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Rationale: The chemical composition of the new compound aloe capsule (NCAC) has not been fully elucidated to date, which poses challenges for pharmacology, scientific, and rational drug use. In this study, a rapid and sensitive method was established to comprehensively study the constituents in the NCAC. The contents of the NCAC were analyzed by UPLC‐Q‐Orbitrap‐MS and data postprocessing technology. Methods: Firstly, the extract was separated by UPLC system, and the fragment information was obtained under positive and negative ions and then compared with the characteristic fragments described in the literature, so as to achieve the purpose of rapid identification of the compound of NCAC. Results: A total of 56 compounds including 21 chromones, 6 pyranones, 7 anthraquinones, 7 anthrone, 5 alkaloids, 4 amino acids, and 6 other components were detected in NCAC by comparing the retention time and mass spectrometry information and retrieving the reference literature. Conclusions: The UPLC‐Q‐Orbitrap‐MS method was developed and utilized successfully to identify the major constituents in NCAC and would be helpful for improving the quality control standard of NCAC. [ABSTRACT FROM AUTHOR]

The integrated two-stage electric centrifugal compressors are most widely used in the present fuel cell vehicles. Air compressors influence the efficiency of fuel cell systems significantly, so it is crucial to improve the energy efficiency of centrifugal compressors. However, there is a lack of centrifugal compressor performance models that can reflect the thermodynamic characteristics of two-stage compression system, which is the main focus of this paper. In this paper, an analytical model of two-stage centrifugal compressor performance considering the thermodynamic characteristics of two-stage compression was first derived and experimentally validated. The single-stage centrifugal compressor model (SSCCM) can be treated as a lumped parameter model of the two-stage centrifugal compressor to predict the compressor performance. Therefore, the SSCCM and the two-stage centrifugal compressor model (TSCCM) were compared. The results show that the TSCCM is more accurate and robust. Furthermore, a novel compressor structure equipped with an intercooler in the inter-stage piping was proposed to improve the energy efficiency of the centrifugal compressor. Based on this novel structure, the TSCCM was modified. Finally, a quantitative analysis was performed to study the effect of an inter-stage intercooler on compressor efficiency. Compared to the original compressor without the inter-stage intercooler, the efficiency improvement by the inter-stage intercooler can be in the range of 3.29–3.97%, with power savings of 0.332–0.635 kW. The study can be used to support engineers and researchers in fast identifying effective solutions in terms of design for the next generation of centrifugal compressors. [ABSTRACT FROM AUTHOR]

Melothria scabra has gradually become an economically important plant worldwide. The complete chloroplast genome of M. scabra has a length of 156,744 bp, contains a large single-copy (LSC) region (86,387 bp), a small single-copy (SSC) region (18,055 bp), and two inverted repeats (IRs) with the same length of 26,151 bp. In total, 126 genes were detected, including 83 protein-encoding genes, 35 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. For phylogenetic analysis, M. scabra has a closer genetic relationship with Cucumis sativus and Citrullus lanatus. The complete chloroplast genome sequence of M. scabra would promote the germplasm exploration, phylogenetic relationships, and molecular biology researches in Melothria. [ABSTRACT FROM AUTHOR]

Despite extensive research on the network structure of tourism destinations, literature on the spatial network structure of cross-border tourism–economic connections is relatively limited, specifically the complex geopolitical relationship between China and the Association of Southeast Asian Nations (ASEAN). Thus, in this study we explored the relevant characteristics and influencing factors of the spatial structure of tourism economic networks. The results first indicate that the China–ASEAN tourism economic network exhibits distinct stage characteristics, with an 'N'-shaped fluctuating growth trend, evolving from a point-like network to a multipolar development in spatial structure. In addition, China demonstrates a distinctive personality in the network and occupies a central leadership position. Secondly, an analysis of influencing factors shows that institutional distance and geographic distance have a significant impact on the network. Geopolitical risk plays a notable indirect moderating role in the network through its association with tourism policies and regulations, tourism promotion, and cooperation. This further reveals the diverse pathways through which geopolitical risk affects the network, providing a novel perspective for research on the tourism economic network. [ABSTRACT FROM AUTHOR]

Background and Purpose Experimental Approach Key Results Conclusion and Implications Pathological retinal angiogenesis is a typical manifestation of vision‐threatening ocular diseases. Many patients exhibit poor response or resistance to anti‐vascular endothelial growth factor (VEGF) agents. Bruton's tyrosine kinase (BTK) controls the proliferation and function of immune cells. Therefore, we examined the anti‐inflammatory and anti‐angiogenic effects of BTK inhibition on retinal angiogenesis.Retinal neovascularisation and vascular leakage in oxygen‐induced retinopathy in C57/BL6J mice were assessed by whole‐mount retinal immunofluorescence. PLX5622 was used to deplete microglia and Rag1‐knockout mice were used to test the contribution of lymphocytes to the effects of BTK inhibition. The cytokines, activation markers, inflammatory and immune‐regulatory activities of retinal microglia/macrophages were detected using qRT‐PCR and immunofluorescence. NLRP3 was detected by western blotting, and the effects of BTK inhibition on the co‐culture of microglia and human retinal microvascular endothelial cells (HRMECs) were examined.BTK inhibition suppressed pathological angiogenesis and vascular leakage, and significantly reduced retinal inflammation, which involved microglia/macrophages but not lymphocytes. BTK inhibition increased anti‐inflammatory factors and reduced pro‐inflammatory cytokines that resulted from NLRP3 inflammasome activation. BTK inhibition suppressed the inflammatory activity of microglia/macrophages, and acted synergistically with anti‐VEGF without retinal toxicity. Moreover, the supernatant of microglia incubated with BTK‐inhibitor reduced the proliferation, tube formation and sprouting of HRMECs.BTK inhibition suppressed retinal neovascularisation and vascular leakage by modulating the inflammatory activity of microglia and macrophages. Our study suggests BTK inhibition as a novel and promising approach for alleviating pathological retinal angiogenesis. [ABSTRACT FROM AUTHOR]

Maxillofacial bone defects exhibit intricate anatomy and irregular morphology, presenting challenges for effective treatment. This study aimed to address these challenges by developing an injectable bioactive composite microsphere, termed D‐P‐Ak (polydopamine‐PLGA‐akermanite), designed to fit within the defect site while minimizing injury. The D‐P‐Ak microspheres biodegraded gradually, releasing calcium, magnesium, and silicon ions, which, notably, not only directly stimulated the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) but also activated sensory nerve cells to secrete calcitonin gene‐related peptide (CGRP), a key factor in bone repair. Moreover, the released CGRP enhanced the osteogenic differentiation of BMSCs through epigenetic methylation modification. Specifically, inhibition of EZH2 and enhancement of KDM6A reduced the trimethylation level of histone 3 at lysine 27 (H3K27), thereby activating the transcription of osteogenic genes such as Runx2 and Osx. The efficacy of the bioactive microspheres in bone repair is validated in a rat mandibular defect model, demonstrating that peripheral nerve response facilitates bone regeneration through epigenetic modification. These findings illuminated a novel strategy for constructing neuroactive osteo‐inductive biomaterials with potential for further clinical applications. [ABSTRACT FROM AUTHOR]

This study examines Taiwanese investment in Mainland China as it is an important part of cross-strait economic cooperation. Using sample data from Taiwanese-listed electronic information enterprises in Mainland China (1990-2016), this study combines ArcGIS spatial visualization and case analysis to investigate their value chain organization models and spatiotemporal evolution regularity. The results show that the value chain of the electronic information industry for Taiwanese investments in Mainland China has three models: vertical integration, modularization in production sharing, and production extension. Vertical integration is the main production organization model of these Taiwanese listed electronic information enterprises, expanding from single production to the entire manufacturing value chain, followed by sales, and finally R&D. This model is still in use in the Western Taiwan Straits Economic Zone, whereas the other four Taiwanese investment agglomerations, namely the Bohai Economic Rim, Yangtze River Delta, Pearl River Delta, and Western Delta Economic Circle, began to expand to both ends of the production link, particularly to the sales link. High-value -added enterprises adopting production sharing models began to show a trend of expansion to inland cities, and enterprises adopting the manufacturing-sales model (a production expansion model) had the widest distribution. Finally, at the city level, the value chain fragmentation structure of Taiwanese and developed countries' cross-border (multinational) enterprises in Mainland China were consistent, that is, they matched the Chinese city hierarchy; at the regional level, however, the Western Delta Economic Circle pioneered to become a hub for Taiwanese electronic to information enterprises set up their R&D and sales links in Mainland China. Investigating chain-alike spatiotemporal expansion of Taiwanese investment in Mainland China is important for the integration and development of the value chain, production network, and enterprise spatial organization theories.

Zanthoxylum, as a medicinal and edible herbal medicine, has a long history and complex chemical composition. There are many varieties of Zanthoxylum, and there are differences in composition between varieties. In this study, a rapid classification and identification method for the main components of Zanthoxylum was established using ultra‐high‐performance‐liquid chromatography quadrupole‐orbitrap‐mass spectrometry. The components of Shandong Zanthoxylum bungeanum, Wudu Zanthoxylum bungeanum, and Zanthoxylum schinifolium were identified by studying the characteristic fragmentations and neutral losses of characteristic components. A total of 48 common components and 24 different components were identified and the fragmentation patterns of the main components, such as flavonoids, alkaloids, and organic acids were summarized. These findings provided a reference for the study of pharmacodynamic substance basis and quality control of different varieties of Zanthoxylum. [ABSTRACT FROM AUTHOR]

Regional integration, as an essential measurement for solving unbalanced and uncoordinated regional development, plays an important role in achieving regional sustainable development. In this study, we aimed to construct a systematic research framework to facilitate the development of regional integration. Using 31 prefecture-level cities in the urban agglomeration in the Middle Reaches of the Yangtze River (MYR-UA) as case sites, this study applied box plots, kernel density estimation, GIS visualization tools, Markov chains, and geographic detectors to reveal the dynamic spatiotemporal evolution and factors influencing regional integration from 2009 to 2018. The results indicate that the level of regional integration and its subsystem development is suboptimal in MYR-UA; the temporal characteristic shows an upward fluctuating trend, and the spatial distribution shows remarkable spatial correlation and clustering characteristics. Additionally, we found that the level of regional integration development in MYR-UA has both "path dependence" and "self-locking" effects, and the spatial lag type has a crucial impact on the degree of regional transfer stability. The dominant factors affecting regional integration development include the GDP per capita, economic openness, industrial structure, proportion of education expenditure in fiscal expenditure, urbanization rate, proportion of environmental investment in fiscal expenditure, population density, capital flow, information flow, and technology flow. Finally, based on the findings of this study, policy recommendations for promoting regional integration are proposed. [ABSTRACT FROM AUTHOR]

Leonurus japonicus Houtt (LJH) is a bulk medicinal material commonly used in clinical practice, but its complex constituents have not been completely understood, posing challenges to pharmacology, pharmacokinetic research, and scientific and rational drug use. As a result, it is critical to develop an efficient and accurate method for classifying and identifying the chemical composition of LJH. In this study, ultra‐performance liquid chromatography‐quadrupole electrostatic field‐orbital trap high resolution mass spectrometry (UPLC‐Q‐Orbitrap‐MS) was successfully established, along with two data post‐processing techniques, characteristic fragmentations (CFs) and neutral losses (NLs), to quickly classify and identify the chemical constituents in LJH. As a result, 44 constituents of LJH were identified, including four alkaloids, 20 flavonoids, two phenylpropanoids, 17 organic acids, and one amino acid. The method in this paper enables classification and identification of chemical compositions rapidly, providing a scientific foundation for further research on the effective and toxic substances of LJH. [ABSTRACT FROM AUTHOR]

Schisandra chinensis is a traditional Chinese medicine, which has played an important role in the field of medicine and food. In this study, ultra‐high‐performance liquid chromatography quadrupole‐orbitrap‐mass spectrometry was used to rapidly classify and identify the chemical compositions. Note that 32, 28, and 30 kinds of compounds were successfully identified from northern Schisandra chinensis, vinegar‐processed Schisandra chinensis, and wine‐processed Schisandra chinensis, respectively. The cleavage patterns of various components including lignans, organic acids, flavonoids, and terpenoids were summarized, and the effects of different processing methods on Schisandra chinensis were analyzed through chemical composition. This method realized the rapid classification and identification of raw Schisandra chinensis and two different processed products, and provided references for improving the traditional processing methods, strengthening quality control, and ensuring safe clinical application. [ABSTRACT FROM AUTHOR]

The highly error-prone nature of wireless environments and limited computational power of mobile devices necessitates the implementation of robust yet simple error concealment in H.264/AVC. In this paper, we propose to use data hiding to facilitate the error concealment on intra-coded frames that utilizes the temporal redundancy in a wireless video bitstream. At the encoder side, the motion vector of a macroblock (MB) is encoded and imperceptibly embedded into other MB within the same intra-frame. If an MB is found missing at the decoder, the embedded information will be retrieved from the corresponding MB for the recovery of the lost MB. In order to isolate erroneous MBs caused by packet loss, a block shuffling scheme is applied. It is shown that the proposed method is able to shift the computation burden from decoder to encoder, and reduce the computation complexity of conventional error concealment methods. In addition, due to the use of real motion vectors for temporal concealment, the proposed method provides improved picture quality over the reference methods in H.264/AVC. Index Terms--Error concealment, video transmission, wireless video.

Installing video cameras in public facilities for surveillance becomes more and more popular. This paper proposes a novel authentication scheme based on chaotic semi-fragile watermarking. The timing information of video frames is modulated into the parameters of a chaotic system. The system output, which is a noise-like signal, is used as a watermark and embedded into the block-based discrete cosine transform domain. The embedded information is demodulated by a maximum likelihood estimator. Temporal tampering can be detected by the mismatch between the extracted and the observed timing information. In addition, the deviation of the extracted watermark from the original one allows us to locate spatial tampering. It is shown that the proposed scheme can satisfy the peculiar requirements of authenticating a digital video surveillance system. Index Terms--Chaotic parameter modulation, digital watermarking, video authentication, video surveillance.

The accurate prediction and analysis of electromagnetic excitation source is the pre-condition for the investigation of electromagnetic vibration and noise. In this work, an analytical model for electromagnetic (EM) force calculation of interior permanent magnet synchronous motors (IPMSMs) is proposed by coupling the 2-D model in polar coordinates and the Maxwell stress tensor method (MSTM). In the modeling, the boundary conditions for solving the air-gap magnetic field are firstly simplified based on the equivalent conversion of permanent magnets (PMs). Then, the magnetic field is acquired by solving the governing equation based on the simplified boundary conditions. Finally, the EM force is obtained according to the MSTM. The effectiveness is fully verified by finite element (FE) analysis that the analytical model can be applied not only for the calculation of radial EM force of IPMSMs with/without load but also for the calculation of tangential EM force. Besides, the tangential EM force is further analyzed by 2-D Fourier decomposition, and the relationship between tangential EM force and torque fluctuation is also clarified. The results show that the radial EM force harmonics and the tangential EM force harmonics have the same spatiotemporal characteristics no matter under no-load or load. Moreover, the high-frequency components of tangential EM force harmonics with low spatial orders, which have the highest contribution to vibration and noise, are comparable to those of radial EM force harmonics. Meanwhile, the torque fluctuation of IPMSMs with/without load only comes from the zero-order tangential EM force harmonics in space. [ABSTRACT FROM AUTHOR]

The efficiency and accuracy of the synthesis of structural lipids are closely related to the regiospecificity of lipases. Understanding the structural mechanism of their regiospecificity contributes to the regiospecific redesign of lipases for meeting the technological innovation needs. Here, we used a thermostable lipase from Streptomyces sp. W007 (MAS1), which has been recently reported to show great potential in industry, to gain an insight into the structural basis of its regiospecificity by molecular modelling and mutagenesis experiments. The results indicated that increasing the steric hindrance of the site for binding a non-reactive carbonyl group of TAGs could transform the non-specific MAS1 to a α-specific lipase, such as the mutants G40E, G40F, G40Q, G40R, G40W, G40Y, N45Y, H108W and T237Y (PSI > 80). In addition, altering the local polarity of the site as well as the conformational stability of its composing residues could also impact the regiospecificity. Our present study could not only aid the rational design of the regiospecificity of lipases, but open avenues of exploration for further industrial applications of lipases. [ABSTRACT FROM AUTHOR]