Densely Connected Networks with Multiple Features for Classifying Sound Signals with Reverberation.

In indoor environments, reverberation can distort the signalseceived by active noise cancelation devices, posing a challenge to sound classification. Therefore, we combined three speech spectral features based on different frequency scales into a densely connected network (DenseNet) to accomplish sound classification with reverberation effects. We adopted the DenseNet structure to make the model lightweight A dataset was created based on experimental and simulation methods, andhe classification goal was to distinguish between music signals, song signals, and speech signals. Using this framework, effectivexperiments were conducted. It was shown that the classification accuracy of the approach based on DenseNet and fused features reached 95.90%, betterhan the results based on other convolutional neural networks (CNNs). The size of the optimized DenseNet model is only 3.09 MB, which is only 7.76% of the size before optimization. We migrated the model to the Android platform. The modified model can discriminate sound clips faster on Android thanhe network before the modification. This shows that the approach based on DenseNet and fused features can dealith sound classification tasks in different indoor scenes, and the lightweight model can be deployed on embedded devices.

Estimation of Target Motion Parameters from the Tonal Signals with a Single Hydrophone.

In the shallow-water waveguide environment, the tonal signals radiated by moving targets carry modal interference and Doppler shift information. The modal interference can be used to obtain the time of the closest point of approach (tCPA) and the ratio of the range at the closest point of approach to the velocity of the source (rCPA/v). However, parameters rCPA and v cannot be solved separately. When tCPA is known, the rCPA and the v of the target can be obtained theoretically by using the Doppler information. However, when the Doppler frequency shift is small or at a low signal-to-noise ratio, there will be a strong parametric coupling between rCPA and v. In order to solve the above parameter coupling problem, a target motion parameter estimation method from tonal signals with a single hydrophone is proposed in this paper. The method uses the Doppler and modal interference information carried by the tonal signals to obtain two different parametric coupling curves. Then, the parametric coupling curves can be used to estimate the two motion parameters. Simulation experiments verified the rationality of this method. The proposed method was applied to the SWellEx-96 and speedboat experiments, and the estimation errors of the motion parameters were within 10%, which shows the method is effective in its practical applications.

Training a U-Net based on a random mode-coupling matrix model to recover acoustic interference striations.

A U-Net is trained to recover acoustic interference striations (AISs) from distorted ones. A random mode-coupling matrix model is introduced to generate a large number of training data quickly, which are used to train the U-Net. The performance of AIS recovery of the U-Net is tested in range-dependent waveguides with nonlinear internal waves (NLIWs). Although the random mode-coupling matrix model is not an accurate physical model, the test results show that the U-Net successfully recovers AISs under different signal-to-noise ratios and different amplitudes and widths of NLIWs for different shapes.

Modal dispersion compensation receiver for the long range shallow water acoustic communications.

The received low frequency signals in the long range shallow water will suffer severe attenuation and modal dispersion effect, which will distort the signal and deteriorate the communication performance. In this letter, a modal dispersion compensation receiver is proposed, which exploits the de-dispersion transform to compensate intra-mode dispersion and the rake combination to combine the multi-mode components. With the proposed receiver, the waveform expansion of high order modes is compensated, and thus more modes can be distinguished from the noise and the rake combination gain is improved, which leads to high communication accuracy. Simulation results show that the proposed receiver can achieve about 3 dB gain for the 40 km range and signal with a center frequency 400 Hz.

Sound source ranging using a feed-forward neural network trained with fitting-based early stopping.

When a feed-forward neural network (FNN) is trained for acoustic source ranging in an ocean waveguide, it is difficult evaluating the FNN ranging accuracy of unlabeled test data. The label is the distance between source and receiver array. A fitting-based early stopping (FEAST) method is introduced to evaluate the FNN ranging error on test data where the distance to the source is unknown. Based on FEAST, when the evaluated ranging error is minimum on test data, training is stopped. This will improve the FNN ranging accuracy on the test data. The FEAST is demonstrated on simulated and experimental data.

Extraction of scattering echo time by surf noise background subtracted autocorrelation.

Extracting echo time is an important step in scatterer detection by ambient noise, while in general the scattered signal is weak and submerged in the background. An experiment of a Polyvinyl chloride pipe in a coastline surf noise environment is designed to extract the pipe's echo time by noise autocorrelation. As expected, the scattered wave of the pipe is submerged in an autocorrelation signal. A method called background subtracted autocorrelation is proposed in this paper, which can retrieve scattered echo time from autocorrelation signal effectively. And the biggest relative error of extracted echo time is less than 2% in the experiment.

Flux projection beamforming for monochromatic source localization in enclosed space.

Monochromatic sound source localization becomes difficult in enclosed space. According to the reciprocity theorem, a self-consistent method of source localization in enclosed space, referred to as the flux projection beamforming, is proposed, only using the measurement of the sound pressure and normal velocity on the closed boundary at a single frequency. Its validity is examined both by experiment and simulation.

Localizing scatterers from surf noise cross correlations.

The backscattered travel-time structure is obtained by cross-correlating air-acoustic ocean surf noise recorded on microphone pairs (separation ∼2 m) on the beach. The scatterer is a 20 cm radius Polyvinyl chloride pipe 2.5 m landside of the microphone array. Arrivals corresponding to the time-difference (travel-time difference between two scatterer-receiver paths) and scattered (travel time for receiver-scatterer-receiver path) waves emerge in the cross-correlation functions in a backscattering configuration. Theoretically, only a microphone pair is needed to locate the scatterer using the time-difference and scattered travel times. Localization of the scatterer is demonstrated with the microphone array on the beach.

The influence of mode coupling on waveguide invariant.

The waveguide invariant ß is typically discussed in terms of either a range-independent environment or a range-dependent environment under the adiabatic approximation, with few studies considering the effects of mode coupling. In this work, how internal solitary waves (ISWs) affect the waveguide invariant is investigated, and it is shown that mode-coupling effects introduce many additional components in the acoustic interference intensity. It is found that the striation slope and value of ß for these additional components are determined not only by the acoustic modal dispersion, but are also dependent on the position where the mode coupling occurs. This can lead to a very complicated acoustic interference pattern and result in multiple peaks in the distribution of ß. The sensitivity of ß to the parameters of ISWs, such as amplitude, horizontal scale, and position, is analyzed. It is found that although all parameters can affect the energy of the peaks, only the position of the internal wave has an obvious impact on the peak values. This indicates that the peak values of ß can be utilized for monitoring the position of the internal wave.

Experimental Study on the Transport Properties of 12 Novel Deep Eutectic Solvents.

Deep eutectic solvents (DESs) are complex substances composed of two or three components, wherein hydrogen bond donors and acceptors engage in intricate interactions within a hydrogen bond network. They have attracted extensive attention from researchers due to their easy synthesis, cost-effectiveness, broad liquid range, good stability, and for being green and non-toxic. However, studies on the physical properties of DESs are still scarce and many theories are not perfect enough, which limits the application of DESs in engineering practice. In this study, twelve DESs were synthesized by using choline chloride and betaine as HBAs, and ethylene glycol, polyethylene glycol 600, o-cresol, glycerol, and lactic acid as HBDs. The variation rules of their thermal conductivity and viscosity with temperature at atmospheric pressure were systematically investigated. The experimental results showed that the thermal conductivity of the 1:4 choline chloride/glycerol solvent was the largest at 294 K, reaching 0.2456 W·m-1·K-1, which could satisfy the demand for high efficiency heat transfer by heat-transferring workpieces. The temperature-viscosity relationship of the DESs was fitted using the Arrhenius model, and the maximum average absolute deviation was 6.77%.

Boron carbon nitride as efficient oxygen reduction reaction support.

The electrocatalytic oxygen reduction reaction (ORR) is crucial for energy conversion systems such as fuel cells and metal-air batteries. Boron carbon nitrogen (BCN) is a novel functional material with a high specific surface area, excellent corrosion resistance, and outstanding electrochemical stability. These properties make BCN an effective ORR catalyst and a promising support for metal catalysts. This study leveraged the strong interaction between BCN and metals to anchor platinum nanoparticles (Pt NPs) onto the BCN surface (Pt/BCN), significantly enhancing the durability of traditional Pt/C catalysts in ORR. The half-wave potential of Pt/BCN is 0.927 V, higher than Pt/XC-72R (0.857 V) and commercial Pt/C (0.879 V). Notably, after 10,000 durability test cycles, the mass activity (MA) of Pt/XC-72R and commercial Pt/C decreased by 67 % and 75 %, respectively. Even after 50,000 cycles, Pt/BCN exhibited only a 54 % decrease in MA. Experimental data and density functional theory calculations confirmed increased electron transfer from Pt to the BCN support, indicating a strong electronic metal-support interaction (EMSI) between Pt and BCN. This strong EMSI effectively anchored the Pt NPs, preventing migration and aggregation during the ORR process. Consequently, our research introduces a novel electrocatalyst support material with significant potential for ORR and broader applications.

Combination of Peglated-H1/HGFK1 Nanoparticles and TAE in the Treatment of Hepatocellular Carcinoma.

Transarterial embolization (TAE) constitutes the gold standard for the treatment of hepatocellular carcinoma. The effect of combination of TAE and peglated-H1/HGFK1 nanoparticles was explored on hepatocellular carcinoma. MTT and Annexin V-FITC were used to determine the cell viability and apoptosis of HepG2, ml-1, LO2, and VX2 cells after the treatment of HGFK1. Next, the orthotopic rabbit was selected to establish the in situ models of VX2 hepatocellular carcinoma. Nanoparticles were synthesized with peglated-PH1 and used to deliver HGFK1 overexpressing plasmids. MRI was performed to monitor tumor volume after being treated with TAE. The protein expression levels of CD31, CD90, and Ki67 were determined by immunohistochemistry. H&E and TUNEL staining were used to determine the necrosis and apoptosis in vivo. HGFK1 significantly inhibited the proliferation and increased the apoptosis of HepG2 and ml-1 cells (P < 0.05). MRI on 14 days after modeling suggested that the tumor showed ring enhancement. MRI on 7 days and 14 days after interventional therapy showed that tumor volume was significantly inhibited after the treatment with TAE and HGFK1 (P < 0.05). The immunohistochemical results 7 days after interventional therapy indicated that the expressions of CD31, CD90, and Ki67 were significantly lower after treatment with TAE and HGFK1 (P < 0.05). TAE and HGFK1 all extended the survival period of rabbits (P < 0.05). PH1/HGFK1 nanoparticle is an innovative and effective embolic agent, which could limit angiogenesis post-TAE treatment. The combination of TAE with PH1/HGFK1 is a promising strategy and might alter the way that surgeons manage hepatocellular carcinoma (HCC).

A Hamiltonian method for finding broadband modal eigenvalues.

For shallow water waveguides over a layered elastic bottom, modal eigenvalues can be determined by searching the locations in the complex plane of the horizontal wave number at which the complex phase function is a multiple of π [C. T. Tindle and N. R. Chapman, J. Acoust. Soc. Am. 96, 1777-1782 (1994)]. In this paper, a Hamiltonian method is introduced for tracing the path in the complex plane along which the phase function keeps real. The Hamiltonian method can also be extended to compute the broadband modal eigenvalues or the modal dispersion curves in the Pekeris waveguide with fluid/elastic bottoms. For each proper or leaky normal mode, a different Hamiltonian is constructed in the complex plane and used to trace automatically the complex dispersion curve with the eigenvalue in a reference frequency as the initial value. In contrast to the usual methods, the dispersion curve for each mode is determined individually. The Hamiltonian method shows good performance by comparing with KRAKEN.

3-{[Bis(pyridin-2-ylmeth-yl)amino]-meth-yl}-2-hy-droxy-5-methyl-benz-aldehyde.

In the title compound, C(21)H(21)N(3)O(2), the pyridine rings and the benzene ring lie in a propeller arrangement around the central tertiary amine N atom. The dihedral angles formed by the benzene ring with the pyridine rings are 61.0 (3) and 49.6 (3)°, while the dihedral angle between the pyridine rings is 69.7 (3)°. The mol-ecular conformation is stabilized by intramolecular bifurcated O-H⋯N hydrogen bonds. In the crystal, inversion dimers are formed via pairs of C-H⋯N hydrogen bonds.

Waveguide invariant in a gradual range- and azimuth-varying waveguide.

Experimental data indicate that in a sloped area, the value of ß abruptly changes before and after a given source arrives at the closest point of approach to the hydrophone, which has not been previously reported. The adiabatic approximation is employed to explain the above abrupt change in ß, and it is found that the azimuthal variance in the sound path is the reason for this phenomenon. Simulations are performed to confirm the model and experimental data, and perfect agreement is achieved. This work suggests that ß should be carefully set in related applications in a sloped area.

Expression profile and prognostic significance of HOXB13 in rectal cancer.

BACKGROUND: This study aimed to investigate the expression pattern and prognostic significance of HOXB13 in rectal cancer. METHODS: HOXB13 expression in rectal cancer and normal adjacent tissues was detected by reverse transcriptase-polymerase chain reaction and immunohistochemistry, and its clinicopathological characteristics and prognosis were statistically tested. Furthermore, we evaluated the association between tumor immune infiltrating cells and HOXB13 using the tumor immune estimation resource (TIMER) database. The potential biological mechanism associated with HOXB13 overexpression was investigated by gene set enrichment analysis (GSEA). RESULTS: The expression of HOXB13 messenger RNA and protein in human rectal cancer tissues were significantly higher than those in the normal adjacent tissues (P < 0.05). HOXB13 expression was significantly correlated with depth of invasion, lymphatic invasion, lymph node metastasis, distant metastasis, and pathological tumor node metastasis stage (P < 0.05). Kaplan-Meier survival curves confirmed that HOXB13 overexpression was correlated negatively with overall survival and disease-free survival in rectal cancer (P < 0.05). Also, multivariate Cox regression analysis demonstrated that HOXB13 expression, age, and lymphatic invasion were independent prognostic factors in rectal cancer (P < 0.05). Plus, the results from the TIMER database indicated that HOXB13 expression has a significant association with several immune cell infiltrates. Finally, the GSEA results indicated that HOXB13 participated in the various immune-associated processes, including natural killer cell-mediated cytotoxicity and the T-cell receptor signaling pathway. CONCLUSION: Our study showed an essential role of HOXB13 in rectal cancer immunity and prognosis. Significantly, the overexpression of HOXB13 leads to the worse prognosis for patients with rectal cancer, which will contribute to understanding molecular mechanisms associated with tumor pathogenesis and prognosis in this disease.

Guidewire simulation of endovascular intervention: A systematic review.

BACKGROUND: Endovascular intervention is an important minimally invasive surgery that requires professional skills to operate surgical instruments. Such skills are mainly gained through the traditional training paradigm of "see one, do one, teach one", rather than the guidewire simulation system. METHODS: To identify limitations of existing guidewire simulation research and suggest further research orientations, a comprehensive search on literature published from 2007 to 2021 is performed in 11 selected electronic databases. Through our scrutiny and filtration, 34 articles are selected as major studies for careful examinations. RESULTS: We identify challenges faced in the field of endovascular intervention guidewire simulation. We examine and classify guidewire simulation techniques (including guidewire models, collision detection methods and collision response methods), accuracy evaluation methods, error sources, and performance optimization methods. CONCLUSIONS: Guidewire simulation can satisfy the urgent need to train surgeons, thus more efforts should be dedicated enabling its wide application in clinical environment.

Recent advances in the development of transplanted colorectal cancer mouse models.

Despite progress in prevention and treatment, colorectal cancer (CRC) remains the third most common malignancy worldwide and the second most common cause of cancer death in 2020. To evaluate various characteristics of human CRC, a variety of mouse models have been established. Transplant mouse models have distinct advantages in studying the clinical behavior and therapeutic progress of CRC. Host, xenograft, and transplantation routes are the basis of transplant mouse models. As the effects of the tumor microenvironment and the systemic environment on cancer cells are gradually revealed, 3 key elements of transplanted CRC mouse models have been revolutionized. This has led to the development of humanized mice, patient-derived xenografts, and orthotopic transplants that reflect the human systemic environment, patient's tumor of origin, and tumor growth microenvironments in immunodeficient mice, respectively. These milestone events have allowed for great progress in tumor biology and the treatment of CRC. This article reviews the evolution of these events and points out their strengths and weaknesses as innovative and useful preclinical tools to study CRC progression and metastasis and to exploit novel treatment schedules by establishing a testing platform. This review article depicts the optimal transplanted CRC mouse models and emphasizes the significance of surgical models in the study of CRC behavior and treatment response.

Deep learning-based framework for segmentation of multiclass rib fractures in CT utilizing a multi-angle projection network.

PURPOSE: Clinical rib fracture diagnosis via computed tomography (CT) screening has attracted much attention in recent years. However, automated and accurate segmentation solutions remain a challenging task due to the large sets of 3D CT data to deal with. Down-sampling is often required to face computer constraints, but the performance of the segmentation may decrease in this case. METHODS: A new multi-angle projection network (MAPNet) method is proposed for accurately segmenting rib fractures by means of a deep learning approach. The proposed method incorporates multi-angle projection images to complementarily and comprehensively extract the rib characteristics using a rib extraction (RE) module and the fracture features using a fracture segmentation (FS) module. A multi-angle projection fusion (MPF) module is designed for fusing multi-angle spatial features. RESULTS: It is shown that MAPNet can capture more detailed rib fracture features than some commonly used segmentation networks. Our method achieves a better performance in accuracy (88.06 ± 6.97%), sensitivity (89.26 ± 5.69%), specificity (87.58% ± 7.66%) and in terms of classical criteria like dice (85.41 ± 3.35%), intersection over union (IoU, 80.37 ± 4.63%), and Hausdorff distance (HD, 4.34 ± 3.1). CONCLUSION: We propose a rib fracture segmentation technique to deal with the problem of automatic fracture diagnosis. The proposed method avoids the down-sampling of 3D CT data through a projection technique. Experimental results show that it has excellent potential for clinical applications.

Abdominal rebleeding after transcatheter arterial embolization for ruptured pseudoaneurysms associated with severe acute pancreatitis: a retrospective study.

INTRODUCTION: Patients are at risk of abdominal rebleeding after transcatheter arterial embolization (TAE) for pancreatitis-related pseudoaneurysm, which increases the mortality rate. AIM: This study was performed to evaluate the effects of an intestinal fistula (IF) and the anatomical location of the pseudoaneurysm on abdominal rebleeding after TAE of a ruptured pseudoaneurysm associated with severe acute pancreatitis (SAP). MATERIAL AND METHODS: From February 2013 to November 2019, 24 patients with SAP-related pseudoaneurysm rupture and hemorrhage in our hospital underwent TAE. All patients' epidemiological data and related medical histories were collected and statistically analyzed. We classified the pseudoaneurysms as type I, II, and III according to their anatomical locations and as type A (without an IF) and type B (with an IF). RESULTS: The interventions for abdominal infection in patients with type I pseudoaneurysms were percutaneous drainage in 6 patients, endoscopic necrotic tissue removal in 5, and surgical necrotic tissue removal or enterostomy in none, with a rebleeding rate of 33.3% (3/9 patients). The interventions for abdominal infection in patients with type II pseudoaneurysms were percutaneous drainage in 7 patients, endoscopy in three, and surgery in one, with a rebleeding rate of 20.0% (2/10 patients). The interventions for abdominal infection in patients with type III pseudoaneurysms were percutaneous drainage in 3 patients, endoscopy in 1, and surgery in 2, with a rebleeding rate of 80.0% (4/5 patients). There was no statistically significant difference in the types of interventions for abdominal infection among patients with type I, II, and III pseudoaneurysms (p = 0.355) or in the rate of abdominal rebleeding after TAE for type III pseudoaneurysms (p = 0.111). The interventions for abdominal infection in patients with type A pseudoaneurysms were percutaneous drainage in 13 patients, endoscopy in 6, and surgery in 1, with a rebleeding rate of 22.2% (4/18 patients) and mortality rate of 11.1% (2/18 patients). The interventions for abdominal infection in patients with type B pseudoaneurysms were percutaneous drainage in 3 patients, endoscopy in 3, and surgery in 2, with a rebleeding rate of 83.3% (5/6 patients) and mortality rate of 66.7% (4/6 patients). There was no significant difference in the types of interventions for abdominal infection in patients with and without IF (p = 0.215); however, the rebleeding rate and mortality rate were significantly higher in patients with IF (p = 0.015 and 0.018, respectively). CONCLUSIONS: IF may increase the rate of abdominal rebleeding after TAE for ruptured SAP-related pseudoaneurysms, while the anatomical location of the pseudoaneurysm may not affect the rate of rebleeding after TAE.