Catalytic System for Inhibition of Amination‐Type Reaction and Palladium‐Catalysed Direct Arylation using Non‐Protected Pyrazole Derivatives

The palladium‐catalysed direct arylation at C‐4 of non‐protected 5‐aminopyrazoles was found to proceed in high yields using a variety of aryl bromides. The choice of potassium acetate as the base was found to be crucial to inhibit the amination reaction and to promote the direct arylation.     

Betulinic Acid Derivatives NVX-207 and B10 for Treatment of Glioblastoma—An in Vitro Study of Cytotoxicity and Radiosensitization

Betulinic acid (BA), a pentacyclic triterpene, represents a new therapeutic substance that has potential benefits for treating glioblastoma. Recently, new strategies for producing BA derivatives with improved properties have evolved. However, few studies have examined the combination of BA or BA derivatives using radiotherapy. The effects of two BA derivatives, NVX-207 and B10, on cellular and radiobiological behavior were analyzed using glioblastoma cell lines (U251MG, U343MG and LN229). Based on IC₅₀ values under normoxic conditions, we detected a 1.3–2.9-fold higher cytotoxicity of the BA derivatives B10 and NVX-207, respectively, compared to BA. Incubation using both BA derivatives led to decreased cell migration, cleavage of PARP and decreased protein expression levels of Survivin. Weak radiation sensitivity enhancement was observed in U251MG cells after treatment with both BA derivatives. The enhancement factors at an irradiation dose of 6 Gy after treatment with 5 µM NVX-207 and 5 µM B10 were 1.32 (p = 0.029) and 1.55 (p = 0.002), respectively. In contrast to BA, neither NVX-207 nor B10 had additional effects under hypoxic conditions. Our results suggest that the BA derivatives NVX-207 and B10 improve the effects of radiotherapy on human malignant glioma cells, particularly under normoxic conditions.     

Tuning the interphase adhesion in high-density polyethylene–silica nanocomposites with ionic liquids

This work addresses the use of ionic liquids (ILs) as multifunctional additives in the formation of high-density polyethylene (HDPE)/sol–gel silica nanocomposites via the melt-mixing process. Different approaches for nanocomposite formation were studied and compared, including (1) silica modification with ILs during the sol–gel process and further addition into the polymer matrix, (2) reactive mixing in which silica-IL filler was formed in situ, and (3) direct IL application in the melt-mixing chamber with nonmodified silica xerogel and HDPE. The nanocomposites were characterized by thermogravimetric analyses, differential scanning calorimetry, scanning electron microscopy, dynamic thermomechanical analyses, transmission electron microscopy, and contact angle analyses. To improve the silica compatibilization with HDPE, we investigated imidazolium ILs that presented at least one nonpolar ionic counterpart. This permitted control of the silica structure, morphology, dispersion, and interfacial interactions, providing enhancements in thermomechanical properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47366.     

Improvement of surface quality on peritectic steel slabs

Peritectic steel grades are very sensitive to microcracking along austenitic grain boundaries in continuous casting. Irsid and Aktiengesellschaft der Dillinger Hüttenwerke (DH) have combined laboratory studies and industrial trials to improve surface quality on these sensitive grades. Laboratory studies at Irsid confirmed the hypothesis that a very thin layer of ferrite along austenitic grain boundaries is detrimental for cracking and indicate that the risk of cracking decreases as soon as ferrite ratio is above 10 %. Dilatometric investigations demonstrate that there is a strong shift between thermodynamic equilibrium and beginning of γ→α phase transformation under casting conditions. Furthermore, at the slab surface, there is no cyclic transformation γ→α→γ induced by thermal cycling in front of spray nozzles and supporting rolls. DH performed trials with various cooling strategies on its new vertical caster No. 5. No cracks appear with intensive cooling whereas microcracks are present with soft cooling. These results are in agreement with laboratory studies. Intensive cooling is the standard condition at DH. With this process, microcracking is avoided for all slab formats.     

Images médicales, sécurité et tatouage

In this article, security issues for medical information and technical solutions to protect these data in Medical Information Systems are examined. We then introduce the watermarking as a complementary security tool. The relevance of this new technology in healthcare is discussed from the application viewpoints and through the implementation constraints. A solution is proposed, based on an original approach which consists in watermarking image areas that are not relevant for the diagnosis. This system is transparent to the user and allows image integrity control. In addition, it provides information on the location of potential alterations and an evaluation of image modifications which is of major importance in a medico-legal framework. An example using head Magnetic Resonance Imaging illustrates the overall method.     

Another Alternative to Quantum Cryptography

Quantum cryptography has several unorthodox attributes: it is invulnerable to passive eavesdropping; communicators need no initial shared secret (cryptographic key), but they do need an auxiliary tamper-proof link; the scheme requires an uninterrupted light path (no repeater), and a one-time pad of keystream must be prepared in advance of the secure transmission. At least two other cryptologic schemes share these same attributes. This is quite remarkable because each of the three schemes has an entirely different physical basis for its message secrecy. In quantum cryptography an eavesdropper cannot measure or clone the state of a photon without revealing the attempt to the authorized receiver. The second scheme is the Yuen–Kim protocol. Potential bits for the keystream are masked by classical noise. The eavesdropper cannot extract the same useful bits that the authorized receiver extracts because their receivers are statistically independent. Our own scheme, called QDRN, distributes broadband noisy light to terminals, where interferometers provide identical keystreams. Security presumes that there exists some bandwidth broad enough so that the eavesdropper cannot store the phase information either optically or digitally for some period like minutes, or even hours if necessary, after which the users may safely transmit data. The Yuen–Kim protocol is by far the simplest to implement. However, it is limited to point-to-point links and distances of some tens of kilometers. By contrast, QDRN operates with full power, is compatible with amplifiers and networks, and extends to hundreds of kilometers, quite possibly a megameter. PACS: 03.67.Dd     

Non-linear optimization of a new robotic induction process for local heat treatment using thermal finite element analysis

Performing high-quality repair on aging hydro power equipment is a challenging issue for utilities. Weld repair deteriorates the mechanical properties of the base metal in and around the heat-affected zone. For martensitic stainless steel runners, there is no way to perform post-weld heat treatment (PWHT) on site to restore those properties without dismantling, a very expensive job for such large components, typical of power utilities. To perform in situ high-quality repairs on such components, a new robotic heat treatment process is developed. Heat is generated and controlled using a flat spiral coil mounted on a compact, portable robot and moved over the area needing heat treatment. Unlike conventional induction heating, which requires a customized coil, this new approach combines a universal coil and a flexible robot to heat a broad range of complex shapes. One critical aspect is to set heating and path parameters in order to generate a target spatial and temporal temperature field. This paper proposes a numerical method combining thermal finite element analysis and a non-linear optimization algorithm to set these parameters. The temperature resulting from the electromagnetic field induced by the coil is modeled using an average heat input source to improve computation speed. Good agreement is obtained between numerical and experimental results for PWHT under laboratory conditions.     

The wave concept iterative process (WCIP) method for electrical circuit network with triangular and hexagonal topology

This paper deals with an RLC circuit network with triangular or hexagonal grid. It is about a planar equilateral triangular grid where the passive (resistor, capacitor, and inductor) or active (voltage source for example) components are located at the sides or/and at nodes attached to the ground. The planar graph is oriented by three main direction vectors phase shifted to 60° degrees. The wave concept iterative process (WCIP) method was employed to the theoretical formulation of the problem. In the formulation, the potential difference across each circuit component is represented by an auxiliary source defined in the spectral domain. The proposed theory is developed into two definition domains: a spectral domain in which periodicity and coupling between the circuit components are defined and a spatial domain describing the network topology and imposing the continuities conditions (Kirchhoff laws). The transition between the spectral and spatial domain is ensured by the so-called fast hexagonal Fourier transform. Numerical applications demonstrate the ability of the method for solving the inhomogeneous triangular lattices. Various conceptions have been proposed including an RL, RC, and RLC triangular network circuit, a perturbed triangular RLC circuit, and a triangular circuit excited by many lumped sources.     

Atmospheric photosensitized heterogeneous and multiphase reactions: from outdoors to indoors

This proposal involves direct photolysis processes occurring in the troposphere incorporating photochemical excitation and intermolecular energy transfer. The study of such processes could provide a better understanding of ·OH radical formation pathways in the atmosphere and in consequence, of a more accurate prediction of the oxidative capacity of the atmosphere. Compounds that readily absorb in the tropospheric actinic window (ionic organic complexes, PAHs, aromatic carbonyl compounds) acting as potential photosensitizers of atmospheric relevant processes are explored. The impact of hotosensitation on relevant systems which could act as powerful atmospheric reactors,that is, interface ocean-atmosphere, urban and forest surfaces and indoor air environments is also discussed.