Search results for: Advanced Sheet Molding Compounds
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5221

Search results for: Advanced Sheet Molding Compounds

4951 An Endophyte of Amphipterygium adstringens as Producer of Cytotoxic Compounds

Authors: Karol Rodriguez-Peña, Martha L. Macias-Rubalcava, Leticia Rocha-Zavaleta, Sergio Sanchez

Abstract:

A bioassay-guided study for anti-cancer compounds from endophytes of the Mexican medicinal plant Amphipteryygium adstringens resulted in the isolation of a streptomycete capable of producing a group of compounds with high cytotoxic activity. Microorganisms from surface sterilized samples of various sections of the plant were isolated and all the actinomycetes found were evaluated for their potential to produce compounds with cytotoxic activity against cancer cell lines MCF7 (breast cancer) and HeLa (cervical cancer) as well as the non-tumoural cell line HaCaT (keratinocyte). The most active microorganism was picked for further evaluation. The identification of the microorganism was carried out by 16S rDNA gene sequencing, finding the closest proximity to Streptomyces scabrisporus, but with the additional characteristic that the strain isolated in this study was capable of producing colorful compounds never described for this species. Crude extracts of dichloromethane and ethyl acetate showed IC50 values of 0.29 and 0.96 μg/mL for MCF7, 0.51 and 1.98 μg/mL for HeLa and 0.96 and 2.7 μg/mL for HaCaT. Scaling the fermentation to 10 L in a bioreactor generated 1 g of total crude extract, which was fractionated by silica gel open column to yield 14 fractions. Nine of the fractions showed cytotoxic activity. Fraction 4 was chosen for subsequent purification because of its high activity against cancerous cell lines, lower activity against keratinocytes. HPLC-UV-MS/ESI was used for the evaluation of this fraction, finding at least 10 different compounds with high values of m/z (≈588). Purification of the compounds was carried out by preparative thin-layer chromatography. The prevalent compound was Steffimycin B, a molecule known for its antibiotic and cytotoxic activities and also for its low solubility in aqueous solutions. Along with steffimycin B, another five compounds belonging to the steffimycin family were isolated and at this moment their structures are being elucidated, some of which display better solubility in water: an attractive property for the pharmaceutical industry. As a conclusion to this study, the isolation of endophytes resulted in the discovery of a strain capable of producing compounds with high cytotoxic activity that need to be studied for their possible utilization.

Keywords: amphipterygium adstringens, cytotoxicity, streptomyces scabrisporus, steffimycin

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4950 Synthesis and Characterisation of New Heteropolyanion Substitute by CO2+

Authors: Ouahiba Bechiri, Mostefa Abbessi

Abstract:

In recent year, polyoxometallates are intensely being explored because of their applications as new materiels, structural aesthetics, catalysts, and biologically active compounds. heteropolyanions of general formulae [X2M18O62] n- (X= heteroatom, e.g. P, Si) and (M=W, Mo), known as Dawson-type anions, constitue a special class of polyoxometallate compounds. In this present work, cobalt substituted heteropolyanion Dawson-type [HP2W15Mo3CoO61] were synthesized and characterized by IR spectroscopy, 31 P NMR, cyclic voltammetry.

Keywords: heteropolyanions, nanomaterials, Dawson-type, characterization

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4949 The Effects of Modern Materials on the Moisture Resistance Performance of Architectural Buildings

Authors: Leyli Hashemi Rafsanjani, Hoda Mortazavi Alavi, Amirhossein Habibzadeh

Abstract:

At present, the atmospheric and environmental factors impose massive damages to buildings. Thus, to reduce these damages, researchers pay more attention on qualitative and quantitative characteristic of buildings materials. Condensation is one of the problems in Contemporary Sustecture Design. It could cause serious damages to the frontage, interior and structural elements of buildings. As a result, taking preventative steps to avoid condensation from occurring in buildings will help prevent avoidable and costly problems in the future. Hence, the aim of this paper is to answer the question: “Does the use of advanced materials cause the reduction of condensation formed on the walls?" In response to those flaws, this paper considered similar articles and selected 20 buildings randomly from contemporary architecture of developing countries which have been built in recent decade from 2002 to 2012, to find out the mutual relation between the usage of advanced materials and level of condensation damages. This consideration shows that by using advanced materials, we will have fewer damages.

Keywords: condensation, advanced materials, contemporary sustecture, moisture

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4948 Impact of Pulsing and Trickle Flow on Catalytic Wet Air Oxidation of Phenolic Compounds in Waste Water at High Pressure

Authors: Safa'a M. Rasheed, Saba A. Gheni, Wadood T. Mohamed

Abstract:

Phenolic compounds are the most carcinogenic pollutants in waste water in effluents of refineries and pulp industry. Catalytic wet air oxidation is an efficient industrial treatment process to oxidize phenolic compounds into unharmful organic compounds. Mode of flow of the fluid to be treated is a dominant factor in determining effectiveness of the catalytic process. The present study aims to obtain a mathematical model describing the conversion of phenolic compounds as a function of the process variables; mode of flow (trickling and pulsing), temperature, pressure, along with a high concentration of phenols and a platinum supported alumina catalyst. The model was validated with the results of experiments obtained in a fixed bed reactor. High pressure and temperature were employed at 8 bar and 140 °C. It has been found that conversion of phenols is highly influenced by mode of flow and the change is caused by changes occurred in hydrodynamic regime at the time of pulsing flow mode, thereby a temporal variation in wetting efficiency of platinum prevails; which in turn increases and/or decreases contact time with phenols in wastewater. The model obtained was validated with experimental results, and it is found that the model is a good agreement with the experimental results.

Keywords: wastewater, phenol, pulsing flow, wet oxidation, high pressure

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4947 Clustering of Natural and Nature Derived Compounds for Cardiovascular Disease: Pharmacophore Modeling

Authors: S. Roy, R. Rekha, K. Sriram, G. Subhadra, R. Johana

Abstract:

Cardiovascular disease remains a leading cause of death in most industrialized countries. Many chemical drugs are available in the market which targets different receptor proteins related to cardiovascular diseases. Of late the traditional herbal drugs are safer when compared to chemical drugs because of its side effects. However, many herbal remedies used in treating cardiovascular diseases have not undergone scientific assessment to prove its pharmacological activities. There are many natural compounds, nature derived and Natural product mimic compounds are available which are in the market as approved drug. In the most of the cases drug activity at the molecular level are not known. Here we have categorized those compounds with our experimental compounds in different classes based on the structural similarity and physicochemical properties, using a tool, Chemmine and has attempted to understand the mechanism of the action of a experimental compound, which are clustered with Simvastatin, Lovastatin, Mevastatin and Pravastatin. Target protein molecule for Simvastatin, Lovastatin, Mevastatin and Pravastatin is HMG-CoA reductase, so we concluded that the experimental compound may be able to bind to the same target. Molecular docking and atomic interaction studies with simvastatin and our experimental compound were compared. A pharmacophore modeling was done based on the experimental compound and HMG-CoA reductase inhibitor.

Keywords: molecular docking, physicochemical properties, pharmacophore modeling structural similarity, pravastatin

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4946 Comparison of Silica-Filled Rubber Compound Prepared from Unmodified and Modified Silica

Authors: Thirawudh Pongprayoon, Watcharin Rassamee

Abstract:

Silica-filled natural rubber compounds were prepared from unmodified and surface-modified silica. The modified silica was coated by ultrathin film of polyisoprene by admicellar polymerization. FTIR and SEM were applied to characterize the modified silica. The cure, mechanic, and dynamics properties were investigated with the comparison of the compounds. Cure characterization of modified silica rubber compound was shorter than that of unmodified silica compound. Strength and abrasion resistance of modified silica compound were better than those of unmodified silica rubber compound. Wet grip and rolling resistance analyzed by DMA from tanδ at 0°C and 60°C using 5 Hz were also better than those of unmodified silica rubber compound.

Keywords: silica, admicellar polymerization, rubber compounds, mechanical properties, dynamic properties

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4945 Characterization of Surface Suction Grippers for Continuous-Discontinuous Fiber Reinforced Semi-Finished Parts of an Automated Handling and Preforming Operation

Authors: Jürgen Fleischer, Woramon Pangboonyanon, Dominic Lesage

Abstract:

Non-metallic lightweight materials such as fiber reinforced plastics (FRP) become very significant at present. Prepregs e.g. SMC and unidirectional tape (UD-tape) are one of raw materials used to produce FRP. This study concerns with the manufacturing steps of handling and preforming of this UD-SMC and focuses on the investigation of gripper characteristics regarding gripping forces in normal and lateral direction, in order to identify suitable operating pressures for a secure gripping operation. A reliable handling and preforming operation results in a higher adding value of the overall process chain. As a result, the suitable operating pressures depending on travelling direction for each material type could be shown. Moreover, system boundary conditions regarding allowable pulling force in normal and lateral directions during preforming could be measured.

Keywords: continuous-discontinuous fiber reinforced plastics, UD-SMC-prepreg, handling, preforming, prepregs, sheet moulding compounds, surface suction gripper

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4944 High Strength, High Toughness Polyhydroxybutyrate-Co-Valerate Based Biocomposites

Authors: S. Z. A. Zaidi, A. Crosky

Abstract:

Biocomposites is a field that has gained much scientific attention due to the current substantial consumption of non-renewable resources and the environmentally harmful disposal methods required for traditional polymer composites. Research on natural fiber reinforced polyhydroxyalkanoates (PHAs) has gained considerable momentum over the past decade. There is little work on PHAs reinforced with unidirectional (UD) natural fibers and little work on using epoxidized natural rubber (ENR) as a toughening agent for PHA-based biocomposites. In this work, we prepared polyhydroxybutyrate-co-valerate (PHBV) biocomposites reinforced with UD 30 wt.% flax fibers and evaluated the use of ENR with 50% epoxidation (ENR50) as a toughening agent for PHBV biocomposites. Quasi-unidirectional flax/PHBV composites were prepared by hand layup, powder impregnation followed by compression molding.  Toughening agents – polybutylene adiphate-co-terephthalate (PBAT) and ENR50 – were cryogenically ground into powder and mechanically mixed with main matrix PHBV to maintain the powder impregnation process. The tensile, flexural and impact properties of the biocomposites were measured and morphology of the composites examined using optical microscopy (OM) and scanning electron microscopy (SEM). The UD biocomposites showed exceptionally high mechanical properties as compared to the results obtained previously where only short fibers have been used. The improved tensile and flexural properties were attributed to the continuous nature of the fiber reinforcement and the increased proportion of fibers in the loading direction. The improved impact properties were attributed to a larger surface area for fiber-matrix debonding and for subsequent sliding and fiber pull-out mechanisms to act on, allowing more energy to be absorbed. Coating cryogenically ground ENR50 particles with PHBV powder successfully inhibits the self-healing nature of ENR-50, preventing particles from coalescing and overcoming problems in mechanical mixing, compounding and molding. Cryogenic grinding, followed by powder impregnation and subsequent compression molding is an effective route to the production of high-mechanical-property biocomposites based on renewable resources for high-obsolescence applications such as plastic casings for consumer electronics.

Keywords: natural fibers, natural rubber, polyhydroxyalkanoates, unidirectional

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4943 Theoretical Analysis of the Existing Sheet Thickness in the Calendering of Pseudoplastic Material

Authors: Muhammad Zahid

Abstract:

The mechanical process of smoothing and compressing a molten material by passing it through a number of pairs of heated rolls in order to produce a sheet of desired thickness is called calendering. The rolls that are in combination are called calenders, a term derived from kylindros the Greek word for the cylinder. It infects the finishing process used on cloth, paper, textiles, leather cloth, or plastic film and so on. It is a mechanism which is used to strengthen surface properties, minimize sheet thickness, and yield special effects such as a glaze or polish. It has a wide variety of applications in industries in the manufacturing of textile fabrics, coated fabrics, and plastic sheeting to provide the desired surface finish and texture. An analysis has been presented for the calendering of Pseudoplastic material. The lubrication approximation theory (LAT) has been used to simplify the equations of motion. For the investigation of the nature of the steady solutions that exist, we make use of the combination of exact solution and numerical methods. The expressions for the velocity profile, rate of volumetric flow and pressure gradient are found in the form of exact solutions. Furthermore, the quantities of interest by engineering point of view, such as pressure distribution, roll-separating force, and power transmitted to the fluid by the rolls are also computed. Some results are shown graphically while others are given in the tabulated form. It is found that the non-Newtonian parameter and Reynolds number serve as the controlling parameters for the calendering process.

Keywords: calendering, exact solutions, lubrication approximation theory, numerical solutions, pseudoplastic material

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4942 Synthesis and Molecular Docking of Isonicotinohydrazide Derivatives as Anti-Tuberculosis Candidates

Authors: Ruswanto Ruswanto, Richa Mardianingrum, Tita Nofianti, Nur Rahayuningsih

Abstract:

Tuberculosis (TB) is a chronic disease as a result of Mycobacterium tuberculosis. It can affect all age groups, and hence, is a global health problem that causes the death of millions of people every year. One of the drugs used in tuberculosis treatment is isonicotinohydrazide. In this study, N'-benzoylisonicotinohydrazide derivative compounds (a-l) were prepared using acylation reactions between isonicotinohydrazide and benzoyl chloride derivatives, through the reflux method. Molecular docking studies suggested that all of the compounds had better interaction with Mycobacterium tuberculosis enoyl-acyl carrier protein reductase (InhA) than isonicotinohydrazide. It can be concluded that N'-benzoylisonicotinohydrazide derivatives (a-l) could be used as anti-tuberculosis candidates. From the docking results revealed that all of the compounds interact well with InhA, with compound g (N'-(3-nitrobenzoyl)isonicotinohydrazide) exhibiting the best interaction.

Keywords: anti-tuberculosis , docking, InhA, N'-benzoylisonicotinohydrazide, synthesis

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4941 Effectiveness of ATMS (Advanced Transport Management Systems) in Asuncion, Paraguay

Authors: Sung Ho Oh

Abstract:

The advanced traffic lights, the system of traffic information collection and provision, the CCTVs for traffic control, and the traffic information center were installed in Asuncion, capital of Paraguay. After pre-post comparison of the installation, significant changes were found. Even though the traffic volumes were increased, travel speed was higher, so that travel time from origin to destination was decreased. the saving values for travel time, gas cost, and environmental cost are about 47 million US dollars per year. Satisfaction survey results for the installation were presented with statistical significance analysis.

Keywords: advanced transport management systems, effectiveness, Paraguay, traffic lights

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4940 Methodology for the Determination of Triterpenic Compounds in Apple Extracts

Authors: Mindaugas Liaudanskas, Darius Kviklys, Kristina Zymonė, Raimondas Raudonis, Jonas Viškelis, Norbertas Uselis, Pranas Viškelis, Valdimaras Janulis

Abstract:

Apples are among the most commonly consumed fruits in the world. Based on data from the year 2014, approximately 84.63 million tons of apples are grown per annum. Apples are widely used in food industry to produce various products and drinks (juice, wine, and cider); they are also used unprocessed. Apples in human diet are an important source of different groups of biological active compounds that can positively contribute to the prevention of various diseases. They are a source of various biologically active substances – especially vitamins, organic acids, micro- and macro-elements, pectins, and phenolic, triterpenic, and other compounds. Triterpenic compounds, which are characterized by versatile biological activity, are the biologically active compounds found in apples that are among the most promising and most significant for human health. A specific analytical procedure including sample preparation and High Performance Liquid Chromatography (HPLC) analysis was developed, optimized, and validated for the detection of triterpenic compounds in the samples of different apples, their peels, and flesh from widespread apple cultivars 'Aldas', 'Auksis', 'Connel Red', 'Ligol', 'Lodel', and 'Rajka' grown in Lithuanian climatic conditions. The conditions for triterpenic compound extraction were optimized: the solvent of the extraction was 100% (v/v) acetone, and the extraction was performed in an ultrasound bath for 10 min. Isocratic elution (the eluents ratio being 88% (solvent A) and 12% (solvent B)) for a rapid separation of triterpenic compounds was performed. The validation of the methodology was performed on the basis of the ICH recommendations. The following characteristics of validation were evaluated: the selectivity of the method (specificity), precision, the detection and quantitation limits of the analytes, and linearity. The obtained parameters values confirm suitability of methodology to perform analysis of triterpenic compounds. Using the optimised and validated HPLC technique, four triterpenic compounds were separated and identified, and their specificity was confirmed. These compounds were corosolic acid, betulinic acid, oleanolic acid, and ursolic acid. Ursolic acid was the dominant compound in all the tested apple samples. The detected amount of betulinic acid was the lowest of all the identified triterpenic compounds. The greatest amounts of triterpenic compounds were detected in whole apple and apple peel samples of the 'Lodel' cultivar, and thus apples and apple extracts of this cultivar are potentially valuable for use in medical practice, for the prevention of various diseases, for adjunct therapy, for the isolation of individual compounds with a specific biological effect, and for the development and production of dietary supplements and functional food enriched in biologically active compounds. Acknowledgements. This work was supported by a grant from the Research Council of Lithuania, project No. MIP-17-8.

Keywords: apples, HPLC, triterpenic compounds, validation

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4939 Antireflection Performance of Graphene Directly Deposited on Silicon Substrate by the Atmospheric Pressure Chemical Vapor Deposition Method

Authors: Samira Naghdi, Kyong Yop Rhee

Abstract:

Transfer-free synthesis of graphene on dielectric substrates is highly desirable but remains challenging. Here, by using a thin sacrificial platinum layer as a catalyst, graphene was deposited on a silicon substrate through a simple and transfer-free synthesis method. During graphene growth, the platinum layer evaporated, resulting in direct deposition of graphene on the silicon substrate. In this work, different growth conditions of graphene were optimized. Raman spectra of the produced graphene indicated that the obtained graphene was bilayer. The sheet resistance obtained from four-point probe measurements demonstrated that the deposited graphene had high conductivity. Reflectance spectroscopy of graphene-coated silicon showed a decrease in reflectance across the wavelength range of 200-800 nm, indicating that the graphene coating on the silicon surface had antireflection capabilities.

Keywords: antireflection coating, chemical vapor deposition, graphene, the sheet resistance

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4938 Study on the Mechanical Properties of Bamboo Fiber-Reinforced Polypropylene Based Composites: Effect of Gamma Radiation

Authors: Kamrun N. Keya, Nasrin A. Kona, Ruhul A. Khan

Abstract:

Bamboo fiber (BF) reinforced polypropylene (PP) based composites were fabricated by a conventional compression molding technique. In this investigation, bamboo composites were manufactured using different percentages of fiber, which were varying from 25-65% on the total weight of the composites. To fabricate the BF/PP composites untreated and treated fibers were selected. A systematic study was done to observe the physical, mechanical, and interfacial behavior of the composites. In this study, mechanical properties of the composites such as tensile, impact, and bending properties were observed precisely. Maximum tensile strength (TS) and bending strength (BS) were found for 50 wt% fiber composites, 65 MPa, and 85.5 MPa respectively, whereas the highest tensile modulus (TM) and bending modulus (BM) was examined, 5.73 GPa and 7.85 GPa respectively. The BF/PP based composites were treated with irradiated under gamma radiation (the source strength 50 kCi Cobalt-60) of various doses (i.e. 10, 20, 30, 40, 50 and 60 kGy doses). The effect of gamma radiation on the composites was also investigated, and it found that the effect of 30.0 kGy (i.e. units for radiation measurement is 'gray', kGy=kilogray) gamma dose showed better mechanical properties than other doses. After flexural testing, fracture sides of the untreated and treated both composites were studied by scanning electron microscope (SEM). SEM results of the treated BF/PP based composites showed better fiber-matrix adhesion and interfacial bonding than untreated BF/PP based composites. Water uptake and soil degradation tests of untreated and treated composites were also investigated.

Keywords: bamboo fiber, polypropylene, compression molding technique, gamma radiation, mechanical properties, scanning electron microscope

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4937 Part Variation Simulations: An Industrial Case Study with an Experimental Validation

Authors: Narendra Akhadkar, Silvestre Cano, Christophe Gourru

Abstract:

Injection-molded parts are widely used in power system protection products. One of the biggest challenges in an injection molding process is shrinkage and warpage of the molded parts. All these geometrical variations may have an adverse effect on the quality of the product, functionality, cost, and time-to-market. The situation becomes more challenging in the case of intricate shapes and in mass production using multi-cavity tools. To control the effects of shrinkage and warpage, it is very important to correctly find out the input parameters that could affect the product performance. With the advances in the computer-aided engineering (CAE), different tools are available to simulate the injection molding process. For our case study, we used the MoldFlow insight tool. Our aim is to predict the spread of the functional dimensions and geometrical variations on the part due to variations in the input parameters such as material viscosity, packing pressure, mold temperature, melt temperature, and injection speed. The input parameters may vary during batch production or due to variations in the machine process settings. To perform the accurate product assembly variation simulation, the first step is to perform an individual part variation simulation to render realistic tolerance ranges. In this article, we present a method to simulate part variations coming from the input parameters variation during batch production. The method is based on computer simulations and experimental validation using the full factorial design of experiments (DoE). The robustness of the simulation model is verified through input parameter wise sensitivity analysis study performed using simulations and experiments; all the results show a very good correlation in the material flow direction. There exists a non-linear interaction between material and the input process variables. It is observed that the parameters such as packing pressure, material, and mold temperature play an important role in spread on functional dimensions and geometrical variations. This method will allow us in the future to develop accurate/realistic virtual prototypes based on trusted simulated process variation and, therefore, increase the product quality and potentially decrease the time to market.

Keywords: correlation, molding process, tolerance, sensitivity analysis, variation simulation

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4936 Free Raducal Scavenging Activity of Fractionated Extract and Structural Elucidation of Isolated Compounds from Hydrocotyl Bonariensis Comm. Ex Lam Leaves

Authors: Emmanuel O Ajani, Sabiu S, Mariam Zakari, Fisayo A Bamisaye

Abstract:

Hydrocotyl bonariensis is a plant which anticataractogenic potentials have been reported. In the present study an attempt was made to evaluate the in vitro antioxidant activity of the fractionates of the leaves extract and also characterize some of its chemical constituents. DPPH, H₂O₂, OH and NO free radical scavenging, metal chelating and reducing power activity was used to evaluate the antioxidant activity of the crude extract fractionates. Fresh leaves of Hydrocotyl bonariensis leaves were extracted in 70% methanol. The extract was partitioned with different solvent system of increasing polarity (n-hexane, chloroform, ethyl acetate methanol and water). Compounds were isolated from the aqueous practitionate using accelerated gradient chromatography, vacuum liquid chromatography, preparative TLC and conventional column chromatography. The presence of the chemical groups was established with HPLC and Fourier Transform Infra Red. The structures of isolated compounds were elucidated by spectroscopic study and chemical shifts. Data from the study indicates that all the fractionates contain compounds with free radical scavenging activity. This activity was more pronounced in the aqueous fractionate (DPPH IC₅₀, 0025 ± 0.011 mg/ml, metal chelating capacity 27.5%, OH- scavenging IC₅₀, 0.846 ± 0.037 mg/ml, H₂O₂ scavenging IC₅₀ 0.521 ± 0.015 mg/ml, reducing power IC₅₀ 0.248 ± 0.025 mg/ml and NO scavenging IC₅₀ 0.537 ± 0.038 mg/ml). Two compounds were isolated and when compared with data from the literature; the structures were suggestive of polyphenolic flavonoid, quercetin and 3-O-β-D-glucopyranosyl-sitosterol. The result indicates that H. bonariensis leaves contain bioactive compounds with antioxidant activity.

Keywords: antioxidant, cataract, free radical, flavonoids, hydrocotyl bonariensis

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4935 Synthesis and Prediction of Activity Spectra of Substances-Assisted Evaluation of Heterocyclic Compounds Containing Hydroquinoline Scaffolds

Authors: Gizachew Mulugeta Manahelohe, Khidmet Safarovich Shikhaliev

Abstract:

There has been a significant surge in interest in the synthesis of heterocyclic compounds that contain hydroquinoline fragments. This surge can be attributed to the broad range of pharmaceutical and industrial applications that these compounds possess. The present study provides a comprehensive account of the synthesis of both linear and fused heterocyclic systems that incorporate hydroquinoline fragments. Furthermore, the pharmacological activity spectra of the synthesized compounds were assessed using the in silico method, employing the prediction of activity spectra of substances (PASS) program. Hydroquinoline nitriles 7 and 8 were prepared through the reaction of the corresponding hydroquinolinecarbaldehyde using a hydroxylammonium chloride/pyridine/toluene system and iodine in aqueous ammonia under ambient conditions, respectively. 2-Phenyl-1,3-oxazol-5(4H)-ones 9a,b and 10a,b were synthesized via the condensation of compounds 5a,b and 6a,b with hippuric acid in acetic acid in 30–60% yield. When activated, 7-methylazolopyrimidines 11a and b were reacted with N-alkyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline-6-carbaldehydes 6a and b, and triazolo/pyrazolo[1,5-a]pyrimidin-6-yl carboxylic acids 12a and b were obtained in 60–70% yield. The condensation of 7-hydroxy-1,2,3,4-tetramethyl-1,2-dihydroquinoline 3 h with dimethylacetylenedicarboxylate (DMAD) and ethyl acetoacetate afforded cyclic products 16 and 17, respectively. The condensation reaction of 6-formyl-7-hydroxy-1,2,2,4-tetramethyl-1,2-dihydroquinoline 5e with methylene-active compounds such as ethyl cyanoacetate/dimethyl-3-oxopentanedioate/ethyl acetoacetate/diethylmalonate/Meldrum’s acid afforded 3-substituted coumarins containing dihydroquinolines 19 and 21. Pentacyclic coumarin 22 was obtained via the random condensation of malononitrile with 5e in the presence of a catalytic amount of piperidine in ethanol. The biological activities of the synthesized compounds were assessed using the PASS program. Based on the prognosis, compounds 13a, b, and 14 exhibited a high likelihood of being active as inhibitors of gluconate 2-dehydrogenase, as well as possessing antiallergic, antiasthmatic, and antiarthritic properties, with a probability value (Pa) ranging from 0.849 to 0.870. Furthermore, it was discovered that hydroquinoline carbonitriles 7 and 8 tended to act as effective progesterone antagonists and displayed antiallergic, antiasthmatic, and antiarthritic effects (Pa = 0.276–0.827). Among the hydroquinolines containing coumarin moieties, compounds 17, 19a, and 19c were predicted to be potent progesterone antagonists, with Pa values of 0.710, 0.630, and 0.615, respectively.

Keywords: heterocyclic compound, hydroquinoline, Vilsmeier–Haack formulation, quinolone

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4934 Light and Electron Study of Acrylamide–Induced Hypothalamic Changes

Authors: Keivan Jamshidi

Abstract:

Distal swelling and eventual degeneration of axon in the CNS and PNS have been considered to be the characteristic neuropathological effects of acrylamide (ACR) neuropathy. This study was conducted to determine the neurotoxic effects of different doses of ACR (0.5, 5, 50, 100, and 500 mg/kg per day × 11days i. p.) on hypothalamus of rat using the de Olmos amino cupric-silver stain and electron microscopy. For this purpose 60 adult male rats (Wistar, approximately 250 g) were randomly assigned in 5 treatment groups as A, B, C, D, E) exposed to 0.5, 5, 50, 100, and 500 mg/kg per dayx11days i. p. and one control group as F received daily i. p. injections of 0.9% saline (3ml/kg). As indices of developing neurotoxicity, weight gain, gait scores and landing hindlimb foot splay were determined. After 11 days, two rats for silver stain, and two rats for EM were randomly selected; dissected and proper samples were collected from hypothalamus. Results did show no neurological behavior in groups A, B and F were observed in group C. Rats in groups D and E died within 1-2 hours due to sever toxemia. In histopathological studies based on de Olmos technique no argyrophilic neurons or processes were observed in stained sections obtained from hypothalamus of rats belong to groups A, B, and F while moderate to severe argyrophilic changes were observed in different nuclei and regions of stained sections obtained from hypothalamus of rats belong to group C. In ultra-structural studies some variations in the myelin sheet of injured axons including decompactation, interlaminar space formation, disruption of the laminar sheet, accumulation of neurofilaments, vacculation, and clumping inside the axolem, and finally complete disappearance of laminar sheet were observed.

Keywords: acrylamide, hypothalamus, rat, de Olmos amino cupric, silver stain, electron microscopy

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4933 Isolation, Characterization and Biological Activities of Compounds Isolated from Callicarpa maingayi

Authors: Muhammad A. Ado, Intan S. Ismail, Hasanah M. Ghazali, Faridah Abas

Abstract:

In this study, we have investigated the phytochemical constituents of soluble fractions of dichloromethane (DCM) of methanolic leaves extract of the Callicarpa maingayi. The phytochemicals investigation has resulted in the isolation of three triterpenoids (euscaphic acid (1), arjunic acid (2), and ursolic acid (3)) together with two flavones apigenin (4) and acacetin (5)), two phytosterols (stigmasterol 3-O-β-glycopyranoside (6) and sitosterol 3-O-β-glycopyranoside (7)), and one fatty acid (n-hexacosanoic acid (8)). Six (6) compounds isolated from this species were isolated for the first time (1, 2, 3, 4, 5, and 8). Their structures were elucidated and identified by spectral methods of one and two-dimensional NMR techniques, gas chromatography-mass spectrometry, and comparison with the previously reported literature. The biological activity of three compounds (1-3) was carried out on acetylcholinesterase inhibition activity. Compound (3) was found to displayed good inhibition against AChE with an IC₅₀ value of 21.5 ± 0.022 μM.

Keywords: acetylcholinesterase, Callicarpa maingayi, euscaphic acid, ursolic acid

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4932 Synthesis of Mg/B Containing Compound in a Modified Microwave Oven

Authors: Gülşah Çelik Gül, Figen Kurtuluş

Abstract:

Magnesium containing boron compounds with hexagonal structure have been drawn much attention due to their superconductive nature. The main target of this work is new modified microwave oven by on our own has an ability about passing through a gas in the oven medium for attainment of oxygen-free compounds such as c-BN.  Mg containing boride was synthesized by modified-microwave method under nitrogen atmosphere using amorphous boron and magnesium source in appropriate molar ratio. Microwave oven with oxygen free environment has been modified to aimed to obtain magnesium boride without oxygen. Characterizations were done by powder X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Mg containing boride, generally named magnesium boride, with amorphous character without oxygen is obtained via designed microwave oven system.

Keywords: magnesium containing boron compounds, modified microwave synthesis, powder X-ray diffraction, FTIR

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4931 Acetalization of Carbonyl Compounds by Using Al2 (HPO4)3 under Green Condition Mg HPO4

Authors: Fariba Jafari, Samaneh Heydarian

Abstract:

Al2(HPO4)3 was easily prepared and used as a solid acid in acetalization of carbonyl compounds at room temperature and under solvent-free conditions. The protection was done in short reaction times and in good to high isolated yields. The cheapness and availability of this reagent with easy procedure and work-up make this method attractive for the organic synthesis.

Keywords: acetalization, acid catalysis, carbonylcompounds, green condition, protection

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4930 Effects of Biocompatible Substrates on the Electrical Properties of Graphene

Authors: M. Simchi, M. Amiri, E. Rezvani, I. Mirzaei, M. Berahman, A. Simchi, M. Fardmanesh

Abstract:

Graphene is a single-atomic two-dimensional crystal of carbon atoms that has considerable properties due to its unique structure and physics with applications in different fields. Graphene has sensitive electrical properties due to its atomic-thin structure. Along with the substrate materials and their influence on the transport properties in graphene, design and fabrication of graphene-based devices for biomedical and biosensor applications are challenging. In this work, large-area high-quality graphene nanosheets were prepared by low pressure chemical vapor deposition using methane gas as carbon source on copper foil and transferred on the biocompatible substrates. Through deposition of titanium and gold contacts, current-voltage response of the transferred graphene on four biocompatible substrates, including PDMS, SU-8, Nitrocellulose, and Kapton (Fig. 2) were experimentally determined. The considerable effect of the substrate type on the electrical properties of graphene is shown. The sheet resistance of graphene is changed from 0.34 to 14.5 kΩ/sq, depending on the substrate.

Keywords: biocompatible substrates, electrical properties, graphene, sheet resistance

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4929 Synthesis, Molecular-Docking, and Biological Evaluation of Thiazolopyrimidine Carboxylates as Potential Antidiabetic and Antibacterial Agents

Authors: Iram Batool, Aamer Saeed, Irfan Zia Qureshi, Ayesha Razzaq, Saima Kalsoom

Abstract:

Heterocyclic compounds analogues and their derivatives have attracted strong interest in medicinal chemistry due to their biological and pharmacological properties. A series of new thiazolopyrimidine carboxylates were conveniently synthesized by one-pot three-component reaction of ethyl acetoacetate, 2-aminothiazole and benzaldehyde substituted with electron-donating and electron-withdrawing groups in order to find some more potent antidiabetic and antibacterial drugs. The structures of synthesized compounds were characterized by elemental analysis, IR, 1H NMR, 13C NMR spectroscopy. An in vitro antidiabetic effect was evaluated in adult male BALB/c mice and antibacterial activities were tested against Micrococcus luteus, Salmonella typhimurium, Bacillus subtilis, Bordetella bronchiseptica and Escherichia coli. Some of the tested compounds proved to possess good to excellent activities more than the reference drugs. An in silico molecular docking was also performed on synthesized compounds. The current study is expected to provide useful insights into the design of antidiabetic and antibacterial drugs and understanding the mechanism by which such drugs interact with RNA and diabetes target and exert their biochemical action.

Keywords: antidiabetic, antibacterial, MOE docking, thiazolopyrimidine

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4928 Effect of Structure on Properties of Incrementally Formed Titanium Alloy Sheets

Authors: Lucie Novakova, Petr Homola, Vaclav Kafka

Abstract:

Asymmetric incremental sheet forming (AISF) could significantly reduce costs incurred by the fabrication of complex industrial components with a minimal environmental impact. The AISF experiments were carried out on commercially pure titanium (Ti-Gr2), Timetal (15-3-3-3) alloy, and Ti-6Al-4V (Ti-Gr5) alloy. A special testing geometry was used to characterize the titanium alloys properties from the point of view of the forming zone and titanium structure effect. The structure and properties of the materials were assessed by means of metallographic analyses and microhardness measurements.The highest differences in the parameters assessed as a function of the sampling zone were observed in the case of alpha-phase Ti-Gr2at the expense of the most substantial sheet thinning occurrence. A springback causes a smaller stored deformation in Timetal (β alloy) resulting in less pronounced microstructure refinement and microhardness increase. Ti-6Al-4V alloy exhibited early failure due to its poor formability at ambient temperature.

Keywords: incremental forming, metallography, hardness, titanium alloys

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4927 Bioactive Compounds and Antioxidant Capacity of Instant Fruit Green Tea Powders

Authors: Akanit Pisalwadcharin, Komate Satayawut, Virachnee Lohachoompol

Abstract:

Green tea, mangosteen and pomegranate contain high levels of bioactive compounds which have antioxidant effects and great potential in food applications. The aim of this study was to produce and determine catechin contents, total phenolic contents, antioxidant activity and phenolic compounds of two instant fruit green tea powders which were green tea fortified with mangosteen juice and green tea fortified with pomegranate juice. Seventy percent of hot water extract of green tea was mixed with 30% of mangosteen juice or pomegranate juice, and then spray-dried using a spray dryer. The results showed that the drying conditions optimized for the highest total phenolic contents, catechin contents and antioxidant activity of both powders were the inlet air temperature of 170°C, outlet air temperatures of 90°C and maltodextrin concentration of 30%. The instant green tea with mangosteen powder had total phenolic contents, catechin contents and antioxidant activity of 19.18 (mg gallic acid/kg), 85.44 (mg/kg) and 4,334 (µmoles TE/100 g), respectively. The instant green tea with pomegranate powder had total phenolic contents, catechin contents and antioxidant activity of 32.72 (mg gallic acid/kg), 156.36 (mg/kg) and 6,283 (µmoles TE/100 g), respectively. The phenolic compounds in instant green tea with mangosteen powder comprised of tannic acid (2,156.87 mg/kg), epigallocatechin-3-gallate (898.23 mg/kg) and rutin (13.74 mg/kg). Also, the phenolic compounds in instant green tea with pomegranate powder comprised of tannic acid (2,275.82 mg/kg), epigallocatechin-3-gallate (981.23 mg/kg), rutin (14.97 mg/kg) and i-quercetin (5.86 mg/kg).

Keywords: green tea, mangosteen, pomegranate, antioxidant activity

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4926 Quantitative Structure-Activity Relationship Analysis of Binding Affinity of a Series of Anti-Prion Compounds to Human Prion Protein

Authors: Strahinja Kovačević, Sanja Podunavac-Kuzmanović, Lidija Jevrić, Milica Karadžić

Abstract:

The present study is based on the quantitative structure-activity relationship (QSAR) analysis of eighteen compounds with anti-prion activity. The structures and anti-prion activities (expressed in response units, RU%) of the analyzed compounds are taken from CHEMBL database. In the first step of analysis 85 molecular descriptors were calculated and based on them the hierarchical cluster analysis (HCA) and principal component analysis (PCA) were carried out in order to detect potential significant similarities or dissimilarities among the studied compounds. The calculated molecular descriptors were physicochemical, lipophilicity and ADMET (absorption, distribution, metabolism, excretion and toxicity) descriptors. The first stage of the QSAR analysis was simple linear regression modeling. It resulted in one acceptable model that correlates Henry's law constant with RU% units. The obtained 2D-QSAR model was validated by cross-validation as an internal validation method. The validation procedure confirmed the model’s quality and therefore it can be used for prediction of anti-prion activity. The next stage of the analysis of anti-prion activity will include 3D-QSAR and molecular docking approaches in order to select the most promising compounds in treatment of prion diseases. These results are the part of the project No. 114-451-268/2016-02 financially supported by the Provincial Secretariat for Science and Technological Development of AP Vojvodina.

Keywords: anti-prion activity, chemometrics, molecular modeling, QSAR

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4925 Model Predictive Control Applied to Thermal Regulation of Thermoforming Process Based on the Armax Linear Model and a Quadratic Criterion Formulation

Authors: Moaine Jebara, Lionel Boillereaux, Sofiane Belhabib, Michel Havet, Alain Sarda, Pierre Mousseau, Rémi Deterre

Abstract:

Energy consumption efficiency is a major concern for the material processing industry such as thermoforming process and molding. Indeed, these systems should deliver the right amount of energy at the right time to the processed material. Recent technical development, as well as the particularities of the heating system dynamics, made the Model Predictive Control (MPC) one of the best candidates for thermal control of several production processes like molding and composite thermoforming to name a few. The main principle of this technique is to use a dynamic model of the process inside the controller in real time in order to anticipate the future behavior of the process which allows the current timeslot to be optimized while taking future timeslots into account. This study presents a procedure based on a predictive control that brings balance between optimality, simplicity, and flexibility of its implementation. The development of this approach is progressive starting from the case of a single zone before its extension to the multizone and/or multisource case, taking thus into account the thermal couplings between the adjacent zones. After a quadratic formulation of the MPC criterion to ensure the thermal control, the linear expression is retained in order to reduce calculation time thanks to the use of the ARMAX linear decomposition methods. The effectiveness of this approach is illustrated by experiment and simulation.

Keywords: energy efficiency, linear decomposition methods, model predictive control, mold heating systems

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4924 Synthesis, Inhibitory Activity, and Molecular Modelling of 2-Hydroxy-3-Oxo-3-Phenylpropionate Derivatives as HIV-1-Integrase Inhibitors

Authors: O. J. Jesumoroti, Faridoon, R. Klein, K. A. Iobb, D. Mnkadhla, H. C. Hoppe, P. T. Kaye

Abstract:

The 1, 3-aryl diketo acids (DKA) based agents represent an important class of HIV integrase (IN) strand transfer inhibitors. In other to study the chelating role of the divalent metal ion in the inhibition of IN strand transfer, we designed and synthesized a series of 2-hydroxy-3-oxo-3-phenyl propionate derivatives with the notion that such compounds could interact with the divalent ion in the active site of IN. The synthetic sequence to the desired compounds involves the concept of Doebner knoevenagel condensation, Fischer esterification and ketohydroxylation using neuclophilic re-oxidant; compounds were characterized by their IR, IHNMR, 13CNMR, HRMS spectroscopic data and melting point determination. Also, molecular docking was employed in this study and it was revealed that there is interaction with the active site of the enzyme. However, there is disparity in the corresponding anti-HIV activity determined by the experimental bioassay. These compounds lack potency at low micromolar concentration when compared to the results of the docking studies. Nevertheless, the results of the study suggest modification of the aryl ring with one or two hydroxyl groups to improve the inhibitory activity.

Keywords: anti-HIV-1 integrase, ketohydroxylation, molecular docking, propionate derivatives

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4923 Enthalpies of Formation of Equiatomic Binary Hafnium Transition Metal Compounds HfM (M=Co, Ir, Os, Pt, Rh, Ru)

Authors: Hadda Krarcha, S. Messaasdi

Abstract:

In order to investigate Hafnium transition metal alloys HfM (M= Co, Ir, Os,Pt, Rh, Ru) phase diagrams in the region of 50/50% atomic ratio, we performed ab initio Full-Potential Linearized Augmented Plane Waves calculations of the enthalpies of formation of HfM compounds at B2 (CsCl) structure type. The obtained enthalpies of formation are discussed and compared to some of the existing models and available experimental data.

Keywords: enthalpy of formation, transition metal, binarry compunds, hafnium

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4922 Synthesis, Characterization, and Biological Evaluation of 1,3,4-Mercaptooxadiazole Ether Derivatives Analogs as Antioxidant, Cytotoxic, and Molecular Docking Studies

Authors: Desta Gebretekle Shiferaw, Balakrishna Kalluraya

Abstract:

Oxadiazoles and their derivatives with thioether functionalities represent a new and exciting class of physiologically active heterocyclic compounds. Several molecules with these moieties play a vital role in pharmaceuticals because of their diverse biological activities. This paper describes a new class of 1,3,4- oxadiazole-2-thioethers with acetophenone, coumarin, and N-phenyl acetamide residues (S-alkylation), with the hope that the addition of various biologically active molecules will have a synergistic effect on anticancer activity. The structure of the synthesized title compounds was determined by the combined methods of IR, proton-NMR, carbon-13-NMR, and mass spectrometry. Further, all the newly prepared molecules were assessed against their antioxidant activity. Furthermore, four compounds were assessed for their molecular docking interactions and cytotoxicity activity. The synthesized derivatives have shown moderate antioxidant activity compared to the standard BHA. The IC50 of the tilted molecules (11b, 11c, 13b, and 14b) observed for in vitro anti-cancer activities were 11.20, 15.73, 59.61, and 27.66 g/ml at 72-hour treatment time against the A549 cell lines, respectively. The tested compounds' biological evaluation showed that 11b is the most effective molecule in the series.

Keywords: antioxidant activity, cytotoxicity activity, molecular docking, 1, 3, 4-Oxadiazole-2 thioether derivatives

Procedia PDF Downloads 89