scholarly journals Adsorption of plant phenols by polystyrene resins

2014 ◽  
Vol 56 (3) ◽  
pp. 485-497 ◽  
Author(s):  
Akiyoshi Fukushima ◽  
Hioaki Hase ◽  
Koshi Saito
Keyword(s):  
Synthetic Polymers ◽  
Model System ◽  
Experimental Conditions ◽  
Phenol Adsorption ◽  
Plant Phenols ◽  
Cation Exchangers ◽  
Phenolic Constituents ◽  
Different Types ◽  
Exchange Resins ◽  
Dowex 1

Adsorption of nine plant phenols by nine polystyrene ion-exchange resins was investigated in an experimental model system. The phenols were adsorbed by Amberlite CG-120 more efficiently than any other acidically charged resins tested in this study. They were also taken up by anion exchangers. Among them Dowex 1-X8 was found to show the strongest effect on the adsorption of the phenolic constituents applied. A comparison of the efficiency of plant phenol adsorption between two different types of the synthetic polymers revealed that the basically charged polystyrenes had more prefarable affinities for phenols than cation exchangers. For example, the ratio of the efficiency between Amberlite CG-120 and Dowex 1-X8 was roughly calculated to be 3:7 under the present experimental conditions. The adsorption rate of the test phenols was raised mostly by increasing the amount of the resins added, if they were mixed with effective polymers in the incubation model system.

scholarly journals Further studies on the adsorption of plant phenols by synthetic polymers

2014 ◽  
Vol 58 (4) ◽  
pp. 583-592 ◽  
Author(s):  
Akiyoshi Fukushima ◽  
Hiroaki Hase ◽  
Koshi Saito
Keyword(s):  
Chlorogenic Acid ◽  
Caffeic Acid ◽  
Average Rate ◽  
Synthetic Polymers ◽  
Buffer Solution ◽  
Phenol Adsorption ◽  
Plant Phenols ◽  
Amberlite Resins ◽  
Xad Resins

Pyrocatechol, catechol, caffeic acid, chlorogenic acid, safflor yellow A, safflor yellow B, precarthamin and carthamin were effectively adsorbed by insoluble polyvinyl-N-pyr­rolidone (PVP) in a neutral buffer solution. These eight phenols also bound with Amberlite XAD resins, however, the rate was found to be far less efficient than that of PVP. The average rate of the phenol binding was calculated as following order (%): PVP (42.7), Amberlite XAD-2 (16.6), Amberlite XAD-4 (10.1), Amberlite XAD-7 (13.0), Amberlite XAD-8 (17.7). No 3,4-dihydroxyphenylalanine was adsorbed by PVP, while the O-dihydroxylic acid could be removed by Amberlite XAD-4, XAD-7 and XAD-8. Data from using different weights of the test polymers showed that the rate of the phenol adsorption rose in proportion to each increasing amount of the adsorbents. PVP also admittedly maintained its predominent capacity for phenol binding over that of each member of the Amberlite resins.

An Insight into the Polymeric Nanoparticles Applications in Diabetes Diagnosis and Treatment

2021 ◽  
Vol 21 ◽  
Author(s):  
Parisa Dehghani ◽  
Monireh Esameili Rad ◽  
Atefeh Zarepour ◽  
Ponnurengam Malliappan Sivakumar ◽  
Ali Zarrabi
Keyword(s):  
Polymeric Nanoparticles ◽  
Synthetic Polymers ◽  
Diagnostic Methods ◽  
Diagnosis And Treatment ◽  
Diabetes Diagnosis ◽  
Transport Mechanisms ◽  
Different Types ◽  
Treatment And Diagnosis ◽  
Insight Into

: Diabetes mellitus (DM) is a type of chronic metabolic disease that has affected millions of people worldwide and is known with a defect in the amount of insulin secretion, insulin functions, or both. This deficiency leads to an increase in the amounts of glucose, which could be accompanied by long-term damages to other organs such as eyes, kidneys, heart, and nervous system. Thus, introducing an appropriate approach for diagnosis and treatment of different types of DM is the aim of several researches. By the emergence of nanotechnology and its application in medicine, new approaches were presented for these purposes. The object of this review article is to introduce different types of polymeric nanoparticles (PNPs), as one of the most important classes of nanoparticles, for diabetic management. To achieve this goal, at first, some of the conventional therapeutic and diagnostic methods of DM will be reviewed. Then, different types of PNPs, in two forms of natural and synthetic polymers with different properties, as a new method for DM treatment and diagnosis will be introduced. In the next section, the transport mechanisms of these types of nano-carriers across the epithelium, via paracellular and transcellular pathways will be explained. Finally, the clinical use of PNPs in the treatment and diagnosis of DM will be summarized. Based on the results of this literature review, PNPs could be considered one of the most promising methods for DM management.

scholarly journals Phosphorus extracted by ion exchange resins and mehlich-1 from oxisols (latosols) treated with different phosphorus rates and sources for varied soil-source contact periods

2013 ◽  
Vol 37 (3) ◽  
pp. 667-677 ◽  
Author(s):  
Irio Fernando de Freitas ◽  
Roberto Ferreira Novais ◽  
Ecila Mercês de Albuquerque Villani ◽  
Sarah Vieira Novais
Keyword(s):  
Sandy Loam ◽  
Extraction Methods ◽  
Available P ◽  
Molar Ratio ◽  
P Availability ◽  
Triple Superphosphate ◽  
Experimental Conditions ◽  
Reactive Phosphate ◽  
Exchange Resins ◽  
P Sources

Despite the large number of studies addressing the quantification of phosphorus (P) availability by different extraction methods, many questions remain unanswered. The aim of this paper was to compare the effectiveness of the extractors Mehlich-1, Anionic Resin (AR) and Mixed Resin (MR), to determine the availability of P under different experimental conditions. The laboratory study was arranged in randomized blocks in a [(3 x 3 x 2) + 3] x 4 factorial design, with four replications, testing the response of three soils with different texture: a very clayey Red Latosol (LV), a sandy clay loam Red Yellow Latosol (LVA), and a sandy loam Yellow Latosol (LA), to three sources (triple superphosphate, reactive phosphate rock from Gafsa-Tunisia; and natural phosphate from Araxá-Minas Gerais) at two P rates (75 and 150 mg dm-3), plus three control treatments (each soil without P application) after four contact periods (15, 30, 60, and 120 days) of the P sources with soil. The soil acidity of LV and LVA was adjusted by raising base saturation to 60 % with the application of CaCO3 and MgCO3 at a 4:1 molar ratio (LA required no correction). These samples were maintained at field moisture capacity for 30 days. After the contact periods, the samples were collected to quantify the available P concentrations by the three extractants. In general, all three indicated that the available P-content in soils was reduced after longer contact periods with the P sources. Of the three sources, this reduction was most pronounced for triple superphosphate, intermediate for reactive phosphate, while Araxá phosphate was least sensitive to the effect of time. It was observed that AR extracted lower P levels from all three soils when the sources were phosphate rocks, while MR extracted values close to Mehlich-1 in LV (clay) and LVA (medium texture) for reactive phosphate. For Araxá phosphate, much higher P values were determined by Mehlich-1 than by the resins, because of the acidity of the extractor. For triple superphosphate, both resins extracted higher P levels than Mehlich-1, due to the consumption of this extractor, particularly when used for LV and LVA.

Early Spelling Acquisition: Does Writing Really Beat the Computer?

1992 ◽  
Vol 15 (3) ◽  
pp. 223-228 ◽  
Author(s):  
Sharon Vaughn ◽  
Jeanne Shay Schumm ◽  
Jane Gordon
Keyword(s):  
Learning Disabled ◽  
Primary Grade ◽  
Group Differences ◽  
Experimental Conditions ◽  
Spelling Acquisition ◽  
Instructional Activity ◽  
Study Results ◽  
Different Types ◽  
Computer Based ◽  
Based Instruction

This research evaluated the efficacy of handwriting, letter tiles, and computer-based instruction on the early spelling acquisition of normal achieving (NLD) and learning disabled (LD) elementary students. The study replicated and extended the Cunningham and Stanovich (1990) study. Forty-eight primary-grade students (24 non-learning disabled; 24 learning disabled) received spelling training under three experimental conditions that involved different types of instructional activity: writing, sorting letter tiles, or typing on the computer. Results indicated no significant differences between the LD and NLD groups on words spelled correctly for any of the three conditions. Since the number of spelling words learned was low across conditions and groups, the number of correctly learned bigrams was examined. No within-group differences emerged for condition (writing, tile, computer); however, significant differences between the groups were found on number of bigrams learned for writing, tile, and computer, with the NLD group outperforming the LD group on all three conditions. Statistically significant time effects for bigrams were also noted for all three conditions. Unlike the Cunningham and Stanovich (1990) study, results did not replicate the superiority of the handwriting condition for the NLD group, nor was the handwriting condition found to be significantly more effective for the LD group.

scholarly journals Reaction of Ion Exchange Resins with Fenton’s Reagent

Environments ◽  
2018 ◽  
Vol 5 (11) ◽  
pp. 123 ◽  
Author(s):  
Leandro de Araujo ◽  
Júlio Marumo
Keyword(s):  
Ion Exchange ◽  
Catalyst Concentration ◽  
Setting Time ◽  
Ion Exchange Resins ◽  
Experimental Conditions ◽  
Final Volume ◽  
Different Temperatures ◽  
Axial Compressive Strength ◽  
Exchange Resins ◽  
Two Parameters

One of the most common treatment methods for spent ion exchange resins is their immobilization in cement, which reduces the release of radionuclides into the environment. Although this method is efficient, it considerably increases the final volume of the waste due to its low incorporation capacity. This work aims to evaluate the degradation of ion exchange resins by the Fenton process (H2O2/Fe2+). The resin evaluated was a mixture of cationic and anionic resins, both non-radioactive. The reactions were conducted by varying the catalyst concentration (25, 50, 100, and 150 mmol L−1) and the volume of hydrogen peroxide. Three different temperatures were evaluated by varying the flow of reactants, which were 50, 60, and 70 °C. Cement specimens were prepared from the treated solutions and two parameters were assessed—namely, final setting time and axial compressive strength. The results showed that the experimental conditions were suitable to dissolve the resins, and the Fe3+ produced as precipitate during the experiments increased the resistance of the final product. The immobilized product complied with the limits established by regulation.

scholarly journals Combination of Autohydrolysis and Catalytic Hydrolysis of Biomass for the Production of Hemicellulose Oligosaccharides and Sugars

Reactions ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 30-46
Author(s):  
Léa Vilcocq ◽  
Agnès Crepet ◽  
Patrick Jame ◽  
Florbela Carvalheiro ◽  
Luis C. Duarte
Keyword(s):  
Agricultural Waste ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Energy Crop ◽  
Catalytic Hydrolysis ◽  
Experimental Conditions ◽  
Different Types ◽  
Hemicellulosic Sugars ◽  
Hydrolysis Of

Three different types of biomass sourced from forestry waste (eucalyptus residues), agricultural waste (wheat straw), and energy crop (miscanthus) were used as starting materials to produce hemicellulosic sugars, furans (furfural and hydroxymethylfurfural), and oligosaccharides. A two-step hybrid process was implemented; biomass was first autohydrolysed without any additive to extract hemicelluloses and dissolve it in water. Then, the hydrolysate was treated with a solid acid catalyst, TiO2-WOx, in order to achieve hydrolysis and produce monomeric sugars and furans. This article investigates the role of the biomass type, autohydrolysis experimental conditions, polymerisation degree and composition of hemicelluloses on the performance of the process coupling autohydrolysis and catalytic hydrolysis. The highest global yields of both oligosaccharides and monomeric sugars were obtained from Eucalyptus (37% and 18%, respectively).

scholarly journals Simultaneous Exposure of Different Nanoparticles Influences Cell Uptake

Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 136
Author(s):  
Isa de Boer ◽  
Ceri J. Richards ◽  
Christoffer Åberg
Keyword(s):  
Drug Delivery ◽  
Individual Cell ◽  
Model System ◽  
Cell Uptake ◽  
Target Cells ◽  
Cell Level ◽  
Polystyrene Nanoparticles ◽  
Simultaneous Exposure ◽  
Different Types ◽  
Uptake Studies

Drug delivery using nano-sized carriers holds tremendous potential for curing a range of diseases. The internalisation of nanoparticles by cells, however, remains poorly understood, restricting the possibility for optimising entrance into target cells, avoiding off-target cells and evading clearance. The majority of nanoparticle cell uptake studies have been performed in the presence of only the particle of interest; here, we instead report measurements of uptake when the cells are exposed to two different types of nanoparticles at the same time. We used carboxylated polystyrene nanoparticles of two different sizes as a model system and exposed them to HeLa cells in the presence of a biomolecular corona. Using flow cytometry, we quantify the uptake at both average and individual cell level. Consistent with previous literature, we show that uptake of the larger particles is impeded in the presence of competing smaller particles and, conversely, that uptake of the smaller particles is promoted by competing larger particles. While the mechanism(s) underlying these observations remain(s) undetermined, we are partly able to restrain the likely possibilities. In the future, these effects could conceivably be used to enhance uptake of nano-sized particles used for drug delivery, by administering two different types of particles at the same time.

scholarly journals Biocatalysis for terpene-based polymers

2019 ◽  
Vol 74 (3-4) ◽  
pp. 91-100 ◽  
Author(s):  
Wissam Farhat ◽  
Arne Stamm ◽  
Maxime Robert-Monpate ◽  
Antonino Biundo ◽  
Per-Olof Syrén
Keyword(s):  
Renewable Resources ◽  
Building Blocks ◽  
Synthetic Polymers ◽  
Model System ◽  
Advanced Materials ◽  
Carbon Carbon Bonds ◽  
Carbon Bonds

Abstract Accelerated generation of bio-based materials is vital to replace current synthetic polymers obtained from petroleum with more sustainable options. However, many building blocks available from renewable resources mainly contain unreactive carbon-carbon bonds, which obstructs their efficient polymerization. Herein, we highlight the potential of applying biocatalysis to afford tailored functionalization of the inert carbocyclic core of multicyclic terpenes toward advanced materials. As a showcase, we unlock the inherent monomer reactivity of norcamphor, a bicyclic ketone used as a monoterpene model system in this study, to afford polyesters with unprecedented backbones. The efficiencies of the chemical and enzymatic Baeyer–Villiger transformation in generating key lactone intermediates are compared. The concepts discussed herein are widely applicable for the valorization of terpenes and other cyclic building blocks using chemoenzymatic strategies.

scholarly journals In vivo mucoadhesive strength appraisal of gum Manilkara zapota

2015 ◽  
Vol 51 (3) ◽  
pp. 689-698 ◽  
Author(s):  
Singh Sudarshan ◽  
Bothara Sunil B
Keyword(s):  
Drug Delivery Systems ◽  
Guar Gum ◽  
Methyl Cellulose ◽  
Synthetic Polymers ◽  
Chemical Modifications ◽  
Experimental Conditions ◽  
Manilkara Zapota ◽  
Seed Mucilage

The mucilage (MMZ) extracted from the seeds of Manilkara zapota(Linn.) P. Royen syn. using maceration techniques was evaluated for mucoadhesive strength by various in vitro and in vivo methods. The result showed that mucoadhesive strength of seeds mucilage have comparable property toward natural and synthetic polymers such as Guar Gum and hydroxyl propyl methyl cellulose (HPMC E5LV) under the experimental conditions used in this study. Briefly, it could be concluded that the seed mucilage of Manilkara zapota can be used as a pharmaceutical excipient in oral mucoadhesive drug delivery systems. Further, it may be appropriate to study the changes in these properties after chemical modifications.

SEPARATION OF BILE ACID CONJUGATES BY ION EXCHANGE CHROMATOGRAPHY

1963 ◽  
Vol 41 (1) ◽  
pp. 77-89 ◽  
Author(s):  
B. A. Gordon ◽  
A. Kuksis ◽  
J. M. R. Beveridge
Keyword(s):  
Bile Acid ◽  
Ion Exchange ◽  
Complete Separation ◽  
Exchange Chromatography ◽  
Ethanol Solution ◽  
Anion Exchange Column ◽  
Exchange Resins ◽  
Dowex 1 ◽  
Cholanic Acid ◽  
Acetate Form

A simple and reliable method for the separation of bile acid conjugates in quantities ranging from a few milligrams to several grams has been developed utilizing ion exchange resins. The bile acid conjugates were absorbed from an aqueous 25% ethanol solution on a Dowex-1 anion exchange column (acetate form). After the column was washed with aqueous 25% ethanol, the glycine conjugates were eluted with 0.05 N HCl in 25% ethanol and the taurine conjugates with 0.5 N HCl in 25% ethanol. The method permitted a complete resolution of the glycine and taurine conjugates. In addition, there was an effective though not complete separation of the tri- and di-hydroxy cholanic acid derivatives within each conjugate group. Using this method satisfactory fractionations have been performed on gallbladder bile from dog, ox, and man.

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