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271.
Maciel Marcel Hark Soares Gabriela Simões Romano Roberto Cesar de Oliveira Cincotto Maria Alba 《Journal of Thermal Analysis and Calorimetry》2019,136(3):1269-1284
Journal of Thermal Analysis and Calorimetry - Cement hydration occurs according to a sequence of reactions whose products have a direct influence on the working properties of concretes and mortars... 相似文献
272.
Alba Marcellan Anthony Bunsell Roland Piques Lucien Laiarinandrasana 《Journal of Polymer Science.Polymer Physics》2019,57(11):680-690
Single fiber mechanical testing is challenging to perform, especially when the diameter is as small as tens of micrometers. For this reason, real‐time observations of crack propagation mechanisms have been rarely been investigated experimentally. This article presents experimental and numerical investigations of fracture of monofilamentary high performance polyamide 66 fibers. Their engineering stress–strain curves are compared. The mechanisms of failure starting from crack initiation until the final brittle fracture are studied by in situ tests in Scanning Electron and optical microscopes. Finite element modeling at the individual fiber scale has been performed in three‐dimensional (3D), as a reverse engineering method. The compliance method was used to determine the crack depth that triggers the final failure. The fracture toughness was numerically determined using the J‐integral concept, accounting for the geometry of the crack front (3D) together with plastic deformation. 3D meshes were designed especially from postmortem observations. The average value deduced was about 47 ± 7 kJ m?2, which will be discussed with other estimates using linear elastic fracture mechanics. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 680–690 相似文献
273.
Danila Gasperini Dr. Alba Collado Dr. Adrián Goméz‐Suárez Dr. David B. Cordes Prof. Dr. Alexandra M. Z. Slawin Prof. Dr. Steven P. Nolan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(14):5403-5412
A new synthetic strategy was devised leading to the formation of complexes, such as [Au(IPr)(CH2COCH3)]. The approach capitalizes on the formation of a decomposition product observed in the course of the synthesis of [Au(IPr)(Cl)]. A library of gold acetonyl complexes containing the most common N‐heterocyclic carbene (NHC) ligands has been synthesized. These acetonyl complexes are good synthons for the preparation of numerous organogold complexes. Moreover, they have proven to be precatalysts in common gold(I)‐catalyzed reactions. 相似文献
274.
Dr. Ana B. Caballero Laia Terol‐Ordaz Dr. Alba Espargaró Guillem Vázquez Dr. Ernesto Nicolás Dr. Raimon Sabaté Prof. Patrick Gamez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(21):7268-7280
Brain copper imbalance plays an important role in amyloid‐β aggregation, tau hyperphosphorylation, and neurotoxicity observed in Alzheimer's disease (AD). Therefore, the administration of biocompatible metal‐binding agents may offer a potential therapeutic solution to target mislocalized copper ions and restore metallostasis. Histidine‐containing peptides and proteins are excellent metal binders and are found in many natural systems. The design of short peptides showing optimal binding properties represents a promising approach to capture and redistribute mislocalized metal ions, mainly due to their biocompatibility, ease of synthesis, and the possibility of fine‐tuning their metal‐binding affinities in order to suppress unwanted competitive binding with copper‐containing proteins. In the present study, three peptides, namely HWH , HKCH , and HAH , have been designed with the objective of reducing copper toxicity in AD. These tripeptides form highly stable albumin‐like complexes, showing higher affinity for CuII than that of Aβ(1‐40). Furthermore, HWH , HKCH , and HAH act as very efficient inhibitors of copper‐mediated reactive oxygen species (ROS) generation and prevent the copper‐induced overproduction of toxic oligomers in the initial steps of amyloid aggregation in the presence of CuII ions. These tripeptides, and more generally small peptides including the sequence His‐Xaa‐His at the N‐terminus, may therefore be considered as promising motifs for the future development of new and efficient anti‐Alzheimer drugs. 相似文献
275.
276.
Summary In this paper flow at low Reynolds number is studied in a plane duct with injection along its boundaries, by determining the Green function for the Stokes equation in the strip: in this way it is possible to calculate the fluid-dynamic field for any distribution of injection. To obtain the bi-harmonic function that governs this problem we write the stream function in terms of two harmonic functions f and g, represent these functions using the relevant Green function and write the integral equations that determine f and g. The solution is obtained by means of the Fourier transform technique. An asymptotic representation of this solution is also given.
Sommario In questo lavoro si studia il campo fluidodinamico determinato) dall'apporto di fluido in un condotto in cui scorre un fluido a piccoli numeri di Reynolds, determinando la funzione di Green per l'equazione di Stokes nella striscia: in tal modo si può calcolare il campo fluidodinamico per una qualsiasi distribuzione di iniezione. Per determinare la funzione biarmonica con derivata longitudinale infinita in alcuni punti della frontiera che governa questo problema, si scrive l'incognita in termini di funzioni armoniche, si utilizza la funzione di Green per rappresentare tali funzioni ausiliarie e si scrivono le equazioni integrali che le determinano. La soluzione di queste equazioni integrali viene ottenuta mediante la trasformata di Fourier. I risultati vengono presentati sia in forma numerica che con serie asintotiche.相似文献
277.
Hugo Fanlo‐Virgós Dr. Andrea‐Nekane R. Alba Saleh Hamieh Mathieu Colomb‐Delsuc Prof. Dr. Sijbren Otto 《Angewandte Chemie (International ed. in English)》2014,53(42):11346-11350
In biology enzyme concentrations are continuously regulated, yet for synthetic catalytic systems such regulatory mechanisms are underdeveloped. We now report how a substrate of a chemical reaction induces the formation of its own catalyst from a dynamic molecular network. After complete conversion of the substrate, the network disassembles the catalyst. These results open up new opportunities for controlling catalysis in synthetic chemical systems. 相似文献
278.
A Trifluorinated Thiazoline Scaffold Leading to Pro‐apoptotic Agents Targeting Prohibitins
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Dr. Alba Pérez‐Perarnau Dr. Sara Preciado Dr. Claudia Mariela Palmeri Cristina Moncunill‐Massaguer Dr. Daniel Iglesias‐Serret Dr. Diana M. González‐Gironès Dr. Miriam Miguel Dr. Satoki Karasawa Dr. Satoshi Sakamoto Dr. Ana M. Cosialls Dr. Camila Rubio‐Patiño José Saura‐Esteller Dr. Rosario Ramón Dr. Laia Caja Dr. Isabel Fabregat Dr. Gabriel Pons Prof. Hiroshi Handa Prof. Fernando Albericio Prof. Joan Gil Prof. Rodolfo Lavilla 《Angewandte Chemie (International ed. in English)》2014,53(38):10150-10154
A new class of small molecules, with an unprecedented trifluorothiazoline scaffold, were synthesized and their pro‐apoptotic activity was evaluated. With an EC50 in the low micromolar range, these compounds proved to be potent inducers of apoptosis in a broad spectrum of tumor cell lines, regardless of the functional status of p53. Fast structure–activity relationship studies allowed the preparation of the strongest apoptosis‐inducing candidate. Using a high performance affinity purification approach, we identified prohibitins 1 and 2, key proteins involved in the maintenance of cell viability, as the targets for these compounds. 相似文献
279.
NMR Fingerprints of the Drug‐like Natural‐Product Space Identify Iotrochotazine A: A Chemical Probe to Study Parkinson’s Disease
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Dr. Tanja Grkovic Dr. Rebecca H. Pouwer Marie‐Laure Vial Luca Gambini Alba Noël Dr. John N. A. Hooper Dr. Stephen A. Wood Dr. George D. Mellick Prof. Dr. Ronald J. Quinn 《Angewandte Chemie (International ed. in English)》2014,53(24):6070-6074
The NMR spectrum of a mixture of small molecules is a fingerprint of all of its components. Herein, we present an NMR fingerprint method that takes advantage of the fact that fractions contain simplified NMR profiles, with minimal signal overlap, to allow the identification of unique spectral patterns. The approach is exemplified in the identification of a novel natural product, iotrochotazine A ( 1 ), sourced from an Australian marine sponge Iotrochota sp. Compound 1 was used as a chemical probe in a phenotypic assay panel based on human olfactory neurosphere‐derived cells (hONS) from idiopathic Parkinson’s disease patients. Compound 1 at 1 μM was not cytotoxic but specifically affected the morphology and cellular distribution of lysosomes and early endosomes. 相似文献
280.