MELEXIR: maximum entropy Legendre expanded image reconstruction. A fast and efficient method for the analysis of velocity map imaging or photoelectron imaging data

2019 ◽  
Vol 21 (35) ◽  
pp. 19499-19512 ◽  
Author(s):  
Bernhard Dick
Keyword(s):  
Velocity Distribution ◽  
Maximum Entropy ◽  
Efficient Method ◽  
Velocity Map Imaging ◽  
Imaging Data ◽  
Photoelectron Imaging ◽  
Low Intensity ◽  
Intensity Images ◽  
Legendre Expansion ◽  
2D Images

The MELEXIR program obtains a Legendre expansion of the 3D velocity distribution from 2D images of ions or photoelectrons. The maximum entropy algorithm avoids inverse Abel transforms, is fast and applicable to low-intensity images.

scholarly journals Rotationally inelastic scattering of CD3 and CH3 with He: comparison of velocity map-imaging data with quantum scattering calculations

2013 ◽  
Vol 4 (11) ◽  
pp. 4199 ◽  
Author(s):  
Ondřej Tkáč ◽  
Alan G. Sage ◽  
Stuart J. Greaves ◽  
Andrew J. Orr-Ewing ◽  
Paul J. Dagdigian ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
Quantum Scattering ◽  
Velocity Map Imaging ◽  
Imaging Data ◽  
Rotationally Inelastic Scattering

The efficient method of design optical element for low-intensity obstruction light

2020 ◽  
Author(s):  
Nikolay Bogdanov ◽  
Igor S. Potemin ◽  
Dmitry Zhdanov ◽  
Andrey Zhdanov ◽  
Yan Wang
Keyword(s):  
Efficient Method ◽  
Optical Element ◽  
Low Intensity ◽  
Method Of Design

scholarly journals The effects of symmetry and rigidity on non-adiabatic dynamics in tertiary amines: a time-resolved photoelectron velocity-map imaging study of the cage-amine ABCO

2016 ◽  
Vol 18 (14) ◽  
pp. 9715-9723 ◽  
Author(s):  
Liv B. Klein ◽  
Thorbjørn J. Morsing ◽  
Ruth A. Livingstone ◽  
Dave Townsend ◽  
Theis I. Sølling
Keyword(s):  
Imaging Study ◽  
Velocity Map Imaging ◽  
Tertiary Amines ◽  
Relaxation Dynamics ◽  
Photoelectron Imaging ◽  
Time Resolved ◽  
Adiabatic Dynamics

The non-adiabatic relaxation dynamics of the tertiary cage-amine azabicyclo[2.2.2]octane (ABCO) have been investigated following 3p Rydberg excitation at 201 nm using femtosecond time-resolved photoelectron imaging.

scholarly journals Mechanical time-of-flight filter based on slotted disks and helical rotor for measurement of velocities of nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pavel Solař ◽  
Jaroslav Kousal ◽  
Jan Hanuš ◽  
Kateřina Škorvánková ◽  
Anna Kuzminova ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
High Precision ◽  
Time Of Flight ◽  
The Real ◽  
Low Intensity

AbstractA mechanical time-of-flight filter intended for measurement of velocities of nanoparticles exiting a gas aggregation source has been developed. Several configurations maximizing simplicity, throughput or resolution are suggested and investigated both theoretically and experimentally. It is shown that the data measured using such filters may be easily converted to the real velocity distribution with high precision. Furthermore, it is shown that properly designed filters allow for the monitoring of the velocity of nanoparticles even at the conditions with extremely low intensity of the nanoparticle beam.

scholarly journals Artificial intelligence velocimetry and microaneurysm-on-a-chip for three-dimensional analysis of blood flow in physiology and disease

2021 ◽  
Vol 118 (13) ◽  
pp. e2100697118
Author(s):  
Shengze Cai ◽  
He Li ◽  
Fuyin Zheng ◽  
Fang Kong ◽  
Ming Dao ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Experimental Data ◽  
Neural Networks ◽  
Blood Flow ◽  
Vision Loss ◽  
Three Dimensional ◽  
Flow Fields ◽  
Diabetic Patients ◽  
Imaging Data ◽  
2D Images

Understanding the mechanics of blood flow is necessary for developing insights into mechanisms of physiology and vascular diseases in microcirculation. Given the limitations of technologies available for assessing in vivo flow fields, in vitro methods based on traditional microfluidic platforms have been developed to mimic physiological conditions. However, existing methods lack the capability to provide accurate assessment of these flow fields, particularly in vessels with complex geometries. Conventional approaches to quantify flow fields rely either on analyzing only visual images or on enforcing underlying physics without considering visualization data, which could compromise accuracy of predictions. Here, we present artificial-intelligence velocimetry (AIV) to quantify velocity and stress fields of blood flow by integrating the imaging data with underlying physics using physics-informed neural networks. We demonstrate the capability of AIV by quantifying hemodynamics in microchannels designed to mimic saccular-shaped microaneurysms (microaneurysm-on-a-chip, or MAOAC), which signify common manifestations of diabetic retinopathy, a leading cause of vision loss from blood-vessel damage in the retina in diabetic patients. We show that AIV can, without any a priori knowledge of the inlet and outlet boundary conditions, infer the two-dimensional (2D) flow fields from a sequence of 2D images of blood flow in MAOAC, but also can infer three-dimensional (3D) flow fields using only 2D images, thanks to the encoded physics laws. AIV provides a unique paradigm that seamlessly integrates images, experimental data, and underlying physics using neural networks to automatically analyze experimental data and infer key hemodynamic indicators that assess vascular injury.

scholarly journals Manifestations of Hepatic Focal Nodular Hyperplasia in Hepatobiliary Phase of Enhancement by Hepatocyte-specific Contrast Agent: Comparison With Pathologic Findings

2021 ◽  
Author(s):  
Jiangfeng Xu ◽  
Liqing Zhang ◽  
Jianxun Li ◽  
Xiaojian Cui ◽  
Qingping Jiang ◽  
...  
Keyword(s):  
Focal Nodular Hyperplasia ◽  
High Intensity ◽  
The Other ◽  
Hepatobiliary Phase ◽  
Imaging Data ◽  
Low Intensity ◽  
Enhanced Mri ◽  
Pathologic Findings ◽  
Nodular Hyperplasia ◽  
Fibrous Tissues

Abstract Background: To explore the signals and diagnostic value of hepatic focal nodular hyperplasia (FNH) in the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA) enhanced MRI.Methods: Imaging data of 43 pathologically proven FNH lesions from 39 patients who underwent Gd-EOB-DTPA enhanced MRI scanning at our hospital between January 2016 and June 2019 were retrospectively analyzed. The signal characteristics in the hepatobiliary phase were analyzed and compared with the pathologic findings.Results: According to the characteristics of signals in the hepatobiliary phase, the signals were classified as follows: homogenous iso-high intensity signals in 20.93% (9/43) lesions, heterogeneous iso-high intensity signals in 67.44% (29/43) lesions, homogenous low-intensity signals in 4.65% (2/43) lesions, and heterogeneous low-intensity signals in 6.98% (3/43) lesions. Two patients were with multiple lesions, where one was with 2 lesions of heterogeneous high-intensity signals, and the other with 3 lesions of heterogeneous low-intensity signals. Pathologic findings were as follows: the slices of the 38 lesions with high-intensity signals in a hepatobiliary phase were with hyperplasic hepatocytes, inflammatory cell infiltration, and malformed blood vessels. Twenty-nine of the lesions were with fiber tissues of different degrees and were classified as classic type. The remaining 9 lesions were without fibrous scars and were classified as non-classic type. The other 5 of the 43 lesions were non-classic FNH with no evident fibrous tissues, while 4 of them were with >40% steatosis in the hyperplasic hepatocytes; the immunohistochemistry showed CK7(-)/CK19(-) in 1 lesion and β-catenin (nucleus +) in another lesion. Comparisons of pathologic with imaging findings were as follows: twenty-nine lesions were with heterogeneous iso-high intensity signals, of which the slices showed evident fibrous tissues of different degrees, and the slices of 9 lesions with homogenous iso-high intensity signals in the hepatobiliary phase showed no fibrous tissues. Three lesions with heterogeneous low-intensity signals in the hepatobiliary phase showed about 80% mixed steatosis in hyperplasic hepatocytes. The other two lesions both showed homogeneous low-intensity signals in the hepatobiliary phase, where 1 lesion was with >40% macrovesicular steatosis and CK7/CK19 (-), while the other only showed β-catenin (nucleus +) by immunohistochemistry. Conclusions: The signals of FNH in the hepatobiliary phase showed various characteristics, where the signal differences were mainly associated with the number of hyperplastic hepatocytes in lesions, presence of steatosis, fibrous scars, and conditions of small bile ducts, and potentially associated with β-catenin (nucleus+). Low-intensity signals were relatively rare for FNH, thus representing a relatively major challenge for diagnosing this type FNH.

Development of the Youth Emotion Picture Set

Perception ◽  
2018 ◽  
Vol 47 (10-11) ◽  
pp. 1029-1042 ◽  
Author(s):  
Bruno Novello ◽  
Anelise Renner ◽  
Guilherme Maurer ◽  
Soraia Musse ◽  
Adriane Arteche
Keyword(s):  
Facial Expression ◽  
Facial Expressions ◽  
Initial Screening ◽  
Software Validation ◽  
Data Set ◽  
Basic Emotions ◽  
Low Intensity ◽  
Intensity Images ◽  
Image Set ◽  
Final Selection

Several facial expression image sets have been developed. Nevertheless, there is a lack of facial expression sets comprising adolescents’ images depicting all basic emotions. This study aimed to fill this gap through the development of an image database of youth facial expressions, containing pictures of six basic emotions plus neutral. Posed and spontaneous expressions were collected from 31 youths, 12 to 20 years old; 2,279 frames were obtained, and an initial screening was conducted through the exclusion of similar frames, low intensity images, and ambiguous or blended expressions; 256 frames met criteria and were rechecked by two expert judges. Images were retained if they depicted all the prototypical features of the designated expression. A final selection was conducted to assure an image set that covered all age ranges, both sexes and an even number of images by expression, resulting in 42 frames (21 male, six of each emotion). Expert judges, independent adults, independent teenagers, and a software validation were used to assure database validity. Agreement across raters was high, and no differences were observed for posed and spontaneous images. The data set developed in this study can be a valid tool in studies of facial expressions, in particular, with adolescents’ samples.

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