37 research outputs found
Evaluation of thermal conductivity of heat-cured acrylic resin mixed with A1203
One of the most important characteristics of denture base is thermal conductivity. This property has a major role in secretions of salivary glands and their enzymes, taste of the food and gustatory response. Polymethyl methacrylate used in prosthodontics is relatively an insulator. Different materials such as metal fillers and ceramics have been used to solve this problem. The aim of this study was the evaluation of AI2O3 effect on thermal conductivity of heat-cured acrylic resin. Acrylic resin was mixed with AI2O3 in two different weight rates (15 and 20 % of weight). So, group 1 and 2 were divided on this basis. Samples with pure acrylic resin were considered as control group. 18 cylindrical patterns were made in 9x9 mm dimensions and thermocouple wires embedded in each sample to act as conductor. The specimens were put in water with 70±1°C thermal range for 10 minutes. Then, thermal conductivity was measured. The results were analyzed with variance analysis and Dunken test. There was significant difference between thermal conductivity of all groups in all period times. It the first seconds, thermal conductivity in groups 1 and 2 were more than control group. Therefore, for developing of thermal conductivity of acrylic resin, A1203 can be used. Certainly, other characteristic of new resin should be evaluated
Does 2.4 GHz Radiofrequency Radiation (RFR) Has Potential to Treat SARS-CoV-2?– A Preliminary Observation
This preliminary study aimed to investigate the effect of 2.4 GHz continuous radiofrequency radiation (RFR) on SARS-CoV-2 viral load. Samples of control and exposure groups were selected from twelve cases who were confirmed positive for SARS-CoV-2RNA by the SARS-CoV-2 Double Gene RT-qPCR kit. All groups consisted of the same patient and used 50 μl of sample. The control group was formed with 50 μl samples separated before RFR exposure and it was not exposed. The samples in the exposure groups were placed in a circle with a radius of 3 cm, 5 cm, and 10 cm. RFR antenna was placed in the middle of this circle. The samples and RFR antenna were enclosed in a Faraday cage. These samples were exposed during 1 min, 5 min, 10 min, and 20 min by RFR antenna. After exposure, determination of SARS-CoV-2RNA in exposure groups were investigated using the same kit. In this study, the effect of 2.45 GHz RF on the SARS-CoV-2 viral load was quantitatively investigated different distances and exposure times. The statistical results of the study indicated that in all distances, 5 minutes exposure of 2.4 GHz RF altered the SARS-CoV-2 viral load (p0.005). Determining the ideal irradiation time can give a different perspective to the treatment of the disease © 2022, Journal of International Dental and Medical Research. All Rights Reserved
On Multinational Corporations and the Provision of Positive Rights
dependence, humanitarian investment, Locke, multinational corporations, negative rights, the political, positive rights, the private,