Smart activatable fluorescent probe provides high-quality signal-to-noise ratio and detection limits for electrochemiluminescence

2022 ◽  
pp. 131363
Author(s):  
Chaoyun Ma ◽  
Chulei Zhao ◽  
Chenglin Hong ◽  
Yu Qi
Keyword(s):  
Fluorescent Probe ◽  
Signal To Noise Ratio ◽  
Detection Limits ◽  
Signal To Noise ◽  
High Quality ◽  
Quality Signal ◽  
Noise Ratio

Signal to Noise Ratio in Stem and Low-Loss Images

1980 ◽  
Vol 38 ◽  
pp. 236-237
Author(s):  
A. N. Broers
Keyword(s):  
Signal To Noise Ratio ◽  
High Contrast ◽  
Low Loss ◽  
Signal To Noise ◽  
High Quality ◽  
High Brightness ◽  
Electron Sources ◽  
Noise Ratio

The number of pixels or resolution elements in STEM images has frequently been relatively low (< 105) and in many images only a few gray levels can be distinguished. This is surprising considering the high brightness of the electron sources used in most cases, and the high contrast typically present in STEM images. While it is technologically expensive to match the several million resolution elements resolved in high quality TEM images, it is shown here that it is relatively straightforward to produce STEM images containing at least a million resolution elements.

Accurate Measurement of Trace Elements Using an Innovative Fixed Goniometer for a Simultaneous Spectrometer

1994 ◽  
Vol 38 ◽  
pp. 691-698
Author(s):  
K. Kansai ◽  
K. Toda ◽  
H. Kohno ◽  
T. Arai ◽  
R. Wilson
Keyword(s):  
Trace Elements ◽  
Exposure Time ◽  
Background Subtraction ◽  
Signal To Noise Ratio ◽  
Detection Limits ◽  
Background Correction ◽  
Analysis Time ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Selection Of

Advancements in trace clement analysis require improvements in both the signal-to-noise ratio and accurate background correction. With a sequential spectrometer, one can obtain detection limits of around 0.1 ppm for medium to heavy Z elements. Conditions can be individually optimized for each element, for example, selection of filters, collimators, crystals and background subtraction. The disadvantage is that the analysis time may become “long” if many elements are to be analyzed. This long exposure time can lead to the deterioration of some samples.

Micro-crack detection method of steel beam surface using stacked autoencoders on massive full-scale sensing strains

2019 ◽  
Vol 19 (4) ◽  
pp. 1175-1187 ◽  
Author(s):  
Qingsong Song ◽  
Yu Chen ◽  
Elias Abdoli Oskoui ◽  
Zheng Fang ◽  
Todd Taylor ◽  
...  
Keyword(s):  
Deep Learning ◽  
Crack Detection ◽  
Detection Method ◽  
Signal To Noise Ratio ◽  
Full Scale ◽  
Signal To Noise ◽  
High Quality ◽  
Strain Measurements ◽  
Feature Representations ◽  
Noise Ratio

Accurate micro-crack detections on the whole surface of civil structures have great significance. Distributed optical fiber sensor based on Brillouin optical time-domain analysis technology exhibits great facility to measure strain distributions along the whole surface of structures with a high spatial resolution, thus providing a potential and competitive solution to the detection problem. However, mainly due to low signal-to-noise ratio in measurements, such sensor system is still limited in crack detection–based structural health monitoring applications. How to extract high-quality micro-crack feature representations from the low signal-to-noise ratio–distributed strain measurements is crucial to solve the problem. It has been demonstrated in field of pattern recognition that deep learning can automatically extract high-quality noise-robust feature representations from mass chaos data. Therefore, a micro-crack detection method is proposed herein based on deep learning to analyze the full-scale strain measurements. Each measurement is normalized and segmented into a set of equal-length subsequences. Autoencoders, a typical kind of building block of deep neural network, are stacked layer-wise into a deep network and then exploited to automatically extract feature representations from the subsequences. Each extracted feature representation is labeled as one of the two categories by a Softmax regression. One category originates in the subsequences acquired from structure sections with crack defects and another from sections without any cracks. The micro-crack detections are achieved by solving such a crack/non-crack binary classification problem. A 15-m-long steel I-beam with artifact crack defects is built up in laboratory to verify the proposed method. Experimental results demonstrate that the minimum size of detectable crack opening width reaches to 23 μm, and besides, the proposed method is significantly better than traditional Fisher linear discriminant analysis method and classical support vector machine on the detection accuracy.

scholarly journals The HARPS search for southern extra-solar planets

2018 ◽  
Vol 614 ◽  
pp. A133 ◽  
Author(s):  
J.-B. Delisle ◽  
D. Ségransan ◽  
X. Dumusque ◽  
R. F. Diaz ◽  
F. Bouchy ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Signal To Noise Ratio ◽  
Dynamical Analysis ◽  
Velocity Measurements ◽  
Signal To Noise ◽  
Huge Amount ◽  
High Quality ◽  
Period Ratio ◽  
Noise Ratio ◽  
Orbital Periods

We report the discovery of four super-Earth planets around HD 215152, with orbital periods of 5.76, 7.28, 10.86, and 25.2 d, and minimum masses of 1.8, 1.7, 2.8, and 2.9 M⊕ respectively. This discovery is based on 373 high-quality radial velocity measurements taken by HARPS over 13 yr. Given the low masses of the planets, the signal-to-noise ratio is not sufficient to constrain the planet eccentricities. However, a preliminary dynamical analysis suggests that eccentricities should be typically lower than about 0.03 for the system to remain stable. With two pairs of planets with a period ratio lower than 1.5, with short orbital periods, low masses, and low eccentricities, HD 215152 is similar to the very compact multi-planet systems found by Kepler, which is very rare in radial-velocity surveys. This discovery proves that these systems can be reached with the radial-velocity technique, but characterizing them requires a huge amount of observations.

Ultrafast labeling and high-fidelity imaging of mitochondria in cancer cells using an aggregation-enhanced emission fluorescent probe

2019 ◽  
Vol 55 (97) ◽  
pp. 14681-14684 ◽  
Author(s):  
Li Liu ◽  
Qian Zou ◽  
Jong-Kai Leung ◽  
Jia-Li Wang ◽  
Chuen Kam ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Fluorescent Probe ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
High Fidelity ◽  
Signal To Noise ◽  
Noise Ratio

An aggregation-enhanced emission probe was developed for ultrafast labeling and high-fidelity imaging of mitochondria in cancer cells with a high signal-to-noise ratio.

scholarly journals Fast and High-Resolution Neonatal Brain MRI Through Super-Resolution Reconstruction From Acquisitions With Variable Slice Selection Direction

2021 ◽  
Vol 15 ◽  
Author(s):  
Yao Sui ◽  
Onur Afacan ◽  
Ali Gholipour ◽  
Simon K. Warfield
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Signal To Noise Ratio ◽  
Brain Mri ◽  
Super Resolution ◽  
Neonatal Brain ◽  
Signal To Noise ◽  
High Quality ◽  
Noise Ratio

The brain of neonates is small in comparison to adults. Imaging at typical resolutions such as one cubic mm incurs more partial voluming artifacts in a neonate than in an adult. The interpretation and analysis of MRI of the neonatal brain benefit from a reduction in partial volume averaging that can be achieved with high spatial resolution. Unfortunately, direct acquisition of high spatial resolution MRI is slow, which increases the potential for motion artifact, and suffers from reduced signal-to-noise ratio. The purpose of this study is thus that using super-resolution reconstruction in conjunction with fast imaging protocols to construct neonatal brain MRI images at a suitable signal-to-noise ratio and with higher spatial resolution than can be practically obtained by direct Fourier encoding. We achieved high quality brain MRI at a spatial resolution of isotropic 0.4 mm with 6 min of imaging time, using super-resolution reconstruction from three short duration scans with variable directions of slice selection. Motion compensation was achieved by aligning the three short duration scans together. We applied this technique to 20 newborns and assessed the quality of the images we reconstructed. Experiments show that our approach to super-resolution reconstruction achieved considerable improvement in spatial resolution and signal-to-noise ratio, while, in parallel, substantially reduced scan times, as compared to direct high-resolution acquisitions. The experimental results demonstrate that our approach allowed for fast and high-quality neonatal brain MRI for both scientific research and clinical studies.

Fourier Transform Infrared Spectrochemical Imaging: Review of Design and Applications with a Focal Plane Array and Multiple Beam Synchrotron Radiation Source

2012 ◽  
Vol 66 (5) ◽  
pp. 475-491 ◽  
Author(s):  
Carol J. Hirschmugl ◽  
Kathleen M. Gough
Keyword(s):  
Synchrotron Radiation ◽  
Focal Plane ◽  
Signal To Noise Ratio ◽  
Focal Plane Array ◽  
Quality Data ◽  
Small Scale ◽  
Signal To Noise ◽  
High Quality ◽  
Mid Infrared ◽  
Noise Ratio

The beamline design, microscope specifications, and initial results from the new mid-infrared beamline (IRENI) are reviewed. Synchrotron-based spectrochemical imaging, as recently implemented at the Synchrotron Radiation Center in Stoughton, Wisconsin, demonstrates the new capability to achieve diffraction limited chemical imaging across the entire mid-infrared region, simultaneously, with high signal-to-noise ratio. IRENI extracts a large swath of radiation (320 hor. × 25 vert. mrads 2 ) to homogeneously illuminate a commercial infrared (IR) microscope equipped with an IR focal plane array (FPA) detector. Wide-field images are collected, in contrast to single-pixel imaging from the confocal geometry with raster scanning, commonly used at most synchrotron beamlines. IRENI rapidly generates high quality, high spatial resolution data. The relevant advantages (spatial oversampling, speed, sensitivity, and signal-to-noise ratio) are discussed in detail and demonstrated with examples from a variety of disciplines, including formalin-fixed and flash-frozen tissue samples, live cells, fixed cells, paint cross-sections, polymer fibers, and novel nanomaterials. The impact of Mie scattering corrections on this high quality data is shown, and first results with a grazing angle objective are presented, along with future enhancements and plans for implementation of similar, small-scale instruments.

Determination of the Best Emulsion for the Microscopy of Crystals

1981 ◽  
Vol 39 ◽  
pp. 32-33
Author(s):  
David A. Grano ◽  
Kenneth H. Downing
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Experimental Situation ◽  
Photographic Emulsion ◽  
Modulation Transfer ◽  
Signal To Noise ◽  
Frequency Space ◽  
Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

Experiments in Bright-Field Imaging with Hollow-Cone Illumination

1981 ◽  
Vol 39 ◽  
pp. 226-227
Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler
Keyword(s):  
Signal To Noise Ratio ◽  
Carbon Support ◽  
Electronic System ◽  
Optic Axis ◽  
Hollow Cone ◽  
Signal To Noise ◽  
Bright Field ◽  
Noise Ratio ◽  
Single Field ◽  
Field Imaging

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.

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