In this research, a new 1, 3, 4-Thiadiazole derivatives have been synthesized by many heterocyclic reactions. Starting from (2, 5 – dimercapto -1, 3, 4-Thiadiazole) a variety of derivatives have been synthesis. Compound (1) was synthesized by the reaction of hydrazine hydrate with carbon disulphide in absolute ethanol. The compound (1) was reacted with 1, 2-dibromoethane in presence of alkali ethanol to give the compound (2). The compound (3) was formed from the reaction of compound (2) with hydrazine hydrate. Schiff base (4) was obtained by reacting of compound (3) with the compound (p-hydroxybenzaldehyde) in absolute ethanol. A variety of phenolic Schiff base (Methylolic, Etheric, and Epoxy) derivatives have been synthesized. Methylolic derivative was synthesized by the reaction of Schiff base (4) with formaldehyde in tetrahydrofuran (THF). Etheric derivative was formed from the reaction of a methylolic Schiff base (5) with saturated alcohol (Methanol).Epoxy derivative was synthesized by the reaction of epichlorohydrine with etheric derivative (6) .The last step of this research was the preparation of a composite material from mixing the Epoxy resin derivative(7), TiO2and morpholine via ring opening. All these derivatives were verified by using (FT-IR, UV) spectra photometer and 1H-NMR spectra. Also, these derivatives were characterized using elemental analysis (C.H.N.S) .
Objective: To evaluate the changes in the surface quality of irreversible hydrocolloid impression material
hydrogum following disinfection with 0.525% sodium hypochlorite, 0.2% Chlorehexidine Gluconate, and 4%
Povidone Iodine.
Methodology: Forty specimens of alginate impression materials hydrogum were fabricated according to the
ISO 1563 and were divided into four groups according to the method of solution dipping: group 1: Dip in
0.525% sodium hypochlorite, group 2: Dip in 0.2% chlorhexidine gluconate, Group 3: Dip in 4% Povidone Iodine,
Group 4: No treatment with any solution (control group). Then the specimens were poured in type II stone.
Surface detail was determined using a stainless steel block in accordance w
Cholinesterases are among the most efficient enzymes known. They are divided into two groups: acetylcholinesterase (AChE) involved in the hydrolysis of the neurotransimitter acetylcholine, and butyrylcholinesterase (BChE) of unknown function. Several crystal structures of the former have shown that the active site is located at the bottom of a deep and narrow gorge. Human BChE has attracted attention because it can hydrolyze toxic esters and nerve agents. Here we analyze the complexes of cholinesterase with soman by describing the 3D geometry of the complex, the active site, the changes happened through the inhibition and provide a description for the mechanism of inhibition. Soman undergoes degradation in the active site of the AChE and B
... Show MoreThe most important contemporary issues which related to the survey of the influence of communication development technology to land use sustainability. The research aims to explain the changes that happened in the quality & land use activities performance by understanding the transformations due to modern technology and its impact on current uses and its impact on changing functional relationships between those uses to create new combinations or hybrid uses.Research will follow the analytical descriptive approach in presenting the problem of research. Research has several conclusions & recommendations, one of conclusions is the change of the place concept and its relation to changing the concept of land use and its sustai
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In this part of programme , different bacterial isolates mainly Salmonella spp, Shigella spp and Escherichia coli were used for antagonism with Saccharomyces boulardii under different conditions . S.boulardii was grown under aerobic conditions and antagonized with young overnight nutrient broth cultures of test bacterial isolates and other kept in refrigerator for a week after full growth . Young cultures were more susceptible to antagonistic effect of yeast compared to old cultures and on isolates grown on solid medium for 24 hr. S.boulardii grown under aerobic and microaerobic conditions and antagonized with overnight broth cultures of test bacterial isolates , The results revealed that aerobic cultures of yeast had more inhibito
... Show MoreInthis investigation the epoxy was reinforced by orange peel and carbonized orange peel particles with percentages (5%, 10%, 15% and 20% by weight).Mechanical tests like:Tensile, flexural,Hardness, impact and compression were carried out on these natural epoxy composites. The results showed the tensile strength have a higher value by adding (15% by weight )of orange peel and carbonized orange peel particles to epoxy,while the value (10% by weight ) of addition is suitable to get improvement in the other mechanical properties as flexural strength, Hardness, impact and compressive strength. The epoxy / carbonized orange peel powder have the best valuesin all mechanical properties than t
Free radicals are reactive compounds, their excessive production is considered to be an important cause of oxidative damage in biomolecules causing degenerative diseases. Polyphenols are one of the most important groups of secondary metabolites of plants, which have an antioxidant activity depending on their properties as hydrogen donors. Echinops polyceras Boiss. (Asteraceae) is one of Echinops genus species that spread in Syria, Lebanon, and Palestine. Phytochemicals found in this species leaves have been extracted with gradient polarity solvents, and primary screening of the secondary metabolites was established. The phenolic compounds and flavonoids contents were determined. The free radicals scavenging activity was evaluated for all
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