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3.
Rev Med Suisse ; 16(683): 404-408, 2020 Feb 26.
Artigo em Francês | MEDLINE | ID: mdl-32129017

RESUMO

Cheap and easy to access, ethylene glycol is used in the synthesis of antifreezes. Intoxication has potentially irreversible morbid consequences. Ingestion of a small amount can lead to death. Due to its ubiquitous distribution and potential complications, it is of paramount importance for the practitioner to recognize its manifestations and metabolic complications in order to implement its therapy in partnership with the nephrologist and the intensivist. A successful treatment depends on rapid and multidisciplinary management, as reviewed in this article.


Assuntos
Etilenoglicol/toxicidade , Nefropatias/induzido quimicamente , Humanos
4.
PLoS One ; 15(3): e0229939, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130274

RESUMO

OBJECTIVE: This study aims to provide basic data on the types and frequency of chemical ingestions and the clinical outcomes of chemical ingestion injury. METHODS: This study retrospectively analyzed the data obtained from the Emergency Department-Based Injury In-depth Surveillance of the Korea Centers for Disease Control and Prevention (South Korea) from 2011 to 2016. Patients ingesting chemicals aged ≥ 18 years were included, but those ingesting unknown chemical substances or with unknown clinical outcomes were excluded. RESULTS: This study included 2,712 (47.2% were men and 52.8% were women, mean age, 47.05 years) patients ingesting chemicals. Unintentional and intentional ingestions were reported in 1,673 (61.7%) and 1,039 (38.3%), respectively. The most commonly ingested chemical substances were hypochlorites, detergents, ethanol, and acetic acid. In the unintentional ingestion group, the most common chemicals upon admission were hypochlorites (74), glacial acetic acid (60), and detergent (33). The admission rates were 60% for glacial acetic acid, 58.3% ethylene glycol, and 30.4% other alkali agents. In the intentional ingestion group, the most common chemicals upon admission were hypochlorites (242), glacial acetic acid (79), ethylene glycol (42), and detergent (41). The admission rates were 91.9% for glacial acetic acid, 87.5% ethylene glycol, 85.7% potassium cyanide, and 81.4% hydrochloric acid. In total, 79 deaths (10 unintentional ingestions, 69 intentional ingestion) were reported, and glacial acetic acid had an odds ratio of 9.299 for mortality. CONCLUSION: We compared the intentional and unintentional ingestion groups, and analyzed the factors affecting hospital admission and mortality in each group. The types and clinical outcomes of chemical ingestion varied depending on the purpose of chemical ingestion. The findings are considered beneficial in establishing treatment policies for patients ingesting chemicals.


Assuntos
Ingestão de Alimentos , Substâncias Perigosas/toxicidade , Envenenamento/epidemiologia , Ácido Acético/toxicidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antídotos/uso terapêutico , Detergentes/toxicidade , Serviço Hospitalar de Emergência/estatística & dados numéricos , Etanol/toxicidade , Etilenoglicol , Feminino , Humanos , Ácido Hipocloroso/toxicidade , Masculino , Pessoa de Meia-Idade , Centros de Controle de Intoxicações/estatística & dados numéricos , Envenenamento/fisiopatologia , República da Coreia/epidemiologia , Adulto Jovem
5.
Waste Manag ; 105: 309-316, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32097877

RESUMO

The recycling of packaging plastics is hindered by the various plastic mixtures and their similar surface properties. Plastic separation is a key step to improve recycling efficiency of waste plastics. We proposed a simple and efficient protocol to separate polyethylene terephthalate (PET) from polycarbonate (PC), acrylonitrile-butadienestyrene copolymer (ABS), and polyvinyl chloride (PVC) by converting PET surface from hydrophobicity to hydrophilicity. PET surface was modified by potassiumhydroxide (KOH)and ethylene glycol ((CH2OH)2) with the aid of sonication. Contact angle, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were used to research the reactions on PET surface. It can be confirmed that the reaction of base-catalyzed transesterification occurs, leading to a hydrophilic PET plastic. We investigated the effects of ultrasonic power, ultrasonic time, (CH2OH)2 dosage, KOH dosage, flotation time, and frother concentration on the flotation separation. The flotation recovery and purity of PET are 98.8% and 100%, respectively when (CH2OH)2 dosage is 10 mL, KOH dosage is 2 g, ultrasonic time is 5 min, ultrasonic intensity is 160 W, flotation time is 4 min, and frother concentration is 52.7 mg/L. This study provided a novel surface modification with reliable mechanisms for the flotation of PET from plastic mixtures.


Assuntos
Plásticos , Eliminação de Resíduos , Etilenoglicol , Polietilenotereftalatos , Cloreto de Polivinila , Reciclagem , Sonicação
6.
Nat Commun ; 11(1): 721, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024848

RESUMO

Myo-inositol hexakisphosphate (IP6) is a natural product known to inhibit vascular calcification (VC), but with limited potency and low plasma exposure following bolus administration. Here we report the design of a series of inositol phosphate analogs as crystallization inhibitors, among which 4,6-di-O-(methoxy-diethyleneglycol)-myo-inositol-1,2,3,5-tetrakis(phosphate), (OEG2)2-IP4, displays increased in vitro activity, as well as more favorable pharmacokinetic and safety profiles than IP6 after subcutaneous injection. (OEG2)2-IP4 potently stabilizes calciprotein particle (CPP) growth, consistently demonstrates low micromolar activity in different in vitro models of VC (i.e., human serum, primary cell cultures, and tissue explants), and largely abolishes the development of VC in rodent models, while not causing toxicity related to serum calcium chelation. The data suggest a mechanism of action independent of the etiology of VC, whereby (OEG2)2-IP4 disrupts the nucleation and growth of pathological calcification.


Assuntos
Fosfatos de Inositol/química , Fosfatos de Inositol/farmacologia , Calcificação Vascular/tratamento farmacológico , 6-Fitase/metabolismo , Adenina/efeitos adversos , Animais , Células Cultivadas , Avaliação Pré-Clínica de Medicamentos/métodos , Difusão Dinâmica da Luz , Etilenoglicol/química , Humanos , Injeções Subcutâneas , Fosfatos de Inositol/farmacocinética , Masculino , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Ratos Sprague-Dawley , Uremia/tratamento farmacológico , Uremia/fisiopatologia , Calcificação Vascular/induzido quimicamente , Difração de Raios X
7.
Anal Bioanal Chem ; 412(8): 1795-1806, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31982923

RESUMO

Biopharmaceuticals are in direct contact with different plastic materials, which can contribute to process-related impurities. Polyethylene terephthalate glycol (PETG) is used for storage and transportation of biopharmaceuticals and it is synthetized from the poly-condensation reaction between ethylene glycol, 1,4-cyclodimethanol and dimethyl terephthalate. PETG bottles are analyzed for such impurities prior to release; however, the nature of the pharmaceutical matrix can extract impurities, so it is important to measure these contaminants in biopharmaceuticals. This study shows a liquid chromatography method for the quantification of ethylene glycol in PETG materials as an alternative to the standard USP colorimetric method. The method is based on the derivatization of ethylene glycol with benzoyl chloride in a Schotten-Baumann reaction. We present a comprehensive method development and validation. The method allows the detection and quantification of leached and extracted ethylene glycol directly in biopharmaceuticals after years of storage in contact with PETG bottles. Results showed residual ethylene glycol in drug substances to a level of ≈  0.1-0.5 µg/mL exposed during 2-6 years of storage in PETG bottles and ≈ 0.2-0.9 µg/mL in biopharmaceuticals. Graphical abstract Biopharmaceuticals must be free or low concentration for leachables, FR-UHPLC-UV analysis is a precise and accurate analytical method for ethylene glycol measurement. This leachable is commonly present in products in direct contact with PETG plastic.


Assuntos
Produtos Biológicos/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia de Fase Reversa/métodos , Etilenoglicol/análise , Limite de Detecção , Plásticos/química , Polímeros/química , Reprodutibilidade dos Testes
8.
J Chromatogr A ; 1612: 460653, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-31706581

RESUMO

We introduce an integrated chip-approach for a postcolumn segmentation of normal phase liquid chromatography. This is achieved by the seamless integration of a chiral NP-chip-HPLC column, a flow-focusing droplet generator, and a segmented flow channel in a single microfluidic glass chip. This allows a continuous segmentation of the eluent into droplets which are picked up and transported via an immiscible continuous phase. The combination of NP-chip-HPLC and droplet microfluidics enables to fractionate and conserve chromatographic runs for further downstream processes at picoliter scale. An essential aspect is the proper choice of the continuous phase concerning polarity, wetting properties and viscosity. For this purpose, ethylene glycol is introduced which facilitates this first combination of normal phase chromatography and droplet microfluidics. By adjusting the flow rates and varying the generator geometry, the size and frequency of the droplets could be precisely controlled.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Etilenoglicol/química , Heptanos/química , Dispositivos Lab-On-A-Chip , Microfluídica/instrumentação , Microfluídica/métodos , Viscosidade
9.
Magn Reson Chem ; 58(2): 163-169, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31671221

RESUMO

The chemical shift difference, Δσ, between the methylene and hydroxyl protons in the high resolution 1 H nuclear magnetic resonance spectrum of ethylene glycol is shown to be pressure dependent. The equilibrium Δσ values for ethylene glycol are reported as a function of temperature and pressure between ambient conditions, 323 K and 2 kbar, respectively. This surface is used along with Δσ values measured in response to a rapid pressure increase to calculate a temperature rise that is used to infer a temperature change for water that is consistent with theoretical estimates. This work implies that compression heating and decompression cooling are not significant enough to interfere with pressure induced protein folding studies.


Assuntos
Temperatura Baixa , Etilenoglicol/química , Temperatura Alta , Fenômenos Físicos , Pressão , Espectroscopia de Prótons por Ressonância Magnética
10.
PLoS One ; 14(12): e0225784, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31790487

RESUMO

Our primary goal is to therapeutically target the oncogenic transcription factor MYC to stop tumor growth and cancer progression. Here, we report aspects of the biophysical states of the MYC protein and its interaction with one of the best-characterized MYC cofactors, TRansactivation/tRansformation-domain Associated Protein (TRRAP). The MYC:TRRAP interaction is critical for MYC function in promoting cancer. The interaction between MYC and TRRAP occurs at a precise region in the MYC protein, called MYC Homology Box 2 (MB2), which is central to the MYC transactivation domain (TAD). Although the MYC TAD is inherently disordered, this report suggests that MB2 may acquire a defined structure when complexed with TRRAP which could be exploited for the investigation of inhibitors of MYC function by preventing this protein-protein interaction (PPI). The MYC TAD, and in particular the MB2 motif, is unique and invariant in evolution, suggesting that MB2 is an ideal site for inhibiting MYC function.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Intrinsicamente Desordenadas/química , Proteínas Nucleares/química , Proteínas Proto-Oncogênicas c-myc/química , Etilenoglicol/farmacologia , Células HEK293 , Humanos , Ligação Proteica/efeitos dos fármacos , Conformação Proteica , Estabilidade Proteica , Espectroscopia de Prótons por Ressonância Magnética
11.
Int J Mol Sci ; 20(24)2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31817544

RESUMO

(+)-(S) and (-)-(R)-5-methyl-Wieland-Miescher ketone (+)-1 and (-)-1, are important synthons in the diastereo and enantioselective syntheses of biological and/or pharmacological interesting compounds. A key step in these syntheses is the chemoselective C(1)O acetalization to (+)-5 and (-)-5, respectively. Various procedures for this transformation have been described in the literature. Among them, the classical procedure based on the use of 1,2-ethanediol and TsOH in refluxing benzene in the presence of a Dean-Stark apparatus. Within our work on bioactive natural products, it occurred to us to observe the partial racemization of (+)-5 in the course of the acetalization of (+)-1 by means of the latter methodology. Aiming to investigate this drawback, which, to our best knowledge, has no precedents in the literature, we acetalized with 1,2-ethanediol and TsOH in refluxing benzene and in the presence of a Dean-Stark apparatus under various experimental conditions, enantiomerically pure (+)-1. It was found that the extent of racemization depends on the TsOH/(+)-1 and 1,2-ethanediol/(+)-1 ratios. Mechanism hypotheses for this partial and unexpected racemization are provided.


Assuntos
Etilenoglicol/química , Cetonas/química , Modelos Químicos , Estereoisomerismo
12.
Praxis (Bern 1994) ; 108(16): 1097-1099, 2019.
Artigo em Alemão | MEDLINE | ID: mdl-31822237

RESUMO

A Sweet Drink with Consequences Abstract. Intoxications with ethylene glycol are rare, however, small quantities from the substance can be life-threatening. Regarding the treatment it is important to recognize the intoxication quickly and to immediately start the appropriate treatment. Intoxications with ethylene glycol or with methanol should always be considered as differential diagnosis in patients with severe metabolic acidosis. It is also very important to calculate the osmolal gap.


Assuntos
Etilenoglicol , Metanol , Diagnóstico Diferencial , Etilenoglicol/envenenamento , Humanos , Metanol/envenenamento , Envenenamento/diagnóstico
13.
Int J Nanomedicine ; 14: 8739-8751, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31806968

RESUMO

Objective: Nintedanib (NDNB) is a triple receptor tyrosine kinase inhibitor with poor solubility in neutral conditions and low bioavailability. A self-microemulsifying drug delivery system (SMEDDS) of NDNB was developed to improve drug solubility in physical conditions and absorption in vivo. Methods: The NDNB-SMEDDS formulation was optimized via pseudo-ternary phase diagrams. The physicochemical properties of NDNB-SMEDDS, viz., morphological observation, droplet size, stability, compatibility and in vitro release were investigated. The permeability of NDNB-SMEDDS was detected using both a Caco-2 cell monolayer in vitro and an intestinal perfusion study in vivo. Furthermore, the pharmacokinetic characteristics of NDNB-SMEDDS were evaluated. Results: The optimal formulation was composed of MCT as an oil phase, RH 40 as a surfactant and ethylene glycol as a co-surfactant. The average droplet size of the microemulsion was about 23 nm with good stability within 30 days. The formulation did not exhibit any obvious cytotoxic effect on Caco-2 cells. Permeability of nintedanib in a Caco-2 cell monolayer was enhanced by 2.8-fold upon incorporation in SMEDDS compared with the drug solution. The intestinal perfusion study demonstrated that the P app of NDNB-SMEDDS increased by 3.0-fold in the entire intestine and 3.2-fold in the colon in comparison with the drug solution. The pharmacokinetics study showed that the AUC of the NDNB-SMEDDS increased significantly. Conclusion: This study showed that the self-microemulsion formulations could improve the absorption of nintedanib, and can thus serve as a promising carrier for the oral delivery of nintedanib.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Emulsões/administração & dosagem , Indóis/administração & dosagem , Indóis/farmacocinética , Administração Oral , Animais , Disponibilidade Biológica , Células CACO-2 , Liberação Controlada de Fármacos , Emulsões/química , Emulsões/farmacocinética , Etilenoglicol/química , Humanos , Masculino , Permeabilidade , Ratos Sprague-Dawley , Solubilidade , Tensoativos/química
14.
Cryobiology ; 91: 53-60, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31678072

RESUMO

The objective was to evaluate different permeating cryoprotectants to vitrify testicular tissue biopsies from adult collared peccaries. Five pairs of testicles were dissected into fragments (9 mm³) that were allocated to non-vitrified (control) and vitrified groups using a solid-surface method following exposure to different cryoprotectants (3.0 M dimethyl sulfoxide (DMSO), 3.0 M ethylene glycol (EG) or 1.5 M DMSO + 1.5 M EG). After warming, samples were evaluated for histomorphology, ultrastructure, viability, and proliferative capacity potential. The appropriate conservation of the ultrastructural organization of the seminiferous tubule in terms of lumen presence and cell junctions was only observed at the use of DMSO/EG combination. Regardless of the cryoprotectant, the vitrification effectively preserved cell nuclear visualization and condensation similarly as observed at the non-vitrified group. Moreover, DMSO/EG combination provided a better preservation of basal membranes of seminiferous tubules than DMSO (P < 0.05). The occurrence of cell swelling was more evident in the use of DMSO than EG (P < 0.05), but both isolate cryoprotectants were similar to the DMSO/EG combination. Only the DMSO/EG combination maintained the proliferative capacity potential for spermatogonia (3.69 NORs/cell) and Sertoli cell (3.19 NORs/cell) similar to controls (3.46 and 3.31 NORS/cell, respectively). Moreover, ~40% cell viability was found after vitrification independent of cryoprotectant. In conclusion, DMSO/EG in combination is better than DMSO or EG alone for SSV of testicular tissue biopsies from adult collared peccaries.


Assuntos
Criopreservação/veterinária , Crioprotetores/farmacologia , Dimetil Sulfóxido/farmacologia , Etilenoglicol/farmacologia , Testículo/citologia , Animais , Artiodáctilos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Criopreservação/métodos , Crioprotetores/química , Feminino , Masculino , Vitrificação
15.
Molecules ; 24(22)2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31739495

RESUMO

Dendrons consisting of two phosphonate functions and three oligo(ethylene glycol) (OEG) chains grafted on a central phenoxyethylcarbamoylphenoxy group were synthesized and investigated as Langmuir monolayers at the surface of water. The OEG chain in the para position was grafted with a t-Bu end-group, a hydrocarbon chain, or a partially fluorinated chain. These dendrons are models of structurally related OEG dendrons that were found to significantly improve the stability of aqueous dispersions of iron oxide nanoparticles when grafted on their surface. Compression isotherms showed that all OEG dendrons formed liquid-expanded Langmuir monolayers at large molecular areas. Further compression led to a transition ascribed to the solubilization of the OEG chains in the aqueous phase. Brewster angle microscopy (BAM) provided evidence that the dendrons fitted with hydrocarbon chains formed liquid-expanded monolayers throughout compression, whilst those fitted with fluorinated end-groups formed crystalline-like domains, even at large molecular areas. Dimyristoylphosphatidylcholine and dendron molecules were partially miscible in monolayers. The deviations to ideality were larger for the dendrons fitted with a fluorocarbon end-group chain than for those fitted with a hydrocarbon chain. Brewster angle microscopy and atomic force microscopy supported the view that the dendrons were ejected from the phospholipid monolayer during the OEG conformational transition and formed crystalline domains on the surface of the monolayer.


Assuntos
Dendrímeros/química , Etilenoglicol/química , Fosfolipídeos/química , Água/química , Ar , Microscopia de Força Atômica , Propriedades de Superfície
16.
Artigo em Chinês | MEDLINE | ID: mdl-31594136

RESUMO

Objective: To development of ethylene glycol samples in silicone tubes, and the samples were applied to inter-laboratory comparison, through it to evaluate the detection capacity of occupational health testing laboratories. Methods: Three content levels of ethylene glycol samples in silicone tubes were prepared, and the homogeneity and stability of samples were investigated, the results were statistically analyzed. A robust statistical four-point distance method was used to calculate the results submitted by each participant laboratory and the test capability of the laboratory was assessed by the z-score method. Results: The statistic of the homogeneity of ethylene glycol samples in silicone tubes were less than the critical value (P>0.05) , and the samples were stable at room temperature for one month. The satisfactory rate of comparison between 204 laboratories was 88.24%. Conclusion: The homogeneity and stability of the ethylene glycol samples in the silicone tubes can meet the requirements of proficiency testing and can be used for laboratory comparison. Most of the laboratories that participated in the comparison had the ability to detect ethylene glycol.


Assuntos
Etilenoglicol , Laboratórios/normas , Silicones , Saúde do Trabalhador
17.
Cryobiology ; 91: 77-83, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31639331

RESUMO

This study aimed to evaluate different vitrification methods using distinct cryoprotectants (CPAs) for the preservation of collared peccary ovarian preantral follicles (PFs). Ovarian pairs from six females were fragmented and three fragments (fresh control group) were immediately evaluated for morphology, viability, cell proliferation capacity (assessed by quantifying the number of argyrophilic nucleolus organizer regions - NORs), and apoptosis (by the identification of activated caspase-3 expression). The remaining 18 fragments were vitrified using the solid surface vitrification (SSV) method or the ovarian tissue cryosystem (OTC) with 3 M ethylene glycol (EG), 3 M dimethylsulfoxide (DMSO), or a combination of the two (1.5 M EG/1.5 M DMSO). After two weeks, samples were rewarmed and evaluated as described previously. The OTC with any of the CPAs provided a similar conservation of morphologically normal PFs as the fresh control group (75.6 ±â€¯8.6%); however, the SSV was only efficient with DMSO alone (63.9 ±â€¯7.6%). Regarding the viability or cell proliferation, all tested groups provided post rewarming values similar to those observed for the fresh control group, 84.0 ±â€¯2.9% viable cells with 2.0 ±â€¯0.2 NORs. Related to apoptosis analysis, only the OTC with EG (46.7%) and the SSV method with EG (43.4%) or the combination of EG and DMSO (33.4%) provided similar values to those found for the fresh control group (36.7%). Our findings indicate the utilization of a closed system, the OTC, with 3 M EG as the CPA for the vitrification of collared peccary ovarian tissue.


Assuntos
Artiodáctilos/fisiologia , Criopreservação/veterinária , Crioprotetores/farmacologia , Dimetil Sulfóxido/farmacologia , Etilenoglicol/farmacologia , Folículo Ovariano/fisiologia , Animais , Apoptose/efeitos dos fármacos , Contagem de Células , Proliferação de Células/efeitos dos fármacos , Criopreservação/métodos , Feminino , Folículo Ovariano/citologia , Vitrificação
18.
Analyst ; 144(21): 6327-6333, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31552929

RESUMO

A protein-based molecularly imprinted monolithic column was synthesized based on ionic liquids (ILs) and deep eutectic solvents (DESs) in a stainless steel column (50 mm × 4.6 mm id). An IL (1-allyl-3-butylimidazolium Br) and acrylamide were used as dual monomers. Another type of IL (1,2-bis [N,N'-vinylimidazolium] ethane bis Br) and N,N'-methylenebisacrylamide were used as dual cross-linking agents, and the DES (choline chloride : ethylene glycol 1 : 2) was used as a porogen in the preparation of a monolithic polymer. Bovine serum albumin (BSA) and lysozyme (Lyz), which differ greatly in molecular size, isoelectric point, and charge, were selected for imprinting templates to evaluate the recognition property of the green solvent-based MIP monolithic column. Some important factors, such as template-monomer molar ratio, total monomer concentration, and cross-linking density, were investigated systematically. Under optimal conditions, the MIP monolithic column obtained showed higher binding affinity for the templates than its corresponding non-imprinted (NIP) monolithic column.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Impressão Molecular , Muramidase/isolamento & purificação , Polímeros/química , Soroalbumina Bovina/isolamento & purificação , Solventes/química , Acrilamidas/química , Animais , Bovinos , Galinhas , Colina/química , Cromatografia Líquida de Alta Pressão/instrumentação , Reagentes para Ligações Cruzadas , Etilenoglicol/química , Química Verde/métodos , Líquidos Iônicos/química
19.
Comput Methods Programs Biomed ; 182: 105057, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31499421

RESUMO

BACKGROUND: Here we have conducted a magnetohydrodynamic (MHD) flow of viscous material with alumina water and ethylene glycol over a stretched surface. The flow is discussed with and without effective Prandtl number. MHD liquid is considered. Electric field is absent. Effect of uniform magnetic field is taken in the vertical direction to the surface. Influence of thermal radiation as well as Joule heating are taken into account for both aluminum oxide-water and aluminum oxide-Ethylene glycol nanofluids. Velocity slip and melting heat effects are considered. METHODS: The nonlinear flow expressions are numerically solved via ND-solve technique (built-in-Shooting). RESULTS: The physical impacts of flow variables like mixed convection parameter, magnetic parameter, Reynold number, Eckert number, melting parameter and heat source/sink parameter are graphically discussed. Moreover, entropy generation (irreversibility) and Bejan number are discussed graphically through various flow variables. Physical quantities like skin friction coefficient and Sherwood and Nusselt numbers are numerically calculated and discussed through Tables. CONCLUSIONS: Impact of magnetic and slip parameters on the velocity field show decreasing behavior for both effective and without effective Prandtl number. Temperature field increases for both effective and without effective Prandtl number for higher values of magnetic and radiative parameters. Entropy number is an increasing function of Reynolds number while Bejan number shows opposite impact against Reynolds number. Moreover, heat transfer rate upsurges versus larger melting and radiative parameter.


Assuntos
Alumínio/química , Entropia , Etilenoglicol/química , Hidrodinâmica , Modelos Teóricos , Nanopartículas/química
20.
Biosens Bioelectron ; 143: 111636, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31476596

RESUMO

Ketamine is one of the most widely abused drugs in the world and poses a serious threat to human health and social stability; therefore, the ability to accurately monitor the substance in real-time is necessary. However, several problems still exists towards this goal, such as the generally low concentration of the target molecules disturbed in the complex samples that undergo analysis during criminal investigations. In this work, the sensitive and selective detection of ketamine was accomplished by molecularly imprinted electrochemical sensor. The molecularly imprinted membrane as a biomimetic recognition element was fabricated by the UV-induced polymerization of methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) on a metal-organic framework/graphene nanocomposite (MOFs@G) modified screen-printed electrode. The screen printed electrode (SPE) provided good adhesion for the formation of the imprinted membranes and increased the stability of the sensor. The morphology and performance of the imprinted films were characterized in detail by scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The experimental results demonstrated that the imprinted sensor had excellent sensitivity, selectivity, and long-term stability. It offered a low detection limit (4.0 × 10-11 mol L-1) and had a dynamic range from 1.0 × 10-10 mol L-1 to 4.0 × 10-5 mol L-1. Furthermore, the established method was successfully applied for the determination of ketamine in urine and saliva samples.


Assuntos
Técnicas Biossensoriais , Grafite/isolamento & purificação , Ketamina/isolamento & purificação , Impressão Molecular , Etilenoglicol/química , Grafite/química , Humanos , Ketamina/química , Estruturas Metalorgânicas/química , Metacrilatos/química , Nanocompostos/química
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