High Concentrations Of Ethylene Glycol Research Articles

Effects of solution concentration and surface supercooling on the spreading characteristics of an impact binary droplet

We investigate the effect of liquid properties and surface supercooling on the spreading dynamics of an impact binary ethylene-glycol and ethanol droplet. Surface supercooling and solution concentration, affecting the physical properties of a droplet, jointly determine the maximum spreading factor. At a high concentration of ethylene-glycol, the maximum spreading factor decreases with surface supercooling. At a low concentration of ethylene-glycol, the maximum spreading factor decreases and then increases with surface supercooling. The relation between the maximum spreading factor and surface supercooling is resulting from the opposite surface-supercooling-dependencies of the maximum internal spreading factor and the dimensionless fingering length. The maximum spreading factor decreases with the ethylene-glycol concentration due to increased liquid surface tension and viscosity. A new model of the maximum spreading factor, taking into account the effect of surface cooling in viscous dissipation, is proposed based on energy conservation, which optimizes the prediction of spreading of an impact droplet on a surface with different supercooling degrees.

Concentration dependent effect of ethylene glycol on the structure and stability of holo α-lactalbumin: Characterization of intermediate state amidst soft interactions

The interior of the cell is crowded with different kinds of biological molecules with varying sizes, shapes and compositions which may affect physiological processes especially protein folding, protein conformation and protein stability. To understand the consequences of such a crowded environment, pH-induced unfolding of holo alpha-lactalbumin (holo α-LA) was studied in the presence of ethylene glycol (EG). The effect of EG on the folding and stability of holo α-LA in aqueous solution was investigated using several spectroscopic techniques. The results indicate that stabilization/destabilization of holo α-LA by EG is concentration- and pH-dependent. Low concentration of EG stabilizes the protein at pH near its pI. From the results of far-UV CD, UV–visible and ANS fluorescence, intermediate state (MG state) was characterized in the presence of high concentration of ethylene glycol. The results invoke a new mechanism for the formation of MG state identical to active component of BAMLET. MG state of holo α-LA has a direct implication to cancer therapy. MG state of α-LA in complex with specific type of lipid is a novel class of protein-based anti-cancer complexes that incorporate oleic acid and deliver it to the cancer cells.

Ethylene glycol intoxication following brake fluid ingestion complicated with unilateral facial nerve palsy: a case report

BackgroundBrake oil is an automobile transmission fluid composed of a mixture of toxic alcohols such as ethylene glycols and glycol ethers. Both accidental and intentional ingestion cases have been reported and they can present with multisystem involvement. Life-threatening complications evolve from deleterious effects on cardiopulmonary and renal systems. Effects on neurological and gastrointestinal systems give rise to a multitude of complications although non-fatal in nature. The biochemical panel consists of a high concentration of ethylene glycol with severe metabolic acidosis, high anion gap, high osmolar gap, oxaluria, and hypocalcemia. The mainstay of treatment is enhanced elimination of ethylene glycol and its metabolites by hemodialysis, together with general supportive care, gastric decontamination, and vitamins such as thiamine and pyridoxine to minimize the adverse effects of intoxication.Case presentationA 26-year-old Sinhalese woman presented with reduced urine output, shortness of breath, reduced level of consciousness, abdominal pain, and vomiting with mild degree fever of 2 days’ duration. She had bilateral lower limb edema, crepitations over bilateral lower lung fields, and right-sided lower motor type facial nerve palsy. Investigations showed severe metabolic acidosis with high anion gap and high osmolar gap. With regular hemodialysis she made a complete recovery after 3 months.ConclusionEven without a clear history of poisoning, the presence of a high anion, high osmolar gap metabolic acidosis should prompt one to search for ethylene glycol ingestion. Uncommon manifestations like cranial neuropathies need to be examined and considered. Timely aggressive treatment leads to a better prognosis.

RNA‐Capturing Microsphere Particles (R‐CAMPs) for Optimization of Functional Aptamers

RNA aptamers are useful building blocks for constructing functional nucleic acid-based nanoarchitectures. The abilities of aptamers to recognize specific ligands have also been utilized for various biotechnological applications. Solution conditions, which can differ depending on the application, impact the affinity of the aptamers, and thus it is important to optimize the aptamers for the solution conditions to be employed. To simplify the aptamer optimization process, an efficient method that enables re-selection of an aptamer from a partially randomized library is developed. The process relies on RNA-capturing microsphere particles (R-CAMPs): each particle displays different clones of identical DNA and RNA sequences. Using a fluorescence-activated cell sorter, the R-CAMPs that are linked to functional aptamers are sorted. It is demonstrated that after a single round of reselection, several functional aptamers, including the wild-type, are selected from a library of 16 384 sequences. The selection using R-CAMPs is further performed under the solution containing high concentration of ethylene glycol, suggesting applicability in various conditions to optimize an aptamer for a particular application. As any type of RNA clone can be displayed on the microspheres, the technology demonstrated here will be useful for the selection of RNAs based on diverse functions.

Hydroxyapatite wrapped multiwalled carbon nanotubes composite, a highly efficient template for palladium loading for electrooxidation of alcohols

A new electrocatalyst is introduced by loading palladium nanoparticles on the unique structured composite of hydroxyapatite and multiwalled carbon nanotubes. The structure and morphology of the designed electrocatalyst are characterized by X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The efficiency of the resulted nanostructure is explored toward the electrooxidation of some common alcohols in alkaline media. The electrooxidation of ethylene glycol (EG) is explored more extensively which provides a large peak current density (more than 1810 mA mg−1Pd). Surprisingly, the efficiency of oxidation is maintained even for relatively high concentrations of EG. In terms of the current density and the onset potential, significant improvements are observed for the proposed structure versus hydroxyapatite free catalyst. The high efficiency of the proposed electrocatalyst is explained via the presence of hydroxyl rich surface of hydroxyapatite which causes a more effective oxidation of alcohols over the loaded Pd nanoparticles.

Presence of appreciable amounts of ethylene glycol, propylene glycol, and diethylene glycol in human urine of healthy subjects

In a previous study, we found that appreciable amounts of ethylene glycol (EG), propylene glycol (PG), and diethylene glycol (DEG) were present in the blood of nonoccupational healthy humans. In this study, we measured the three glycols in the urine of healthy subjects by the same isotope dilution gas chromatography–mass spectrometry method, and found the concentrations to be much higher than those in blood. The concentrations of EG, PG, and DEG in urine samples (mean ± standard deviation) obtained from 23 subjects at random were 604 ± 360, 5,450 ± 9,290, and 59.0 ± 49.3 ng/ml, respectively. These values were 9.44, 30.1, and 5.31 times higher than those in whole blood samples, respectively. The much higher concentrations of the three glycols found in urine samples of nonoccupational healthy humans suggest that the three glycols, once incorporated into the human body, are rapidly excreted into urine. To our knowledge, this is the first demonstration of the presence of relatively high concentrations of EG, PG, and DEG in urine of healthy human subjects.

Study of Malachite Green Fading in Water–Ethanol–Ethylene Glycol Ternary Mixtures

The rate constant of malachite green (MG+) alkaline fading was measured in water–ethanol–ethylene glycol ternary mixtures. This reaction was studied under pseudo-first-order conditions at 283–303 K. In each series of experiments, the concentration of ethanol was kept constant and the concentration of ethylene glycol was changed. It was shown that due to hydrogen bonding and hydrophobic interaction between MG+ and alcohol molecules the observed reaction rate constant, $$ k_{\text{obs}} $$ , increased in the water–ethanol–ethylene glycol ternary mixtures. The fundamental rate constants of MG+ fading in these solutions ( $$ k_{1} $$ , $$ k_{ - 1} $$ and $$ k_{2} $$ ) were obtained by the SESMORTAC model. Analysis of $$ k_{1} $$ and $$ k_{2} $$ values in solutions containing constant ethanol concentrations show that in low concentrations of ethylene glycol, hydrogen bonding formed between ethanol and ethylene glycol molecules and in high concentrations of ethylene glycol, ethanol as a solvent for ethylene glycol affected the reaction rate.

Thermal effect of carboxylic acids in the degradation by photo-Fenton of high concentrations of ethylene glycol

The degradation by Fenton and photo-Fenton of high concentrations of ethylene glycol (1000–25,000mg/L), similar to those found in wastewater has been studied. Strongly exothermic reactions led to temperature increments up to 70–94°C. In most experiments, temperature increments favored radical formation that provided almost complete mineralization. Oxalic, formic and acetic acids were identified as degradation intermediates. The obtained results indicate that the radicals formed in the degradation of formic and acetic acids with H2O2 were responsible for the exothermic reactions. Nonetheless, Fe–oxalic complexes inhibited the previous reactions by slowing down the process in such a way that complete mineralization did not occur until those complexes were degraded.FTIR studies allowed the identification of some of the complexes and species formed in the process.

Assessment of the genotoxicity of three cryoprotectants used for human oocyte vitrification: Dimethyl sulfoxide, ethylene glycol and propylene glycol

Vitrification requires high concentrations of cryoprotectants that may induce long-term toxic effects on cells. The aim of this study was to evaluate the possible genotoxicity of three cryoprotectants extensively used for oocyte vitrification: dimethyl sulfoxide (DMSO), ethylene glycol (EG) and propylene glycol (PROH). For this purpose, a Chinese Hamster Ovary cell line (CHO), commonly used in genetic toxicology, was selected as an in vitro biological model to assess both the induction of DNA strand-breaks as identifiable by the alkaline comet assay and the persistence of chromosomal damages (micronuclei) as analyzed by the micronucleus assay. Results showed that DMSO was not genotoxic. EG did not exert direct genotoxic activity, however EG exhibited significant genotoxic and clastogenic activities in the presence of an external cytochrome-based P450 oxidation system (S9 Mix). PrOH produced in vitro DNA-damage leading to chromosome mutations in the presence and absence of the S9 Mix. These results showed that high concentrations of EG and PrOH could induce in vitro chromosomal damage in eukaryotic cells.

A Fatal Case Involving Extremely High Levels of Ethylene Glycol Without Elevation of its Metabolites or Crystalluria

A unique case of an intentional overdose of ethylene glycol resulting in a fatality is described. The decedent had a very high concentration of ethylene glycol without elevated concentrations of its metabolites or crystalluria. The ethylene glycol concentrations in blood, urine, and vitreous fluid were 2340, 2261, and 1028 mg/dL, respectively. Osmolality of blood and vitreous fluid was also very high at 1426 and 534 mOsm/kg, respectively. No crystals were found in the urine. Furthermore, on the urine organic acids profile the ethylene glycol metabolites oxalic, glycolic, and glyoxylic acids were within the reference ranges. In addition to ethylene glycol, the decedent had an elevated level of mirtazapine, an antidepressant, and a low level of bupropion. It was estimated that the subject consumed 1034 g of ethylene glycol. To our knowledge, this is the first case of death from severe ethylene glycol poisoning in the absence of ethylene glycol metabolites or crystalluria.

Mechanism of Adsorption of Three Recombinant Streptococcus pneumoniae (Sp) Vaccine Antigens by an Aluminum Adjuvant

The adsorption of three Streptococcus pneumoniae (Sp) vaccine antigens byaluminum-containing adjuvants was studied. The antigens showed high binding affinityisotherms with aluminum hydroxide adjuvant described by the Langmuir equation butvirtually no binding to aluminum phosphate adjuvant. The effects of ionic strength andethylene glycol were evaluated to determine whether electrostatic or hydrophobicinteractions were responsible for the observed binding to aluminum hydroxide, but nosignificant change in the adsorptive capacity was observed at either high ionic strengthnor high concentrations of ethylene glycol for any of the antigens. This indicates thatneither electrostatic nor hydrophobic interactions appear to be responsible for theobserved binding, which means that ligand exchange may be the primary mechanism forthis interaction. Further studies to evaluate the ability to elute a Sp antigen fromaluminum hydroxide using fibrinogen (adsorptive coefficient 2.2 mL/µg) as acompetitive protein resulted in evidence that Sp antigen follows the trend that proteinswith higher adsorptive coefficients are able to displace those with lower adsorptivecoefficients. It was also noted that the Sp antigens and ?-lactalbumin (adsorptivecoefficient 1.8 mL/µg) have similar adsorptive coefficients indicative of high affinitybinding isotherms but do not contain phosphate, which has previously been used toexplain ligand exchange for such proteins as ?-casein and hepatitis B surface antigen(HBsAg). Further investigations using ?-lactalbumin as a model protein may elucidatethe binding interaction between the antigens in this study and aluminum adjuvants.

Offspring resulting from transfer of cryopreserved embryos in camel (Camelus dromedarius)

The dromedary embryos, collected at hatched blastocyst stage, survived freezing and thawing in the presence of a high concentration of ethylene glycol (7.0 mol/L) with sucrose (0.5 mol/L) and direct plunging in liquid nitrogen. The rate of survival, as judged by the morphological appearance of the embryos after thawing, was high (92%). The transfer of frozen-thawed embryos into the recipients during the breeding ( n = 20) and non-breeding season ( n = 25) resulted in two and one pregnancy, respectively. One of the two pregnant recipients, with embryos transferred during the breeding season, delivered a normal healthy male calf at term. To our knowledge, this offspring is the first camelid produced following transfer of a frozen-thawed embryo.

Cryopreservation of bos taurus vs bos indicus embryos: are they really different?

Cryopreservation with storage at very low temperatures is essential to make full use of this technology for both biological and commercial reasons. However, most mammalian cells will die if exposed to these temperatures unless they are exposed to cryoprotectant solutions and cooled and warmed at specific rates. Lowering temperature below 0°C introduces the risk of intracellular ice formation, which likely increases rapidly as the temperature falls. Evidence indicates that ice formation during cooling can cause significantly more damage than ice formation during warming. Comparisons of the toxicity of various cryoprotectants indicated that ethylene glycol (EG) is a nontoxic compound for murine and bovine embryos. The 3.6 M EG solution resulted in similar high survival rates when compared with nonfrozen embryos; deleterious effects of high concentrations of EG became apparent at 7.2 M. The use of EG provides a nontoxic method for the rapid and simplified controlled freezing of in vivo bovine compact morulae-early blastocyst, avoiding the risk of injury caused by high concentrations of cryoprotectants usually required for vitrification. However, in vivo embryos used for freezing and thawing require further studies to understand the ultrastructural changes during the freezing procedure with EG as the single cryoprotectant, especially between Holstein and Nelore cows. This paper describes the ultrastructure of bovine compact morulae-early blastocysts derived by in vivo methods from Holstein and Nelore cows to investigate the fresh morphology as well as that after exposure to cryoprotectant and cryopreservation by conventional slow freezing, quick freezing (nitrogen vapor), and vitrification.

Purification, Crystallization, and Preliminary X-ray Analysis of L-A: A dsRNA Yeast Virus

TheL-A virus (LAV) particle is a specialized compartment for the transcription and replication of double-stranded RNA. It is 390 Å in diameter and infects yeast. The particle is formed by a capsid containing 120 copies of a 680-residue gene product arranged with T = 1 icosahedral symmetry, approximately two copies of an RNA-directed RNA polymerase, and a 4.6-kb linear, duplex RNA. LAV crystals diffracting to at least 4.5-Å resolution were grown in a combination of polyethylene glycol 8000, ethylene glycol, and lithium chloride. Following crystallization the reservoir solution was replaced by a 2× concentrated reservoir solution in order for ethylene glycol to function as a cryoprotectant even though initial crystals would not grow at sufficiently high concentrations of ethylene glycol for cryoprotection. A complete data set was collected to 6-Å resolution from a frozen crystal obtained with this procedure. The crystals belong to space group P21. The unit cell dimensions are a = 406.7 Å, b = 403.3 Å, c = 572.5 Å, β = 90.3° with two virus particles in the unit cell. The particle orientation was determined with the rotation function and the particle center was estimated on the basis of packing considerations.

New evidence for the mechanism of the tin(II) chloride catalyzed reactions of vicinal diols with diazodiphenylmethane in 1,2-dimethoxyethane

A kinetic study of the tin(II) chloride catalyzed reaction of diazodiphenylmethane with ethylene glycol in dimethoxyethane is reported. The preparation and characterization of ethylene glycol monodiphenylmethyl ether, the main product from this reaction, is also reported as well as the preparation of the two diphenylmethyl monoethers of methyl 4,6- O-benzylidene-α- d-glucopyranoside. An unexpected relationship between the concentration of ethylene glycol and the pseudo first-order rate constant, k′, was observed in these reactions. For low concentrations of ethylene glycol (below 0.06 M), k′ increases with increasing concentration of the diol. This trend is reversed for high concentrations of ethylene glycol (from about 0.06 to about 0.2 M). The apparent rate constant was also inversely related to the initial concentration of diazodiphenylmethane for the concentrations investigated. These results make the previously proposed involvement of a 1,3,2-dioxastannolane intermediate very unlikely [Petursson, S.; Webber, J.M. Carbohydr. Res. 1982, 103, 41–52]. The results suggest that more likely intermediates for these reactions involve tin(II) chloride complexes in a dynamic equilibrium with the diol.

Changes in membrane integrity, cytoskeletal structure, and developmental potential of murine oocytes after vitrification in ethylene glycol.

A systematic approach was taken to assess and optimize a protocol for intracellular vitrification by introducing high concentrations of the cryoprotectant agent (CPA) ethylene glycol (EG) into unfertilized murine oocytes. The effects of EG on membrane integrity, microfilament organization, and developmental potential were evaluated. During exposure to 0.5-2 M EG, oocytes showed maximum shrinkage to 55.5% of the isotonic volume within the first minute and reexpanded to their initial volume within 15 min. Transferral of oocytes to higher concentrations of EG (4-8 M EG) for 1-5 min after 15 min of equilibration at 2 M EG was tolerated well. Microfilament organization appeared normal after this equilibration period. During prolonged exposure (> 5 min) to high concentrations of EG (> 4 M), membrane blebs were noticed on the surface of the cells, and microfilament distribution was disturbed. After treatment with 6 M EG and vitrification with 6 M EG + f2p40.5 M sucrose, there were no significant differences in development to the two-cell and blastocyst stages between CPA-treated, vitrified, and control oocytes. These results indicate that EG is an effective CPA for mouse oocyte vitrification protocols without any observed compromise in morphology and developmental functions.

Nanostructure and Electrical Properties of Anodized Al Gate Insulators for Thin-Film Transistors

AbstractA novel anodic oxidation method for aluminum thin-film on the glass substrate is proposed for the fabrication of a gate insulator in thin-film transistor (TFT). A proposed rear-positioned cathode makes for much more smooth surface with an average surface roughness of under 4 nm in comparison with conventional cathode positions. The anodic oxidation conditions were comprehensively investigated. The current density, ethylene glycol concentration, and cathode position were chosen as the elements of anodic oxidation condition matrix, and all these conditions affected the film formation. The surface morphology and nanostructure of the anodized films were characterized with an atomic force microscopy (AFM) and cross-sectional transmission electron microscopy (TEM). Films formed at higher ethylene glycol concentrations of over 50% and higher current densities of over 0.9 mA/cm2 exhibited higher breakdown electric fields of over 7 MV/cm, and lower leakage currents. These films had relatively smooth surfaces and took on the shapes of the underlying aluminum. In contrast, films formed at lower ethylene glycol concentrations of under 50% and lower current densities of under 0.9 mA/cm2 had rough surfaces and microvoids. A high concentration of ethylene glycol increases the cost of mass production, however, the proposed rear-positioned cathode method can be achieved even when the concentration of ethylene glycol is under 50%.

A new enzymatic method for glycolaldehyde production from ethylene glycol

A new enzymatic method for glycolaldehyde production from ethylene glycol was investigated using alcohol oxidase from Pichia pastoris or glycerol oxidase from Aspergillus japonicus. Both alcohol and glycerol oxidases oxidize ethylene glycol to glyoxal via glycolaldehyde, but glycolaldehyde was remarkably accumulated using a high concentration of ethylene glycol. The glycolaldehyde formation was also affected by buffer species and reaction pH. Under the optimum conditions, 0.92 or 0.97 M glycolaldehyde was formed from 1.0 M ethylene glycol using alcohol oxidase or glycerol oxidase. This enzymatic method was superior to the chemical method in terms of conversion yields and selectivity of glycolaldehyde.

Large-scale purification and further characterization of rat pristanoyl-CoA oxidase.

The elution of pristanoyl-CoA oxidase from butyl-Sepharose required unusually high concentrations of ethylene glycol, enabling the large-scale purification of this oxidase in a single chromatographic step. The enzyme, the native molecular mass of which was estimated previously at 415 kDa by gel filtration (Van Veldhoven, P.P., Vanhove, G., Vanhoutte, F., Dacremont, G., Eyssen, H. J. & Mannaerts, G. P. (1991) J. Biol. Chem. 266, 24676-24683), migrated as a 513-kDa protein during native gel electrophoresis. It showed a typical flavoprotein spectrum and probably binds 4 mol FAD/mol enzyme. Its amino acid composition was different from those of other known acyl-CoA oxidases. Screening of different rat tissues, either for enzyme activity or by immunoblotting, revealed the highest level of pristanoyl-CoA oxidase in liver, followed by kidney, intestinal mucosa, spleen and lung. The oxidase activities, measured with 2-methylpalmitoyl-CoA as the substrate, in livers from other vertebrates including man were low compared to rat. This was also confirmed by immunoblotting which provided a clear signal only in rat liver, possibly indicating that pristanoyl-CoA oxidase might be a rat-specific oxidase.

Phase transitions of phospholipid vesicles under osmotic stress and in the presence of ethylene glycol

The effects of poly(ethylene glycol) (PEG) on the phase transition of phospholipid multilamellar vesicles (MLVs) were investigated by using differential scanning calorimetry (DSC). Main transition temperature ( T m) and the pre-transition temperature ( T p) of neutral phospholipid-, DMPC- 1, DPPC- and DSPC-MLVs increased with an increase in PEG concentration. The subtransition temperature of DPPC-MLVs also increased with an increase in PEG concentration. These results could be qualitatively explained by enhancement of the lateral packing on the basis of the osmoelastic coupling theory. The pretransition temperature increased faster than the main transition temperature did with an increase in PEG concentration. The increment of T m depended on the hydrocarbon chain length, the shorter the hydrocarbon chain length was, the larger the increment was. The transition width in the DSC peak was broadened with an increase in PEG concentration. These three above-mentioned effects are the main differences between the effects of the osmotic stress on the phase transition of MLVs and those of hydrostatic pressure. On the other hand, ethylene glycol (EG), which is the monomer of PEG, had a biphasic effect on transition temperature of DPPC-, DSPC-, and DMPC-MLV, reducing T m and T p at low concentrations, but increasing T m and extinguishing pretransition at high concentrations. This is explained by the induction of an interdigitated gel phase at high concentrations of EG, which indicates that EG can easily penetrate into the head group region of the lipid, in contrast with PEG 6K, because EG is small. Temperature-EG concentration phase diagrams for the various PC-MLVs were determined. The minimum concentration of EG where interdigitation occurs is largely dependent on the hydrocarbon chain length.