A novel multiple-target chemoprobe (E)-N′-((9-pentyl-9H-carbazole-3-yl)methylene)thiophene-2-carbohydrazide (CTH) was designed, successfully synthesized and employed for the detection of Hg2+ and Fe3+ ions as off–on fluorometric and colorimetric responses, respectively, in H2O/DMF (10/90, v/v, Britton–Robinson buffer, pH 7) medium. The chemoprobe CTH demonstrated high sensitivity towards Hg2+ and Fe3+, among wide range of competitive cations with low recognition limits of 5.1 nM and 5.89 µM, respectively. The complexes of the chemoprobe CTH were synthesized and characterized by 1H-NMR titration, FT-IR and MALDI-TOF MS techniques, which confirmed the binding stoichiometries and the possible sensing mechanisms, were suggested based on the hydrolysis reaction of C=N group. The practical utility of the chemoprobe CTH was revealed in quantification of the trace amounts of Hg2+ and Fe3+ in water samples. Also, a silica-coated test paper was used for the fluorescent monitoring of Hg2+, providing a novel approach for the quantitative and on-site detection in real samples. More excitingly, a smartphone application was employed for the visual detection of Fe3+ by recognizing the RGB (red/green/blue) of the chemoprobe CTH solution.
We present a mini review of the Stueckelberg mechanism, which was proposed to make the abelian gauge theories massive as an alternative to Higgs mechanism, within the framework of Minkowski as well as curved spacetimes. The higher the scale the tighter the bounds on the photon mass, which might be gained via the Stueckelberg mechanism, may be signalling that even an extremely small mass of the photon which cannot be measured directly could have far reaching effects in cosmology. We present a cosmological model where Stueckelberg fields, which consist of both scalar and vector fields, are non-minimally coupled to gravity and the universe could go through a decelerating expansion phase sandwiched by two different accelerated expansion phases. We discuss also the possible anisotropic extensions of the model. 相似文献
Described herein is a new printing method—direct writing of conducting polymers (CPs)—based on pipette‐tip localized continuous electrochemical growth. A single barrel micropipette containing a metal wire (Pt) is filled with a mixture of monomer, supporting electrolyte, and an appropriate solvent. A droplet at the tip of the pipette contacts the substrate, which becomes the working electrode of a micro‐electrochemical cell confined to the tip droplet and the pipette. The metallic wire in the pipette acts as both counter and reference electrode. Electropolymerization forms the CP on the working electrode in a pattern controlled by the movement of the pipette. In this study, various width poly(pyrrole) 2D and 3D structures are extruded and characterized in terms of microcyclic voltammetry, Raman spectroscopy, and scanning electron microscopy.
A microscale chemistry improvement engine: a pre-dosed microscale high-throughput experimentation additives platform enables rapid, serendipitous reaction improvement. This platform allowed one chemist to set up 475 experiments and analyze the results using MISER chromatography in a single day, thus resulting in two high-quality catalytic systems for the construction of the title compound 1. Support for a single-electron transfer mechanism was obtained. 相似文献
This article aims to demonstrate an electrochemically stable and reliable gold electrode‐electrolyte system to develop an insect odorant receptor (Drosophila melanogaster Or35a) based bioelectronic nose. Cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS) of bare gold electrodes, after modification with the self‐assembled monolayer (SAM) of 6‐mercaptohexanoic acid (MHA) and after immobilization with Or35a integrated into the lipid bilayers of liposomes were conducted in the presence of four different redox probes. Potassium ferri/ferrocyanide [Fe(CN)6]3?/[Fe (CN)6]4? and hydroquinone (H2Q) redox probes revealed variable and irreversible signals at the time scale of our measurements, with atomic force microscopy (AFM) images and x‐ray photoelectron spectroscopy (XPS) results suggesting gold surface etching due to the presence of CN? ions in case of [Fe(CN)6]3?/[Fe (CN)6]4?. Although the hexaammineruthenium complex showed stable electrochemical behaviour at all stages of biosensor development, changes in CV and EIS readings after each surface modifications were insignificant. PBS buffer as a non‐Faradaic medium, was found to provide reliable systems for electrochemical probing of modified gold electrodes with Or35a/liposomes in aqueous media. Using this system, we have shown that this novel biosensor can detect its known odorant E2‐hexenal selectively compared to methyl salicylate down to femtomolar concentration. 相似文献
Olympic class sailing is a competitive sport and requires several abilities. An understanding of the responses to aerobic and anaerobic loading will be useful for assessing the training programs, protective strategies and possibility of injuries. Therefore, the aim of this study is to determine lower extremity main muscles skin temperature responses to aerobic and anaerobic test conditions in Turkish Olympic Sailing Athletes. Eighteen sailing athletes were assessed during preseasonal assessment period. Temperatures of quadriceps and hamstring muscle groups were evaluated bilaterally during rest and after Wingate Treadmill tests. Wingate test was accepted as an indicator of anaerobic performance and Treadmill test as an aerobic performance. Infrared thermography was performed to assess the skin temperature at anterior and posterior parts of thigh for both legs. In the triplicate comparison, the temperature changes between the rest, aerobic test and anaerobic test conditions were significant (p?<?0.05). In the analysis to determine the difference between the compared groups; for both muscle groups, temperature change after anaerobic performance was not significant; in contrast to this result the change in muscle temperature after aerobic performance was significant (p?<?0.05). Energetic—metabolic activity of major muscle groups of lower extremities during aerobic and anaerobic performance are important for injury prevention, treatment, rehabilitation and return to play. Present study shows that aerobic performance or activities requires higher energetic-metabolic activity.