•Nano emulsions of neem and citronella oils developed and standardized.•Nano emulsions of neem and citronella oils mixture exhibited promising antifungal activity against phytopathogenic ...fungi.•Morphology, stability and particle size of nano emulsions were determined.•Nano emulsions could be useful to control of plant diseases caused by R. solani and S. rolfsii.
Biopesticides are considered to be safe, target specific, biodegradable and eco-friendly. These, especially Azadirachta indica A. Juss. (neem) based biopesticides, are mainly used as emulsified concentrate (EC). There is growing interest in nano emulsions based on phytochemical mixtures due to their better efficacy compared to conventional biopesticides. A. indica seed oil and Cymbopogon nardus (L.) Rendle (Citronella) oil are known to have pest control properties. However, their utilization is often restricted due to relatively low water solubility. This drawback can be overcome by encapsulating oils in oil-in-water (O/W) emulsions or nano emulsions using low or high energy methods. In this study, various nano emulsions of crude neem and citronella oils with surfactants were developed and characterised by Dynamic Light Scattering (DLS) and Transmission Electron Microscope (TEM). Composition of various ingredients of nano emulsions was standardised. TEM study showed the spherical shape of neem and citronella oil nano emulsions. The average size of droplets of neem nano emulsion (NNE) with different percentage of citronella oil ranged from 11.23±3.86nm to 17.80±4.52nm while that of citronella nano emulsion (CNE) with different percentage of neem oil ranged from 8.12±2.80nm to 12.04±3.74nm. It was found that increase in surfactant ratio to neem oil or citronella oil decreases the size of droplets in nano emulsions. Further, in vitro antifungal study of against Rhizoctonia solani and Sclerotium rolfsii was carried out by poisoned food technique. Results showed that neem nano emulsion 10 (NNE10) and citronella nano emulsion 10 (CNE10) were most active against R. solani (ED50 13.67mgL−1 and 25.64mgL−1) and S. rolfsii (ED50 14.71mgL−1 and 20.88mgL−1). The standardization of the composition and development of citronella essential oil and neem oil based nano emulsions and their antifungal activity against these two fungi has been reported for the first time.
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Nonionic surfactants have been widely used in agri-sprays to enhance the solubility and mobility of pesticides, but what happens when pesticides become solubilized into surfactant ...micelles remains poorly characterized. To facilitate physical characterisations, we used the nonionic surfactant hexaethylene glycol monododecyl ether (C12E6) as a model system to solubilize 4 pesticides including Cyprodinil (CP), Diuron (DN), Azoxystrobin (AZ) and Difenoconazole (DF). The investigation focused on the influence of solubilizate and temperature in driving changes to the micellar nanostructures. Dynamic light scattering (DLS), cryogenic transmission electron microscopy (Cryo-TEM) and small-angle neutron scattering (SANS) measurements were used to reveal changes to the micellar structure before and after pesticide solubilisation. Nuclear magnetic resonance (NMR) was also applied to investigate the solubility and location of each pesticide in the micelles. Pesticides clearly altered the micellar structure, by increasing the aggregation number and micellar lengths, whilst shrinking and dehydrating the shells, leading to a consequent decrease in the dispersion cloud points. Increases in temperature affected micellar structures in a similar way. Thus, temperature increases and the solubilisation of pesticides can both make the surfactant effectively more hydrophobic, altering the micellar nanostructures and shifting the pesticide location within the micelles. These changes subsequently implicate how pesticides are delivered into plants through the natural wax films.
Light scattering methods permit the determination of molar mass and hydrodynamic radius for a protein from first principles. They are, therefore, particularly useful for the biophysical ...characterization of any protein. Molar mass and hydrodynamic radius determinations may be used to demonstrate that the protein of interest multimerizes. In the endomembrane system, reversible and regulated assembly and multimerization of proteins is critical for building coats required for vesicle budding, for the function of membrane remodeling machines, for fission and fusion and for assembling and disassembling trafficking intermediates. Light scattering methods have therefore significantly contributed to the understanding of the underlying trafficking processes. Herein, we describe methods to express and purify the recombinant fungal SNX-BAR Mvp1, a membrane remodeling protein required for retrograde trafficking at the endosome. Using Mvp1 as an example, we provide protocols for determining its molar mass and hydrodynamic radius by multiangle static light scattering and dynamic light scattering, respectively. These methods can be applied directly to the study of other membrane trafficking proteins, yielding a wealth of biophysical and biochemical information.
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•AgNPs synthesized by successfully using Solanum surattense.•TEM results show the particle size of about 24 nm.•Synthesized AgNPs exhibits excellent antibacterial and anti-cancer ...activity.•AgNPs exhibits superior photocatalytic activity.
A novel eco-friendly and biocompatible method has been used with the help of Solanum surattense aqueous leaves extract to synthesis silver nanoparticles (AgNPs). The cost-effective green synthesis route has been given much care to ensure an environmentally friendly and straightforward approach, as it is most demanded in the biomedical industry. The proposed novel synthesis method offers additional compensations over other synthesizing approaches. Different analytical systems such as UV–vis, IR, XRD, DLS, SEM, EDAX, XPS, and TEM characterization techniques were used to understand the quality of the green synthesized nanoparticles for biomedical applications. The surface plasmon resonance peak of green synthesized silver nanoparticles at 446 nm was observed by UV absorbance spectral analysis. The XRD, SEM, and TEM analysis using to study the crystal structure, particle size, and surface morphology of the AgNPs. The results confirmed the synthesized spherical shape silver nanoparticles were crystallized in a face-centered cubic structure. The zeta potential measurement was used to authorize the excellent stability of AgNPs employing the dynamic light scattering method. FTIR spectral study confirmed that phytocompound participate in the bioreduction as well as stabilization of biosynthesized AgNPs by Solanum surattense. Also, the phytochemical content acts as the capping agent on surface AgNPs. The synthesized silver nanoparticles are subjected to antibacterial activity against both gram-positive and negative pathogenic bacteria for finding suitability in biocompatible applications. Also, the cytotoxicity of AgNPs was studied against the human breast cancer cell line and compared with one of the commercially available cancer drugs. Also, we have shown that the prepared AgNPs could serve as an excellent photocatalyst for degrading the Rhodamine B (RhB) dye and Acid Violet 7 (AV 7) dye under direct sunlight radiation.
The early stage of aggregation of titanium oxide (TiO2) nanoparticles was investigated in the presence of extracellular polymeric substance (EPS) constituents and common monovalent and divalent ...electrolytes through time-resolved dynamic light scattering (DLS). The hydrodynamic diameter was measured and the subsequent aggregation kinetics and attachment efficiencies were calculated across a range of 1–500 mM NaCl and 0.05–40 mM CaCl2 solutions. TiO2 particles were significantly aggregated in the tested range of monovalent and divalent electrolyte concentrations. The aggregation behavior of TiO2 particles in electrolyte solutions was in excellent agreement with the predictions based on Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Divalent electrolytes were more efficient in destabilizing TiO2 particles, as indicated by the considerably lower critical coagulation concentrations (CCC) (1.3 mM CaCl2 vs 11 mM NaCl). The addition of EPS to the NaCl and low concentration CaCl2 (0.05–10 mM) solutions resulted in a dramatic decrease in the aggregation rate and an increase in the CCC values. For solutions of 11 mM NaCl (the CCC values of TiO2 in the absence of EPS) and above, the resulting attachment efficiency was less than one, suggesting that the adsorbed EPS on the TiO2 nanoparticles led to steric repulsion, which effectively stabilized the nanoparticle suspension. At high CaCl2 concentrations (10–40 mM), however, the presence of EPS increased the aggregation rate. This is attributed to the aggregation of the dissolved extracellular polymeric macromolecules via intermolecular bridging, which in turn linked the TiO2 nanoparticles and aggregates together, resulting in enhanced aggregate growth. These results have important implications for assessing the fate and transport of TiO2 nanomaterials released in aquatic environments.
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•TiO2 particles were significantly aggregated in the tested electrolyte solutions.•Ca2+ ions were more efficient in destabilizing TiO2 NP than Na+ ions.•The aggregation of TiO2 NP in solutions was agreement with DLVO theory.•In NaCl and low CaCl2, EPS stabilized the NP suspension due to steric repulsion.•At high CaCl2, EPS increased aggregation rate of NPs by intermolecular bridging.
The photo differential scanning calorimetry (photo-DSC) is an appropriate method to characterize photopolymers used in additive manufacturing (AM). Important process parameters such as optimal ...ultraviolet (UV) exposure time and reaction heat can be attained by this method. However, achieving reliable and meaningful results from photo-DSC experiments requires careful sample preparation, i.e. the selection of a suitable sample shape, sample mass and sample holder (crucible). The sample shapes drop and spread with 1.0 mg and 2.8 mg sample masses were investigated in this study. Three different times from sample preparation until the start of the measurement (0, 4 and 7 h) were tested, in order to investigate different surface effects such as oxygen-diffusion, prior UV-curing through ambient radiation and evaporation of volatile components. While the 1.0 mg spread sample shape offers the thinnest film thickness (40 μm) and thus the closest comparability to high resolution print jobs, the 2.8 mg drop shape offers a more robust sample preparation with minimized surface effects. To further reduce time-dependent surface effects, this study shows how a preexisting test protocol was shortened from 42 min to 24 min without losing measuring accuracy. Furthermore, to reduce evaporation, different covers were placed on different crucibles, which were tested over time in the device’s automated sample changer (ASC) that enables automated and consecutive measurements. The combination of a cold pressed 85 μL crucible covered with a 300 μL Al2O3 crucible, which is removed shortly before the actual measurement, provides the best sample preparation for the ASC since mass loss remains below 1% for up to 10 h. Finally, two two-part resin systems, namely a methacrylate-urethane and an acrylate-epoxy based resin that are used in Digital Light Synthesis (DLS) are characterized part by part as well as in mixed state. Together with the investigation of different temperatures and atmospheres, it was possible to identify not only the part with the photoinitiator and the type of system (radical or cationic), but also a difference between methacrylates and acrylates with the aid of the photo-DSC method.
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•The 1.0 mg spread sample shape has shortest times to peak.•The 2.8 mg drop sample shape is more robust towards time-dependent surface effects.•EPX 82 follows a radical not a cationic or hybrid reaction system.•The reaction heat of EPX 82 is almost twice as much compared to RPU 70.•Sample preparation for reduced mass loss with the ASC of the DSC is presented.
•A strong emitting luminophore, CNH showing AIEE behavior has been synthesized.•The aggregate formation at higher water content is confirmed by AFM and DLS methods•CNH probe is utilized for solvent ...dependent colorimetric detection of Cu2+ and F−.•CNH interacts with Cu2+ and F− in 1:1 stoichiometry.•The color change of CNH probe with Cu2+ is due to ligand to metal charge transfer.
A 3-acetyl coumarin appended probe 3-((Z)-1-((E)-((2-hydroxynaphthalen-1-yl) methylene) hydrazono)ethyl)-2H-chromen-2-one (CNH) has been successfully synthesized and characterized by different spectroscopic tools via IR, 1H & 13C NMR and HRMS. The probe displays solvent dependent colorimetric detection of Cu2+ and F− ions in THF and DMF media, respectively. CNH interacts with Cu2+ in 1:1 stoichiometry with limit of detection 1.4 × 10−6 M. The color change of probe with addition of Cu2+ ions is due to ligand to metal charge transfer (LMCT) as suggested by UV–Vis spectra and DFT studies. Furthermore, CNH interacts with F− in 1:1 stoichiometry with detection limit 1.32 × 10−6 M by proton transfer mechanism from O-H to F−, which enhances the electron density on CNH molecule as suggested by UV–Vis, NMR titration and DFT studies. In addition to intriguing colorimetric sensing applications, CNH displays remarkable aggregation induced emission (AIE) property in DMF/water binary mixture. The probe is almost non-fluorescent in solution but becomes strongly emissive in aggregate/solid state. The formation of aggregates at higher water content is confirmed by atomic force microscopy (AFM) and dynamic light scattering (DLS) studies in mixed water media. DLS measurements suggest the increase in average particle size from 100 nm to 299 nm upon increasing water fractions from (fw = 10%) to (fw = 90%). AFM studies also provide additional information about the aggregates at higher water fraction. In the range of 100–500 nm, the topography of surface shows that the aggregates are spherical in shape (fw = 90%).
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Hypothesis: Common amphiphilic drug molecules often have a more rigid nonpolar part than conventional surfactants. The rigidity is expected to influence the self-assembling properties ...and possibly give rise to aggregation patterns different from that of regular surfactants.
Experiments: We have investigated self-assembling properties of the hydrochloride salts of adiphenine (ADP), pavatrine (PVT), and amitriptyline (AMT) at concentrations up to 50 wt% using small-angle x-ray scattering, dynamic light scattering, cryo-transmission electron microscopy, and surface tension measurements.
Findings: All drugs form small micelles of oblate spheroidal shape at concentrations above the critical micelle concentrations (CMC). The micelles grow weakly in size up to about 20 wt%, where the aggregation number reaches a maximum followed by a slight decrease in size at higher drug concentrations. We observe a correlation between the decrease in micelle size at high concentrations and an increasing charge of the micelles, as the degree of ionization increases with increasing drug concentration and decreasing pH. In contrast to what has previously been reported, the aggregation behavior of all studied drugs resembles the closed association behavior of conventional surfactants with a short aliphatic chain as hydrophobic tail group i.e. the micelles are always small in size and lack a second CMC. CMC values were determined with surface tension measurements, including also lidocaine hydrochloride (LDC) and chlorpromazine hydrochloride (CHL).
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