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BackgroundHeat pipe cooled reactors (HPR) have good inherent safety. In the early stage of core design, heat pipe failure accident is usually one of the design basis accidents that need to be considered.PurposeThis study aims to analyze the neutronic-thermalhydraulic coupling performance of a new type of megawatt heat pipe reactor.MethodsFirstly the heat pipe cooled reactor system physical models, including the point kinetics model, the core and heat pipe model and radiation heat transfer model for the inner core cavity, were established according to the designed HPR prototype composed of heat pipe stack and supercritical CO2 Brayton cycle system with thermal power of 3.5 MW. Then, the finite element software FLUENT was employed to conduct neutronic-thermalhydraulic coupling calculation for the three-dimensional reactor core under the steady-state and heat pipe failure accidents. Finally, the core safety performance was evaluated by comparing the peak temperature of each component with the melting point of material.Results & ConclusionsThe results show the designed HPR has good safety performance under the steady state and single heat pipe failure. Radiation heat transfer in the core cavity cannot be ignored in the serious cascade three heat pipe failure accident in high power region. Meanwhile, the design cannot withstand cascading four heat pipe failure. By comparing the peak temperature of the multiple heat pipe failure with the peak temperature of the single heat pipe failure, it shows that the design has good inherent safety.

With the increased attention given to culture in recent years in developmental psychology, there remains a need to overcome limitations of certain existing approaches. Such limitations include tendencies to adopt approaches to culture that are overly global, ignore its symbolic aspects, and that reduce culture to an individual difference variable that can be assessed by conventional psychological scale measures. In the present article, we focus on theoretical and methodological challenges involved in conceptualizing and measuring culture. In the first section, we discuss theoretical work on culture, including how to define culture and considerations to take into account when operationalizing culture, such as attending to its symbolic aspects, its embodiment in everyday social practices, and its dynamic nature. In the second section, we describe the theoretical and methodological approaches that we have adopted in incorporating culture in our own cross-cultural developmental research. Finally, in conclusion, we identify key challenges that arise in integrating attention to culture with psychological work in neuroscience, making the case for the continued importance of attention to culture even with the move toward neurologically based accounts of developmental processes. [ABSTRACT FROM AUTHOR]

Cultural studies on sacrifices made by emerging adults have given limited attention to the cost involved. We addressed this issue in studies among U.S. and Chinese emerging adults. Assessing real-life instances of sacrifice, Study 1 (N = 130) showed that Chinese sacrifice for their parents in a higher cost way than do European Americans. In a vignette-based experiment, Study 2 (N = 254) demonstrated that family obligation motivates high-cost sacrifice among Chinese emerging adults but not among European American emerging adults. The findings underscore the importance in cultural research of recognizing the distinctive impact of cultural and immigration effects, while highlighting methodological limitations associated with the use of scale measures. [ABSTRACT FROM AUTHOR]

Microsurgery is a highly complex surgical procedure on small body parts performed by a dedicated surgical team. An operating microscope is typically used to obtain a precise view of the soft tissues. The complexity of the microsurgical procedure makes it a suitable application of virtual/augmented reality technology for training purpose. In this paper, we present an overview of our simulator and then describe in details the visualization work that reconstructs the magnified view of the operating area from medical images. The visualization component is based entirely on our newly proposed dynamic linear level octree (DLLO)-based volume rendering methods. In comparison with the conventional ray casting algorithms, our computational method achieves fast rendering speed, reduces hardware requirement and combines surface-volume rendering for realistic and interactive PC-based medical simulations. The new algorithms are suitable for rendering dynamic medical data which are increasingly popular clinically. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical efficacy of modified electroconvulsive therapy (MECT) in patients with schizophrenia and provide a reference for the selection of safe and effective treatment options in clinical practice., Methods: A total of 200 patients with schizophrenia, who were admitted to Wuhan Wudong Hospital Psychiatric Hospital from January 2019 to December 2020, were selected as the study subjects. They were divided into an observation group and a control group (100 cases in each group) according to a random number table. The control group was treated with conventional antipsychotics (risperidone and aripiprazole), and the observation group was given conventional antipsychotics (risperidone and aripiprazole) with MECT. After 8 weeks, the clinical efficacy, cognitive and memory functions and the occurrence of adverse reactions between the two groups were compared., Results: The total clinical effective rate of the observation group was 90%, which was higher than that of the control group (74%), and the difference was statistically significant (p<0.05). The Wisconsin Card Sorting Test results of the observation group were better than those of the control group, and the cognitive function of the observation group was better than that of the control group (p<0.05). The Wechsler Adult Intelligence Scale-Fourth Edition index of the observation group was higher than that of the control group, and the memory function of the observation group was better than that of the control group (p<0.05). The overall incidence of adverse reactions in the observation group was lower than that in the control group, and the difference was statistically significant (p=0.001)., Conclusion: The application of MECT in patients with schizophrenia can produce a good clinical curative effect, which is beneficial to the improvement and promotion of memory and cognitive functions in patients. Since the occurrence of adverse reactions is controllable, and safety is ideal, MECT has value in clinical application.

Chemoembolization is an important therapeutic procedure. A catheter was navigated to the artery that feeds the tumor, and chemotherapy drugs and embolus are injected directly into the tumor. There is a risk that embolus may lodge incorrectly and deprive normal tissue of its blood supply. This paper focuses on visualization of the flow particles in simulation of chemotherapy drugs injection for training of hand-eye coordination skills. We assume that the flow follows a defined path in the hepatic vascular system from the catheter tip. The vascular model is constructed using sweeping and blending operations. Quadrilaterals which are aligned to face the viewer are drawn for the trail of each particle. The quadrilateral in the trail is determined using bilinear interpolation. On simulated fluoroscopic image, the flow is rendered as overlaying and semitransparent quadrilaterals representing the particles' trails. This visualization model achieves a good visual approximation of the flow of particles inside the vessels under fluoroscopic imaging.

In vertebroplasty, physician relies on both sight and feel to properly place the bone needle through various tissue types and densities, and to help monitor the injection of PMMA or cement into the vertebra. Incorrect injecting and reflux of the PMMA into areas where it should not go can result in detrimental clinical complication. This paper focuses on the human-computer interaction for simulating PMMA injection in our virtual spine workstation. Fluoroscopic images are generated from the CT patient volume data and simulated volumetric flow using a time varying 4D volume rendering algorithm. The user's finger movement is captured by a data glove. Immersion CyberGrasp is used to provide the variable resistance felt during injection by constraining the user's thumb. Based on our preliminary experiments with our interfacing system comprising simulated fluoroscopic imaging and haptic interaction, we found that the former has a larger impact on the user's control during injection.

A PC based system for simulating image-guided interventional neuroradiological procedures for physician training and patient specific pretreatment planning is described. The system allows physicians to manipulate and interface interventional devices such as catheters, guidewires, stents and coils within 2-D and hybrid surface and volume rendered 3-D patient vascular images in real time. A finite element method is employed to model the interaction of the catheters and guidewires with the vascular system. Fluoroscopic, roadmapping and volume rendered 3-D presentations of the vasculature are provided. System software libraries allow for the use of commonly employed catheters, guidewires, stents and occluding coils of various shapes and sizes. The results of an initial clinical validation suggest that the experience gained from our simulator is comparable with that of using a vascular phantom. We are conducting further validation with the aim of providing patient specific pretreatment planning.