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The single value fluctuation of impact work occurs frequently in high strength steel, especially for medium or super thick plates. With respect to the single value fluctuation of impact work in 700 MPa low alloy thin tempered plate, the present study carried out a comprehensive and comparative analysis through metallographic microstructure, second-phase precipitated particle and inclusion distribution. The results show that the microstructure type, grain boundary ratio of HAGBs/LAGBs, grain size and orientation of the specimens with 37 J and 7 J impact work are basically the same. The two specimens show excellent process-microstructure consistency, which fully indicate that the temperature fields of the two specimens are consistent. Since the temperature field is basically the same, the (Ti, Nb, Mo)C compound precipitated particles in the two specimens maintain a good Baker-Nutting relationship with the matrix, and the interface between the precipitated particles and the matrix maintain a stable coherent/semi-coherent relationship. The main reason for the decrease of impact work of tempered plate is related to the distribution of inclusions. There are more spherical and square large size inclusion particles and microcracks in the specimen with lower impact work. Among them, the large square inclusion particles dominate mostly. And with the increase of the plastic deformation degree of the metal matrix, the large square inclusion has an obvious evolution by separation from the matrix to forming microcracks, and then to fracture.

To alleviate social problems in agriculture such as aging and labor force shortages, automatic growth monitoring based on image measurement has been introduced to tomato cultivation in greenhouses. The overlap of leaves and fruits makes precise observations challenging. In this study, we applied context recognition to tomato growth monitoring by using a Bayesian network. The proposed method combines image recognition using convolutional networks and context recognition using Bayesian networks. It enables not only the recognition of individual tomatoes but also the evaluation of tomato plants. An accurate number of tomatoes and the condition of the stocks can be estimated based on the number of ripe and unripened tomatoes in addition to their density information. The verification experiments clarified that a more accurate number of tomatoes could be estimated than with simple tomato detection, and the stock states could also be evaluated correctly. Compared to conventional methods, the method used in this study has improved tomato decision accuracy by 23%.

Rapid heating is a promising technique for achieving excellent mechanical properties. This study innovatively applies rapid heating to a novel Ti–Mo martensite steel through in-situ observation experiments. By comparing the microstructure evolutions at heating rates of 1 and 30 °C/s, the relationship between microstructure and property evolution was elucidated. The results indicate that the refined austenite grains resulting from rapid heating stem from enhanced grain nucleation, accumulated dislocations, and the increased formation of new carbides under the large superheat. Furthermore, carbide maturation predominates during the slow heating process, while rapid heating accelerates new carbide precipitation with limited carbide maturation. Moreover, during rapid heating, both coherent and non-coherent relationships were observed between the (Ti, Mo, Fe)C particles and the martensite matrix, demonstrating a remarkable pinning effect on grain boundary migration. Nevertheless, during slow heating, large-sized (Ti, Mo)C carbides were formed, presenting a non-coherent relationship with the martensite matrix. Additionally, the primary differences in strength caused by rapid heating compared to slow heating include grain refinement, dislocation, and precipitation strengthenings, with dislocation strengthening playing the dominant role.

Indirect matrix converters (IMC) feature an AC-AC configuration without an intermediate DC link and wide application prospects in wind power generation, AC transmission, and various other fields, known for their sinusoidal input/output, high power density, and superior operating efficiency. However, these converters inevitably generate common-mode voltages during modulation operations, causing motor damage and affecting the reliable functioning of the systems. This paper aims to enhance the operational reliability of IMCs by suppressing common-mode voltage output, and focuses on five classical modulation methods for suppressing common-mode voltage peaks by 42.3% in IMCs, including the modulation method for synthesizing reference output voltage vectors using adjacent four effective voltage vectors at the inverter stage, that for synthesizing reference output voltage vectors using adjacent three effective voltage vectors at the inverter stage, that for synthesizing reference current vectors using adjacent three effective current vectors at the rectifier stage, that for synthesizing reference current vectors using two adjacent 120° effective current vectors plus a zero-current vector at the rectifier stage, and that for synthesizing reference current vectors using weighted three effective current vectors at the rectifier stage. By modeling the effective value (root mean square, rms) of output common-mode voltages, which incorporates the influence of voltage transfer ratios on these values, a quantitative analysis was conducted to explore the variation patterns of the rms value of common-mode voltages. Following this, an evaluation was performed on the suppression capability of different modulation methods on common-mode voltages. The comparative analysis results indicated that the space vector modulation method of synthesizing reference voltage using adjacent four effective voltage vectors at the inverter stage exhibited the best suppression effect on the rms value of common-mode voltages in IMCs. Additionally, the correctness of the theoretical analysis results was verified through simulations and experiments.

To examine flavor variations in Xuanwei ham due to different cooking methods, we selected one-year cured Xuanwei ham and applied four techniques: dry frying (DF), baking (BA), steaming (ST), and boiling (BO). Organoleptic evaluation revealed ST received the highest overall sensory score. High-performance liquid chromatography (HPLC) revealed that the total nucleotide content was significantly different (P 1). This study aimed to support comprehensive research on the flavor characteristics of cooked Xuanwei ham and guide the selection of appropriate processing methods.

Ratiometric DNA biosensors, which utilize DNA as the recognition element and integrate dual signals from diverse sensing platforms including fluorescence, electrochemistry, and surface-enhanced Raman scattering (SERS), have demonstrated remarkable proficiency in detecting a wide range of targets. In this review, we showcase the significant progress achieved by ratiometric biosensors. Firstly, ratiometric biosensors have made notable advancements in analyzing real samples. These include the analysis of pH values near cancer cells, quantification of miRNA in human cell lysates, detection of human telomerase RNA in cell extracts, and performing DNA logic-gated in situ bioimaging on cell membranes. Secondly, excellent sensitivity has been attained through the utilization of effective amplification methods such as RCA, HCR, and CHA, among others. Thirdly, the construction of stable reference signals has resulted in significantly improved precision for ratiometric biosensors. This breakthrough has overcome matrix effects, enabling reliable detection in real samples with high selectivity. This review provides a comprehensive overview of recent advancements in strategies employed by ratiometric DNA biosensors. We present three types of biosensors based on distinct sensing platforms: fluorescent, electrochemical, and SERS biosensors. Additionally, we discuss future directions and primary challenges in the development of ratiometric DNA biosensors.

Affective data is the basis of emotion recognition, which is mainly acquired through extrinsic elicitation. To investigate the enhancing effects of multi-sensory stimuli on emotion elicitation and emotion recognition, we designed an experimental paradigm involving visual, auditory, and olfactory senses. A multimodal emotional dataset (OVPD-II) that employed the video-only or video-odor patterns as the stimuli materials, and recorded the electroencephalogram (EEG) and electrooculogram (EOG) signals, was created. The feedback results reported by subjects after each trial demonstrated that the video-odor pattern outperformed the video-only pattern in evoking individuals’ emotions. To further validate the efficiency of the video-odor pattern, the transformer was employed to perform the emotion recognition task, where the highest accuracy reached 86.65% (66.12%) for EEG (EOG) modality with the video-odor pattern, which improved by 1.42% (3.43%) compared with the video-only pattern. What’s more, the hybrid fusion (HF) method combined with the transformer and joint training was developed to improve the performance of the emotion recognition task, which achieved classify accuracies of 89.50% and 88.47% for the video-odor and video-only patterns, respectively.

The color of a product is one of the main factors that affect consumer choices. However, it can be difficult to discern the subtle differences in color in order to inspect or classify products without expensive and specialized equipment. In this study, we proposed an approach where standard off-the-shelf components (digital camera and RGB LED lights) can be used to robustly classify products based on their color. By varying the color of the illumination, environment-independent information of the color of the object can be obtained. Then, using a Log-Linearized Gaussian Mixture Neural Network (LLGMN), a neural network based on a statistical model, the objects can be effectively and robustly classified based on their color without requiring a large number of training data. An experiment was performed to verify the effectiveness of this approach. 8 samples with only a subtle difference in color were prepared, and a prototype was developed to be used to classify these 8 samples. We demonstrate that we are able to classify the 8 samples an accuracy of 100% when there was no ambient light and were still able to maintain an accuracy of 94.1% when there was ambient light in the room.

In this paper, we propose a novel system in which a human and a device work in unison on a single task with the aim to simultaneously support human cognitive and physical functions. In this system, the cognitive and physical burdens of the task are shared between the human and device, with the human understanding the entire task and performing rough upstream actions. Additionally, the device understands the surrounding environment, objects, and the human and executes detailed downstream actions. A prototype device was developed to assist in solving silhouette puzzles that abstract and generalize cognitive and physical tasks. The prototype is a pen-shaped device held in the user’s hand. The device picks up puzzle pieces and rotates them to the appropriate position. A display is placed in front of the user and provides feedback information for communication between the system and user. Experiments showed that the proposed device reduced the time required to solve these puzzles. Furthermore, the work was found to be accurate with no errors, and the time required was stable with no irregularities. The subjective evaluation results using the NASA Task Load Index showed that the proposed system can decrease mental load and burden. Moreover, it was confirmed that the human and device must communicate with each other to work simultaneously on one task. In conclusion, the proposed device can support human cognitive and physical functions simultaneously.

Abstract Over recent decades, heritage conservation has developed in concept and scope. This paper uses a systematic literature review approach to collect charters and documents on heritage conservation issued by UNESCO and ICOMOS, divided into two periods, before 2000 and from 2000 to the present, for analysis from a qualitative perspective. The study results show that the scope of architectural heritage is expanding, and the definition of conservation is changing from individual to holistic conservation and from holistic to sustainable conservation. The focus of conservation has evolved from tangible to intangible attributes. The changing scale of conservation, from object to landscape, incorporates a more comprehensive range of heritage values, and the status of conservation has changed from static to living conservation. This study systematically structures the development of the concept of architectural heritage conservation, providing insight in the international field of architectural heritage conservation and encouraging reflection on the conservation of architectural heritage in historic cities.

In this study, we experimentally analyzed whether people can perceive the accuracy or smartness of AI judgments, and whether the judgment accuracy of AI and the level of confidence in those judgments affect people’s decision-making. The results showed that people may perceive an AI’s smartness even when it only presents information on the results of its judgments. The results also suggest that AI accuracy and confidence affect human decision-making, and that the magnitude of the effect of AI confidence varies with AI accuracy. We also found that when a person’s ability to make a decision is less than or equal to the AI’s ability to make a decision, the human performance in a binary decision task improves regardless of AI accuracy. The results obtained in this study are similar in some respects to relationships in which people make decisions while interacting, and the findings from research on human interactions may apply to the research and development of human–AI interactions.

Leg prostheses specially adapted for cycling in patients with transtibial amputation can be advantageous for recreational practice; however, their required features are not fully understood. Therefore, we aimed to evaluate the efficiency of unilateral cycling with a transtibial prosthesis and the characteristics of different attachment positions (middle and tip of the foot) between the prosthetic foot and the pedal. The cycling practice was performed on an ergometer at 40 W and 60 W resistance levels while participants (n = 8) wore custom-made orthoses to simulate prosthesis conditions. Using surface electromyogram, motion tracking, and power meter pedals, biomechanical data were evaluated and compared with data obtained through regular cycling. The results showed that power delivery became more asymmetrical at lower workloads for both orthosis conditions, while hip flexion and muscle activity of the knee extensor muscles in the sound leg increased. While both pedal attachment positions showed altered hip and knee joint angles for the leg wearing the orthosis, the middle of the foot attachment presented more symmetric power delivery. In conclusion, the middle of the foot attachment position presented better symmetry between the intact and amputated limbs during cycling performed for rehabilitation or recreation.

Abstract Fundus image captures rear of an eye which has been studied for disease identification, classification, segmentation, generation, and biological traits association using handcrafted, conventional, and deep learning methods. In biological traits estimation, most of the studies have been carried out for the age prediction and gender classification with convincing results. The current study utilizes the cutting-edge deep learning (DL) algorithms to estimate biological traits in terms of age and gender together with associating traits to retinal visuals. For the trait’s association, we embed aging as the label information into the proposed DL model to learn knowledge about the effected regions with aging. Our proposed DL models named FAG-Net and FGC-Net, which correspondingly estimates biological traits (age and gender) and generates fundus images. FAG-Net can generate multiple variants of an input fundus image given a list of ages as conditions. In this study, we analyzed fundus images and their corresponding association in terms of aging and gender. Our proposed models outperform randomly selected state-of-the-art DL models.

Unmanned aerial vehicle (UAV), which is one of the significant means of maritime and aviation reconnaissance, is recognized as the main reconnaissance force to obtain information control and air control in the future sea battlefield. By combing the models and attribute characteristics of foreign small and medium-sized UAVs on the sea, this paper studies the application mode and application advantages of small and medium-sized ISR UAVs in the sea battlefield, and discusses their problems faced by the application, then analyzes the key technologies, such as launch and recovery, autonomous control, mission load, communication link, platform design, finally looks forward to their development trend. This paper provides reference and ideas for the popularization, application and planning development of small and medium-sized ISR UAVs in the field of maritime.

ABSTRACTBackground The maintenance of nursing professional competency is essential to ensure patients’ health outcomes. With the current shortage of nursing workforce, a novel approach is necessary to refresh clinical skills and update practice.Objective This study aims to examine the effectiveness of using head-mounted display virtual reality to refresh knowledge and skills and explore nurses’ perceptions towards using this technology for refresher training.Design A pre-test post-test mixed-method experimental design was employed.Results Participants (n = 88) were registered nurses with a diploma in nursing. The intravenous therapy and subcutaneous injection procedures were implemented using head-mounted display virtual reality. The study showed significant improvement in knowledge for the procedures, cognitive absorption, online readiness, self-directed learning, and motivation for learning. In the qualitative focus group discussions, three themes were identified using thematic analyses: enjoyable way to refresh clinical knowledge; learning outside classroom and limitations in maneuver.Conclusion Using head-mounted display virtual reality is promising in refreshing clinical skills for nurses. Training and refresher courses can explore using this novel technology, which may be a viable alternative to ensure professional competence with reduced manpower and resources used by the healthcare institution.

Polycyclic aromatic hydrocarbon (PAH) contamination in soil poses a serious threat to ecological safety, human life, and health. Thermal desorption is commonly used to remediate PAH-contaminated soil. Current thermal desorption research primarily focuses on parameters for engineering designs through in-house simulations. In this study, based on a PAH-contaminated site thermal desorption remediation project, the removal efficiency of PAHs in soil (S1, S2) after disposal at different heating temperatures (400, 450, 500, 550 °C) and different residence times (20, 25 min) was investigated, and changes in soil properties before and after disposal were analyzed. The removal rate of 16 PAHs from soil at two concentrations reached 100% after 20 min at 500 °C and 550 °C, respectively. The three-phase structural distances of S1 and S2 soils, respectively, increased by 1.65 and 2.99 times after disposal, sand content increased by 3.20% and 8.27%, water-stable macroaggregates decreased by 8.14% and 2.06%, organic carbon content decreased by 7.27% and 27.05%, heavy fraction organic carbon increased by 33.68% and 5.12%, pH decreased from 10.00 and 10.35 to 8.81 and 8.69, and cation exchange decreased by 13.79% and 26.65%. Soil nutrient content such as TP, AP, TK, and AK increased after thermal desorption, and TN content decreased; approximately 1.0 mg/kg of NO3−-N remained. Our results are expected to support the design of programs for soil reuse after disposal.

Electroencephalogram (EEG) signals are very weak and have low spatial resolution, which has led to less satisfactory accuracy in cross-subject EEG-based emotion classification studies. Microstate analyses of EEG sources can be performed to determine the important spatiotemporal characteristics of EEG signals. Such analyses can be used to cluster rapidly changing EEG signals into multiple brain prototype topographies, fully utilizing the spatial information contained in the EEG signals and providing a neural representation for emotional dynamics. To better utilize the spatial information of brain signals, source localization analysis on the EEG signals was first conducted. Then, a microstate analysis on the source-reconstructed EEG signals is conducted to extract the microstate features of the data. We conducted source microstate analysis on the participant data from the odor-video physiological signal database (OVPD-II) dataset. The experimental results show that the source microstate feature topologies of different participants under the same emotion exhibited a high degree of correlation, which was proven by the analysis of microstate feature topographic maps and the comparison of two-dimensional feature visualization maps of the differential entropy (DE) and power spectral density (PSD). The microstate features represent more abstract emotional information and are more robust. The extracted microstate features were then used with the style transfer mapping method to transfer the feature data from the source domain to the target domain and were then used in support vector machines (SVMs) and convolutional neural networks (CNNs) for emotion recognition. The experimental results show that the cross-subject classification accuracies of the microstate features in SVMs were 84.90 ± 8.24% and 87.43 ± 7.54%, which were 7.19 and 6.95% higher than those obtained with the PSD and 0.51 and 1.79% higher than those obtained with the DE features. In CNN, the average cross-subject classification accuracies of the microstate features were 86.44 and 91.49%, which were 7.71 and 19.41% higher than those obtained with the PSD and 2.7 and 11.76% higher than those obtained with the DE features.

BackgroundTo summarize the clinical features of severe influenza in children and the high-risk factors for influenza-related deaths and to raise awareness among pediatricians.MethodsA retrospective study of clinical manifestations, laboratory tests, and diagnosis and treatment of 243 children with severe influenza admitted to Shenzhen Children's Hospital from January 2009 to December 2022 was conducted. Univariate logistic regression analysis and Boruta analysis were also performed to identify potentially critical clinical characteristics associated with death, and clinically significant were used in further multivariate logistic regression analysis. Subject receiver operating characteristic (ROC) curves were applied to assess the efficacy of death-related independent risk factors to predict death from severe influenza.ResultsThere were 169 male and 74 female patients with severe influenza, with a median age of 3 years and 2 months and 77.4% of patients under six. There were 46 cases (18.9%) in the death group. The most common pathogen was Influenza A virus (IAV) (81.5%). The most common complication in the death group was influenza-associated acute necrotizing encephalopathy (ANE [52.2%]). Severe influenza in children decreased significantly during the COVID-19 pandemic, with a median age of 5 years, a high predominance of neurological symptoms such as ANE (P = 0.001), and the most common pathogen being H3N2 (P

Oral mucosal infection, especially oral candidiasis, is currently the most common oral mucosal disease. Traditional drug treatment regimens have difficulty adhering to mucous membranes, coupled with the unique anatomical and physiological characteristics of the oral cavity, thus reducing drug availability and limiting the effective time of drug action. Inspired by cell membrane-coated nanoparticles, this study aimed to construct a bionic adherent oral mucosal drug delivery system and investigated its therapeutic potential for oral candidiasis. The system was obtained by encapsulating Streptococcus salivarius K12 membranes on triclosan-loaded PLGA nanoparticles using an extrusion method. The constructed nanocomplexes (K12/TCS@PLGA-NPs) inherited the properties of the source cell membrane, bionically adhering to the oral mucosa and binding to the candida albicans hypha. Our in vitro and in vivo experiments have confirmed that K12/TCS@PLGA-NPs nanocomplexes significantly inhibits the formation of C. albicans biofilms and the development of oral candidiasis by enhancing the accumulation of drugs in lesions, optimizing drug efficacy. Furthermore, the biomimetic nanocomplexes could be considered safe and effective drug delivery systems, which hold considerable therapeutic promise for oral mucosal infections including candidiasis.

Chinese continental margins are experiencing remarkable environmental changes driven by anthropogenic activities and climate change. As an important habitat and sea-based fish farming resource in China, the Bohai was selected as a case study to understand how ecosystems and social interactions are influenced by multi-stressors. The Bohai ecosystem has been considerably modified. The Bohai coastline has been significantly changed (e.g., total sea area decreased and morphology changed) by sea reclamation and riverine sediment transport related to agriculture and erosion. Therefore, the strict reclamation policy and “Grain-for-Green” program have been issued to protect the coastline. Nutrient concentrations and composition have been changed by fertilizer application, wastewater discharge, and variations in seasonal patterns of riverine nutrient fluxes. Hence, pollution control and prevention are necessary. More seriously, fishing resources have been altered, as a result of environmental changes and overfishing. Therefore, a summer fishing ban and stock enhancement should be vital besides environmental improvement. This study can help to predict and mitigate impacts on global continental margins that are experiencing similar environmental stress.

Modern production lines for molded plastic parts often have automated inspection systems to detect defective parts reliably and efficiently. However, these conventional inspection systems have low flexibility and versatility, leading to difficulties when dealing with complicated requests such as when small quantities of many different parts are manufactured on the same production line. The proposed system can be implemented quickly using low-cost off-the-shelf components and does not require accurate alignment of production parts, reducing the need for manual inspections and increasing work efficiency when handling complex workloads. The inspection algorithm combines higher-order local auto correlation (HLAC) features with one-class support vector machine (one-class SVM) and principal component analysis (PCA) to extract, transform, and classify the differential feature vector between conforming and nonconforming plastic parts. To verify its validity and effectiveness, we compared defect detection accuracy and speed between the developed inspection system and manual inspection experimentally. Extremely high accuracy (Recall = 0.93, Specificity = 1.00) and speed (10 inspections in 30[sec]) was obtained with 7 types (1 conforming type, 6 nonconforming types) of sample parts (30 samples each). We demonstrated a 400 % increase in speed can be gained relative to manual inspection.

The historic district is a carrier to show the urban landscape, and the analysis of the spatial form of the historic district from human behavioral activities is beneficial to grasp the social and functional attributes of the space. Combining with the spatial layout of the Sishengci historic district, the overall spatial structure of the Sishengci historic district is analyzed in terms of integration, connectivity, control, depth, and intelligibility by using the analysis of the axial lines in space syntax through the relationship diagram and quantitative description of the syntax. Based on the findings, targeted conservation strategies are proposed, namely the conservation of the core area of the district, the shaping of the local spirit, and the reconstruction of the social space, which have a guiding significance for the conservation and renewal of the Sishengci historic district.

According to the boundary information of the coal wall and roof in the 3D laser scanning model of fully mechanized working face, the shearer can automatically adjust the cutting height of the drum to realize the coal precise mining. The existing technology realizes the automatic extraction of the roof line of coal cutting based on the laser point cloud of the working face. But the extraction results cannot be directly applied to the digital automatic coal cutting. In order to solve this problem, the overall scheme of 3D laser scanning modeling for fully mechanized working face is proposed. The key technologies such as boundary extraction of coal wall and roof, target ball detection, point cloud registration and coordinate transformation are studied. The near real-time acquisition of boundary information of coal wall and roof under 3D geological coordinate system is realized. The information can be directly sent to the shearer drum to provide data reference for the next cutting of the shearer. The scanning of the working surface is realized through an inspection robot to obtain the inspection point cloud. Based on the curvature characteristics of the boundary of the coal wall and roof, the string and normal vector method is used to extract the boundary of the coal wall and roof roughly. The angle information between the normal vector of data points and the normal vector of adjacent points is introduced. The obvious intersection points of non coal wall and roof are eliminated through the threshold. As the inspection point cloud and the extracted boundary information are both located in a local coordinate system, the head and tail point clouds and the inspection point cloud are registered through the detection and registration of the positioning target ball. The working face combined point cloud is obtained. According to the 3D geological coordinate and the local coordinate of the positioning target ball, the transformation relation between the coordinates is obtained. The combined point cloud is transformed into the 3D geological coordinate system through coordinate transformation. Therefore, the boundary information of the coal wall and the roof under the 3D geological coordinate system is obtained. The underground industrial test results show that the error of the boundary between the coal wall and roof extracted by 3D laser scanning technology in fully mechanized working face is less than 10 cm. The sampling points with error less than 4 cm account for 50%. The sampling points with error less than 8 cm account for 96.67%.

BackgroundThe capacity of health care professionals to perform clinical procedures safely and competently is crucial as it will directly impact patients’ outcomes. Given the ability of head-mounted virtual reality to simulate the authentic clinical environment, this platform should be suitable for nurses to refine their clinical skills for knowledge and skills acquisition. However, research on head-mounted virtual reality in learning clinical procedures is limited. ObjectiveThe objectives of this study were (1) to describe the design of a head-mounted virtual reality system and evaluate it for education on clinical procedures for nursing students and (2) to explore the experience of nursing students using head-mounted virtual reality for learning clinical procedures and the usability of the system. MethodsThis usability study used a mixed method approach. The stages included developing 3D models of the necessary instruments and materials used in intravenous therapy and subcutaneous injection procedures performed by nurses, followed by developing the procedures using the Unreal Engine (Epic Games). Questionnaires on the perception of continuance intention and the System Usability Scale were used along with open-ended questions. ResultsTwenty-nine nursing students took part in this questionnaire study after experiencing the immersive virtual reality (IVR) intervention. Participants reported largely favorable game perception and learning experience. Mean perception scores ranged from 3.21 to 4.38 of a maximum score of 5, while the mean system usability score was 53.53 of 100. The majority found that the IVR experience was engaging, and they were immersed in the game. The challenges encountered included unfamiliarity with the new learning format; technological constraints, such as using hand controllers; and physical discomfort. ConclusionsThe conception of IVR for learning clinical procedures through deliberate practice to enhance nurses’ knowledge and skills is promising. However, refinement of the prototypes is required to improve user experience and learning. Future research can explore other ways to use IVR for better education and health care purposes.

Abstract Doped organic semiconductors play a central role in the development of several innovative optoelectronic and energy harvesting applications. Currently, the realization of thermoelectric generators, which require both hole‐ and electron‐transporting materials with high electrical conductivity, is strongly hindered by the scarce availability of stable solution‐processable n‐dopants and their limited efficiency. Herein, the synthesis of 4‐(1,3‐dimethyl‐2,3‐dihydro‐1H‐benzimidazol‐2‐yl)‐dibenzazepine (IStBI), a novel derivative belonging to the well‐known family of the benzimidazoline compounds, is presented. The functionalization with the planarized and rigid iminostilbene substituent allows, without significantly affecting the compound electronic structure, an efficient intercalation of the dopant molecules inside the ordered regions of thin films of the benchmark n‐type polymer poly(N,N′‐bis‐2‐octyldodecylnaphthalene‐1,4,5,8‐bis‐dicarboximide‐2,6‐diyl‐alt‐5,5′‐2,2′‐bithiophene) P(NDI2OD‐T2). Consequently, a maximum electrical conductivity of (1.14 ± 0.13) × 10−2 S cm−1 is recorded, exceeding by one order of magnitude what previously achieved upon solution doping of the reference P(NDI2OD‐T2) with benzimidazoline derivatives. The thermoelectric power factor is also simultaneously increased. The findings confirm that tailoring of the dopant chemical structure to improve structural interactions with the host semiconductors can be employed as a successful strategy to achieve more effective n‐doping, helping to close the performance gap with p‐type materials.

Objective To study the epidemiological correlation and drug resistance of external factors of infection caused by open injury of limbs to pathogens. Methods This experiment is a retrospective study. We took the geographical location and climate of Nanchang, Jiangxi Province, China as the background, analyzed 2017 strains of pathogens from 1589 patients with limb trauma infection in a University Affiliated Hospital from 2012 to 2017. Patients were divided into three groups according to the type of incision: I, In‐hospital infection of clean limb incision, II, In‐hospital infection with open injury, III, Community infection with open injury of the limb. Groups II and Groups III were divided into six subgroups according to the causes of trauma, including: accidents from non‐motor vehicles, machinery, cutting/piercing, pedestrian injuries, struck by/against, pedal cycles, and other injuries. We found eight common pathogens of orthopedic infection, which were mainly divided into Gram‐positive bacteria (G+, mainly including Staphylococcus) and Gram‐negative bacteria (G‐, mainly Enterobacteriaceae). The relationship between main pathogens and damage mechanism, apparent temperature and relative humidity was discussed in this study. SPSS v22.0 was used for statistical analysis of the data. Friedman's two‐way ANOVA was used to analyze the difference between the injury mechanism and incidence of pathogenic bacteria. Linear regression was used to determine the trend between the incidence of major pathogens and seasonal temperature and humidity. The level of significance was set as P 0.05). The drug resistance of Groups III was significantly higher than that of Groups II and Groups I. G+ bacteria were resistant to cephalosporin, ceftriaxone and other cephalosporins and erythromycin and other macrolides. They were sensitive to vancomycin and linezolid. G‐ were resistant to the first‐ and the second‐generation cephalosporins, including cefotetan and cefazolin, and ampicillin and other penicillins, while they were sensitive to third‐generation cephalosporins, such as ceftazidime, as well as to levofloxacin and other quinolones, meropenem, and other beta‐lactamases. The correlation between the injury mechanism and infection of pathogenic bacteria was not significant. The monthly average apparent temperature and relative humidity were correlated with the infection rate of pathogenic bacteria. Conclusion In open injury of extremities, apparent temperature and relative humidity is an important risk factor for infection by pathogenic bacteria and the drug resistance of pathogenic bacteria in out‐of‐hospital infection was lower than that of hospital infection.

Abstract Background Due to their prevalence, dental caries ranks first among all diseases endangering human health. Therefore, the prevention of caries is of great significance, as caries have become a serious public health problem worldwide. Currently, using nanoscale drug delivery systems to prevent caries has received increased attention. However, the preventive efficacy of these systems is substantially limited due to the unique physiological structure of cariogenic biofilms. Thus, novel strategies aimed at combating cariogenic biofilms to improve preventive efficiency against caries are meaningful and very necessary. Herein, inspired by cell membrane coating technology and Lactobacillus strains, we coated triclosan (TCS)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (TCS@PLGA-NPs) with an envelope of Lactobacillus (LA/TCS@PLGA-NPs) and investigated their potential as a nanoparticle delivery system against cariogenic biofilms and dental caries. Results LA/TCS@PLGA-NPs were successfully prepared with favorable properties, including a coated envelope, controllable size, negative charge, sustained drug-release kinetics and so on. The LA/TCS@PLGA-NPs inherited native properties from the source cell surface, thus the LA/TCS@PLGA-NPs adhered to S. mutans, integrated into the S. mutans biofilm, and interfered with the biofilm formation of S. mutans. The nanoparticles significantly inhibited the activity, biomass and virulence gene expression of S. mutans biofilms in vitro. Additionally, LA/TCS@PLGA-NPs exhibited a long-lasting inhibitory effect on the progression of caries in vivo. The safety performance of the nanoparticles is also favorable. Conclusions Our findings reveal that the antibiofilm effect of LA/TCS@PLGA-NPs relies not only on the inheritance of native properties from the Lactobacillus cell surface but also on the inhibitory effect on the activity, biomass and virulence of S. mutans biofilms. Thus, these nanoparticles could be considered feasible candidates for a new class of effective drug delivery systems for the prevention of caries. Furthermore, this work provides new insights into cell membrane coating technology and presents a novel strategy to combat bacterial biofilms and associated infections. Graphical Abstract

Abstract The molecular orientations of conjugated materials on the substrate mainly include edge‐on, face‐on, and end‐on. Edge‐on and face‐on orientations have been widely observed, while end‐on orientation has been rarely reported. Since in organic solar cells (OSCs) charge transport is along the vertical direction, end‐on orientation with conjugated backbones perpendicular to the substrate is recognized as the ideal microstructure for OSCs. In this work, we for the first time obtained the preferential end‐on orientation in a conjugated molecular dyad that contains a conjugated backbone as donor and perylene bisimide side units as acceptor. This was realized by introducing a fused‐ring structure to replace linear terthiophenes with conjugated backbones, yielding F‐MDPBI and L‐MDPBI respectively. Surprisingly, a shifting trend of the molecular orientation from dominating edge‐on in L‐MDPBI to preferential end‐on in F‐MDPBI was observed. As a consequence, vertical charge carrier mobilities in F‐MDPBI are one order of magnitude higher than those with preferential edge‐on orientation, so single‐component OSCs based on this molecular dyad as a single photoactive layer provided a power conversion efficiency of 4.89% compared to 1.70% based on L‐MDPBI with preferential edge‐on orientation.

The dissolution efficiency of sedssimentary biogenic silica (bSiO2) dramatically affects the regeneration of dissolved silicic acid (dSi) at the sediment-water interface, which is a crucial pathway to maintain Si balance and silicic productivity growth in marine environments. We conducted wet alkaline leach and flow-through experiments to explore the dissolution behaviors of sedimentary bSiO2 in the northern South China Sea (NSCS), one of the largest marginal sea continental shelves. The bSiO2 contents of surface sediments were 0.64 - 2.06%, with an average of 1.04 ± 0.35%, varying with isobath water depth. The solubility of bSiO2 in surface sediments ranged from 227 μmol L-1 to 519 μmol L-1, and the dissolution rate constants varied from 0.67 to 1.53 yr-1 under specific conditions in lab incubation. The correlation between the biogenic materials (bSiO2, OC, and TN) revealed a different preservation pattern of bSiO2 in finer (Φ > ~ 5.5) and coarser (Φ< ~ 5.5) sediments. The high concentration of Al in sea water and “Al – detrital – bSiO2” interactions in sediments significantly interfered with the apparent solubility and dissolution dynamics of bSiO2. We combined the regional characteristics (primary production, bottom current, and resuspension-deposition) and the reconstructed dissolution kinetics of bSiO2 explained the mismatch between the surface (diatom biomass)/(total phytoplankton biomass) ratio and the sedimentary bSiO2/OC ratio, and the mismatch between the surface bSiO2 primary productivity and the bSiO2 sediment records in the NSCS. The resuspension-deposition, the higher reconstructed rate constants (0.94 ± 0.13 yr-1), and the dissolution rate (0.20 ± 0.01 yr-1) were responsible for the lower bSiO2/OC ratio (0.45 ± 0.28) at the inner shelf, and the winnowing process at the outer shelf with the lower reconstructed reactivity (0.30 yr-1) and dissolution rate (0.001 yr-1) led to the good preservation of bSiO2 in the upper slope. Furthermore, through the comparison with other sea areas, the relatively lower reactivity (1.12 ± 0.3 yr-1) of bSiO2 in sediments supported the notion that the NSCS sediments may serve as an important silica sink in the world ocean silica cycle.

Abstract Chinese herbal medicines (CHMs) have unique advantages in the prevention and treatment of diseases, which are widely recognized in the world. More and more CHMs are becoming increasingly popular in the international markets. However, the quality control of CHMs is a significant issue for their acceptance and recognition in the international market. This review mainly focuses on the quality requirements for CHMs to enter the European Union (EU) market. Both Chinese and European regulations and quality controls are compared. Firstly, the EU medicinal regulatory system and relevant regulations were reviewed. Secondly, the key factors of the quality control of CHMs, including Chinese herbal drugs, extracts and products were compared with those of European herbal medicines in the EU market. Subsequently, three main registration routes for herbal medicinal products including Chinese herbal medicinal products entering the EU were introduced. Furthermore, the legal status of traditional Chinese medicine granules in the EU was also discussed. Through the comparison of the key quality factors for CHMs in China and the EU, the similarities and differences in terms of quality requirements and regulations are addressed, which provides a reference for the development of CHMs into the EU market.

Aiming at the problem that the vibration signal in diesel engine fault diagnosis is non-stationary and nonlinear, and the original signal is directly input into the Convolutional Neural Network（CNN） for fault diagnosis with poor effect, a new method based on PCA-EDT-CNN is proposed. Firstly, use Principal Component Analysis（PCA） to adaptively reduce the original data collected by the sensor, and construct a qualified Principal Component Eigenvector Matrix（PCEM）; secondly, perform Euclidean Distance Transformation（EDT） on PCEM, calculate the Euclidean distance between each row and construct the Euclidean Distance Matrix（EDM）; finally, flatten PCEM and EDM into one-dimensional vectors and synthesize a one-dimensional sample sequence, input into One-Dimensional Convolutional Neural Network（1 DCNN） to train and diagnosis the model. A diesel engine preset failure test bench was built to verify the effectiveness of the method, and through comparison with traditional methods, the results show that the method has high accuracy in diagnosing different fault states of diesel engines and has practical engineering application value.

The Bohai Sea is a habitat for economically important fish in China, but its ecological environment has changed significantly, and it is necessary to further clarify the dynamics and the internal resupply channels of nutrients in the Bohai Sea. Based on four field observations in the Bohai Sea from May to December 2019, the nutrient dynamics were addressed. The concentration of dissolved inorganic nutrients was depleted throughout the water column in spring and in the euphotic zone in summer and accumulated in the bottom water in summer and in the water column in autumn and winter. Relative phosphorus limitation was present in Laizhou Bay and its surrounding area in all seasons, while relative silicon limitation was evident in spring and relative nitrogen limitation was significant in summer in most other study aeras. The results of end-member mixing model illustrated significant seasonal differences in the nutrient uptake ratios, which may be related to various factors such as different phytoplankton composition and phosphorus turnover rates. Turbulent entrainment was an important nutrient pathway for primary production in the euphotic zone of Central Bohai Sea during the stratification season, with an estimated average nutrient flux of 6.04 ± 9.63, 0.22 ± 0.19 and 6.97 ± 6.61 mmol·m-2·d-1 for DIN, DIP and DSi, respectively.

Diclofenac (DCF) is one of the most frequently detected pharmaceuticals in groundwater, posing a great threat to the environment and human health due to its toxicity. To mitigate the DCF contamination, experiments on DCF degradation by the combined process of zero-valent iron nanoparticles (nZVI) and nano calcium peroxide (nCaO2) were performed. A batch experiment was conducted to examine the influence of the adding dosages of both nZVI and nCaO2 nanoparticles and pH value on the DCF removal. In the meantime, the continuous-flow experiment was done to explore the sustainability of the DCF degradation by jointly adding nZVI/nCaO2 nanoparticles in the reaction system. The results show that the nZVI/nCaO2 can effectively remove the DCF in the batch test with only 0.05 g/L nZVI and 0.2 g/L nCaO2 added, resulting in a removal rate of greater than 90% in a 2-hour reaction with an initial pH of 5. The degradation rate of DCF was positively correlated with the dosage of nCaO2, and negatively correlated with both nZVI dosage and the initial pH value. The order of significance of the three factors is identified as pH value > nZVI dosage > nCaO2 dosage. In the continuous-flow reaction system, the DCF removal rates remained above 75% within 150 minutes at the pH of 5, with the applied dosages of 0.5 g/L for nZVI and 1.0 g/L for nCaO2. These results provide a theoretical basis for the nZVI/nCaO2 application to remove DCF in groundwater.

Abstract Organic solar cells (OSCs) based on polymer donor and non‐fullerene acceptor achieve power conversion efficiency (PCE) more than 19% but their poor absorption below 550 nm restricts the harvesting of high‐energy photons. In contrast, wide bandgap all‐inorganic perovskites limit the absorption of low‐energy photons and cause serious below bandgap loss. Therefore, a 2‐terminal (2T) monolithic perovskite/organic tandem solar cell (TSC) incorporating wide bandgap CsPbI2Br is demonstrated as front cell absorber and organic PM6:Y6 blend as rear cell absorber, to extend the absorption of OSCs into high‐energy photon region. The perovskite sub‐cell, featuring a sol–gel prepared ZnO/SnO2 bilayer electron transporting layer, renders a high open‐circuit voltage (VOC). The VOC is further enhanced by employing thermal annealing (TA)‐free process in the fabrication of rear sub‐cell, demonstrating a record high VOC of 2.116 V. The TA‐free Ag/PFN‐Br interface in organic sub‐cell facilitates charge transport and restrains nonradiative recombination. Consequently, a remarkable PCE of 20.6% is achieved in monolithic 2T‐TSCs configuration, which is higher than that of both reported single junction and tandem OSCs, demonstrating that tandem with wide bandgap all‐inorganic perovskite is a promising strategy to improve the efficiency of OSCs.

Introduction:. Tissue rearrangement after an oncoplastic breast reduction may complicate identification of margins during reexcision. Little is known about outcomes of reoperation in this setting. Methods:. This is a single-institution, retrospective analysis of outcomes of margin reexcisions after lumpectomy with concurrent oncoplastic Wise-pattern reduction from 2015 to 2020. Outcomes assessed were the rate of successful breast conservation, in-breast recurrence, wound issues or complications, effect on cosmesis, and delay to onset of adjuvant therapy. Results:. From 2015 to 2020, 649 patients underwent lumpectomy with oncoplastic Wise-pattern reduction. Forty-seven patients (7.2%) had greater than or equal to one positive margin(s); of these, 28 went directly to mastectomy, and 19 underwent margin reexcision. Residual disease was found in seven of 19 patients (37%) at reexcision. The rate of successful breast-conserving therapy was 95% with a mean follow-up of 31 months. There was one (5%) in-breast recurrence (invasive ductal carcinoma [IDC] occurring 30 months after the original operation); this patient had a mastectomy for treatment of her recurrence. The overall complication rate was 37%. Radiation was administered to 18 patients (95%), and two patients (11%) had delay of radiation past 6 weeks due to wound complications. Of the 14 patients with photographs available, 12 of 14 patients (86%) were blindly assessed to have equivalent or better cosmesis after margin reexcision (versus initial lumpectomy). Conclusion:. Margin reexcision after oncoplastic breast reduction with Wise-pattern is feasible and effective, and can be done without compromising the initial cosmetic results.

The dissolved silicate concentrations in the supernatant of sediment trap sampling bottles retrieved from deep water (1000-3000 m) at four stations in the South China Sea (SCS) were measured to calculate the underestimated flux of biogenic silica (bSi) in sinking particles due to bSi dissolution. High dissolved silicate concentrations in the supernatant, ranging from 122.6 to 1365.8 μmol/L, indicated significant dissolution of particulate bSi in the sampling bottles. Underestimation of the bSi flux in the SCS by ~2% to ~34% (average: ~10%) due to bSi dissolution was revealed, and the degree of underestimation increased with decreasing total bSi flux. The amount of bSi dissolved within the sampling series at each station was generally positively correlated with dissolution time and to a certain extent influenced by the bSi amount collected by the sampling bottles under a low bSi sinking flux. Apparently stronger bSi dissolution was found at two of the four stations due to relatively high bSi dissolution rates, which were possibly related to a higher reactive surface area of the bSi or bacterial activity. Overall, our results demonstrated that the considerable bSi dissolution in sediment trap sampling bottles should not be ignored, especially in the low-productivity oligotrophic ocean, and bSi flux calibration via measurement of the dissolved silicate in sampling bottles is necessary. To reduce bSi flux underestimation due to the deployment of time-series sediment traps, larger-volume sampling bottles should be avoided in the oligotrophic open ocean, and sinking particle samples should be analyzed as soon as the sediment traps are recovered.

ObjectiveThe purposes of this study are to explore (1) whether comorbid depressive symptoms in patients with chronic back pain (CBP) affect the pain matrix. And (2) whether the interaction of depression and CBP exacerbates impaired brain function.MethodsThirty-two patients with CBP without comorbid depressive symptoms and thirty patients with CBP with comorbid depressive symptoms were recruited. All subjects underwent functional magnetic resonance imaging (fMRI) scans. The graph theory analysis, mediation analysis, and functional connectivity (FC) analysis were included in this study. All subjects received the detection of clinical depressive symptoms and pain-related manifestations.ResultCompared with the CBP group, subjects in the CBP with comorbid depressive symptoms (CBP-D) group had significantly increased FC in the left medial prefrontal cortex and several parietal cortical regions. The results of the graph theory analyses showed that the area under the curve of small-world property (t = −2.175, p = 0.034), gamma (t = −2.332, p = 0.023), and local efficiency (t = −2.461, p = 0.017) in the CBP-D group were significantly lower. The nodal efficiency in the ventral posterior insula (VPI) (t = −3.581, p = 0.0007), and the network efficiency values (t = −2.758, p = 0.008) in the pain matrix were significantly lower in the CBP-D group. Both the topological properties and the FC values of these brain regions were significantly correlated with self-rating depression scale (SDS) scores (all FDR corrected) but not with pain intensity. Further mediation analyses demonstrated that pain intensity had a mediating effect on the relationship between SDS scores and Pain Disability Index scores. Likewise, the SDS scores mediated the relationship between pain intensity and PDI scores.ConclusionOur study found that comorbid depressive symptoms can aggravate the impairment of pain matrix function of CBP, but this impairment cannot directly lead to the increase of pain intensity, which may be because some brain regions of the pain matrix are the common neural basis of depression and CBP.

The effects of finishing rolling temperature on the microstructure and mechanical properties of a direct quenched and partitioned (DQ&P) steel were investigated by a thermal simulation machine, a field emission scanning electron microscope (FE-SEM), electron backscattering diffraction (EBSD), and a transmission electron microscope (TEM). The results show that the original austenite grain size was refined by 31% as the finishing rolling temperature decreased from 920 °C to 840 °C, leading to the formation of the finest martensite lath at 840 °C. At the same time, the lower finishing rolling temperature resulted in a higher dislocation density, and consequently improved the stability of the retained austenite. Moreover, compared to the conventional Q&P process, the comprehensive mechanical properties of a steel with similar chemical composition can be enhanced by DQ&P processing. With the decrease of finishing rolling temperature from 920 °C to 840 °C, the strength and total elongation increases. The yield strength, tensile strength, and total elongation reach the maximum values of 1121 MPa, 1134 MPa, and 11.7%, respectively, at 840 °C.

We present the machine learning inspired design of two types of GaN zero contrast subwavelength gratings (SWGs): a polynomial-shaped grating and, for reference, a conventional rectangular grating, using the differential evolution algorithm to optimize the designs for high broadband reflectivity and separately for large fabrication tolerance. Two wavelength regimes with 500 nm and 1.55 μm center wavelengths (λcenter) are investigated. Our results indicate that both polynomial and rectangular grating designs can achieve comparable stopband widths of 170 nm (Δλ) for 500 nm (Δλ/λcenter = 34%). For the 1.55 μm center wavelength, the 482 nm (Δλ/λcenter = 31%) stopband width of the polynomial grating is slightly less than that of the rectangular grating at 498 nm (Δλ/λcenter = 32%). We also demonstrate design for enhanced fabrication tolerance while placing a minimum constraint on the stopband width. Our results show the rectangular grating exhibits slightly higher fabrication tolerances for grating parameters than the polynomial-shaped grating in general. This work also outlines the technique we have adopted for the inverse design of these gratings.

The nucleating agent acts as a crystal nucleus during polypropylene (PP) crystallization, affecting the structure and size distribution of the crystal, and in turn the properties of PP products. It is a hot research topic to study the mechanisms by which the nucleating agent promotes polymer crystallization. Currently it is still unclear how the structure of nucleating agent affects polymer crystallization. In addition, a nucleating agent may have different chemical structures due to isomerization, further complicating the nucleation mechanism study. Structural studies of nucleating agents are therefore the foundation of the nucleation mechanism studies. In this work, the structure and configuration of a β nucleating agent used in PP crystallization were studied by the combination of nuclear magnetic resonance (NMR) spectroscopy, Fourier transform-infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The FT-IR data suggested that the chelating way of calcium salt of cis-Δ4-tetrahydrophthalic acid in the nucleating agent belongs to the bridge type, while the cis-Δ4-tetrahydrophthalic acid is a mesomer.

A laser tailor welding experiment of 1800 MPa press hardening steel and low-alloy high-strength steel CR340LA was carried out using an optical fiber laser. The microstructure evolution and hot stamping formability of tailor-welded blanks were investigated under different laser welding powers and welding speeds, and the mechanical properties and distribution of the microhardness of the welding joints were analyzed and studied. Results show that the comprehensive mechanical properties of the laser tailor-welded blanks have little difference under three welding processes. The loss of elongation and tensile strength caused by welding joints is within 28.3% and 9.1% of the base metal. After laser welding, the fusion zone of the tailor-welded blanks is a martensite structure, which is bulky and has high hardness. The microstructure in the heat-affected zone on both sides is mainly ferrite and martensite, and there is no obvious softening zone in the joint under the welding processes. The tensile specimens of the tailor-welded blanks are all broken in the CR340LA base metal zone, approximately 12 mm away from the weld center, and a weld heave phenomenon occurs, which may be due to the uneven distribution of material properties after welding. Hot stamping of the tailor-welded blanks with a welding power and welding speed of 4000 W and 0.18 m·s−1, respectively, was carried out at high temperature, and no weld cracks were found during the experiment. Thus, these tailor-welded blanks have good performance and meet the requirements of automobile laser tailor-welded blanks. The tensile test results show that the fracture location of the specimens is the same as that before hot stamping, both of which are located in the CR340LA base metal area. During the stretching process, the fusion zone shifts to the side of the high-strength base metal, which results in a stress concentration and necking fracture on the side of the weak-strength base metal.

Perovskite solar cells have substantial potential for solar conversion, but developing simple and scalable fabrication processes is challenging. Here, a drop-casting process compatible with roll-to-roll production of quasi-2D/3D perovskite layers is developed, with a conversion efficiency of up to 16%.

The in-situ X-ray diffraction (XRD) and Raman spectra of synthetic (Mg, Fe, Mn)CO3 single crystals for (Mg0.37Fe0.31Mn0.32)CO3, (Mg0.49Fe0.51)CO3, (Fe0.47Mn0.53)CO3, and (Mg0.50Mn0.50)CO3 were investigated up to 871 K. Lattice parameters and the volumetric thermal expansion coefficients were achieved, demonstrating an inherent anisotropy of c/a near to 3.0. The Raman spectra of our intermediate components all exhibit a negative temperature dependence similar to that of the end members. The temperature dependence of the external modes T, L, anti-symmetric stretching mode ν3, and out-of-plane bending mode 2ν2 is generally more prominent than the in-plane bending mode ν4 and symmetric stretching mode ν1 except for siderite FeCO3. Combining thermal expansion coefficients αV with the relative changes in frequency δνi/δT of Raman spectra, the average thermodynamic Grüneisen parameters (γth) for (Mg0.37Fe0.31Mn0.32)CO3, (Fe0.47Mn0.53)CO3, (Mg0.50Mn0.50)CO3, MgCO3, and MnCO3 were obtained as 1.18, 1.36, 1.34, 1.13, and 1.53, respectively. The relationship between Fe2+ and Mn2+ contents and γth illustrates that the concentration of Fe2+ causes a negative effect while the concentration of Mn2+ causes a positive effect on γth. These results could provide a reference for the contribution of Fe2+ and Mn2+ on the structural and thermodynamic properties of (Mg, Fe, Mn)CO3 carbonates.

Abstract Fine particulate matter (PM) has seriously affected human life, such as affecting human health, climate, and ecological environment. Recently, many researchers use electrospinning to prepare nanofiber air filters for effective removal of fine particle matter. However, electrospinning of the polymer fibers onto the window screen uniformly is only achieved in the laboratory, and the realization of industrialization is still very challenging. Here, we report an electrospinning method using a rotating bead spinneret for large-scale electrospinning of thermoplastic polyurethane (TPU) onto conductive mesh with high productivity of 1000 m2/day. By changing the concentration of TPU in the polymer solution, PM2.5 removal efficiency of nanofiber-based air filter can be up to 99.654% with good optical transparency of 60%, and the contact angle and the ventilation rate of the nanofiber-based air filter is 128.5° and 3480 mm/s, respectively. After 10 times of filtration, the removal efficiency is only reduced by 1.6%. This transparent air filter based on TPU nanofibers has excellent filtration efficiency and ventilation rate, which can effectively ensure indoor air quality of the residential buildings.

Forward walking (FW) is a common balance assessment tool. However, its sensitivity is limited by the ceiling effect. Reverse gait, such as backward walking (BW), has been reported to have more advantages than FW for balance assessment. Three factors related to postural instability (i.e., increased speeds, restricted arm swing, and reduced visual feedback) during BW were investigated to determine BW conditions that have the potential to predict falls. Three-dimensional analyses were used to analyze seven walking conditions. FW and BW at self-selected and fast speeds were analyzed to identify the effects of speed. Walking with normal arm swings, crossed arms, and abducted arms during BW was tested to determine the effects of arm position. BW with closed and open eyes was compared to investigate the effects of visual feedback. BW had a significantly shorter step length than FW at high speeds. When the arms were abducted, the stance phase (%) was significantly lower compared to when arms were crossed during BW. Moreover, BW with closed eyes revealed significantly higher mediolateral center of mass (COM) displacements than with open eyes. We observed that BW with fast speeds, a crossed arm position, and closed eyes has the potential to help assess fall risk because it requires higher balance ability through spatiotemporal and COM adjustment.