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Tritium causes internal dose hazards to humans. Currently, tritium in the environment mainly comes from nuclear power plants, and tritiated water (HTO) is the main form of liquid emission. Therefore, online monitoring activity of tritium in the aqueous medium is vital for protecting human health, and it can warn of the operation status of nuclear power plants. In this paper, we present an improved structure of plastic scintillating fiber (PSF) and a PSF array design, and the detection parameters of PSF arrays with different radii and lengths under different radius detection chambers are simulated using Geant4. Based on the simulation results, the detector is designed, and the minimum detectable activity concentration (MDAC) of the detector is calculated. With calculated MDACs down to 3.09 Bq/L, the proposed design can meet the Chinese requirements for HTO release of inland nuclear power plants of <100 Bq∙L−1. Therefore, the detector designed with a PSF array can be applied to online monitoring of tritium in the aqueous medium. [ABSTRACT FROM AUTHOR]

Maize (Zea mays) is one of the most important crops in the world, but its yield and quality are seriously affected by diverse diseases. Identifying broad-spectrum resistance genes is crucial for developing effective strategies to control the disease in maize. In a genome-wide study in maize, we identified a G-type lectin receptor kinase ZmLecRK1, as a new resistance protein against Pythium aphanidermatum , one of the causal pathogens of stalk rot in maize. Genetic analysis showed that the specific ZmLecRK1 allele can confer resistance to multiple pathogens in maize. The cell death and disease resistance phenotype mediated by the resistant variant of ZmLecRK1 requires the co-receptor ZmBAK1. A naturally occurring A404S variant in the extracellular domain of ZmLecRK1 determines the ZmLecRK1-ZmBAK1 interaction and the formation of ZmLecRK1-related protein complexes. Interestingly, the ZmLecRK1 susceptible variant was found to possess the amino acid S404 that is present in the ancestral variants of ZmLecRK1 and conserved among the majority of grass species, while the resistance variant of ZmLecRK1 with A404 is only present in a few maize inbred lines. Substitution of S by A at position 404 in ZmLecRK1-like proteins of sorghum and rice greatly enhances their ability to induce cell death. Further transcriptomic analysis reveals that ZmLecRK1 likely regulates gene expression related to the pathways in cell wall organization or biogenesis in response to pathogen infection. Taken together, these results suggest that the ZmLecRK1 resistance variant enhances its binding affinity to the co-receptor ZmBAK1, thereby enhancing the formation of active complexes for defense in maize. Our work highlights the biotechnological potential for generating disease-resistant crops by precisely modulating the activity of ZmLecRK1 and its homologs through targeted base editing. The G-type lectin receptor kinase ZmLecRK1 confers multiple disease resistance in maize. A naturally occurring A404S variant in ZmLecRK1 determines the ZmLecRK1-ZmBAK1 interaction for defense. The susceptible variant of ZmLecRK1 with S404 that is conserved among the majority of grass species constitutes the ancestral variants of ZmLecRK1, while the resistance variant with A404 is only present in a few maize inbred lines. [ABSTRACT FROM AUTHOR]

Metal ions are widely present in biological systems and participate in many critical biochemical processes such as material transportation, energy conversion, information transmission and metabolic regulation, making them indispensable substance in our body. They can cause health problems when deficiency or excess occurs. To understand various metabolic processes and facilitate diseases diagnosis, it is very important to measure the content and monitor the distribution of metal ions in individual cells, tissues and whole organisms. Among the various methods for metal ion detection, fluorescent sensors with organic dyes have attracted tremendous attention due to many advantages such as high fluorescence quantum yield, facile modification approaches and biocompatibility in addition to operation ease, high sensitivity, fast detection speed, and real-time detection. This review summarizes the recent progress on the detection and imaging of the metal ions in biological systems including Na+, K+, Ca2+, Mg2+, Fe2+/Fe3+, Zn2+, and Cu2+ provides an opinion on remaining challenges to be addressed in this field.

Loess is strongly sensitive to water, and its properties are substantially affected by weathering and other factors. Loess landslides, which are widely distributed in Ili, are closely related to seasonal freeze-thaw effects. In this study, multiple freeze-thaw cycle tests were conducted on loess samples with different moisture contents from the Ili region, and triaxial shear tests were conducted to study mechanical characteristics of the loess. Variations in the microstructure of the loess samples were analysed using scanning electron microscopy images to reveal the underlying mechanisms. The results showed that the freeze-thaw cycles significantly influence failure mode of the stress-strain curve of loess samples with a lower moisture content of 10%, which transitioned from strain softening to strain hardening with six cycles as the turning point, whereas the stress-strain curve transitioned from strong to weak hardening for the loess samples with higher moisture content of 18%. As the number of freeze-thaw cycles increased, failure strength and shear strength parameters of loess gradually decreased, and tended to stabilize after the 10th cycle. In addition, strength parameters deterioration is most significant after the first cycle, and the degree of cohesion deterioration was much greater than that of internal friction angle. Cohesion and internal friction angle showed attenuation exponential function and polynomial function relationship, respectively, with the number of freeze-thaw cycles, and their fitting parameters underwent a sudden change with increasing moisture content, with 14% as the turning point. Microscopic SEM revealed that the number of overhead pores increased, and point-to-point contact between particles increased after freeze-thaw, which was consistent with increase in of loess porosity. This revealed the fundamental reason for the significant deterioration in loess strength caused by freeze-thaw cycles. [ABSTRACT FROM AUTHOR]

Carrier‐free nanodrugs that integrate chemodrugs and other therapeutic agents demonstrate good efficacy and minimized side effects, showing promise for combined therapy. However, a key challenge lies in enhancing the bioavailability and therapeutic potential of the nanodrugs through a controllable assembly process. Herein, a carrier‐free photothermal nanodrug (ZPQ NPs) is constructed through flavonol‐driven assembly with amine‐substituted perylene diimide for enhanced chemo‐photothermal combined cancer therapy. The flavonol, particularly quercetin, facilitates J‐aggregation of perylene diimide derivatives within the nanodrug and contributes to multiple improvements, including red‐shifted absorption, enhanced fluorescence intensity, improved photothermal conversion efficiency as well as excellent photostability. Moreover, the nanodrug also demonstrates enhanced cellular uptake and intracellular reactive oxygen species scavenging capability. The combination of quercetin and photothermal effect effectively kills cancer cells, as well as alleviates inflammation following photothermal therapy. Guided by in vivo fluorescence imaging, the application of ZPQ NPs results in complete tumor elimination and effectively inhibits tumor recurrence through chemo‐photothermal combined therapy. This work presents a straightforward strategy for constructing carrier‐free nanodrugs that exhibit simultaneous enhancements in both photophysical properties and biological activity. [ABSTRACT FROM AUTHOR]

Metal cutting is considered a process of severe plastic deformation (SPD) and often compared to other SPD processes used to develop submicron and nanostructured metallurgical structure in metallics materials. To validate this assumption, a proper determination of the distribution of plastic strain in the machined surface and subsurface is required. This research work deals with the determination of the distribution of the plastic strain in the machined surface and subsurface in orthogonal cutting of Ti-6Al-4V titanium alloy using both experimental and modeling approaches. Plastic strain distribution in the machined subsurface is determined experimentally using in-situ Digital Image Correlation (DIC), while numerical simulation using FEM is used to determine plastic strain distribution up to the machined surface. The experimental plastic strain distribution obtained by DIC and by X-ray diffraction peak broadening is used to validate the predicted plastic strain distribution obtained by FEM simulation. The results show a strong gradient of plastic strain in a thin layer less than 50 µm, with high plastic strain values at the machined surface exceeding 50%. [ABSTRACT FROM AUTHOR]

Measurement standard management is an important link to ensure the unity of national measurement unit system and the consistency and accuracy of value transfer. The establishment of measurement standard management system aims to provide technical support for traceability of social measurement. On the basis of ensuring the unity of national measurement unit system and the accuracy and reliability of measurement value, it undertakes the task of legal measurement. Its management level, technical ability and service quality not only directly determine the correctness of the measurement results, but also have a crucial impact on the social activities related to the measurement results. Based on the analysis of the current situation of measurement standard management in power industry, this paper expounds the significance of continuous optimization of measurement standard management system and the results achieved.

Doping Magnéli phase Ti4O7 by cation substitution has attracted some interest for modulating structure and properties enhancement, but it remains a big problem to understand how doping elements impact the thermodynamic and structural stability of Ti4O7. We utilized first-principles calculations based on density functional theory (DFT) combined with machine learning (ML) to forecast the stability of doped Ti4O7. DFT calculations are used to model the thermodynamic and structural stability, as well as the electronic structure, of doped (Ti,M)4O7 complexes (M = Sc, Y, La, Ce, Zr, Hf, V, Nb, Ta, Cr, Mo, and W). The results reveal that even if all (Ti,M)4O7 are thermodynamically stable, the introduction of rare earth elements Y, La, and Ce causes great structural distortion. Employing Zr, Nb, Mo, and W can improve Ti4O7 thermodynamic stability due to strong bond strength and minimal lattice distortion. The relevance of 78 doping element qualities and one processing feature (doping site) for (Ti,M)4O7 stability is discovered using ML. The results show that modulus of rigidity and entropy of solid of doping atoms have the greatest influence on the thermodynamic and structural stability of doped Ti4O7, which is useful for predicting additional (Ti,M)4O7 stability without DFT calculations. At a low doping concentration, Ce-doped Ti4O7 with massive lattice distortion was synthesized, supporting the DFT results. This study not only applies to all doped Ti4O7 complexes, setting the groundwork for stability of the planned high-performance cation substitution in defect Ti4O7, but also introduces a unique way of predicting stability in defect engineering. [ABSTRACT FROM AUTHOR]