INTRODUCTION: CAD/CAM denture base materials are milled from pre-polymerized pucks of resin that are highly condensed. So, they provide no polymerization shrinkage eliminating its subsequent disadvantages. This technology offered improved fit, strength properties and more bio-hygienic denture bases compared with conventional processing of the denture base material. OBJECTIVES: The aim of the study was to evaluate the physico-mechanical properties of CAD/CAM denture base material and the effect of thermo-cycling on it compared with the conventional one. MATERIALS AND METHODS: The study was conducted on two parallel groups, divided according to the denture material used. Group (1) conventional PMMA (control group), group (II) CAD/CAM PMMA (study group) of 40 specimens each (16 for impact strength, 16 for flexural strength, 8 for surface roughness and grinded powder form both materials for residual monomer test). Each group was divided into 2 sub-groups: (A) No thermo-cycling and (B) Thermo-cycling, then subjected to 4 different tests, impact strength, flexural strength, surface roughness and residual monomer tests. Data were collected, tabulated and statistically analyzed. Significance level was set at 5%. Bar charts were used for graphical presentations. RESULTS: Our study revealed a highly statistically significant decrease in residual monomer of CAD/CAM PMMA material in both conditions before and after thermo-cycling when compared to conventional PMMA material, which therefore leads to enhanced impact strength and significantly reduced surface roughness after heat treatment. On the other hand, also a highly significant reduction of its flexural strength after thermocycling has been observed. CONCLUSIONS: CAD/CAM dentures with lower amount of methacrylate monomer exhibit more favourable physico-mechanical properties and they have a long-term biocompatibility even with thermal changes making them a more satisfactory as a denture base material for edentulous patients.
Yusra Muftah Saad Elfaidy, Ahmed M. Abdelhamid, Sonia M. Elshabrawy(12-2018)

The most common preparation of tocotrienols is the tocotrienol-rich fraction (TRF). This study aimed to investigate whether TRF induced liver Nrf2 nuclear translocation and influenced the expression of Nrf2-regulated genes. Methods: In the Nrf2 induction study, mice were divided into control, 2000 mg/kg TRF and diethyl maleate treated groups. After acute treatment, mice were sacrificed at specific time points. Liver nuclear extracts were prepared and Nrf2 nuclear translocation was detected through Western blotting. To determine the effect of increasing doses of TRF on the extent of liver nuclear Nrf2 translocation and its implication on the expression levels of several Nrf2-regulated genes, mice were divided into 5 groups (control, 200, 500 and 1000 mg/kg TRF, and butylated hydroxyanisole-treated groups). After 14 days, mice were sacrificed and liver RNA extracted for qPCR assay. Results: 2000 mg/kg TRF administration initiated Nrf2 nuclear translocation within 30 min, reached maximum level around 1 h and dropped to half-maximal levels by 24 h. Incremental doses of TRF resulted in dose-dependent increases in liver Nrf2 nuclear levels, along with concomitant dose-dependent increases in the expressions of Nrf2-regulated genes. Conclusion: TRF activated the liver Nrf2 pathway resulting in increased expression of Nrf2-regulated cytoprotective genes.
Ahmed Elbadri M Atia(9-2020)

طالما أن الفرد والمجتمع متلازمان ولا ينفصلان، فإنه يجب تنظيم العلاقة بين سلطة الدولة وحريات الأفراد وبما أن ،في المجتمع الدستور يمثل وسيلة الحكم الديمقراطي في المجتمعات المتقدمة، فعليه تقع مهمة تنظيم هذه العلاقة تحيل كونه يس تصور مجتمع بشري بدون تشريع، فالرابطة الاجتماعية هي رابطة قانونية قبل كل شيء وحيث يكون المجتمع يكون القانون. وفي الواقع، لا تكون حماية ممارسة الحريات العامة دائما وفي كل مكان بنفس الطريقة، حتى داخل الدولة كما أن ال ،الواحدة حلول تختلف تبعا للحريات المعنية، أي تبعا للنشاط الإنساني المعني، وأنماط تنظيمها لا يقع دائما على ذات المستوى ، وإنما يتغير تبعا للحالات العادية التي يكون فيها المجتمع والظروف الاستثنائية التي تمر .بها البلاد لذلك فإن أساليب تنظيم الحرية ليست واحدة فقد تكون عن طريق الدستور أو القانون كما قد تكون عن طريق القرارات الإدارية التنظيمية .
حسام علي الحاج (6-2019)