Background: Periodontal diseases (PD) are common chronic inflammatory diseases caused by pathogenic microorganisms colonizing the gingival area and inducing local and systemic elevations of pro-inflammatory cytokines resulting in tissue destruction by a destructive inflammatory process. Stress was considered as one of the important risk factors that cause many inflammatory diseases including PD. The purpose of this study wasto determines and compares clinical periodontal parameters (PLI, GI and BOP), stress level and salivary IL-1? level among dental students before, during and after mid-year exam, also to find the correlation among stress, IL-1? and clinical periodontal parameters. Materials and methods: The sample was consisted of 24 dental students; 12 male and 12 female aged (21-23) years, theywere examined in this follow up study at three main periods; first period at least one month before mid-year exam (Period I), second period during mid-year exam (Period II) and third period at least one month after mid-year exam (Period III). DASS-21 was used to measure stress level in all periods. Saliva samples were collected to determine the salivary IL-1? level by ELISA. Clinical periodontal parameters were recorded at four sites per tooth. Results: The means of all clinical periodontal parameters were higher in the period II than in the periods I and III with highly significant differencesat (P ? 0.01). As well as, the means concentrations of salivary IL-1? were higher in the period II than in the periods I and III with highly significant differencesat (P ? 0.01). Also, by using Pearson's Correlation Coefficient, stress shows highly significant strong correlation with IL-1? and clinical periodontal parametersat (P ? 0.01). Conclusions: The results of this study provided strong evidence of association between examination stress and PD, where dental students during mid-year exam have higher levels of stress, clinical periodontal parameters and salivary IL-1? as compared with before and after mid-year exam periods.
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Todays, World is faced an energy crisis because of a continuous increasing the consumption of fuels due to intension demand for all types of vehicles. This study is one of the efforts dealing with reduce the weight of vehicles by using a new material of sandwich steel, which consists of two skin steel sheets with core of a polymer material. Resistance spot welding (RSW) can be easily implemented on metals; however a cupper shunt tool was designed to perform the resistance welding of sandwich steel with DP800 cover sheets to resolve a non-conductivity problem of a polymer core. Numerical simulations with SORPAS®3D were employed to test the weldability of this new material and supported by many practical experiments. In conclus
... Show MoreThis study aims to develop a recommendation engine methodology to enhance the model’s effectiveness and efficiency. The proposed model is commonly used to assign or propose a limited number of developers with the required skills and expertise to address and resolve a bug report. Managing collections within bug repositories is the responsibility of software engineers in addressing specific defects. Identifying the optimal allocation of personnel to activities is challenging when dealing with software defects, which necessitates a substantial workforce of developers. Analyzing new scientific methodologies to enhance comprehension of the results is the purpose of this analysis. Additionally, developer priorities were discussed, especially th
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Eleven yoghurt samples were collected from local markets in Baghdad to isolate Lactobacillus buchneri. Only 3 isolates of L. buchneri were found and the isolate No. 3 was the most producer of bacteriocin. Bacteriocin was adsorbed 100% onto silicic acid at pH 6.0-7.0. Below or above these pH values, adsorption was decreased, ranging between 35 and 90%. Therefore, pH 6.0 was used for the purification procedure. The purification procedure including silicic acid adsorption/desorption and cation-exchange chromatography (CEC) resulted in a 11.11 fold increase in the final specific activity of pure bacteriocin (1176.47 Au/mg) compared to the culture supernatant which was 32.64 Au/mg. The molecular weight was determined to be about 3.4 kDa. The bac
... Show MoreThe effects of BaCl2 dopant on the optical properties of poly (vinyl alcohol) have been investigated. Pure and BaCl2 doped PVA films were prepared using solvent casting method. These films were characterized using UV/VIS technique in order to estimate the kind of transition which was found to be indirect transition. The value of the optical energy gap was decrease with increasing dopant concentration.
Refractive index, extinction coefficient and Urbach tail have been also investigated; it was found that all the above parameters affects by doping.
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Activated carbon was Produced from coconut shell and was used for removing sulfate from industrial waste water in batch Processes. The influence of various parameter were studied such as pH (4.5 – 9.) , agitation time (0 – 120)min and adsorbent dose (2 – 10) gm.
The Langmuir and frandlich adsorption capacity models were been investigated where showed there are fitting with langmmuir model with squre regression value ( 0.76). The percent of removal of sulfate (22% - 38%) at (PH=7) in the isotherm experiment increased with adsorbent mass increasing. The maximum removal value of sulfate at different pH experiments is (43%) at pH=7.