Background: Sliding mechanics is widely used during orthodontic treatment. One of the disadvantages of this mechanics is the friction generated at the bracket/archwire interface, which may reduce the amount of desired orthodontic movement obtained. The aim of the present in vitro study was to evaluate and compare the static frictional forces produced by two passive self-ligating brackets stainless-steel and hybrid and two conventional brackets stainless-steel and monocrystal ligated with stainless-steel ligature wire at two degrees of torque(zero and twenty) under dry condition. Materials and method: One hundred and sixty brackets were used in this study divided into four groups each group consisted of forty brackets these are: Two self-ligating (stainless-steel and Hybrid) while the two conventional types are the (stainless-steel and monocrystal).twenty of each group examined with 0.016"x0.022"archwire, ten at 0? torque and ten at 20? torque while the other twenty of each group examined with 0.019"x0.025", ten at 0? torque and ten at 20? torque. Results: There was a significant different between all groups except in case when self-ligating brackets (both types) ligated to both wires at 0?torque there was no significant difference. Conclusions: The self- ligating brackets produce significantly lower static friction than the conventional types at both degrees of torque. There was no significant different between both self-ligating brackets at0?torque while at 20? torque the stainless- steel self –ligating produce lower static friction than the clear self-ligating type.
A new spectrophotometric method for individual and simultaneous determination of cefixime and cephalexin depending on the first and second derivative mode techniques. The first and second derivative spectra of these compounds permitted individual and simultaneous determination of cefixime and cephalexin in concentration interval of (4– 24μg.ml-1 ) by measuring the amplitude of peak-to-base line, pea to peak at certain wavelengths and the area under peak at selected spectrum intervals. The methods showed reasonable precision and accuracy and have been applied to determine cefixime and cephalexin in two different pharmaceutical preparations.
This study aimed to determine the measurements and classification of Schneider membrane thickness correlated to age and sex factors using cone beam computed tomography (CBCT). Methods: The study included CBCT images for 100 maxillary sinuses of 50 consecutive patients, and the thickness of the maxillary sinus membrane (Schneiderian membrane) was measured in coronal view from the lowest point in the floor of the maxillary sinus to the highest point. The thickness of the Schneiderian membrane was classified into 4 types. Results: The study result revealed that out of the total cases, 45% of sinus membranes were classified as type 2, while only 10% were classified as type 4. The most frequent type of membrane thickness diagnosed in the age gro
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Objective(s): To evaluate youth's health risk behaviors in Baghdad City and to determine the relationship between such behaviors and the youth's demographic characteristics of age, gender and grade. Methodology: A descriptive study, using the evaluation approach, is carried out to evaluate youth's health risk behaviors in Baghdad City for the period of January 26th 2016 to May 20th 2016. A non-probability "purposive" sample of (160) University students is selected for the purpose of the study from four groups of colleges (medical, engineering, sciences, and education) and it is equally distributed of
The study aims to introduce the Islamic sites available on the Internet and determine the criteria that contribute to evaluating these sites to indicate their value, topics, and services, while evaluating a simple random sample of the general Islamic sites, which number (35) sites. The results were presented in (8) tables. The study concluded To a set of conclusions, including: (465) “Islamic” websites were seized during the research period, and they are constantly increasing. They were classified according to the name of the website (domain name) com, org, net, edu, and also according to topics such as general Islamic websites and websites of holy places. Mosques, sites of sheikhs, etc. Among the best general Islamic websites are: Isla
... Show MoreIn this work, N-hydroxy phthalimide derivatives (NHPID) were synthesized from the nucleuphilic substitution reactions of (NHPI) with different halides (alkyl halides, sulfonyl halides, benzoyl halides and benzyl halides). The products were distinguished using FTIR spectrum and Nuclear magnetic resonsnce (1H-NMR and 13CNMR), in addition to other characteristic methods such as sodium fution for sulfur determination. followed by measuring antibacterial (with different types of gram positive/gram negative bacteria) and antifungal activities of these compounds.
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Background: Acute coronary syndrome (ACS) is a common disease, and a major determinant of morbidity and mortality in all races. The pleiotropic effects of the receptor activator of nuclear factor-kappa B ligand (RANKL) such as modulation of cell survival, mineralization and inflammation, make it an interesting candidate mediator in the progression and destabilization of atherosclerotic lesions.Objectives: This study was performed to investigate the role of RANKL in the pathogenesis of ACS.Methods: The levels of RANKL were measured by ELISA method in sera of 60 ACS patients, 31 patients with unstable angina (UA) and 29 patients with myocardial infarction (MI) in comparison with 20 apparently healthy controls.Results: Current data indicate
... Show MoreNowadays, the field of radionuclide treatment is enjoying an exciting stage and preparing for further growth and progress in the future. For instance, in Asia, the large spread of liver and thyroid diseases has resulted in several new developments/clinical trials using molecular radiotherapy (i.e. targeted radionuclide therapy). Iodine-124 has unique physical properties including long half-life that adding an advantage for pharmacokinetics and radiopharmaceutical analysis. One of its applications in nuclear medicine is in Positron Emission Tomography (PET).
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The water scarcity that Iraq suffers from and the low irrigation efficiency in irrigation projects, therefore, it was necessary to evaluate the performance of the irrigation system of the western canal for the Ishaqi irrigation project in Salah al-Din Governorate to determine the water management strategies that can be used to improve the irrigation efficiency in the project. The performance of the field irrigation system was evaluated on two fields of different crops and irrigation methods according to the agricultural reality of the study area in the Western canal for the Al-Ishaqi Irrigation Project in Salah Al-Din Governorate. The fieldwork included measurements of the moisture content before and after irrigation, fi
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This paper aims to evaluate the reliability analysis for steel beam which represented by the probability of Failure and reliability index. Monte Carlo Simulation Method (MCSM) and First Order Reliability Method (FORM) will be used to achieve this issue. These methods need two samples for each behavior that want to study; the first sample for resistance (carrying capacity R), and second for load effect (Q) which are parameters for a limit state function. Monte Carlo method has been adopted to generate these samples dependent on the randomness and uncertainties in variables. The variables that consider are beam cross-section dimensions, material property, beam length, yield stress, and applied loads. Matlab software has be
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