14 research outputs found
Effects of vitamin D deficiency on bone and root re-sorption post-orthodontic retention in rats
Background: Orthodontic therapy often causes external root resorption. Serum vitamin D (VD) level is important for tooth mineralization and bone remodeling. This study aimed to test the impact of vitamin D (VD) supplements on bone and root remodelling in a vitamin D (VD) deficient rat model following orthodontic retention. Methods and Material: 30 male Wistar rats were divided into three groups: a control group of 10 rats and two experimental groups of 10 rats each with vitamin D deficiency (VDD) induced by a VD-free diet for 21 days. And a third group with VD supplementAll groups received orthodontic active treatment using a modified orthodontic appliance that applied 50 gm of force for 14 days to move the maxillary right first molar mesially, followed by 7 days of retention and relapse. The VDD group received no intervention, while the VDS group received 40,000 IU/kg of systemic VD3 by intramuscular injection on the first and fifteenth day of orthodontic treatment. Histomorphometric analysis was performed to assess bone and cementum resorption and deposition. Results: The VDD group exhibited a significant increase in bone and root resorption and a decrease in bone deposition and ce-mentum deposition ratio. In addition, bone deposition and the ratio of cementum deposition were substantially greater in the VDS group compared to the control group. Conclusion: VDD may increase bone and root cementum resorption and decrease deposition after orthodontic retention, which may play a significant role in relapse after retention. Prior to beginning orthodontic treatment, routine VD screening may be beneficial
Enhancement Performance of High Electron Mobility Transistor (HEMT) Based on Dimensions Downscaling
This paper aims to enhance the performance of the High Electron Mobility Transistor (HEMT) according to downscaling dimensions based on the electrical properties and semiconductor materials (GaN, Si3N4, ALGaN and Si). This is to solve difficulties with reducing dimensions and ensuring HEMT has the highest performance possible. This goal was met when the physical scaling restrictions of channel diameters for different HEMTs were concurrently shrunk without compromising their performance. A simula-tion study was done using four variable factors (length, width, of the channel and length, width of the source and drain). Three electrical characteristics were used to assess the impact of altering dimensions on the performance of each kind of HEMT: threshold voltage Vt, ON-state/OFF-state current (ION/IOFF) ratio, and transconductance gm. To conduct experimental simulations under the specified situation, the well-known Silvaco TCAD simulation tool was used. The acquired simulation results revealed that the optimum performance for the downscaling device was achieved at the channel length of 1.6μm, the channel width of 0.3μm, the length of source and drain is 0.4μm and finally the width of source and drain is 0.05 μm
Information security: Listening to the perspective of organisational insiders
Aligned with the strategy-as-practice research tradition, this article investigates how organisational insiders understand and perceive their surrounding information security practices, how they interpret them, and how they turn such interpretations into strategic actions. The study takes a qualitative case study approach, and participants are employees at the Research & Development department of a multinational original brand manufacturer. The article makes an important contribution to organisational information security management. It addresses the behaviour of organisational insiders – a group whose role in the prevention, response and mitigation of information security incidents is critical. The article identifies a set of organisational insiders’ perceived components of effective information security practices (organisational mission statement; common understanding of information security; awareness of threats; knowledge of information security incidents, routines and policy; relationships between employees; circulation of stories; role of punishment provisions; and training), based on which more successful information security strategies can be developed
Salivary neuron specific enolase: an indicator for neuronal damage in patients with ischemic stroke and stroke-prone patients
Background: The blood-brain barrier is compromised in patients with stroke. The release of neuro-biochemical protein markers, such as neuron specific enolase (NSE) into the circulation may allow the pathophysiology and prognosis of patients with cerebrovascular diseases to be evaluated further. The present study was designed to measure the marker of neuronal damage, NSE, in saliva and serum of patients with acute ischemic stroke and patients with stroke related diseases as a diagnostic and/or monitoring tool for early prediction of ischemic stroke. Methods: Salivary and serum NSE concentrations were measured in 150 individuals. Fifty were patients recently diagnosed as having ischemic stroke, 75 were gender and age-matched risk-group patients (patients with hypertension, type 2 diabetes and ischemic heart disease). Another 25 were gender and age-matched healthy controls. Results: Salivary and serum NSE concentrations were significantly higher than that of healthy controls. The cut-off threshold for salivary NSE of 3.7 μg/L was optimum, showing 80% accuracy for differentiation of ischemic stroke from normal individuals. Conclusions: Salivary NSE (alone or in combination with serum) can be used as a valuable diagnostic and possibly prognostic tool for measurement of neuronal damage in patients with stroke and stroke-related diseases. Clin Chem Lab Med 2009;47:1519–24.Peer Reviewe
PIK3CB and K-ras in oral squamous Cell carcinoma. A possible cross-talk!
Background: PIK3 and K-ras are signal transducing proteins involved and mediating many responses related to cell cycle growth regulation. Until date, there has been only limited evidence about the expression of K-ras and PKI3CB in oral squamous cell carcinoma (OSCC). AIMS : This study aimed to examine both proteins in OSCC and their relation to clinic- pathological findings. Setting and Design: A total of 31 formalin-fixed paraffin-embedded specimens of OSCC were selected in this study. PIK3CB and K-ras expressions were detected using standard immunohistochemical techniques. Materials and Methods: PIK3CB and k-ras immune reactivity was semi-quantitatively evaluated in at least five representative fields at 400X magnification and recorded as percentage of PIK3CB and k-ras positive tumor cells over the total number of cells examined in the same area. Results and Conclusion: All examined specimens of OSCC were positive for monoclonal antibodies directed against PIK3CB and K-ras proteins especially at advanced stage of the disease. No significant relation was observed between the tested proteins and the clinic-pathological findings of OSCC; however a highly significant direct relationship was observed between K-ras and PIK3CB. This lead to conclusion that both K-ras and PIK3CB signaling pathway were activated in the advanced stage of OSCC, and possibly a cross-talk between them. This could make these mutant proteins a potential target for an effective molecular therapy
Enhancement Performance of High Electron Mobility Transistor (HEMT) Based on Dimensions Downscaling
This paper aims to enhance the performance of the High Electron Mobility Transistor (HEMT) according to downscaling dimensions based on the electrical properties and semiconductor materials (GaN, Si3N4, ALGaN and Si). This is to solve difficulties with reducing dimensions and ensuring HEMT has the highest performance possible. This goal was met when the physical scaling restrictions of channel diameters for different HEMTs were concurrently shrunk without compromising their performance. A simula-tion study was done using four variable factors (length, width, of the channel and length, width of the source and drain). Three electrical characteristics were used to assess the impact of altering dimensions on the performance of each kind of HEMT: threshold voltage Vt, ON-state/OFF-state current (ION/IOFF) ratio, and transconductance gm. To conduct experimental simulations under the specified situation, the well-known Silvaco TCAD simulation tool was used. The acquired simulation results revealed that the optimum performance for the downscaling device was achieved at the channel length of 1.6μm, the channel width of 0.3μm, the length of source and drain is 0.4μm and finally the width of source and drain is 0.05 μm
Comparison of Propensity toward Water Treeing in XLPE Insulated Power Cables Produced in Arab Gulf Countries
Towards Extended Gate Field Effect Transistor-Based Radiation Sensors: Impact of Thicknesses and Radiation Doses on Al-Doped Zinc Oxide Sensitivity
Radiation measurements are critical in radioanalytical, nuclear chemistry, and biomedical physics. Continuous advancement in developing economical, sensitive, and compact devices designed to detect and measure radiation has increased its capability in many applications. In this work, we presented and investigated the performance of a cost-effective X-ray radiation detector based on the extended gate field effect transistors (EGFET). We examined the sensitivity of Al-doped Zinc oxide (AZO) of varying thicknesses, fabricated by chemical bath deposition (CBD), following X-ray irradiation with low and high doses. EGFETs were used to connect samples for their detection capabilities. As a function of the absorbed dose, the response was analyzed based on the threshold voltage shift, and the sensitivity of each device was also evaluated. We demonstrated that thin films are less sensitive to radiation than their disk-type EG devices. However, performance aspects of the devices, such as radiation exposure sensitivity and active dosage region, were found to be significantly reliant on the composition and thickness of the materials used. These structures may be a cost-effective alternative for real-time, room-temperature radiation detectors
Traumatic Injuries of the Dorso-lumbar Spine, Review of Surgical Approaches
In this review we supply information on medical methods for thoraco-lumbar spine fracture management, their efficiency and complication rates, based on previously published researches and also give background information on epidemiology and classification of thoraco-lumbar fractures. We conducted a narrative review over the literature using electronic databases as; MEDLINE, and EMBASE for studies involving data on Dorso-lumbar Spine traumatic injuries, published in September 2019. Spine fractures account for a large portion of musculoskeletal injuries worldwide. A classification of back cracks is essential in order to establish a typical language for therapy indicators and results. Clinical exam, mechanism of injury, and imaging are heavily trusted to choose regarding medical versus non-surgical management