Background: This study aimed to compare the surface microhardness (MH) and mineral content of white spot lesions(WSLs) after using bioactive glass (BAG)casein phosphopep-tides-amorphous calcium phosphate(CPP-ACP),and nanohydroxyapatite(Nano-HAP) under pHcycling. Material and method:18 sound maxillary first premolar were used for the study.10 were selected for the vickers microhardness test, For Energy-dispersive X-ray spectroscopy analysis (EDX), the remaining 8 premolar teeth were used, 40 sections of enamel blocks (Four from each tooth) were produced from the middle part of the buccal and palatal surfaces of teeth for MH test while 48 sections of enamel blocks (Six from each tooth) were produced for EDX analysis. Enamel slabs were divided into four groups: control group that preserved in DDW, Nano-HAP, CPP-ACP and BAG group, then were demineralised using 0.1 M lactic acid and 8 wt.% carboxymethylcellulose gel to create artificial WSL. The speci-mens were subjected to a pH cycling regime for 20 days. The remineralisation potential of the specimens was studied by evaluating the surface MH, calcium (Ca), and phosphrous (P) at different stages: baseline, after production of WSLs, and after treatment with different ma-terials. The gathered data were statistically analyzed using repeated measures one-way ANOVA test and the Bonferroni test. Results: The results showed that Nano-HAP had the highest mean values of MH (157.699 kg/ mm2), Ca (50.108), and P (24.840) followed by BAG (MH=147.769 kg/ mm2, Ca=47.408, P=22.285), and the lowest mean value was found in the control group (MH=52.299 kg/ mm2, Ca=35.291, P=17.228). Bonferroni’s and Tukey's HSD test showed higher significant difference (p<0.05) from demineralization to remineralization phase in all groups, except when compared control group with WSL (Demineralization) showed non-significant difference (P>0.05). Conclusion:all tested agents have highly signif-icant remineralizing potential. Nano-HAP has the highest potential for remineralizing initial enamel caries lesions
The purpose of this study is to compare the influence of three teaching methods, as represented by problem-based learning (PBL), the PBL with lecture method, and the conventional teaching on undergraduate physics students' group work skills among bachelor’s degree physics students. In this study, the pre- and post-test were done and the instruments were administered to the students for data collection. The actual sample size comprises of 122 students, who were selected randomly from the physics department, college of education in iraq. Overall, the statistical results rejected null hypothesis of this study. Thus, using the PBL without or with lecture method enhances the skills of the group work among the bachelor’s degree physics studen
... Show MoreThe objective of this paper was to study the laser spot welding process of low carbon steel sheet. The investigations were based on analytical and finite element analyses. The analytical analysis was focused on a consistent set of equations representing interaction of the laser beam with materials. The numerical analysis based on 3-D finite element analysis of heat flow during laser spot welding taken into account the temperature dependence of the physical properties and latent heat of transformations using ANSYS code V.10.0 to simulate the laser welding process. The effect of laser operating parameters on the results of the temperature profile were studied in addition to the effect on thermal stresses and dimensions of the laser w
... Show MoreTransport is a problem and one of the most important mathematical methods that help in making the right decision for the transfer of goods from sources of supply to demand centers and the lowest possible costs, In this research, the mathematical model of the three-dimensional transport problem in which the transport of goods is not homogeneous was constructed. The simplex programming method was used to solve the problem of transporting the three food products (rice, oil, paste) from warehouses to the student areas in Baghdad, This model proved its efficiency in reducing the total transport costs of the three products. After the model was solved in (Winqsb) program, the results showed that the total cost of transportation is (269,
... Show MoreObjective: This study evaluated the effect of immediate dentin sealing on the marginal adaptation of lithium disilicate overlays with three different types of resin-luting agents: preheated composite, dual-cure adhesive resin, and flowable composite. Materials and Methods: Forty-eight maxillary first premolars of similar size were prepared with a butt joint preparation design. The teeth were separated into two primary groups, each with twenty-four teeth: Group DDS: Delay dentin sealing (non-IDS) teeth were not treated. Group IDS: dentin sealing was applied immediately after teeth preparation. Each group was subsequently separated into three separate subgroups. Subgroups (DDS+Phc, IDS+Phc): cemented with preheated composite (Enamel plus HRi,
... Show MoreThe present study aimed to identify the therapeutic evaluation of chitosan extracted from the fungus cushroom and pure chitosan on glucose and lipid profile in the blood of 35 male rabbits with hyperlipidemia induced experimentally by cholesterol. The tests included estimation of glucose levels, total cholesterol, triglycerides, high-density lipoproteins, low-density lipoproteins, and very low-density lipoproteins. hyperlipidemia was induced in the male rabbits used in the study which was administered orally with cholesterol 150mg/kg body weight for a week. rabbits were divided into seven groups: control, cholesterol, pure chitosan, mushroom chitosan, cholesterol and pure chitosan, cholesterol and mushroom chitosan and cholestero
... Show MoreResistance spot welding (RSW) aluminum alloys has a major problem of inconsistent quality from weld to weld, because of the problems of the non-uniform oxide layer. The high resistivity of the oxide causes strong heat released which influence significantly on the electrode lifetime and the weld quality. Much effort has been devoted experimentally to the study of the sheet surface characteristics for as-received sheet and surface pretreatment sheet by pickling in NaOH and glassblasted with three thicknesses (0.6, 1.0, and 1.5 mm) of AA1050. Three different welding process parameters energy setup as a low, medium, and high were carried. Tensile-shear strength tests were performed to indicate the weld quality. Moreover, microhardness tests,
... Show MoreAbstract
Mitoxantrone is an antitumor agent used in the treatment of breast and prostate cancer, acute leukemia, lymphoma, and also in the treatment of multiple sclerosis due to its immunosuppressive properties. The mitoxantrone's cardiotoxicity is irreversible, dose-dependent, and it may occur years after treatment. Zinc is considered as an essential mineral for cell division and the synthesis of DNA and protein; furthermore, such mineral has an important role in states of cardiovascular diseases; and may have protective effects in coronary artery disease and cardiomyopathy.
Objective: The current study is designed to investigate effects of two different doses of zinc sulfat
... Show MoreObjective(s): To determine the effectiveness of lactation counseling on maintenance of breastfeeding after
cesarean section for study group.
Methodology: A quasi-experimental study was conducted on non probability sample (purposive) of (60) women
who had cesarean section and sample divided in to two groups (30) of them as a study group from Fatima AlZahra'a
Maternity and Pediatric Teaching Hospital & implement lactation counseling on it and another group (30)
as control group from Baghdad Teaching Hospital in Baghdad City. Study implemented for the period of April 24th
2011 to August 2nd 2011. A questionnaire was used as a tool of data collection to fulfill with objective of the study
and consisted of three parts
Friction stir spot welding (FSSW) is a relatively new welding process that may have significant advantages compared to the fusion processes as follows joining of conventionally non-fusion weldable alloys, reduced distortion and improved mechanical properties of weldable alloys joints due to the pure solidstate joining of metals. In this paper, a three-dimensional model based on finite element analysis is used to study the thermal history in the spot-welding of aluminum alloy 2024. The model take place the thermomechanical property on the process of the welded metals. The thermal history and the evolution results with numerical model at the measured point in the friction stirred spot weld have a good matching, then the prediction of the t
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