Low-frequency multiplex CARS microscopy with a high-repetition near-infrared supercontinuum laser

2021 ◽  
Author(s):  
Yusuke Arashida ◽  
Atsushi Taninaka ◽  
Takayuki Ochiai ◽  
Hiroyuki Mogi ◽  
Shoji YOSHIDA ◽  
...  
Keyword(s):  
Near Infrared ◽  
High Efficiency ◽  
Signal To Noise Ratio ◽  
Low Frequency ◽  
High Sensitivity ◽  
High Repetition ◽  
Spectrum Shaping ◽  
Crystal Phase Transition ◽  
Wavenumber Region ◽  
Anti Stokes

Abstract We have developed a multiplex Coherent anti-Stokes Raman scattering (CARS) microscope effective for low-wavenumber measurement by combining a high-repetition supercontinuum light source of 1064 nm and an infrared high-sensitivity InGaAs diode array. This system could observe the low-wavenumber region down to 55 cm-1 with high sensitivity. In addition, using spectrum shaping and spectrum modulation techniques, we simultaneously realized a wide bandwidth (<1800 cm-1), high wavenumber resolution (9 cm-1), high efficiency, and increasing signal to noise ratio by reducing the effect of the background shape in low-wavenumber region. Spatial variation of a sulfur crystal phase transition with metastable states was visualized.

Near IR multichannel Raman spectroscopy with μm spatial resolution

1992 ◽  
Vol 50 (2) ◽  
pp. 1500-1501
Author(s):  
J. Barbillat ◽  
B. Roussel
Keyword(s):  
Spatial Resolution ◽  
Near Infrared ◽  
Low Frequency ◽  
Diffraction Limit ◽  
Small Samples ◽  
Optical Elements ◽  
Near Ir ◽  
Photodiode Arrays ◽  
Silicon Based ◽  
Anti Stokes

The techniques and capabilities of near infrared (NIR) multichannel microprobing are described in detail in this paper.The advantages and drawbacks of various kinds of instruments used to measure Raman spectra excited in the NIR spectral range have been extensively studied and compared. We demonstrate that a dispersive spectrometer specially designed to match the recently improved NIR multichannel detectors (silicon-based CCD,Germanium and InGaAs photodiode arrays) may provide better results than a Fourier Transform Interferometer in two fields:- spatial resolution close to the diffraction limit in a micro-Raman confocal configuration (1.5 to 2 μm) and- extension of the Raman spectrum to the low-frequency region (Stokes and Anti-Stokes).Moreover, to observe the excitation profiles of both resonance and fluorescence, a combined multichannel instrument covering the entire range from 0.4 to 1.5 μm enables the user to select the best conditions of measurement.For the study of very small samples (close to the diffraction limit),it is optically impossible to fill in the wide entrance aperture of the interferometer with the image of the sample while covering correctly the optical elements inside the interferometer.

scholarly journals Sensitivity Improvement of Extremely Low Light Scenes with RGB-NIR Multispectral Filter Array Sensor

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1256
Author(s):  
Seunghoon Jee ◽  
Moon Gi Kang
Keyword(s):  
Near Infrared ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Color Channel ◽  
Low Light ◽  
Pixel Resolution ◽  
Edge Preserving ◽  
Linear Coefficient ◽  
Reconstruction Methods ◽  
Color Channels

Recently, several red-green-blue near-infrared (RGB-NIR) multispectral filter arrays (MFAs), which include near infrared (NIR) pixels, have been proposed. For extremely low light scenes, the RGB-NIR MFA sensor has been extended to receive NIR light, by adding NIR pixels to supplement for the insufficient visible band light energy. However, the resolution reconstruction of the RGB-NIR MFA, using demosaicing and color restoration methods, is based on the correlation between the NIR pixels and the pixels of other colors; this does not improve the RGB channel sensitivity with respect to the NIR channel sensitivity. In this paper, we propose a color restored image post-processing method to improve the sensitivity and resolution of an RGB-NIR MFA. Although several linear regression based color channel reconstruction methods have taken advantage of the high sensitivity NIR channel, it is difficult to accurately estimate the linear coefficients because of the high level of noise in the color channels under extremely low light conditions. The proposed method solves this problem in three steps: guided filtering, based on the linear similarity between the NIR and color channels, edge preserving smoothing to improve the accuracy of linear coefficient estimation, and residual compensation for lost spatial resolution information. The results show that the proposed method is effective, while maintaining the NIR pixel resolution characteristics, and improving the sensitivity in terms of the signal-to-noise ratio by approximately 13 dB.

scholarly journals A High-Through Technique to Measure DNA Methylation

2010 ◽  
Vol 3 ◽  
pp. GEG.S5035 ◽  
Author(s):  
Zhiming Zhang ◽  
Jian Gao ◽  
Cheng Qin ◽  
Li Liu ◽  
Haijian Lin ◽  
...  
Keyword(s):  
Dna Methylation ◽  
High Efficiency ◽  
Simple Procedure ◽  
Point Mutations ◽  
Low Frequency ◽  
High Sensitivity ◽  
Snp Analysis ◽  
Allelic Series ◽  
Low Frequencies ◽  
Powerful Approach

MethyLight is a sodium-bisulfite-dependent, quantitative, fluorescence-based, real-time PCR strategy that is used to detect and quantify DNA methylation in genomic DNA. High-throughput MethyLight allows the rapid and sensitive detection of very low frequencies of hypermethylated alleles in populations of alternated individuals. The high sensitivity and specificity of MethyLight can be applied not only to make it uniquely suited disease clinical but also quantitatively assessed of these low-frequency methylation events. Owing to its full of advantages of simple procedure, high efficiency and high sensitivity, MethyLight provides a powerful approach for clinical examination, Gene expression analysis, SNP analysis and allele analysis. Coupled with other techniques, MethyLight can be used immediately in identifying allelic alterations in genes exhibiting expressions correlating with phenotypes, Locating an allelic series of induced point mutations in genes of interest. The development of this technique should considerably enhance our ability to rapidly and accurately generate epigenetic profiles of samples.

scholarly journals All-nanofiber–based, ultrasensitive, gas-permeable mechanoacoustic sensors for continuous long-term heart monitoring

2020 ◽  
Vol 117 (13) ◽  
pp. 7063-7070 ◽  
Author(s):  
Md Osman Goni Nayeem ◽  
Sunghoon Lee ◽  
Hanbit Jin ◽  
Naoji Matsuhisa ◽  
Hiroaki Jinno ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
Signal To Noise Ratio ◽  
Low Frequency ◽  
High Sensitivity ◽  
Frequency Region ◽  
Sound Waves ◽  
Signal To Noise ◽  
Low Intensity ◽  
Heart Monitoring

The prolonged and continuous monitoring of mechanoacoustic heart signals is essential for the early diagnosis of cardiovascular diseases. These bodily acoustics have low intensity and low frequency, and measuring them continuously for long periods requires ultrasensitive, lightweight, gas-permeable mechanoacoustic sensors. Here, we present an all-nanofiber mechanoacoustic sensor, which exhibits a sensitivity as high as 10,050.6 mV Pa−1 in the low-frequency region (<500 Hz). The high sensitivity is achieved by the use of durable and ultrathin (2.5 µm) nanofiber electrode layers enabling a large vibration of the sensor during the application of sound waves. The sensor is ultralightweight, and the overall weight is as small as 5 mg or less. The devices are mechanically robust against bending, and show no degradation in performance even after 1,000-cycle bending. Finally, we demonstrate a continuous long-term (10 h) measurement of heart signals with a signal-to-noise ratio as high as 40.9 decibels (dB).

scholarly journals Defogging Technology Based on Dual-Channel Sensor Information Fusion of Near-Infrared and Visible Light

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Yubin Yuan ◽  
Yu Shen ◽  
Jing Peng ◽  
Lin Wang ◽  
Hongguo Zhang
Keyword(s):  
Visible Light ◽  
Image Fusion ◽  
Near Infrared ◽  
High Efficiency ◽  
Infrared Image ◽  
Low Frequency ◽  
Visible Image ◽  
Primary Color ◽  
Image Defogging ◽  
Channel Image

Since the method to remove fog from images is complicated and detail loss and color distortion could occur to the defogged images, a defogging method based on near-infrared and visible image fusion is put forward in this paper. The algorithm in this paper uses the near-infrared image with rich details as a new data source and adopts the image fusion method to obtain a defog image with rich details and high color recovery. First, the colorful visible image is converted into HSI color space to obtain an intensity channel image, color channel image, and saturation channel image. The intensity channel image is fused with a near-infrared image and defogged, and then it is decomposed by Nonsubsampled Shearlet Transform. The obtained high-frequency coefficient is filtered by preserving the edge with a double exponential edge smoothing filter, while low-frequency antisharpening masking treatment is conducted on the low-frequency coefficient. The new intensity channel image could be obtained based on the fusion rule and by reciprocal transformation. Then, in color treatment of the visible image, the degradation model of the saturation image is established, which estimates the parameters based on the principle of dark primary color to obtain the estimated saturation image. Finally, the new intensity channel image, the estimated saturation image, and the primary color image are reflected to RGB space to obtain the fusion image, which is enhanced by color and sharpness correction. In order to prove the effectiveness of the algorithm, the dense fog image and the thin fog image are compared with the popular single image defogging and multiple image defogging algorithms and the visible light-near infrared fusion defogging algorithm based on deep learning. The experimental results show that the proposed algorithm is better in improving the edge contrast and the visual sharpness of the image than the existing high-efficiency defogging method.

scholarly journals Precise Diagnosis and Therapy of Bone Cancer Using Near-Infrared Lights

2021 ◽  
Vol 9 ◽  
Author(s):  
Qing Cai ◽  
Zuntai Li ◽  
Baosheng Li ◽  
Jiayang Jiang ◽  
Xiaoyu Li ◽  
...  
Keyword(s):  
Bone Tumors ◽  
Near Infrared ◽  
High Efficiency ◽  
Bone Cancer ◽  
High Sensitivity ◽  
Conventional Radiography ◽  
Spatiotemporal Resolution ◽  
Guided Surgery ◽  
Precise Diagnosis ◽  
Intraoperative Visualization

Bone is a preferred site for both primary and metastasis tumors. Current diagnosis of osteopathia typically relies on noninvasive skeleton radiography technology. However, due to the limited resolution of ionizing radiation, accurate diagnosis and effective identification impairment areas are still lacking. Near-infrared (NIR) bioimaging, especially in the NIR-II (1000-1700 nm) regions, can provide high sensitivity and spatiotemporal resolution bioimaging compared to the conventional radiography. Thus, NIR bioimaging affords intraoperative visualization and imaging-guided surgery, aiming to overcome challenges associated with theranostics of osteopathia and bone tumors. The present review aimed to summarize the latest evidence on the use of NIR probes for the targeting bone imaging. We further highlight the recent advances in bone photoX (X presents thermal, dynamic, and immuno) therapy through NIR probes, in particular combination with other customized therapeutic agents could provide high-efficiency treatment for bone tumors.

Trends in Diagnosis for Active Tuberculosis Using Nanomaterials

2019 ◽  
Vol 26 (11) ◽  
pp. 1946-1959 ◽  
Author(s):  
Le Minh Tu Phan ◽  
Lemma Teshome Tufa ◽  
Hwa-Jung Kim ◽  
Jaebeom Lee ◽  
Tae Jung Park
Keyword(s):  
Sensitivity And Specificity ◽  
High Efficiency ◽  
Point Of Care ◽  
High Sensitivity ◽  
Signs And Symptoms ◽  
Diagnostic Methods ◽  
Advantages And Disadvantages ◽  
Treatment And Prevention ◽  
Clinical Tools ◽  
Diagnostic Applications

Background:Tuberculosis (TB), one of the leading causes of death worldwide, is difficult to diagnose based only on signs and symptoms. Methods for TB detection are continuously being researched to design novel effective clinical tools for the diagnosis of TB.Objective:This article reviews the methods to diagnose TB at the latent and active stages and to recognize prospective TB diagnostic methods based on nanomaterials.Methods:The current methods for TB diagnosis were reviewed by evaluating their advantages and disadvantages. Furthermore, the trends in TB detection using nanomaterials were discussed regarding their performance capacity for clinical diagnostic applications.Results:Current methods such as microscopy, culture, and tuberculin skin test are still being employed to diagnose TB, however, a highly sensitive point of care tool without false results is still needed. The utilization of nanomaterials to detect the specific TB biomarkers with high sensitivity and specificity can provide a possible strategy to rapidly diagnose TB. Although it is challenging for nanodiagnostic platforms to be assessed in clinical trials, active TB diagnosis using nanomaterials is highly expected to achieve clinical significance for regular application. In addition, aspects and future directions in developing the high-efficiency tools to diagnose active TB using advanced nanomaterials are expounded.Conclusion:This review suggests that nanomaterials have high potential as rapid, costeffective tools to enhance the diagnostic sensitivity and specificity for the accurate diagnosis, treatment, and prevention of TB. Hence, portable nanobiosensors can be alternative effective tests to be exploited globally after clinical trial execution.

scholarly journals Magnetoelastic Coupling and Delta-E Effect in Magnetoelectric Torsion Mode Resonators

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2022
Author(s):  
Benjamin Spetzler ◽  
Elizaveta V. Golubeva ◽  
Ron-Marco Friedrich ◽  
Sebastian Zabel ◽  
Christine Kirchhof ◽  
...  
Keyword(s):  
Low Frequency ◽  
High Sensitivity ◽  
Element Model ◽  
Mode Number ◽  
Frequency Change ◽  
General Description ◽  
Resonance Modes ◽  
Field Sensor ◽  
Magnetic Sensitivity ◽  
Bending Modes

Magnetoelectric resonators have been studied for the detection of small amplitude and low frequency magnetic fields via the delta-E effect, mainly in fundamental bending or bulk resonance modes. Here, we present an experimental and theoretical investigation of magnetoelectric thin-film cantilevers that can be operated in bending modes (BMs) and torsion modes (TMs) as a magnetic field sensor. A magnetoelastic macrospin model is combined with an electromechanical finite element model and a general description of the delta-E effect of all stiffness tensor components Cij is derived. Simulations confirm quantitatively that the delta-E effect of the C66 component has the promising potential of significantly increasing the magnetic sensitivity and the maximum normalized frequency change ∆fr. However, the electrical excitation of TMs remains challenging and is found to significantly diminish the gain in sensitivity. Experiments reveal the dependency of the sensitivity and ∆fr of TMs on the mode number, which differs fundamentally from BMs and is well explained by our model. Because the contribution of C11 to the TMs increases with the mode number, the first-order TM yields the highest magnetic sensitivity. Overall, general insights are gained for the design of high-sensitivity delta-E effect sensors, as well as for frequency tunable devices based on the delta-E effect.

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