MyMedR

Displaying publications 61 - 80 of 99 in total

Abstract:

Sort:

An investigation on the relationship between physicochemical characteristics of alumina-supported cobalt catalyst and its performance in dry reforming of methane

Khairudin NF, Mohammadi M, Mohamed AR

Environ Sci Pollut Res Int, 2021 Jun;28(23):29157-29176.
PMID: 33550559 DOI: 10.1007/s11356-021-12794-0

This study deals with the development of alumina-supported cobalt (Co/Al2O3) catalysts with remarkable performance in dry reforming of methane (DRM) and least carbon deposition. The influence of Co content, calcination, and reduction temperatures on the physicochemical attributes and catalyst activity of the developed catalysts was extensively studied. For this purpose, several characterization techniques including ICP-MS, H2 pulse chemisorption, HRTEM, H2-TPR, N2 adsorption desorption, and TGA were implemented, and the properties of the developed catalysts were carefully analyzed. The impact of reaction temperature, feed gas ratio, and gas hourly space velocity (GHSV) on the reactants conversion and products yield was investigated. Use of 10%Co/Al2O3 catalyst, calcined at 500°C and reduced under H2 at 900°C in DRM reaction at 850°C, CH4/CO2 ratio of 1:1, and GHSV of 6 L.g-1.h-1 resulted in a remarkable catalytic activity and sustainable performance in long-term operation where great CO2 (96%) and CH4 (98%) conversions and high H2 (83%) and CO (91%) yields with a negligible carbon deposition (3 wt%) were attained in 100-h on-stream reaction. The good performance of the developed catalyst in DRM reaction was attributed to the small Co particle size with well-dispersion on the alumina support which increased the catalytic activity and also the strong metal-support interaction which inhibited any serious metal sintering and enhanced the catalyst stability.

Matched MeSH terms: Cobalt
Fulltext Preparation and characterization of yttrium barium copper oxide (YBCO) superconductor with addition of cobalt oxide (Co3O4)

Jannah, A.N., Erwana, N.Y., Jamion, N.A.

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2018;6(1):31-38.
MyJurnal

This study was carried out to investigate the electrical properties of YBCO sample as superconductor
and the effect of addition of Co3O4 on the superconducting properties of YBCO superconductor. The
YBCO sample was prepared by solid state reaction route. The samples were prepared by each with
weight percentage of cobalt oxide of x= 0.00, x= 0.01, x= 0.02 and x= 0.03. Electrical Conduction by
Multimeter, Fourier Transform Infrared (FTIR), Critical temperature (Tc) measurement, X-ray
Diffraction (XRD), and Scanning Electron Microscopy (SEM) were conducted for analysis.
Multimeter showed all samples were in electric conduction, FTIR showed that carbonyl compound in
the sample was removed after calcinations. Tc measurement showed that the critical temperature of
sample of x= 0.02 was increased compared to sample of x= 0.00. XRD showed all samples have
orthorhombic structure and SEM showed that the grain size was increased as increased the cobalt
addition in YBCO superconductor. Besides, the EDX also showed the composition of elements
YBCO were tally with chemicals used for pure YBCO and addition cobalt oxide into YBCO
superconductor.

Matched MeSH terms: Cobalt
Evaluation of rectal dose discrepancies between planned and in vivo dosimetry using MOSkin detector and PTW 9112 semiconductor probe during 60Co HDR CT-based intracavitary cervix brachytherapy

Jamalludin Z, Jong WL, Malik RA, Rosenfeld AB, Ung NM

Phys Med, 2020 Jan;69:52-60.
PMID: 31830631 DOI: 10.1016/j.ejmp.2019.11.025

PURPOSE: Dose to the rectum during brachytherapy treatment may differ from an approved treatment plan which can be quantified with in vivo dosimetry (IVD). This study compares the planned with in vivo doses measured with MOSkin and PTW 9112 rectal probe in patients undergoing CT based HDR cervical brachytherapy with Co-60 source.
METHODS: Dose measurement of a standard pear-shaped plan carried out in phantom to verify the MOSkin dose measurement accuracy. With MOSkin attached to the third diode, RP3 of the PTW 9112, both detectors were inserted into patients' rectum. The RP3 and MOSkin measured doses in 18 sessions as well as the maximum measured doses from PTW 9112, RPmax in 48 sessions were compared to the planned doses.
RESULTS: Percentage dose differences ΔD (%) in phantom study for two MOSkin found to be 2.22 ± 0.07% and 2.5 ± 0.07%. IVD of 18 sessions resulted in ΔD(%) of -16.3% to 14.9% with MOSkin and ΔD(%) of -35.7% to -2.1% with RP3. In 48 sessions, RPmax recorded ΔD(%) of -37.1% to 11.0%. MOSkin_measured doses were higher in 44.4% (8/18) sessions, while RP3_measured were lower than planned doses in all sessions. RPmax_measured were lower in 87.5% of applications (42/47).
CONCLUSIONS: The delivered doses proven to deviate from planned doses due to unavoidable shift between imaging and treatment as measured with MOSkin and PTW 9112 detectors. The integration of MOSkin on commercial PTW 9112 surface found to be feasible for rectal dose IVD during cervical HDR ICBT.

Matched MeSH terms: Cobalt Radioisotopes*
Characterization of MOSkin detector for in vivo dose verification during Cobalt-60 high dose-rate intracavitary brachytherapy

Jamalludin Z, Jong WL, Abdul Malik R, Rosenfeld A, Ung NM

Phys Med, 2019 Feb;58:1-7.
PMID: 30824140 DOI: 10.1016/j.ejmp.2019.01.010

In vivo dosimetry in high dose-rate (HDR) intracavitary brachytherapy (ICBT) is important for assessing the true dose received by surrounding organs at risk during treatment. It also serves as part of the treatment delivery quality assurance and verification program with the use of a suitable dosimeter. Such a dosimeter should be characterized under brachytherapy conditions before clinical application to ensure the accuracy of in vivo measurement. In this study, a MOSFET-based detector, MOSkin, was calibrated and characterized under HDR Cobalt-60 (Co-60) brachytherapy source. MOSkin possessed the major advantages of having small physical and dosimetric sizes of 4.8 × 10-6 mm3 with the ability to provide real-time measurements. Using solid water and polymethyl methacrylate (PMMA) phantom, the detectors' reproducibility, linearity, angular and distance dependency was tested for its suitability as an in vivo detector. Correction factors to account for differences in depth measurements were determined. The MOSkin detector showed a reliable response when tested under Co-60 brachytherapy range of doses with an excellent linearity of R2 = 0.9997 and acceptable reproducibility. A phantom verification study was also conducted to verify the differences between MOSkin responses and treatment planning (TPS) calculated doses. By taking into account several correction factors, deviations ranging between 0.01 and 0.4 Gy were found between MOSkin measured and TPS doses at measurement distance of 20-55 mm. The use of MOSkin as the dosimeter of choice for in vivo dosimetry under Co-60 brachytherapy condition is feasible.

Matched MeSH terms: Cobalt Radioisotopes/therapeutic use*
Correlation analysis of CT-based rectal planning dosimetric parameters with in vivo dosimetry of MOSkin and PTW 9112 detectors in Co-60 source HDR intracavitary cervix brachytherapy

Jamalludin Z, Malik RA, Ung NM

Phys Eng Sci Med, 2021 Sep;44(3):773-783.
PMID: 34191272 DOI: 10.1007/s13246-021-01026-x

Intracavitary cervical brachytherapy delivers high doses of radiation to the target tissue and a portion of these doses will also hit the rectal organs due to their close proximity. Rectal dose can be evaluated from dosimetric parameters in the treatment planning system (TPS) and in vivo (IV) dose measurement. This study analyzed the correlation between IV rectal dose with selected volume and point dose parameters from TPS. A total of 48 insertions were performed and IV dose was measured using the commercial PTW 9112 semiconductor diode probe. In 18 of 48 insertions, a single MOSkin detector was attached on the probe surface at 50 mm from the tip. Four rectal dosimetric parameters were retrospectively collected from TPS; (a) PTW 9112 diode maximum reported dose (RPmax) and MOSkin detector, (b) minimum dose to 2 cc (D2cc), (c) ICRU reference point (ICRUr), and (d) maximum dose from additional points (Rmax). The IV doses from both detectors were analyzed for correlation with these dosimetric parameters. This study found a significantly high correlation between IV measured dose from RPmax (r = 0.916) and MOSkin (r = 0.959) with TPS planned dose. The correlation between measured RPmax with both D2cc and Rmax revealed high correlation of r > 0.7, whereas moderate correlation (r = 0.525) was observed with ICRUr. There was no significant correlation between MOSkin IV measured dose with D2cc, ICRUr and Rmax. The non-significant correlation between parameters was ascribable to differences in both detector position within patients, and dosimetric volume and point location determined on TPS, rather than detector uncertainties.

Matched MeSH terms: Cobalt Radioisotopes
Fulltext Electrospinning synthesis and assessment of physicochemical properties and biocompatibility of cobalt nitrate fibers for wound healing applications

Jaganathan SK, Mani MP

An Acad Bras Cienc, 2019 Jul 29;91(3):e20180237.
PMID: 31365648 DOI: 10.1590/0001-3765201920180237

The aim of this study was to develop polyurethane (PU) wound dressing incorporated with cobalt nitrate using electrospinning technique. The morphology analysis revealed that the developed composites exhibited reduced fiber and pore diameter than the pristine PU. The electrospun membranes exhibited average porosity in the range of 67% - 71%. Energy-dispersive X-ray spectra (EDS) showed the presence of cobalt in the PU matrix. The interaction of cobalt nitrate with PU matrix was evident in Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The contact angle results indicated the improved wettability of the prepared PU/cobalt nitrate composites (82° ± 2) than the pure PU (100° ± 1). The incorporation of cobalt nitrate into the PU matrix enhanced the surface roughness and mechanical strength as evident in the atomic force microscopy (AFM) and tensile test analysis. The blood compatibility assays revealed the anticoagulant nature of the prepared composites by displaying prolonged blood clotting time than the PU control. Further, the developed composite exhibited less toxicity nature as revealed in the hemolysis and cytotoxicity studies. It was observed that the PU wound dressing added with cobalt nitrate fibers exhibited enhanced physicochemical, better blood compatibility parameters and enhanced fibroblast proliferation rates which may serve as a potential candidate for wound dressings.

Matched MeSH terms: Cobalt/administration & dosage*; Cobalt/chemistry
Fulltext Investigation of attributes of bourbon oil and cobalt nitrate constituted electrospun nanoscaffolds for blood compatibility and in vitro bone formation

Jaganathan SK, Mani MP

An Acad Bras Cienc, 2021;93(4):e20201140.
PMID: 34705943 DOI: 10.1590/0001-3765202120201140

This work aims to fabricate scaffold using polyurethane (PU) integrated with bourbon oil (BB) and cobalt nitrate (CoNO3) using the electrospinning technique. Morphological investigation signified a fall in fibre diameter for the PU/BB and PU/BB/CoNO3 nanocomposite than the PU. Spectral analysis indicated that BB and CoNO3 were added within the PU matrix. Wettability analysis insinuated an increase in the hydrophobic nature of the PU/BB than the PU. PU/BB/CoNO3 turned to be hydrophilic due to the integration of CoNO3 in the polymer matrix. Mechanical testing of PU/BB and PU/BB/CoNO3 indicated an increase in the tensile strength of the fabricated composites. Atomic force microscopy (AFM) portrayed the reduction in the roughness of the PU/BB and PU/BB/CoNO3 compared to the PU. The coagulation studies invariably documented the improved anticoagulant behaviour and less toxic nature of the PU/BB and PU/BB/CoNO3 in comparison with the PU. Further, bone mineralization testing revealed the enhanced apatite formation of the nanocomposite. Nanocomposite scaffolds with the fore-mentioned properties hold good potential for bone tissue engineering.

Matched MeSH terms: Cobalt
Dose response characteristics of polymethacrylic acid gel (PMAAG) for a polymerization-based dosimeter using NMR

Iskandar SM, Elias S, Jumiah H, Asri MT, Masrianis A, Ab Rahman MZ, et al.

Med J Malaysia, 2004 May;59 Suppl B:212-3.
PMID: 15468893

The radiation-response characteristics of polymetharylic acid gel dosimeter prepared with different concentrations of monomer and cross-linker is described in these studies. The dosimeters were prepared under the hypoxic condition in a glove box and were then irradiated with gamma-rays produced by Co-60 radionuclide that was generated at 1.25MeV energy. The irradiation took place at different doses ranged from 0Gy to 19Gy. Due to the radiation activities, chain-reaction polymerisation processes had taken place in the formation of polymethacrylic acid (PMAA) gel, which cause the dose response mechanism increased in the NMR relaxation rates of protons. It has been observed that for higher concentration of monomer and cross-linker, the polymerization rate was increased.

Matched MeSH terms: Cobalt Radioisotopes
Cobalt(II) selective membrane electrode based on palladium(II) dichloro acetylthiophene fenchone azine

Isa IM, Mustafar S, Ahmad M, Hashim N, Ghani SA

Talanta, 2011 Dec 15;87:230-4.
PMID: 22099672 DOI: 10.1016/j.talanta.2011.10.002

A new cobalt(II) ion selective electrode based on palladium(II) dichloro acetylthiophene fenchone azine(I) has been developed. The best membrane composition is found to be 10:60:10:21.1 (I)/PVC/NaTPB/DOP (w/w). The electrode exhibits a Nerstian response in the range of 1.0 × 10(-1)-1.0 × 10(-6)M with a detection limit and slope of 8.0 × 10(-7)M and 29.6 ± 0.2 mV per decade respectively. The response time is within the range of 20-25s and can be used for a period of up to 4 months. The electrode developed reveals good selectivity for cobalt(II) and could be used in pH range of 3-7. The electrode has been successfully used in the determination of cobalt(II) in water samples.

Matched MeSH terms: Cobalt/analysis*
Fulltext Cobalt Oxide Nanograins and Silver Nanoparticles Decorated Fibrous Polyaniline Nanocomposite as Battery-Type Electrode for High Performance Supercapattery

Iqbal J, Numan A, Omaish Ansari M, Jafer R, Jagadish PR, Bashir S, et al.

Polymers (Basel), 2020 Nov 27;12(12).
PMID: 33261072 DOI: 10.3390/polym12122816

In this study, silver (Ag) and cobalt oxide (Co3O4) decorated polyaniline (PANI) fibers were prepared by the combination of in-situ aniline oxidative polymerization and the hydrothermal methodology. The morphology of the prepared Ag/Co3O4@PANI ternary nanocomposite was studied by scanning electron microscopy and transmission electron microscopy, while the structural studies were carried out by X-ray diffraction and X-ray photoelectron spectroscopy. The morphological characterization revealed fibrous shaped PANI, coated with Ag and Co3O4 nanograins, while the structural studies revealed high purity, good crystallinity, and slight interactions among the constituents of the Ag/Co3O4@PANI ternary nanocomposite. The electrochemical performance studies revealed the enhanced performance of the Ag/Co3O4@PANI nanocomposite due to the synergistic/additional effect of Ag, Co3O4 and PANI compared to pure PANI and Co3O4@PANI. The addition of the Ag and Co3O4 provided an extended site for faradaic reactions leading to the high specific capacity. The Ag/Co3O4@PANI ternary nanocomposite exhibited an excellent specific capacity of 262.62 C g-1 at a scan rate of 3 mV s-1. The maximum energy and power density were found to be 14.01 Wh kg-1 and 165.00 W kg-1, respectively. The cyclic stability of supercapattery (Ag/Co3O4@PANI//activated carbon) consisting of a battery type electrode demonstrated a gradual increase in specific capacity with a continuous charge-discharge cycle until ~1000 cycles, then remained stable until 2500 cycles and later started decreasing, thereby showing the cyclic stability of 121.03% of its initial value after 3500 cycles.

Matched MeSH terms: Cobalt
Synthesis of cephradine metal complexes and its anti-bacterial evaluation

Iqbal Hussain, Syed Salman, Sarwat Iftikhar, Samin Jan, Junaid Akhter, Muhammad Ramzan, et al.

Sains Malaysiana, 2018;47:749-754.

Cephradine belongs to the first generation cephalosporin having a broad range of anti-bacterial activities. In the
present work, Cephradine wasreacted with different metal salts. These metal salts were Iron, Copper, Cobalt and Nickel
salts. All the complexes of Cephradine metals were synthesized at room temperature using a mechanical vibrator.
The reactions yielded the coordinated complexes within 5-10 min with improved product yield. The synthesized
complexes were analyzed for their antibacterial power using disc diffused assay. All the Cephradine complexes showed
powerful antibacterial activity. The Co, Cu, Ni and Sn complexes showed good antibacterial activities 18.5 mm by Cu
complexes against S. typhi, 17 mm against B. subtillus 16.5 mm against S. aureus, 16 mm against S. coccus. Similarly
Sn complexes exhibited 17 mm zone of inhibition against S. coccus and 15.5 mm against B. subtillus. Cobalt and Ni
complexes also shed significant inhibition activities against bacterial pathogenic bacterial strains. The study is of
particular importance and new, using mechanical vibrator for the first time. The product yield is also comparatively
good with short reaction time.

Matched MeSH terms: Cobalt
Fulltext Field demonstration of irradiated sodium alginate as tea production booster

Hossain MA, Islam JMM, Hoque MM, Nahar S, Khan MA

Heliyon, 2021 Jan;7(1):e05881.
PMID: 33458447 DOI: 10.1016/j.heliyon.2020.e05881

Sodium alginate oligomers were tested for tea plant growth promoter and anti-fungal agent in this experiment. Sodium alginate solutions were irradiated by Co-60 gamma radiation with different radiation doses to produce the oligomers. Irradiated solutions were then diluted into 150, 300 and 500 ppm prior to foliar application. Solutions were applied through foliar spraying at 7 days interval and the best response of tea plants in terms of various attributes were recorded. Tea buds were collected in 10 days of interval and the growth attributes like- total number of buds, fresh weight of buds, average leaf area and weight per bud, weight of made tea etc. were calculated. The experiment was continued up to 12 weeks and the attributes were averaged to get results per plucking. 12 kGy radiation doses along with 300ppm solution showed the best results and about 36% increase in productivity was found based on the fresh weight of buds. Total fungal count in tea leaves was also found to be reduced greatly. Based on the present study, irradiated sodium alginate could be used as safe and environmentally friendly agent to increase tea production.

Matched MeSH terms: Cobalt Radioisotopes
Fulltext Ursodeoxycholic acid upregulates ERK and Akt in the protection of cardiomyocytes against CoCl2

Hanafi NI, Mohamed AS, Md Noor J, Abdu N, Hasani H, Siran R, et al.

Genet. Mol. Res., 2016 Jun 17;15(2).
PMID: 27323195 DOI: 10.4238/gmr.15028150

Ursodeoxycholic acid (UDCA) is used to treat liver diseases and demonstrates cardioprotective effects. Accumulation of the plasma membrane sphingolipid sphingomyelin in the heart can lead to atherosclerosis and coronary artery disease. Sphingomyelinases (SMases) break down sphingomyelin, producing ceramide, and inhibition of SMases activity can promote cell survival. We hypothesized that UDCA regulates activation of ERK and Akt survival signaling pathways and SMases in protecting cardiac cells against hypoxia. Neonatal cardiomyocytes were isolated from 0- to 2-day-old Sprague Dawley rats, and given 100 μM CoCl2, 150 μM H2O2, or placed in a hypoxia chamber for 24 h. The ameliorative effects of 100-μM UDCA treatment for 12 h were then assessed using MTS, QuantiGene Plex (for Smpd1 and Smpd2), and SMase assays, beating rate assessment, and western blotting (for ERK and Akt). Data were analyzed by the paired Student t-tests and one-way analyses of variance. Cell viability decreased significantly after H2O2 (85%), CoCl2 (50%), and hypoxia chamber (52%) treatments compared to the untreated control (100%). UDCA significantly counteracted the effects of chamber- and CoCl2- induced hypoxia on viability and beating rate. However, no significant differences were observed in acid SMase gene and protein expression between the untreated, CoCl2, and UDCA-CoCl2 groups. In contrast, neutral SMase gene and protein expression did significantly differ between the latter two groups. ERK and Akt phosphorylation was higher in hypoxic cardiomyocytes treated with UDCA than those given CoCl2 alone. In conclusion, UDCA regulates the activation of survival signaling proteins and SMases in neonatal rat cardiomyocytes during hypoxia.

Matched MeSH terms: Cobalt/pharmacology
Fulltext Tool Wear and Surface Evaluation in Drilling Fly Ash Geopolymer Using HSS, HSS-Co, and HSS-TiN Cutting Tools

Ghazali MF, Abdullah MMAB, Abd Rahim SZ, Gondro J, Pietrusiewicz P, Garus S, et al.

Materials (Basel), 2021 Mar 26;14(7).
PMID: 33810517 DOI: 10.3390/ma14071628

This paper reports on the potential use of geopolymer in the drilling process, with respect to tool wear and surface roughness. The objectives of this research are to analyze the tool life of three different economy-grade drill bit uncoated; high-speed steel (HSS), HSS coated with TiN (HSS-TiN), and HSS-cobalt (HSS-Co) in the drilling of geopolymer and to investigate the effect of spindle speed towards the tool life and surface roughness. It was found that, based on the range of parameters set in this experiment, the spindle speed is directly proportional to the tool wear and inversely proportional to surface roughness. It was also observed that HSS-Co produced the lowest value of surface roughness compared to HSS-TiN and uncoated HSS and therefore is the most favorable tool to be used for drilling the material. For HSS, HSS coated with TiN, and HSS-Co, only the drilling with the spindle speed of 100 rpm was able to drill 15 holes without surpassing the maximum tool wear of 0.10 mm. HSS-Co exhibits the greatest tool life by showing the lowest value of flank wear and produce a better surface finish to the sample by a low value of surface roughness value (Ra). This finding explains that geopolymer is possible to be drilled, and therefore, ranges of cutting tools and parameters suggested can be a guideline for researchers and manufacturers to drill geopolymer for further applications.

Matched MeSH terms: Cobalt
Utilization of greenhouse gases through dry reforming: screening of nickel-based bimetallic catalysts and kinetic studies

Fan MS, Abdullah AZ, Bhatia S

ChemSusChem, 2011 Nov 18;4(11):1643-53.
PMID: 22191096

A series of bimetallic catalysts containing nickel supported over MgO-ZrO2 were tested for activity in the dry reforming of carbon dioxide. A nickel-cobalt bimetallic catalyst gave the best performance in terms of conversion and coke resistance from a range of Ni-X bimetallic catalysts, X=Ca, K, Ba, La, and Ce. The nitrogen-adsorption and hydrogen-chemisorption studies showed the Ni-Co bimetallic supported catalyst to have good surface area with high metal dispersion. This contributed to the high catalytic activity, in terms of conversion activity and stability of the catalyst, at an equimolar methane/carbon dioxide feed ratio. The kinetics of methane dry reforming are studied in a fixed-bed reactor over an Ni-Co bimetallic catalyst in the temperature range 700-800 °C by varying the partial pressures of CH4 and CO2. The experimental data were analyzed based on the proposed reaction mechanism using the Langmuir-Hinshelwood kinetic model. The activation energies for methane and carbon dioxide consumption were estimated at 52.9 and 48.1 kJ mol(-1), respectively. The lower value of CO2 activation energy compared to the activation energy of CH4 indicated a higher reaction rate of CO2, which owes to the strong basicity of nanocrystalline support, MgO-ZrO2.

Matched MeSH terms: Cobalt/chemistry*
Eco-friendly fabrication of nonenzymatic electrochemical sensor based on cobalt/polymelamine/nitrogen-doped graphitic-porous carbon nanohybrid material for glucose monitoring in human blood

Elancheziyan M, Prakasham K, Eswaran M, Duraisamy M, Ganesan S, Lee SL, et al.

Environ Res, 2023 Apr 15;223:115403.
PMID: 36754108 DOI: 10.1016/j.envres.2023.115403

The design and development of eco-friendly fabrication of cost-effective electrochemical nonenzymatic biosensors with enhanced sensitivity and selectivity are one of the emerging area in nanomaterial and analytical chemistry. In this aspect, we developed a facile fabrication of tertiary nanocomposite material based on cobalt and polymelamine/nitrogen-doped graphitic porous carbon nanohybrid composite (Co-PM-NDGPC/SPE) for the application as a nonenzymatic electrochemical sensor to quantify glucose in human blood samples. Co-PM-NDGPC/SPE nanocomposite electrode fabrication was achieved using a single-step electrodeposition method under cyclic voltammetry (CV) technique under 1 M NH4Cl solution at 20 constitutive CV cycles (sweep rate 20 mV/s). Notably, the fabricated nonenzymatic electroactive nanocomposite material exhibited excellent electrocatalytic sensing towards the quantification of glucose in 0.1 M NaOH over a wide concentration range from 0.03 to 1.071 mM with a sensitive limit of detection 7.8 μM. Moreover, the Co-PM-NDGPC nanocomposite electrode with low charge transfer resistance (Rct∼81 Ω) and high ionic diffusion indicates excellent stability, reproducibility, and high sensitivity. The fabricated nanocomposite materials exhibit a commendable sensing response toward glucose molecules present in the blood serum samples recommends its usage in real-time applications.

Matched MeSH terms: Cobalt
Fabrication of CoTiO3-TiO2 composite films from a heterobimetallic single source precursor for electrochemical sensing of dopamine

Ehsan MA, Naeem R, Khaledi H, Sohail M, Hakeem Saeed A, Mazhar M

Dalton Trans, 2016 Jun 21;45(25):10222-32.
PMID: 27230711 DOI: 10.1039/c6dt01016d

Cobalt titanate-titania composite oxide films have been grown on FTO-coated glass substrates using a single-source heterometallic complex [Co2Ti4(μ-O)6(TFA)8(THF)6]·THF () which was obtained in quantitative yield from the reaction of diacetatocobalt(ii) tetrahydrate, tetraisopropoxytitanium(iv), and trifluoroacetic acid from a tetrahydrofuran solution. Physicochemical investigations of complex have been carried out by melting point, FT-IR, thermogravimetric and single-crystal X-ray diffraction analyses. CoTiO3-TiO2 films composed of spherical objects of various sizes have been grown from by aerosol-assisted chemical vapor deposition at different temperatures of 500, 550 and 600 °C. Thin films characterized by XRD, Raman and X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis have been explored for electrochemical detection of dopamine (DA). The cyclic voltammetry with the CoTiO3-TiO2 electrode showed a DA oxidation peak at +0.215 V while linear sweep voltammetry displayed a detection limit (LoD) of 0.083 μM and a linear concentration range of 20-300 μM for DA. Thus, the CoTiO3-TiO2 electrode is a potential candidate for the sensitive and selective detection of DA.

Matched MeSH terms: Cobalt/chemistry*
Effect of Sintering on Di-Electric Characteristics of Al-Cu Doped Cobalt Ferrite Nanoparticles

Dabagh S, Chaudhary K, Haider Z, Ali J

J Nanosci Nanotechnol, 2019 Jul 01;19(7):4142-4146.
PMID: 30764983 DOI: 10.1166/jnn.2019.16331

Aluminium substituted cobalt-copper Co1-xCuxFe2-xAlxO₄, (x ═ 0.8) nanoparticles are grown and sintered at different temperature in the range 600 to 900 °C. XRD analysis on nanoparticles prepared at sintered temperatures of 700 °C and 800 °C confirms the spinel structure and presence of hematite phase (alpha ferrite) in them. The dielectric behaviour of the prepared nano-particles is investigated. Although crystallinity improved with increase in sintering temperature and there was a dielectric loss at higher probe analyser frequency. The synthesized nanoparticles an average particle size of 20-24 nm while the FTIR absorption in regions of 586-595 cm-1 and 450-460 cm-1 indicated the presence of intrinsic vibrations of the tetrahedral and octahedral complexes respectively. Electrical resistivity as a function of temperature confirms the semiconducting nature of the Cu-Al substituted cobalt ferrite, and is attributed to the hopping mechanism between Fe2+ Fe3+ ions and Co2+ Cu2+, Co2+ Al3+. The lower values of dielectric constants and dielectric losses make Al-Cu doped cobalt ferrite, a potential material for microwave and radio wave absorber applications.

Matched MeSH terms: Cobalt
Studies of oxygen binding energy to hemoglobin molecule

Chow YW, Pietranico R, Mukerji A

Biochem Biophys Res Commun, 1975 Oct 27;66(4):1424-31.
PMID: 6
Matched MeSH terms: Cobalt/blood
Impacts of trace element supplementation on the performance of anaerobic digestion process: A critical review

Choong YY, Norli I, Abdullah AZ, Yhaya MF

Bioresour Technol, 2016 Jun;209:369-79.
PMID: 27005788 DOI: 10.1016/j.biortech.2016.03.028

This paper critically reviews the impacts of supplementing trace elements on the anaerobic digestion performance. The in-depth knowledge of trace elements as micronutrients and metalloenzyme components justifies trace element supplementation into the anaerobic digestion system. Most of the earlier studies reported that trace elements addition at (sub)optimum dosages had positive impacts mainly longer term on digester stability with greater organic matter degradation, low volatile fatty acids (VFA) concentration and higher biogas production. However, these positive impacts and element requirements are not fully understood, they are explained on a case to case basis because of the great variance of the anaerobic digestion operation. Iron (Fe), nickel (Ni) and cobalt (Co) are the most studied and desirable elements. The right combination of multi-elements supplementation can have greater positive impact. This measure is highly recommended, especially for the mono-digestion of micronutrient-deficient substrates. The future research should consider the aspect of trace element bioavailability.

Matched MeSH terms: Cobalt

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links