Colorectal cancer (CRC) prevention requires early detection and removal of adenomas. We aimed to develop a computational model for real-time detection and classification of colorectal adenoma. ...Computationally constrained background based on real-time detection, we propose an improved adaptive lightweight ensemble model for real-time detection and classification of adenomas and other polyps. Firstly, we devised an adaptive lightweight network modification and effective training strategy to diminish the computational requirements for real-time detection. Secondly, by integrating the adaptive lightweight YOLOv4 with the single shot multibox detector network, we established the adaptive small object detection ensemble (ASODE) model, which enhances the precision of detecting target polyps without significantly increasing the model's memory footprint. We conducted simulated training using clinical colonoscopy images and videos to validate the method's performance, extracting features from 1148 polyps and employing a confidence threshold of 0.5 to filter out low-confidence sample predictions. Finally, compared to state-of-the-art models, our ASODE model demonstrated superior performance. In the test set, the sensitivity of images and videos reached 87.96% and 92.31%, respectively. Additionally, the ASODE model achieved an accuracy of 92.70% for adenoma detection with a false positive rate of 8.18%. Training results indicate the effectiveness of our method in classifying small polyps. Our model exhibits remarkable performance in real-time detection of colorectal adenomas, serving as a reliable tool for assisting endoscopists.
This paper is a review of recent work done on accelerated stress tests in the study of PEM fuel cell durability, with a primary focus on the main components of the membrane electrode assembly (MEA). ...The accelerated stressors for each component under different conditions are outlined, in an attempt to gain a detailed understanding of cell degradation with respect to microstructural change and performance attenuation in the perfluorosulfonic acid membrane, catalyst, and gas diffusion layers. Various techniques for evaluating the components' performance are presented, along with representative mitigation strategies. In addition, different degradation mechanisms proposed in recent publications are briefly reviewed.
In this study, the machining characteristics of pulse short arc milling (SEAM) Ti6Al4V alloy were studied. In this regard, the influence of SEAM parameters on the material removal rate (MRR), ...relative electrode wear ratio (REWR), and surface integrity of Ti6Al4V is studied. A wide variety of processing parameters, including different voltages, frequencies, duty cycles, flushing pressures, electrode rotation speeds, and electrode feed rates, are considered in the investigation. Scanning electron microscope (SEM), energy dispersive spectrograph (EDS), and micro-hardness analysis are applied to analyze results. Moreover, a multichannel data acquisition system is used to measure gap voltage and gap current. Obtained results cover the variation of MRR, REWR, surface roughness (Ra), average resolidified layer thickness, and average heat-affected zone thickness with different processing parameters. Furthermore, the electrode surface morphology and chemical composition of the negative growth of REWR are studied. Based on the obtained results, the microstructure of the resolidified layer and heat-affected zone of the workpiece cross-section is confirmed. This study provides a basis for the high-quality pulse SEAM technology of difficult-to-machine (DTM) materials to enter the semi-finishing field.
SUMMARY
The Gonghe Basin in the northeast Tibetan Plateau presents significant potential for hot dry rock (HDR) geothermal resources. A 1990 Mw 6.4 earthquake in the basin furthers the need for an ...improved understanding of its sedimentary structure. In this study, we utilize data from a dense seismic array of 88 short-period seismometers deployed at an interstation spacing of approximately 3 km to scrutinize the sedimentary structure of the Gonghe Basin. By analysing teleseismic P waveforms, we identify P-to-S converted waves (Ps wave) originating from the sedimentary basement. We then determine the delay time between the Ps waves and the direct P waves (P wave) through waveform cross-correlation. By integrating this delay time with empirical velocity structure models, HDR borehole data and results from teleseismic receiver function analysis, we derive a sediment thickness model of the Gonghe Basin for the Qabqa geothermal area. Our findings reveal a gradual increase in sediment thickness from around 500 m in the east to approximately 3000 m in the west, which is consistent with other geophysical surveys and borehole data. The thick sediments in the basin could potentially serve as an excellent thermal storage cover for HDR. The strong ground motion simulation using our sediment thickness model shows that thick sediments can amplify seismic waves, increasing the risk of seismic hazards. Moreover, our study indicates that the clear Ps waves can be effectively extracted to construct a dependable sediment thickness model using teleseismic P waves recorded by a short-period dense seismic array.
•Two types of high-temperature geothermal resources are identified in the Gonghe-Guide area.•The current knowledge of the geology, geophysics, geochemistry and geothermal investigations are ...described.•Comparative analysis of the characteristics of the geothermal resources between the Gonghe-Guide area and other geothermal fields is conducted.
The new discoveries of the high-temperature geothermal resources in the Gonghe-Guide area mark the significant breakthrough in the exploration of geothermal resources in the northeastern Tibetan Plateau. In this paper, we systematically reviewed all the available data presented in the geological, geophysical, geochemical and fundamental geothermal works that have been undertaken, in order to fully understand the characteristics of the geothermal resources in this area.
The main features of the geothermal resources in this area can be summarized as follows: two distinct types of high-temperature geothermal resources have been identified, i.e., the hot dry rock (HDR) and hydrothermal geothermal resources in the Qiabuqia and Zhacang geothermal areas, respectively. The HDR reservoir in the Qiabuqia geothermal area is mainly composed of the Indosinian granitic rocks with the temperature gradient of 39 to 45.2 °C/km, thermal conductivity of 2.07 to 3.10 W/(m•K), and radiogenic heat production rate (RHPR) of 1.17 to 5.81 μW/m3. The geothermal water in the Zhacang geothermal area is meteoric origin with the relative enrichment of δ18O caused by the fluid-rock interaction under the high temperature condition. The chemical type of the geothermal water is SO4•Cl-Na. The local crustal partial melting or magma chamber at the 15 ∼ 35 km beneath the Gonghe basin, which is characterized with a relatively high geothermal background induced by the continental collision between the Indian and Eurasian plates, is the main cause of the HDR resources, whereas the hydrothermal resources in the Zhacang geothermal area are related to the deep circulation of the meteoric water in the damage zone of the west-east trending conductive Zhacang fault and upward transporting at the intersection of the Zhacang and the NNW-trending impermeable Reguang faults. Such a detailed review of the both geothermal resources can provide a glimpse of the geothermal resources of the northeastern Tibetan plateau as well as provide the direction for the subsequent searches for high-temperature resources elsewhere in China.
Inflammatory bowel disease (IBD) is a refractory disorder characterized by chronic and recurrent inflammation. The progression and pathogenesis of IBD is closely related to oxidative stress and ...irregularly high concentrations of reactive oxygen species (ROS). A new oxidation-responsive nano prodrug was constructed from a phenylboronic esters-modified carboxylmethyl chitosan (OC-B) conjugated with berberine (BBR) that degrades selectively in response to ROS. The optimized micelles exhibited well-controlled physiochemical properties and stability in a physiological environment. OC-B-BBR micelles could effectively encapsulate the anti-inflammatory drug berberine and exhibit ideal H
O
-triggered release behavior as confirmed by
drug loading and release studies. The
anti-inflammatory effect and regulation of gut microbiota caused by it were explored in mice with colitis induced by dextran sodium sulfate (DSS). The results showed that OC-B-BBR significantly ameliorated colitis symptoms and colon damage by regulating the expression levels of IL-6 and remodeling gut microbiota. In summary, this study exhibited a novel BBR-loaded Carboxylmethyl Chitosan nano delivery system which may represent a promising approach for improving IBD treatment.
This paper proposes a novel combined machining approach. The approach is focused on combining short electric arc machining and electrochemical machining (SEAM-ECM). It aims to improve the surface ...integrity of TC4 titanium alloy by adding compressed air and electrolyte into the SEAM. This approach can change the material removal mechanism of the conventional SEAM and improve the gap flow field distribution and discharge state using the dual fluid properties of electrolyte and air mixed medium. Flow field simulation demonstrates the effects of gas addition on the state of the gap flow field and the electrical conductivity of the mixed medium. The experiments compare the effects of the presence or absence of air and the electrical conductivity of the solution on the machining performance. The results show that SEAM-ECM with electrolyte and air reduces the relative electrode wear rate (REWR) while maintaining a good material removal rate (MRR). In addition, SEAM-ECM utilizes the electrolytic effect to weaken the recast layer compared to SEAM with deionized water and air. The addition of high-speed air reduces defects such as melt drops, particles, and holes. It performs with higher precision and finish than ECM alone, and the overall surface integrity is significantly improved.
► We summarize established conditioning protocols for polymer electrolyte membrane fuel cells. ► We review various reported conditioning methods and their underlying mechanisms. ► We provide ...guidelines for researchers/practitioners to accelerate their conditioning processes. ► We identify areas for future research efforts.
A newly fabricated polymer electrolyte membrane (PEM) fuel cell usually needs a so-called break-in/conditioning/incubation period to activate it and reach its best performance. Typically, during this activation period the cell performance increases gradually, and then reaches a plateau without further increase. Depending on the membrane electrode assemblies, this process can take hours and even days to complete, which consumes a considerable amount of hydrogen fuel, leading to a higher operating cost. To provide for accelerated conditioning techniques that can complete the process in a short time period, this paper reviews established conditioning protocols and reported methods to condition PEM single cells and stacks, in an attempt to summarize available information on PEM fuel cell conditioning and the underlying mechanisms. Various techniques are arranged into two categories: on-line conditioning and off-line conditioning. For each technique, the experimental procedure and outcomes are outlined. Finally, weaknesses of the currently used conditioning techniques are indicated and further research efforts are proposed.
—The state of urban road traffic flow shows discontinuity and jumping phenomenon in the process of running. There was a data gap in the collected traffic flow data. Through the data analysis, it was ...found that the traffic flow state had the characteristics of multimode, mutation, inaccessibility, divergence and hysteresis, which were similar to the mutation characteristics of the basic model of catastrophe theory when the system state changed. The cusp catastrophe model of traffic flow based on traffic wave theory was established by analyzing the movement process of traffic flow. In this model, the traffic density was taken as the state variable, and traffic flow and wave speed were taken as the control variable. Referring to the basic idea of catastrophe theory, the solution method of the model was given, and the structural stability of the traffic flow state was analyzed. Through the critical equilibrium surface equation, the stability of the extreme value of the system potential function can be analyzed, and the bifurcation set equation when the traffic flow state changed can be obtained, which can be used to determine the critical range of the structural stability of the system. This paper discussed and analyzed the changing trend and constraint relationship among the wave speed, traffic density and traffic flow when the traffic flow state changed suddenly in different running environments. The analysis results were consistent with the actual road traffic flow state. A case was given, and the results showed that the cusp catastrophe model could describe the relationship among the three parameters of traffic flow from three-dimensional space, and could effectively analyze the internal relationship of the parameters when the traffic flow state changed. The validity of the model and analysis method was verified. The goal of this paper is to provide an analysis method for the judgment of urban road traffic state.
Ulcerative colitis (UC) impairs the health-related quality of life (HRQOL). The difference in HRQOL between patients with mild and moderately active UC is not well-defined. Few studies have been ...conducted to explore the factors that influence HRQOL in Chinese patients. Our study aims were to (1) compare HRQOL of mildly active UC patients with moderate patients; (2) explore the factors that influence HRQOL in Chinese patients with UC; and (3) analyze demographic and disease characteristics of UC in China.
A total of 110 mild and 114 moderate patients with UC were enrolled. The demographic and disease characteristics were recorded. HRQOL was measured by the Chinese version of the inflammatory bowel disease questionnaire (IBDQ) between mild and moderate patients, male and female patients, and different disease distributions. Stepwise regression analysis was used to assess factors influencing the IBDQ score.
Patients with moderate UC had significantly lower IBDQ total scores compared to patients with mild UC (P=0.001). The IBDQ total score had a negative correlation with the Mayo score (r=-0.263, P<0.001). Stepwise regression analysis showed that the disease activity index and gender had an influence on the IBDQ total score (P<0.05). The female patients had a lower score than the male patients (P<0.05), especially in the emotional function domain (P=0.002). Different disease distributions were not statistically significant in the IBDQ total score (P=0.183).
UC has a negative influence on HRQOL. HRQOL in patients with moderate UC was lower than HRQOL in patients with mild UC, as measured by the IBDQ. UC disease activity has a negative correlation with HRQOL. Gender and the disease activity index are important factors involved in the impairment of HRQOL in Chinese patients with UC. Chinese females may benefit from increased psychological care as part of UC therapy.
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