Experimental and Numerical Simulation Research on Boundary Layer Transition Front over a Swept Wing at M = 6

Fluid Dynamics - To predict the boundary layer transition on swept wings, experimental and numerical researches were conducted to obtained the accurate boundary layer transition front and to...     

Dynamic effect of constant inertial acceleration on vibration isolation system with high-order stiffness and Bouc–Wen hysteresis

Nonlinear Dynamics - Nonlinear vibration isolation provides with an effective way for vibration reduction with broad band and high efficiency. This investigation focuses on the dynamic effects of a...     

An AIE-Active probe for detection and bioimaging of pH values based on lactone hydrolysis reaction

Cellular pH homeostasis is essential for many physiological and pathological processes. pH monitoring is helpful for the diagnosis, treatment and prevention of disorders and diseases. Herein, we developed a ratiometric fluorescent pH probe (TCC) based on a coumarin derivative containing a highly active lactone ring. TCC exhibited a typical AIE effect and emitted blue fluorescence under weak acidic condition. When under weak basic condition, the active lactone moiety underwent a hydrolysis reaction to afford a water-soluble product, which gave red-shifted emission. The emission color change from blue through cyan and then to yellow within pH 6.5–9.0 which is approximate to the biological pH range. And the fluorescence color change along with pH value is reversible. Furthermore, TCC was successfully utilized in the detection of the intracellular pH change of live HeLa cells, which indicated that TCC had practical potential in biomedical research.

     

Simultaneous quantification of five biogenic amines based on LC–MS/MS and its application in honeybee venom from different subspecies

The use of honeybee venom in traditional medicine is increasing due to its unexpected beneficial effects in the treatment of diseases. In this study, a simple and environmentally friendly sample preparation procedure was developed to quantify five biogenic amines—histamine, 5-hydroxytryptamine, dopamine, adrenaline, and noradrenaline—in honeybee venom using high-performance liquid chromatography tandem mass spectrometry. The instrument and sample preparation method were optimized to achieve stable, sensitive, and accurate quantification of the five biogenic amines. The peak purities of five biogenic amines in bee venom were examined using a diode array detector to ensure that endogenous impurities will not interfere with biogenic amines during the chromatographic separation procedure. The correlation coefficient of each compound was higher than 0.998 in the range of 0.5–1000 ng/mL. The limits of detection and quantification of the developed method ranged between 0.09 and 0.17, and 0.3 and 0.59 μg/g, respectively. The average recoveries of spiked biogenic amines with different concentrations were higher than 70.95%, and the intra- and intermediate-day precisions were lower than 7.51% and 10.17%, respectively. The carry-over between each injection and the stability of the target analytes were also evaluated to ensure the effectiveness of this method. The data obtained are presented in various formats, including boxplot, heat map, and principal component analysis diagram, to visualize the differences in the biogenic amine contents of the honeybee venoms from different subspecies. This method hopes to provide the opportunity to distinguish the bee venom produced by different subspecies.     

Linear Arboricity of NIC-Planar Graphs

Acta Mathematicae Applicatae Sinica, English Series - A graph is NIC-planar if it admits a drawing in the plane with at most one crossing per edge and such that two pairs of crossing edges share at...     

Finite-time boundedness of uncertain Hamiltonian systems via sliding mode control approach

Nonlinear Dynamics - This paper seeks to address the problem of finite-time stabilization for a class of uncertain Hamiltonian systems via sliding mode control approach. A novel sliding function in...     

Synthesis and Structural Characterization of a Di-nuclear Uranyl Complex with Quinoline-6-carboxylate

Crystallography Reports - A di-nuclear uranyl complex with the formula of [(UO2)2(L)4(H2O)2]?4H2O (1) (HL = quinoline-6-carboxylic acid) was synthesized hydrothermally and characterized by...     

Two new sesquiterpenes from cultures of the higher fungus Pholiota nameko

Two new sesquiterpenes (1–2), along with one known sesquiterpene (3), were isolated from cultures of the higher fungus Pholiota nameko. The structures of new compounds were elucidated by extensive spectroscopic methods. The known compound was identified by comparing its spectroscopic data with those reported in the literature. All compounds were evaluated for their cytotoxicities against five human cancer cell lines.     

Self‐Assembly through Coordination and π‐Stacking: Controlled Switching of Circularly Polarized Luminescence

Multiple noncovalent interactions can drive self‐assembly through different pathways. Here, by coordination‐assisted changes in π‐stacking modes between chromophores in pyrene‐conjugated histidine (PyHis), a self‐assembly system with reversible and inversed switching of supramolecular chirality, as well as circularly polarized luminescence (CPL) is described. It was found that l ‐PyHis self‐assembled into nanofibers showing P‐chirality and right‐handed CPL. Upon Zn^II coordination, the nanofibers changed into nanospheres with M‐chirality, as well as left‐handed CPL. The process is reversible and the M‐chirality can change to P‐chirality by removing the Zn^II ions. Experimental and theoretical models unequivocally revealed that the cooperation of metal coordination and π‐stacking modes are responsible the reversible switching of supramolecular chirality. This work not only provides insight into how multiple noncovalent interactions regulate self‐assembly pathways.