Asymmetric Synthesis of Three Alkenyl Epoxides: Crafting the Sex Pheromones of the Elm Spanworm and the Painted Apple Moth.

A concise synthesis of the sex pheromones of elm spanworm as well as painted apple moth has been achieved. The key steps were the alkylation of acetylide ion, Sharpless asymmetric epoxidation and Brown's P2-Ni reduction. This approach provided the sex pheromone of the elm spanworm (1) in 31% total yield and those of the painted apple moth (2, 3) in 26% and 32% total yields. The ee values of three final products were up to 99%. The synthesized pheromones hold promising potential for use in the management and control of these pests.

Tip-like Fe-N4 Sites Induced Surface Microenvironments Regulation Boosts the Oxygen Reduction Reaction.

Single atom catalysts with defined local structures and favorable surface microenvironments are significant for overcoming slow kinetics and accelerating O2 electroreduction. Here, enriched tip-like FeN4 sites (T-Fe SAC) on spherical carbon surfaces were developed to investigate the change in surface microenvironments and catalysis behavior. Finite element method (FEM) simulations, together with experiments, indicate the strong local electric field of the tip-like FeN4 and the more denser interfacial water layer, thereby enhancing the kinetics of the proton-coupled electron transfer process. In situ spectroelectrochemical studies and the density functional theory (DFT) calculation results indicate the pathway transition on the tip-like FeN4 sites, promoting the dissociation of O-O bond via side-on adsorption model. The adsorbed OH* can be facilely released on the curved surface and accelerate the oxygen reduction reaction (ORR) kinetics. The obtained T-Fe SAC nanoreactor exhibits excellent ORR activities (E1/2 =0.91 V vs. RHE) and remarkable stability, exceeding those of flat FeN4 and Pt/C. This work clarified the in-depth insights into the origin of catalytic activity of tip-like FeN4 sites and held great promise in industrial catalysis, electrochemical energy storage, and many other fields.

Reducing the Ir-O Coordination Number in Anodic Catalysts based on IrOx Nanoparticles towards Enhanced Proton-exchange-membrane Water Electrolysis.

Due to the robust oxidation conditions in strong acid oxygen evolution reaction (OER), developing an OER electrocatalyst with high efficiency remains challenging in polymer electrolyte membrane (PEM) water electrolyzer. Recent theoretical research suggested that reducing the coordination number of Ir-O is feasible to reduce the energy barrier of the rate-determination step, potentially accelerating the OER. Inspired by this, we experimentally verified the Ir-O coordination number's role at model catalysts, then synthesized low-coordinated IrOx nanoparticles toward a durable PEM water electrolyzer. We first conducted model studies on commercial rutile-IrO2 using plasma-based defect engineering. The combined in situ X-ray absorption spectroscopy (XAS) analysis and computational studies clarify why the decreased coordination numbers increase catalytic activity. Next, under the model studies' guidelines, we explored a low-coordinated Ir-based catalyst with a lower overpotential of 231 mV@10 mA cm-2 accompanied by long durability (100 h) in an acidic OER. Finally, the assembled PEM water electrolyzer delivers a low voltage (1.72 V@1 A cm-2 ) as well as excellent stability exceeding 1200 h (@1 A cm-2 ) without obvious decay. This work provides a unique insight into the role of coordination numbers, paving the way for designing Ir-based catalysts for PEM water electrolyzers.

Analysis of Influencing Factors in the Preparation of Mullite Whiskers from Recovering Silicon-Rich Waste under Low-Temperature Conditions.

A large amount of catalyst waste containing silicon is deposited or buried every year, resulting in serious environmental pollution and a waste of resources. In this paper, a method to prepare mullite whiskers by recycling silica-rich waste under low-temperature conditions was investigated. The effects of raw materials, sintering temperature, catalyst addition, holding time and co-solvent addition on the structure, morphology and phase transition of the synthesized whiskers were investigated and characterized with SEM, XRD, TEM, TG and DTA. The results show that the addition of 10% Na2SO4 as the liquid-phase mass transfer medium could effectively improve the crystallization efficiency of mullite whiskers, while providing an ideal living environment for the growth of whiskers. The crystallinity and uniformity of mullite were positively correlated with the addition of aluminum fluoride trihydrate and the holding time, respectively. The growth law and conditions of mullite whiskers are discussed, and the optimal growth process conditions of mullite whiskers were optimized. The optimal conditions for mullite whiskers were determined as follows: the addition of aluminum fluoride is 5 wt%, the sintering temperature is 825 °C, and the holding time is 5 h at the time of sintering. This work offers new prospects for the industrial production of mullite whiskers from recycled silica-rich waste.

Analysis of Factors Influencing the Efficiency of Catalysts Used in Waste PU Degradation.

Polyurethane (PU) is an indispensable part of people's lives. With the development of polyurethane, the disposal of polyurethane waste has become a significant issue around the world. Conventional degradation catalysts have poor dispersion and low degradation efficiency when used in the process of solid degradation into liquid. Therefore, this paper innovatively adopts self-made core-shell nanoscale titanium catalysis, traditional alkali metal catalyst (KOH), and polyol to carry out the glycolysis of waste polyurethane (PU) pipeline foam. The homogenized nanoscale titanium catalyst coated with alcohol gel has an obvious core-shell structure. The alcohol gel not only protects the catalyst but also dissolves with the alcoholysis agent in the process of glycolysis and disperses more evenly into the alcoholysis agent to avoid the phenomenon of nanocatalyst agglomeration, so as to facilitate catalytic cracking without reducing catalyst activity. In this study, investigated and compared the production of renewable polyurethane foam via a one-step method based on use of a homogeneous core-shell nanostructured titanium catalyst vs. a traditional alkaline catalyst in terms of the properties of regenerated polyether polyols as well as of the foams produced from these polyols. The physicochemical properties of regenerated polyether polyols that were analyzed included viscosity, hydroxyl value, and average molecular weight. The regenerated polyurethane foams were characterized based on water absorption, TG, SEM, and thermal conductivity analyses. The results show that, when the addition of homogeneous titanium catalyst was T2 0.050 wt.%, the viscosity of regenerated polyether polyols was the lowest, at 5356.7 mPa·s, which was reduced by 9.97% compared with those obtained using the alkali metal catalyst (KOH). When the amount of titanium catalyst was T3 0.075 wt.%, the hard foam made of regenerated polyurethane prepared by the catalyst showed the best properties, with a compressive strength of 0.168 MPa, which is 4.76% higher than that of the foam prepared using KOH catalyst.

A comparative study of bacterial diversity based on effects of three different shade shed types in the rhizosphere of Panax quiquefolium L.

BACKGROUND: Shading is an important factor affecting the cultivation of American ginseng, as it influences crop quality and yield. Rhizosphere microorganisms are also crucial for normal plant growth and development. However, whether different shade types significantly change American ginseng rhizosphere microorganisms is unknown. METHODS: This study evaluated the rhizosphere soils of American ginseng under traditional, high flag and high arch shade sheds. High-throughput 16S rRNA gene sequencing determined the change of rhizosphere bacterial communities. RESULTS: The microbial diversity in rhizosphere soils of American ginseng significantly changed under different shading conditions. The bacteria diversity was more abundant in the high arch shade than flat and traditional shades. Different bacterial genera, including Bradyrhizobium, Rhizobium, Sphingomonas, Streptomyces and Nitrospira, showed significantly different abundances. Different shading conditions changed the microbial metabolic function in the American ginseng rhizosphere soils. The three types of shade sheds had specific enriched functional groups. The abundance of ATP-binding cassette (ABC) transporters consistently increased in the bacterial microbiota. These results help understand the influence of shading systems on the rhizosphere microecology of American ginseng, and contribute to the American ginseng cultivation.

Design and Evaluation of Asphalt Concrete Incorporating Plastic Aggregates Fabricated Using 3D Printing Technology.

Environmental protection and sustainability have been a serious challenge due to the excess amount of waste plastic, and the inefficient methods of its disposal. This study aims at exploring the feasibility of using plastic material in asphalt concrete followed by the design and evaluation of modified asphalt mix. Four different types of asphalt mixtures were made by mixing mineral aggregates with plastic aggregates of different shapes and sizes. The conventional dense-graded asphalt concrete incorporating mineral aggregates was selected as control material, whereas the other three types of asphalt mixtures were produced by substituting 3D-printed plastic aggregates for mineral aggregates. Marshall characteristics were utilized to evaluate the volumetric and mechanical properties of the asphalt mixtures. Test results show that the asphalt mixture containing solid plastic aggregate appears to have a 14.3% reduction in bulk density, thereby potentially reducing the haul costs. Due to the angular shape of the aggregate, the stability for the asphalt mixture containing the 3D-printed aggregate is 1.95 times higher than that for the asphalt mixture incorporating all mineral aggregates. The addition of the plastic printed aggregate enhances the strain capacity to achieve failure of the asphalt mixture. However, caution should be taken when incorporating the hollow or fine printed aggregates into the asphalt mixture due to their variation of volumetric properties.

Scalp EEG high frequency oscillations as a biomarker of treatment response in epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS).

PURPOSE: We investigated whether the presence of interictal scalp EEG high frequency oscillations (HFOs) in children with epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) can predict seizure and cognitive outcome after steroid therapy. METHODS: Twenty-two children with CSWS were prospectively enrolled and received methylprednisolone therapy. Interictal scalp HFOs, spike wave index (SWI) and intelligence quotient (IQ) were assessed before and after the treatment. The children were divided into two groups based on the early seizure reduction ratio at 2 weeks (≥50%, "response group"; otherwise "non-response group"). The "response group" was further divided into two subgroups ("relapse" and "non-relapse" subgroups) according to the late seizure outcome (after 3 months). RESULTS: Interictal HFOs and electrical status epilepticus in sleep (ESES) (defined as SWI ≥ 85%) were detected in all children at the baseline. In the response with relapse group (n = 11), the detection ratio of HFOs was significantly higher than that of ESES at 2 weeks (81.2 vs. 27.3%), 3 months (90.9 vs. 36.4%), and 6 months (100 vs. 54.5%) post-therapy. In the non-response group (n = 4), both HFOs and ESES persisted in all children. The average IQ improved significantly only in the response with non-relapse group. The persistence of HFOs negatively correlated with both the average IQ, yet the persistence of ESES did not. CONCLUSION: Interictal scalp HFOs may be a favorable non-invasive biomarker of predicting seizure and cognitive outcome in CSWS.

First Application of Ketogenic Diet on a Child With Intractable Epilepsy in Ghana.

The prevalence of epilepsy in sub-Saharan Africa is higher than in other parts of the world, but it is short of the effective measure on treating intractable epilepsy. Epilepsy surgery is not easy to be performed due to the high cost and demand of operational skills. The authors planned to perform ketogenic diet therapy for the children with intractable epilepsy in Ghana with regard to its low cost and simple procedure. The candidate is a 10-month-old girl with epilepsy with unknown etiology. Her seizures couldn't be controlled by more than 3 antiepileptic drugs. Her development delayed severely due to frequent seizures. The authors successfully applied ketogenic diet for her. Her seizures were completely controlled after 2 weeks' therapy. Her mental condition was improved after that. The authors get much experience from this case for further developing ketogenic diet in Africa. This is the first report that ketogenic diet was applied to control intractable epilepsy in West Africa.

Modulation of viability of live cells by focused ion-beam exposure.

Introduction of membrane-impermeant substances into living cells is the key method to understand contemporary cellular processes by investigating cellular responses and phenotypes. Here, we performed gold ion beam exposure into live cells by using the focused ion beam implantation method, which was originally developed to precisely control semiconductor device performances. We evaluated the viability of the gold-irradiated cells by measuring the concentration of adenosine triphosphate (ATP), which is an intracellular energy source produced in the mitochondrial membrane. The viability of the irradiated cells was found to be 20% higher than that of the unirradiated control cells. The atoms might promote the energy generating processes within the mitochondrion. Our results suggest that the viability of living cells can be modulated by accurately controlling the dopant atom numbers. Our technique may be considered as a potential tool in life and medical sciences to quantitatively elucidate the dose-dependent effects of dopants.

[Effects of Yifei Kangliu Oral Liquid on cell cycle and protein-nucleic acid synthesis of experimental lung cancer].

OBJECTIVE: To explore the effect of the traditional Chinese medicine Yifei Kangliu (YFKL) Oral Liquid on the proliferation, cell cycle and protein-nucleic acid synthesis of murine Lewis lung cancer cell and human lung adenocarcinoma cell line SPC-A-1. METHODS: The inhibiting rates of tumor growth were calculated by weighing the weight of tumor inoculated in vivo, combined by counting cancer cells in vitro. The ratio of the cell cycle and exponents of DNA, RNA, and protein were measured by flow cytometry (FCM). RESULTS: The inhibiting rate of tumor growth in the treated group with YFKL Oral Liquid was 30.38% (P<0.05). The proportion of cells in S phase of the treated groups with YFKL Oral Liquid was lower than that of the control group. In the group with most significant result, 72% of the cells were stagnated in G0/G1 phase. The inhibiting rates of DNA, RNA and protein in murine Lewis lung cancer were 7.4%, 23.73% and 23.31% respectively. In SPC-A-1 cell line, the inhibiting rates were 9.3%, 10.1% and 14.7% respectively, demonstrating amplified effects on lower levels. CONCLUSION: YFKL Oral Liquid significantly inhibited the proliferation of murine Lewis lung cancer cell and human lung adenocarcinoma cell line SPC-A-1 by blocking the cancer cells entering the proliferative phase resulted from its inhibition of DNA.