Identification of archaeal proteins that affect the exosome function in vitro

Background  

The archaeal exosome is formed by a hexameric RNase PH ring and three RNA binding subunits and has been shown to bind and degrade RNA in vitro. Despite extensive studies on the eukaryotic exosome and on the proteins interacting with this complex, little information is yet available on the identification and function of archaeal exosome regulatory factors.     

Sub-wavelength and non-periodic holes array based fully lensless imager

We present a novel concept for microscopic imaging. The proposed microscope-like device does not include an objective lens neither a condenser. Instead, a metallic plate of sub-wavelength hole-array with a varying pitch is used to illuminate the inspected object that is mounted very close to it. As a result, the transmitted spectrum through each hole differs from the others and therefore, each spot of the detected object is illuminated with a unique spectrum. By measuring a single spectrum that is the sum of all the spectra that are transmitted through the sample and by using spectral decomposition algorithms, the spatial transmission pattern of the object can be extracted.     

Search for sub-eV mass solar axions by the CERN Axion Solar Telescope with 3He buffer gas

The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using (3)He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with (4)He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV?m(a)?0.64 eV. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g(aγ)?2.3×10(-10) GeV(-1) at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m(a)?1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.     

Dual-Vivaldi wideband nanoantenna with high radiation efficiency over the infrared frequency band

A dual-Vivaldi nanoantenna is proposed to demonstrate the possibility of wideband operation at IR frequencies. The antenna geometry design is guided by the material properties of metals at IR frequencies. According to our numerical results, this nanoantenna has both high radiation efficiency and good impedance-matching properties over a wide frequency band (more than 122%) in the IR frequency band. The design is based on the well-known Vivaldi antenna placed on quartz substrate but operating as a pair instead of a single element. Such a pair of Vivaldi antennas oriented in opposite directions produces the main lobe in the broadside direction (normal to the axes of the antennas) rather than the usual peak gain along the axis (end fire) of a single Vivaldi antenna. The dual-Vivaldi nanoantenna is easy to fabricate in a conventional electron-beam lithography process, and it provides a large number of degrees of freedom, facilitating design for ultra-wideband operation.     

Tempered wave functions: Schrödinger's equation within the light cone

The standard derivation of Schrödinger's equation from a Lorentz-invariant Feynman path integral consists in taking first the limit of infinite speed of light and then the limit of short time slice. In this order of limits the light cone of the path integral disappears, giving rise to an instantaneous spread of the wave function to the entire space. We ascribe the failure of the propagation in time according to Schrödinger's equation to retain the light cone of the path integral to the very nature of the limiting process: it is a regular expansion of a singular approximation problem, because the time-dependent boundary conditions of the path integral on the light cone are lost in this limit. We propose a distinguished limit of the time-sliced relativistic path integral, which produces Schrödinger's equation and preserves the zero boundary conditions on and outside the original light cone of the path integral. This produces an intermediate model between non-relativistic and relativistic mechanics of a single particle quantum particle. These boundary conditions relieve the solutions of Schrödinger's equation in the entire space of several annoying, seemingly unrelated unphysical artifacts, including non-analytic wave functions, spontaneous appearance of discontinuities, non-existence of moments when the initial wave function has a jump discontinuity (e.g., a collapsed wave function after a measurement), and so on. The practical implications of the present formulation are yet to be seen.     

Minimal time of controllability of two parabolic equations with disjoint control and coupling domains

We consider two parabolic equations coupled by a matrix A(x)=q(x)A₀$A(x)=q(x)A_0$, where A₀$A_0$ is a Jordan block of order 1, and controlled by a single localized function, or by a single boundary control. The support of the coupling coefficient, q  , and the control domain may be disjoint. We exhibit an explicit minimal time of null-controllability, T₀(q)∈[0,+∞]$T_0(q)\in [0,+\infty ]$.     

Singular solutions for second-order non-divergence type elliptic inequalities in punctured balls

We study the existence and non-existence of positive singular solutions of second-order non-divergence type elliptic inequalities of the form $\sum\limits_{i,j = 1}^N {a_{ij} (x)\frac{{\partial ^2 u}} {{\partial x_i \partial x_j }}} + \sum\limits_{i = 1}^N {b_i (x)\frac{{\partial u}} {{\partial x_i }} \geqslant K(x)u^p ,} - \infty < p - \infty , $ with measurable coefficients in a punctured ball B _R \{0} of ? ^N , N ≥ 1. We prove the existence of a critical value p* which separates the existence region from the non-existence region. We show that in the critical case p = p*, the existence of a singular solution depends on the rate at which the coefficients (a _{i j} ) and (b _i ) stabilize at zero, and we provide some optimal conditions in this setting.     

Spatial information transmission using axial temporal coherence coding

We present an approach that can be used for transmission of information through space-limited systems or for superresolution. The spatial information is coded with different axial temporal coherence by interfering every spatial region in the input with the same region, but with a certain known delay in the longitudinal axis. Every spatial region has different delay. After mixing all of the spatial information, it is transmitted through the space-limited system. At the detection the information is passed through a similar interference setup containing certain axial delay. By temporally scanning along the longitudinal axis, each time a different spatial region that was coded with the corresponding axial delay is reconstructed. To allow coding of different spatial regions with different and small axial delays, we use a thermal light source that has very short coherence length. We include experimental validation of the presented approach.     

High Sensitive Microsensor Based on Organic‐Inorganic Composite for Two‐Dimensional Mapping of H2O2 by SECM

The present work describes the development of a selective, sensitive and stable sensing microsensor for scanning electrochemical microscopy (SECM) to measure H₂O₂ during electrochemical reduction of oxygen. The microsensor is based on graphene and Poly(3,4‐ethylenedioxythiophene) composite as support to iron (III) hexacyanoferrate (II) (PEDOT/graphene/Fe^III₄[Fe^II(CN)₆]₃ microsensor). The electrochemical properties of the PEDOT/graphene/Fe^III₄[Fe^II(CN)₆]₃ microsensor were investigated by cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). The PEDOT/graphene/Fe^III₄[Fe^II(CN)₆]₃ microsensor showed an excellent electrocatalytic activity toward hydrogen peroxide (H₂O₂) reduction with a diminution of the overpotential of about 500 mV in comparison to the process at a bare gold microelectrode. The microsensor presented excellent performance for two dimensional mapping of H₂O₂ by SECM in 0.1 mol L^?1 phosphate buffer solution (pH 7.0). Under optimized conditions, a linear response range from 1 up to 1000 µmol L^?1 was obtained with a sensitivity of 0.08 nA L µmol^?1 and limit of detection of 0.5 µmol L^?1.