We propose using faster regions with convolutional neural network features (faster R-CNN) in the TensorFlow tool package to detect and number teeth in dental periapical films. To improve detection ...precisions, we propose three post-processing techniques to supplement the baseline faster R-CNN according to certain prior domain knowledge. First, a filtering algorithm is constructed to delete overlapping boxes detected by faster R-CNN associated with the same tooth. Next, a neural network model is implemented to detect missing teeth. Finally, a rule-base module based on a teeth numbering system is proposed to match labels of detected teeth boxes to modify detected results that violate certain intuitive rules. The intersection-over-union (IOU) value between detected and ground truth boxes are calculated to obtain precisions and recalls on a test dataset. Results demonstrate that both precisions and recalls exceed 90% and the mean value of the IOU between detected boxes and ground truths also reaches 91%. Moreover, three dentists are also invited to manually annotate the test dataset (independently), which are then compared to labels obtained by our proposed algorithms. The results indicate that machines already perform close to the level of a junior dentist.
Scoliosis is a medical condition where a person’s spine has a sideways curve. The Cobb angle quantifying the degree of spinal curvature is the gold standard for a scoliosis assessment. Recently, the ...deep learning methods based on segmentation and landmark estimation both achieve high performance for automated Cobb angle measurement on X-rays. However, we notice that these methods utilize segmentation and landmark information separately. In this light, we propose an automated architecture that uses combined segmentation with landmark information to estimate 68 landmarks of 17 vertebrae. In addition, we consider spinal curvature described by 68 landmarks as a constraint to estimate the Cobb angle. Extensive experiment results which test on 240 X-rays demonstrate that our method improves the landmark estimation performance effectively and reduces the Cobb angle error.
Photocatalytic nitrogen fixation and pollutants degradation at ambient temperature and pressure as a clean and efficient means represents a sustainable direction. In this paper, novel two-dimensional ...(2D) ZnIn2S4/2D BiOCl (ZIS/BOC) nanosheets heterostructures were successfully synthesized by in-situ solvothermal techniques. XPS and TEM results showed the formation of heterostructure. The photocatalytic properties of these materials were further studied by degradating phenol and nitrogen fixation under visible light irradiation. In particular, heterostructure obtained with a mass ratio of 0.5 wt % of ZnIn2S4 had a good application prospect and can achieve 77.4% phenol degradation rate within 6 h and a rate of ammonium production of 14.6 µmol∙gcat−1·h−1. The reaction rate of 0.5 wt % ZIS/BOC heterostructure exhibited 8.6 and 2.6 times relative to BiOCl for the degradation of phenol and nitrogen fixation, respectively. The enhanced photocatalytic activity was attributed to the collaboration of low recombination rate of photo-generated carriers and enhanced visible light absorption. Based on capture experiments and electron spin resonance (ESR) techniques, the main active species that may appear in photocatalytic systems were explored, and the corresponding photocatalytic mechanism was also proposed appropriately. This strategy will open up new ideas for the design and manufacture of more energy-efficient materials with high photocatalytic activity.
The cavitation effect is an important geochemical phenomenon, which generally exists under strong hydrodynamic conditions. Therefore, developing an economical and effective sonocatalyst becomes a ...vital method in capitalizing on the cavitation effect for energy generation. In this study, we first report a novel Fe3O4 sonocatalyst that can be easily separated using a magnetic field and does not require any additional cocatalysts for H2 production from H2O. When subjected to ultrasonic vibration, this catalyst achieves an impressive H2 production rate of up to 175 μmol/h/USD (where USD stands for dollars), surpassing most previously reported mechanical catalytic materials. Furthermore, the ease and efficiency of separating this catalyst using an external magnetic field, coupled with its effortless recovery, highlight its significant potential for practical applications. By addressing the key limitations of conventional sonocatalysts, our study not only demonstrates the feasibility of using Fe3O4 as a highly efficient sonocatalyst but also showcases the exciting possibility of using a new class of magnetically separable sonocatalysts to productively transform mechanical energy into chemical energy.
Simultaneous pressure waves (SPWs) in manometry recordings of the human colon have been associated with gas expulsion. Our hypothesis was that the SPW might be a critical component of most colonic ...motor functions, and hence might act as a biomarker for healthy colon motility. To that end, we performed high-resolution colonic manometry (HRCM), for the first time using an 84-sensor (1 cm spaced) water-perfused catheter, in 17 healthy volunteers. Intraluminal pressure patterns were recorded during baseline, proximal and rectal balloon distention, after a meal and following proximal and rectal luminal bisacodyl administration. Quantification was performed using software, based on Image J, developed during this study. Gas expulsion was always associated with SPWs, furthermore, SPWs were associated with water or balloon expulsion. SPWs were prominently emerging at the termination of proximal high amplitude propagating pressure waves (HAPWs); we termed this motor pattern HAPW-SPWs; hence, SPWs were often not a pan-colonic event. SPWs and HAPW-SPWs were observed at baseline with SPW amplitudes of 12.0 ± 8.5 mmHg and 20.2 ± 7.2 mmHg respectively. The SPW occurrence and amplitude significantly increased in response to meal, balloon distention and luminal bisacodyl, associated with 50.3% anal sphincter relaxation at baseline, which significantly increased to 59.0% after a meal, and 69.1% after bisacodyl. Often, full relaxation was achieved. The SPWs associated with gas expulsion had a significantly higher amplitude compared to SPWs without gas expulsion. SPWs could be seen to consist of clusters of high frequency pressure waves, likely associated with a cluster of fast propagating, circular muscle contractions. SPWs were occasionally observed in a highly rhythmic pattern at 1.8 ± 1.2 cycles/min. Unlike HAPWs, the SPWs did not obliterate haustral boundaries thereby explaining how gas can be expelled while solid content can remain restrained by the haustral boundaries. In conclusion, the SPW may become a biomarker for normal gas transit, the gastrocolonic reflex and extrinsic neural reflexes. The SPW assessment reveals coordination of activities in the colon, rectum and anal sphincters. SPWs may become of diagnostic value in patients with colonic dysmotility.
Photo-Fenton degradation of pollutants in wastewater is an ideal choice for large scale practical applications. Herein, two-dimensional (2D) in-plane CuS/Bi2WO6 p-n heterostructures have been ...successfully constructed by an in situ assembly strategy and characterized using XRD, XPS, SEM/TEM, EDX, UV-Vis-DRS, PL, TR-PL, ESR, and VB-XPS techniques. The XPS and the TEM results confirm the formation of CuS/Bi2WO6 heterostructures. The as-constructed CuS/Bi2WO6 showed excellent absorption in visible region and superior charge carrier separation efficiency due to the formation of a type-II heterojunctions. Under visible light irradiation, 0.1% CuS/Bi2WO6 heterostructure exhibited the best photo-Fenton-like catalytic performance. The degradation efficiency of Rhodamine B (RhB, 20 mg·L−1) can reach nearly 100% within 25 min, the apparent rate constant (kapp/min−1) is approximately 40.06 and 3.87 times higher than that of pure CuS and Bi2WO6, respectively. The degradation efficiency of tetracycline hydrochloride (TC-HCl, 40mg·L−1) can reach 73% in 50 min by employing 0.1% CuS/Bi2WO6 heterostructure as a photo-Fenton-like catalyst. The promoted photo-Fenton catalytic activity of CuS/Bi2WO6 p-n heterostructures is partly ascribed to its low carriers recombination rate. Importantly, CuS in CuS/Bi2WO6 heterostructures is conducive to the formation of heterogeneous photo-Fenton catalytic system, in which Bi2WO6 provides a strong reaction site for CuS to avoid the loss of Cu2+ in Fenton reaction, resulting in its excellent stability and reusability. The possible photo-Fenton-like catalytic degradation mechanism of RhB and TC-HCl was also elucidated on the basis of energy band structure analysis and radical scavenger experiments. The present study provides strong evidence for CuS/Bi2WO6 heterostructures to be used as promising candidates for photo-Fenton treatment of organic pollutants.
In this article, we propose a novel and effective system based on multiple cameras to extract the events for soccer matches. A precise ontological definition of the soccer events is still an open ...point. According to our definition, the events include the free kick, corner kick, penalty kick and the goal, because they are the representative shots for the audience to watch. The events are very important for highlights selection and sport data analysis. At present, the events including the ball and players information are selected and labeled manually from the images, which is a big workload for the staffs. Addressing this problem, our system provides an automatic extraction of the events. For soccer videos, our system first uses the local-based deep neural network for the ball and player detection from the input images. Then, we handle with the ball and player bounding boxes separately. For players, a player can be labeled as one of the three types: two teams or the referee, and a novel unsupervised U-encoder is designed for the player labeling. For soccer ball, the application of multiple cameras allows us to refine the ball detection results. We can get the world coordinate of ball according to the camera parameters and then rebuild the ball trajectory and the court in a top view. Based on the reconstructed map, we get the soccer events by motion analysis of ball trajectory and then apply the ball location and player classification results to display the events for each camera. The test results on real videos of European soccer league show the good detection and labeling performance of our system. We find all the events in the test videos. Our proposed system can deal with many complex cases such as occlusion and pose variation that happen frequently in real applications.
Semiconductor photocatalytic hydrogen production technology is a pollution‐free and low‐cost technology, which is principal to alleviate the energy crisis. The metal–organic frameworks (MOFs)‐based ...materials have been widely used in this field because of their regular and controllable pore structure and high specific surface area. Accordingly, the recent progress of MOFs‐based materials in the production of hydrogen through water splitting is reviewed. First, the mechanism of photocatalytic hydrogen production and the existing problems are proposed and then their advantages in photocatalytic hydrogen production and various photocatalytic hydrogen production catalysts based on MOFs are summarized. Subsequently, several methods to improve their photocatalytic hydrogen production property are summarized. Finally, some views on the prospects and challenges of the use of MOFs‐based catalysts for photocatalytic hydrolysis are expounded. Although some reviews associated with MOFs for solar‐driven H2 production have been published, most of them focus on the classification of MOFs photocatalysts. This is the first comprehensive review concentrating on the strategies for optimizing the photocatalytic activity of MOFs‐based materials for H2 production. It is believed that the suggestions provided here can help to study MOFs‐based photocatalytic reactions and to further promote the development of this research direction in the future.
Metal–organic frameworks (MOFs) possess unique pore structure, large specific surface area, modifiable skeleton, and highly crystalline nature, which can not only supply abundant reactive sites, but also extend the light response range and promote the charge carrier migration. Thus, they are widely studied in the field of photocatalysis and considered as good candidates for photocatalyzing the water reduction.
The calcium leaching effect leads to a decrease in the impermeability of the impervious curtain. The inverse analysis strategy was introduced in this study because the calcium leaching parameters of ...the curtain are not easy to determine. An orthogonal design and the finite element method were used in the strategy. The time-series data of hydraulic head and leakage volume were applied to construct the objective function. The extreme learning machine (ELM) was proposed to build the reflection sets. Genetic algorithm (GA), simulated annealing (SA), sparrow search algorithm (SSA), and particle swarm optimization (PSO) were employed to accelerate the iterative search for the target parameters. The target parameters of the calcium leaching model were used for finite element verification by comparing the monitored and simulated values. The simulated values of hydraulic head and leakage by PSO show good agreement with measurements. The evolution of the curtain permeability coefficient in 100 years was analyzed. The results demonstrate the strategy’s feasibility in determining the curtain’s calcium leaching parameters and permeability coefficients.
Abnormal colonic motility may be associated with dysfunction of the autonomic nervous system (ANS). Our aim was to evaluate if associations between colonic motor patterns and autonomic neural ...activity could be demonstrated by assessing changes in heart rate variability (HRV) in healthy volunteers. A total of 145 colonic motor patterns were assessed in 11 healthy volunteers by High-Resolution Colonic Manometry (HRCM) using an 84-channel water-perfused catheter. Motor patterns were evoked by balloon distention, a meal and luminal bisacodyl. The electrocardiogram (ECG) and cardiac impedance were assessed during colonic manometry. Respiratory sinus arrhythmia (RSA) and root mean square of successive differences of beat-to-beat intervals (RMSSD) served as measures of parasympathetic reactivity while the Baevsky's Stress Index (SI) and the pre-ejection period (PEP) were used as measures of sympathetic reactivity. Taking all motor patterns into account, our data show that colonic motor patterns are accompanied by increased parasympathetic activity and decreased sympathetic activity that may occur without eliciting a significant change in heart rate. Motor Complexes (more than one motor pattern occurring in close proximity), High-Amplitude Propagating Pressure Waves followed by Simultaneous Pressure Waves (HAPW-SPWs) and HAPWs without SPWs are all associated with an increase in RSA and a decrease in SI. Hence RSA and SI may best reflect autonomic activity in the colon during these motor patterns as compared to RMSSD and PEP. SI and PEP do not measure identical sympathetic reactivity. The SPW, which is a very low amplitude pressure wave, did not significantly change the autonomic measures employed here. In conclusion, colonic motor patterns are associated with activity in the ANS which is reflected in autonomic measures of heart rate variability. These autonomic measures may serve as proxies for autonomic neural dysfunction in patients with colonic dysmotility.
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