Development of Gating Nanopores for Next-Generation DNA Sequencing Using Mechanically Controllable Break Junctions

2011 ◽  
Author(s):  
Masateru Taniguchi ◽  
Tomoji Kawai
Keyword(s):  
Microfluidic Channel ◽  
Atomic Level ◽  
Break Junction ◽  
Level Control ◽  
Electrode Gap ◽  
Break Junctions ◽  
Next Generation Dna Sequencing ◽  
Single Atoms ◽  
Dna Molecule ◽  
The Individual

We have developed two types of devices—vertical and parallel—for incorporating a microfluidic channel into a gating nanopore. The vertical device consists of a single nanogap electrode with a nanopore perpendicular to the surface of a silicon substrate. The parallel device is similar, except the nanopore is parallel to the surface of the substrate. Furthermore, while the vertical device was fabricated using nanofabrication technologies, the parallel device was fabricated using a mechanically controllable break junction that enables atomic-level control of the electrode gap; hence, measurement of single atoms and molecules is possible. Both devices can identify single gold nanoparticles passing through them by measuring the strength of their electrical signals. The parallel device can also identify the individual nucleotides in a DNA molecule.

scholarly journals Resolving Entangled JH-H-Coupling Patterns for Steroidal Structure Determinations by NMR Spectroscopy

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2643
Author(s):  
Danni Wu ◽  
Kathleen Joyce Carillo ◽  
Jiun-Jie Shie ◽  
Steve S.-F. Yu ◽  
Der-Lii M. Tzou
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr Spectroscopy ◽  
Chemical Shifts ◽  
Atomic Level ◽  
Molecular Structures ◽  
Naturally Occurring ◽  
Structure Determinations ◽  
Ligand Interactions ◽  
Synthetic Steroids ◽  
The Individual

For decades, high-resolution 1H NMR spectroscopy has been routinely utilized to analyze both naturally occurring steroid hormones and synthetic steroids, which play important roles in regulating physiological functions in humans. Because the 1H signals are inevitably superimposed and entangled with various JH–H splitting patterns, such that the individual 1H chemical shift and associated JH–H coupling identities are hardly resolved. Given this, applications of thess information for elucidating steroidal molecular structures and steroid/ligand interactions at the atomic level were largely restricted. To overcome, we devoted to unraveling the entangled JH–H splitting patterns of two similar steroidal compounds having fully unsaturated protons, i.e., androstanolone and epiandrosterone (denoted as 1 and 2, respectively), in which only hydroxyl and ketone substituents attached to C3 and C17 were interchanged. Here we demonstrated that the JH–H values deduced from 1 and 2 are universal and applicable to other steroids, such as testosterone, 3β, 21-dihydroxygregna-5-en-20-one, prednisolone, and estradiol. On the other hand, the 1H chemical shifts may deviate substantially from sample to sample. In this communication, we propose a simple but novel scheme for resolving the complicate JH–H splitting patterns and 1H chemical shifts, aiming for steroidal structure determinations.

scholarly journals A flexible platform for controlled optical and electrical effects in tailored plasmonic break junctions

Nanophotonics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1391-1400
Author(s):  
Florian Laible ◽  
Kai Braun ◽  
Otto Hauler ◽  
Martin Eberle ◽  
Dieter P. Kern ◽  
...  
Keyword(s):  
Electrical Characterization ◽  
Tunneling Current ◽  
Plasmonic Nanostructures ◽  
Break Junction ◽  
Metal Contacts ◽  
Break Junctions ◽  
Constant Bias ◽  
Confocal Scanning ◽  
Atomic Point Contacts

AbstractMechanically controllable break junctions are one suitable approach to generate atomic point contacts and ultrasmall and controllable gaps between two metal contacts. For constant bias voltages, the tunneling current can be used as a ruler to evaluate the distance between the contacts in the sub-1-nm regime and with sub-Å precision. This ruler can be used to measure the distance between two plasmonic nanostructures located at the designated breaking point of the break junction. In this work, an experimental setup together with suitable nanofabricated break junctions is developed that enables us to perform simultaneous gap-dependent optical and electrical characterization of coupled plasmonic particles, more specifically bowtie antennas in the highly interesting gap range from few nanometers down to zero gap width. The plasmonic break junction experiment is performed in the focus of a confocal microscope. Confocal scanning images and current measurements are simultaneously recorded and exhibit an increased current when the laser is focused in the proximity of the junction. This setup offers a flexible platform for further correlated optoelectronic investigations of coupled antennas or junctions bridged by nanomaterials.

In-situ photoconductivity measurement of imidazole in optical fiber break-junctions

2021 ◽  
Author(s):  
Zhikai Zhao ◽  
Chenyang Guo ◽  
Lifa Ni ◽  
Xueyan Zhao ◽  
Surong Zhang ◽  
...  
Keyword(s):  
Electron Transport ◽  
Optical Fiber ◽  
Transport Properties ◽  
Molecular Junctions ◽  
Break Junction ◽  
Break Junctions ◽  
Fiber Break ◽  
Electron Transport Properties ◽  
Photoconductivity Measurement

We develop a method based on the mechanically controllable break junction technique to investigate the electron transport properties of single molecular junctions upon fiber waveguided light. In our strategy, a...

Measurement and control of detailed electronic properties in a single molecule break junction

2014 ◽  
Vol 174 ◽  
pp. 91-104 ◽  
Author(s):  
Kun Wang ◽  
Joseph Hamill ◽  
Jianfeng Zhou ◽  
Cunlan Guo ◽  
Bingqian Xu
Keyword(s):  
Data Analysis ◽  
Molecular Electronics ◽  
Single Molecule ◽  
Molecular Orbitals ◽  
Break Junction ◽  
Break Junctions ◽  
Single Molecule Level ◽  
Analysis Techniques ◽  
Future Design ◽  
Molecule Junction

The lack of detailed experimental controls has been one of the major obstacles hindering progress in molecular electronics. While large fluctuations have been occurring in the experimental data, specific details, related mechanisms, and data analysis techniques are in high demand to promote our physical understanding at the single-molecule level. A series of modulations we recently developed, based on traditional scanning probe microscopy break junctions (SPMBJs), have helped to discover significant properties in detail which are hidden in the contact interfaces of a single-molecule break junction (SMBJ). For example, in the past we have shown that the correlated force and conductance changes under the saw tooth modulation and stretch–hold mode of PZT movement revealed inherent differences in the contact geometries of a molecular junction. In this paper, using a bias-modulated SPMBJ and utilizing emerging data analysis techniques, we report on the measurement of the altered alignment of the HOMO of benzene molecules with changing the anchoring group which coupled the molecule to metal electrodes. Further calculations based on Landauer fitting and transition voltage spectroscopy (TVS) demonstrated the effects of modulated bias on the location of the frontier molecular orbitals. Understanding the alignment of the molecular orbitals with the Fermi level of the electrodes is essential for understanding the behaviour of SMBJs and for the future design of more complex devices. With these modulations and analysis techniques, fruitful information has been found about the nature of the metal–molecule junction, providing us insightful clues towards the next step for in-depth study.

scholarly journals Two Phase Separation using Liquid Level Control System using PLC and SCADA

2019 ◽  
Vol 9 (2) ◽  
pp. 2389-2391
Keyword(s):  
Supervisory Control ◽  
Programmable Logic ◽  
Level Control ◽  
Fluid Level ◽  
Two Phase ◽  
Two Fluids ◽  
Control Framework ◽  
Set Up ◽  
The Individual ◽  
Fluid Levels

Activity of the plant requires a great deal of work and human asset and requires a ton of diligent work and persistence as the individual needs to take note of every single an incentive at various occasions by taking readings physically. With the advancement of Industrial Automation, fluid level control framework has been generally utilized in different fields. In this paper, in light of PLC a control framework is set up by PID calculation and this control framework can alter two diverse fluid levels consequently. On the off chance that there are two distinct kinds of fluids with various densities in an equivalent tank and so as to isolate those two fluids, Level control framework dependent on SCADA and PLC is actualized. This framework satisfies splendidly the need of various fluid level control framework in industry, and it brings advantageous and exact for controlling. The proposed framework gives the fluid Level control, with the assistance of Programmable Logic Controllesr (PLCs), and Supervisory Control and Data Acquisition (SCADA).

Atomic level control of pattern fidelity during SAC etch

2021 ◽  
Author(s):  
Mingmei Wang ◽  
Du Zhang ◽  
Shinya Morikita ◽  
Yanxiang Shi ◽  
Hojin Kim ◽  
...  
Keyword(s):  
Atomic Level ◽  
Level Control

Effects of altitude acclimatization and deacclimatization on bone and marrow volume in dog

1965 ◽  
Vol 209 (2) ◽  
pp. 347-352 ◽  
Author(s):  
Joseph K. Gong
Keyword(s):  
Sea Level ◽  
Relative Distribution ◽  
Level Control ◽  
Marrow Fat ◽  
Cortical Volume ◽  
Altitude Acclimatization ◽  
The Individual ◽  
And Sea Level

Skeletons of altitude-acclimatized, altitude-deacclimatized, and sea-level control dogs were completely analyzed for water, fat, and nonfatty organic and inorganic fractions. The total skeletal and marrow volumes as well as their contents were calculated and compared. Neither the marrow volume nor the bone (trabecular and cortical) volume was affected by the altitude changes. The relative distribution of marrow and bone in the various parts of the skeleton was also unchanged. Marrow fat in the whole skeleton as well as in the individual parts of the skeleton was lowered on acclimatization and increased on deacclimatization. Of the fat lost, one-third was from the flat bones while one-half of the fat deposited on deacclimatization occurred in flat bones. The marrow water as well as the functional marrow (fat-free, by definition) in either the whole or the various parts of the skeleton was increased on acclimatization and decreased on deacclimatization.

scholarly journals Ahmed Hassan Zewail. 26 February 1946—2 August 2016

2019 ◽  
Vol 68 ◽  
pp. 431-453
Author(s):  
John Meurig Thomas
Keyword(s):  
Electron Microscopy ◽  
Gas Phase ◽  
Ultrafast Lasers ◽  
Atomic Level ◽  
Women In Science ◽  
President Obama ◽  
Structure And Dynamics ◽  
Transmission Electron ◽  
The Individual ◽  
Gas Phase Electron Diffraction

Ahmed Zewail will forever be remembered for three main reasons: first, he was the individual who first demonstrated that the structure and dynamics of atoms in the transition state of chemical reactions could be determined through the judicious use of ultrafast lasers, in a field that he pioneered, for which he coined, called femtochemistry; second, he transformed both gas phase electron diffraction and transmission electron microscopy by improving their temporal resolution some 10 orders of magnitude, while simultaneously retaining the spatial resolution of electron microscopy at the atomic level; and third, he was the first US Science Envoy to the Middle East (appointed by President Obama). To all who knew him, he was a warm-hearted, life-enhancing person endowed with exceptional technical virtuosity as an experimentalist and a profound thinker, whose prodigality of output was also exceptional. He exhibited remarkable skills as an enterprising fundraiser in his determination to establish the Zewail City of Science and Technology on the outskirts of his beloved Cairo. He also influenced greatly the L'Oréal–UNESCO scheme for awarding prizes to women in science.

scholarly journals Direct Observation of Deformation in Microgel Filtration

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
John Linkhorst ◽  
Jonas Rabe ◽  
Lukas T. Hirschwald ◽  
Alexander J. C. Kuehne ◽  
Matthias Wessling
Keyword(s):  
Soft Matter ◽  
Filter Cake ◽  
Productivity Loss ◽  
Microfluidic Channel ◽  
Transmembrane Flux ◽  
Colloidal Matter ◽  
Realistic Description ◽  
On Line ◽  
The Individual ◽  
Crystalline Domains

AbstractColloidal filtration processes using porous membranes suffer from productivity loss due to colloidal matter retention and continuous build-up by the retained matter. Especially during filtration of soft matter, the deformation of the individual colloids that make up the filter cake may be significant; however, this deformation and its impact remain unresolved so far. Yet, understanding the deformation on the single colloid level as well as on the ensemble level is important to be able to deconvolute filter cake properties from resistance increase of the membrane either by simultaneous internal adsorption or blocking of pores. Here, we report on the compression of a filter cake by filtrating soft microgels in a microfluidic channel in front of a model membrane. To study the single colloid deformation amorphous and crystalline domains were built up in front of the membrane and visualized on-line using confocal fluorescence microscopy while adjusting the degree of permeation, i.e., the transmembrane flux. Results show locally pronounced asymmetric deformation in amorphous domains, while the microgels in colloidal crystals approached regular polyeder shape. Increasing the flux beyond the maximum colloid deformation results in non-isochoric microgel behavior. The presented methodology enables a realistic description of complex colloidal matter deposits during filtration.

scholarly journals Thermodynamic contribution of nucleoside modifications to yeast tRNA(Phe) anticodon stem loop analogs.

1999 ◽  
Vol 46 (1) ◽  
pp. 163-172 ◽  
Author(s):  
P F Agris ◽  
R Guenther ◽  
E Sochacka ◽  
W Newman ◽  
G Czerwińska ◽  
...  
Keyword(s):  
Thermodynamic Parameters ◽  
Atomic Level ◽  
Modified Nucleosides ◽  
Automated Synthesis ◽  
Modified Nucleotides ◽  
Stem Loop ◽  
Yeast Trna ◽  
Naturally Occurring ◽  
The Individual

The determination of the structural and functional contributions of natural modified nucleosides to tRNA has been limited by lack of an approach that can systematically incorporate the modified units. We have produced a number of oligonucleotide analogs, of the anticodon of yeast tRNA(Phe) by, combining standard automated synthesis for the major nucleosides with specialty chemistries for the modified nucleosides. In this study, both naturally occurring and unnatural modified nucleotides were placed in native contexts. Each oligonucleotide was purified and the nucleoside composition determined to validate the chemistry. The RNAs were denatured and analyzed to determine the van't Hoff thermodynamic parameters. Here, we report the individual thermodynamic contributions for Cm, Gm, m1G, m5C, psi. In addition m5m6U, m1psi, and m3psi, were introduced to gain additional understanding of the physicochemical contribution of psi and m5C at an atomic level. These oligonucleotides demonstrate that modifications have measurable thermodynamic contributions and that loop modifications have global contributions.

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