scholarly journals Turn-on mode diarylethenes for bioconjugation and fluorescence microscopy of cellular structures

2021 ◽  
Vol 118 (14) ◽  
pp. e2100165118
Author(s):  
Kakishi Uno ◽  
Ayse Aktalay ◽  
Mariano L. Bossi ◽  
Masahiro Irie ◽  
Vladimir N. Belov ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Visible Light ◽  
Ultraviolet Light ◽  
Cellular Structures ◽  
High Signal ◽  
Signal To Noise ◽  
Turn On ◽  
The Core ◽  
Maleimide Group ◽  
532 Nm

The use of photoswitchable fluorescent diarylethenes (fDAEs) as protein labels in fluorescence microscopy and nanoscopy has been limited by labeling inhomogeneity and the need for ultraviolet light for fluorescence activation (on-switching). To overcome these drawbacks, we prepared “turn-on mode” fDAEs featuring thienyl substituents, multiple polar residues, and a reactive maleimide group in the core structure. Conjugates with antibodies and nanobodies displayed complete on-switching and excitation with violet (405 nm) and yellow-green (<565 nm) light, respectively. Besides, they afforded high signal-to-noise ratios and low unspecific labeling in fluorescence imaging. Irradiation with visible light at 532 nm or 561 nm led to transient on-off switching (“blinking”) of the fDAEs of double-labeled nanobodies so that nanoscale superresolution images were readily attained through switching and localization of individual fluorophores.

The development of an ICT-based formaldehyde-responsive fluorescence turn-on probe with a high signal-to-noise ratio

2018 ◽  
Vol 42 (15) ◽  
pp. 12361-12364 ◽  
Author(s):  
Xueling Yang ◽  
Longwei He ◽  
Kaixin Xu ◽  
Yunzhen Yang ◽  
Weiying Lin
Keyword(s):  
Signal To Noise Ratio ◽  
High Signal ◽  
Signal To Noise ◽  
Turn On ◽  
Noise Ratio ◽  
Fluorescence Turn On

An ICT-based formaldehyde fluorescence turn-on probe (PBD-FA) with a high signal-to-noise ratio was judiciously constructed for bio-applications.

scholarly journals Near-infrared turn-on fluorescent probe for discriminative detection of Cys and application in in vivo imaging

RSC Advances ◽  
2019 ◽  
Vol 9 (71) ◽  
pp. 41431-41437 ◽  
Author(s):  
Shaolong Qi ◽  
Lubao Zhu ◽  
Xinyu Wang ◽  
Jianshi Du ◽  
Qingbiao Yang ◽  
...  
Keyword(s):  
Fluorescent Probes ◽  
Biological Samples ◽  
In Vivo Imaging ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Biological Detection ◽  
Signal To Noise ◽  
Turn On

Near-infrared (NIR) fluorescent probes are widely employed in biological detection because of their lower damage to biological samples, low background interference, and high signal-to-noise ratio.

Nickel L2,3 core energy loss studies in NiSi2

1992 ◽  
Vol 50 (2) ◽  
pp. 1358-1359
Author(s):  
Kaikee Wong ◽  
John Silcox
Keyword(s):  
Energy Loss ◽  
Signal To Noise Ratio ◽  
Core Loss ◽  
Spot Size ◽  
High Signal ◽  
Signal To Noise ◽  
The Core ◽  
Dipole Excitation ◽  
Core Energy ◽  
Initial States

The L2 and L3 edges in EELS spectra of 3d transition metals arise primarily from dipole excitation of the 2p1/2 and 2p3/2 electrons to unfilled 3d states. Since the initial states have narrow energy widths, the L2,3 edges reflect the conduction band density of states (DOS) with d character. By comparing the Ni L2,3 edges in NiSi2 to those in pure Ni, the bonding between Ni and Si can be studied.Experiments were carried out in an UHV HB501A STEM operating at 100 keV with a serial EELS spectrometer. The spot size and the current were estimated to be 5 Å and 0.1 nA respectively. Both the convergence and the detector angles were about 11 mrad. The spectra were recorded in steps of 0.25 eV for Ni and 0.5 eV for NiSi2. Long dwell times were necessary to achieve high signal to noise ratio in the core loss spectra and typically 5 sec per energy step was used.

A compact guided-wave EMAT with pulsed electromagnet for ferromagnetic tube inspection

2020 ◽  
Vol 64 (1-4) ◽  
pp. 951-958
Author(s):  
Tianhao Liu ◽  
Yu Jin ◽  
Cuixiang Pei ◽  
Jie Han ◽  
Zhenmao Chen
Keyword(s):  
Power Plants ◽  
Signal To Noise Ratio ◽  
Small Diameter ◽  
Performance Testing ◽  
Guided Wave ◽  
High Signal ◽  
Receiver Coil ◽  
Signal To Noise ◽  
Corrosion Defects

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.

Computationally Assisted Design of High Signal-to-Noise Photoinduced Electron Transfer-Based Voltage-Sensitive Dyes

2020 ◽  
Author(s):  
Rishikesh Kulkarni ◽  
Anneliese Gest ◽  
Chun Kei Lam ◽  
Benjamin Raliski ◽  
Feroz James ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dft Calculations ◽  
Photoinduced Electron Transfer ◽  
Density Functional ◽  
Embryonic Stem ◽  
High Sensitivity ◽  
Md Simulations ◽  
High Signal ◽  
Signal To Noise ◽  
Green Fluorescent

<p>High signal-to-noise optical voltage indicators will enable simultaneous interrogation of membrane potential in large ensembles of neurons. However, design principles for voltage sensors with high sensitivity and brightness remain elusive, limiting the applicability of voltage imaging. In this paper, we use molecular dynamics (MD) simulations and density functional theory (DFT) calculations to guide the design of a bright and sensitive green-fluorescent voltage-sensitive fluorophore, or VoltageFluor (VF dye), that uses photoinduced electron transfer (PeT) as a voltage-sensing mechanism. MD simulations predict an 11% increase in sensitivity due to membrane orientation, while DFT calculations predict an increase in fluorescence quantum yield, but a decrease in sensitivity due to a decrease in rate of PeT. We confirm these predictions by synthesizing a new VF dye and demonstrating that it displays the expected improvements by doubling the brightness and retaining similar sensitivity to prior VF dyes. Combining theoretical predictions and experimental validation has resulted in the synthesis of the highest signal-to-noise green VF dye to date. We use this new voltage indicator to monitor the electrophysiological maturation of human embryonic stem cell-derived medium spiny neurons. </p>

Electroanalysis of Catecholamine Drugs using Graphene Modified Electrodes

2019 ◽  
Vol 15 (4) ◽  
pp. 443-466 ◽  
Author(s):  
Mahya Karami Mosammam ◽  
Mohammad Reza Ganjali ◽  
Mona Habibi-Kool-Gheshlaghi ◽  
Farnoush Faridbod
Keyword(s):  
Electrochemical Sensors ◽  
Modified Electrodes ◽  
Electrochemical Methods ◽  
High Signal ◽  
Signal To Noise ◽  
Low Level ◽  
Biological Studies

Background: Catecholamine drugs are a family of electroactive pharmaceutics, which are widely analyzed through electrochemical methods. However, for low level online determination and monitoring of these compounds, which is very important for clinical and biological studies, modified electrodes having high signal to noise ratios are needed. Numerous materials including nanomaterials have been widely used as electrode modifies for these families during the years. Among them, graphene and its family, due to their remarkable properties in electrochemistry, were extensively used in modification of electrochemical sensors. Objective: In this review, working electrodes which have been modified with graphene and its derivatives and applied for electroanalyses of some important catecholamine drugs are considered.

Naked-Eye Detection of Hg(II) Ions by Visible Light-Induced Polymerization Initiated by a Hg(II)-Selective Photoredox Catalyst

2021 ◽  
Author(s):  
Hyungwook Kim ◽  
Young Jae Jung ◽  
Jungkyu K. Lee
Keyword(s):  
Visible Light ◽  
Signal Amplification ◽  
Eye Detection ◽  
Naked Eye ◽  
Turn On ◽  
Novel Strategy ◽  
Amplification Strategy ◽  
Naked Eye Detection

We developed a novel strategy for signal amplification strategy using a visible light-induced photopolymerization, initiated by a selective turn-on photoredox catalyst. As photoredox catalysts, fluorescein derivatives are able to initiate...

Narrow-frequency sharp-angular filters using all-dielectric cascaded meta-gratings

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3443-3450 ◽  
Author(s):  
Wei-Nan Liu ◽  
Rui Chen ◽  
Wei-Yi Shi ◽  
Ke-Bo Zeng ◽  
Fu-Li Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Signal To Noise Ratio ◽  
Incident Angle ◽  
Design Strategy ◽  
Transmission Peak ◽  
High Signal ◽  
Waveguide Array ◽  
Signal To Noise ◽  
Center Wavelength ◽  
Noise Ratio

AbstractSelective transmission or filtering always responds to either frequency or incident angle, so as hardly to maximize signal-to-noise ratio in communication, detection and sensing. Here, we propose compact meta-filters of narrow-frequency sharp-angular transmission peak along with broad omnidirectional reflection sidebands, in all-dielectric cascaded subwavelength meta-gratings. The inherent collective resonance of waveguide-array modes and thin film approximation of meta-grating are employed as the design strategy. A unity transmission peak, locating at the incident angle of 44.4° and the center wavelength of 1550 nm, is demonstrated in a silicon meta-filter consisting of two-layer silicon rectangular meta-grating. These findings provide possibilities in cascaded meta-gratings spectroscopic design and alternative utilities for high signal-to-noise ratio applications in focus-free spatial filtering and anti-noise systems in telecommunications.

scholarly journals Low-dose, phase-contrast mammography with high signal-to-noise ratio

2016 ◽  
Vol 7 (2) ◽  
pp. 381 ◽  
Author(s):  
Lukas B. Gromann ◽  
Dirk Bequé ◽  
Kai Scherer ◽  
Konstantin Willer ◽  
Lorenz Birnbacher ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Low Dose ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Signal To Noise ◽  
Noise Ratio
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