Unstable parallel flows triggered by a fast chemical reaction

We present an experimental investigation of an instability triggered by a fast chemical reaction in a low inertia parallel flow in a small channel. Two fluids evenly injected in a straight channel react creating a strongly stratified distribution of viscosity near their interface, which destabilizes the flow. Depending on the flow rates and the aspect ratio of the flow channel, several unstable regimes are observed: mixing regime, weakly stratified regime and a stable stratified regime. In channels of 1:1 aspect ratio we find most efficient mixing (and highest flow resistance) at an intermediate pressure drops, as the flow transitions between a fully 3D regime and more stratified regime. For channels of small aspect ratio the non-monotonicity is less evident: higher pressure drops lead to increased mixing.     

Expression,Purification, Crystallization and X-Ray Crystallographic Analysis of MoDabb1 from Magnaporthe oryzae

Crystallography Reports - Protein acetylation is one of the most common post-translational modifications. Many acetylated proteins in Magnaporthe oryzae play key roles in vegetative growth and...     

Aqueous dispersion of graphene sheets stabilized by ionic liquid-based polyether

Graphene sheets can be effectively dispersed by a novel ionic liquid-based polyether, poly(1-glycidyl-3-methylimidazolium chloride) (PGMIC), in aqueous solution. The reduction of graphene oxide to graphene is confirmed by UV–Vis and Raman spectrum in aqueous solution of PGMIC. TEM image showed that the stable and uniform dispersion of graphene sheets were obtained. Both the TGA and AFM analysis indicated that the graphene sheet was covered by PGMIC. FTIR spectra demonstrated that n–π, cation–π interactions and electrostatic repulsions played important roles in the dispersion of graphene sheets.     

Characterization of the metabolites of H3B-6545 in vitro and in vivo by using ultra-high performance liquid chromatography combined with electrospray ionization linear ion trap-orbitrap tandem mass spectrometry

H3B-6545 is a selective ERα covalent antagonist, which has been demonstrated to be effective in anti-tumor. To fully understand its mechanism of action, it is necessary to investigate the in vitro and in vivo metabolic profiles. For in vitro metabolism, H3B-6545 (50 μM) was incubated with the hepatocytes of rat and human for 2 h. For in vivo metabolism H3B-6545 was orally administered to rats at a single dose of 10 mg/kg, and plasma, urine and fecal samples were then collected. All samples were analyzed by using ultra-high performance liquid chromatography combined with linear ion trap-orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS) operated in positive ion mode. The structures of the metabolites were elucidated by comparing their MS and MS² spectra with those of parent drug. A total of 11 metabolites, including a GSH adduct, were detected and structurally identified. M2, M7 and M8 were further unambiguously identified by using reference standards. Among these metabolites, M1, M5, M7 and M10 were newly found and reported for the first time. The metabolic pathways of H3B-6545 included deamination (M8 and M9), dealkylation (M2, M3 and M10), N-hydroxylation (M6), hydroxylation (M1 and M4), formation of amide derivatives (M5 and M7) and GSH conjugation (G1).     

Quantum Protocols for Private Set Intersection Cardinality and Union Cardinality Based on Entanglement Swapping

International Journal of Theoretical Physics - Quantum private set intersection cardinality (PSI-CA) and private set union cardinality (PSU-CA) are two specific primitives of classical secure...     

Construction of a novel cell-trappable fluorescent probe for hydrogen sulfide (H2S) and its bio-imaging application

Analytical and Bioanalytical Chemistry - Fluorescence detection of H2S in living organisms is greatly advantageous because it is nondestructive and can be used for in situ analysis. We have...     

Arsenic Speciation of Edible Shrimp by High-Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry (HPLC-ICP-MS): Method Development and Health Assessment

This study aimed at developing an accurate method for determining the levels of total arsenic (As) and arsenic species in edible shrimp with the collision/reaction cell (CRC) in the O₂ mass-shift mode to remove interferences. The microwave-assisted extraction method demonstrated satisfactory efficiency (86.9%), and As species were separated rapidly within 11?min when the optimized chromatographic conditions were adopted. During the study, the limits of detection, precision, and spike recovery for six arsenic species were in the ranges from 0.010 to 0.028?μg/L, 1.89 to 3.14%, and 96.9 to 103.2%, respectively. The analytical methods were successfully applied to determine the concentrations of total arsenic and As species in eight shrimp samples. The results showed that arsenobetaine was the predominant As species, and inorganic arsenic contents were below 0.5?mg/kg in the shrimp samples analyzed. The health risk assessment indicated that the shrimp samples detected posed no particular risk of As to local consumers.     

Wideband switchable dual-functional terahertz polarization converter based on vanadium dioxide-assisted metasurface

The terahertz technology has attracted considerable attention because of its potential applications in various fields.However,the research of functional devices,including polarization converters,remains a major demand for practical applications.In this work,a reflective dual-functional terahertz metadevice is presented,which combines two different polarization conversions through using a switchable metasurface.Different functions can be achieved because of the insulator-to-metal transition of vanadium dioxide(VO₂).At room temperature,the metadevice can be regarded as a linear-to-linear polarization convertor containing a gold circular split-ring resonator(CSRR),first polyimide(PI)spacer,continuous VO₂ film,second PI spacer,and gold substrate.The converter possesses a polarization conversion ratio higher than 0.9 and a bandwidth ratio of 81%in a range from 0.912 THz to 2.146 THz.When the temperature is above the insulator-to-metal transition temperature(approximately 68℃)and VO₂ becomes a metal,the metasurface transforms into a wideband linear-to-circular polarization converter composed of the gold CSRR,first PI layer,and continuous VO₂ film.The ellipticity is close to-1,while the axis ratio is lower than 3 dB in a range of 1.07 THz-1.67 THz.The metadevice also achieves a large angle tolerance and large manufacturing tolerance.     

Carbon fibers modified with carbon nanoparticles by a facile and fast flame preparation for in-tube solid-phase microextraction

Carbon fibers (CFs) were modified with carbon nanoparticles (CNPs) by a facile and fast flame preparation method. CNPs-CFs were observed by scanning electron microscope, and the nano-scaled granular structure on the surface was found. This material was also characterized by Raman microscope and X-ray photoelectron spectroscope. It was placed into a polyetheretherketone tube to get an extraction tube, which was connected with high performance liquid chromatography for online analysis. The tube displayed the effective extraction to several polycyclic aromatic hydrocarbons (PAHs), based on the possible hydrophobic and π stacking mechanism. Under the optimized conditions (60 mL of sample volume, 2.00 mL min^?1 of sample rate, 0.5% of methanol in sample, 2.0 min of desorption time), an analytical method towards these PAH targets was established. The low limits of detection (0.001–0.005 μg L^?1), satisfactory linear ranges (0.003–5.0 μg L^?1, 0.003–10.0 μg L^?1) and efficient enrichment factors (1012–3164) were presented. The method was applied to detect trace targets in several water samples and satisfactory results were obtained. The method provided some superiorities over other analytical methods, like online test, shorter time and better sensitivity.     

A facile approach to [1,2,4]triazolo[3,4-i]purine via PIDA oxidation ring-closing reaction

A facile conversion of 6-(2-arylidenehydrazineyl) purines to [1,2,4] triazolo [3,4-i] purines is presented using PhI(OAc)₂ as oxidant in only 10 min under room temperature. This approach is metal-free, wide functional group tolerant, and provides an efficient and convenient method to synthesize purine-fused tricyclics.