Adventitial Tertiary Lymphoid Organs as Potential Source of MicroRNA Biomarkers for Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is an inflammatory disease associated with marked changes in the cellular composition of the aortic wall. This study aims to identify microRNA (miRNA) expression in aneurysmal inflammatory cells isolated by laser microdissection from human tissue samples. The distribution of inflammatory cells (neutrophils, B and T lymphocytes, mast cells) was evaluated in human AAA biopsies. We observed in half of the samples that adventitial tertiary lymphoid organs (ATLOs) with a thickness from 0.5 to 2 mm were located exclusively in the adventitia. Out of the 850 miRNA that were screened by microarray in isolated ATLOs (n = 2), 164 miRNAs were detected in ATLOs. The three miRNAs (miR-15a-3p, miR-30a-5p and miR-489-3p) with the highest expression levels were chosen and their expression quantified by RT-PCR in isolated ATLOs (n = 4), M1 (n = 2) and M2 macrophages (n = 2) and entire aneurysmal biopsies (n = 3). Except for the miR-30a-5p, a similar modulation was found in ATLOs and the two subtypes of macrophages. The modulated miRNAs were then evaluated in the plasma of AAA patients for their potential as AAA biomarkers. Our data emphasize the potential of miR-15a-3p and miR-30a-5p as biomarkers of AAA but also as triggers of ATLO evolution. Further investigations will be required to evaluate their targets in order to better understand AAA pathophysiology.     

科技奖——“孵蛋机器”

设计师将这件作品比喻成一个孕育生命的机器。像鸡蛋一样的外形最适合孕育生命，生命成长所需要的养分通过与“蛋体”连接的金线来传输，生命的生长情况可以通过一个透明的小窗来观察。     

SURFACE ALLOYING OF MILD STEEL BY LASER MELTING OF AN ELECTROLESS NICKEL DEPOSIT CONTAINING CHROMIUM CARBIDES

It is possible to realize surface alloys by laser melting an electroless nickel layer containing chromium carbide particles predeposited on a mild steel substrate. By this way the surface alloy is expected to have not only a high nickel content but also an important chromium content in order to improve the corrosion resistance. The presence of chromium in solid solution results from the dissolution or melting of the carbide particles. Typical laser solidification microstructures are obtained. Dendrites consist of an austenitic Fe-Ni-Cr solid solution and interdendritic regions are constituted by an eutectic mixture containing the same austenitic solid solution and complex Fe, Ni, Cr carbides and phosphides. In comparison with a surface alloy obtained by laser melting of an electroless nickel layer without carbide particles, the corrosion resistance was slightly improved in saline aqueous solutions. The limited effect was due to the fact that the final chromium content in the present experimental conditions was not as high as that initially expected.     

Nonholonomic Mobile Manipulators: Kinematics, Velocities and Redundancies

We consider nonholonomic mobile manipulators built from an n _a joint robotic arm and a nonholonomic mobile platform with two independently driven wheels. Actually, there is no efficient kinematic formalism for these systems which are generally characterized by their high number of actuators. So, kinematic modelling is presented with particular emphasis on redundancy. Whereas kinematic redundancy is well known in the holonomic case, it is pointed out that it is necessary to define velocity redundancy in the case of nonholonomic systems. Reduced velocity kinematics based on quasi-velocities are shown to provide an efficient formalism. Two examples of mobile manipulators are presented. Finally, reduced velocity kinematics and velocity redundancy are shown to be adequate tools in order to realize operational task while optimizing criteria such as manipulability.     

Toward two-dimensional self-organization of nanostructures using wafer bonding and nanopatterned silicon surfaces

The structure of ultrathin silicon layers obtained by molecular hydrophobic bonding is investigated. The twist and tilt angles between the two crystals are accurately controlled. The buried Si|Si interface is observed by transmission electron microscopy and by grazing incidence X-ray techniques. For low twist angle values (/spl psi/<5/spl deg/) plane view observations reveal well-defined dislocation networks. Cross-section observations give evidence that the dislocation networks are localized at the bonding interfacial plane with no threading dislocation. Grazing incidence small angle X-ray scattering measurements confirm the good quality of the bonding interface as well as the quality of the dislocation networks. Grazing incidence X-ray diffraction is also used and shows the long-range order of the periodic strain field in the silicon layer. It shows, especially, the interaction between the dislocations. X-ray reflectivity was employed and estimated that the interfacial thickness (i.e., thickness of the bonding) lower than 1 nm decreases when the twist angle increases. The nanopatterned surface is then investigated by scanning tunneling microscopy and X-ray methods. To validate these substrates for long-range order self-organization, the growth of Si and Ge quantum dots is finally achieved.     

An EKV-based high voltage MOSFET model with improved mobility and drift model

An EKV-based high voltage MOSFET model is presented. The intrinsic channel model is derived based on the charge based EKV-formalism. An improved mobility model is used for the modeling of the intrinsic channel to improve the DC characteristics. The model uses second order dependence on the gate bias and an extra parameter for the smoothening of the saturation voltage of the intrinsic drain. An improved drift model [Chauhan YS, Anghel C, Krummenacher F, Ionescu AM, Declercq M, Gillon R, et al. A highly scalable high voltage MOSFET model. In: IEEE European solid-state device research conference (ESSDERC), September 2006. p. 270–3; Chauhan YS, Anghel C, Krummenacher F, Maier C, Gillon R, Bakeroot B, et al. Scalable general high voltage MOSFET model including quasi-saturation and self-heating effect. Solid State Electron 2006;50(11–12):1801–13] is used for the modeling of the drift region, which gives smoother transition on output characteristics and also models well the quasi-saturation region of high voltage MOSFETs. First, the model is validated on the numerical device simulation of the VDMOS transistor and then, on the measured characteristics of the SOI-LDMOS transistor. The accuracy of the model is better than our previous model [Chauhan YS, Anghel C, Krummenacher F, Maier C, Gillon R, Bakeroot B, et al. Scalable general high voltage MOSFET model including quasi-saturation and self-heating effect. Solid State Electron 2006;50(11–12):1801–13] especially in the quasi-saturation region of output characteristics.     

Modeling of submicrometer gate GaAs field effect transistors

Before describing the mainFet modelings today available, the main technological evolutions ofMesfet andTegfet are summarized. It is brought some information on the various physical effects that occur in the devices and that must be taken into account in the models. It is shown that the different kinds of modelings (Monte Carlo, two dimensional, one dimensional) constitute a continuous chain, where the different elements appear strictly complementary. Finally, the present situation concerning modeling ofMesfet andTegfet will be presented.     

Rheological behaviour of polysaccharide aqueous solutions

Several data relative to the viscosity of water-soluble polysaccharide solutions were collected from the literature and processed by different rheological models. Some relationships between the viscosity of these polymer solutions, their molecular weight and their solution concentrations, were established and their validity checked. Thus, an accurate equation correlating the viscosity and both the shear rate and the solution concentration of different water soluble polysaccharides (xanthan, hyaluronan, carboxymethylcellulose) was deduced on the basis of Cross' model which suggests two domains in which the viscosity is constant, i.e. very low and very high shear rate ranges. Then, an expression relating the zero-shear viscosity (A) and the concentration of their solutions was proposed. Finally, an alternative equation to that of Mark–Houwink correlating the molecular weight and the intrinsic viscosity of the water-soluble polysaccharides studied in this paper was found.