Dental caries (tooth decay) is one of the most prevalent infectious disease and although of multifactorial origin, Streptococcus mutans is considered the principal pathogen in its development (i.e. bacterial processes damage hard tooth structure (enamel, dentine and cementum), producing dental cavities (holes in the teeth). The bactericidal properties of the Nd:YAG laser has been researched analyzing its use in caries prevention and bacterial reduction. One hundred twenty five samples were collected from carious teeth and isolated bacteria were diagnosed using microscopic examination, culture, biochemical tests, and Api 20 strep system. The results of this study showed that a noticeable decrease in the viability of Streptococcus mutans were obtained using Q-switched Nd:YAG laser (1064 nm), (3 Hz) repetition frequency, (0.796 ,0.955) J/ cm2 energy density by applying (900,1260) number of pulses. It was concluded that the bactericidal effect of laser irradiation being dependent on the type of bacteria, energy density, number of pulses, and laser dose. Suggesting that the results obtained in this study may be useful in the treatment of dental plaque-related disease.
The effects of temperature on an exotic aquatic snail Pomacea canaliculata (Lamarck, 1819) collected from the Shatt Al-Arab intertidal zone were investigated. A series of laboratory experiments were conducted during the summer period of 2017. Individuals of new born snails hatched in the laboratory from adult snails were collected from Shatt Al-Arab intertidal zone, and subjected to five fixed temperatures: 15, 25, 35, 40 and 45 Cº, after short term thermal acclimation. The heartbeats (HB) were counted at each temperature level. The results showed significant direct increase of HB from 15 Cº (19.8 HB/min) up to 25 Cº (76 HB/min) (P<0.05) as well as from 25 Cº to 35 Cº (93 HB/min). At 40 Cº the snail HB
... Show MoreLeishmaniosis is a tropical neglected parasitic disease that is endemic in many countries, including Middle East, with no existing effective vaccines. The bite of female sand-fly transmits the causative agent, Leishmania spp., to humans. High toxicity, resistance and treatment failure of the available chemotherapy against visceral leishmaniosis demands the investigation of new anti-leishmanial compounds. Lupeol is a form of triterpene isolated from several medicinal plants and possesses an antimicrobial property. In this study, cytotoxic effect of lupeol was screened against the mammalian amastigotes form and insect promastigote form of Leishmania donovani, following three cycles of incubation at different concentrations by MTT assay. Resul
... Show MoreS a mples of compact magnesia and alumina were evaporated
using CO2-laser .The
Processed powders were characterized by electron microscopy
and both scanning and transmission electron microscope. The results
indicated that the particle size for both powders have reduced largely
to 0.003 nm and 0.07 nm for MgO and Al2O3, with increasing in
shape sphericity.
Introduction: We aimed to assess the impact of adhesive and wires types on the tensile bond strength of fixed lingual retainers. Methods: A total of 160 intact bovine teeth were collected, cleaned, stored in 25% sodium hypochlorite, and randomly assigned to two groups based on the adhesive type: a two-step adhesive and a one-step adhesive. Each group was further divided into four subgroups based on the type of lingual retainer wire, which included (A) 8-strand braided stainless steel wire, (B) three-strand titanium retainer wire, (C) stainless steel chain, and (D) fiber-reinforced retainer. A tensile bond strength test was conducted using a universal testing machine at a controlled speed of 10 mm/min. Result: The 8-strand braided stainles
... Show MoreThe topic of the research revolves around constructivist theory, which is one of the most important theories that added weight to the theoretical and epistemological field of international relations. The constructivist theory studies international relations from a completely different side of theories by focusing on the social aspects of international relations, and by looking at international relations as social constructs. Ideas, cultures, norms, standards and language play a major role in their formation. The study also examines the state of the war on terrorism as it represents one of the most international cases in which its composition and composition coincide with constructive ideas and a
... Show MoreRecommender Systems are tools to understand the huge amount of data available in the internet world. Collaborative filtering (CF) is one of the most knowledge discovery methods used positively in recommendation system. Memory collaborative filtering emphasizes on using facts about present users to predict new things for the target user. Similarity measures are the core operations in collaborative filtering and the prediction accuracy is mostly dependent on similarity calculations. In this study, a combination of weighted parameters and traditional similarity measures are conducted to calculate relationship among users over Movie Lens data set rating matrix. The advantages and disadvantages of each measure are spotted. From the study, a n
... Show MoreExtraction and Description of Urease Enzyme Produced from Staphylococcus saprophyticus and study of its effect on kidney and bladder of white mice
Abstract
Heavy-duty diesel vehicle idling consumes fossil fuel and reduces atmospheric quality at idle period, but its restriction cannot simply be proscribed. A comprehensive tailpipe emissions database to describe idling impacts is not yet available. This paper presents a substantial data set that incorporates results from DI multi-cylinders Fiat diesel engine. Idle emissions of CO, hydrocarbon (HC), oxides of nitrogen (NOx), smoke opacity, carbon dioxide (CO2) and noise have been reported, when three EGR ratios (10, 20 and 30%) were added to suction manifold.
CO2 concentrations increased with increasing idle time and engine idle speed, but it didn’t show clear effect for IT adva
... Show MoreThis study was conducted in the poultry field of the Department of Animal Production - Faculty of Agriculture - University of Baghdad (Abu Ghraib) for the period from 28/9/2017 to 9/11/2017 for a period of six weeks (42 days), was used in the experiment 300 chick of broiler (Ross 308) one day old. The aim of this study was to effect of adding supplementing different levels of bee pollen (0, 250, 500, 750 and 1000) gm/100kg on Productive Performance. The chicks were randomly distributed in to five treatments, T1 control (without any addition), (T2, T3, T4 and T5) adding bee pollen in the diet 250, 500, 750 and 1000 gm/100kg respectively. The results showed that bee pollen in the diet level 1000 gm/100 kg led to significant increase in the we
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