Search results for: vacuum induced freezing

Authors: Innocent Pangapanga-Phiri, Eric Dada Mungatana

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This study estimates the effect of climate-induced rural-urban migrants (RUM) on maize productivity. It uses panel data gathered by the National Statistics Office and the World Bank to understand the effect of RUM on the technical efficiency of maize production in rural Malawi. The study runs the two-stage Tobit regression to isolate the real effect of rural-urban migration on the technical efficiency of maize production. The results show that RUM significantly reduces the technical efficiency of maize production. However, the interaction of RUM and climate-smart agriculture has a positive and significant influence on the technical efficiency of maize production, suggesting the need for re-investing migrants’ remittances in agricultural activities.

Keywords: climate-smart agriculture, farm productivity, rural-urban migration, panel stochastic frontier models, two-stage Tobit regression

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Authors: Shaban Saad, Syed Ahmed, Suher Aburawi, Isabel Fong

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Ruta graveolens is a plant commonly found in north Africa and south Europe. It is reported that Ruta graveolens is used traditionally for epilepsy and some other illnesses. The acute and sub-acute effects of alcoholic extract residue were tested for possible anti-epileptic and skeletal muscle relaxation activity. The effect of extract on rat spontaneous motor activity (SMA) was also investigated using open filed. We previously proved the anti convulsant activity of the plant against pentylenetetrazol and electrically induced convulsions. Therefore in this study strychnine was used to induce convulsions in order to explore the mechanism of anti-convulsant activity of the plant. The skeletal muscle relaxation activity of Ruta graveolens was studied using pull-up and rod hanging tests in rats. At concentration of 5%w/v the extract protected mice against strychnine induced myoclonic jerks and death. The pull-up and rod hanging tests pointed to a skeletal muscle relaxant activity at higher concentrations. Ruta graveolens extract also significantly decreased the number of squares visited by rats in open field apparatus at all tested concentrations (3.5-20%w/v). However, the significant decrease in number of rearings was only noticed at concentrations of (15 and 20%w/v). The results indicate that Ruta graveolens contains compound(s) capable to inhibit convulsions, decrease SMA and/or diminish skeletal muscle tone in animal models. This data and the previously generated data together point to a general depression trend of CNS produced by Ruta graveolens.

Keywords: Ruta graveolens, open field, skeletal muscle relaxation

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Authors: Cyoung-Huei Huang, Chiu-Li Yeh, Man-Hui Pai, Sung-Ling Yeh

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This study evaluated the effect of different dietary n-6/n-3 polyunsaturated fatty acid (PUFA) ratios on modulating helper T (Th) and regulatory T (Treg) lymphocytes in mice with dextran sulfate sodium (DSS)-induced colitis. There were 3 control and 3 colitis groups in this study. Mice were fed for 24 d with an AIN-93G diet either with soybean oil (S), a mixture of soybean oil and low fish oil content (LF) or high fish oil content (HF). The ratio of n-6/n-3 PUFA in the LF diet was 4:1, and that in the HF diet was 2:1. The control groups drank distilled water while colitis groups provided 2% DSS in drinking water during day 15-19. All mice drank distilled water from day 20-24 for recovery and sacrificed on day 25. The results showed that colitis resulted in higher Th1, Th2, and Th17 and lower Treg percentages in the blood. Also, plasma haptoglobin and proinflammatory chemokines were elevated in colon lavage fluid. Colitic groups with fish oil had lower inflammatory mediators in the plasma and colon lavage fluid. Further, the percentages of Th1, Th2, and Th17 cells in the blood were lower, whereas Treg cell percentages were higher than those in the soybean oil group. The colitis group with n-6/n-3 PUFA ratio 2:1 had more pronounce effects than ratio 4:1. These results suggest that diets with an n-6/n-3 PUFA ratio of 2:1 or 4:1 regulate the Th/Treg balance and attenuate inflammatory mediator production in colitis. Compared to the n-6/n-3 PUFA ratio 4:1, the ratio of 2:1 was more effective in reducing inflammatory reactions in DSS-induced colitis.

Keywords: inflammatory bowel disease, n-3 polyunsaturated fatty acids, helper T lymphocyte, regulatory T lymphocyte

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Authors: R. Hasan

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Male factor infertility due to endocrine disturbances such as abnormalities in prolactin levels are encountered in a significant proportion. This case control study was carried out to determine the effects of prolactin on the male reproductive tract, using 200 male white rats. The rats were maintained as the control group (G1), hypoprolactinaemic group (G2), 3 hyperprolactinaemic groups induced using oral largactil (G3), low dose fluphenazine (G4) and high dose fluphenazine (G5). After 100 days, rats were subjected to serum prolactin (PRL) level measurements and for basic seminal fluid analysis (BSA). The difference between serum PRL concentrations of rats in G2, G3, G4 and G5 as compared to the control group were highly significant by Student’s t-test (p<0.001). There were statistically significant differences in seminal fluid characteristics of rats with induced prolactin abnormalities when compared with those of control group (p value <0.05), effects were more marked as the PRL levels rise.

Keywords: male factor infertility, prolactin, seminal fluid analysis, animal studies

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Authors: Jarek Krajewski, Andre Wittenborn, Martin Sauerland

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This abstract describes a promising approach for estimating post-traumatic stress disorder (PTSD) based on prosodic speech characteristics. It illustrates the validity of this method by briefly discussing results from an Arabic refugee sample (N= 47, 32 m, 15 f). A well-established standardized self-report scale “Reaction of Adolescents to Traumatic Stress” (RATS) was used to determine the ground truth level of PTSD. The speech material was prompted by telling about autobiographical related sadness inducing experiences (sampling rate 16 kHz, 8 bit resolution). In order to investigate PTSD-induced speech changes, a self-developed set of 136 prosodic speech features was extracted from the .wav files. This set was adapted to capture traumatization related speech phenomena. An artificial neural network (ANN) machine learning model was applied to determine the PTSD level and reached a correlation of r = .37. These results indicate that our classifiers can achieve similar results to those seen in speech-based stress research.

Keywords: speech prosody, PTSD, machine learning, feature extraction

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Authors: Walaa H. Salama, Azza M. Abdel-Aty, Afaf S. Fahmy

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Background: Egyptian Cobra; Naja haje (Elapidae) is one of most common snakes, widely distributed in Egypt and its envenomation causes multi-organ failure leading to rapid death. Thus, Different medicinal plants showed a protective effect against venom toxicity and may complement the conventional antivenom therapy. Aim: The present study was designed to assess both the antioxidant capacity of methanolic extract of rosemary leaves and evaluate the neutralizing ability of the extract against hepatotoxicity induced by Naja haje venom. Methods: The total phenolic and flavonoid contents and the antioxidant capacity of the methanolic rosemary extract were estimated by DPPH and ABTS Scavenging methods. In addition, the rosemary extract were assessed for anti-venom properties under in vitro and in vivo standard assays. Results: The rosemary extract had high total phenolic and flavonoid content as 12 ± 2 g of gallic acid equivalent per 100 gram of dry weight (g GAE/100g dw) and 5.5 ± 0.8 g of catechin equivalent per 100 grams of dry weight (g CE/100g dw), respectively. In addition, the rosemary extract showed high antioxidant capacity. Furthermore, The rosemary extract were inhibited in vitro the enzymatic activities of phospholipase A₂, L-amino acid oxidase, and hyaluronidase of the venom in a dose-dependent manner. Moreover, indirect hemolytic activity, hepatotoxicity induced by venom were completely neutralized as shown by histological studies. Conclusion: The phenolic compounds of rosemary extract with potential antioxidant activity may be considered as a promising candidate for future therapeutics in snakebite therapy.

Keywords: antioxidant activity, neutralization, phospholipase A₂ enzyme, snake venom

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Authors: Lopez J., Mehrvar M., Quinones E., Suarez A., Romero C.

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Membrane Distillation is an emerging technology that uses thermal and membrane steps for the desalination process to get drinking water. In this study, silver nanoparticles (AgNP) were deposited by dip-coating process over Polyvinylidene Fluoride, Fiberglass hydrophilic, and Polytetrafluoroethylene hydrophobic commercial membranes as substrate. Membranes were characterized and used in a Vacuum Membrane Distillation cell under Ultraviolet light with sea salt feed solution. The presence of AgNP increases the absorption of energy on the membrane, which improves the transmembrane flux.

Keywords: silver nanoparticles, membrane distillation, desalination technologies, heat deliver

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Authors: Khadijeh Abhari, Seyed Shahram Shekarforoush, Saeid Hosseinzadeh

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Probiotics have been considered as an approach to treat and prevent a wide range of inflammatory diseases. The spore forming probiotic strain Bacillus coagulans has demonstrated anti-inflammatory and immune-modulating effects in both animals and humans. The prebiotic, inulin, also potentially affects the immune system as a result of the change in the composition or fermentation profile of the gastrointestinal microbiota. An in vivo trial was conducted to evaluate the effects of probiotic B. coagulans, and inulin, either separately or in combination, on down regulate immune responses and progression of rheumatoid arthritis using induced arthritis rat model. Forty-eight male Wistar rats were randomly divided into 6 groups and fed as follow: 1) control: Normal healthy rats fed by standard diet, 2) Disease control (RA): Arthritic induced (RA) rats fed by standard diet, 3) Prebiotic (PRE): RA+ 5% w/w long chain inulin, 4) Probiotic (PRO): RA+ 109 spores/day B. coagulans by orogastric gavage, 5) Synbiotic (SYN): RA+ 5% w/w long chain inulin and 109 spores/day B. coagulans and 6) Treatment control: (INDO): RA+ 3 mg/kg/day indomethacin by orogastric gavage. Feeding with mentioned diets started on day 0 and continued to the end of study. On day 14, rats were injected with complete Freund’s adjuvant (CFA) to induce arthritis. Arthritis activity was evaluated by biochemical parameters and paw thickness. Biochemical assay for Fibrinogen (Fn), Serum Amyloid A (SAA), TNF-α and Alpha-1-acid glycoprotein (α1AGp) was performed on day 21, 28 and 35 (1, 2 and 3 weeks post RA induction). Pretreatment with PRE, PRO and SYN diets significantly inhibit SAA and Fn production in arthritic rats (P < 0.001). A significant decrease in production of pro-inflammatory cytokines, TNF-α, was seen in PRE, PRO and SYN groups (P < 0.001) which was similar to the effect of the anti-inflammatory drug Indomethacin. Further, there were no significant anti-inflammatory effects observed following different treatments using α1AGp as a RA indicator. Pretreatment with all supplied diets significantly inhibited the development of paw swelling induced by CFA (P < 0.001). Conclusion: Results of this study support that oral intake of probiotic B. coagulans and inulin are able to improve biochemical and clinical parameters of induced RA in rat.

Keywords: rheumatoid arthritis, bacillus coagulans, inulin, animal model

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Authors: Liang Ning, Chung Hau Yin

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Angiogenesis is the process of new blood vessel development. It has been recognized as a therapeutic target for blocking cancer growth four decades ago. Vascular sprouting is initiated by pro-angiogenic factors. Vascular endothelial cell growth factor (VEGF) plays a central role in angiogenic initiation, many patients with cancer or ocular neovascularization have been benefited from anti-VEGF therapy. Emerging approaches impacting in the later stages of vessel remodeling and maturation are expected to improve clinical efficacy. TIE receptor as well as the corresponding angiopoietin ligands, were identified as another endothelial cell specific receptor tyrosine kinase signaling system. Much efforts were made to reduce the activity of angiopoietin-TIE receptor axis. Two eudesmane-type sesquiterpenes from laggera alata, namely, 15-dihydrocostic acid and ilicic acid were found with strong anti-angiogenic properties in zebrafish model. Meanwhile, the mRNA expression levels of VEGFR2 and TIE2 pathway related genes were down-regulated in the sesquiterpenes treated zebrafish embryos. Besides, in human umbilical vein endothelial cells (HUVECs), the sesquiterpenes have the ability to inhibit VEGF-induced HUVECs proliferation and migration at non-toxic concentration. Moreover, angiopoietin-2 induced TIE2 phosphorylation was inhibited by the sesquiterpenes, the inhibitory effect was detected in angiopoietin-1 induced HUVECs proliferation as well. Thus, we hypothesized the anti-angiogenic activity of the compounds may via the inhibition of VEGF and TIE2 related pathways. How the compounds come into play as the pathways inhibitors need to be evaluated in the future.

Keywords: Laggera alata, eudesmane-type sesquiterpene, anti-angiogenesis, VEGF, angiopoietin, TIE2

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Authors: A. N. Ukwuani, M. G. Abubakar, S. W. Hassan

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Grewia crenata is used locally in the treatment of fractured bones, wound healing and inflammatory conditions. The anti-inflammatory activity of hydromethanolic extract of G. crenata leaves was investigated using egg albumin induced-hind paw oedema model in albino rat. The extract produced a time-dependent inhibition of egg albumin induced-hind paw oedema at 30th minutes up to 150th minutes in all the groups compared to the control. Significant reduction (p<0.05) of hind paw oedema was observed 150 minutes after egg albumin injection. The percentage inhibition produced by the extract at 200 mg/kg (22.1%) was comparable to that produced by 10 mg/kg indomethacin (24.9%) at the 150th minutes of post-egg albumin injection. Preliminary qualitative phytochemical analysis revealed the presence of saponins, steroids, flavonoids, anthraquinones and glycosides. The results obtained in this study suggest that Grewia crenata can be a potential source of anti-inflammatory agent and validates its use in the treatment of inflammatory conditions.

Keywords: Grewia crenata, anti-inflammatory, hind paw, oedema

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Authors: Alev Yüksel Aydar, Tuncay Yılmaz, Melisa Özçeli̇k, Tuba Aydın, Elif Karabaş

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In this study, response surface methodology (RSM) was used to obtain the optimum conditions for the freeze-drying of Gemlik variety olive seeds of to achieve the desired quality characteristics. The Box Behnken Design (BBD) was applied with three-variable and three replications in the center point. The effects of the different drying parameters including initial temperature of olive seed, pressure and time for freezing on the DPPH activity, total phenolic contents, and oleuropein absorbance value of the samples were investigated. Temperature (50 – 82 °C), pressure (0.2-0.5 mbar), time (6-10 hours) were chosen as independent variables. The analysis revealed that, while the temperature of the product prior to lyophilization and the drying time had no statistically significant effect on DPPH activity (p>0.05), the pressure was more important than the other two variables , and the quadratic effect of pressure had a significant effect on DPPH activity (p<0.05). The R2 and Adj-R2 values of the DPPH activity model were calculated to be 0.8962 and 0.7045, respectively.

Keywords: olive seed, gemlik variety, DPPH, phenolics, optimization

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Authors: Amritanshu Shriwastav, Purnendu Bose

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Algal photo bioreactors were operated at incident light intensities of 0.24, 2.52 and 5.96 W L-1 to determine the impact of light on algal growth. Low specific Chlorophyll-a content of algae was a strong indicator of light induced stress on algal cells. It was concluded that long term operation of photo bioreactors in the continuous illumination mode was infeasible under the range of incident light intensities examined and provision of a dark period after each light period was necessary for algal cells to recover from light-induced stress. Long term operation of photo bioreactors in the intermittent illumination mode was however possible at light intensities of 0.24 and 2.52 W L-1. Further, the incident light intensity in the photo bioreactors was found to decline exponentially with increase in algal concentration in the reactor due to algal ‘self-shading’. This may be an important determinant for photo bioreactor performance at higher algal concentrations.

Keywords: Algae, algal growth, photo bioreactor, photo-inhibition, ‘self-shading’

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Authors: Aleksandr A. Gajour, Vladimir G. Merzlikin, Vladimir I. Veselov

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This paper refers to the analysis of the characteristics of industrial and lifestyle facilities heat- energy objects as a part of the thermal envelope of Earth's surface for inclusion in any database of economic forecasting. The idealized model of the Earth's surface is discussed. This model gives the opportunity to obtain the energy equivalent for each element of terrain and world ocean. Energy efficiency criterion of comfortable human existence is introduced. Dynamics of changes of this criterion offers the possibility to simulate the possible technogenic catastrophes with the spontaneous industrial development of the certain Earth areas. Calculated model with the confirmed forecast of the Gulf Stream freezing in the polar regions in 2011 due to the heat-energy balance disturbance for the oceanic subsurface oil polluted layer is given. Two opposing trends of human development under limited and unlimited amount of heat-energy resources are analyzed.

Keywords: Earth's surface, heat-energy consumption, energy criteria, technogenic catastrophes

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Authors: Yuping Liu, Li Tao, Yin Lu

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Accumulating evidence has been shown that diallyl trisulfide (DATS) from garlic may reduce the risk of developing several types of cancer. In view of the dynamic crosstalk interplayed by tumor cells and platelets in hematogenous metastasis, we demonstrate the effectiveness of DATS on the metastatic behaviors of MDA-MB-435s human breast cancer cell line co-incubated with activated platelets. Indeed, our data identified that DATS significantly blocked platelets fouction induced by PAF, followed by the decreased production of TXB2. DATS was found to dose-dependently suppressed MDA-MB-435s cell migration and invasion in presence of activated platelets by PAF in vitro. Furthermore, the expression, secretion and enzymatic activity of matrix metalloproteinase (MMP)-2/9, as well as the luciferase activity of upstream regulator NF-κB in MDA-MB-435s, were obviously diminished by DATS. In parallel, DATS blocked upstream NF-κB activation signaling complexes composed of extracellular signal-related kinase (ERK) as assessed by measuring the levels of the phosphorylated forms.

Keywords: DATS, ERK, metastasis, MMPs, NF-κB, platelet

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Authors: Chaozhi Yang, Xinzhong Chen, Guoqing Huang

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Inerter is a two-terminal inertial element that can produce apparent mass far larger than its physical mass. A double tuned inertial mass damper (DTIMD) is developed by combining a spring with an inerter and a dashpot in series to replace the viscous damper of a tuned mass damper (TMD), and its performance is investigated. Firstly, the DTIMD is optimized numerically with H∞ and H2 methods considering the system’s damping based on the single-degree-of-freedom (SDOF)-DTIMD system, and the optimal structural parameters are obtained. Then, compared with a TMD, the control effect of the DTIMD with the optimal structural parameters on wind-induced vibration of a wind turbine in downwind direction under the shutdown condition is studied. The results demonstrate that the vibration suppression of the DTIMD is superior than that of a TMD at the same mass ratio. And at the identical vibration suppression, the tuned mass of the DTIMD can be reduced by up to 40% compared with a TMD.

Keywords: wind-induced vibration, vibration control, inerter, tuned mass damper, damped system

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Authors: Angalabiri-Owei E. Bekekeme, Brambaifa Nelson

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In view of the peculiar environment of the Niger Delta, access to modern health care is limited, hence the inhabitants especially those in the swampy areas resorts to sourcing for alternatives cure for their ailments using plants commonly found in this area without scientific evaluation. Rhizophora racemosa, G. F. Meyer (Rhizophoraceae) is the most abundant mangrove plant in the Niger Delta Area of Nigeria. The plant has been observed to be used for relief of a toothache and dysmenorrhoea among some Ijaw communities in the region. This work has revealed the likely potential of the plant in drug discovery and development. The crude methanol extract at doses of 300 mg/kg and 600 mg/kg (intraperitoneal) were tested for analgesic effect using fresh egg albumin induced inflammatory pain and Randall–Sellito method to assess the pain threshold. The anti-inflammatory effect was also evaluated with the extract at doses of 300 mg/kg and 600 mg/kg (intraperitoneal) using acute inflammatory model; fresh egg albumin induced paw oedema and assessed using Plethysmometer in rats. The methanol extracts 300 mg/kg and 600 mg/kg exhibited a significant (P < 0.001) and dose-dependent analgesic activity compared with the negative control and a standard drug diclofenac using ANOVA with Least Significant Difference post hoc test as evidenced by increased pain threshold. Also, the extract significantly (P < 0.001) reduced the rat paw oedema induced by the sub plantar injection of fresh egg albumin when compared with the negative control and a standard diclofenac using above statistical methods. This study revealed that the plant possesses analgesic and anti-inflammatory activities hence provide scientific bases for use as medicine.

Keywords: analgesic, anti-inflammatory, plethysmometer, Rhizophora racemosa

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Authors: Moshe Mello, Hilary Rutto, Tumisang Seodigeng

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The nature of tires makes them extremely challenging to recycle due to the available chemically cross-linked polymer and, therefore, they are neither fusible nor soluble and, consequently, cannot be remolded into other shapes without serious degradation. Open dumping of tires pollutes the soil, contaminates underground water and provides ideal breeding grounds for disease carrying vermins. The thermal decomposition of tires by pyrolysis produce char, gases and oil. The composition of oils derived from waste tires has common properties to commercial diesel fuel. The problem associated with the light oil derived from pyrolysis of waste tires is that it has a high sulfur content (> 1.0 wt.%) and therefore emits harmful sulfur oxide (SOx) gases to the atmosphere when combusted in diesel engines. Desulphurization of TPO is necessary due to the increasing stringent environmental regulations worldwide. Hydrodesulphurization (HDS) is the commonly practiced technique for the removal of sulfur species in liquid hydrocarbons. However, the HDS technique fails in the presence of complex sulfur species such as Dibenzothiopene (DBT) present in TPO. This study aims to investigate the viability of photodegradation (Photocatalytic oxidative desulphurization) and adsorptive desulphurization technologies for efficient removal of complex and non-complex sulfur species in TPO. This study focuses on optimizing the cleaning (removal of impurities and asphaltenes) process by varying process parameters; temperature, stirring speed, acid/oil ratio and time. The treated TPO will then be sent for vacuum distillation to attain the desired diesel like fuel. The effect of temperature, pressure and time will be determined for vacuum distillation of both raw TPO and the acid treated oil for comparison purposes. Polycyclic sulfides present in the distilled (diesel like) light oil will be oxidized dominantly to the corresponding sulfoxides and sulfone via a photo-catalyzed system using TiO2 as a catalyst and hydrogen peroxide as an oxidizing agent and finally acetonitrile will be used as an extraction solvent. Adsorptive desulphurization will be used to adsorb traces of sulfurous compounds which remained during photocatalytic desulphurization step. This desulphurization convoy is expected to give high desulphurization efficiency with reasonable oil recovery.

Keywords: adsorption, asphaltenes, photocatalytic oxidation, pyrolysis

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Authors: Diptoshi Roy, G. Sreevidya Varma, S. Asokan, Chandasree Das

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Germanium Telluride based quaternary thin film switching devices with composition Ge₁₅In₅Te₅₆Ag_24, have been deposited in sandwich geometry on glass substrate with aluminum as top and bottom electrodes. The bulk glassy form of the said composition is prepared by melt quenching technique. In this technique, appropriate quantity of elements with high purity are taken in a quartz ampoule and sealed under a vacuum of 10^-5 mbar. Then, it is allowed to rotate in a horizontal rotary furnace for 36 hours to ensure homogeneity of the melt. After that, the ampoule is quenched into a mixture of ice - water and NaOH to get the bulk ingot of the sample. The sample is then coated on a glass substrate using flash evaporation technique at a vacuum level of 10^-6 mbar. The XRD report reveals the amorphous nature of the thin film sample and Energy - Dispersive X-ray Analysis (EDAX) confirms that the film retains the same chemical composition as that of the base sample. Electrical switching behavior of the device is studied with the help of Keithley (2410^c) source-measure unit interfaced with Lab VIEW 7 (National Instruments). Switching studies, mainly SET (changing the state of the material from amorphous to crystalline) operation is conducted on the thin film form of the sample. This device is found to manifest memory switching as the device remains 'ON' even after the removal of the electric field. Also it is found that amorphous Ge₁₅In₅Te₅₆Ag₂₄ thin film unveils clean memory type of electrical switching behavior which can be justified by the absence of fluctuation in the I-V characteristics. The I-V characteristic also reveals that the switching is faster in this sample as no data points could be seen in the negative resistance region during the transition to on state and this leads to the conclusion of fast phase change during SET process. Scanning Electron Microscopy (SEM) studies are performed on the chosen sample to study the structural changes at the time of switching. SEM studies on the switched Ge₁₅In₅Te₅₆Ag₂₄ sample has shown some morphological changes at the place of switching wherein it can be explained that a conducting crystalline channel is formed in the device when the device switches from high resistance to low resistance state. From these studies it can be concluded that the material may find its application in fast switching Non-Volatile Phase Change Memory (PCM) Devices.

Keywords: Chalcogenides, Vapor deposition, Electrical switching, PCM.

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Authors: Tanveer Beg, Yasir H. Siddique, Gulshan Ara, Asfar S. Azmi, Mohammad Afzal

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Doxorubicin is a well-known DNA intercalating chemotherapy drug that is widely used for treatment of different cancers. Its clinical utility is limited due to the observed genotoxic side effects on healthy cells suggesting that newer combination and genoprotective regimens are urgently needed for the management of doxorubicin chemotherapy. Some dietary phytochemicals are well known for their protective mechanism of action and genistein from soy is recognized as an anti-oxidant with similar properties. Therefore, the present study investigates the effect of genistein against the genotoxic doses of doxorubicin by assessing chromosomal aberrations, sister chromatid exchanges, cell cycle kinetics, cell viability, apoptosis, and DNA damage markers in cultured human lymphocytes. Our results reveal that genistein treatment significantly suppresses genotoxic damage induced by doxorubicin. It is concluded that genistein has the potential to reduce the genotoxicity induced by anti-cancer drugs, thereby reducing the chances of developing secondary tumors during the therapy.

Keywords: apoptosis, DNA damage markers, doxorubicin, genistein, genotoxicity, human lymphocyte culture

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Authors: Rama Krishna Supramanian, Marzuki Isahak, Noran Naqiah Hairi

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Noise-induced hearing loss (NIHL) is one of the highest recorded occupational diseases, despite being preventable. Hearing Conservation Program (HCP) is designed to protect workers hearing and prevent them from developing hearing impairment due to occupational noise exposures. However, there is still a lack of evidence regarding the effectiveness of this program. The purpose of this study was to determine the effectiveness of a Hearing Conservation Program (HCP) in preventing or reducing audiometric threshold changes among vector control workers. This study adopts a cluster randomized controlled trial study design, with district health offices as the unit of randomization. Nine district health offices were randomly selected and 183 vector control workers were randomized to intervention or control group. The intervention included a safety and health policy, noise exposure assessment, noise control, distribution of appropriate hearing protection devices, training and education program and audiometric testing. The control group only underwent audiometric testing. Audiometric threshold changes observed in the intervention group showed improvement in the hearing threshold level for all frequencies except 500 Hz and 8000 Hz for the left ear. The hearing threshold changes range from 1.4 dB to 5.2 dB with largest improvement at higher frequencies mainly 4000 Hz and 6000 Hz. Meanwhile for the right ear, the mean hearing threshold level remained similar at 4000 Hz and 6000 Hz after 3 months of intervention. The Hearing Conservation Program (HCP) is effective in preserving the hearing of vector control workers involved in fogging activity as well as increasing their knowledge, attitude and practice towards noise-induced hearing loss (NIHL).

Keywords: adult, hearing conservation program, noise-induced hearing loss, vector control worker

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Authors: Aastha Arora, Vikas Bhuria, Saurabh Singh, Uma Pathak, Shweta Mathur, Puja P. Hazari, Rajat Sandhir, Ravi Soni, Anant N. Bhatt, Bilikere S. Dwarakanath

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Radiotherapy is an effective curative and palliative option for patients with thoracic malignancies. However, lung injury, comprising of pneumonitis and fibrosis, remains a significant clin¬ical complication of thoracic radiation, thus making it a dose-limiting factor. Also, injury to the lung is often reported as part of multi-organ failure in victims of accidental radiation exposures. Radiation induced inflammatory response in the lung, characterized by leukocyte infiltration and vascular changes, is an important contributing factor for the injury. Therefore, countermeasure agents to attenuate radiation induced inflammatory response are considered as an important approach to prevent chronic lung damage. Although Amifostine, the widely used, FDA approved radio-protector, has been found to reduce the radiation induced pneumonitis during radiation therapy of non-small cell lung carcinoma, its application during mass and field exposure is limited due to associated toxicity and ineffectiveness with the oral administration. The amifostine analogue (DRDE-30) overcomes this limitation as it is orally effective in reducing the mortality of whole body irradiated mice. The current study was undertaken to investigate the potential of DRDE-30 to ameliorate radiation induced lung damage. DRDE-30 was administered intra-peritoneally, 30 minutes prior to 13.5 Gy thoracic (60Co-gamma) radiation in C57BL/6 mice. Broncheo- alveolar lavage fluid (BALF) and lung tissues were harvested at 12 and 24 weeks post irradiation for studying inflammatory and fibrotic markers. Lactate dehydrogenase (LDH) leakage, leukocyte count and protein content in BALF were used as parameters to evaluate lung vascular permeability. Inflammatory cell signaling (p38 phosphorylation) and anti-oxidant status (MnSOD and Catalase level) was assessed by Western blot, while X-ray CT scan, H & E staining and trichrome staining were done to study the lung architecture and collagen deposition. Irradiation of the lung increased the total protein content, LDH leakage and total leukocyte count in the BALF, reflecting endothelial barrier dysfunction. These disruptive effects were significantly abolished by DRDE-30, which appear to be linked to the DRDE-30 mediated abrogation of activation of the redox-sensitive pro- inflammatory signaling cascade, the MAPK pathway. Concurrent administration of DRDE-30 with radiation inhibited radiation-induced oxidative stress by strengthening the anti-oxidant defense system and abrogated p38 mitogen-activated protein kinase activation, which was associated with reduced vascular leak and macrophage recruitment to the lungs. Histopathological examination (by H & E staining) of the lung showed radiation-induced inflammation of the lungs, characterized by cellular infiltration, interstitial oedema, alveolar wall thickening, perivascular fibrosis and obstruction of alveolar spaces, which were all reduced by pre-administration of DRDE-30. Structural analysis with X-ray CT indicated lung architecture (linked to the degree of opacity) comparable to un-irradiated mice that correlated well with the lung morphology and reduced collagen deposition. Reduction in the radiation-induced inflammation and fibrosis brought about by DRDE-30 resulted in a profound increase in animal survival (72 % in the combination vs 24% with radiation) observed at the end of 24 weeks following irradiation. These findings establish the potential of the Amifostine analogue, DRDE-30, in reducing radiation induced pulmonary injury by attenuating the inflammatory and fibrotic responses.

Keywords: amifostine, fibrosis, inflammation, lung injury radiation

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Authors: Gagan Kumar, Koijam M. Devi, Amarendra K. Sarma, Dibakar Roy Chowdhury

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Research in metamaterials has been gaining momentum over the past decade owing to its ability in controlling electromagnetic wave properties through careful design at the sub-wavelength scale. The metamaterials have led to several important phenomena which are useful in a variety of applications. One such phenomenon is the electromagnetically induced transparency (EIT) effect in which a narrow transparency region is created in an otherwise absorptive spectrum. In our work, we explore plasmon induced transparency (PIT) in terahertz metamaterials which is analogues to EIT effect. The PIT effect is achieved using the plasmonic metamaterials in which a unit cell is comprised of two C (2C) shaped resonators and a cut-wire (CW). When terahertz wave of a particular polarization is normally incident on the proposed metamaterials geometry, it strongly couples with the cut wire, resulting in the excitation of the bright mode. However due to the specific polarization of the incident beam, the fundamental modes of the C-shaped resonators are not excited by the incident terahertz, hence they are termed as the dark mode. The PIT effect occurs as a result of interference between the bright and the dark mode. In order to observe PIT effect, both the bright and dark modes should have similar resonant frequencies with a little deviation. We further have examined that the PIT window can be modulated by displacing the C-shaped resonators w.r.t. the cut-wire. The numerical observations for different coupling configurations can be explained through an equivalent lumped element circuit model. Moving ahead the PIT effect is further explored in a metamaterial comprising of a cross like structure and four C-shaped resonators. For such configuration, equally strong PIT effect is observed for two orthogonally polarized lights. Therefore, such metamaterials demonstrate a polarization independent PIT response w.r.t the incident terahertz radiation. The proposed study could be significant in the development of slow light devices and polarization independent sensing applications.

Keywords: terahertz, metamaterial, split ring resonator, plasmon

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Authors: Azza A. Ali, Asmaa Abdelaty, Mona G. Khalil, Mona M. Kamal, Karema Abu-Elfotuh

Abstract:

Background: Aluminium (Al) is known as a neurotoxin environmental pollutant that can cause certain diseases as Dementia, Alzheimer's disease, and Parkinsonism. It is widely used in antacid drugs as well as in food additives and toothpaste. Stresses have been linked to cognitive impairment; Social isolation (SI) may exacerbate memory deficits while protein malnutrition (PM) increases oxidative damage in cortex, hippocampus and cerebellum. The risk of cognitive decline may be lower by maintaining social connections. Epigallocatechin-3-gallate (EGCG) is the most abundant catechin in green tea and has antioxidant, anti-inflammatory and anti-atherogenic effects as well as health-promoting effects in CNS. Objective: To study the influence of different stressful conditions as social isolation, electric shock (EC) and inadequate Nutritional condition as PM on neurotoxicity induced by Al in rats as well as to investigate the possible protective effect of EGCG in these stressful and PM conditions. Methods: Rats were divided into two major groups; protected group which was daily treated during three weeks of the experiment by EGCG (10 mg/kg, IP) or non-treated. Protected and non-protected groups included five subgroups as following: One normal control received saline and four Al toxicity groups injected daily for three weeks by ALCl3 (70 mg/kg, IP). One of them served as Al toxicity model, two groups subjected to different stresses either by isolation as mild stressful condition (SI-associated Al toxicity model) or by electric shock as high stressful condition (EC- associated Al toxicity model). The last was maintained on 10% casein diet (PM -associated Al toxicity model). Isolated rats were housed individually in cages covered with black plastic. Biochemical changes in the brain as acetyl cholinesterase (ACHE), Aβ, brain derived neurotrophic factor (BDNF), inflammatory mediators (TNF-α, IL-1β), oxidative parameters (MDA, SOD, TAC) were estimated for all groups. Histopathological changes in different brain regions were also evaluated. Results: Rats exposed to Al for three weeks showed brain neurotoxicity and neuronal degenerations. Both mild (SI) and high (EC) stressful conditions as well as inadequate nutrition (PM) enhanced Al-induced neurotoxicity and brain neuronal degenerations; the enhancement induced by stresses especially in its higher conditions (ES) was more pronounced than that of inadequate nutritional conditions (PM) as indicated by the significant increase in Aβ, ACHE, MDA, TNF-α, IL-1β together with the significant decrease in SOD, TAC, BDNF. On the other hand, EGCG showed more pronounced protection against hazards of Al in both stressful conditions (SI and EC) rather than in PM .The protective effects of EGCG were indicated by the significant decrease in Aβ, ACHE, MDA, TNF-α, IL-1β together with the increase in SOD, TAC, BDNF and confirmed by brain histopathological examinations. Conclusion: Neurotoxicity and brain neuronal degenerations induced by Al were more severe with stresses than with PM. EGCG can protect against Al-induced brain neuronal degenerations in all conditions. Consequently, administration of EGCG together with socialization as well as adequate protein nutrition is advised especially on excessive Al-exposure to avoid the severity of its neuronal toxicity.

Keywords: environmental pollution, aluminum, social isolation, protein malnutrition, neuronal degeneration, epigallocatechin-3-gallate, rats

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Authors: Alexander Mikkelsen, Khobaib Khobaib, Zbigniew Rozynek

Abstract:

Drops covered by particles have found important uses in various fields, ranging from stabilization of emulsions to production of new advanced materials. Particles at drop interfaces can be interlocked to form solid capsules with properties tailored for a myriad of applications. Despite the huge potential of particle-laden drops and capsules, the knowledge of their deformation and stability are limited. In this regard, we contribute with experimental studies on the deformation and manipulation of silicone oil drops covered with micrometer-sized particles subjected to electric fields. A mixture of silicone oil and particles were immersed in castor oil using a mechanical pipette, forming millimeter sized drops. The particles moved and adsorbed at the drop interfaces by sedimentation, and were structured at the interface by electric field-induced electrohydrodynamic flows. When applying a direct current electric field, free charges accumulated at the drop interfaces, yielding electric stress that deformed the drops. In our experiments, we investigated how particle properties affected drop deformation, break-up, and particle structuring. We found that by increasing the size of weakly-conductive clay particles, the drop shape can go from compressed to stretched out in the direction of the electric field. Increasing the particle size and electrical properties were also found to weaken electrohydrodynamic flows, induce break-up of drops at weaker electric field strengths and structure particles in chains. These particle parameters determine the dipolar force between the interfacial particles, which can yield particle chaining. We conclude that the balance between particle chaining and electrohydrodynamic flows governs the observed drop mechanics.

Keywords: drop deformation, electric field induced stress, electrohydrodynamic flows, particle structuring at drop interfaces

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Authors: Yury S. Shpanskiy, Boris V. Kuteev

Abstract:

Development of a fusion-fission hybrid facility based on superconducting conventional tokamak DEMO-FNS runs in Russia since 2013. The main design goal is to reach the technical feasibility and outline prospects of industrial hybrid technologies providing the production of neutrons, fuel nuclides, tritium, high-temperature heat, electricity and subcritical transmutation in Fusion-Fission Hybrid Systems. The facility should operate in a steady-state mode at the fusion power of 40 MW and fission reactions of 400 MW. Major tokamak parameters are the following: major radius R=3.2 m, minor radius a=1.0 m, elongation 2.1, triangularity 0.5. The design provides the neutron wall loading of ~0.2 MW/m², the lifetime neutron fluence of ~2 MWa/m², with the surface area of the active cores and tritium breeding blanket ~100 m². Core plasma modelling showed that the neutron yield ~10¹⁹ n/s is maximal if the tritium/deuterium density ratio is 1.5-2.3. The design of the electromagnetic system (EMS) defined its basic parameters, accounting for the coils strength and stability, and identified the most problematic nodes in the toroidal field coils and the central solenoid. The EMS generates toroidal, poloidal and correcting magnetic fields necessary for the plasma shaping and confinement inside the vacuum vessel. EMC consists of eighteen superconducting toroidal field coils, eight poloidal field coils, five sections of a central solenoid, correction coils, in-vessel coils for vertical plasma control. Supporting structures, the thermal shield, and the cryostat maintain its operation. EMS operates with the pulse duration of up to 5000 hours at the plasma current up to 5 MA. The vacuum vessel (VV) is an all-welded two-layer toroidal shell placed inside the EMS. The free space between the vessel shells is filled with water and boron steel plates, which form the neutron protection of the EMS. The VV-volume is 265 m³, its mass with manifolds is 1800 tons. The nuclear blanket of DEMO-FNS facility was designed to provide functions of minor actinides transmutation, tritium production and enrichment of spent nuclear fuel. The vertical overloading of the subcritical active cores with MA was chosen as prospective. Analysis of the device neutronics and the hybrid blanket thermal-hydraulic characteristics has been performed for the system with functions covering transmutation of minor actinides, production of tritium and enrichment of spent nuclear fuel. A study of FNS facilities role in the Russian closed nuclear fuel cycle was performed. It showed that during ~100 years of operation three FNS facilities with fission power of 3 GW controlled by fusion neutron source with power of 40 MW can burn 98 tons of minor actinides and 198 tons of Pu-239 can be produced for startup loading of 20 fast reactors. Instead of Pu-239, up to 25 kg of tritium per year may be produced for startup of fusion reactors using blocks with lithium orthosilicate instead of fissile breeder blankets.

Keywords: fusion-fission hybrid system, conventional tokamak, superconducting electromagnetic system, two-layer vacuum vessel, subcritical active cores, nuclear fuel cycle

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Authors: Agatha Swasti Ayuning Tyas

Abstract:

Hyperglycemia in Diabetes Mellitus (DM) is an important factor in cellular and vascular damage, which is caused by activation of C Protein Kinase, polyol and hexosamine track, and production of Advanced Glycation End-Products (AGE). Those mentioned before causes the accumulation of Reactive Oxygen Species (ROS). Oxidative stress increases the expression of proinflammatory factors IL-6 as one of many signs of endothelial disfunction. Genistein in soy milk has a high immunomodulator potential. Goat milk contains amino acids which have antioxidative potential. Fermented kefir has an anti-inflammatory activity which believed will also contribute in potentiating goat milk and soy milk. This study is a quasi-experimental posttest-only research to 30 Wistar mice. This study compared the levels of IL-6 between healthy Wistar mice group (G1) and 4 DM Wistar mice with intervention and grouped as follows: mice without treatment (G2), mice treated with 100% goat milk kefir (G3), mice treated with combination of 50% goat milk kefir and 50% soy milk kefir (G4), and mice treated with 100% soy milk kefir (G5). DM animal models were induced with Streptozotocin & Nicotinamide to achieve hyperglycemic condition. Goat milk kefir and soy milk kefir are given at a dose of 2 mL/kg body weight/day for four weeks to intervention groups. Blood glucose was analyzed by the GOD-POD principle. IL-6 was analyzed by enzyme-linked sandwich ELISA. The level of IL-6 in DM untreated control group (G2) showed a significant difference from the group treated with the combination of 50% goat milk kefir and 50% soy milk kefir (G3) (p=0,006) and the group treated with 100% soy milk kefir (G5) (p=0,009). Whereas the difference of IL-6 in group treated with 100% goat milk kefir (G3) was not significant (p=0,131). There is also synergism between glucose level and IL-6 in intervention groups treated with combination of 50% goat milk kefir and 50% soy milk kefir (G3) and the group treated with 100% soy milk kefir (G5). Combination of 50 % goat milk kefir and 50% soy milk kefir and administration of 100% soy milk kefir alone can control the level of IL-6 remained low in DM Wistar mice induced with streptozocin and nicotinamide.

Keywords: diabetes mellitus, goat milk kefir, soy milk kefir, interleukin 6

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Authors: Golnar Hasheminasab, Mehrdad Faizi, Mona Khoramjouy

Abstract:

Introduction: Benzodiazepines (BZDs) have pharmacological effects, including anxiolytic, sedative-hypnotic, anticonvulsant, and muscle relaxant properties. However, they have adverse effects such as interaction with alcohol, ataxia, impaired learning, and psychological and physical dependence. According to the structure of zolpidem and on the basis of the structure-activity relationship of BZD receptor ligands, six novel derivatives of 2-fluorobenzyloxy 4,6- diphenylpyramidin-2-ol have been synthesized. We studied the hypnotic, sedative, and anticonvulsant effects of the novel compounds. Method: In this study, we used male mice (18 to 25 g). All the substances were injected intraperitoneally. The hypnotic effect of the compounds was examined by pentobarbital induced sleeping test. The locomotor activities and sedative effects of the novel compounds were evaluated by open field and loss of righting reflex test, respectively. The anticonvulsant effects of the novel compounds were assessed by PTZ and MES tests. Results: In the pentobarbital induced sleeping and open field tests, compound 4-(2-((2-fluorobenzyl)oxy)phenyl)-6-(p-tolyl) pyrimidine-2-ol with ED50=14.20 mg/kg and ED50=47.88 mg/kg, respectively, was the most effective compound. None of the novel compounds showed a significant anticonvulsant effect in the PTZ test. In MES test, compound 4-(2-((2-fluorobenzyl)oxy)phenyl)-6-(p-tolyl)pyrimidine-2-ol with ED50=12.92 mg/kg was the most effective compound. Flumazenil blocked the sedation and hypnosis of all the compounds. Conclusion: All of the novel derivatives showed significant sedative-hypnotic activities and caused the reduction of locomotor activities. The results show that the methyl lipophilic substitutes on the phenyl ring of 4,6-diphenylpyramidin-2-ol derivatives can increase the sedative and hypnotic effects of the derivatives. Flumazenil antagonized the sedative, and the hypnotic effects of the compounds indicate that BZD receptors are involved in the effects.

Keywords: BZD, sedative, hyptonic, anticonvulsant, zolpidem, MES, PTZ, benzodiazepine, locomotor activities, pentobarbital induced sleeping tests

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Authors: Saba Rahman, Arvind K. Jain, S. D. Bharti, T. K. Datta

Abstract:

Chimneys are generally tall and slender structures with circular cross-sections, due to which they are highly prone to wind forces. Wind exerts pressure on the wall of the chimneys, which produces unwanted forces. Vortex-induced oscillation is one of such excitations which can lead to the failure of the chimneys. Therefore, vortex-induced oscillation of chimneys is of great concern to researchers and practitioners since many failures of chimneys due to vortex shedding have occurred in the past. As a consequence, extensive research has taken place on the subject over decades. Many laboratory experiments have been performed to verify the theoretical models proposed to predict vortex-induced forces, including aero-elastic effects. Comparatively, very few proto-type measurement data have been recorded to verify the proposed theoretical models. Because of this reason, the theoretical models developed with the help of experimental laboratory data are utilized for analyzing the chimneys for vortex-induced forces. This calls for reliability analysis of the predictions of the responses of the chimneys produced due to vortex shedding phenomena. Although several works of literature exist on the vortex-induced oscillation of chimneys, including code provisions, the reliability analysis of chimneys against failure caused due to vortex shedding is scanty. In the present study, the reliability analysis of chimneys against vortex shedding failure is presented, assuming the uncertainty in vortex shedding phenomena to be significantly more than other uncertainties, and hence, the latter is ignored. The vortex shedding is modeled as a stationary random process and is represented by a power spectral density function (PSDF). It is assumed that the vortex shedding forces are perfectly correlated and act over the top one-third height of the chimney. The PSDF of the tip displacement of the chimney is obtained by performing a frequency domain spectral analysis using a matrix approach. For this purpose, both chimney and random wind forces are discretized over a number of points along with the height of the chimney. The method of analysis duly accounts for the aero-elastic effects. The double barrier threshold crossing level, as proposed by Vanmarcke, is used for determining the probability of crossing different threshold levels of the tip displacement of the chimney. Assuming the annual distribution of the mean wind velocity to be a Gumbel type-I distribution, the fragility curve denoting the variation of the annual probability of threshold crossing against different threshold levels of the tip displacement of the chimney is determined. The reliability estimate is derived from the fragility curve. A 210m tall concrete chimney with a base diameter of 35m, top diameter as 21m, and thickness as 0.3m has been taken as an illustrative example. The terrain condition is assumed to be that corresponding to the city center. The expression for the PSDF of the vortex shedding force is taken to be used by Vickery and Basu. The results of the study show that the threshold crossing reliability of the tip displacement of the chimney is significantly influenced by the assumed structural damping and the Gumbel distribution parameters. Further, the aero-elastic effect influences the reliability estimate to a great extent for small structural damping.

Keywords: chimney, fragility curve, reliability analysis, vortex-induced vibration

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Authors: Ghada Al-Kafaji, Mohamed Sabry

Abstract:

Mitochondria are the site of cellular respiration and produce energy in the form of adenosine triphosphate (ATP) via oxidative phosphorylation. They are the major source of intracellular reactive oxygen species (ROS) and are also direct target to ROS attack. Oxidative stress and ROS-mediated disruptions of mitochondrial function are major components involved in the pathogenicity of diabetic complications. In this work, the changes in mitochondrial DNA (mtDNA) copy number, biogenesis, gene expression of mtDNA-encoded subunits of electron transport chain (ETC) complexes, and mitochondrial function in response to hyperglycemia-induced ROS and the effect of direct inhibition of ROS on mitochondria were investigated in an in vitro model of diabetic nephropathy using human renal mesangial cells. The cells were exposed to normoglycemic and hyperglycemic conditions in the presence and absence of Mn(III)tetrakis(4-benzoic acid) porphyrin chloride (MnTBAP) or catalase for 1, 4 and 7 days. ROS production was assessed by the confocal microscope and flow cytometry. mtDNA copy number and PGC-1a, NRF-1, and TFAM, as well as ND2, CYTB, COI, and ATPase 6 transcripts, were all analyzed by real-time PCR. PGC-1a, NRF-1, and TFAM, as well as ND2, CYTB, COI, and ATPase 6 proteins, were analyzed by Western blotting. Mitochondrial function was determined by assessing mitochondrial membrane potential and adenosine triphosphate (ATP) levels. Hyperglycemia-induced a significant increase in the production of mitochondrial superoxide and hydrogen peroxide at day 1 (P < 0.05), and this increase remained significantly elevated at days 4 and 7 (P < 0.05). The copy number of mtDNA and expression of PGC-1a, NRF-1, and TFAM as well as ND2, CYTB, CO1 and ATPase 6 increased after one day of hyperglycemia (P < 0.05), with a significant reduction in all those parameters at 4 and 7 days (P < 0.05). The mitochondrial membrane potential decreased progressively at 1 to 7 days of hyperglycemia with the parallel progressive reduction in ATP levels over time (P < 0.05). MnTBAP and catalase treatment of cells cultured under hyperglycemic conditions attenuated ROS production reversed renal mitochondrial oxidative stress and improved mtDNA, mitochondrial biogenesis, and function. These results show that hyperglycemia-induced ROS caused an early increase in mtDNA copy number, mitochondrial biogenesis and mtDNA-encoded gene expression of the ETC subunits in human mesangial cells as a compensatory response to the decline in mitochondrial function, which precede the mtDNA defect and mitochondrial dysfunction with a progressive oxidative response. Protection from ROS-mediated damage to renal mitochondria induced by hyperglycemia may be a novel therapeutic approach for the prevention/treatment of DN.

Keywords: diabetic nephropathy, hyperglycemia, reactive oxygen species, oxidative stress, mtDNA, mitochondrial dysfunction, manganese superoxide dismutase, catalase

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Authors: James S. Kwame, E. Yakushina, P. Blackwell

Abstract:

The challenges in forming titanium alloys at room temperature are well researched and are linked both to the limitations imposed by the basic crystal structure and their ability to form texture during plastic deformation. One major issue of concern for the sheet forming of titanium alloys is their high sensitivity to surface inhomogeneity. Various machining processes are utilised in preparing sheet hole edges for edge flanging applications. However, the response of edge forming tendencies of titanium to different edge surface finishes is not well investigated. The hole expansion test is used in this project to elucidate the impact of abrasive water jet (AWJ) and electro-discharge machining (EDM) cutting techniques on the edge formability of CP-Ti (Grade 2) and Ti-3Al-2.5V alloys at room temperature. The results show that the quality of the edge surface finish has a major effect on the edge formability of the materials. The work also found that the variations in the edge forming performance are mainly the result of the influence of machining induced edge surface defects.

Keywords: titanium alloys, hole expansion test, edge formability, non-conventional machining

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