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Effects of Different Concentrations of Melatonin on the Time-course of Nitrite–induced Oxidation of Hemoglobin: In vitro Study
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         Melatonin is a potent scavenger of reactive oxygen species or free radicals like superoxide and hydroxyl radicals. The oxidation of hemoglobin to methemoglobin (meth-Hb) by oxidizing compounds has been widely studied. The present work was designed to evaluate the ability of different concentrations of melatonin to inhibit nitrite–induced oxidation of hemoglobin. Blood samples were obtained from apparently healthy individuals from which erythrocyte hemolysate was prepared. Different concentrations of melatonin (10-9-1.0 mg/ml) were incubated for 10 min with the hemolysate, then to the resultant mixture 1 ml of sodium nitrite (final concentration 0.6 mM) was added, and the formation of meth-Hb was measured by monitoring absorbance of light at 631 nm each min for 30 min. Control samples without melatonin were utilized for comparison. Nitrite caused rapid oxidation of hemoglobin to meth-Hb in control samples; in the presence of melatonin, the oxidation process was delayed in a dose–dependent manner. The effect of melatonin on the time course of nitrite-induced oxidation of Hb showed that melatonin has a protective effect initiated early after addition along with nitrite. Melatonin also affect the time required for the formation of meth-Hb, the   time required to convert 50% of the available Hb to meth-Hb was 4 min in the absence of melatonin, and became  17, 22, 26, 30, 114 and 383  min with increasing melatonin concentrations (10-9, 10-6, 0.001, 0.01, 0.1, and 1.0 mg/ml  respectively). In conclusion, melatonin in a concentration  and time dependent manner can protect Hb from oxidation by nitrite; melatonin delays the onset of autocatalytic stage and the protective effect extended over long period of time.

Key words: melatonin, erythrocytes oxidation

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Publication Date
Wed Jan 01 2020
Journal Name
Iraqi Journal Of Science
Paper based glucose biosensor depending on SPCE modified with hemoglobin and silver nanoparticles
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The direct electron transfer behavior of hemoglobin that is immobilized onto screen-printed carbon electrode (SPCE) modified with silver nanoparticles (AgNPs) and chitosan (CS) was studied in this work. Cyclic voltametry and spectrophotometry were used to characterize the hemoglobin (Hb) bioconjunction with AgNPs and CS. Results of the modified electrode showed quasi-reversible redox peaks with a formal potential of (-0.245 V) versus Ag/AgCl in 0.1 M phosphate buffer solution (PBS), pH7, at a scan rate of 0.1 Vs-1. The charge transfer coefficient (α) was 0.48 and the apparent electron transfer rate constant (Ks) was 0.47 s-1. The electrode was used as a hydrogen peroxide biosensor with a linear response over 3 to 240 µM and a detection li

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Scopus
Publication Date
Mon Jun 01 2020
Journal Name
Sensing And Bio-sensing Research
Hydrogen peroxide biosensor based on hemoglobin-modified gold nanoparticles–screen printed carbon electrode
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Publication Date
Sun Dec 09 2018
Journal Name
Baghdad Science Journal
A Comparative Study on the Electrical Characteristics of Generating Plasma by Using Different Target Sources
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In this research, the electrical characteristics of glow discharge plasma were studied. Glow discharge plasma generated in a home-made DC magnetron sputtering system, and a DC-power supply of high voltage as input to the discharge electrodes were both utilized. The distance between two electrodes is 4cm. The gas used to produce plasma is argon gas which flows inside the chamber at a rate of 40 sccm. The influence of work function for different target materials (gold, copper, and silver), - 5cm in diameter and around 1mm thickness - different working pressures, and different applied voltages on electrical characteristics (discharge current, discharge potential, and Paschen’s curve) were studied. The results showed that the discharge cur

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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
The effects of raddiation on the optical properties of GERMANIUM SELENIDE semiconductor.
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Study was made on the optical properties of Ge2oSe8othinfilms prepared by vac-uum evaporation as radiated by (0,34,69) Gy of 13 ray.The optical band gab Eg and tailing band A.Et were studied in the photon energy range ( 1 to 3)eV. The a-Ge20Se8o film was found to be indirect gap with energy gap of (1.965,1.9 , 1.82) eV at radiated by B ray with absorption doses of (0,34,69)Gy respectively.The Ea and AEt of Ge20Se80 films showed adecrease in E8 and an increase in AEt with radiation. This be-havior may be related to structural defects and dangling bonds.

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Publication Date
Sun Sep 05 2010
Journal Name
Baghdad Science Journal
The Effects of ? – Rays on The Optical Constants of ZnS Thin Films
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ZnS thin films were grown onto glass substrates by flash evaporation technique, the effects of ? – rays on the optical constants of ZnS these films were studied. It was found that ? – rays affected all the parameters under investigation.

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Publication Date
Wed Oct 16 2019
Journal Name
Journal Of Research In Medical And Dental Science
Evaluation of the Antibacterial Efficacy of Silver Nanoparticles as an Irrigant against Enterococcus faecalis In vitro Study
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Background: Successful root canal therapy depends on thorough chemo mechanical debridement of pulpal tissue, dentin debris and infective microorganisms. Objective: This study aimed to investigate the antibacterial effect of silver nanoparticles, sodium hypochlorite and chlorhexidine in reducing the bacterial infection of the root canals. Materials and Methods: The root canals of 55 single-rooted teeth were cleaned, shaped, and sterilized. All the teeth samples were inoculated with Enterococcus faecalis and incubated at 37°C for 2 weeks. Then, the teeth were divided into four groups. Group I (n=15): 100 ppm silver nanoparticles, Group II (n=15): 2.5 sodium hypochlorite, Group III (n=15): 2% chlorhexidine, IV (n=10): Normal saline as a contr

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Publication Date
Sun Jun 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Performance evaluation of vocational and administrative institutions in the media using the bench-marking of new media: analytical study in the Journal of time
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Provides the style of benchmarking the best possible use whenevaluating the performance and evaluation, as well as improved performance,due to its consistency with the principles of good evaluation of theperformance, an extension of the completion of several functions of the timeand cost less, thereby increasing the efficiency of the management of theinstitutions, especially institutions, the media, as it became public the future ofthe message sender to the same time Zaorosaúl new media is challenging thetraditional media of what distinguishes this new interactive media and mass ledto this transition . However, the media Aljdidhoosaúl traditional mediacontinue to coexist and reinforce each Menhmaalakhr, for his wealth offreedom of opin

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Influence of Aging Time on Asphalt Pavement Performance
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Aging of asphalt pavements typically occurs through oxidation of the asphalt and evaporation of the lighter maltenes from the binder. The main objective of this study is to evaluate influence of aging on performance of asphalt paving materials.nAsphalt concrete mixtures, were prepared, and subjected to short term aging (STA) procedure which involved heating the loose mixtures in an oven for two aging period of (4 and 8) hours at a temperature of 135 o C. Then it was subject to Long term aging (LTA) procedure using (2 and 5) days aging periods at 85 o C for Marshall compacted specimens. The effect of aging periods on properties of asphalt concrete at optimum asphalt content such as Marshall Properties, indirect tensile strength at 25 o C,

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Publication Date
Sun Dec 16 2018
Journal Name
Al-academy
An Educational Model in Journalistic Production Course to Develop the Creative Thinking Skills of Printing Design Students
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The printing designer's creative thinking is a deliberate  mental process based on specific skills that stimulate the motivation of  the student to learn and call for  new information for the investigation and research to discover the problems and attitudes and through reformulating the experience in new patterns depending on the active imagination and the flexible scientific thinking through providing the largest number possible  of various unfamiliar  printing design models, and testing their suitability and then readjusting the results with the availability of  suitable educational, learning and academic atmosphere.

The designer's creative thinking depends on main skills. Fluency skill is to put t

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Publication Date
Mon Jan 01 2007
Journal Name
Journal Of Educational And Psychological Researches
Evaluating the Professional Efficiency of Primary School Teachers in Teaching Rafidain English Course for Iraq, Book I
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      Teaching techniques are the vehicles, which are used by teachers to help pupils learn and gain experiences and create positive classroom activities, as much as these techniques are varied, they lead to successful and fruitful learning in the foreign language. They help teachers achieve their objectives (Asowrth, 1985: 124).

    The English language teacher's work is an active and purposeful one when he can plan carefully and frequently make the necessary changes in the contents and methods of teaching programme to fit the interest and needs of pupils. It seems that the majority of primary English teachers' interests does not go far in planning their work, and do not understand which o

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