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951.
David Miralles Josep Manel Parra Jayme Vaz Jr. 《International Journal of Theoretical Physics》2001,40(1):229-242
Given the real Clifford algebra of a quadratic space with a given signature, we define a new product in this structure such that it simulates the Clifford product of a quadratic space with another signature different from the original one. Among the possible applications of this new product, we use it in order to write the Minkowskian Dirac equation over the Euclidean spacetime and to define a new duality operation in terms of which one can find self-dual and anti-self-dual solutions of gauge fields over Minkowski spacetime analogous to the ones over Euclidean spacetime and without needing to complexify the original real algebra. 相似文献
952.
Josep Maria Font 《Mathematical Logic Quarterly》1999,45(1):117-126
In her well-known book, Rasiowa states without proof that in implicative algebras there is a one-to-one correspondence between kernels of epimorphisms and the so-called special implicative filters, and that in the logic whose algebraic counterpart is the class of implicative algebras the deductive filters coincide with the special implicative filters. We show that neither claim is true, and how to repair the situation by redefining some of the notions involved. We answer other questions concerning special implicative filters, taking the theory of algebraizable logics of Blok and Pigozzi as a framework to approach the question in a systematic way. 相似文献
953.
Dr. Josep Garcia Dr. J. Marcos Fernández-Pradas Dr. Anna Lladó Dr. Pere Serra Dr. Dobryna Zalvidea Dr. Marcelo J. Kogan Prof. Dr. Ernest Giralt Dr. Macarena Sánchez-Navarro 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(14):4670-4675
Cytosolic protein delivery remains elusive. The inability of most proteins to cross the cellular membrane is a huge hurdle. Here we explore the unique photothermal properties of gold nanorods (AuNRs) to trigger cytosolic delivery of proteins. Both partners, protein and AuNRs, are modified with a protease-resistant cell-penetrating peptide with nuclear targeting properties to induce internalization. Once internalized, spatiotemporal control of protein release is achieved by near-infrared laser irradiation in the safe second biological window. Importantly, catalytic amounts of AuNRs are sufficient to trigger cytosolic protein delivery. To the best of our knowledge, this is the first time that AuNRs with their maximum of absorption in the second biological window are used to deliver proteins into the intracellular space. This strategy represents a powerful tool for the cytosolic delivery of virtually any class of protein. 相似文献
954.
Mata-Padilla J. M. Ávila-Orta C. A. Almendárez-Camarillo A. Martínez-Colunga J. G. Hernández-Hernández E. Cruz-Delgado V. J. González-Morones P. Solís-Rosales S. G. González-Calderón J. A. 《Journal of Thermal Analysis and Calorimetry》2021,143(4):2919-2932
Journal of Thermal Analysis and Calorimetry - The Non-isothermal crystallization behavior of isotactic polypropylene (iPP)/copper nanocomposites with four different mass percentages (0.5, 1.0, 2.0... 相似文献
955.
Danick Reynard Dr. Sunny Maye Dr. Pekka Peljo Vimanshu Chanda Prof. Hubert H. Girault Dr. Solène Gentil 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(32):7250-7257
The MnIII/MnII redox couple with a standard potential of +1.51 V versus the standard hydrogen electrode (SHE) has attracted interest for the design of V/Mn redox flow batteries (RFBs). However, MnIII disproportionation leads to a loss of capacity, an increase in pressure drop, and electrode passivation caused by the formation of MnO2 particles during battery cycling. In this work, the influence of TiIV or/and VV on MnIII stability in acidic conditions is studied by formulating four different electrolytes in equimolar ratios (Mn, Mn/Ti, Mn/V, Mn/V/Ti). Voltammetry studies have revealed an ECi process for MnII oxidation responsible for the electrode passivation. SEM and XPS analysis demonstrate that the nature and morphology of the passivating oxides layer depend strongly on the electrolyte composition. Spectroelectrochemistry highlights the stabilization effect of TiIV and VV on MnIII. At a comparable pH, the amount of MnIII loss through disproportionation is decreased by a factor of 2.5 in the presence of TiIV or/and VV. Therefore, VV is an efficient substitute for TiIV to stabilize the MnIII electrolyte for RFB applications. 相似文献
956.
Wei W. Chen Dr. Anton Cunillera Dandan Chen Dr. Sébastien Lethu Albert López de Moragas Prof. Dr. Jun Zhu Prof. Dr. Miquel Solà Dr. Ana B. Cuenca Dr. Alexandr Shafir 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(45):20376-20382
A metal-free C−H allylation strategy is described to access diverse functionalized ortho-allyl-iodoarenes. The method employs hypervalent (diacetoxy)iodoarenes and proceeds through the iodane-guided “iodonio-Claisen” allyl transfer. The use of allylsilanes bearing electron-withdrawing functional groups unlocks the functionalization of a broad range of substrates, including electron-neutral and electron-poor rings. The resulting ortho-allylated iodoarenes are versatile building blocks, with examples of downstream transformation including a concise synthesis of the experimental antimitotic core of Dosabulin. DFT calculations shed additional light on the reaction mechanism, with notable aspects including the aromatic character of the transition-state structure for the [3,3] sigmatropic rearrangement, as well as the highly stereoconvergent nature of the trans-product formation. 相似文献
957.
Ansótegui Carlos Manyà Felip Ojeda Jesus Salvia Josep M. Torres Eduard 《Journal of Heuristics》2022,28(4):377-431
Journal of Heuristics - We present a Satisfiability (SAT)-based approach for building Mixed Covering Arrays with Constraints of minimum length, referred to as the Covering Array Number problem.... 相似文献
958.
Edwin J. Gonzalez Lopez Prof. Ariel M. Sarotti Dr. Sol R. Martínez Dr. Lorena P. Macor Dr. Javier E. Durantini Melisa Renfige Dr. Miguel A. Gervaldo Prof. Luis A. Otero Dr. Andrés M. Durantini Prof. Dr. Edgardo N. Durantini Dr. Daniel A. Heredia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(5):e202103884
A novel BOPHY–fullerene C60 dyad ( BP-C60 ) was designed as a heavy-atom-free photosensitizer (PS) with potential uses in photodynamic treatment and reactive oxygen species (ROS)-mediated applications. BP-C60 consists of a BOPHY fluorophore covalently attached to a C60 moiety through a pyrrolidine ring. The BOPHY core works as a visible-light-harvesting antenna, while the fullerene C60 subunit elicits the photodynamic action. This fluorophore–fullerene cycloadduct, obtained by a straightforward synthetic route, was fully characterized and compared with its individual counterparts. The restricted rotation around the single bond connecting the BOPHY and pyrrolidine moieties led to the formation of two atropisomers. Spectroscopic, electrochemical, and computational studies disclose an efficient photoinduced energy/electron transfer process from BOPHY to fullerene C60. Photodynamic studies indicate that BP-C60 produces ROS by both photomechanisms (type I and type II). Moreover, the dyad exhibits higher ROS production efficiency than its individual constitutional components. Preliminary screening of photodynamic inactivation on bacteria models (Staphylococcus aureus and Escherichia coli) demonstrated the ability of this dyad to be used as a heavy-atom-free PS. To the best of our knowledge, this is the first time that not only a BOPHY–fullerene C60 dyad is reported, but also that a BOPHY derivative is applied to photoinactivate microorganisms. This study lays the foundations for the development of new BOPHY-based PSs with plausible applications in the medical field. 相似文献
959.
Salivary gland stem cells (SGSCs) are potential cell sources for the treatment of salivary gland diseases. The control of cell survival is an essential factor for applying stem cells to regenerative medicine or stem cell-based research. The purpose of this study was to investigate the effects of the ROCK inhibitor Y-27632 on the survival of SGSCs and its underlying mechanisms. SGSCs were isolated from mouse submandibular glands and cultured in suspension. Treatment with Y-27632 restored the viability of SGSCs that was significantly decreased during isolation and the subsequent culture. Y-27632 upregulated the expression of anti-apoptotic protein BCL-2 in SGSCs and, in the apoptosis assay, significantly reduced apoptotic and necrotic cell populations. Matrigel was used to mimic the extracellular environment of an intact salivary gland. The expression of genes regulating apoptosis and the ROCK signaling pathway was significantly reduced when SGSCs were embedded in Matrigel. SGSCs cultured in Matrigel and treated with Y-27632 showed no difference in the total numbers of spheroids and expression levels of apoptosis-regulating genes. Matrigel-embedded SGSCs treated with Y-27632 increased the number of spheroids with budding structures and the expression of acinar cell-specific marker AQP5. We demonstrate the protective effects of Y-27632 against dissociation-induced apoptosis of SGSCs during their culture in vitro. 相似文献
960.
A spin state‐selective Heteronuclear Single‐Quantum Multiple‐Bond Connectivities (HSQMBC‐COSY) experiment is proposed to measure the sign and the magnitude of long‐range proton‐carbon coupling constants (nJ(CH); n > 1) either for protonated or for non‐protonated carbons in small molecules. The simple substitution of the selective 180° 1H pulse in the original selHSQMBC pulse scheme by a hard one allows the simultaneous evolution of both proton‐proton and proton‐carbon coupling constants during the refocusing period and enables a final COSY transfer between coupled protons. The successful implementation of the IPAP principle leads to separate mixed‐phase α/β cross‐peaks from which nJ(CH) values can be easily measured by analyzing their relative frequency displacements in the detected dimension. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献