Encapsulation and Sustained Release of Curcumin using Superparamagnetic Silica Reservoirs

For controlled release and targeted delivery of curcumin in an aqueous medium a method of encapsulating curcumin and magnetic nanoparticles inside porous silica matrix has been developed. Curcumin and superparamagnetic nanoparticles are loaded inside porous silica in a single process. The graphic shows the TEM image of microtomed sample of Fe₃O₄ particles surrounded by a silica matrix.

     

Univalent polynomials and fractional order differences of their coefficients

Using fractional order differences, we find sufficient conditions on the coefficients of certain polynomials defined on the unit disk such that the zeros of these polynomials does not lie in D.     

Use of ultrasound in leather processing Industry: Effect of sonication on substrate and substances – New insights

Influence of ultrasound (US) on various unit operations in leather processing has been studied with the aim to improve the process efficiency, quality, reduce process time and achieve near-zero discharge levels in effluent streams as a cleaner option. Effect of US on substrate (skin/leather) matrix as well as substances used in different unit operations have been studied and found to be useful in the processing. Absorption of US energy by leather in process vessel at different distances from US source has been measured and found to be significant. Effect of particle-size of different substances due to sonication indicates positive influence on the diffusion through the matrix. Our experimental results suggest that US effect is better realized for the cases with pronounced diffusion hindrance. Influence of US on bioprocessing of leather has been studied and found beneficial. Attempts have also been made to improve the US aided processing using external aids. Operating US in pulse mode operation could be useful in order to reduce the electrical energy consumption. Use of US has also been studied in the preparation of leather auxiliaries involving mass-transfer resistance. Preliminary cost analysis carried out for ultrasound-assisted leather-dyeing process indicates scale-up possibility. Therefore, US application provide improvement in process efficiency as well as making cleaner production methods feasible. Hence, overall results suggest that use of US in leather industry is imminent and potential viable option in near future.     

Elastic and thermodynamical properties of A15 Nb3X (X = Al,Ga, In,Sn and Sb) compounds — First principles DFT study

Elastic and thermodynamical properties of Nb₃X (X = Al, Ga, In, Sn and Sb) compounds are obtained by performing the band structure calculations, using the FP-LAPW method. The calculated lattice constants, elastic constants, Bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, Debye temperature and anisotropy ratio are reported and the results agree with the available data. From the present study, it is observed that stiffness and shear resistance are found to be greater in Nb₃Sb than in other compounds. It is more brittle in nature and comparatively harder than other materials under study. The degree of anisotropy decreases as one moves across Nb₃Ga, Nb₃Al, Nb₃In, Nb₃Sb and Nb₃Sn. From the calculated values of the Debye temperature, it is observed that thermal conductivity is greater for Nb₃Sb and less for Nb₃In.     

Effect of A Sun Protection Intervention on the Immune Response to Measles Booster Vaccination in Infants in Rural South Africa

The incidence of many serious childhood infections can be reduced by vaccination. High sun exposure at the time of vaccination has been associated with a reduced antigen‐specific immune response. We hypothesized that providing sun protection advice and equipment to mothers of children who were waiting to be vaccinated would result in a more robust immunization response. We conducted a pilot study in 2015/2016 (data analyzed in 2017–2018) among 98 Black African children (~18 months of age) receiving the booster measles vaccination at two clinics in South Africa. Clinics were randomized to receive (or not) sun protection advice and equipment. We recorded demographic information on children and mothers and data on the child's usual sun exposure. At approximately 4 weeks’ postmeasles vaccination, we measured measles immunoglobulin G levels in children. All children with blood results (n = 87, 89%) across both groups had antibody titers higher than 200 mIU mL^?1 which was considered the protective antibody concentration. There was no statistically significant difference in titers between groups: geometric difference in mean titers 1.13 mIU mL^?1 (95% CI 0.85, 1.51; P = 0.39) and 1.38 mIU mL^?1 (95% CI 0.90, 2.11, P = 0.14) for unadjusted and adjusted analyses, respectively. This study demonstrated that a sun protection intervention study could be performed in a developing‐world pediatric vaccination setting. Although the sun protection intervention around the time of vaccination was not associated with a higher antibody level, given the potential importance of such an effect, a larger study should be considered.     

Enhancing the interfacial strength of glass/epoxy composites using ZnO nanowires

This paper investigated the application of ZnO nanowires (ZnO NW) to enhance the interfacial strength of glass/epoxy composites. ZnO NW were grown on glass fibers by hydrothermal method, tensile properties of bare and ZnO NW coated fibers were measured by single fiber tensile testing, wettability of fiber with resin was studied by contact angle measurements and finally the interfacial strength and mechanisms were determined by single fiber fragmentation testing of glass/epoxy composites. The surface coverage of ZnO NW on glass fibers was fairly uniform without formation of major clusters. The coating of ZnO NW slightly reduced the tensile strength and improved the tensile modulus of fibers. Wettability tests showed reduction in contact angles for ZnO NW coated fibers because of enhanced wetting and infiltration of epoxy resin into nanowires. In fragmentation testing of microcomposites, smaller and concentrated interfacial debonding zones for ZnO NW coated fibers indicated good stress transfer and strong interfacial adhesion. A new form of crossed and closely spaced stress patterns were observed for nanowires of high aspect ratios. The interfacial strength of ZnO NW coated fibers increased by at least 109% and by 430% on average, which was attributed to the increased surface area and mechanical interlocking provided by ZnO NW.     

Fluorimetric Study on Molecular Recognition of β-cyclodextrin with 2-amino-9-fluorenone

The molecular recognition interaction of β-cyclodextrin (β-CDx) was investigated using 2-amino-9-fluorenone (2AFN) by UV, steady-state fluorescence and time-resolved fluorescence measurements in aqueous solution at various pH. The effect of acidity on the ground and excited state equilibria between the neutral and the monocationic forms of 2AFN in water and in β-CDx environments are studied. Based on the change in the fluorescence spectrum and lifetimes of 2AFN by the addition of β-CDx, it is found that the unsubstituted part of the 2AFN is encapsulated in the hydrophobic cavity of β-CDx. The unusual red shift obtained for the protonation of amino group in water and β-CDx solution is due to large solvent relaxation of the monocation. The structure of the 1:1 inclusion complex between 2AFN and β-CDx has been proposed on the basis of ground and excited state pK _a values and the bond distances obtained by MOPAC/AM 1 data.     

Inclusion Complexation of 2-Amino-7-bromofluorene by β-Cyclodextrin: Spectral Characteristics and the Effect of pH

Spectral characteristics of 2-amino-7-bromofluorene (2ABF) have been studied in aqueous beta-cyclodextrin (beta-CDx) solution. Enhancement in the fluorescence intensity of the neutral from of 2ABF was observed due to the formation of 1:1 complex with beta-CDx. The formation of this complex was confirmed by time-resolved fluorescence spectroscopy. The ground state pKa value for the monocation-neutral equilibrium of 2ABF in beta-CDx shows no change with that in aqueous solution, but the excited state pKa value changes. Based on its photophysical and photoprototropic characteristics in beta-CDx, the structure of the 1:1 inclusion complex is proposed.     

Effects of Nonpolar Solvents on the Solubilization of Pepsin into Bis(2-Ethylhexyl) Sodium Sulfosuccinate and Cetyltrimethylammonium Bromide Reverse Micelles

Solubilization of pepsin by bis(2-ethylhexyl) sodium sulfosuccinate (AOT) and cetyltrimethylammonium bromide (CTAB) reverse micelles has been studied at 20C. Isooctane, cyclohexane and hexane were used as solvents, and n-butanol, amyl alcohol and hexanol were used as cosurfactants for CTAB. AOT concentrations were varied from 50 to 500 mM and pepsin concentrations were varied from 2 to 10 mg-mL^–1. At 250 mM, AOT can solubilize more than 85% of the Pepsin in each solvent. The effect of aqueous-phase pH on the solubilization of Pepsin has been studied from pH 1 to 8. The maximum solubilization of pepsin was observed below the isoelectric point (pI = 1.5) of the protein at pH 1.0 with 300 mM of AOT. The CTAB solutions were prepared by dissolving CTAB in isooctane with varying concentrations (0–100% v/v) of n-butanol, amyl alcohol or hexanol cosurfactants. It was found that 5% cosurfactant with 100 mM of CTAB was sufficient to solubilize more than 90% of the total pepsin. Pepsin solubilization by AOT reverse micelles increases with increasing polarizability and molar volume of the solvents.