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31.
Oana Moldovan Pedro Lameiras Eric Henon Flavia Popa Agathe Martinez Dominique Harakat Carmen Sacalis Yvan Ramondenc Mircea Darabantu 《Central European Journal of Chemistry》2012,10(4):1119-1136
The highly chemoselective preparation of new elaborated N-unsymmetrically substituted chlorodiamino-s-triazines and melamines, seen as building-blocks for iterative synthesis, is reported. It consisted of amination of cyanuric
chloride with commercial C-2-substituted 2-aminopropane-1,3-diols (“serinols”), playing the role as “open-chain” unit and enantiopure (1S,2S)-2-amino-1-(4-nitrophenyl)propane-1,3-diols (“p-nitrophenylserinols”) based amino-1,3-dioxanes (“closed-chain” unit). Issued from the restricted rotation about C(s-triazine)-N(exocyclic) partial double bonds, seen as axes of (pro)diastereomerism,
a global four-component rotational equilibrium involving the title compounds is discussed based on DFT computation and (VT)
NMR data. Depending on π-deficiency of the s-triazine core, an (un)synchronised deblocking of the generated rotational diastereomers was observed. They are discussed
as influence of intra-vs. intermolecular NH...OH (dynamic) interactions occurring in the “open-chain” unit and the anancomeric, axial vs. equatorial, amino-anchorage of the “closed-chain” unit.
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32.
We study the relation on linear orders induced by order preserving surjections. In particular we show that its restriction to countable orders is a bqo. 相似文献
33.
The known, very efficient base‐free copper(I) oxide catalyzed N‐arylation reaction performed in MeOH at room temperature for the synthesis of N‐substituted azoles and amines was extended to the heterocyclic series, i.e., we report herein the base‐free copper(I) oxide catalyzed N‐heteroarylation of 1H‐(benz)imidazole, by means of electron‐rich or electron‐deficient B‐heteroarylboronic acids or 2‐heteroaryl‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolanes (Schemes 1 and 2). Under these conditions, N‐heteroarylated 1H‐(benz)imidazoles were obtained in good to excellent yields (Tables 1 and 2). This is the first time that 2‐heteroaryl‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolanes were used in this type of reaction. 相似文献
34.
Juš Kocijan Agathe Girard Blaž Banko Roderick Murray-Smith 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2013,19(4):411-424
This paper describes the identification of nonlinear dynamic systems with a Gaussian process (GP) prior model. This model is an example of the use of a probabilistic non-parametric modelling approach. GPs are flexible models capable of modelling complex nonlinear systems. Also, an attractive feature of this model is that the variance associated with the model response is readily obtained, and it can be used to highlight areas of the input space where prediction quality is poor, owing to the lack of data or complexity (high variance). We illustrate the GP modelling technique on a simulated example of a nonlinear system. 相似文献
35.
Hadariah Bahron Leslie F. Larkworthy Agathe Marécaux David C. Povey Gallienus W. Smith 《Journal of chemical crystallography》1994,24(2):145-150
The cobalt(II)-Schiff base complexes [Co(nbsal)2] and [Co(tbsal)2] [nbsal=N-n-butylsalicylideneiminate and tbsal=N-tert-butysalicylideneiminate,o-OC6H4CH=NR,R+Bun and But, respectively] both have distorted tetrahedral structures, but the presence of thetert-butyl groups in [Co(tbsal)2] causes much greater angular distortion, of the coordination tetrahedron. Although [Co(nbsal)2] will react with nitric oxide and oxygen, [Co(tbsal)2] reacts with neither and this appears to be due to the shielding of the cobalt by thetert-vutyl groups. The reactive complex [Co(nbsal)2] crystallizes in the tetragonal system,a+14.244,c+5.395, Å,Z+2 and space group $P\bar 4$ . The structure was determined by the heavy-atom method, using MoKα diffractometer data, and refined by full matrix least-squares toR+0.035 for 777 reflections. The unreactive complex [Co(tbsal)2] crystallizes in the orthorhombic systemPbc21,a+10.977,b+20.037,c+9.866 Å,Z+4. The structure was determined as above toR+0.051 for 1458 reflections. 相似文献
36.
Zakaria Baka Claire Godier Laureline Lamy Abhik Mallick Varvara Gribova Agathe Figarol Lina Bezdetnaya Alicia Chateau Zoé Magne Marie Stiefel Dounia Louaguef Philippe Lavalle Eric Gaffet Olivier Joubert Halima Alem 《Macromolecular bioscience》2023,23(3):2200434
Ovarian cancer remains a major public health issue due to its poor prognosis. To develop more effective therapies, it is crucial to set-up reliable models that closely mimic the complexity of the ovarian tumor's microenvironment. 3D bioprinting is currently a promising approach to build heterogenous and reproducible cancer models with controlled shape and architecture. However, this technology is still poorly investigated to model ovarian tumors. In this study, a 3D bioprinted ovarian tumor model combining cancer cells (SKOV-3) and cancer associated fibroblasts (CAFs) are described. The resulting tumor models show their ability to maintain cell viability and proliferation. Cells are observed to self-assemble in heterotypic aggregates. Moreover, CAFs are observed to be recruited and to circle cancer cells reproducing an in vivo process taking place in the tumor microenvironment. Interestingly, this approach also shows its ability to rapidly generate a high number of reproducible tumor models that can be subjected to usual characterizations (cell viability and metabolic activity; histology and immunological studies; and real-time imaging). Therefore, these ovarian tumor models can be an interesting tool for high throughput drug screening applications. 相似文献
37.
Raja Chouket Agns Pellissier-Tanon Annie Lemarchand Agathe Espagne Thomas Le Saux Ludovic Jullien 《Chemical science》2020,11(11):2882
Interrogating living cells requires sensitive imaging of a large number of components in real time. The state-of-the-art of multiplexed imaging is usually limited to a few components. This review reports on the promise and the challenges of dynamic contrast to overcome this limitation.Interrogating living cells requires sensitive imaging of a large number of components in real time. 相似文献
38.
Jared E. Abramson Nancy M. Avalos Agathe L. M. Bourchy Sarah A. Saslow Gerald T. Seidler 《X射线光谱测定》2022,51(2):151-162
The evolution of sulfur chemistry in cements is best known in the bailiwick of failure mechanisms via sulfate attack, but is equally important for its contributions to the reduction capacity of cementitious materials often used for immobilizing nuclear waste streams destined for long-term storage, for example, cementitious waste forms (CWF). The total reduction capacity of CWFs, encompassing contributions from both S and Fe reductants, and its implications toward radionuclide immobilization is most often studied by destructive wet chemistry methods requiring acid digestion in the presence of Ce(IV) and subsequent titration and colorimetric interpretation. Here, we investigate a similarly analytical but nondestructive alternative, benchtop high resolution wavelength-dispersive X-ray fluorescence spectroscopy, most commonly known as X-ray emission spectroscopy (XES), for probing the bulk sulfur oxidation state distribution. We present here an initial investigation of S XES, including an improved experimental protocol for lab XES of inhomogeneous samples, both as a complement to the Ce(IV) test and for new scientific opportunities that it enables for observing changes in sulfur chemistry. We discuss future improvements and opportunities, including: (1) the practical challenges associated with coordinating XES and Ce(IV) liquid extraction for a more comprehensive perspective on reduction capacity and for a high-precision evaluation of uncertainties in the Ce(IV) test; and (2) new opportunities, due to the nondestructive nature of XES, for controlled evolution studies aimed at elucidating specific chemical responses of CWFs exposed to invasive gas or liquid species or to accelerated aging by radiative dose or thermal treatment. 相似文献
39.
Synthesis and properties of renewable nonisocyanate polyurethanes (NIPUs) from dimethylcarbonate 下载免费PDF全文
Charlotte Duval Nasreddine Kébir Agathe Charvet Amélie Martin Fabrice Burel 《Journal of polymer science. Part A, Polymer chemistry》2015,53(11):1351-1359
Novel fully renewable AA‐BB type nonisocyanate polyurethanes (NIPUs) were synthesized using the transurethanization approach. Dicarbamate monomers were prepared by the reaction of a diamine with an excess of dimethylcarbonate (DMC), in presence of 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD) as catalyst. Then, the dicarbamate was reacted with a diol to afford the polymer, in presence of TBD or K2CO3 as catalyst. Several renewable diamines and diols were tested. The two steps were conducted under neat conditions. The obtained materials exhibited Tg values varying from ?38 to 42 ° C, Tm values varying from 42 to 204 °C , and thermal stabilities above 200 ° C. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1351–1359 相似文献
40.
We provide a game theoretical proof of the fact that if f is a function from a zero-dimensional Polish space to \( \mathbb N^{\mathbb N}\) that has a point of continuity when restricted to any non-empty compact subset, then f is of Baire class 1. We use this property of the restrictions to compact sets to give a generalisation of Baire’s grand theorem for functions of any Baire class. 相似文献