Displaying publications 1 - 20 of 1080 in total

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  1. Yap DYH, McMahon LP, Hao CM, Hu N, Okada H, Suzuki Y, et al.
    Nephrology (Carlton), 2021 Feb;26(2):105-118.
    PMID: 33222343 DOI: 10.1111/nep.13835
    Renal anaemia is a common and important complication in patients with chronic kidney disease (CKD). The current standard-of-care treatment for renal anaemia in CKD patients involves ensuring adequate iron stores and administration of erythropoietin stimulating agents (ESA). Hypoxia inducible factor (HIF) is a key transcription factor primarily involved in the cellular regulation and efficiency of oxygen delivery. Manipulation of the HIF pathway by the use of HIF-prolyl hydroxylase inhibitors (HIF-PHI) has emerged as a novel approach for renal anaemia management. Despite it being approved for clinical use in various Asia-Pacific countries, its novelty mandates the need for nephrologists and clinicians generally in the region to well understand potential benefits and harms when prescribing this class of drug. The Asian Pacific society of nephrology HIF-PHI Recommendation Committee, formed by a panel of 11 nephrologists from the Asia-Pacific region who have clinical experience or have been investigators in HIF-PHI studies, reviewed and deliberated on the clinical and preclinical data concerning HIF-PHI. This recommendation summarizes the consensus views of the committee regarding the use of HIF-PHI, taking into account both available data and expert opinion in areas where evidence remains scarce.
    Matched MeSH terms: Oxygen
  2. Ling Ty, Lee Nyanti, Theresa Muan, Jongkar Grinang, Siong-fong Sim, Aazani Mujahid
    Sains Malaysiana, 2016;45:157-166.
    Determining the water quality of Bakun Reservoir 13 months after it operates at full supply level is crucial for better understanding of changes in the physicochemical parameters, which may enable the prediction of its effects on the survival of aquatic life in the reservoir. This study determined 13 physicochemical parameters at six stations within the reservoir at fixed depths. The results showed that the minimum 5 mg/L of dissolved oxygen (DO) required for sensitive aquatic organisms was recorded at 6 m depth. However, DO was not detectable at depths exceeding 7 m. The water was acidic at depths of more than 10 m. Turbidity and total suspended solids increased corresponding with depth. Inorganic nitrogen were predominantly in the form of ammonia-nitrogen, creating an unhealthy environment for aquatic life. Concentration of Chl-a was significantly higher at the subsurface water than 30 m depth in four out of six stations. The present study shows changes in water quality as compared to the pre-impounded period and 15 months after the filling phase, in particular, stratification of dissolved oxygen, thermocline conditions and alkalinity. The changes varied according to the distance from the dam and may have been influenced by existing land developments within the area such as the construction of the Murum Hydroelectric Dam, oil palm plantations and timber concessionares. Though the water quality might have deteriorated, further study is needed to determine if this condition will prolong.
    Matched MeSH terms: Oxygen
  3. Nur Ikhwan Mohamad, Rumpf, Michael C., Tan, Erik C.H., Abas, Nicholas Garaman
    Movement Health & Exercise, 2015;4(1):15-26.
    MyJurnal
    This paper aims to determine acute responses of standardized resistance training load on cardio-respiratory variables in recreationally active participants. The methodology involved twelve recreationally active males with an age of 23.5 (± 4.07) years, a mass of 70.5 (± 7.84 kg), a height of 1.69 (± 0.06 m), and a body mass index of 24.8 (± 2.14) kg/m2). The participants performed an exercise protocol that comprises five exercises on a standardized load. Each exercise was performed in a duration of 60 seconds with uncontrolled lifting velocity. Cardio-respiratory responses were measured using a portable metabolic system analyzer during the exercises. A wrist digital blood pressure monitor was used to determine pre- and postprotocol blood pressure responses. Based on the results, pre- and postprotocol systolic (p=0.744) and diastolic (p=0.758) blood pressure indicated no significant responses. However, significant differences were observed in pre- and post-heart rate responses (p=0.000). Peak cardio-respiratory responses recorded during the protocol were 30.2 (± 4.02) ml/Kg/min for oxygen consumption, 138 (± 61.9) bpm for heart rate, and 633 (± 71.2) kcal for energy expenditure (estimated per hour). On average, the Metabolic Equivalent of Task (MET) was recorded at a value of 8.62 (± 1.19). For a short duration standardized load circuit training exercise protocol, cardio respiratory responses were similar to other protocols. The metabolic cost of the predefined exercises was nearly half of the recommended energy expenditure through exercise per week. The prescribed protocol was comparable with other exercise protocols for cardiorespiratory variables. The single set protocol used was efficient in terms of caloric expenditure, and was less strenuous over similar exercise duration. Furthermore, the prescribed protocol is applicable and beneficial for active and healthy individuals.
    Matched MeSH terms: Oxygen Consumption
  4. Naje AS, Chelliapan S, Zakaria Z, Abbas SA
    J Environ Manage, 2016 Jul 1;176:34-44.
    PMID: 27039362 DOI: 10.1016/j.jenvman.2016.03.034
    This paper investigates the optimum operational conditions of a novel rotated bed electrocoagulation (EC) reactor for the treatment of textile wastewater. The effect of various operational parameters such as rotational speed, current density (CD), operational time (RT), pH, temperature, and inter-electrode distance (IED) on the pollutant removal efficiency were examined. In addition, the consumption of aluminum (Al) and electrical energy, as well as operating costs at optimum conditions were also calculated. The results indicated that the optimum conditions for the treatment of textile wastewater were achieved at CD = 4 mA/cm(2), RT = 10 min, rotational speed = 150 rpm, pH = 4.57, temperature = 25 °C, and IED = 1 cm. The electrode consumption, energy consumption, and operating costs were 0.038 kg/m(3), 4.66 kWh/m(3) and 0.44 US$/m(3), respectively. The removal efficiencies of chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solid (TSS), turbidity and color were 97.10%, 95.55%, 98%, 96% and 98.50%, respectively, at the first 10 min of reaction time, while the phenol compound of the wastewater was almost entirely removed (99.99%). The experimental results confirm that the new reactor design with rotated anode impellers and cathode rings provided high treatment efficiency at a reduced reaction time and with lower energy consumption.
    Matched MeSH terms: Biological Oxygen Demand Analysis
  5. Muhamad MH, Sheikh Abdullah SR, Abu Hasan H, Abd Rahim RA
    J Environ Manage, 2015 Nov 1;163:115-24.
    PMID: 26311084 DOI: 10.1016/j.jenvman.2015.08.012
    The complexity of residual toxic organics from biologically treated effluents of pulp and paper mills is a serious concern. To date, it has been difficult to choose the best treatment technique because each of the available options has advantages and drawbacks. In this study, two different treatment techniques using laboratory-scale aerobic sequencing batch reactors (SBRs) were tested with the same real recycled paper mill effluent to evaluate their treatment efficiencies. Two attached-growth SBRs using granular activated carbon (GAC) with and without additional biomass and a suspended-growth SBR were used in the treatment of real recycled paper mill effluent at a chemical oxygen demand (COD) level in the range of 800-1300 mg/L, a fixed hydraulic retention time of 24 h and a COD:N:P ratio of approximately 100:5:1. The efficiency of this biological treatment process was studied over a 300-day period. The six most important wastewater quality parameters, namely, chemical oxygen demand (COD), turbidity, ammonia (expressed as NH3-N), phosphorus (expressed as PO4(3)-P), colour, and suspended solids (SS), were measured to compare the different treatment techniques. It was determined that these processes were able to almost completely and simultaneously eliminate COD (99%) and turbidity (99%); the removals of NH3-N (90-100%), PO4(3)-P (66-78%), colour (63-91%), and SS (97-99%) were also sufficient. The overall performance results confirmed that an attached-growth SBR system using additional biomass on GAC is a promising configuration for wastewater treatment in terms of performance efficiency and process stability under fluctuations of organic load. Hence, this hybrid system is recommended for the treatment of pulp and paper mill effluents.
    Matched MeSH terms: Biological Oxygen Demand Analysis
  6. Mohd Jai NA, Mat Rosly M, Abd Razak NA
    Games Health J, 2021 Apr;10(2):73-82.
    PMID: 33297818 DOI: 10.1089/g4h.2020.0078
    Objective: Studies investigating the effects of exergaming in available platforms are still limited. This review aims to systematically identify available studies on physiological intensities of exergaming boxing in able-bodied adults and recategorize them based on different platforms or environments. The meta-analysis further analyzes the physiological responses during exergaming boxing into a set of pooled data for any evidence of outliers, heterogeneity, or publication bias. Materials and Methods: A systematic search was conducted by using databases from Google Scholar, PubMed, and Web of Science. Population, intervention, comparison, and outcomes (PICO) and preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were used in the study selection process for the review. Results: From the 1534 articles examined, 16 articles were included for further analyses. Results indicated that exergaming boxing exhibits a wide range of metabolic equivalent of task (MET) values and intensity, from very light to vigorous, with elements of heterogeneity and bias detected. The Xbox® Kinect boxing platform produced higher MET (mean = 5.3) compared with the Nintendo® Wii™ boxing (mean = 3.8). Conclusion: The results of this review suggest that boxing exergames can produce intensity-adequate physical activity among younger adults that are beneficial for cardiometabolic improvements, regardless of platforms used. Exergaming boxing may be employed as an effective exercise tool to increase energy expenditure and physical activity level in young adults.
    Matched MeSH terms: Oxygen Consumption/physiology
  7. Taha MM, Sheikh BY, Salim LZ, Mohan S, Khan A, Kamalidehghan B, et al.
    Cell Mol Biol (Noisy-le-grand), 2016 May 30;62(6):97-101.
    PMID: 27262811
    Nigella sativa is also known for its properties as a traditional herbal healing for many ailments. In this study, the anticancer properties of thyomquinone (TQ), the active ingredient of N. sativa, were studied using ovarian cancer cell line (Caov-3 cells). The anti-proliferative activity of TQ was determined using MTT and the apoptosis was investigated using Flowcytometry and Annexin-V Assays. Multiparameteric cytotoxicity bioassays were used to quantify the changes in cell permeability and mitochondrial membrane potential. Reactive oxygen species (ROS) and apoptosis-involved cell markers were examined to verify cell death mechanism. The MTT-assay showed that TQ induces anti-proliferative activity on Caov-3 with an IC50 of 6.0±0.03 μg/mL, without any cytotoxic activity towards WRL-68 normal hepatocytes. A significant induction of early phase of apoptosis was shown by annexin-V analysis. Treatment of Caov-3 cells with TQ induces decreases in plasma membrane permeability and mitochondrial membrane potential. Visible decrease in the nuclear area was also observed. A significant decrease is observed in Bcl-2 while Bax is down-regulated. TQ-triggered ROS-mediated has found to be associated with Hsp70 dysregulation, an indicator of oxidative injury. We found that TQ induced anti-cancer effect involves intrinsic pathway of apoptosis and cellular oxidative stress. Our results considered collectively indicated that thyomquinone may be a potential agent for ovarian cancer drug development.
    Matched MeSH terms: Reactive Oxygen Species/metabolism*
  8. Arezoo E, Mohammadreza E, Maryam M, Abdorreza MN
    Int J Biol Macromol, 2020 Aug 15;157:743-751.
    PMID: 31805325 DOI: 10.1016/j.ijbiomac.2019.11.244
    This study describes a sago starch-based film by incorporation of cinnamon essential oil (CEO) and nano titanium dioxide (TiO2-N). Different concentrations (i.e., 0%, 1%, 3%, and 5%, w/w) of TiO2-N and CEO (i.e., 0%, 1%, 2%, and 3%, v/w) were incorporated into sago starch film, and the physicochemical, barrier, mechanical, and antimicrobial properties of the bionanocomposite films were estimated. Incorporation of CEO into the sago starch matrix increased oxygen and water vapor permeability of starch films while increasing TiO2-N concentration decreased barrier properties. Moisture content also decreased from 12.96% to 8.04%, solubility in water decreased from 25% to 13.7%, and the mechanical properties of sago starch films improved. Sago starch bionanocomposite films showed excellent antimicrobial activity against Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus. Results also showed that incorporation of TiO2-N and CEO had synergistic effects on functional properties of sago starch films. In summary, sago starch films incorporated with both TiO2-N and CEO shows potential application for active packaging in food industries such as fresh pistachio packaging.
    Matched MeSH terms: Oxygen/chemistry
  9. Adenan DM, Jaafar Z, Jayapalan JJ, Abdul Aziz A
    PeerJ, 2020;8:e9230.
    PMID: 32477840 DOI: 10.7717/peerj.9230
    Introduction: A high body fat coupled with low cardiopulmonary fitness and an increase in oxidative stress has been connoted as contributing factors in developing cardiovascular comorbidities. This study aimed to investigate the correlation between antioxidants and oxidative stress status with cardiopulmonary responses in women of different body mass index (BMI).

    Subjects and Methods: Eighty female adults were recruited and divided into three groups; normal weight (n = 23), overweight (n = 28) and obese (n = 29), according to their BMI. Blood samples were obtained prior to cardiopulmonary exercise testing. Plasma samples were separated by centrifugation and analysed for enzymatic antioxidant activity including catalase, glutathione peroxidase and superoxide dismutase. Non-enzymatic antioxidant activities were assessed using 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging and ferric reducing ability of plasma (FRAP) assays. To evaluate the oxidative stress status of subjects, levels of reactive oxygen species and malondialdehyde, the by-product of lipid peroxidation, were measured. Cardiopulmonary responses were analysed using cardiopulmonary exercise testing (CPET) which involved 15 various parameters such as peak oxygen consumption, metabolic equivalents and respiratory exchange ratio.

    Results: The obese group had significantly lower ABTS radical scavenging and FRAP activities than the normal weight group. A higher catalase activity was observed in the obese group than the normal weight group. Spearman's correlation showed an inverse relationship between catalase and peak oxygen consumption, while partial correlation analysis showed inverse correlations between superoxide dismutase and respiratory frequency, ABTS activity and oxygen pulse, and between ABTS activity and cardiac output.

    Conclusion: Our results demonstrate a lower cardiovascular fitness and antioxidant capacity in obese women; the higher catalase activity may be a compensatory mechanism. The negative correlations found between these two parameters may indicate the potential effect of antioxidants on the cardiopulmonary system and deserve further analysis in a larger population. Nevertheless, this study provides the basis for future studies to further explore the relationships between redox status and cardiopulmonary responses. This can potentially be used to predict future risk of developing diseases associated with oxidative stress, especially pulmonary and cardiovascular diseases.

    Matched MeSH terms: Reactive Oxygen Species
  10. Ramli NSF, Mat Junit S, Leong NK, Razali N, Jayapalan JJ, Abdul Aziz A
    PeerJ, 2017;5:e3365.
    PMID: 28584708 DOI: 10.7717/peerj.3365
    BACKGROUND: Synthesis of thyroid hormones and regulation of their metabolism involve free radicals that may affect redox balance in the body. Thyroid disorders causing variations in the levels of thyroid hormones may alter cellular oxidative stress. The aim of this study was to measure the antioxidant activities and biomarkers of oxidative stress in serum and red blood cells (RBC) of patients with benign and malignant thyroid disorders and to investigate if changes in the antioxidant activities in these patients were linked to alterations in genes encoding the antioxidant enzymes.

    METHODS: Forty-one patients with thyroid disorders from University of Malaya Medical Centre were recruited. They were categorised into four groups: multinodular goitre (MNG) (n = 18), follicular thyroid adenoma (FTA) (n = 7), papillary thyroid cancer (PTC) (n = 10), and follicular thyroid cancer (FTC) (n = 6). Serum and RBC of patients were analysed for antioxidant activities, antioxidant enzymes, and biomarkers of oxidative stress. Alterations in genes encoding the antioxidant enzymes were analysed using whole exome sequencing and PCR-DNA sequencing.

    RESULTS: Patients with thyroid disorders had significantly higher serum superoxide dismutase (SOD) and catalase (CAT) activities compared to control, but had lower activities in RBC. There were no significant changes in serum glutathione peroxidase (GPx) activity. Meanwhile, GPx activity in RBC was reduced in PTC and FTC, compared to control and the respective benign groups. Antioxidant activities in serum were decreased in the thyroid disorder groups when compared to the control group. The levels of malondialdehyde (MDA) were elevated in the serum of FTA group when compared to controls, while in the RBC, only the MNG and PTC groups showed higher MDA equivalents than control. Serum reactive oxygen species (ROS) levels in PTC group of both serum and RBC were significantly higher than control group. Whole exome sequencing has resulted in identification of 49 single nucleotide polymorphisms (SNPs) in MNG and PTC patients and their genotypic and allelic frequencies were calculated. Analyses of the relationship between serum enzyme activities and the total SNPs identified in both groups revealed no correlation.

    DISCUSSION: Different forms of thyroid disorders influence the levels of antioxidant status in the serum and RBC of these patients, implying varying capability of preventing oxidative stress. A more comprehensive study with a larger target population should be done in order to further evaluate the relationships between antioxidant enzymes gene polymorphisms and thyroid disorders, as well as strengthening the minor evidences provided in literatures.

    Matched MeSH terms: Reactive Oxygen Species
  11. Hosseini SM, Abdul Aziz H
    Bioresour Technol, 2013 Apr;133:240-7.
    PMID: 23428821 DOI: 10.1016/j.biortech.2013.01.098
    The effects of thermochemical pretreatment and continuous thermophilic conditions on the composting of a mixture of rice straw residue and cattle manure were investigated using a laboratory-scale composting reactor. Results indicate that the composting period of rice straw can be shortened to less than 10 days by applying alkali pre-treatment and continuous thermophilic composting conditions. The parameters obtained on day 9 of this study are similar to the criteria level published by the Canadian Council of Ministers of the Environment. The moisture content, organic matter reduction, pH level, electrical conductivity, total organic carbon reduction, soluble chemical oxygen demand reduction, total Kjeldahl nitrogen, carbon-to-nitrogen ratio, and germination index were 62.07%, 16.99%, 7.30%, 1058 μS/cm, 17.00%, 83.43%, 2.06%, 16.75%, and 90.33%, respectively. The results of this study suggest that the application of chemical-biological integrated processes under thermophilic conditions is a novel method for the rapid degradation and maturation of rice straw residue.
    Matched MeSH terms: Biological Oxygen Demand Analysis
  12. Kamarudin MN, Mohd Raflee NA, Hussein SS, Lo JY, Supriady H, Abdul Kadir H
    Drug Des Devel Ther, 2014;8:1765-80.
    PMID: 25336920 DOI: 10.2147/DDDT.S67980
    Alpha-lipoic acid, a potent antioxidant with multifarious pharmacological benefits has been reported to be neuroprotective in several neuronal models and used to treat neurological disorders such as Alzheimer's disease. Nonetheless, conclusive mechanisms of alpha-lipoic acid for its protective effects particularly in NG108-15 cells have never been investigated. In this study, the intricate neuroprotective molecular mechanisms by (R)-(+)-alpha-lipoic acid (R-LA) against H2O2-induced cell death in an in vitro model of neurodegeneration were elucidated. Pretreatment with R-LA (2 hours) significantly increased NG108-15 cell viability as compared to H2O2-treated cells and mitigated the induction of apoptosis as evidenced by Hoechst 33342/propidium iodide staining. R-LA (12.5-50 μM) aggrandized the reduced glutathione over glutathione disulfide ratio followed by a reduction in the intracellular reactive oxygen species level and an increase in mitochondrial membrane potential following H2O2 exposure. Moreover, pretreatment with R-LA stimulated the activation of PI3K-Akt through mTORC1 and mTORC2 components (mTOR, rictor and raptor) and production of antiinflammatory cytokine, IL-10 which led to the inactivation of glycogen synthase kinase-3β (GSK-3β) and reduction of both Bax/Bcl2 and Bax/Bcl-xL ratios, accompanied by inhibition of the cleaved caspase-3. Additionally, this observation was preceded by the suppression of NF-κβ p65 translocation and production of proinflammatory cytokines (IL-6 and TNF-α). The current findings accentuate new mechanistic insight of R-LA against apoptogenic and brain inflammatory factors in a neuronal model. These results further advocate the therapeutic potential of R-LA for the treatment of neurodegenerative diseases.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  13. Zorofchian Moghadamtousi S, Karimian H, Rouhollahi E, Paydar M, Fadaeinasab M, Abdul Kadir H
    J Ethnopharmacol, 2014 Oct 28;156:277-89.
    PMID: 25195082 DOI: 10.1016/j.jep.2014.08.011
    ETHNOPHARMACOLOGICAL RELEVANCE: Annona muricata known as "the cancer killer" has been widely used in the traditional medicine for the treatment of cancer and tumors. The purpose of this study is to investigate the anticancer properties of ethyl acetate extract of Annona muricata leaves (EEAM) on HT-29 and HCT-116 colon cancer cells and the underlying mechanisms.
    MATERIALS AND METHODS: The effect of EEAM on the cell proliferation of HT-29 and HCT-116 cells was analyzed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) assay. High content screening system (HCS) was applied to investigate the cell membrane permeability, mitochondrial membrane potential (MMP), nuclear condensation and cytochrome c translocation from mitochondria to cytosol. Reactive oxygen species (ROS) formation, lactate dehydrogenase (LDH) release and activation of caspase-3/7, -8 and -9 were measured while treatment. Flow cytometric analysis was used to determine the cell cycle distribution and phosphatidylserine externalization. The protein expression of Bax and Bcl-2 was determined using immunofluorescence analysis. In addition, the potential of EEAM to suppress the migration and invasion of colon cancer cells was also examined.
    RESULTS: EEAM exerted significant cytotoxic effects on HCT-116 and HT-29 cells as determined by MTT and LDH assays. After 24 h treatment, EEAM exhibited the IC₅₀ value of 11.43 ± 1.87 µg/ml and 8.98 ± 1.24 µg/ml against HT-29 and HCT-116 cells, respectively. Flow cytometric analysis demonstrated the cell cycle arrest at G1 phase and phosphatidylserine externalization confirming the induction of apoptosis. EEAM treatment caused excessive accumulation of ROS followed by disruption of MMP, cytochrome c leakage and activation of the initiator and executioner caspases in both colon cancer cells. Immunofluorescence analysis depicted the up-regulation of Bax and down-regulation of Bcl-2 proteins while treated with EEAM. Furthermore, EEAM conspicuously blocked the migration and invasion of HT-29 and HCT-116 cells.
    CONCLUSIONS: These findings provide a scientific basis for the use of A. muricata leaves in the treatment of cancer, although further in vivo studies are still required.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  14. Goh BH, Chan CK, Kamarudin MN, Abdul Kadir H
    J Ethnopharmacol, 2014 Apr 28;153(2):375-85.
    PMID: 24613274 DOI: 10.1016/j.jep.2014.02.036
    Swietenia macrophylla King is a traditional herb used to treat various diseases including hypertension, diabetes and cancer. Previous study demonstrated its anti-tumor effect but the potential mechanisms have not been clearly defined. The current study was to further investigate the underlying mechanism of ethyl acetate fraction of Swietenia macrophylla (SMEAF)-induced anti-proliferative effect and apoptosis in HCT116 colorectal carcinoma cell.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  15. Zafar R, Malik AS, Kamel N, Dass SC, Abdullah JM, Reza F, et al.
    J Integr Neurosci, 2015 Jun;14(2):155-68.
    PMID: 25939499 DOI: 10.1142/S0219635215500089
    Brain is the command center for the body and contains a lot of information which can be extracted by using different non-invasive techniques. Electroencephalography (EEG), Magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) are the most common neuroimaging techniques to elicit brain behavior. By using these techniques different activity patterns can be measured within the brain to decode the content of mental processes especially the visual and auditory content. This paper discusses the models and imaging techniques used in visual decoding to investigate the different conditions of brain along with recent advancements in brain decoding. This paper concludes that it's not possible to extract all the information from the brain, however careful experimentation, interpretation and powerful statistical tools can be used with the neuroimaging techniques for better results.
    Matched MeSH terms: Oxygen/blood
  16. Zaini Hamzah, Wan Noorhayani Wan Rosdi, Abdul Khalik Wood
    MyJurnal
    Well water is a renewable natural resources and one of the drinking water sources. The well water may constituted of dissolved essential chemicals such as K+, Ca''+ and Na+ ; and natural radionuclides such as radioisotopes from uranium-thorium decay series. The geology and mineral composition of the soil will determined the kinds and levels of chemical contents in the groundwater resources. The water flows through the geological formation and dissolved the chemicals before reaching the aquifers. To evaluate how much chemicals and natural radioactive in the water resources, a study has been carried out. Well water samples in this study were taken from 3 districts in Kelantan, which is Bachok, Machang and Kuala Krai. Similarly, in situ water quality parameters were measured using YSI portable water quality parameter include pH, salinity, dissolve oxygen(DO), conductivity, turbidity and total dissolved solids(TDS). The concentrations of K', Ca" and Na' were determined using Energy Dispersive X-ray Fluorescence (EDXRF). Five ml of filtered sample was pipette into the sample cup and, irradiated and measured for 100 seconds counting times. The type of filter used for measuring If+ and Cat{ was Al-thin and default for Nat The ranged of concentration of Kt Ce and Na+ is 23.04-251.89, 3.12-.45.41, and 3.71-125.75 ppm, respectively.
    Matched MeSH terms: Oxygen
  17. Nur Suhaili Abd Aziz, Muhammad Khairullah Nor Azmi, Abdul Manaf Hashim
    Sains Malaysiana, 2017;46:1083-1088.
    A one-pot green sonochemical process assisted by ascorbic acid as the reducing agent to produce highly reduced graphene oxide (rGO) decorated with silver nanoparticles (AgNPs) is demonstrated. A complete removal of oxygen-containing group in the GO sheets was confirmed by no observation of the peak corresponds to C-O, C=O and -OH bond. The unexpected decrease of peak intensity corresponds to sp2 hybridized C=C group is explained by a so-called bond polarity effect. The peak observed at ~400 nm seems to show the presence of AgNPs and the red shifting of C=C peak to ~270 nm after the introduction of ascorbic acid indicates the formation of highly reduced GO. The increase of AgNPs size and the crumpled silk-like morphology after the introduction of ascorbic acid also indicate the aggressive reduction of both AgNPs and GO. The increase of ID/IG ratio after the introduction of ascorbic acid seems to indicate the increase of the number of small sp2 domains, the presence of unrepaired defects and the restoration of the sp2 network. This work provides the promising green sonochemical approach by utilizing non-toxic and environmental-friendly reducing agent to produce highly reduced GO decorated with AgNPs for various applications.
    Matched MeSH terms: Oxygen
  18. Ishadi NA, Rawi CS, Ahmad AH, Abdul NH
    Trop Life Sci Res, 2014 Dec;25(2):61-79.
    PMID: 27073600 MyJurnal
    The hemipteran (Insecta) diversity in the upper part of the Kerian River Basin was low with only 8 families and 16 genera recorded at 4 study sites from 3 rivers. Water bug composition varied among sampling sites (Kruskal-Wallis χ (2) = 0.00, p<0.05) but was not affected by wet-dry seasons (Z = 0.00, p>0.05). All recorded water parameters were weakly associated with generic abundance but the biochemical oxygen demand (BOD), chemical oxygen demand (COD), Water Quality Index (WQI) and heavy metals (zinc and manganese) showed relatively strong positive or negative relations with hemipteran diversity and richness (H' and R2). Within the ranges of measured water parameters, the WQI was negatively associated with hemipteran diversity and richness, implying the tolerance of the water bugs to the level of pollution encountered in the river basin. Based on its highest abundance and occurrence (ISI), Rhagovelia was the most important genus and along with Rheumatogonus and Paraplea, these genera were common at all study sites. In conclusion, habitat availability and suitability together with some environmental parameters influenced the abundance and composition of hemipterans in this river basin.
    Matched MeSH terms: Oxygen; Biological Oxygen Demand Analysis
  19. Yaacob N, Mohamad Ali MS, Salleh AB, Abdul Rahman NA
    PeerJ, 2016;4:e1751.
    PMID: 26989608 DOI: 10.7717/peerj.1751
    Background. Not all yeast alcohol dehydrogenase 2 (ADH2) are repressed by glucose, as reported in Saccharomyces cerevisiae. Pichia stipitis ADH2 is regulated by oxygen instead of glucose, whereas Kluyveromyces marxianus ADH2 is regulated by neither glucose nor ethanol. For this reason, ADH2 regulation of yeasts may be species dependent, leading to a different type of expression and fermentation efficiency. Lachancea fermentati is a highly efficient ethanol producer, fast-growing cells and adapted to fermentation-related stresses such as ethanol and organic acid, but the metabolic information regarding the regulation of glucose and ethanol production is still lacking. Methods. Our investigation started with the stimulation of ADH2 activity from S. cerevisiae and L. fermentati by glucose and ethanol induction in a glucose-repressed medium. The study also embarked on the retrospective analysis of ADH2 genomic and protein level through direct sequencing and sites identification. Based on the sequence generated, we demonstrated ADH2 gene expression highlighting the conserved NAD(P)-binding domain in the context of glucose fermentation and ethanol production. Results. An increase of ADH2 activity was observed in starved L. fermentati (LfeADH2) and S. cerevisiae (SceADH2) in response to 2% (w/v) glucose induction. These suggest that in the presence of glucose, ADH2 activity was activated instead of being repressed. An induction of 0.5% (v/v) ethanol also increased LfeADH2 activity, promoting ethanol resistance, whereas accumulating acetic acid at a later stage of fermentation stimulated ADH2 activity and enhanced glucose consumption rates. The lack in upper stream activating sequence (UAS) and TATA elements hindered the possibility of Adr1 binding to LfeADH2. Transcription factors such as SP1 and RAP1 observed in LfeADH2 sequence have been implicated in the regulation of many genes including ADH2. In glucose fermentation, L. fermentati exhibited a bell-shaped ADH2 expression, showing the highest expression when glucose was depleted and ethanol-acetic acid was increased. Meanwhile, S. cerevisiae showed a constitutive ADH2 expression throughout the fermentation process. Discussion. ADH2 expression in L. fermentati may be subjected to changes in the presence of non-fermentative carbon source. The nucleotide sequence showed that ADH2 transcription could be influenced by other transcription genes of glycolysis oriented due to the lack of specific activation sites for Adr1. Our study suggests that if Adr1 is not capable of promoting LfeADH2 activation, the transcription can be controlled by Rap1 and Sp1 due to their inherent roles. Therefore in future, it is interesting to observe ADH2 gene being highly regulated by these potential transcription factors and functioned as a promoter for yeast under high volume of ethanol and organic acids.
    Matched MeSH terms: Oxygen
  20. Nadarajah K, Abdul Hamid NW, Abdul Rahman NSN
    Int J Mol Sci, 2021 May 25;22(11).
    PMID: 34070465 DOI: 10.3390/ijms22115591
    Environmental or abiotic stresses are a common threat that remains a constant and common challenge to all plants. These threats whether singular or in combination can have devastating effects on plants. As a semiaquatic plant, rice succumbs to the same threats. Here we systematically look into the involvement of salicylic acid (SA) in the regulation of abiotic stress in rice. Studies have shown that the level of endogenous salicylic acid (SA) is high in rice compared to any other plant species. The reason behind this elevated level and the contribution of this molecule towards abiotic stress management and other underlying mechanisms remains poorly understood in rice. In this review we will address various abiotic stresses that affect the biochemistry and physiology of rice and the role played by SA in its regulation. Further, this review will elucidate the potential mechanisms that control SA-mediated stress tolerance in rice, leading to future prospects and direction for investigation.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
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