Search

As the important high temperature structural materials and advanced functional materials， Ta-W alloy plays an indispensable role in aerospace， national defense equipment， chemical and other national livelihood industries.With the increasingly stringent service conditions of engineering equipment， the disadvantage of poor high-temperature oxidation resistance of Ta-W alloy became more severe， which seriously restricts its engineering application.Surface protective coatings are increasingly used in the field of material protection as an effective means of reducing the failure behaviors of the substrate， improving the overall performance of the material and extending the service life of the device，and their subsequent development also has a very broad prospect.This work firstly introduced the basic properties of Ta-W alloy， and then summarized the research progresses of silicide coatings，noble metal coatings，ceramic coatings and composite coatings in prolonging the service life of Ta-W alloy in high-temperature oxidative environment.Finally， the future development direction of anti-high temperature oxidative protective coatings on Ta-W alloy surfaces was prospected.

NaCl is the main curing agent in dry-cured meat products, and a large amount of NaCl addition leads to high salt content of final products. Salt content and composition are important factors affecting the activity of endogenous proteases, which in turn could affect proteolysis as well as the quality of dry-cured meat products. With the increasing emphasis on the relationship between diet and health, reducing sodium content without sacrificing quality and safety of products is a great challenge for dry-cured meat industry. In this review, the change of endogenous proteases activity during processing, the potential relationship between sodium reduction strategy, endogenous proteases activity, and quality were summarized and discussed. The results showed that sodium replacement strategy and mediated-curing had a complementary advantage in influencing endogenous proteases activity. In addition, mediated-curing had the potential to salvage the negative effects of sodium substitution by affecting endogenous proteases. Based on the results, a sodium reduction strategy that sodium replacement in conjunction with mediated-curing based on endogenous proteases was proposed for the future perspective. [ABSTRACT FROM AUTHOR]

BackgroundRadionuclide labeled somatostatin analogs can specifically bind to somatostatin receptors (SSTRs) on the cell surface of neuroendocrine tumors (NETs), hence be used for imaging or treatment of NETs.PurposeThis study aims to label glycosylated KE108 protein with 18F nuclide, and to investigate the distributions and PET imaging of this probe in mice in vivo.MethodsA novel 18F-radiolabeled somatostatin analogue probe Gluc-Lys([Al18F]NOTA)-KE108 was designed and synthesized, which linked 18F nuclide and glycosylated KE108 protein by coupling bifunctional chelator (NOTA) to target SSTR positive tumors. The in vitro physicochemical properties, in vitro cell binding, ex vivo biodistribution and in vivo imaging of Gluc-Lys([Al18F]NOTA)-KE108 were further investigated to evaluate the SSTR targeting ability and feasibility of PET imaging in the diagnosis of NETs.ResultsThe efficiency of Gluc-Lys([Al18F]NOTA)-KE108 obtained with moderate labelling is (30±5)% without corrected (n=6), and the radiochemical purity is higher than >95%. The radiochemical yield is ((20±5)%, uncorrected) (n=6), and the total synthesis time is about 20 min. The specific activity is more than 1.37 GBq∙μmol-1. The probe shows expected nanomolar binding affinity in SSTR-positive AR42J and BON1 tumor cells, which Kd values are (152.3±49.1) nmol∙L-1 and (45.5±13.6) nmol∙L-1, respectively, and can be specifically inhibited, showing high SSTR targeting ability. In PET imaging of AR42J tumor bearing mice, Gluc-Lys([Al18F]NOTA)-KE108 has a high uptake of radioactivity and a high ratio of tumor to muscle uptake.ConclusionsGluc-Lys([Al18F]NOTA)-KE108 has high hydrophilicity and good stability in vitro, hence be served as a potential imaging agent for SSTR-positive tumors.

The supply chain of medical 99Tcm in the world is still very fragile, so the development of 99Mo-99Tcm separation devices and processes based on non-fission 99Mo is very important to improve the security of 99Tcm supply in China. Activated carbon fiber (ACF) is a molybdenum technetium chromatographic separation material with excellent performance, which can be used to prepare non-fission 99Mo-99Tcm chromatographic generator with multi-column selective reverse generator (MSIG) structure. Based on the modification and evaluation of ACF, a three-column 99Mo-99Tcm separation and purification process was developed by using an automatic non-fission 99Mo-99Tcm generator, and the sodium pertechnetate ［99Tcm］ injection obtained by this device was used to label MDP and MIBI kits. The yield of 99Tcm in 99Mo-99Tcm simulated solution by nonfission 99Mo-99Tcm generator three-column separation process was 78%. The resulting sodium pertechnetate ［99Tcm］ injection, radiochemical purity and labeling rate of MDP and MIBI kits all met the requirements of Chinese Pharmacopoeia. The three-column selectivity inversion 99Mo-99Tcm generator based on ACF is expected to be used to extract 99Tcm from non-fission 99Mo.

The use of the chromatographic method to extract 99Tcm from the low specific activity 99Mo solution is an effective way to obtain medical isotope 99Tcm that meeting clinical requirements. It has been reported that the separation technologies must use strong acid or strong alkaline solutions, which require additional treatments. Exploring the method of separating technetium from neutral molybdenum solution can simplify the treatment process. A kind of activated carbon fiber was used to extract technetium from neutral low specific activity 99Mo (＜0.2 Ci/g Mo) in 1 mol/L NaCl solution. Neutral eluent was used to desorb technetium throughout the process, and the separation of molybdenum and technetium was realized. The recoveries of 99Tcm were more than 90%. The obtained sodium pertechnetate ［99Tcm］ injection met the requirements of the Chinese Pharmacopoeia without pH adjustation, and the labeling rate of MIBI and MDP for met the Chinese Pharmacopoeia claim. The results show that the extraction of 99Tcm from 99Mo with low specific activity (

Leveraging the anisotropic shape of DNA-functionalized nanoparticles holds potential for shape-directed crystallization of a wide collection of superlattice structures. Using coarse-grained molecular dynamics simulations, we study the self-assembly of a binary mixture of cubic gold nanoparticles, which are functionalized by complementary DNA strands. We observe the spontaneous self-assembly of simple cubic (SC), plastic body-centered tetragonal (pBCT), and compositionally disordered plastic body-centered tetragonal (d-pBCT) phases due to hybridization of the DNA strands. We systematically investigate the effect of length, grafting density, as well as rigidity of the DNA strands on the self-assembly behavior of cubic nanoparticles. We measure the potential of mean force between DNA-functionalized nanocubes for varying rigidity of the DNA strands and DNA lengths. Using free-energy calculations, we find that longer and flexible DNA strands can lead to a phase transformation from SC to the pBCT phase due to a gain in entropy arising from the orientational degrees of freedom of the nanocubes in the pBCT phase. Our results may serve as a guide for self-assembly experiments on DNA-functionalized cubic nanoparticles. [ABSTRACT FROM AUTHOR]

The field of academic stress detection has gained significant attention recently because mental and physical health is crucial for academic success. The goal of academic stress detection is to identify a student's level of stress during the learning process using observable markers including physiological, behavioral, and psychological data. In recent years, detection methods that utilize wearable and nonwearable sensors have gained increased attention owing to their rich functionalities. In order to discover contemporary developments, coping strategies, limitations, difficulties, and potential research areas for addressing academic stress in educational settings, this study conducted an exhaustive review of the existing literature. First, we discussed how stressful events influence students’ psychological and physical health as well as the statistics frequently utilized to monitor academic stress. Then, using machine learning and deep learning methods, we described academic stress detection models. In addition, we described self-regulated strategy, computer-supported strategy and interactive learning technology-supported strategy. This comprehensive analysis of the latest techniques and recommendations for potential research avenues for tackling academic stress in educational settings will help other researchers in this field carry out and assess user research and build academic stress detection systems. [ABSTRACT FROM AUTHOR]

In the quest to enhance urban green mobility and promote sustainable leisure activities, this study presents a comprehensive analysis of the potential for cycling greenways within the urban fabric of Chengdu, China. Leveraging the built environment and cycling routes, simulated by dockless bike-sharing (DBS) big data on weekend afternoons, the cycling flow on existing networks reflects the preference for leisure cycling in surroundings, thus indicating the potential for future enhancements to cycling greenway infrastructure. Employing Multi-Scale Geographically Weighted Regression (MGWR), this research captures the spatial heterogeneity in environmental factors influencing leisure cycling behaviors. The findings highlight the significant roles of mixed land use, network diversity, public transit accessibility, human-scale urban design, road network thresholds, and the spatially variable impacts of architectural form in determining cycling greenway potential. This study culminates with the development of an evaluation model, offering a scientific approach for cities to identify and prioritize the expansion of cycling infrastructure. Contributing to urban planning efforts for more livable and sustainable environments, this research underscores the importance of data-driven decision-making in urban green mobility enhancement by accurately identifying and efficiently upgrading infrastructure guided by public preferences. [ABSTRACT FROM AUTHOR]

The cracking of geopolymer caused by its brittleness characteristics could reduce the stability and durability of the building structure. Studying the cracking behavior of fiber-reinforced geopolymer composites (FRGCs) is important to evaluate the toughness strengthening of geopolymer. This paper presents a real-time study on the cracking characteristics of FRGCs under splitting tensile load based on high-speed digital image correlation (HDIC) technology. The splitting tensile test was conducted on the FRGC with different fiber content. The real-time variation of strain and displacement field during the splitting process was analyzed. The influence of fiber content on the mechanical properties and crack behavior of FRGCs was discussed. Considering the splitting strength and crack width, the optimal fiber content for FRGCs that satisfied the crack resistance requirement was proposed. The results show that the incorporation of fiber can delay the cracking time and reduce strain change during the splitting process. The splitting tensile strength and the deformation increase as fiber content increases, while the crack width decreases as fiber content increases. The FRGC with 2.0% fiber content can maintain a crack width smaller than 0.1 mm, which satisfies the crack resistance requirements of practical engineering for economic consideration. [ABSTRACT FROM AUTHOR]

Dental caries and trauma are the most common oral diseases in children, which could result in defects of the teeth or detention. Maintenance of the primary dentition in a nonpathologic condition is important for oral health, craniofacial development, and the overall well-being of the children. In contemporary dentistry, primary anterior teeth defects are mainly treated with drugs, restorative treatments, or both. Restorative treatment is the most preferred method and includes direct restoration, full coronal restoration, post-and-core crowns, etc. This article reviews the available information regarding a variety of restorative treatments for primary incisor defects, including their backgrounds, clinical indications, clinical pathways, and related studies. The literature review shows that intraconal direct restoration is widely used on single surfaces. There are many kinds of full coronal restorations, and each has its own advantages. Pediatric resin-bonded strip crowns and zirconia crowns are the most popular and have excellent aesthetics. The use of post-and-core crowns for primary incisors is controversial. The absorbable post may be the next research hotspot. Therefore, treatment of severely destroyed primary incisors poses a challenge for pediatric dentists, as three important considerations must be kept in mind: children′s behavioral management, preservation of the tooth structure and parental satisfaction.

Most trajectory compression methods primarily focus on geometric similarity between compressed and original trajectories, lacking explainability of compression results due to ignoring semantic information. This paper proposes a spatio-temporal semantic constrained trajectory compression method. It constructs a new trajectory distance measurement model integrating both semantic and spatio-temporal features. This model quantifies semantic features using information entropy and measures spatio-temporal features with synchronous Euclidean distance. The compression principle is to retain feature points with maximum spatio-temporal semantic distance from the original trajectory until the compression rate is satisfied. Experimental results show these methods closely resemble each other in maintaining geometric similarity of trajectories, but our method significantly outperforms DP, TD-TR, and CascadeSync methods in preserving semantic similarity of trajectories. This indicates that our method considers both geometric and semantic features during compression, resulting in the compressed trajectory becoming more interpretable. [ABSTRACT FROM AUTHOR]

Background: This study aims to investigate the potential significance of mean platelet volume (MPV) and platelet distribution width (PDW) in predicting surgical neonatal necrotizing enterocolitis (NEC) and establish the correlation between MPV/PDW levels and the severity/prognosis of NEC. Methods: A retrospective study was conducted on a cohort of 372 patients diagnosed with NEC. The patients were categorized into two groups based on whether they underwent surgical therapy. Univariate /multivariate analysis were employed to compare the MPV and PDW between the two groups. Moreover, patients in surgical group were categorized into multiple subgroups based on intraoperative findings and postoperative prognosis, and the levels of MPV and PDW were compared among these subgroups. Results: Of the 372 patients, the operative group exhibited significantly higher levels of MPV and PDW than the nonoperative group (P < 0.05). Logistic regression analysis revealed that MPV (OR = 4.895, P < 0.001) and PDW (OR = 1.476, P < 0.001) independently associated with surgical NEC. The analysis of the receiver operating characteristic (ROC) curve revealed that the area under the curve (AUC) was 0.706 for MPV alone, with a cut-off value of 11.8 fL. Similarly, the AUC was 0.728 for PDW alone, with a cut-off value of 16%. However, when MPV and PDW were combined, the AUC increased to 0.906 for predicting surgical NEC. In accordance with the intraoperative findings, the levels of MPV and PDW were found to be higher in the large area necrosis group than in the partial or mild necrosis group (P < 0.01). Furthermore, the MPV and PDW values in the death group were significantly greater than those in the survival group (P =0.040, P =0.008). Conclusion: MPV and PDW may serve as potentially valuable indicators for determining the need for surgical intervention and predicting the prognosis of patients with NEC. [ABSTRACT FROM AUTHOR]