scholarly journals Modeling the Electrostatic Actuation of Nanomechanical Pillar Dimers

2021 ◽  
Vol 6 ◽  
Author(s):  
Andreas Kainz ◽  
Roman Beigelbeck ◽  
Silvan Schmid
Keyword(s):  
Mass Spectrometry ◽  
External Field ◽  
Single Molecule ◽  
Electrostatic Actuation ◽  
Major Obstacle ◽  
Sensor Technology ◽  
Vibrational Motion ◽  
Electrostatic Forces ◽  
Promising Alternative ◽  
Nanomechanical Resonators

With their unparalleled mass sensitivity, enabling single-molecule mass spectrometry, nanomechanical resonators have the potential to considerably improve existing sensor technology. Vertical pillar resonators are a promising alternative to the existing lateral resonator designs. However, one major obstacle still stands in the way of their practical use: The efficient transduction (actuation & detection) of the vibrational motion of such tiny structures, even more so when large arrays of such nanopillars need to be driven. While electrostatic forces are typically weak and, on the nanoscale even weaker when compared to a cantilever-like stiffness, it is worth revisiting the possibility of electrostatic actuation of nanomechanical pillars and other nanomechanical structures. In this paper, these forces produced by an external field are studied both analytically and numerically, and their dependencies on the geometric dimensions are discussed. Furthermore, the expected deflections for different configurations of pillar geometries are calculated and compared.

scholarly journals Single-molecule mass spectrometry in solution using a solitary nanopore

2007 ◽  
Vol 104 (20) ◽  
pp. 8207-8211 ◽  
Author(s):  
J. W. F. Robertson ◽  
C. G. Rodrigues ◽  
V. M. Stanford ◽  
K. A. Rubinson ◽  
O. V. Krasilnikov ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Single Molecule

scholarly journals Mass Spectrometry Imaging (MSI) Delineates Thymus-Centric Metabolism In Vivo as an Effect of Systemic Administration of Dexamethasone

2021 ◽  
Vol 11 (22) ◽  
pp. 11038
Author(s):  
Yudai Tsuji ◽  
Shinichi Yamaguchi ◽  
Tomoyuki Nakamura ◽  
Masaya Ikegawa
Keyword(s):  
Mass Spectrometry ◽  
Single Molecule ◽  
Mass Spectrometry Imaging ◽  
Apoptotic Cell ◽  
Systemic Administration ◽  
Ionization Mass ◽  
Laser Desorption Ionization ◽  
Energy Status ◽  
Cortex Of The Thymus

Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) is increasingly used in a broad range of research due to its ability to visualize the spatial distribution of metabolites in vivo. Here, we have developed a method, named thoracic Mass Spectrometry Imaging (tMSI), as a standard protocol of molecular imaging of whole-animal sectioning in various settings of mice in vivo. Further application of the strategy that involved the systemic administration of dexamethasone (DEX) in mice, enabled a dynamic shift in the energy status of multiple thoracic organs to be visualized, based on tMSI data of purine and pyrimidine metabolites. Furthermore, with the introduction of uniform manifold approximation and projection (UMAP) for tMSI data, metabolic profiles normally localized in the cortex and cortico-medullary junction (CMJ) of the thymus were drastically shifted as minor profiles into the medulla of DEX-treated thymus. As a massive apoptotic cell death in the thymic cortex was noticeable, a single molecule, which was upregulated in the cortex of the thymus, enabled us to predict ongoing immunosuppression by in vivo DEX-administration.

An Analytical Solution to the Electrostatic Actuation of an Asymmetric Combdrive

1999 ◽  
Author(s):  
J.-L. Andrew Yeh ◽  
Norman C. Tien ◽  
Chung-Yuen Hui
Keyword(s):  
Analytical Solution ◽  
Closed Form ◽  
Complex Variable ◽  
Electrostatic Actuation ◽  
Peak Force ◽  
Constant Force ◽  
Electrostatic Forces ◽  
Critical Engagement ◽  
Out Of Plane

Abstract A model for the electrostatic forces generated by an asymmetric combdrive has been developed. Using complex variable techniques, an analytical solution to out-of-plane electrostatic actuation is obtained in closed form. The peak force depends on the thickness of the movable fingers and the amount of overlap between the combs. In addition, the in-plane actuation of an in-plane interdigitated combdrive can also be interpreted using our solution. For an in-plane combdrive, the critical engagement length of the combs, which is required for generating a constant force with variation within 1%, is a factor of 1.24 times the separation gap.

scholarly journals Assessment of the Potential of Wrist-Worn Wearable Sensors for Driver Drowsiness Detection

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1029 ◽  
Author(s):  
Thomas Kundinger ◽  
Nikoletta Sofra ◽  
Andreas Riener
Keyword(s):  
Machine Learning ◽  
User Study ◽  
Driving Simulator ◽  
Machine Learning Algorithms ◽  
Sensor Technology ◽  
Physiological Data ◽  
Promising Alternative ◽  
Drowsiness Detection ◽  
Driver Drowsiness ◽  
Medical Grade

Drowsy driving imposes a high safety risk. Current systems often use driving behavior parameters for driver drowsiness detection. The continuous driving automation reduces the availability of these parameters, therefore reducing the scope of such methods. Especially, techniques that include physiological measurements seem to be a promising alternative. However, in a dynamic environment such as driving, only non- or minimal intrusive methods are accepted, and vibrations from the roadbed could lead to degraded sensor technology. This work contributes to driver drowsiness detection with a machine learning approach applied solely to physiological data collected from a non-intrusive retrofittable system in the form of a wrist-worn wearable sensor. To check accuracy and feasibility, results are compared with reference data from a medical-grade ECG device. A user study with 30 participants in a high-fidelity driving simulator was conducted. Several machine learning algorithms for binary classification were applied in user-dependent and independent tests. Results provide evidence that the non-intrusive setting achieves a similar accuracy as compared to the medical-grade device, and high accuracies (>92%) could be achieved, especially in a user-dependent scenario. The proposed approach offers new possibilities for human–machine interaction in a car and especially for driver state monitoring in the field of automated driving.

Mass Spectrometry of Heavy Analytes and Large Biological Aggregates by Monitoring Changes in the Quality Factor of Nanomechanical Resonators in Air

ACS Sensors ◽  
2020 ◽  
Vol 5 (7) ◽  
pp. 2128-2135
Author(s):  
Ivo Stachiv ◽  
Lifeng Gan ◽  
Chih-Yun Kuo ◽  
Petr Šittner ◽  
Oldřich Ševeček
Keyword(s):  
Mass Spectrometry ◽  
Quality Factor ◽  
Nanomechanical Resonators

scholarly journals Theory for polymer analysis using nanopore-based single-molecule mass spectrometry

2010 ◽  
Vol 107 (27) ◽  
pp. 12080-12085 ◽  
Author(s):  
J. E. Reiner ◽  
J. J. Kasianowicz ◽  
B. J. Nablo ◽  
J. W. F. Robertson
Keyword(s):  
Mass Spectrometry ◽  
Single Molecule ◽  
Polymer Analysis

scholarly journals Unpicking allosteric mechanisms of homo-oligomeric proteins by determining their successive ligand binding constants

2018 ◽  
Vol 373 (1749) ◽  
pp. 20170176 ◽  
Author(s):  
Ranit Gruber ◽  
Amnon Horovitz
Keyword(s):  
Mass Spectrometry ◽  
Ligand Binding ◽  
Single Molecule ◽  
Binding Constants ◽  
Molecular Machines ◽  
Native Mass Spectrometry ◽  
Oligomeric Proteins ◽  
Allosteric Mechanisms ◽  
The Relationship

Advances in native mass spectrometry and single-molecule techniques have made it possible in recent years to determine the values of successive ligand binding constants for large multi-subunit proteins. Given these values, it is possible to distinguish between different allosteric mechanisms and, thus, obtain insights into how various bio-molecular machines work. Here, we describe for ring-shaped homo-oligomers, in particular, how the relationship between the values of successive ligand binding constants is diagnostic for concerted, sequential and probabilistic allosteric mechanisms. This article is part of a discussion meeting issue ‘Allostery and molecular machines’.

Enhanced Single Molecule Mass Spectrometry via Charged Metallic Clusters

2014 ◽  
Vol 86 (22) ◽  
pp. 11077-11085 ◽  
Author(s):  
Christopher E. Angevine ◽  
Amy E. Chavis ◽  
Nuwan Kothalawala ◽  
Amala Dass ◽  
Joseph E. Reiner
Keyword(s):  
Mass Spectrometry ◽  
Single Molecule ◽  
Metallic Clusters

scholarly journals Breakage of the Oligomeric CaMKII Hub by the Regulatory Segment of the Kinase

2020 ◽  
Author(s):  
Deepti Karandur ◽  
Moitrayee Bhattacharyya ◽  
Beryl Xia ◽  
Young Kwang Lee ◽  
Serena Muratcioglu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Dynamics ◽  
Single Molecule ◽  
Mammalian Cells ◽  
Intensity Analysis ◽  
Single Molecule Fluorescence ◽  
Dependent Protein Kinase ◽  
Large Fluctuations ◽  
Dependent Protein ◽  
Dynamics Simulations

AbstractCa2+/calmodulin dependent protein kinase II (CaMKII) is a dodecameric or tetradecameric enzyme with crucial roles in neuronal signaling and cardiac function. Activation of CaMKII is reported to trigger the exchange of subunits between holoenzymes, which can increase spread of the active state. Using mass spectrometry, we now show that peptides derived from the sequence of the CaMKII-α regulatory segment can bind to the CaMKII-α hub assembly and break it into smaller oligomers. Molecular dynamics simulations show that the regulatory segments can dock spontaneously at the interface between hub subunits, trapping large fluctuations in hub structure. Single-molecule fluorescence intensity analysis of human CaMKII-α isolated from mammalian cells shows that activation of CaMKII-α results in the destabilization of the holoenzyme. Our results show how the release of the regulatory segment by activation and phosphorylation could allow it to destabilize the hub, producing smaller CaMKII assemblies that can reassemble to form new holoenzymes.

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