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1.
Artigo em Inglês | MEDLINE | ID: mdl-38656855

RESUMO

We present a novel framework named NeuralRecon for real-time 3D scene reconstruction from a monocular video. Unlike previous methods that estimate single-view depth maps separately on each key-frame and fuse them later, we propose to directly reconstruct local surfaces represented as sparse TSDF volumes for each video fragment sequentially by a neural network. A learning-based TSDF fusion module based on gated recurrent units is used to guide the network to fuse features from previous fragments. This design allows the network to capture local smoothness prior and global shape prior of 3D surfaces when sequentially reconstructing the surfaces, resulting in accurate, coherent, and real-time surface reconstruction. The fused features can also be used to predict semantic labels, allowing our method to reconstruct and segment the 3D scene simultaneously. Furthermore, we purpose an efficient self-supervised fine-tuning scheme that refines scene geometry based on input images through differentiable volume rendering. This fine-tuning scheme improves reconstruction quality on the fine-tuned scenes as well as the generalization to similar test scenes. The experiments on ScanNet, 7-Scenes and Replica datasets show that our system outperforms state-of-the-art methods in terms of both accuracy and speed.

2.
IEEE Trans Med Imaging ; PP2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38578852

RESUMO

High intensity focused ultrasound (HIFU) is a thriving non-invasive technique for thermal ablation of tumors, but significant challenges remain in its real-time monitoring with medical imaging. Ultrasound imaging is one of the main imaging modalities for monitoring HIFU surgery in organs other than the brain, mainly due to its good temporal resolution. However, strong acoustic interference from HIFU irradiation severely obscures the B-mode images and compromises the monitoring. To address this problem, we proposed a frequency-domain robust principal component analysis (FRPCA) method to separate the HIFU interference from the contaminated B-mode images. Ex-vivo and in-vivo experiments were conducted to validate the proposed method based on a clinical HIFU therapy system combined with an ultrasound imaging platform. The performance of the FRPCA method was compared with the conventional notch filtering method. Results demonstrated that the FRPCA method can effectively remove HIFU interference from the B-mode images, which allowed HIFU-induced grayscale changes at the focal region to be recovered. Compared to notch-filtered images, the FRPCA-processed images showed an 8.9% improvement in terms of the structural similarity (SSIM) index to the uncontaminated B-mode images. These findings demonstrate that the FRPCA method presents an effective signal processing framework to remove the strong HIFU acoustic interference, obtains better dynamic visualization in monitoring the HIFU irradiation process, and offers great potential to improve the efficacy and safety of HIFU treatment and other focused ultrasound related applications.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38507384

RESUMO

This paper addresses the challenge of reconstructing 3D indoor scenes from multi-view images. Many previous works have shown impressive reconstruction results on textured objects, but they still have difficulty in handling low-textured planar regions, which are common in indoor scenes. An approach to solving this issue is to incorporate planar constraints into the depth map estimation in multi-view stereo-based methods, but the per-view plane estimation and depth optimization lack both efficiency and multi-view consistency. In this work, we show that the planar constraints can be conveniently integrated into the recent implicit neural representation-based reconstruction methods. Specifically, we use an MLP network to represent the signed distance function as the scene geometry. Based on the Manhattan-world assumption and the Atlanta-world assumption, planar constraints are employed to regularize the geometry in floor and wall regions predicted by a 2D semantic segmentation network. To resolve the inaccurate segmentation, we encode the semantics of 3D points with another MLP and design a novel loss that jointly optimizes the scene geometry and semantics in 3D space. Experiments on ScanNet and 7-Scenes datasets show that the proposed method outperforms previous methods by a large margin on 3D reconstruction quality. The code and supplementary materials are available at https://zju3dv.github.io/ manhattan sdf.

4.
Phys Med Biol ; 69(7)2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38382109

RESUMO

Objective.One big challenge with high-intensity focused ultrasound (HIFU) is that the intense acoustic interference generated by HIFU irradiation overwhelms the B-mode monitoring images, compromising monitoring effectiveness. This study aims to overcome this problem using a one-dimensional (1D) deep convolutional neural network.Approach. U-Net-based networks have been proven to be effective in image reconstruction and denoising, and the two-dimensional (2D) U-Net has already been investigated for suppressing HIFU interference in ultrasound monitoring images. In this study, we propose that the one-dimensional (1D) convolution in U-Net-based networks is more suitable for removing HIFU artifacts and can better recover the contaminated B-mode images compared to 2D convolution.Ex vivoandinvivoHIFU experiments were performed on a clinically equivalent ultrasound-guided HIFU platform to collect image data, and the 1D convolution in U-Net, Attention U-Net, U-Net++, and FUS-Net was applied to verify our proposal.Main results.All 1D U-Net-based networks were more effective in suppressing HIFU interference than their 2D counterparts, with over 30% improvement in terms of structural similarity (SSIM) to the uncontaminated B-mode images. Additionally, 1D U-Nets trained usingex vivodatasets demonstrated better generalization performance ininvivoexperiments.Significance.These findings indicate that the utilization of 1D convolution in U-Net-based networks offers great potential in addressing the challenges of monitoring in ultrasound-guided HIFU systems.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Redes Neurais de Computação , Ultrassonografia , Processamento de Imagem Assistida por Computador/métodos , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Artefatos
5.
Ultrasound Med Biol ; 50(5): 760-767, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38360493

RESUMO

OBJECTIVE: In the treatment of uterine fibroids with ultrasound-guided high-intensity focused ultrasound (HIFU), water balloons are considered to be a valuable aid for improving safety and efficiency. However, the water balloons worsen the pathway for acoustic transmission, causing degraded performance both in ultrasound therapy and in ultrasound imaging. This study was aimed at establishing a protocol to evaluate the effects of the water balloon. METHODS: Simulations and experiments were carefully conducted to quantitatively investigate the effects of water ballons on the efficiency of HIFU energy delivery and on the quality of ultrasound guiding images. More specifically, HIFU-induced temperature increases in the focal region, together with spatial resolution, contrast and signal-to-noise ratio in the ultrasound guiding images, were compared under the conditions with and without the water balloon. RESULTS: Experiment results revealed that the use of water balloons led to decreases in temperature up to 10ºC within the focal region in some specific situations, but the quality of the guiding images was relatively less affected. CONCLUSION: The study provided knowledge on what influence the water balloon could have in ultrasound-guided HIFU treatment; it also established a practical and standardized evaluation scheme for further optimizing the water balloon, for example, its material and internal liquid compositions. This study can potentially help improve the efficiency and safety of treating uterine fibroids with ultrasound-guided HIFU systems.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Leiomioma , Neoplasias Uterinas , Feminino , Humanos , Neoplasias Uterinas/diagnóstico por imagem , Neoplasias Uterinas/terapia , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Resultado do Tratamento , Leiomioma/diagnóstico por imagem , Leiomioma/terapia , Ultrassonografia , Imageamento por Ressonância Magnética/métodos
6.
iScience ; 27(3): 109046, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38384848

RESUMO

Poor endometrial receptivity results in embryo implantation failure. Acquisition of endometrial receptivity involves substantial structural alterations in the cytoskeleton and plasma membrane of epithelial cells, which facilitate embryo adhesion. However, the underlying molecular mechanism remains largely unknown. In this study, we identified that α-actinin-1 (ACTN1) was significantly downregulated in the mid-secretory phase of the endometrium compared with other phases; however, ACTN1 significantly increased in women with recurrent implantation failure (RIF). In Ishikawa and human endometrial epithelial cells (HEECs), ACTN1 overexpression significantly decreased NEBL levels, enhanced F-actin fiber levels, and caused a notable impairment in blastocyst adhesion, which mimicked the process of embryo adhesion. However, NEBL overexpression notably restored adhesion. Moreover, NEBL expression was reduced in patients with RIF compared with that in controls. Finally, our data showed that ACTN1 upregulation impaired endometrial receptivity in women with RIF, possibly by regulating NEBL expression and subsequent cell-adhesion capability.

7.
Int J Legal Med ; 138(3): 833-838, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38197924

RESUMO

A 28-year-old woman collapsed in her home, and her companion rushed to call emergency services. Upon arrival, a physician performed CPR and endotracheal intubation, successfully restoring her voluntary heart rhythm. However, while en route to the hospital, ventricular fibrillation recurred. Despite the restoration of her voluntary rhythm through electrical defibrillation, she remained in a comatose state, which eventually led to multiple organ failures. Family members revealed that she had a 2-month history of taking diet pills. Histological examination revealed cardiomyocyte necrosis, contraction band necrosis, interstitial hemorrhage, collagen deposition, interstitial fiber proliferation, and myofiber remodeling. Analysis of blood and urine using GC-MS and LC-MS detected sibutramine and its primary metabolites, M1 and M2, which were consistent with the composition of the medication she was taking. The deceased was in good health with no underlying heart disease. The above information confirmed that the cause of her death was sibutramine.


Assuntos
Ciclobutanos , Cardiopatias , Humanos , Feminino , Adulto , Choque Cardiogênico/induzido quimicamente , Ciclobutanos/efeitos adversos
8.
Artigo em Inglês | MEDLINE | ID: mdl-38231799

RESUMO

This paper addresses the challenge of reconstructing an animatable human model from a multi-view video. Some recent works have proposed to decompose a non-rigidly deforming scene into a canonical neural radiance field and a set of deformation fields that map observation-space points to the canonical space, thereby enabling them to learn the dynamic scene from images. However, they represent the deformation field as translational vector field or SE(3) field, which makes the optimization highly under-constrained. Moreover, these representations cannot be explicitly controlled by input motions. Instead, we introduce blend weight fields to produce the deformation fields. Based on the skeleton-driven deformation, blend weight fields are used with 3D human skeletons to generate observation-to-canonical and canonical-to-observation correspondences. Since 3D human skeletons are more observable, they can regularize the learning of deformation fields. Moreover, the blend weight fields can be combined with input skeletal motions to generate new deformation fields to animate the human model. To improve the quality of human modeling, we further represent the human geometry as a signed distance field in the canonical space. Additionally, a neural point displacement field is introduced to enhance the capability of the blend weight field on modeling detailed human motions. Experiments show that our approach significantly outperforms recent human modeling methods. The code is available at https://zju3dv.github.io/animatable nerf/.

9.
Molecules ; 29(2)2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38257252

RESUMO

Dianthus superbus L. has been extensively studied for its potential medicinal properties in traditional Chinese medicine and is often consumed as a tea by traditional folk. It has the potential to be exploited in the treatment of inflammation, immunological disorders, and diabetic nephropathy. Based on previous studies, this study continued the separation of another subfraction of Dianthus superbus and established reversed-phase/reversed-phase and reversed-phase/hydrophilic (RPLC) two-dimensional (2D) high-performance liquid chromatography (HPLC) modes, quickly separating two C-glycosylflavones, among which 2″-O-rhamnosyllutonarin was a new compound and isomer with 6‴-O-rhamnosyllutonarin. This is the first study to investigate the effects of 2″-O-rhamnosyllutonarin and 6‴-O-rhamnosyllutonarin on cellular glucose metabolism in vitro. First, molecular docking was used to examine the effects of 2″-O-rhamnosyllutonarin and 6″-O-rhamnosyllutonarin on AKT and AMPK; these two compounds exhibited relatively high activity. Following this, based on the HepG2 cell model of insulin resistance, it was proved that both of the 2″-O-rhamnosyllutonarin and 6‴-O-rhamnosyllutonarin demonstrated substantial efficacy in ameliorating insulin resistance and were found to be non-toxic. Simultaneously, it is expected that the methods developed in this study will provide a basis for future studies concerning the separation and pharmacological effects of C-glycosyl flavonoids.


Assuntos
Dianthus , Resistência à Insulina , Simulação de Acoplamento Molecular , Metabolismo dos Carboidratos , Glucose
10.
Langmuir ; 40(1): 348-361, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38154090

RESUMO

In this study, hollow and hierarchical CuO micro-nano cubes wrapped by reduced graphene oxide (H-CuO MNCs@rGO) were designed and successfully fabricated via a novel three-step wet-chemical method. Benefiting from its unique hollow and hierarchical micro-nano structures, H-CuO MNCs@rGO exhibited significantly enhanced electrochemical Na+ storage performance when utilized as anode material for sodium-ion batteries (SIBs). Specifically, H-CuO MNCs@rGO demonstrated a specific capacity of 380.9 mAh g-1 in the initial reversible cycle and a capacity retention of 218.9 mAh g-1 after 150 cycles at a current density of 300 mA g-1. Furthermore, through the dominant pseudocapacitive behavior, an optimized rate capability of 221.2 mAh g-1 at 800 mA g-1 can be obtained for H-CuO MNCs@rGO. The comprehensive Na+ storage properties of H-CuO MNCs@rGO obviously exceeded those of hollow CuO cubes (H-CuO MNCs) and bulk CuO anodes. Such enhanced Na+ storage performances of H-CuO MNCs@rGO can be attributed to its reasonable hollow and hierarchical micro-nano structures, which provide abundant redox active sites, shorten Na+ migration pathway, buffer volume expansion, and improve electronic/ionic conductivity during sodiation/desodiation process. Our strategy provides a facile and innovative approach for the design of CuO with rational micro-nano structure as a high-performance anode for SIBs, which would also be a guiding way for tailoring transition metal oxides in other scalable and functional applications.

11.
Artigo em Inglês | MEDLINE | ID: mdl-38109244

RESUMO

Super-resolution ultrasound (SRUS) through localizing spatially isolated microbubbles (MBs) has been demonstrated to overcome the wave diffraction limit and reveal the microvascular structure and flow information at the microscopic scale. However, 3-D SRUS imaging remains a challenge due to the fabrication and computational complexity of 2-D matrix array probes. Inspired by X-ray radiography which can present information within a volume in a single projection image with much simpler hardware than X-ray computerized tomography (CT), this study investigates the feasibility of broad elevation projection super-resolution (BEP-SR) ultrasound using a 1-D unfocused linear array. Both simulation and in vitro experiments were conducted on 3-D microvessel phantoms. In vivo demonstration was done on the Rabbit kidney. Data from a 1-D linear array with and without an elevational focus were synthesized by summing up row signals acquired from a 2-D matrix array with and without delays. A full 3-D reconstruction was also generated as the reference, using the same data of the 2-D matrix array but without summing row signals. Results show that using an unfocused 1-D array probe, BEP-SR can capture significantly more information within a volume in both vascular structure and flow velocity than the conventional 1-D elevational-focused probe. Compared with the 2-D projection image of the full 3-D SRUS results using the 2-D array probe with the same aperture size, the 2-D projection SRUS image of BEP-SR has similar volume coverage, using 32 folds fewer independent elements. This study demonstrates BEP-SR's ability of high-resolution imaging of microvascular structures and flow velocity within a 3-D volume at significantly reduced costs. The proposed BEP method could significantly benefit the clinical translation of the SRUS imaging technique by making it more affordable and repeatable.


Assuntos
Microvasos , Tomografia Computadorizada por Raios X , Animais , Coelhos , Ultrassonografia/métodos , Imagens de Fantasmas , Microvasos/diagnóstico por imagem , Microbolhas
12.
Langmuir ; 39(45): 16128-16137, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37916685

RESUMO

The Gram-negative bacteria Marinomonas primoryensis secrete an ice-binding protein (MpIBP), which is a vital bacterial adhesin facilitating the adaptation and survival of the bacteria in the harsh Antarctic environment. The C-terminal region of MpIBP, known as region V (RV), is the first domain to be exported into the Ca2+-rich extracellular environment and acts as a folding nucleus for the entire adhesin. However, the mechanisms underlying the secretion and folding of RV remain poorly understood. Here, we used optical tweezers (OT) to investigate the secretion and folding mechanisms of RV at the single-molecule level. In the absence of Ca2+, apo-RV remains unstructured, while Ca2+-bound RV folds into a mechanically stable structure. The folding of RV could occur via the formation of an intermediate state. Even though this folding intermediate is "hidden" during the folding process of wild type RV in vitro, it likely forms in vivo and plays an important role in facilitating protein secretion. Additionally, our results revealed that the N-terminal part of the RV can significantly stabilize its C-terminal structure. Our study paves the way for further investigations into the structure and functions of MpIBP that help bacteria survive in challenging environments.


Assuntos
Proteínas de Transporte , Gelo , Adesinas Bacterianas/química , Adesinas Bacterianas/metabolismo , Bactérias , Análise Espectral , Dobramento de Proteína
13.
Artigo em Inglês | MEDLINE | ID: mdl-37924417

RESUMO

Dimethyl sulfate (DMS) is a highly toxic chemical that appears innocuous and is commonly used as a methylating agent in industry. It can be readily absorbed leading to poisoning or death through the skin or mucous membranes of the respiratory tract in the process of production or transportation. Although there are some articles on treatment for DMS poisoning, reports of death resulting from acute fatal DMS poisoning are very rare. Here, we present a case of a 50-year-old Chinese man who died accidentally from DMS poisoning after he broke a plastic storage tank full of DMS during transportation. The patient complained of eye irritation. In addition, the corrosive damage could be seen in his corneas and skin. The autopsy revealed erosions and ulcers in the respiratory tract, as well as massive congestion, necrosis, edema, and pseudomembrane formation on the mucous layer of the trachea and main bronchi. Histopathological examination confirmed extensive pulmonary edema, multifocal hemorrhages, whole-cell swelling in the brain, as well as disintegration of the neuronal cell. We inferred that DMS poisoning caused the symptoms resulting from the production of methanol and sulfate through hydrolysis, including respiratory toxicity and neurotoxicity, and these symptoms had temporal continuity. Toxicological analysis revealed no DMS or methanol, but formic acid was detected in the brain, both qualitatively and quantitatively. In this report, we also present a retrospective study of 8 similar cases of DMS poisoning in literature in China, including some clinical data and autopsy information.

14.
Med Phys ; 50(9): 5449-5459, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37345709

RESUMO

BACKGROUND: High-intensity focused ultrasound (HIFU) is currently used for the treatment of various diseases, but it still lacks a reliable technique in the preoperative stage to accurately place its "energy blade" onto diseased targets. Acoustic radiation force imaging (ARFI) was recently introduced to tackle this issue, but its applicability and limitations were not clear. PURPOSE: The aim of this study was to evaluate the performance of ARFI method in prediction of HIFU focal location at the preoperative stage. METHODS: A point spread function (PSF) localization method, which was borrowed from the ultrasound super resolution field, was used to validate the core autocorrelation-based motion estimation algorithm in the ARFI procedure. Accuracy of the ARFI method for estimating the HIFU focus were tested with in vitro and ex vivo experiments with a clinically equivalent HIFU system. Comparisons were made between the estimated focal locations and those of the damaged area after the testing objects were cut open. RESULTS: Results showed that the PSF localization was able to serve as a validating method for motion detection only when the tissue displacement was large. With the ARFI method, location of the HIFU focus could be accurately predicted by a 2D motion map preoperatively, and the axial spatial errors were less than 0.5 mm. However, the derived 2D motion maps can only be valuable when the acoustic stimulation in ARFI were strong enough, which was probably due to the fact that the HIFU focal locations were at large depths and the ultrasound imaging signal had low signal to noise ratio. CONCLUSION: The ARFI method was indeed an accurate technique for preoperatively predicting HIFU focus in vitro and ex vivo. If clinical applications were to be considered, particularly in deep tissues, efforts might need to be made to improve ability of the ultrasound motion estimation technique.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Fenômenos Mecânicos , Ultrassonografia , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Acústica
15.
IEEE Trans Biomed Eng ; 70(12): 3413-3424, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37339046

RESUMO

OBJECTIVE: One big challenge with high intensity focused ultrasound (HIFU) is the difficulty in accurate prediction of focal location due to the complex wave propagation in heterogeneous medium even with imaging guidance. This study aims to overcome this by combining therapy and imaging guidance with one single HIFU transducer using the vibro-acoustography (VA) strategy. METHODS: Based on the VA imaging method, a HIFU transducer consisting of 8 transmitting elements was proposed for therapy planning, treatment and evaluation. Inherent registration between the therapy and imaging created unique spatial consistence in HIFU transducer's focal region in the above three procedures. Performance of this imaging modality was first evaluated through in-vitro phantoms. In-vitro and ex-vivo experiments were then designed to demonstrate the proposed dual-mode system's ability in conducting accurate thermal ablation. RESULTS: Point spread function of the HIFU-converted imaging system had a full wave half maximum of about 1.2 mm in both directions at a transmitting frequency of 1.2 MHz, which outperformed the conventional ultrasound imaging (3.15 MHz) in in-vitro situation. Image contrast was also tested on the in-vitro phantom. Various geometric patterns could be accurately 'burned out' on the testing objects by the proposed system both in vitro and ex vivo. CONCLUSION: Implementation of imaging and therapy with one HIFU transducer in this manner is feasible and it has potential as a novel strategy for addressing the long-standing problem in the HIFU therapy, possibly pushing this non-invasive technique forward towards wider clinical applications.


Assuntos
Técnicas de Imagem por Elasticidade , Ablação por Ultrassom Focalizado de Alta Intensidade , Ultrassonografia , Imagens de Fantasmas , Transdutores , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos
16.
Reprod Biomed Online ; 47(2): 103203, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37349244

RESUMO

RESEARCH QUESTION: What is the underlying mechanism of IVF and embryo transfer (IVF-ET) failure in patients with elevated peripheral blood natural killer cell (pNK) counts? DESIGN: Patients undergoing IVF-ET cycles for tubal obstruction or pelvic adhesion (n = 486) were assigned to three groups: high (CD56+CD16+pNK >30% [n = 49]); medium (15< CD56+CD16+pNK ≤30% [n = 211]); and normal pNK groups (5≤ CD56+CD16+pNK ≤15% [n = 226]). Their general condition, previous pregnancy history and IVF outcomes were compared. Uterine fluid and endometrial tissue from patients in the high and normal pNK groups were collected during the mid-secretory phase and studied to elucidate the molecular mechanism underlying impaired endometrial receptivity. RESULTS: The highest incidence of IVF-ET cycles (P < 0.0001) and biochemical pregnancy losses (P < 0.0001), and lowest implantation and clinical pregnancy rates (both P < 0.0001), were observed in patients with pNK over 30%. No significant difference was found in the number of previous miscarriages and rate of spontaneous miscarriage in IVF outcomes. Lower Septin11 (SEPT11) expression in the uterine fluid and endometrial epithelial cells (EEC), and higher endometrial IFN-γ, was observed in patients with high pNK. Ishikawa cell and human endometrial epithelial cell (HEEC) adhesion was inhibited after SEPT11 knock-down. Elevated IFN-γ decreased the SEPT11 protein levels in Ishikawa cells and HEECs. CONCLUSIONS: CD56+CD16+pNK above 30% may be a threshold for adverse IVF-ET outcomes. Low SEPT11 expression in EEC inhibits cell adhesion, which may cause impaired endometrial receptivity in patients with elevated pNK. The level of SEPT11 in mid-secretory uterine fluid could serve as a non-invasive marker to assess endometrial receptivity in these patients.


Assuntos
Aborto Espontâneo , Implantação do Embrião , Septinas , Feminino , Humanos , Gravidez , Regulação para Baixo , Implantação do Embrião/fisiologia , Endométrio/metabolismo , Células Epiteliais , Células Matadoras Naturais , Septinas/genética , Septinas/metabolismo
17.
Opt Express ; 31(8): 12397-12409, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37157400

RESUMO

High-precision axial localization measurement is an important part of micro-nanometer optical measurement, but there have been issues such as low calibration efficiency, poor accuracy, and cumbersome measurement, especially in reflected light illumination systems, where the lack of clarity of imaging details leads to the low accuracy of commonly used methods. Herein, we develop a trained residual neural network coupled with a convenient data acquisition strategy to address this challenge. Our method improves the axial localization precision of microspheres in both reflective illumination systems and transmission illumination systems. Using this new localization method, the reference position of the trapped microsphere can be extracted from the identification results, namely the "positioning point" among the experimental groups. This point relies on the unique signal characteristics of each sample measurement, eliminates systematic repeatability errors when performing identification across samples, and improves the localization precision of different samples. This method has been verified on both transmission and reflected illumination optical tweezers platforms. We will bring greater convenience to measurements in solution environments and will provide higher-order guarantees for force spectroscopy measurements in scenarios such as microsphere-based super-resolution microscopy and the surface mechanical properties of adherent flexible materials and cells.

18.
Sci Prog ; 106(2): 368504231172613, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37198909

RESUMO

As the largest consumer of coal energy, coal-fired power plants emit large amounts of PbCl2 each year, which is of wide concern due to its high toxicity, global migration, and accumulation. Unburned carbon is considered a promising adsorbent for effective PbCl2 removal. However, there is a problem that the current unburned carbon model cannot show the structure of carbon defects on the actual unburned carbon surface. Therefore, it is important to construct defective unburned carbon models with practical significance. In addition, the adsorption mechanism of PbCl2 by an unburned model is not studied deeply enough and the reaction mechanism is not clear yet. This has seriously affected the development of effective adsorbents. To reveal the adsorption mechanism of PbCl2 on unburned carbon, the adsorption mechanism of PbCl2 on defective unburned carbon surfaces was analyzed by using the density flooding theory to investigate the adsorption process of PbCl2 on different unburned carbon models. This will provide theoretical guidance for the design and development of adsorbents for the removal of PbCl2 from coal-fired power plants.

19.
IEEE Trans Pattern Anal Mach Intell ; 45(8): 9895-9907, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37027766

RESUMO

This paper addresses the challenge of novel view synthesis for a human performer from a very sparse set of camera views. Some recent works have shown that learning implicit neural representations of 3D scenes achieves remarkable view synthesis quality given dense input views. However, the representation learning will be ill-posed if the views are highly sparse. To solve this ill-posed problem, our key idea is to integrate observations over video frames. To this end, we propose Neural Body, a new human body representation which assumes that the learned neural representations at different frames share the same set of latent codes anchored to a deformable mesh, so that the observations across frames can be naturally integrated. The deformable mesh also provides geometric guidance for the network to learn 3D representations more efficiently. Furthermore, we combine Neural Body with implicit surface models to improve the learned geometry. To evaluate our approach, we perform experiments on both synthetic and real-world data, which show that our approach outperforms prior works by a large margin on novel view synthesis and 3D reconstruction. We also demonstrate the capability of our approach to reconstruct a moving person from a monocular video on the People-Snapshot dataset.


Assuntos
Algoritmos , Corpo Humano , Humanos , Aprendizagem
20.
Front Neurol ; 14: 1121656, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37006497

RESUMO

Objective: Limited research has focused on the clinical features of sudden sensorineural hearing loss (SSNHL) in pediatric patients. This study is aimed to investigate the relationship between clinical features and the baseline hearing severity and outcomes of SSNHL in the pediatric population. Method: We conducted a bi-center retrospective observational study in 145 SSNHL patients aged no more than 18 years who were recruited between November 2013 and October 2022. Data extracted from medical records, audiograms, complete blood count (CBC) and coagulation tests have been assessed for the relationship with the severity (the thresholds of the initial hearing) and outcomes (recovery rate, hearing gain and the thresholds of the final hearing). Results: A lower lymphocyte count (P = 0.004) and a higher platelet-to-lymphocyte ratio (PLR) (P = 0.041) were found in the patient group with profound initial hearing than in the less severe group. Vertigo (ß = 13.932, 95%CI: 4.082-23.782, P = 0.007) and lymphocyte count (ß = -6.686, 95%CI: -10.919 to -2.454, P = 0.003) showed significant associations with the threshold of the initial hearing. In the multivariate logistic model, the probability of recovery was higher for patients with ascending and flat audiograms compared to those with descending audiograms (ascending: OR 8.168, 95% CI 1.450-70.143, P = 0.029; flat: OR 3.966, 95% CI 1.341-12.651, P = 0.015). Patients with tinnitus had a 3.2-fold increase in the probability of recovery (OR 3.222, 95% CI 1.241-8.907, P = 0.019), while the baseline hearing threshold (OR 0.968, 95% CI 0.936-0.998, P = 0.047) and duration to the onset of therapy (OR 0.942, 95% CI 0.890-0.977, P = 0.010) were negatively associated with the odds of recovery. Conclusions: The present study showed that accompanying tinnitus, the severity of initial hearing loss, the time elapse and the audiogram configuration might be related to the prognosis of pediatric SSNHL. Meanwhile, the presence of vertigo, lower lymphocytes and higher PLR were associated with worse severity.

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