431 research outputs found

    Energy regeneration from suspension dynamic modes and self-powered actuation

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    Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper concerns energy harvesting from vehicle suspension systems. The generated power associated with bounce, pitch and roll modes of vehicle dynamics is determined through analysis. The potential values of power generation from these three modes are calculated. Next, experiments are carried out using a vehicle with a four jack shaker rig to validate the analytical values of potential power harvest. For the considered vehicle, maximum theoretical power values of 1.1kW, 0.88kW and 0.97kW are associated with the bounce, pitch and roll modes, respectively, at 20 Hz excitation frequency and peak to peak displacement amplitude of 5 mm at each wheel, as applied by the shaker. The corresponding experimentally power values are 0.98kW, 0.74kW and 0.78kW. An experimental rig is also developed to study the behavior of regenerative actuators in generating electrical power from kinetic energy. This rig represents a quarter-vehicle suspension model where the viscous damper in the shock absorber system is replaced by a regenerative system. The rig is able to demonstrate the actual electrical power that can be harvested using a regenerative system. The concept of self-powered actuation using the harvested energy from suspension is discussed with regard to applications of self-powered vibration control. The effect of suspension energy regeneration on ride comfort and road handling is presented in conjunction with energy harvesting associated with random road excitations.Peer reviewedFinal Accepted Versio

    MicroRNA expression analysis in endometriotic serum treated mesenchymal stem cells

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    Endometriosis is defined by presence of endometrial-like-tissue outside the uterus. Recently, ectopic endometriotic lesions have been suggested to originate by abnormal differentiation of endometrial mesenchymal stem cells (eMSCs). MicroRNAs (miRNAs) play an important role in the pathophysiology of endometriosis. Through a PCR array approach, we aimed to assess the differential expression of microRNAs in human eMSC treated in culture with sera derived from women with severe endometriosis. Sera were collected from five patients with severe endometriosis and three control women and added individually in the culture medium to conduct experimental and control eMSC sets, respectively. Regular microscopic follow-up for cell morphology was performed. SYBR Green based real-time PCR array was used to assess the expression of 84 miRNAs. Bioinformatics analysis was done to predict the target genes of the significantly dysregulated miRNAs and their enriched biological processes and pathways. Thirty-two miRNAs were found significantly dysregulated in experimental cultures. Functional enrichment analysis revealed several endometriosis associated biological processes and pathways were enriched by target genes of these miRNAs. In conclusion, treatment of human eMSCs with sera of severe endometriosis cases affects the expression of certain miRNAs and their target genes. This may result in altering cell functions and consequently, endometriosis development

    General versus Spinal Anesthesia: Comparison of Complications and Outcomes in Lumbar Laminectomy Surgery

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    Background: This study was designed to compare the complications and outcomes of lumbar laminectomy surgery performed by general and spinal anesthesia. Methods: In this prospective study, 110 patients with two common degenerative spinal diseases (lumbar discopathy and spinal canal stenosis) were enrolled. All the patients were operated in Bahonar hospital, Kerman City, Iran, via either spinal or general anesthesia by a unique surgeon. Intraoperative and postoperative complications and outcomes were compared between the two groups using descriptive and analytic statistics methods. Results: Surgeon satisfaction of anesthesia, blood loss, and admission time were not statistically significant between the groups. But, postoperative pain at recovery room, and 1, 2, and 12 hours after the operation was significantly higher in general anesthesia compared to lumbar anesthesia. Morphine request was also significantly higher with general anesthesia (P < 0.001). Conclusion: This study demonstrates that general anesthesia has greater pain in comparison with spinal anesthesia that should be considered in degenerative spinal diseases surgeries. Keywords Laminectomy; Lumbar region; surgery; General anesthesia; Spinal anesthesi

    The possible role of heat shock protein-70 induction in collagen-induced arthritis in rats

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    Aim This study aimed to evaluate the possible role of heat shock protein-70 (HSP70) induction by 17-allylaminodemethoxygeldanamycin (17-AAG) in collagen-induced arthritis in rats. Material and methods Male Wistar rats were divided into five groups (n = 10/group) and were treated intraperitoneally twice a week for 4 weeks, namely normal control (saline), arthritis control (AR; saline), AR + 17-AAG, AR + methotrexate (MTX), and AR + 17-AAG + MTX. At the end of the treatments, arthritic score was determined and then the animals were sacrificed. Erythrocyte sedimentation rate (ESR), serum levels of HSP70, interleukin-17 (IL-17), tumor necrosis factor-alpha (TNF-α), rheumatic factor (RF), C-reactive protein (CRP), malondialdehyde (MDA), glutathione peroxidase (GPx), and matrix metalloproteinase-9 (MMP-9) were determined. Results In the AR group, all parameters increased significantly, except for GPx, which showed a pronounced decrease. The 17-AAG and/or MTX treatments significantly reduced arthritic score, ESR, IL-17, TNF-α, RF, CRP, MDA, and MMP-9 with significant increase in GPx compared to the AR group. The HSP70 level was significantly higher in the AR + 17-AAG and the AR + 17-AAG + MTX groups but significantly lower in the AR + MTX group as compared to the AR group. Also, it was significantly lower in the AR + MTX group as compared to the AR + 17-AAG group. Conclusion We concluded that HSP70 induction by 17-AAG attenuated the inflammatory process in a rheumatoid arthritis (RA) model induced by collagen, which suggested that HSP70 inducers can be promising agents in the treatment of RA

    A Critical Review on the Book The Fantasy Film

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    The fantasy genre is of the most problematic genres in cinema and has been neglected by cinema adherents for decades. Although the first so-called fantasy works date back to the early years of cinema and the works of George Millis, by the late 1970s, for many reasons, including the relatively high cost of producing such works and the lack of progress in cinematic technology, fewer fantasy works appeared in cinema. One of the important theoretical issues about fantasy works is the confusion of such films with other works of cinema such as horror and science fiction. An accurate definition of the concept of fantasy is problematic; Therefore, considering the creation of brilliant works that carry the attribute of fantasy after the 21st century, and the audience's interest in these works in recent times, as well as the growth of cinematic technology, find specific frameworks to determine the characteristics of fantasy works and distinguish them from other similar works such as science-fiction and horror seem necessary. The Importance of “The Fantasy Film” book by” “Katherine A. Fowkes”, the translation of “Ali Zafar Ghahremani Nejad” is due to the attempt to find answers to these questions and ambiguities that this kind of works have created among cinema people and therefore it is necessary to examine how the author explains the concept of fantasy. This book was published in 2016 by Nashrbidgol in 324 pages

    An Efficient In Vitro Propagation Protocol of Cocoyam [Xanthosoma sagittifolium (L) Schott]

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    Sprouted corm sections of “South Dade” white cocoyam were potted and maintained in a greenhouse for 8 weeks. Shoot tips of 3–5 mm comprising the apical meristem with 4–6 leaf primordial, and approximately 0.5 mm of corm tissue at the base. These explants were treated to be used into the culture medium. A modified Gamborg's B5 mineral salts supplemented with 0.05 μM 1-naphthaleneacetic acid (NAA) were used throughout the study. Thidiazuron (TDZ) solution containing 0.01% dimethyl sulfoxide (DMSO) was used. Erlenmeyer flasks and test tubes were used for growing cultures. The effect of different media substrate, thidiazuron, and the interaction between TDZ and Benzylaminopurine (BAP) on cocoyam culture were tested. Results indicated that cocoyam can be successfully micropropagated in vitro through various procedures. All concentrations tested (5–20 μM BAP and 1–4 μM TDZ) produced more axillary shoots per shoot tip than the control without cytokinins. Greater proliferation rates were obtained through the use of 20 μM BAP and 2 μM TDZ, respectively, 12 weeks from initiation. Shoots produced with BAP were larger and more normal in appearance than those produced with TDZ, which were small, compressed, and stunted. The use of stationary liquid media is recommended for economic reasons

    The New Perceptions on Life of Iranian Patients with Ankylosing Spondylitis: A Qualitative Study

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    Various studies suggest that ankylosing spondylitis (AS) as a chronic inflammatory disease with many disabilities can have impacts on different aspects of patients’ life. Despite many quantitative studies, only few qualitative studies have thus far been published on this subject. For the first time, the present study aims at gaining insight into the life experience of Iranian AS patients. We performed a content analysis through semi-structured interviews with twenty-eight patients diagnosed with AS, including three females and twenty-five males with an average age of 38.5 years, to gain insight into their experiences. Whatever the patients expressed was written and transcribed verbatim. Then, we did analysis of the results after each interview. The detailed information completely extracted from the interviews was classified as sub-themes and main themes. Three main themes were identified by the analysis: (i) “Always with pain” describing the effects were found in regard to pain on patients’ life, (ii) “The perceived limitation” describing many difficulties that people may face in the society as a result of their disease, and (iii) “Fearing the unknown future” which implies to both patients and their families have concerns about the future and what will happen. Our research findings in line with other qualitative studies showed that AS disease puts a heavy and intolerable burden on patients and their family. It seems that the experiences of people living with AS can be useful to meet challenges caused by the disease and it can enhance their coping with the disease

    Free Vibration and Stability of Axially Functionally Graded Tapered Euler-Bernoulli Beams

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    Structural analysis of axially functionally graded tapered Euler-Bernoulli beams is studied using finite element method. A beam element is proposed which takes advantage of the shape functions of homogeneous uniform beam elements. The effects of varying cross-sectional dimensions and mechanical properties of the functionally graded material are included in the evaluation of structural matrices. This method could be used for beam elements with any distributions of mass density and modulus of elasticity with arbitrarily varying cross-sectional area. Assuming polynomial distributions of modulus of elasticity and mass density, the competency of the element is examined in stability analysis, free longitudinal vibration and free transverse vibration of double tapered beams with different boundary conditions and the convergence rate of the element is then investigated
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