Displaying publications 501 - 520 of 1086 in total

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  1. Performance of a novel casing made of chitosan under traditional sausage manufacturing conditions
    Adzaly NZ, Jackson A, Kang I, Almenar E
    Meat Sci, 2016 Mar;113:116-23.
    PMID: 26656870 DOI: 10.1016/j.meatsci.2015.11.023
    The goal of this study was to validate the commercial feasibility of a novel casing formed from chitosan containing cinnamaldehyde (2.2%, w/v), glycerol (50%, w/w) and Tween 80 (0.2% w/w) under traditional sausage manufacturing conditions. Meat batter was stuffed into both chitosan and collagen (control) casings and cooked in a water bath. Before and after cooking, both casings were compared for mechanical, barrier, and other properties. Compared to collagen, the chitosan casing was a better (P≤0.05) barrier to water, oxygen, liquid smoke, and UV light. In mechanical and other properties, the chitosan casing had higher (P≤0.05) tensile strength, lower (P≤0.05) elongation at break and tensile energy to break, and better (P≤0.05) transparency whereas a similar (P>0.05) water solubility to the collagen casing. Overall, the chitosan casing was less affected by sausage manufacturing conditions than the collagen casing, indicating that chitosan casing has potential as an alternative to the current collagen casing in the manufacture of sausages.
    Matched MeSH terms: Oxygen
  2. Fulltext Structural, Optical and Antibacterial Efficacy of Pure and Zinc-Doped Copper Oxide against Pathogenic Bacteria
    Khalid A, Ahmad P, Alharthi AI, Muhammad S, Khandaker MU, Rehman M, et al.
    Nanomaterials (Basel), 2021 Feb 10;11(2).
    PMID: 33578945 DOI: 10.3390/nano11020451
    Copper oxide and Zinc (Zn)-doped Copper oxide nanostructures (CuO-NSs) are successfully synthesized by using a hydrothermal technique. The as-obtained pure and Zn-doped CuO-NSs were tested to study the effect of doping in CuO on structural, optical, and antibacterial properties. The band gap of the nanostructures is calculated by using the Tauc plot. Our results have shown that the band gap of CuO reduces with the addition of Zinc. Optimization of processing conditions and concentration of precursors leads to the formation of pine needles and sea urchin-like nanostructures. The antibacterial properties of obtained Zn-doped CuO-NSs are observed against Gram-negative (Pseudomonasaeruginosa,Klebsiellapneumonia,Escherichiacoli) and Gram-positive (Staphylococcusaureus) bacteria via the agar well diffusion method. Zn doped s are found to have more effective bacterial resistance than pure CuO. The improved antibacterial activity is attributed to the reactive oxygen species (ROS) generation.
    Matched MeSH terms: Reactive Oxygen Species
  3. Lineage-related and particle size-dependent cytotoxicity of chitosan nanoparticles on mouse bone marrow-derived hematopoietic stem and progenitor cells
    Omar Zaki SS, Katas H, Hamid ZA
    Food Chem Toxicol, 2015 Nov;85:31-44.
    PMID: 26051352 DOI: 10.1016/j.fct.2015.05.017
    Chitosan nanoparticles (CSNPs) have potential applications in stem cell research. In this study, ex vivo cytotoxicity of CSNPs on mouse bone marrow-derived (MBMCs) hematopoietic stem and progenitor cells (HSPCs) was determined. MBMCs were exposed to CSNPs of different particle sizes at various concentrations for up to 72 h. Cytotoxicity effect of CSNPs on MBMCs was determined using MTT, Live/Dead Viability/Cytotoxicity assays and flow cytometry analysis of surface antigens on HSCs (Sca-1(+)), myeloid-committed progenitors (CD11b(+), Gr-1(+)), and lymphoid-committed progenitors (CD45(+), CD3e(+)). At 24 h incubation, MBMCs' viability was not affected by CSNPs. At 48 and 72 h, significant reduction was detected at higher CSNPs concentrations. Small CSNPs (200 nm) significantly reduced MBMCs' viability while medium-sized particle (∼400 nm) selectively promoted MBMCs growth. Surface antigen assessment demonstrated lineage-dependent effect. Significant decrease in Sca-1(+) cells percentage was observed for medium-sized particle at the lowest CSNPs concentration. Meanwhile, reduction of CD11b(+) and Gr-1(+) cells percentage was detected at high and intermediate concentrations of medium-sized and large CSNPs. Percentage of CD45(+) and CD3e(+) cells along with ROS levels were not significantly affected by CSNPs. In conclusion, medium-sized and large CSNPs were relatively non-toxic at lower concentrations. However, further investigations are necessary for therapeutic applications.
    Matched MeSH terms: Reactive Oxygen Species
  4. Fulltext Is targeting autophagy mechanism in cancer a good approach? The possible double-edge sword effect
    Lim SM, Mohamad Hanif EA, Chin SF
    Cell Biosci, 2021 Mar 20;11(1):56.
    PMID: 33743781 DOI: 10.1186/s13578-021-00570-z
    Autophagy is a conserved cellular process required to maintain homeostasis. The hallmark of autophagy is the formation of a phagophore that engulfs cytosolic materials for degradation and recycling to synthesize essential components. Basal autophagy is constitutively active under normal conditions and it could be further induced by physiological stimuli such as hypoxia, nutrient starvation, endoplasmic reticulum stress,energy depletion, hormonal stimulation and pharmacological treatment. In cancer, autophagy is highly context-specific depending on the cell type, tumour microenvironment, disease stage and external stimuli. Recently, the emerging role of autophagy as a double-edged sword in cancer has gained much attention. On one hand, autophagy suppresses malignant transformation by limiting the production of reactive oxygen species and DNA damage during tumour development. Subsequently, autophagy evolved to support the survival of cancer cells and promotes the tumourigenicity of cancer stem cells at established sites. Hence, autophagy is an attractive target for cancer therapeutics and researchers have been exploiting the use of autophagy modulators as adjuvant therapy. In this review, we present a summary of autophagy mechanism and controlling pathways, with emphasis on the dual-role of autophagy (double-edged sword) in cancer. This is followed by an overview of the autophagy modulation for cancer treatment and is concluded by a discussion on the current perspectives and future outlook of autophagy exploitation for precision medicine.
    Matched MeSH terms: Reactive Oxygen Species
  5. Fulltext Biochemical and molecular aspects of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis: a review
    Venkatachalam K, Vinayagam R, Arokia Vijaya Anand M, Isa NM, Ponnaiyan R
    Toxicol Res (Camb), 2020 Feb;9(1):2-18.
    PMID: 32440334 DOI: 10.1093/toxres/tfaa004
    1,2-dimethylhydrazine (DMH) is a member in the class of hydrazines, strong DNA alkylating agent, naturally present in cycads. DMH is widely used as a carcinogen to induce colon cancer in animal models. Exploration of DMH-induced colon carcinogenesis in rodent models provides the knowledge to perceive the biochemical, molecular, and histological mechanisms of different stages of colon carcinogenesis. The procarcinogen DMH, after a series of metabolic reactions, finally reaches the colon, there produces the ultimate carcinogen and reactive oxygen species (ROS), which further alkylate the DNA and initiate the development of colon carcinogenesis. The preneolpastic lesions and histopathological observations of DMH-induced colon tumors may provide typical understanding about the disease in rodents and humans. In addition, this review discusses about the action of biotransformation and antioxidant enzymes involved in DMH intoxication. This understanding is essential to accurately identify and interpret alterations that occur in the colonic mucosa when evaluating natural or pharmacological compounds in DMH-induced animal colon carcinogenesis.
    Matched MeSH terms: Reactive Oxygen Species
  6. Fulltext Pregnancy with COVID-19 in Malaysia: A case series
    Siti Hayati Mohd Nahwari, Bahiyah Abdullah, Suzanna Daud, Norhana Mohd Kasim, Norhana Mohd Kasim
    Journal of Clinical and Health Sciences, 2021;6(1):58-63.
    MyJurnal
    This case series highlights the outcome of four pregnancies complicated with COVID-19, as
    the pandemic of coronavirus disease 2019 (COVID-19) poses a lot of uncertainties due to lack
    of scientific evidence in guiding the management of pregnancy with COVID-19. The women
    were between 25 and 31 years of age and of 35 - 39 weeks of gestation with no underlying
    medical problems. Three women were delivered via caesarean section and one woman was
    delivered via ventouse delivery due to poor progress during the second stage of labour. Two
    women were in stage 4 of the disease (having breathing difficulties and requiring oxygen
    support) at presentations. One of them was treated with hydroxychloroquine (HC) only while
    another one was treated with both HC and antiviral medications; none required assisted
    ventilation during their hospitalizations. There is no vertical transmission of COVID-19 disease
    observed in this case series.
    Matched MeSH terms: Oxygen
  7. Fulltext Physicochemical properties and water quality parameter of paddy soil and water and their relationship with pesticides concentration
    Siti Zulfa Zaidon, Yu Bin Ho, Zailina Hashim, Nazamid Saari, Sarva Mangala Praveena
    Malaysian Journal of Medicine and Health Sciences, 2020;16(2):206-214.
    MyJurnal
    Introduction: Pesticides may influence the physicochemical properties of soil and the water quality parameters, which is vital in maintaining soil fertility and producing high quality crops. Objective: This study aims to determine the relationship between the concentration of pesticides, the physicochemical properties of the paddy soil samples and the water quality parameters of paddy water samples. Methods: A total of 72 soil and 72 water samples were collected in Tanjung Karang, Malaysia. The paddy soil and water were extracted using Quick, Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) and solid phase extraction (SPE) techniques respectively. The concentrations of pesti- cides were analysed in ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The relationship of the concentration of target pesticides and the paddy soil and water physicochemical properties were studied using Spearman correlation. Results: In paddy soil, the concentration of propiconazole shows moderate positive correlation with manganese (Mn) (r = 0.587) (p 0.01). Meanwhile buprofezin-total organic carbon (TOC) (r = -0.55) (p 0.01), imidacloprid-cation exchange capacity (CEC) (r = -0.519) (p 0.01), pymetrozine-sodium (Na) (r = -0.588) (p 0.01), and trifloxystrobin-calcium (Ca) (r = 0.566) (p 0.01) showed moderate negative correlation. Whereas in water, trifloxystrobin showed significant positive correlation with turbidity (r = 0.718) (p 0.01) and te- buconazole showed negative correlation to dissolved oxygen (DO) (r = 0.634) (p 0.01). Conclusion: The presence of pesticides in paddy field may influence the soil and water quality, thus regular monitoring of pesticides usage and nutrient management in soil is deemed important.
    Matched MeSH terms: Oxygen
  8. PHOTOSYNTHETIC AND RESPIRATORY CHARACTERISTICS OF MALAYAN SUN AND SHADE FERNS
    Nasrulhaq-Boyce A, Mohamed MAH
    New Phytol, 1987 Jan;105(1):81-88.
    PMID: 33874033 DOI: 10.1111/j.1469-8137.1987.tb00112.x
    A comparative study of four Malayan ferns, Christensenia aesculifolia (Bl.) Maxon, Tectaria singaporeana (Wall.) Ching, Abacopteris multilineata (Wall.) Ching and Hymenophyllum polyanthos Sw. from shady habitats and another four, Dicranopteris linearis (Burm.) Und., Lygodium scandens (L.) Sw., Blechnum orientate Linn, and Stenochlaena palustris (Burm.) Bedd. from sunlit habitats showed that the total chlorophyll content expressed on a gram fresh weight basis was greater in the shade ferns. There was little difference in the chlorophyll content between the sun and shade ferns when it was expressed on a per unit leaf area basis. The protein and protohaem content was greater in the sun ferns. Measurements of the in vitro photochemical activities of the photosystems I and II in isolated chloroplasts by means of an oxygen electrode showed higher rates in the sun ferns. As determined by spectrophotometric analysis, the photosynthetic cytochrome content from isolated chloroplasts was greater in the sun ferns. The results indicate that the sun ferns have physiological characteristics favouring greater capacity for photosynthesis. Mitochondria isolated from the sun ferns showed faster rates of electron transport using exogenous NADH as substrate.
    Matched MeSH terms: Oxygen
  9. Differential genotoxicity mechanisms of silver nanoparticles and silver ions
    Li Y, Qin T, Ingle T, Yan J, He W, Yin JJ, et al.
    Arch Toxicol, 2017 Jan;91(1):509-519.
    PMID: 27180073 DOI: 10.1007/s00204-016-1730-y
    In spite of many reports on the toxicity of silver nanoparticles (AgNPs), the mechanisms underlying the toxicity are far from clear. A key question is whether the observed toxicity comes from the silver ions (Ag(+)) released from the AgNPs or from the nanoparticles themselves. In this study, we explored the genotoxicity and the genotoxicity mechanisms of Ag(+) and AgNPs. Human TK6 cells were treated with 5 nM AgNPs or silver nitrate (AgNO3) to evaluate their genotoxicity and induction of oxidative stress. AgNPs and AgNO3 induced cytotoxicity and genotoxicity in a similar range of concentrations (1.00-1.75 µg/ml) when evaluated using the micronucleus assay, and both induced oxidative stress by measuring the gene expression and reactive oxygen species in the treated cells. Addition of N-acetylcysteine (NAC, an Ag(+) chelator) to the treatments significantly decreased genotoxicity of Ag(+), but not AgNPs, while addition of Trolox (a free radical scavenger) to the treatment efficiently decreased the genotoxicity of both agents. In addition, the Ag(+) released from the highest concentration of AgNPs used for the treatment was measured. Only 0.5 % of the AgNPs were ionized in the culture medium and the released silver ions were neither cytotoxic nor genotoxic at this concentration. Further analysis using electron spin resonance demonstrated that AgNPs produced hydroxyl radicals directly, while AgNO3 did not. These results indicated that although both AgNPs and Ag(+) can cause genotoxicity via oxidative stress, the mechanisms are different, and the nanoparticles, but not the released ions, mainly contribute to the genotoxicity of AgNPs.
    Matched MeSH terms: Reactive Oxygen Species/antagonists & inhibitors; Reactive Oxygen Species/metabolism; Reactive Oxygen Species/agonists
  10. Fulltext Comparison of biogenic silver nanoparticles formed by Momordica charantia and Psidium guajava leaf extract and antifungal evaluation
    Nguyen DH, Vo TNN, Nguyen NT, Ching YC, Hoang Thi TT
    PLoS One, 2020;15(9):e0239360.
    PMID: 32960911 DOI: 10.1371/journal.pone.0239360
    Exploiting plant extracts to form metallic nanoparticles has been becoming the promising alternative routes of chemical and physical methods owing to environmentally friendly and abundantly renewable resources. In this study, Momordica charantia and Psidium guajava leaf extract (MC.broth and PG.broth) are exploited to fabricate two kinds of biogenic silver nanoparticles (MC.AgNPs and PG.AgNPs). Phytoconstituent screening is performed to identify the categories of natural compounds in MC.broth and PG.broth. Both extracts contain wealthy polyphenols which play a role of reducing agent to turn silver (I) ions into silver nuclei. Trace alkaloids, rich saponins and other oxygen-containing compounds creating the organic corona surrounding nanoparticles act as stabilizing agents. MC.AgNPs and PG.AgNPs are characterized by UV-vis and FTIR spectrophotometry, EDS and TEM techniques. FTIR spectra indicate the presence of O-H, C = O, C-O-C and C = C groups on the surface of silver nanoparticles which is corresponded with three elements of C, O and Ag found in EDS analysis. TEM micrographs show the spherical morphology of MC.AgNPs and PG.AgNPs. MC.AgNPs were 17.0 nm distributed in narrow range of 5-29 nm, while the average size of PG.AgNPs were 25.7 nm in the range of 5-53 nm. Further, MC.AgNPs and PG.AgNPs exhibit their effectively inhibitory ability against A. niger, A. flavus and F. oxysporum as dose-dependence. Altogether, MC.AgNPs and PG.AgNPs will have much potential in scaled up production and become the promising fungicides for agricultural applications.
    Matched MeSH terms: Oxygen Compounds
  11. Fulltext Data set on trace metals in surface sediment and water from a sub-tropical estuarine system, Bay of Bengal, Bangladesh
    Hossain MB, Habib SB, Hossain MS, Jolly YN, Kamal AHM, Idris MH, et al.
    Data Brief, 2020 Aug;31:105911.
    PMID: 32637507 DOI: 10.1016/j.dib.2020.105911
    Meghna River Estuary, the largest estuarine system (GBM, Ganges-Brahmaputra-Meghna) in Bangladesh, is a major spawning ground of national fish, Hilsha shad. In this study, we collected 24 surface sediment and 24 water samples from the entire lower estuary (4 sites, 3 sampling points from each site, 2 replicas from each sampling point) to detect trace/heavy metals. Sediment samples were collected from the top surface soil (0-5 cm) using Ekman grab sampler and water samples from 5 cm below the surface layer using plastic water bottles. After collection, sediment and water samples were preserved as necessary using HNO3 (for water). Immediately after reaching the laboratory, sediment samples were dried in an oven at 70°C until the constant weight gained. The metals were then analyzed using energy-dispersive X-ray fluorescence method (EDXRF) and calculated the metal concentrations. In total, 12 metals were detected and the average value (mg/Kg) of all metals for sediment samples followed the descending order of Fe > Ca > K >Ti >Sr >Zr >Rb> Cu > Zn >Pb >As > Ni, and for water the order (µg/mL) of Fe >Ti > Ca > Co >Mn > Ni > Zn >Sr > Cu > As > Se . Besides, several physicochemical parameters i.e. water pH, soil pH, temperature, salinity, dissolved oxygen, hardness, and alkalinity of the 12 sampling points were also measured in-situ using handheld instruments.
    Matched MeSH terms: Oxygen
  12. Fulltext Bystander Effect Induced in Breast Cancer (MCF-7) and Human Osteoblast Cell Lines (hFOB 1.19) with HDR-Brachytherapy
    Zainudin Nh M, R A, W N R
    J Biomed Phys Eng, 2020 Jun;10(3):319-328.
    PMID: 32637376 DOI: 10.31661/jbpe.v0i0.1135
    Background: Radiation induced bystander effects (RIBEs) occurs in unirradiated cells exhibiting indirect biological effect as a consequence of signals from other irradiated cells in the population.

    Objective: In this study, bystander effects in MCF-7 breast cancer cells and hFOB 1.19 normal osteoblast cells irradiated with gamma emitting HDR Brachytherapy Ir-192 source were investigated.

    Material and Methods: In this in-vitro study, bystander effect stimulation was conducted using medium transfer technique of irradiated cells to the non-irradiated bystander cells. Cell viability, reactive oxygen species (ROS) generation and colony forming assay was employed to evaluate the effect.

    Results: Results indicate that the exposure to the medium irradiated MCF-7 induced significant bystander killing and decreased the survival fraction of bystander MCF-7 and hFOB from 1.19 to 81.70 % and 65.44 %, respectively. A significant decrease in survival fraction was observed for hFOB 1.19 bystander cells (p < 0.05). We found that the rate of hFOB 1.19 cell growth significantly decreases to 85.5% when added with media from irradiated cells. The ROS levels of bystander cells for both cell lines were observed to have an increase even after 4 h of treatment. Our results suggest the presence of bystander effects in unirradiated cells exposed to the irradiated medium.

    Conclusion: These data provide evidence that irradiated MCF-7 breast cancer cells can induce bystander death in unirradiated MCF-7 and hFOB 1.19 bystander cells. Increase in cell death could also be mediated by the ROS generation during the irradiation with HDR brachytherapy.

    Matched MeSH terms: Reactive Oxygen Species
  13. Fulltext A review on development of blood substitute
    Mislia Othman, Muhammad Azrul Zabidi
    Jurnal Sains Kesihatan Malaysia, 2020;18(2):59-71.
    MyJurnal
    This review paper aims to present an overview of the development of blood substitute particularly red blood cell substitute or artificial oxygen carrier. Knowledge on human blood inspired from the understanding of human blood circulation system. Ibn Nafis was first to describe that blood flow through respiratory system before entering the heart. This finding denied the claim that tiny pores present within the septum of the heart. Then, William Harvey further described human cardiovascular system in detail and contributed to better understanding on the roles of blood in body. Several blood transfusions were attempted using blood collected from human, animal and other blood substitutes such as milk before the practice was banned for almost 150 years in Europe. Major discoveries on blood group and antibody reaction have made blood transfusion safer. However, several issues and challenges have re-triggered the exploration to develop red cell substitutes. Two approaches have been taken to develop the red blood cell substitute which are classified into biological and chemical based oxygen carriers. The earliest efforts have been on haemoglobin based oxygen carrier (HBOC) and perfluorocarbon (PFC) while the recent developement are on polymer-based oxygen carrier and in-vitro stem cell derived red blood cell.
    Matched MeSH terms: Oxygen
  14. Data on combustion, performance and emissions of a 6.8 L, 6-cylinder, Tier II diesel engine
    Wan Mansor WN, Abdullah S, Jarkoni MNK, Vaughn JS, Olsen DB
    Data Brief, 2020 Dec;33:106580.
    PMID: 33304969 DOI: 10.1016/j.dib.2020.106580
    A diesel engine has been a desirable machine due to its better fuel efficiency, reliability, and higher power output. It is widely used in transportations, locomotives, power generation, and industrial applications. The combustion of diesel fuel emits harmful emissions such as unburned hydrocarbons (HC), particulate matter (PM), nitrogen oxides (NOx), and carbon monoxides (CO). This article presents data on the efficiency, combustion, and emission of a 4-stroke diesel engine. The engine is a 6.8 L turbocharged 6-cylinder Tier II diesel engine fitted with a common rail injection system. The test was carried out at the Powerhouse Energy Campus, Colorado State University Engines and Energy Conversion facility. The ISO Standard 8178:4 Cycle D2 cycle was adopted for this study consists of five test runs at 1800 rpm. During the testing, CO, carbon dioxide (CO2), oxygen (O2), NOx, PM, unburned HC as a total HC (THC), methane (CH4), formaldehyde (CH2O), and volatile organic compound (VOC) emissions were measured. At the same time, the data acquisition system recorded the combustion data. The engine's performance is characterized by the brake specific fuel combustion (BSFC) and thermal efficiency. A dataset of correlations among the parameters was also presented in this article.
    Matched MeSH terms: Oxygen
  15. Ancillary palm oil fuel ash (POFA) in sequencing batch reactor for enhancing recalcitrant pollutants removal from domestic wastewater
    Lyn CW, Bashir MJ, Wong LY, Lim JW, Sethupathi S, Ng CA
    Chemosphere, 2020 Nov 25.
    PMID: 33276996 DOI: 10.1016/j.chemosphere.2020.129050
    Domestic wastewater has been generated massively along with rapid growth of population and economic. Biological treatment using sequencing batch reactor (SBR) augmented with palm oil fuel ash (POFA) was investigated for the first time. The performance of POFA in enhancing biological treatment of wastewater has not been tested. The porosity property of POFA can improve SBR efficiency by promoting growth of mixed liquor suspended solids (MLSS) and formation of larger flocs for settling and facilitating attachment of microorganisms and pollutants onto POFA surfaces. The properties of POFA were tested to identify morphological properties, particle size, surface area, chemical compositions. Four SBRs, namely SBR1, SBR2, SBR3 and SBR4 were provided with aeration rate of 1, 2, 3 and 4 L/min, respectively. Each reactor was augmented with different dosages of POFA. Optimum aeration rate and POFA concentration were identified by the performance of SBRs in removing chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N) and colour from domestic wastewater. The results showed the most efficient COD (97.8%), NH3-N (99.4%) and colour (98.8%) removals were achieved at optimum POFA concentration of 4 g/L in SBR and aeration rate of 1 L/min. The study also found that higher aeration rate would contribute to the smaller specific size of flocs and decrease the pollutant removal efficiency.
    Matched MeSH terms: Biological Oxygen Demand Analysis
  16. Water Quality Modelling for River Activities Management: Example from a Low- and Middle-Income Country
    Zahidi I, Wilson G, Brown K, Hou FKK
    J Health Pollut, 2020 Dec;10(28):201207.
    PMID: 33324504 DOI: 10.5696/2156-9614-10.28.201207
    Background: Rivers are susceptible to pollution and water pollution is a growing problem in low- and middle-income countries (LMIC) with rapid development and minimal environmental protections. There are universal pollutant threshold values, but they are not directly linked to river activities such as sand mining and aquaculture. Water quality modelling can support assessments of river pollution and provide information on this important environmental issue.

    Objectives: The objective of the present study was to demonstrate water quality modelling methodology in reviewing existing policies for Malaysian river catchments based on an example case study.

    Methods: The MIKE 11 software developed by the Danish Hydraulic Institute was used to model the main pollutant point sources within the study area - sand mining and aquaculture. Water quality data were obtained for six river stations from 2000 to 2015. All sand mining and aquaculture locations and approximate production capacities were quantified by ground survey. Modelling of the sand washing effluents was undertaken with the advection-dispersion module due to the nature of the fine sediment. Modelling of the fates of aquaculture deposits required both advection-dispersion and Danish Hydraulic Institute ECO Lab modules to simulate the detailed interactions between water quality determinants.

    Results: According to the Malaysian standard, biochemical oxygen command (BOD) and ammonium (NH4) parameters fell under Class IV at most of the river reaches, while the dissolved oxygen (DO) parameter varied between Classes II to IV. Total suspended solids (TSS) fell within Classes IV to V along the mid river reaches of the catchment.

    Discussion: Comparison between corresponding constituents and locations showed that the water quality model reproduced the long-term duration exceedance for the main body of the curves. However, the water quality model underestimated the infrequent high concentration observations. A standard effluent disposal was proposed for the development of legislation and regulations by authorities in the district that could be replicated for other similar catchments.

    Conclusions: Modelling pollutants enables observation of trends over the years and the percentage of time a certain class is exceeded for each individual pollutant. The catchment did not meet Class II requirements and may not be able to reach Class I without extensive improvements in the quality and reducing the quantity of both point and non-point effluent sources within the catchment.

    Competing Interests: The authors declare no competing financial interests.

    Matched MeSH terms: Oxygen
  17. [Molecular regulatory mechanisms of hypoxia-inducible factor and interventional effect of Chinese herbal medicine]
    Bu-Hui L, Mei-Zi W, Wei S, Yi-Gang W, Wei WU, Qi-Jun F, et al.
    Zhongguo Zhong Yao Za Zhi, 2020 Oct;45(20):4805-4811.
    PMID: 33350250 DOI: 10.19540/j.cnki.cjcmm.20200630.602
    Hypoxia-inducible factors(HIFs)are the key transcription factors that sense and regulate cellular oxygen concentration in vivo. HIF-1 is composed of 2 subunits,α and β,in which,the molecular regulatory mechanism of HIF-1α involves the main processes of its degradation and activation. The degradation of HIF-1α is regulated by oxygen-dependent pathways,including "von hippel-lindau protein(pVHL)-dependent pathway" and "pVHL-independent pathway". The activation of HIF-1α is regulated by oxygen-independent pathways,including mammalian target of rapamycin(mTOR)/eukaryotic initiation factor 4 E-binding protein 1(4 EBP1)/HIF-1α pathway,phosphatidylinositol 3-kinase(PI3 K)/proteirrserinc-threonine kinases(Akt)/HIF-1α pathway and silent information regulator1(Sirt1)/HIF-1α pathway. In recent years,based on the molecular regulatory mechanism of HIFs,Roxadustat,a new drug for the treatment of renal anemia has been developed. Besides, some macromolecular substances with similar pharmacological effect to HIFs have been found in the extracts from Chinese herbal medicine(CHM),such as emodin,notoginseng triterpenes,honokiol and clematichinenoside. These natural macromolecular substances play the regulatory roles in inflammatory response,epigenetic modification and auto-phagy. It is worth noting that,for common hypoxic-related diseases including diabetic kidney disease,HIFs-mediated "pyroptosis" may be a new target of CHMs for clearing dampness and heat and its representative classical prescriptions(Ermiao Pills)in treating inflammatory injury in cells and tissues.
    Matched MeSH terms: Oxygen
  18. Fulltext o-Vanillin Derived Schiff Bases and Their Organotin(IV) Compounds: Synthesis, Structural Characterisation, In-Silico Studies and Cytotoxicity
    Yusof ENM, Latif MAM, Tahir MIM, Sakoff JA, Simone MI, Page AJ, et al.
    Int J Mol Sci, 2019 Feb 15;20(4).
    PMID: 30781445 DOI: 10.3390/ijms20040854
    Six new organotin(IV) compounds of Schiff bases derived from S-R-dithiocarbazate [R = benzyl (B), 2- or 4-methylbenzyl (2M and 4M, respectively)] condensed with 2-hydroxy-3-methoxybenzaldehyde (oVa) were synthesised and characterised by elemental analysis, various spectroscopic techniques including infrared, UV-vis, multinuclear (¹H, 13C, 119Sn) NMR and mass spectrometry, and single crystal X-ray diffraction. The organotin(IV) compounds were synthesised from the reaction of Ph₂SnCl₂ or Me₂SnCl₂ with the Schiff bases (S2MoVaH/S4MoVaH/SBoVaH) to form a total of six new organotin(IV) compounds that had a general formula of [R₂Sn(L)] (where L = Schiff base; R = Ph or Me). The molecular geometries of Me₂Sn(S2MoVa), Me₂Sn(S4MoVa) and Me₂Sn(SBoVa) were established by X-ray crystallography and verified using density functional theory calculations. Interestingly, each experimental structure contained two independent but chemically similar molecules in the crystallographic asymmetric unit. The coordination geometry for each molecule was defined by thiolate-sulphur, phenoxide-oxygen and imine-nitrogen atoms derived from a dinegative, tridentate dithiocarbazate ligand with the remaining positions occupied by the methyl-carbon atoms of the organo groups. In each case, the resulting five-coordinate C₂NOS geometry was almost exactly intermediate between ideal trigonal-bipyramidal and square-pyramidal geometries. The cytotoxic activities of the Schiff bases and organotin(IV) compounds were investigated against EJ-28 and RT-112 (bladder), HT29 (colon), U87 and SJ-G2 (glioblastoma), MCF-7 (breast) A2780 (ovarian), H460 (lung), A431 (skin), DU145 (prostate), BE2-C (neuroblastoma) and MIA (pancreatic) cancer cell lines and one normal breast cell line (MCF-10A). Diphenyltin(IV) compounds exhibited greater potency than either the Schiff bases or the respective dimethyltin(IV) compounds. Mechanistic studies on the action of these compounds against bladder cancer cells revealed that they induced the production of reactive oxygen species (ROS). The bladder cancer cells were apoptotic after 24 h post-treatment with the diphenyltin(IV) compounds. The interactions of the organotin(IV) compounds with calf thymus DNA (CT-DNA) were experimentally explored using UV-vis absorption spectroscopy. This study revealed that the organotin(IV) compounds have strong DNA binding affinity, verified via molecular docking simulations, which suggests that these organotin(IV) compounds interact with DNA via groove-binding interactions.
    Matched MeSH terms: Reactive Oxygen Species
  19. Fulltext Basic technology and proper usage of home health monitoring devices
    Mondal H, Mondal S
    Malays Fam Physician, 2021 Mar 25;16(1):8-14.
    PMID: 33948137 DOI: 10.51866/rv1097
    Home health monitoring devices are consumer-grade devices that help to monitor the health of individuals at home. These devices are usually low-cost and easily procurable, and they can be operated by patients or their caretakers with minimal training. However, improper usage of these devices may provide erroneous results, which can lead to an unnecessary hospital visit or teleconsultation. In this article, we discuss the basic technology and proper usage of some of these devices, namely automatic blood pressure monitors, blood glucose monitors, body fat monitors, pulse oximeters, electrocardiographs, digital thermometers, and infrared thermometers. This brief document intends to help primary health care professionals and their patients use these devices.
    Matched MeSH terms: Oxygen
  20. Fulltext PHYTOTOXIC ACTIVITY OF GERANIOL-TREATED LEMONGRASS LEAF MULCH AGAINST COMMON WEEDS IN NURSERIES
    NORLIYANA FATIN OMAR, CHUAH TSE SENG
    UMT Journal of Undergraduate Research, 2019;1(1):1-11.
    MyJurnal
    Hand weeding continues to be one of the most laborious aspects of nursery
    maintenance. Oxygenated monoterpene, an important group of secondary metabolite found in
    essential oils, has a potential herbicidal activity that could be exploited as natural herbicide
    whereas organic mulch could delay weed emergence. Thus, this study aimed to examine the
    phytotoxicity of geraniol, an oxygenated monoterpene compound, in combination with
    lemongrass leaf mulch against three common weeds, Eleusine indica (grass), Cyperus distans
    (sedge), and Tridax procumbens (broadleaf). Greenhouse experiments were carried out by
    treating 4.0 t/ha lemongrass leaf mulch with 7.5% (v/v) geraniol compound. The pretreated
    mulch acted synergistically and inhibited the emergence and shoot growth of T. procumbens
    completely. However, the pretreated mulch exhibited a moderate inhibitory effect on C. distans
    emergence and growth. Geraniol-treated lemongrass leaf mulch acted synergistically and
    inhibited the emergence of E. indica by 72%, but it acted antagonistically and caused a 45%
    reduction of shoot biomass. The present findings suggest that geraniol-treated lemongrass leaf
    mulch has potent herbicidal activity but its phytotoxic effect is species-dependent.
    Matched MeSH terms: Oxygen
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