492 research outputs found

    Fault evaluation and adaptive threshold detection of helicopter pilot using bond graph method

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    Hitherto, in the field of aerospace science and industry, some acceptable results from control behavior of human operator (pilot), are caught using usual methods. However, very fewer research, has been done based on personal characteristics. The performed investigations, show that many of happened faults (especially in helicopter), would result to the loss of natural behavior of system, and eventually some fatal accidents. Therefore, development of tools of assessment of pilot in this dynamical system, is one of the vital necessities. The tools of management of system, should be such that, can show the fault. The object of this paper is assessment of the modelled pilot in a simulator, in presence of standard fly inputs. For this purpose the performance of the pilot for collective and cyclic control of the helicopter, is investigated. The used methods are based on mathematical models and by bond graph modeling method. The existence of uncertainties in the simulator system and the modeled pilot’s behavior, causes creation of fault threshold, for human behavior of pilot. By having these fault thresholds, the improper actions of the pilot, cause creation of behavioral reminders, which can perform the assessment of the pilot. By other speech, using fault detection and isolation (FDI), by bond graph method in state space, the assessment is performed and a non-zero reminder shows existence of fault in the system. Therefore, in this paper there is the novelties for modeling the pilot’s body performance and the helicopter’s systems integrally and designing a fault detection system for it that shows the source of the fault, and obviously it can be useful in aviation industry.Keywords: Helicopter Control, Fault Detection and Isolation, Human Fault, Bond Grap

    Digestive enzymes activity and growth indices of rainbow trout (Oncorhynchus mykiss) fed diets supplemented with silymarin and Nickle Oxide nanoparticles

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    There is growing concern regarding nano-sized material discharge into water bodies and their subsequent toxicity to aquatic lives owing to increasingly rapid development and industrial applications of nanoparticles. This study evaluates the oral prescription of silymarin and Nickel Oxide nanoparticles in rainbow trout with an emphasis on growth indices and digestive enzymes activity. To that end, 1200 fish (3.83±0.01g) were randomly allotted into 8 distinct treatments including control group without any supplemental dietary Nickel Oxide nanopartcles or silymarin and the remaining seven experimental groups comprised of different combinations of Nickel Oxide nanoparticles (0, 100 and 500 mg /kg feed) and silymarin (0 and 1 g /kg feed) in the first and second month of the trial. All treatments were carried out in trplicate and the experiment lasted for 60 days. Results showed that the highest amylase activity was recorded in treatment 6 (16.56±1.00) (0 mg Nickel nanoparticle along with 1 g silymaryn - 500 mg Nickel nanoparticle and 1 g silymarin) which significantly differed from treatments 5 (0 mg Nickel Oxide nanoparticles and 1 mg silymarin-100 mg Nickel Oxide nanoparticles with 1 mg silymarin), 7 and 8 (fed diets containing 100 and 500 mg Nickel Oxide nanoparticles, respectively) (P≤0.05). The highest alkaline protease activity was observed in treatment 1 (0.54±0.05) (without any supplemental Nickel or silymarin), which was significantly different from those of treatments 7 and 8 (P≤0.05). The highest lipase activity was reported for treatment 4 (1.03±0.04) (500 mg Nickel nanoparticle with 1 g silymaryn- 0 mg nanoparticle and 1 g silymarin) which was significantly different from other treatments (P≤0.05). The results showed that simultaneous use of Nickel nanoparticle and silymarin in treatments 3, 4, 5 and 6 led to higher digestive enzymes activities in comparison to treatments 7 and 8. However, growth indices did not show any noticeable differences amongst studied treatments. It seems that in a long term exposure to Nickel Oxide nanoparticles and simoltanoues dietary silymarin inclusion, it would also be possible to observe differences in growth and nutritional indices, requiring further clarification

    Studying the chronic effects of silver nanoparticles on survival, growth rate and reproductive traits of Urmia Lake Artemia (Artemia urmiana)

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    The application and environmental hazards of nanotechnology to aquatic species are increasingly growing. To address the issue, the present study was designed and carried out to elucidate the toxic effects of silver nanoparticles on growth, survival and reproductive traits of Artemia urmiana. The experiment consisted of five treatments, namely control group and those exposed to 0.001, 0.01, 0.1 and 1 mgl-1 silver nanoparticles, with four respective replicates. To do so, 500 newly hatched nauplii were counted and transferred to 1 liter containers exposing to various concentrations of the silver nanoparticles. Microalgae Dunaliella tertiolecta and zymogenic was used to feed Artemia. Growth and survival rates were recorded on days 8, 11, 17, 20 and 23. After sexual maturation, Artemia were transferred to a new environment free from nanoparticles and their reproductive traits were studied. Results showed that higher concentrations of silver nanoparticles led to lower survival rate and augmented growth rate of Artemia (p<0.05). Regarding reproductive traits, group exposed to 1mgl-1 silver nanoparticles showed the lowest total offspring, offspring per day, offspring per brood and life span (p<0.05). In conclusion, the discharge of silver nanoparticles even at lower concentrations would undesirably influence reproductive cycle of A. urmiana and result in lower survival and reproductive performance of the animal

    Efficacy of fentanyl transdermal patch in the treatment of chronic soft tissue cancer pain

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    Background: Cancer pain may be a major problem for health care providers worldwide. According to different studies reporting the pain severity, one-third of patients reported to have moderate to severe pain. Management of cancer pain is one of the most important goals of palliative care. Recently, different research results on the efficacy of opioid analgesics in chronic pain management have played a role to implement standards in pain control by government agencies worldwide. Objectives: This study aimed to investigate the efficacy of fentanyl transdermal patch in the treatment of chronic soft tissue cancer pain. Patients and Methods: In a prospective descriptive study, we evaluated 86 patients with soft tissue tumors with chronic pain referred to cancer institute of Imam Khomeini Hospital, Tehran, Iran, during 2006-2007. For all patients, transdermal fentanyl patch (25 μg/h) was administered. The appearance of patches was the same. Pain severity was measured by Visual Analogue Scale (VAS) initially and 24, 48 and 72 hours after the initiation of treatment. Results: Patients' characteristics and VAS score before the treatment were not significantly different (P > 0.05). According to our findings, the pain severity was significantly reduced after the treatment (P = 0.001). The incidence of adverse events in patients was significantly high (72). The most common adverse events were sleepiness, nausea and vomiting in 30.2 and 18.6, respectively. Conclusions: Transdermal fentanyl patch was an effective and safe method to reduce pain in patients with soft tissue tumors. Moreover, it could improve the quality of life in these patients, but adverse events occurred in approximately 72 of patients. © 2015, Iranian Society of Regional Anesthesia and Pain Medicine (ISRAPM)

    Stimulation of oxytocin receptor during early reperfusion period protects the heart against ischemia/reperfusion injury: The role of mitochondrial ATP-sensitive potassium channel, nitric oxide, and prostaglandins

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    Postconditioning is a simple and safe strategy for cardioprotection and infarct size limitation. Our previous study showed that oxytocin (OT) exerts postconditioning effect on ischemic/reperfused isolated rat heart. The aim of this study was to investigate the involvement of OT receptor, mitochondrial ATP-sensitive potassium channel (mKATP), nitric oxide (NO) and cyclooxygenase (COX) pathways in OT postconditioning. Isolated rat hearts were divided into10 groups and underwent 30 min of regional ischemia followed by 120 min of reperfusion (n =6). In I/R (ischemia/reperfusion) group, ischemia and reperfusion were induced without any treatment. In OT group, oxytocin was perfused 5 min prior to beginning of reperfusion for 25 min. In groups 3-6, atosiban (oxytocin receptor blocker), L-NAME (N-Nitro-L-Arginine Methyl Ester, non-specific nitric oxide synthase inhibitor), 5-HD (5-hydroxydecanoate, mKATP inhibitor) and indomethacin (cyclooxygenase inhibitor) were infused prior to oxytocin administration. In others, the mentioned inhibitors were perfused prior to ischemia without oxytocin infusion. Infarct size, ventricular hemodynamic, coronary effluent, malondialdehyde (MDA) and lactate dehydrogenase (LDH) were measured at the end of reperfusion. OT perfusion significantly reduced infarct size, MDA and LDH in comparison with IR group. Atosiban, 5HD, L-NAME and indomethacin abolished the postconditioning effect of OT. Perfusion of the inhibitors alone prior to ischemia had no effect on infarct size, hemodynamic parameters, coronary effluent and biochemical markers as compared with I/R group. In conclusion, this study indicates that postconditioning effects of OT are mediated by activation of mKATP and production of NO and Prostaglandins (PGs). © 2015 Tehran University of Medical Sciences. All rights reserved

    A new approach to urban water management: Safe and sure

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    This paper introduces a new approach to water management that is 'Safe & SuRe'. This includes presenting a conceptual framework to link the emerging threats of climate change and variability, rapid urbanization and population growth, energy constraint and tightening environmental regulation through to their consequences on social, economic and environmental recipients. The framework allows identification of the role and need for mitigation, adaptation and coping strategies. The paper proposes definitions and discusses what engineering, organizational and/or social options can potentially develop the degree of resilience and sustainability needed to deal with these 21st century threats. The paper goes on to propose how these approaches might be objectively assessed and identifies gaps in our knowledge that require further research

    The abundance of endofungal bacterium Rhizobium radiobacter (syn. Agrobacterium tumefaciens) increases in its fungal host Piriformospora indica during the tripartite sebacinalean symbiosis with higher plants

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    Rhizobium radiobacter (syn. Agrobacterium tumefaciens, syn. "Agrobacterium fabrum") is an endofungal bacterium of the fungal mutualist Piriformospora (syn. Serendipita) indica (Basidiomycota), which together form a tripartite Sebacinalean symbiosis with a broad range of plants. R. radiobacter strain F4 (RrF4), isolated from P. indica DSM 11827, induces growth promotion and systemic resistance in cereal crops, including barley and wheat, suggesting that R. radiobacter contributes to a successful symbiosis. Here, we studied the impact of endobacteria on the morphology and the beneficial activity of P. indica during interactions with plants. Low numbers of endobacteria were detected in the axenically grown P. indica (long term lab-cultured, lcPiri) whereas mycelia colonizing the plant root contained increased numbers of bacteria. Higher numbers of endobacteria were also found in axenic cultures of P. indica that was freshly re-isolated (riPiri) from plant roots, though numbers dropped during repeated axenic re-cultivation. Prolonged treatments of P. indica cultures with various antibiotics could not completely eliminate the bacterium, though the number of detectable endobacteria decreased significantly, resulting in partial-cured P. indica (pcPiri). pcPiri showed reduced growth in axenic cultures and poor sporulation. Consistent with this, pcPiri also showed reduced plant growth promotion and reduced systemic resistance against powdery mildew infection as compared with riPiri and lcPiri. These results are consistent with the assumption that the endobacterium R. radiobacter improves P. indica's fitness and thus contributes to the success of the tripartite Sebacinalean symbiosis

    On/off-switchable anti-neoplastic nanoarchitecture.

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    Throughout the world, there are increasing demands for alternate approaches to advanced cancer therapeutics. Numerous potentially chemotherapeutic compounds are developed every year for clinical trial and some of them are considered as potential drug candidates. Nanotechnology-based approaches have accelerated the discovery process, but the key challenge still remains to develop therapeutically viable and physiologically safe materials suitable for cancer therapy. Here, we report a high turnover, on/off-switchable functionally popping reactive oxygen species (ROS) generator using a smart mesoporous titanium dioxide popcorn (TiO2 Pops) nanoarchitecture. The resulting TiO2 Pops, unlike TiO2 nanoparticles (TiO2 NPs), are exceptionally biocompatible with normal cells. Under identical conditions, TiO2 Pops show very high photocatalytic activity compared to TiO2 NPs. Upon on/off-switchable photo activation, the TiO2 Pops can trigger the generation of high-turnover flash ROS and can deliver their potential anticancer effect by enhancing the intracellular ROS level until it crosses the threshold to open the 'death gate', thus reducing the survival of cancer cells by at least six times in comparison with TiO2 NPs without affecting the normal cells

    Multiple cavernous hemangiomas presenting as orbital apex syndrome

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    A 41-year-old man presented with a 7-year history of gradually increasing right proptosis and a 2-year history of decreased vision and limited eye movements. Right proptosis (11 mm), limitation of movement in all gazes, anisocoria, and visual impairment implied orbital apex compression. Computed tomography showed several distinct lesions with mild delayed enhancement extending to the orbital apex. Through a lateral orbitotomy, 10 discrete hemangiomas were removed uneventfully. Histopathologic findings were consistent with cavernous hemangioma in all tumors removed. Proptosis resolved after surgery at 3 to 4 weeks. Visual acuity was unchanged (20/25), and eye movement significantly improved at last follow-up, 15 months after surgery. ©2005 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc
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