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C15H14MnN3O8, monoclinic, P21/m (no. 11), a = 7.3212(3) Å, b = 11.9120(4) Å, c = 9.3666(3) Å, β = 94.345(3)∘, V = 814.51(5) Å3, Z = 2, R gt(F) = 0.0242, wR ref(F 2) = 0.0685, T = 293 K.

Transglutaminase (TG) is a widely used enzyme with excellent protein cross-linking capacity. TG is commonly found in plants, animals and microorganisms, and microbial TG (mTG) is widely used in industrial production and application because of its good enzymatic properties. This paper describes the physicochemical properties and activation mechanism of mTG, and summarizes recent progress in mTG production by wild and different genetically engineered strains. Meanwhile, the application and potential of mTG in various industrial fields are reviewed. This review is expected to provide a reference and new ideas for research on the potential of mTG for industrial production and application.

The pitch angle of the contra rotation propeller (CRP) has important effect on the aerodynamic interference between the front and aft blades,which can change the aerodynamic performance of the propeller. In order to study the aerodynamic influence of pitch angle on the contra rotation propeller and improve the aerodynamic performance of propellers,at the inlet Mach number of 0.453,the numerical calculation is carried out by adjusting the blade pitch angle after about 6×6 configuration contra rotation propeller,in which the method is used by combining unsteady Reynolds-averaged Navier-Stokes (URANS) equation with SST turbulence model. The T-Rex high quality grid generation technique is used to study the change rule of the pitch angle of contra rotating propeller on aerodynamic interference. The results show that the aft propellers are under the action of pre-swirling air from the front propellers,the aft propellers can absorb a part of the tangential slip flow energy of the front propellers,and the aerodynamic efficiency is higher than that of the front propellers. The aerodynamic parameters of the front and aft propellers fluctuate 12 times in a rotating cycle. When the rotating speed of frond and aft propellers maintains the same,the pitch angle of the front propellers maintains constant,and the pitch angle of the aft propellers is reduced,the aerodynamic efficiency of the front and aft propellers is increased,and the efficiency of aft propellers is improved significantly.

The external-combustion wave rotor utilizes the unsteady pressure wave formed by the opening and clos-ing of the ports to perform high-efficiency energy conversion, which has a wide range of application prospects. The typical structures of internal flow field of the external combustion wave rotor are analyzed, the global important re-sults of performance tests are reviewed, and the advantages and challenges of supercharging gas turbine are summa-rized. It is pointed out that under the influence of port gradual opening and closing, circumferential clearance leak-age, centrifugal force and Coriolis force acceleration, and solid wall heat transfer, the internal flow field structure presents multi-dimensional characteristics, and the leakage loss accounts for the largest proportion. Under model test condition, a pressure gain of 15%~30% and a compression efficiency of 70%~85% can be obtained when used in conjunction with a gas turbine, it has the advantages of through-flow self-cooling, outstanding steady-state performance, excellent dynamic response and insignificant size effect. However, it is necessary to overcome the bottlenecks such as compact overall stricture design, high performance wave rotor design, wide operating condition wave system structure control, low-loss transition duct design, and compound loss suppression.

Based on the aircraft measurements on 28 February 2021, combined with ERA5 reanalysis data and sounding data, the weather background and the characteristics of cloud structure of a severe icing case on the aircraft are analyzed. The severe icing process is induced by the joint influence of high-level trough, low-level shear line, low-level jet and cold front. The ERA5 reanalysis data show that the maximum value area of supercooled water is mainly distributed at the height of 700 hPa to 600 hPa on the warm side of the front area and the ambient temperature is -4 to -12℃, accompanied by an upward movement of -0.2 to -0.8 Pa·s-1. The sounding data show that the cloud system is distributed in multiple layers. There is a deep dry layer between the upper ice crystal cloud and the lower supercooled water cloud. The temperature in the aircraft detection area is -9 to -3℃ and the dew-point spread is 0℃, which are favorable for icing. During the icing process, the air temperature is -8 to -5℃. Aircraft measurements show that there is abundant supercooled water in clouds. The average liquid water content by cloud particles probe is 0.35 g·m-3, and the maximum value is 0.7 g·m-3. The average liquid water content by total water content measurement probes is 0.5 g·m-3, the maximum value is 0.85 g·m-3, and for 11 minutes the liquid water content is larger than 0.45 g·m-3. The average median volume diameter of cloud particles is 20.3 μm, and the number concentration of cloud particles is 149.3 cm-3 on average. The number concentration of cloud particles tends to increase from low level to high level and vice versa for the median volume diameter of cloud particles. Finally, the conditions with different icing intensity that the King-air 350 aircraft may encounte during weather modification work in the cloud are discussed. The calculation shows that the King-air 350 aircraft carries out observation research or weather modification tasks when the liquid water content in the cloud is higher than 0.04 g·m-3, 0.15 g·m-3 and 0.45 g·m-3, it may encounter light, moderate, and severe icing, under certain conditions.

Gravimeter measures gravitational acceleration, which is valuable for geophysical applications such as hazard forecasting and prospecting. Gravimeters have historically been large and expensive instruments. Micro-Electro-Mechanical-System gravimeters feature small size and low cost through scaling and integration, which may allow large-scale deployment. However, current Micro-Electro-Mechanical-System gravimeters face challenges in achieving ultra-high sensitivity under fabrication tolerance and limited size. Here, we demonstrate a μGal-level Micro-Opto-Electro-Mechanical-System gravimeter by combining a freeform anti-spring design and an optical readout. A multi-stage algorithmic design approach is proposed to achieve high acceleration sensitivity without making high-aspect ratio springs. An optical grating-based readout is integrated, offering pm-level displacement sensitivity. Measurements reveal that the chip-scale sensing unit achieves a resonant frequency of 1.71 Hz and acceleration-displacement sensitivity of over 95 μm/Gal with an etching aspect ratio of smaller than 400:30. The benchmark with a commercial gravimeter PET demonstrates a self-noise of 1.1 μGal Hz−1/2 at 0.5 Hz, sub-1 μGal Hz−1/2 at 0.45 Hz, and a drift rate down to 153 μGal/day. The high performance and small size of the Micro-Opto-Electro-Mechanical-System gravimeter suggest potential applications in industrial, defense, and geophysics. MEMS gravimeters are compact and cost-effective but face challenges in achieving ultra-high sensitivity due to fabrication tolerances and size limitations. Here, authors introduce a μGal MOEMS gravimeter with locally adjustable free-form anti-springs, achieving picometer-level displacement sensitivity. [ABSTRACT FROM AUTHOR]

Planting aluminum-tolerant legume green manure is a cost-effective and sustainable method to increase soil fertility as well as decrease Al toxicity in acidic soils. By analyzing the relative root elongation of seven legume green manure species, common vetch (Vicia sativa L.) was identified as an Al-resistant species. Furthermore, cultivars 418 (cv. Sujian No.3) and 426 (cv. Lanjian No.3) were identified as Al-resistant and -sensitive cultivars, respectively, among 12 common vetch germplasms. The root growth of 418 was less inhibited by Al toxicity in both the germination stage and seedling stage than that of 426. Under Al toxicity, 418 accumulated less Al in both roots and shoots. Citrate is more abundant in the roots of common vetch compared to oxalate or malate. The internal citrate contents showed no significant difference between 418 and 426 under either control or Al treatment. However, the citrate efflux increased in response to Al in 418 but not in 426 and was higher in 418 under Al stress than in 426. Consistently, VsMATE1 expression increased faster and to a greater extent in 418 than 426 in response to Al stress. These results indicated that a VsMATE1-mediated citrate efflux might play an important role in Al resistance in common vetch. It is suggested that VsMATE1 is a valuable candidate gene for aluminum resistance breeding. [ABSTRACT FROM AUTHOR]

Plastic-covered greenhouse (PCG) is widely used in agricultural production due to its temperature control, water conservation, and wind protection characteristics, significantly enhancing crop yields and economic benefits. However, its long-term and extensive use can lead to environmental issues, such as the accumulation of local toxic gases and the degradation of soil physicochemical properties. Therefore, obtaining a comprehensive distribution of PCGs is essential. To monitor PCGs on a large scale, this study developed a novel approach for producing the first global 10-meters PCGs dataset (Global-PCG-10) with high-quality. Firstly, the globe was divided into multiple 5-degree grids, and grids for classification were organized based on global cropland layer. Then, multi-temporal Sentinel-2 data and initial labels of PCGs were obtained through Google Earth Engine (GEE) to create a training set for deep learning. Next, initial labels were optimized with the active learning strategy combined with the deep learning model, APC-Net. Finally, the PCGs classification results were predicted, spatially analyzed, and compared with publicly released land use and land cover (LULC) datasets. Experimental results indicate that the proposed Global-PCG-10 dataset has a high overall accuracy of 92.08 %. The global area of PCGs is 14,259.85 km², and 69.24 % of PCGs are located in Asia, covering around 9,874.51 km2. China has the largest PCGs area of 8,224.90 km2, accounting for 57.67 % of the globe and 83.29 % of Asia. Comparisons with other LULC datasets revealed that PCGs, which should be classified as cropland, are often misclassified as bareland, impervious surfaces, ice/snow, etc. [ABSTRACT FROM AUTHOR]

Hairy vetch (Vicia villosa Roth) and smooth vetch (V. villosa Roth var. glabrescens) are important cover crops and legume forage with great economic and ecological values. Due to the large and highly heterozygous genome, full-length transcriptome reconstruction is a cost-effective route to mining their genetic resources. In this study, a hybrid sequencing approach combining SMRT and NGS technologies was applied. The results showed that 28,747 and 40,600 high-quality non-redundant transcripts with an average length of 1808 bp and 1768 bp were generated from hairy vetch and smooth vetch, including 24,864 and 35,035 open reading frames (ORFs), respectively. More than 96% of transcripts were annotated to the public databases, and around 25% of isoforms underwent alternative splicing (AS) events. In addition, 987 and 1587 high-confidence lncRNAs were identified in two vetches. Interestingly, smooth vetch contains more specific transcripts and orthologous clusters than hairy vetch, revealing intraspecific transcript diversity. The phylogeny revealed that they were clustered together and closely related to the genus Pisum. Furthermore, the estimation of Ka/Ks ratios showed that purifying selection was the predominant force. A putative 3-dehydroquinate dehydratase/shikimate dehydrogenase (DHD/SDH) gene underwent strong positive selection and might regulate phenotypic differences between hairy vetch and smooth vetch. Overall, our study provides a vital characterization of two full-length transcriptomes in Vicia villosa, which will be valuable for their molecular research and breeding. [ABSTRACT FROM AUTHOR]

Bright biocompatible fluorescent imaging dyes with red to near-infrared (NIR) emissions are ideal candidates for fluorescence microscopy applications. Pyrene–benzothiazolium hemicyanine dyes are a new class of lysosome-specific probes reported on recently. In this work, we conduct a detailed implementation study for a pyrene–benzothiazolium derivative, BTP, to explore its potential imaging applications in fluorescence microscopy. The optical properties of BTP are studied in intracellular environments through advanced fluorescence microscopy techniques, with BTP exhibiting a noticeable shift toward blue (λem ≈ 590 nm) emissions in cellular lysosomes. The averaged photon arrival time (AAT)-based studies exhibit two different emissive populations of photons, indicating the probe's dynamic equilibrium between two distinctively different lysosomal microenvironments. Here, BTP is successfully utilized for time-lapse fluorescence microscopy imaging in real-time as a 'wash-free' imaging dye with no observed background interference. BTP exhibits an excellent ability to highlight microorganisms (i.e., bacteria) such as Bacillus megaterium through fluorescence microscopy. BTP is found to be a promising candidate for two-photon fluorescence microscopy imaging. The two-photon excitability of BTP in COS-7 cells is studied, with the probe exhibiting an excitation maximum at λTP ≈ 905 nm. [ABSTRACT FROM AUTHOR]

The prediction of hypersonic inlet starting performance is crucial for the successful ignition of the combustion chamber, directly impacting the overall performance of the propulsion system. This challenge arises especially when freestream conditions vary. Therefore, this paper proposes the concept of the equivalent contraction ratio, and establishes and analyzes the intrinsic correlation between the geometric contraction ratio and angle of attack on the starting performance of three-dimensional inward-turning inlet. The results indicate the following: (1) The startability index can be applied to determine the start boundary of the three-dimensional inward-turning inlet under conditions of the freestream Mach number of 6.0 and an altitude of 27 km, with a deviation of no more than 6.6% from the optimal SI = 0.087 criterion; (2) The start boundary after applying the equivalent contraction ratio shows deviations not exceeding 4.0% under positive angle-of-attack conditions compared to the startability index, while the deviation is larger under negative angle-of-attack conditions, reaching a maximum of 13.3%. After applying a correction formula, the deviations can be reduced to within 2.0%; (3) For the same equivalent contraction ratio, the differences in starting performance between different positive and negative angle-of-attack conditions may fundamentally arise from the degree of compression of the inlet. Finally, the equivalent contraction ratio theory is proven to be able to quickly and easily predict the accurate starting performance of the inward-turning inlet at different angles of attack, improving the breadth and efficiency of engineering predictions. [ABSTRACT FROM AUTHOR]

As a propulsor with a good application prospect, the flapping foil has been a hot research topic in the past decade. Although the research results of flapping foils have been very abundant, the performance-influencing mechanism of flapping foils is still not perfect, and the research considering three-dimensional (3D) effects for engineering applications is still very limited. Based on the above considerations, a systematic and parametric analysis of a small aspect ratio flapping foil is conducted to correlate the influencing factors including angle of attack (AoA) characteristics and wake vortex on the propulsive efficiency. Three-dimensional numerical analyses of full-active and semi-active flapping foils are carried out in this paper, in which the former focuses on different heave amplitudes and pitch amplitudes, and the latter concentrates on different spring stiffnesses. The analysis covers the full range of advance coefficient, which starts around 0 and ends at a thrust drop of 0. Firstly, the influence of the maximum AoA (αmax) on the efficiency and thrust coefficient of these two kinds of flapping foils is analyzed. The results show that for the small aspect ratio flapping foil in this paper, regardless of the full-active or semi-active form, the peak efficiency as high as 75% for both generally appears around αmax = 0.2 rad, while the peak thrust coefficient of 0.5 occurs near αmax = 0.3 rad. Then, by analyzing the wake flow field, it is found that the lower efficiency of larger αmax working points is mainly due to the larger vortex dissipation loss, while the lower efficiency of smaller αmax working points is mainly due to the larger friction loss of the foil surface. Furthermore, the plumpness of different AoA curves is compared and analyzed. It was found that, unlike the results of full-active flapping foils, the shape of the AoA curve of semi-active flapping foils with different spring stiffnesses is similar, and the relationship with efficiency is not strictly corresponding. This study is expected to provide guidance on both academics and industries in relevant fields. [ABSTRACT FROM AUTHOR]

With the growing demand for new energy sources, electrochemical water splitting for hydrogen production is a technology that must be vigorously promoted. Therefore, to improve the efficiency of the oxygen evolution reaction (OER) at the anode, high-performance OER catalysts are essential. Given their advantages in electrocatalysis, nanoporous materials have garnered considerable attention in previous studies for OER applications. This review provides a comprehensive overview of various strategies to optimize active site utilization in nanoporous materials. These strategies include regulating pore size and porosity, constructing hierarchical nanoporous structures, and enhancing material conductivity. Additionally, it covers approaches to boost the intrinsic OER activity of nanoporous materials, such as tuning the composition of anions and cations, creating vacancies, constructing interfaces, and forming boundary active sites. While nanoporous materials offer significant potential for advancing OER, challenges remain, including difficulties in quantifying activity within nanopores, the unclear impact of nanoporous material morphology, challenges in accessing nanopore interiors with in situ techniques, and a lack of theoretical calculations on pore structure. However, these challenges also present opportunities, and we hope this review provides a fresh perspective to inspire future research. [ABSTRACT FROM AUTHOR]

Insulin resistance (IR) is the principal pathophysiological change occurring in diabetes mellitus (DM). Baicalein, a bioactive flavonoid primarily extracted from the medicinal plant Scutellaria baicalensis Georgi, has been shown in our previous research to be a potential natural glucagon-like peptide-1 receptor (GLP-1R) agonist. However, the exact therapeutic effect of baicalein on DM and its underlying mechanisms remain elusive. In this study, we investigated the therapeutic effects of baicalein on diabetes and sought to clarify its underlying molecular mechanisms. Our results demonstrated that baicalein improves hyperglycemic, hyperinsulinemic, and glucometabolic disorders in mice with induced diabetes via GLP-1R. This was confirmed by the finding that baicalein's effects on improving IR were largely diminished in mice with whole-body Glp1r ablation. Complementarily, network pharmacology analysis highlighted the pivotal involvement of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) insulin signaling pathway in the therapeutic actions of baicalein on IR. Our mechanism research significantly confirmed that baicalein mitigates hepatic and muscular IR through the PI3K/AKT signal pathway, both in vitro and in vivo. Furthermore, we demonstrated that baicalein enhances glucose uptake in skeletal muscle cells under IR conditions through the Ca2+/calmodulin-dependent protein kinase II (CaMKII)-adenosine 5′-monophosphate-activated protein kinase (AMPK)-glucose transporter 4 (GLUT4) signaling pathway in a GLP-1R-dependent manner. In conclusion, our findings confirm the therapeutic effects of baicalein on IR and reveal that it improves IR in liver and muscle tissues through the PI3K/AKT insulin signaling pathway in a GLP-1R dependent manner. Moreover, we clarified that baicalein enhances the glucose uptake in skeletal muscle tissue through the Ca2+/CaMKII-AMPK-GLUT4 signal pathway. [ABSTRACT FROM AUTHOR]

Aiming to accurately identify apple targets and achieve segmentation and the extraction of branch and trunk areas of apple trees, providing visual guidance for a picking robot to actively adjust its posture to avoid branch trunks for obstacle avoidance fruit picking, the spindle-shaped fruit trees, which are widely planted in standard modern apple orchards, were focused on, and an algorithm for apple tree fruit detection and branch segmentation for picking robots was proposed based on an improved YOLOv8s model design. Firstly, image data of spindle-shaped fruit trees in modern apple orchards were collected, and annotations of object detection and pixel-level segmentation were conducted on the data. Training set data were then augmented to improve the generalization performance of the apple detection and branch segmentation algorithm. Secondly, the original YOLOv8s network architecture's design was improved by embedding the SE module visual attention mechanism after the C2f module of the YOLOv8s Backbone network architecture. Finally, the dynamic snake convolution module was embedded into the Neck structure of the YOLOv8s network architecture to better extract feature information of different apple targets and tree branches. The experimental results showed that the proposed improved algorithm can effectively recognize apple targets in images and segment tree branches and trunks. For apple recognition, the precision was 99.6%, the recall was 96.8%, and the mAP value was 98.3%. The mAP value for branch and trunk segmentation was 81.6%. The proposed improved YOLOv8s algorithm design was compared with the original YOLOv8s, YOLOv8n, and YOLOv5s algorithms for the recognition of apple targets and segmentation of tree branches and trunks on test set images. The experimental results showed that compared with the other three algorithms, the proposed algorithm increased the mAP for apple recognition by 1.5%, 2.3%, and 6%, respectively. The mAP for tree branch and trunk segmentation was increased by 3.7%, 15.4%, and 24.4%, respectively. The proposed detection and segmentation algorithm for apple tree fruits, branches, and trunks is of great significance for ensuring the success rate of robot harvesting, which can provide technical support for the development of an intelligent apple harvesting robot. [ABSTRACT FROM AUTHOR]

Deep learning technology can automatically learn features from large amounts of data, with powerful feature extraction and pattern recognition capabilities, thereby improving the accuracy and efficiency of object detection. [The objective of this study]: In order to improve the accuracy and speed of mask wearing deep learning detection models in the post pandemic era, the [Problem this study aimed to resolve] was based on the fact that no research work has been reported on standardized detection models for mask wearing with detecting nose targets specially. [The topic and method of this study]: A mask wearing normalization detection model (towards the wearing style exposing the nose to outside, which is the most obvious characteristic of non-normalized style) based on improved YOLOv5s (You Only Look Once v5s is an object detection network model) was proposed. [The improved method of the proposed model]: The improvement design work of the detection model mainly includes (1) the BottleneckCSP (abbreviation of Bottleneck Cross Stage Partial) module was improved to a BottleneckCSP-MASK (abbreviation of Bottleneck Cross Stage Partial-MASK) module, which was utilized to replace the BottleneckCSP module in the backbone architecture of the original YOLOv5s model, which reduced the weight parameters' number of the YOLOv5s model while ensuring the feature extraction effect of the bonding fusion module. (2) An SE module was inserted into the proposed improved model, and the bonding fusion layer in the original YOLOv5s model was improved for better extraction of the features of mask and nose targets. [Results and validation]: The experimental results indicated that, towards different people and complex backgrounds, the proposed mask wearing normalization detection model can effectively detect whether people are wearing masks and whether they are wearing masks in a normalized manner. The overall detection accuracy was 99.3% and the average detection speed was 0.014 s/pic. Contrasted with original YOLOv5s, v5m, and v5l models, the detection results for two types of target objects on the test set indicated that the mAP of the improved model increased by 0.5%, 0.49%, and 0.52%, respectively, and the size of the proposed model compressed by 10% compared to original v5s model. The designed model can achieve precise identification for mask wearing behaviors of people, including not wearing a mask, normalized wearing, and wearing a mask non-normalized. [ABSTRACT FROM AUTHOR]

C15H14MnN3O8, monoclinic, P21/m (no. 11), a = 7.3212(3) Å, b = 11.9120(4) Å, c = 9.3666(3) Å, β = 94.345(3)∘, V = 814.51(5) Å3, Z = 2, Rgt(F) = 0.0242, wRref(F2) = 0.0685, T = 293 K. [ABSTRACT FROM AUTHOR]