In Vivo Photovoltaic Performance of a Silicon Nanowire Photodiode-Based Retinal Prosthesis.

Purpose:For more than 20 years, there has been an international, multidisciplinary effort to develop retinal prostheses to restore functional vision to patients blinded by retinal degeneration. We developed a novel subretinal prosthesis with 1512 optically addressed silicon nanowire photodiodes, which transduce incident light into an electrical stimulation of the remaining retinal circuitry. This study was conducted to evaluate the efficacy of optically driving the subretinal prosthesis to produce visual cortex activation via electrical stimulation of the retina. Methods:We measured electrically evoked potential responses (EEPs) in rabbit visual cortex in response to illumination of the subretinal nanowire prosthesis with pulsed 852-nm infrared (IR) light. We compared the EEP responses to visually evoked potential responses (VEPs) to pulsed 532-nm visible light (positive control) and pulsed 852-nm IR light (negative control). Results:Activating the devices with IR light produced EEP responses with a significantly higher trough-to-peak amplitude (54.17 ± 33.4 μV) than IR light alone (24.07 ± 22.1 μV) or background cortical activity (23.22 ± 17.2 μV). EEP latencies were significantly faster than focal VEP latencies. Focal VEPs produced significantly higher amplitudes (94.88 ± 43.3 μV) than EEPs. We also demonstrated how an electrode placed on the cornea can be used as a noninvasive method to monitor the function of the implant. Conclusions:These results show that subretinal electrical stimulation with nanowire electrodes can elicit EEPs in the visual cortex, providing evidence for the viability of a subretinal nanowire prosthetic approach for vision restoration

TWO-DEGREE-OF-FREEDOM ELECTRIC MACHINE AND ITS OPERATION MODES

This paper is devoted to the problems of developing an electric machine with two-degrees-of-freedom (2-DOF) of rotor movement and its control system. The structure of the machine with the possibility of rotation of the rotor along two angular coordinates in a limited range of rotation angles is considered. The machine is designed to control the position of the axis of the optical beam along the line and frame trajectories. Based on the electrodynamic state model of the 2-DOF electric machine, a block diagram of the servo system was developed to control the trajectory of the rotor in two coordinates. Relationships between the time constant of the angle controller and the time constants of the high-frequency part of the amplitude-frequency characteristic of an open-loop system are determined. The dependences of the effective values of the currents in the control windings on the frequency of the frames and the duration of the linear part of the triangular signal are obtained. The dependences of the modules of relative accuracy of the rotor movement along a given trajectories on the system tunings are obtained. Ref. 12, fig. 8

Influence of heat treatment on magnetic properties of Cu-Sn-Co-based materials produced by powder metallurgy

In the foundation of this work is the issue for production of non-magnetic materials with predetermined weak magnetic properties. Preferable solution is to dope these materials with ferromagnetic impurities in low concentrations. One of the efficient ways to obtain such materials is the use of powder metallurgy which gives an opportunity to produce complex powder compositions with variety of components in precisely specified concentrations

The Priorities of Socio-economic and Financial Development of the North Caucasus Federal District in the Current Geopolitical Situation

The aim of the research is to establish the priorities of the socio-economic and financial development of the North Caucasus macro-region within the boundaries of the federal district in the current geopolitical situation. The results of the research show in details the priorities of socio-economic and financial development of the North Caucasus Federal District in terms of import substitution and finance rationalization under the current financial crisis and international sanctions against the Russian Federation. It is a well-known fact that more than 30 nations declared this territory the area of their strategic interests. The Caucasus became the subject of so-called “pipe wars”; it also became “a buffer zone” in the distribution of the Islamic state model. We have a new strategy of working with migrants in the Islamic regions of Russia (Gabdrafikov et al., 2015). Previously, the Caucasus region has been the outcome for migrants, but today it has become to develop new models for the socio-economic attractiveness of the region (Karepova et al., 2015). Statistical, monographic, sociological methods as well as logical modelling have been used in the research. Keywords: sanctions, strategy, cluster, import substitution, finance rationalization. JEL Classifications: A14, C38, G

NORTH-EASTERN SHARED RESEARCH FACILITIES OF NEISRI FEB RAS: EQUIPMENT AND DIRECTIONS OF RESEARCH

The activity of the North-Eastern Shared Research Facilities of the Shilo North-East Interdisciplinary Scientific Research Institute, Far Eastern Branch of the Russian Academy of Sciences (NEISRI FEB RAS) is aimed at conducting analytical studies of rocks, minerals, ores, soils, lake and sea sediments, water bodies using various methods: optical microscopy, X-ray microanalysis, X-ray fluorescence analysis, quantitative emission spectral analysis, atomic absorption spectrometry, isotope geochronology, paleomagnetism and petromagnetism. The results of mineralogical, geochemical, petrophysical, isotope-geochronological (including radiocarbon) and palynological studies have been published in national and international scientific journals

A 144MHz integrated resonant regulating rectifier with hybrid pulse modulation

This paper presents a CMOS fully-integrated resonant regulating rectifier (IR3) for inductive power telemetry in implantable devices. Employing PWM and PFM feedback, the IR3 achieves 1.87% of delta VDD/VDD ratio despite a tenfold change in load with a 1nF decoupling capacitor. At 1V regulation of a 100μW load from a 144MHz RF input, the measured voltage conversion efficiency is greater than 92% at under 5.2mVpp ripple and 54% power conversion efficiency. Implemented in 180nm SOI CMOS, the IR3 circuit occupies 0.078mm2 active area

A 16-channel wireless neural interfacing SoC with RF-powered energy-replenishing adiabatic stimulation

This paper presents a fully-integrated 16-channel wireless neural interfacing SoC that employs an adiabatic stimulator powered directly from a 190-MHz on-chip antenna to eliminate bulky external components while simultaneously avoiding rectifier and regulator losses. Using a charge replenishing architecture, the stimulator outputs up to 145-μA, while achieving a 63.1% charge replenishing ratio and a stimulation efficiency factor of 6.0. Analog front-ends (AFEs) and telemetry circuitry are also included

СЕВЕРО-ВОСТОЧНЫЙ ЦЕНТР КОЛЛЕКТИВНОГО ПОЛЬЗОВАНИЯ СВКНИИ ДВО РАН: АППАРАТУРА И НАПРАВЛЕНИЯ ИССЛЕДОВАНИЙ

The activity of the North-Eastern Shared Research Facilities of the Shilo North-East Interdisciplinary Scientific Research Institute, Far Eastern Branch of the Russian Academy of Sciences (NEISRI FEB RAS) is aimed at conducting analytical studies of rocks, minerals, ores, soils, lake and sea sediments, water bodies using various methods: optical microscopy, X-ray microanalysis, X-ray fluorescence analysis, quantitative emission spectral analysis, atomic absorption spectrometry, isotope geochronology, paleomagnetism and petromagnetism. The results of mineralogical, geochemical, petrophysical, isotope-geochronological (including radiocarbon) and palynological studies have been published in national and international scientific journals.Деятельность центра направлена на проведение аналитических исследований горных пород, минералов, руд, почв, озерных и морских осадков, водных объектов с использованием различных методов: оптической микроскопии, рентгеноспектрального микроанализа, рентгенофлюоресцентного анализа, эмиссионного количественного спектрального анализа, атомно-абсорбционной спектрометрии, изотопной геохронологии, палеомагнетизма и петромагнетизма. Полученные результаты минералого-геохимических, петрофизических, изотопно-геохронологических, радиоуглеродных и палинологических исследований опубликованы в отечественных и зарубежных научных журналах.

Complex subvolcanic magma plumbing system of an alkali basaltic maar-diatreme volcano (Elie Ness, Fife, Scotland)

Alkali basaltic diatremes such as Elie Ness (Fife, Scotland) expose a range of volcanic lithofacies that points to a complex, multi-stage emplacement history. Here, basanites contain phenocrysts including pyrope garnet and sub-calcic augites from depths of ~60km. Volcanic rocks from all units, pyroclastic and hypabyssal, are characterised by rare earth element (REE) patterns that show continuous enrichment from heavy REE (HREE) to light REE (LREE), and high Zr/Y that are consistent with retention of garnet in the mantle source during melting of peridotite in a garnet lherzolite facies. Erupted garnets are euhedral and unresorbed, signifying rapid ascent through the lithosphere. The magmas also transported abundant pyroxenitic clasts, cognate with the basanite host, from shallower depths (~35–40km). These clasts exhibit wide variation in texture, mode and mineralogy, consistent with growth from a range of compositionally diverse melts. Further, clinopyroxene phenocrysts from both the hypabyssal and pyroclastic units exhibit a very wide compositional range, indicative of polybaric fractionation and magma mixing. This is attributed to stalling of earlier magmas in the lower crust — principally from ~22 to 28km — as indicated by pyroxene thermobarometry. Many clinopyroxenes display chemical zoning profiles, occasionally with mantles and rims of higher magnesium number (Mg#) suggesting the magmas were mobilised by juvenile basanite magma. The tuffs also contain alkali feldspar megacrysts together with Fe-clinopyroxene, zircon and related salic xenoliths, of the ‘anorthoclasite suite’ — inferred to have crystallised at upper mantle to lower crustal depths from salic magma in advance of the mafic host magmas. Despite evidence for entrainment of heterogeneous crystal mushes, the rapidly ascending melts experienced negligible crustal contamination. The complex association of phenocrysts, megacrysts and autoliths at Elie Ness indicates thorough mixing in a dynamic system immediately prior to explosive diatreme-forming eruptions.Clough and Mykura Fund of the Geological Society of Edinburgh; Timothy Jefferson Fund of the Geological Society of Londo