排序方式: 共有64条查询结果,搜索用时 781 毫秒
41.
Diana Pendin Rosa Norante Andrea DeNadai Gaia Gherardi Nicola Vajente Emy Basso Nina Kaludercic Cristina Mammucari Cristina Paradisi Tullio Pozzan Andrea Mattarei 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(29):10022-10027
Ca2+ handling by mitochondria is crucial for cell life and the direct measure of mitochondrial Ca2+ concentration in living cells is of pivotal interest. Genetically‐encoded indicators greatly facilitated this task, however they require demanding delivery procedures. On the other hand, existing mitochondria‐targeted synthetic Ca2+ indicators are plagued by several drawbacks, for example, non‐specific localization, leakage, toxicity. Here we report the synthesis and characterization of a new fluorescent Ca2+ sensor, named mt‐fura‐2, obtained by coupling two triphenylphosphonium cations to the molecular backbone of the ratiometric Ca2+ indicator fura‐2. Mt‐fura‐2 binds Ca2+ with a dissociation constant of ≈1.5 μm in vitro. When loaded in different cell types as acetoxymethyl ester, the probe shows proper mitochondrial localization and accurately measures matrix [Ca2+] variations, proving its superiority over available dyes. We describe the synthesis, characterization and application of mt‐fura‐2 to cell types where the delivery of genetically‐encoded indicators is troublesome. 相似文献
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Constantin D. Sahm Anna Ciotti Eric Mates-Torres Vivek Badiani Kamil Sokoowski Gaia Neri Alexander J. Cowan Max García-Melchor Erwin Reisner 《Chemical science》2022,13(20):5988
Sunlight-driven CO2 reduction to renewable fuels is a promising strategy towards a closed carbon cycle in a circular economy. For that purpose, colloidal quantum dots (QDs) have emerged as a versatile light absorber platform that offers many possibilities for surface modification strategies. Considerable attention has been focused on tailoring the local chemical environment of the catalytic site for CO2 reduction with chemical functionalities ranging from amino acids to amines, imidazolium, pyridines, and others. Here we show that dithiols, a class of organic compounds previously unexplored in the context of CO2 reduction, can enhance photocatalytic CO2 reduction on ZnSe QDs. A short dithiol (1,2-ethanedithiol) activates the QD surface for CO2 reduction accompanied by a suppression of the competing H2 evolution reaction. In contrast, in the presence of an immobilized Ni(cyclam) co-catalyst, a longer dithiol (1,6-hexanedithiol) accelerates CO2 reduction. 1H-NMR spectroscopy studies of the dithiol-QD surface interactions reveal a strong affinity of the dithiols for the QD surface accompanied by a solvation sphere governed by hydrophobic interactions. Control experiments with a series of dithiol analogues (monothiol, mercaptoalcohol) render the hydrophobic chemical environment unlikely as the sole contribution of the enhancement of CO2 reduction. Density functional theory (DFT) calculations provide a framework to rationalize the observed dithiol length dependent activity through the analysis of the non-covalent interactions between the dangling thiol moiety and the CO2 reduction intermediates at the catalytic site. This work therefore introduces dithiol capping ligands as a straightforward means to enhance CO2 reduction catalysis on both bare and co-catalyst modified QDs by engineering the particle''s chemical environment.ZnSe quantum dots (yellow sphere) are modified with dithiols of various lengths for enhanced visible light-driven CO2 to CO reduction in either the absence or presence of a molecular Ni co-catalyst. 相似文献
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Chiappini Barbara Scavia Gaia Conte Michela Morelli Luisella Perrotta Maria Gabriella Agrimi Umberto Vaccari Gabriele 《Accreditation and quality assurance》2019,24(1):49-55
Accreditation and Quality Assurance - Scrapie of sheep belongs to a group of fatal neurodegenerative diseases known as prion diseases. Scrapie is a naturally transmissible disease and sheep... 相似文献
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Vincenzo Barone Silvana De Lillo Gaia Lupo Antonino Polimeno 《Studies in Applied Mathematics》2011,126(2):145-155
A nonlinear diffusive equation with moving boundaries is analyzed by constructing the corresponding Dirichlet‐to‐Neumann map. In particular, the Dirichlet boundary value and the initial condition are used to derive the unknown Neumann boundary value. Then, a contraction‐mapping technique is used to prove existence and uniqueness of the solution for small times. 相似文献
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In this paper, the problem of finding the minimum cost flow line able to produce different products is considered. This problem
can be formulated as a shortest path problem on an acyclic di-graph when the machines graph associated with each product family
is a chain or a comb. These graphs are relevant in production planning when dealing with pipelined assembly systems. We solve
the problem using A
* algorithm which can be efficiently exploited when there is a good estimate on the value of an optimal solution. Therefore,
we adapt a known bound for the Shortest Common Supersequence problem to our case and show the effectiveness of the approach
by presenting an extensive computational experience. 相似文献
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Introduction During the past several decades, diamines and their derivatives have been extensively investigated in both basic research and their application. The result shows that they can form stable complexes with many transi-tion metals. These complexes would be widely applied in various fields such as biotechnology,1 synthesis,2 food processing industry,3 environmental science,4 biochemistry,5 etc. Especially, in recent years, more and more attention is placed on their other peculiarities.… 相似文献
48.
Gaia Pupillo Juan Esposito Mauro Gambaccini Ferid Haddad Nathalie Michel 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(2):911-917
The high-specific activity 99Mo accelerator-based production, via the (α,n) reaction on 96Zr-enriched target, has been investigated in the present work. The excitation function measurement has been performed in the energy range 8–34 MeV at the ARRONAX facility, using the well-known stacked foils technique on natural zirconium as target. A general good agreement in the cross section trend has been observed, once compared to former measurements. A different (i.e. higher) peak value and a shift of about 2 MeV towards larger energies have however been found. Assuming a fully enriched 96Zr target irradiated by an α-beam at suitable energy (E = 25 MeV), the 99Mo production yield has thus been estimated. At last the alternative production routes, based on the 96Zr(α,n)99Mo and 100Mo(p,x)99Mo/99mTc reactions, are compared. 相似文献
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Alessandro Agnetis Hans Kellerer Gaia Nicosia Andrea Pacifici 《European Journal of Operational Research》2012
A set of n nonpreemptive tasks are to be scheduled on m parallel dedicated machines with a regular criterion. Chain precedence constraints among the tasks, deterministic processing times and processing machine of each task are given. 相似文献
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Margherita De Marzio Gaia Camisasca Mauro Rovere Paola Gallo 《Frontiers of Physics》2018,13(1):136103
The aim of this paper is to discuss the relationship between the dynamics and thermodynamics of water in the supercooled region. Reviewed case studies comprehend bulk water simulated with the SPC/E, TIP4P and TIP4P/2005 potentials, water at protein interfaces, and water in solution with electrolytes. Upon supercooling, the fragile to strong crossover in the α-relaxation of water is found to occur when the Widom line emanating from the liquid-liquid critical point is crossed. This appears to be a general characteristic of supercooled water, not depending on the applied interaction potential and/or different local environments. 相似文献