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Fulltext NiO nanoparticles induce cytotoxicity mediated through ROS generation and impairing the antioxidant defense in the human lung epithelial cells (A549): Preventive effect of Pistacia lentiscus essential oil

Mohamed K, Zine K, Fahima K, Abdelfattah E, Sharifudin SM, Duduku K

Toxicol Rep, 2018;5:480-488.
PMID: 29854619 DOI: 10.1016/j.toxrep.2018.03.012

Nickel oxide nanoparticles (NiO NPs) have attracted increasing attention owing to potential capacity to penetrate to several human cell systems and exert a toxic effect. Elsewhere, the use of medicinal plants today is the form of the most widespread medicine worldwide. Utilizing aromatic plants as interesting source of phytochemicals constitute one of the largest scientific concerns. Thus this study was focused to investigate antioxidant and cytoprotective effects of essential oil of a Mediterranean plant P. lentiscus (PLEO) on NiO NPs induced cytotoxicity and oxidative stress in human lung epithelial cells (A549). The obtained results showed that cell viability was reduced by NiO NPs, who's also found to induce oxidative stress in dose-dependent manner indicated by induction of reactive oxygen species and reduction of antioxidant enzymes activities. Our results also demonstrated that PLEO contains high amounts in terpinen-4-ol (11.49%), germacrene D (8.64%), α-pinene (5.97%), sabinene (5.19%), caryophyllene (5.10%) and δ-Cadinene (4.86%). PLEO exhibited a potent antioxidant capacity by cell viability improving, ROS scavenging and enhancing the endogenous antioxidant system against NiO NPs in this model of cells. The present work demonstrated, for the first time, the protective activity of PLEO against cell oxidative damage induced by NiO NPs. It was suggested that this plant essential oil could be use as a cells protector.

Matched MeSH terms: Reactive Oxygen Species
Ciproxifan improves cholinergic transmission, attenuates neuroinflammation and oxidative stress but does not reduce amyloid level in transgenic mice

Mani V, Jaafar SM, Azahan NSM, Ramasamy K, Lim SM, Ming LC, et al.

Life Sci, 2017 Jul 01;180:23-35.
PMID: 28501482 DOI: 10.1016/j.lfs.2017.05.013

AIM: The present study is aimed to investigate the ability of ciproxifan, a histamine H3 receptor antagonist to inhibit β-amyloid (Aβ)-induced neurotoxicity in SK-N-SH cells and APP transgenic mouse model.
MATERIALS AND METHODS: In vitro studies was designed to evaluate the neuroprotective effects of ciproxifan in Aβ25-35 - induced SK-N-SH cells. For the in vivo study, ciproxifan (1 and 3mg/kg, i.p.) was administrated to transgenic mice for 15days and behaviour was assessed using the radial arm maze (RAM). Brain tissues were collected to measure Aβ levels (Aβ1-40 and Aβ1-42), acetylcholine (ACh), acetylcholinesterase (AChE), nitric oxide (NO), lipid peroxidation (LPO), antioxidant activities, cyclooxygenases (COX) and cytokines (IL-1α, IL-1β and IL-6), while plasma was collected to measure TGF-1β.
RESULTS: The in vitro studies demonstrated neuroprotective effect of ciproxifan by increasing cell viability and inhibiting reactive oxygen species (ROS) in Aβ25-35-induced SK-N-SH cells. Ciproxifan significantly improved the behavioural parameters in RAM. Ciproxifan however, did not alter the Aβ levels in APP transgenic mice. Ciproxifan increased ACh and showed anti-oxidant properties by reducing NO and LPO levels as well as enhancing antioxidant levels. The neuroinflammatory analysis showed that ciproxifan reduced both COX-1 and COX-2 activities, decreased the level of pro-inflammatory cytokines IL-1α, IL-1β and IL-6 and increased the level of anti-inflammatory cytokine TGF-1β.
CONCLUSION: This present study provides scientific evidence of the use of ciproxifan via antioxidant and cholinergic pathways in the management of AD.

Matched MeSH terms: Reactive Oxygen Species
Fulltext Systematic Review and Meta-Analysis of the Efficacy and Safety of Combined Epinephrine and Corticosteroid Therapy for Acute Bronchiolitis in Infants

Kua KP, Lee SWH

Front Pharmacol, 2017;8:396.
PMID: 28690542 DOI: 10.3389/fphar.2017.00396

Objective: To evaluate the effectiveness of combined epinephrine and corticosteroid therapy for acute bronchiolitis in infants. Methods: Four electronic databases (MEDLINE, EMBASE, CINAHL, and CENTRAL) were searched from their inception to February 28, 2017 for studies involving infants aged less than 24 months with bronchiolitis which assessed the use of epinephrine and corticosteroid combination therapy. The methodological quality of the included studies was assessed using the Cochrane Collaboration's Risk of Bias Tool. A random-effects meta-analysis was used to pool the effect estimates. The primary outcomes were hospital admission rate and length of hospital stay. Results: Of 1,489 citations identified, 5 randomized controlled trials involving 1,157 patients were included. All studies were of high quality and low risk of bias. Results of the meta-analysis showed no significant differences in the primary outcomes. Hospitalization rate was reduced by combinatorial therapy of epinephrine and corticosteroid in only one out of five studies, whereas pooled data indicated no benefit over epinephrine plus placebo. Clinical severity scores were significantly improved in all five RCTs when assessed individually, but no benefit was observed compared to epinephrine monotherapy when the data were pooled together. Pooled data showed that combination therapy was more effective at improving oxygen saturation level (mean difference: -0.70; 95% confidence interval: -1.17 to -0.22, p = 0.004). There was no difference in the risk of serious adverse events in infants treated with the combined epinephrine and corticosteroid therapy. Conclusions: Combination treatment of epinephrine and dexamethasone was ineffective in reducing hospital admission and length of stay among infants with bronchiolitis.

Matched MeSH terms: Oxygen
Self-assembled heteropolyacid on nitrogen-enriched carbon nanofiber for vanadium flow batteries

Etesami M, Abouzari-Lotf E, Sha'rani SS, Miyake M, Moozarm Nia P, Ripin A, et al.

Nanoscale, 2018 Jul 13;10(27):13212-13222.
PMID: 29971298 DOI: 10.1039/c8nr02450b

A novel polyoxometalate-based electrode was developed by incorporating phosphotungstic acid (PWA) in nylon-6,6 nanofiber, followed by carbonization. The developed PWA-carbon nanofiber (PWA-CNF) showed the characteristics of the dual-scale porosity of micro- and mesoporous substrate with surface area of around 684 m2 g-1. The compound exhibited excellent stability in vanadium electrolyte and battery cycling. Evaluation of electrocatalytic properties toward V2+/V3+ and VO2+/VO2+ redox couples indicated promising advantages in electron transfer kinetics and increasing energy efficiency, particularly for the VO2+/VO2+ couple. Moreover, the developed electrode exhibited substantially improved energy efficiency (14% higher than that of pristine carbon felt) in the single cell vanadium redox flow battery. This outstanding performance was attributed to high surface area and abundant oxygen-containing linkages in the developed electrode.

Matched MeSH terms: Oxygen
Fulltext The effect of tocotrienol supplementation on plasma estradiol levels and quality of embryos in aging mice

Norerlyda, H., Fathimah, M., Nuraliza, A.S.

Malaysian Journal of Microscopy, 2015;11(1):32-38.
MyJurnal

Accumulation of reactive oxygen species leads to oxidative stress condition that can accelerate ovarian aging. Ovarian aging caused a reduction in plasma estradiol levels, quality of embryo and eventually will lead to infertility. Tocotrienol has been proven to possess antioxidant properties by protecting the cellular membrane from free radicals damage. Therefore, the aim of this study was to determine the effect of tocotrienol supplementation on the plasma estradiol levels, quality and development of embryos in aging mice. Female mice (Mus musculus) used in this study were divided into six groups. Six weeks old mice (young group) were used as negative control while eight months old mice (aging group) were used as age-matched (positive control) group. Group 1 (6 months old mice) were given corn oil as control, group 2, 3 and 4 (6 months old mice) were supplemented orally for two months with tocotrienol (TCT) at the dose of 90, 120 and 150 mg/kg body weight (BW), respectively. Subsequently, after two months the mice were superovulated, euthanized and 2- cell stage embryos were harvested and cultured in vitro to monitor the embryonic development. Plasma was analysed using enzyme-like immunosorbent assay. The results of this study showed that there was no significant correlation between plasma estradiol levels and the quality of embryo between young and aging group. Similarly, no significant change on plasma estradiol levels were noted in all TCT supplemented groups as compared to its vehicle control. On the other hand, there was a significant reduction on the percentage of normal embryo in all aging groups including TCT supplemented groups as compared to young group. Conversely, TCT supplementation at the dose of 150 mg/kg BW was able to increase the percentage of embryos that developed to blastocyst stage as compared to control. This finding proposed that TCT supplementations for two months are not able to cause a significant change in plasma estradiol levels and quality of embryo but it can delay the consequence of aging in embryonic development.

Matched MeSH terms: Reactive Oxygen Species
Fulltext Morphological change of human exfoliated deciduous teeth and the effect of vascular endothelial growth factor on human amniotic membrane scaffold

Md Hashim, S.N., Yusof, M.F.H., Alshehadat, S.A., Kannan, T.P., Azlina, A., Suzina, S.A.H., et al.

Malaysian Journal of Microscopy, 2015;11(1):22-27.
MyJurnal

Angiogenicity is one of the essential components to enable tissue function. It is important to develop a construct that would help in catering oxygen and nutrient to the engineered tissue area. Thus, this study aims to investigate the attachment, spreading and growth of stem cells from human exfoliated deciduous teeth (SHED) on human AM (HAM) with or without vascular endothelial growth factor (VEGF) using scanning electron microscope (SEM), and indirectly see the potential of the HAM as a scaffold to promote angiogenic micro-environment. Since day 1, there were continuous changes of the cell morphology until day 28, SHED treated with VEGF seemed to change its shape from fibroblast-like into a round-shape cell, similar structure as an endotheliallike cell. The structures of filopodia-like were also observed on the treated SHED. SHED without VEGF treatment showed only normal morphological growth on HAM. VEGF is a protein produced to stimulate angiogenesis, and is believed to contribute to the morphological changes of SHED seeded on HAM. This indicates that HAM could be used as a scaffold to allow SHED differentiation into endothelial-like cells with the induction of VEGF.

Matched MeSH terms: Oxygen
Application of an optimal class of antisymmetric wavelet filter banks for obstructive sleep apnea diagnosis using ECG signals

Sharma M, Agarwal S, Acharya UR

Comput Biol Med, 2018 09 01;100:100-113.
PMID: 29990643 DOI: 10.1016/j.compbiomed.2018.06.011

Obstructive sleep apnea (OSA) is a sleep disorder caused due to interruption of breathing resulting in insufficient oxygen to the human body and brain. If the OSA is detected and treated at an early stage the possibility of severe health impairment can be mitigated. Therefore, an accurate automated OSA detection system is indispensable. Generally, OSA based computer-aided diagnosis (CAD) system employs multi-channel, multi-signal physiological signals. However, there is a great need for single-channel bio-signal based low-power, a portable OSA-CAD system which can be used at home. In this study, we propose single-channel electrocardiogram (ECG) based OSA-CAD system using a new class of optimal biorthogonal antisymmetric wavelet filter bank (BAWFB). In this class of filter bank, all filters are of even length. The filter bank design problem is transformed into a constrained optimization problem wherein the objective is to minimize either frequency-spread for the given time-spread or time-spread for the given frequency-spread. The optimization problem is formulated as a semi-definite programming (SDP) problem. In the SDP problem, the objective function (time-spread or frequency-spread), constraints of perfect reconstruction (PR) and zero moment (ZM) are incorporated in their time domain matrix formulations. The global solution for SDP is obtained using interior point algorithm. The newly designed BAWFB is used for the classification of OSA using ECG signals taken from the physionet's Apnea-ECG database. The ECG segments of 1 min duration are decomposed into six wavelet subbands (WSBs) by employing the proposed BAWFB. Then, the fuzzy entropy (FE) and log-energy (LE) features are computed from all six WSBs. The FE and LE features are classified into normal and OSA groups using least squares support vector machine (LS-SVM) with 35-fold cross-validation strategy. The proposed OSA detection model achieved the average classification accuracy, sensitivity, specificity and F-score of 90.11%, 90.87% 88.88% and 0.92, respectively. The performance of the model is found to be better than the existing works in detecting OSA using the same database. Thus, the proposed automated OSA detection system is accurate, cost-effective and ready to be tested with a huge database.

Matched MeSH terms: Oxygen
Chemopreventive effects of standardized papaya leaf fraction on oxidatively stressed human liver cells

Tan SA, Goya L, Ramanathan S, Sulaiman SF, Alam M, Navaratnam V

Food Res Int, 2014 Oct;64:387-395.
PMID: 30011665 DOI: 10.1016/j.foodres.2014.06.040

Extract from papaya leaves, a waste material from fruit farms in Malaysia was previously reported to possess remarkable antioxidative activities. In this study, papaya leaf extract was separated into fractions of different polarities [petroleum ether (PE), ethyl acetate (EA), n-butanol (NB) and water (W) fractions]. The aim of this research was to determine the most active fraction in terms of its chemopreventive effects towards oxidative stress and the chemical constituents involved. The cytoprotective nature of the papaya fractions was observed against t-BOOH-induced oxidative stress on HepG2 liver cell line. ROS assay indicated that only PE and EA effectively reduced the increment of radical due to the pro-oxidant, t-BOOH. Nevertheless, PE was a stronger ROS scavenger by demonstrating ROS reducing activity in a dose-dependent manner to the basal level. This fraction was also found to inhibit cell death caused by t-BOOH toxicity, attenuating lactate dehydrogenase enzyme leakage by more than 90% (p<0.05). In addition, gene expression of phase II antioxidant enzymes (hmox-1 and nqo-1) and their transcription factor (nrf-2) were shown to be upregulated upon PE treatment during a time-course study. A GC-MS fingerprint of the active fraction was subsequently obtained with standardization using the marker compound; α-tocopherol, a well known antioxidant. However, this pure compound was not as effective as its corresponding PE concentrations in ROS reduction. Hence, PE of papaya leaf extract was a strong antioxidant and cytoprotectant with tremendous potential to be harnessed into the next therapeutic remedy against oxidative stress of the liver.

Matched MeSH terms: Reactive Oxygen Species
Fulltext Pollen-Structured Gold Nanoclusters for X-ray Induced Photodynamic Therapy

Tew LS, Cai MT, Lo LW, Khung YL, Chen NT

Materials (Basel), 2018 Jul 09;11(7).
PMID: 29987236 DOI: 10.3390/ma11071170

Photodynamic therapy (PDT) is a cancer treatment that employs the production of cytotoxic reactive oxygen species (ROS), subsequently triggering tumor apoptosis and tumor size reduction. However, this approach suffers from insufficient light penetration depth. In order to mitigate this issue, pollen-structured gold clusters (PSGCs) were designed for mediating X-ray-induced PDT for radiotherapy enhancement. The structure of PSGCs provides a large surface area that is able to generate ROS upon X-ray irradiation. The synthesized PSGCs were exposed to different X-ray doses and the generated ROS was then quantified by dihydroethidium (DHE) assay. Furthermore, at the cellular level, the PDT efficacy of PSGCs was evaluated via immunofluorescence staining with γ-H2AX and comet assay. The results demonstrated that PSGCs possess a significantly high ROS-generating capacity and a remarkable PDT efficacy in the treatment of breast cancer cells, thus showing potential clinical uses in deep-tissue cancer treatment.

Matched MeSH terms: Reactive Oxygen Species
Fulltext Performance of combined persulfate/aluminum sulfate for landfill leachate treatment

Abu Amr SS, Alkarkhi AFM, Alslaibi TM, Abujazar MSS

Data Brief, 2018 Aug;19:951-958.
PMID: 29900392 DOI: 10.1016/j.dib.2018.05.111

Although landfilling is still the most suitable method for solid waste disposal, generation of large quantity of leachate is still considered as one of the main environmental problem. Efficient treatment of leachate is required prior to final discharge. Persulfate (S2O82-) recently used for leachate oxidation, the oxidation potential of persulfate can be improved by activate and initiate sulfate radical. The current data aimed to evaluate the performance of utilizing Al2SO4 reagent for activation of persulfate to treat landfill leachate. The data on chemical oxygen demand (COD), color, and NH3-H removals at different setting of the persulfate, Al2SO4 dosages, pH, and reaction time were collected using a central composite design (CCD) were measured to identify the optimum operating conditions. A total of 30 experiments were performed, the optimum conditions for S2O82-/Al2SO4 oxidation process was obtained. Quadratic models for chemical oxygen demand (COD), color, and NH3-H removals were significant with p-value 

Matched MeSH terms: Biological Oxygen Demand Analysis
Fulltext First reported case of Haemoglobin-M Hyde Park in a Malay family living in Malaysia

Loong TY, Chong DL, Jamal AR, Murad NA, Sabudin RZ, Fun LC

EXCLI J, 2016;15:630-635.
PMID: 28096792 DOI: 10.17179/excli2016-613

Haemoglobin (Hb)-M Hyde Park, also known as Hb-M Akita is a rare type of hereditary Hb M due to autosomal dominant mutation of CAC>TAC on codon 92 of β globin gene resulting in the replacement of histidine by tyrosine on β globin chain. This variant Hb has a tendency to form methaemoglobin (metHb). The iron ion in metHb is oxidized to ferric (Fe3+) which is unable to carry oxygen and the patients manifest as cyanosis clinically. A 9-year-old Malay girl was incidentally found to be cyanotic when she presented to a health clinic. Laboratory investigations revealed raised methaemoglobin levels and Hb analysis findings were consistent with Hb-M Hyde Park. β gene sequencing confirmed a point mutation of CAC>TAC on codon 92 in one of the β genes. The family study done on the individuals with cyanosis showed similar findings. A diagnosis of heterozygous Hb-M Hyde Park was made. Patients with this variant Hb usually presented with cyanosis with mild haemolysis and maybe misdiagnosed as congenital heart disease. No further treatment is needed as patients are relatively asymptomatic. Although the disease is harmless in the heterozygous carriers but the offspring of the carriers may suffer severe haemolytic anaemia when the offspring also inherit other β haemoglobinopathies/thalassemia. This can happen due to high prevalence of β thalassemia carrier (3.5-4 %) found in Malaysia. At the time of writing, this is the first case of hereditary Hb-M Hyde Park diagnosed in a Malay family living in Malaysia.

Matched MeSH terms: Oxygen
Dihydroorotate dehydrogenase (DHODH) inhibitors affect ATP depletion, endogenous ROS and mediate S-phase arrest in breast cancer cells

Mohamad Fairus AK, Choudhary B, Hosahalli S, Kavitha N, Shatrah O

Biochimie, 2017 Apr;135:154-163.
PMID: 28196676 DOI: 10.1016/j.biochi.2017.02.003

Dihydroorotate dehydrogenase (DHODH) is the key enzyme in de novo biosynthesis of pyrimidine in both prokaryotes and eukaryotes. The de novo pathway of pyrimidine biosynthesis is essential in cancer cells proliferation. Leflunomide is an approved DHODH inhibitor that has been widely used for the treatment of arthritis. Similarly, brequinar sodium is another DHODH inhibitor that showed anti-tumour effect in MC38 colon carcinoma cells when used in combination with fluorouracil. Despite the potential role of DHODH inhibitors in cancer therapy, their mechanisms of action remain obscure and await further elucidation. Here, we evaluated the effect of DHODH inhibitors on the production of ATP and ROS in sensitive and non-sensitive breast cancer cells. Subsequently, the effects of DHODH inhibitors on cell cycle as well as on signalling molecules such as p53, p65 and STAT6 were evaluated in sensitive T-47D and non-sensitive MDAMB-436 cells. The correlations between DHODH protein expression, proliferation speed and sensitivity to DHODH inhibitors were also investigated in a panel of cancer cell lines. DHODH inhibitors-sensitive T-47D and MDAMB-231 cells appeared to preserve ROS production closely to endogenous ROS level whereas the opposite was observed in non-sensitive MDAMB-436 and W3.006 cells. In addition, we observed approximately 90% of intracellular ATP depletion in highly sensitive T-47D and MDAMB-231 cells compared to non-sensitive MDAMB-436 cells. There was significant over-expression of p53, p65 and STAT6 signalling molecules in sensitive cells which may be involved in mediating the S-phase arrest in cell cycle progression. The current study suggests that DHODH inhibitors are most effective in cells that express high levels of DHODH enzyme. The inhibition of cell proliferation by these inhibitors appears to be accompanied by ROS production as well as ATP depletion. The increase in expression of signalling molecules observed may be due to pyrimidine depletion which subsequently leads to cell cycle arrest at S-phase.

Matched MeSH terms: Reactive Oxygen Species
Fulltext A Holistic Approach to Managing Microalgae for Biofuel Applications

Show PL, Tang MS, Nagarajan D, Ling TC, Ooi CW, Chang JS

Int J Mol Sci, 2017 Jan 22;18(1).
PMID: 28117737 DOI: 10.3390/ijms18010215

Microalgae contribute up to 60% of the oxygen content in the Earth's atmosphere by absorbing carbon dioxide and releasing oxygen during photosynthesis. Microalgae are abundantly available in the natural environment, thanks to their ability to survive and grow rapidly under harsh and inhospitable conditions. Microalgal cultivation is environmentally friendly because the microalgal biomass can be utilized for the productions of biofuels, food and feed supplements, pharmaceuticals, nutraceuticals, and cosmetics. The cultivation of microalgal also can complement approaches like carbon dioxide sequestration and bioremediation of wastewaters, thereby addressing the serious environmental concerns. This review focuses on the factors affecting microalgal cultures, techniques adapted to obtain high-density microalgal cultures in photobioreactors, and the conversion of microalgal biomass into biofuels. The applications of microalgae in carbon dioxide sequestration and phycoremediation of wastewater are also discussed.

Matched MeSH terms: Oxygen
Fulltext Cytomegalovirus infection associated with Atypical Bronchopulmonary Dysplasia in a Preterm Neonate: a case report

Aisha Fadhilah Abang Abdullah, Zurina Zainudin, Dg. Zuraini Sahadan

Malaysian Journal of Medicine and Health Sciences, 2018;14(2):97-99.
MyJurnal

Cytomegalovirus (CMV) is frequently isolated from neonates. Symptomatic infection is only apparent in 10% of affected babies with particular predilection for the reticuloendothelial and central nervous system. Isolated respiratory system involvement is rarely encountered. We report a case of a premature 32 weeks infant who required prolonged oxygen dependency and treated for bronchopulmonary dysplasia. The diagnosis of CMV pneumonitis was only discovered after detection of CMV DNA in the bronchoalveolar lavage. A high level of clinical awareness is crucial as a definite diagnosis and treatment will significantly alter the morbidity and the cost of therapy.

Matched MeSH terms: Oxygen
Optimization of co-culture inoculated microbial fuel cell performance using response surface methodology

Islam MA, Ong HR, Ethiraj B, Cheng CK, Rahman Khan MM

J Environ Manage, 2018 Nov 01;225:242-251.
PMID: 30092551 DOI: 10.1016/j.jenvman.2018.08.002

Microbial fuel cells (MFCs) are considered as promising technology to achieve simultaneous wastewater treatment and electricity generation. However, operational and technological developments are still required to make it as a sustainable technology. In the present study, response surface methodology (RSM) was used to evaluate the effects of substrate concentration, co-culture composition, pH and time on the performance of co-culture (Klebsiella variicola and Pseudomonas aeruginosa) inoculated double chamber MFC. From the statistical analysis, it can be seen that the performance of MFC was not influenced by the interaction between the initial COD and time, pH and time, pH and initial COD, time and initial COD. However, the interaction between the inoculum composition and time, pH and the inoculum composition, initial COD and inoculum composition significantly influenced the performance of MFC. Based on the RSM results, best performance (power density and COD removal efficiency) was obtained when the inoculum composition, initial COD, pH and time were about 1:1, 26.690 mg/L, 7.21 and 15.50 days, respectively. The predictions from the model were in close agreement with the experimental results suggesting that the proposed model could adequately represent the actual relationships between the independent variables generating electricity and the COD removal efficiency.

Matched MeSH terms: Biological Oxygen Demand Analysis
Fulltext Effect of Ratio in Ammonium Nitrate on the Structural, Microstructural, Magnetic, and AC Conductivity Properties of BaFe12O19

Azis RS, Che Muda NN, Hassan J, Shaari AH, Ibrahim IR, Mustaffa MS, et al.

Materials (Basel), 2018 Nov 06;11(11).
PMID: 30404131 DOI: 10.3390/ma11112190

This paper investigates the effect of the ratio of ammonium nitrate (AN) on the structural, microstructural, magnetic, and alternating current (AC) conductivity properties of barium hexaferrite (BaFe12O19). The BaFe12O19 were prepared by using the salt melt method. The samples were synthesized using different powder-to-salt weight ratio variations (1:3, 1:4, 1:5, 1:6 and 1:7) of BaCO₃ + Fe₂O₃ and ammonium nitrate salt. The NH₄NO₃ was melted on a hot plate at 170 °C. A mixture of BaCO₃ and Fe₂O₃ were added into the NH₄NO₃ melt solution and stirred for several hours using a magnetic stirrer under a controlled temperature of 170 °C. The heating temperature was then increased up to 260 °C for 24 hr to produce an ash powder. The x-ray diffraction (XRD) results show the intense peak of BaFe12O19 for all the samples and the presence of a small amount of the impurity Fe₂O₃ in the samples, at a ratio of 1:5 and 1:6. From the Fourier transform infra-red (FTIR) spectra, the band appears at 542.71 cm - 1 and 432.48 cm - 1 , which corresponding to metal⁻oxygen bending and the vibration of the octahedral sites of BaFe12O19. The field emission scanning electron microscope (FESEM) images show that the grains of the samples appear to stick each other and agglomerate at different masses throughout the image with the grain size 5.26, 5.88, 6.14, 6.22, and 6.18 µm for the ratios 1:3, 1:4, 1:5, 1:6, and 1:7 respectively. From the vibrating sample magnetometer (VSM) analysis, the magnetic properties of the sample ratio at 1:3 show the highest value of coercivity Hc of 1317 Oe, a saturation magnetization Ms of 91 emu/g, and a remnant Mr of 44 emu/g, respectively. As the temperature rises, the AC conductivity is increases with an increase in frequency.

Matched MeSH terms: Oxygen
Fulltext Radiation dose enhancement effects of superparamagnetic iron oxide nanoparticles to the t24 bladder cancer cell lines irradiated with megavoltage photon beam radiotherapy

Rosmazihana Mat Lazim, Raizulnasuha Ab Rashid, Wan Nordiana Rahman, Binh. T.T. Pham, Brian S. Hawkett, Moshi Geso

Jurnal Sains Nuklear Malaysia, 2018;30(2):30-38.
MyJurnal

Therapeutic application of metallic nanoparticles such as gold nanoparticles have been extensively investigated and intriguing finding have been reported. Superparamagnetic iron oxide nanoparticles (SPION) could also potentially have therapeutic properties that can be exploited to enhance radiotherapy outcome. In this study, investigations on the dose enhancement effects inflicted by SPIONs under irradiation with megavoltage photon beam radiotherapy were conducted. T24 human bladder cancer cell lines were pretreated with 1 mMol/L of SPION and irradiated with 6 MV and 10 MV photon beam at different doses.The non-treated cells irradiation was used as a control. Clonogenic assay was performed to determine the cell survival. Linear quadratic (LQ) model are used as fitting curve and does enhancement factors (DEF) were extrapolated from the curves. The cytotoxicity indicated cell growth normally after 72 hours and no long term cytotoxicity effects of SPIONs towards the cells were observed. The dose enhancement effects were observed for both 6 MV and 10 MV photon beam with DEF obtained 1.71 and 2.50, respectively. This reduction of cell colonies growth could be resulted from the interaction that induced free radical and reactive oxygen species (ROS) by megavoltage photon beams. The SPIONs were therefore act as multifunction nanoparticle both in diagnostic agent and radiotherapy as radiation dose enhancer, thus clearly qualified as future theranostic agents.

Matched MeSH terms: Reactive Oxygen Species
Optimum conditions for the production of polyhydroxybutyrate from cassava wastewater by the newly isolated Cupriavidus sp. KKU38

Sangyoka S, Poomipuk N, Reungsang A

Sains Malaysiana, 2012;41:1211-1216.

The Cassava starch manufacturing wastewater (CSW) was used as a substrate to produce polyhydroxybutyrate (PHB) by Cupriavidus sp. KKU38. The acidogenic fermentation process of CSW was first conducted to obtain volatile fatty acids (VFAs), which are more efficient in PHB production than raw CSW. The effect on substrate concentration and nutrients, i.e. nitrogen and phosphorus concentrations, by means of chemical oxygen demand: nitrogen: phosphorus ratio (COD:N:P ratio) variation was investigated. The results indicated that PHB production from fermented CSW by Cupriavidus sp. KKU38 was optimized at the soluble COD:N:P ratio of 100:0.5:11. This ratio gave the maximum PHB content and yield of 85.53% and 0.31 g PHB/g COD consumed, respectively. By using the proposed PHB production process, the potential to produce 0.19 kg of PHB from 1.0 kg of soluble chemical oxygen demand (sCOD) contained in CSW was exhibited. The relatively high COD removal efficiency of 73.82% at the optimal condition could be achieved, which demonstrated the concept of water quality improvements alongside the production of the value-added by-product, PHB.

Matched MeSH terms: Biological Oxygen Demand Analysis
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
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

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