Nanocrystalline BiVO4 on monoclinic phase was obtained by a modified-solution combustion synthesis (SCS) using poly(ethylene glycol) (PEG 6000) and polyvinylpyrrolidone (PVP) as stabilizing and ...surfactant agents, respectively. An active photoanode was built using a simple procedure by dip-coating deposition process on fluorine-doped tin dioxide (FTO). The structure, morphology and optical properties of FTO/BiVO4 photoanode were evaluated by means of X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and diffuse reflectance UV-Vis spectroscopy. The photoelectrochemical performance measurements were carried out by linear sweep voltammetry (LSV), chronoamperometry and electrochemical impedance spectroscopy (EIS) under InGaN blue light emitting diode (LED) illumination condition (about 450 nm). In Na2SO4 electrolyte solution, the electrode has presented better photoelectroactivity than in NaNO3 solution, as evidenced by photoelectrochemical parameters such as: the highest photocurrent density (js) value, cathodic shifts of the onset potential (OP) and lower charge-transfer resistence (Rct). In the methyl orange (MO) degradation reaction the FTO/BiVO4 electrode has presented high photoelectroactivity, where the estimated kinetic constant rate (kobs) is 4.74 × 10−3 and 7.54 × 10−3 min−1 in NaNO3 and Na2SO4 solutions, respectively. This remarkable performance of the as-prepared electrode is due to the morphological BiVO4 structure,with elongated-shape nano-sized domain particles, besides the considerable porosity and roughness levels on electrode surface.
Produktivitas jagung yang rendah di Pulau Madura disebabkan oleh ketersediaan air yang rendah. Salah satu strategi yang digunakan untuk mengatasi permasalahan rendahnya produktivitas jagung di ...Madura adalah dengan merakit varietas jagung yang tahan terhadap cekaman kekeringan. Penelitian ini bertujuan untuk mengetahui ketahanan kandidat jagung hibrida pada fase perkecambahan menggunakan Polyethylene Glicol (PEG 6000). Penelitian ini menggunakan metode RAL (Rancangan acak lengkap) dengan dua faktor yaitu genotip jagung dan konsentrasi PEG 6000. Semua genotip dikecambahkan dengan metode uji kertas gulung dalam plastik (UKDdp), kemudian dilembabkan menggunakan campuran aqudesh dengan PEG 6000 sesuai perlakuan. Data yang diperoleh dianalisis menggunakan Analysis of Variance (ANOVA) pada taraf 5 % dan apabila menunjukkan pengaruh nyata maka dilakukan uji lanjut Duncan Multiple Range Test (DMRT) pada taraf 5%. Hasil penelitian menunjukkan bahwa genotip jagung dan Konsentrasi PEG 6000 berpengaruh terhadap semua parameter yang diujikan sehingga terdapat perbedaan karakter antara genotip satu dengan genotip lainnya. Genotip yang tahan terhadap cekaman kekeringan pada fase perkecambahan menggunakan PEG 6000 adalah G1 dan G5. Genotip yang moderat toleran adalah G3, G7, dan G8, sedangkan genotip yang peka terhadap cekaman kekeringan adalah G2, G4, G6, G9, dan G10.
A fast melt tablet (FMT) is well regarded as an alternative delivery system that might help resolve a patient's non-compliance issue. The main objective of this study was to develop a cocoa ...butter-based FMT. Additives, namely 5-15% of PEG 6000, beeswax, paraffin wax, and corn starch, were incorporated into the cocoa butter-based FMT to study the effects of these additives with the physical characteristic of a cocoa butter FMT. An optimum-based formulation was chosen according to the desired hardness and disintegration time and the taste masking property achieved with the model drug-dapoxetine. The analysis demonstrated that incorporating beeswax (15%) and paraffin wax (15%) could prolong the disintegration time by at least two-fold. On the contrary, the presence of corn starch was found to cause an increase in the hardness and reduction of the disintegration time. The disintegration mechanism might be presumed due to the synergistic effect of starch swelling and cocoa butter melting. The hardness value and in vitro disintegration time of the optimum formulation were recorded at 2.93 ± 0.22 kg and 151.67 ± 6.98 s. In terms of dissolution, 80% of dapoxetine was released within 30 min and the dissolution profile was comparable to the innovator product. The formulation was palatable and stable for at least 1 year. The exposure of the FMT formulation at 30 °C for 12 months was reported to be stable. Along with the sound palatability profile and high drug load capacity, the current formulation possesses the desired characteristics to be scaled up and marketed.
Large amounts of nitrogen (N) enter ecosystems via N deposition. The increased drought stress has incurred serious threats to plant seed germination and seedling growth (SGe-SGr). It is significant ...to characterize the combined impacts of N deposition and drought stress on SGe-SGr of plants to enable a further explanation of the response mechanism of SGe-SGr to N deposition and drought stress. This study aims to explore the combined impacts of N deposition with a concentration gradient and drought stress (mimicked using PEG 6000) with different levels on SGe-SGr of wheat. N treatment raises seedling growth of wheat mainly due to the increased levels of available N and the decreased level of peroxidation of the cell cytoplasm membrane of wheat. Drought stress declines SGe-SGr of wheat mostly due to the progressively enlarged osmotic pressure triggered by water deficit and the advanced level of peroxidation of the cell cytoplasm membrane of wheat. N treatment regardless of the concentration dramatically mitigates the adverse impacts of drought stress on seedling growth of wheat. This may be owed to the improved competitive ability for sunlight acquisition and leaf photosynthetic area via the deactivation of nutrition limits (wheat can absorb more N nutrients and improve its drought resistance ability) implemented by N addition. This may also due to the down-regulated level of peroxidation of the cell cytoplasm membrane of wheat under the combined N and drought stress. However, the combined treatments of the high level of N supply and light drought stress decline seed germination of wheat. This may be due to the promoted osmotic pressure contributed by the high level of N supply under water deficit. Thus, N deposition mitigates the adverse impacts of drought stress on seedling growth of wheat but aggravates the adverse impacts of drought stress on seed germination of wheat mostly.
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•Nitrogen increases seedling growth of wheat.•Drought declines seed germination and seedling growth of wheat.•Nitrogen alleviates the adverse effects of drought on seedling growth of wheat.•Nitrogen intensifies the adverse effects of drought on seed germination of wheat.
β-lapachone (βlap) has shown potential use in various medical applications. However, its poor solubility has limited its systemic administration and clinical applications. The aim of this work is to ...develop solid dispersions of βlap using poly (ethylene glycol) (PEG 6000) and polyvinylpyrrolidone (PVP K30) as hydrophilic polymers and evaluate the dissolution rate in aqueous medium. Solid dispersions were prepared by solvent evaporation method using different weight ratios of βlap and hydrophilic polymer (1:1, 1:2, and 1:3). Characterization performed by differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy showed that βlap was molecularly dispersed within the polymer matrix. The in vitro dissolution tests showed an enhancement in the dissolution profile of βlap as solid dispersions prepared in both PVP and PEG, although the former showed better results. The drug:polymer ratio influenced βlap dissolution rate, as higher amounts of hydrophilic polymer led to enhanced drug dissolution. Thus, this study demonstrated that solid dispersions of βlap in PVP offers an effective way to overcome the poor dissolution of βlap.
În lucrare sunt prezentate rezultatele cercetării reacției comparative a unui set din 40 de soiuri și linii de susan la acțiunea stresului hidric creat prin modelarea lui în condiții de laborator. ...Inițial, pe semințele a 5 mostre au fost testate diverse concentrații de polietilenglicol PEG 6000 (5%, 10%, 15%, 20% și 25%) în scopul determinării condiției optimale de efectuare a evaluărilor. S-a stabilit că pentru elucidarea toleranței la secetă a mostrelor de colecție trebuie utilizată concentrația de 15% de PEG 6000. În urma studiului efectuat s-a ajuns la concluzia că din numărul total de genotipuri estimate 5 pot fi considerate cele mai rezistente, având gradul de inhibiție la mostrele de susan cuprins între 41,98 și 51,71%; pentru 13 mostre considerate tolerante gradul de inhibiție variază de la 53,56 la 60,71%; la 11 mostre cu stabilitate mică a funcțiilor în timpul stresului și capacitate de reversie mare gradul de inhibiție este cuprins între valorile 61,78% și 68,49% și la 11 mostre sensibile cu stabilitate mică și capacitate mică de restabilire a funcțiilor gradul de inhibiție este cel mai mare – cu valori de la 69,39 la 77,02%.
SESAME GENOTYPES (SESAMUM INDICUM L.) TOLERANCE IN HYDRIC STRESS IN
THE CONDITIONS OF ARTIFICIAL MODELLINGThe paper presents the results of the research of the comparative reaction of a set of 40 sesame varieties and lines to the action of the water stress created by its modelling in laboratory conditions. Initially, various concentrations of polyethylene glycol PEG 6000 (5%, 10%, 15%, 20% and 25%) were tested on the seeds of 5 samples in order to determine the optimal condition for carrying out the evaluations. It was established that for the elucidation of the drought tolerance of the collection samples, the concentration of 15% of PEG 6000 should be used. Following the study, it was concluded that out of the total number of estimated genotypes, 5 can be considered the most resistant, with the degree of inhibition included. Between 41.98-51.71%, for 13 samples considered tolerant, the degree of inhibition varies from 53.56 to 60.71%, in 11 samples with low stability of functions during stress and high reversal capacity, the degree of inhibition is between 61,78% - 68,49% and in 11 sensitive samples with low stability and low ability to restore functions, the degree of inhibition is the highest with values from 69.39 to 77.02%.
Accelerated thermal cycle test of polyethylene glycol (PEG) of molecular weight 6000, an organic phase change material (O-PCM), has been carried out for 1500 melt/freeze cycles. The latent heat of ...fusion and melting temperature is measured using differential scanning calorimeter between 0th and 1500th melt–freeze cycles to study the changes in its thermal properties. Also, the changes in the compositional/functional groups of the material during the cycle test are also measured using FT-IR spectroscopy technique. The melting temperature is found to be stable in the quoted range of 55–60°C with a maximum deviation of 6.5% when compared to that of at 0th cycle. However, a gradual drop in the latent heat of fusion with the increasing number of thermal cycles is measured. The FT-IR spectra do not show any noticeable changes in the peaks which confirm its compositional stability even after the higher number of thermal cycles. Thermal and chemical reliability tests of PEG 6000 along with the techno-economic analysis have shown that this PCM has a significant potential to be used as a thermal energy storage system.
•Accelerated thermal cycle test cycles conducted for the first time for PEG 6000.•Melting temperature was found in the stable range.•Polyethylene glycol was found chemically stable.
The choice of carrier and drug ratio are critical factors as far as the type of solid dispersion is concerned. Amorphous solid dispersion has been cited as the most desirable type among the different ...types of solid dispersion due to the benefit of amorphicity in increasing the drug solubility of a poorly soluble drug. Recent reports delineated that a partially crystalline solid dispersion system may perform better due to the inherent issue of solution mediated recrystallisation of a completely amorphous system. In oppose to the conventional choice of using amorphous polymer, this study aimed to investigate the use of a crystalline carrier, polyethylene glycol (PEG) for dissolution enhancement of a model poorly soluble drug, Flurbiprofen (FBP), a BCS Class II candidate. Solid dispersions of different FBP to PEG 6000 molar ratios via solvent evaporation were prepared. Physical characterisation of preparations was performed using differential scanning calorimetry (DSC), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and optical microscope. DSC and ATR-FTIR analyses suggest the obtained solid dispersion exhibits crystalline FBP. This is then supported by the optical microscope analysis as the birefringence of crystals was noted. Further increasing the drug-carrier molar ratio to one-to-three and one-to-six showed that there was an amorphous FBP constituent in the system. DSC analysis revealed the melting point depression of FBP by the carrier which signifies interaction between the drug and polymer. Dissolution study showed the solid dispersion of FBP improves the drug solubility and drug release compared to the pure drug. A higher carrier ratio in the formulation results in a higher drug release.
Background
. Bitter melon (
Momordica charantia
L.) is a vegetable and medicinal crop new for Russia. Its high heat demand is the main factor limiting the possibilities of its cultivation in a ...temperate continental climate. Evaluation and selection of more cold-resistant accessions is required for breeding new cultivars and expanding production. Previously obtained data attest to a possibility of assessing cold hardiness in the mature male gametophyte phase
in vitro
.
Materials and methods
. Eight bitter melon accessions, including parent forms, F hybrids and cv. ‘Gosha’, were grown in the unheated film greenhouse of the Central Siberian Botanical Garden, Novosibirsk (54°49’ N, 83°06’ E) for evaluation and selection for cold resistance. The ratio of pollen germination in vitro on a 15% polyethylene glycol solution with a molecular weight of 6000 (PEG 6000) with the addition of boric acid (0.006%) at a temperature of 10°C for 24 h to the same indicator at 25°C / 3 h (in %) was used as a criterion of cold resistance.
Results
. The cultivar ‘Gosha’, the accession Okinawa green from Japan, and the F
1
hybrid (Feng Guang × Okinawa green) had the highest cold resistance, with the values of 59.7; 53.8 and 48.2%, respectively. The inheritance of cold resistance in F , assessed by the pollen germination index, depending on the crossing combination, changed from intermediate in two hybrids F
1
Feng Guang × Gosha) and F
1
Feng Guang × Okinawa green) to overdominant (positive heterosis) in the hybrid F
1
(Feng Guang × Okinawa white).
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