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91.
Clède S Lambert F Sandt C Gueroui Z Réfrégiers M Plamont MA Dumas P Vessières A Policar C 《Chemical communications (Cambridge, England)》2012,48(62):7729-7731
A rhenium tris-carbonyl derivative has been designed to couple infrared and luminescent detection in cells. Both spectroscopies are consistent with one another; they point out the reliability of the present SCoMPI (for Single Core Multimodal Probe for Imaging) for bimodal imaging and unambiguously indicate a localization at the Golgi apparatus in MDA-MB-231 breast cancer cells. 相似文献
92.
Matthieu Tissot Daniele Poggiali Dr. Hélène Hénon Daniel Müller Dr. Laure Guénée Dr. Marc Mauduit Prof. Alexandre Alexakis 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(28):8731-8747
The copper‐catalyzed conjugate addition of various Grignard reagents to polyconjugated enones (dienone and enynone derivatives) is reported. The catalyst system, composed of copper triflate and an NHC ligand, led to the unusual selective formation of the 1,4‐addition products. This reaction allows for the creation of all‐carbon chiral quaternary centers with enantiomeric excesses up to 99 %. The remaining unsaturation on the 1,4 adducts give access to valuable synthetic transformations. 相似文献
93.
94.
Smooth and compact Pb5Sb8S17 and Pb9Sb8S21 thin films were synthesized via sulfurization of unique layered precursor films of amorphous (Sb,S) and crystalline PbS; our syntheses suggest that these plagionite group phases are metastable and indicate that their formation does not require hydrogen incorporation. 相似文献
95.
Queueing Systems - We consider Poisson streams of exponentially distributed jobs arriving at each edge of a hypergraph of queues. Upon arrival, an incoming job is routed to the shortest queue among... 相似文献
96.
97.
Matthieu Lancry Bertrand Poumellec John Canning Kevin Cook Jean‐Claude Poulin Francois Brisset 《Laser \u0026amp; Photonics Reviews》2013,7(6):953-962
A type of glass modifications occurring after femto‐second laser irradiation gives rise to strong (10−2) from birefringence. This form birefringence is thought to be related to index nanostructure (called nanogratings). Analyzing induced tracks in fused silica using scanning electron microscopy (SEM) with nm resolution shows that nanostructures are porous nanoplanes with an average index lower than typical silica (Δn ∼ –0.20). Their origin is explained as arising from fast decomposition of the glass under localized, high‐intensity femtosecond laser radiation where strong nonlinear, multiphoton‐induced photoionization leads to plasma generation. Mechanistic details include Coulombic explosions characteristic of strong photoionization and the production of self‐trapped exciton (STE). Rapid relaxation of these STE prevents recombination and dissociated atomic oxygen instead recombines with each other to form molecular oxygen pointed out using Raman microscopy. Some of it is dissolved in the condensed glass whilst the rest is trapped within nanovoids. A chemical recombination can only occur at 1200 °C for many hours. This explains the thermal stability of such a nanostructure. Precise laser translation and control of these birefringent nanoporous structures allo arbitrarily tuning and positioning within the glass, an important tool for controlling optical properties for photonic applications, catalysts, molecular sieves, composites and more. 相似文献
98.
A synthesis of spiroketals from carbohydrate lactones is reported. A modified Julia olefination is used to synthesize trisubstituted and highly functionalized exo-glycals, which were subsequently transformed into spiroketals under acidic conditions. 相似文献
99.
Introduction of one or more functions on a cyclodextrin in a regioselective manner is a complex task. The discovery of a blueprint strategy involving regioselective deprotection reactions of fully protected cyclodextrins, instead of functionalization of native cyclodextrins, allowed us to propose an efficient alternative to reach this goal. In this paper, we have applied previously delineated strategies, based on steric decompression, to duplicate our deprotection reaction, using a combination of mono- or di-deprotections to access cyclodextrins with two, three and five points of attachment for one, two or three different new functions. The patterns of multi-functionalization delineated here are not accessible by any other methods. Indeed, it is the first time ever a cyclodextrin bearing four different groups is synthesized in a completely controlled manner. This work paves the way to the use of cyclodextrins as multi-functional macrocyclic scaffolds, a use they have long been meant for, but lack of reliable functionalization methods hindered this development. 相似文献
100.
Matthew Weidman Santiago Palanco Matthieu Baudelet Martin C. Richardson 《Spectrochimica Acta Part B: Atomic Spectroscopy》2009,64(10):961-967
Double-Pulse Laser-Induced Breakdown Spectroscopy of iron using both Nd:YAG and TEA–CO2 lasers has been investigated to better understand mechanisms of signal enhancement. The signal dependence on the delay between the two laser pulses shows an enhanced signal when the CO2 laser pulse interacts with the sample before the Nd:YAG pulse. Signal kinetics and a simple model of sample heating by the CO2 pulse show that the enhancement during the first 700 ns is due primarily to sample heating. Images of the sample surface after ablation as well as time-integrated pictures of the plasma suggest that particles are ejected from the surface during the first microseconds after the arrival of the CO2 pulse and provide fuel for the subsequent plasma created by the Nd:YAG laser. 相似文献