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111.
The flexibility of DNA is of central importance in biology, medicine, materials science, and mechanical engineering. In this study, we report an unprecedented electrochemical approach for investigating the flexibility of a short (typically 20-base), surface end-tethered single-stranded synthetic DNA oligonucleotide and of its postformed DNA duplex, taking as an example the homopolymer (dT)20 sequence in the regime of very high ionic strength ( approximately 1 M). 相似文献
112.
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114.
Sofia Pessanha Mauro Guerra Stephane Longelin Agnès Le Gac Marta Manso Maria Luisa Carvalho 《X射线光谱测定》2014,43(2):79-82
In this work, the thickness of the gold leaf applied in the Manueline foral charter of Murça (illuminated in 1512) will be determined using X‐ray fluorescence. In the frontispiece of the Manueline foral charter of Murça, the capital D was gilded using a gold leaf over a priming made of lead white. The characteristic lines of Pb (namely Lα and Lβ), although attenuated in the Au layer, are still visible in the X‐ray fluorescence spectra. By determining the intensity ratio Lα/Lβ and comparing it with the ratio for an infinitely thick sample, the thickness of the attenuating material can be determined. Using this methodology, the thickness of the gold leaf applied in the charter of Murça was estimated as 1.6 µm. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
115.
Using a high-resolution Fourier transform spectrum recorded at SOLEIL for a rather large value of the (pressure?×?path length) product a new investigation of the very weak 2ν 1 absorption band of nitrogen dioxide, located at 2627.377?cm?1 was performed, together with an extension up to higher N and Ka values of a previous investigation of the strong ν 1?+?ν 3 band [J.-Y. Mandin, V. Dana, A. Perrin, J.-M. Flaud, C. Camy-Peyret, L. Régalia and A. Barbe, J. Mol. Spectrosc. 181, 379 (1997)]. The 2ν 1 lines proved to be perturbed by local vibration–rotation resonances which couple the (2,0,0) energy levels with those of the (1,2,0) and (1,0,1) states. Also the (1,0,1) energy levels are also coupled by a C-type Coriolis resonance with those of the (1,2,0) and (2,0,0) energy levels. The final energy levels calculation involves six interacting states of NO2, {(2,0,0), (1,2,0), (1,0,1), (0,0,2), (0,4,0), (0,0,2)}. An estimation of line intensities parameters was performed for the very weak 2ν 1 band. Finally a list of line parameters (positions, intensities and shapes) for the 2ν 1, ν 1?+?2ν 2 and ν 1?+?ν 3 bands of NO2, was generated and is now included in the GEISA database (https://geisa.aeris-data.fr/). 相似文献
116.
Le Moigne F Durieux M Bancel B Boublay N Boussel L Ducerf C Berthezène Y Rode A 《Magnetic resonance imaging》2012,30(5):656-665
Purpose
The purpose of this study was to determine whether or not adding diffusion-weighted magnetic resonance imaging (DWI) to conventional magnetic resonance (MR) imaging sequences improves the characterization of small hepatocellular carcinoma (HCC) (≤2 cm) in the setting of cirrhotic liver compared to conventional sequences alone.Materials and Methods
A total of 62 cirrhotic liver patients with 82 nodules smaller than 2 cm in diameter were enrolled, and all lesions were pathologically confirmed. For the first reading session, which included precontrast T1- and T2-weighted images and T1 dynamic contrast-enhanced images, preindicated lesions by a study coordinator were characterized by two radiologists. They determined the confidence levels in consensus for the presence of small HCC into four grades. In another session, respiratory-triggered diffusion-weighted MR images (b factor=50, 400 and 800 s/mm2) were added to the previously reviewed images, and the same two radiologists again determined the confidence levels. The diagnostic performance of the combined DWI–conventional sequences set and the conventional sequences alone set was evaluated using receiver operating characteristic curves. Sensitivity and specificity values for characterizing small HCCs were also calculated.Results
The area under the receiver operating characteristic curve for the second interpretation session (0.86) was significantly higher (P=.038) than that of the first session (0.76). The sensitivity was significantly increased from 75.7% to 87.8% by adding DWI to the conventional sequences (P=.015). No significant differences were observed for specificity values.Conclusion
Adding DWI to conventional imaging modalities improves the diagnosis of small HCCs in the cirrhotic liver in terms of diagnostic performance and sensitivity by increasing reader confidence. 相似文献117.
Bertrand L Robinet L Cohen SX Sandt C Le Hô AS Soulier B Lattuati-Derieux A Echard JP 《Analytical and bioanalytical chemistry》2011,399(9):3025-3032
The study of varnishes from musical instruments presents the difficulty of analysing very thin layers of heterogeneous materials
on samples most of which are generally brittle and difficult to prepare. Such study is crucial to the understanding of historical
musical instrument varnishing practices since written sources before 1800 are very rare and not precise. Fourier-transform
infrared (FTIR) spectroscopy and imaging methods were applied to identify the major chemical components within the build-up
of the varnish layers on a cello made by one of the most prominent French violin-makers of the eighteenth century (Jacques
Boquay, ca. 1680–1730). Two types of FTIR imaging methods were used: scanning with a synchrotron-based microscope and full-field
imaging using a 2D imager with a conventional source. An interpretation of the results obtained from these studies on the
Boquay cello is that the maker first applied a proteinaceous layer, probably gelatine-based animal glue. He later applied
a second layer based on a mixture of a drying oil and diterpenic resin from Pinaceae sp. From an historical perspective, the results complement previous studies by describing a second technique used for musical
instrument finishes at the beginning of the eighteenth century in Europe. 相似文献
118.
Moloney Mícheál P. Massoni Nicolas Grandjean Agnès 《Journal of Thermal Analysis and Calorimetry》2021,145(5):2353-2362
Journal of Thermal Analysis and Calorimetry - It is well known that the physical properties of nanoparticles can be tuned by controlling synthetic factors such as pH, temperature, reactant ratio or... 相似文献
119.
Roxana Dumitrescu Bernt Øksendal Agnès Sulem 《Journal of Optimization Theory and Applications》2018,176(3):559-584
We study optimal control for mean-field stochastic partial differential equations (stochastic evolution equations) driven by a Brownian motion and an independent Poisson random measure, in case of partial information control. One important novelty of our problem is represented by the introduction of general mean-field operators, acting on both the controlled state process and the control process. We first formulate a sufficient and a necessary maximum principle for this type of control. We then prove the existence and uniqueness of the solution of such general forward and backward mean-field stochastic partial differential equations. We apply our results to find the explicit optimal control for an optimal harvesting problem. 相似文献
120.
A simple cladding procedure was developed to apply monolithic silica rods in chromatography. This was used to evaluate the performances of new monolithic silica phases synthesised using a triblock copolymer as a phase separation inducer. The cladding procedure is found efficient after several tests, including scanning electron microscopy and mercury porosimetry, and the obtained columns present a relatively good efficiency in adsorption chromatography (H min is about 50 μm) as compared to other lab-scale developed columns. 相似文献