Displaying publications 521 - 540 of 1116 in total

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  1. Chemically modified multi-walled carbon nanotubes (MWCNTs) with anchored acidic groups
    Nuruzatulifah Bt Asari @ Mansor, Tessonnier JP, Rinaldi A, Reiche S, Kutty M
    Sains Malaysiana, 2012;41:603-609.
    Surface functionalization of multi-walled carbon nanotubes (MWCNTs) was carried out using a gas phase treatment in a Universal Temperature Program (UTP) reactor by flowing SO3 gas onto the CNTs while being heated at different temperatures. The functionalized nanotubes were characterized using X-ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FT-IR) and Raman spectroscopy. The amount of oxyen and sulfur containing groups was determined by acid-base titration. The titration results were in good agreement with elemental analysis using x-ray fluorescence. FTIRanalysis showed the presence of oxygen and sulfur containing groups, S=O, C-S, C=O and -COOH. Raman spectroscopy confirmed that oxygen and sulfur containing acidic groups covalently attached to the sidewall of the MWCNTs.
    Matched MeSH terms: Oxygen
  2. Fulltext Shape-Dependent antibacterial activity against Staphylococcus aureus of Zinc Oxide Nanoparticles
    Nor Hazliana Harun, Rabiatul Basria S. M. N. Mydin, Khairul Arifah Saharudin, Sreekantan, Srimala, Khor Yong Ling, Norfatehah Basiron, et al.
    Malaysian Journal of Medicine and Health Sciences, 2018;14(102):1-6.
    MyJurnal
    There is a growing concern in using zinc oxide nanoparticles (ZnO NPs) for medical devices as alternative options in reducing hospital-acquired infections (HAIs). The commensal HAIs; Staphylococcus aureus (S.aureus) infect patients and lead to increased rates of morbidity and mortality. This study aims to investigate the antibacterial action of ZnO NPs in three different shapes; nanorod, nanoflakes and nanospheres impregnated in low-density polyethylene (LDPE) against S.aureus ATCC 25923. Methods: The antibacterial efficiency of ZnO NPs was studied through two standard test methods included were based on Clinical Laboratory Standards Institute (CLSI) guidelines MO2-A11 under light conditions of 5.70 w/m2 and American standard test method (ASTM) E-2149. Results: Preliminary screening did show a significant growth inhibition against S.aureus with ZnO NPs nanorod and nanoflakes, approximately in 7 to 8 mm zones of inhibition. Further analysis using ASTM E-2149 in dynamic conditions revealed variable activity depending on incubation treatment periods. It demonstrated the ZnO NPs in nanoflakes and nanosphere shape showed better inhibition against S.aureus with maximum reduction (100%). The FESEM results strongly suggest that the structure of ZnO nanoflakes and nanosphere played an importance role in nanomaterial-bacteria interaction which consequently cause cell membrane damage. Additionally, the irradiation under light treatment also enhance the generation of ROS and free radicals which helps the bactericidal activity against S.aureus. Conclusion: This study provides new insights for the antibacterial action of ZnO NPs/LDPE thin films in future biomedical appliances to reduce HAIs risks.
    Matched MeSH terms: Reactive Oxygen Species
  3. The ‘black waters’ of Malaysia: tracking water quality from the peat swamp forest to the sea
    IRVINE K, VERMETTE S, FIRUZA BEGHAM MUSTAFA
    Sains Malaysiana, 2013;42:1539-1548.
    Longitudinal water quality trends were assessed in the Tengi River system, Selangor, Malaysia, as the water moved from a peat swamp forest, through different agricultural land uses and finally through a town and then to the Straits of Malacca. Water draining from the peat swamp forest was dark in color due to its organic content and low in dissolved oxygen, pH, E. coli, calcium, nitrate and ammonia. The normal diurnal pattern for water temperature was observed for the peat swamp forest drainage, but there was no clear diurnal pattern evident in the dissolved oxygen data. The E. coli levels increased monotonically from the peat swamp forest waters (0 colonies/100 mL) through the agricultural areas (100-2000 colonies/100 mL) and town (7100 colonies/100 mL) and similarly pH increased along the same continuum. Dissolved oxygen increased from the peat swamp forest through the agricultural areas, but was lower in the town-impacted reach of the Tengi River.
    Matched MeSH terms: Oxygen
  4. Surface morphology studies of low carbon steel treated in aqueous lignin
    YAHYA S, OTHMAN N, DAUD A, JALAR A
    Sains Malaysiana, 2013;42:1793-1798.
    The effect of corrosion inhibition of low carbon steel in water based medium containing lignin was investigated via weight loss method. The evolution of surface morphology has been carried out for 7 to 42 days via optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron microscopy (XPS). Immersion of metal specimen without lignin shows that significant increase in the surface roughness. The longer the immersion time, the more the oxide crust formed. The surface degradation of metal specimen was well protected by immersion in lignin solution. A protective layer containing of lignin was formed on the surface of metal specimens after 7 and 21 days immersion. The corrosion inhibition gives about 13 and 53% inhibition for both 7 and 21 days immersion, respectively. The protective layers were spalling and separated from the metal surface after 42 days immersion in lignin solution possibly due to the increase in corrosion attack after long time immersion according to the increase in dissolved oxygen and may also due to the thermal mismatch between oxide and substrate. The adsorption of protective layer containing lignin was temporary adsorbed on the surface.
    Matched MeSH terms: Oxygen
  5. Combined extract of Moringa oleifera and Centella asiatica modulates oxidative stress and senescence in hydrogen peroxide-induced human dermal fibroblasts
    Abdul Hisam EE, Rofiee MS, Khalid AM, Jalaluddin AF, Mohamad Yusof MI, Idris MH, et al.
    Turk J Biol, 2018;42(1):33-44.
    PMID: 30814868 DOI: 10.3906/biy-1708-23
    Moringa oleifera Lam. and Centella asiatica (L.) Urb. leaves have been previously reported to exhibit antioxidant activity. The objective of the present study is to determine the in vitro antioxidant activity of the combined extracts of M. oleifera and C. asiatica (TGT-PRIMAAGE) and its effect on hydrogen peroxide (H 2O2)-induced oxidative stress in human dermal fibroblasts. TGTPRIMAAGE acted on the mechanism of hydrogen transfer as it showed scavenging activity in the DPPH assay. This is due to the presence of phenolics and flavonoids in TGT-PRIMAAGE. TGT-PRIMAAGE effectively reduced cellular generation of reactive oxygen species induced by H O2. The activities of superoxide dismutase and catalase were also increased in cells treated with TGT-PRIMAAGE. 2 Treatment with TGT-PRIMAAGE showed significant reduction (P < 0.05) in the number of senescent cells. Significant reduction (P < 0.05) of malondialdehyde was also seen in cells treated with TGT-PRIMAAGE. The p53 protein level was reduced in TGT-PRIMAAGEtreated cells, which indicates its potential in protecting the cells from oxidative stress induced by H2O2.
    Matched MeSH terms: Reactive Oxygen Species
  6. A stepwise approach to the management of chronic obstructive pulmonary disease
    Liam CK
    Family Physician, 1993;5:46-53.
    Smoking cessation helps patients with COPD more than any specific medical treatment. By commencing treatment early, the main symptoms of COPD, i.e. cough, dyspnoea, and excessive mucus production, can be relieved and premature mortality from respiratory failure can, in many cases, be prevented. An anticholinergic aerosol offers the greatest bronchodilator benefit with the least side-effects to a patient with COPD. After maximising the dosage of an anticholinergic agent, either an inhaled beta2-agonist or oral theophylline may be added for additional bronchodilator effects. Corticosteroids may be beneficial in a subset of the patients. Selected patients with exercise limitation despite optimal medical therapy may gain from an increased sense of well-being enrolled in a supervised exercise rehabilitation progromrne. Long-term domiciliary oxygen therapy improves survival for patients who are chronically hypoxaemic. Antibiotics are reserved for acute exacerbations. The role of alpha-1-antitrypsin replacement and lung transplantation is still investigational.
    Matched MeSH terms: Oxygen
  7. Fulltext Transcriptional regulation of Lonicera japonica Thunb. during flower development as revealed by comprehensive analysis of transcription factors
    Wang T, Yang B, Guan Q, Chen X, Zhong Z, Huang W, et al.
    BMC Plant Biol, 2019 May 14;19(1):198.
    PMID: 31088368 DOI: 10.1186/s12870-019-1803-1
    BACKGROUND: Lonicera japonica Thunb. flower has been used for the treatment of various diseases for a long time and attracted many studies on its potential effects. Transcription factors (TFs) regulate extensive biological processes during plant development. As the restricted reports of L. japonica on TFs, our work was carried out to better understand the TFs' regulatory roles under different developmental stages in L. japonica.

    RESULTS: In this study, 1316 TFs belonging to 52 families were identified from the transcriptomic data, and corresponding expression profiles during the L. japonica flower development were comprehensively analyzed. 917 (69.68%) TFs were differentially expressed. TFs in bHLH, ERF, MYB, bZIP, and NAC families exhibited obviously altered expression during flower growth. Based on the analysis of differentially expressed TFs (DETFs), TFs in MYB, WRKY, NAC and LSD families that involved in phenylpropanoids biosynthesis, senescence processes and antioxidant activity were detected. The expression of MYB114 exhibited a positive correlation with the contents of luteoloside; Positive correlation was observed among the expression of MYC12, chalcone synthase (CHS) and flavonol synthase (FLS), while negative correlation was observed between the expression of MYB44 and the synthases; The expression of LSD1 was highly correlated with the expression of SOD and the total antioxidant capacity, while the expression of LOL1 and LOL2 exhibited a negative correlation with them; Many TFs in NAC and WRKY families may be potentially involved in the senescence process regulated by hormones and reactive oxygen species (ROS). The expression of NAC19, NAC29, and NAC53 exhibited a positive correlation with the contents of ABA and H2O2, while the expression of WRKY53, WRKY54, and WRKY70 exhibited a negative correlation with the contents of JA, SA and ABA.

    CONCLUSIONS: Our study provided a comprehensive characterization of the expression profiles of TFs during the developmental stages of L. japonica. In addition, we detected the key TFs that may play significant roles in controlling active components biosynthesis, antioxidant activity and flower senescence in L. japonica, thereby providing valuable insights into the molecular networks underlying L. japonica flower development.

    Matched MeSH terms: Reactive Oxygen Species
  8. Aquatic insect biodiversity and water quality parameters of streams in northern Thailand
    Prommi T, Payakka A
    Sains Malaysiana, 2015;44:707-717.
    Biodiversity of aquatic insect and physicochemical water quality parameters in Mae Tao and Mae Ku watersheds were
    assessed bi-monthly from February 2011 to February 2012. A total of 59 families representing 9 orders were recorded.
    At order level, Trichoptera was found at the highest frequency in total abundance (45.75%) followed by Ephemeroptera
    (18.06%), Hemiptera (13.45%), Odonata (9.62%), Diptera (8.17%), Coleoptera (4.6%), Megaloptera (0.17%),
    Lepidoptera (0.11%) and Plecoptera (0.07%). The family Hydropsychidae was the most prominent and the most abundant
    aquatic insect taxa followed by Chironomidae. Water temperature, dissolved oxygen and ammonia-nitrogen were similar
    at all sampling stations. Significant variations in pH, electrical conductivity, total dissolved solids, sulfate, nitrate-nitrogen
    and alkalinity were found at all sampling stations. Taxa richness and diversity index significantly correlated with dissolved
    oxygen, sulfate, nitrate-nitrogen and ammonia-nitrogen (p<0.05, p<0.01). Physicochemical data and biological data
    showed that mostly the surface water quality in Mae Tao and Mae Ku watersheds were within Type III of The Surface
    Water Standard for Agriculture and Water Quality for Protection of Aquatic Resources in Thailand.
    Matched MeSH terms: Oxygen
  9. Oxidative stress-associated pathology: A review
    Sarawoot Palipoch, Phanit Koohmin
    Sains Malaysiana, 2015;44:1441-1451.
    Currently, oxidative stress (OS) has become a major interest in point of basic science and clinical research. The imbalance between generations and clearances of oxidants leads to OS. Oxidants are mainly composed of reactive oxygen species (ROS) and reactive nitrogen species (RNS) which are manifested as oxidized macromolecules causing deleterious effects in several organs. Lipid, protein and DNA oxidation products can provide extensively approach of potential oxidative stress biomarkers. OS leads to the fundamental cellular and tissue damages and consequence effect to various organs or systems. This review emphasizes the systemic pathology induced by OS that particularly affect to specialized organs or systems including the nervous system, the cardiovascular system, the lung, the liver and the kidney.
    Matched MeSH terms: Reactive Oxygen Species
  10. Enhanced photodegradation of phenol by ZnO nanoparticles synthesized through sol-gel method
    Nikathirah Yusoff, Li-ngee Ho, Soon-an Ong, Yee-shian Wong, Wanfadhilah Khalik, Muhammad Fahmi Ridzwan
    Sains Malaysiana, 2017;46:2507-2514.
    Zinc oxide (ZnO) utilization in advanced oxidation process (AOP) via solar-photocatalytic process was a promising method for alternative treating wastewater containing phenol. The ZnO photocatalyst semiconductor was synthesized by sol-gel method. The morphology of the ZnO nanostructures was observed by using scanning electron microscope (SEM) and the crystallite phase of the ZnO was confirmed by x-ray diffraction (XRD). The objective of this study was to synthesis ZnO nanoparticles through a sol-gel method for application as a photocatalyst in the photodegradation of phenol under solar light irradiation. The photodegradation rate of phenol increased with the increasing of ZnO loading from 0.2 until 1.0 g. Only 2 h were required for synthesized ZnO to fully degrade the phenol. The synthesized ZnO are capable to totally degrade high initial concentration up until 45 mg L-1 within 6 h of reaction time. The photodegradation of phenol by ZnO are most favoured under the acidic condition (pH3) where the 100% removal achieved after 2 h of reaction. The mineralization of phenol was monitored through chemical oxygen demand (COD) reduction and 92.6% or removal was achieved. This study distinctly utilized natural sunlight as the sole sources of irradiation which safe, inexpensive; to initiate the photocatalyst for degradation of phenol.
    Matched MeSH terms: Biological Oxygen Demand Analysis
  11. The relationship between heavy metals and trophic properties in Sembrong Lake, Johor
    Nor Bakhiah Baharim, Ismail Yusoff, Wan Zakaria Wan Muhd Tahir, Muhamad Askari, Zainudin Othman, Mohamed Roseli Zainal Abidin, et al.
    Sains Malaysiana, 2016;45:43-53.
    The relationship between heavy metal and trophic properties in polymictic lake at Sembrong Lake, Peninsular Malaysia was assessed. Sixteen parameters, including heavy metals and trophic parameters were monitored. pH, temperature, dissolved oxygen and heavy metals level changes significantly influenced by the dynamic of polymictic mixing pattern. The mean concentrations of heavy metals in the reservoir decreased in the following order: Fe > Mn > Zn > Cu > As > Pb. The result showed that this polymictic lake is being threatened by cultural eutrophication with TSI value range from 72.40 to 80.41 and classified as a hypereutrophic lake. The levels of heavy metal pollution in the reservoir range from slightly polluted to polluted. Factor analysis was performed to determine the relationship between heavy metals and trophic parameters. Five factors were responsible for data structure and explained the 83% of total variance. These factors differentiate each group of parameters according to their common characteristics. Photosynthesis, respiration and redox processes were main factors contributing to the variability of both properties.
    Matched MeSH terms: Oxygen
  12. Profiling of anti-oxidative enzymes and lipid peroxidation in leaves of salt tolerant and salt sensitive maize hybrids under nac1 and cd stress
    Ghulam Hasan Abbasi, Javaid Akhtar, Muhammad Anwar-ul-haq, Moazzam Jamil, Shafaqat Ali, Rafiq Ahmad, et al.
    Sains Malaysiana, 2016;45:177-184.
    Effects of NaCl salinity and cadmium on the anti-oxidative activity of enzymes like superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) and lipid peroxidation contents; malondialdehyde (MDA) were studied in two maize hybrids of different salt tolerance characteristics. An increase in the amount of lipid peroxidation indicated the oxidative stress induced by NaCl and Cd. The results also depicted that NaCl stress caused an increase in the activities of POD, SOD, CAT, APX and GR while cadmium stress increased the activities of POD, SOD and APX but showed no significant effect on CAT and GR in both the studied hybrids. The combined effect of salinity and cadmium on these parameters was higher than that of sole effect of either NaCl or Cd. It was also found that maize hybrid 26204 had better tolerance against both stresses with strong antioxidant system as compared to that of maize hybrid 8441. A comparison of the antioxidants and lipid peroxidation in two maize hybrids having varying level of NaCl and Cd stress tolerance corroborated the importance of reactive oxygen species (ROS) in defense against abiotic stresses.
    Matched MeSH terms: Reactive Oxygen Species
  13. Effects of environmental conditions and nutrients on the occurrence and distribution of potentially harmful phytoplankton in mesotrophic water
    Soon TK, Julian Ransangan
    Sains Malaysiana, 2016;45:865-877.
    Marudu Bay, north coast of Sabah is characterized with mesotrophic water body and typical environmental parameters
    throughout the year. The current study was undertaken to evaluate the effect of environmental parameters and nutrients
    in mesotrophic water on the occurrence and distribution of potentially harmful phytoplankton species. The samplings
    were conducted over a period of thirteen months, covering southwest monsoon (SWM), inter-monsoon (IM), and northeast
    monsoon (NEM), at ten stations throughout the bay. Physical parameters (temperature, salinity, pH, dissolved oxygen,
    current speed and secchi depth), biological parameters (cell densities of phytoplankton) and chemical parameters
    (phosphate, nitrate, silicate and ammonia) were examined. The results indicated at least eight potentially harmful
    phytoplankton species (Dinophysis caudata, D. miles, Ceratium furca, C. fursus, Prorocentrum micans, P. sigmoides, P.
    triestinum and Pseudo-nitzschia sp.) were detected in north coast of Sabah. However, the potentially harmful phytoplankton
    species contributed only about 1.3% of the total phytoplankton community. Under nutrient deprivation conditions, the
    potentially harmful phytoplankton species distribution was mainly influenced by the ability to utilize other nitrogen
    sources, cell mobility and toleration to low nutrients environments.
    Matched MeSH terms: Oxygen
  14. XPS study of sulfur and phosphorus compounds with different oxidation states
    Leanne Britcher, Sunil Kumar, Hans J. Griesser, Kim S. Siow
    Sains Malaysiana, 2018;47:1913-1922.
    In this report, we demonstrate that continuous improvement in XPS instruments and the calibration standards as well
    as analysis with standard component-fitting procedures can be used to determine the binding energies of compounds
    containing phosphorus and sulfur of different oxidation states with higher confidence. Based on such improved XPS
    analyses, the binding energies (BEs) of S2p signals for sulfur of increasing oxidation state are determined to be 166-167.5
    eV for S=O in dimethyl sulfoxide, 168.1 eV for S=O2
    in polysulfone, 168.4 eV for SO3
    in polystyrene sulfonate and 168.8
    eV for SO4
    in chondroitin sulfate. The BEs of P2p signals show the following values: 132.9 eV for PO3
    in triisopropyl
    phosphite, 133.3 eV for PO4
    in glycerol phosphate, 133.5 eV for PO4
    in sodium tripolyphosphate and 134.0 eV for PO4
    in sodium hexametaphosphate. These results showed that there are only small increases in the binding energy when
    additional oxygen atoms are added to the S-O chemical group. A similar result is obtained when the fourth oxygen or
    poly-phosphate environment is added to the phosphorus compound. These BE values are useful to researchers involved
    in identifying oxidation states of phosphorus and sulfur atoms commonly observed on modified surfaces and interfaces
    found in applications such as biomaterials, super-capacitors and catalysis.
    Matched MeSH terms: Oxygen
  15. Interaction study of binary solvent systems ionic liquid and deep eutectic solvent with rotenone
    Zetty Shafiqa Othman, Nurul Huda Abd Karim, Saiful Irwan Zubairi, Nur Hasyareeda Hassan, Mamoru Koketsu
    Sains Malaysiana, 2018;47:1473-1482.
    [BMIM]OTf and alcohol-based DES combination with a selected organic solvent (acetone and acetonitrile) have
    been proven to efficiently extracting rotenone (isoflavonoid biopesticide) compound compared to individual organic
    solvents. Their efficiency builds up interest to study the solvent-solute interaction that occurs between both selected
    solvent systems with rotenone. The interaction study was analyzed using FTIR, 1D-NMR and 2D- NMR (NOESY, HMBC).
    Correlation portrayed by NOESY and HMBC of [BMIM]OTf - standard rotenone mixture predicted probable hydrogen
    bonding between the oxygen of rotenone with acidic proton C2-H of [BMIM]OTf. While for the alcohol-based DESrotenone
    mixture, the correlation shows probable interaction to occur between methyl and methoxy group rotenone
    with the hydroxyl group of 1,4-butanediol. In conclusion, potential hydrogen bonding that occurs between solvent
    and solute aid towards the solvent efficiency in extracting rotenone compound while emphasizing on the low cost and
    green mediated solvent systems.
    Matched MeSH terms: Oxygen
  16. Fulltext Synthesis of lignin based composites of TiO2 for potential application as radical scavengers in sunscreen formulation
    Ibrahim MNM, Iqbal A, Shen CC, Bhawani SA, Adam F
    BMC Chem, 2019 Dec;13(1):17.
    PMID: 31384766 DOI: 10.1186/s13065-019-0537-3
    Titanium dioxide (TiO2) is added in sunscreens due to its ability to absorb ultraviolet (UV) light. However, upon irradiation of UV light, reactive oxygen species particularly hydroxyl radical which can damage human skin will be generated. In this study, lignin/TiO2 composites were employed to quench the hydroxyl radicals generated by the TiO2. The lignin was extracted from oil palm empty fruit bunch (OPEFB) via kraft and soda pulping processes. The kraft lignin composite was labelled as KL/TiO2 whereas the soda lignin composite was labelled as SL/TiO2. The lignins and the composites were characterized by FTIR, UV spectroscopy, 13C NMR, SEM, EDX, and XRD. The relative hydroxyl radical production of composites and TiO2 were compared through photo-oxidation of coumarin to 7-hydroxycoumarin as a test medium. The effect of types and amounts of lignin used were studied. The KL/TiO2 composite showed the least radical production due to higher phenolic hydroxyl content of kraft lignin. The activity of the hydroxyl radicals will be quenched when it abstract hydrogen atoms from the phenolic hydroxyl groups.
    Matched MeSH terms: Reactive Oxygen Species
  17. Endophytic strains of Trichoderma increase plants' photosynthetic capability
    Harman GE, Doni F, Khadka RB, Uphoff N
    J Appl Microbiol, 2021 Feb;130(2):529-546.
    PMID: 31271695 DOI: 10.1111/jam.14368
    The world faces two enormous challenges that can be met, at least in part and at low cost, by making certain changes in agricultural practices. There is need to produce enough food and fibre for a growing population in the face of adverse climatic trends, and to remove greenhouse gases to avert the worst consequences of global climate change. Improving photosynthetic efficiency of crop plants can help meet both challenges. Fortuitously, when crop plants' roots are colonized by certain root endophytic fungi in the genus Trichoderma, this induces up-regulation of genes and pigments that improve the plants' photosynthesis. Plants under physiological or environmental stress suffer losses in their photosynthetic capability through damage to photosystems and other cellular processes caused by reactive oxygen species (ROS). But certain Trichoderma strains activate biochemical pathways that reduce ROS to less harmful molecules. This and other mechanisms described here make plants more resistant to biotic and abiotic stresses. The net effect of these fungi's residence in plants is to induce greater shoot and root growth, increasing crop yields, which will raise future food production. Furthermore, if photosynthesis rates are increased, more CO2 will be extracted from the atmosphere, and enhanced plant root growth means that more sequestered C will be transferred to roots and stored in the soil. Reductions in global greenhouse gas levels can be accelerated by giving incentives for climate-friendly carbon farming and carbon cap-and-trade programmes that reward practices transferring carbon from the atmosphere into the soil, also enhancing soil fertility and agricultural production.
    Matched MeSH terms: Reactive Oxygen Species
  18. Physiological and metabolic responses of Scenedesmus quadricauda (Chlorophyceae) to nickel toxicity and warming
    Yong WK, Sim KS, Poong SW, Wei D, Phang SM, Lim PE
    3 Biotech, 2019 Aug;9(8):315.
    PMID: 31406637 DOI: 10.1007/s13205-019-1848-8
    An ecologically important tropical freshwater microalga, Scenedesmus quadricauda, was exposed to Ni toxicity under two temperature regimes, 25 and 35 °C to investigate the interactive effects of warming and different Ni concentrations (0.1, 1.0 and 10.0 ppm). The stress responses were assessed from the growth, photosynthesis, reactive oxygen species (ROS) generation and metabolomics aspects to understand the effects at both the physiological and biochemical levels. The results showed that the cell densities of the cultures were higher at 35 °C compared to 25 °C, but decreased with increasing Ni concentrations at 35 °C. In terms of photosynthetic efficiency, the maximum quantum yield of photosystem II (Fv/Fm) of S. quadricauda remained consistent across different conditions. Nickel concentration at 10.0 ppm affected the maximum rate of relative electron transport (rETRm) and saturation irradiance for electron transport (Ek) in photosynthesis. At 25 °C, the increase of non-photochemical quenching (NPQ) values in cells exposed to 10.0 ppm Ni might indicate the onset of thermal dissipation process as a self-protection mechanism against Ni toxicity. The combination of warming and Ni toxicity induced a strong oxidative stress response in the cells. The ROS level increased significantly by 40% after exposure to 10.0 ppm of Ni at 35 °C. The amount of Ni accumulated in the biomass was higher at 25 °C compared to 35 °C. Based on the metabolic profile, temperature contributed the most significant differentiation among the samples compared to Ni treatment and the interaction between the two factors. Amino acids, sugars and organic acids were significantly regulated by the combined factors to restore homeostasis. The most affected pathways include sulphur, amino acids, and nitrogen metabolisms. Overall, the results suggest that the inhibitory effect of Ni was lower at 35 °C compared to 25 °C probably due to lower metal uptake and primary metabolism restructuring. The ability of S. quadricauda to accumulate substantial amount of Ni and thrive at 35 °C suggests the potential use of this strain for phycoremediation and outdoor wastewater treatment.
    Matched MeSH terms: Reactive Oxygen Species
  19. Fulltext Synthesis, characterization and application of gelatin-carboxymethyl cellulose blend films for preservation of cherry tomatoes and grapes
    Samsi MS, Kamari A, Din SM, Lazar G
    J Food Sci Technol, 2019 Jun;56(6):3099-3108.
    PMID: 31205364 DOI: 10.1007/s13197-019-03809-3
    In the present study, gelatin-carboxymethyl cellulose blend film was synthesized, characterized and applied for the first time to preserve cherry tomatoes (Solanum lycopersicum var. cerasiforme) and grapes (Vitis vinifera). Gelatin (Gel) film forming solution was incorporated with carboxymethyl cellulose (CMC) at three volume per volume (Gel:CMC) ratios, namely 75:25, 50:50 and 25:75. CMC treatment has improved the transparency, tensile strength (TS), elongation at break (EAB), water vapor permeability and oxygen permeability of gelatin films. A pronounced effect was obtained for 25Gel:75CMC film. The TS and EAB values were increased from 25.98 MPa and 2.34% (100Gel:0CMC) to 37.54 MPa and 4.41% (25Gel:75CMC), respectively. A significant improvement in antimicrobial property of gelatin films against two food pathogens, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was obtained in the presence of CMC. The effectiveness of gelatin-CMC blend films to extend the shelf life of agricultural products was evaluated in a 14-day preservation study. The gelatin-CMC films were successfully controlled the weight loss and browning index of the fruits up to 50.41% and 31.34%, respectively. Overall, gelatin-CMC film is an environmental friendly film for food preservation.
    Matched MeSH terms: Oxygen
  20. Fulltext Pathogenic Mitochondria DNA Mutations: Current Detection Tools and Interventions
    Mustafa MF, Fakurazi S, Abdullah MA, Maniam S
    Genes (Basel), 2020 02 12;11(2).
    PMID: 32059522 DOI: 10.3390/genes11020192
    Mitochondria are best known for their role in energy production, and they are the only mammalian organelles that contain their own genomes. The mitochondrial genome mutation rate is reported to be 10-17 times higher compared to nuclear genomes as a result of oxidative damage caused by reactive oxygen species during oxidative phosphorylation. Pathogenic mitochondrial DNA mutations result in mitochondrial DNA disorders, which are among the most common inherited human diseases. Interventions of mitochondrial DNA disorders involve either the transfer of viable isolated mitochondria to recipient cells or genetically modifying the mitochondrial genome to improve therapeutic outcome. This review outlines the common mitochondrial DNA disorders and the key advances in the past decade necessary to improve the current knowledge on mitochondrial disease intervention. Although it is now 31 years since the first description of patients with pathogenic mitochondrial DNA was reported, the treatment for mitochondrial disease is often inadequate and mostly palliative. Advancements in diagnostic technology improved the molecular diagnosis of previously unresolved cases, and they provide new insight into the pathogenesis and genetic changes in mitochondrial DNA diseases.
    Matched MeSH terms: Reactive Oxygen Species
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