The ability to record images with extreme temporal resolution enables a diverse range of applications, such as fluorescence lifetime imaging, time-of-flight depth imaging and characterization of ...ultrafast processes. Recently, ultrafast imaging schemes have emerged, which require either long acquisition times or raster scanning and have a requirement for sufficient signal that can only be achieved when light is reflected off an object or diffused by a strongly scattering medium. Here we present a demonstration of the potential of single-photon detector arrays for visualization and rapid characterization of events evolving on picosecond time scales. The single-photon sensitivity, temporal resolution and full-field imaging capability enables the observation of light-in-flight in air, as well as the measurement of laser-induced plasma formation and dynamics in its natural environment. The extreme sensitivity and short acquisition times pave the way for real-time imaging of ultrafast processes or visualization and tracking of objects hidden from view.
Myclobutanil residue poses a potential threat to consumers’ health. This work aims to investigate the degradation behavior, residue levels, processing factors (PFs) and dietary risk of myclobutanil ...in tomato. Myclobutanil was analyzed using a modified quick, easy, cheap, effective, rugged, safe (QuEChERS) method combined with ultra-performance liquid chromatography–mass spectrometry (UPLC-MS/MS), and average recoveries ranged from 82% to 102% with relative standard deviations RSDs ≤ 9.1%. After spraying myclobutanil miscible oil under field conditions, the initial concentration of myclobutanil was 0.055 mg/kg, and its dissipation followed the first-order kinetics equation with a half-life of 2.88 days. Myclobutanil was mainly present in the tomato skin, and its concentration was about four times that in the whole tomato. The initial concentration of myclobutanil in raw tomato was 0.100 mg/kg. After washing, peeling, homogenization, simmering and canning, the residual level of myclobutanil decreased to 0.067 mg/kg, 0.023 mg/kg, 0.013 mg/kg, 0.044 mg/kg and 0.041 mg/kg, respectively. Although the procedure of simmering led to an increase in myclobutanil concentration, the PFs were all less than 1 in the whole process, showing that the processing procedure significantly decreased the residual level of myclobutanil canned tomato paste in comparison with the raw agricultural commodity. Washing, peeling, and homogenization played critical roles in reducing pesticide residues. The residues of myclobutanil during the processing of tomato pose low dietary exposure risks to consumers in China, which were acceptable. However, the acute and chronic risk quotient for children revealed that it was necessary to monitor the dietary exposure of pesticide residues for children closely.
Biometric recognition technology based on eye-movement dynamics has been in development for more than ten years. Different visual tasks, feature extraction and feature recognition methods are ...proposed to improve the performance of eye movement biometric system. However, the correct identification and verification rates, especially in long-term experiments, as well as the effects of visual tasks and eye trackers' temporal and spatial resolution are still the foremost considerations in eye movement biometrics. With a focus on these issues, we proposed a new visual searching task for eye movement data collection and a new class of eye movement features for biometric recognition. In order to demonstrate the improvement of this visual searching task being used in eye movement biometrics, three other eye movement feature extraction methods were also tested on our eye movement datasets. Compared with the original results, all three methods yielded better results as expected. In addition, the biometric performance of these four feature extraction methods was also compared using the equal error rate (EER) and Rank-1 identification rate (Rank-1 IR), and the texture features introduced in this paper were ultimately shown to offer some advantages with regard to long-term stability and robustness over time and spatial precision. Finally, the results of different combinations of these methods with a score-level fusion method indicated that multi-biometric methods perform better in most cases.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Functional magnetic resonance imaging (fMRI) combined with behavioral assessments was used in our study to investigate the dynamic process of motor cortical functional reorganization after ...infarction. Therefore, we could provide a theoretical basis and build a useful evaluation system for rehabilitation after stroke and various other cerebral injuries.
Acute stroke patients with a single lesion in the middle cerebral artery supply area and age- and sex-matched healthy volunteers were recruited. A longitudinal observational study involving 20 patients with stroke was conducted using repeated fMRI. Task-based fMRI data were acquired 3 times over a period of 3 months. The behavioral assessment included dynamometer and finger-tapping tests to evaluate the strength and dexterity of each upper arm.
Behavioral results: The behavioral assessments demonstrated large improvements in session 2 and session 3. fMRI results: The healthy group showed activation in the contralateral primary sensory-motor cortex (S1M1) when executing tasks with either the left or right hand. Compared with the healthy subjects, the patients demonstrated greater activation in the ipsilateral frontal and parietal cortices and supplementary motor areas (SMAs). Across all sessions, more motor activation was observed in the left infarction group.
Our results show that motor cortical activation induced by moving the paretic hand changes over time. There were differences in motor functional recovery and motor cortex compensation between the dominant hemisphere and nondominant hemisphere after stroke.
We describe the photophysical processes that give rise to thermally activated delayed fluorescence in the excited state intramolecular proton transfer (ESIPT) molecule, triquinolonobenzene (TQB). ...Using transient absorption and time-resolved photoluminescence spectroscopy, we fully characterize prompt and delayed emission, phosphorescence, and oxygen quenching to reveal the reverse intersystem crossing mechanism (rISC). After photoexcitation and rapid ESIPT to the TQB-TB tautomer, emission from S1 is found to compete with thermally activated ISC to an upper triplet state, T2, very close in energy to S1 and limiting photoluminescence quantum yield. T2 slowly decays to the lowest triplet state, T1, via internal conversion. In the presence of oxygen, T2 is quenched to the ground state of the double proton transferred TQB-TC tautomer. Our measurements demonstrate that rISC in TQB occurs from T2 to S1 driven by thermally activated reverse internal conversion from T1 to T2 and support recent calculations by Cao et al. ( Cao, Y. ; Eng, J. ; Penfold, T. J. Excited State Intramolecular Proton Transfer Dynamics for Triplet Harvesting in Organic Molecules. J. Phys. Chem. A 2019, 123, 2640−2649 ).
Mental rotation is an important paradigm for spatial ability. Mental-rotation tasks are assumed to involve five or three sequential cognitive-processing states, though this has not been demonstrated ...experimentally. Here, we investigated how processing states alternate during mental-rotation tasks. Inference was carried out using an advanced statistical modelling and data-driven approach - a discriminative hidden Markov model (dHMM) trained using eye-movement data obtained from an experiment consisting of two different strategies: (I) mentally rotate the right-side figure to be aligned with the left-side figure and (II) mentally rotate the left-side figure to be aligned with the right-side figure. Eye movements were found to contain the necessary information for determining the processing strategy, and the dHMM that best fit our data segmented the mental-rotation process into three hidden states, which we termed encoding and searching, comparison, and searching on one-side pair. Additionally, we applied three classification methods, logistic regression, support vector model and dHMM, of which dHMM predicted the strategies with the highest accuracy (76.8%). Our study did confirm that there are differences in processing states between these two of mental-rotation strategies, and were consistent with the previous suggestion that mental rotation is discrete process that is accomplished in a piecemeal fashion.
Fatigue is dangerous for certain jobs requiring continuous concentration. When faced with new datasets, the existing fatigue detection model needs a large amount of electroencephalogram (EEG) data ...for training, which is resource-consuming and impractical. Although the cross-dataset fatigue detection model does not need to be retrained, no one has studied this problem previously. Therefore, this study will focus on the design of the cross-dataset fatigue detection model.
This study proposes a regression method for EEG-based cross-dataset fatigue detection. This method is similar to self-supervised learning and can be divided into two steps: pre-training and the domain-specific adaptive step. To extract specific features for different datasets, a pretext task is proposed to distinguish data on different datasets in the pre-training step. Then, in the domain-specific adaptation stage, these specific features are projected into a shared subspace. Moreover, the maximum mean discrepancy (MMD) is exploited to continuously narrow the differences in the subspace so that an inherent connection can be built between datasets. In addition, the attention mechanism is introduced to extract continuous information on spatial features, and the gated recurrent unit (GRU) is used to capture time series information.
The accuracy and root mean square error (RMSE) achieved by the proposed method are 59.10% and 0.27, respectively, which significantly outperforms state-of-the-art domain adaptation methods.
In addition, this study discusses the effect of labeled samples. When the number of labeled samples is 10% of the total number, the accuracy of the proposed model can reach 66.21%. This study fills a vacancy in the field of fatigue detection. In addition, the EEG-based cross-dataset fatigue detection method can be used for reference by other EEG-based deep learning research practices.
Background/Aims: Our previous reports suggested that dietary supplementation with lysine influenced intestinal absorption and metabolism of amino acids. In this study, we further investigated the ...effect of lysine restriction (30%) on feed intake and we also tested the hypothesis that gut microbiome contributed to the potential mechanism of lysine restriction-mediated feeding behavior. Here, we profiled gut microbial communities by sequencing 16S ribosomal ribonucleic acid (rRNA) genes from gut samples as well as growth performance, serum hormones, and intestinal lysine transport in a piglet model. Results: Piglets preferred to the lysine restricted diet when giving three diets and the feed intake was markedly higher in the lysine-restricted group than that in the control group. Altered hormones (leptin, CCK, and ghrelin) might contribute to the feeding behavior caused by lysine restriction. Meanwhile, lysine transporting ability (SLC7A1 and SLC7A2 expression, intestinal electrophysiological changes, and amino acid pool in mesenteric vein) was decreased in response to lysine restriction. Through deep sequencing of bacterial rRNA markers, we observed that bacterial diversity was enhanced in the lysine-restricted group (Shannon H, PD, and Chao1). At the phylum level, lysine restriction enhanced gut Actinobacteria, Saccharibacteria, and Synergistetes abundances. At the family level, Moraxellaceae, Halomonadaceae, Shewanellaceae, Corynebacteriaceae, Bacillaceae, Comamonadaceae, Microbacteriaceae, Caulobacteraceae, and Synergistaceae abundances were increased in response to lysine restriction. Predictive functional profiling of microbial communities by PICRUSt also confirmed that dietary lysine restriction affected gut microbiome, which might further mediate amino acid metabolism, membrane transport, and endocrine system. Conclusion: Our results indicated that lysine restriction inhibited intestinal lysine transport and promoted feed intake, which might be associated with gut microbiome.
Rectal cancer is one of the most common lower gastrointestinal diseases worldwide. Currently, the common treatment is low anterior resection (LAR) of the rectum, which preserves the anus of the ...patient. However, it is easy to cause low anterior resection syndrome after surgery, which has a significant negative impact on the life of patients, and there is no unified evaluation standard for postoperative rectal function. To solve this problem, a multi‐sensor fusion rectal information acquisition system is designed in this paper, and a rectal signal processing method is proposed to theoretically evaluate the rectal function of postoperative patients. The method uses the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) to decompose the one‐dimensional rectal signal to solve the underdetermined ICA problem, uses the Fast independent component analysis (Fast‐ICA) to separate the pure rectal signal, uses the wavelet packet to extract features, and uses the particle swarm optimization optimizes support vector machine (PSO‐SVM) to classify and evaluate postoperative function. According to the experimental results, the rectal signal preprocessing effect is good, the evaluation prediction rate is 99.5565%, and the algorithm classification results are accurate, which provides a certain preliminary theoretical basis and reference value for the evaluation of rectal function after LAR.
In this work, aiming at the problems in the diagnosis of rectal function after low anterior resection of rectal cancer, our team designed a multi‐sensor fusion rectal information acquisition system. Based on this system, a rectal signal processing method based on CEEMDAN fast ICA is proposed. The method uses CEEMDAN to decompose the one‐dimensional rectal signal to solve the underdetermined ICA problem, uses the Fast‐ICA algorithm to separate the pure rectal signal, uses the wavelet packet to extract features, and uses the PSO‐SVM pattern recognition to achieve postoperative functional evaluation. According to the experimental results, the accuracy of rectal function evaluation based on this system was 99.5565%. This method can obtain the dynamic characteristics of rectum and realize the prediction and diagnosis of rectal function after operation. It is helpful for the recovery of rectal function in patients undergoing low anterior resection for rectal cancer. This study laid a foundation for the diagnosis of rectal dynamics after LAR surgery.
In this work, we investigate the temperature dependence of the photoluminescence decay and integrated photoluminescence of oleic acid capped PbS quantum dots with diameters ranging from 2.3 to 3.5 nm ...over a broad temperature range (6–290 K). All the investigated samples exhibit similar behavior, consisting of three different temperature regimes. The low-temperature regime (<180 K) is characterized by an increase in the average decay rate and a decrease in integrated photoluminescence. The intermediate regime (∼180–250 K) is described by an enhancement in the photoluminescence intensity and a decrease in the average decay rate. The high-temperature regime (>250 K) is governed by quenched photoluminescence intensity and acceleration in the average lifetimes. We propose a three-level system, composed of bright, dark, and surface states, which describes the observed photoluminescence dynamics of oleic acid capped PbS QDs.
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