An effective separation and purification of rutin and scoparone from Herba Artemisiae Scopariae by solid-phase extraction cartridges packed with an ionic liquid-based silica

Five types of ionic liquid-based silica were synthesized as solid-phase extraction (SPE) sorbents for separation and purification of bioactive compounds, that is, rutin and scoparone extracted from Herba Artemisiae Scopariae. The SilprBImCl material with the highest adsorption capacity was selected as the sorbent for SPE packing. Ethyl acetate and water were found to be suitable washing and eluting solvents, respectively. SilprBImCl was then applied to multi-phase extraction, and its superiority as a sorbent over the commercial cartridge was proven with high rutin and scoparone recoveries of 90.5% and 83.9%, respectively. This highlights the potential of ionic liquid-based silica materials applied to SPE and MPE.     

Photochemical Decomposition of Pesticide Chemicals in Aerosol Particles and Thin Films Relevant to Environmental Conditions

Contamination of the environment by pesticides is the inevitable aftermath of plant protection, and a substantial portion of pesticide pollutants exists in the form of aerosol particles levitated in the air and deposited on plants, and as the pesticide residues （thin films） on the surface of plant leaves. The sunlight photolysis could be the resource for the accelerated photochemical decomposition of pesticide compounds to minimize the long-term environmental contamination. The rates of photochemical decomposition of pesticide chemicals propiconazole （commercial formulation Tilt） and haloxyfop-ethoxyethyl （Zellek） were measured in particles of 0.12-1.3 μm in diameter and in films 0.04-0.2 μm thick. A specific polyaromatic sensitizer Shirvanol was used to induce accelerated decomposition of the above pesticide particulates under both the solar radiation and the artificial UV light. It was established that propiconazole decomposes by the sensitized photo-oxidation only, but haloxyfop-ethoxyethyl reacts in both the oxygen （air） and oxygen-free mediums via both the direct and sensitized reactions. The photochemical mechanisms are hypothesized and argued for the oxidative and non-oxidative decompositions. The haloxyfop-ethoxyethyl （Zellek） residues lbrmed on foliage upon pesticide treatments of agricultural fields would essentially decompose under sunlight via a direct photoreaction in 4-6 weeks, but the propiconazole （Tilt） contaminants probably need more time.     

Electrostatic Control of Structure in Self‐Assembled Membranes

Self‐assembling peptide amphiphiles (PAs) can form hierarchically ordered membranes when brought in contact with aqueous polyelectrolytes of the opposite charge by rapidly creating a diffusion barrier composed of filamentous nanostructures parallel to the plane of the incipient membrane. Following this event, osmotic forces and charge complexation template nanofiber growth perpendicular to the plane of the membrane in a dynamic self‐assembly process. In this work, we show that this hierarchical structure requires massive interfacial aggregation of PA molecules, suggesting the importance of rapid diffusion barrier formation. Strong PA aggregation is induced here through the use of heparin‐binding PAs with heparin and also with polyelectrolytes of varying charge density. Small angle X‐ray scattering shows that in the case of weak PA‐polyelectrolyte interaction, membranes formed display a cubic phase ordering on the nanoscale that likely results from clusters of PA nanostructures surrounded by polyelectrolyte chains.     

Forming Nanocrystalline Structures in Metal Particle Impact

Grain refinement by plastic deformation is becoming increasingly popular as a way of producing metals with improved properties, such as higher mechanical strength. Surface treatment techniques in which a metallic substrate is bombarded with metallic particles can generate nanocrystalline layers in the impact zone. Understanding the physical mechanisms underlying this grain refinement is crucial for achieving an improvement of existing experimental processes. In this article, we propose a numerical framework combining finite element (FE) simulations with a dislocation-based material model to predict the evolution of the microstructure under particle impact. A single particle normally impacting on a metallic substrate was simulated at different initial velocities. The simulations were compared with previously reported numerical and experimental data. The results indicate that our model accurately captures the grain refinement in the impact zone for a broad range of velocities. This approach provides valuable information on the formation of nanocrystalline layers in both the substrate and the impacting particle. Its potential applications include processes involving surface treatment by high velocity particles, such as shot peening, surface mechanical attrition treatment, kinetic metallization, cold spray, etc.     

Multifunctional Silver‐Exchanged Zeolite Micromotors for Catalytic Detoxification of Chemical and Biological Threats

Multifunctional reactive‐zeolite‐based micromotors have been developed and characterized toward effective and rapid elimination of chemical and biological threats. The incorporation of silver ions (Ag⁺) into aluminosilicate zeolite framework imparts several attractive functions, including strong binding to chemical warfare agents (CWA) followed by effective degradation, and enhanced antibacterial activity. The new zeolite‐micromotors protocol thus combines the remarkable adsorption capacity of zeolites and the efficient catalytic properties of the reactive Ag⁺ ions with the autonomous movement of the zeolite micromotors for an accelerated detoxification of CWA. Furthermore, the high antibacterial activity of Ag⁺ along with the rapid micromotor movement enhances the contact between bacteria and reactive Ag⁺, leading to a powerful “on‐the‐fly” bacteria killing capacity. These attractive adsorptive/catalytic features of the self‐propelled zeolite micromotors eliminate secondary environmental contamination compared to adsorptive micromotors. The distinct cubic geometry of the zeolite micromotors leads to enhanced bubble generation and faster movement, in unique movement trajectories, which increases the fluid convection and highly efficient detoxification of CWA and killing of bacteria. The attractive capabilities of these zeolite micromotors will pave the way for their diverse applications in defense, environmental and biomedical applications in more economical and sustainable manner.     

Rewired Cellular Metabolic Profiles in Response to Metformin under Different Oxygen and Nutrient Conditions

Metformin is a metabolic disruptor, and its efficacy and effects on metabolic profiles under different oxygen and nutrient conditions remain unclear. Therefore, the present study examined the effects of metformin on cell growth, the metabolic activities and consumption of glucose, glutamine, and pyruvate, and the intracellular ratio of nicotinamide adenine dinucleotide (NAD⁺) and reduced nicotinamide adenine dinucleotide (NADH) under normoxic (21% O₂) and hypoxic (1% O₂) conditions. The efficacy of metformin with nutrient removal from culture media was also investigated. The results obtained show that the efficacy of metformin was closely associated with cell types and environmental factors. Acute exposure to metformin had no effect on lactate production from glucose, glutamine, or pyruvate, whereas long-term exposure to metformin increased the consumption of glucose and pyruvate and the production of lactate in the culture media of HeLa and HaCaT cells as well as the metabolic activity of glucose. The NAD⁺/NADH ratio decreased during growth with metformin regardless of its efficacy. Furthermore, the inhibitory effects of metformin were enhanced in all cell lines following the removal of glucose or pyruvate from culture media. Collectively, the present results reveal that metformin efficacy may be regulated by oxygen conditions and nutrient availability, and indicate the potential of the metabolic switch induced by metformin as combinational therapy.     

Use of photodegradable inhibitors in UV-curable compositions to form polymeric 2D-structures by visible light

The process of two-wave photopolymerization of a UV-curable composition with an optically degrading inhibitor is considered. By numerical simulation, it is shown that in the composition layer uniformly exposed to UV-radiation, such systems allow getting segments with different conversion under the action of inhomogeneous visible light. Based on the data on the photopolymerization kinetics of the compositions from triethylene glycol dimethacrylate (TEGDMA) and bisphenol-A glycidyl dimethacrylate (bis-GMA) with the UV-initiator 2,2-dimethoxy-2-phenylacetophenone (DMPA), it was shown that 3,5-di-tert-butyl-o-benzoquinone (35Q) with N,N-dimethylaniline (DMA, “Aldrich”, 99%) can serve as an inhibitor that degrades under action of visible radiation. Combining inhomogeneous visible light generated with a conventional DLP-projector and uniform UV-radiation of LED (365 nm) the two-wave lithographic process was implemented to create polymeric 2D-structures in 20 μm layer of the compositions from TEGDMA (70)/bis-GMA (30)/DMPA (0.05 wt%)/35Q (0.5 wt%)/DMA (1 wt%).