Search results for: protein synthesis
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4392

Search results for: protein synthesis

3702 Effect of Cooking Time, Seed-To-Water Ratio and Soaking Time on the Proximate Composition and Functional Properties of Tetracarpidium conophorum (Nigerian Walnut) Seeds

Authors: J. O. Idoko, C. N. Michael, T. O. Fasuan

Abstract:

This study investigated the effects of cooking time, seed-to-water ratio and soaking time on proximate and functional properties of African walnut seed using Box-Behnken design and Response Surface Methodology (BBD-RSM) with a view to increase its utilization in the food industry. African walnut seeds were sorted washed, soaked, cooked, dehulled, sliced, dried and milled. Proximate analysis and functional properties of the samples were evaluated using standard procedures. Data obtained were analyzed using descriptive and inferential statistics. Quadratic models were obtained to predict the proximate and functional qualities as a function of cooking time, seed-to-water ratio and soaking time. The results showed that the crude protein ranged between 11.80% and 23.50%, moisture content ranged between 1.00% and 4.66%, ash content ranged between 3.35% and 5.25%, crude fibre ranged from 0.10% to 7.25% and carbohydrate ranged from 1.22% to 29.35%. The functional properties showed that soluble protein ranged from 16.26% to 42.96%, viscosity ranged from 23.43 mPas to 57 mPas, emulsifying capacity ranged from 17.14% to 39.43% and water absorption capacity ranged from 232% to 297%. An increase in the volume of water used during cooking resulted in loss of water soluble protein through leaching, the length of soaking time and the moisture content of the dried product are inversely related, ash content is inversely related to the cooking time and amount of water used, extraction of fat is enhanced by increase in soaking time while increase in cooking and soaking times result into decrease in fibre content. The results obtained indicated that African walnut could be used in several food formulations as protein supplement and binder.

Keywords: African walnut, functional properties, proximate analysis, response surface methodology

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3701 Advanced Humidity Sensors Using Cobalt and Iron-Doped ZnO-rGO Composites

Authors: Wallia Majeed

Abstract:

Humidity sensors based on doped ZnO-rGO composites have shown promise due to their sensitivity to humidity changes. Here, it report on the hydrothermal synthesis of ZnO-rGO and doped ZnO-rGO nanocomposites, incorporating cobalt and iron dopants at 2% concentration. X-ray diffraction confirmed successful doping, while scanning electron microscopy revealed the composite's layered structure with embedded ZnO rods. To evaluate their performance, humidity sensors were fabricated by depositing aluminum electrodes on silicon substrates coated with the composites. The Fe-doped ZnO-rGO sensor exhibited rapid response (27 s) and recovery times (24 s) across a wide humidity range (11% to 97% RH), surpassing ZnO-rGO and Co-doped ZnO-rGO variants in sensitivity (2.2k at 100 Hz). These findings highlight Fe-doped ZnO-rGO composites as ideal candidates for humidity sensing applications, offering enhanced performance crucial for environmental monitoring and industrial processes.

Keywords: humidity sensors, nanocomposites, hydrothermal synthesis, sensitivity

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3700 High Frequency Sonochemistry: A New Field of Cavitation‐Free Acoustic Materials Synthesis and Manipulation

Authors: Amgad Rezk, Heba Ahmed, Leslie Yeo

Abstract:

Ultrasound presents a powerful means for material synthesis. In this talk, we showcase a new field demonstrating the possibility for harnessing sound energy sources at considerably higher frequencies (10 MHz to 1 GHz) compared to conventional ultrasound (kHz and up to ~2 MHz) for crystalising and manipulating a variety of nanoscale materials. At these frequencies, cavitation—which underpins most sonochemical processes—is largely absent, suggesting that altogether fundamentally different mechanisms are at dominant. Examples include the crystallization of highly oriented structures, quasi-2D metal-organic frameworks and nanocomposites. These fascinating examples reveal how the highly nonlinear electromechanical coupling associated with high-frequency surface vibration gives rise to molecular ordering and assembly on the nano and microscale.

Keywords: high-frequency acoustics, microfluidics, crystallisation, composite nanomaterials

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3699 Green Organic Chemistry, a New Paradigm in Pharmaceutical Sciences

Authors: Pesaru Vigneshwar Reddy, Parvathaneni Pavan

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Green organic chemistry which is the latest and one of the most researched topics now-a- days has been in demand since 1990’s. Majority of the research in green organic chemistry chemicals are some of the important starting materials for greater number of major chemical industries. The production of organic chemicals has raw materials (or) reagents for other application is major sector of manufacturing polymers, pharmaceuticals, pesticides, paints, artificial fibers, food additives etc. organic synthesis on a large scale compound to the labratory scale, involves the use of energy, basic chemical ingredients from the petro chemical sectors, catalyst and after the end of the reaction, seperation, purification, storage, packing distribution etc. During these processes there are many problems of health and safety for workers in addition to the environmental problems caused there by use and deposition as waste. Green chemistry with its 12 principles would like to see changes in conventional way that were used for decades to make synthetic organic chemical and the use of less toxic starting materials. Green chemistry would like to increase the efficiency of synthetic methods, to use less toxic solvents, reduce the stage of synthetic routes and minimize waste as far as practically possible. In this way, organic synthesis will be part of the effort for sustainable development Green chemistry is also interested for research and alternatives innovations on many practical aspects of organic synthesis in the university and research labaratory of institutions. By changing the methodologies of organic synthesis, health and safety will be advanced in the small scale laboratory level but also will be extended to the industrial large scale production a process through new techniques. The three key developments in green chemistry include the use of super critical carbondioxide as green solvent, aqueous hydrogen peroxide as an oxidising agent and use of hydrogen in asymmetric synthesis. It also focuses on replacing traditional methods of heating with that of modern methods of heating like microwaves traditions, so that carbon foot print should reduces as far as possible. Another beneficiary of this green chemistry is that it will reduce environmental pollution through the use of less toxic reagents, minimizing of waste and more bio-degradable biproducts. In this present paper some of the basic principles, approaches, and early achievements of green chemistry has a branch of chemistry that studies the laws of passing of chemical reactions is also considered, with the summarization of green chemistry principles. A discussion about E-factor, old and new synthesis of ibuprofen, microwave techniques, and some of the recent advancements also considered.

Keywords: energy, e-factor, carbon foot print, micro-wave, sono-chemistry, advancement

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3698 Synthesis and Characterization of New Polyesters Based on Diarylidene-1-Methyl-4-Piperidone

Authors: Tareg M. Elsunaki, Suleiman A. Arafa, Mohamed A. Abd-Alla

Abstract:

New interesting thermal stable polyesters containing 1-methyl-4-piperidone moiety in the main chain have been synthesized. These polyesters were synthesized by interfacial polycondensation technique of 3,5-bis(4-hydroxybenzylidene)-1-methyl-4-piperidone (I) and 3,5-bis(4-hydroxy-3-methoxy benzyli-dene)-1-methyl-4-piperidone (II) with terphthaloyl, isophthaloyl, 4,4'-diphenic, adipoyl and sebacoyl dichlorides. The yield and the values of the reduced viscosity of the produced polyesters were found to be affected by the type of an organic phase. In order to characterize these polymers, the necessary model compounds (A), (B) were prepared from (I), (II) respectively and benzoyl chloride. The structure of monomers (I), (II), model compounds and resulting polyesters were confirmed by IR, elemental analysis and 1HNMR spectroscopy. The various characteristic of the resulting polymers including solubility, thermal properties, viscosity and X-ray analysis were also studied.

Keywords: synthesis, characterization, new polyesters, chemistry

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3697 Pervaporation of Dimethyl Carbonate / Methanol / Water Mixtures Using Zeolite Membranes

Authors: Jong-Ho Moon, Dong-Ho Lee, Hyunuk Kim, Young Cheol Park, Jong-Seop Lee, Jae-deok Jeon, Hyung-Keun Lee

Abstract:

A novel membrane reactor process for DMC synthesis from carbon dioxide has been developing in Korea Institute of Energy Research. The scheme of direct synthesis of DMC from CO₂ and Methanol is 'CO₂ + 2MeOH ↔ DMC + H₂O'. Among them, reactants are CO₂ and MeOH, product is DMC, and byproduct is H₂O (water). According to Le Chatelier’s principle, removing byproduct (water) can shift the reaction equilibrium to the right (DMC production). The main purpose of this process is removing water during the reaction. For efficient in situ water removal (dehydration) and DMC separation, zeolite 4A membranes with very small pore diameter and hydrophilicity were introduced. In this study, pervaporation performances of binary and ternary DMC / methanol / water mixtures were evaluated.

Keywords: dimehtyl carbonate, methanol, water, zeolite membrane, pervaporation

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3696 Usy-Cui Zeolite: An Efficient and Reusable Catalyst for Derivatives Indole Synthesis

Authors: Hassina Harkat, Samiha Taybe, Salima Loucif, Valérie Beneteau, Patrick Pale

Abstract:

Indole and its derivatives have attracted great interest because of their importance in the synthetic organic and medicinal chemistry. They are widely used as anti hypertension, anti tubercular, anticancer activity, antiviral, Alzheimer's disease, antioxidant properties, and free radical induced lipid peroxidation. Many drugs and natural products contain indole moiety, such as the vinca alkaloids, fungal metabolites and marine natural products. Generally applicable synthetic methods for indole moiety involve ring closure to form the pyrrole. Indole derivatives can also be accessed by further functionalization of the indole nucleus. Therefore we report a mild and efficient protocol for the synthesis of analogues of indole catalyzed via zeolithe USY doped with CuI under solvent-free conditions.

Keywords: indole, zeolithe, USY-CuI, heterogeneous catalysis

Procedia PDF Downloads 584
3695 Green Synthesis of Silver and Silver-Gold Alloy Nanoparticle Using Cyanobacteria as Bioreagent

Authors: Piya Roychoudhury, Ruma Pal

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Cyanobacteria, commonly known as blue green algae were found to be an effective bioreagent for nanoparticle synthesis. Nowadays silver nanoparticles (AgNPs) are very popular due to their antimicrobial and anti-proliferative activity. To exploit these characters in different biotechnological fields, it is very essential to synthesize more stable, non-toxic nano-silver. For this reason silver-gold alloy (Ag-AuNPs) nanoparticles are of great interest as they are more stable, harder and more effective than single metal nanoparticles. In the present communication we described a simple technique for rapid synthesis of biocompatible AgNP and Ag-AuNP employing cyanobacteria, Leptolyngbya and Lyngbya respectively. For synthesis of AgNP the biomass of Leptolyngbya valderiana (200 mg Fresh weight) was exposed to 9 mM AgNO3 solution (pH 4). For synthesis of Ag-AuNP Lyngbya majuscula (200 mg Fresh weight) was exposed to equimolar solution of hydrogen tetra-auro chlorate and silver nitrate (1mM, pH 4). After 72 hrs of exposure thallus of Leptolyngyba turned brown in color and filaments of Lyngbya turned pink in color that indicated synthesis of nanoparticles. The produced particles were extracted from the cyanobacterial biomass using nano-capping agent, sodium citrate. Firstly, extracted brown and pink suspensions were taken for Energy Dispersive X-ray (EDAX) analysis to confirm the presence of silver in brown suspension and presence of both gold and silver in pink suspension. Extracted nanoparticles showed a distinct single plasmon band (AgNP at 411 nm; Ag-Au NP at 481 nm) in Uv-vis spectroscopy. It was revealed from Transmission electron microscopy (TEM) that all the synthesized particles were spherical in nature with a size range of ~2-25 nm. In X-ray powder diffraction (XRD) analysis four intense peaks appeared at 38.2°, 44.5°, 64.8°and 77.8° which confirmed the crystallographic nature of synthesized particles. Presence of different functional groups viz. N-H, C=C, C–O, C=O on the surface of nanoparticles were recorded by Fourier transform infrared spectroscopy (FTIR). Scanning Electron microscopy (SEM) images showed the surface topography of metal treated filaments of cyanobacteria. The stability of the particles was observed by Zeta potential study. Antibiotic property of synthesized particles was tested by Agar well diffusion method against gram negative bacteria Pseudomonas aeruginosa. Overall, this green-technique requires low energy, less manufacturing cost and produces rapidly eco-friendly metal nanoparticles.

Keywords: cyanobacteria, silver nanoparticles, silver-gold alloy nanoparticles, spectroscopy

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3694 CuFeOx-Based Nano-Rose Electrocatalysts for Oxygen Evolution Reaction

Authors: Hamad Almohamadi, Nabeel H. Alharthi, Abdulrahman Aljabri

Abstract:

In this study, two-dimensional CuFeOx is deposited on nickel foam for the fabrication of electrocatalyst for oxygen evolution reaction (OER). The in-situ hydrothermal synthesis of CuFeOx in presence of aloe vera extract was found to yield unique nano-rose-like morphology which aided to improve the electrochemical surface area of the electrode. The phytochemical assisted synthesis of CuFeOx using 75% aloe vera extract resulted in improved OER electrocatalytic performance by attaining the overpotential of 310 mV for 50 mA cm−2 and 410 mV for 100 mA cm−2. The electrode also sustained robust stability throughout the 50 h of chronopotentiometry studies under alkaline electrolyte conditions, thus proving to be prospective electrode material for efficient OER in electrochemical water splitting.

Keywords: water splitting, phytochemicals, oxygen evaluation reaction, Tafel's slope, stability

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3693 Synthesis of Ni/Mesopore Silica-Alumina Catalyst for Hydrocracking of Pyrolyzed α-Cellulose

Authors: Wega Trisunaryanti, Hesty Kusumastuti, Iip Izul Falah, Muhammad Fajar Marsuki, Rahmad Nuryanto

Abstract:

Synthesis of Ni supported on mesopore silica-alumina (MSA) for hydrocracking of pyrolyzed α-cellulose had been carried out. The silica and alumina were extracted from Sidoarjo mud. Gelatin from catfish bone was used as a template for the mesopore design. The MSA was synthesized by using hydrothermal method at 100 °C for 24 h and calcined at 550 °C for 4 h then characterized by using X-Ray Diffraction Spectrometer (XRD) and Nitrogen Gas Sorption Analyzer (GAS). The Ni metal was loaded to the MSA by wet impregnation method. The catalytic activity in the hydrocracking reaction of pyrolyzed α-cellulose was carried out at 450 °C for 2 h. The MSA synthesized in this work is an amorphous material with specific surface area, total pore volume, and average pore diameter of 212.29 m²/g, 1.29 cm³/g, and 20.05 nm, respectively. The Ni/MSA catalyst produced 73.02 wt.% of liquid product in hydrocracking of pyrolyzed α-cellulose.

Keywords: catalyst, gelatin, hydrocracking, mesopore silica-alumina, α-cellulose

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3692 Biospiral-Detect to Distinguish PrP Multimers from Monomers

Authors: Gulyas Erzsebet

Abstract:

The multimerisation of proteins is a common feature of many cellular processes; however, it could also impair protein functions and/or be associated with the occurrence of diseases. Thus, development of a research tool monitoring the appearance/presence of multimeric protein forms has great importance for a variety of research fields. Such a tool is potentially applicable in the ante-mortem diagnosis of certain conformational diseases, such as transmissible spongiform encephalopathies (TSE) and Alzheimer’s disease. These conditions are accompanied by the appearance of aggregated protein multimers, present in low concentrations in various tissues. This detection is particularly relevant for TSE where the handling of tissues derived from affected individuals and of meat products of infected animals have become an enormous health concern. Here we demonstrate the potential of such a multimer detection approach in TSE by developing a facile approach. The Biospiral-Detect system resembles a traditional sandwich ELISA, except that the capturing antibody that is attached to a solid surface and the detecting antibody is directed against the same or overlapping epitopes. As a consequence, the capturing antibody shields the epitope on the captured monomer from reacting with the detecting antibody, therefore monomers are not detected. Thus, MDS is capable of detecting only protein multimers with high specificity. We developed an alternative system as well, where RNA aptamers were employed instead of monoclonal antibodies. In order to minimize degradation, the 3' and 5' ends of the aptamer contained deoxyribonucleotides and phosphorothioate linkages. When compared the monoclonal antibodies-based system with the aptamers-based one, the former proved to be superior. Thus all subsequent experiments were conducted by employing the Biospiral -Detect modified sandwich ELISA kit. Our approach showed an order of magnitude higher sensitivity toward mulimers than monomers suggesting that this approach may become a valuable diagnostic tool for conformational diseases that are accompanied by multimerization.

Keywords: diagnosis, ELISA, Prion, TSE

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3691 Frequency of Polymorphism of Mrp1/Abcc1 And Mrp2/Abcc2 in Healthy Volunteers of the Center Savannah (Colombia)

Authors: R. H. Bustos, L. Martinez, J. García, F. Suárez

Abstract:

MRP1 (Multi-drug resistance associated protein 1) and MRP2 (Multi-drug resistance associated protein 2) are two proteins belonging to the transporters of ABC (ATP-Binding Cassette). These transporter proteins are involved in the efflux of several biological drugs and xenobiotic and also in multiple physiological, pathological and pharmacological processes. Evidence has been found that there is a correlation among different polymorphisms found and their clinical implication in the resistance to antiepileptic, chemotherapy and anti-infectious drugs. In our study, exonic regions of MRP1/ABCC1 y MRP2/ABCC2 were studied in the Colombian population, specifically in the region of the central Savannah (Cundinamarca) to determinate SNP (Single Nucleotide Polymorphisms) and determinate its allele frequency and its genomics frequency. Results showed that for our population, SNP are found that have been previously reported for MRP1/ABCC1 (rs200647436, rs200624910, rs150214567) as well as for MRP2/ABCC2 (rs2273697, rs3740066, rs142573385, rs17216212). In addition, 13 new SNP were identified. Evidences show an important clinic correlation for polymorphisms rs3740066 and rs2273697. The study object population displays genetic variability as compared to the one reported in other populations.

Keywords: ATP-binding cassette (ABCC), Colombian population, multidrug-resistance protein (MRP), pharmacogenetic, single nucleotide polymorphism (SNP)

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3690 Synthesis of SnO Novel Cabbage Nanostructure and Its Electrochemical Property as an Anode Material for Lithium Ion Battery

Authors: Yongkui Cui, Fengping Wang, Hailei Zhao, Muhammad Zubair Iqbal, Ziya Wang, Yan Li, Pengpeng LV

Abstract:

The novel 3D SnO cabbages self-assembled by nanosheets were successfully synthesized via template-free hydrothermal growth method under facile conditions.The XRD results manifest that the as-prepared SnO is tetragonal phase. The TEM and HRTEM results show that the cabbage nanosheets are polycrystalline structure consisted of considerable single-crystalline nanoparticles. Two typical Raman modes A1g=210 and Eg=112 cm-1 of SnO are observed by Raman spectroscopy. Moreover, galvanostatic cycling tests has been performed using the SnO cabbages as anode material of lithium ion battery and the electrochemical results suggest that the synthesized SnO cabbage structures are a promising anode material for lithium ion batteries.

Keywords: electrochemical property, hydrothermal synthesis, lithium ion battery, stannous oxide

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3689 Prospects of Milk Protein as a Potential Alternative of Natural Antibiotic

Authors: Syeda Fahria Hoque Mimmi

Abstract:

Many new and promising treatments for reducing or diminishing the adverse effects of microorganisms are being discovered day by day. On the other hand, the dairy industry is accelerating the economic wheel of Bangladesh. Considering all these facts, new thoughts were developed to isolate milk proteins by the present experiment for opening up a new era of developing natural antibiotics from milk. Lactoferrin, an iron-binding glycoprotein with multifunctional properties, is crucial to strengthening the immune system and also useful for commercial applications. The protein’s iron-binding capacity makes it undoubtedly advantageous to immune system modulation and different bacterial strains. For fulfilling the purpose, 4 of raw and 17 of commercially available milk samples were collected from different farms and stores in Bangladesh (Dhaka, Chittagong, and Cox’s Bazar). Protein quantification by nanodrop technology has confirmed that raw milk samples have better quantities of protein than the commercial ones. All the samples were tested for their antimicrobial activity against 18 pathogens, where raw milk samples showed a higher percentage of antibacterial activity. In addition to this, SDS-PAGE (Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis) was performed to identify lactoferrin in the milk samples. Lactoferrin was detected in 9 samples from which 4 were raw milk samples. Interestingly, Streptococcus pyogenes, Klebsiella pneumoniae, Bacillus cereus, Pseudomonas aeruginosa, Vibrio cholera, Staphylococcus aureus, and enterotoxigenic E. coli significantly displayed sensitivity against lactoferrin collected from raw milk. Only Bacillus cereus, Pseudomonas aeruginosa, Streptococcus pneumonia, Enterococcus faecalis, and ETEC (Enterotoxigenic Escherichia coli) were susceptible to lactoferrin obtained from a commercial one. This study suggested that lactoferrin might be used as the potential alternative of antibiotics for many diseases and also can be used to reduce microbial deterioration in the food and feed industry.

Keywords: alternative of antibiotics, commercially available milk, lactoferrin, nanodrop technology, pathogens, raw milk

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3688 Synthesis of Magnesium Oxide in Spinning Disk Reactor and Its Applications in Cycloaddition of Carbon Dioxide to Epoxides

Authors: Tzu-Wen Liu, Yi-Feng Lin, Yu-Shao Chen

Abstract:

CO_2 is believed to be partly responsible for changes to the global climates. Carbon capture and storage (CCS) is one way to reduce carbon dioxide emissions in the past. Recently, how to convert the captured CO_2 into fine chemicals gets lots of attention owing to reducing carbon dioxide emissions and providing greener feedstock for the chemicals industry. A variety of products can be manufactured from carbon dioxide and the most attractive products are cyclic carbonates. Therefore, the kind of catalyst plays an important role in cycloaddition of carbon dioxide to epoxides. Magnesium oxide can be an efficiency heterogeneous catalyst for the cycloaddition of carbon dioxide to epoxides because magnesium oxide has both acid and base active sites and can provide the adsorption of carbon dioxide, promoting ring-opening reaction. Spinning disk reactor (SDR) is one of the device of high-gravity technique and has successfully used for synthesis of nanoparticles by precipitation methods because of the high mass transfer rate. Synthesis of nanoparticles in SDR has advantages of low energy consumption and easy to scale up. The aim of this research is to synthesize magnesium hydroxide nanoparticles in SDR as precursors for magnesium oxide. Experimental results showed that the calcination temperature of magnesium hydroxide to magnesium oxide, and the pressure and temperature of cycloaddition reaction had significantly effect on the conversion and selectivity of the reaction.

Keywords: magnesium oxide, catalyst, cycloaddition, spinning disk reactor, carbon dioxide

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3687 Chiral Amine Synthesis and Recovery by Using High Molecular Weight Amine Donors

Authors: Claudia Matassa, Matthias Hohne, Dominic Ormerod, Yamini Satyawali

Abstract:

Chiral amines integrate the backbone of several active pharmaceutical ingredients (APIs) used in modern medicine for the treatment of a vast range of diseases. Despite the demand, their synthesis remains challenging. Besides a range of chemicals and enzymatical methods, chiral amine synthesis using transaminases (EC 2.6.1.W) represents a useful alternative to access this important class of compounds. Even though transaminases exhibit excellent stereo and regioselectivity and the potential for high yield, the reaction suffers from a number of challenges, including the thermodynamic equilibrium, product inhibition, and low substrate solubility. In this work, we demonstrate a membrane assisted strategy for addressing these challenges. It involves the use of high molecular weight (HMW) amine donors for the transaminase-catalyzed synthesis of 4-phenyl-2-butylamine in both aqueous and organic solvent media. In contrast to common amine donors such as alanine or isopropylamine, these large molecules, provided in excess for thermodynamic equilibrium shifting, are easily retained by commercial nanofiltration membranes; thus a selective permeation of the desired smaller product amine is possible. The enzymatic transamination in aqueous media, combined with selective product removal shifted the equilibrium enhancing substrate conversion by an additional 25% compared to the control reaction. Along with very efficient amine product removal, there was undesirable loss of ketone substrate and low product concentration was achieved. The system was therefore further improved by performing the reaction in organic solvent (n-heptane). Coupling the reaction system with membrane-assisted product removal resulted in a highly concentrated and relatively pure ( > 97%) product solution. Moreover, a product yield of 60% was reached, compared to 15% without product removal.

Keywords: amine donor, chiral amines, in situ product removal, transamination

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3686 SARS-CoV-2: Prediction of Critical Charged Amino Acid Mutations

Authors: Atlal El-Assaad

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Viruses change with time through mutations and result in new variants that may persist or disappear. A Mutation refers to an actual change in the virus genetic sequence, and a variant is a viral genome that may contain one or more mutations. Critical mutations may cause the virus to be more transmissible, with high disease severity, and more vulnerable to diagnostics, therapeutics, and vaccines. Thus, variants carrying such mutations may increase the risk to human health and are considered variants of concern (VOC). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) - the contagious in humans, positive-sense single-stranded RNA virus that caused coronavirus disease 2019 (COVID-19) - has been studied thoroughly, and several variants were revealed across the world with their corresponding mutations. SARS-CoV-2 has four structural proteins, known as the S (spike), E (envelope), M (membrane), and N (nucleocapsid) proteins, but prior study and vaccines development focused on genetic mutations in the S protein due to its vital role in allowing the virus to attach and fuse with the membrane of a host cell. Specifically, subunit S1 catalyzes attachment, whereas subunit S2 mediates fusion. In this perspective, we studied all charged amino acid mutations of the SARS-CoV-2 viral spike protein S1 when bound to Antibody CC12.1 in a crystal structure and assessed the effect of different mutations. We generated all missense mutants of SARS-CoV-2 protein amino acids (AAs) within the SARS-CoV-2:CC12.1 complex model. To generate the family of mutants in each complex, we mutated every charged amino acid with all other charged amino acids (Lysine (K), Arginine (R), Glutamic Acid (E), and Aspartic Acid (D)) and studied the new binding of the complex after each mutation. We applied Poisson-Boltzmann electrostatic calculations feeding into free energy calculations to determine the effect of each mutation on binding. After analyzing our data, we identified charged amino acids keys for binding. Furthermore, we validated those findings against published experimental genetic data. Our results are the first to propose in silico potential life-threatening mutations of SARS-CoV-2 beyond the present mutations found in the five common variants found worldwide.

Keywords: SARS-CoV-2, variant, ionic amino acid, protein-protein interactions, missense mutation, AESOP

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3685 Characteristics of Sorghum (Sorghum bicolor L. Moench) Flour on the Soaking Time of Peeled Grains and Particle Size Treatment

Authors: Sri Satya Antarlina, Elok Zubaidah, Teti Istiana, Harijono

Abstract:

Sorghum bicolor (Sorghum bicolor L. Moench) has the potential as a flour for gluten-free food products. Sorghum flour production needs grain soaking treatment. Soaking can reduce the tannin content which is an anti-nutrient, so it can increase the protein digestibility. Fine particle size decreases the yield of flour, so it is necessary to study various particle sizes to increase the yield. This study aims to determine the characteristics of sorghum flour in the treatment of soaking peeled grain and particle size. The material of white sorghum varieties KD-4 from farmers in East Java, Indonesia. Factorial randomized factorial design (two factors), repeated three times, factor I were the time of grain soaking (five levels) that were 0, 12, 24, 36, and 48 hours, factor II was the size of the starch particles sifted with a fineness level of 40, 60, 80, and 100 mesh. The method of making sorghum flour is grain peeling, soaking peeled grain, drying using the oven at 60ᵒC, milling, and sieving. Physico-chemical analysis of sorghum flour. The results show that there is an interaction between soaking time of grain with the size of sorghum flour particles. Interaction in yield of flour, L* color (brightness level), whiteness index, paste properties, amylose content, protein content, bulk density, and protein digestibility. The method of making sorghum flour through the soaking of peeled grain and the difference in particle size has an important role in producing the physicochemical properties of the specific flour. Based on the characteristics of sorghum flour produced, it is determined the method of making sorghum flour through sorghum grain soaking for 24 hours, the particle size of flour 80 mesh. The sorghum flour with characteristic were 24.88% yield of flour, 88.60 color L* (brightness level), 69.95 whiteness index, 3615 Cp viscosity, 584.10 g/l of bulk density, 24.27% db protein digestibility, 90.02% db starch content, 23.4% db amylose content, 67.45% db amylopectin content, 0.22% db crude fiber content, 0.037% db tannin content, 5.30% db protein content, ash content 0.18% db, carbohydrate content 92.88 % db, and 1.94% db fat content. The sorghum flour is recommended for cookies products.

Keywords: characteristic, sorghum (Sorghum bicolor L. Moench) flour, grain soaking, particle size, physicochemical properties

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3684 Inclusion Body Refolding at High Concentration for Large-Scale Applications

Authors: J. Gabrielczyk, J. Kluitmann, T. Dammeyer, H. J. Jördening

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High-level expression of proteins in bacteria often causes production of insoluble protein aggregates, called inclusion bodies (IB). They contain mainly one type of protein and offer an easy and efficient way to get purified protein. On the other hand, proteins in IB are normally devoid of function and therefore need a special treatment to become active. Most refolding techniques aim at diluting the solubilizing chaotropic agents. Unfortunately, optimal refolding conditions have to be found empirically for every protein. For large-scale applications, a simple refolding process with high yields and high final enzyme concentrations is still missing. The constructed plasmid pASK-IBA63b containing the sequence of fructosyltransferase (FTF, EC 2.4.1.162) from Bacillus subtilis NCIMB 11871 was transformed into E. coli BL21 (DE3) Rosetta. The bacterium was cultivated in a fed-batch bioreactor. The produced FTF was obtained mainly as IB. For refolding experiments, five different amounts of IBs were solubilized in urea buffer with protein concentration of 0.2-8.5 g/L. Solubilizates were refolded with batch or continuous dialysis. The refolding yield was determined by measuring the protein concentration of the clear supernatant before and after the dialysis. Particle size was measured by dynamic light scattering. We tested the solubilization properties of fructosyltransferase IBs. The particle size measurements revealed that the solubilization of the aggregates is achieved at urea concentration of 5M or higher and confirmed by absorption spectroscopy. All results confirm previous investigations that refolding yields are dependent upon initial protein concentration. In batch dialysis, the yields dropped from 67% to 12% and 72% to 19% for continuous dialysis, in relation to initial concentrations from 0.2 to 8.5 g/L. Often used additives such as sucrose and glycerol had no effect on refolding yields. Buffer screening indicated a significant increase in activity but also temperature stability of FTF with citrate/phosphate buffer. By adding citrate to the dialysis buffer, we were able to increase the refolding yields to 82-47% in batch and 90-74% in the continuous process. Further experiments showed that in general, higher ionic strength of buffers had major impact on refolding yields; doubling the buffer concentration increased the yields up to threefold. Finally, we achieved corresponding high refolding yields by reducing the chamber volume by 75% and the amount of buffer needed. The refolded enzyme had an optimal activity of 12.5±0.3 x104 units/g. However, detailed experiments with native FTF revealed a reaggregation of the molecules and loss in specific activity depending on the enzyme concentration and particle size. For that reason, we actually focus on developing a process of simultaneous enzyme refolding and immobilization. The results of this study show a new approach in finding optimal refolding conditions for inclusion bodies at high concentrations. Straightforward buffer screening and increase of the ionic strength can optimize the refolding yield of the target protein by 400%. Gentle removal of chaotrope with continuous dialysis increases the yields by an additional 65%, independent of the refolding buffer applied. In general time is the crucial parameter for successful refolding of solubilized proteins.

Keywords: dialysis, inclusion body, refolding, solubilization

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3683 Detection Kit of Type 1 Diabetes Mellitus with Autoimmune Marker GAD65 (Glutamic Acid Decarboxylase)

Authors: Aulanni’am Aulanni’am

Abstract:

Incidence of Diabetes Mellitus (DM) progressively increasing it became a serious problem in Indonesia and it is a disease that government is priority to be addressed. The longer a person is suffering from diabetes the more likely to develop complications particularly diabetic patients who are not well maintained. Therefore, Incidence of Diabetes Mellitus needs to be done in the early diagnosis of pre-phase of the disease. In this pre-phase disease, already happening destruction of pancreatic beta cells and declining in beta cell function and the sign autoimmunity reactions associated with beta cell destruction. Type 1 DM is a multifactorial disease triggered by genetic and environmental factors, which leads to the destruction of pancreatic beta cells. Early marker of "beta cell autoreactivity" is the synthesis of autoantibodies against 65-kDa protein, which can be a molecule that can be detected early in the disease pathomechanism. The importance of early diagnosis of diabetic patients held in the phase of pre-disease is to determine the progression towards the onset of pancreatic beta cell destruction and take precautions. However, the price for this examination is very expensive ($ 150/ test), the anti-GAD65 abs examination cannot be carried out routinely in most or even in all laboratories in Indonesia. Therefore, production-based Rapid Test Recombinant Human Protein GAD65 with "Reverse Flow Immunchromatography Technique" in Indonesia is believed to reduce costs and improve the quality of care of patients with diabetes in Indonesia. Rapid Test Product innovation is very simple and suitable for screening and routine inspection of GAD65 autoantibodies. In the blood serum of patients with diabetes caused by autoimmunity, autoantibody-GAD65 is a major serologic marker to detect autoimmune reaction because their concentration level of stability.GAD65 autoantibodies can be found 10 years before clinical symptoms of diabetes. Early diagnosis is more focused to detect the presence autontibodi-GAD65 given specification and high sensitivity. Autoantibodies- GAD65 that circulates in the blood is a major indicator of the destruction of the islet cells of the pancreas. Results of research in collaboration with Biofarma has produced GAD65 autoantibodies based Rapid Test had conducted the soft launch of products and has been tested with the results of a sensitivity of 100 percent and a specificity between 90 and 96% compared with the gold standard (import product) which worked based on ELISA method.

Keywords: diabetes mellitus, GAD65 autoantibodies, rapid test, sensitivity, specificity

Procedia PDF Downloads 267
3682 The Effect of Arbutin Powder and Arctostaphylos uvaursi Aqueous Leaf Extract on Synthesis of Melanin by Madurella mycetomatis

Authors: Amina Omer, Ikram Elsiddig

Abstract:

Arctostaphylos uvaursi is a plant of the family Ericaceae, it’s used in skin care products mostly for its depigmenting action, due to the presence of hydroquinones that are well known inhibitors of tyrosinase, an enzyme involved in melanin biosynthesis in humans. The main hydroquinone found within the A. uvaursi is arbutin, which is found with varying percentage within the plant depending on the season, and area from which the plant is harvested. An in vitro experiment has shown that the arbutin found within the bearberry leaf extract inhibited the biosynthesis of melanin in human melanoma cells and in three-dimensional human skin model. Madurella mycetomatis is filamentous fungus that causes the fungal form of mycetoma known as eumycetoma, with existing anti-fungals and surgery, only 35% of people living eumycetoma are treated, M. mycetomatis has been found to shield itself against the antifungal therapy through the production of melanin decreasing the effectiveness of the therapy, therefore there is a need for a new and more effective therapy. The aim of the study was to investigate and compare the effect of arbutin powder and aqueous extract of A. uvaursi containing arbutin on the biosynthesis of melanin by M. mycetomatis. The experiment was carried out by culturing M. mycetomatis on minimal media composed of 2% agar, 15 mM glucose, 10 mM MgSO4, 29.4 mM KH2PO4, 13 mM glycin and 80mg/l gentamicin, the media was supplied with different concentration of arbutin solution (5, 25 50,and 75mg) and aqueous extract of A. uvaursi to contain arbutin with concentrations (5, 25 50,and 75mg), the plates were incubated for two month and the result was observed by the naked eye. The results revealed that the arbutin powder had an inhibitory effect on melanin synthesis by M. mycetomatis that correlated with its established inhibitory effect on melanin synthesis in humans. The inhibitory effect of arbutin on melanin synthesis by M. mycetomatis was found to be dose dependent. A. uvaursi aqueous leaf extract containing arbutin was also found to decrease melanin production by M. mycetomatis, however plates containing high concentrations of aqueous extract couldn’t be assessed for its melanin inhibitory effect due to the high content of carbohydrates in the extract that promoted the growth of fungi Asperigullus niger rendering the plates unsuitable for visual inspection. In conclusion inhibition of melanin synthesis was observed on the arbutin powder as well as the aqueous extract containing arbutin. A. uvaursi is known to exhibit anti-inflammatory activity, which can aid in wound healing that is beneficial in the chronic inflammation caused by M. mycetomatis.

Keywords: arbutin, arctostaphylos, Madurella, melanin

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3681 Production and Evaluation of Jam Made from Pineapple (Ananas comosus) and Grape (Vitis vinifera)

Authors: Z. O. Apotiola, J. F. Fashakin

Abstract:

This project studied the production and evaluation of jam produced from pineapple and grape at different level of ratio (90:10, 80:20, 70:30, 60:40, 50:50, and 100%). The proximate and sensory properties were determined using standard methods. The (GDZ) was the highest for protein, moisture, fat and ash, (KFJ) was the highest for carbohydrate. There were significant differences (p<0.05) in samples (PAB, GDZ, BEN) for moisture. Also, there were significant differences (p<0.05) in samples (PAB, BBL, GDZ, KFJ) for protein. There were significant differences (p<0.05) in samples (PAB, BBL, BEN) for carbohydrate. Also, there were significant differences (p<0.05) in samples (PAB, BBL, QCM, GDZ, BEN) for fat and there were significant differences (p<0.05) in samples (PAB, BBL, GDZ) for ash. (KFJ) was the highest for pH, (BBL and QCM) was the highest for Vitamin C; (GDZ) was the highest for titratable acidity. For sensory properties, for aroma, colour, flavour, and overall acceptability were tested using panellists; the result showed that (KFJ) had the highest for all samples. From the results of chemical and sensory characteristics sample BBL was the best combination.

Keywords: chemical, characteristic, combination, titratable, sensory, significant

Procedia PDF Downloads 275
3680 Effect of the Nature of Silica Precursor in Zeolite ZSM-22 Synthesis

Authors: Nyiko M. Chauke, James Ramontja, Richard M. Moutloali

Abstract:

The zeolite ZSM-22 material demonstrated effective hydrophilic character as a nanoadditive filler in the preparation of nanocomposite membranes. In this study, nanorods ZSM-22 zeolite materials were hydrothermally synthesised from a homogenous gel mixture prepared using different silica precursors: colloidal silica, fumed silica, tetraethylorthosilicate (TEOS), and aluminium precursor: aluminium sulphate octadecahydrate (Al₂(SO₄)₃.18H₂O to Si/Al of 60. This was focused on developing a defect-free zeolite framework for effective use in applications such as membrane separation process, adsorption, and catalysis. The obtained ZSM-22 zeolite materials with 60 Si/Al ratio exhibits high crystallinity, hydrophilicity, and needle-like morphologies, suggesting successful synthesis as shown by X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier-Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) physicochemical analysis. It was revealed that the use of different nature of silica precursors significantly influenced the properties of the final product and contributed to the development of defect-free zeolite material. As such, the crystalline nanorods of Theta-1 (TON) ZSM-22 obtained from TEOS silica showed high phase purity, defect-free, and narrow particle size distribution. Morphological analysis exhibited that the use of TEOS as silica precursor was effective than its counterparts and produced high crystalline need-like agglomerated particles.

Keywords: silica precursor, hydrothermal synthesis, zeolite material, ZSM-22

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3679 In vitro Cytotoxicity Study on Silver Powders Synthesized via Different Routes

Authors: Otilia Ruxandra Vasile, Ecaterina Andronescu, Cristina Daniela Ghitulica, Bogdan Stefan Vasile, Roxana Trusca, Eugeniu Vasile, Alina Maria Holban, Carmen Mariana Chifiriuc, Florin Iordache, Horia Maniu

Abstract:

Engineered powders offer great promise in several applications, but little information is known about cytotoxicity effects. The aim of the current study was the synthesis and cytotoxicity examination of silver powders using pyrosol method at temperatures of 600°C, 650°C and 700°C, respectively sol-gel method and calcinations at 500°C, 600°C, 700°C and 800°C. We have chosen to synthesize and examine silver particles cytotoxicity due to its use in biological applications. The synthesized Ag powders were characterized from the structural, compositional and morphological point of view by using XRD, SEM, and TEM with SAED. In order to determine the influence of the synthesis route on Ag particles cytotoxicity, different sizes of micro and nanosilver synthesized powders were evaluated for their potential toxicity. For the study of their cytotoxicity, cell cycle and apoptosis have been done analysis through flow cytometry on human colon carcinoma cells and mesenchymal stem cells and through the MTT assay, while the viability and the morphological changes of the cells have been evaluated by using cloning studies. The results showed that the synthesized silver nanoparticles have displayed significant cytotoxicity effects on cell cultures. Our synthesized silver powders were found to present toxicity in a synthesis route and time-dependent manners for pyrosol synthesized nanoparticles; whereas a lower cytotoxicity has been measured after cells were treated with silver nanoparticles synthesized through sol-gel method.

Keywords: Ag, cytotoxicity, pyrosol method, sol-gel method

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3678 Turmeric Mediated Synthesis and Characterization of Cerium Oxide Nanoparticles

Authors: Nithin Krisshna Gunasekaran, Prathima Prabhu Tumkur, Nicole Nazario Bayon, Krishnan Prabhakaran, Joseph C. Hall, Govindarajan T. Ramesh

Abstract:

Cerium oxide and turmeric have antioxidant properties, which have gained interest among researchers to study their applications in the field of biomedicine, such asanti-inflammatory, anticancer, and antimicrobial applications. In this study, the turmeric extract was prepared and mixed with cerium nitrate hexahydrate, stirred continuously to obtain a homogeneous solution and then heated on a hot plate to get the supernatant evaporated, then calcinated at 600°C to obtain the cerium oxide nanoparticles. Characterization of synthesized cerium oxide nanoparticles through Scanning Electron Microscopy determined the particle size to be in the range of 70 nm to 250 nm. Energy Dispersive X-Ray Spectroscopy determined the elemental composition of cerium and oxygen. Individual particles were identified through the characterization of cerium oxide nanoparticles using Field Emission Scanning Electron Microscopy, in which the particles were determined to be spherical and in the size of around 70 nm. The presence of cerium oxide was assured by analyzing the spectrum obtained through the characterization of cerium oxide nanoparticles by Fourier Transform Infrared Spectroscopy. The crystal structure of cerium oxide nanoparticles was determined to be face-centered cubic by analyzing the peaks obtained through theX-Ray Diffraction method. The crystal size of cerium oxide nanoparticles was determined to be around 13 nm by using the Debye Scherer equation. This study confirmed the synthesis of cerium oxide nanoparticles using turmeric extract.

Keywords: antioxidant, characterization, cerium oxide, synthesis, turmeric

Procedia PDF Downloads 163
3677 Cdk1 Gates Cell Cycle-Dependent tRNA Synthesis by Regulating RNA Polymerase III Activity

Authors: Maricarmen Herrera, Pierre Chymkowitch, Joe Robertson, Jens Eriksson, Jorrit Enserink

Abstract:

tRNA genes are transcribed by RNA polymerase III. During recent years, it has become clear that tDNA transcription fluctuates during the cell cycle. However, the mechanism by which the cell cycle controls the amplitude of tDNA transcription remains unknown. We found that the cyclin Clb5 recruits the cyclin dependent kinase Cdk1 to tRNA genes to sharply increase tRNA synthesis during a brief interval in the cell cycle. We show that Cdk1 promotes the interaction of TFIIIB with TFIIIC, that it stimulates the recruitment of TFIIIC to tRNA genes, that it prevents the formation of an overly stable TFIIIB-tDNA complex and that it augments the dynamics of RNA polymerase III. Furthermore, we identify Bdp1 as a novel Cdk1 substrate, and phosphorylation of Bdp1 is required for the cell cycle-dependent increase in tDNA transcription. In addition, we show that phosphorylation of the Cdk1 substrate Nup60 mediates formation of a Nup60-Nup2 complex at tRNA genes, which is also required for cell cycle-dependent tDNA transcription. Together, our findings indicate that Cdk1 activity gates tRNA synthesis by regulating the dynamics of the TFIIIB-TFIIIC-RNAPIII complex, and that it may promote the formation of a nuclear pore microenvironment conducive to efficient tDNA transcription.

Keywords: Cdk1, cell cycle, RNAPIII machinery, tRNA

Procedia PDF Downloads 181
3676 The Effects of Highly Active Antiretroviral Therapy (HAART) on the Expression of Muc1 and P65 in a Cervical Cancer Cell Line, HCS-2

Authors: K. R. Thabethe, G. A. Adefolaju, M. J. Hosie

Abstract:

Cervical cancer is the third most commonly diagnosed cancer globally and it is one of three AIDS defining malignancies. Highly active antiretroviral therapy (HAART) is a combination of three or more antiretroviral drugs and has been shown to play a significant role in reducing the incidence of some AIDS defining malignancies, although its effect on cervical cancer is still unclear. The aim of this study was to investigate the relationship between cervical cancer and HAART. This was achieved by studying the expression of two signalling molecules expressed in cervical cancer; MUC1 and P65. Following the 24 hour treatment of a cervical cancer cell line, HCS-2, with drugs which are commonly used as part of HAART at their clinical plasma concentrations, real-time qPCR and immunofluorescence were used in order to study gene and protein expression. A one way ANOVA followed by a Tukey Kramer Post Hoc test was conducted using JMP 11 software on both sets of data. The drug classified as a protease inhibitor (PI) (i.e. LPV/r) reduced MUC1 and P65 gene and protein expression more than the other drug tested. PIs are known to play a significant role in cell death, therefore the cells were thought to be more susceptible to cell death following treatment with PIs. In conclusion, the drugs used, especially the PI showed some anticancer effects by facilitating cell death through decreased gene and protein expression of MUC1 and P65 and present promising agents for cancer treatment.

Keywords: cervical cancer, haart, MUC1, P65

Procedia PDF Downloads 333
3675 Seamless MATLAB® to Register-Transfer Level Design Methodology Using High-Level Synthesis

Authors: Petri Solanti, Russell Klein

Abstract:

Many designers are asking for an automated path from an abstract mathematical MATLAB model to a high-quality Register-Transfer Level (RTL) hardware description. Manual transformations of MATLAB or intermediate code are needed, when the design abstraction is changed. Design conversion is problematic as it is multidimensional and it requires many different design steps to translate the mathematical representation of the desired functionality to an efficient hardware description with the same behavior and configurability. Yet, a manual model conversion is not an insurmountable task. Using currently available design tools and an appropriate design methodology, converting a MATLAB model to efficient hardware is a reasonable effort. This paper describes a simple and flexible design methodology that was developed together with several design teams.

Keywords: design methodology, high-level synthesis, MATLAB, verification

Procedia PDF Downloads 139
3674 The Effects and Interactions of Synthesis Parameters on Properties of Mg Substituted Hydroxyapatite

Authors: S. Sharma, U. Batra, S. Kapoor, A. Dua

Abstract:

In this study, the effects and interactions of reaction time and capping agent assistance during sol-gel synthesis of magnesium substituted hydroxyapatite nanopowder (MgHA) on hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) ratio, Ca/P ratio and mean crystallite size was examined experimentally as well as through statistical analysis. MgHA nanopowders were synthesized by sol-gel technique at room temperature using aqueous solution of calcium nitrate tetrahydrate, magnesium nitrate hexahydrate and potassium dihydrogen phosphate as starting materials. The reaction time for sol-gel synthesis was varied between 15 to 60 minutes. Two process routes were followed with and without addition of triethanolamine (TEA) in the solutions. The elemental compositions of as-synthesized powders were determined using X-ray fluorescence (XRF) spectroscopy. The functional groups present in the as-synthesized MgHA nanopowders were established through Fourier Transform Infrared Spectroscopy (FTIR). The amounts of phases present, Ca/P ratio and mean crystallite sizes of MgHA nanopowders were determined using X-ray diffraction (XRD). The HA content in biphasic mixture of HA and β-TCP and Ca/P ratio in as-synthesized MgHA nanopowders increased effectively with reaction time of sols (p < 0.0001, two way Anova), however, these were independent of TEA addition (p > 0.15, two way Anova). The MgHA nanopowders synthesized with TEA assistance exhibited 14 nm lower crystallite size (p < 0.018, 2 sample t-test) compared to the powder synthesized without TEA assistance.

Keywords: capping agent, hydroxyapatite, regression analysis, sol-gel, 2- sample t-test, two-way analysis of variance (ANOVA)

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3673 Efficient Ni(II)-Containing Layered Triple Hydroxide-Based Catalysts: Synthesis, Characterisation and Their Role in the Heck Reaction

Authors: Gabor Varga, Krisztina Karadi, Zoltan Konya, Akos Kukovecz, Pal Sipos, Istvan Palinko

Abstract:

Nickel can efficiently replace palladium in the Heck, Suzuki and Negishi reactions. This study focuses on the synthesis and catalytic application of Ni(II)-containing layered double hydroxides (LDHs) and layered triple hydroxides (LTHs). Our goals were to incorporate Ni(II) ions among the layers of LDHs or LTHs, or binding it to their surface or building it into their layers in such a way that their catalytic activities are maintained or even increased. The LDHs and LTHs were prepared by the co-precipitation method using ethylene glycol as co-solvent. In several cases, post-synthetic modifications (e.g., thermal treatment) were performed. After optimizing the synthesis conditions, the composites displayed good crystallinity and were free of byproducts. The success of the syntheses and the post-synthetic modifications was confirmed by relevant characterization methods (XRD, SEM, SEM-EDX and combined IR techniques). Catalytic activities of the produced and well-characterized solids were investigated through the Heck reaction. The composites behaved as efficient, recyclable catalysts in the Heck reaction between 4-bromoanisole and styrene. Through varying the reaction parameters, we were able to obtain acceptable conversions under mild conditions. Our study highlights the possibility of the application of Ni(II)-containing composites as efficient catalysts in coupling reactions.

Keywords: layered double hydroxide, layered triple hydroxide, heterogeneous catalysis, heck reaction

Procedia PDF Downloads 174