β-Cyclodextrin-Modified Mesoporous Silica Nanoparticles with Photo-Responsive Gatekeepers for Controlled Release of Hexaconazole

In the present research, photo-responsive controlled-release hexaconazole (Hex) nanoparticles (Nps) were successfully prepared with azobenzene (Azo)-modified bimodal mesoporous silica (BMMs), in which β-cyclodextrin (β-CD) was capped onto the BMMs-Azo surface via host–guest interactions (Hex@BMMs/Azo/β-CD). Scanning electron microscopy (SEM) confirmed that the nanoparticles had a spherical structure, and their average diameter determined by dynamic light scattering (DLS) was found to be 387.2 ± 3.8 nm. X-ray powder-diffraction analysis and N2-adsorption measurements indicated that Hex was loaded into the pores of the mesoporous structure, but the structure of the mesoporous composite was not destroyed. The loading capacity of Hex@BMMs/Azo/β-CD nanoparticles for Hex was approximately 27.3%. Elemental components of the nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS) and electron dispersive spectroscopy (EDS). Ultraviolet–visible-light (UV–Vis) absorption spectroscopy tests showed that the azophenyl group in BMMs-Azo undergoes effective and reversible cis-trans isomerization under UV–Vis irradiation. Hex@BMMs/Azo/β-CD Nps exhibited excellent light-sensitive controlled-release performance. The release of Hex was much higher under UV irradiation than that in the dark, which could be demonstrated by the bioactivity test. The nanoparticles also displayed excellent pH-responsive properties, and the sustained-release curves were described by the Ritger–Peppas release kinetic model. BMMs nanocarriers had good biological safety and provided a basis for the development of sustainable agriculture in the future.

High-performance ternary organic photovoltaics with NC70BA as the third component material enabling thickness-insensitive photoactive performance

In this work, a thinner (100 nm) and thicker (150 nm and 200 nm) ternary organic photovoltaic (OPV) are fabricate by D18 as donor, Y6 as acceptor and NC70BA as third component materials. The addition of the hollow 3D spherical structure of NC70BA into D18:Y6 binary films is helpful for improving phase separation and smooth surface of ternary photoactive layer, and form more continuous electron transport channels in ternary photoactive layers. It is enhance photovoltaic performance under not only thinner photoactive layer thickness but also thicker photoactive layer thickness. Our results demonstrate the feasibility of employing D18:Y6 as a binary photovoltaic layer and fullerene derivative NC70BA as a third component material and has construct high-efficiency thickness-insensitive ternary OPVs; this approach would promote the development of thicker photoactive layer ternary OPVs to fulfil the requirements of solution coating processes.

TEST OF A NET DOME FRAGMENT

A geodesic or net dome, also known as a Fuller’s dome, is a spherical structure. Geodesic domes are well receptive to asymmetric loads, especially snow and wind, have high aerodynamics, increased rigidity and stability. It should be noted that the larger the diameter of the sphere, the greater its bearing capacity, and the strength of such dome slightly depends on the building materials used. With significant advantages, the design and construction of wooden net domes has not become widespread. The fact is that net domes are spatial structures with a large number of elements, which accordingly entails a large number of nodes. The elements of the dome are connected with dowels, wet film gauge, bolts, wood screws, staples, screws, nails. Adhesive connections on washers are used, also steel clamps, straps, overlays are applied. However, they all have disadvantages, the scope of each connector is different, and their cost is often comparable to the cost of the dome elements. We offer a universal connector for connecting dome parts at any angle. As a result of introduction of such technical decision of knot, we receive essential simplification of a design, reduction of quantity of components, at the same time with increase of its manufacturability. To study the operation of the joint of wooden glue-board elements of the dome with the use of a universal connector, its experimental studies were carried out. The purpose of the study: to study the actual operation of the connection of wooden parts of the dome with a universal connector in the form of rotating fasteners that rotate freely on the draw bolt, to assess its strength and deformability, to assess the possibility of using such a connection in the design of spatial structures. To solve the tasks, a full-scale fragment of the dome was tested, which includes characteristic nodes with rigid adjacency of elements to each other.

Insight role of TiO2 to improve the photocatalytic performance of WO3 nanostructures for the efficient degradation of ciprofloxacin

The current research work is to investigate the photocatalytic efficiency and degradation of ciprofloxacin using WO3/TiO2 nanoparticles under visible light irradiation. The nanoparticles of tungsten trioxide (WO3) and its composite with titanium dioxide (TiO2) i.e. WO3/TiO2 was prepared by hydrothermal method. Four basic characterizations were performed to study the prepared sample materials. To study the morphology of the prepared samples, scanning electron microscopy (SEM) was used. The results of SEM clearly showed that tungsten trioxide (WO3) has Rectangular shaped structure. The average size of the pure Tungsten trioxide nanoparticles was about 40–540 nm. The composite of WO3/TiO2 has spherical structure. The reason behind that was the addition of TiO2 in WO3 changes the morphology of pure WO3, and transformed the rectangular structure to a spherical structure. The presence of TiO2 changes the position and orientation of the nanorods in all possible directions. For the detailed analysis of the functional groups present in these samples, band gap, and optical properties of these samples, Fourier transform infrared spectroscopy (FTIR), ultraviolet visible (UV–VIS) spectroscopy and Photoluminescence (PL) emission spectroscopy was used. UV–Vis spectroscopy results showed that the bandgaps of prepared catalysts vary within the range of 2.76 – 2.5 eV. This decrease in bandgap is directly related with the concentration ratio of TiO2 in WO3. The maximum excitation wavelength observed at 440 nm. The maximum degradation efficiency was at 2% of WO3/TiO2 composite catalyst due to unique morphological structure and increase rate of photo absorption.

Cryo-EM structure of the NLRP3 decamer bound to the cytokine release inhibitory drug CRID3

NLRP3 is an intracellular sensor protein whose activation by a broad spectrum of exogenous and endogenous stimuli leads to inflammasome formation and pyroptosis. The mechanisms leading to NLRP3 activation and the way how antagonistic small molecules function remain poorly understood. Here we report the cryo-electron microscopy structures of full-length NLRP3 in its native form and complexed with the inhibitor CRID3 (also named MCC950). Inactive, ADP-bound NLRP3 is a decamer composed of homodimers of intertwined LRR domains that assemble back-to-back as pentamers with the NACHT domain located at the apical axis of this spherical structure. Molecular contacts between the concave sites of two opposing LRRs are mediated by an acidic loop extending from an LRR transition segment. Binding of CRID3 significantly stabilizes the NACHT and LRR domains relative to each other, allowing structural resolution of 3.9-4.2 Ang. CRID3 binds into a cleft, connecting four subdomains of the NACHT with the transition LRR. Its central sulfonylurea group interacts with the Walker A motif of the NLRP3 nucleotide-binding domain and is sandwiched between two arginines from opposing sites, explaining the specificity of NLRP3 for this chemical entity. With the determination of the binding site of this lead therapeutic, specific targeting of NLRP3 for the treatment of autoinflammatory and autoimmune diseases and rational drug optimization are within reach.

Nanocellulose Production Using Ionic Liquids with Enzymatic Pretreatment

Nanocellulose has gained increasing attention during the past decade, which is related to its unique properties and wide application. In this paper, nanocellulose samples were produced via hydrolysis with ionic liquids (1-ethyl-3-methylimidazole acetate (EmimOAc) and 1-allyl-3-methylimidazolium chloride (AmimCl)) from microcrystalline celluloses (Avicel and Whatman) subjected to enzymatic pretreatment. The obtained material was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS), scanning electron microscopy (SEM), and thermogravimetric analysis (TG). The results showed that the nanocellulose had a regular and spherical structure with diameters of 30–40 nm and exhibited lower crystallinity and thermal stability than the material obtained after hydrolysis with Trichoderma reesei enzymes. However, the enzyme-pretreated Avicel had a particle size of about 200 nm and a cellulose II structure. A two-step process involving enzyme pretreatment and hydrolysis with ionic liquids resulted in the production of nanocellulose. Moreover, the particle size of nanocellulose and its structure depend on the ionic liquid used.

The influence of Gum Arabic on the physicochemical and antimicrobial activity of the microencapsulated Mahkota Dewa (Phaleria macrocarpa) leaves

Mahkota Dewa (Phaleria macrocarpa) also known as God's Crown has been historically used as an indispensable alternative herbal medicine. Microencapsulation is a process whereby tiny particles or droplets are engulfed or enclosed in a coating matrix to produce small capsules. Generally, without microencapsulation, powders are fragile materials that could easily interfere with other components that are difficult to dissolve in water, lose their beneficial properties and decrease shelf life. It is hoped that the microencapsulation would increase the consistency of the powder during storage and maintain its beneficial properties. The goal of this research is to investigate the physicochemical and antimicrobial activity of Mahkota Dewa leaves encapsulated in different concentrations of gum Arabic (GA) and to determine the form of antioxidant and their role and properties. Mahkota Dewa leaves powders were microencapsulated in 0%, 2%, 4%, 6%, 8% and 10% gum Arabic using an ultrasonic spray dryer at 90οC. The microencapsulated Mahkota Dewa leaves (MMDL) samples were subjected to physicochemical and antimicrobial activity. The results showed that the 6% GA MMDL exhibited the highest yield (3.91%) while 0% GA was the lowest yield (1.64%). The highest total phenolic and flavonoid content was exhibited by 2% GA. The highest DPPH inhibition was depicted in 0% GA which indicates the highest antioxidant activity (54.9±0.01%) and is significantly (p<0.05) different from other samples. The highest inhibition was exhibited in 0% GA in the TBA method and FTC analysis. The encapsulated powders were identified to have weak antimicrobial activity against Bacillus cereus, Escherichia coli, Staphylococcus aureus, Salmonella and Listeria monocytogenes. The powders produced have an irregularly spherical structure and smooth surface with some dented spots on the surface. The different concentration of gum Arabic resulted in different antioxidant activity, flavonoid content and antimicrobial activity of MMDL.