Different Concentrations Of Ethylene Glycol Research Articles

Molecular Dynamic Simulation Study on Replacement of Methane Hydrates with Carbon Dioxide Under Different Temperatures, Pressures, and Concentrations of Ethylene Glycol.

In order to alleviate the world energy resources crisis, the research and development of natural gas hydrates has a very important economic value and strategic significance. The CH4-CO2 replacement method can not only achieve geological storage of carbon dioxide but also more effectively mine natural gas hydrates. Based on molecular dynamics theory and the properties of natural gas hydrates, this paper delves into the replacement of methane hydrate with carbon dioxide under different temperatures, pressures, and concentrations of ethylene glycol (EG). We established a CO2-Hydrate model and three CO2/EG-Hydrate models with different concentrations of EG, and we simulated the radial distribution function (RDF), mean square displacement (MSD), and relative density distribution of each particle in the system in different conditions. The higher the temperature, the more unstable the methane hydrates are, and the methane hydrates are more prone to decomposition. Compared with 280 and 290 K, the temperature of 270 K is more favorable for carbon dioxide molecules to enter the hydrate layer and form carbon dioxide hydrates. The changes in pressure have little impact on the decomposition of methane hydrates, the rupture of water cages of methane hydrates, and the number of carbon dioxide molecules entering the hydrate layer under temperatures of 280 K and pressures of 1, 4, and 7 MPa. But overall, a pressure of 1 MPa is more conducive for carbon dioxide molecules to enter the hydrate layer and form carbon dioxide hydrates. Adding EG to CO2 molecules can inhibit the decomposition of methane hydrates. However, the higher the concentration of EG, the faster the decomposition of methane hydrates. The degree of fracture of the water cages in methane hydrates is greater under pure CO2 conditions. Adding EG to CO2 molecules is more conducive for CO2 molecules to enter the hydrate layer and form carbon dioxide hydrates. This review is of great significance to improve the mining efficiency and CO2 storage efficiency of the replacement of natural gas hydrates with CO2.

Terahertz resonance frequency through ethylene glycol phononic multichannel sensing via 2D MoS2/PtSe2 structure

Artificial periodic structures drew a lot of attention because of their ability to be built with novel acoustic features. A novel nanostructured phononic superlattice (NPhS) based two-dimensional multilayer structure as a high-sensitive multichannel liquid sensor that provided bright multichannel band gap windows has been introduced. Theoretically, the designed structure is composed of [(MoS2/PtSe2)4] NPhS with a cavity filled with different concentrations of Ethylene Glycol at room temperature toward acoustic bandgap engineering multichannel sensor. We examined the interaction of acoustic waves with nano and bulk phononic superlattice (PhS) structures. In addition, we studied the effect of using different analyte layer thicknesses on the resonance peaks that appeared inside the band gaps. Many sharp resonance peaks appeared in multi-band gaps, which introduced high sensitivity, Q-factor, and figure of merit (FOM) values for each concentration of Ethylene Glycol. Furthermore, the effect of resonance peaks' full width at half maximum (FWHM) on the Q-factor of the NPhS multichannel sensor has been studied. From our results, the relation between the sensitivity of our multichannel sensor and the resonance frequency of each concentration shows a linear behavior. The highest sensitivity was obtained for a 1.00 m% concentration of 0.21 (GHz/(kg/m3)) at a resonance frequency value of 0.21 THz. In addition, the NPhS multichannel sensor recorded the highest Q-factor for 0.8069 m% with a value of 1744 and the highest FOM for 0.3819 m% with a value of 0.05988 (m3/kg). Moreover, we studied the effect of temperature on the sensitivity of the NPhS multichannel sensor. We showed the highest sensitivity value of 1.79 (GHz/o C) at 10 °C towards Ethylene Glycol. Further, the dispersion relation of an acoustic wave propagating inside perfect and defected nano and bulk PhS structures has been introduced. Our proposed multichannel liquid sensor can introduce a novel sensitivity at Terahertz frequency ranges.

Stabilizing nano-Pd on porous Li2TiO3via chemical and electrochemical reduction systems for the electrooxidation of ethylene glycol

The challenge of breaking the C–C bond in ethylene glycol oxidation requires an efficient electrocatalyst. A porous oxide as the promoter boosts the dispersion of noble metal onto the electrocatalyst surface. Porous Li2TiO3 (LT) was synthesized, characterized, and applied as a promoter for palladium nanoparticles. The nano-Pd as a stable and efficient catalyst was stabilized on spinel LT promoter via two different reduction approaches including chemical (NaBH4) and electrochemical (Zn sheet/HCl) systems. Different techniques such X-ray diffraction, Fourier Transform Infrared Spectroscopy, Energy-Dispersive X-Ray Spectroscopy, Differential scanning calorimetry, thermogravimetric analysis, Barrett-Joyner-Halenda test, scanning electron microscopy, and transition electron microscopy were characterization of LT and LT/Pd. The size of the mesopores is between 2 and 19 nm. In comparison with non-promoted Pd, Pd/LT electrocatalyst was shown an excellent efficiency in parameters like electrochemical active surface area and anti-CO poisoning behaviour. The LT increases the removal of intermediates created in the oxidation of ethylene glycol that can poison the surface of Pd catalyst. This is due to the presence of the lattice oxygens in LT structure and Ti switching between its high and low valances. The morphology of as-synthesized electrocatalysts that was probed by FESEM micrographs demonstrates the embedment of nano-Pd onto the surface and into LT cavities. The results showed that the nano-Pd manufactured with the chemical reduction has a smaller size with high dispersion than the electrochemical reduction system. In this study, for the first time, the adsorption isotherms of fuel on the catalyst's surface were determined through the calculations of adsorption and desorption of hydrogen in the different concentrations of ethylene glycol.

Effects of Organic Solvent Doping on the Structural and Conductivity Properties of PEDOT: PSS Fabric

The development of highly conductive fabrics for application in electronic textiles on non-rigid substrates has gained much interest owing to their potential for realizing next-generation wearable conductive fabrics. Besides, it could be used as a portable device in the energy and healthcare industries. However, pristine PEDOT: PSS has been reported to have low conductivity values due to excessive PSS chains that wrapped up around the PEDOT conductive chain structure. In this context, one of the most successful techniques to include dopant is to use ethylene glycol (EG) to improve the conductivity of poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS). Immersing or coating of fabrics with PEDOT: PSS is one of the facile methods used for obtaining functional and smart properties. Our studies prepared conductive polymer; PEDOT: PSS with ethylene glycol (EG) dopant) at different concentrations on polyester (PES) fabric substrates by a facile immersion process. The effect of the different concentrations of EG on the conductivity is shown when Electrochemical Impedance Spectroscopy (EIS) is conducted. It shows that 6% v/v of EG gives the optimum conductivity value up to 4.06 × 10-3 Scm-1. Meanwhile, Scanning Electron Microscopy (SEM) imaging is focusing on the morphology of the immersed fabric. The improvement in crystallinity of the doped PEDOT: PSS was revealed and evaluated using X-ray Diffraction (XRD). As a result, it has been demonstrated that EG is an excellent dopant because it efficiently increases the electrical conductivity and crystallinity of PEDOT: PSS fabric.

Effect of diluent variation on cryopreservation of large yellow croaker Larimichthys crocea

The aim of this research was to investigate different factors, including cryoprotective agents (CPAs), diluents, dilution ratios, equilibrium times, freezing rates, and thawing methods to optimize cryopreservation protocols for large yellow croaker (Larimichthys crocea). The parameters evaluated were sperm motility, sperm activity index (SAI), survival rate, and DNA damage. Different types of CPAs, such as dimethyl sulfoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), methanol, and glycerol, were tested for sperm preservation. The highest motility, SAI, and survival rate were observed when EG was used. Different diluents such as Stein’s solution, Hank’s balanced salt solution, marine fish Ringer’s solution, artificial seminal plasma (ASP) of small yellow croaker, and Cortland solution were investigated. The highest post-thaw motility was observed upon using ASP as the diluent. Different concentrations of EG were then mixed with ASP to identify the optimal EG concentration. Experimental results showed that the motility (70.33 ± 1.20%), SAI (5), and survival rate (78.30 ± 0.42%) of post-thaw sperm were optimum when 10% EG and ASP were used as the CPA and diluent of cryopreservation, respectively. Post-thaw sperm motility was high at equilibration times below 150 s and at an optimum dilution ratio of 1:1 (sperm: CPA + diluent) and was not significantly different compared with fresh sperm motility. The freezing rate was found to be slow below −10°C/min. The thawing temperature of 45°C was identified as ideal. The percentage of tail DNA in post-thaw sperm at 10% EG and ASP was also investigated and was found to have more significant DNA damage than that in fresh sperm but significantly lower damage than that in post-thaw sperm at EG concentrations of 5%, 15%, and 20% (p < 0.05). The cryopreservation protocols obtained in this study will be useful in large yellow croaker hatcheries.

Biotechnological approaches to the preservation and use of bovine ovarian cumulus-oocyte complexes in the system of reproductive technologies

Aim. To study the effect of different concentrations of ethylene glycol and glycerin in equilibration and vitrifi cation solutions on 1) the viability and further development of frozen-thawed bovine ovarian cumulus-oocyte complexes (COCs), cryopreserved by vitrifi cation method, 2) on the effectiveness of inseminating mature oocytes, obtained from them, and 3) on the formation of embryos. Methods. Biotechnological, cryobiological, morphological, cytogenetic, and statistical methods, as well as methods of statistical data processing were used in the research. Results. The results of experimental studies on the effect of different concentrations of ethylene glycol and glycerin in the equilibration solution during cryopreservation of bovine ovarian COCs (n = 502) on their viability and further development after freezing-thawing are presented. We also show the results of the comparative analysis of cryoresistant properties of bovine ovarian COCs (n = 560) using different concentrations of ethylene glycol and glycerin, as cryoprotectants, in the vitrifi cation solution in terms of the viability and maturation of the oocytes, which originated from these COCs, up to metaphase II of meiosis. A comparative analysis of the application of ethylene glycol and glycerol in differ- ent concentrations for the equilibration and vitrifi cation solutions in cryopreserving bovine ovarian COCs (n = 220) demonstrated a relationship between the level of concentration of these cryoprotectants and the number of embryos after in vitro insemination of mature gametes, obtained from these frozen-thawed COCs. Conclusions. It was found that the use of 25 % ethylene glycol and 5 % glycerin in the equilibration solution and 10 % ethylene glycol and 40 % glycerin in the vitrifi cation solution during cryopreservation of bovine ovarian COCs ensures lower toxicity of these solutions and promotes more effi cient (up to 14.3 %) formation and development of embryos after in vitro insemina- tion of mature gametes, obtained from these COCs

Cryopreservation of Indonesian native chicken semen by using dimethyl sulfoxide and various level of ethylene glycol as cryoprotectants

Abstract. Khaeruddin, Junaedi, Hastuti. 2020. Cryopreservation of Indonesian native chicken semen by using dimethyl sulfoxide and various level of ethylene glycol as cryoprotectants. Biodiversitas 21: 5718-5722. Imported purebred chickens are becoming more popular and a regular staple in Indonesia. Therefore, it is necessary to strengthen conservation efforts to preserve Indonesian chickens, one of which is by means of sperm cryopreservation. This study aimed to determine the effects of the addition of DMSO and different concentrations of ethylene glycol to a Ringer’s lactate egg yolk (RLY)-or coconut water egg yolk (CWY)-based extender on the quality of frozen-thawed Indonesian chicken sperm. This study was used nine Indonesian native roosters about 20 months of age. The semen extenders used in this study were RLY + DMSO 7%, RLY + ethylene glycol 3%, RLY + ethylene glycol 5%, RLY + ethylene glycol 7%, CWY + DMSO 7%, CWY + ethylene glycol 3%, CWY + ethylene glycol 5% and CWY + ethylene glycol 7%. Liquid semen was packaged in 0.25 mL straw, then cooled at 5oC for 2 hours, frozen at 5 cm above liquid nitrogen for 10 minutes, following stored in a liquid nitrogen container for 24 hours. The semen straws were thawed at 37oC for 30 seconds. Statistical analysis for multiple comparisons was performed as a completely randomized design with eight treatment levels and seven replications. The results showed that there were no differences in sperm motility, recovery rate, and abnormality between extenders after the freeze-thaw process. Whereas, RLY + DMSO 7% was the highest sperm viability.

Conformational changes in cytochrome c directed by ethylene glycol accompanying complex formation: Protein-solvent preferential interaction or/and kosmotropic effect.

When proteins interact with solvent or co-solutes with a high specificity and affinity, protein-ligand complexes may be formed. Such phenomenon may involve the processes like intra- and intermolecular interactions, which result in interaction based protein folding. In this study, cytochrome c (cyt c) was treated with different concentrations of ethylene glycol (EG) in crowded and confined media to check its structural stability using various spectroscopic techniques at pH7.0 and 25°C. The various spectroscopic techniques including circular dichroism (Soret, far- and near-UV regions), Fourier transform infrared (FTIR), absorption (UV and visible) and Trp fluorescence shows both secondary and tertiary structure of cyt c increases when treated with EG. The investigations using dynamic light scattering (DLS), time resolved fluorescence and isothermal titration calorimetry (ITC) for binding studies shows weak interaction between EG and cyt c. Small increase in the structure of the protein and insignificant decrease in hydrodynamic radii of the protein was observed from the studies. Molecular docking studies showed that EG has binding site on the protein and interact with few amino acid residues by weak interactions such as van der Waals and hydrogen bonding. This study helps in understanding the protein-ligand interactions, provides facts and the mechanisms that mediates the recognition of binding site for specific ligand to the receptor protein, which make possible of the discovery, design, and development of drugs at molecular level without affecting proteins within an organism.

Spectropolarimetric Surface Plasmon Resonance Sensor and the Selection of the Best Polarimetric Function

Intensity based spectral surface plasmon resonance (SPR) sensors are becoming more and more used due to the availability of miniature and low-cost spectrometers, however, they still lack the low limit of detection, because the SPR dip spectral width is around 50 nm even though the spectral sensitivity is considered relatively high. Profiting from the sharp jump in phase under SPR, several works suggested the extraction of the phase of the reflected wave. In this work, we propose a simple spectral polarimetric setup, which involves the addition of an analyzer at three different orientations and performing measurements of the intensity spectrum. Measurements at different concentrations of ethylene glycol in water were carried out using this technique and showed a comparable performance to some of the best spectral interrogation techniques. Theoretical simulations showed that the derivative of the phase difference between the TM and TE waves gives the highest resolution, although practically the more directly measured cosine function of the phase difference is the best one to use. Another important result is that the tolerance on the metal layer thickness is improved significantly when the spectropolarimetric method is used.

Synthesis and Gas-sensing Performance of Column-shaped Zinc Oxide Doped with-graphene

Graphene-doped zinc oxide with column-like morphology was synthesized by an in-situ hydrothermal method. Their gas-sensing properties were then studied. The results indicated that zinc oxide decorated with graphene exhibits high selectivity for detection of ethylene glycol upon exposure to mixture of various volatile gases, and it has an enhanced response to different concentrations of ethylene glycol at 160°C. The response and recovery times for 5ppm ethylene glycol are 1 and 14 s, respectively, implying the unique-shape zinc oxide doped with graphene is effective for detection of low-concentration ethylene glycol.

Preservation of mouse ovarian tissue follicle morphology and ultra-structure after vitrifying in biotechnological protocols.

BackgroundThe aim of the present study was to characterize the morphological and ultrastractural of mouse ovarian tissue with different cryoprotectant solution.ObjectiveAim of this study, is to demonstrae an improved convetional vitrification method on mouse ovarian tissue using different concentrations of ethylene glycol (EG) and/or dimetyl sulfoxide (DMSO) and EG.Materials and methodsMouse ovarian tissue dissected and were randomly assigned to three groups: control, conventional vitrification (CV) and toxicity test. Then ovaries were vitrified by 5%, 10% EG or DMSO CV1-CV4, 5%, 10% EG plus DMSO CV5-CV6 and EG plus DMSO in climbing concentrations CV7. The effect of cryoprotectant solutions on ovarian tissue were evaluated by histological examination hematotoxillin & eosin stain, H&E, viability assessment trypan blue stain and ultrastructural analyses transmission electron microscopy, TEM.ResultsOvarian tissue frozen in CV7 solution showed a higher percentage of morphologically normal follicles or viable follicles than other cryoprotectant solutions P < 0.05. Ultrastructural analysis of ovarian tissue showed that less damage was observed in CV7 and it was very similar to the control group.ConclusionVitrification of ovarian tissue with optimal cryoprotectant solutions such as EG plus DMSO is the most effective for preserving the structural efficiency of ovarian follicles.

Diffusion characteristics of ethylene glycol in skeletal muscle.

Part of the optical clearing study in biological tissues concerns the determination of the diffusion characteristics of water and optical clearing agents in the subject tissue. Such information is sufficient to characterize the time dependence of the optical clearing mechanisms—tissue dehydration and refractive index (RI) matching. We have used a simple method based on collimated optical transmittance measurements made from muscle samples under treatment with aqueous solutions containing different concentrations of ethylene glycol (EG), to determine the diffusion time values of water and EG in skeletal muscle. By representing the estimated mean diffusion time values from each treatment as a function of agent concentration in solution, we could identify the real diffusion times for water and agent. These values allowed for the calculation of the correspondent diffusion coefficients for those fluids. With these results, we have demonstrated that the dehydration mechanism is the one that dominates optical clearing in the first minute of treatment, while the RI matching takes over the optical clearing operations after that and remains for a longer time of treatment up to about 10 min, as we could see for EG and thin tissue samples of 0.5 mm.

Vitrification of in vitro mature alpaca oocyte: Effect of ethylene glycol concentration and time of exposure in the equilibration and vitrification solutions

The effect of different ethylene glycol concentrations, times of exposure and vitrification procedure on viability, cleavage and blastocyst rate of in vitro matured alpaca oocytes chemically activated after vitrification was analyzed. In Experiment 1, oocytes were incubated for 12–15min with different concentrations of ethylene glycol (EG) in the equilibration solution (ES) followed by chemical activation and in vitro cultured for 8 days to determine oocyte viability, cleavage and blastocyst rates. In Experiment 2, oocytes were incubated in the equilibration solution containing 4% of EG for 12–15min and then randomly assigned to vitrification solutions containing 25, 35 or 45% of EG for 30s, vitrified and stored at −196°C. In Experiment 3, oocytes were incubated in the equilibration solution containing 4% of EG for 12–15min and then randomly assigned to the vitrification solution containing 35% of EG for 15, 30 or 45s, vitrified and stored at −196°C.For Experiments 2 and 3, non-vitrified and vitrified oocytes were activated and cultured in vitro. In Experiment 1, oocyte viability was lowest at concentrations of 6 or 8%, intermediate at 2 or 4% and highest at 0% of EG. Oocyte viability and cleavage rate were affected by EG concentration, time of exposure in the vitrification solution or vitrification procedure in Experiment 2 and 3. Alpaca oocytes were viable after vitrification, given that oocyte viability, cleavage and blastocyst rate were affected by the vitrification procedure, EG concentration and time of exposure in the equilibration and vitrification solutions.

Experimental renal calcium oxalate calculus models without severe renal damage in rats

Objective To screen a short-term,economical and satisfied model of renal calcium oxalate calculus in rats with minimal renal damage.Methods Ninety male Sprague-Dawley (SD) rats were randomly divided into two groups.In group 1,the rats were treated with 1.0％ ammonium chloride and different concentrations of ethylene glycol (0.1％,0.2％,0.4％ and 0.8％).In group 2,the rats were treated with different concentrations of ethylene glycol (0.1％,0.2％,0.4％ and 0.8％).The body mass change,the serum creatinine and urine creatinine,and urinary oxalate excretion were measured.Conventional HE dyeing was carried out for kidney tissues and pathological changes,and the status of kidney stone formation was further observed.Results In group 1 treated with 1.0％ ammonium chloride and 0.1％ ethylene glycol for 7 days,the urinary oxalate excretion days was significantly higher than in control group (P ＜0.05).In group 1 treated with 0.4％ or 0.8％ ethylene glycol + 1.0％ ammonium chloride for 14 days,the creatinine clearance was lower than in control group (P ＜ 0.01).Light microscopy showed that calcium oxalate crystals formed in renal cortex,medulla and renal papilla,and inflammatory damage of renal tissue was aggravated.In group 2 treated with 0.4％ or 0.8％ ethylene glycol for 7 days,the urine oxalate excretion was higher than in control group (P ＜0.01),however,there was no statistically significant difference in the creatinine clearance (P ＞ 0.05).Light microscopy showed no obvious interstitial edema in renal cortex and a small amount of stone crystals were seen with no inflammatory cells infiltration.Conclusion Ethylene glycol alone is a quich,economic and good calcium oxalate crystallized method in rats without severe renal damage. Key words: Urolithiasis ; Calcium oxalate ; Ethylene glycol; Model,animal

Utilization of moving bed biofilm reactor for industrial wastewater treatment containing ethylene glycol: kinetic and performance study

One of the requirements for environmental engineering, which is currently being considered, is the removal of ethylene glycol (EG) as a hazardous environmental pollutant from industrial wastewater. Therefore, in a recent study, a moving bed biofilm reactor (MBBR) was applied at pilot scale to treat industrial effluents containing different concentrations of EG (600, 800, 1200, and 1800 mg L−1). The removal efficiency and kinetic analysis of the system were examined at different hydraulic retention times of 6, 8, 10, and 12 h as well as influent chemical oxygen demand (COD) ranged between values of 1000 and 3000 mg L−1. In minimum and maximum COD Loadings, the MBBR showed 95.1% and 60.7% removal efficiencies, while 95.9% and 66.2% EG removal efficiencies were achieved in the lowest and highest EG concentrations. The results of the reactor modelling suggested compliance of the well-known modified Stover–Kincannon model with the system.

Ice blockers improve vitrification outcome of mouse embryos by allowing lower cryoprotectant concentration in vitrification media within a closed system

To evaluate the effect of ice blockers (IB) (super cool X-1000 and Z-1000) with different concentrations of Ethylene Glycol (EG) on the survival and blastocyst formation rates after the Vitrification/warming process of mouse embryos.

Crioprotetores etileno glicol ou acetamida na viabilidade in vitro de espermatozoides congelados de ovinos

Objetivando-se avaliar o efeito de diferentes concentrações dos crioprotetores etileno glicol ou acetamida na viabilidade in vitro de espermatozoides congelados de ovinos, foram utilizados seis pools de sêmen de quatro reprodutores mestiços da raça Santa Inês. Após aprovação, o pool dos ejaculados foi diluído em Tris-gema, acrescido de glicerol (G1=5%; controle), etileno glicol (G2=3%; G3=5%) ou acetamida (G4=2%; G5=7%), envasado em palhetas (0,25mL; 100x106 espermatozoides) e congelado. As amostras descongeladas (37oC/30 segundos) foram avaliadas quanto a motilidade progressiva (MP), vigor, integridade da membrana plasmática (iMP), potencial de membrana mitocondrial (PMM) e integridade do acrossoma (iAC). Constatou-se que a MP do G1 foi superior (P&lt;0,05) à dos G3, G4 e G5, e que o vigor dos G1, G2 e G3 foi maior (P&lt;0,05) do que o dos G4 e G5. A iMP do G1 foi superior (P&lt;0,05) à dos G2, G3, G4 e G5, assim como os G2 e G3 foram superiores (P&lt;0,05) a G4 e G5. O PMM e a iAC não diferiram (P&gt;0,05) entre os grupos. Conclui-se que o etileno glicol (3 e 5%) e a acetamida (2 e 7%) não são eficazes para a proteção dos espermatozoides ovinos submetidos à congelação.

Fabry–Pérot Cavity Based on a High-Birefringent Fiber Bragg Grating for Refractive Index and Temperature Measurement

A fiber-optic sensor for simultaneous measurement of refractive index and temperature is described. The refractive index measurement is based on the visibility variations of a Fabry-Pérot interferometer. It is formed with the interfering waves generated from a low reflectivity Bragg grating inscribed on a Panda fiber and from the fiber end tip (Fresnel reflection) in contact with the liquid. The sensor is characterized by immersing the fiber tip in distilled water with different concentrations of ethylene glycol. A linear relation of the interferometer fringe visibility with refractive index variation is observed. The temperature is determined by the wavelength shift of the FBG peaks. Results show the feasibility of simultaneous measurement of refractive index and temperature and also the possibility of adjusting fringe visibility via polarization control.

53 VITRIFICATION OF HANDMADE CLONED BUFFALO EMBRYOS USING ETHYLENE GLYCOL AND DIMETHYL SULPHOXIDE AND SUBSEQUENT EFFECT ON CRYOSURVIVAL AND APOPTOSIS

The objective of the present work was to optimize concentration of cryoprotectants ethylene glycol (EG) and dimethyl sulphoxide (DMSO) to facilitate the vitrification of buffalo embryos produced by somatic cell nuclear transfer (SCNT). Cloned embryos were produced according to standardized protocols of our laboratory using handmade cloning (Shah et al. 2008). Three different concentrations of EG and DMSO (7.5, 10 and 15%, having 0.5 M sucrose in TCM-199 containing 20% serum) were selected in combination for vitrification of cloned blastocysts in French ministraws (0.25 mL). The numbers of cloned blastocysts vitrified for each concentration were 51, 51 and 52, respectively. The post-thaw viability was accessed by re-expansion rate of blastocysts after culturing in RVCL media (K-RVCL-50, Cook® Australia, Queensland, Australia) for 18 to 24 h. On the basis of re-expansion rate, there was no significant effect of any selected concentrations (7.5, 10 and 15%) on post-thaw viability (25.33 ± 2.43%, 29.00 ± 2.52% and 30.83 ± 3.01%, respectively; P &gt; 0.05). The effect of vitrification on apoptosis level was checked after 18 to 24 h post-thaw by TUNEL assay and the apoptosis index was calculated by dividing the total number of nuclei with DNA-fragmented positive nuclei of the respective blastocyst. We found that, 7.5%-group embryos resulted with a significantly higher apoptotic index (8.28 ± 0.57) than that of the 10 and 15% groups (5.09 ± 0.46 and 4.28 ± 0.24, respectively; P &lt; 0.05). These results clearly indicate that a lower concentration of cryoprotectants (7.5%) increased the chance of apoptosis in blastocysts that were frozen-thawed. The quantitative expression of apoptosis-related genes (Bax, Bid, Mcl-1 and Bcl-xl) in all 3 treatment groups and fresh control embryos were determined by RT-qPCR. Three replications were performed and the mRNA level of each sample was normalized to that of glyceride-3-phosphate dehydrogenase mRNA level. Results of RT-qPCR were analysed using the 2–ΔΔCT method to compare the relative transcriptional levels of the target genes in each group. The RT-qPCR data revealed that the 7.5% vitrified group embryos possessed high expression of pro-apoptotic genes (Bax and Bid) and lower expression of anti-apoptotic genes (Mcl-1 and Bcl-xl) in comparison to the 10 and 15% groups. However, there was no significant change in gene expression between the 10 or 15% groups in comparison with fresh non-vitrified embryos. Our results conclude that the best choice is to use 10 or 15% EG and DMSO cryoprotectants for in-straw zona-free cloned buffalo embryo vitrification. However, further experiments are needed to enhance survival after vitrification. This work was supported by research grants from the National Agriculture Innovative Project (1(5)/2007-NAIP-2) to S. K. Singla.

Effect of ethylene glycol on micellization and micellar-catalyzed alkaline hydrolysis reaction of a cationic surfactant at 293–313 K

Changes in critical micellar concentrations (CMC’s) of gemini surfactant, α, ω-ethane bis(dimethyl cetyl ammonium bromide) (C16-2-C16) with different concentrations of ethylene glycol (EG) addition have been investigated by electrical conductivity method. Subsequently, alkaline hydrolysis of ethyl acetate (EA) in the presence of C16-2-C16 and C16-2-C16-EG has been studied conductometrically at 303.2 and 313.2 K, respectively. It was found that an increase in concentrations of EG added to C16-2-C16 aqueous solutions caused an increase in CMC’s of C16-2-C16, provoked by the decrease in the interfacial Gibbs energy contribution to GM∘. The hydrolysis of EA showed catalytic and restrained dual behavior in the presence of surfactant, it may be related to higher microviscosity and change of morphology with increased surfactant for C16-2-C16 at higher concentration. Addition of EG did not change microenvironment in micellar interfacial region significantly, which had less effect on gemini C16-2-C16 micellar catalytic efficiency.