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1.
J Colloid Interface Sci ; 606(Pt 2): 1673-1683, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34534835

RESUMO

HYPOTHESIS: Although protein adsorption at an interface is very common and important in biology and biotechnology, it is still not fully understood - mainly due to the intricate balance of forces that ultimately control it. In food processing (and medicine), controlling and manipulating protein adsorption, as well as avoiding protein adsorption (biofilm formation or membrane fouling) by the production of protein-resistant surfaces is of substantial interest. A major factor conferring resistance towards protein adsorption to a surface is the presence of tightly bound water molecules, as is the case in oligo ethylene glycol (OEG)-terminated self-assembled monolayers (SAMs). Due to strong attractive protein-protein and protein-surface interactions observed in systems containing trivalent salt ions, we hypothesize that these conditions may lead to a breakdown of protein resistance in OEG SAMs. EXPERIMENTS: We studied the adsorption behavior of BLG in the presence of a lanthanum(III) chloride (LaCl3) at concentrations of 0, 0.1, 0.8 and 5.0 mM on normally protein resistant triethylene glycol-termianted (EG3) SAMs on a gold surface. We used quartz-crystal microbalance with dissipation (QCM-D) and neutron reflectivity (NR) to characterize the morphology of the interfacial region of the SAM. FINDINGS: We demonstrate that the protein resistance of the EG3 SAM breaks down beyond a threshold salt concentration c∗ and mirrors the bulk behaviour of this system, showing reduced adsorption beyond a second critical salt concentration c∗∗. These results demonstrate for the first time the controlled switching of the protein-resistant properties of this type of SAM by the addition of trivalent salt.


Assuntos
Etilenoglicol , Lactoglobulinas , Adsorção , Ouro , Propriedades de Superfície , Água
2.
IET Nanobiotechnol ; 15(3): 266-276, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34694671

RESUMO

A large population is suffering from multifactorial urolithiasis worldwide with a reoccurrence rate of almost 70%-80% in males and 47%-60% in females. In the present study, the nephroprotective effect of silver nanoparticles (AgNPs) synthesised by Bryophyllum pinnatum was evaluated in ethylene glycol-induced urolithiasis in rat. B. pinnatum-mediated AgNPs which were found to be spherical and polydispersed particles with an average size of 32.65 nm determined by transmission electron microscopy analysis, and showing an absorption peak at 432 nm by the UV-Vis spectrophotometric analysis, revealing the role of hydroxyl group in the synthesis by Fourier Transformed Infrared Spectroscopy analysis, with a zeta potential value of -15.7 mV. The crystalline nature and fcc structure was demonstrated based on X-ray diffraction analysis. Animal study was performed on 36 male Wistar rats divided into six equal groups, which demonstrated significant increase in serum total protein, albumin and globulin and significant decrease in AST, ALT, creatinine, BUN, calcium and phosphorus in group V and VI when compared with group II and IV. No crystalluria was observed in rats given B. pinnatum AgNPs. Histopathological observations in group V and VI showed mild degenerative changes and restoration or maintenance of kidney parenchyma when compared with group II and IV rats. Thus, the authors conclude with the beneficial preventive and therapeutic nephroprotective effect of B. pinnatum-mediated AgNPs against ethylene glycol-induced urolithiasis in rats.


Assuntos
Kalanchoe , Nanopartículas Metálicas , Urolitíase , Animais , Etilenoglicol/toxicidade , Nanopartículas Metálicas/toxicidade , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Prata/toxicidade , Urolitíase/induzido quimicamente , Urolitíase/tratamento farmacológico , Urolitíase/prevenção & controle
3.
FASEB J ; 35(11): e21937, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34606628

RESUMO

Defective permeability barrier is considered to be an incentive of hyperuricemia, however, the link between them has not been proven. Here, we evaluated the potential preventive effects of Lactiplantibacillus plantarum N-1 (LPN1) on gut microbiota and intestinal barrier function in rats with hyperoxaluria-induced kidney stones. Male rats were supplied with 1% ethylene glycol (EG) dissolved in drinking water for 4 weeks to develop hyperoxaluria, and some of them were administered with LPN1 for 4 weeks before EG treatment as a preventive intervention. We found that EG not only resulted hyperoxaluria and kidney stone formation, but also promoted the intestinal inflammation, elevated intestinal permeability, and gut microbiota disorders. Supplementation of LPN1 inhibited the renal crystalline deposits through reducing urinary oxalic acid and renal osteopontin and CD44 expression and improved EG-induced intestinal inflammation and barrier function by decreasing the serum LPS and TLR4/NF-κB signaling and up-regulating tight junction Claudin-2 in the colon, as well as increasing the production of short-chain fatty acid (SCFAs) and the abundance of beneficial SCFAs-producing bacteria, mainly from the families of Lachnospiraceae and Ruminococcaceae. Probiotic LPN1 could prevent EG-induced hyperoxaluria by regulating gut microbiota and enhancing intestinal barrier function.


Assuntos
Etilenoglicol/efeitos adversos , Microbioma Gastrointestinal/genética , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Cálculos Renais/induzido quimicamente , Cálculos Renais/prevenção & controle , Lactobacillaceae , Permeabilidade , Probióticos/administração & dosagem , Animais , Colo/metabolismo , Colo/microbiologia , Ácidos Graxos Voláteis/análise , Ácidos Graxos Voláteis/biossíntese , Fezes/química , Fezes/microbiologia , Hiperoxalúria/induzido quimicamente , Hiperoxalúria/prevenção & controle , Hiperuricemia/induzido quimicamente , Hiperuricemia/prevenção & controle , Inflamação/metabolismo , Masculino , RNA Ribossômico 16S/genética , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Junções Íntimas/metabolismo
4.
J Org Chem ; 86(19): 13491-13502, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34514788

RESUMO

In this study we found that 2,6-dimethanolpyridine displays good complementarity toward di(ethylene glycol) for the complexation of Na+ ions, allowing us to use this recognition system for the efficient synthesis of hetero[2]catenanes; indeed, it allowed us to attach multiple copies of [2]catenanes to branched systems presenting multiple isophthalaldehyde units. When we attempted to form a catenane from a preformed macrocycle featuring only a single di(ethylene glycol) unit, reacting it with a di(ethylene glycol) derivative presenting two amino termini, isophthalaldehyde, and templating Na+ ions [i.e., with the aim of using di(ethylene glycol)·Na+·di(ethylene glycol) recognition to template the formation of the interlocked imino macrocycle], the yields of the hetero[2]catenane and homo[2]catenane, comprising two imino macrocyclic units, were both poor (14% and 7%, respectively). In contrast, when one or two 2,6-dimethanolpyridine units were present in the preformed macrocycles, their reactions with the same diamine, dialdehyde, and Na+ ions provided the hetero[2]catenanes with high selectivity and efficiency (44% and 64% yields, respectively), with minimal formation of the competing homo[2]catenane. The high complementary of the 2,6-dimethanolpyridine·Na+·di(ethylene glycol) ligand pair allowed us to synthesize [2]catenane dimers and trimers directly from corresponding isophthalaldehyde-presenting cores, with yields, after subsequent reduction and methylation, of 42% and 31%, respectively.


Assuntos
Catenanos , Etilenoglicol , Antracenos , Íons , Espectroscopia de Ressonância Magnética
5.
Molecules ; 26(18)2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34577084

RESUMO

Smoke-derived taint has become a significant concern for the U.S. wine industry, particularly on the west coast, and climate change is anticipated to aggravate it. High volatile phenols such as guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-ethylphenol, and o-, p-, m-cresols have been suggested to be related to smoke-exposed grape and wine. This paper describes an analytical approach based on ethylene glycol/polydimethylsiloxane (EG/PDMS)-stir bar sorptive extraction-gas chromatography-mass spectrometry (SBSE-GC-MS) to quantify or estimate the concentrations of some smoke-related volatile phenols in wines. Correlation coefficients with R2 ≥ 0.990 were obtained. This method can quantify most smoked-related volatile phenols down to 0.5 µg/L in wine in selective ion monitoring mode. Recovery for the targeted volatile phenols ranged from 72.2% to 142.4% in the smoke-tainted wine matrix, except for 4-vinylguaiacol. The standard deviations of the volatile phenols were from 0 to 23% in smoke-tainted wine. The approach provides another tool to evaluate wine smoke exposure and potential smoke taint.


Assuntos
Fracionamento Químico/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Fenóis/análise , Fenóis/química , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Vinho/análise , Adsorção , Calibragem , Dimetilpolisiloxanos/química , Etilenoglicol/química , Padrões de Referência , Reprodutibilidade dos Testes , Fumaça , Vitis/química , Vitis/crescimento & desenvolvimento
6.
Ann Pathol ; 41(6): 549-553, 2021 Nov.
Artigo em Francês | MEDLINE | ID: mdl-34483010

RESUMO

Ethylene glycol poisoning is relatively rare, with around a hundred cases reported each year in France. Its diagnosis is often challenging and delayed because of a several hours' free interval between ingestion of the toxic and the onset of the first symptoms. Ethylene glycol is a colorless and odorless liquid primarily found in automotive coolants, whose toxicity is linked to its hepatic metabolites. Histologically, ethylene glycol poisoning is characterized by abundant tissular deposits of calcium oxalate crystals. Under polarized light, these crystals appear birefringent and iridescent. Their microscopic appearance and their distribution are pathognomonic of oxalosis. Due to its frequent misleading presentation, the diagnosis of ethylene glycol poisoning is sometimes only made after an autopsy. Hereafter, we report the case of a 59-year-old man diagnosed with ethylene glycol intoxication after a post-mortem histopathological examination of organs.


Assuntos
Oxalato de Cálcio , Etilenoglicol , Autopsia , França , Humanos , Masculino , Pessoa de Meia-Idade
7.
Acc Chem Res ; 54(19): 3700-3709, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34496564

RESUMO

Transmembrane proteins located within biological membranes play a crucial role in a variety of important cellular processes, such as energy conversion and signal transduction. Among them, ion channel proteins that can transport specific ions across the biological membranes are particularly important for achieving precise control over those processes. Strikingly, approximately 20% of currently approved drugs are targeted to ion channel proteins within membranes. Thus, synthetic molecules that can mimic the functions of natural ion channel proteins would possess great potential in the sensing and manipulation of biologically important processes, as well as in the purification of key industrial materials.Inspired by the sophisticated structures and functions of natural ion channel proteins, our research group developed a series of multiblock amphiphiles (MAs) composed of a repetitive sequence of flexible hydrophilic oligo(ethylene glycol) chains and rigid hydrophobic oligo(phenylene-ethynylene) units. These MAs can be effectively incorporated into the hydrophobic layer of lipid bilayer membranes and adopt folded conformations, with their hydrophobic units stacked in a face-to-face configuration. Moreover, the folded MAs can self-assemble within the membranes and form supramolecular nanopores that can transport ions across the membranes. In these studies, we focused on the structural flexibility of the MAs and decided to design new molecules able to respond to various external stimuli in order to control their transmembrane ion transport properties. For this purpose, we developed new MAs incorporating sterically bulky groups within their hydrophobic units and demonstrated that their transmembrane ion transport properties could be controlled via mechanical forces applied to the membranes. Moreover, we developed MAs incorporating phosphate ester groups that functioned as ligand-binding sites at the boundary between hydrophilic and hydrophobic units and found that these MAs exhibited transmembrane ion transport properties upon binding with aromatic amine ligands, even within the biological membranes of living cells. We further modified the hydrophobic units of the MAs with fluorine atoms and demonstrated their voltage-responsive transmembrane ion transport properties. These molecular design principles were extended to the development of a transmembrane anion transporter whose transport mechanism was studied by all-atom molecular dynamics simulations.This Account describes the basic principles of the molecular designs of MAs, the characterization of their self-assembled structures within a lipid bilayer, and their transmembrane ion transport properties, including their responsiveness to stimuli. Finally, we discuss future perspectives on the manipulation of biological processes based on the characteristic features of MAs.


Assuntos
Proteínas de Membrana/química , Alcinos/química , Éteres/química , Etilenoglicol/química , Interações Hidrofóbicas e Hidrofílicas , Substâncias Macromoleculares/química , Modelos Moleculares
8.
Langmuir ; 37(32): 9694-9700, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34369779

RESUMO

Water-stable gold nanoparticle vesicles (GNVs) with hollow interiors have attracted attention due to their great potential for biological applications; however, their preparation through the self-assembly approaches has been restricted due to the limited understanding of their critical mechanistic issues. In this paper, we demonstrate that a fluorinated tetra (ethylene glycol) (FTEG)-terminated tetra (ethylene glycol) (EG4), namely, FTEG-EG4, ligand can self-assemble with gold nanoparticles (5 and 10 nm) into GNVs with a hollow structure in THF due to the solvophobic feature of the ligand. Time-dependent studies showed that the GNVs with a closely packed surface derived from the incomplete and irregular GNVs, but not through the fusion of the GNV precursors. After dialysis in water, the assemblies retained vesicular structures in water, even though GNVs aggregated together, which was initiated by the hydrophobic interactions between the FTEG heads of the surface ligands on GNVs. This study provides a new insight into the design of novel small surface ligands to produce water-stable GNVs for biological applications.


Assuntos
Ouro , Nanopartículas Metálicas , Etilenoglicol , Ligantes , Propriedades de Superfície , Água
9.
Cells ; 10(7)2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34359838

RESUMO

The open carrier system (OC) is used for vitrification due to its high efficiency in preserving female fertility, but concerns remain that it bears possible risks of cross-contamination. Closed carrier systems (CC) could be an alternative to the OC to increase safety. However, the viability and developmental competence of vitrified/warmed (VW) oocytes using the CC were significantly lower than with OC. We aimed to improve the efficiency of the CC. Metaphase II oocytes were collected from mice after superovulation and subjected to in vitro fertilization after vitrification/warming. Increasing the cooling/warming rate and exposure time to cryoprotectants as key parameters for the CC effectively improved the survival rate and developmental competence of VW oocytes. When all the conditions that improved the outcomes were applied to the conventional CC, hereafter named the modified vitrification/warming procedure using CC (mVW-CC), the viability and developmental competence of VW oocytes were significantly improved as compared to those of VW oocytes in the CC. Furthermore, mVW-CC increased the spindle normality of VW oocytes, as well as the cell number of blastocysts developed from VW oocytes. Collectively, our mVW-CC optimized for mouse oocytes can be utilized for humans without concerns regarding possible cross-contamination during vitrification in the future.


Assuntos
Blastocisto/citologia , Criopreservação/métodos , Fertilização In Vitro/métodos , Oócitos/citologia , Vitrificação , Animais , Biomarcadores/metabolismo , Blastocisto/metabolismo , Fator de Transcrição CDX2/genética , Fator de Transcrição CDX2/metabolismo , Caderinas/genética , Caderinas/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Crioprotetores/farmacologia , Dimetil Sulfóxido/farmacologia , Etilenoglicol/farmacologia , Feminino , Expressão Gênica , Masculino , Metáfase , Camundongos , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Espermatozoides/fisiologia , Sacarose/farmacologia
10.
J Chem Theory Comput ; 17(8): 5322-5341, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34232662

RESUMO

Deep eutectic solvents (DESs) have become popular as environmental-friendly solvents for biocatalysis. Molecular dynamics (MD) simulations offer an in-depth analysis of enzymes in DESs, but their performance depends on the force field chosen. Here, we present a comprehensive validation of three biomolecular force fields (CHARMM, Amber, and OPLS) for simulations of alcohol dehydrogenase (ADH) in DESs composed of choline chloride and glycerol/ethylene glycol with varying water contents. Different properties (e.g., protein structure and flexibility, solvation layer, and H-bonds) were used for validation. For two properties (viscosity and water activity) also experiments were performed. The viscosity was calculated with the periodic perturbation method, whereby its parameter dependency is disclosed. A modification of Amber was identified as the best-performing model for low water contents, whereas CHARMM outperforms the other models at larger water concentrations. An analysis of ADH's structure and interactions with the DESs revealed similar predictions for Amber and CHARMM.


Assuntos
Álcool Desidrogenase/química , Solventes/química , Água/química , Álcool Desidrogenase/metabolismo , Colina/química , Etilenoglicol/química , Glicerol/química , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Termodinâmica , Viscosidade , Água/metabolismo
11.
Appl Environ Microbiol ; 87(18): e0002021, 2021 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-34260304

RESUMO

Poly(ethylene terephthalate) (PET) is a commonly used synthetic plastic; however, its nonbiodegradability results in a large amount of waste accumulation that has a negative impact on the environment. Recently, a PET-degrading bacterium, Ideonella sakaiensis 201-F6 strain, was isolated, and the enzymes involved in PET digestion, PET hydrolase (PETase), and mono(2-hydroxyethyl) terephthalic acid (MHET) hydrolase (MHETase) were identified. Despite the great potentials of I. sakaiensis in bioremediation and biorecycling, approaches to studying this bacterium remain limited. In this study, to enable the functional analysis of PETase and MHETase genes in vivo, we have developed a gene disruption system in I. sakaiensis. The pT18mobsacB-based disruption vector harboring directly connected 5'- and 3'-flanking regions of the target gene for homologous recombination was introduced into I. sakaiensis cells via conjugation. First, we deleted the orotidine 5'-phosphate decarboxylase gene (pyrF) from the genome of the wild-type strain, producing the ΔpyrF strain with 5-fluoroorotic acid (5-FOA) resistance. Next, using the ΔpyrF strain as a parent strain and pyrF as a counterselection marker, we disrupted the genes for PETase and MHETase. The growth of both Δpetase and Δmhetase strains on terephthalic acid (TPA; one of the PET hydrolytic products) was comparable to that of the parent strain. However, these mutant strains dramatically decreased the growth level on PET to that on a no-carbon source. Moreover, the Δpetase strain completely abolished PET degradation capacity. These results demonstrate that PETase and MHETase are essential for I. sakaiensis metabolism of PET. IMPORTANCE The poly(ethylene terephthalate) (PET)-degrading bacterium Ideonella sakaiensis possesses two unique enzymes able to serve in PET hydrolysis. PET hydrolase (PETase) hydrolyzes PET into mono(2-hydroxyethyl) terephthalic acid (MHET), and MHET hydrolase (MHETase) hydrolyzes MHET into terephthalic acid (TPA) and ethylene glycol (EG). These enzymes have attracted global attention, as they have potential to be used for bioconversion of PET. Compared to many in vitro studies, including biochemical and crystal structure analyses, few in vivo studies have been reported. Here, we developed a targeted gene disruption system in I. sakaiensis, which was then applied for constructing Δpetase and Δmhetase strains. Growth of these disruptants revealed that PETase is the sole enzyme responsible for PET degradation in I. sakaiensis, while PETase and MHETase play essential roles in its PET assimilation.


Assuntos
Proteínas de Bactérias/genética , Burkholderiales/genética , Burkholderiales/metabolismo , Hidrolases/genética , Polietilenotereftalatos/metabolismo , Proteínas de Bactérias/metabolismo , Etilenoglicol/metabolismo , Genes Bacterianos , Hidrolases/metabolismo , Hidrólise , Engenharia Metabólica , Ácidos Ftálicos/metabolismo , Reciclagem
12.
J Phys Chem B ; 125(35): 10035-10046, 2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34323499

RESUMO

To find an alternative way for improving the efficacy of deep eutectic solvents (DESs) to dissolve carbon dioxide, a computational study of DES systems comprising choline chloride and different hydrogen-bond donors (ethylene glycol and glycerol) immobilized on hydrophobic (graphite) and hydrophilic (titanium dioxide) solid surfaces was performed. This research provides quantitative molecular understanding of the role of the DES thickness and also the type of solid support in CO2 sorption and diffusion using molecular dynamics simulations. In general, the proposed model based on supported DESs immobilized on different supports was developed to correlate the solubility of CO2 in DESs based on choline chloride. The simulated systems illustrate that CO2 molecules mainly accumulate at the gas/DES interface in short times, whereas diffusion of CO2 to the bulk DESs is slower as the thickness of the immobilized DES increases. In addition, the CO2 absorption capacity of both DESs coated on the TiO2 surface is larger than that on the graphite surface. Structural and dynamic characteristics were determined using density profiles, distribution functions, orientational analysis, and mean-square displacements. We further demonstrate the effective interaction parameters associated with CO2 capture by DESs via density functional theory.


Assuntos
Dióxido de Carbono , Glicerol , Colina , Etilenoglicol , Ligação de Hidrogênio , Solventes
13.
Sci Rep ; 11(1): 15387, 2021 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-34321576

RESUMO

The plasma membrane permeability to water and cryoprotectant (CPA) significantly impacts vitrification efficiency of bovine oocytes. Our study was designed to determine the concentration-dependent permeability characteristics for immature (GV) and mature (MII) bovine oocytes in the presence of ethylene glycol (EG) and dimethyl sulphoxide (Me2SO), and to compare two different modeling approaches: the two parameter (2P) model and a nondilute transport model. Membrane permeability parameters were determined by consecutively exposing oocytes to increasing concentrations of Me2SO or EG. Higher water permeability was observed for MII oocytes than GV oocytes in the presence of both Me2SO and EG, and in all cases the water permeability was observed to decrease as CPA concentration increased. At high CPA concentrations, the CPA permeability was similar for Me2SO and EG, for both MII and GV oocytes, but at low concentrations the EG permeability of GV oocytes was substantially higher. Predictions of cell volume changes during CPA addition and removal indicate that accounting for the concentration dependence of permeability only has a modest effect, but there were substantial differences between the 2P model and the nondilute model during CPA removal, which may have implications for design of improved methods for bovine oocyte vitrification.


Assuntos
Criopreservação , Dimetil Sulfóxido/farmacologia , Etilenoglicol/farmacologia , Oócitos/efeitos dos fármacos , Animais , Bovinos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Crioprotetores/farmacologia , Oócitos/crescimento & desenvolvimento
14.
Sci Rep ; 11(1): 15428, 2021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-34326357

RESUMO

Cryopreservation is the only reliable method for long-term storage of biological material that guarantees genetic stability. This technique can be extremely useful for the conservation of endangered species and restock natural populations for declining species. Many factors have negatively affected the populations of high economical value shellfish in Spain and, as a result, many are declining or threatened nowadays. This study was focused on early-life stages of Venerupis corrugata, Ruditapes decussatus and Ruditapes philippinarum to develop successful protocols to enhance the conservation effort and sustainable shellfishery resources. Firstly, common cryoprotecting agents (CPAs) were tested to select the suitable permeable CPA attending to toxicity. Cryopreservation success using different combinations of CPA solutions, increasing equilibrium times and larval stages was evaluated attending to survival and shell growth at 2 days post-thawing. Older clam development stages were more tolerant to CPA toxicity, being ethylene-glycol (EG) and Propylene-glycol (PG) the least toxic CPAs. CPA solution containing EG yielded the highest post-thawing survival rate and the increase of equilibration time was not beneficial for clam larvae. Cryopreservation of trochophores yielded around 50% survivorship, whereas over 80% of cryopreserved D-larvae were able to recover after thawing.


Assuntos
Bivalves , Conservação dos Recursos Naturais/métodos , Criopreservação/métodos , Espécies em Perigo de Extinção , Pesqueiros , Larva , Frutos do Mar , Animais , Bivalves/efeitos dos fármacos , Crioprotetores/farmacologia , Dimetil Sulfóxido/farmacologia , Etilenoglicol/farmacologia , Glicerol/farmacologia , Larva/efeitos dos fármacos , Propilenoglicol/farmacologia , Espanha
15.
J Phys Chem B ; 125(22): 5909-5919, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-34060849

RESUMO

Trajectories of atomic positions derived from ab initio molecular dynamics (AIMD) simulations of H-bonded liquids contain a wealth of information on dominant structural motifs and recurrent patterns of association. Extracting this information from a detailed search of the trajectories over multiple time frames is, however, a daunting exercise. Here, we use a machine learning strategy based on the neural inspired approach of the self-organizing maps (SOM), a type of artificial neural network that uses unsupervised competitive learning, to analyze the AIMD trajectories of liquid ethylene glycol (EG). The objective was to find whether there are H-bonded fragments, of two or more H-bonded EG molecules, that are recurrent in the liquid and to identify them. The SOM represents a set of high-dimensional data mapped onto a two-dimensional, grid of neurons or nodes, while preserving the topological properties of the input space. We show here that clustering of the fragments by SOM in terms of the molecular conformation of the individual EG molecules of the fragment and their H-bond connectivity pattern facilitates the search for H-bonded motifs. Using this approach, we are able to identify a H-bonded cyclic dimer and a bifurcated H-bonded structure as recurring motifs that appear in the longer H-bonded fragments present in liquid EG.


Assuntos
Etilenoglicol , Aprendizado de Máquina , Algoritmos , Análise por Conglomerados , Redes Neurais de Computação
16.
J Mol Graph Model ; 107: 107966, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34174555

RESUMO

Deep-eutectic solvents (DESs) gained attention of researchers as green solvents. Making binary mixtures of DESs with appropriate cosolvents is a strategy to obtain more favorable mixtures. Here, structural features and hydrogen bonding (H-bonding) properties of binary mixtures containing ethaline (ETH) DES, (choline chloride (ChCl):2 ethylene glycol (EG)) with N,N-dimethylformamide (DMF) are reported. Such investigations are carried out by density functional theory (DFT) calculations. The results show that in ETH-DMF mixtures, DMF molecules can hardly overcome the strong Columbic interaction and doubly ionic H-bonds between the ions Ch+ and Cl- or the ionic H-bonds between Ch+ and EG. Upon EG addition to ChCl to obtain ETH or DMF addition to ETH, the Cl- … Ch+ connectivity decreases, implying charge delocalization from Cl- to other components rather than Ch+. This is supported by the blue shift of Ch+ hydroxyl observed in the calculated infrared spectra.


Assuntos
Dimetilformamida , Glicerol , Colina , Etilenoglicol , Solubilidade , Solventes
17.
Theriogenology ; 172: 47-54, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34098168

RESUMO

Protein-free media are essential for the sanitary cryopreservation of bovine genetic resources. Our aim was to set up an optimized protocol for the vitrification of immature bovine oocytes using protein free media which can provide the highest embryo development rates and embryo quality after subsequent in vitro maturation and fertilization. First, using a protein free NCSU-37 as base medium we compared the efficacy of vitrification on Cryotop device with two different CPA protocols. "Protocol A″ employed a combination of ethylene glycol and propylene glycol as permeating cryoprotectants (pCPA) and equilibration in 4% total pCPA (2% ethylene glycol + 2% propylene glycol). "Protocol B″ employed a combination of ethylene glycol and DMSO and equilibration in 15% total pCPA (7.5% ethylene glycol + 7.5% DMSO). The 2 protocols were equally effective in terms of oocyte survival and subsequent development to the blastocyst stage. However, blastocyst cell numbers were significantly higher with "Protocol A". TCM-199 and NCSU-37 were equally effective as base media for vitrification. Vitrification with "Protocol A″ reduced the percentage of live oocytes and subsequent development to blastocyst stage but did not affect the hatching and cell numbers of blastocysts when compared to the non-treated group. CPA treatment of "Protocol A″ without cooling did not affect embryo development. Storage of ovaries in PBS at 15 °C for overnight reduced the percentage of surviving oocytes after vitrification but not their subsequent development to the blastocyst stage. In conclusion we established a vitrification protocol for the cryopreservation of immature bovine oocytes employing protein-free media which provided high blastocyst quality without noticeable toxic effects.


Assuntos
Ovário , Vitrificação , Animais , Blastocisto , Bovinos , Protocolos Clínicos , Criopreservação/veterinária , Crioprotetores/farmacologia , Meios de Cultura Livres de Soro , Etilenoglicol/farmacologia , Feminino , Fertilização In Vitro/veterinária , Oócitos
18.
Cryobiology ; 101: 67-77, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34077709

RESUMO

Stallion sperm is typically cryopreserved using low cooling rates and low concentrations of cryoprotective agents (CPAs). The inevitable water-to-ice phase transition during cryopreservation is damaging and can be prevented using vitrification. Vitrification requires high cooling rates and high CPA concentrations. In this study, the feasibility of stallion sperm vitrification was investigated. A dual-syringe pump system was used to mix sperm equilibrated in a solution with a low concentration of CPAs, with a solution containing a high CPA concentration, and to generate droplets of a defined size (i.e., ~20 µL) that were subsequently cooled by depositing on an aluminum alloy block placed in liquid nitrogen. Mathematical modeling was performed to compute the heat transfer and rate of cooling. The minimum CPA concentration needed for vitrification was determined for various CPAs (glycerol, ethylene glycol, propylene glycol, dimethyl sulfoxide) and combinations thereof, while effects of droplet size and carrier solution were also identified. Sperm vitrification was eventually done using a glycerol/propylene glycol (1/1) mixture at a final concentration of 45% in buffered saline supplemented with 3% albumin and polyvinylpyrrolidon, while warming was done in standard diluent supplemented with 100 mM sucrose. The sperm concentration was found to greatly affect sperm membrane integrity after vitrification-and-warming, i.e., was found to be 21 ± 12% for 10 × 106 sperm mL-1 and 54 ± 8% for 1 × 106 sperm mL-1. However, an almost complete loss of sperm motility was observed. In conclusion, successful sperm vitrification requires establishing the narrow balance between droplet size, sperm concentration, CPA type and concentration, and exposure time.


Assuntos
Crioprotetores , Preservação do Sêmen , Animais , Criopreservação/métodos , Crioprotetores/farmacologia , Dimetil Sulfóxido/farmacologia , Etilenoglicol/farmacologia , Cavalos , Masculino , Preservação do Sêmen/veterinária , Motilidade Espermática , Espermatozoides , Vitrificação
19.
Sci Total Environ ; 792: 148435, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34147796

RESUMO

A diesel engine running on diesel/biodiesel mixtures containing ethylene glycol diacetate (EGDA) was investigated from the exergoeconomic and exergoenvironmental viewpoints. Biodiesel was mixed with petrodiesel at 5% and 20% volume ratios, and the resultant mixtures were then doped with EGDA at 1-3% volume ratios. The exergetic sustainability indicators of the engine operating on the prepared fuel formulations were determined at varying engine loads. The indicators were selected to support decision-making on fuel composition and engine load following thermodynamic, economic, and environmental considerations. The engine load markedly affected all the studied exergetic parameters. The highest engine exergetic efficiency (39.5%) was obtained for petrodiesel doped with 1 v/v% EGDA at the engine load of 50%. The minimum value of the unit cost of brake power exergy (49.6 US$/GJ) was found for straight petrodiesel at full-load conditions, while the minimum value of the unit environmental impact of brake power exergy (29.9 mPts/GJ) was observed for petrodiesel mixed with 5 v/v% biodiesel at the engine load of 75%. Overall, adding EGDA to fuel mixtures did not favorably influence the outcomes of both exergetic methods due to its energy-intensive and cost-prohibitive production process. In conclusion, although petrodiesel fuel improvers such EGDA used in the present study could properly mitigate pollutant emissions, the adverse effects of such additives on thermodynamic parameters of diesel engines, particularly on exergoeconomic and exergoenvironmental indices, need to be taken into account, and necessary optimizations should be made before their real-world application.


Assuntos
Biocombustíveis , Poluentes Ambientais , Etilenoglicol , Gasolina , Emissões de Veículos
20.
Molecules ; 26(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068693

RESUMO

The intracellular environment is overcrowded with a range of molecules (small and large), all of which influence protein conformation. As a result, understanding how proteins fold and stay functional in such crowded conditions is essential. Several in vitro experiments have looked into the effects of macromolecular crowding on different proteins. However, there are hardly any reports regarding small molecular crowders used alone and in mixtures to observe their effects on the structure and stability of the proteins, which mimics of the cellular conditions. Here we investigate the effect of different mixtures of crowders, ethylene glycol (EG) and its polymer polyethylene glycol (PEG 400 Da) on the structural and thermal stability of myoglobin (Mb). Our results show that monomer (EG) has no significant effect on the structure of Mb, while the polymer disrupts its structure and decreases its stability. Conversely, the additive effect of crowders showed structural refolding of the protein to some extent. Moreover, the calorimetric binding studies of the protein showed very weak interactions with the mixture of crowders. Usually, we can assume that soft interactions induce structural perturbations while exclusion volume effects stabilize the protein structure; therefore, we hypothesize that under in vivo crowded conditions, both phenomena occur and maintain the stability and function of proteins.


Assuntos
Substâncias Macromoleculares/química , Mioglobina/química , Redobramento de Proteína , Temperatura , Animais , Difusão Dinâmica da Luz , Etilenoglicol/química , Fluorescência , Guanidina/farmacologia , Cavalos , Hidrodinâmica , Simulação de Acoplamento Molecular , Polietilenoglicóis/química , Conformação Proteica , Desnaturação Proteica/efeitos dos fármacos , Redobramento de Proteína/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos
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