Background: Exposure to microwaves radiation from microwave oven may be harmful for users especially for the one who have highest contact with microwave oven. Because the body is electrochemical in nature, any force that disrupts or changes human electrochemical events will affect the physiology of the body by destabilization and interruption of many chemical body substance including growth factors.The insulin-like growth factors (IGFs) are a family of mitogenic proteins that control growth, differentiation, and the maintenance of differentiated function in numerous tissues. It fulfils an important role in growth and development of teeth, mandible, maxillae, and tongue. Platelet derived growth factors (PDGF) are proteins that regulate cell growth and division. In particular, it plays a significant role in blood vessel formation (angiogenesis). It seems that IGF and PDGF share in much tissue developmental process. Therefore they included in the present study in correlation to tooth growth & development. This study Illustrates the expression of insulin like growth factor and platelet derived growth factor by dental cells of rat embryos at periods of gestation 16th,18thday intrauterine life(I.U.L) and one day neonatal life. Materials and Methods: Animal model: Thirty-six female rats were used in this study .Starting from zero days (time of gestation that recorded) the pregnant rats were divided into three groups. Group A serve as a control, groups B exposed to microwave oven radiation For (15 /minutes; 5/min /hour for 3 hours continuously) daily and C exposed to EMF radiation for (45 minutes ;15 min /hour for3hours continuously)daily starting from zero day of gestation till the last day. The embryo of rats at 16thday and 18th day of intrauterine life and one day old rat (new born rat) were studied immunohistochemically for localized of platelet derived growth factor (PDGF) and insulin growth factor (IGF) markers. Results:The results showed that experimental group (B) exposed to short duration of radiation (5/ min.) stimulates the development of tooth germ and faster tooth growing in comparison to control with immunohistochemical results show strong to moderate intense stain for positive expression of growth factors(PDGF,IGF) by dental tissue.For long exposure period of radiation( group C) , it showed retardation in the tooth growth withimmunohistochemical findings record weak to negative intense stain for the expression of growth factors(PDGF,IGF) by dental tissue. Conclusion: Exposure to microwave (oven) radiation during pregnancy may play a role in the expression of IGF and PDGF by cells of tooth germ thatinfluence on cell differentiation and physiological activity of specialized dental cells, depending on exposure time.
A numerical investigation is adopted for two dimensional thermal analysis of rocket thrust chamber wall (RL10), employing finite difference model with iterative scheme (implemented under relaxation factor of 0.9 for convergence) to compute temperature distribution within thrust chamber wall (which is composed of Nickel and Copper layers). The analysis is conducted for different boundary conditions: only convection boundary conditions then combined radiation, convection boundary conditions also for different aspect ratio (AR) of cooling channel. The results show that Utilizing cooling channels of high aspect ratio leads to decrease in temperature variation across thrust chamber wall, while no effects on heat transferred to the
... Show MoreIn this work, ZnO nanostructures for powder ZnO were synthesized by Hydrothermal Method. Size and shape of ZnO nanostructureas can be controlled by change ammonia concentration. In the preparation of ZnO nanostructure, zinc nitrate hexahydrate [Zn(NO3)2·6H2O] was used as a precursor. The structure and morphology of ZnO nanostructure have been characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD). The synthesized ZnO nanostructures have a hexagonal wurtzite structure. Also using Zeta potential and Particle Size Analyzers and size distribution of the ZnO powder
Bekhme formation, Dernir Dagh well -1 has been divided into two facies units using core
sample slides and depending on sedimentary structures and diagenetic processes .The facies
reflect the environment of the foreslope.This work proves the absence of Bekhme formation
in Dernir Dagh
Well- 1 as a tongue as reported by the Oil Exploration Company. Some species and genera of
bentonic foraminifera were identified. The age of Bekhme formation was estimated
depending on the recognized index fossils to be lower Maastrichtian.
The political parties are considered to be the basic infrastructure in the political process for their great role in achieving the political movement in the country and to work on implementing the goals and interests of its voters in the event of their coming to power. If the parties that totalitarianism led to monopoly and monopolization, We can not talk in these countries about the liberal concept of the party and can not talk about the existence of a law or laws and regulations governing and regulate the work of parties. But on the other hand, which is represented by the liberal state, we find a lot of talk and practice about the form and nature of the legitimate law in regulating the formation of parties and their work in a manner th
... Show MoreIdioms are a very important part of the English language: you are told that if you want to go far (succeed) you should pull your socks up (make a serious effort to improve your behaviour, the quality of your work, etc.) and use your grey matter (brain).1 Learning and translating idioms have always been very difficult for foreign language learners. The present paper explores some of the reasons why English idiomatic expressions are difficult to learn and translate. It is not the aim of this paper to attempt a comprehensive survey of the vast amount of material that has appeared on idioms in Adams and Kuder (1984), Alexander (1984), Dixon (1983), Kirkpatrick (2001), Langlotz (2006), McCarthy and O'Dell (2002), and Wray (2002), among others
... Show MoreThe adsorption of zirconium, on manganese dioxide from nitric
acid solutions has been studied as a function of shaking time, concentration of electrolytes, concentration of adsorbate and temperature effects (25- 90°C).
Four hours of shaking was appropriate to ensure that the
adsorption plateau was reached and the adsorption of zirconium decrease with an increase in nitric acid concentration. The limiting adsorption capacities at 3 molar nitric acid was 0.2 Zr per mole of Mn02. Working at elevated temperature was in favour
... Show MoreIn this paper we have studied the optical properties of CuBr thin
films. Different sample thicknesses have been prepared by using thermal evaporation technique with 14.4 runlsec as the average deposition rate and 1 00°C as the substrate temperature.
In this paper , some of lexical stylistic , syntactical stylistic devices , and one phonetic stylistic device are going to be illustrated in the study of the aphorisms of “life and death” . These stylistic devices are parallelism , hyperbole , alliteration , meiosis , irony , oxymoron , cliché , litotes , metalepsis , and loose sentences. This paper aims at identifying the functions and the frequencies of these devices. These stylistic devices make one speech and writing more interesting and help to get the attention of readers/ listeners
ABSTRACT Porous silicon has been produced in this work by photochemical etching process (PC). The irradiation has been achieved using ordinary light source (150250 W) power and (875 nm) wavelength. The influence of various irradiation times and HF concentration on porosity of PSi material was investigated by depending on gravimetric measurements. The I-V and C-V characteristics for CdS/PSi structure have been investigated in this work too.
Morphologies of ceramic hollow fiber membranes prepared by a combined phase-inversion and sintering method were studied. The organic binder spinning solution containing suspended Al₂O₃ powders was spun to a hollow fiber precursor, which was then sintered at elevated temperatures( 300 ˚C, 1400 ˚C, 25 ˚C) in order to obtain the Al₂O₃ hollow fiber membranes. The spinning solution consisted of polyether sulfone (PES), N-methyl-2-pyrrolidone (NMP), which were used as polymer binder, solvent, respectively. The prepared Al₂O₃ hollow fiber membranes were characterized by a scanning electron microscope (SEM). It is believed that finger-like void formation in asymmetric ceramic membranes is initiated by hydrodynamically unstable vis
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