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  1. Fulltext Oil Palm Waste-Based Precursors as a Renewable and Economical Carbon Sources for the Preparation of Reduced Graphene Oxide from Graphene Oxide
    Nasir S, Hussein MZ, Yusof NA, Zainal Z
    Nanomaterials (Basel), 2017 Jul 13;7(7).
    PMID: 28703757 DOI: 10.3390/nano7070182
    Herein, a new approach was proposed to produce reduced graphene oxide (rGO) from graphene oxide (GO) using various oil palm wastes: oil palm leaves (OPL), palm kernel shells (PKS) and empty fruit bunches (EFB). The effect of heating temperature on the formation of graphitic carbon and the yield was examined prior to the GO and rGO synthesis. Carbonization of the starting materials was conducted in a furnace under nitrogen gas for 3 h at temperatures ranging from 400 to 900 °C and a constant heating rate of 10 °C/min. The GO was further synthesized from the as-carbonized materials using the 'improved synthesis of graphene oxide' method. Subsequently, the GO was reduced by low-temperature annealing reduction at 300 °C in a furnace under nitrogen gas for 1 h. The IG/ID ratio calculated from the Raman study increases with the increasing of the degree of the graphitization in the order of rGO from oil palm leaves (rGOOPL) < rGO palm kernel shells (rGOPKS) < rGO commercial graphite (rGOCG) < rGO empty fruit bunches (rGOEFB) with the IG/ID values of 1.06, 1.14, 1.16 and 1.20, respectively. The surface area and pore volume analyses of the as-prepared materials were performed using the Brunauer Emmett Teller-Nitrogen (BET-N₂) adsorption-desorption isotherms method. The lower BET surface area of 8 and 15 m2 g-1 observed for rGOCG and rGOOPL, respectively could be due to partial restacking of GO layers and locally-blocked pores. Relatively, this lower BET surface area is inconsequential when compared to rGOPKS and rGOEFB, which have a surface area of 114 and 117 m² g-1, respectively.
    Matched MeSH terms: Nitrogen
  2. Enhancing the biocompatibility of the polyurethane methacrylate and off-stoichiometry thiol-ene polymers by argon and nitrogen plasma treatment
    Chen TF, Siow KS, Ng PY, Majlis BY
    Mater Sci Eng C Mater Biol Appl, 2017 Oct 01;79:613-621.
    PMID: 28629060 DOI: 10.1016/j.msec.2017.05.091
    Our studies focused on improving the biocompatibility properties of two microfluidic prototyping substrates i.e. polyurethane methacrylate (PUMA) and off-stoichiometry thiol-ene (OSTE-80) polymer by Ar and N2plasma treatment. The contact angle (CA) measurement showed that both plasma treatments inserted oxygen and nitrogen moieties increased the surface energy and hydrophilicity of PUMA and OSTE-80 polymer which corresponded to an increase of nitrogen to carbon ratios (N/C), as measured by XPS, to provide a conducive environment for cell attachments and proliferation. Under the SEM observation, the surface topography of PUMA and OSTE-80 polymer showed minimal changes after the plasma treatments. Furthermore, ageing studies showed that plasma-treated PUMA and OSTE-80 polymer had stable hydrophilicity and nitrogen composition during storage in ambient air for 15days. After in vitro cell culture of human umbilical vein endothelial cells (HUVECs) on these surfaces for 24h and 72h, both trypan blue and alamar blue assays indicated that PUMA and OSTE-80 polymer treated with N2plasma had the highest viability and proliferation. The polar nitrogen moieties, specifically amide groups, encouraged the HUVECs adhesion on the plasma-treated PUMA and OSTE-80 surfaces. Interestingly, PUMA polymer treated with Ar and N2plasma showed different HUVECs morphology which was spindle and cobblestone-shaped respectively after 72h of incubation. On the contrary, a monolayer of well-spread HUVECs formed on the Ar and N2plasma-treated OSTE-80 polymers. These variable morphologies observed can be ascribed to the adherence HUVECs on the different elastic moduli of these surfaces whereby further investigation might be needed. Overall, Ar and N2plasma treatment had successfully altered the surface properties of PUMA and OSTE-80 polymer by increasing its surface energy, hydrophilicity and chemical functionalities to create a biocompatible surface for HUVECs adhesion and proliferation.
    Matched MeSH terms: Nitrogen
  3. Fulltext Development of catalytic converter by washcoat of γ-alumina on nickel oxide (Nio) catalyst in FeCrAl substrate for exhaust emission control : proposed study
    Leman, A.M., Fatin Afiqah Jajuli, Dafit Feriyanto
    Journal of Occupational Safety and Health, 2015;12(2):65-70.
    MyJurnal
    Automobile exhaust emission control is one of the trending issues in automobile research field. It caused by high
    pollution such as carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HC) distributed by automobile
    especially form diesel engine. These pollutants give a harmful effect to the environment and human health. Therefore,
    this paper proposed in reviewing methods on fabrication of modified catalytic converter. FeCrAl is used as substrate
    which treated using ultrasonic bath technique which could improve the exhaust emission control. This metallic catalytic converter used as the replacement of precious metal that have high production cost.
    Matched MeSH terms: Nitrogen Oxides
  4. Fulltext Bioremediation of high-strength agricultural wastewater using Ochrobactrum sp. strain SZ1
    Neoh CH, Lam CY, Ghani SM, Ware I, Sarip SH, Ibrahim Z
    3 Biotech, 2016 Dec;6(2):143.
    PMID: 28330215 DOI: 10.1007/s13205-016-0455-1
    The biggest agricultural sector that contributes to the Malaysian economy is the oil palm industry. The effluent generated during the production of crude palm oil known as palm oil mill effluent (POME). POME undergoes anaerobic treatment that requires long retention time and produces large amount of methane that consequently contributes to global warming. In this study, an isolated bacteria was selected based on its ability to degrade kraft lignin (KL) and identified as Ochrobactrum sp. The bacteria were able to treat POME (from anaerobic pond) under the aerobic condition without addition of nutrient, resulting in a significant chemical oxygen demand (COD) removal of 71 %, removal rate of 1385 mg/l/day, and 12.3 times higher than that of the ponding system. It has also resulted in 60 % removal of ammoniacal nitrogen and 55 % of total polyphenolic after 6-day treatment period with the detection of lignocellulolytic enzymes.
    Matched MeSH terms: Nitrogen
  5. Data on modeling mycelium growth in Pleurotus sp. cultivation by using agricultural wastes via two level factorial analysis
    Dzulkefli NA, Zainol N
    Data Brief, 2018 Oct;20:1710-1720.
    PMID: 30263925 DOI: 10.1016/j.dib.2018.09.008
    In this article, five variables including type of substrates, sizes of substrates, mass ratio of spawn to substrates (SP/SS), temperature and pretreatment of substrates were used to model mycelium growth in Pleurotus sp. (oyster mushroom) cultivation by using agricultural wastes via two level factorial analysis. Two different substrates which were empty fruit bunch (EFB) and sugarcane bagasse (SB) were used. Analysis of Variance (ANOVA) for both mycelium extension rate (M) and nitrogen concentration in mycelium (N) showed that the confidence level was greater than 95% while p-value of both models were less than 0.05 which is significant. The coefficient of determination (R2) for both M and N were 0.8829 and 0.9819 respectively. From the experiment, the best condition to achieve maximum M (0.8 cm/day) and N (656 mg/L) was by using substrate B, 2.5 cm size of substrate, 1:14 for SP/SS, incubated at ambient temperature and application of steam treatment. The data showed that EFB can be used to replace sawdust as a media for the oyster mushroom cultivation. Data analysis was performed using Design Expert version 7.0.
    Matched MeSH terms: Nitrogen
  6. Fulltext Palm Kernel Shell Activated Carbon as an Inorganic Framework for Shape-Stabilized Phase Change Material
    Nicholas AF, Hussein MZ, Zainal Z, Khadiran T
    Nanomaterials (Basel), 2018 Sep 05;8(9).
    PMID: 30189654 DOI: 10.3390/nano8090689
    The preparation of activated carbon using palm kernel shells as the precursor (PKSAC) was successfully accomplished after the parametric optimization of the carbonization temperature, carbonization holding time, and the ratio of the activator (H₃PO₄) to the precursor. Optimization at 500 °C for 2 h of carbonization with 20% H₃PO₄ resulted in the highest surface area of the activated carbon (C20) of 1169 m² g-1 and, with an average pore size of 27 Å. Subsequently, the preparation of shape-stabilized phase change material (SSPCM-C20) was done by the encapsulation of n-octadecane into the pores of the PKSAC, C20. The field emission scanning electron microscope images and the nitrogen gas adsorption-desorption isotherms show that n-octadecane was successfully encapsulated into the pores of C20. The resulting SSPCM-C20 nano-composite shows good thermal reliability which is chemically and thermally stable and can stand up to 500 melting and freezing cycles. This research work provided a new strategy for the preparation of SSPCM material for thermal energy storage application generated from oil palm waste.
    Matched MeSH terms: Nitrogen
  7. Determination of optimum harvest maturity and non-destructive evaluation of pod development and maturity in cacao (Theobroma cacao L.) using a multiparametric fluorescence sensor
    Tee YK, Balasundram SK, Ding P, M Hanif AH, Bariah K
    J Sci Food Agric, 2019 Mar 15;99(4):1700-1708.
    PMID: 30206959 DOI: 10.1002/jsfa.9359
    BACKGROUND: A series of fluorescence indices (anthocyanin, flavonol, chlorophyll and nitrogen balance) were deployed to detect the pigments and colourless flavonoids in cacao pods of three commercial cacao (Theobroma cacao L.) genotypes (QH1003, KKM22 and MCBC1) using a fast and non-destructive multiparametric fluorescence sensor. The aim was to determine optimum harvest periods (either 4 or 5 months after pod emergence) of commercial cacao based on fluorescence indices of cacao development and bean quality.

    RESULTS: As pod developed, cacao exhibited a rise with the peak of flavonol occurring at months 4 and 5 after pod maturity was initiated while nitrogen balance showed a decreasing trend during maturity. Cacao pods contained high chlorophyll as they developed but chlorophyll content declined significantly on pods that ripened at month 5.

    CONCLUSION: Cacao pods harvested at months 4 and 5 can be considered as commercially-ready as the beans have developed good quality and comply with the Malaysian standard on cacao bean specification. Thus, cacao pods can be harvested earlier when they reach maturity at month 4 after pod emergence to avoid germinated beans and over fermentation in ripe pods harvested at month 5. © 2018 Society of Chemical Industry.

    Matched MeSH terms: Nitrogen
  8. Pyrus pyrifolia fruit peel as sustainable source for spherical and porous network based nanocellulose synthesis via one-pot hydrolysis system
    Chen YW, Hasanulbasori MA, Chiat PF, Lee HV
    Int J Biol Macromol, 2019 Feb 15;123:1305-1319.
    PMID: 30292586 DOI: 10.1016/j.ijbiomac.2018.10.013
    In the present study, we attempted revalorization of pear (Pyrus pyrifolia L.) peel residue into high value-added nanomaterials. A green and facile one-pot isolation procedure was designed to simplify the isolation process of nanocellulose directly from pear peel residue. The one-pot approach employed in this work is interesting as the reaction involved less harmful chemicals usage and non-multiple steps. The reaction was carried out by adding hydrogen peroxide as an oxidant and chromium (III) nitrate as catalyst in the acidic medium under mild process conditions. FTIR spectroscopy proved that the pear peel derived nanocellulose was purely cellulose phases without the presence of non-cellulosic layer. XRD study indicated that the isolated nanocellulose possessed of cellulose I polymorph with high crystallinity index of 85.7%. FESEM analysis clearly revealed that the considerable size reduction during one-pot process. Remarkably, TEM analysis revealed that the isolated nanocellulose consisted of network-liked nature and spherical shaped morphologies with high aspect ratio of 24.6. TGA showed nanocellulose has lower thermal stability compared to pear peel residue. This study provided a cost-effective method and straightforward one-pot process for fabrication of nanocellulose from pear peel residue. This is the first investigation on the nanocellulose extraction from pear fruit.
    Matched MeSH terms: Nitrogen Oxides
  9. Fulltext Acrylamide toxicity and its biodegradation
    Gafar, A.A., Khayat, M.E., Abdul Rahim, M.B.H., Shukor, M.Y.
    Bioremediation Science and Technology Research, 2017;5(2):8-12.
    MyJurnal
    Acrylamide is a synthetic monomer that has been classified as toxic and carcinogenic apart
    from its diverse application in the industry. Its application is in the formation of
    polyacrylamide. Polyacrylamide usage is diverse and is found as herbicide formulation, as soil
    treatment agent and in water treatment plants. Deaths and sickness due to the accidental
    exposure to acrylamide have been reported while chronic toxicity is also a source of the
    problem. This review highlighted the toxic effect of acrylamide to various organisms like
    human, animal and plant. This review also discusses on the potential use of biological
    technologies to remediate acrylamide pollution in the environment and the degradation
    pathways these microorganisms utilize to assimilate acrylamide as a nitrogen, carbon or both as
    carbon and nitrogen sources.
    Matched MeSH terms: Nitrogen
  10. CTP synthase knockdown during early development distorts the nascent vertebral column and causes fluid retention in multiple tissues in zebrafish
    Dzaki N, Wahab W, Azlan A, Azzam G
    Biochem Biophys Res Commun, 2018 10 20;505(1):106-112.
    PMID: 30241946 DOI: 10.1016/j.bbrc.2018.09.074
    CTP Synthase (CTPS) is a metabolic enzyme that is recognized as a catalyst for nucleotide, phospholipid and sialoglycoprotein production. Though the structural characteristics and regulatory mechanisms of CTPS are well-understood, little is known regarding the extent of its involvement during the early developmental stages of vertebrates. Zebrafish carries two CTPS genes, annotated as ctps1a and ctps1b. Phylogenetic analyses show that both genes had diverged from homologues in the ancestral Actinopterygii, Oreochromis niloticus. Conservation of common CTPS-catalytic regions further establishes that both proteins are likely to be functionally similar to hsaCTPS. Here, we show that ctps1a is more critical throughout the initial period of embryonic development than ctps1b. The effects of concurrent partial knockdown are dependent on ctps1a vs ctps1b dosage ratios. When these are equally attenuated, abnormal phenotypes acquired prior to the pharyngula period disappear in hatchlings (48hpf); however, if either gene is more attenuated than the other, these only become more pronounced in advanced stages. Generally, disruption to normal ctps1a or ctps1b expression levels by morpholinos culminates in the distortion of the early spinal column as well as multiple-tissue oedema. Other effects include slower growth rates, increased mortality rates and impaired structural formation of the young fish's extremities. Embryos grown in DON, a glutamine-analogue drug and CTPS antagonist, also exhibit similar characteristics, thus strengthening the validity of the morpholino-induced phenotypes observed. Together, our results demonstrate the importance of CTPS for the development of zebrafish embryos, as well as a disparity in activity and overall importance amongst isozymes.
    Matched MeSH terms: Carbon-Nitrogen Ligases/classification; Carbon-Nitrogen Ligases/genetics*; Carbon-Nitrogen Ligases/metabolism
  11. Fulltext Hydroxyl Functionalized Pyridinium Ionic Liquids: Experimental and Theoretical Study on Physicochemical and Electrochemical Properties
    Lethesh KC, Evjen S, Raj JJ, Roux DCD, Venkatraman V, Jayasayee K, et al.
    Front Chem, 2019;7:625.
    PMID: 31620423 DOI: 10.3389/fchem.2019.00625
    Structurally modified hydroxyl functionalized pyridinium ionic liquids (ILs), liquid at room temperature, were synthesized and characterized. Alkylated N-(2-hydroxyethyl)-pyridinium ILs were prepared from alkylpyridines via corresponding bromide salts by N-alkylation (65-93%) and final anion exchange (75-96%). Pyridinium-alkylation strongly influenced the IL physicochemical and electrochemical properties. Experimental values for the ILs physicochemical properties (density, viscosity, conductivity, and thermal decomposition temperature), were in good agreement with corresponding predicted values obtained by theoretical calculations. The pyridinium ILs have electrochemical window of 3.0-5.4 V and were thermally stable up to 405°C. The IL viscosity and density were measured over a wide temperature range (25-80°C). Pyridine alkyl-substitution strongly affected the partial positive charge on the nitrogen atom of the pyridinium cations, as shown by charge distribution calculations. On-going studies on Mg complexes of the new ILs demonstrate promising properties for high current density electrodeposition of magnesium.
    Matched MeSH terms: Nitrogen
  12. Deoxygenation of pyrolysis vapour derived from durian shell using catalysts prepared from industrial wastes rich in Ca, Fe, Si and Al
    Tan YL, Hameed BH, Abdullah AZ
    Sci Total Environ, 2020 Feb 10;703:134902.
    PMID: 31753498 DOI: 10.1016/j.scitotenv.2019.134902
    Catalysts prepared from industrial wastes rich in Fe, Ca, Si, and Al were used in catalytic upgrading of pyrolysis vapour derived from durian shell and their effect on product yield and properties were compared. With same silica-to-alumina ratio, catalyst prepared from oil palm ash (AS-OPA) with lower Fe and Ca contents gave higher liquid yield (8.32 wt%) with alcohols (28.90%), hydrocarbons (46.00%), and nitrogen-containing compounds (21.46%) while catalyst prepared from electric arc furnace slag (AS-EAF) with higher Fe and Ca contents produced lower liquid yield (50.21 wt%) with high amount of esters (25.80%) and hydrocarbons (72.82%). The presence of AS-OPA and AS-EAF catalysts enhanced deoxygenation degree of bio-oil to 81.13% and 85.49%, respectively. The catalytic performance of AS-EAF at different temperatures (400-600 °C) and AS-EAF/durian shell ratios (1:30, 2:30, 3:30) was investigated. Increasing catalytic temperature enhanced production of bio-oil, reduced oxygenates and enhanced formation of esters. The liquid yield and yield of esters decreased with increasing catalyst loading. Hydrocarbons (mainly neopentane) were the major chemical compounds found in bio-oil produced over AS-EAF. Besides that, AS-EAF showed good deoxygenation performance with highest selectivity of hydrocarbons at 500 °C and AS-EAF/durian shell ratio of 2:30. Catalytic fast pyrolysis of durian shell using waste-derived catalysts is an effective waste management strategy as the bio-oil produced can be a potential alternative source of energy or chemical feedstocks.
    Matched MeSH terms: Nitrogen Compounds
  13. Effect of storage conditions on maintaining anammox cell viability during starvation and recovery
    Ganesan S, Vadivelu VM
    Bioresour Technol, 2020 Jan;296:122341.
    PMID: 31711905 DOI: 10.1016/j.biortech.2019.122341
    Anammox bacteria can easily undergo starvation due to fluctuations in feed flowrate and concentration in wastewater treatment plants. In this study, we analyzed the effects of different types of storage conditions (presence of ammonium (Ra), nitrite (Rn), hydrazine (Rh), and no substrate (Rc)) in aiding the viability of anammox bacteria during starvation and recovery. After starvation, the bacteria were subjected to a 15-week recovery period. Anammox bacteria showed better results during starvation and recovery in Rh as compared to other conditions. Decay rate values obtained after starvation in Ra, Rn, Rh, and Rc were 0.032/day, 0.042/day, 0.019/day, and 0.037/day, respectively. Meanwhile, µmax values obtained in Rh, Ra, Rn, and Rc on the 15th week of recovery were 0.092, 0.075, 0.011, and 0.067 d-1, respectively. This indicated that the availability of hydrazine helps to reduce the mortality rate of anammox bacteria during starvation and enhances the recovery of anammox process.
    Matched MeSH terms: Nitrogen
  14. Growth characteristics, water and Nitrogen use efficiencies of spinach in different water and Nitrogen levels
    Jinxiu Zhang, Zhigang Bei, Yi Zhang, Linkui Cao
    Sains Malaysiana, 2014;43:1665-1671.
    Water deficit and environmental pollution owing to excessive nitrogen use have caused considerable attention. In a field experiment, a combination of three water levels (20, 40 and 60 cm) and nitrogen fertilizer rates (0, 85 and 170 kg ha-1) was applied. The main objectives of this study were to optimize water and nitrogen application and exploit their interactive effects on the growth characteristics, yield and water and nitrogen use efficiency of spinach. The results showed that water and nitrogen significantly influenced average plant height and leaf area. Total aboveground biomass (TB) was affected by nitrogen fertilizer and TB decreased in water deficit. Adding nitrogen fertilizer amount resulted in higher leaf chlorophyll content and chlorophyll content obtained the maximum value in N2 treatment, but chlorophyll content was not affected by water deficit. Spinach yield was higher at N1 compared with N0 and N2 at all water levels. Abundant water supply resulted in the highest spinach yield, but yield reduced at lower water level (W3). The correlation analysis between spinach yield and leaf number was relatively weak (R2=0.58). On the contrast, the correlation analysis between spinach yield and leaf weight showed a correlationship (R2=0.91), indicating that leaf weight was the primary reason for yield increase in all treatments. Nitrogen fertilization significantly decreased NUE in all the treatments. WUE of spinach increased with adding nitrogen application in most conditions.
    Matched MeSH terms: Nitrogen
  15. Microbial fuel cells using mixed cultures of wastewater for electricity generation
    Zain S, Roslani N, Hashim R, Anuar N, Suja F, Basri N, et al.
    Sains Malaysiana, 2011;40.
    Fossil fuels (petroleum, natural gas and coal) are the main resources for generating electricity. However, they have been major contributors to environmental problems. One potential alternative to explore is the use of microbial fuel cells (MFCs), which generate electricity using microorganisms. MFCs uses catalytic reactions activated by microorganisms to convert energy preserved in the chemical bonds between organic molecules into electrical energy. MFC has the ability to generate electricity during the wastewater treatment process while simultaneously treating the pollutants. This study investigated the potential of using different types of mixed cultures (raw sewage, mixed liquor from the aeration tank & return waste activated sludge) from an activated sludge treatment plant in MFCs for electricity generation and pollutant removals (COD & total kjeldahl nitrogen, TKN). The MFC in this study was designed as a dual-chambered system, in which the chambers were separated by a NafionTM membrane using a mixed culture of wastewater as a biocatalyst. The maximum power density generated using activated sludge was 9.053 mW/cm2, with 26.8% COD removal and 40% TKN removal. It is demonstrated that MFC offers great potential to optimize power generation using mixed cultures of wastewater.
    Matched MeSH terms: Nitrogen
  16. Molecularly imprinted polymer synthesis using RAFT polymerisation
    Peter A.G. Cormack, Faizatul Shimal Mehamod
    Sains Malaysiana, 2013;42:529-535.
    In this paper, the synthesis and characterisation of caffeine-imprinted polymers are described. The polymers were prepared in monolithic form via both reversible addition-fragmentation chain-transfer (RAFT) polymerisation and conventional free radical polymerisation, using methacrylic acid and ethylene glycol dimethacrylate as the functional monomer and crosslinking agent, respectively. The potential benefits in applying RAFT polymerisation techniques towards the synthesis of molecularly imprinted polymers (MIPs) are explored and elucidated. The pore structures of the polymers produced were characterised by nitrogen sorption porosimetry and the molecular recognition properties of representative products were evaluated in high-performance liquid chromatography (HPLC) mode. Molecular imprinting effects were confirmed by analysing the relative retentions of analytes on imprinted and non-imprinted HPLC
    stationary phases. It was found that a caffeine-imprinted polymer synthesised by RAFT polymerisation was superior to a polymer prepared using a conventional synthetic approach; the imprinting factor and column efficiency were found to be higher for the former material.
    Matched MeSH terms: Nitrogen
  17. A preliminary study of water quality index in Terengganu River Basin, Malaysia
    Suratman S, Mohd Sailan M, Hee Y, Bedurus E, Latif M
    Sains Malaysiana, 2015;44:67-73.
    The Malaysian Department of Environment-Water Quality Index (DOE-WQI) was determined for the Terengganu River basin which is located at the coastal water of the southern South China Sea between July and October 2008. Monthly samplings were carried out at ten sampling stations within the basin. Six parameters listed in DOE-WQI were measured based on standard methods: pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS) and ammonical nitrogen (AN). The results indicated the impact of various anthropogenic activities which contribute to high values of BOD, COD, TSS and AN at middle and downstream stations, as compared with the upstream of the basin. The reverses were true for the pH and DO values. The DOE-WQI ranged from 71.5-94.6% (mean 86.9%), which corresponded to a classification status range from slightly polluted to clean. With respect to the Malaysia National Water Quality Standards (NWQS), the level of most of the parameters measured remained at Class I which is suitable for the sustainable conservation of the natural environment, for water supply without treatment and as well as for very sensitive aquatic species. It is suggested that monitoring should be carried out continuously for proper management of this river basin.
    Matched MeSH terms: Nitrogen
  18. Fulltext Characterization data of titanate compounds synthesized using hydrothermal method at various temperature
    Razali MH, Ismail NA, Osman UM, Rozaini MZH, Yusoff M
    Data Brief, 2020 Feb;28:104992.
    PMID: 31890823 DOI: 10.1016/j.dib.2019.104992
    Titanate compounds was synthesized using hydrothermal method at various temperature (100, 150, 200, and 250 °C) for 24 hours. As-synthesized titanate was characterized using FTIR, XRD and nitrogen gas adsorption. FTIR spectra was scanned from 4000 to 400 cm-1 using Perkin Elmer Spectrum 100 FTIR spectrophotometer. XRD diffractogram was performed by using Rigaku Miniflex (II) X-ray diffractometer operating at a scanning rate of 2.00° min-1. The diffraction spectra were recorded at the diffraction angle, 2θ from 10° to 80° at room temperature. Nitrogen gas adsorption analysis was studied by using Micromeritics ASAP2020 (Alaska) to determine the surface area and pores size distribution. The nitrogen adsorption and desorption was measured at 77 K (temperature of liquid nitrogen) and the samples were degassed in a vacuum at 110 °C under nitrogen flow for overnight prior to analysis.
    Matched MeSH terms: Nitrogen
  19. Energy recovery and carbon/nitrogen removal from sewage and contaminated groundwater in a coupled hydrolytic-acidogenic sequencing batch reactor and denitrifying biocathode microbial fuel cell
    Al-Mamun A, Jafary T, Baawain MS, Rahman S, Choudhury MR, Tabatabaei M, et al.
    Environ Res, 2020 04;183:109273.
    PMID: 32105886 DOI: 10.1016/j.envres.2020.109273
    Developing cost-effective technology for treatment of sewage and nitrogen-containing groundwater is one of the crucial challenges of global water industries. Microbial fuel cells (MFCs) oxidize organics from sewage by exoelectrogens on anode to produce electricity while denitrifiers on cathode utilize the generated electricity to reduce nitrogen from contaminated groundwater. As the exoelectrogens are incapable of oxidizing insoluble, polymeric, and complex organics, a novel integration of an anaerobic sequencing batch reactor (ASBR) prior to the MFC simultaneously achieve hydrolytic-acidogenic conversion of complex organics, boost power recovery, and remove Carbon/Nitrogen (C/N) from the sewage and groundwater. The results obtained revealed increases in the fractions of soluble organics and volatile fatty acids in pretreated sewage by 52 ± 19% and 120 ± 40%, respectively. The optimum power and current generation with the pretreated sewage were 7.1 W m-3 and 45.88 A m-3, respectively, corresponding to 8% and 10% improvements compared to untreated sewage. Moreover, the integration of the ASBR with the biocathode MFC led to 217% higher carbon and 136% higher nitrogen removal efficiencies compared to the similar system without ASBR. The outcomes of the present study represent the promising prospects of using ASBR pretreatment and successive utilization of solubilized organics in denitrifying biocathode MFCs for simultaneous energy recovery and C/N removal from both sewage and nitrate nitrogen-contaminated groundwater.
    Matched MeSH terms: Nitrogen
  20. Analysis of core protein clusters identifies candidate variable sites conferring metronidazole resistance in Helicobacter pylori
    Chua EG, Debowski AW, Webberley KM, Peters F, Lamichhane B, Loke MF, et al.
    Gastroenterol Rep (Oxf), 2019 Feb;7(1):42-49.
    PMID: 30792865 DOI: 10.1093/gastro/goy048
    Background: Metronidazole is one of the first-line drugs of choice in the standard triple therapy used to eradicate Helicobacter pylori infection. Hence, the global emergence of metronidazole resistance in Hp poses a major challenge to health professionals. Inactivation of RdxA is known to be a major mechanism of conferring metronidazole resistance in H. pylori. However, metronidazole resistance can also arise in H. pylori strains expressing functional RdxA protein, suggesting that there are other mechanisms that may confer resistance to this drug.

    Methods: We performed whole-genome sequencing on 121 H. pylori clinical strains, among which 73 were metronidazole-resistant. Sequence-alignment analysis of core protein clusters derived from clinical strains containing full-length RdxA was performed. Variable sites in each alignment were statistically compared between the resistant and susceptible groups to determine candidate genes along with their respective amino-acid changes that may account for the development of metronidazole resistance in H. pylori.

    Results: Resistance due to RdxA truncation was identified in 34% of metronidazole-resistant strains. Analysis of core protein clusters derived from the remaining 48 metronidazole-resistant strains and 48 metronidazole-susceptible identified four variable sites significantly associated with metronidazole resistance. These sites included R16H/C in RdxA, D85N in the inner-membrane protein RclC (HP0565), V265I in a biotin carboxylase protein (HP0370) and A51V/T in a putative threonylcarbamoyl-AMP synthase (HP0918).

    Conclusions: Our approach identified new potential mechanisms for metronidazole resistance in H. pylori that merit further investigation.

    Matched MeSH terms: Carbon-Nitrogen Ligases
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