226 research outputs found
Molecular fluorescent probes for monitoring pH changes in living cells
No full textThe availability of synthetic fluorescent probes and the development of powerful new approaches to microscopy have made fluorescence microscopy an essential tool for biomedical science and biology. Intracellular pH plays vital roles in physiological and pathological processes (e.g., receptor-mediated signal transduction, cell growth and apoptosis, ion transport, and homeostasis). Due to the presence of an H+ acceptor linked to the fluorophore, some small molecular fluorescent probes display pH-sensitive absorption and fluorescence emission. Such behavior has been employed to engineer pH indicators for studies of pH regulation in vivo. The review summarizes advances in the creation of novel molecular fluorescent pH probes and their applications in biomedicine and cell biology, especially focusing on the design and the synthesis of small molecular probes for monitoring pH changes in living cells. (C) 2010 Elsevier Ltd. All rights reserved.The availability of synthetic fluorescent probes and the development of powerful new approaches to microscopy have made fluorescence microscopy an essential tool for biomedical science and biology. Intracellular pH plays vital roles in physiological and pathological processes (e.g., receptor-mediated signal transduction, cell growth and apoptosis, ion transport, and homeostasis). Due to the presence of an H+ acceptor linked to the fluorophore, some small molecular fluorescent probes display pH-sensitive absorption and fluorescence emission. Such behavior has been employed to engineer pH indicators for studies of pH regulation in vivo. The review summarizes advances in the creation of novel molecular fluorescent pH probes and their applications in biomedicine and cell biology, especially focusing on the design and the synthesis of small molecular probes for monitoring pH changes in living cells. (C) 2010 Elsevier Ltd. All rights reserved
Highly sensitive and selective colorimetric and off-on fluorescent probe for Cu2+ based on rhodamine derivative
No full textA new probe for Cu2+ based on the Cu2+-induced reversible ring-opening mechanism of the rhodamine spirolactam was described. It displayed a highly selective and sensitive "turn-on" fluorescent and colorimetric response toward Cu2+.A new probe for Cu2+ based on the Cu2+-induced reversible ring-opening mechanism of the rhodamine spirolactam was described. It displayed a highly selective and sensitive "turn-on" fluorescent and colorimetric response toward Cu2+
Stereoisomeric profiling of pharmaceuticals ibuprofen and iopromide in wastewater and river water, China
No full textEnhancing thermoelectric output in a molecular heat engine utilizing Yu-Shiba-Rusinov bound states
No full textAbstract Particle exchange heat engines are a novel class of cyclic heat engines that are all-electrical, contain no moving parts and can therefore be scaled down to nanometer size. At the center of their operation is the manipulation of a particle flow between a hot and a cold reservoir through energy filtering mechanisms, where their efficiency depends primarily on the sharpness of the energy filter. In this study, we investigate the efficiency enhancement of such engines by utilizing ultra-sharp transmission resonances formed by magnetic impurities interacting with superconductors, known as Yu-Shiba-Rusinov bound states. To this end, we couple a neutral and stable diradical molecule to superconducting break-junction electrodes, and study its thermoelectric properties at ultra-low temperatures. By driving the molecular heat engine through a phase transition from a Kondo state into the Yu-Shiba-Rusinov regime, we observe a five fold increase in the thermoelectric power factor. This observation could pave the way for practical applications such as cryogenic waste heat recovery and efficient spot-cooling for future quantum computing architectures
Enhancing thermoelectric output in a molecular heat engine utilizing Yu-Shiba-Rusinov bound states
Get PDFParticle exchange heat engines are a novel class of cyclic heat engines that are all-electrical, contain no moving parts and can therefore be scaled down to nanometer size. At the center of their operation is the manipulation of a particle flow between a hot and a cold reservoir through energy filtering mechanisms, where their efficiency depends primarily on the sharpness of the energy filter. In this study, we investigate the efficiency enhancement of such engines by utilizing ultra-sharp transmission resonances formed by magnetic impurities interacting with superconductors, known as Yu-Shiba-Rusinov bound states. To this end, we couple a neutral and stable diradical molecule to superconducting break-junction electrodes, and study its thermoelectric properties at ultra-low temperatures. By driving the molecular heat engine through a phase transition from a Kondo state into the Yu-Shiba-Rusinov regime, we observe a five fold increase in the thermoelectric power factor. This observation could pave the way for practical applications such as cryogenic waste heat recovery and efficient spot-cooling for future quantum computing architectures
Swing response measuring and nonlinear error modification of suspended structure system in pendulum vibration mode
No full textIn order to solve the state measurement problem of pendulum vibration of a suspended mass system in multi-motion modes, the inclinometer sensors based on acceleration measuring principle are introduced and the formulation of the gain coefficients from the signal of sensor acceleration to structural pendulum angle is established through the theoretical analysis, which can be used to solve the measurement of planar motion of the system. Furthermore, after nonlinear modifications, the measurement results can reach a high precision. While, similar to the motion control problem, the acceleration-based inclinometer sensor will lose its effectiveness owing to the gyrus motion mode of the suspended structure, and the gyroscope is needed to measure the angular velocity, then the pendulum angle is acquired through mathematical integration calculations. At last, the two motion modes of the suspended mass system are both measured through experimental verifications, the results of which soundly prove the feasibility and accuracy of the measuring method proposed in this paper. In addition, for the complicated planar and rotary coupled motion modes, the inclinometer and the gyroscope should be integrated together to measure the pendulum motion state of the suspended mass system
Synthesis, characterization, and antioxidant properties of novel inulin derivatives with amino-pyridine group
No full textA series of novel inulin derivatives were synthesized via reaction of chloracetyl inulin (CAR) with amino-pyridines, including 2-(2-amino-pyridyl)acetyl inulin chloride (2APAIL), 2-(3-amino-pyridyl)acetyl inulin chloride (3APAIL), 2-(4-amino-pyridyl)acetyl inulin chloride (4APAIL), 2-(2,3-diaminopyridyl)acetyl inulin chloride (2,3DAPAIL), and 2-(3,4-diamino-pyridyl)acetyl inulin (3,4DAPAIL). The antioxidant property of the products and 2-pyridylacetyl inulin chloride (PAIL) against hydroxyl radicals ((OH)-O-center dot), superoxide radicals (O-2(center dot)), and DPPH radicals (DPPH center dot) were evaluated in vitro, respectively. Results showed that 4APAIL and 3,4DAPAIL exhibited remarkable improvement on scavenging (OH)-O-center dot and DPPH center dot, which can scavenge the radical of (OH)-O-center dot completely at 0.4 mg/mL. Besides, the scavenging activity of 2,3DAPAIL to O-2(center dot) was excellent among all of the tested samples, reaching 85% at 1.6 mg/mL. These data indicate that all of the inulin derivatives have better antioxidant activities than inulin, and the scavenging effect indices are affected by the number and position of the amino group on pyridine grafted to the inulin derivatives. (C) 2014 Elsevier B.V. All rights reserved
Fluorescent probe for copper(II) ion based on a rhodamine spirolactame derivative, and its application to fluorescent imaging in living cells
No full textA fluorescent probe for Cu(II) ion is presented. It is based on the rhodamine fluorophore and exhibits high selectivity and sensitivity for Cu(II) ion in aqueous methanol (2:8, v/v) at pH 7.0. The response is based on a ring opening reaction and formation of a strongly fluorescent 1:1 complex. The response is reversible and linear in the range between 50 nM and 900 nM, with a detection limit of 7.0 nM. The probe was successfully applied to fluorescent imaging of Cu(II) ions in HeLa cells.A fluorescent probe for Cu(II) ion is presented. It is based on the rhodamine fluorophore and exhibits high selectivity and sensitivity for Cu(II) ion in aqueous methanol (2:8, v/v) at pH 7.0. The response is based on a ring opening reaction and formation of a strongly fluorescent 1:1 complex. The response is reversible and linear in the range between 50 nM and 900 nM, with a detection limit of 7.0 nM. The probe was successfully applied to fluorescent imaging of Cu(II) ions in HeLa cells
(Dynamic response of reinforced masonry structure under blast load)
No full textBased on the numerical analysis with LS-DYNA, the deformation and damage of the reinforced masonry walls were investigated by considering the following factors：ｗall-borne constraint, masonry material, strength grade, vertical reinforcement ratio, height-to-span ratio, load peak, distance from explosive center to wall, a hole in the wall and GFRP on the wall. And the distance-time curves of the walls were obtained as well as the stress-time curves of the masonry materials and steel bars. Meanwhile, the anti-explosion performances of the reinforced masonry walls were compared in the different cases and the important factors influencing the structure response were determinded. It is helpful for the anti-explosion design about the reinforced masonry structure
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