Increase In Polyethylene Glycol Research Articles

Multistimuli-responsive circularly polarized luminescent material of achiral Eu-containing polyoxometalates and cellulose nanocrystals

The stimuli-responsive circularly polarized luminescence (CPL) material was made using photonic cellulose nanocrystals (CNC) and achiral luminescent Eu-containing polyoxometalates Na₉EuW₁₀O₃₆·32H₂O (EuW₁₀). The CPL of EuW₁₀ with high dissymmetric factor <i>g</i>_lum ~ −0.37 was achieved based on the selective reflection property of CNC photonic films. With the increase of polyethylene glycol (PEG) content, the photonic bandgaps (PBG) of CNC/PEG/EuW₁₂ composite films were redshifted, successfully achieving the chirality of EuW₁₀ in various emission bands (⁵D₀→⁷F_<i>n</i>, <i>n</i> = 1, 2, 3, 4). The CPL materials also showed excellent humidity responsiveness. The <i>g</i>_lum of the emission band was closely correlated to the PBG of composite films.

Water Stress Inhibits Germination While Maintaining Embryo Viability of Subtropical Wetland Seeds: A Functional Approach With Phylogenetic Contrasts.

Wetland species commonly exhibit a range of strategies to cope with water stress, either through drought tolerance or through avoidance of the period of limited water availability. Natural populations provide a genetic resource for ecological remediation and may also have direct economic value. We investigated the effects of drought stress on the seed germination of wetland species. Nineteen species were germinated in four concentrations of polyethylene glycol 6000 (PEG) and were evaluated daily (12-h light photoperiod) or after 35 days (continuous darkness) to determine seed germination under water stress. Germination percentage decreased with an increase in polyethylene glycol 6000 (PEG) concentration, but species’ germination response to PEG concentration varied significantly. Seeds recovered their germinability after the alleviation of water stress, but the extent of recovery was species-dependent.

Storage Period and Different Abiotic Factors Regulate Seed Germination of Two Apocynum Species - Cash Crops in Arid Saline Regions in the Northwestern China.

On degraded land in arid regions, cultivation of Apocynum species can provide significant environmental benefits by preventing soil erosion and desertification. Furthermore, Apocynum venetum and Apocynum pictum, which are mainly distributed in salt-barren lands in the northwestern region of China, are traditionally used to produce natural fiber and herbal tea. Direct sowing of both species may encounter various abiotic stresses such as drought and salinity. However, these effects on germination remain largely unknown, especially for seeds with different storage periods. The aim of this study was to evaluate the effects of storage period, light condition, temperature regime, drought, and salinity on germination performances of both species. Germination experiment was carried out in November 2017. There were four replicates for each treatment, and each petri dish contained 25 seeds. The results indicated that prolongation of storage period significantly decreased the germination percentage and velocity, especially under abiotic stresses. Light did not affect seed germination of A. venetum and A. pictum under any conditions. Seeds had better germination performance at 10/25 and 15/30°C than those of seeds incubated at any other temperatures. With the increase of polyethylene glycol (PEG) and salinity concentrations, seed germination for both species gradually decreased, especially for seeds stored for 2 years. Low PEG (0–20%) and salinity concentration (0–200 mM) did not significantly affect germination percentage of freshly matured seeds. However, long-time storage significantly decreased drought and salinity tolerance in A. venetum and A. pictum during germination stage. For saline soils in arid and semi-arid regions, freshly matured seeds or 1-year-stored seeds of both Apocynum species are recommended to be sown by using drip-irrigation in spring.

Non-Invasive Extraction of Gabapentin for Therapeutic Drug Monitoring by Reverse Iontophoresis: Effect of pH, Ionic Strength, and Polyethylene Glycol 400 in the Receiving Medium

Background: Monitoring of plasma concentrations is a necessity for narrow therapeutic index potent drugs. Development of non-invasive methods can save the patients from the trauma of needles and hence is considered as a research priority. Introduction: Gabapentin, an anti-epileptic drug requires therapeutic monitoring because of its narrow therapeutic index. The objective of the study was to develop a suitable method for the non-invasive extraction of gabapentin for the same. Methods: Transdermal reverse iontophoresis was performed using pig ear skin as a barrier membrane. Three compartment iontophoretic cells were used for the extraction study. Extractions were carried out under low intensity electric field (current intensity- 0.5 mA/cm2, electrical field approximately 5 V). The donor compartment was charged with aqueous gabapentin (10 µg/ml in phosphate buffer of pH 7.4). For studying the effect of receiving vehicle (pH, ionic strength, and enhancer) on the extraction efficiency of gabapentin, the two receiver chambers were charged with media having varying concentration of these factors. Drug content was determined by HPLC. Results: Compared to other pHs, cumulative extraction of gabapentin at pH 5 was significantly higher at both anode and cathode (p&lt;0.001). At low ionic strength, extraction of gabapentin increased linearly with the increase in concentration of ions up to a certain value but at very high ionic strength the pattern reversed. Similar results were obtained with enhancer (polyethylene glycol 400). Extraction increased with increase in polyethylene glycol 400 up to 3% and then decreased. Conclusion: Extraction flux can be optimized by manipulation of the receiver media.

INVESTIGATION ON THE EFFECT OF THE POLYETHYLENE GLYCOL ON THE ELECTROPHORTIC DEPOSITION OF ALUMINA AND ZIRCONIA

This work is a study of the effect of polyethylene glycol (PEG) on electrophoretic deposition) EPD) of alumina and zirconia particles. The effect of polyethylene glycol as a binder material and the toluene as a dielectric liquid, on the pH of suspension, the final thickness and green density of the deposed parts were studied. There was a difference in the behavior of polyethylene glycol when added for the alumina suspension and the zirconia suspension. The increase in polyethylene glycol was useful to deposit the zirconia more than alumina. The pH for both alumina and zirconia suspension increases with the increase of polyethylene glycol content and with the addition of toluene due to increase of the OH– concentration in the suspension. This increase of pH enhances the particle surface charge and enhances the deposition rate, which led to the increase of density of the deposit

Study of biodegradation and biocompatibility of PEGylated rosin derivatives

PEGylated rosin derivatives are improved in series ester-adduct derivatives of rosin. The aim of this study was to assess biodegradation and biocompatibility of PEGylated rosin derivatives. Study employed two different PEGylated rosin derivatives, namely, D1 and D2, with constant weight of rosin and increasing amounts of polyethylene glycol 400. PEGylated rosin derivatives were synthesized and tailored into spherical beads and disks with smooth surface for use. In vitro degradation was studied at pH 4.0, 7.4, and 10 for 60 days. In vivo study was performed in Wistar rats using poly(d,l-lactide- co-glycolide) (50:50) as a control. Post 3, 7, 14, and 21 days of implantation, PEGylated rosin derivatives disks were retrieved and evaluated for weight loss, molecular weight decline, morphology, and tissue response. D1 and D2 beads showed 21.68% and 32.37% weight loss, respectively, at pH 7.4 post 60 days. Degradation was increased substantially with increase in pH of medium. Degradation of disks was markedly slower than that of beads. In vivo degradation of PEGylated rosin derivative disks was faster than in vitro. Post 60 days of implantation, weight loss of D1 and D2 disk was 7.57% and 11.84%, whereas molecular weight was declined by about 19% and 26%, respectively. Owing to higher amounts of polyethylene glycol 400, in vitro and in vivo degradation of D2 was faster than D1. Poly(d,l-lactide- co-glycolide) as well as PEGylated rosin derivative implants evoked mild inflammatory responses characterized by few macrophages and absence of exudation at tissue–disk interface. The cellular density in tissue surrounding PEGylated rosin derivative disks increased initially with time up to 7 days and decreased eventually at the end of 21 days. The trend was similar for poly(d,l-lactide- co-glycolide) implants. Increase in polyethylene glycol 400 improved biodegradation and biocompatibility of PEGylated rosin derivatives. Results revealed that PEGylated rosin derivatives degrade slowly in vivo over a period of time, possess fair biocompatibility, and thus are promising biomaterial for drug delivery applications.

Nanosilica Sol Leads to Further Increase in Polyethylene Glycol (PEG) 1000-Enhanced Thermostability of β-Cyclodextrin Glycosyltransferase from Bacillus circulans

A major disadvantage of cyclodextrin production is the limited thermostability of cyclodextrin glycosyltransferase. The ability of combinations of nanosilica sol with polyethylene glycol (PEG) 1000 to enhance the thermostability of the β-cyclodextrin glycosyltransferase from Bacillus circulans was investigated. It was found that 10% PEG 1000 combined with 0.05% nanosilica sol could activate the β-cyclodextrin glycosyltransferase by 17.2%. Furthermore, 0.05% nanosilica sol leads to further increase in PEG 1000-enhanced thermostability of β-cyclodextrin glycosyltransferase. With the simultaneous addition of 10% PEG 1000 and 0.05% nanosilica into the enzyme solution, which was allowed to incubate for 60 min at 60 °C, 61.3% of β-cyclodextrin-forming activity could be retained, which was much higher than that with only 10% PEG 1000 added. Atomic force microscopy, fluorescence spectroscopy, and circular dichroism analysis indicated that silica nanoparticles helped PEG 1000 further protect the tertiary and secondary structures of β-cyclodextrin glycosyltransferase. This study provides an effective approach for improving the thermostability of cyclodextrin glycosyltransferase and related enzymes.

Effects of drought stress on the seed germination and early seedling growth of the endemic desert plant Eremosparton songoricum (Fabaceae).

Eremosparton songoricum (Litv.) Vass. is an endemic and extremely drought-resistant desert plant with populations that are gradually declining due to the failure of sexual recruitment. The effects of drought stress on the seed germination and physiological characteristics of seeds and seedlings were investigated. The results showed that the germination percentage decreased with an increase of polyethylene glycol 6000 (PEG) concentration: -0.3 MPa (5 % PEG) had a promoting effect on seed germination, -0.9 MPa (15 % PEG) dramatically reduced germination, and -1.8 MPa (30 % PEG) was the threshold for E. songoricum germination. However, the contents of proline and soluble sugars and the activity of CAT increased with increasing PEG concentrations. At the young seedling stage, the proline content and CAT, SOD and POD activities all increased at 2 h and then decreased; except for a decrease at 2 h, the MDA content also increased compared to the control (0 h). These results indicated that 2 h may be a key response time point for E. songoricum to resist drought stress. The above results demonstrate that drought stress can suppress and delay the germination of E. songoricum and that the seeds accumulate osmolytes and augment the activity of antioxidative enzymes to cope with drought injury. E. songoricum seedlings are sensitive to water stress and can quickly respond to drought but cannot tolerate drought for an extended period. Although such physiological and biochemical changes are important strategies for E. songoricum to adapt to a drought-prone environment, they may be, at least partially, responsible for the failure of sexual reproduction under natural conditions.

Contribution à l’amélioration de la germination chez une endémique forestière du Maroc, le cyprès de l’Atlas

La cupressacée à Cupressus atlantica, qui abrite une diversité biologique originale, joue un rôle socio-économique et écologique important. Cependant, ces formations, souvent présteppiques, sont soumises à des pressions croissantes d’origine principalement antropique. En outre, d’autres facteurs tels que la sécheresse, l’absence de régénération ou encore les ravageurs des cônes et des graines, menacent à terme l’avenir du cyprès de l’Atlas. Actuellement, les services forestiers marocains adoptent des orientations qui consistent à utiliser de plus en plus des espèces autochtones, notamment le Cyprès atlasique, dans les programmes de reboisement. Ainsi, il est très important de maîtriser l’itinéraire technique de production des plants de qualité. Cela nécessite une intensification des efforts en matière de recherche pour améliorer les connaissances des différentes étapes de ce processus, depuis la collecte des semences jusqu’à l’acclimatation des plants en passant par le stockage et la germination des graines. La présente étude vise à apporter une contribution concernant le comportement germinatif de ce conifère. En premier lieu, plusieurs traitements de prégermination (traitement chimique, traitement par l’eau à différentes températures, traitement mécanique qui consiste à frotter les graines avec du papier à sable) ont été expérimentés afin d’améliorer la germination par la levée de la dormance des graines. Les résultats relatifs à ces prétraitements ont montré que ces derniers jouent un rôle primordial dans la levée de la dormance et améliorent par conséquence la germination. En effet, les taux de germination les plus élevés 67,77 % et 75,55 % ont été enregistrés respectivement au niveau des graines traitées avec de l’eau chaude (60 oC) et par la scarification mécanique. Le traitement avec de l’acide sulfurique concentré a conduit à des taux de germination très faibles voire nuls, contrairement à ce qui a été observé chez d’autres espèces forestières et à ce qui avait été précédemment reporté chez le Cyprès atlasique. C. atlantica possèdent une dormance physique attribuée au tégument dur, qui peut entraver la régénération naturelle. La scarification mécanique et l’eau chaude (60 oC) sont les traitements les plus efficaces pour améliorer la germination des graines du C. atlantica. Le stress hydrique et le stress salin ont un effet inhibiteur sur la germination des graines du cyprès de l’Atlas. Ces résultats, concernant la germination, premier maillon de l’opération de reboisement, peuvent contribuer à la restauration des espaces dégradés et la réhabilitation des écosystèmes aride et semi-aride.

Effect of polymers on crystallo-co-agglomeration of ibuprofen-paracetamol: Factorial design

The purpose of this research was to study the effect of concentration of polyethylene glycol and ethyl cellulose on the properties of agglomerates of ibuprofen-paracetamol obtained by crystallo-co-agglomeration technique. The process of crystallo-co-agglomeration involved recrystallization of ibuprofen and its simultaneous agglomeration with paracetamol in presence polymers. The effect of combination of polyethylene glycol and ethylcellulose was studied by 2 2 factorial design. Ibuprofen content of the agglomerate increased with increase in ethyl cellulose while paracetamol content was decreased with increase in polyethylene glycol. Differential scanning calorimetry thermograms of agglomerates showed the unchanged endotherm for ibuprofen melting, whereas paracetamol endotherm was diffused with low enthalpy. The agglomerates were spherical but increase in polyethylene glycol caused its deformation. Agglomerates containing ethylcellulose with polyethylene glycol have higher resistance for fragmentation, modulus of elasticity but impart high tensile strength.