20 research outputs found

    Using TurbSim stochastic simulator to improve accuracy of computational modelling of wind in the built environment

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    Small wind turbines are often sited in more complex environments than in open terrain. These sites include locations near buildings, trees and other obstacles, and in such situations, the wind is normally highly three-dimensional, turbulent, unstable and weak. There is a need to understand the turbulent flow conditions for a small wind turbine in the built environment. This knowledge is crucial for input into the design process of a small wind turbine to accurately predict blade fatigue loads and lifetime and to ensure that it operates safely with a performance that is optimized for the environment. Computational fluid dynamics is a useful method to provide predictions of local wind flow patterns and to investigate turbulent flow conditions at small wind turbine sites, in a manner that requires less time and investment than actual measurements. This article presents the results of combining a computational fluid dynamics package (ANSYS CFX software) with a stochastic simulator (TurbSim) as an approach to investigate the turbulent flow conditions on the rooftop of a building where small wind turbines are sited. The findings of this article suggest that the combination of a computational fluid dynamics package with the TurbSim stochastic simulator is a promising tool to assess turbulent flow conditions for small wind turbines on the roof of buildings. In particular, in the prevailing wind direction, the results show a significant gain in accuracy in using TurbSim to generate wind speed and turbulence kinetic energy profiles for the inlet of the computational fluid dynamics domain rather than using a logarithmic wind-speed profile and a pre-set value of turbulence intensity in the computational fluid dynamics code. The results also show that small wind turbine installers should erect turbines in the middle of the roof of the building and avoid the edges of the roof as well as areas on the roof close to the windward and leeward walls of the building in the prevailing wind direction

    Liquid nitrogen cryotherapy versus 70 trichloroacetic acid in the treatment of anogenital warts: A randomized controlled trial

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    Background: Cryotherapy is one of the most common and effective treatments of anogenital warts, and trichloroacetic acid is one of the methods commonly used. The aim of this study was to compare the effect of cryotherapy and trichloroacetic acid in the treatment of anogenital warts. Methods: This randomized clinical trial was conducted on patients with anogenital warts. The patients were divided into two groups; one group was treated with liquid nitrogen and the other with 70 trichloroacetic acid. In both groups, the treatment was done every two weeks until complete disappearance of the lesions or for 6 sessions. Results: In this study, 68 patients with anogenital warts were studied. After the 6th session, the cure rate of in the patients treated with trichloroacetic acid (94.1) was higher than the patients treated with cryotherapy (85.3) (P>0.05). Conclusion: It seems that cryotherapy and trichloroacetic acid therapy have similar results in the treatment of anogenital warts. © 2015 Iranian Society of Dermatology

    Quality of life in epileptic patients compared with healthy people

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    Background: Epilepsy is a common chronic neurological disorder that has a great impact on people's lives. Patients with epilepsy are at increased risk for poor Quality of Life (QoL). The objective of this study was to evaluate the QoL of epileptic patients in comparison to healthy persons. Methods: This cross-sectional study was conducted on 52 epileptic patients from Golbu region in Neyshabur (a city in northeast of Iran). Using Short Form Health Survey (SF-36) scale, the data were collected between April and Jun 2012. Every patient were compared with two healthy persons. Epileptic and healthy persons were similar for age, sex and local residence. Pearson's correlation coefficient and t-independent test applied for data analysis through SPSS v. 16 software. Results: Of 52 epileptic patients, 24 were female (46.2) and 28 were male (53.8). The mean±SD age of epileptic patients was 40.92±20.33yr (Rang: 15-86yr). The total mean score of SF- 36 in patient group was 55.88 and in healthy group 68.52and this difference was statistically significant (p < 0.001). Among the different subscales of SF-36 in epileptic patients, the highest and the lowest mean scores were found for social functioning and general health subscales, respectively. The mean scores in patient group in comparison to healthy group were lower in all subscales of SF-36 and these differences were statistically significant in all domains (except role limitations due to physical problems domain and role limitations due to emotional problems domain). Conclusion: The study showed that epilepsy disease has an important role in QoL of patients, thus some interventional programs are necessary to improve their QOL

    Quality of life in epileptic patients compared with healthy people

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    Background: Epilepsy is a common chronic neurological disorder that has a great impact on people's lives. Patients with epilepsy are at increased risk for poor Quality of Life (QoL). The objective of this study was to evaluate the QoL of epileptic patients in comparison to healthy persons. Methods: This cross-sectional study was conducted on 52 epileptic patients from Golbu region in Neyshabur (a city in northeast of Iran). Using Short Form Health Survey (SF-36) scale, the data were collected between April and Jun 2012. Every patient were compared with two healthy persons. Epileptic and healthy persons were similar for age, sex and local residence. Pearson's correlation coefficient and t-independent test applied for data analysis through SPSS v. 16 software. Results: Of 52 epileptic patients, 24 were female (46.2) and 28 were male (53.8). The mean±SD age of epileptic patients was 40.92±20.33yr (Rang: 15-86yr). The total mean score of SF- 36 in patient group was 55.88 and in healthy group 68.52and this difference was statistically significant (p < 0.001). Among the different subscales of SF-36 in epileptic patients, the highest and the lowest mean scores were found for social functioning and general health subscales, respectively. The mean scores in patient group in comparison to healthy group were lower in all subscales of SF-36 and these differences were statistically significant in all domains (except role limitations due to physical problems domain and role limitations due to emotional problems domain). Conclusion: The study showed that epilepsy disease has an important role in QoL of patients, thus some interventional programs are necessary to improve their QOL

    The role of solution heat treatment on corrosion and mechanical behaviour of Mg-Zn biodegradable alloys

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    The mechanical properties and bio-corrosion behaviours of T4 solid solution heat-treated Mg–1.5Zn and Mg–9Zn alloys at 340°C under different heat treatment durations were investigated. In vitro corrosion behaviour of the heat-treated alloys immersed in simulated body fluid (SBF) were measured by electrochemical, hydrogen evolution and mass loss tests. Surface examination and analytical studies were carried out using optical and scanning electron microscopy, EDX, and X-ray diffractometry. The results show that the grains size of both the alloys apparently remained unchanged after T4 treatment. T4 treatment at 340°C for 6?h slightly increased the strength and elongation of Mg–1.5Zn alloy while it significantly improved the strength and elongation of the Mg–9Zn alloy because of the presence of residual Mg51Zn20 and Mg12Zn13 secondary phase at the grain boundary. The results of electrochemical tests show that the corrosion rate of both the alloys decrease with increasing treatment temperature. The result also shows corrosion resistance of both the T4 tread alloys much better than that of as-cast samples. The corrosion mechanism exhibited that the occurrence of galvanic and pitting corrosion, which varied with the alloy composition and treatment time

    Biomolecular Corona Dictates Aβ Fibrillation Process

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    Amyloid beta (Aβ), which forms toxic oligomers and fibrils in brain tissues of patients with Alzheimer's disease, is broadly used as a model protein to probe the effect of nanoparticles (NPs) on oligomerization and fibrillation process. However, majority of the reports in the field, ignored the effect of biomolecular corona on the fibrillogenesis of the Aβ proteins. Biomolecular corona, which is a layer composed of various types of biomolecules that covers surface of NPs upon their interaction with biological fluids, determines the biological fates of NPs. Therefore, during in vivo interaction of NPs with Aβ protein, what the Aβ actually "sees" is the human plasma- and/or cerebrospinal fluid (CSF)-biomolecular coated NPs rather than the pristine surface of NPs. Here, to mimic the in vivo effects of therapeutic NPs as anti-fibrillation agents, we probed the effects of biomolecular corona derived from human CSF and/or plasma on Aβ fibrillation. The results demonstrated that the type of biomolecular corona can dictate the inhibitory or acceleratory effect of NPs on Aβ1-42 and Aβ25-35 fibrillation processes. More specifically, we found that the plasma biomolecular corona coated gold NPs, with sphere and rod shapes, has less inhibitory effects on Aβ1-42 fibrillation kinetics compared to CSF biomolecular corona coated- and pristine- NPs. Opposite results obtained for Aβ25-35 peptide, where the pristine NPs accelerated the Aβ25-35 fibrillation process while corona-coated ones demonstrated an inhibitory effect. In addition, the CSF biomolecular corona had less inhibitory effects than those obtained from plasma. © 2018 American Chemical Society

    Magnetic bio-metal–organic framework nanocomposites decorated with folic acid conjugated chitosan as a promising biocompatible targeted theranostic system for cancer treatment

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    © 2019 Elsevier B.V. In this work, a multifunctional magnetic Bio-Metal-Organic Framework (Fe 3 O 4 @Bio-MOF) coated with folic acid-chitosan conjugate (FC) was successfully prepared for tumor-targeted delivery of curcumin (CUR) and 5-fluorouracil (5-FU) simultaneously. Bio-MOF nanocomposite based on CUR as organic linker and zinc as metal ion was prepared by hydrothermal method in the presence of amine-functionalized Fe 3 O 4 magnetic nanoparticles (Fe 3 O 4 @NH 2 MNPs). 5-FU was loaded in the magnetic Bio-MOF and the obtained nanocarrier was then coated with FC network. The prepared nanocomposite (NC) was fully characterized by high resolution-transmission electron microscope (HR-TEM), field emission scanning electron microscopy (FE-SEM), Dynamic light scattering (DLS), X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), nuclear magnetic resonance (NMR), and UV–vis analyses. In vitro release study showed controlled release of CUR and 5-FU in acidic pH confirming high selectivity and performance of the carrier in cancerous microenvironments. The selective uptake of 5-FU-loaded Fe 3 O 4 @Bio-MOF-FC by folate receptor-positive MDA-MB-231 cells was investigated and verified. The ultimate nanocarrier exhibited no significant toxicity, while drug loaded nanocarrier showed selective and higher toxicity against the cancerous cells than normal cells. SDS PAGE was also utilized to determine the protein pattern attached on the surface of the nanocarriers. In vitro and in vivo MRI studies showed negative signal enhancement in tumor confirming the ability of the nanocarrier to be applied as diagnostic agent. Owing to the selective anticancer release and cellular uptake, acceptable blood compatibility as well as suitable T 2 MRI contrast performance, the target nanocarrier could be considered as favorable theranostic in breast cancer

    Curcumin-lipoic acid conjugate as a promising anticancer agent on the surface of gold‑iron oxide nanocomposites: A pH-sensitive targeted drug delivery system for brain cancer theranostics

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    © 2017 Elsevier B.V. Brain tumor is a lethal, fast growing cancer and a difficult case for treatment. Receptor-mediated endocytosis has been recognized as one of the most effective methods for drug delivery to brain tissue by overcoming obstacles associated with conventional therapeutics. In this work, a targeted theranostic drug delivery system (DDS) was prepared based on gold‑iron oxide nanocomposites (Fe3O4@Au NCs). Lipoic acid-curcumin (LA-CUR) was synthesized and introduced as a novel anticancer drug, and glutathione (GSH) was exploited as the targeting ligand. Both LA-CUR and GSH were easily attached to Fe3O4@Au NCs via Au-S interaction. As a negatively charged nanocarrier, the prepared DDS showed relatively less protein adsorption. Accordingly, hemocompatibility assays (complement, platelet, and leucocyte activation) revealed its hemocompatible virtue, especially in respect of free LA-CUR. GSH functionalization led to 2-fold increase of cellular uptake in GSH receptor-positive astrocyte cells which could primarily indicate the probable ability of the DDS to bypass BBB. Cytotoxicity and apoptosis assays together showed the noticeably enhanced cytotoxicity of LA-CUR against cancerous U87MG cells (IC50 = 2.69 μg/ml) in comparison with curcumin (IC50 = 21.31 μg/ml); moreover, the DDS demonstrated relatively higher cytotoxicity against cancerous U87MG cells than normal astrocyte cells which was in accordance with pH sensitive mechanism of LA-CUR release. Besides, the results of in vitro magnetic resonance imaging (MRI) (relaxation rate (r2) = 80.73 (s− 1·mM− 1)) primarily revealed that the DDS can be applied as a negative MRI contrast agent. In sum, the prepared DDS appeared to be a promising candidate for brain cancer treatment and a favorable MRI contrast agent
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