Search results for: induced amplitude modulation method (IAM) coupled with amplitude multiplication (PM)

Authors: Guankai Lin, Wei Tong, Hong Zhu

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The electric current induced Joule heating effects have been investigated in La₀.₈Ba₀.₂MnO₃ ultrathin films deposited on LaAlO₃(001) single crystal substrate with smaller lattice constant by using the sol-gel method. By applying moderate bias currents (~ 10 mA), it is found that Joule self-heating simply gives rise to a temperature deviation between the thermostat and the test sample, but the intrinsic ρ(T) relationship measured at a low current (0.1 mA) changes little. However, it is noteworthy that the low-temperature transport behavior degrades from metallic to insulating state after applying higher bias currents ( > 31 mA) in a vacuum. Furthermore, metallic transport can be recovered by placing the degraded film in air. The results clearly suggest that the oxygen vacancy in the La₀.₈Ba₀.₂MnO₃ films is controllable in different atmospheres, particularly with the aid of the Joule self-heating. According to the SEM images, we attribute the controlled oxygen vacancy to the nano-sized labyrinth pattern of the films, where the large surface-to-volume ratio plays a curial role.

Keywords: controlling oxygen vacancy, joule self-heating, manganite, sol-gel method

Procedia PDF Downloads 153

Authors: Qing Cao, Fei Wang, Yu-Qiang Wang, Li-Ya Huang, Tian-Tian Sang, Shu-Yan Chen

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Aims: TNF Receptor-Associated Factor 6 (TRAF6) acts as a multifunctional regulator of the Transforming Growth Factor (TGF)-β signaling pathway, and mediates Smad-independent JNK and p38 activation via TGF-β. This study was performed to test the hypothesis that TGF-β/TRAF6 is essential for angiotensin-II (Ang II)-induced differentiation of rat c-kit+ Cardiac Stem Cells (CSCs). Methods and Results: c-kit+ CSCs were isolated from neonatal Sprague Dawley (SD) rats, and their c-kit status was confirmed with immunofluorescence staining. A TGF-β type I receptor inhibitor (SB431542) or the small interfering RNA (siRNA)-mediated knockdown of TRAF6 were used to investigate the role of TRAF6 in TGF-β signaling. Rescue of TRAF6 siRNA transfected cells with a 3'UTR deleted siRNA insensitive construct was conducted to rule out the off target effects of the siRNA. TRAF6 dominant negative (TRAF6DN) vector was constructed and used to infect c-kit+ CSCs, and western blotting was used to assess the expression of TRAF6, JNK, p38, cardiac-specific proteins, and Wnt signaling proteins. Physical interactions between TRAF6 and TGFβ receptors were studied by coimmunoprecipitation. Cardiac differentiation was suppressed in the absence of TRAF6. Forced expression of TRAF6 enhanced the expression of TGF-β-activated kinase1 (TAK1), and inhibited Wnt signaling. Furthermore, TRAF6 increased the expression of cardiac-specific proteins (cTnT and Cx-43) but inhibited the expression of Wnt3a. Conclusions: Our data suggest that TRAF6 plays an important role in Ang II induced differentiation of c-kit+ CSCs via the non-canonical signaling pathway.

Keywords: cardiac stem cells, differentiation, TGF-β, TRAF6, ubiquitination, Wnt

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Authors: Saidi Abdelkrim, Hamouine Abdelmadjid, Abdellatif Megnounif

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The study of interaction between vehicles and bridge structures has become extremely important. Large deflections and vibration induced by heavy and high-speed vehicles affect significantly the safety and efficiency of bridge. The vibration of a bridge caused by passage of vehicles is one of the most imperative considerations in the design of a bridge as a common sort of transportation structure. A major goal of this study is to create a simplified model of a vehicle bridge system in MATLAB. The model will then be used to study the influence of parameters to vehicle-bridge vibrations.

Keywords: vehicle-bridge interaction, Newmark-β, MATLAB code

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Authors: Azza H. El-Medany, Hanan H. Hagar, Jamila H. El-Medany

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Ulcerative colitis (UC) is one of chronic inflammatory diseases primarily affecting colon with unknown etiology. Some researches papers mentioned the possibility of the use of drugs that affect the angiotensin II in reducing the complication of ulcerative colitis. The aim of the present study is to evaluate the potential protective and therapeutic effects of captopril and valsartan on ulcerative colitis induced experimentally in rats using acetic acid. The results were assessed by histological assessment of colonic tissues and measurement of malondialdehyde (MDA), tumor necrosis factor (TNF-α), transforming growth factor (TGF-1B), angiotensin converting enzyme (ACE), reduced glutathione (GSH) and platelet activating factor (PAF) levels in colonic tissues. Oral pre-treatment with captopril or valsartan in a dose of 30 mgkg-1 body weight for 2 weeks before induction of colitis (prophylactic groups) and continuously for 2 weeks after induction (therapeutic groups) significantly reduce MDA, TNF-α, PAF, TGF-1B and ACE levels in colonic tissues as compared to acetic acid control group. Also, a significant increase in GSH level was observed in colonic tissues. Captopril and valsartan attenuated the macroscopic and microscopic colonic damage induced by acetic acid. These results suggest that either captopril or valsartan may be effective as prophylactic or treatment of UC through inhibition of ACE and scavenging effect on oxygen-derived free radicals.

Keywords: captopril, valsartan, angiotensin converting enzyme, reduced glutathione, tumor necrosis factor

Procedia PDF Downloads 269

Authors: Djebbar Atmani, Aghiles Karim Aissat, Nadjet Debbache-Benaida, Nassima Chaher-Bazizi, Dina Atmani-Kilani, Meriem Rahmani-Berboucha, Naima Saidene, Malika Benloukil, Lila Azib

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Medicinal plants are believed to be an important source for the discovery of potential antioxidant, anti-inflammatory and anti-diabetic substances. The present study was designed to investigate the neuroprotective, anti-inflammatory, anti-diabetic and anti-hyperuricemic potential of Pistacia lentiscus, as well as the identification of active compounds. The antioxidant potential of plant extracts against known radicals was measured using various standard in vitro methods. Anti-inflammatory activity was determined using the paw edema model in mice and by measuring the secretion of the pro-inflammatory cytokine, whereas the anti-diabetic effect was assessed in vivo on streptozotocin-induced diabetic rats and in vitro by inhibition of alpha-amylase. The anti-hyperuricemic activity was evaluated using the xanthine oxidase assay, whereas neuroprotective activity was investigated using an Aluminum-induced toxicity test. Pistacia lentiscus extracts and fractions exhibited high scavenging capacity against DPPH, NO. and ABTS+ radicals in a dose-dependent manner and restored blood glucose levels, in vivo, to normal values, in agreement with the in vitro anti-diabetic effect. Oral administration of plant extracts significantly decreased carrageenan-induced mice paw oedema, similar to the standard drug, diclofenac, was effective in reducing IL-1β levels in cell culture and induced a significant increase in urinary volume in mice, associated to a promising anti-hyperuricemic activity. Plant extracts showed good neuroprotection and restoration of cognitive functions in mice. HPLC-MS and NMR analyses allowed the identification of known and new phenolic compounds that could be responsible for the observed activities. Therefore, Pistacia lentiscus could be beneficial in the treatment of inflammatory conditions and diabetes complications and the enhancement of cognitive functions.

Keywords: Pistacia lentiscus, anti-inflammatory, antidiabetic, flavanols, neuroprotective

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Authors: Jadranka Blazhevska Gilev

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IR laser-induced ablation of poly(butylacrylate-methylmethacrylate/hydroxyl ethyl methacrylate)/reduced graphene oxide (p(BA/MMA/HEMA)/rGO) was examined with 0.5, 0.75 and 1 wt% reduced graphene oxide content in relation to polymer. The irradiation was performed with TEA (transversely excited atmosphere) CO₂ laser using incident fluence of 15-20 J/cm², repetition frequency of 1 Hz, in an evacuated (10-3 Pa) Pyrex spherical vessel. Thin deposited nanocomposites films with large specific area were obtained using different substrates. The properties of the films deposited on these substrates were evaluated by TGA, FTIR, (Thermogravimetric analysis, Fourier Transformation Infrared) Raman spectroscopy and SEM microscopy. Homogeneous distribution of graphene sheets was observed from the SEM images, making polymer/rGO deposit an ideal candidate for SERS application. SERS measurements were performed using Rhodamine 6G as probe molecule on the substrate Ag/p(BA/MMA/HEMA)/rGO.

Keywords: laser ablation, reduced graphene oxide, polymer/rGO nanocomposites, thin deposited film

Procedia PDF Downloads 198

Authors: Kunal D. Bhagat, Truong V. Vu, John C. Wells, Hideyuki Takakura, Yu Kawano, Fumio Ogawa

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Hollow germanium alloy quasi-spheres of diameters 1 to 2 mm with a relatively smooth inner and outer surface have been produced. The germanium was first melted at around 1273 K and then exuded from a coaxial nozzle into an inert atmosphere by argon gas supplied to the inner nozzle. The falling spheres were cooled by water spray and collected in a bucket. The spheres had a horn type of structure on the outer surface, which might be caused by volume expansion induced by the density difference between solid and gas phase. The frequency of the sphere formation was determined from the videos to be about 133 Hz. The outer diameter varied in the range of 1.3 to 1.8 mm with a wall thickness in the range of 0.2 to 0.5 mm. Solid silicon spheres are used for spherical silicon solar cells (S₃CS), which have various attractive features. Hollow S₃CS promise substantially higher energy conversion efficiency if their wall thickness can be kept to 0.1–0.2 mm and the inner surface can be passivated. Our production of hollow germanium spheres is a significant step towards the production of hollow S₃CS with, we hope, higher efficiency and lower material cost than solid S₃CS.

Keywords: hollow spheres, semiconductor, compound jet, dropping method

Procedia PDF Downloads 208

Authors: Myung Kwon Cho, Seul Ki Min, Gwang Heum Yoon, Jung Hyun Joo, Sang Jun Sim, Hwa Sung Shin

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Mechanotransduction is a mechanism that external mechanical stimulation is converted to biochemical activity in the cell. When applying this mechanism to the unicellular green algae Chlamydomonas reinhardtii, the dramatic result that the accumulation of intracellular lipid was up to 60% of dry weight basis occurred. Furthermore, various variations in cellular physiology occurred, but there is a lack of the development of the system and related research for applying that technology to control the mechanical stress and facilitate molecular analyses. In this study, applying a mechanical stress to microalgae, the microfluidic device system that finely induced direct membrane distortion of microalgae. Cellular membrane distortion led to deflagellation, calcium influx and lipid accumulation in microalgae. In conclusion, cytological studies such as mechanotransduction can be actualized by using this system and membrane distortion is a promising inducer for biodiesel production.

Keywords: mechanotransduction, microalgae, membrane distortion, biodiesel

Procedia PDF Downloads 323

Authors: Salma Baig, Bakrudeen Ali Ahmad, Ainnul Hamidah Syahadah Azizan, Hapipah Mohd Ali, Elham Rouhollahi, Mahmood Ameen Abdulla

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Free radical damage induced by reactive oxygen species (ROS) contributes to etiology of many chronic diseases, cancer being one of them. Recent studies have been successful in ROS targeted therapies via antioxidants using mouse models in cancer therapeutics. The present study was designed to scrutinize anticancer activity, antioxidant activity of 5 different extracts of Thymus serpyllum in MDA-MB-231, MCF-7, HepG2, HCT-116, PC3, and A549. Identification of the phytochemicals present in the most active extract of Thymus serpyllum was conducted using gas chromatography coupled with mass spectrophotometry and antioxidant activity was measured by using DPPH radical scavenging and FRAP assay. Anticancer impact of the extract in terms of IC50 was evaluated using MTT cell viability assay. Results revealed that the hexane extract showed the best anticancer activity in HepG2 (Liver Carcinoma Cell Line) with an IC50 value of 23 ± 0.14 µg/ml followed by 25 µg/ml in HCT-116 (Colon Cancer Cell Line), 30 µm/ml in MCF-7 (Breast Cancer Cell Line), 35 µg/ml in MDA-MB-231 (Breast Cancer Cell Line), 57 µg/ml in PC3 (Prostate Cancer Cell Line) and 60 µg/ml in A549 (Lung Carcinoma Cell Line). GC-MS profile of the hexane extract showed the presence of 31 compounds with carvacrol, thymol and thymoquione being the major compounds. Phenolics such as Vitamin E, terpinen-4-ol, borneol and phytol were also identified. Hence, here we present the first report on cytotoxicity of hexane extract of Thymus serpyllum extract in HepG2 cell line with a robust anticancer activity with an IC50 of 23 ± 0.14 µg/ml.

Keywords: Thymus serpyllum L., hexane extract, GC-MS profile, antioxidant activity, anticancer activity, HepG2 cell line

Procedia PDF Downloads 517

Authors: Wu Di, Yeo Khoon Seng, Lim Tee Tai

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The typical insects employ a flapping-wing mode of flight. The numerical simulations on free flight of a model fruit fly (Re=143) including hovering and are presented in this paper. Unsteady aerodynamics around a flapping insect is studied by solving the three-dimensional Newtonian dynamics of the flyer coupled with Navier-Stokes equations. A hybrid-grid scheme (Generalized Finite Difference Method) that combines great geometry flexibility and accuracy of moving boundary definition is employed for obtaining flow dynamics. The results show good points of agreement and consistency with the outcomes and analyses of other researchers, which validate the computational model and demonstrate the feasibility of this computational approach on analyzing fluid phenomena in insect flight. The present modeling approach also offers a promising route of investigation that could complement as well as overcome some of the limitations of physical experiments in the study of free flight aerodynamics of insects. The results are potentially useful for the design of biomimetic flapping-wing flyers.

Keywords: free hovering flight, flapping wings, fruit fly, insect aerodynamics, leading edge vortex (LEV), computational fluid dynamics (CFD), Navier-Stokes equations (N-S), fluid structure interaction (FSI), generalized finite-difference method (GFD)

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Authors: Jangje Park, So Young Kim

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The market demand for audio quality in mobile devices continues to increase, and audible buzz noise generated in time division communication is a chronic problem that goes against the market demand. In the case of time division type communication, the RF Power Amplifier (RF PA) is driven at the audio frequency cycle, and it makes various influences on the audio signal. In this paper, we measured the ground bounce noise generated by the peak current flowing through the ground network in the RF PA with the audio frequency; it was confirmed that the noise is the cause of the audible buzz noise during a call. In addition, a grounding method of the microphone device that can improve the buzzing noise was proposed. Considering that the level of the audio signal generated by the microphone device is -38dBV based on 94dB Sound Pressure Level (SPL), even ground bounce noise of several hundred uV will fall within the range of audible noise if it is induced by the audio amplifier. Through the grounding method of the microphone device proposed in this paper, it was confirmed that the audible buzz noise power density at the RF PA driving frequency was improved by more than 5dB under the conditions of the Printed Circuit Board (PCB) used in the experiment. A fundamental improvement method was presented regarding the buzzing noise during a mobile phone call.

Keywords: audio frequency, buzz noise, ground bounce, microphone grounding

Procedia PDF Downloads 136

Authors: Hua Li, Hongwu Deng

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The turbine blade's leading edge is usually cooled by jet impingement cooling technology due to the heaviest heat load. For a rotating turbine blade, however, the channel orientation (β, the angle between the jet direction and the rotating plane) could play an important role in influencing the flow field and heat transfer. Therefore, in this work, the effects of channel orientation (from 90° to 180°) on heat transfer in a jet impingement cooling channel are experimentally investigated. Furthermore, the investigations are conducted under an isothermal boundary condition. Both the jet-to-target surface distance and jet-to-jet spacing are three times the jet hole diameter. The jet Reynolds number is 5,000, and the maximum jet rotation number reaches 0.24. The results show that the rotation-induced variations of heat transfer are different in each channel orientation. In the cases of 90°≤β≤135°, a vortex generated in the low-radius region of the supply channel changes the mass-flowrate distribution in each jet hole. Therefore, the heat transfer in the low-radius region decreases with the rotation number, whereas the heat transfer in the high-radius region increases, indicating that a larger temperature gradient in the radial direction could appear in the turbine blade's leading edge. When 135°<β≤180°; however, the heat transfer of the entire stagnant zone decreases with the rotation number. The rotation-induced jet deflection is the primary factor that weakens the heat transfer, and jets cannot reach the target surface at high rotation numbers. For the downstream regions, however, the heat transfer is enhanced by 50%-80% in every channel orientation because the dead zone is broken by the rotation-induced secondary flow in the impingement channel.

Keywords: heat transfer, jet impingement cooling, channel orientation, high rotation number, isothermal boundary

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Authors: Lamiek Abraham, Xinli Du, Yohan Noh, Polin Hsu, Tingting Wu, Tom Logan, Ifan Yen

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In the field of minimally invasive, smart medical instruments such as catheters and guidewires are typically used at a remote distance to gain access to the diseased artery, often negotiating tortuous, complex, and diseased vessels in the process. Three optical fiber sensors with a diameter of 1.5mm each that are 120° apart from each other is proposed to be mounted into a catheter-based pump device with a diameter of 10mm. These sensors are configured to solve the challenges surgeons face during insertion through curvy major vessels such as the aortic arch. Moreover, these sensors deal with providing information on rubbing the walls and shape sensing. This study presents an experimental and mathematical models of the optical fiber sensors with 2 degrees of freedom. There are two eight gear-shaped tubes made up of 3D printed thermoplastic Polyurethane (TPU) material that are connected. The optical fiber sensors are mounted inside the first tube for protection from external light and used TPU material as a prototype for a catheter. The second tube is used as a flat reflection for the light intensity modulation-based optical fiber sensors. The first tube is attached to the linear guide for insertion and withdrawal purposes and can manually turn it 45° by manipulating the tube gear. A 3D hard material phantom was developed that mimics the aortic arch anatomy structure in which the test was carried out. During the insertion of the sensors into the 3D phantom, datasets are obtained in terms of voltage, distance, and position of the sensors. These datasets reflect the characteristics of light intensity modulation of the optical fiber sensors with a plane project of the aortic arch structure shape. Mathematical modeling of the light intensity was carried out based on the projection plane and experiment set-up. The performance of the system was evaluated in terms of its accuracy in navigating through the curvature and information on the position of the sensors by investigating 40 single insertions of the sensors into the 3D phantom. The experiment demonstrated that the sensors were effectively steered through the 3D phantom curvature and to desired target references in all 2 degrees of freedom. The performance of the sensors echoes the reflectance of light theory, where the smaller the radius of curvature, the more of the shining LED lights are reflected and received by the photodiode. A mathematical model results are in good agreement with the experiment result and the operation principle of the light intensity modulation of the optical fiber sensors. A prototype of a catheter using TPU material with three optical fiber sensors mounted inside has been developed that is capable of navigating through the different radius of curvature with 2 degrees of freedom. The proposed system supports operators with pre-scan data to make maneuverability and bendability through curvy major vessels easier, accurate, and safe. The mathematical modelling accurately fits the experiment result.

Keywords: Intensity modulated optical fiber sensor, mathematical model, plane projection, shape sensing.

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Authors: Haw-Long Lee, Win-Jin Chang, Yu-Ching Yang

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In the paper, the coupled equation of motion for the dynamic displacement of a fullerene moving in a (10,10) single-walled carbon nanotube (SWCNT) is derived using nonlocal Timoshenko beam theory, including the effects of rotary inertia and shear deformation. The effects of confined stiffness between the fullerene and nanotube, foundation stiffness, and nonlocal parameter on the dynamic behavior are analyzed using the Runge-Kutta Method. The numerical solution is in agreement with the analytical result for the special case. The numerical results show that increasing the confined stiffness and foundation stiffness decrease the dynamic displacement of SWCNT. However, the dynamic displacement increases with increasing the nonlocal parameter. In addition, result using the Euler beam theory and the Timoshenko beam theory are compared. It can be found that ignoring the effects of rotary inertia and shear deformation leads to an underestimation of the displacement.

Keywords: single-walled carbon nanotube, nanoparticle delivery, Nonlocal Timoshenko beam theory, Runge-Kutta Method, Van der Waals force

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Authors: Hasan Afarnegan, Ali Shahraki, Jafar Shahraki

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Paraquat is widely used as a strong nitrogen-based herbicide for controlling of weeds in agriculture. This poison is extremely toxic for humans which induces several – organ failure by accumulation in cells and many instances of death occurred due to its poisoning. Paraquat metabolized primarily in the liver. The purpose of this study was to assess the effects of aquatic extract of levisticum officinale on oxidative status and biochemical factors in hepatocytes exposed to paraquat. Our results determined that hepatocytes destruction induced by paraquat is mediated by reactive oxygen species (ROS) production, lipid peroxidation and decrease of mitochondrial membrane potential were significantly (P<0.05) prevented by aquatic extract of Levisicum officinale (100, 200 and 300 µg/ml). These effects of paraquat also prevented via antioxidants and ROS scavengers (α-tocopherol, DMSO, manitol), mitochondrial permeability transition (MPT) pore sealing compound (carnitine).MPT pore sealing compound inhibited the hepatotoxicity, indicating that paraquat induced cell death via mithochondrial pathway. Pretreatment of hepatocytes with aquatic extracts of Levisticum officinale, antioxidants and ROS scavengers also blocked hepatic cell death caused by paraquat, suggesting that oxidative stress may be directly induced decline of mithochondrial membrane potential. In conclusion, paraquat hepatotoxicity can be attributed to oxidative stress and continued by mithochondrial membrane potential disruption. Levisticum officinale aquatic extract, presumably due to its strong antoxidant properties, could protect the destructive effects of paraquat on rat hepatocytes.

Keywords: hepatocyte protection, levisticum officinale, oxidative stress, paraquat

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Authors: Hemin Yuan, Yun Wang, Xiangchun Wang

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Gas hydrate is drawing attention due to the fact that it has an enormous amount all over the world, which is almost twice the conventional hydrocarbon reserves, making it a potential alternative source of energy. It is widely distributed in permafrost and continental ocean shelves, and many countries have launched national programs for investigating the gas hydrate. Gas hydrate is mainly explored through seismic methods, which include bottom simulating reflectors (BSR), amplitude blanking, and polarity reverse. These seismic methods are effective at finding the gas hydrate formations but usually contain large uncertainties when applying to invert the micro-scale petrophysical properties of the formations due to lack of constraints. Rock physics modeling links the micro-scale structures of the rocks to the macro-scale elastic properties and can work as effective constraints for the seismic methods. A number of rock physics models have been proposed for gas hydrate modeling, which addresses different mechanisms and applications. However, these models are generally not well classified, and it is confusing to determine the appropriate model for a specific study. Moreover, since the modeling usually involves multiple models and steps, it is difficult to determine the source of uncertainties. To solve these problems, we summarize the developed models/methods and make four classifications of the models according to the hydrate micro-scale morphology in sediments, the purpose of reservoir characterization, the stage of gas hydrate generation, and the lithology type of hosting sediments. Some sub-categories may overlap each other, but they have different priorities. Besides, we also analyze the priorities of different models, bring up the shortcomings, and explain the appropriate application scenarios. Moreover, by comparing the models, we summarize a general workflow of the modeling procedure, which includes rock matrix forming, dry rock frame generating, pore fluids mixing, and final fluid substitution in the rock frame. These procedures have been widely used in various gas hydrate modeling and have been confirmed to be effective. We also analyze the potential sources of uncertainties in each modeling step, which enables us to clearly recognize the potential uncertainties in the modeling. In the end, we explicate the general problems of the current models, including the influences of pressure and temperature, pore geometry, hydrate morphology, and rock structure change during gas hydrate dissociation and re-generation. We also point out that attenuation is also severely affected by gas hydrate in sediments and may work as an indicator to map gas hydrate concentration. Our work classifies rock physics models of gas hydrate into different categories, generalizes the modeling workflow, analyzes the modeling uncertainties and potential problems, which can facilitate the rock physics characterization of gas hydrate bearding sediments and provide hints for future studies.

Keywords: gas hydrate, rock physics model, modeling classification, hydrate morphology

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Authors: Dalila Bouamra, Chekib Arslane Baki, Abdelhamid Bouchebour, Fatiha Koussa, Amel Benamara, Seoussen Kada

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The activity of methanolic extract from Anacyclus pyrethrum was evaluated using λ-carrageenan 1% induced paw edema in Wistar Albinos rats. The oral administration of 200 mg/kg, 400 mg/kg and 600 mg/kg, body weight of methanolic extract, one hour before induction of inflammation, exerted a significant inhibition effect of 47%, 57% and 62% respectively after 4h λ-carrageenan treatment and highly significant inhibition effect of 57%, 66% and 75% respectively after 8h λ-carrageenan treatment, compared to non treated group (100%) and that treated with aspirin, a standard anti-inflammatory drug. On the other hand, the effect of the plant extract on stomach was macroscopically and microscopically studied. The plant extract has an impact on the loss ratio of granulocytes that have invaded the stomach after a period of inflammation at a dose of 600 mg/kg body weight.

Keywords: inflammation, Anacyclus pyrethrum, gastritis, Wistar Albinos rats

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Authors: V. Gareyan, Zh. Gevorkian

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We study oblique incident light absorption in opaque media with rough surfaces. An analytical approach with modified boundary conditions taking into account the surface roughness in metallic or dielectric films has been discussed. Our approach reveals interference-linked terms that modify the absorption dependence on different characteristics. We have discussed the limits of our approach that hold valid from the visible to the microwave region. Polarization and angular dependences of roughness-induced absorption are revealed. The existence of an incident angle or a wavelength for which the absorptance of a rough surface becomes equal to that of a flat surface is predicted. Based on this phenomenon, a method of determining roughness correlation length is suggested.

Keywords: light, absorption, surface, roughness

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Authors: Mei-Ling Chan, Jin-Ming Wu, Konstantin V. Kudryavtsev, Jih-Hwa Guh

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Prostate cancer is one of the most common malignant disease in men. KUD983 is an enantiomerically pure β-dipeptide derivative, which may have anti-cancer effects. In the present study, KUD983 exhibits powerful activity against hormone-refractory prostate cancer (HRPC) PC-3 and DU145 cells. The IC50 values of KUD983 in PC-3 and DU145 cells are 0.56±0.07M and 0.50±0.04 M respectively. KUD983 induced G1 arrest of the cell cycle and subsequent apoptosis associated with the down-regulation of several related proteins including cyclin D1, cyclin E and Cdk4, and the de-phosphorylation of RB. The protein expressions of nuclear and total c-Myc protein, which was able to regulate the expression of both cyclin D1 and cyclin E, were significantly suppressed by KUD983. Phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) is an important signaling pathway that influences the energy metabolism, cell cycle, proliferation, survival and apoptosis of cells, and is associated with numerous other signaling pathways. The Western Blot data revealed that KUD983 inhibited PI3K/Akt and mTOR/p70S6K/4E-BP1 pathways. The transient transfection of constitutively active myristylated Akt (myr-Akt) cDNA significantly reversed KUD983-induced caspase activation but did not abolish the suppression of mTOR/p70S6K/4E-BP1 signaling cascade indicating the presence of both Akt-dependent and -independent pathways. Moreover, KUD983-induced effect was collaborated with the down-regulation of anti-apoptotic Bcl-2 members (e.g., Bcl-2, and Mcl-1) and IAP family members (e.g., survivin). Furthermore, KUD983 induced autophagic cell death using confocal microscopic examination, investigating the level of conversion of LC3-I to LC3-II and flow cytometric detection of AVO-positive cells. Taken together, the data suggest that KUD983 is an anticancer β-dipeptide against HRPCs through the inhibition of cell proliferation and induction of apoptotic and autophagic cell death. The suppression of signaling pathways mediated by c-Myc, PI3K/Akt and mTOR/p70S6K/4E-BP1 and the collaboration with down-regulation of Mcl-1 and survivin may indicate the mechanism of KUD983 against HRPC.

Keywords: β-dipeptide, hormone-refractory prostate cancer, mTOR, PI3K/Akt

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Authors: Hassan Saghi, Gholam Reza Askarzadeh Garmroud, Seyyed Ali Reza Emamian

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Sloshing phenomenon is a complicated free surface flow problem that increases the dynamic pressure on the sidewalls and the bottom of the storage tanks. When the storage tanks are partially filled, it is essential to be able to evaluate the fluid dynamic loads on the tank’s perimeter. In this paper, a numerical code was developed to determine the pressure distribution on the rectangular and trapezoidal storage tanks’ perimeters due to liquid sloshing impact. Assuming the fluid to be inviscid, the Laplace equation and the nonlinear free surface boundary conditions are solved using coupled BEM-FEM. The code performance for sloshing modeling is validated against available data. Finally, this code is used for partially filled rectangular and trapezoidal storage tanks and the pressure distribution on the tanks’ perimeters due to liquid sloshing impact is estimated. The results show that the maximum pressure on the perimeter of the rectangular and trapezoidal storage tanks was decreased along the sidewalls from the top to the bottom. Furthermore, the period of the pressure distribution is different for different points on the tank’s perimeter and it is bigger in the trapezoidal tanks compared to the rectangular ones.

Keywords: pressure distribution, liquid sloshing impact, sway motion, trapezoidal storage tank, coupled BEM-FEM

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Authors: Manal M. Shehata, Kawther M. Abdel-Hamid, Nashwa A. Mohamed, Marwa H. Bakr, Maged S. Mahmoud, Hala M. Elbadre

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Introduction: The worldwide rapid increase in diabetes poses a significant challenge to current therapeutic approaches. Therapeutic utility of bone marrow transplantation in diabetes is an attractive approach. However, the oxidative stress generated by hyperglycemia may hinder β-cell regeneration. Curcumin, is a dietary spice with antioxidant activity. Aim of work: The present study was undertaken to investigate the therapeutic potential of curcumin, bone marrow transplantation, and their combined effects in the reversal of experimental diabetes. Material and Methods: Fifty adult male healthy albino rats were included in the present study.They were divided into two groups: Group І: (control group) included 10 rats. Group П: (diabetic group): included 40 rats. Diabetes was induced by single intraperitoneal injection of streptozotocin (STZ). Group II will be further subdivided into four groups (10 rats for each): Group II-a (diabetic control). Group II-b: rats were received single intraperitoneal injection of bone marrow suspension (un-fractionated bone marrow cells) prepared from rats of the same family. Group II-c: rats were treated with curcumin orally by gastric intubation for 6 weeks. Group II-d: rats were received a combination of single bone marrow transplantation and curcumin for 6 weeks. After 6 weeks, blood glucose, insulin levels were measured and the pancreas from all rats were processed for Histological, Immunohistochemical and morphometric examination. Results: Diabetic group, showed progressive histological changes in the pancreatic islets. Treatment with either curcumin or bone marrow transplantation improved the structure of the islets and reversed streptozotocin-induced hyperglycemia and hypoinsulinemia. Combination of curcumin and bone marrow transplantation elicited more profound alleviation of streptozotocin-induced changes including islet regeneration and insulin secretion. Conclusion: The use of natural antioxidants combined with bone marrow transplantation to induce pancreatic regeneration is a promising strategy in the management of diabetes.

Keywords: diabtes, panceatic islets, bone marrow transplantation, curcumin

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Authors: Pooyan Changizian, Zhongwen Yao

Abstract:

The purpose of current study is to make an excellent correlation between mechanical properties and microstructures of ion irradiated X-750 Ni-based superalloy. Towards this end, two different irradiation procedures were carried out, including single Ni ion irradiation and pre-helium implantation with subsequent Ni ion irradiation. Nano-indentation technique was employed to evaluate the mechanical properties of irradiated material. The nano-hardness measurements depict highly different results for two irradiation procedures. Single ion irradiated X-750 shows softening behavior; however, pre-helium implanted specimens present significant hardening compared to the un-irradiated material. Cross-section TEM examination demonstrates that softening is attributed to the γ׳-precipitate instability (disordering/dissolution) which overcomes the hardening effect of irradiation-induced defects. In contrast, the presence of cavities or helium bubbles is probably the main cause for irradiation-induced hardening of helium implanted samples.

Keywords: Inconel X-750, nanoindentation, helium bubbles, defects

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Authors: Larissa M. Vargas, Julia M. Sacchi, Renata O. Pereira, Lucas S. Asano, Iara C. Araújo, Patricia Fiorino, Vera Farah

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The aim of this study was to evaluate the occurrence of subclinical organ injuries induced by high-fat diet. Male wistar rats (n=5/group) were divided in control diet group (CD), commercial rat chow, and hyperlipidic diet (30% lipids) group (HD) administrated during 8 weeks, starting after weaning. All the procedures followed the rules of the Committee of Research and Ethics of the Mackenzie University (CEUA Nº 077/03/2011). At the end of protocol the animals were euthanized by anesthesia overload and the left kidney was removed. Intrarenal lipid deposition was evaluated by histological analyses with oilred. Kidney slices were stained with picrosirius red to evaluate the area of the Bowman's capsule (AB) and space (SB), and glomerular tuft area (GT). The renal expression of sterol regulatory element–binding protein (SREBP-2) was performed by Western Blotting. Creatinine concentration (serum and urine) and lipid profile were determined by colorimetric kit (Labtest). At the end of the protocol there was no differences in body weight between the groups, however the HD showed a marked increase in lipid deposits, glomeruli and tubules, and biochemical analysis for cholesterol and triglycerides. Moreover, in the kidney, the high-fat diet induced a reduction in the AB (13%), GT (18%) and SB (17%) associated with a reduction in glomerular filtration rate (creatinine clearance). The renal SRBP2 expression was increased in HD group. These data suggests that consumption of high-fat diet starting in childhood is associated with subclinical renal damage and function.

Keywords: high-fat diet, kidney, intrarenal lipid deposition, SRBP2

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Authors: Habiba Rechek, Ammar Haouat, Ratiba Mekkiou, Diana C. G. A. Pinto, Artur M. S. Silva

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Satureja hispidula is an aromatic and medicinal plant belonging to the family of Lamiaceae native to Algeria, just like mint or thyme. Although she is less known to the general public than her more famous cousins, this species has many therapeutic properties that have been used for centuries in traditional medicine of some regions. For generations, Satureja hispidula has been used in traditional medicine to treat various ailments, including respiratory diseases and diabetes. Its aroma, often described as close to that of mint, gives it a special interest in aromatherapy. Due to the growing interest in the beneficial properties of plant-derived essential oils, the aim of this study is to analyze the chemical composition of S. hispidula essential oil by gas chromatography coupled with mass spectrometry (GC-MS). Identifying the main constituents of essential oil will allow better understanding its chemical nature and exploring its potential for culinary and therapeutic application. The study of the essential oil of S. hispidula reveals a composition rich in 83 compounds, including menthone, pulegone and piperitone as main constituents. This gas chromatography analysis coupled with mass spectrometry provides valuable information about the chemical nature of this oil. However, more in-depth studies are needed to explore the potentially health-enhancing properties of this essential oil.

Keywords: satureja hispidula, GC-MS, essential oil, menthone, pulegone

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Authors: Narin Salehiyan, Ramin Ghasemi Shayan

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The largest genus of plant viruses, the potyvirus, is responsible for significant crop losses. Potyviruses are aphid sent in a nonpersistent way, and some of them are likewise seed communicated. As significant microorganisms, potyviruses are substantially more examined than other plant infections having a place with different genera, and their review covers numerous parts of plant virology, like utilitarian portrayal of viral proteins, sub-atomic communication with hosts and vectors, structure, scientific classification, development, the study of disease transmission, and determination. Biotechnological utilizations of potyviruses are likewise being investigated. During this last ten years, significant advances have been made in the comprehension of the sub-atomic science of these infections and the elements of their different proteins. Potyvirus multiplication, movement, and transmission, as well as potyvirus/plant compatible interactions, including pathogenicity and symptom determinants, are updated following a general overview of the family Potyviridae and the potyviral proteins. it end the survey giving data on biotechnological uses of potyviruses.

Keywords: virology, poty, virus, genome, genetic

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Authors: Kuladip Jana

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Benzo(a)pyrene [B(a)P] is an environmental toxicant present mostly in cigarette smoke and car exhaust, is an aryl hydrocarbon receptor (AhR) ligand that exerts its toxic effects on both male and female reproductive systems. In this study, the effect of B(a)P at different doses (0.1, 0.25, 0.5, 1 and 5 mg /kg body weight) was studied on male reproductive system of rat. A significant decrease in cauda epididymal sperm count and motility along with the presence of sperm head abnormalities and altered epididymal and testicular histology were documented following B(a)P treatment. B(a)P treatment resulted apoptotic sperm cells as observed by TUNEL and Annexin V-PI assay with increased ROS, altered sperm mitochondrial membrane potential (ΔΨm) with a simultaneous decrease in the activity of antioxidant enzymes and GSH status. TUNEL positive apoptotic cells also observed in testis as well as isolated germ and Leydig cells following B(a)P exposure. Western Blot analysis revealed the activation of p38MAPK, cytosolic translocation of cytochrome-c, up-regulation of Bax and inducible nitric oxide synthase (iNOS) with cleavage of PARP and down-regulation of BCl2 in testis upon B(a)P treatment. The protein and mRNA levels of testicular key steroidogenesis regulatory proteins like StAR, cytochrome P450 IIA1 (CYPIIA1), 3β HSD, 17β HSD showed a significant decrease in a dose dependent manner while an increase in the expression of cytochrome P450 1A1 (CYP1A1), Aryl hydrocarbon Receptor (AhR), active caspase- 9 and caspase- 3 following B(a)P exposure. We conclude that exposure of benzo(a)pyrene caused testicular gamatogenic and steroidogenic disorders by induction of oxidative stress, inhibition of StAR and other steroidogenic enzymes along with activation of p38MAPK and initiated caspase-3 mediated germ and Leydig cell apoptosis.The possible protective role of naturally occurring phytochemicals against B(a)P induced testicular toxicity needs immediate consideration. Curcumin and resveratrol separately were found to protect against B(a)P induced germ cell apoptosis, and their combinatorial effect was more significant. Our present study in isolated testicular germ cell population from adult male Wistar rats, highlighted their synergistic protective effect against B(a)P induced germ cell apoptosis. Curcumin-resveratrol co-treatment decreased the expression of pro-apoptotic proteins like cleaved caspase 3,8,9, cleaved PARP, Apaf1, FasL, tBid. Curcumin-resveratrol co-treatment decreased Bax/Bcl2 ratio, mitochondria to cytosolic translocation of cytochrome c and activated the survival protein Akt. Curcumin-resveratrol decreased the expression of p53 dependent apoptotic genes like Fas, FasL, Bax, Bcl2, Apaf1.Curcumin-resveratrol co-treatment thus prevented B(a)P induced germ cell apoptosis. B(a)P induced testicular ROS generation and oxidative stress were significantly ameliorated with curcumin and resveratrol. Curcumin-resveratrol co-treatment prevented B(a)P induced nuclear translocation of AhR and CYP1A1 production. The combinatorial treatment significantly inhibited B(a)P induced ERK 1/2, p38 MAPK and JNK 1/2 activation. B(a)P treatment increased the expression of p53 and its phosphorylation (p53 ser 15). Curcumin-resveratrol co-treatment significantly decreased p53 level and its phosphorylation (p53 ser 15). The study concludes that curcumin-resveratrol synergistically modulated MAPKs and p53, prevented oxidative stress, regulated the expression of pro and anti-apoptotic proteins as well as the proteins involved in B(a)P metabolism thus protected germ cells from B(a)P induced apoptosis.

Keywords: benzo(a)pyrene, germ cell, apoptosis, oxidative stress, resveratrol, curcumin

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Authors: Surapol Raadnui

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This paper describes an experimental investigation on a pair of gears in which wear and pitting were intentionally allowed to occur, namely, moisture corrosion pitting, acid-induced corrosion pitting, hard contaminant-related pitting and mechanical induced wear. A back-to-back spur gear test rig was used. The test samples of wear debris were collected and assessed through the utilization of an optical microscope in order to correlate and compare the debris morphology to pitting and wear degradation of the worn gears. In addition, weight loss from all test gear pairs was assessed with the utilization of the statistical design of the experiment. It can be deduced that wear debris characteristics exhibited a direct relationship with different pitting and wear modes. Thus, it should be possible to detect and diagnose gear pitting and wear utilization of worn surfaces, generated wear debris and quantitative measurement such as weight loss.

Keywords: tribology, spur gear wear, predictive maintenance, wear particle analysis

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Authors: Mark Berry

Abstract:

A number of studies have identified several factors involved in the malignant progression of cancer cells. The Primary modulator in driving inflammation to these transformed cells has been identified as the transcription factor known as nuclear factor-κB. This essential regulator of inflammation and the development of cancer, combined with a microenvironment of inflammation and signaling molecules, plays a major role in the malignant progression of cancer, and this progression is the result of the mutagenic predisposition of persistent substances that combat infection at tumor sites and other areas of chronic inflammation. Inflammation-induced tumors, and their inflammatory cells and regulators may be the primary source of metastasis of tumor cells through angiogenesis. Previous research on cytokines and chemokines, including their downstream targets, has been the focus of the cancer/inflammation connection. The identification of the biological mechanisms of other proteins vital to the inflammation cascade and their interactions are crucial to novel and effective therapeutic protocols for the treatment of inflammation-induced cancers. The Ancelim HSRP Protocol is just such a therapeutic intervention.

Keywords: ancelim, cancer, inflammation, tumor

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Authors: Chandra Upadhyaya, Arup Kumar Sarma

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In the North Eastern part of India several hydro power projects are being proposed and execution for some of them are already initiated. There are controversies surrounding these constructions. Impact of these dams in the downstream part of the rivers needs to be assessed so that eco-system and people living downstream are protected by redesigning the projects if it becomes necessary. This may result in reducing the stresses to the affected ecosystem and people living downstream. At present many index based ecological methods are present to assess impact on ecology. However, none of these methods are capable of assessing the affect resulting from dam induced diurnal variation of flow in the downstream. We need environmental flow methodology based on hydrological index which can address the affect resulting from dam induced diurnal variation of flow and play an important role in a riverine ecosystem management and be able to provide a qualitative idea about changes in the habitat for aquatic and riparian species.

Keywords: ecosystem, environmental flow assessment, entropy, IHA, TNC

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Authors: Adem Acır

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In this study, time dependent neutronic analysis of incineration of minor actinides of a Laser Fusion Inertial Confinement Fusion Fission Energy (LIFE) engine was performed. The calculations were carried out by using MCNP codes with ENDF/B.VI neutron data library. In the neutronic calculations, TRISO particles fueled with minor actinides with natural lithium coolant were performed. The natural lithium cooled LIFE engine used 10 % TRISO fuel minor actinides composition. Tritium breeding ratios (TBR) and energy multiplication factor (M) burnup values were computed as 1.46 and 3.75, respectively. The reactor operation time was calculated as ~ 21 years. The burnup values were obtained as ~1060 GWD/MT, respectively. As a result, the very higher burnup were achieved of LIFE engine.

Keywords: Monte Carlo, minor actinides, nuclear waste, LIFE engine

Procedia PDF Downloads 293