Polyethylene Glycol In Medium Research Articles

Induksi Mutasi Kromosom Dengan Iradiasi Sinar Gamma Cobalt 60 Untuk Merakit Padi (Oryza sativa) Tahan Kekeringan Secara In Vitro

A lot of people in the world choose rice as their main source of carbohydrate beside maize and wheat. The increasing of world population make increasing of the rice demand. Increasing of the rice demand doesn’t followed by the rice supply. In order to solve that problem, researcher try to find a new paddy cultivar which is can be planted in dry area. This research aims to study the osmotic pressure that still can be accepted by paddy var. Sintanur, to study LD50 (lethal dose 50) value in the paddy especially in Sintanur and to study the interaction between irradiation and the osmotic pressure. In this research, paddy var. Sintanur is irradiated by gamma ray of Cobalt60 at six dosages 0 Gy, 100 Gy, 200 Gy, 300 Gy, 400 Gy, 500 Gy. Then each irradiated seed is planted at four kind of mediums that contains Polyethylene glycol (PEG) at four levels of concentration are I0 (0 g/l PEG), I1 (116,538 g/l PEG), I2 (174,6 g/l PEG) and I3 (219,547 g/l PEG). Based on the data analyzed, the highest PEG concentration for drought tolerant selection in paddy var. Sintanur is 174,674 g/l PEG. There is an interaction between irradiation and PEG medium that influencing plant height and shoot multiplication. LD 50 (lethal dose 50) of paddy var. Sintanur is 375 Gy.
 
 Keyword: paddy, Sintanur, cobalt60, drought tolerant, irradiation

Fumed Silica-Based Suspensions for Shear Thickening Applications: A Full-Scale Rheological Study.

Understanding shear thickening fluids (STFs) is critically important in a broad spectrum of fields ranging from biology to military. STFs are referred to the suspension of solid particles in an inert carrier liquid. Customizing the thickening behavior is vital for obtaining desired properties. Hence, comprehending shear thickening mechanisms is necessary to fully understand the factors affecting the shear thickening response of the STFs. Herein, we systematically investigate the effects of a wide range of parameters, from inherent properties of the constituents, including size and surface chemistry of the suspended particles, to practical conditions such as temperature and shear history, on the shear thickening behavior of fumed silica nanoparticles (NPs)-based suspensions in a polyethylene glycol (PEG) medium. Accordingly, increasing the hydrophobicity of the silica NPs or decreasing the NP size transforms the suspensions from sol to gel. The sol systems exhibit a strong shear thickening response, while shear thinning behavior is prominent in the strong gel systems. Hybridization of different silica NPs is also leveraged to tune the shear thickening behavior. In addition, we showcase the decisive role of operating temperature or shear history on the shear thickening behavior of suspensions. For instance, in terms of the shear history, above a critical value of preshear, the shear thickening behavior occurs at lower shear rates for STFs containing hydrophilic NPs. It is believed that the provided insights in this study can pave the way for developing advanced STFs with prescribed features.

Effect of Ground Vulcanizate Modification Methods on Properties of Oil-Petroleum-Resistant Rubber

In this paper, the influence of the modification method applied to ground vulcanizate (GV) on the properties of elastomeric compositions based on nitrile rubber is discussed. Modified GV has been mixed with the elastomeric composition, which is used for the manufacturing of oil-petroleum-resistant rubber products.The work takes into consideration two types of GV with different chemical nature. The first GV type is rubber crumb produced from end-of-life tires. The second GV type was obtained from rubber wastes based on nitrile rubber. Three methods of the modification are compared in the research: mechanical activation in a planetary ball mill, swelling in a Polyethylene glycol (PEG-400) medium, and the mechano-chemical transformation of GV with PEG-4000. It is shown that depending on the dosage addition of GV modified with PEG-4000 reduce the compression set up for (16.1±0.7%), the strength decreases only by 2.1–8.3%, and the elongation at break increases by 0.8–10.3% compared to rubber without additives.

Comparing the in vitro digestibility of leaves from tropical trees when using the rumen liquor from cattle, sheep or goats

This study compared the effect of ruminal inoculum from different donor species (goat vs. cattle and sheep vs. cattle) on the in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) of leaves from tropical plant species. Comparisons were performed with and without the addition of N and polyethylene glycol (PEG). Leaves from six tropical trees with different condensed tannin content were used (Caesalpinia gaumeri, Cordia alliodora, Gymnopodium floribundum, Neomillspaughia emarginata, Piscidia piscipula and Senegalia gaumeri). Donors of ruminal liquor included a ruminal cannulated adult cow (500 kg live weight [LW]), two growing Criollo goats (22 ± 3 kg LW, study one) and two growing Pelibuey lambs (24.8 ± 0.28 LW, study two). Donors were maintained in individual pens and received a basal diet with concentrate feed and Pennisetum purpureum grass. The IVDMD and IVOMD using sheep or goat vs. cow rumen liquor were determined from dry samples of a commercial concentrate feed, P. purpureum grass, and the leaves from experimental plants with a 2 × 2 factorial arrangement: with or without N-enriched media (+N and -N), and with or without polyethylene glycol (+PEG and -PEG). Respective standard linear regressions and orthogonal regressions were used to compare equivalence of IVDMD and IVOMD results between ruminal inoculum from different donor species (cattle vs. goat in study one and cattle vs. sheep in study two). The standard linear regressions suggested strong associations between the ruminal inocula compared, in both IVDMD and IVOMD with the four treatments (R2 > 87 % for study one and R2 > 89 % for study two, P < 0.001). However, orthogonal regressions showed differences between inocula of cattle and goats on IVDMD, when using + PEG media, and on IVDMD and IVOMD when using + N media (P < 0.05). Differences between inocula of cattle and sheep were only evident in the absence of PEG (P < 0.05). The standard linear and orthogonal regressions suggested that the IVDMD and IVOMD of leaves from tropical trees obtained with sheep or goats’ ruminal liquors, within the evaluated range of digestibilities (c. 0.2 to 0.65), can be predicted from the IVDMD and IVOMD obtained with the cattle ruminal liquor. However, when evaluating digestibilities of leaves from tropical trees it is important to evaluate the specific incubation conditions using the donor species of interest to improve accuracy of results.

Effect of Stabilizing Agent of Sodium Citrate and Polyethylene Glycol on Structure of Fe&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; Nanoparticles

Magnetic nanomaterials are studied extensively because of their wide range of possible applications. Synthesis of Fe3O4 with citrate and polyethylene glycol (PEG) as stabilizing agents was carried out. In this study, the effect of media of water, sodium citrate and polyethylene glycol as stabilizing agents on the shape and size of Fe3O4 magnetite nanoparticles was investigated. The synthesis of Fe3O4, Fe3O4/citrate, and Fe3O4/PEG was carried out by the coprecipitation method at controlled pH. The products were characterized by infrared spectrophotometry, X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX). Qualitative test of magnetism was also carried out on the three materials. The results showed that Fe3O4 nanoparticles prepared with sodium citrate and PEG have a diameter of 12 and 10 nm, respectively. In the sodium citrate medium, it gives Fe3O4 colloidal nanoparticle with electrostatic stabilization mode, while in the PEG medium it shows steric stabilization mode. Magnetite produced in PEG medium has the homogeneous size and is much more stable than that obtained in citrate medium

Morphological, antioxidant enzyme activity and secondary metabolites accumulation in response of polyethylene glycol-induced osmotic stress in embryo-derived plantlets and callus cultures of Salvia leriifolia

In this study, different levels of polyethylene glycol (PEG) 6000 (5, 7.5 and 10% w/v) were applied to induce drought stress in the embryo and callus culture of Salvia leriifolia Benth, an Iranian medicinal plant. The results related to the embryo culture showed that the germination percentage, stem length, root and stem diameter and total chlorophyll content of plantlets decreased by increasing the PEG concentration, while the highest root length was obtained at the lower PEG concentration (5%). The short-term callus culturing on the media containing different concentrations of PEG resulted in an insignificant difference in the fresh weight, dry weight, and browning intensity of calli between the PEG-free and 5% PEG medium. The proline, hydrogen peroxide, and malondialdehyde contents as indicators of oxidative stress significantly increased in the plantlets and calli at all PEG concentrations. The activity of antioxidant enzymes including catalase and guaiacol peroxidase also increased while superoxide dismutase activity decreased. The rosmarinic acid, caffeic acid, and salvianolic acid B contents increased significantly in all the plantlets and calli culture media containing the PEG. However, the highest contents of these secondary metabolites in plantlets and callus cultures were observed in the medium with 5% PEG. Totally, the results showed that, the short-term reduction in the osmotic potential of culture medium by low concentration of PEG elicitor can effectively improve the content of rosmarinic acid, caffeic acid, and salvianolic acid B in S. leriifolia, especially in callus cultures. Polyethylene glycol elicitor as a drought stress inducer can be effectively improved the content of rosmarinic acid, caffeic acid, and salvianolic acid B in plantlet and callus culture of Salvia leriifolia benth.

Tuning the Frictional Properties of Carbon Fabrics Using Boron Carbide Particles

In recent years, researches have made many efforts to improve the frictional properties of high performance fabrics by using different methods such as applying natural rubber latex, developing metal oxide nano-rods and treating with shear thickening fluids. Even though these methods have provided beneficial results for enhanced frictional behavior, they exhibit some drawbacks in terms of flexibility, stability and ease of application. For this reason, an attempt has been made in this research to tune the frictional properties of carbon fabric through a simple process such as coating the fabric with boron carbide particles in polyethylene glycol medium. The surface friction as well as yarn-to-yarn friction were evaluated and it was found that the presence of only polyethylene glycol (PEG) or the mixture of PEG/boron carbide enhances the surface friction and yarn-to-yarn friction in the fabric. In addition, the role of boron carbide concentration used in the treatment process was investigated. It was found that the friction in carbon fabric can be controlled by altering the amount of boron carbide particles used in the treatment process.

Tuning the Rheology of Nano-Sized Silica Suspensions with Silicon Nitride Particles

In this paper, a non-Newtonian fluid was fabricated dispersing nanosized silica particles in a polyethylene glycol medium. The rheology of the suspension was investigated in a stress-controlled rheometer under increasing shear rate. Based on the rheological measurements, the suspension exhibited shear thickening behavior which gives a drastic viscosity grow with the increase in the shear rate. In order to investigate the role of the micro-sized additive particles on the rheology of silica based suspension, silicon nitride particles were included in the suspension with three different concentrations. The results were discussed in terms of important parameters for the shear thickening mechanism such as critical shear rate, peak viscosity, thickening ratio and initial viscosity. According to the results, shear thickening behavior can be controlled altering the amount of silicon nitride particles in the suspension.

Synthetic routes, structure and catalytic activity of Ag/BN nanoparticle hybrids toward CO oxidation reaction

Nanohybrid materials made of h-BN nanoparticles (BNNPs) with Ag nanoparticles (AgNPs), covering their surfaces, were employed as catalysts in CO oxidation reaction. Ag/BN nanohybrids (NHs) were produced via AgNO3 decomposition under UV irradiation in polyethylene glycol (PEG) and its solutions at room temperature. Influence of the synthetic media composition on the synthesis process and resultant NHs structures were investigated. Two different structural types (Ag/BN and polymer-based structure) formed during the synthesis were studied. It was demonstrated that Ag/BN NHs synthesized in a PEG media had possessed the highest Ag concentration and uniform distribution of AgNPs. Catalytic activity tests revealed that the lowest temperature of full CO conversion (194 °C) had been attained to the sample with the highest Ag content. CO oxidation mechanism on the surface of AgNPs was finally proposed based on DFT calculations.

Extraction of Bi(III) subsalicylate in micellar aggregation and its sustained release using an aqueous biphasic system

Bismuth (III) subsalicylate shows a characteristic absorption band at 300±5nm in polyethylene glycol (PEG) (50%, w/v) solution and could be determined spectrophotometrically at a trace concentration in PEG medium with a detection limit of 0.027μg/L. The extraction of Bi (III) subsalicylate salt was studied using a simple aqueous biphasic system (ABS) composed of Na2SO4 (1.5M) solution and 50% (w/v) aqueous PEG (#6000) solution at 300K. Extraction was found to be quantitative at acidic pH (2–3). The aggregation numbers (Nagg) of micellar pristine solution of PEG, PEG rich phase extracted from ABS and the top phase of ABS containing bismuth subsalicylate (BSS) after extraction from different pH of the salt rich phase were studied. Kinetic spectrophotometric studies reveal that the BSS drug has a sustained release mechanism from the micellar medium of PEG solutions when added to a simulated gastric fluid. The results may have prospective pharmaceutical applications for a controlled drug release of BSS.

PEG Induces High Expression of the Cell Cycle Checkpoint Gene WEE1 in Embryogenic Callus of Medicago truncatula: Potential Link between Cell Cycle Checkpoint Regulation and Osmotic Stress.

Polyethylene glycol (PEG) can be used to mimic osmotic stress in plant tissue cultures to study mechanisms of tolerance. The aim of this experiment was to investigate the effects of PEG (M.W. 6000) on embryogenic callus of Medicago truncatula. Leaf explants were cultured on MS medium with 2 mg L-1 NAA and 0.5 mg L-1 BAP for 5 months. Then, calli were transferred to the same medium further supplemented with 10% (w/v) 6000 PEG for 6 months in order to study physiological and putative molecular markers of water stress. There were no significant differences in growth rate of callus or mitotic index ± PEG although embryogenic potential of PEG treated callus was morphologically enhanced. Cells were rounder on PEG medium and cell size, nuclear size and endoreduplication increased in response to the PEG treatment. Significant increases in soluble sugar and proline accumulation occurred under PEG treatment compared with the control. Significantly, high MtWEE1 and MtCCS52 expression resulted from 6 months of PEG treatment with no significant differences in MtSERK1 or MtP5CS expression but down regulation of MtSOS expression. The results are consistent in showing elevated expression of a cell cycle checkpoint gene, WEE1. It is likely that the cell cycle checkpoint surveillance machinery, that would include WEE1 expression, is ameliorating the effects of the stress imposed by PEG.

Photocatalytic Activity of ZnO Nanoparticles Prepared by a Microwave Method in Ethylene Glycol and Polyethylene Glycol Media: A Comparative Study

Zinc oxide nanoparticles have been synthesized by a sol-gel microwave assisted method using either ethylene glycol (ZnO-EG) or poly ethylene glycol ethanolic solution (ZnO-PEG) as dispersing media. The nanoparticles were characterized by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared. X-ray analysis revealed a hexagonal phase structure of both zinc oxides. The average crystallite size calculated from Scherrer equation was 27 nm and 53 nm in good agreement with 24 nm and 55 nm microscopic results for ZnO-EG and ZnO-PEG, respectively. The catalytic activity of the as-prepared nanoparticles was compared by the photodegradation of 2-nitrophenol under UVC. The effect of various parameters such as pH, catalyst weight, and pollutant concentration on the percent degradation was investigated. Best optimization was pH=7, 0.06g of nanoparticles weight, and 10 mg.L-1 pollutant concentration. Furthermore, pseudo first order kinetic based on Langmuir–Hinshelwood (L–H) model was proposed for degradation reactions and experimental data were in good agreement with this model.

Copper oxide nanoparticles in an epoxy network: microstructure, chain confinement and mechanical behaviour.

Copper oxide nanoparticles (nCOPs) having octahedral morphology, synthesized through hydrazine reduction reaction were employed to formulate an epoxy based novel nanocomposite. The synthesis of copper oxide nanoparticles was carried out in polyethylene glycol medium to enhance their interfacial adhesion with the epoxy matrix. The extent of conservation of the crystalline nature and octahedral morphology of the nCOP in its epoxy nanocomposites was confirmed by X-ray diffraction and electron microscopy analysis. The mechanical properties including tensile, impact, fracture toughness and surface hardness of epoxy-nCOP nanocomposites were evaluated as a function of nCOP content. The maximum enhancement in strength, modulus, impact strength, fracture toughness and surface hardness of epoxy-nCOP nanocomposites was observed for 5 phr nCOP content. This may be due to the strong interaction between the nCOP and epoxy chains at this composition arising from its fairly uniform dispersion. A quantitative measurement of constrained epoxy chains immobilized by the nCOP octahedra was carried out using dynamic mechanical analysis. The enhancement in the storage modulus is related to the amount of the added nCOP as well as the volume of the constrained epoxy chains in the proximity of nCOP. The behaviour of epoxy-nCOP nanocomposites in this study has been explained by proposing a mechanism based on the distribution of nCOP domains in the epoxy matrix and the existing volume of constrained epoxy chains.

Synthesis And Luminescent Performance Of LaPO4: Dy Nanophosphor

Nowadays the research on synthesis of inorganic luminescent material with proper dimensions and morphologies has attracted great attention. Inorganic luminescent materials like LaPO4 have found many practical applications in the field of electroluminescent devices, integrated optics, biological labels, modern lighting and display fields. We have prepared Dysprosium (Dy) doped LaPO4 nanoparticles at relatively low temperature in polyethylene glycol (PEG) medium by wet chemical method. Dy 3+ is doped in LaPO4 at various atomic concentrations (1, 2, 5 and 10 at %). All the samples have been characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) and thermoluminescence (TL) techniques. XRD study reveals the monoclinic structure of prepared nanoparticles. Unit cell volume is found to be decrease linearly with increasing Dy 3+ concentration indicating homogeneous substitution of La 3+ ions in LaPO4 by Dy 3+ . From the FTIR study it is found that the band at 1044 cm -1 assigned to the phosphate group PO4 3- in the region of υ3 anti-symmetric stretching of P-O band. The PL spectrum shows emission band at about 435 nm is observed due to the transision of Dy 3+ ions corresponding to wavelength in the blue color region. The glow curve of LaPO4: Dy phosphor obeys second order kinetics. Copyright © 2014 VBRI press.

Polyethylene glycol (PEG-400): an efficient green reaction medium for the synthesis of benzo[4,5]imidazo[1,2-a]-pyrimido[4,5-d]pyrimidin-4(1H)-ones under catalyst-free conditions

A simple and an efficient eco-friendly methodology has been developed for the synthesis of benzo[4,5]imidazo[1,2-a]-pyrimido[4,5-d]pyrimidin-4(1H)-ones in excellent yields under catalyst-free-conditions using inexpensive and non-toxic polyethylene glycol (PEG-400) medium. This new protocol offers an environmental acceptability, shorter reaction time, room temperature, low cost, high yields, and recyclability of the PEG-400 medium are the important features. This method provides a green and much improved protocol over the existing methods.

Stability of luminescence in LaPO4, LaPO4 :RE(3+) (RE = Dy, Eu) nanophosphors.

The property of high refractive index, low solubility in water as well as stability to high temperature variation of lanthanum phosphate (LaPO4 ) proved it was the most effective candidate for the production of display lamps, and plasma display panel devices and sensors. The morphological and nanostructural characteristics play a key role in the working efficiency of the luminescent material. These properties can be controlled by the synthesis method, which we have adopted in this paper. We have prepared LaPO4 nanoparticles at a relatively low temperature (110 ºC) in polyethylene glycol medium by using a wet chemical one-step synthesis. The phase composition and structural properties of the sample have been characterized by X-ray diffraction, Fourier transform infrared, transmission electron microscopy and the luminescent property by photoluminescence and thermoluminescence. The samples were well crystallized and the average crystallite size of 15 nm has been calculated for pure LaPO4 using the Debye-Scherrer equation. The result from heat-treated samples shows the phase combination and morphological structure of the powder depend on the annealing temperature. The heat treatment changes the structure of LaPO4 from cuboid rods to fine grains at about 600 °C. The emission spectrum of LaPO4 shows the broad emission band at 368 nm and shoulder at 465 nm with emission of blue color when monitored at an excitation wavelength at 256 nm. The stability of phosphor has been studied with respect to humidity, temperature, doping, doping concentration, γ-ray exposures, etc. The prepared nanosized phosphors were thermally stable and may be a promising blue phosphor for lighting technology as well as radiation dosimetry.

Microbial evaluation for biodegradability of recalcitrant organic in textile wastewater using an immobilized-cell activated sludge process

Textile wastewater is difficult to be treated because it contains recalcitrant matters. This study evaluated the performance of an immobilized-cell process using polyethylene glycol media and microbial properties of the immobilized-cells for biodegradation of recalcitrant organics. The immobilized-cell process could remove hardly-biodegradable soluble COD more than 50% at various Hydraulic Retention Times (HRTs) over 8∼24 hours. Active microbial distribution was fluctuated at the start-up operation, but became stable at both lower and upper part of the reactor after 92 days of operation. Cell mass in the media at the bottom was higher than at the middle or top parts of the reactor. The microbial decay in the media was more dependent on oxygen than organics. Stentrophomonas sp. and Pseudomonas putida, known as aromatic and aliphatic compound degraders, were identified in the media, confirming spontaneous selection and growth of cells that could oxidize the hardly biodegradable contaminants in the textile wastewater.

New Approach for the Determination of Tricyclic Antidepressant Amitriptyline Using &amp;lt;i&amp;gt;β&amp;lt;/i&amp;gt;-Cyclodextrin-PEG System via Spectrophotomerty

A new and simple procedure for the spectrophotometric determination of the tricyclic antidepressant drug amitriptyline is proposed. The method is based on enhancement of sensitivity of the [AMIYTP]+ β-cyclodextrin and PEG molecules involved in formation of molecules inclusion complex, in presence of polyethylene glycol (PEG) medium. The mole ratio of [AMIYTP]+ β-cyclodextrin and PEG molecules in inclusion complex were determined by the curve fitting method. The value of molar absorptivity of {[AMIYTP: (β CD)] PEG} complex in term of the drug lies in rage of (2.20 - 2.23) × 104 L·mole–1·cm–1 at absorption maximum 242 nm. The slope, intercept and correlation co-efficient were found to be 14.21, 0.0046, and 0.998, respectively. The effect of analytical variables on the determination of the drug and composition of the ion associated complex are discussed in the paper. This method is applicable in the determina-tion of amitriptyline in the pharmaceutical preparations.

ChemInform Abstract: The Ugi Reaction in a Polyethylene Glycol Medium: A Mild, Protocol for the Production of Compound Libraries.

AbstractAn efficient, mild und eco‐friendly method for the Ugi reaction in PEG‐water is described.

The Ugi Reaction in a Polyethylene Glycol Medium: A Mild, Protocol for the Production of Compound Libraries

A mild, efficient, and eco-friendly method for the Ugi reaction between a carboxylic acid, an amine, a carbonyl compound and an isocyanide to give a bisamide is described using PEG–H2O as a solvent. Reactants of poor water-solubility could be used in an aqueous medium without significant decrease in the yield. No side products were observed. The advantages of this protocol are short reaction time and easy isolation of the precipitated product when compared to reactions carried out in methanol.