Displaying publications 61 - 80 of 188 in total

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  1. Golbabapour S, Hajrezaie M, Hassandarvish P, Abdul Majid N, Hadi AHA, Nordin N, et al.
    Biomed Res Int, 2018;2018:1509057.
    PMID: 30515386 DOI: 10.1155/2018/1509057
    [This corrects the article DOI: 10.1155/2013/974185.].
  2. Zainal Abidin S, Fam SZ, Chong CE, Abdullah S, Cheah PS, Nordin N, et al.
    Gene, 2019 May 20;697:201-212.
    PMID: 30769142 DOI: 10.1016/j.gene.2019.02.014
    MicroRNA-3099 is highly expressed during neuronal differentiation and development of the central nervous system. Here we characterised the role of miR-3099 during neural differentiation and embryonic brain development using a stable and regulatable mouse embryonic stem cell culture system for miR-3099 expression and in utero electroporation of miR-3099 expression construct into E15.5 embryonic mouse brains. In the in vitro system, miR-3099 overexpression upregulated gene related to neuronal markers such as Tuj1, NeuN, Gat1, vGluT1 and vGluT2. In contrast, gene related to astrocyte markers (Gfap, S100β and Slc1a3) were suppressed upon overexpression of miR-3099. Furthermore, miR-3099 overexpression between E15.5 and E18.5 mouse embryonic brains led to disorganised neuronal migration potentially due to significantly decreased Gfap+ cells. Collectively, our results indicated that miR-3099 plays a role in modulating and regulating expression of key markers involved in neuronal differentiation. In silico analysis was also performed to identify miR-3099 homologues in the human genome, and candidates were validated by stem-loop RT-qPCR. Analysis of the miR-3099 seed sequence AGGCUA against human transcriptomes revealed that a potential miRNA, mds21 (Chr21:39186698-39186677) (GenBank accession ID: MK521584), was 100% identical to the miR-3099 seed sequence. Mds21 expression was observed and validated in various human cell lines (293FT, human Wharton's jelly and dental pulp mesenchymal stem cells, and MCF-7, MDA-MB-231, C-Sert, SW780, RT112, 5637, EJ28 and SH-SY5Y cells), with the highest levels detected in human mesenchymal stem cell lines. The analysis validated mds21 as a novel miRNA and a novel homologue of miR-3099 in the human genome.
  3. Ong YP, Ho LN, Ong SA, Banjuraizah J, Ibrahim AH, Lee SL, et al.
    Chemosphere, 2019 Mar;219:277-285.
    PMID: 30543963 DOI: 10.1016/j.chemosphere.2018.12.004
    Photocatalytic fuel cell (PFC) is considered as a sustainable green technology which could degrade organic pollutant and generate electricity simultaneously. A synergistic double-sided ZnO/BaTiO3 loaded carbon plate heterojunction photoanode was fabricated in different ratios by using simple ultrasonication and mixed-annealed method. The double-sided design of photoanode allowed the lights irradiated at both sides of the photoanode. The ferroelectricity fabricated photoanode was applied in a membraneless PFC with platinum-loaded carbon as the cathode. Results revealed that the photoanode with 1:1 ratio of BaTiO3 and ZnO exhibited a superior photocatalytic activity among all the photoanodes prepared in this study. The heterojunction of this photoanode was able to achieve up to a removal efficiency of 93.67% with a maximum power density of 0.5284 μW cm-2 in 10 mg L-1 of Reactive Red 120 (RR120) without any supporting electrolyte. This photoanode was able to maintain at high performance after recycling 3 times. Overloading of ZnO above 50% on BaTiO3 could lead to deterioration of the performance of PFC due to the charge defects and light trapping ability. The interactions, interesting polarizations of the photocatalysts and proposed mechanism of the n-n type heterojunction in the photoanode of ZnO/BaTiO3 was also discussed.
  4. Lee KW, Ching SM, Hoo FK, Ramachandran V, Chong SC, Tusimin M, et al.
    BMC Pregnancy Childbirth, 2019 Oct 21;19(1):367.
    PMID: 31638930 DOI: 10.1186/s12884-019-2519-9
    BACKGROUND: Research on antenatal depressive, anxiety and stress symptoms among women with gestational diabetes mellitus (GDM) is lacking in Malaysia. This study aimed to determine the prevalence and factors associated with antenatal depressive, anxiety and stress symptoms among Malaysian women with GDM.

    METHODS: This was a descriptive, cross-sectional study of 526 women with GDM. Depressive, anxiety and stress symptoms are defined as the final score in mild to extremely severe risk in the severity rating scale. Data analysis was performed using SPSS v.21, while multiple logistic regression was used to identify predictors of depressive, anxiety and stress symptoms.

    RESULTS: Prevalence of anxiety symptoms was highest (39.9%), followed by depressive symptoms (12.5%) and stress symptoms (10.6%) among women with GDM. According to multiple logistic regression analyses, younger age (OR = 0.955, 95% CI = 0.919-0.993), comorbidity with asthma (OR = 2.436, 95% CI = 1.219-4.870) and a family history of depression and anxiety (OR = 4.782, 95% CI = 1.281-17.853) had significant associations with antenatal anxiety symptoms. Being non-Muslim (OR = 2.937, 95% CI = 1.434-6.018) and having a family history of depression and anxiety (OR = 4.706, 95% CI = 1.362-16.254) had significant associations with antenatal depressive symptoms. Furthermore, being non-Muslim (OR = 2.451, 95% CI = 1.273-4.718) had a significant association with antenatal stress symptoms.

    CONCLUSIONS: Within a population of women with GDM in Malaysia, those at higher risk of having depressive, anxiety and stress symptoms can be identified from several baseline clinical characteristics. Clinicians should be more alert so that the high-risk patients can be referred earlier for further intervention.

  5. Jaafaru MS, Nordin N, Rosli R, Shaari K, Bako HY, Noor NM, et al.
    Biomed Pharmacother, 2019 Nov;119:109445.
    PMID: 31541852 DOI: 10.1016/j.biopha.2019.109445
    The antioxidant and neuroprotective activity of Glucomoringin isothiocyanate (GMG-ITC) have been reported in in vivo and in vitro models of neurodegenerative diseases. However, its neuroprotective role via mitochondrial-dependent pathway in a noxious environment remains unknown. The main objective of the present study was to unveil the mitochondrial apoptotic genes' profile and prospectively link with neuroprotective activity of GMG-ITC through its ROS scavenging. The results showed that pre-treatment of differentiated SH-SY5Y cells with 1.25 μg/mL purified isolated GMG-ITC, significantly reduced reactive oxygen species (ROS) production level, compared to H2O2 control group, as evidenced by flow cytometry-based evaluation of ROS generation. Presence of GMG-ITC prior to development of oxidative stress condition, downregulated the expression of cyt-c, p53, Apaf-1, Bax, CASP3, CASP8 and CASP9 genes with concurrent upregulation of Bcl-2 gene in mitochondrial apoptotic signalling pathway. Protein Multiplex revealed significant decreased in cyt-c, p53, Apaf-1, Bax, CASP8 and CASP9 due to GMG-ITC pre-treatment in oxidative stress condition. The present findings speculated that pre-treatment with GMG-ITC may alleviate oxidative stress condition in neuronal cells by reducing ROS production level and protect the cells against apoptosis via neurodegenerative disease potential pathways.
  6. Muhammad SA, Nordin N, Hussin P, Mehat MZ, Tan SW, Fakurazi S
    Cartilage, 2021 12;13(2_suppl):872S-884S.
    PMID: 31540551 DOI: 10.1177/1947603519876333
    OBJECTIVE: Cartilage tissue engineering has evolved as one of the therapeutic strategies for cartilage defect, which relies on a large number of viable chondrocytes. Because of limited availability of cartilage and low chondrocytes yield from cartilage, the need for an improve isolation protocol for maximum yield of viable cells is a key to achieving successful clinical constructs. This study optimizes and compares different protocols for isolation of chondrocytes from cartilage.

    DESIGN: We employed enzymatic digestion of cartilage using collagenase II and trypsin. The chondrocytes yield, growth kinetics, aggrecan, and collagen type 2 (COL2) expression were evaluated. Collagen type 1 (COL1) mRNA expression was assessed to monitor the possibility of chondrocytes dedifferentiation.

    RESULTS: Chondrocyte yield per gram of cartilage was significantly higher (P < 0.05) using collagenase II in Hank's balanced salt solution (HBSS) compared with 0.25% trypsin. The number of chondrocyte yield per gram was higher in cartilage digested with collagenase in HBSS compared with Dulbecco's modified Eagle medium/F12; however, the difference was not statistically significant. Chondrocytes seeded at lower densities had shorter population doubling time compared to those seeded at higher density. Protein and gene expression of chondrocyte phenotype indicates the expression of aggrecan and COL2. The expression of COL1 was significantly increased (P < 0.05) in passage 3 compared with primary chondrocytes. The mRNA expression of chondrocyte phenotype was similar in primary and passaged one cells.

    CONCLUSIONS: Collagenase in HBSS yield the highest number of viable chondrocytes and the isolated cells expressed chondrocyte phenotype. This protocol can be employed to generate large number of viable chondrocytes, particularly with limited cartilage biopsies.

  7. Azri FA, Selamat J, Sukor R, Yusof NA, Ahmad Raston NH, Nordin N, et al.
    Molecules, 2019 Aug 29;24(17).
    PMID: 31470528 DOI: 10.3390/molecules24173141
    This work presents a simple green synthesis of gold nanoparticles (AuNPs) by using an aqueous extract of Etlingera elatior (torch ginger). The metabolites present in E. elatior, including sugars, proteins, polyphenols, and flavonoids, were known to play important roles in reducing metal ions and supporting the subsequent stability of nanoparticles. The present work aimed to investigate the ability of the E. elatior extract to synthesise AuNPs via the reduction of gold (III) chloride hydrate and characterise the properties of the nanoparticles produced. The antioxidant properties of the E. elatior extract were evaluated by analysing the total phenolic and total flavonoid contents. To ascertain the formation of AuNPs, the synthesised particles were characterised using the ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray (EDX) microscopy, and dynamic light scattering (DLS) measurement. The properties of the green synthesised AuNPs were shown to be comparable to the AuNPs produced using a conventional reducing agent, sodium citrate. The UV-Vis measured the surface plasmon resonance of the AuNPs, and a band centered at 529 nm was obtained. The FTIR results proved that the extract contained the O-H functional group that is responsible for capping the nanoparticles. The HRTEM images showed that the green synthesized AuNPs were of various shapes and the average of the nanoparticles' hydrodynamic diameter was 31.5 ± 0.5 nm. Meanwhile, the zeta potential of -32.0 ± 0.4 mV indicates the high stability and negative charge of the AuNPs. We further successfully demonstrated that using the green synthesised AuNPs as the nanocomposite to modify the working surface of screen-printed carbon electrode (SPCE/Cs/AuNPs) enhanced the rate of electron transfer and provided a sensitive platform for the detection of Cu(II) ions.
  8. Fakiruddin KS, Lim MN, Nordin N, Rosli R, Zakaria Z, Abdullah S
    Cancers (Basel), 2019 08 28;11(9).
    PMID: 31466290 DOI: 10.3390/cancers11091261
    Mesenchymal stem cells (MSCs) are emerging as vehicles for anti-tumor cytotherapy; however, investigation on its efficacy to target a specific cancer stem cell (CSC) population in non-small cell lung cancer (NSCLC) is lacking. Using assays to evaluate cell proliferation, apoptosis, and gene expression, we investigated the efficacy of MSCs expressing tumour necrosis factor (TNF)-related apoptosis inducing ligand (MSC-TRAIL) to target and destroy CD133+ (prominin-1 positive) NSCLC-derived CSCs. Characterization of TRAIL death receptor 5 (DR5) revealed that it was highly expressed in the CD133+ CSCs of both H460 and H2170 cell lines. The human MSC-TRAIL generated in the study maintained its multipotent characteristics, and caused significant tumor cell inhibition in NSCLC-derived CSCs in a co-culture. The MSC-TRAIL induced an increase in annexin V expression, an indicator of apoptosis in H460 and H2170 derived CD133+ CSCs. Through investigation of mitochondria membrane potential, we found that MSC-TRAIL was capable of inducing intrinsic apoptosis to the CSCs. Using pathway-specific gene expression profiling, we uncovered candidate genes such as NFKB1, BAG3, MCL1, GADD45A, and HRK in CD133+ CSCs, which, if targeted, might increase the sensitivity of NSCLC to MSC-TRAIL-mediated inhibition. As such, our findings add credibility to the utilization of MSC-TRAIL for the treatment of NSCLC through targeting of CD133+ CSCs.
  9. Mansor NI, Nordin N, Mohamed F, Ling KH, Rosli R, Hassan Z
    Curr Drug Deliv, 2019;16(8):698-711.
    PMID: 31456519 DOI: 10.2174/1567201816666190828153017
    Many drugs have been designed to treat diseases of the central nervous system (CNS), especially neurodegenerative diseases. However, the presence of tight junctions at the blood-brain barrier has often compromised the efficiency of drug delivery to target sites in the brain. The principles of drug delivery systems across the blood-brain barrier are dependent on substrate-specific (i.e. protein transport and transcytosis) and non-specific (i.e. transcellular and paracellular) transport pathways, which are crucial factors in attempts to design efficient drug delivery strategies. This review describes how the blood-brain barrier presents the main challenge in delivering drugs to treat brain diseases and discusses the advantages and disadvantages of ongoing neurotherapeutic delivery strategies in overcoming this limitation. In addition, we discuss the application of colloidal carrier systems, particularly nanoparticles, as potential tools for therapy for the CNS diseases.
  10. Shoesmith W, Awang Borhanuddin AFB, Pereira EJ, Nordin N, Giridharan B, Forman D, et al.
    BJPsych Open, 2019 Dec 12;6(1):e4.
    PMID: 31829292 DOI: 10.1192/bjo.2019.92
    BACKGROUND: The systems that help people with mental disorders in Malaysia include hospitals, primary care, traditional and religious systems, schools and colleges, employers, families and other community members.

    AIMS: To better understand collaboration between and within these systems and create a theoretical framework for system development.

    METHOD: A total of 26 focus groups and 27 individual interviews were undertaken with patients, carers, psychiatric hospital staff, primary care and district hospital staff, religious and traditional healers, community leaders, non-governmental organisation workers, and school and college counsellors. Grounded theory methods were used to analyse the data and create a theory of collaboration.

    RESULTS: Three themes both defined and enabled collaboration: (a) collaborative behaviours; (b) motivation towards a common goal or value; and (c) autonomy. Three other enablers of collaboration were identified: (d) relatedness (for example trusting, understanding and caring about the other); (e) resources (competence, time, physical resources and opportunities); and (f) motivation for collaboration (weighing up the personal costs versus benefits of acting collaboratively).

    CONCLUSIONS: The first three themes provided a definition of collaboration in this context: 'two or more parties working together towards a common goal or value, while maintaining autonomy'. The main barriers to collaboration were lack of autonomy, relatedness, motivation and resources, together with the potential cost of acting collaboratively without reciprocation. Finding ways to change these structural, cultural and organisational features is likely to improve collaboration in this system and improve access to care and outcomes for patients.

  11. Hanis TM, Yaacob NM, Hairon SM, Abdullah S, Nordin N, Abdullah NH, et al.
    BMC Public Health, 2019 Dec 30;19(1):1754.
    PMID: 31888561 DOI: 10.1186/s12889-019-8113-2
    BACKGROUND: Measurement of breast cancer burden and identification of its influencing factors help in the development of public health policy and strategy against the disease. This study aimed to examine the variability of the excess mortality of female breast cancer patients in the North East Region of Peninsular Malaysia.

    METHODS: This retrospective cohort study was conducted using breast cancer data from the Kelantan Cancer Registry between 2007 and 2011, and Kelantan general population mortality data. The breast cancer cases were followed up for 5 years until 2016. Out of 598 cases, 549 cases met the study criteria and were included in the analysis. Modelling of excess mortality was conducted using Poisson regression.

    RESULTS: Excess mortality of breast cancer varied according to age group (50 years old and below vs above 50 years old, Adj. EHR: 1.47; 95% CI: 1.31, 4.09; P = 0.004), ethnicity (Malay vs non-Malay, Adj. EHR: 2.31; 95% CI: 1.11, 1.96; P = 0.008), and stage (stage III and IV vs. stage I and II, Adj. EHR: 5.75; 95% CI: 4.24, 7.81; P 

  12. Shapi'i RA, Othman SH, Nordin N, Kadir Basha R, Nazli Naim M
    Carbohydr Polym, 2020 Feb 15;230:115602.
    PMID: 31887886 DOI: 10.1016/j.carbpol.2019.115602
    Chitosan nanoparticles (CNP) were synthesized via ionic gelation and used for the preparation of starch-based nanocomposite films containing different concentration of CNP (0, 5, 10, 15, 20% w/w). Antimicrobial properties of starch/CNP films was evaluated via in vitro (disc diffusion analysis) and in vivo (microbial count in wrapped cherry tomatoes) study. It was found that inhibitory zone of the 15 and 20% of starch/CNP films were clearly observed for all the tested bacteria including Bacillus cereus, Staphylococcus aureus, Escherichia coli and Salmonella typhimurium. In vivo study revealed that the starch/CNP film (15% w/w) was more efficient to inhibit the microbial growth in cherry tomatoes (7 × 102 CFU/g) compared to neat starch film (2.15 × 103 CFU/g) thus confirmed the potential application of the films as antimicrobial food packaging.
  13. Nordin N, Ho LN, Ong SA, Ibrahim AH, Abdul Rani AL, Lee SL, et al.
    Chemosphere, 2020 Apr;244:125459.
    PMID: 31790991 DOI: 10.1016/j.chemosphere.2019.125459
    The hybrid electrochemical system of photocatalytic fuel cell - peroxi-coagulation (PFC-PC) is a combined technology of advanced oxidation process (AOP) which involve the hydroxyl radical formation for simultaneous degradation of organic pollutant and electricity generation. The p-nitrosodimethylaniline (RNO) spin trapping technique was applied by analyzing the RNO bleaching performance to detect the OH at the PFC and PC reactors. The presence of UV light showed higher RNO bleaching rate at the PFC reactor (11.7%) with maximum power density (Pmax = 3.14 mW cm-2). Results revealed that the optimum of maximum power density was observed at iron plate size of 30 cm2. UV light became a limiting factor in the PFC system as a power source in the PFC-PC system. Meanwhile, iron plate plays an important role to supply the soluble Fe2+ ions by oxidation process and become a suitable catalyst for in-situ production of H2O2 and OH through the PC process to degrade the organic molecules.
  14. Lee KW, Ching SM, Ramachandran V, Tusimin M, Mohd Nordin N, Chong SC, et al.
    Genes (Basel), 2019 11 30;10(12).
    PMID: 31801286 DOI: 10.3390/genes10120988
    The association of candidate genes and psychological symptoms of depression, anxiety, and stress among women with gestational diabetes mellitus (GDM) in Malaysia was determined in this study, followed by the determination of their odds of getting psychological symptoms, adjusted for socio-demographical background, maternal, and clinical characteristics. Single nucleotide polymorphisms (SNPs) recorded a significant association between SNP of EPHX2 (rs17466684) and depression symptoms (AOR = 7.854, 95% CI = 1.330-46.360) and stress symptoms (AOR = 7.664, 95% CI = 1.579-37.197). Associations were also observed between stress symptoms and SNP of OXTR (rs53576) and (AOR = 2.981, 95% CI = 1.058-8.402) and SNP of NRG1 (rs2919375) (AOR = 9.894, 95% CI = 1.159-84.427). The SNP of EPHX2 (rs17466684) gene polymorphism is associated with depression symptoms among Malaysian women with GDM. SNP of EPHX2 (rs17466684), OXTR (rs53576) and NRG1 (rs2919375) are also associated with stress symptoms.
  15. Omar NH, Mohd Nordin NA, Chai SC, Abdul Aziz AF
    Med J Malaysia, 2020 03;75(2):146-151.
    PMID: 32281596
    INTRODUCTION: There is scarcity of research information on upper limb (UL) functionality among Malaysian post-stroke population despite the increasing number of stroke survivors. This study intends to evaluate functionality among stroke survivors residing in the community, with a specific focus on the UL.

    METHODS: This cross-sectional study involved 65 stroke survivors with UL dysfunction (mean (SD) age = 64.83 (8.05) years, mean (SD) post-stroke duration 41.62 (35.24) months) who attended community-based rehabilitation program. Upper limb functionality was assessed using the UL items of Stroke Specific Quality of Life Scale (SSQOL), the Lawton Instrumental Activities of Daily Living (IADL) Scale and the Jebsen-Taylor Hand Function Test (JTHFT). The stroke survivors' performance in completing JTHFT using their affected dominant hand was compared with standard norms.

    RESULTS: The three most affected UL daily living tasks were writing (64.7%, n=42), opening a jar (63.1%, n=41) and putting on socks (58.5%, n=38). As for IADL, the mean (SD) score of Lawton scale was 3.26 (2.41), with more than 50% unable to handle finance, do the laundry and prepare meals for themselves. Performances of stroke survivors were much slower than normal population in all tasks of JTHFT (p<0.05), with largest speed difference demonstrated for 'stacking objects' task (mean difference 43.24 secs (p=0.003) and 24.57 (p<0.001) in males and females, respectively.

    CONCLUSION: UL functions are significantly impaired among stroke survivors despite undergoing rehabilitation. Rehabilitation professionals should prioritize highly problematic tasks when retraining UL for greater post-stroke functionality.

  16. Nordin N, Mohd Hairon S, Yaacob NM, Abdul Hamid A, Hassan N
    PMID: 32182755 DOI: 10.3390/ijerph17051765
    The implementation of Family Doctor Concept (FDC) to restructure the primary healthcare systems in Malaysia were expected to enhance patient's satisfaction on doctor-patient interaction and subsequently improved glycaemic control among Type 2 Diabetes Mellitus (T2DM) patients. Thus, this study aims to determine the difference in doctor-patient interaction satisfaction between T2DM patients attended FDC-implemented clinic vs non-FDC clinics, and to determine the association between FDC-implemented clinic and doctor-patient interaction satisfaction towards glycaemic control. A cross-sectional study was conducted throughout 10 districts in Kelantan from February until May 2019 using interview-guided Skala Kepuasan Interaksi Perubatan-11 (SKIP-11) and proforma checklist. Data were analyzed using SPSS ver.24. Chi-square statistic used to determine the difference in doctor-patient interaction satisfaction between both clinics type. Multiple logistic regression used to examine the association between FDC-implemented clinic and doctor-patient interaction satisfaction towards glycaemic control. Twenty primary health clinics involved, and 772 T2DM patients recruited. FDC clinics attendees has higher proportion of satisfaction (40.1%) compared to non-FDC attendees (33.7%) (p = 0.070). Multiple logistic regression confirmed the association of FDC-implemented health clinics (Adj. OR 1.63, p = 0.021), and doctor-patients interaction satisfaction (Adj. OR 1.77, p = 0.005) towards glycaemic control. Hence, strengthening of FDC in primary healthcare and improve the doctor-patient interaction satisfaction were essential to escalate good glycaemic control.
  17. Talib MHN, Ibrahim Z, Abd Rahim N, Zulhani R, Nordin N, Farah N, et al.
    ISA Trans, 2020 Oct;105:230-239.
    PMID: 32475537 DOI: 10.1016/j.isatra.2020.05.040
    Fuzzy Logic Speed Controller (FLSC) has been widely used for motor drive due to its robustness and its non-reliance to real plant parameters. However, it is computationally expensive to be implemented in real-time and prone to the fuzzy rules' selection error which results in the failure of the drive's system. This paper proposes an improved simplified rules method for Fuzzy Logic Speed Controller (FLSC) based on the significant crisp output calculations to address these issues. A systematic procedure for the fuzzy rules reduction process is first described. Then, a comprehensive evaluation of the activated crisp output data is presented to determine the fuzzy dominant rules. Based on the proposed method, the number of rules was significantly reduced by 72%. The simplified FLSC rule is tested on the Induction Motor (IM) drives system in which the real-time implementation was carried out in the dSPACE DS1103 controller environment. The simulation and experimental results based on the proposed FLSC have proved the workability of the simplified rules without degrading the motor performance.
  18. Davoodi H, Nordin N, Bordonali L, Korvink JG, MacKinnon N, Badilita V
    Lab Chip, 2020 08 26;20(17):3202-3212.
    PMID: 32734975 DOI: 10.1039/d0lc00364f
    Combining microfluidic devices with nuclear magnetic resonance (NMR) has the potential of unlocking their vast sample handling and processing operation space for use with the powerful analytics provided by NMR. One particularly challenging class of integrated functional elements from the perspective of NMR are conductive structures. Metallic electrodes could be used for electrochemical sample interaction for example, yet they can cause severe NMR spectral and SNR degradation. These issues are more entangled at the micro-scale since the distorted volume occupies a higher ratio of the sample volume. In this study, a combination of simulation and experimental validation was used to identify an electrode geometry that, in terms of NMR spectral parameters, performs as well as for the case when no electrodes are present. By placing the metal tracks in the side-walls of a microfluidic channel, we found that NMR RF excitation performance was actually enhanced, without compromising B0 homogeneity. Monitoring in situ deposition of chitosan in the microfluidic platform is presented as a proof-of-concept demonstration of NMR characterisation of an electrochemical process.
  19. Peter Mshelia L, Selamat J, Iskandar Putra Samsudin N, Rafii MY, Abdul Mutalib NA, Nordin N, et al.
    Toxins (Basel), 2020 07 28;12(8).
    PMID: 32731333 DOI: 10.3390/toxins12080478
    Climate change is primarily manifested by elevated temperature and carbon dioxide (CO2) levels and is projected to provide suitable cultivation grounds for pests and pathogens in the otherwise unsuitable regions. The impacts of climate change have been predicted in many parts of the world, which could threaten global food safety and food security. The aim of the present work was therefore to examine the interacting effects of water activity (aw) (0.92, 0.95, 0.98 aw), CO2 (400, 800, 1200 ppm) and temperature (30, 35 °C and 30, 33 °C for Fusarium verticillioides and F. graminearum, respectively) on fungal growth and mycotoxin production of acclimatised isolates of F. verticillioides and F. graminearum isolated from maize. To determine fungal growth, the colony diameters were measured on days 1, 3, 5, and 7. The mycotoxins produced were quantified using a quadrupole-time-of-flight mass spectrometer (QTOF-MS) combined with ultra-high-performance liquid chromatography (UHPLC) system. For F. verticillioides, the optimum conditions for growth of fumonisin B1 (FB1), and fumonisin B2 (FB2) were 30 °C + 0.98 aw + 400 ppm CO2. These conditions were also optimum for F. graminearum growth, and zearalenone (ZEA) and deoxynivalenol (DON) production. Since 30 °C and 400 ppm CO2 were the baseline treatments, it was hence concluded that the elevated temperature and CO2 levels tested did not seem to significantly impact fungal growth and mycotoxin production of acclimatised Fusarium isolates. To the best of our knowledge thus far, the present work described for the first time the effects of simulated climate change conditions on fungal growth and mycotoxin production of acclimatised isolates of F. verticillioides and F. graminearum.
  20. Alhaji SY, Nordin N, Ngai SC, Al Abbar A, Mei L, Abdullah S
    Gene, 2020 Oct 20;758:144958.
    PMID: 32683073 DOI: 10.1016/j.gene.2020.144958
    Short-lived therapeutic gene expression in mammalian cells by DNA methylation is one of the major challenges in gene therapy. In this study, we assessed the implication of DNA methylation on the duration of GFP expression in mouse embryonic stem (ES) and mouse induced pluripotent stem (iPS) cells. The cells were transduced with lentivirus (LV) carrying green fluorescent protein (GFP) driven by either human elongation factor (EF1α) or cytomegalovirus (CMV) promoter. Transduced iPS cells exhibited higher percentage of GFP+ cells with persistent mean fluorescent intensity than transduced ES cells. Analysis on the integrated copy of transgene in the population of the transduced cells demonstrated similar copy number. However, significant increase in GFP intensity following 5-azaC treatment was observed in transduced ES cells only, suggesting the influence of DNA methylation in transgene silencing. Subsequent DNA methylation analysis showed that the promoter and the GFP region of the provirus in iPS cells had negligible methylation profile compared to transduced ES cells. Interestingly, sustained transgene expression was observed upon directed differentiation of transduced iPS cells towards CD34+ CD45+ cells. Hence, this study has shown that favourable transgene activity from lentiviral transduced iPS cells was due to the lack of methylation at the proviral regions.
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