In this study, the optimum conditions for chitin deacetylase (CDA) production by Aspergillus flavus F1 in solid-state fermentation were investigated via two optimization strategies: classical optimization based on the method of one factor at a time and statistical optimization using response surface methodology. The result of classical optimization showed that corn supplemented with 2% chitin moisturized with mineral salts solution at pH=7 and five days of incubation time were the optimum conditions for increasing CDA production with approximately yield of 219.5 U/g solid substrate. Furthermore, pH, moisture level and inoculum size were systemically evaluated to improve CDA production based on a central composite design using the Design expert 7 software. Based on the enhanced regression model, a maximum predicted CDA enzyme production of 283.8 U/g could be obtained with pH 8, moisture level 1:1 (w/v) and inoculum size 3 ml/10g solid substrate, which contain 1×106 spore/ml. The verification of optimization results and determine accuracy of model showed that the actual response of CDA was 312 U/g, which approximately closed to predicted value 283.89 U/g. The crude extract of CDA was concentrated by sucrose. The results showed that 61% of CDA enzyme was yielded with a purification fold of 1.1 In addition. Then CDA was purified partially by gel filtration chromatography after concentration by sucrose with total enzyme activity and specific activity of 1476 U and 12300 (U/mg protein) respectively. Furthermore, the produced CDA enzyme showed maximum activity in pH ranged from (6-8); in which enzyme activity was 69 U/ ml. however; the enzyme stability has a wide range in acidic and alkaline pH. In addition, the enzyme was maintained its activity at temperatures from 30 to 55C˚. Whereas, the activity was declined in temperature up to 55Cº with a minimum activity (8 U/ml) observed at 80Cº.
The solidification process in a multi-tube latent heat energy system is affected by the natural convection and the arrangement of heat exchanger tubes, which changes the buoyancy effect as well. In the current work, the effect of the arrangement of the tubes in a multi-tube heat exchanger was examined during the solidification process with the focus on the natural convection effects inside the phase change material (PCM). The behavior of the system was numerically analyzed using liquid fraction and energy released, as well as temperature, velocity and streamline profiles for different studied cases. The arrangement of the tubes, considering seven pipes in the symmetrical condition, are assumed at different positions in the system, i
... Show MoreIn this study the Entrance Surface Dose (ESD) received by pediatrics patients undergoing chest, abdomen and skull X-ray examinations was estimated. The study was conducted in two hospitals in Najaf city where three radiographic systems were considered. The study participants were classified into four age groups 0-1 , 1-5 , 5-10 and 10-15 years. Calculations were performed using exposure factors, kVp, mAs and focal-skin distance, together with patient data age. The ESD was calculated for the involved patients who underwent an Antero-posterior (AP) chest, abdomen and skull X-ray examination. The resulted data were analyzed and compared with international dose references. For all studied radiographic examinations and all X-ray mac
... Show MoreNew nitrone and selenonitrone compounds were synthesized. The condensation method between N-(2-hydroxyethyl) hydroxylamine and substituted carbonyl compounds such as [benzil, 4, 4́-dichlorobenzil and 2,2́ -dinitrobenzil] afforded a variety of new nitrone compounds while the condensation between N-benzylhydroxylamine and substituted selenocarbonyl compounds such as [di(4-fluorobenzoyl) diselenide and (4-chlorobenzoyl selenonitrile] obtained selenonitrone compounds. The condensation of N-4-chlorophenylhydroxylamine with dibenzoyl diselenide obtained another type of selenonitrone compounds. The structures of the synthesized compounds were assigned based on spectroscopic data (FT-IR,
... Show MoreFor the treatment of pathogenic bacterial infections, multidrug resistance (MDR) has become a major issue. The use of nanoparticles is a promising strategy for combating medication resistance in a variety of pathogens that cause deadly diseases. The goal of our research was to extract multidrug-resistant bacteria from wound infections and then use iron oxide nanoparticles (Fe3O4) as alternative therapeutic agents in vitro. Gram staining, morphological attributes evaluation, and biochemical testing were used to assess the microbes. The Kirby-Bauer disk diffusion method was used to test MDR-bacterial strains against several antibiotics; the majority of these isolates were resistant to ceftazidime, amoxicillin
... Show MoreCreatinine and Schiff`s bases are well known for their diverse range of biological activities and are thought to be emerging and useful therapeutic targets for the treatment of several diseases. The present work was aimed at the synthesis of new imidazolidine-4-one, thiazolidine-4-one, and oxazolidine-4-one derivatives derived from creatinine and to illustrate their influence on a colon cancer cell line and assess their antioxidant activity. Creatinine was reacted with α-chloroethyl acetate to produce 2-ethyl acetate creatinine 1. Then, the reaction of compound 1 with n-propyl bromide afforded N-propyl-2-ethylacetate creatinine 2. Compound 2
... Show MoreBackground: A great dental and biomedical interest had been paid to silver nanoparticles because of their antimicrobial activity. Objective: To evaluate the antimicrobial and cytotoxic activity of a newly developed Nano-silver fluoride that was synthesized from moringa oleifera leaf extract against S. mutants. Material and method: The green synthesis method was used to prepare Nano-silver fluoride from moringa oleifera leaf extract. The minimum inhibitory concentration and the minimum bactericidal concentration were evaluated using brain heart infusion plates, while the cytotoxicity was evaluated by the hemolytic activity. Results: Nano-silver fluoride had a bactericidal and bacteriostatic effect (MIC was 60 ppm a
... Show MoreBackground:
Multiple sclerosis is a chronic disease believed to be the result of autoimmune disorders of the central nervous system, characterised by inflammation, demyelination, and axonal transection, affecting primarily young adults. Disease modifying therapies have become widely used, and the rapid development of these drugs highlighted the need to update our knowledge on their short- and long-term safety profile.
Objective:
The study aim is to evaluate the impact of disease-modifying treatments on thyroid functions and thyroid autoantibodies with subsequent effects on the outcome of the disease.
Materials and Methods:
A retro prospective study
... Show MoreAbstract
A series of new 4(3H)-quinazolinone derivatives (S1-S4) were synthesized and characterized by FTIR,1HNMR and 13CNMR .Their cytotoxic activity against a set of human cancer cell lines MCF-7 (breast) and A549 (lung) was evaluated using MTT assay. To detect their selectivity toward cancer cells, the compounds were also tested against epithelial cells derived from normal human fibroblast (NHF). Methotrexate (MTX) was used as a reference for comparison . All the tested compounds exhibited toxicity against the normal cells lower than cancer cells. All the tested compounds displayed higher cytotoxicity against lung cancer cell line (A549) than MTX with the most
... Show MoreThe structure of the interrogation process in cross-examinations is said to be diverse and complex in terms of question-response typology. This is because the counsel has to extract truth from an opposing party’s witness whose views are expected to advocate that party's views regarding the case. Accordingly, the study which is basically quantitative in nature aims to investigate what the examining party intends to obtain out of these questions and which of these questions are the most prevalently used. It also aims to measure the amount of cooperativity in witnesses' responses. Accordingly, three transcripts of cross-examination have been analyzed, using a pragmatically-oriented approach. The approach draws on Stenstorm (1984) and Arch
... Show MoreThe differential cross sections of the pre - equilibrium stage are calculated at different energies using the Kalbach Systematic approach in Exciton model with Feshbach, Kerman and Koonin (FKK) statistical theory of Multistep Compound and direct reactions. In this work, the emission rate of light nuclei with emission energy in the centre of mass system in the isospin mixed case is considered in calculations to predict the cross-sections at the pre-equilibrium and equilibrium stages. The nucleons and light nuclei (2D and 3T) have been used as a projectile at the target 63Cu nuclei and at different incident energies (4MeV, 14 MeV and 14.8MeV). The comparisons between the present calculated results with other, theoretical and experimental w
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