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Hydrophilic Properties (hydrophilic + property)
Selected AbstractsApplication of hydrophilic finished of synthetic fabrics coated with CMC/acrylic acid cured by electron beam irradiation in the removal of metal cations from aqueous solutionsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Sayeda M. Ibrahim Abstract Modified textile fabrics were used to remove Cu+2 and Cr+3 ions from aqueous solutions. For this purpose, modified Nylon-6, polyester woven and knitted fabrics were prepared by coating the surface with a thin layer of aqueous solution of carboxymethyl cellulose (CMC) and acrylic acid (AAc) of thickness 25 ,m. Radiation crosslinking of the coated layer was carried out by electron beam irradiation with a constant dose of 30 kGy. Morphology of the coated fabrics was examined by scanning electron microscope (SEM) which indicated the compatibility between the coated layer and fabrics. Properties attributed to the hydrophilicity, especially water uptake and weight loss before and after several washing cycles were followed up. The effect of AAc concentration on the hydrophilic properties of the coated fabrics was studied. A considerable enhancement in water uptake has been attained on increasing AAc content in solution in case of nylon-6 followed by polyester woven followed by polyester knitted fabrics. The performances of the modified textile fabrics were evaluated for the recovery of Cu+2 and Cr+3 from aqueous solution. The metal ion absorption efficiency of the modified textile fabrics was measured using UV Spectrophotometer analysis and EDX. Parameters affecting the efficiency of these textile fabrics in the removal of metal ions from aqueous solution namely, concentration of AAc and the immersion time were studied. It was found that there was a marked increase in the recovery of metal ions on increasing both immersion time and concentration of AAc. This study evidences that the modified textile fabrics can be used for the purpose of removal of some heavy metals such as Cu and Cr. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] In-vitro and in-vivo studies of cefpirom using bile salts as absorption enhancersJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2003Yahya Mrestani ABSTRACT Cephalosporins have to be administered by injection because of the poor intestinal absorption of the orally delivered drugs. Because of the obvious drawbacks of drug delivery by injection, the development of alternatives with enhanced oral bioavailability is receiving much attention in pharmaceutical research. Cefpirom (Cp) is a new semi-synthetic amino-2-thiazolyl-methoxyimino cephalosporin that has been substituted in position 3 with a cyclopenteno-pyridinium group in order to create a zwitterionic compound. It exhibits highly hydrophilic properties, as shown from its extremely low partition coefficient, and therefore its lipophilicity was increased using bile salts. The effect of this on the partition coefficients determined in the n-octanol/buffer system was confirmed using an in-vitro transport model with artificial and biological membranes. The pharmacokinetic properties of Cp were investigated in rabbits after intraduodenal administration with and without bile salts. Furthermore, the physiological compatibility of the bile salts was investigated using active D-glucose transport. [source] Sugars-grafted aliphatic biodegradable poly(L -lactide- co -carbonate)s by click reaction and their specific interaction with lectin moleculesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2007Changhai Lu Abstract A novel biodegradable aliphatic poly(L -lactide- co -carbonate) bearing pendant acetylene groups was successfully prepared by ring-opening copolymerization of L -lactide (LA) with 5-methyl-5-propargyloxycarbonyl-1,3-dioxan-2-one (PC) in the presence of benzyl alcohol as initiator with ZnEt2 as catalyst in bulk at 100 °C and subsequently used for grafting 2-azidoethyl ,- D -glucopyranoside and 2-azidoethyl ,-lactoside by the typical "click reaction," that is Cu(I)-catalyzed cycloaddition of azide and alkyne. The density of acetylene groups in the copolymer can be tailored by the molar ratio of PC to LA during the copolymerization. The aliphatic copolymers grafted with sugars showed low cytotoxicity to L929 cells, improved hydrophilic properties and specific recognition and binding ability with lectins, that is Concanavalin A (Con A) and Ricinus communis agglutinin (RCA). Therefore, this kind of sugar-grafted copolymer could be a good candidate in variety of biomedical applications. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3204 ,3217, 2007 [source] Comparison of mixed-mode anion-exchange performance of N -vinylimidazole-divinylbenzene sorbentJOURNAL OF SEPARATION SCIENCE, JSS, Issue 11 2006Núria Fontanals Abstract A newly synthesized copolymer based on N -vinylimidazole-divinylbenzene (NVIm-DVB) was evaluated as a mixed-mode anion-exchange sorbent for SPE, since the NVIm monomer apart from its hydrophilic properties can be protonated at a certain pH, and then performs as an anion-exchanger. To investigate the behavior of the NVIm-based sorbent, the SPE performance was evaluated under reversed-phase (RP), weak anion-exchange, and strong anion-exchange conditions. The results for the NVIm-DVB sorbent were also compared to commercial reference sorbents from each group: Oasis HLB, Oasis WAX, and Oasis MAX, respectively. SPE results from this evaluation showed that NVIm-DVB can be used as an RP material, compared to Oasis HLB. It also has the potential to act as a strong anion-exchange sorbent, compared to Oasis MAX, since under the proper conditions it was able to fraction and quantitatively recover a group of selected solutes. [source] Synthesis and morphology transformation of amphiphilic diblock polyurethane copolymers in aqueous solutionPOLYMER INTERNATIONAL, Issue 8 2010Qing Miao Abstract Amphiphilic block copolymers possess both hydrophobic and hydrophilic properties and can form versatile micellar structures in aqueous solution. The aim of the research presented was to prepare a series of non-ionic amphiphilic diblock polyurethane copolymers (PUn) based on isophorone diisocyanate, monoallyl-end-capped poly(ethylene oxide) and poly(propylene oxide) (PPO), followed by an investigation of their micellization properties and morphology transformation in aqueous solution. The PUn samples were synthesized by condensation polymerization. These polyurethanes exhibit surface tension as low as 33.7,37.0 mN m,1. There is an obvious decrease in critical micelle concentration as the hydrophobic PPO molecular weight increases. According to transmission electron microscopy, the morphology of aggregates of the copolymers can be tuned by varying the concentration in aqueous solution rather than organic solvent. For example, for PU7, large compound micelles are produced instead of vesicles. For PU17, the concentration can be used to control the size and thickness of vesicles. Vesicle size increases from 60 to 500 nm and vesicle thickness from 40 to 60 nm with concentration ranging from 0.003 to 0.03 wt%. The study shows that the copolymers in aqueous solution have excellent surface activities. In addition, they can self-assemble into large compound micelles or vesicles at certain concentrations. Moreover, the synthesis method described allows one to obtain a desired morphology of aggregates by adjusting the composition of hydrophilic and hydrophobic segments, which provides a novel and simple way to obtain particles on the nanometer scale. Copyright © 2010 Society of Chemical Industry [source] Hydrophobic `lock and key' recognition of N -4-nitrobenzoylamino acid by strychnineACTA CRYSTALLOGRAPHICA SECTION B, Issue 6 2006Zbigniew Ciunik During racemic resolution of N -4-nitrobenzoyl- dl -amino acids (alanine, serine and aspartic acid) by a fractional crystallization of strychninium salts, crystals of both diastereomeric salts were grown, and the crystal structures of strychninium N -4-nitrobenzoyl- l -alaninate methanol disolvate (1a), strychninium N -4-nitrobenzoyl- d -alaninate dihydrate (1b), strychninium N -4-nitrobenzoyl- d -serinate dihydrate (2a), strychninium N -4-nitrobenzoyl- l -serinate methanol solvate hydrate (2b), strychninium hydrogen N -4-nitrobenzoyl- l -aspartate 3.75 hydrate (3a) and strychninium hydrogen N -4-nitrobenzoyl- d -aspartate 2.25 hydrate (3b) were determined. The strychninium cations form corrugated layers, which are separated by hydrogen-bonded anions and solvent molecules. Common features of the corrugated layers are deep hydrophobic grooves at their surfaces, which are occupied by the 4-nitrobenzoyl groups of suitable anions. The hydrophobic `lock and key' recognition of 4-nitrobenzoyl groups of amino acid derivatives in deep grooves of the strychnine self-assembly causes the resulting surface to have more hydrophilic properties, which are more appropriate for interactions in the hydrophilic environments from which strychninium salts were crystallized. In the crystal structure of (2a) and (3a), such hydrophobic `lock and key' recognition is responsible for the lack of N,H+,O, hydrogen bonds that are usually formed between the protonated tertiary amine N atom of the strychninium cation and the deprotonated carboxyl group of the resolved acid. In the crystal structure of (2a) and (3a), the protonated amine N atom is a donor of hydrogen bonds, while the hydroxyl group of the serine derivative and water molecules are their acceptors. In light of the hydrophobic recognition, chiral discrimination depends on the nature of the hydrogen-bond networks, which involve anions, solvent molecules and the protonated amine N atom of strychninium cations. [source] Synthesis, characterization and hydroformylation activity of 7-azaindolate-bridged dinuclear rhodium(I)phosphines with pendant polar-groupsAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2009Chandra Sekhar Vasam Abstract New dinuclear Rh(I),Phosphines of the types [Rh(µ-azi)(CO)(L)]2 (1,3,7) and [Rh(µ-azi)(L)]2 (8) with pendant polar groups, and a chealated mononuclear compound [Rh(azi-H)(CO)(L)] (2) (where azi = 7-azaindolate, L = polar phosphine) were isolated from the reaction of [Rh(µ-Cl)(CO)2]2 with 7-azaindolate followed by some polar mono - and bis -phosphines (L1,L8). A relationship between ,,31P-NMR and ,(CO) values was considered to define the impact of polar-groups on ,-donor properties of the phosphines. These compounds were evaluated as catalyst precursors in the hydroformylation of 1-hexene and 1-dodecene both in mono- and biphasic aqueous organic systems. While the biphasic hydroformylations (water + toluene) gave exclusively the aldehydes, the monophasic one (aqueous ethanol) showed propensity to form both aldehydes and alcohols. The influence of bimetallic cooperative effects, and ,-donor and hydrophilic properties of the phosphines with pendant polar-groups in enhancing the yields and selectivity of hydroformylation products was emphasized. In addition, when strong ,-donor phosphine was used, the ,-acceptor nature of pyridine ring of 7-azaindolate spacer was found to be a considerable factor in facilitating the facile cleavage of CO group during hydroformylation and in supplementing the cooperative effects. Copyright © 2009 John Wiley & Sons, Ltd. [source] Beneficial properties of lactic acid bacteria isolated from a Rana catesbeiana hatcheryAQUACULTURE RESEARCH, Issue 14 2009Sergio E Pasteris Abstract This work addresses the selection of potentially probiotic lactic acid bacteria (LAB) to be used in raniculture. Thus, strains belonging to the genera Pediococcus pentosaceus, Leuconostoc mesenteroides, Lactococcus lactis and Enterococcus faecium isolated from a Rana catesbeiana hatchery were evaluated for their inhibitory properties against RLS-associated pathogens (Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus epidermidis) and food-borne bacteria. Cell-free supernatants of LAB strains inhibited the growth of at least one of the pathogens by organic acids, but L. lactis CRL 1584 also produced a bacteriocin-like metabolite. The ability of LAB strains to produce H2O2 in MRS+TMB medium was also studied. Seventy-eight to ninety six per cent of the strains showed some level of H2O2 production. Moreover, different organic solvents were used to determine the hydrophobicity and Lewis acid/base characteristic of LAB strain surfaces. Most of the strains presented hydrophilic properties, but no acidic or basic surface characters. However, some strains isolated from the skin showed a high degree of hydrophobicity and basic components in the cell surface due to their adhesion to chloroform. These properties were not observed in LAB from balanced feed and freshwater. Taking into account general guidelines and the beneficial properties studied, five strains were selected as potential candidates to be included in a probiotic for raniculture. [source] Alcohol Pretreatment of Small-diameter Expanded Polytetrafluoroethylene Grafts: Quantitative Analysis of Graft Healing Characteristics in the Rat Abdominal Aorta Interposition ModelARTIFICIAL ORGANS, Issue 7 2009Erman Pektok Abstract Long-term patency rates of small-diameter expanded polytetrafluoroethylene (ePTFE) vascular prostheses are unsatisfactory. Treatment of ePTFE grafts by alcohol before implantation was reported to increase hydrophilic properties, yielding better endothelialization and cellular in-growth, thus improving graft healing. The effect of alcohol pretreatment on ePTFE grafts and postoperative healing characteristics of wet ePTFE grafts were evaluated in this study. Ten sterile ePTFE grafts (2 mm ID, 30 µ thru-pore, 12 mm long) were implanted in the infrarenal aorta of male Sprague-Dawley rats (324,380 g). Five grafts were treated with ethanol 70% and soaked with saline solution before implantation (wet); five nontreated grafts served as control. All rats were sacrificed after digital subtraction angiography and sampling of the graft for histological investigation after 3 weeks. Histomorphometric analysis was performed for endothelial coverage, cellular in-growth, and intimal hyperplasia. All grafts were patent at the end of 3 weeks in both groups. Histological evaluation revealed significantly better endothelial coverage and prominent infiltration by fibroblasts and lymphocytes in the wet group. Endothelial coverage (31.03 ± 10.61% vs. 13.03 ± 9.46%, P = 0.03) and cellular infiltration of grafts (50.91 ± 8.55% vs. 39.29 ± 10.70%, P = 0.11) were higher in the wet group. Area of intimal hyperplasia per graft length was also higher in the wet group (5.32 ± 4.75 µm2/µm vs. 2.69 ± 3.41 µm2/µm, P = 0.36). Wetting of ePTFE grafts with ethanol 70% pretreatment before implantation might have a beneficial effect on long-term patency of small-diameter vascular grafts due to facilitated graft healing. [source] Three-Dimensional Polycaprolactone Hierarchical Scaffolds Supplemented with Natural Biomaterials to Enhance Mesenchymal Stem Cell ProliferationMACROMOLECULAR RAPID COMMUNICATIONS, Issue 19 2009Hyeon Yoon Abstract A hybrid technology that combines a three-dimensional (3-D) dispensing system with an electrospinning process was used to produce a hierarchical 3-D scaffold consisting of micro-sized polycaprolactone (PCL) strands and micro/nano-sized fibres. The micro/nanofibre biocomposites electrospun with PCL/small intestine submucosa (SIS) and PCL/Silk fibroin were layered between melt-plotted micro-strands. The scaffold containing SIS exhibited a stronger hydrophilic property than other scaffolds due to the various hydrophilic components in SIS. The 3-D hierarchical scaffold having biocomposites exhibited an incredibly enhanced initial cell attachment and proliferation of bone marrow-derived mesenchymal stem cells relative to the normally designed 3-D scaffold. [source] Study to compare the efficacy and safety of fluconazole cream with flutrimazole cream in the treatment of superficial mycosis: a multicentre, randomised, double-blind, phase III trialMYCOSES, Issue 6 2010S. M. Yim Summary Fluconazole, which is a drug of the azole family, is safely used in systemic treatment of oral and intravenous injection, but it is difficult to use fluconazole as a topical application because of its large molecular weight and strong hydrophilic property. This study is a multicentre, double-blind, randomised, non-inferiority study to compare the antifungal effect and safety of fluconazole cream 0.5% and 1% with flutrimazole cream 1% in superficial mycosis. A total of 162 subjects selected to participate in this study were equally divided into three groups and assigned to be given fluconazole cream 0.5%, fluconazole cream 1%, and flutrimazole cream 1% in the ratio of 1 : 1. The primary index of drug efficacy was determined by complete mycological cure in which no fungus was detected on KOH smear test 4 weeks after application of fluconazole. The secondary index of efficacy was defined as complete mycological cure 4 weeks after the application of fluconazole, improvement of clinical symptoms and overall effectiveness assessed by the research staff. According to this study, on comparing the efficacy of cure of superficial dermatomycosis after 4 weeks of application, both fluconazole 0.5% and fluconazole 1% cream were found to be equally effective and non-inferior to flutrimazole 1% cream. Given the effectiveness and safety of the drug, both fluconazole 0.5% and 1% cream might be said to be optimal concentration in the treatment of superficial dermatomycosis. [source] Synthesis and utilization of E. coli -encapsulated PEG-based microdroplet using a microfluidic chip for biological applicationBIOTECHNOLOGY & BIOENGINEERING, Issue 4 2010Kyoung G. Lee Abstract We report herein an effective strategy for encapsulating Escherichia coli in polyethylene glycol diacrylate (PEGDA) microdroplets using a microfluidic device and chemical polymerization. PEGDA was employed as a reactant due to the biocompatibility, high porosity, and hydrophilic property. The uniform size and shape of microdroplets are obtained in a single-step process using microfluidic device. The size of microdroplets can be controlled through the changing continuous flow rate. The combination of microdroplet generation and chemical polymerization techniques provide unique environment to produce non-toxic ways of fabricating microorganism-encapsulated hydrogel microbeads. Due to these unique properties of micro-sized hydrogel microbeads, the encapsulated E. coli can maintain viability inside of microbeads and green fluorescent protein (GFP) and red fluorescent protein (RFP) genes are efficiently expressed inside of microbeads after isopropyl- , - D -thiogalactopyranoside induction, suggesting that there is no low-molecular weight substrate transfer limitation inside of microbeads. Furthermore, non-toxic, gentle, and outstanding biocompatibility of microbeads, the encapsulated E. coli can be used in various applications including biotransformation, biosensing, bioremediation, and engineering of artificial cells. Biotechnol. Bioeng. 2010;107:747,751. © 2010 Wiley Periodicals, Inc. [source] Foam fractionation of ,-lactalbumin and ,-lactoglobulin from a whey solutionASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2009A. P. Shea Abstract Whey, a byproduct of cheese production, is often considered a waste stream. Separation and purification of whey proteins is a difficult and expensive task. Occasionally, it is transported out of the dairy plant for a per volume charge. One possible method to reduce the waste volume and disposal cost is to concentrate whey by foam fractionation and potentially produce a valuable coproduct, a concentrated whey protein solution. Foam fractionation is an adsorptive bubble separation method based on the hydrophobic/hydrophilic properties of proteins. In this study, foam fractionation was evaluated for the concentration of whey proteins, specifically ,-lactalbumin and ,-lactoglobulin, from a dilute whey protein solution. The effects of initial whey protein concentration (0.075 and 0.15 mg/ml), pH (3.8,5.5), superficial gas velocity (0.85 and 0.95 cm/s) and temperature (4 and 65 °C) on protein enrichment and recovery were examined. Higher enrichment was achieved with the lower initial protein concentration (0.075 mg/ml), and at pH values that were near the isoelectric points (pI) of ,-lactalbumin and ,-lactoglobulin (pH 3.8, 4.2, 4.5, and 5.2). Higher superficial gas velocity enhanced the amount of proteins recovered with a decrease in the enrichment. Cold temperature treatment and partial heat denaturation of whey proteins reduced enrichment and increased protein recovery simultaneously. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] | ||||||||||||||||