8 research outputs found

    Novel Thermal Coating for High-Speed Airplanes

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    In comparison to various other materials, Carbon Fiber, specifically Carbon Fiber Reinforced Polymers (CFRP), is pre-eminent amongst other materials for use on aeronautical systems. Due to its high specific strength (strength-to-weight ratio), CFRP is prominent for carrying heavy loads while maintaining a lightweight build. However, when influenced by heat resulting from air resistance, CFRP is known to undergo serious degradation that would significantly decrease the effectiveness of the polymers. To prevent this degradation and maintain the strength of the CFRP, thermal protective layers (TPLs) are designed to shield the CFRP from heat exposure. This research is focused on the examination of the effectiveness of a specific hybrid TPL composed of epoxy resins and buckypaper (carbon nanotubes). Heat gun and heating plate tests will be used at temperatures of 200-250°C to examine these specific properties at these temperatures. The effectiveness of the specific thermal resistance of TPL will be examined by analysis of its ability to successfully cause heat dispersion across the face surface with minimal heat allowed through the axis perpendicular to the front surface. Front and back surface temperature measurements will be performed to test these properties from both contact and non-contact temperature measuring devices. Additionally, there will also be thermal composite analysis performed through finite element analysis (FEA) simulations on Ansys using the steady-state thermal analysis system. To supplement the thermal property examination, the mechanical strength properties of these composites will also be analyzed before and after heat exposure through FEA simulations on Ansys using the static structural simulation analysis system. This mechanical analysis will allow for a stronger comprehension of the thermal protection’s effectiveness in improving the Carbon Fiber’s retention of strength after heat exposure. The results from the experiment and simulation will be collectively used to determine the TPL’s potential success in the aerospace industry

    Radiographic knee osteoarthritis in ex-elite table tennis players

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    <p>Abstract</p> <p>Background</p> <p>Table tennis involves adoption of the semi-flexed knee and asymmetrical torsional trunk movements creating rotational torques on the knee joint which may predispose players to osteoarthritis (OA) of the knee. This study aims to compare radiographic signs of knee OA and associated functional levels in ex-elite male table tennis players and control subjects.</p> <p>Methods</p> <p>Study participants were 22 ex-elite male table tennis players (mean age 56.64 ± 5.17 years) with 10 years of involvement at the professional level and 22 non-athletic males (mean age 55.63 ± 4.08 years) recruited from the general population. A set of three radiographs taken from each knee were evaluated by an experienced radiologist using the Kellgren and Lawrence (KL) scale (0-4) to determine radiographic levels of OA severity. The intercondylar distance was taken as a measure of lower limb angulation. Participants also completed the pain, stiffness, and physical function categories of the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) 3.1 questionnaire.</p> <p>Results</p> <p>The results showed 78.3% of the ex-elite table tennis players and 36.3% of controls had varying signs of radiographic knee OA with a significant difference in the prevalence levels of definite radiographic OA (KL scale > 2) found between the two groups (<it>P </it>≀ 0.001). Based on the WOMAC scores, 68.2% of the ex-elite table tennis players reported symptoms of knee pain compared with 27.3% of the controls (<it>p </it>= 0.02) though no significant differences were identified in the mean physical function or stiffness scores between the two groups. In terms of knee alignment, 73.7% of the ex-elite athletes and 32% of the control group had signs of altered lower limb alignment (genu varum) (<it>p </it>= 0.01). Statistical differences were found in subjects categorized as having radiographic signs of OA and altered lower limb alignment (<it>p </it>= 0.03).</p> <p>Conclusions</p> <p>Ex-elite table tennis players were found to have increased levels of radiological signs of OA in the knee joint though this did not transpire through to altered levels of physical disability or knee stiffness in these players when compared with subjects from the general population suggesting that function in these players is not severely impacted upon.</p

    Videographic analysis of blink dynamics in patients with chronic progressive external ophthalmoplegia, myogenic ptosis, and facial nerve palsy using smartphone camera: A comparative analysis

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    Abstract Background and Aims Congenital myogenic ptosis (CMP), chronic progressive external ophthalmoplegia (CPEO), and facial nerve palsy (FNP) are among the disorders which can seriously affect the blink dynamics of patients. Smartphone videography is a simple, convenient, and inexpensive way to capture eyelid movement. This study has measured and compared a variety of blink dynamics in these patients compared to healthy controls using 2‐dimensional smartphone videography to enhance the utility of this method in both clinical and research settings. Methods A total of 30 adult participants with a complaint of impaired eyelid movements including 10 with CMP, 10 with CPEO, and 10 with unilateral FNP, as well as 10 healthy controls were recruited. Using a smartphone camera with a resolution of 240 frames per second in 720 p, various blink dynamics were measured. Results All case groups had significantly lower values of peak and average closing velocities, average opening velocity, and palpebral aperture and significantly higher values of eyelid closing duration, compared to controls. FNP participants also had significantly lower values in the full blink rate and peak opening velocity (POV) measures, and CPEO patients showed significantly lower values in the POV. Other measures were not statistically significantly different compared to healthy controls. Conclusion Our results indicated that all patients with CMP, FNP, and CPEO had different blinking dynamics compared to healthy controls, which is consistent with previous studies. Smartphone videography has achieved sufficient resolution and frame‐rate to provide valuable information and anatomic details for clinical and research purposes. Further studies could utilize smartphone videography for further investigation and confirmation of the methodology in various conditions

    Dietary antioxidants and liver enzymes in Rafsanjan, a Region in Southeast Iran

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    Abstract Oxidative stress has been considered the main contributor to liver injury. Dietary antioxidants would be expected to improve liver function. The hepatoprotective effects of antioxidants are controversial. In the present study, the associations of some dietary antioxidants and the levels of serum liver enzymes were examined. This cross-sectional study was conducted using the Rafsanjan Cohort Study (RCS) data as a population-based prospective cohort which is a part of the Prospective Epidemiological Research Studies in IrAN (PERSIAN). A total of 9942 participants aged 35–70 years old were included in this study. Among this population, 4631 (46.59%) were male, and 5311 (53.42%) were female. Dietary intakes were collected by a validated food frequency questionnaire (FFQ) with 128 items. Aspartate transaminase (AST), Alanine transaminase (ALT), Îł-glutamyl transferase (GGT), and Alkaline phosphatase (ALP) were measured by a biotecnica analyzer. Dichotomous logistics regression models were used to investigate the association between the elevated liver enzymes and intake of dietary antioxidants using crude and adjusted models. In the adjusted model, in subjects with higher consumption of Se, Vit A, Vit E, ÎČ-carotene, α-carotene, and ÎČ-cryptoxanthin, the odds ratios of elevated ALP were decreased compared to the reference group (ORs 0.79 (0.64–0.96), 0.80 (0.66–0.98), 0.73 (0.60–0.89), 0.79 (0.64–0.96), 0.78 (0.64–0.95), 0.80 (0.66–0.98), and 0.79 (0.64–0.98), respectively). Subjects with higher consumption of Se, Vit A, Vit E, and provitamin A carotenoids (ÎČ-carotene, α-carotene, ÎČ-cryptoxanthin) showed decreased odds of elevated ALP. These findings support the hypothesis that Se, Vit A, Vit E, and provitamin A carotenoids may be associated with improvements in ALP and act as suppressors against the development of liver injury

    Establishment and Characterization of Primary Cultures from Iranian Oral Squamous Cell Carcinoma Patients by Enzymatic Method and Explant Culture

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    Objectives: Oral Squamous Cell Carcinoma (OSCC) is the most frequent oral cancer worldwide. It is known as the eighth most common cancer in men and as the fifth most common cancer in women. Cytogenetic and biochemical studies in recent decades have emphasized the necessity of providing an appropriate tool for such researches. Cancer cell culture is a useful tool for investigations on biochemical, genetic, molecular and immunological characteristics of different cancers, including oral cancer. Here, we explain the establishment process of five primary oral cancer cells derived from an Iranian population. Materials and Methods: The specimens were obtained from five oral cancer patients. Enzymatic, explant culture and magnetic-activated cell sorting (MACS) methods were used for cell isolation. After quality control tests, characterization and authentication of primary oral cancer cells were performed by short tandem repeats (STR) profiling, chromosome analysis, species identification, and monitoring the growth, morphology and the expression of CD326 and CD133 markers. Results: Five primary oral cancer cells were established from an Iranian population. The flow cytometry results showed that the isolated cells were positive for CD326 and CD133 markers. Furthermore, the cells were free from mycoplasma, bacterial and fungal contamination. No misidentified or cross-contaminated cells were detected by STR analysis. Conclusions: Human primary oral cancer cells provide an extremely useful platform for studying carcinogenesis pathways of oral cancer in Iranian population. They may be helpful in explaining the ethnic differences in cancer biology and the individuality in anticancer drug response in future studies.

    Regeneration of the peripheral nerve via multifunctional electrospun scaffolds

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