A YOLOX-Based Automatic Monitoring Approach of Broken Wires in Prestressed Concrete Cylinder Pipe Using Fiber-Optic Distributed Acoustic Sensors.

Wire breakage is a major factor in the failure of prestressed concrete cylinder pipes (PCCP). In the presented work, an automatic monitoring approach of broken wires in PCCP using fiber-optic distributed acoustic sensors (DAS) is investigated. The study designs a 1:1 prototype wire break monitoring experiment using a DN4000 mm PCCP buried underground in a simulated test environment. The test combines the collected wire break signals with the previously collected noise signals in the operating pipe and transforms them into a spectrogram as the wire break signal dataset. A deep learning-based target detection algorithm is developed to detect the occurrence of wire break events by extracting the spectrogram image features of wire break signals in the dataset. The results show that the recall, precision, F1 score, and false detection rate of the pruned model reach 100%, 100%, 1, and 0%, respectively; the video detection frame rate reaches 35 fps and the model size is only 732 KB. It can be seen that this method greatly simplifies the model without loss of precision, providing an effective method for the identification of PCCP wire break signals, while the lightweight model is more conducive to the embedded deployment of a PCCP wire break monitoring system.

Influences of governance mechanisms on patients' usage intention: A study on web-based consultation platforms.

The study object is the doctor-patient online community, an online health service model with the greatest growth potential during the global COVID-19 pandemic. In the web-based medical market, patients are in a weak position, relying on web-based medical platform operators to ensure medical service quality. Following social exchange theory, this empirical study divides governance mechanisms into three-supervision, reputation, and communication-to determine their influence on online patients willingness to use web-based medical platforms. It also explores the moderating effect of perceived uncertainty on the influence of social exchange and transaction cost theory. A questionnaire survey was conducted to determine online patients' attitudes toward medical service providers including physicians and medical websites. Hierarchical linear regression analysis showed the significant positive effect of the supervision, reputation, and communication mechanisms on online patients' usage willingness. Perceived uncertainty of doctors' behavior has a significant moderating effect on the relationship between the three mechanisms and online patients' usage willingness. Website-perceived uncertainty moderates the relationship between the supervision and reputation mechanisms and online patients' usage willingness. This study provides a reference for improving online patients' usage willingness through the platform governance of Internet medical treatment.

Combined effects of cues influencing patients' purchasing behavior in online health-care communities: qualitative comparative analysis based on cue utilization theory.

BACKGROUND: The sudden outbreak of COVID-19 in early 2020 pushed the online health-care communities (OHCs) into the public eye in China. However, OHCs is an emerging service model, which still has many problems such as low patient trust and low patient utilization rate. Patients are the users and recipients of web-based medical services, as well as the core of medical services. Thus, based on cue utilization theory, this paper studies combination effect of influencing factors in patients' purchase of web-based medical services through the qualitative comparative analysis method of fuzzy sets (fsQCA). METHODS: This paper discards statistical methods based on variance theory-based relationships between explanatory and explained variables and uses a construct theory-based fuzzy set qualitative comparative analysis (fsQCA) approach to elucidate such complex relationships of patients' online purchasing behavior. We use a crawler to automatically download information from Haodf.com. This study crawled data in August 2020, involving 1210 physicians. RESULTS: Service price, reputation and service quality are the key factors for patients' purchasing behavior. Physician's online reputation, online medical service price, number of published articles, mutual-help group, and appointment registration affect patients' purchasing behavior by means of weighted variation. Only when a high scope of internal attribute-related cue elements and a low scope of external attribute-related cue elements are combined with each other in a specific form, patients will generate purchase behavior. CONCLUSION: This paper clarifies the complex causes that promote to patients' purchasing behavior of web-based medical services, enriches and develops the relevant theories in the field of consumer purchasing behavior and online health-care communities market research, and has implications for governments, platforms, physicians and patients in the event of web-based medical service purchases.

Motivation to participate in secondary science communication.

The rise of social media provides convenient mechanisms for audiences to participate in secondary science communication (SSC). The present study employs the theory of consumption values and theory of planned behavior to predict audiences' SSC intentions. The results indicate that emotional value, social value, altruistic value, attitude, internal perceived behavioral control and subjective norm are significant predictors of audiences' intentions to share or to repost science content on their social media. These results suggest that the theory of consumption values, together with the theory of planned behavior, is a useful framework for understanding SSC behaviors.

Effectiveness of Interactive Tools in Online Health Care Communities: Social Exchange Theory Perspective.

BACKGROUND: Although the COVID-19 pandemic will have a negative effect on China's economy in the short term, it also represents a major opportunity for internet-based medical treatment in the medium and long term. Compared with normal times, internet-based medical platforms including the Haodf website were visited by 1.11 billion people, the number of new registered users of all platforms increased by 10, and the number of new users' daily consultations increased by 9 during the pandemic. The continuous participation of physicians is a major factor in the success of the platform, and economic return is an important reason for physicians to provide internet-based services. However, no study has provided the effectiveness of interactive tools in online health care communities to influence physicians' returns. OBJECTIVE: The effect of internet-based effort on the benefits and effectiveness of interactive effort tools in internet-based health care areas remains unclear. Thus, the goals of this study are to examine the effect of doctors' internet-based service quality on their economic returns during COVID-19 social restrictions, to examine the effect of mutual help groups on doctors' economic returns during COVID-19 social restrictions, and to explore the moderating effect of disease privacy on doctors' efforts and economic returns during COVID-19 social restrictions. METHODS: On the basis of the social exchange theory, this study establishes an internet-based effort exchange model for doctors. We used a crawler to download information automatically from Haodf website. From March 5 to 7, 2020, which occurred during the COVID-19 pandemic in China, cross-sectional information of 2530 doctors were collected. RESULTS: Hierarchical linear regression showed that disease privacy (ß=.481; P<.001), reputation (ß=.584; P<.001), and service quality (ß=.560; P<.001) had a significant positive effect on the economic returns of the physicians. The influence of mutual help groups on earnings increases with an increase in the degree of disease privacy (ß=.189; P<.001), indicating that mutual help groups have a stronger effect on earnings when patients ask questions about diseases regarding which they desire privacy. CONCLUSIONS: For platform operators, the results of this study can help the platform understand how to improve doctors' economic returns, especially regarding helping a specific doctor group improve its income to retain good doctors. For physicians on the platform, this study will help doctors spend their limited energy and time on tools that can improve internet-based consultation incomes. Patients who receive internet-based health care services extract information about a doctor based on the doctor's internet-based efforts to understand the doctor's level of professionalism and personality to choose the doctor they like the most. The data used in this study may be biased or not representative of all medical platforms, as they were collected from a single website.

Effects of Monovacancy and Divacancies on Hydrogen Solubility, Trapping and Diffusion Behaviors in fcc-Pd by First Principles.

The hydrogen blistering phenomenon is one of the key issues for the target station of the accelerator-based neutron source. In the present study, the effect of monovacancies and divacancies defects on the solution, clustering and diffusion behaviors of H impurity in fcc-Pd were studied through first principles calculations. Our calculations prove that vacancies behave as an effective sink for H impurities. We found that, although the H-trap efficiency of the larger vacancy defect was reduced, its H-trap ability strengthened. There is a short-ranged area around the vacancy defects in which H impurities tend to diffuse to vacancy defects, gather and form hydrogen bubbles. Therefore, the characteristic of large vacancy defects formation in materials should be considered when screening anti-blistering materials for neutron-producing targets or when designing radiation resistant composite materials.

Ultrastable Triazine-Based Covalent Organic Framework with an Interlayer Hydrogen Bonding for Supercapacitor Applications.

Covalent organic frameworks (COFs) with redox-active units are a class of ideal materials for electrochemical-energy-storage devices. A novel two-dimensional (2D) PDC-MA-COF with redox-active triazine units was prepared via aldehyde-amine condensation reaction by using 1,4-piperazinedicarboxaldehyde (PDC) and melamine (MA) as structural units, which possessed high specific surface area (SBET = 748.2 m2 g-1), narrow pore width (1.9 nm), large pore volume (1.21 cm3 g-1), and high nitrogen content (47.87%), for pseudocapacitance application. The interlayer C-H···N hydrogen bonding can "lock" the relative distance between two adjacent layers to avoid an interlayer slip, which is more conducive to maintaining the ordered pore structure of the COF and improving a fast charge transfer between the electrode interface and triazine units. The PDC-MA-COF exhibited an excellent electrochemical performance with the highest specific capacitance of 335 F g-1 along with 19.71% accessibility of the redox-active triazine units in a three-electrode system and 94 F g-1 in a two-electrode system at 1.0 A g-1 current density. Asymmetric supercapacitor of PDC-MA-COF//AC assembled using PDC-MA-COF and activated carbon (AC) as positive and negative electrode materials, respectively, exhibited a high energy density of 29.2 W h kg-1 with a power density of 750 W kg-1. At the same time, it also showed an excellent cyclic stability and could retain 88% of the initial capacitance after 20 000 charge-discharge cycles, which was better than those of the most of the analogous materials reported previously. This study provided a new strategy for designing redox-active COFs for pseudocapacitive storage.

Shielding design of a target station and radiation dose level investigation of proton linac for a compact accelerator-driven neutron source applied at industrial sites.

The shielding design for a compact accelerator-driven neutron source (CANS) that is applied in industries was studied using both theoretical simulations and experimental measurements. Neutron shielding material composition for CANS was optimized by coupling the genetic algorithm with the Monte Carlo code. A multi-layer shielding structure was developed and successfully applied to a CANS target station. The high radiation dose of CANS proton linac was investigated in detail on the basis of experimental measurements, and the radiation dose was significantly reduced by replacing the material of its bellow pipes.

[Preparation of Biological Functional Magnetic Nanoparticles and Study on the Effect of Guiding Endothelial Progenitor Cells In Vitro].

Coprecipitation method was used to prepare triiron tetroxide magnetic nanoparticles enclosed in L-DOPA, and then EDC was used to activate the carboxyl group of L-DOPA after the nanoparticles were synthesized. The carboxyl group of L-DOPA formed amide bond with specific amino on the aptamer by dehydration condensation reaction. The surfaces of magnetic nanoparticles were modified with aptamer and L-DOPA. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), nanoparticle size analysis (SEM), magnetic measurement (VSM) and other testing methods were used to detect the magnetic nanoparticles in different stages. The endothelial progeni-tor cells (EPCs) were cocultured with the surface modified magnetic nanoparticles to evaluate cell compatibility and the combination effect of nanoparticles on EPCs in a short period of time. Directional guide of the surface-modified magnetic nanoparticles to endothelial progenitor cells (EPCs) was evaluated under an applied magnetic field and simulated dynamic blood flow condition. The results showed that the prepared magnetic nanoparticles had good magnetic response, good cell compatibility within a certain range of the nanoparticle concentrations. The surface modified nanoparticles could combine with EPCs effectively in a short time, and those nanoparticles combined EPCs can be directionally guided on to a stent surface under the magnetic field in the dynamic flow environment.

Guidance of stem cells to a target destination in vivo by magnetic nanoparticles in a magnetic field.

Stem cells contribute to physiological processes such as postischemic neovascularization and vascular re-endothelialization, which help regenerate myocardial defects or repair vascular injury. However, therapeutic efficacy of stem cell transplantation is often limited by inefficient homing of systemically administered cells, which results in a low number of cells accumulating at sites of pathology. In this study, anti-CD34 antibody-coated magnetic nanoparticles (Fe3O4@PEG-CD34) are shown to have high affinity to stem cells. The results of hemolysis rate and activated partial thromboplastin time (APTT) tests indicate that such nanoparticle may be used safely in the blood system. In vitro studies showed that a nanoparticle concentration of 100 µg/mL gives rise to a significant increase in cell retention using an applicable permanent magnet, exerting minimal negative effect on cell viability and migration. Subsequent in vivo studies indicate that nanopartical can specifically bind stem cells with good magnetic response. Anti-CD34 antibody coated magnetic nanoparticle may be used to help deliver stem cells to a lesion site in the body for better treatment.