Simulation of evolution-selected propeptide by high-throughput selection of a peptidomimetic inhibitor on a capillary DNA sequencer platform

Many proteinases, including gelatinase B/MMP-9, fulfill crucial regulatory or effector functions in disease states and may be pharmacologically targeted by specific inhibitors. Denatured collagen type II provides one of the best gelatinase B substrates, and the characteristics of its cleavage were employed to define the requirements of a novel optimal substrate probe. A synthetic fluorescent derivative was used for the development of a new high-throughput technology for the selection of inhibitors on the principles of sensitivity of confocal fluorescence detection, resolution capacity of capillary electrophoresis, and multichannel power of DNA sequencers. Combinatorial chemical synthesis of a library of peptide-based inhibitors, library deconvolution, high-throughput screening, isolation, and mass spectrometric techniques enabled us to identify a novel single-peptide gelatinase B inhibitor. A notable finding is that the in vitro-selected inhibitor mimics many of the characteristics of the evolution-selected MMP propeptide sequence.     

Modele de comportement mecanique d'element combustible dans un assemblage PWR

Irradiated fuel in pressurized water reactors (PWRs) frequently displays rod bowing, due to two kinds of assymmetry. The first originates in the fabrication of the sheath, causing eccentricity, ovalization and thickness non-uniformity. The other comes from in-pile fuel element conditions such as off-line grids compressing the rods, circumferential thermal gradients on the sheath, and pellet-clad interactions.The MAC code was developed for parametric studies of some of these effects. It shows that:In the case of fuel rods undergoing compressive forces by the spacer grids the usual friction forces are unable to bow the rods significantly, except when the rods are blocked by the spacer grid springs.In some assembly configurations, the temperature difference between adjacent rods is able to bow them, requiring an increase in number of spacer grids.Localized pellet-clad interactions may cause significant bowing, particularly when they occur near the grids.     

Modification of thermal barrier coating architecture by in situ laser remelting

Yttria partially stabilized zirconia thermal barrier coatings (TBCs) are widely used to protect components of aero gas turbines against high heat fluxes and hence increase their properties by reducing their in-service temperature. However, these coatings degrade in service conditions.

Therefore, manufacturing TBC which present both low thermal conductivity and high life-time is a real challenge. Engineering the coating architecture by an adapted process is a prerequisite to modify TBC characteristics. In this study, laser remelting was combined to thermal spraying in order to modify the TBC properties.

In situ laser treatment (i) changes structure from lamellar to dendritic columnar; (ii) generates a pore architecture less sensitive to sintering, maintaining the TBC thermal and mechanical properties during thermal treatments at high temperatures; (iii) improves the thermal insulation properties of the TBC by decreasing its thermal conductivity of about 30%; (iv) decreases its permeability permitting to reduce oxidation and corrosion phenomena of the underneath layers and substrate; (v) increases the resistance to isothermal shocks (with the possibility to double the number of cycles); (vi) conducts to a metastable tetragonal phase more stable during thermal shocks; (vii) without modifying the elastic response of the deposit.     

22层框架楼房定向爆破拆除倒塌过程分析

河源市龙川县远东花园4号楼为22层框架结构楼房,系违章建筑需爆破拆除.紧挨楼房5 m处有一栋3层别墅,别墅的围墙与待拆除楼房只有0.5 m,需防止楼房产生后座.根据周围环境条件,采用定向倾倒的方式爆破拆除,采用梯形爆破缺口,爆破高度13.5 m.为确定最佳延期时间,用ANSYS/LS-DYNA对排间延期时间300 ms...     

Interval-based global optimization in engineering using model reformulation and constraint propagation

This paper deals with the preliminary design problem when the product is modeled as an analytic model. The analytic models based method aims to use mathematical equations to address both multi-physic and economic characteristics of a product. The proposed approach is to convert the preliminary design problem into a global constrained optimization problem. The objective is to develop powerful optimization methods enough to handle complex analytical models. We propose to adapt an approach to solve this problem based on interval analysis, constraint propagation and model reformulation. In order to understand the optimization algorithm used for engineering design problems, some basic definitions and properties of interval analysis are introduced. Then, the basic optimization algorithms for both unconstrained and constrained problems are introduced and illustrated. The next section introduces the reformulation technique as main accelerating device. An application of the reformulation device and its global optimization algorithm on the optimal design of electrical actuators is presented.     

Tunable acousto-optic spectral imager for atmospheric composition measurements in the visible spectral domain

We describe a new spectral imaging instrument using a TeO₂ acousto-optical tunable filter (AOTF) operating in the visible domain (450-900?nm). It allows for fast (～1 second), monochromatic (FWHM ranges from 0.6?nm at 450?nm to 3.5?nm at 800?nm) picture acquisition with good spatial resolution. This instrument was designed as a breadboard of the visible channel of a new satellite-borne atmospheric limb spectral imager, named the Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere (ALTIUS), that is currently being developed. We tested its remote sensing capabilities by observing the dense, turbulent plume exhausted by a waste incinerator stack at two wavelengths sensitive to NO₂. An average value of 6.0±0.4×10¹⁷ molecules?cm^-2 has been obtained for the NO₂ slant column density within the plume, close to the stack outlet. Although this result was obtained with a rather low accuracy, it demonstrates the potential of spectral imaging by using AOTFs in remote sensing.     

Are cellulose nanocrystals “alien particles” to human experience?

A wide family of cellulose‐based additives are authorized worldwide as fillers and thickening agents in foods, pills, and tablets, and microcrystalline cellulose (MCC) is, among these, the most important one. Since MCC manufacturing is similar to the main production route of cellulose nanocrystals (CNCs), it is reasonable to wonder whether the MCC would contain CNCs as minor components. In this Short Communication, we provide first results about the occurrence of CNCs in MCC, observed by dynamic light scattering and transmission electron microscopy after serial filtrations of MCC suspensions. The incidence of cellulose nanoparticles has been proved in several different trials in our ongoing works on diverse MCC samples, and the nanoparticles isolated showed shape and dimensions similar to those commonly produced by acidic hydrolysis at laboratory level. Therefore, the presence of CNCs in many products is considered as a certainty. The foods and the pharmaceuticals we have been consuming so far do indeed contain traces of CNCs to such an extent that this wide presence in consumed products should be taken into account when considering possible limitations of the use of these nanoparticles in food contact materials manufacture.     

Harmful risks for workers in thermal spraying: A review completed by a survey in a French company

Thermal spray technologies are implemented in spray booths either manually or automatically. In both cases, workers can be exposed to several potential and real risks. The major risks are to workers’ respiratory systems and result from harmful feedstock materials. To the authors’ knowledge, very few specific studies have been conducted to assess the significance of these risks. This study describes the major risks encountered and reviews the results of a survey conducted in a French company that uses thermal spray technology on a large scale.     

Evaluation of the termination mode in the radical polymerization of 2,2,2‐trifluoroethyl α‐fluoroacrylate

The mode of termination of 2,2,2‐trifluoroethyl α‐fluoroacrylate (FATRIFE) in radical polymerization was studied, and only termination by recombination occurred, which led to telechelic macromolecular structures. The radical polymerization in acetonitrile was carried out to synthesize oligomers with a low number average degree of polymerization ( )_cum (about 20), using tert‐butylcyclohexyl peroxydicarbonate (TBCPC) as initiator at 75 °C. The initial [TBCPC]₀/[FATRIFE]₀ molar ratio was monitored to evaluate its influence on the ( )_cum of α‐fluoroacrylic oligomers. The ¹H NMR analysis of the polymers showed that the ( )_cum values obtained were higher than 40, in spite of a high C₀ value. To explain these results, the mode of termination was evaluated using the following kinetic law: . The development of kinetic relationships allowed us to calculate the ratio k_prt/k_i·k_p as about 17–30 mol s l^?1, and to confirm that primary radical termination (PRT) was in competition with bimolecular macromolecular termination (BMT). © 2002 Society of Chemical Industry