Titanium dental implant therapy is the recent modality to replace missing teeth. Following implant placement, bone around the implant will undergo remodeling, involving osteoblast and osteoclast activity, leading to lifetime osseointegration. Implant surface may leach titanium particles leading to generation of reactive oxygen species (ROS) and inflammation in the peri-implant site. The aim of this in-vitro study is to investigate the influence of titanium dioxide particles and reactive oxygen species production on osteoblast proliferation and differentiation. Human osteoblast cell lines were exposed to different concentration of titanium dioxide particles, with and without anti-oxidant, and ROS assay, cell viability and cytokine release were measured. Our results demonstrated good cell viability and ROS were generated in a dose-dependent manner associated with pro-inflammatory cytokine release. Addition of anti-oxidant reduce ROS production and cytokine secretion. Therefore, treatment with antioxidants may mitigate the effects of ROS and improve osteoblast function during bone remodeling
Citrullus colocynthis is a herbal medicinal plant widely used for its antioxidant and antimicrobial activities. This study assesses the effects of seasonal variation on the antioxidant activity and total polyphenols of several accessions of C. colocynthis from a population in the arid environment of UAE. Extracts were prepared from fruit parts collected in winter and summer seasons. The antioxidant capacity and total phenolic contents were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical test, and Folin-Ciocalteau assay, respectively. Antioxidant activity varied between different seasons and different fruit parts of the same accession, but not between different accessions of the same population. However, the phenolic contents varied between different seasons, different accessions of the same population, and different fruit parts. Fruits collected from the winter season showed more antioxidant activity than the summer season. In conclusion, the antioxidant activity and phenolic contents were partially correlated but mainly influenced by the time of fruit collection.
Alveolar ridge atrophy results from horizontal and vertical bone loss occurring after tooth extraction. Dental implants can only be placed if there is sufficient bone to stabilize them. The aim of this study was to compare the efficacy of horizontal alveolar ridge augmentation using three different materials, namely autogenous, bovine and customized bone blocks. Dental implant patients with deficient alveolar ridge were recruited. Twenty-six patients underwent alveolar ridge augmentation, with nine patients in Group 1 received autogenous bone graft, 10 patients in Group 2 had a bovine bone substitute and 7 patients in Group 3 received customized bone block. Twenty-five cases were successful and only one failure was encountered. Alveolar ridge augmentation using various bone grafting substitutes has a predictable outcome with a high patient's satisfaction rate.
Introduction: Migrant workers account for 80% of the total population of the United Arab Emirates (UAE), and most of the migrants work in the construction industry. Aims & Objectives: The present study aimed to determine the prevalence and associated characteristics of time-loss injuries among constructor workers in Al Ain, Abu Dhabi Emirate. Materials & Methods: We recruited a random sample of 1634 construction workers from a list of construction-related industries in Al Ain. Results: A total of 1634 construction workers were surveyed (mean age: 35.9?8.4, range: 19-63). A total of 109 workers reported time-loss injuries (19.9%; 95% CI [16.8-23.5]). Of those with time-loss injuries, 10.7% were hospitalized for the treatment of the injury. Conclusion: The information in this study can guide the prevention efforts of Abu Dhabi Emirate initiatives to reduce injury and illness rates in the construction sector in the UAE.
The cytotoxic aggregation of Amyloid Beta (A?) and Islet Amyloid polypeptide (IAPP) is implicated in the pathogenesis of Alzheimer's disease and Type 2 diabetes, respectively. Understanding the molecular interactions that drive the early aggregation process of both IAPP and A? will be required for designing potent inhibitors against their aggregation. In this research, we employed protein-protein docking to model the first step of the aggregation process which is the dimerization of two misfolded monomers. In specific, we modeled the interaction interfaces that form within the homo-dimeric IAPP-IAPP and A?-A? and the hetero-dimeric IAPP-A? complexes. Our results show that the interaction interfaces of both homo-dimers and hetero-dimers are stabilized with strong hydrogen bonding and hydrophobic interaction networks. Our results can aid in designing potent inhibitors to prevent the self- or cross-interactions of IAPP and A? which, in turn could prevent their cytotoxic self- and co-aggregation pathways.
We compared the machine learning technique and well-known polygenic risk score for genotype-phenotype prediction. PRS is a more informative quantity as compared to classification in machine learning. PRS predicts the tendency that a particular person will have a specific disease whereas machine learning only classifies it into a phenotype. There are some standard quality control steps that must be performed on the dataset before further analysis. For PRS calculation we used different p-value thresholds and for machine learning, we used mutation difference between SNPs to reduce the number of SNPs. We analyzed the depression phenotype. With machine learning, the accuracy we got was 0.56 and with PRS it was about 0.024.
In this work, single-curvature V-bending experiments are carried out on pre-consolidated Carbon Fibre/Poly Ether Ketone (CF/PEKK) composites to determine their formability during thermo-forming operations. A Design of Experiments (DoE) approach is used to investigate the spring-back by varying forming parameters systematically. The formed sample is examined under an optical microscope to visualise inter-ply and intra-ply deformations that occurred during the forming operation. The DoE results indicate the contribution of the bending radius factor on the spring-back of CF/PEKK composites to be the greatest. Image analysis shows inter-ply slip to be the primary mode of deformation during the forming operation, followed by intra-ply movement, causing a negligible decrease in the laminate thickness.
The compaction plays a major role in characterizing the behavior of prepreg. Prepregs are known to exhibit viscoelastic behavior. This study will investigate the compaction rate effect of uncured glass/epoxy prepreg. The results showed that as the rate decreases the prepreg can achieve higher volume fraction. A non-linear elastic model was used to capture the compaction results. However, a viscoelastic model is needed to predict the behavior more accurately.
Prepregs have been widely used in composite manufacturing of advance aero structure. Compaction of prepreg in its uncured state is a key step in the manufacturing process techniques such as autoclave, out-of-autoclave, and automated tape layup processing. Prepreg are known to exhibit viscoelastic behaviour because of the presence of resin and fabric reinforcement. Modelling the compaction of prepreg in such process would enable to develop process models. In this paper, a hyper-viscoelastic model based on QLV approach is utilized to model the time dependent response of prepreg. Experimental data at different compaction were used and the model parameters were determined using the least square fitting
This paper involves an investigation of the ability of steady, quasi-steady and unsteady aerodynamic models to predict aeroelastic flutter in incompressible subsonic flow on aircraft wings. The wing structure is modelled as a Euler-Bernoulli cantilever beam, with shape functions incorporated for bending and torsional modes via Rayeligh-Ritz method, and aerodynamic models are constructed using strip theory. The equations of motion for the 2 degrees of freedom wing in pitch and plunge are developed using Lagrangian method. Three aerodynamic models in frequency domain and one unsteady model in time-domain are presented and all results are compared to available literature data. It is shown that quasi-steady models possess inadequate accuracy in determination of flutter phenomena. Steady aerodynamic model underpredicts flutter velocity, however, can be used for initial design stages. Unsteady flow models are the most reliable either in frequency or time-domain and predict the flutter velocity with highest accuracy.
