UPLC-ELSD Determination of 1-Octacosanol in Raw Material and Health Products

Determination of the levels of 1-octacosanol is important in food stuff for the study of its pharmacological activities and health benefits. In this study, a novel, simple and fast internal standard method for the non-derivatization ultra-performance liquid chromatographic determination of 1-octacosanol in raw materials and health products was developed and validated based on evaporative light scattering detection. The linearity (r ² > 0.998), recovery (99.1–100.2%, RSD <2.7%), intra- and inter-day precision (RSD <3.8%), limit of detection (1.0 mg/L), limit of quantification (2.2 mg/L) of the 1-octacosanol were determined. The method was successfully applied to nine real 1-octacosanol products. The results of analyses had close agreement with the labeled claims of 1-octacosanol content in these products. Compared with the classical gas chromatography method, the developed method was simpler, faster and more environmentally friendly due to avoiding any derivatization step. This protocol represents a rapid and feasible method for quality control of 1-octacosanol products.

     

Synthesis and Insecticidal Activities of Chlorothiazolyl Analogs of Nitromethylene Neonicotinoids with Tetrahydropyridine Fixed cis‐Configuration

The chlorothiazolyl moiety was an effective bioisoster of chloropyridyl in pesticide molecular design. Replacement of chloropyridyl in cis‐nitromethylene neonicotinoids with chlorothiazolyl generated the chlorothiazolyl counterpart of nitromethylene neonicotinoids with tetrahydropyridine fixed cis‐configuration. Bioassay against cowpea aphis (Aphis craccivora) indicated that the chlorothiazolyl analogs could maintain the high insecticidal activity.     

Ternary blends based on poly (ethylene-naphthalate)/glass fibers/nitrile rubber: Preparation,properties and effect of dynamic vulcanization

This work studied the possibility of utilizing nitrile rubber (NBR) to modify the impact properties of poly (ethylene-naphthalate) (PEN). The PEN/NBR ratio used changed from 100/0 to 60/40. At the same time, glass fibers (GF), 40% weight of the PEN component, were used to reinforce the blends to compensate for the loss of mechanical properties of PEN by incorporation of NBR. The results showed that the impact strength of the PEN/GF/NBR blend (PEN/NBR = 60/40) was increased up to 27.6J/m, nearly 5 times higher than that of the neat PEN. Meanwhile, the tensile strength and flexural strength were still maintained at as high as 66.1 MPa and 98.2 MPa, respectively. Dynamic vulcanization further improved the mechanical properties of the PEN/GF/NBR blends, which provided routes to the design of new PEN/elastomer blends. Other properties of the PEN/GF/NBR blends were also investigated in terms of morphology of fractured surface, dynamic mechanical behavior, thermal stability and crystallization, by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively.     

High‐Order Soliton Solution of Landau–Lifshitz Equation

The Landau–Lifshitz equation is analyzed via the inverse scattering method. First, we give the well‐posedness theory for Landau–Lifshitz equation with the frame of inverse scattering method. The generalized Darboux transformation is rigorous considered in the frame of inverse scattering transformation. Finally, we give the high‐order soliton solution formula of Landau–Lifshitz equation and vortex filament equation.     

Preparation of polypropylene/ethylene‐propylene‐diene terpolymer/nitrile rubber ternary thermoplastics vulcanizates with good mechanical properties and oil resistance by core‐shell dynamic vulcanization

As the most successful commercialized thermoplastic vulcanizates (TPVs), polypropylene (PP)/ethylene propylene rubber (EPDM) TPVs exhibit poor oil resistance. In this work, we prepared PP/EPDM/butadiene acrylonitrile rubber (NBR) ternary TPVs with good oil resistance using core‐shell dynamic vulcanization. According to the theoretical analysis of the spreading coefficient and the transmission electron microscopy results, the rubber phases exhibited a special core‐shell structure, in which the cross‐linkedNBR‐core was encapsulated by the EPDM‐shell. The core‐shell structure effectively improved the interfacial compatibility between PP and NBR phase as the EPDM‐shell could avoid the direct contact of them, thus improving the mechanical properties of the TPVs. For example, the PP/EPDM/NBR (40/30/30) ternary TPV showed enhanced tensile strength of 12.57 MPa, compared with 10.71 MPa of PP/EPDM (40/60) TPV and 11.11 MPa of PP/NBR (40/60) TPV, respectively. Moreover, the oil resistance of the TPVs was also improved. Compared with PP/EPDM TPV, the change rates in mass, volume, tensile strength and elongation at break of PP/EPDM/NBR TPV after oil immersion decreased by 42.18%, 48.69%, 52.68% and 28.77%, respectively.     

High‐Performance K–CO2 Batteries Based on Metal‐Free Carbon Electrocatalysts

Metal–CO₂ batteries have attracted much attention owing to their high energy density and use of greenhouse CO₂ waste as the energy source. However, the increasing cost of lithium and the low discharge potential of Na–CO₂ batteries create obstacles for practical applications of Li/Na–CO₂ batteries. Recently, earth‐abundant potassium ions have attracted considerable interest as fast ionic charge carriers for electrochemical energy storage. Herein, we report the first K–CO₂ battery with a carbon‐based metal‐free electrocatalyst. The battery shows a higher theoretical discharge potential (E^?=2.48 V) than that of Na–CO₂ batteries (E^?=2.35 V) and can operate for more than 250 cycles (1500 h) with a cutoff capacity of 300 mA h g^?1. Combined DFT calculations and experimental observations revealed a reaction mechanism involving the reversible formation and decomposition of P12₁/c1‐type K₂CO₃ at the efficient carbon‐based catalyst.     

A Phototheranostic Strategy to Continuously Deliver Singlet Oxygen in the Dark and Hypoxic Tumor Microenvironment

Continuous irradiation during photodynamic therapy (PDT) inevitably induces tumor hypoxia, thereby weakening the PDT effect. In PDT‐induced hypoxia, providing singlet oxygen from stored chemical energy may enhance the cell‐killing effect and boost the therapeutic effect. Herein, we present a phototheranostic (DPPTPE@PEG‐Py NPs) prepared by using a 2‐pyridone‐based diblock polymer (PEG‐Py) to encapsulate a semiconducting, heavy‐atom‐free pyrrolopyrrolidone‐tetraphenylethylene (DPPTPE) with high singlet‐oxygen‐generation ability both in dichloromethane and water. The PEG‐Py can trap the ¹O₂ generated from DPPTPE under laser irradiation and form a stable intermediate of endoperoxide, which can then release ¹O₂ in the dark, hypoxic tumor microenvironment. Furthermore, fluorescence‐imaging‐guided phototherapy demonstrates that this phototheranostic could completely inhibit tumor growth with the help of laser irradiation.     

Circularly Polarized Luminescence of Aluminum Complexes for Chiral Sensing of Amino Acid and Amino Alcohol

Determination of the absolute configuration (AC) of chiral molecules is a key issue in many fields related to chirality such as drug development, the asymmetric reaction screening, and the structure determination of natural compounds. Although various methods, such as X‐ray crystallography and NMR spectroscopy, are used to determine the AC, a simple and cheap alternative method is always anticipated. So far, electronic circular dichroism (ECD) spectroscopy has been widely used to ascertain the AC and enantiomeric excess (ee) values by applying appropriate organic probes. Here, circularly polarized luminescence (CPL) spectroscopy was applied to determine the AC and ee values of a series of amino acid and amino alcohol. The measurements were conducted by mixing the amino acids or amino alcohols with an achiral 1‐hydroxy‐2‐naphthaldehyde. Upon in situ formation of the Schiff base complexes, the system showed emission enhancement and CPL in the presence of Al³⁺, whose intensity and sign can be used to assign the chiral sense of the amino acids and amino alcohols. The authenticity of the method was further compared with the established CD spectroscopy, revealing that CPL spectra of formed Al³⁺ complex were effective to determine the AC of chiral species.