Objective This study evaluated the effects of adding titanium oxide (TiO2) nanofillers on the tear strength, tensile strength, elongation percentage, and hardness of room-temperature-vulcanized (RTV) VST50F and high-temperature-vulcanized (HTV) Cosmesil M511 maxillofacial silicone elastomers. Methods Two types of maxillofacial elastomers, VST50F RTV and Cosmesil M511 HTV, were used. Nano-TiO2 powder was applied as a nanofiller. A total of 120 specimens were fabricated, 60 each of VST50F and Cosmesil M511. The specimens of each type of elastomer were divided into three equal groups on which tests were conducted for tear strength, tensile strength, and hardness i.e., 20 specimens were used for each test. Each group of 20 specimens was further divided into two equal subgroups: (A) control i.e., silicone without nano-TiO2, and (B) experimental i.e., VST50F and Cosmesil M511 silicone incorporated with 0.25 wt% and 0.2 wt% nano-TiO2, respectively. Each subgroup thus had 10 specimens. The specimens were evaluated, and data were studied using descriptive statistical analysis and two-way analysis of variance (ANOVA). Results The addition of 0.25 wt% and 0.2 wt% TiO2 nanofiller into VST50F and Cosmesil M511 elastomers, respectively, resulted in a statistically significant increase in the mean values (p < 0.01) of tear strength, tensile strength, elongation percentage, and hardness of the materials. Conclusion The mechanical properties of the VST50F and Cosmesil M511 maxillofacial silicone materials improved with the addition of select concentrations of nano-TiO2.
This study was conducted for evaluating the cytotoxic effect of heat stable enterotoxin a (STa) produced by enterotoxigenic Escherichia coli on the proliferation of primary cancer cell cultures, obtained from tumor samples that were collected from (13) cancer patients and as follows: (five colon cancer patients, two bladder cancer patients, two breast cancer patients, two stomach cancer patients and two lung cancer patients), and on normal cell line (rat embryonic fibroblast / REF) (in vitro) with the use of different concentrations starting from (1) mg/ml and ending with (0.0002) mg/ml by making two fold serial dilutions by using the 96- well microtiter plate, and in comparison with negative (PBS) and positive (MMC, at concentration
... Show MoreBackground: Fruits and their by-products are the primary sources of bioactive chemicals in plants. Because of its phytochemical richness, Annona squamosa fruits have gained the alertness of people willing in health-promoting diets. The purpose of this in vitro study was to evaluate the cytocompatibility effect of ethanolic crude extract of Annona squamosa pulp against a human normal cell line as a mouthwash for children. Material and method: The ethanolic extract of Annona squamosa pulp was extracted using the ultrasonic method and then lyophilized to make it powder. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) test was performed to investigate the cytotoxic activity of the pulp extract on a human normal cell l
... Show MoreIn this work, chemical oxidation was used to polymerize conjugated polymer "Polypyrrole" at room temperature Graphene nanoparticles were added by in situ-polymerization to get (PPY-GN) nano. Optical and Electrical properties were studied for the nanocomposites. optical properties of the nanocomposites were studied by UV-Vis spectroscopy at wavelength range (200 -800 nm). The result showed optical absorption spectra were normally determined and the result showed that the maximum absorbance wave length at 280nm and 590nm. The optical energy gap has been evaluated by direct transition and the value has decreased from (2.1 eV for pure PPy) to (1.3 eV for 5 %wt. of GN). The optical constants such as the band tail width ΔE was evaluated, the
... Show MoreThe aim of the research is to shed light on the dimensions of the strategic lens and its impact on achieving the pioneer tax performance and represented by the dimensions (strategic direction, growth, pilot indicator, renewal and modernization, efficiency and effectiveness) in the General Tax Authority. The questionnaire was adopted as a tool to collect data and information from the adult sample They are (91) who are on the site (Assistant Director General, Head of Division, First Division Deputy, Second Division Deputy, Division Officer, Division Officer Associate) The statistical program (SPSS) has been used to calculate (the mean, the standard deviation, the correlation coefficient, the difference coefficient, the F test, the
... Show MoreThe present study examines the main points of differences in the subject of greetings between the English language and the Arabic language. From the review of the related literature on greetings in both languages, it is found that Arabic greeting formulas are more elaborate than the English greetings, because of the differences in the social customs and the Arabic traditions and the Arabic culture. It is also found that Arabic greetings carry a religious meaning basing on the Islamic principle of “the same or more so”, which might lead to untranslatable loopholes when rendered in English.
The aim of this work is studying many concepts of a pure submodule related to sub-module L and introducing the two concepts, T_pure submodule related to submodule and the crossing property of T_pure related to submodule. Another characterizations and study some properties of this concept.