.
    Res Social Adm Pharm, 2024 Mar 13.
    PMID: 38514293 DOI: 10.1016/j.sapharm.2024.03.005
    INTRODUCTION: Pain is a significant healthcare challenge, impacting millions worldwide. Pharmacists have increasingly taken on expanded roles in managing pain, particularly in primary and ambulatory care contexts. This umbrella review aims to systematically evaluate evidence from published systematic reviews that explore the impact of pharmacist-delivered interventions on clinical, humanistic, and economic outcomes related to pain.

    METHODS: A systematic search was conducted across six electronic databases, including Ovid Embase, MEDLINE, CINAHL, Scopus, CENTRAL, APA PsycINFO, and DARE, from inception until June 2023. Prior to inclusion, two independent reviewers assessed study titles and abstracts. Following inclusion, an assessment of the methodological quality of the included studies was conducted. AMSTAR 2 was used to evaluate the methodological quality of the included SRs.

    RESULTS: From 2055 retrieved titles, 11 systematic reviews were included, with 5 out of 11 being meta-analyses. These SRs encompassed diverse pharmacist-led interventions such as education, medication reviews, and multi-component strategies targeting various facets of pain management. These findings showed favorable clinical outcomes, including reduced pain intensity, improved medication management, enhanced overall physical and mental well-being, and reduced hospitalization durations. Significant pain intensity reductions were found due to pharmacists' interventions, with standardized mean differences (SMDs) ranging from -0.76 to -0.22 across different studies and subgroups. Physical functioning improvements were observed, with SMDs ranging from -0.38 to 1.03. Positive humanistic outcomes were also reported, such as increased healthcare provider confidence, patient satisfaction, and quality of life (QoL). QoL improvements were reported, with SMDs ranging from 0.29 to 1.03. Three systematic reviews examined pharmacist interventions' impact on pain-related economic outcomes, highlighting varying cost implications and the need for robust research methodologies to capture costs and benefits.

    CONCLUSION: This umbrella review highlights the effectiveness of pharmacist-delivered interventions in improving clinical, humanistic, and economic outcomes related to pain management. Existing evidence emphasises on the need to integrate pharamacists into multi-disciplinary pain management teams. Further research is needed to investigate innovative care models, such as pharmacist-independent prescribing initiatives within collaborative pain management clinics.

  16. 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.
  17. 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).
  18. Lim YA, Iqbal A, Surin J, Sim BL, Jex AR, Nolan MJ, et al.
    Infect Genet Evol, 2011 Jul;11(5):968-74.
    PMID: 21439404 DOI: 10.1016/j.meegid.2011.03.007
    Given the HIV epidemic in Malaysia, genetic information on opportunistic pathogens, such as Cryptosporidium and Giardia, in HIV/AIDS patients is pivotal to enhance our understanding of epidemiology, patient care, management and disease surveillance. In the present study, 122 faecal samples from HIV/AIDS patients were examined for the presence of Cryptosporidium oocysts and Giardia cysts using a conventional coproscopic approach. Such oocysts and cysts were detected in 22.1% and 5.7% of the 122 faecal samples, respectively. Genomic DNAs from selected samples were tested in a nested-PCR, targeting regions of the small subunit (SSU) of nuclear ribosomal RNA and the 60kDa glycoprotein (gp60) genes (for Cryptosporidium), and the triose-phosphate isomerase (tpi) gene (for Giardia), followed by direct sequencing. The sequencing of amplicons derived from SSU revealed that Cryptosporidium parvum was the most frequently detected species (64% of 25 samples tested), followed by C. hominis (24%), C. meleagridis (8%) and C. felis (4%). Sequencing of a region of gp60 identified C. parvum subgenotype IIdA15G2R1 and C. hominis subgenotypes IaA14R1, IbA10G2R2, IdA15R2, IeA11G2T3R1 and IfA11G1R2. Sequencing of amplicons derived from tpi revealed G. duodenalis assemblage A, which is of zoonotic importance. This is the first report of C. hominis, C. meleagridis and C. felis from Malaysian HIV/AIDS patients. Future work should focus on an extensive analysis of Cryptosporidium and Giardia in such patients as well as in domestic and wild animals, in order to improve the understanding of transmission patterns and dynamics in Malaysia. It would also be particularly interesting to establish the relationship among clinical manifestation, CD4 cell counts and genotypes/subgenotypes of Cryptosporidium and Giardia in HIV/AIDS patients. Such insights would assist in a better management of clinical disease in immuno-deficient patients as well as improved preventive and control strategies.
  19. 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.
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