I-V characteristics of single electron tunneling from symmetric and asymmetric double-barrier tunneling junctions

Copyright 2007 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters, 90(22), 223112, 2007 and may be found at http://dx.doi.org/10.1063/1.274525

Fabrication of nanoscale gaps using a combination of self-assembled molecular and electron beam lithographic techniques

Copyright 2006 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters, 88(22), 223111, 2006 and may be found at http://dx.doi.org/10.1063/1.220920

Reservoir Computing Approach to Robust Computation using Unreliable Nanoscale Networks

As we approach the physical limits of CMOS technology, advances in materials science and nanotechnology are making available a variety of unconventional computing substrates that can potentially replace top-down-designed silicon-based computing devices. Inherent stochasticity in the fabrication process and nanometer scale of these substrates inevitably lead to design variations, defects, faults, and noise in the resulting devices. A key challenge is how to harness such devices to perform robust computation. We propose reservoir computing as a solution. In reservoir computing, computation takes place by translating the dynamics of an excited medium, called a reservoir, into a desired output. This approach eliminates the need for external control and redundancy, and the programming is done using a closed-form regression problem on the output, which also allows concurrent programming using a single device. Using a theoretical model, we show that both regular and irregular reservoirs are intrinsically robust to structural noise as they perform computation

Integration of various stacking processes in carrier ampholyte-based capillary electrophoresis

Field-enhanced sample stacking, field-enhanced sample injection as well as electrokinetic supercharging have been successfully integrated in carrier ampholyte-based capillary electrophoresis. Through the analysis of different test sample mixtures, it has been shown that the carrier ampholyte-based background electrolytes, in spite of their very low conductivity, allow efficient online preconcentration of analytes by fieldamplified techniques. Sensitivity enhancement factors of the same magnitude as those usually encountered with classical conductive background electrolytes have been obtained in such carrier ampholyte-based buffers. Depending on the online preconcentration method that has been integrated, sensitivity enhancement factors between 50 and several thousands have been reached

An Open-label Single-arm Trial of a Novel Extramedullary Guide Coordinated with 3D Surgical Assistive Software for Total Knee Arthroplasty

There is no assistive device for extramedullary surgery coordinated with 3D surgical assistive software for the total knee arthroplasty (TKA). We developed a novel extramedullary universal guide coordinated with 3D surgical assistive software and a novel extramedullary patient-specific assistive guide for the placement of femoral components by referring to an area not affected by cartilage or bone spurs, and filed a patent application. In this study, we visualize and reconstruct the total alignment of the lower extremity in TKA using these surgical devices, and validate their precision. A report releasing study results will be submitted in an appropriate journal

Transforming Growth Factor-β Production and Myeloid Cells Are an Effector Mechanism through Which CD1d-restricted T Cells Block Cytotoxic T Lymphocyte–mediated Tumor Immunosurveillance: Abrogation Prevents Tumor Recurrence

Our previous work demonstrated that cytotoxic T lymphocyte (CTL)-mediated tumor immunosurveillance of the 15-12RM tumor could be suppressed by a CD1d-restricted lymphocyte, most likely a natural killer (NK) T cell, which produces interleukin (IL)-13. Here we present evidence for the effector elements in this suppressive pathway. T cell–reconstituted recombination activating gene (RAG)2 knockout (KO) and RAG2/IL-4 receptor α double KO mice showed that inhibition of immunosurveillance requires IL-13 responsiveness by a non–T non–B cell. Such nonlymphoid splenocytes from tumor-bearing mice produced more transforming growth factor (TGF)-β, a potent inhibitor of CTL, ex vivo than such cells from naive mice, and this TGF-β production was dependent on the presence in vivo of both IL-13 and CD1d-restricted T cells. Ex vivo TGF-β production was also abrogated by depleting either CD11b+ or Gr-1+ cells from the nonlymphoid cells of tumor-bearing mice. Further, blocking TGF-β or depleting Gr-1+ cells in vivo prevented the tumor recurrence, implying that TGF-β made by a CD11b+ Gr-1+ myeloid cell, in an IL-13 and CD1d-restricted T cell–dependent mechanism, is necessary for down-regulation of tumor immunosurveillance. Identification of this stepwise regulation of immunosurveillance, involving CD1-restricted T cells, IL-13, myeloid cells, and TGF-β, explains previous observations on myeloid suppressor cells or TGF-β and provides insights for targeted approaches for cancer immunotherapy, including synergistic blockade of TGF-β and IL-13

食塩過剰摂取防止に関する調理学的研究(第2報) : めん類の調理による食塩量の検討

"1)乾めんの食塩量は1.5～8.2%の間でかなり差がみられ,手打ちめんは機械打ちめんの約2倍量であった. 2)ゆでめんの食塩量は乾めんの約1/10となり,各めん間の食塩含有量の差は小さくなった.また,水さらし操作により,わずかながら食塩量は減少したが乾めん時に食塩量の多かっためんは水さらし後も他に比べて食塩量が多かった. 3)最終調理後の食塩量は,いずれのめんについても煮こみめんが最大で,次いでかけめん,つけめんで調理方法による影響が大きかった.すなわち,その食塩量は調味液の食塩量,調理時の温度および時間等に大きく影響を受けると考えられる. 4)めん料理において,めんのみ喫食する場合に比べ,汁もめんも全て喫食する場合に食塩摂取量は2～3倍に増大する.なお,本研究は日本家政学会第31回総会において発表した.終りに臨み,本研究にご協力いただきました伊藤博美・加藤紀子・木子あけみ.・小林恵子・吉川澄子諸氏に感謝いたします.

Quantum Conductance in Memristive Devices: Fundamentals, Developments, and Applications

Quantum effects in novel functional materials and new device concepts represent a potential breakthrough for the development of new information processing technologies based on quantum phenomena. Among the emerging technologies, memristive elements that exhibit resistive switching, which relies on the electrochemical formation/rupture of conductive nanofilaments, exhibit quantum conductance effects at room temperature. Despite the underlying resistive switching mechanism having been exploited for the realization of next-generation memories and neuromorphic computing architectures, the potentialities of quantum effects in memristive devices are still rather unexplored. Here, a comprehensive review on memristive quantum devices, where quantum conductance effects can be observed by coupling ionics with electronics, is presented. Fundamental electrochemical and physicochemical phenomena underlying device functionalities are introduced, together with fundamentals of electronic ballistic conduction transport in nanofilaments. Quantum conductance effects including quantum mode splitting, stability, and random telegraph noise are analyzed, reporting experimental techniques and challenges of nanoscale metrology for the characterization of memristive phenomena. Finally, potential applications and future perspectives are envisioned, discussing how memristive devices with controllable atomic-sized conductive filaments can represent not only suitable platforms for the investigation of quantum phenomena but also promising building blocks for the realization of integrated quantum systems working in air at room temperature.status: publishe

Nanoscale Electronic Inhomogeneity in In2Se3 Nanoribbons Revealed by Microwave Impedance Microscopy

Driven by interactions due to the charge, spin, orbital, and lattice degrees of freedom, nanoscale inhomogeneity has emerged as a new theme for materials with novel properties near multiphase boundaries. As vividly demonstrated in complex metal oxides and chalcogenides, these microscopic phases are of great scientific and technological importance for research in high-temperature superconductors, colossal magnetoresistance effect, phase-change memories, and domain switching operations. Direct imaging on dielectric properties of these local phases, however, presents a big challenge for existing scanning probe techniques. Here, we report the observation of electronic inhomogeneity in indium selenide (In2Se3) nanoribbons by near-field scanning microwave impedance microscopy. Multiple phases with local resistivity spanning six orders of magnitude are identified as the coexistence of superlattice, simple hexagonal lattice and amorphous structures with 100nm inhomogeneous length scale, consistent with high-resolution transmission electron microscope studies. The atomic-force-microscope-compatible microwave probe is able to perform quantitative sub-surface electronic study in a noninvasive manner. Finally, the phase change memory function in In2Se3 nanoribbon devices can be locally recorded with big signal of opposite signs.Comment: 11 pages, 4 figure