Objective. This study aimed to evaluate the orthodontic bond strength and enamel-preserving ability of a hydroxyapatite nanoparticles-containingself-etch system following exposure to various ageing methods. Materials and Methods. Hydroxyapatite nanoparticles (nHAp) were incorporated into an orthodontic self-etch primer (SEP, Transbond™ plus) in three different concentrations (5%, 7%, and 9% wt) and tested versus the plain SEP (control) for shear bond strength (SBS), adhesive remnant index (ARI) scores, and enamel damage in range-finding experiments using premolar teeth. The best-performing formulation was further exposed to the following four artificial ageing methods: initial debonding, 24 h water storage, one-month water stora

The study aimed to know the degree to which Islamic education teachers employ the strategy of directed discovery in teaching to develop higher thinking skills (analysis, synthesis, and evaluation) among sixth-grade students at the basic stage in East Nile Province, Khartoum State - Sudan. The researcher used the descriptive-analytical method, and adopted a questionnaire that consisted of (15) indicators representing the skills of analysis, synthesis, and evaluation as a tool of the study. A random sample of (175) Islamic education teachers was selected, from the Department of Basic Education. The data were analyzed according to the Statistical Packages for Social Sciences (SPSS) program, and the results of the study have shown that the u

Abstract As the United Nations approaches its 70th anniversary, the world is going through the most severe accumulation of serious international security failures in recent memory, challenging the UN Security Council’s ability to address them effectively. Over the past four years, crises in Libya, Syria and Ukraine have precipitated a worrisome erosion of great power relations that has complicated Security Council decision making on a number of trouble spots. Its inability to devise consensus responses to the escalating civil war in Syria has been particularly troubling, resulting in the regional spill over into Iraq and the emergence of Islamic State as a new threat to peace in the region and beyond. Meanwhile, the UN’s often under

The research included four topics: the definition of Imam al-Bazzazi, his scientific life, his sheikhs, his students, his writings, his death, and selected issues of his weight in the book of prayer. The Imam al-Bazazi is the son of Muhammad ibnShihabibn Yusuf. He is known as al-Khardizi al-Khawarizmi. The author did not adopt the definitions of language and terminology, and rarely mention the legal evidence adopted by the scholars in their opinions, and only to mention the views only, and the author, may God have mercy on him in his book on the sources of m The Prophet (peace and blessings of Allaah be upon him) said: "The Prophet (peace and blessings of Allaah be upon him) And fall down the order, the third issue, which is to leave the

Fisetin is a plant flavonoid found in strawberries and other fruits and vegetables such as apples, persimmons, and onions. It has many pharmacological effects like anti-inflammatory, antioxidant, cardioprotective, neuroprotective, and anti-carcinogenicity which are attributed to its ability to reduce oxidative stress which considers the main reason for different disease conditions. Genotoxicity refers to the genetic material destruction within the cell which can be caused by different chemicals as well as radiation. The present study evaluates the effect of orally-administered fisetin daily for seven constitutive days on genotoxicity induced by cyclophosphamide in rats’ bone marrow and spleen cells. Results showed that fisetin exh

The reaction paths of the C-C and C-H bond cleavage in the anthracene and phenanthrene aromatic molecules are studied by applying the ab-initio DFT method. It is found that the C-C bond cleavage proceeds via a singlet aromatic transition state, compelled through a disrotatoric ring opening reaction. A suprafacial H atom shift follows the transition state, leading to the formation of a methylene -CH2 and an acetylenic or allenic moiety. The calculated activation energies for anthracene range from 158.81-208.90 kcal/mol and the reaction energies from 96.106-156.976 kcal/mol. For phenanthrene, the energy values are 157.39-202.34 kcal/mol and 62.639-182.423 kcal/mol, respectively. For the C-H cleavage reactions, the calculated reaction energies

The present paper aims at finding out the Variance Ratio of Trips Set Out by Scholars of Both Marrouzzeen and Baihaq  .The researcher has come up with conclusion including certain findings ,one of which is that the trip is considered an essential base with high effectiveness since  the old times and has been evolved .This means that the trip has been the main source of  knowledge and sciences from the scholars directly .This had driven the scholars of both Baihaq and Marrouz cities .It has been noticed , though this paper, that the number of the Marrouz scholars who visited was less than those of Baihaq . The researcher has focused on their meetings or conferences and investigated what has been going on in such meetin

The present paper aims at finding out the Variance Ratio of Trips Set Out by Scholars of Both Marrouzzeen and Baihaq  .The researcher has come up with conclusion including certain findings ,one of which is that the trip is considered an essential base with high effectiveness since  the old times and has been evolved .This means that the trip has been the main source of  knowledge and sciences from the scholars directly .This had driven the scholars of both Baihaq and Marrouz cities .It has been noticed , though this paper, that the number of the Marrouz scholars who visited was less than those of Baihaq . The researcher has focused on their meetings or conferences and investigated what has been going on in suc

The current study is designed to investigate the histological and immunohistochemical characteristics of the thyroid gland in adult male Sciurus anamalus. This study found that the thyroid gland of the Caucasian squirrel is located in the neck area, below the larynx, on both sides of the trachea. It has two lobes (right and left) with cylindrical shape. The histological studies revealed that the thyroid gland is surrounded by a capsule which consists of connective tissue and forming of two layers which are outer layer and inner layer, and a layer of adipose tissue appears overlapping the outer layer. The inner tissue of the gland consists of follicles with different shapes and sizes, and is lined with simple cuboidal epithelial tissue (foll

Background: University dental students perceived a higher level of stress prior to the final exam associated with raised salivary alpha-amylase levels which could be considered as a useful noninvasive biomarker for measuring acute stress. Using a Helkimo anamnestic and clinical dysfunction scoring for temporomandibular disorders can give a better insight about the association of this marker and temporomandibular disorders. The aim of this study was to evaluation level of salivary alpha-amylase in stressor students with temporomandibular disorders and the relation between the marker in relation to temporomandibular disorders severity. This might give a better understanding to the role of psychological stress as an etiological factor for deve