Displaying publications 1 - 20 of 421 in total

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  1. Wang Z, Li P, Ma K, Chen Y, Yan Z, Penfold J, et al.
    J Colloid Interface Sci, 2021 Mar 15;586:876-890.
    PMID: 33309145 DOI: 10.1016/j.jcis.2020.10.122
    HYPOTHESIS: The α-sulfo alkyl ester, AES, surfactants are a class of anionic surfactants which have potential for improved sustainable performance in a range of applications, and an important feature is their enhanced tolerance to precipitation in the presence of multivalent counterions. It is proposed that their adsorption properties can be adjusted substantially by changing the length of the shorter alkyl chain, that of the alkanol group in the ester.

    EXPERIMENTS: Surface tension and neutron reflectivity have been used to investigate the variation in the adsorption properties with the shorter alkyl chain length (methyl, ethyl and propyl), the impact of NaCl on the adsorption, the tendency to form surface multilayer structures in the presence of AlCl3, and the effects of mixing the methyl ester sulfonate with the ethyl and propyl ester sulfonates on the adsorption.

    FINDINGS: The variations in the critical micelle concentration, CMC, the adsorption isotherms, the saturation adsorption values, and the impact of NaCl illustrate the subtle influence of varying the shorter alkyl chain length of the surfactant. The non-ideal mixing of pairs of AES surfactants with different alkanol group lengths of the ester show that the extent of the non-ideality changes as the difference in the alkanol length increases. The surface multilayer formation observed in the presence of AlCl3 varies in a complex manner with the length of the short chain and for mixtures of surfactants with different chains lengths.

  2. Jin NZ, Anniebell S, Gopinath SC, Chen Y
    Nanoscale Res Lett, 2016 Dec;11(1):399.
    PMID: 27637891 DOI: 10.1186/s11671-016-1615-2
    Electrostatic attraction, covalent binding, and hydrophobic absorption are spontaneous processes to assemble and disassemble the molecules of gold nanoparticles (GNP). This dynamic change can be performed in the presence of ions, such as NaCl or charged molecules. Current research encompasses the GNP in mediating non-biofouling and investigating the molecular attachment and detachment. Experiments were performed with different sizes of GNP and polymers. As a proof of concept, poly(ethylene glycol)-b-poly(acrylic acid), called PEG-PAAc, attachment and binding events between factor IX and factor IX-bp from snake venom were demonstrated, and the variations with these molecular attachment on GNP were shown. Optimal concentration of NaCl for GNP aggregation was 250 mM, and the optimal size of GNP used was 30 nm. The polymer PEG-PAAc (1 mg/ml) has a strong affinity to the GNP as indicated by the dispersed GNP. The concentration of 5800 nM of factor IX was proved to be optimal for dispersion of GNP, and at least 100 nM of factor IX-bp was needed to remove factor IX from the surface of GNP. This study delineates the usage of unmodified GNP for molecular analysis and downstream applications.
  3. Citartan M, Gopinath SC, Tominaga J, Chen Y, Tang TH
    Talanta, 2014 Aug;126:103-9.
    PMID: 24881539 DOI: 10.1016/j.talanta.2014.03.043
    Label-free-based detection is pivotal for real-time monitoring of biomolecular interactions and to eliminate the need for labeling with tags that can occupy important binding sites of biomolecules. One simplest form of label-free-based detection is ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy, which measure changes in reflectivity as a means to monitor immobilization and interaction of biomolecules with their corresponding partners. In biosensor development, the platform used for the biomolecular interaction should be suitable for different molecular recognition elements. In this study, gold (Au)-coated polycarbonate was used as a platform and as a proof-of-concept, erythropoietin (EPO), a doping substance widely abused by the athletes was used as the target. The interaction of EPO with its corresponding molecular recognition elements (anti-EPO monoclonal antibody and anti-EPO DNA aptamer) is monitored by UV-vis-NIR spectroscopy. Prior to this, to show that UV-vis-NIR spectroscopy is a suitable method for measuring biomolecular interaction, the interaction between biotin and streptavidin was demonstrated via this strategy and reflectivity of this interaction decreased by 25%. Subsequent to this, interaction of the EPO with anti-EPO monoclonal antibody and anti-EPO DNA aptamer resulted in the decrease of reflectivity by 5% and 10%, respectively. The results indicated that Au-coated polycarbonate could be an ideal biosensor platform for monitoring biomolecular interactions using UV-vis-NIR spectroscopy. A smaller version of the Au-coated polycarbonate substrates can be derived from the recent set-up, to be applied towards detecting EPO abuse among atheletes.
  4. Leddin D, Omary MB, Veitch A, Metz G, Amrani N, Aabakken L, et al.
    Gut, 2021 11;70(11):2025-2029.
    PMID: 34620696 DOI: 10.1136/gutjnl-2021-325789
  5. Leddin D, Omary MB, Veitch A, Metz G, Amrani N, Aabakken L, et al.
    J Clin Gastroenterol, 2021 10 8;55(10):823-829.
    PMID: 34617932 DOI: 10.1097/MCG.0000000000001619
    Climate change has been described as the greatest public health threat of the 21st century. It has significant implications for digestive health. A multinational team with representation from all continents, excluding Antarctica and covering 18 countries, has formulated a commentary which outlines both the implications for digestive health and ways in which this challenge can be faced.
  6. Chen Y, Ge D, Zhang J, Chu R, Zheng J, Wu C, et al.
    Nanoscale, 2018 Sep 20;10(36):17378-17387.
    PMID: 30203824 DOI: 10.1039/c8nr01195h
    Tin-based materials have been intensively studied as attractive candidates for high-capacity and long-cycle-life anodes in Li-ion batteries (LIBs) owing to their low cost and high energy density. However, they all suffer from severe structural decay during the lithium ion insertion/extraction process, which results in deterioration in the overall performance of the batteries. To mitigate this problem, we have synthesized a Mo-doped SnO2 nanostructure via a facile hydrothermal method, which then fragmented into ultrafine particles after dozens of cycles. The fracture-resistant size and ample contact with Super-P and Li2O greatly improved the electrochemical kinetics and cyclability to deliver a reversible capacity of 670 mA h g-1 after 700 cycles, which demonstrated the potential suitability of Mo-doped SnO2 nanoparticles as a long-cycle-life anode material. Then, the compounds were uniformly dispersed in carbon nanofibers and reduced in situ to prepare a free-standing anode via electrospinning and carbonization. When used directly as an anode in LIBs (without a polymeric binder or conductive agent, as well as a current collector), the nanofiber membrane anode delivered comparable cycling performance and capacity to that of a slurry-coated electrode.
  7. Jiang H, Zhang J, Zeng Y, Chen Y, Guo H, Li L, et al.
    Nanotechnology, 2021 Nov 18;33(6).
    PMID: 34724657 DOI: 10.1088/1361-6528/ac3540
    Metal sulfides are promising anode materials for lithium ion batteries because of the high specific capacities and better electrochemical kinetics comparing to their oxide counterparts. In this paper, novel monocrystalline wurtzite ZnS@N-doped carbon (ZnS@N-C) nanoplates, whose morphology and phase are different from the common ZnS particles with cubic phase, are successfully synthesized. The ZnS@N-C nanoplates exhibit long cycle life with a high reversible specific capacity of 536.8 mAh · g-1after 500 cycles at a current density of 500 mA · g-1, which is superior to the pure ZnS nanoplates, illustrating the obvious effect of the N-doped carbon coating for mitigating volume change of the ZnS nanoplates and enhancing the electronic conductivity during charge/discharge processes. Furthermore, it is revealed that the ZnS single crystals with wurtzite phase in the ZnS@N-C nanoplates are transformed to the polycrystalline cubic phase ZnS after charge/discharge processes. In particular, the ZnS@N-C nanoplates are combined with the commercial LiNi0.6Co0.2Mn0.2O2cathode to fabricate a new type of LiNi0.6Co0.2Mn0.2O2/ZnS@N-C complete battery, which exhibits good cycling durability up to 120 cycles at a charge/discharge rate of 1 C after the prelithiation treatment on the ZnS@N-C anode, highlighting the potential of the ZnS@N-C nanoplates anode material applied in lithium ion battery.
  8. Zhao Z, Wei Y, Zou X, Jiang S, Chen Y, Ye J, et al.
    J Agric Food Chem, 2023 Dec 02.
    PMID: 38041637 DOI: 10.1021/acs.jafc.3c06676
    Previously, we reported that marine yeast Scheffersomyces spartinae exhibited biocontrol efficacy against the gray mold of strawberries caused by Botrytis cinerea. Herein, tryptophol, a quorum-sensing molecule, was identified in the metabolites of S. spartinae. Subsequently, we found that 25 μM tryptophol promoted population density, biofilm formation, and cell aggregation of S. spartinae. Furthermore, 25 μM tryptophol improved the biocontrol efficacy of S. spartinae against B. cinerea in vitro and in the strawberry fruit. Under a scanning electronic microscope, tryptophol facilitated colonization and biofilm formation on strawberry wounds, showing that tryptophol increased the biocontrol efficacy of S. spartinae via quorum sensing. Transcriptome analysis revealed that tryptophol upregulated the gene expression of SDS3, DAL81, DSE1, SNF5, SUN41, FLO8, and HOP1, which was associated with cell adhesion or biofilm formation. Thus, to the best of our knowledge, this study was the first to report that tryptophol improved the biocontrol efficacy of S. spartinae via quorum sensing.
  9. Chaikitmongkol V, Sagong M, Lai TYY, Tan GSW, Ngah NF, Ohji M, et al.
    Asia Pac J Ophthalmol (Phila), 2021 Nov 24;10(6):507-518.
    PMID: 34839342 DOI: 10.1097/APO.0000000000000445
    PURPOSE: Review and provide consensus recommendations on use of treat-and-extend (T&E) regimens for neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) management with relevance for clinicians in the Asia-Pacific region.

    METHODS: A systematic search of MEDLINE, EMBASE, and Cochrane databases, and abstract databases of the Asia-Pacific Vitreo-retina Society, European Society of Retina Specialists, American Academy of Ophthalmology, and Controversies in Ophthalmology: Asia-Australia congresses, was conducted to assess evidence for T&E regimens in nAMD. Only studies with ≥100 study eyes were included. An expert panel reviewed the results and key factors potentially influencing the use of T&E regimens in nAMD and PCV, and subsequently formed consensus recommendations for their application in the Asia-Pacific region.

    RESULTS: Twenty-seven studies were included. Studies demonstrated that T&E regimens with aflibercept, ranibizumab, or bevacizumab in nAMD, and with aflibercept in PCV, were efficacious and safe. The recommendation for T&E is, after ≥3 consecutive monthly loading doses, treatment intervals can be extended by 2 to 4 weeks up to 12 to 16 weeks. When disease activity recurs, the recommendation is to reinject and shorten intervals by 2 to 4 weeks until fluid resolution, after which treatment intervals can again be extended. Intraretinal fluid should be treated until resolved; however, persistent minimal subretinal fluid after consecutive treatments may be tolerated with treatment intervals maintained or extended if the clinical condition is stable.

    CONCLUSIONS: T&E regimens are efficacious and safe for nAMD and PCV, can reduce the number of visits, and minimize the overall burden for clinicians and patients.

  10. Chen YP, Sudderuddin KI
    PMID: 749224
    Toxicity tests carried out on the larvae of A. aegypti and C. quinquefasciatus showed the former to be more tolerant of all insecticides tested, the order of toxicity being temephos greater than DDT greater than DDVP greater than malathion greater than lindane greater than carbaryl; also the second instar larvae of A. aegypti were more susceptible than fourth instar larvae. Enzyme kinetic studies on the total non-specific esterases and CarEs of adults and larvae of both species showed the Km values for total esterases of adult A. aegypti to be 0.333 mM vs 0.233 mM for C. quinquefasciatus; for adult CarEs it was 0.250 mM vs 0.220 mM. For total larval esterases of A. aegypti it was 0.112 mM vs 0.175 mM for C. quinquefasciatus: and for larval CarES it was 0.159 mM vs 0.213 mM respectively. Although some correlation between in vivo toxicity (LD50 values) and in vitro esterase inhibition (I50 values) between species could be discerned, overall correlation could not be established.
  11. Wang Z, Li P, Ma K, Chen Y, Penfold J, Thomas RK, et al.
    J Colloid Interface Sci, 2019 Sep 05;557:124-134.
    PMID: 31518834 DOI: 10.1016/j.jcis.2019.09.016
    The ester sulfonate anionic surfactants are a potentially valuable class of sustainable surfactants. The micellar growth, associated rheological changes, and the onset of precipitation are important consequences of the addition of electrolyte and especially multi-valent electrolytes in anionic surfactants. Small angle neutron scattering, SANS, has been used to investigate the self-assembly and the impact of different valence electrolytes on the self-assembly of a range of ester sulfonate surfactants with subtly different molecular structures. The results show that in the absence of electrolyte small globular micelles form, and in the presence of NaCl, and AlCl3 relatively modest micellar growth occurs before the onset of precipitation. The micellar growth is more pronounced for the longer unbranched and branched alkyl chain lengths. Whereas changing the headgroup geometry from methyl ester to ethyl ester has in general a less profound impact. The study highlights the importance of relative counterion binding strengths and shows how the surfactant structure affects the counterion binding and hence the micelle structure. The results have important consequences for the response of such surfactants to different operational environments.
  12. Bo S, Chang SK, Chen Y, Sheng Z, Jiang Y, Yang B
    Crit Rev Food Sci Nutr, 2024;64(9):2490-2512.
    PMID: 36123801 DOI: 10.1080/10408398.2022.2124396
    Rare flavonoids, a special subclass of naturally occurring flavonoids with diverse structures including pterocarpans, aurones, neoflavonoids, homoisoflavones, diphenylpropanes, rotenoids and 2-phenylethyl-chromones. They are mainly found in legumes with numerous health benefits. Rare flavonoids are regarded as minor flavonoids due to their very limited abundance in nature. This review gives an overview of the natural occurrences of rare flavonoids from previous literatures. Recent findings on the biosynthesis of rare flavonoids have been updated by describing their structural characteristics and classifications. Recent findings on the health benefits of rare flavonoids have also been compiled and discussed. Natural rare flavonoids with various characteristics from different subclasses from plant-based food sources are stated. They show a wide range of health benefits, including antibacterial, anticancer, anti-osteoporosis and antiviral activities. Studies reviewed suggest that rare flavonoids possessing different skeletons demonstrate different characteristic bioactivities by discussing their mechanism of actions and structure-activity relationships. Besides, recent advances on the biosynthesis of rare flavonoids, such as pterocarpans, rotenoids and aurones are well-known, while the biosynthesis of other subclasses remain unknown. The perspectives and further applications of rare flavonoids using metabolic engineering strategies also be expected.
  13. Zhao S, Chen J, Cao S, Wang H, Chen H, Wei Y, et al.
    Plant Physiol Biochem, 2024 Feb 29;208:108480.
    PMID: 38437751 DOI: 10.1016/j.plaphy.2024.108480
    It is well established that programmed cell death (PCD) occurred in broccoli during postharvest senescence, but no studies have been conducted on the regulation of broccoli cytochrome f by mannose treatment and its relationship with PCD. In this study, we treated broccoli buds with mannose to investigate the changes in color, total chlorophyll content, gene expression related to chlorophyll metabolism, chloroplast structure, and cytochrome f determination during postharvest storage. In addition, to investigate the effect of cytochrome f on PCD, we extracted cytochrome f from broccoli and treated Nicotiana tabacum L. cv Bright Yellow 2 (BY-2) cells with extracted cytochrome f from broccoli at various concentrations. The results showed that cytochrome f can induce PCD in tobacco BY-2 cells, as evidenced by altered cell morphology, nuclear chromatin disintegration, DNA degradation, decreased cell viability, and increased caspase-3-like protease production. Taken together, our study indicated that mannose could effectively delay senescence of postharvest broccoli by inhibiting the expression of gene encoding cytochrome f which could induce PCD.
  14. Sanjaya EH, Chen Y, Guo Y, Wu J, Chen H, Din MFM, et al.
    Bioresour Technol, 2022 Feb;346:126622.
    PMID: 34958906 DOI: 10.1016/j.biortech.2021.126622
    The simultaneous partial nitritation, anammox, denitrification, and COD oxidation (SNADCO) method was successfully carried out in an air-lift moving bed biofilm reactor (AL-MBBR) with cylinders carriers for the treatment of digested fish processing wastewater (FPW). Synthetic wastewater was used as substrate at stage 1. It changed into the digested FPW with dilution variation in order to increase the nitrogen and COD loading rates. With influent concentration of NH4+-N of 909 ± 101 mg-N/L and COD of 731 ± 26 mg/L, the nitrogen removal efficiency was 86.8% (nitrogen loading rate of 1.21 g-TN/L/d) and the COD removal efficiency was 50.5% (COD loading rate at 0.98 g-COD/L/d). This study showed that the process has the advantages in treating the real high ammonia concentration of digested wastewater containing organic compounds. The nitritation and anammox route was predominant in nitrogen removal, while COD oxidation and microbe proliferation played the main role in COD removal.
  15. Su LL, S K TC, Lim SL, Chen Y, Tan EA, Pai NN, et al.
    Ann Acad Med Singap, 2010 Sep;39(9):675-5.
    PMID: 20957301
    INTRODUCTION: Breast milk fatty acids play a major role in infant development. However, no data have compared the breast milk composition of different ethnic groups living in the same environment. We aimed to (i) investigate breast milk fatty acid composition of three ethnic groups in Singapore and (ii) determine dietary fatty acid patterns in these groups and any association with breast milk fatty acid composition.

    MATERIALS AND METHODS: This was a prospective study conducted at a tertiary hospital in Singapore. Healthy pregnant women with the intention to breastfeed were recruited. Diet profile was studied using a standard validated 3-day food diary. Breast milk was collected from mothers at 1 to 2 weeks and 6 to 8 weeks postnatally. Agilent gas chromatograph (6870N) equipped with a mass spectrometer (5975) and an automatic liquid sampler (ALS) system with a split mode was used for analysis.

    RESULTS: Seventy-two breast milk samples were obtained from 52 subjects. Analysis showed that breast milk ETA (Eicosatetraenoic acid) and ETA:EA (Eicosatrienoic acid) ratio were significantly different among the races (P = 0.031 and P = 0.020), with ETA being the highest among Indians and the lowest among Malays. Docosahexaenoic acid was significantly higher among Chinese compared to Indians and Malays. No difference was demonstrated in n3 and n6 levels in the food diet analysis among the 3 ethnic groups.

    CONCLUSIONS: Differences exist in breast milk fatty acid composition in different ethnic groups in the same region, although no difference was demonstrated in the diet analysis. Factors other than maternal diet may play a role in breast milk fatty acid composition.

  16. He B, Chen Y, Ismail N, Chen G, Ni L
    Heliyon, 2024 Jan 15;10(1):e23812.
    PMID: 38223717 DOI: 10.1016/j.heliyon.2023.e23812
    Based on the framework theory of industrial digitization, digital industrialization, digital governance and digital value-added in a sustainable environment, this paper systematically studies the relevant elements of governance and value distribution in the sustainable environment of global trade, and its impact on the development path of human beings. This paper explores the way to embed digital technology into the global value chain to realize digital empowerment, measures the competitiveness index of Keqiao's textile industry in the global value chain, analyzes the technical and environmental challenges faced by China's textile industry in the digital age, and proposes the corresponding countermeasures to deal with the impact of global value chain participation and to improve the international competitiveness of China's textile industry.
  17. Yap SF, Wong PW, Chen YC, Rosmawati M
    PMID: 12118437
    A retrospective study was carried out to determine the frequency of the pre-core stop codon mutant virus in a group of chronic hepatitis B carriers: 81 cases were considered [33 hepatits B e antigen (HBe) positive and 48 HBe negative]. All of the HBe positive cases had detectable viral DNA by hybridization analysis; in the case of the HBe negative cases, one third had detectable viral DNA by hybridization analysis and two thirds had HBV DNA detectable by polymerase chain reaction (PCR) amplification. Pre-core stop codon mutant detection was carried out on all specimens using allele-specific oligonucleotide hybridization following PCR amplification of the target sequence. The pre-core mutant was detected in 13/33 (39.4%) of HBe positive cases and in 32/48 (66.7%) of HBe negative cases. Sequence analysis was carried out on 8 of the 16 HBe negative specimens that did not carry the pre-core mutant virus to determine the molecular basis for the HBe minus phenotype in these cases: the 1762/1764 TA paired mutation in the second AT rich region of the core promoter was detected in five cases; a start codon mutation was detected in one case. The predominant mutation resulting in the HBe minus phenotype in our isolates was the 1896A pre-core ("pre-core stop codon") mutation; other mutations responsible for the phenotype included the core promoter paired mutation and pre-core start codon mutation. In view of the high frequency of the pre-core mutant virus, sequence analysis was performed to determine the virus genotype on the basis of the nucleotide sequence of codon 15. The sequences of 21 wild type virus (14 HBe positive and 7 HBe negative cases) were examined: 15 were found to be codon 15 CCT variants (71.4%); the frequency in the HBe positive group was 12/14 (85.7%), while that in the HBe negative group was 3/7 (42.9%). The high frequency of the codon 15 CCT variant in association with the frequent occurrence of the pre-core mutant in our isolates concurs with the results of other studies.
  18. Wong JY, Chen YS, Chakravarthi S, Judson JP, L SR, Er HM
    Exp Ther Med, 2013 Nov;6(5):1247-1250.
    PMID: 24223653
    Euphorbia hirta is widely used in traditional remedies and has been used cross-culturally for generations against maladies such as asthma, skin ailments and hypertension. Previous studies have demonstrated that Euphorbia hirta has antibacterial activity, and have also indicated certain antimolluscidal, antimalarial and anti-inflammatory properties, the latter of which have been suggested to be more pronounced than those of the rheumatological drug, etanercept. To date, no studies have identified the anatomical effects of this herb on the organs of test animals. This study aimed to identify the effects of Euphorbia hirta on the ultrastructure of the murine liver, kidney and aorta. A total of 32 adult male Sprague-Dawley rats were divided into four groups; three groups were fed with aqueous extracts of Euphorbia hirta at doses of 1, 10 and 50 mg/kg, respectively, every alternate day for 50 days, while one group served as a control. The animals were later sacrificed and the liver, kidney and aorta harvested for examination by electron microscopy. The aorta showed no ultrastructural changes across the groups. Renal and hepatic tissue from the treated groups demonstrated dose-dependent injuries, which showed architectural damage beginning in the nuclei and spreading outwards. Taking into consideration the properties of Euphorbia hirta that have been described in previous studies, in addition to the results from the present study, it appears that the herb may exhibit similar effects to those of the quinolone group of antibiotics. Further in-depth investigations are required into the potential effects of Euphorbia hirta, deleterious and otherwise.
  19. Chen Y, Li H, Ye Z, Găman MA, Tan SC, Zhu F
    Eur J Pharmacol, 2020 Nov 05;886:173458.
    PMID: 32763300 DOI: 10.1016/j.ejphar.2020.173458
    Metformin administration has been reported to influence the carotid intima-media thickness (CIMT) in humans. However, since previously conducted studies have yielded inconsistent results, the exact effect of metformin on CIMT remains unclear. Causes that could lead to inconsistency in reported research could be the duration and dose of the intervention, as well as the sample size. To address this inconsistency, we conducted a systematic review and meta-analysis to evaluate the influence of metformin on CIMT in human subjects. We identified eligible studies by searching several electronic databases (EMBASE, PubMed-MEDLINE, Web of Science and Google Scholar) up to December 12, 2019. Data were pooled using the random-effects model. Combining data from 1087 participants (9 studies), our meta-analysis revealed that the administration of metformin resulted in a significant reduction in CIMT (WMD = -0.049 mm; 95% CI: -0.095, -0.004). Stratified analyses showed that an intervention lasting ≥12 months (WMD: -0.084 mm, 95% CI: -0.145, -0.024) and an intake of metformin ≤1500 mg/day (WMD: -0.081 mm, 95% CI: -0.132, -0.029) resulted in a significantly greater reduction in CIMT. However, an intervention duration of less than 12 months and an intake of metformin ˃1500 mg/day yielded no significant effects on CIMT. The results of the current study confirm that metformin administration is associated with a significant reduction in CIMT. Taking into account that CIMT reflects the burden of atherosclerosis, the clinical utility of metformin might also be related to its anti-atherogenic effects.
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