Displaying publications 1 - 20 of 28 in total

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  1. Tan YH, Alias Z
    Trop Biomed, 2020 Sep 01;37(3):744-755.
    PMID: 33612787 DOI: 10.47665/tb.37.3.744
    The study was aimed to investigate the expression of cytosolic and thiolated proteins of Musca domestica larvae under oxidative stress. Proteins from acute treatment of hydrogen peroxide (LC50 = 21.52% (v/v)) on 3rd stage larvae of housefly were extracted and purified using an activated Thiol Sepharose® for thiolated protein purification. Two dimensional gel electrophoresis was used for visualizing and analyzing expression of cytosolic and thiolated proteins. Protein spots with more than 5 fold of expression change were identified using liquid chromatography- tandem mass spectrometry (LC-MS/MS). The cytosolic proteins were actin, tropomyosin, ubiquitin, arginine kinase, pheromone binding protein/general odorant binding protein, and ATP: guanidino phosphotransferase. The thiolated proteins with more than 5 fold change in expression as an effect to the acute treatment were fructose bisphosphate aldolase, short chain dehydrogenase and lactate/malate dehydrogenase. The proteins identified in the study should provide vital information for future reference in oxidative stress defence and response occurring in houseflies.
  2. Naderali N, Nejat N, Tan YH, Vadamalai G
    Plant Dis, 2013 Nov;97(11):1504.
    PMID: 30708488 DOI: 10.1094/PDIS-04-13-0412-PDN
    The foxtail palm (Wodyetia bifurcata), an Australian native species, is an adaptable and fast-growing landscape tree. The foxtail palm is most commonly used in landscaping in Malaysia. Coconut yellow decline (CYD) is the major disease of coconut associated with 16SrXIV phytoplasma group in Malaysia (1). Symptoms consistent with CYD, such as severe chlorosis, stunting, general decline, and death were observed in foxtail palms from the state of Selangor in Malaysia, indicating putative phytoplasma infection. Symptomatic trees loses their green and vivid appearance as a decorative and landscape ornament. To determine the presence of phytoplasma, samples were collected from the fronds of 12 symptomatic and four asymptomatic palms in September 2012, and total DNA was extracted using the CTAB method (3). Phytoplasma DNA was detected in eight symptomatic palms using nested PCR with universal phytoplasma 16S rDNA primer pairs, P1/P7 followed by R16F2n/R16R2 (2). Amplicons (1.2 kb in length) were generated from symptomatic foxtail palms but not from symptomless plants. Phytoplasma 16S rDNAs were cloned using a TOPO TA cloning kit (Invitrogen). Several white colonies from rDNA PCR products amplified from one sample with R16F2n/R16R2 were sequenced. Phytoplasma 16S rDNA gene sequences from single symptomatic foxtail palms showed 99% homology with a phytoplasma that causes Bermuda grass white leaf (AF248961) and coconut yellow decline (EU636906), which are both members of the 16SrXIV 'Candidatus Phytoplasma cynodontis' group. The sequences also showed 99% sequence identity with the onion yellows phytoplasma, OY-M strain, (NR074811), from the 'Candidatus Phytoplasma asteris' 16SrI-B subgroup. Sequences were deposited in the NCBI GenBank database (Accession Nos. KC751560 and KC751561). Restriction fragment length polymorphism (RFLP) analysis was done on nested PCR products produced with the primer pair R16F2n/R16R2. Amplified products were digested separately with AluI, HhaI, RsaI, and EcoRI restriction enzymes based on manufacturer's specifications. RFLP analysis of 16S rRNA gene sequences from symptomatic plants revealed two distinct profiles belonging to groups 16SrXIV and 16SrI with majority of the 16SrXIV group. RFLP results independently corroborated the findings from DNA sequencing. Additional virtual patterns were obtained by iPhyclassifier software (4). Actual and virtual patterns yielded identical profiles, similar to the reference patterns for the 16SrXIV-A and 16SrI-B subgroups. Both the sequence and RFLP results indicated that symptoms in infected foxtail palms were associated with two distinct phytoplasma species in Malaysia. These phytoplasmas, which are members of two different taxonomic groups, were found in symptomatic palms. Our results revealed that popular evergreen foxtail palms are susceptible to and severely affected by phytoplasma. To our knowledge, this is the first report of a mixed infection of a single host, Wodyetia bifurcata, by two different phytoplasma species, Candidatus Phytoplasma cynodontis and Candidatus Phytoplasma asteris, in Malaysia. References: (1) N. Nejat et al. Plant Pathol. 58:1152, 2009. (2) N. Nejat et al. Plant Pathol. J. 9:101, 2010. (3) Y. P. Zhang et al. J. Virol. Meth. 71:45, 1998. (4) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.
  3. Tan YH, Ong JYK, Devendra K
    Med J Malaysia, 2021 07;76(4):591-593.
    PMID: 34305127
    Acute pancreatitis (AP) is a serious condition that can occur suddenly in pregnancy. We present a case of sudden onset of epigastric pain with severely deranged serum triglyceride levels in a 32-year-old Vietnamese primigravida with no significant past medical history in the Singapore General Hospital. The patient was managed in the intensive care unit, with plasmapheres and intravenous insulin and was eventually a healthy term foetus was delievered via ceasarian section. This case showcased multidisciplinary co operation between the obstetrics, anaesthetic, endocrinology and intensive care team and serves as a reminder to consider this rare condition for future similar presentations.
  4. Tan YX, Wong GW, Tan YH
    Int J Clin Pharm, 2021 Dec;43(6):1555-1562.
    PMID: 34050873 DOI: 10.1007/s11096-021-01282-7
    Background Non-ventilator associated hospital-acquired pneumonia accounts for significant antibiotic use and is associated with a high rate of resistance emergence. However, the optimal duration of antibiotic treatment is uncertain, especially in cases of non-fermenting gram-negative bacilli. Objective To compare a short course (5-7 days) to a prolonged course (10-14 days) of antibiotics for non-ventilator associated hospital-acquired pneumonia. Methods Data collected retrospectively on patients completed treatment in a Malaysian tertiary hospital from January 2017 till December 2018. Regression analysis determined variables independently associated with clinical outcome. Main outcome measures Clinical resolution, superinfection, 30-day and 90-day all-cause mortality between short and prolonged courses. Results Of the 167 patients included, 112 patients were treated with a short course antibiotic, whereas 55 patients received a prolonged course of therapy. Neither short nor prolonged course group has a significantly higher rate of clinical resolution. Short course group had significantly higher mean ± SD antibiotic-free days (21.9 ± 3.5 versus 15.1 ± 6.2 days, p 
  5. Yazdani D, Zainal Abidin MA, Tan YH, Kamaruzaman S
    Mikrobiologiia, 2011 Sep-Oct;80(5):707-13.
    PMID: 22168015
    Thirty milled rice samples were collected from retailers in 4 provinces of Malaysia. These samples were evaluated for Aspergillus spp. infection by direct plating on malt extract salt agar (MESA). All Aspergillus holomorphs were isolated and identified using nucleotide sequences of ITS 1 and ITS 2 of rDNA. Five anamorphs (Aspergillus flavus, A. oryzae, A. tamarii, A. fumigatus and A. niger) and 5 teleomorphs (Eurotium rubrum, E. amstelodami, E. chevalieri, E. cristatum and E. tonophilum) were identified. The PCR-sequencing based technique for sequences of ITS 1 and ITS 2 is a fast technique for identification of Aspergillus and Eurotium species, although it doesn't work flawlessly for differentiation of Eurotium species. All Aspergillus and Eurotium isolates were screened for their ability to produce aflatoxin and ochratoxin A (OTA) by HPLC and TLC techniques. Only A. flavus isolate UPM 89 was able to produce aflatoxins B1 and B2.
  6. Tan YH, Lim CS, Wong KH, Sabaratnam V
    Int J Med Mushrooms, 2021;23(6):1-11.
    PMID: 34369729 DOI: 10.1615/IntJMedMushrooms.2021038578
    Neuritin is important in neuritogenesis, neurite arborization, and neurite extension. Lignosus rhinocerotis sclerotia extracts and nerve growth factor (NGF) have been well documented to possess positive neurite stimulatory effects. However, the correlation of neuritin expression with neurite outgrowth of L. rhinocerotis and NGF cotreatment of PC12 cells remains unknown. Thus, the present study investigated neuritin expression in PC12 cells treated with 5 ng/mL of NGF and L. rhinocerotis extracts (20-1280 μg/mL) concurrently for 48 h. The neurite outgrowth score was quantitated, and total protein was harvested for enzyme-linked immunosorbent assay. There was a significant difference (P = 0.051) in neuritin protein abundance in 640 μg/mL of L. rhinocerotis aqueous cotreatment with 5 ng/mL of NGF-treated cells (5 ± 0.39 ng/mL) and 50 ng/mL of NGF-treated PC12 cells (5 ± 0.48 ng/mL) compared to untreated cells (1.9 ± 0.65 ng/ mL), with an average neurite length of 98 ± 3.66, 106 ± 3.00, and 73 ± 4.79 μm, respectively. Expression of microtubule element β3 tubulin was increased in PC12 cells treated with 50 ng/mL of NGF (3.5 ± 0.21-fold) and also cells cotreated with 640 μg/mL of extract and 5 ng/mL of NGF (4.9 ± 0.29-fold) compared to untreated cells. Upregulation of β3 tubulin expression in this study confirmed the elongation of PC12 cell processes. Correlation analysis showed that neuritin protein abundance is positively proportional to the average neurite length in PC12 cells cotreated with L. rhinocerotis extract and 5 ng/mL of NGF. This study highlights that neuritin modulation is involved in neurite outgrowth induced by L. rhinocerotis treatment. To our knowledge, this is the first report to show that tiger milk mushroom extracts induce neuritin expression.
  7. Tan YH, Lim CSY, Wong KH, Sabaratnam V
    Int J Med Mushrooms, 2022;24(12):1-17.
    PMID: 36374978 DOI: 10.1615/IntJMedMushrooms.2022045352
    Lignosus rhinocerotis (Cooke) Ryvarden has been reported to possess numerous pharmacological effects. However, little is known about its potential role in mitigating the detrimental effects of oxidative stress. The present study investigated the cytoprotective effects of L. rhinocerotis extracts against hydrogen peroxide (H2O2)-induced oxidative stress of rat pheochromocytoma (PC12) cells. In the pre-treatment model, PC12 cells were pre-treated with aqueous (LRAQ) or ethanolic (LRET) extracts of L. rhinocerotis for 24 h, followed by 30 μM of H2O2 for 24 h. In the co-treatment model, the cells were incubated with LRAQ or LRET and H2O2 for 2 or 24 h to induce oxidative stress. Cell viability, intracellular reactive oxygen species (ROS) levels, mitochondrial membrane potential (MMP), and apoptotic cells with activated caspase-3/7 were quantified. Additionally, LRET was separated into fractions by chromatographic methods prior to analysis by gas chromatography-mass spectrometry (GCMS). 320 μg/ml aqueous extract showed a significant cytoprotective effect of 70.0 ± 22.4% and 133.92 ± 8.8% in the pre-treatment and co-treatment models, respectively, compared to untreated H2O2-challenged cells. LRAQ also showed a reduction (p < 0.05) in the percentage of depolarized cells of 37.6 ± 0.6% at 640 ug/ml and 53.4 ± 4.5% at 320 ug/ml in the pre-treatment and co-treatment models, respectively, compared to untreated H2O2-challenged cells. LRAQ or LRET showed a reduction (p < 0.01) in caspase 3/7 activity compared to untreated H2O2-challenged cells in the co-treatment model. However, LRAQ or LRET did not reduce excessive ROS formation (p > 0.05). The cytoprotective effects could be attributed to the presence of fatty acids, phenols, phytosterols, and dicarboxylic acids. In conclusion, L. rhinocerotis extracts demonstrated cytoprotective effects against H2O2-induced oxidative stress in an in vitro model, contributing to the maintenance of cellular integrity through the regulation of mitochondrial function and apoptosis.
  8. Tee SW, Richards A, Tan YH, Jeyabalan D, Durairaj G
    J Surg Case Rep, 2022 Dec;2022(12):rjac585.
    PMID: 36578629 DOI: 10.1093/jscr/rjac585
    Desmoid fibromatosis is a rare, benign, locally aggressive fibroblastic proliferation that may occur in almost any anatomical location. Due to its rarity and unpredictable clinical course, there has not been a standard guideline of treatment. We encountered a case of desmoid fibromatosis in our centre. A young lady previously fit and well was referred for a symptomatic, rapidly growing left sided abdominal mass. Otherwise, she denied any bowel related symptoms or constitutional manifestation. Imaging demonstrated a large well-defined lobulated solid-cystic mass extending from vertebral level T10 to L5, measuring 10.5 cm × 15 cm × 23 cm. The mass was in close proximity with the left adrenal gland, left kidney, pancreas and spleen. Ultrasound guided biopsy interpreted it as a fibroblastic or myelofibroblastic tumour, favouring desmoid fibromatosis. Surgery was then performed where the mass was removed along with the left adrenal gland and kidney. Post-operative care was complicated with pulmonary embolism, hospital-acquired pneumonia and pancreatitis.
  9. Nejat N, Valdiani A, Cahill D, Tan YH, Maziah M, Abiri R
    ScientificWorldJournal, 2015;2015:982412.
    PMID: 25667940 DOI: 10.1155/2015/982412
    Catharanthus roseus (L.) known as Madagascar periwinkle (MP) is a legendary medicinal plant mostly because of possessing two invaluable antitumor terpenoid indole alkaloids (TIAs), vincristine and vinblastine. The plant has also high aesthetic value as an evergreen ornamental that yields prolific blooms of splendid colors. The plant possesses yet another unique characteristic as an amiable experimental host for the maintenance of the smallest bacteria found on earth, the phytoplasmas and spiroplasmas, and serves as a model for their study. Botanical information with respect to synonyms, vernacular names, cultivars, floral morphology, and reproduction adds to understanding of the plant while the geography and ecology of periwinkle illustrate the organism's ubiquity. Good agronomic practices ensure generous propagation of healthy plants that serve as a source of bioactive compounds and multitudinous horticultural applications. The correlation between genetic diversity, variants, and TIA production exists. MP is afflicted with a whole range of diseases that have to be properly managed. The ethnobotanical significance of MP is exemplified by its international usage as a traditional remedy for abundant ailments and not only for cancer. TIAs are present only in micro quantities in the plant and are highly poisonous per se rendering a challenge for researchers to increase yield and reduce toxicity.
  10. Tan YH, Sidik SM, Syed Husain SN, Lye MS, Chong PP
    Asian Pac J Cancer Prev, 2016;17(1):57-64.
    PMID: 26838255
    BACKGROUND: Tobacco smoking is considered a risk factor for cervical cancer development due to the presence of tobacco based carcinogenic metabolites in cervical cells of female smokers. In this study, we investigated the role of the T3801C (MspI) polymorphism of CYP1A1, a gene encoding an enzyme necessary for the initiation of tobacco based carcinogen metabolism, on cervical cancer risk. The T to C substitution may alter CYP1A1 activities, potentially elevating cervical cancer risk. Since results of gene-disease association studies vary according to the study population, the multi-ethnic population of Malaysia provides an excellent representative cohort for identifying and comparing the cervical cancer risk among the 3 major ethnics in Southeast Asia in relation to CYP1A1 MspI polymorphism.

    MATERIALS AND METHODS: A total of 195 Thin Prep Pap smear samples from HPV negative and cancer free females were randomly selected as controls while 106 formalin fixed paraffin embedded samples from females with invasive cervical cancer were randomly selected for the cases group. The polymorphisms were identified using restriction fragment length polymorphism (RFLP) PCR.

    RESULTS: We found no significant associations between CYP1A1 MspI polymorphism and cervical cancer in the general Malaysian female population. However, upon ethnic stratification, the variant C/C genotype was significantly associated with a 4.66-fold increase in cervical cancer risk in Malay females (95% CI= 1.21-17.9; p=0.03). No significant association was observed in the Chinese and Indian females. Additionally, there were no significant associations in the dominant model and allele frequency model analysis in both the general and ethnically stratified female population of Malaysia.

    CONCLUSIONS: Our findings suggest that the C/C genotype of CYP1A1 MspI polymorphism is associated with the development of cervical carcinoma in the Malay females of Malaysia.

  11. Quah RV, Tan YH, Mubarak NM, Kansedo J, Khalid M, Abdullah EC, et al.
    Waste Manag, 2020 Dec;118:626-636.
    PMID: 33011540 DOI: 10.1016/j.wasman.2020.09.016
    Due to its environment-friendly and replenishable characteristics, biodiesel has the potential to substitute fossil fuels as an alternative source of energy. Although biodiesel has many benefits to offer, manufacturing biodiesel on an industrial scale is uneconomical as a high cost of feedstock is required. A novel sulfonated and magnetic catalyst synthesised from a palm kernel shell (PMB-SO3H) was first introduced in this study for methyl ester or biodiesel production to reduce capital costs. The wasted palm kernel shell (PKS) biochar impregnated with ferrite Fe3O4 was synthesised with concentrated sulphuric acid through the sulfonation process. The SEM, EDX, FTIR, VSM and TGA characterization of the catalysts were presented. Then, the optimisation of biodiesel synthesis was catalysed by PMB-SO3H via the Response Surface Methodology (RSM). It was found that the maximum biodiesel yield of 90.2% was achieved under these optimum operating conditions: 65 °C, 102 min, methanol to oil ratio of 13:1 and the catalyst loading of 3.66 wt%. Overall, PMB-SO3H demonstrated acceptable catalysing capability on its first cycle, which subsequently showed a reduction of the reusability performance after 4 cycles. An important practical implication is that PMB-SO3H can be established as a promising heterogeneous catalyst by incorporating an iron layer which can substantially improve the catalyst separation performance in biodiesel production.
  12. Tan YH, Lim PE, Beardall J, Poong SW, Phang SM
    Aquat Toxicol, 2019 Dec;217:105349.
    PMID: 31734626 DOI: 10.1016/j.aquatox.2019.105349
    Ocean acidification, due to increased levels of anthropogenic carbon dioxide, is known to affect the physiology and growth of marine phytoplankton, especially in polar regions. However, the effect of acidification or carbonation on cellular metabolism in polar marine phytoplankton still remains an open question. There is some evidence that small chlorophytes may benefit more than other taxa of phytoplankton. To understand further how green polar picoplankton could acclimate to high oceanic CO2, studies were conducted on an Antarctic Chlorella sp. Chlorella sp. maintained its growth rate (∼0.180 d-1), photosynthetic quantum yield (Fv/Fm = ∼0.69) and chlorophyll a (0.145 fg cell-1) and carotenoid (0.06 fg cell-1) contents under high CO2, while maximum rates of electron transport decreased and non-photochemical quenching increased under elevated CO2. GCMS-based metabolomic analysis reveal that this polar Chlorella strain modulated the levels of metabolites associated with energy, amino acid, fatty acid and carbohydrate production, which could favour its survival in an increasingly acidified ocean.
  13. Tan YH, Poong SW, Yang CH, Lim PE, John B, Pai TW, et al.
    Mar Environ Res, 2022 Dec;182:105782.
    PMID: 36308800 DOI: 10.1016/j.marenvres.2022.105782
    Human emissions of carbon dioxide are causing irreversible changes in our oceans and impacting marine phytoplankton, including a group of small green algae known as picochlorophytes. Picochlorophytes grown in natural phytoplankton communities under future predicted levels of carbon dioxide have been demonstrated to thrive, along with redistribution of the cellular metabolome that enhances growth rate and photosynthesis. Here, using next-generation sequencing technology, we measured levels of transcripts in a picochlorophyte Chlorella, isolated from the sub-Antarctic and acclimated under high and current ambient CO2 levels, to better understand the molecular mechanisms involved with its ability to acclimate to elevated CO2. Compared to other phytoplankton taxa that induce broad transcriptomic responses involving multiple parts of their cellular metabolism, the changes observed in Chlorella focused on activating gene regulation involved in different sets of pathways such as light harvesting complex binding proteins, amino acid synthesis and RNA modification, while carbon metabolism was largely unaffected. Triggering a specific set of genes could be a unique strategy of small green phytoplankton under high CO2 in polar oceans.
  14. Adeoye JB, Balogun DO, Etemire OJ, Ezeh PN, Tan YH, Mubarak NM
    Sci Rep, 2023 Dec 04;13(1):21373.
    PMID: 38049520 DOI: 10.1038/s41598-023-48675-4
    In this study, zeolite Y was synthesised using a novel method. The heat generated from the reaction of H2SO4 with metakaolin was used as a heat source instead of applying external heat for the dealuminated process. The synthesised zeolite Y produced was analysed by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier-infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDS) and Brunauer-Emmett-Teller (BET). Zeolite Y synthesis was mesoporous because of its pore diameter (30.53 nm), as shown in the BET results. Surface area and pore size decrease after adsorption due to dye deposition on the adsorbent's surface. FTIR has bonds like O-H, C-H, -CH3, and -COOH responsible for adsorption. The maximum adsorption capacity of eosin yellow (EY) and methyl orange (MO) on to zeolite Y by the Langmuir isotherm was 52.91 mg/g and 20.62 mg/g respectively, at pH 2.5 and 8 for EY and MO dye. The batch adsorption studies were conducted, and the influence of different parameters (i.e., adsorbent dose, adsorption time, initial dye concentration, pH and temperature) was investigated. Experimental data were analysed by two linear model equations (Langmuir and Freundlich isotherms), and it was found that the Langmuir isotherm model best describes the adsorption data for methyl orange and Freundlich isotherm for eosin yellow, respectively. Adsorption rate constants were determined using linear pseudo-first-order and pseudo-second-order. The results showed that MO and EY dye adsorption onto zeolite Y followed a pseudo-second-order kinetic model. Thermodynamic studies show that adsorption was an exothermic reaction (enthalpy 
  15. Adeoye JB, Tan YH, Lau SY, Tan YY, Chiong T, Mubarak NM, et al.
    J Environ Manage, 2024 Feb 27;353:120170.
    PMID: 38308991 DOI: 10.1016/j.jenvman.2024.120170
    The stress of pharmaceutical and personal care products (PPCPs) discharging to water bodies and the environment due to increased industrialization has reduced the availability of clean water. This poses a potential health hazard to animals and human life because water contamination is a great issue to the climate, plants, humans, and aquatic habitats. Pharmaceutical compounds are quantified in concentrations ranging from ng/Lto μg/L in aquatic environments worldwide. According to (Alsubih et al., 2022), the concentrations of carbamazepine, sulfamethoxazole, Lutvastatin, ciprofloxacin, and lorazepam were 616-906 ng/L, 16,532-21635 ng/L, 694-2068 ng/L, 734-1178 ng/L, and 2742-3775 ng/L respectively. Protecting and preserving our environment must be well-driven by all sectors to sustain development. Various methods have been utilized to eliminate the emerging pollutants, such as adsorption and biological and advanced oxidation processes. These methods have their benefits and drawbacks in the removal of pharmaceuticals. Successful wastewater treatment can save the water bodies; integrating green initiatives into the main purposes of actor firms, combined with continually periodic awareness of the current and potential implications of environmental/water pollution, will play a major role in water conservation. This article reviews key publications on the adsorption, biological, and advanced oxidation processes used to remove pharmaceutical products from the aquatic environment. It also sheds light on the pharmaceutical adsorption capability of adsorption, biological and advanced oxidation methods, and their efficacy in pharmaceutical concentration removal. A research gap has been identified for researchers to explore in order to eliminate the problem associated with pharmaceutical wastes. Therefore, future study should focus on combining advanced oxidation and adsorption processes for an excellent way to eliminate pharmaceutical products, even at low concentrations. Biological processes should focus on ideal circumstances and microbial processes that enable the simultaneous removal of pharmaceutical compounds and the effects of diverse environments on removal efficiency.
  16. Goh JE, Rahman AY, Hari R, Lim MP, Najimudin N, Yap WS, et al.
    Microbiol Resour Announc, 2020 May 21;9(21).
    PMID: 32439681 DOI: 10.1128/MRA.01485-19
    A type strain of Lactarius deliciosus was obtained from the CBS-KNAW culture collection. The mycelium was cultured using potato dextrose agar, and the extracted genomic DNA was subjected to PacBio genome sequencing. Upon assembly and annotation, the genome size was estimated to be 54 Mbp, with 12,753 genes.
  17. Khan FSA, Mubarak NM, Tan YH, Khalid M, Karri RR, Walvekar R, et al.
    J Hazard Mater, 2021 07 05;413:125375.
    PMID: 33930951 DOI: 10.1016/j.jhazmat.2021.125375
    Industrial effluents contain several organic and inorganic contaminants. Among others, dyes and heavy metals introduce a serious threat to drinking waterbodies. These pollutants can be noxious or carcinogenic in nature, and harmful to humans and different aquatic species. Therefore, it is of high importance to remove heavy metals and dyes to reduce their environmental toxicity. This has led to an extensive research for the development of novel materials and techniques for the removal of heavy metals and dyes. One route to the removal of these pollutants is the utilization of magnetic carbon nanotubes (CNT) as adsorbents. Magnetic carbon nanotubes hold remarkable properties such as surface-volume ratio, higher surface area, convenient separation methods, etc. The suitable characteristics of magnetic carbon nanotubes have led them to an extensive search for their utilization in water purification. Along with magnetic carbon nanotubes, the buckypaper (BP) membranes are also favorable due to their unique strength, high porosity, and adsorption capability. However, BP membranes are mostly used for salt removal from the aqueous phase and limited literature shows their applications for removal of heavy metals and dyes. This study focuses on the existence of heavy metal ions and dyes in the aquatic environment, and methods for their removal. Various fabrication approaches for the development of magnetic-CNTs and CNT-based BP membranes are also discussed. With the remarkable separation performance and ultra-high-water flux, magnetic-CNTs, and CNT-based BP membranes have a great potential to be the leading technologies for water treatment in future.
  18. Ng PY, Chye SM, Ng ChH, Koh RY, Tiong YL, Pui LP, et al.
    Asian Pac J Cancer Prev, 2017 04 01;18(4):917-926.
    PMID: 28545188
    Background: Clinacanthus nutans (C.nutans) is a plant consumed as a cancer treatment in tropical Asia. Despite
    the availability of numerous anecdotal reports, evaluation of active anticancer effects has remained elusive. Therefore
    we here examined antiproliferative, reactive oxygen species (ROS)-inducing and apoptosis mechanisms of whole plant
    extracts in different cancer cell lines. Methods: Antiproliferative actions of five solvent extracts (hexane, chloroform,
    ethyl acetate, methanol and water) of C.nutans were tested on non-small cell lung cancer (A549), nasopharygeal cancer
    (CNE1) and liver cancer (HepG2) cells using MTT assay. The most potent anticancer extract was then assessed by flow
    cytometry to study cell cycle changes . Intracellular levels of ROS were quantified by DCFH-DA assay. Involvement of
    the caspase pathway in induction of apoptosis was assessed using caspase assay kits. GC-MS analysis was performed
    to identify phytoconstituents in the extracts. Results: Hexane and chloroform extracts were antiproliferative against
    all three cell lines, while the ethyl acetate extract, at 300 μg/mL, was antiproliferative in the CNE1 but not A549 and
    HepG2 cases. Methanol and water extracts did not inhibit cancer cell proliferation. The most potent anticancer hexane
    extract was selected for further testing. It induced apoptosis in all three cell lines as shown by an increase in the
    percentage of cell in sub-G1 phase. Dose-dependent increase in ROS levels in all three cell lines indicated apoptosis to
    be possibly modulated by oxidative stress. At high concentrations (>100 μg/mL), hexane extracts upregulated caspases
    8, 9 and 3/7 across all three cell lines. GC-MS analysis of the hexane extract revealed abundance of 31 compounds.
    Conclusion : Among the five extracts of C.nutans, that with hexane extract demonstrated the highest antiproliferative
    activity against all three cancer cell lines tested. Action appeared to be via ion of intracellular ROS, and induction of
    apoptosis via intrinsic and extrinsic caspase pathways.
  19. Naderali N, Nejat N, Vadamalai G, Davis RE, Wei W, Harrison NA, et al.
    Int J Syst Evol Microbiol, 2017 Oct;67(10):3765-3772.
    PMID: 28905707 DOI: 10.1099/ijsem.0.002187
    Landscape-grown foxtail palm (Wodyetia bifurcata A. K. Irvine) trees displaying symptoms of severe foliar chlorosis, stunting, general decline and mortality reminiscent of coconut yellow decline disease were observed in Bangi, Malaysia, during 2012. DNA samples from foliage tissues of 15 symptomatic palms were analysed by employing a nested PCR assay primed by phytoplasma universal ribosomal RNA operon primer pairs, P1/P7 followed by R16F2n/R2. The assay yielded amplicons of a single band of 1.25 kb from DNA samples of 11 symptomatic palms. Results from cloning and sequence analysis of the PCR-amplified 16S rRNA gene segments revealed that, in three palms, three mutually distinct phytoplasmas comprising strains related to 'Candidatus Phytoplasma asteris' and 'Candidatus Phytoplasma cynodontis', as well as a novel phytoplasma, were present as triple infections. The 16S rRNA gene sequence derived from the novel phytoplasma shared less than 96 % nucleotide sequence identity with that of each previously describedspecies of the provisional genus 'Ca. Phytoplasma', justifying its recognition as the reference strain of a new taxon, 'Candidatus Phytoplasma wodyetiae'. Virtual RFLP profiles of the R16F2n/R2 portion of the 16S rRNA gene and the pattern similarity coefficient value (0.74) supported the delineation of 'Ca. Phytoplasma wodyetiae' as the sole representative subgroup A member of a new phytoplasma ribosomal group, 16SrXXXVI.
  20. Hor CJ, Tan YH, Mubarak NM, Tan IS, Ibrahim ML, Yek PNY, et al.
    Environ Res, 2023 Mar 01;220:115169.
    PMID: 36587722 DOI: 10.1016/j.envres.2022.115169
    To date, the development of renewable fuels has become a normal phenomenon to solve the problem of diesel fuel emissions and the scarcity of fossil fuels. Biodiesel production has some limitations, such as two-step processes requiring high free fatty acids (FFAs), oil feedstocks and gum formation. Hydrotreated vegetable oil (HVO) is a newly developed international renewable diesel that uses renewable feedstocks via the hydrotreatment process. Unlike FAME, FFAs percentage doesn't affect the HVO production and sustains a higher yield. The improved characteristics of HVO, such as a higher cetane value, better cold flow properties, lower emissions and excellent oxidation stability for storage, stand out from FAME biodiesel. Moreover, HVO is a hydrocarbon without oxygen content, but FAME is an ester with 11% oxygen content which makes it differ in oxidation stability. Waste sludge palm oil (SPO), an abundant non-edible industrial waste, was reused and selected as the feedstock for HVO production. Techno-economical and energy analyses were conducted for HVO production using Aspen HYSYS with a plant capacity of 25,000 kg/h. Alternatively, hydrogen has been recycled to reduce the hydrogen feed. With a capital investment of RM 65.86 million and an annual production cost of RM 332.56 million, the base case of the SPO-HVO production process was more desirable after consideration of all economic indicators and HVO purity. The base case of SPO-HVO production could achieve a return on investment (ROI) of 89.03% with a payback period (PBP) of 1.68 years. The SPO-HVO production in this study has observed a reduction in the primary greenhouse gas, carbon dioxide (CO2) emission by up to 90% and the total annual production cost by nearly RM 450 million. Therefore, SPO-HVO production is a potential and alternative process to produce biobased diesel fuels with waste oil.
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