SACM - United States of America
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Item Restricted Assessing the initial Primary Stability of Dental Implants via various Osteotomy Preparation Techniques: An Ex Vivo Comparative Study Utilizing Two Distinct Non-invasive Methods(University at Buffalo, 2023) Fadhl Almawla, Sawsan; Sebastiano, AndreanaBackground and aim: Stable connection between dental implants and bone is crucial in implant dentistry. Osteotomy preparation methods, such as Conventional drilling (C), Piezoelectric Bone Surgery (P), and Osseodensification (Densah bur) (D), play a major role in this process. The primary stability of implants, which influences prognosis and loading protocols, is affected by several factors, including cortical bone thickness. . Two innovative noninvasive devices like Periotest® (Siemens AG, Bensheim, Germany) and resonance frequency analysis (RFA) (Osstell Mentor) (Integration Diagnostics AB, Göteborg, Sweden) have been introduced to measure implant primary stability. The aim of this study is to assess and compare the primary stability of dental implants inserted through (C), (P), and (D), utilizing Resonance Frequency Analysis and Periotest, and to explore the effect of cortical bone thickness on the primary stability. Methods: Ten porcine ribs were utilized, with three osteotomies per rib employing (C), (P), and (D) techniques. Each technique involved ten implant preparation sites for 4.1 x 10 mm implants. Primary stability was assessed using Periotest and RFA. Bone thickness was measured using a calibrated dental ruler after bone sectioning at osteotomy sites. Statistical analysis involved one-way repeated measures ANOVA and multiple comparison tests, with significance set at p < 0.05 for the first objective. The second objective utilized the Pearson Correlation Coefficient (r) test. v Results: The mean ISQ for RFA was reported as 69.85, 68.25, and 73.05 for (C), (P), and (D), respectively. The PTV (Periotest Value) was recorded as -5.2300, -3.2250, and -3.5000 for (C), (P), and (D), respectively. The (D) technique exhibited a higher mean RFA score compared to (C) and (P) techniques, while Periotest scores were lower for (C) than (P) and (O). Interestingly, there was no consistent ranking between the RFA and Periotest results. Furthermore, no significant correlation was found between cortical bone thickness and either RFA or Periotest scores. Conclusions: While statistically significant differences were observed, all three techniques demonstrated results falling within the range of good clinical primary stability. The study suggests that there is no significant clinical distinction between (RFA) and Periotest. Additionally, cortical bone thickness did not show a significant correlation with either RFA or Periotest results.9 0Item Restricted Theoretical Studies of Cu (110) Surface with the Different Carbon Coverages(Texas Tech University, 2023) Alsharari, Sami; Sanati, MahdiA Monte Carlo simulation program has been developed to model the secondary electron emission from metal surfaces. This new program is capable of simulating more than 100,000 primary incident electrons in a few minutes. The required input parameters for the Monte Carlo simulations are obtained from first-principles calculations. The calculated dielectric constants, total electron density of states, and work function were used to obtain the inelastic mean free path and stopping power of systems. As a case study, the Cu surface was chosen since it has been thoroughly explored and simulations can be compared with available experimental measurements of secondary electron emission. The goal of this thesis is to investigate the secondary electron emission of both clean Cu (110) surfaces and carbon-coated Cu systems. It was shown that the adsorption of the carbon layer on the Cu (110) surface can reduce the secondary electron emission.83 0Item Restricted DISTINCT CLINICAL MANIFESTATIONS ASSOCIATED WITH AUTOANTIBODIES AND CYTOKINES IN SYSTEMIC LUPUS ERYTHEMATOSUS(University of Alabama at Birmingham, 2022) Alduraibi , Fatima K; John Mountz, CommitteeObjective: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease charac-terized by production of autoantibodies (autoAbs) and cytokines. Moreover, lupus nephritis (LN) occurs in approximately 50% of SLE patients. AutoAb and cytokine levels produced by B and T cells are high in LN patients, although their relationship with histological patterns requires inves-tigation. Methods: We analyzed the relationship between B cell cytokines and major T cell cyto-kines, including their association with autoAbs, and the clinical manifestations of SLE, espe-cially LN. We also analyzed endogenous intracellular interferon beta (IFNβ) expression in the peripheral blood mononuclear cells and serum circulating nephritogenic autoAbs from patients with SLE (n = 80) and healthy controls (n = 16). Subsequently, plasma levels of T-helper cell cy-tokines and autoAbs were determined in patients with SLE (n = 60) and healthy controls (n = 11). Results: IFNβ expression was significantly higher in patients with SLE than in healthy controls (HC; P < 0.001) and positively associated with LN (P = 0.008) but not cutaneous mani-festations. Additionally, it was associated with increased circulating IgG anti-DNA and IgG anti- ii Smith autoAbs (P = 0.0130, P = 0.0010, respectively), and elevated urinary protein/creatinine ra-tio (P = 0.064). Histopathological evaluation of kidney biopsies revealed that higher IFNβ levels correlated with severe LN—higher degree of activity and chronicity (P < 0.0001, P = 0.0225 and P = 0.0327, respectively). Immune complex deposition in the kidney was not associated with in-creased IFNβ. Interferon gamma (IFNɣ) and interleukin (IL)-17 were generalized features in pa-tients with SLE. However, higher IL-10 levels occurred in patients with LN. IL-17 levels were significantly higher in patients with LN class V and discoid lupus (P = 0.0055 and P = 0.0238, respectively). IFNɣ was positively correlated with anti-double stranded DNA and anti-Sjogren's syndrome A (P = 0.0355 and p = 0.0402, respectively), while IL-17 was correlated with anti-Ro/SSA (P = 0.0130). Conclusions: IFNβ represents a potential biomarker for LN, while IL-10 and IL-17 could be used in combination with other diagnostic markers. Our results show the pathogenic mecha-nisms underlying LN to guide diagnosis and therapy.19 0Item Restricted Understanding Controls on Spring Hydrographs in an Eogenetic Karst Aquifer in North-Central Florida(University of South Florida, 2023) Almeqhem, Ryan; Gulley, JasonFlorida has one of the largest karst aquifers in the United States, with a significant portion of its water resources originating from the eogenetic karst system in north central Florida. Despite the importance of this system, eogenetic karst still needs to be studied compared to telogenetic karst. The hydrological behavior of karst aquifers is complex, with numerous factors influencing the timing, magnitude, and shape of spring hydrographs. One hypothesis, by Florea and Vacher (2006), suggests that matrix permeability is the primary control of spring hydrographs in karst systems. However, this thesis challenges this hypothesis by presenting evidence that the recharge mechanism plays a more significant role in controlling spring hydrographs in karst aquifers. The study focuses on Santa Fe River Rise and Ichetucknee River in north central Florida. They share similar rock types and matrix permeability but differ in their recharge mechanism. The Santa Fe River Rise is primarily recharged by a sinking stream, while the spring-fed Ichetucknee River is recharged via diffuse infiltration. Discharge and precipitation data were downloaded and analyzed from 2010 to 2021, to examine the behavior of Santa Fe River Rise and Ichetucknee River. The results demonstrate that the recharge mechanism primarily controls spring hydrographs in karst aquifers rather than matrix permeability. The study found that Santa Fe River Rise responds more rapidly to precipitation events, with high peak flows and short recession periods, like telogenetic karst in Florea and Vacher (2006). In contrast, the Ichetucknee River has a delayed response to precipitation, with lower peak flows, like most Florida springs in Florea and Vacher (2006). Thus, this thesis highlights the importance of considering the recharge mechanism when analyzing the hydrological behavior of karst aquifers. The findings have significant implications for managing water resources in karst regions, emphasizing the need for a more nuanced understanding of the complex hydrogeological processes that regulate spring hydrographs.14 0Item Restricted HYBRID ARCHITECTURE WITHIN NAJD REGION, SAUDI ARABIA(Virginia Polytechnic Institute and State University, 2023-11-29) Almatani, Bashair Saad; Bryon, Hilary; Galloway, William; Tomer, SharoneACADEMIC ABSTRACT The thesis investigates the concept of hybrid architecture as a juxtaposition of multiple architectural factors, including environmental, cultural, structural, and functional ones. The work examines the Najd region of Saudi Arabia and its historical and contemporary contexts concerning functional utility, cultural frameworks, tectonic architectural elements, and site-based environmental forces. The thesis proposes that architectural hybridity can enhance the human experience. The design project, a building combining a water purification facility with a cafe, exhibition hall, and other community functions, integrate traditional and contemporary cultural aesthetics by purposefully juxtaposing and relating: unlikely functions, temporally varied cultural forms, structural and ornamental tectonic elements, and contrasting environmental qualities.39 0Item Restricted Accuracy of milled lithium disilicate crowns fabricated by using CBCT and IOS-based digital models(Rutgers school of dental medicine, 2023) Jassoma, Elaf; Morgano, Steven; Muadab, RamiObjectives To evaluate the trueness and precision of digital casts generated from intraoral scanning (IOS) and cone beam computed tomography (CBCT). Also, to assess the marginal integrity of milled lithium disilicate (LD) crowns that were fabricated from the IOS and CBCT digital casts. Materials and methods Tooth preparation for an all-ceramic crown was performed on a segmented cast that was later scanned as a master model. Scans were obtained; 10 conventional polyvinyl siloxane impressions were made that were scanned by using CBCT, 10 digital scans by using IOS, and 10 digital scans by using a desktop scanner. DICOM data of the CBCT were converted to STL files. The reference STL file was segmented and prepared for 3D comparison. The 3D comparison was performed to compare the IOS group and CBCT group to the reference STL files. Trueness was determined by measuring the root mean square (RMS) for each group. The data were analyzed by using paired samples t-test. The digital casts from each group were used to fabricate all-ceramic crowns; 10 crowns from a tabletop scanner (reference) digital model, 10 crowns from the IOS digital model, and 10 crowns from the CBCT digital model. Crowns were milled by using IPS emax CAD. The replica method was used to evaluate the marginal integrity of the milled crowns. The thickness of the cross-section of the replica was measured under scanning electron microscopy (SEM). Descriptive statistics of mean and standard error of trueness and marginal gaps for all groups were recorded and compared by applying paired sample t-test and repeated measures ANOVA test, respectively. All the data were analyzed by using statistical analysis software program SPSS, version 29.0. Results The accuracy of the CBCT group was shown to be statistically significantly different from that of the IOS group, based on the results of the paired sample t-test. Crowns made from digital models created by CBCT exhibited a marginal gap that was substantially higher (P < 0.001) than crowns made by using IOS models. Conclusions Within the limitations of this study, it can be concluded that CBCT generated models are statistically significantly less accurate when compared with a Trios 3 IOS, and when compared with a reference tabletop scanner. Additionally, lithium disilicate all-ceramic crowns fabricated from CBCT models recorded more marginal gap when compared with both the control and IOS groups.32 0Item Restricted Evaluation of Surface and Mechanical Properties of Ceramic-Reinforced PEEK as a Denture Base Material(The State University of New York- University at Buffalo, 2023) Almogbel, Lolowh; Li, RuiPurpose: This in vitro study aimed to compare flexural strength, surface roughness, and biofilm formation of ceramic-reinforced polyetheretherketone (PEEK) with conventionally heat-compressed and milled polymethylmethacrylate (PMMA) denture base materials. Materials and methods: Thirty strips (6.4 mm × 10 mm × 3 mm) and 30 discs (10 mm × 1 mm) were fabricated from a heat-compressed PMMA, milled PMMA, and ceramic-reinforced PEEK, 10 each. One surface of each sample was polished to mimic the laboratory procedure for denture base materials. Strips were then subjected to a three-point bend test using a universal testing machine at a crosshead speed of 5.0 mm/min. An optical profilometer was used to assess the Ra value (mm) of the discs on polished and unpolished sides. Biofilm formation behavior was analyzed by measuring the colony-forming unit (CFU)/mL of Candida albicans on the unpolished surface of the discs. One-way ANOVA followed by Tukey multiple comparison tests were used to compare the flexural strength, Ra value, and biofilm formation of the studied materials (a = 0.05). Results: Ceramic-reinforced PEEK showed significantly higher flexural strength (178.2 ± 3.2 MPa) than milled PMMA (89.6 ± 0.8 MPa; p < 0.001) and heat-compressed PMMA (67.3 ± 5.3 MPa; p < 0.001). Ceramic-reinforced PEEK exhibited a significantly higher Ra value than the other groups on unpolished sides; however, the polishing process significantly reduced the Ra values of all studied groups (p < 0.05). There was no significant difference in C. albicans adhesion among the groups (p < 0.05). Conclusion: The flexural strength of tested materials was within acceptable limits for clinical use as a denture base material. Ceramic-reinforced PEEK had the highest surface roughness; however, its similarity in biofilm formation to other groups indicates its clinical acceptability as denture base material.15 0Item Restricted Engineering Amphiphilic Platinum(IV) Prodrugs for Treating Drug Resistant Ovarian Cancer(Kent State University, 2022-12) Alqarni, Suha; Zheng, YaorongThe platinum(IV) prodrug approach is a promising method to develop a replacement for classic platinum-based chemotherapy. The mitochondria-damaging Pt(IV) prodrugs have proven effective against drug-resistant ovarian cancer cells and cancer stem cells, which represent long-standing issues in classic platinum chemotherapy. In this work, we present a comprehensive study on engineering novel amphiphilic Pt(IV) prodrugs as mitochondria-damaging agents. The key findings in this study include: 1). Hydrophobicity of the head group of such prodrugs dictates their cell entry and cytotoxicity; 2). Amphiphilic Pt(IV) prodrugs exhibits superior therapeutic effects compared to cisplatin and overcomes drug resistance in ovarian cancer; 3). Amphiphilic Pt(IV) prodrugs trigger mitochondrial damage.10 0Item Restricted LIQUID CRYSTALS NUCLEI COEXISTING WITH AN ISOTROPIC PHASE(Kent State University, 2022-08) Alqarni, Ali; Lavrentovich, OlegThe morphology of finite-size condensed materials is influenced by surface tension. To reduce surface area, tiny droplets of water in the air have spherical shapes, but solid crystals have facetted shapes defined by the orientation dependency of surface tension. Bulk interactions are unimportant in these two examples because they are either too weak to overcome surface tension in the first case or too powerful to enable internal curvatures in the second case. In liquid crystal droplets, the bulk and surface energies are more closely balanced, resulting in a more diversified morphology of structures such as smectic "batonnets", nematic spindle-like tactoids, and even the possibility for droplet division . Liquid crystals are well-known examples of ordered materials whose nuclei emerge from an isotropic state and have a shape topologically equivalent to a sphere. In the first part of the thesis, we explore experimentally and theoretically the nuclei of columnar lyotropic chromonic liquid crystal coexisting with the isotropic phase that is toroidal in shape. We study the lyotropic chromonic liquid crystal (LCLC) composed by plank-like molecules of disodium chromoglycate (DSCG) with hydrophobic polyaromatic cores and hydrophilic peripheries. The goal is to establish the physical mechanisms in the balance of elasticity and anisotropic surface tension that produce toroidal shapes and establish how these shapes depend on parameters such as molecular concentrations and the presence of a crowding agents. The second part of the thesis will focus on the droplets of chiral and ferroelectric liquid crystal materials.24 0Item Restricted ELECTROCHEMICAL NITROGEN REDUCTION TO AMMONIA USING MOLYBDENUM DISULFIDE-BASED NANOCATALYSTS(UA Little Rock, 2019-12) Basurrah, Assem; Zhao, WeiAmmonia is the basis for producing fertilizers for food production. The Haber Bosch process is the main method to produce ammonia. Because of the energy and environmental problems associated with the Haber-Bosch process, extensive research is being explored for other ammonia production methods, including electrochemical methods based on nitrogen reduction reaction (NRR). In this thesis, molybdenum disulfide (MoS2) nanocatalysts (~4 nm) on carbon fibers were synthesized by hydrothermal reactions. The resulting composites were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of the composites were measured by using linear sweep voltammetry, cyclic voltammetry, and controlled potential electrolysis to evaluate their NRR performances and effectiveness in the production of ammonia. Ammonia was produced with a yield rate of 1.5810-10 mole s −1 cm−2 and Faradaic efficiency 9.39% for NRR, both of them were higher than or close to those in literatures in aqueous solutions without using co-catalysts15 0