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  1. Wong YM, Siow LF
    J Food Sci Technol, 2015 May;52(5):3086-92.
    PMID: 25892813 DOI: 10.1007/s13197-014-1362-2
    Red-fleshed dragon fruit (Hylocereus polyrhizus) is rich in antioxidants. The aim of this study was to determine the effects of heat pasteurization, pH adjustment, ascorbic acid addition as well as storage under agitation and light or dark condition on betacyanin content in red-fleshed dragon fruit (Hylocereus polyrhizus) juice and concentrate. The concentrate was produced by concentrating clarified red-fleshed dragon fruit juice in a rotary evaporator at 40 °C. UV-Visible spectrophotometer was used for analyzing betacyanin content. Addition of 0.25 % ascorbic acid, pH 4.0, and pasteurization at 65 °C for 30 min were selected as the best processing conditions to retain betacyanin content in red-fleshed dragon fruit juice. Storage at the agitation speed of 220 rpm showed that the concentrated samples had higher betacyanin stability compared to juice, while both juice and concentrate had almost similar betacyanin stability when tested for storage in the presence of light. In summary, ascorbic acid stabilized betacyanin in both juice and concentrate at agitated or non-agitated conditions. In contrast, light degraded betacyanin in both juice and concentrate models.
  2. Chow TWP, Wong YM
    Med J Malaysia, 2001 Dec;56(4):418-27.
    PMID: 12014760
    Thromboembolic disease remains an important cause of maternal mortality worldwide. The risk assessments for prevention of thromboembolism in pregnancy are controversial due to lack of large-scale randomised controlled trials. Unfractionated heparin is at present, the anticoagulant of choice during pregnancy. However, it may be superseded by low-molecular-weight heparin in the near future because of its safety and efficacy.
  3. Wong YM, Juan JC, Gan HM, Austin CM
    Genome Announc, 2014;2(2).
    PMID: 24604639 DOI: 10.1128/genomeA.00077-14
    Clostridium bifermentans strain WYM is an effective biohydrogen producer isolated from landfill leachate sludge. Here, we present the assembly and annotation of its genome, which may provide further insights into the metabolic pathways involved in efficient biohydrogen production.
  4. Wong YM, Juan JC, Gan HM, Austin CM
    Genome Announc, 2014;2(2).
    PMID: 24604637 DOI: 10.1128/genomeA.00064-14
    Clostridium perfringens strain JJC is an effective biohydrogen and biochemical producer that was isolated from landfill leachate sludge. Here, we present the assembly and annotation of its genome, which may provide further insights into the gene interactions involved in efficient biohydrogen production.
  5. Wong YM, Masunaga H, Chuah JA, Sudesh K, Numata K
    Biomacromolecules, 2016 Oct 10;17(10):3375-3385.
    PMID: 27642764
    Amyloid fibers are classified as a new generation of tunable bionanomaterials that exhibit new functions related to their distinctive characteristics, such as their universality, tunability, and stiffness. Here, we introduce the catalytic residues of serine protease into a peptide catalyst (PC) via an enzyme-mimic approach. The rational design of a repeating pattern of polar and nonpolar amino acids favors the conversion of the peptides into amyloid-like fibrils via self-assembly. Distinct fibrous morphologies have been observed at different pH values and temperatures, which indicates that different fibril packing schemes can be designed; hence, fibrillar peptides can be used to generate efficient artificial catalysts for amidolytic activities at mild pH values. The results of atomic force microscopy, Raman spectroscopy, and wide-angle X-ray scattering analyses are used to discuss and compare the fibril structure of a fibrillar PC with its amidolytic activity. The pH of the fibrillation reaction crucially affects the pKa of the side chains of the catalytic triads and is important for stable fibril formation. Temperature is another important parameter that controls the self-assembly of peptides into highly stacked and laminated morphologies. The morphology and stability of fibrils are crucial and represent important factors for demonstrating the capability of the peptides to exert amidolytic activity. The observed amidolytic activity of PC4, one of the PCs, was validated using an inhibition assay, which revealed that PC4 can perform enzyme-like amidolytic catalysis. These results provide insights into the potential use of designed peptides in the generation of efficient artificial enzymes.
  6. Zhang X, Lim CZF, Chhablani J, Wong YM
    Eye Vis (Lond), 2023 Jul 11;10(1):33.
    PMID: 37430344 DOI: 10.1186/s40662-023-00349-y
    Central serous chorioretinopathy (CSCR), first described by Albrecht von Graefe in 1866, is characterized by focal serous detachment of the neural retina and/or retinal pigment epithelium (RPE) in the posterior pole. CSCR is the first ever described pachychoroid disease. Most recently, hypothetical venous overload choroidopathy is also proposed due to its distinguished morphological and pathological characteristics, including choroidal thickening, choriocapillaris hyperpermeability, remodelling, and intervortex venous anastomoses. Identification of genetic variants is necessary to comprehend the pathophysiology of CSCR. The novel multimodality imaging platforms, including the ultra-widefield imaging system, flavoprotein fluorescence, fluorescence lifetime imaging ophthalmoscopy, and multispectral imaging system, have been used for diagnosing and managing CSCR. Half-dose photodynamic therapy (PDT) remains the mainstay of clinical practice, with about 95% of patients with chronic CSCR improving to visual acuity (VA) of 20/30 or better. The use of oral eplerenone for routine clinical care remains controversial, and long-term randomized clinical trials are warranted to investigate its efficacy in acute and chronic CSCR. While CSCR has generally been recognized as a self-limiting disease with good prognosis, the underlying pathogenesis is still not fully understood, and treatments are often not fully effective. With new evidence emerging about pachydrusen being a disease precursor in both CSCR and polypoidal choroidal vasculopathy (PCV), it would be interesting to investigate whether CSCR can be a precursor to PCV. In this review, we highlighted the currently available evidence on the pathogenesis, diagnosis, multimodality imaging features, and management strategies, including recent findings related to CSCR.
  7. Wong YM, Juan JC, Ting A, Wu TY, Gan HM, Austin CM
    Genome Announc, 2014;2(2).
    PMID: 24604640 DOI: 10.1128/genomeA.00078-14
    Clostridium sp. strain Ade.TY is potentially a new biohydrogen-producing species isolated from landfill leachate sludge. Here we present the assembly and annotation of its genome, which may provide further insights into its gene interactions for efficient biohydrogen production.
  8. Wong YM, Brigham CJ, Rha C, Sinskey AJ, Sudesh K
    Bioresour Technol, 2012 Oct;121:320-7.
    PMID: 22858502 DOI: 10.1016/j.biortech.2012.07.015
    The potential of plant oils as sole carbon sources for production of P(3HB-co-3HHx) copolymer containing a high 3HHx monomer fraction using the recombinant Cupriavidus necator strain Re2160/pCB113 has been investigated. Various types and concentrations of plant oils were evaluated for efficient conversion of P(3HB-co-3HHx) copolymer. Crude palm kernel oil (CPKO) at a concentration of 2.5 g/L was found to be most suitable for production of copolymer with a 3HHx content of approximately 70 mol%. The time profile of these cells was also examined in order to study the trend of 3HHx monomer incorporation, PHA production and PHA synthase activity. (1)H NMR and (13)C NMR analyses confirmed the presence of P(3HB-co-3HHx) copolymer containing a high 3HHx monomer fraction, in which monomers were not randomly distributed. The results of various characterization analyses revealed that the copolymers containing a high 3HHx monomer fraction demonstrated soft and flexible mechanical properties.
  9. Wong YM, Show PL, Wu TY, Leong HY, Ibrahim S, Juan JC
    J Biosci Bioeng, 2019 Feb;127(2):150-159.
    PMID: 30224189 DOI: 10.1016/j.jbiosc.2018.07.012
    Bio-hydrogen production from wastewater using sludge as inoculum is a sustainable approach for energy production. This study investigated the influence of initial pH and temperature on bio-hydrogen production from dairy wastewater using pretreated landfill leachate sludge (LLS) as an inoculum. The maximum yield of 113.2 ± 2.9 mmol H2/g chemical oxygen demand (COD) (12.8 ± 0.3 mmol H2/g carbohydrates) was obtained at initial pH 6 and 37 °C. The main products of volatile fatty acids were acetate and butyrate with the ratio of acetate:butyrate was 0.4. At optimum condition, Gibb's free energy was estimated at -40 kJ/mol, whereas the activation enthalpy and entropy were 65 kJ/mol and 0.128 kJ/mol/l, respectively. These thermodynamic quantities suggest that bio-hydrogen production from dairy wastewater using pretreated LLS as inoculum was effective and efficient. In addition, genomic and bioinformatics analyses were performed in this study.
  10. Wong YM, Wu TY, Ling TC, Show PL, Lee SY, Chang JS, et al.
    J Biosci Bioeng, 2018 May;125(5):590-598.
    PMID: 29352712 DOI: 10.1016/j.jbiosc.2017.12.012
    Three newly discovered H2 producing bacteria namely Clostridium perfringens strain JJC, Clostridium bifermentans strain WYM and Clostridium sp. strain Ade.TY originated from landfill leachate sludge have demonstrated highly efficient H2 production. The maximum H2 production attained from these isolates are in the descending order of strain C. perfringens strain JJC > C. bifermentans strain WYM > Clostridium sp. strain Ade.TY with yield of 4.68 ± 0.12, 3.29 ± 0.11, and 2.87 ± 0.10 mol H2/mol glucose, respectively. The result has broken the conventional theoretical yield of 4 mol H2/mol glucose. These isolates were thermodynamically favourable with Gibbs free energy between -33 and -35 kJ/mol (under process conditions: pH 6, 37 °C and 5 g/L glucose). All three isolates favour butyrate pathway for H2 production with the ratio of acetate and butyrate of 0.77, 0.65 and 0.80 for strain JJC, WYM and Ade.TY, respectively. This study reported provides a new insight on the potential of unique bacteria in H2 production.
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