Stethoscope-guided Supervised Contrastive Learning for Cross-domain Adaptation on Respiratory Sound Classification

Despite the remarkable advances in deep learning technology, achieving satisfactory performance in lung sound classification remains a challenge due to the scarcity of available data. Moreover, the respiratory sound samples are collected from a variety of electronic stethoscopes, which could potentially introduce biases into the trained models. When a significant distribution shift occurs within the test dataset or in a practical scenario, it can substantially decrease the performance. To tackle this issue, we introduce cross-domain adaptation techniques, which transfer the knowledge from a source domain to a distinct target domain. In particular, by considering different stethoscope types as individual domains, we propose a novel stethoscope-guided supervised contrastive learning approach. This method can mitigate any domain-related disparities and thus enables the model to distinguish respiratory sounds of the recording variation of the stethoscope. The experimental results on the ICBHI dataset demonstrate that the proposed methods are effective in reducing the domain dependency and achieving the ICBHI Score of 61.71%, which is a significant improvement of 2.16% over the baseline.Comment: accepted to ICASSP 202

Combustion behaviour of single pellets of coal–wood mixtures in a hot gas flow field

This experimental study explores the burning characteristics of single pellets made of wood and coal mixtures for co-firing. Three types of pellets were prepared with different wood–coal ratios (100:0, 80:20, and 50:50). Experiments were carried out in a laboratory reactor at rapid heating rates and under oxygen concentrations between 10 and 40%. To investigate their combustion behavior, single pellets were suspended on a wire injected into a hot gas stream at 1340 K and flame and char combustion were recorded through an observation window by means of a high-resolution (4K) camera. The sequential combustion time, volatile flame characteristics, and mass reduction rate were obtained over a time profile by carefully controlled particle injection. The results demonstrated that the char combustion time increased significantly in comparison to the volatile combustion time, which only varied a little, when the pellets contained coal in the mixture. Partially detached flames were also predominantly observed on pure biomass pellets at oxygen concentrations between 21 and 40%. During the homogeneous combustion period, the cross-sectional area of a pellet shrunk by 26.3–37.5% depending upon the type of pellet

Deterministic bead-in-droplet ejection utilizing an integrated plug-in bead dispenser for single bead-based applications

This paper presents a deterministic bead-in-droplet ejection (BIDE) technique that regulates the precise distribution of microbeads in an ejected droplet. The deterministic BIDE was realized through the effective integration of a microfluidic single-particle handling technique with a liquid dispensing system. The integrated bead dispenser facilitates the transfer of the desired number of beads into a dispensing volume and the on-demand ejection of bead-encapsulated droplets. Single bead-encapsulated droplets were ejected every 3 s without any failure. Multiple-bead dispensing with deterministic control of the number of beads was demonstrated to emphasize the originality and quality of the proposed dispensing technique. The dispenser was mounted using a plug-socket type connection, and the dispensing process was completely automated using a programmed sequence without any microscopic observation. To demonstrate a potential application of the technique, bead-based streptavidin-biotin binding assay in an evaporating droplet was conducted using ultralow numbers of beads. The results evidenced the number of beads in the droplet crucially influences the reliability of the assay. Therefore, the proposed deterministic bead-in-droplet technology can be utilized to deliver desired beads onto a reaction site, particularly to reliably and efficiently enrich and detect target biomolecules.112Ysciescopu

Patch-Mix Contrastive Learning with Audio Spectrogram Transformer on Respiratory Sound Classification

Respiratory sound contains crucial information for the early diagnosis of fatal lung diseases. Since the COVID-19 pandemic, there has been a growing interest in contact-free medical care based on electronic stethoscopes. To this end, cutting-edge deep learning models have been developed to diagnose lung diseases; however, it is still challenging due to the scarcity of medical data. In this study, we demonstrate that the pretrained model on large-scale visual and audio datasets can be generalized to the respiratory sound classification task. In addition, we introduce a straightforward Patch-Mix augmentation, which randomly mixes patches between different samples, with Audio Spectrogram Transformer (AST). We further propose a novel and effective Patch-Mix Contrastive Learning to distinguish the mixed representations in the latent space. Our method achieves state-of-the-art performance on the ICBHI dataset, outperforming the prior leading score by an improvement of 4.08%.Comment: INTERSPEECH 2023, Code URL: https://github.com/raymin0223/patch-mix_contrastive_learnin

SALM5 trans-synaptically interacts with LAR-RPTPs in a splicing-dependent manner to regulate synapse development

Synaptogenic adhesion molecules play critical roles in synapse formation. SALM5/Lrfn5, a SALM/Lrfn family adhesion molecule implicated in autism spectrum disorders (ASDs) and schizophrenia, induces presynaptic differentiation in contacting axons, but its presynaptic ligand remains unknown. We found that SALM5 interacts with the Ig domains of LAR family receptor protein tyrosine phosphatases (LAR-RPTPs; LAR, PTPδ, and PTPσ). These interactions are strongly inhibited by the splice insert B in the Ig domain region of LAR-RPTPs, and mediate SALM5-dependent presynaptic differentiation in contacting axons. In addition, SALM5 regulates AMPA receptor-mediated synaptic transmission through mechanisms involving the interaction of postsynaptic SALM5 with presynaptic LAR-RPTPs. These results suggest that postsynaptic SALM5 promotes synapse development by trans-synaptically interacting with presynaptic LAR-RPTPs and is important for the regulation of excitatory synaptic strength

Tuning orbital-selective phase transitions in a two-dimensional Hund's correlated system

Hund's rule coupling ($\textit{J}$) has attracted much attention recently for its role in the description of the novel quantum phases of multi orbital materials. Depending on the orbital occupancy, $\textit{J}$ can lead to various intriguing phases. However, experimental confirmation of the orbital occupancy dependency has been difficult as controlling the orbital degrees of freedom normally accompanies chemical inhomogeneities. Here, we demonstrate a method to investigate the role of orbital occupancy in $\textit{J}$ related phenomena without inducing inhomogeneities. By growing SrRuO$_3$ monolayers on various substrates with symmetry-preserving interlayers, we gradually tune the crystal field splitting and thus the orbital degeneracy of the Ru \textit{t_2_g$}$ orbitals. It effectively varies the orbital occupancies of two-dimensional (2D) ruthenates. Via in-situ angle-resolved photoemission spectroscopy, we observe a progressive metal-insulator transition (MIT). It is found that the MIT occurs with orbital differentiation: concurrent opening of a band insulating gap in the $\textit{d$_x_y} band and a Mott gap in the \textit{d_x$$_z$$_/$$_y$$_z} bands. Our study provides an effective experimental method for investigation of orbital-selective phenomena in multi-orbital materials

Dissection Manual for Open Rhinoseptoplasty in a Silicone Nose Model

Open rhinoseptoplasty has been widely performed in the field of otorhinolaryngology. However, from the perspective of beginners, rhinoseptoplasty is a hard-to-learn surgery that involves a relatively steep learning curve. Therefore, practical guidance is essential to enhance the skills needed for excellent surgical outcomes. Here, we provide a step-wise dissection manual using a commercialized silicone nose model designed for rhinoseptoplasty. The contents include general approaches with regard to transcolumellar inverted V incision, flap elevation, osteotomy, septoplasty, modification of the lower lateral cartilage for tip surgery, and dorsal augmentation using silicone implants. In addition, we introduce novel techniques such as dorsal augmentation using a ready-made mold with tissue glue applied to diced cartilage and polycaprolactone mesh for rhinoseptoplasty. The present study also provides photos of individual surgical procedures using a silicone nose model for actual guidance. The authors expect that this manual will help beginning rhinoseptoplasty surgeons improve their confidence

LRRTM3 Regulates Excitatory Synapse Development through Alternative Splicing and Neurexin Binding

The four members of the LRRTM family (LRRTM1-4) are postsynaptic adhesion molecules essential for excitatory synapse development. They have also been implicated in neuropsychiatric diseases. Here, we focus on LRRTM3, showing that two distinct LRRTM3 variants generated by alternative splicing regulate LRRTM3 interaction with PSD-95, but not its excitatory synapse-promoting activity. Overexpression of either LRRTM3 variant increased excitatory synapse density in dentate gyrus (DG) granule neurons, whereas LRRTM3 knockdown decreased it. LRRTM3 also controlled activity-regulated AMPA receptor surface expression in an alternative splicing-dependent manner. Furthermore, Lrrtm3-knockout mice displayed specific alterations in excitatory synapse density, excitatory synaptic transmission and excitability in DG granule neurons but not in CA1 pyramidal neurons. Lastly, LRRTM3 required only specific splice variants of presynaptic neurexins for their synaptogenic activity. Collectively, our data highlight alternative splicing and differential presynaptic ligand utilization in the regulation of LRRTMs, revealing key regulatory mechanisms for excitatory synapse development.Peer reviewe

Analysis of liquid-type proof mass under oscillating conditions

In this study, the spring constant of an accelerometer with a liquid-type proof mass was analyzed. Unlike a general solid-type microelectromechanical system accelerometer, the Laplace pressure is considered a restoring force in the analyzed accelerometer. Using a base excitation mathematical model, the sensor output could be estimated for a specific spring constant. Although the estimated sensor output data fit well with the experimental results, the spring constant of the device could also be determined dynamically (for oscillations below 5 Hz). Moreover, the damping constants could be inferred depending on whether sandblasting treatment was performed. Finally, the effects of the oscillation, surface condition, and volume of liquid metal droplets on the spring constant were analyzed.11Yscopu