scholarly journals New Antifungal Compound: Impact of Cosolvency, Micellization and Complexation on Solubility and Permeability Processes

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1865
Author(s):  
Tatyana V. Volkova ◽  
Olga R. Simonova ◽  
German L. Perlovich
Keyword(s):  
Complex Analysis ◽  
Driving Forces ◽  
Aqueous Media ◽  
Considerable Effect ◽  
Antifungal Compound ◽  
Cellulose Membrane ◽  
Buffer Solutions ◽  
Solubility Improvement ◽  
Medium Permeability ◽  
Better Than

Poor solubility of new antifungal of 1,2,4-triazole class (S-119)—a structural analogue of fluconazole in aqueous media was estimated. The solubility improvement using different excipients: biopolymers (PEGs, PVP), surfactants (Brij S20, pluronic F-127) and cyclodextrins (α-CD, β-CD, 2-HP-β-CD, 6-O-Maltosyl-β-CD) was assessed in buffer solutions pH 2.0 and pH 7.4. Additionally, 2-HP-β-CD and 6-O-Maltosyl-β-CD were proposed as promising solubilizers for S-119. According to the solubilization capacity and micelle/water partition coefficients in buffer pH 7.4 pluronic F-127 was shown to improve S-119 solubility better than Brij S20. Among biopolymers, the greatest increase in solubility was shown in PVP solutions (pH 7.4) at concentrations above 4 w/v%. Complex analysis of the driving forces of solubilization, micellization and complexation processes matched the solubility results and suggested pluronic F-127 and 6-O-Maltosyl-β-CD as the most effective solubilizing agents for S-119. The comparison of S-119 diffusion through the cellulose membrane and lipophilic PermeaPad barrier revealed a considerable effect of the lipid layer on the decrease in the permeability coefficient. According to the PermeaPad, S-119 was classified as a highly permeated substance. The addition of 1.5 w/v% CDs in donor solution moves it to low-medium permeability class.

A Theoretical and Experimental Approach to E-pH Diagram for the Niobium-Water System

CORROSION ◽  
10.5006/3871 ◽  
2021 ◽  
Author(s):  
Rodney Santandrea ◽  
Simone BRASIL ◽  
Leila Reznik ◽  
Ladimir Carvalho ◽  
Luiz Miranda
Keyword(s):  
Experimental Approach ◽  
Ph Monitoring ◽  
Aqueous Media ◽  
Water System ◽  
Chemical Species ◽  
Polarization Curves ◽  
Buffer Solutions ◽  
Excellent Corrosion Resistance ◽  
Experimental Diagram ◽  
Selection Of

E-pH diagrams are usually built from thermodynamic databases available in the literature or from specific software. However, depending on the conditions and the chemical species defined for elaborating a diagram, it may present completely different immunity, passivation, and corrosion domains. In order to obtain a result closer to a real system, experimental E-pH diagrams can be built from polarization curves obtained in the evaluated conditions. This work discloses the construction of a diagram for the Nb-H<sub>2</sub>O system at 25°C from theoretical study and the specific selection of chemical species in the solutions through computer simulations. The polarization curves for the construction of the experimental diagram were gathered without the use of buffer solutions and under pH monitoring in the solution bulk throughout all assays. The methodology proposed was considered adequate since, from experimental data, a final result compatible with the classic diagram for the Nb-H<sub>2</sub>O system and the excellent corrosion resistance of niobium in aqueous media were achieved.

A Comparison of Gelling Properties Stability of Dry-Heating and Maillard-Type Egg White Proteins

2015 ◽  
Vol 1095 ◽  
pp. 287-290 ◽  
Author(s):  
Wei Xu ◽  
Hai Bin Wang ◽  
Tao Xiang
Keyword(s):  
Storage Time ◽  
Egg White ◽  
Considerable Effect ◽  
Gel Texture ◽  
Gelling Properties ◽  
Egg White Proteins ◽  
Dry Heating ◽  
Water Holding ◽  
Gel Network ◽  
Better Than

Gelling properties stability of the Maillard-type and dry-heating egg white proteins (MEW and DEW) were investigated. MEW were prepared by storing sugar-preserved egg white proteins and glucose at 60 °C and 79% relative humidity for 2 days, and DEW were prepared by storing at 80°C in dry state (7.5% moisture content) for 7 days. The results showed that both MEW and DEW have excellent gelling properties. After storage at room temperature for 180 days, gel hardness, spring and cohesiveness of MEW increased by 1.92%, 1.89% and 4.24% respectively, water holding capacity of MEW gel decreased by 1.42%, while storage time had a considerable effect on those of DEW gels. A tight and more uniform network with constant stability in the course of storage was observed in the gel of MEW (500×), while gaps in EWP gel network were larger and the gel texture became looser with storage time. The results demonstrated that gelling properties stability of MEW is better than DEW.

scholarly journals Colour properties of cigarette smoke-exposed cotton and silk fabrics and their nicotine release

2018 ◽  
Vol 69 (04) ◽  
pp. 328-333
Author(s):  
NONGNUCH WANTANEEPORN ◽  
SUWANRUJI POTJANART ◽  
SETTHAYANOND JANTIP
Keyword(s):  
Cigarette Smoke ◽  
Cotton Fabric ◽  
Potential Risk ◽  
Aqueous Media ◽  
Colour Change ◽  
Colour Properties ◽  
Buffer Solutions ◽  
Colour Strength ◽  
Dyed Fabrics ◽  
Silk Fabrics

Exposure to cigarette smoke caused colour change to undyed cotton and silk fabrics by a yellowing effect. The degree of yellowing was more dominant on cotton fabric. When the dyed fabrics were subjected to cigarette smoke, a more pronounced effect was observed on the pale shade dyed fabrics. Shade alteration was inversely related to the colour strength of the dyed fabrics. In addition, a longer exposure time also induced colour change in the fabrics while the colour strength of the dyed fabrics was unaffected. Nicotine release from the cigarette smoke-exposed fabrics in the wet state was studied in different aqueous media, viz. water, buffer solutions (pH 5.5 and 8.0) and artificial sweats (acid and alkaline) in order to reflect the potential risk to textile users of the toxicants from textiles contaminated with cigarette smoke.

scholarly journals Host-Guest Interaction between Herbicide Oxadiargyl and Hydroxypropyl-β-Cyclodextrin

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sofia Benfeito ◽  
Tiago Rodrigues ◽  
Jorge Garrido ◽  
Fernanda Borges ◽  
E. Manuela Garrido
Keyword(s):  
Aqueous Media ◽  
Industrial Effluents ◽  
Ultrapure Water ◽  
Buffer Solutions ◽  
Water Treatment Plants ◽  
Pesticide Formulations ◽  
The Face ◽  
Ph Buffer ◽  
Environmentally Sound ◽  
And Storage

In the face of a growing human population and increased urbanization, the demand for pesticides will simply rise. Farmers must escalate yields on increasingly fewer farm acres. However, the risks of pesticides, whether real or perceived, may force changes in the way these chemicals are used. Scientists are working toward pest control plans that are environmentally sound, effective, and profitable. In this context the development of new pesticide formulations which may improve application effectiveness, safety, handling, and storage can be pointed out as a solution. As a contribution to the area, the microencapsulation of the herbicide oxadiargyl (OXA) in (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) was performed. The study was conducted in different aqueous media (ultrapure water and in different pH buffer solutions). In all cases an increment of the oxadiargyl solubility as a function of the HP-β-CD concentration that has been related to the formation of an inclusion complex was verified. UV-Vis and NMR experiments allowed concluding that the stoichiometry of the OXA/HP-β-CD complex formed is 1 : 1. The gathered results can be regarded as an important step for its removal from industrial effluents and/or to increase the stabilizing action, encapsulation, and adsorption in water treatment plants.

Cost Effectiveness of Operator Features in Equipment Design

1981 ◽  
Vol 25 (1) ◽  
pp. 385-389
Author(s):  
Jeremy C. Williams
Keyword(s):  
Human Factors ◽  
Synthetic Data ◽  
Considerable Effect ◽  
Negotiation Process ◽  
Additional Tool ◽  
Calls For Service ◽  
Job Aids ◽  
The Cost ◽  
The Relationship ◽  
Better Than

In design negotiation, the attribution of credible values to the incorporation or deletion of operator features allows engineers the freedom to judge the overall effect of human factors recommendations in relation to the achievement of a design specification. Likewise in the development phase, product planners frequently need more precise statements about productivity, training needs and general operational performance than, “it will be greater/less, worse/better than…”. The method described utilises measured and synthetic data, learning theory and Markov processes to calculate the likelihood of operator task failure. These failure rates are then treated via filter factors derived from the application of a variation of Delphi Technique to give a global statement of the likelihood of operator failure resulting in unscheduled calls for service. Using the relationship between the cost of service calls and the overall life cost of developing, manufacturing, marketing and supporting a leased product, it is then possible to place credible values on the design features in question. Thus during the design process it becomes feasible to calculate the likely effects of human factors recommendations and modifications in relation to manufacturing costs, and thereby facilitate rational assessment of their implementation on a sound economic basis. This technique has been used to considerable effect, and represents a useful additional tool for the human factors practitioner in the design negotiation process. Further developments and refinements are planned, and it is anticipated that a similar technique will shortly be available to enable assessment of the effectiveness of product training programs and job aids.

Magnetically recoverable catalysts based on mono- or bis-(NHC) complexes of palladium for the Suzuki–Miyaura reaction in aqueous media: two NHC–Pd linkages are better than one

2016 ◽  
Vol 45 (29) ◽  
pp. 11633-11638 ◽  
Author(s):  
Francisco Martínez-Olid ◽  
Román Andrés ◽  
Ernesto de Jesús ◽  
Juan C. Flores ◽  
Pilar Gómez-Sal ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Aqueous Media ◽  
Recyclable Catalyst ◽  
Magnetically Recoverable Catalysts ◽  
Recoverable Catalysts ◽  
Pd Complexes ◽  
Better Than

Mono- and bis(NHC) Pd complexes grafted onto magnetic particles are compared as catalysts in the Suzuki–Miyaura reaction in aqueous media. The latter is found to be an outstanding recyclable catalyst.

scholarly journals Characterization of Asphalt Mixtures Produced with Coarse and Fine Recycled Asphalt Particles

2019 ◽  
Vol 4 (4) ◽  
pp. 67 ◽  
Author(s):  
S. Saeed Saliani ◽  
Alan Carter ◽  
Hassan Baaj ◽  
Pejoohan Tavassoti
Keyword(s):  
Particle Size ◽  
Fatigue Cracking ◽  
Maximum Tensile Stress ◽  
Considerable Effect ◽  
Environmental Benefits ◽  
Recycled Asphalt ◽  
Rutting Resistance ◽  
Cracking Performance ◽  
Pavement Construction ◽  
Better Than

Utilizing recycled asphalt pavements (RAP) in pavement construction is known as a sustainable approach with significant economic and environmental benefits. While studying the effect of high RAP contents on the performance of hot mix asphalt (HMA) mixes has been the focus of several research projects, limited work has been done on studying the effect of RAP fraction and particle size on the overall performance of high RAP mixes produced solely with either coarse or fine RAP particles. To this end, three mixes including a conventional control mix with no RAP, a fine RAP mix (FRM) made with 35% percent fine RAP, and a coarse RAP mix (CRM) prepared with 54% of coarse RAP were designed and investigated in this study. These mixes were evaluated with respect to their rutting resistance, fatigue cracking resistance, and low temperature cracking performance. The results indicate that although the CRM had a higher RAP content, it exhibited better or at least the same performance than the FRM. The thermal stress restrained specimen testing (TSRST) results showed that the control mix performed slightly better than the CRM, while the FRM performance was adversely affected with respect to the transition temperature midpoint and the maximum tensile stress temperature. Both of the RAP incorporated mixes exhibited better rutting resistance than the control mix. With regard to fatigue cracking, the CRM performed better than the FRM. It can be concluded that the RAP particle size has a considerable effect on its contribution to the total binder content, the aggregate skeleton of the mix, and ultimately the performance of the mix. In spite of the higher RAP content in the CRM versus FRM, the satisfactory performance observed for the CRM mix indicates a great potential in producing high RAP content mixes through optimizing the RAP particle size and content. The results also suggest that the black curve gradation assumption is not representative of the actual RAP particles contribution in a high RAP mix.

scholarly journals Recognition and sequestration of ω-fatty acids by a cavitand receptor

2015 ◽  
Vol 112 (36) ◽  
pp. 11181-11186 ◽  
Author(s):  
Simone Mosca ◽  
Dariush Ajami ◽  
Julius Rebek
Keyword(s):  
Fatty Acids ◽  
Driving Forces ◽  
Aqueous Media ◽  
Hydrophobic Effect ◽  
Binding Pocket ◽  
Binding Modes ◽  
Synthetic Receptors ◽  
Biologically Relevant ◽  
Comparative Binding ◽  
Long Chain

One of the largest driving forces for molecular association in aqueous solution is the hydrophobic effect, and many synthetic receptors with hydrophobic interiors have been devised for molecular recognition studies in water. Attempts to create the longer, narrower cavities appropriate for long-chain fatty acids have been thwarted by solvophobic collapse of the synthetic receptors, giving structures that have no internal spaces. The collapse generally involves the stacking of aromatic panels onto themselves. We describe here the synthesis and application of a deep cavitand receptor featuring “prestacked” aromatic panels at the upper rim of the binding pocket. The cavitand remains open and readily sequesters biologically relevant long-chain molecules—unsaturated ω-3, -6, and -9 fatty acids and derivatives such as anandamide—from aqueous media. The cavitand exists in isomeric forms with different stacking geometries and n-alkanes were used to characterize the binding modes and conformational properties. Long alkyl chains are accommodated in inverted J-shaped conformations. An analogous cavitand with electron-rich aromatic walls was prepared and comparative binding experiments indicated the role of intramolecular stacking in the binding properties of these deep container molecules.

scholarly journals Complex Analysis of Emission Properties of LEDs with 1D and 2D PhC Patterned by EBL

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 748
Author(s):  
Lubos Suslik ◽  
Jaroslava Skriniarova ◽  
Jaroslav Kovac ◽  
Dusan Pudis ◽  
Anton Kuzma ◽  
...  
Keyword(s):  
Complex Analysis ◽  
Near Field ◽  
Optical Microscope ◽  
Considerable Effect ◽  
Light Extraction Efficiency ◽  
Far Field ◽  
Light Emitting ◽  
Surface Emission ◽  
Emission Enhancement ◽  
Radiation Properties

In this paper, we present the optical and electrical properties of surface-patterned GaAs-based Multiquantum Well (MQW) light emitting diodes (LEDs) with one- and two-dimensional photonic crystal (PhC) structures. Optical properties were analyzed in the near and far field, measured by a near-field scanning optical microscope and with a goniophotometer. We demonstrated a strong effect of patterned PhC on the radiation properties and the light extraction efficiency. Enormous surface emission enhancement reaching 110% confirmed the strong effect of the patterned structure on the coupling of the guided modes into the surface emission. Additionally, the considerable effect of the PhC structure diffraction on radiation pattern was confirmed in the near and far field and is in good agreement with the simulated shape of the optical field.

Study of the main extracted species of cobalt(II) ion with dodecylthioglycolic acid as extractor

1986 ◽  
Vol 64 (1) ◽  
pp. 15-18 ◽  
Author(s):  
P. Beneitez ◽  
S. J. Ortiz ◽  
J. Ortega
Keyword(s):  
Acetic Acid ◽  
Ionic Strength ◽  
Sodium Nitrate ◽  
Thermal Gravimetric Analysis ◽  
Sodium Acetate ◽  
Aqueous Media ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Buffer Solutions ◽  
Organic Extractant

The distribution of cobalt(II) between water and an organic extractant (dodecylthioglycolic acid) dissolved in kerosene has been studied using a tracer of 60Co. The aqueous media wee always constituted by buffer solutions (acetic acid – sodium acetate) and the ionic strength was adjusted with sodium nitrate to 1 mol dm−3. The main species of cobalt(II) originating in the organic phase has been isolated and characterized on the basis of elemental analysis, thermal gravimetric analysis, and ir spectra.

Sign in / Sign up

Export Citation Format

Share Document