Role In Solubilization Research Articles

Unstable Spreading of Aqueous Anionic Surfactant Solutions on Liquid Films. 2. Highly Soluble Surfactant

The spreading of a surfactant solution across a thin water film may be accompanied by a fingering instability developing behind the spreading front. In this paper, the role of solubility on this instability is investigated by conducting spreading experiments using highly soluble surfactant solutions of sodium dodecyl sulfate over a range of concentrations on water films ranging from 25 to 100 μm in thickness. It is found that at surfactant concentrations up to and around the critical micelle concentration, spreading is largely accompanied by fingers upstream of the spreading front. In comparison with sparingly soluble AOT solutions (sodium di-2-ethylhexyl sulfosuccinate) studied in part 1 of this series, the instability becomes apparent sooner and the fingers are more pronounced and branched. Above the cmc, the instability takes a different form on thinner films, which was not noted in the sparingly soluble case, while fingering develops on thicker films.

Mineral status of embryos of domestic fowl following exposure in vivo to the carbonic anhydrase inhibitor acetazolamide

Eggs of domestic fowl were given daily injections of vehicle (DMSO) or vehicle plus acetazolamide, a potent inhibitor of the enzyme carbonic anhydrase, beginning on day 12 of incubation. Embryos were removed from eggs on days 16 and 18, and carcasses and yolks were analyzed for calcium, magnesium, and phosphorus. Treatment with acetazolamide did not affect the quantity of calcium or phosphorus in carcasses and the effect, if any, on magnesium in carcasses was small. However, calcium content of yolk was reduced substantially by acetazolamide both on day 16 and day 18. The reduction in calcium content of yolk led, in turn, to a reduction in the total quantity of calcium in eggs on days 16 and 18. Embryos exposed to acetazolamide seemingly mobilized less calcium from the eggshell than did control embryos. When faced with a shortfall in the availability of calcium from the eggshell, embryos defended carcass calcium, and the shortfall was reflected in a reduction in the quantity of calcium deposited in yolk. The results of this study support the concept that the enzyme carbonic anhydrase plays a role in solubilization of the eggshell and provision of calcium to embryos.

A hemolytic factor from Haemonchus contortus alters erythrocyte morphology

A hemolytic factor from adult Haemonchus contortus caused distinct morphological changes in the surface of sheep red blood cells (RBCs). After a 15 min exposure to the hemolytic factor, hemolysis was not detected in incubation media, but RBCs were spherical in shape with numerous surface projections compared to control cells that were smooth-surfaced biconcave disks. After 30 min, a time at which significant hemolysis occurred, echinocytes were formed, and after 90 min, cells were severely disrupted with many visible holes in membranes. No RBC ghosts were observed. RBCs from four other mammalian species were lysed by the H. contortus hemolytic factor. However, the rate of hemolysis varied with a relative order of sheep≈rabbit>goat>pig>calf. The morphology of RBCs from all four species was significantly altered after 30 min incubation with the degree of morphological changes related to the degree of hemolysis. These results support the hypothesis that the hemolytic factor acts as a pore-forming agent, although a phospholipase or other enzyme might play a role in solubilization of cell membranes.

Chromium-induced genotoxicity and apoptosis: relationship to chromium carcinogenesis (review).

The adverse health effects linked with chromium (Cr) exposure, the role of solubility and chemical speciation of Cr compounds, and the diverse cellular and molecular effects of Cr make the study of Cr carcinogenesis and toxicology very interesting and complex. Certain Cr compounds are prominent metal carcinogens in both occupational and environmental settings. Inhaled particulate forms of hexavalent Cr [Cr(VI)] cause lung cancer as well as lung toxicity. Some of the important factors in determining the biological outcome of Cr exposure include the bioavailability, chemical speciation and solubility of Cr compounds, intracellular reduction, and interaction of Cr with DNA. The stable oxidation states of Cr found in nature are Cr(III) and Cr(VI). Cr(III) is unable to enter cells but Cr(VI) enters into cells through membrane anionic transporters. Intracellular Cr(VI) is metabolically reduced to the ultimate Cr(III). Cr(VI) does not react with macromolecules such as DNA, RNA, proteins and lipids. However, both Cr(III) and the reductional intermediate Cr(V) are capable of co-ordinate covalent interactions with macromolecules. At the genomic level, Cr genotoxicity manifests as gene mutations, several types of DNA lesions and inhibition of macromolecular synthesis. At the cellular level, Cr exposure may lead to cell cycle arrest, apoptosis, premature terminal growth arrest, or neoplastic transformation. Cr-induced DNA-DNA interstrand crosslinks (DDC), the tumor suppressor gene p53 and oxidative processes are some of the major factors that may play a significant role in determining the cellular outcome in response to Cr exposure. We have utilized cellular, molecular, pharmacological, and genetic approaches to understand the interrelationship between Cr-induced genotoxicity, apoptosis and carcinogenesis. This review is based on the results and inferences of this research. We hope this review will clarify existing concepts and also introduce novel perspectives in chromium carcinogenesis research.

Mössbauer spectroscopic study of the interaction of indole‐3‐acetic acid with iron(III) in aqueous solution

The data of Mössbauer spectroscopic measurements in rapidly frozen 57FeIII nitrate solutions containing indole-3-acetic acid (IAA) are presented. The results obtained provide direct evidence that iron(III) is gradually reduced by IAA with the formation of soluble iron(II) complex. It has been found that further drying of the solution in air results in complete re-oxidation of iron(II) with the formation of iron(III) complex. The structure of the complexes obtained and their possible role in solubilization and transformation of iron species in soil in the presence of IAA secreted by soil microorganisms into the environment are also discussed.

Intramolecular micelle size of polysoaps by luminescence quenching. Role of solubilization

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntramolecular micelle size of polysoaps by luminescence quenching. Role of solubilizationVincent S. Zdanowicz and Ulrich P. StraussCite this: Macromolecules 1993, 26, 18, 4770–4773Publication Date (Print):August 1, 1993Publication History Published online1 May 2002Published inissue 1 August 1993https://doi.org/10.1021/ma00070a007RIGHTS & PERMISSIONSArticle Views133Altmetric-Citations34LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (539 KB) Get e-Alerts Get e-Alerts

Evaluation of issues relating to the carcinogen risk assessment of chromium

Important issues in the carcinogenic risk assessment of chromium compounds are whether both trivalent and hexavalent chromium compounds are carcinogenic, the role of solubility in the carcinogenic response, and the carcinogenicity of ingested chromium. Hexavalent chromium compounds are carcinogenic to animals via several routes of exposure, while trivalent chromium compounds, although they demonstrate evidence of genotoxicity, have not been shown in animal studies to be carcinogenic. Workers in chromate production plants, where the risk of lung cancer is elevated, are exposed to both trivalent and hexavalent chromium compounds. A cancer unit risk estimate for Wistar rats exposed to a hexavalent chromium aerosol (sodium dichromate) is less than the risk estimate for workers in chromate production. If this difference is biologically real, a possible explanation may be that trivalent compounds also have a carcinogenic effect. For hexavalent chromium compounds, it is contended that only sparingly soluble hexavalent chromium compounds are carcinogenic. Recent evidence, however, indicates that highly soluble hexavalent chromium compounds are also carcinogenic. Animal ingestion studies have not found trivalent chromium compounds to be carcinogenic by ingestion; hexavalent compounds have not been studied. Research by EPA to address the issues of valence state and solubility with respect to carcinogenicity is currently being conducted.

Achievement of well conducting wide band-gap semiconductors: Role of solubility and of nonequilibrium impurity incorporation.

A long-standing problem for wide band-gap semiconductors is that of achieving good bipolar conductivity. I here show that this difficulty can be understood via solubility considerations of dopant incorporation. Reports of good conductivity in such materials are likely due to nonequilibrium impurity incorporation, and prior literature is reinterpreted to provide examples of this view.

Human plasma actin-depolymerizing factor. Purification, biological activity and localization in leukocytes and platelets.

The plasma and serum of humans and various animal species exert an actin-depolymerizing activity. Human actin-depolymerizing factor (ADF) has been purified by ammonium sulfate fractionation, DEAE-cellulose and blue-Sepharose chromatography. It is a single polypeptide of approximately 90 kDa, with a pI between 6.0 and 6.5. ADF is heat and trypsin-sensitive, inactivated by EGTA, not stained by HIO4/Schiff on sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS/PAGE), and not retained on a concanavalin-A-Sepharose column. Incubation of ethanol-fixed cultured cells or unfixed cryostat tissue sections with ADF abolishes immunofluorescent actin staining, by a mechanism which involves extraction of actin from the preparations. ADF promotes fragmentation and depolymerization of actin filaments as shown by electron microscopy, differential ultracentrifugation and DNAse I inhibition assay. This depolymerized actin retains its mobility on SDS/PAGE and is able to repolymerize in the presence of EGTA. Human white blood cells and platelets (but neither human fibroblasts nor white blood cells and platelets from pig, rat and rabbit) contain a 90-kDa protein reacting with an antibody raised in rabbit against human ADF as judged by immunofluorescence and immunoblotting techniques. Immunoblots of human granulocyte subcellular fractions suggest that the protein reacting with ADF antibody is present in the soluble cytoplasmic fraction. ADF may play a role in solubilization of plasma actin and in the intracellular organization of actin, and should be useful for the evaluation of the relative stability of cytoplasmic actin filaments in various physiological and pathological processes.

Dependence of photodegradation of poly(2,6-dimethyl-1,4-phenylene oxide) on ?-relaxation role of solubility of oxygen in photooxydation

The dependence of the rate constants of photoinitiated oxidation of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and of oxygen consumption during this reaction have been ivestigated. The obtained results point out that the changes in the values of the rate constants for both reactions are related to the β-relaxation processes observed in PPO at the same temperature range. The consideration of this effect and of its influence on oxygen solubility in PPO leads to explanation of the determined values of apparent activation energies for PPO photooxidation.

Solubility of polar organic solutes in nonaqueous systems: Role of specific interactions

The changes in solubility of several polar organic solutes when polar organic solvents are added to a relatively inert solvent such as isooctane were determined. The relative changes in solubility predicted from regular solution theory using solubility parameters often did not agree with the observed results. However, the solubilities could be rationalized mathematically by assuming the formation of specific solute–solvent complexes. Agreement of the thermodynamic data reported here with such models provides further evidence that specific interactions, when they occur, are more important than the bulk properties of the pure components in determining drug solubilities in nonaqueous systems. Specific examples demonstrate the relationship between the solubility and molecular structure of the solute and solvent. For example, solubility can be related to the hydrogen-donating and hydrogen-accepting abilities of the solute and solvent. Steric factors also appear to play a role in solubility, while structural modifications in a solute or solvent molecule far removed from the interactive functional group have little influence on molar solubility changes with the added polar cosolvent.

Relationship Between Hydrophobicity and Emulsifying Properties of Some Plant Proteins

Significant positive correlations were observed between bound dodecylsulfate or linoleate and dispersibility of surfactant treated soy, sunflower and rapeseed proteins, suggesting that the bound surfactants played an important role in solubilization of these proteins. Dispersibility was also highly correlated with effective hydrophobicity of the proteins as measured fluorometrically. The effective hydrophobicity thus determined for soy, sunflower and rapeseed proteins treated with surfactants and B. subtilis proteinase for solubilization revealed good correlations with surface tension, interfacial tension and emulsifying activity of the proteins, indicating the importance of protein hydrophobicity when used as emulsifiers.

Role of Solubility in Migration of Petroleum from Source (AAPG Short Course: Physical and Chemical Constraints on Petroleum Migration): ABSTRACT

Role of Solubility in Migration of Petroleum from Source (AAPG Short Course: Physical and Chemical Constraints on Petroleum Migration): ABSTRACT