Polyethylene Glicol Research Articles

Acetylcholinesterase entrapment onto carboxyl-modified single-walled carbon nanotubes and poly (3,4-ethylenedioxythiophene) nanocomposite, film electrosynthesis characterization, and sensor application for dichlorvos detection in apple juice

Carboxylic acid functionalized single-walled carbon nanotubes and poly (3,4-ethylenedioxythiophene), C-SWCNT:PEDOT, were homogenously electrodeposited onto working electrodes (WE) in order to develop an acetylcholinesterase (AChE)-based biosensor. RAMAN, FTIR, SEM, EDX and electrochemical methods provided evidence for the enzyme immobilization and the conducting composite formation. The SWCNT dissolved in poly (sodium 4-styrenesulphonate) (PSS), and 3,4-ethylenedioxythiophene (EDOT) dissolved in polyethyleneglicol (PEG) were used for composite electrodeposition to provide a homogenous layer and a compatible environment around the AChE. The composite C-SWCNT:PEDOT has proved to be highly efficient for retaining the activity and stability of AChE and also for promoting the electron transfer reaction to the gold electrode. Under optimized experimental conditions, the inhibition of dichlorvos (DVSO) on AChE showed a proportional inhibition current signal with increasing concentrations of DVSO in the range 1 ppb to 600 ppb. The correlation coefficient obtained with spectrophotometer enzyme assay method versus a biosensor was 0.989. It showed high accuracy, precision. The detection limits were 5.54 ppb using the CA method and 0.447 ppb using differential pulse voltammetry (DPV). Both values are below the permitted limit for DVSO in fruit and vegetables. The sensor showed stability and could be used as a disposable amperometric sensor with potential application for monitoring organophosphorus pesticides.

Effect of Kirinyuh Leaf Extract (Cromolaena odorata [L.] R.M. King & H. Rob) On Rice Paddy Growth (Oryza sativa L.) Variety of Mekongga in Drought Stress Condition

The purpose of this research was to know whether kirinyuh leaf water extract could improve the growth of mekongga varieties rice paddy under the condition of drought stress.This research was conducted at Botanical Laboratory of Biology Department Faculty of Mathematics and Natural Sciences University of Lampung from September to October 2017. The research was conducted in a 3 x 2 factorial experiment. Factor A was Polyethylene glicol 6000 with 3 levels of concentration: 0% w / v, 15% w / v, and 30% w / v. Factor B was kirinyuh leaf water extract with 2 concentration levels: 0% w / v and 2% w / v. As parameters were the mean of shoots length, fresh weight, dry weight, and the relative water content of rice seedling. Levene test, analysis of vaiance, and Tukey test were performed at 5% significant level. The results showed that water extract of kirinyuh leaves had no significant effect on shoot length, fresh weight, and dry weight of rice seedling, but influenced the relatife water content of rice seedling. From the result of research it was concluded that kirinyuh leaf water extract can not improve the growth of Mekongga rice paddy varieties at drougth stress condition

Preparation and characterization of maltodextrin-based polyurethane

Maltodextrin (MD) based polyurethane (MDPU) was prepared by the reaction of MD and polyethyleneglicol (PEG) polyurethane prepolymer (PUP). The structure and properties of the MDPU were investigated by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscope (SEM), Energy dispersive X-ray spectrometry (EDS), and tensile-testing machine in detail. Chemical structure of MDPU was confirmed by FTIR and 1H NMR. MDPU with 66.7% of PUP (MDPU-0.5) was a thermoset plastic with good elasticity but the others (MDPU-1, MDPU-2, and MDPU-3) were thermoplastics. TGA analysis showed that the MDPUs exhibited three stages of the thermal degradation, mainly including urethane linkage (I, 197–268 °C), MD and PUP components (II, 268–380 °C) and the formed stable structures during thermal degradation (III, 400–505 °C), respectively. The various degrees of miscibility were presented. The mechanical properties of thermoplastic MDPUs exhibited relatively high elongation at break under the given relative humidity.

The effect of amphipilic lignin derivatives addition on enzymatic hydrolysis performance of kraft pulp from sorghum bagasse

Previously, the chemical characteristics of isolated lignin from Acacia mangium black liquor of kraft pulping was characterized. This lignin was blended with natural rubber latex (NR-L) as adhesive in laminated wood. In addition, lignin has potency for biosurfactant materials by modification of the hydrophobic into hydrophilic properties. Therefore, this study was intended to develop lignin as material for amphipilic lignin derivatives (A-LD) biosurfactant by reacting lignin with epoxilated polyethylene glicol (PEG). A-LD addition in slurries was used to improve the enzymatic hydrolysis (EH) of kraft pulp sweet bagasse sorghum (SSB). The main observation in EH performance was to investigate the effect of lignin isolation method (one and two step) in A-LD and A-LD loading addition on reducing sugar yield (RSY) of SSB kraft pulp. The pulp was hydrolyzed at 50°C and 150 rpm for 72 h with 10 FPU cellulase loading in the shaking incubator. A-LD from one (L1S) and two step (L2S) lignin was added with A-LD loading of 0, 1, 2, 5, and 10% (b/v). The RSY of hydrolyzate has been observed after EH. A-LDs addition in EH of SSB kraft pulp enhanced RSY. L1S worked better in reaction performance with PEDGE compared to L2S and LS. A better performance was showed by PEDGE 500 than that of PEDGE 6000. Generally, the higher A-LDs loading resulted higher RSY. The highest RSY (81.33%) was resulted in addition of 10% A-LD L1S using PEDGE 500. A 5% A-LD loading was more considered to be added in EH because the RSY was comparable with 10% A-LD loading.

ENHANCING ANTIFUNGAL CANDIDA ALBICANS ACTIVITY OF Piper bettle LINN. LEAF ESSENTIAL OIL OINTMENT THROUGH FORMATION OF COMPLEX WITH B-CYCLODEXTRIN INCLUSION

The Piper betle leaf essential oil have antimicrobial activity to Candida albicans (Wirna, 2006). However, the essential oil is unstable to high temperature, light, and oxygen. One approach to improve the stability and facilitate in developing various dosage forms is by preparing the essential oil in complex inclusion using β-cyclodextrin (Szejtli, 1989). The aim of the present study was to investigate the effect of inclusion complex formation of the Piper betle leaf essential oil in b-cyclodextrin formulated to polyethylene glicol ointment to antifungal candida albicans activity. The essential oil of Piper betle leaf was isolated by destillation. The inclusion complex of the essential oil - β-cyclodextrin was prepared by coprecipitation of the essential oil : β- cyclodextrin 1:1 (w/w). The inclusion complex formation was studied with thin layer chromatography (TLC) and powder X-ray diffraction (XRD). In the TLC, sillica gel was used as solid phase, whereas toluen-ethyl acetate (7:3) and methanol-water (7:3) was used as mobile phase, then the Rf value of the essential oil and inclusion complex was compared. The XRD pattern of β-cyclodextrin, physical mixtures and inclusion complex was compared, too. Then, the polyethylene glicol ointment of the essential oil and inclusion complex was prepared. The physical properties and antifungal activity was compared. The TLC result showed that the essential oil of Piper betle leaf with methanol-water (7:3) as mobile phase had Rf 0,69 and the inclusion complex had Rf 0,81. With toluen-ethyl acetate (7:3), Rf of the essential oil were 0,63; 0,73; 0,85, whereas the inclusion complex were 0,66; 0,80, and 0,91. The powder XRD analysis showed that the pattern of β-cyclodextrin, physical mixture and inclusion complex were different. The differences of Rf from TLC and XRD patterns were showed that the Piper betle leaf essential oil was complexed with β cyclodextrin. The physical properties studies showed that the homogenity of both formulation was good. The inclusion complex ointment had spreading property, adhering property and antifungal activity which better than the essential oil ointment. The potency of antifungal activity of the inclusion complex of the essential oil - β-cyclodextrin was not significant different than miconazol ointment.

INFLUENCE OF LIGHT, TEMPERATURE AND HYDRIC STRESS IN THE GERMINATION AND VIGOR OF SEEDS OF ANISE

The objective of this work was to evaluate the effects of light, temperature and hydric stress in the germination and vigor of seeds of anise. The work was composed by two experimental stages. In stage I, seeds germinated under constant temperatures of 20, 25, 30 oC and alternate temperatures of 20-30 oC in the presence and absence of light. In stage II, the seeds were soaked in polyethylene glicol (PEG 6000) in osmotic potentials equivalent to zero; -0.05; -0.10; -0.15; -0.20; -0.25; -0.30 MPa. A completely randomized design with four replications was used. It can be concluded that germination of seeds of anise occurs in presence and absence of light. However vigor is favored by light. The seeds of anise, without dormancy, germinate better under constant temperatures of 20 and 25 °C. the temperature of 30 °C was not appropriate for the germination test for the germination process. The decreasing of osmotic potentials reduces germination and vigor of seeds anise. Vigor is more affected than

Priming and drying on the physiological quality of eggplant seeds

We evaluated the effect of the priming with polyethyleneglicol (PEG) 6000 followed or not of drying on two lots of eggplant seeds with medium and low vigor respectively. The seeds were submitted to the treatments of priming with PEG 6000 in the osmotic potentials of -0.6, -0.9 and -1.2 MPa during 48 or 96 hours of priming with and without subsequent drying. For the soaking of seeds in osmotic solutions, these were placed over three sheets of paper boxes such germitest gerbox conditioning moistened with each solution in a 3:1 ratio. The control group was represented by unprimed seeds. The priming for both lots provided higher values in relation to the vigor through the first counting of germination, seedlings and primary root length, germination and emergence rates, emergence and dry weight of seedlings when compared to the non-primed seeds. These results were not verified for germination; significant differences practically were not observed in relation to the controls. Improvements in relation to the vigour were not higher on lot 2 than those obtained on lot 1. The priming with PEG 6000 with subsequent drying increased the vigor of eggplant seeds of the cultivar Morro Grande in relation to those non-primed, however, without differences in the germination.

Photo-Fenton removal of water-soluble polymers

This paper presents the results of experiments carried out in a laboratory-scale photochemical reactor on the photodegradation of different polymers in aqueous solutions by the photo-Fenton process. Solutions of three polymers, polyethyleneglicol (PEG), polyacrylamide (PAM), and polyvinylpyrrolidone (PVP), were tested under different conditions. The reaction progress was evaluated by sampling and analyzing the total organic carbon concentration in solution (TOC) along the reaction time. The behavior of the different polymers is discussed, based on the evolution of the TOC–time curves. Under specific reaction conditions, the formation and coalescence of solid particles was visually observed. Solids formation occurred simultaneously to a sharp decrease in the TOC of the liquid phase. This may be favorable for the treatment of industrial wastewater containing polymers, since the photodegradation process can be coupled with solid separation systems, which may reduce the treatment cost.

Production of cordierite ceramic by aqueous tape casting process

Tape-casting process was used to produce cordierite ceramics in an aqueous system with polyvinylalcohol (PVA), and polyethyleneglicol (PEG), as binder and plasticizer, respectively. Before starting to tape-casting studies, optimum amount of sodium tripolyphosphate (STPP, Na 5 P 3 O 10 ) was used by sedimentation method for dispersing the powders. The sedimentation of raw materials (Kaolin, Al 2 O 3 and Talc) with STPP, as a dispersant for 20 wt.% solid content was performed. Various tape slips with different solid content (50–55–60 wt.%) and 10–12 wt.% PEG + PVA were prepared. The influence of the solid content on the rheological properties of slips and the resultant green tapes were studied. The increase in the PVA + PEG content deteriorated the slip properties and fostered the formation of bubbles in the slip. In addition, the properties of the sintered tapes were investigated. The slip composition, 10 wt.% PVA + PEG for 55 wt.% solid content produced green tapes with good surface properties and flexibility that had higher sintered density.

Efeito da luz, temperatura e estresse hídrico no potencial fisiológico de sementes de funcho

O objetivo deste trabalho foi avaliar os efeitos da luz, temperatura e estresse hídrico no potencial fisiológico de sementes de funcho. O experimento foi conduzido em duas etapas. Na etapa I, as sementes foram semeadas sobre papel nas temperaturas constantes de 20, 25, 30ºC e alternada de 20-30ºC na presença e ausência de luz. Na etapa II, as sementes foram colocadas sobre papel embebido em solução aquosa de polietileno glicol (PEG 6000) nos potenciais osmóticos correspondentes a zero; -0,05; -0,10; -0,15; -0,20; -0,25; -0,30MPa. O delineamento utilizado foi o inteiramente casualizado com quatro repetições. Conforme os resultados pode-se concluir que a germinação das sementes de funcho ocorre tanto na presença quanto na ausência de luz.. As sementes de funcho, germinam melhor nas temperaturas constantes de 20, 25 e e alternada de 20-30ºC e a temperatura de 30ºC não é adequada para o teste de germinação. A diminuição dos potenciais osmóticos com polietileno glicol 6000, a partir de -0,1MPa, reduz drasticamente a germinação e o vigor das sementes de funcho, sendo o vigor mais afetado que a germinação.

Comportamento de sementes de feijão sob diferentes potenciais osmóticos

A hidratação é o fator externo mais importante na germinação de sementes. Para simular as condições complexas do solo, soluções com diferentes potenciais osmóticos têm sido usadas para umedecer os substratos. O objetivo deste trabalho foi avaliar os efeitos do estresse hídrico e salino sobre a germinação e o vigor de sementes de feijão. Sementes da cultivar IAPAR 44 foram colocadas a germinar em papel-toalha embebido em soluções de polietileno glicol (PEG) 6000 e cloreto de sódio (NaCl) nos potenciais osmóticos zero; -0,05; -0,10; -0,15; -0,20; -0,25 e -0,30 MPa. O desempenho das sementes foi avaliado por meio do teste de germinação, primeira contagem da germinação, comprimento e matéria seca de plântulas. Concluiu-se que a redução do potencial osmótico, induzido por PEG 6000 ou NaCl, reduz o vigor e, a partir de -0,20 MPa, reduz a germinação de sementes de feijão. O PEG 6000 produz efeitos adversos mais drásticos do que o NaCl na qualidade fisiológica das sementes.

Temperatura de armazenamento e desempenho de sementes hidratadas e osmocondicionadas de pimentão

A propagação do pimentão (Capsicum annuum L.) é feita pela semente. Normalmente, tanto a germinação quanto a emergência das plântulas são lentas à temperatura ambiente e mais demorada ainda à baixa temperatura, sendo, portanto necessários estudos que propiciem a germinação mais rápida e uniforme principalmente a baixas temperaturas. Observou-se em trabalho anterior que ao submeter as sementes de pimentão à hidratação em água destilada por 24 e 72 horas e ao condicionamento osmótico com polietileno glicol (PEG 6000) no potencial de -0,5 MPa por 21 dias, foi possível aumentar e acelerar a germinação das sementes a baixa temperatura. Este trabalho foi realizado com o objetivo de avaliar as temperaturas de armazenamento das sementes hidratadas por 24 e 72 horas e condicionadas com PEG 6000 a -0,5 MPa por 21 dias, na preservação da sua viabilidade. As sementes foram tratadas, secas e acondicionadas em embalagem impermeável e armazenadas sob temperaturas de 5º e 25ºC. Ao término de cada mês de armazenamento, a germinação e emergência das sementes foram avaliadas sob temperaturas de 20º e 25ºC. Observou-se que as sementes hidratadas por 72 horas não suportaram o armazenamento, devendo estas, serem utilizadas imediatamente após o tratamento. As sementes hidratadas por 24 horas e aquelas osmocondicionadas com PEG quando armazenadas sob temperatura de 5ºC, mantiveram a sua porcentagem de germinação e emergência ao longo dos quatro meses de armazenamento, apresentando os maiores índices de germinação a 20ºC.

Water uptake, priming, drying and storage effects inCassia excelsa Schrad seeds

The aims of this study were to evaluate the effects of osmotic potential on the water uptake curve in Cassia excelsa seeds and use the results to analyze the effects of dehydration and storage on primed seed germination. Seeds were imbibed in distilled water and polyethylene glicol (PEG 6000) osmotic solutions at -0.2, -0.4, and -0.6 MPa, at 20 degrees C. The radicle emergence and seed moisture content were evaluated at 6-hour intervals during 240 hours. Afterwards, seeds were primed in distilled water and PEG 6000 solutions at -0.2, -0.4, and -0.6 MPa for 48, 72, 96, and 168 hours at 20 degrees C, followed by air drying and storage for 15 days at 5 degrees C. The lower the osmotic potential, the higher the time required for priming. The osmoconditioning yields benefits with PEG solutions at 0.0 and -0.2 MPa; seed improvements were maintained during storage for 15 days at 5 degrees C, but were reverted by seed drying.

Synthesis, structure and electrochemical performance of nano-sized LiNi 0.5 Co 0.5 VO 4

Li-ion batteries have received attention as rechargeable power sources for room temperature consumer applications since the commercialization of Sony’s lithium-ion cell in 1990 [1–8]. New lithiated transition-metal oxides, such as LiNiVO4 and LiCoVO4 have been recently proposed as cathode materials for modern rechargeable batteries [9, 10]. These materials are very attractive for their use in the so-called Li ion or rockingchair batteries due to their theoretical capacity of about 148 mA hg−1 and their high potential of 4.8 V vs. Li+/Li [11, 12]. Therefore, the preparation of LiMVO4 (M Ni, Co) for battery applications has been of considerable interest [13–16]. Solid-state reactions are often used to prepare LiMVO4, but they are not economical owing to the amount of energy (high temperature) and long reaction time required. In order to overcome these drawbacks, in the present work, we describe a simple procedure for the preparation of bulk quantities of nanosized particles of high crystalline LiNi0.5Co0.5VO4 at a low temperature of 450 ◦C. LiNi0.5Co0.5VO4 sample was prepared first by dissolving stoichiometric quantities of Li2CO3, Ni2(OH)2CO3, Co(Ac)2 and NH4VO3in de-ionized water. During vigorous stirring and ultrasonic treatment, saturated citric acid solution and polyethylene glicol solution were added, which gave off a great deal of gas, and a brown xerogel was obtained after being heated at 80–100 ◦C. The as-obtained xerogel was heated at 450 ◦C for 4 h, accompanied by obvious combustion, which ultimately gave rise to a brown powder. Thermal analyses of the precursor complex were performed using a Netzsch STA 449C DSC-TG apparatus. Experiment was carried out under ambient atmosphere with a heating rate of 10 ◦C/min. Xray diffraction (XRD) experiments were done on a HZG4/B-PC X-ray diffractrometer with Co Kα radiation and graphite monochrometer. Fourier transform infrared (FTIR) absorption spectra were recorded using a 60-SXB IR spectrometer with a resolution of 4 cm−1. The measuring wavenumber range is 300–3900 cm−1. Transmission electron microscopic (TEM) images were collected by employing a JEM-100CX II transmission electron microscope at 80 kV. The metal contents were determined by inductively coupled plasmaatomic emission spectroscopy (PLASMA 300) with the accuracy of ±0.1%. The cathode preparation and the cell test were similar to that described in Ref. 15.

Research on the polysaccharide antigen of Schistosoma mansoni in sera of hamsters using the crossed immunoelectrophoresis technic

Crossed immunoelectrophoresis (IEC) was used for detection of free and complexed circulating polisaccharide anodic antigen (AgCA) of Schistosoma mansoni in sera of infected hamsters. An attempt was also done to detect AgCA in human sera from patients infected with S. mansoni. The conditions for isolation and detection of complexed AgCA were established. The sensitivity of IEC was increased by incorporation of 2% polyethylene glicol (PEG) to the agarose and by maintaining the system at 4°C during the electrophoretic run. Free AgCA was detected in 12 and the complexed in 30 of the 37 hamsters sera analysed. Correlation between AgCA (free and complexed) and the parasite load was observed. AgCA was not detected, under the experimental conditions used, in human sera from 7 patients in the acute and 23 in the chronic phase of infection.