Background: Green Tea is made from the leaf of the plant “Camellia sinensisâ€. Green tea is reported to contain thousands of bioactive ingredients including catechins which have shown great promise for having antimicrobial effects. Periodontal diseases represent one of the most prevalent diseases around the world and the main etiologic factor behind it, is plaque accumulation, in addition certain kinds of bacteria have been detected frequently in subjects suffering from periodontitis, Several studies suggested that the outcome of periodontal treatment is better if particular pathogens including Aggregatibacteractinomycetemcomitans can no longer be detected after therapy. Materials and Methods: plaque samples were collected from 20 patients suffering from chronic periodontitis with probing pocket depth of at least 6 mm, Aggregatibacteractinomycetemcomitans (A.A) was isolated and diagnosed according to morphological characteristics and biochemical tests. Green tea leaves were extracted by using water and alcohol. The first experiment involved testing the sensitivity of A.A to different concentrations of the extracts using agar well diffusion method,the second experiment involved determination of the minimum inhibitory concentration and then determination of the minimum bactericidal concentration of the extract against the bacteria, laboratory analysis of green tea extracts using high pressure liquid chromatography (HPLC) was performed. Results: Both green tea extracts were effective in inhibition of Aggregatibacteractinomycetemcomitans using agar well diffusion method, 90% and 100% concentrations of alcoholic extract showed larger inhibition zones than chlorhexidinegluconate 0.2% with statistically significant difference, CHX showed higher inhibition zones than all aqueous extract concentrations.The MIC (minimum inhibitory concentration) of alcoholic green tea extract that inhibit Aggregatibacteractinomycetemcomitans growth was 60%, The MIC of aqueous green tea extract that inhibits Aggregatibacteractinomycetemcomitans growth was 70%.The MBC (minimum bactericidal concentration) of alcoholic green tea extract that killsAggregatibacteractinomycetemcomitans was 80%, the MBC of aqueous green tea extract that kills Aggregatibacteractinomycetemcomitans growth was 90%. HPLC analysis of aqueous and alcoholic green tea extracts revealed that alcoholic extract contained higher concentration of EGCG while aqueous extract had higher content of catechin and epicatechin. Conclusion: Green tea extracts were effective against Aggregatibacteractinomycetemcomitans, alcoholic green tea extract showed inhibition ability more than the aqueous green tea extract and more than CHX and it showed bactericidal activity at 80%,90% and 100% concentrations.
This paper investigated the fatigue life behavior of two composite materials subjected to different times of shot peening (2, 4 and 6 min).The first material prepared from unsaturated polyester with E-glass reinforcement by 33% volume fraction. While, the second one was prepared from unsaturated polyester with aluminum powder by2.5% volume fraction. The experimental results showed that the improvement in endurance limit was obtained (for the first material) at 2, 4 and 6 min shot peening times where the percentage of maximum improvement was 25% at shot peening time of 6 min. While, the endurance limit of the second material decreased at shot peening times of 2, 4 and 6 min where the percentage of maximum reduction was 29 % at shot peenin
... Show MoreThe complexity and partially defined nature of jet grouting make it hard to predict the performance of grouted piles. So the trials of cement injection at a location with similar soil properties as the erecting site are necessary to assess the performance of the grouted piles. Nevertheless, instead of executing trial-injected piles at the pilot site, which wastes money, time, and effort, the laboratory cement injection devices are essential alternatives for evaluating soil injection ability. This study assesses the performance of a low-pressure laboratory grouting device by improving loose sandy soil injected using binders formed of Silica Fume (SF) as a chemical admixture (10% of Ordinary Portland Cement OPC mass) to di
... Show MoreA new Schiff base ligand [2,3,8,9–tetra -phenyl-1,4,5,7,10,12-hexa azo-5,12- dihydro -6,11- dione 1,3,7,10-dudec-tetra-ene] [H2L] and its complexes In general formula [M(H2L)]Cl2 (where : M= CoII, NiII, and PdII) were prepared. This ligand was prepared in two steps,in the first step a solution of benzil in methanol was reacted under reflux with semicarbazidhydrochlorid to give an (intermediate compound)[benzyl bis–(Semicarbazone)] which was reacted in the second step with benzil giving the mentioned ligand. The
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In this research provide theoretical aspects of one of the most important statistical distributions which it is Lomax, which has many applications in several areas, set of estimation methods was used(MLE,LSE,GWPM) and compare with (RRE) estimation method ,in order to find out best estimation method set of simulation experiment (36) with many replications in order to get mean square error and used it to make compare , simulation experiment contrast with (estimation method, sample size ,value of location and shape parameter) results show that estimation method effected by simulation experiment factors and ability of using other estimation methods such as(Shrinkage, jackknif
... Show MoreDue to a party's violation of his obligations or responsibilities indicated in the contract, many engineering projects confront extensive contractual disputes, which in turn need arbitration or other forms of dispute resolution, which negatively impact the project's outcome. Each contract has its terms for dispute resolution. Therefore, this paper aims to study the provisions for dispute resolution according to Iraqi (SBDW) and the JCT (SBC/Q2016) and also to show the extent of the difference between the two contracts in the application of these provisions. The methodology includes a detailed study of the dispute settlement provisions for both contracts with a comparative analysis to identify the differences in the appli
... Show MoreIn this study a new composite nano material was prepared and characterized through the polymerization of inter attuplgie layered m-phenylendiamine with p-kresol. The results indicated that the propagated polymer separated the clay aluminosilicate layers as a two dimensional nano-sheets soaked in the prepared polymer matrix with losing the original fibrous structure of Attuplgite clay.
الصيغة العامة للمعقدات الجديدة [M2(BDS)Cl4] الناتجة من تفاعل الليكاند الجديد] ن1,ن4-ثنائي(1أ –بنزو]د[ اميدازول-2-يل)-ن1,ن4-ثنائي(4-ثنائي مثيل امينو) بنزيل) سكسنمايد[ (BDS) مع الايونات الفلزية الكادميوم, الكوبلت, الزئبق, النحاس والنيكل. تم اشتقاق هذا الليكاند من تفاعل المواد الثلاث 4-(ثنائي ميثيل أمينو) بنزالدهيد، 2-أمينو بنزيميدازول، وكلوريد السكسينيل. تم تشخيص المركبات باستخدام مطيافية طيف الاشعة تحت الحمراء وطيف الرن
... Show MoreStudies on the flexural behavior of post-tensioned beams subjected to strand damage and strengthened with near-surface mounted (NSM) technique using carbon fiber-reinforced polymer (CFRP) are limited and fail to examine the effect of CFRP laminates on strand strain and strengthening efficiency systematically. Furthermore, a design approach for UPC structures in existing design guidelines for FRP strengthening techniques is lacking. Hence, the behavior of post-tensioned beams strengthened with NSM-CFRP laminates after partial strand damage is investigated in this study. The testing program consists of seven post-tensioned beams strengthened by NSM-CFRP laminates with three partial strand damage ratios (14.3% symmetrical damage, 14.3%
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