A novel filtration system for polyethylene glycol solutions used in the osmotic method of controlling suction

2008 ◽  
Vol 45 (3) ◽  
pp. 421-424 ◽  
Author(s):  
Pierre Delage ◽  
Yu Jun Cui
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Small Molecules ◽  
Opposite Direction ◽  
Semipermeable Membrane ◽  
Peg 6000 ◽  
Molecular Weight Cutoff ◽  
Filtration System ◽  
Purification System ◽  
Exchange Surface

One of the problems encountered when using the osmotic technique of controlling suction is related to the possible crossing of polyethylene glycol (PEG) molecules through the semipermeable membrane. Of the various hypotheses proposed, the paper considers the hypothesis that the PEG solutions are not pure enough and have molecules that are small enough to cross the semipermeable membrane. The paper presents a novel PEG purification system in which two solutions at different concentrations are put in contact through a semipermeable membrane along a large exchange surface. A peculiarity of the system is that it creates two opposite fluxes through the membrane, where small PEG molecules go from the higher concentration solution towards the lower concentration solution, and water migrates in the opposite direction. It has been observed that a small quantity of small molecules of PEG 6000 crossed the molecular weight cutoff (MWCO) 3500 semipermeable membrane.

scholarly journals Recovery of a Bacteriocin-Like Inhibitory Substance from Lactobacillus bulgaricus FTDC 1211 Using Polyethylene-Glycol Impregnated Amberlite XAD-4 Resins System

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5332
Author(s):  
Nur Fazrin Husna Abdul Aziz ◽  
Sahar Abbasiliasi ◽  
Zhang Jin Ng ◽  
Mazni Abu Zarin ◽  
Siti Nurbaya Oslan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Staphylococcus Aureus ◽  
Polyethylene Glycol ◽  
Sodium Citrate ◽  
Lactobacillus Bulgaricus ◽  
Optimum Conditions ◽  
Inhibitory Substance ◽  
Recovery Yield ◽  
Peg 4000 ◽  
Purification System

Lactobacillus bulgaricus is a LAB strain which is capable of producing bacteriocin substances to inhibit Staphylococcus aureus. The aim of this study was to purify a bacteriocin-like inhibitory substance (BLIS) produced by L. bulgaricus FTDC 1211 using an aqueous impregnated resins system consisting of polyethylene-glycol (PEG) impregnated on Amberlite XAD4. Important parameters influencing on purification of BLIS, such as the molecular weight and concentration of PEG, the concentration and pH of sodium citrate and the concentration of sodium chloride, were optimized using a response surface methodology. Under optimum conditions of 11% (w/w) of PEG 4000 impregnated Amberlite XAD4 resins and 2% (w/w) of sodium citrate at pH 6, the maximum purification factor (3.26) and recovery yield (82.69% ± 0.06) were obtained. These results demonstrate that AIRS could be used as an alternate purification system in the primary recovery step.

INTRUSION OF POLYETHYLENE GLYCOL DURING OSMOTIC TESTS: IDENTIFYING CELLULOSE ACETATE DEGRADING MICROBES

2016 ◽  
Vol 78 (8-5) ◽  
Author(s):  
Mohd Yuhyi Mohd Tadza ◽  
Mohd Fazli Farida Asras ◽  
Muhammad Afiq Mohd Tadza ◽  
Jamil Ismail ◽  
Nurhidayah Mahazam ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Cellulose Acetate ◽  
Structural Integrity ◽  
Cross Contamination ◽  
Soil Specimen ◽  
Test Results ◽  
Semipermeable Membranes ◽  
Peg 6000 ◽  
Microbial Attack

Cellulose acetate semipermeable membranes and polyethylene glycol (PEG) solutions are commonly used to apply suction in soils using the osmotic technique. The structural integrity of the membrane is crucial to maintain a consistent suction value throughout a test. The membrane however, is vulnerable to microbial attack, which in turn could lead to intrusion of PEG into soil specimens. In this study, osmotic test was carried out on initially saturated Andrassy bentonite specimen. PEG 6000 and membrane with molecular weight cut-off (MWCO) value of 3500 was used to apply suction of 3.4 MPa. Soil specimen and PEG solution after the osmotic test were examined for the presence of any potential cellulose or acetate degrading microbes. Test results indicated that cellulose degrading fungi such as Paecilomyces L. and Trichoderma A. were observed in the PEG solutions. Addition of penicillin was found to be less effective in removing these microbes. However, 70% ethanol may be used to prevent cross contamination during handling of specimens. It is anticipated that eliminating these microbes is crucial to prevent intrusion of PEG in osmotic tests

Conjugates of Classical DNA/RNA Binder with Nucleobase: Chemical, Biochemical and Biomedical Applications

2019 ◽  
Vol 26 (30) ◽  
pp. 5609-5624
Author(s):  
Dijana Saftić ◽  
Željka Ban ◽  
Josipa Matić ◽  
Lidija-Marija Tumirv ◽  
Ivo Piantanida
Keyword(s):  
Molecular Weight ◽  
Small Molecules ◽  
Biomedical Applications ◽  
Protein Targets ◽  
New Class ◽  
Rna Targets ◽  
Covalently Linked ◽  
Structural Aspects

: Among the most intensively studied classes of small molecules (molecular weight < 650) in biomedical research are small molecules that non-covalently bind to DNA/RNA, and another intensively studied class is nucleobase derivatives. Both classes have been intensively elaborated in many books and reviews. However, conjugates consisting of DNA/RNA binder covalently linked to nucleobase are much less studied and have not been reviewed in the last two decades. Therefore, this review summarized reports on the design of classical DNA/RNA binder – nucleobase conjugates, as well as data about their interactions with various DNA or RNA targets, and even in some cases protein targets are involved. According to these data, the most important structural aspects of selective or even specific recognition between small molecule and target are proposed, and where possible related biochemical and biomedical aspects were discussed. The general conclusion is that this, rather new class of molecules showed an amazing set of recognition tools for numerous DNA or RNA targets in the last two decades, as well as few intriguing in vitro and in vivo selectivities. Several lead research lines show promising advancements toward either novel, highly selective markers or bioactive, potentially druggable molecules.

Europium and cerium extraction by the nitrobenzene solution of dicarbolide in the presence of polyethylene glycols

1986 ◽  
Vol 51 (3) ◽  
pp. 498-515 ◽  
Author(s):  
Emanuel Makrlík ◽  
Petr Vaňura
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Equilibrium Constants ◽  
Polyethylene Glycols ◽  
Individual Species ◽  
Nitrobenzene Solution ◽  
Separation Factors ◽  
Equilibrium Data

Extraction of Eu3+ and Ce3+ microamounts from 0.1-0.4M perchloric acid by the nitrobenzene solution of dicarbolide H+[Co(C2B9H11)2]- in the presence of polyethylene glycols (Mr = 200, 300, 400) has been studied. The equilibrium data and the typical maxima on the dependence of the metal distribution ratio on the total analytical concentration of polyethylene glycol in the system can be explained assuming that the species ML3+org, ML3+2org, ML3+3org, MLH2+-1org, and HL+org (where M3+ = Eu3+, Ce3+; L = polyethylene glycol) are extracted into the organic phase. The values of extraction and equilibrium constants in the organic phase were determined and the effect of the polyethylene glycol molecular weight on the equilibrium constants and on the abundances of individual species in the organic phase is discussed. It has been found that the addition of polyethylene glycol to the acid - nitrobezene - dicarbolide system increases the values of the separation factors αCe/Eu.

scholarly journals ‘Tanned’ gelatin spheres and granules for exclusion chromatography

1968 ◽  
Vol 108 (4) ◽  
pp. 641-646 ◽  
Author(s):  
A. Polson ◽  
W. Katz
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
High Molecular Weight ◽  
Weight Fraction ◽  
High Flow ◽  
High Molecular Weight Fraction ◽  
Flow Rates ◽  
Protein Molecules ◽  
Exclusion Chromatography

1. The preparation of tanned gelatin spheres and granules from high-molecular-weight gelatin is described. This material is comparatively hard, giving high flow rates, is insoluble in water at temperatures between 0° and 100° and is resistant to digestion by trypsin and chymotrypsin. The high-molecular-weight fraction of gelatin was prepared by precipitation with polyethylene glycol, and the spheres and granules prepared from this fraction were hardened and insolubilized by tanning with either formalin or chromium salts or both. 2. The spheres and granules were used successfully for the separation of protein molecules and other protein-aceous materials ranging in molecular weight from 200 to greater than 6000000. This gel exclusion material has several properties superior to those of other products used for similar purposes. Further, it was noticed that the porosity of the spheres differed considerably from that of the granules.

scholarly journals Mesoporous Properties of Bioactive Glass Synthesized by Spray Pyrolysis with Various Polyethylene Glycol and Acid Additions

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 618
Author(s):  
Tzu-Yu Peng ◽  
Pei-Yun Tsai ◽  
May-Show Chen ◽  
Yuichi Mine ◽  
Shan-Hua Wu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Bioactive Glass ◽  
Spray Pyrolysis ◽  
Mesoporous Structure ◽  
High Specific Surface Area ◽  
Process Time ◽  
In Vitro Bioactivity ◽  
One Pot

Mesoporous bioactive glass (MBG) has a high specific surface area, promoting the reaction area, thereby improving the bioactivity; thus, MBG is currently gaining popularity in the biomaterial field. Spray pyrolysis (SP) is a one-pot process that has the advantages of shorter process time and better particle bioactivity, therefore, MBG was prepared by SP process with various polyethylene glycol (PEG, molecular weight ranged from 2000–12,000) and acid (HCl and CH3COOH) additions. In vitro bioactivity and mesoporous properties of the so-obtained MBG were investigated. The experimental results showed that all the MBG exhibited amorphous and mesoporous structure. Increasing the molecular weight of PEG can improve the mesoporous structure and bioactivity of MBG. Whereas optimized MBG was prepared with suitable concentration of PEG and CH3COOH. In the present work, MBG synthesized via spray pyrolysis by adding 5 g of PEG with a molecular weight of 12,000 and 50 mL of CH3COOH exhibited the best in vitro bioactivity and mesoporous structure.

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