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At present， most smart wearable devices are smart watches， wristbands， etc.， which have the problems of high rigidity， poor comfort and frequent charging， making it difficult to meet the requirements of ergonomics and clothing comfort. They cannot be worn for a long time to achieve all-weather monitoring. Textile triboelectric nanogenerator （T-TENG） can be integrated into shoes and clothing as flexible power sources and self-powered sensors， making it an ideal wearable device for active human health monitoring and enforcement. However， most of the reported T-TENG need to be packaged and then integrated into clothing before use， resulting in a reduced air permeability of clothing. In addition， most of the current studies are in the laboratory stage， and the properties of T-TENG such as durability， sensitivity and stability in actual use are not fully considered. In this paper， the basic working mode， material selection， manufacturing method， integrated footwear and clothing mode， and application scenarios of T-TENG were reviewed. The preparation methods of T-TENG for nanofiber membrane and textile composite materials， fiber/yarn-based T-TENG， and fabric-based T-TENG were mainly discussed. New strategies for the development and integration of comfortable T-TENG in the future were proposed， including the large-scale preparation of T-TENG， the integration of T-TENG and traditional clothing， the compatibility of T-TENG monitoring accuracy and comfort， and the durability and stability of T-TENG.

Abstract Trichosanthes truncata C. B. Clarke, an important medicinal plant, is a dioecious plant belonging to the Cucurbitaceae family. This study presents a chromosomal-level reference genome assembly for T. truncata. Through the integration of PacBio high-fidelity sequencing and high-throughput chromosome conformation capture technology, a final genome sequence of 637.41 Mb was assembled, with an N50 of 57.24 Mb and consisting of 11 pseudochromosomes. Additionally, 97.21 Mb of repetitive sequences and 36,172 protein-coding genes were annotated. This high-quality genome assembly is of utmost significance for studying the molecular mechanisms underlying the biosynthesis of bioactive compounds. Furthermore, this study provided valuable insights into plant comparative genomics research.

Abstract Toll-like receptor (TLR) 4 contributes to be the induction of neuroinflammation by recognizing pathology-associated ligands and activating microglia. In addition, numerous physiological signaling factors act as agonists or antagonists of TLR4 expressed by non-immune cells. Recently, TLR4 was found to be highly expressed in cerebellar Purkinje neurons (PNs) and involved in the maintenance of motor coordination through non-immune pathways, but the precise mechanisms remain unclear. Here we report that mice with PN specific TLR4 deletion (TLR4PKO mice) exhibited motor impairments consistent with cerebellar ataxia, reduced PN dendritic arborization and spine density, fewer parallel fiber (PF) – PN and climbing fiber (CF) – PN synapses, reduced BK channel expression, and impaired BK-mediated after-hyperpolarization, collectively leading to abnormal PN firing. Moreover, the impaired PN firing in TLR4PKO mice could be rescued with BK channel opener. The PNs of TLR4PKO mice also exhibited abnormal mitochondrial structure, disrupted mitochondrial endoplasmic reticulum tethering, and reduced cytosolic calcium, changes that may underly abnormal PN firing and ultimately drive ataxia. These results identify a previously unknown role for TLR4 in regulating PN firing and maintaining cerebellar function.

Castleman disease (CD) is a relatively rare lymphoproliferative disorder. Lesions predominantly originate on the chest and neck and rarely occur on the abdomen. A 34-year-old female presented to our hospital with an unexplained 10-year history of anemia. A pathological diagnosis of plasma cell-type CD was established. One cycle of chemotherapy (thalidomide, cyclophosphamide, and prednisolone) improved her anemia significantly. Prompt etiological diagnosis and early intervention are essential to address systemic manifestations in patients with CD, and it is crucial to consider CD as a differential diagnosis when intra-abdominal masses are detected.

Abstract As the pediatric patient with right pulmonary artery agenesis (PAA) matured, she progressively presented symptoms of pulmonary hypertension and hemoptysis. There is limited clinical literature on this condition, and currently, there is no consensus regarding its diagnosis and treatment. This article presents a case study of a 16-year-old female patient with right pulmonary artery hypoplasia, providing a comprehensive summary and analysis of her developmental progression, pathology, diagnosis, and treatment.

Flavor compounds are important indicators of edible quality and nutritional value of corn. The quality deterioration of corn during storage is closely related to its flavor compounds. Corn samples harvested in four years from 2019 to 2022 were detected by solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry (SPME-GC-MS/MS), and multivariate statistical analysis of flavor compounds relative content was carried out by principal component analysis and partial least squares discriminant analysis. The results showed that 129 volatile flavor compounds were detected in corn, including alcohols, aldehydes, ketones, esters, benzenes, heterocycles, acids, ethers, hydrocarbons and phenols. The multivariate statistical analysis showed that volatile flavor compounds and storage years of corn were correlated. According to the importance of variable projection, 47 compounds had significant diversity between corn samples with various storage years. Among them, the relative contents of 1-octen-3-ol, neryl butyrate and 2-pentylfuran increased with the extension of corn storage years, while the relative content of pantolactone, methyl octanoate and 2-acetylfuran decreased with the extension of corn storage years. These 6 compounds were identified as characteristic differential compounds. The partial least squares discriminant analysis classification model was constructed, and had good discrimination for corn storage years (R2=0.99, Q2=0.97, prediction accuracy was 1). The model will provide technical means for dynamic monitoring of corn storage quality, which is of great significance for ensurance national food security and reduce grain loss.

The growing interests have been witnessed in the evolution and improvement of artificial compound eyes (CE) inspired by arthropods. However, the existing CE cameras are suffering from a defocusing problem due to the incompatibility with commercial CMOS cameras. Inspired by the CEs of South American Shrimps, we report a compact biologically inspired camera that enables wide-field-of-view (FOV), high-resolution imaging and sensitive 3D moving trajectory reconstruction. To overcome the defocusing problem, a deep learning architecture with distance regulation is proposed to achieve wide-range-clear imaging, without any hardware or complex front-end design, which greatly reduces system complexity and size. The architecture is composed of a variant of Unet and Pyramid-multi-scale attention, with designed short, middle and long distance regulation. Compared to the current competitive well-known models, our method is at least 2 dB ahead. Here we describe the high-resolution computational-CE camera with 271 ommatidia, with a weight of 5.4 g an area of 3 × 3 cm2 and 5-mm thickness, which achieves compatibility and integration of CE with commercial CMOS. The experimental result illustrates this computational-CE camera has competitive advantages in enhanced resolution and sensitive 3D live moving trajectory reconstruction. The compact camera has promising applications in nano-optics fields such as medical endoscopy, panoramic imaging and vision robotics.

Abstract Platostoma palustre is an annual herb and an important medicinal and edible plant in southern China. Plastic-film mulching is an effective agronomic practice in the cultivation system of P. palustre, of which black-film mulching is the most common. However, fewer researches have been focused on the use of other colors of plastic films in P. palustre cultivation. In this study, different colors (white, black, red, and green) of plastic film were adopted, and the effects of different colors of plastic film mulching on the soil temperature, yield, and metabolites of P. palustre were investigated. The results showed that the fresh weight of a single plant of the green film treatment was significantly higher than that of the white film treatment (n = top 28). Based on the results of three temperature measurements, the soil temperature was almost the highest in the red film treatment and lowest in the white film treatment. The metabolomic analysis revealed that a total of 103 differential metabolites were identified. Among these, the gluconic acid, deoxyribose, and N-Acetylmannosamine in the red film treatment presented the highest abundance compared with the other treatments, meanwhile, the abundances of the five monosaccharides in the red film treatment were significantly higher than those of the green film treatment. Moreover, the sucrose, trehalose, and D-(+)-trehalose in the green film treatment exhibited the highest abundance, and the abundances of eight different amino acids in the red film treatment were almost the lowest while those in the black film treatment were almost the highest. Further analysis of the membership function values indicated that the black and red film treatments might be more suitable for the cultivation and quality production of P. palustre in comparison with the other two treatments. This study will provide a theoretical basis for improving the efficient cultivation technology of P. palustre and forming a theoretical system of P. palustre film mulching cultivation.

Objective： Clarifying the effects of lipid co-passengers on the stability of rapeseed oil emulsions and prepare high-stability nano-emulsions. Methods： The endogenous lipidassociated compounds of rapeseed oil were subjected to column chromatography filtration, followed by various concentration gradient re-addition. High-pressure microfluidization was utilized to prepare nanoemulsions, which were subsequently characterized. The influence of lipid associated compound content on the stability of rapeseed oil emulsions was also investigated. Results: The preparation of rapeseed oil nanoemulsions reached optimal conditions when the α-tocopherol content was 292 mg/kg, rapeseed polyphenols content was 32 mg/kg, β-sitosterol content was 6 712 mg/kg, and β-carotene content was 31 mg/kg. The average particle size of the resulting rapeseed oil nanoemulsion was (182.4±2.056) nm, indicating good stability. Conclusion： Lipid associated compounds significantly affect the stability of emulsions.

Platostoma palustre (Blume) A. J. Paton is an important edible and medicinal plant. To gain a comprehensive and clear understanding of the variation patterns of metabolites in P. palustre, we employed the UPLC-MS platform along with widely targeted metabolomics techniques to analyze the metabolites in the stems and leaves of P. palustre at different stages. Our results revealed a total of 1228 detected metabolites, including 241 phenolic acids, 203 flavonoids, 152 lipids, 128 terpenes, 106 amino acids, 79 organic acids, 74 saccharides, 66 alkaloids, 44 lignans, etc. As the growth time increased, the differential metabolites (DAMs) mainly enriched in P. palustre leaves were terpenoids, phenolic acids, and lipids, while the DAMs primarily enriched in stems were terpenoids. Compared to stems, there were more differential flavonoids in leaves, and saccharides and flavonoids were significantly enriched in leaves during the S1 and S2 stages. Additionally, we identified 13, 10, and 23 potential markers in leaf, stem, and leaf vs. stem comparison groups. KEGG enrichment analysis revealed that arginine biosynthesis was the common differential metabolic pathway in different growth stages and tissues. Overall, this study comprehensively analyzed the metabolic profile information of P. palustre, serving as a solid foundation for its further development and utilization.

The transcription factors of WRKY genes play essential roles in plant growth, stress responses, and metabolite biosynthesis. Erigeron breviscapus, a traditional Chinese herb, is abundant in flavonoids and has been used for centuries to treat cardiovascular and cerebrovascular diseases. However, the WRKY transcription factors that regulate flavonoid biosynthesis in E. breviscapus remain unknown. In this study, a total of 75 EbWRKY transcription factors were predicted through comprehensive genome-wide characterization of E. breviscapus and the chromosomal localization of each EbWRKY gene was investigated. RNA sequencing revealed transient responses of 74 predicted EbWRKY genes to exogenous abscisic acid (ABA), salicylic acid (SA), and gibberellin 3 (GA3) after 4 h of treatment. In contrast, the expression of key structural genes involved in flavonoid biosynthesis increased after 4 h in GA3 treatment. However, the content of flavonoid metabolites in leaves significantly increased at 12 h. The qRT-PCR results showed that the expression patterns of EbWRKY11, EbWRKY30, EbWRKY31, EbWRKY36, and EbWRKY44 transcription factors exhibited a high degree of similarity to the 11 structural genes involved in flavonoid biosynthesis. Protein-DNA interactions were performed between the key genes involved in scutellarin biosynthesis and candidate WRKYs. The result showed that F7GAT interacts with EbWRKY11, EbWRKY36, and EbWRKY44, while EbF6H has a self-activation function. This study provides comprehensive information on the regulatory control network of flavonoid accumulation mechanisms, offering valuable insights for breeding E. breviscapus varieties with enhanced scutellarin content.

Objective: A recombinase-mediated strand displacement isothermal amplification assay for rapid detection of horse-derived components in meat and meat products was established. Methods: A series of specific primers and Exo probes were designed using the horse-derived ATpase 6 gene as the target gene. The primers were screened and the reaction parameters were optimized. The specificity, sensitivity and stability of the assay were evaluated, and the detection limit, applicability and accuracy were analyzed by detecting simulated samples with different mixing ratios and different processing technologies, and commercial samples. Results: The assay was characterized by rapid response, high sensitivity and specificity. The reaction was completed within 16 minutes under a constant temperature of 39 ℃. The system had good specificity to 23 non-target sources. The detection sensitivity of the target DNA was 1.8 copies/μL. The detection limit was 0.01% for raw meat (mass fraction), and 0.1% (mass fraction) for processed meat products. For 90 commercial samples, the results of this method were consistent with those of the standard method. Conclusion: The recombinase-mediated isothermal amplification assay can be used for the detection of horse-derived components in meat and meat products.

A multiplex real-time polymerase chain reaction (PCR) method for simultaneous and rapid detection of components derived from sweet potato, cassava, potato, and corn was established. The g3pdhs gene of sweet potato and cassava, the UGPase gene of potato and the zSSIIb gene of corn were used as target genes to design specific primers and TaqMan probe, and the 18S rRNA gene was used as the internal reference gene. Methodological validation was performed, and the proposed method was applied to simulated samples with different mixing ratios and actual starch samples. The results showed that this method was high-throughput, sensitive and specific. No cross-reaction was found with 15 non-target sources. The detection sensitivity for template DNA was 3 × 10-3 ng/μL, and the proposed method had a good linear relationship and high amplification efficiency. The detection limit for edible starch samples was 0.1%. The results of the PCR method for 50 actual samples were consistent with those of the reference method, indicating that this method could be used for the detection of common adulterants in edible starches.

The backflow and back-pressure propagation induced in a pulse detonation combustor (PDC) are the main factor in causing the thrust losses of a pulse detonation engine. In order to suppression the backflow propagation of a PDC, the aero-dynamic suppression strategy was implemented in this work. A total of ten isolators composed of different geometries were designed. A single-pulse detonation experiment was conducted by using the stoichiometric ethylene/enriched-oxygen mixture. It is shown that when the back-pressure has propagated about 0.86 the length of PDC, the propagation speeds and the pecks of the back-pressure in the isolator, which composed of the Venturi tube (V) and a long tube with 1.5 times diameter of the PDC, can be reduced by 10% and 20%, respectively, comparing with the base isolator. Comparing with the isolators that without the Tesla valve (T), the propagation speed of the back-pressure in the cases with the Tesla valve can be additionally reduced above 27.3%. Comparing with the isolators that without the slit (S), the peaks of the back-pressure in the cases with the slit can be decreased about 25%. The average decay rate of the back-pressure peaks can be highly increased if the cone (C) is introduced. It is found that the CVST-type isolator is the optimal. Comparing with the base isolator, the backpressure propagated in the CVST-type isolator can decrease about 50% and 40.5% of propagation speed and pressure peaks, respectively, and can increase the average decay rate of the back-pressure peaks by a factor of two.

Pseudomonas stutzeri A1501 is a non-fluorescent denitrifying bacteria that belongs to the gram-negative bacterial group. As a prominent strain in the fields of agriculture and bioengineering, there is still a lack of comprehensive understanding regarding its metabolic capabilities, specifically in terms of central metabolism and substrate utilization. Therefore, further exploration and extensive studies are required to gain a detailed insight into these aspects. This study reconstructed a genome-scale metabolic network model for P. stutzeri A1501 and conducted extensive curations, including correcting energy generation cycles, respiratory chains, and biomass composition. The final model, iQY1018, was successfully developed, covering more genes and reactions and having higher prediction accuracy compared with the previously published model iPB890. The substrate utilization ability of 71 carbon sources was investigated by BIOLOG experiment and was utilized to validate the model quality. The model prediction accuracy of substrate utilization for P. stutzeri A1501 reached 90 %. The model analysis revealed its new ability in central metabolism and predicted that the strain is a suitable chassis for the production of Acetyl CoA-derived products. This work provides an updated, high-quality model of P. stutzeri A1501for further research and will further enhance our understanding of the metabolic capabilities.

The medicinal plant Spatholobus suberectus Dunn is easily exposed to shade stress during growth, but its shade responses and shade stress resistant mechanisms have not been clarified. In this study, shade treatments including four attenuated sunlight intensities (100%, 60%, 40%, and 10%) and three shade durations (30 d, 45 d, and 60 d) were applied to S. suberectus. The shade-induced morphological indicators, phytohormonal regulations, metabolic flavonoids contents, transcriptomic flavonoid pathway gene expressions, and stress physiological changes of S. suberectus were analyzed. The putative promoter cis-regulatory elements (CREs) of 18 flavonoid biosynthetic pathway genes were identified. Results showed the stem growth indicators of S. suberectus were better at 40% light intensity. Phytohormones were involved in the shade-induced responses. Short-term shade (30 d) increased total flavonoids, gallated catechins and especially epigallocatechin gallate contents and favored for boosting medicinal value. Long-term shade (45 d, 60 d) tended to decrease flavonoids. The shade-induced flavonoids changes were attributed to their corresponding biosynthesizing genes expression variations. The high antioxidant capacity and the presence of phytohormone-, stress-, and development-related CREs provided the basis for stress resistance. In conclusion, the multiple responses under shade and the CREs analysis elucidated S. suberectus’ shade tolerance.

Objective: In order to explore the extraction method and antioxidant activity of crude polysaccharide from edible fungus resources of reed. Methods: The characteristic Agrocybe praecox of reed edible fungus of Dongting Lake District was used as raw material, the extraction rate of polysaccharide was used as the index, and the extraction was carried out by ultrasonic-assisted hot water alcohol precipitation method. After taking the liquid-material ratio, ultrasonic extraction time, ultrasonic extraction power, hot water extraction temperature, hot water extraction time as the factors to finish the single factor experiments. Then the experiments was optimized by Box-Behnken center combined experimental design for the crude polysaccharide extraction process of Agrocybe praecox. The scavenging abilities of the crude polysaccharide on DPPH· free radical and ABTS+· free radical were also studied. Results: The results showed that the optimal extraction conditions were determined: the ratio of solid to liquid of 1∶50 (g/mL), ultrasonic extraction time of 20 min, eextraction power of 150 W, Hot water extraction temperature of 80 ℃, extraction time of 4 h. Under the conditions, the extraction rate of crude polysaccharide was 5.08%. The scavenging rates of DPPH· and ABTS+· were 55.05% and 58.47%, respectively. The semi-inhibitory concentrations of IC50 were 1.03 and 0.28 mg/mL, respectively. Conclusion: Under the optimal process parameters of ultrasonic-assisted hot water extraction, the extraction rate of polysaccharide is high, and the crude polysaccharide has a certain antioxidant activity in vitro.

Luminescent solar concentrators (LSCs) are attractive for the easy operation and high compatibility with building integrated photovoltaics due to their low cost, large-scale and applicability. However, underutilized sunlight in visible wavelengths often impedes the advance of LSCs. Here, we demonstrate an orange-emitting carbon nanodots-based LSC (O-CDs) with excitation concentrated in the visible wavelengths. The orange-emitting carbon nanodots (O-CDs) with highly localized excitonic emission are prepared via atomic condensation of doped pyrrolic nitrogen, delivering a high photoluminescence quantum yield of 80 % and a suitable Stokes shift with absorption spectrum situated in the visible region. The O-CDs are embedded in polyvinylpyrrolidone to obtain a highly transparent, stable and environmentally friendly O-CDs-based LSC. Thanks to efficient utilization of solar radiation in visible areas and well match between the emission of O-CDs and the response bands of photovoltaic cells, the O-CDs-based LSC reveals an optical conversion efficiency of 5.17 %, superior to that of most carbon nanodots-based LSCs. These results provide an effective strategy to develop carbon-based luminescent concentrated materials for architectural integrated photovoltaic technology.

The ethylene-regulated hypocotyl elongation of Arabidopsis thaliana involves many transcription factors. The specific role of MYC transcription factors in ethylene signal transduction is not completely understood. The results here revealed that two MYCs, MYC2 and MYC3, act as negative regulators in ethylene-suppressed hypocotyl elongation. Etiolated seedlings of the loss-of-function mutant of MYC2 or MYC3 were significantly longer than wild-type seedlings. Single- or double-null mutants of MYC2 and MYC3 displayed remarkably enhanced response to ACC(1-aminocyclopropane-1-carboxylate), the ethylene precursor, compared to wild-type seedlings. MYC2 and MYC3 directly bind to the promoter zone of ERF1, strongly suppressing its expression. Additionally, EIN3, a key component in ethylene signaling, interacts with MYC2 or MYC3 and significantly suppresses their binding to ERF1’s promoter. MYC2 and MYC3 play crucial roles in the ethylene-regulated expression of functional genes. The results revealed the novel role and functional mechanism of these transcription factors in ethylene signal transduction. The findings provide valuable information for deepening our understanding of their role in regulating plant growth and responding to stress.

Many problems and conjectures in extremal combinatorics concern polynomial inequalities between homomorphism densities of graphs where we allow edges to have real weights. Using the theory of graph limits, we can equivalently evaluate polynomial expressions in homomorphism densities on kernels W, that is, symmetric, bounded and measurable functions W from $[0,1]^2 \to \mathbb {R}$ . In 2011, Hatami and Norin proved a fundamental result that it is undecidable to determine the validity of polynomial inequalities in homomorphism densities for graphons (i.e., the case where the range of W is $[0,1]$ , which corresponds to unweighted graphs or, equivalently, to graphs with edge weights between $0$ and $1$ ). The corresponding problem for more general sets of kernels, for example, for all kernels or for kernels with range $[-1,1]$ , remains open. For any $a> 0$ , we show undecidability of polynomial inequalities for any set of kernels which contains all kernels with range $\{0,a\}$ . This result also answers a question raised by Lovász about finding computationally effective certificates for the validity of homomorphism density inequalities in kernels.

Conducting ecological sensitivity assessment is a crucial approach for pinpointing regional ecological environmental issues, which can offer a scientific basis to aid in the prevention of regional ecological degradation and ensuring regional ecological security. With the protection and high-quality development of the Yellow River Basin (YRB) at the level of a national strategy in China, there is a critical need for a comprehensive assessment of the YRB’s ecological sensitivity. To this end, this study aimed to construct a new ecological sensitivity evaluation index system from three perspectives: natural ecosystem, natural-social ecosystem, and social ecosystem. The ecological sensitivity index was quantified using the entire-array-polygon indicator method, and the spatiotemporal changes of ecological sensitivity in the YRB and its sub-basins were analyzed from 2000 to 2020. The optimal parameters-based geographical detector model was employed to delve into the mechanisms driving the spatial variation in ecological sensitivity. We found that (1) from 2000 to 2020, ecological sensitivity in the YRB exhibited a bimodal trend. Spatially, it tended to be low in the western and eastern parts while it was relatively high in the southern and central regions. (2) The YRB displayed notable clustering effects in terms of ecological sensitivity. The source area showed both “high-high” and “low-low” groupings, the upstream area showed a predominance of “low-low” clusters, while the midstream area and downstream area were demonstrated by concentrated “high-high” clusters. However, the clustering effect in downstream gradually weakened over time. (3) The ecological sensitivity of the YRB was primarily driven by factors like shifts in climate change and soil erosion. There were also marked differences in spatial heterogeneity of ecological sensitivity across different sub-basins. Moreover, the influence of interactive factors on the YRB's ecological sensitivity and its sub-basins was enhanced. The research findings enhance our understanding of ecological issues faced by the YRB and establish a foundation for developing strategies to protect and manage its environmental ecosystem effectively.

A multiplex real-time polymerase chain reaction (PCR) method for simultaneous rapid detection of donkey-, horse-, pig- and duck-derived components was established. For this purpose, the Nad5, ATpase6, ATP8 and cytb were used as target genes to design specific primers and Taqman probes, and the 18S rRNA gene was used as internal reference gene. The developed method was validated and applied to detect simulated adulterated meat products, simulated processed meat products and actual donkey meat samples. This method was characterized by high-throughput, and excellent sensitivity and specificity. The system had no cross-reaction to non-target sources when the cycle threshold (Ct) value did not exceed 35.0. The sensitivity was 2 × 10-4 ng/μL of template DNA. The detection limit for raw and cooked meat was 0.001% and 0.01% of the meat content, respectively. The results of this method for 100 actual samples were consistent with those of the national standard method, indicating that the multiplex real-time PCR method can be used for the detection of commonly adulterants in meat and meat products.

Coupling model for two-dimensional mixed-compression supersonic inlet with Mach number of 2.5 at design point and pulse detonation combustor was established, and three working schemes were designed to investigate multi cycle working process by using unsteady numerical simulation with chemical reaction. The results show that the following two measurements can both restrain the back-propagating compression wave and broaden the stability margin of the inlet and increase the frequency, one of which is the pressure relief at the outlet of the combustor, the other is valve at the inlet of the combustor. Nevertheless, the former will lose thrust, while the latter can greatly increase thrust. Meanwhile, the valve will reflect the compression wave in the production; increase the turbulence in the combustor, and make the gas entrained into the diffuser section of the inlet at the moment of opening the valve. However, the reflected compression wave in the hot production will not affect the velocity and shape of the detonation wave. Furthermore, in the period of detonation wave initiation and propagation, the blockage ratio of physical obstructions at the inlet of the combustor should be expanded as much as possible. At the same time, the flow at the outlet of the inlet should not be blocked to increase the flow resistance.

The intake distortion experiment is one of the important methods for aero-engine aerodynamic stability assessment. In this paper, in order to overcome the shortcomings of traditional design methods such as low accuracy in approximating the target distortion map and many experimental iterations, a design system is proposed to design the target map distortion network using Fluent based on the mapping relationship between screen distance and porous media. Finally, the steady-state total pressure test system is designed, and the physical design of the distortion generator and wind tunnel test are completed, with the error of distortion index of less than 1.5%. The test results show that the design system can simulate the distortion requirements with high accuracy and efficiency.

Abstract Background In Amomum tsaoko breeding, the low germination rate is the major limitation for their large-scale reproduction. We found that warm stratification was an effective treatment to break the seed dormancy of A. tsaoko prior to sowing and could be an important component of improving breeding programs. The mechanism of seed dormancy release during warm stratification remains unclear. Therefore, we studied the differences between transcripts and proteomes at 0, 30, 60, and 90 days of warm stratification, to identify some regulatory genes and functional proteins that may cause seed dormancy release in A. tsaoko and reveal their regulatory mechanism. Results RNA-seq was performed for the seed dormancy release process, and the number of differentially expressed genes (DEGs) was 3196 in three dormancy release periods. Using TMT-labelling quantitative proteome analysis, a total of 1414 proteins were defined as differentially expressed proteins (DEPs). Functional enrichment analyses revealed that the DEGs and DEPs were mainly involved in signal transduction pathways (MAPK signaling, hormone) and metabolism processes (cell wall, storage and energy reserves), suggesting that these differentially expressed genes and proteins are somehow involved in response to seed dormancy release process, including MAPK, PYR/PYL, PP2C, GID1, GH3, ARF, AUX/IAA, TPS, SPS, and SS. In addition, transcription factors ARF, bHLH, bZIP, MYB, SBP, and WRKY showed differential expression during the warm stratification stage, which may relate to dormancy release. Noteworthy, XTH, EXP, HSP and ASPG proteins may be involved in a complex network to regulate cell division and differentiation, chilling response and the seed germination status in A. tsaoko seed during warm stratification. Conclusion Our transcriptomic and proteomic analysis highlighted specific genes and proteins that warrant further study in fully grasping the precise molecular mechanisms that control the seed dormancy and germination of A. tsaoko. A hypothetical model of the genetic regulatory network provides a theoretical basis for overcoming the physiological dormancy in A. tsaoko in the future.

IntroductionIn recent years, more and more attention has been paid to the visual fatigue caused by steady state visual evoked potential (SSVEP) paradigm. It is well known that the large-scale application of brain-computer interface is closely related to SSVEP, and the fatigue caused by SSVEP paradigm leads to the reduction of application effect. At present, the mainstream method of objectively quantifying visual fatigue in SSVEP paradigm is based on traditional canonical correlation analysis (CCA).MethodsIn this paper, we propose a new SSVEP paradigm visual fatigue quantification algorithm based on underdamped second-order stochastic resonance (USSR) to accurately quantify visual fatigue caused by SSVEP paradigm in different working modes using single-channel electroencephalogram (EEG) signals. This scheme uses the fixed-step energy parameter optimization algorithm we designed, combined with the USSR model, to significantly improve the signal-to-noise ratio of the processed signal at the target characteristic frequency. We not only compared the new algorithm with CCA, but also with the traditional subjective quantitative visual fatigue gold standard Likert fatigue scale.ResultsThere was no significant difference (p = 0.090) between the quantitative value of paradigm fatigue obtained by the single channel SSVEP processed by the new algorithm and the gold standard of subjective fatigue quantification, while there was a significant difference (p

The mass transfer enhanced cathode flow field with little pressure loss is a key factor to proton exchange membrane fuel cell (PEMFC) design. A new type of cathode flow field incorporating ship-shaped baffles which enhances mass transfer while causes little parasitic power is proposed in this study. Effects of length, breadth, molded depth, liquid level height and draft depth of the ship-like baffle on water removal in flow field and PEMFC performance are investigated numerically. Results show that ship-like baffles could accelerate water removal. Slim baffle with big surface helps to break droplets into smaller ones. Ship-like baffles also help to pushed reactant downward and distributed reactant evenly, especially in area under ribs. Sloping “bow” of baffle helps to enhance mass transfer downward and sloping “stern” of baffle helps to further split the droplets already divided by baffles into smaller ones and throw them into the upper part of the channel. In general, the proposed flow field with ship-like baffles shows a good performance in PEMFC mass transfer.

With the prevalence of online take-out food, the increasingly generated single-use plastic packaging waste has aroused public concern in the context of combating plastic pollution globally. The majority of present studies have focused on product design and policy design to influence the corporate behaviors in packaging waste management. Few attentions have been concentrated on consumer perceptions, a neglected vital factor in commercial practices, which determines whether the proposed measures can be effectively applied. This study takes college students, the main consumer group of take-out who are most likely to receive new environmental protection concepts, as a case study and employs the contingent valuation method to investigate their perceptions and behaviors toward emerging plastic packaging reduction approaches and taxation mechanisms. It was found that packaging circulation was preferred mostly with a proportion of 73.20% of the respondents, while taxation mechanism was more favored by those who have higher daily expenditure on meals. Gender, living costs and ordering frequency could significantly influence the acceptance levels. Therefore, a circulation mechanism using cabinet near take-out food hot spots and third-party cleaning services could target students and officers as pioneers. Regarding the taxation approach, it was suggested that the payment that most of the respondents could accept is 1.5 CNY. This study serves as a reference for the reduction of plastic waste from take-out packaging on campus, and provides a possible model that could reduce the environmental impacts of take-out food packaging through both taxation and circulation measures. The findings are expected to bring primary insights for take-out food plastic packaging reduction in China. For future studies, the methodology of this study was also well-prepared to investigate a larger scale of consumers and develop a more universal policy.

In the human immunodeficiency virus (HIV)-infected population, especially HIV with concomitant tuberculosis (TB) or Hodgkin’s lymphoma (HL), numerous risk factors have been reported in recent years. Among them, the decreased CD4+ T cell count was recognized as the common risk factor. We report a case of a patient with HIV and TB and HL co-occurrence, in which patient’s CD4+ T cell count was inconsistent with disease. A 58-year-old male presented with fever and shortness of breath that persisted for 2 months. The patient had a 4-year history of HIV infection and underwent antiretroviral therapy (ART) effectively. After blood test, computed tomography, bone biopsy, and lymphoma biopsy, the patient was diagnosed with skeletal TB and HL, underwent TB treatment and received ART, and underwent four cycles of chemotherapy. CD4+ T cell count was not decreased before diagnosed with TB/HL and increased in this case after the fourth cycle of chemotherapy. We collected and analyzed CD4+ T cell counts in our case and reviewed relevant literature. It is suggested that CD4+ T cell count may be insufficient to predict the risk of HIV-related disease, especially lymphoproliferative disorders.

objective: Early diagnosis of infant cerebral palsy (CP) is very important for infant health. In this paper, we present a novel training-free method to quantify infant spontaneous movements for predicting CP. Methods: Unlike other classification methods, our method turns the assessment into a clustering task. First, the joints of the infant are extracted by the current pose estimation algorithm, and the skeleton sequence is segmented into multiple clips through a sliding window. Then we cluster the clips and quantify infant CP by the number of cluster classes. Results: The proposed method was tested on two datasets, and achieved state-of-the-arts (SOTAs) on both datasets using the same parameters. What’s more, our method is interpretable with visualized results. Conclusion: The proposed method can quantify abnormal brain development in infants effectively and be used in different datasets without training. Significance: Limited by small samples, we propose a training-free method for quantifying infant spontaneous movements. Unlike other binary classification methods, our work not only enables continuous quantification of infant brain development, but also provides interpretable conclusions by visualizing the results. The proposed spontaneous movement assessment method significantly advances SOTAs in automatically measuring infant health.

Abstract Histone deacetylase (HDAC) is a kind of protease that modifies histone to regulate gene expression, and is usually abnormally activated in tumors. The approved pan-HDAC inhibitors have demonstrated clinical benefits for patients in some hematologic malignancies. Only limited therapeutic success in breast cancer has been observed in clinical trials. In this study, we declare that pan-HDAC inhibitors targeting NEDD9-FAK pathway exacerbate breast cancer metastasis in preclinical models, which may severely impede their clinical success. NEDD9 is not an oncogene, however, it has been demonstrated recently that there are high level or activity changes of NEDD9 in a variety of cancer, including leukemia, colon cancer, and breast cancer. Mechanistically, pan-HDAC inhibitors enhance H3K9 acetylation at the nedd9 gene promoter via inhibition of HDAC4 activity, thus increase NEDD9 expression, and then activate FAK phosphorylation. The realization that pan-HDAC inhibitors can alter the natural history of breast cancer by increasing invasion warrants clinical attention. In addition, although NEDD9 has been reported to have a hand in breast cancer metastasis, it has not received much attention, and no therapeutic strategies have been developed. Notably, we demonstrate that FAK inhibitors can reverse breast cancer metastasis induced by upregulation of NEDD9 via pan-HDAC inhibitors, which may offer a potential combination therapy for breast cancer.

To study the effects of light quality and salt stress on RNA editing of Mesona chinensis Benth (MCB) chloroplast genome, the RNA editing sites in the MCB chloroplast protein-coding genes were predicted and then partially verified by PCR and RT-PCR. Meanwhile, the RNA editing efficiency and relative expression of accD, ndhB, ndhF, and rpoB under red and blue light and salt stress conditions were analyzed. A total of 45 editing sites were predicted and all the editing sites were C-to-U conversion. 12 predicted editing sites were verified. The expression level of accD was down-regulated under red light compared with the blue light, as well as down-regulated under salt stress compared with the normal condition (CK). Additionally, the editing efficiency of accD-287 was 96.7% under normal condition, higher than that under salt stress (93.3%) but lower than those under blue and red light (both 100%). In ndhB, ndhB-494 was partially edited under normal growth condition but completely edited under blue and red light and salt stress, and other sites were completely edited under all conditions. It was indicated that the editing frequency was not positively relevant to the transcript level. Besides, accD-287 and ndhB-494 might be involved in response to salt stress.

Functional ultrasound (fUS) flow imaging provides a non-invasive method for the in vivo study of cerebral blood flow and neural activity. This study used functional flow imaging to investigate rat brain’s response to ultrasound and colored-light stimuli. Male Long-Evan rats were exposed to direct full-field strobe flashes light and ultrasound stimulation to their retinas, while brain activity was measured using high-frequency ultrasound imaging. Our study found that light stimuli, particularly blue light, elicited strong responses in the visual cortex and lateral geniculate nucleus (LGN), as evidenced by changes in cerebral blood volume (CBV). In contrast, ultrasound stimulation elicited responses undetectable with fUS flow imaging, although these were observable when directly measuring the brain’s electrical signals. These findings suggest that fUS flow imaging can effectively differentiate neural responses to visual stimuli, with potential applications in understanding visual processing and developing new diagnostic tools.

Spatholobus suberectus Dunn (S. suberectus), a plant species within the Leguminosae family, has a long history of use in traditional medicines. The dried stem of S. suberectus exhibits various pharmacological activities because it contains various flavonoids. Diverse functions in plants are associated with the R2R3-MYB gene family, including the biosynthesis of flavonoids. Nonetheless, its role remains unelucidated in S. suberectus. Therefore, the newly sequenced S. suberectus genome was utilized to conduct a systematic genome-wide analysis of the R2R3-MYB gene family. The resulting data identified 181 R2R3-SsMYB genes in total, which were then categorized by phylogenetic analysis into 35 subgroups. Among the R2R3-SsMYB genes, 174 were mapped to 9 different chromosomes, and 7 genes were not located on any chromosome. Moreover, similarity in terms of exon-intron structures and motifs was exhibited by most genes in the same subgroup. The expansion of the gene family was primarily driven by segmental duplication events, as demonstrated by collinearity analysis. Notably, most of the duplicated genes underwent purifying selection, which was depicted through the Ka/Ks analysis. In this study, 22 R2R3-SsMYB genes were shown to strongly influence the level of flavonoids. The elevated expression level of these genes was depicted in the tissues with flavonoid accumulation in contrast with other tissues through qRT-PCR data. The resulting data elucidate the structural and functional elements of R2R3-SsMYB genes and present genes that could potentially be utilized for enhancing flavonoid biosynthesis in S. suberectus.

ABSTRACT Disturbance of commensal intestinal microbiota is related to chronic inflammatory dermatosis. We analyzed the diversity of the gut microbiota to characterize the biological variation of psoriasis (Ps). Significant differences of gut microbiome profiles were revealed in murine model with psoriasis by sequencing 16S rRNA V3-V4 variable region. Group comparisons included the imiquimod cream (IMQ group, n=8), the imiquimod cream and antibiotics (ATB) (PC+IMQ group, n=8) and the healthy control (CTRL group, n=8). The gut microbiota existed in Ps groups including IMQ group and PC+IMQ group encompassed less diversity than controls, which were attributed to decreased presence of several taxa. The two Ps groups were characterized by significant reduction in firmicutes. In this study, microbiota of psoriasis was defined by an increase presence of Bacteroides. After treated with ATB, we found substantial increase of Lactobacillales but significant decrease of Clostridiales and Coriobacteriales. Relative lower abundance of multiple intestinal bacteria was observed in Ps groups. Although part of genera were concomitantly reduced in both IMQ and PC+IMQ conditions, we discovered the specialty of PC+IMQ group samples was that contained lower abundance of beneficial taxa. Characteristics of gut microbiota profiles in Ps mice were comparable to profiles in patients with Ps, which were related to alteration of specific inflammatory proteins in disease groups but were significantly different from control group. Thus, this study emphasizes the role of intestinal microbiota in the pathogenesis of Ps and provides new insight for investigating association between intestinal microbes and immune inflammation.

An extreme torrential rain event occurred in the Jianshi Canyon in the mountainous area of Southwest Hubei on 26 July 2020, which was mainly caused by quasi-stationary mesoscale convection system (MCS). Using conventional observations, the data from regional automatic weather stations, radar data and ERA5 reanalysis data, we have performed analysis on the atmospheric circulation and the evolution and formation mechanism of quasi-static MCS in this event. Results are as follows. (1) Affected by the continental high and the Mongolian cold vortex moving eastward and southward and the stable subtropical high, the MCS forms in the north of the subtropical high and near the low-level convergence line. The mid-and low-level convergence line and the southerly jet in front of the low vortex provide favorable environmental conditions for the development and maintenance of the MCS. (2) The MCS in the Jianshi Canyon shows the characteristics of quasi-stationary with backward propagation, whose direction is consistent with the canyon trend, and it experienced two stages: quasi-stationary backward propagation and quasi-stationary merging. (3) Under the complex terrain of Jianshi Canyon and Enshi "bell mouth", the interaction between cold outflow and continuously strengthened and sinking low-level southerly jet has a significant effect on the formation and development of the MCS. The low-level jet is forced to rise on the windward slope for sustained weak cold outflow, forming a stable lifting condition in front of the mountain, which is the main reason for the maintenance of quasi-stationary backward propagation. The blocking effect of the low-level jet and the terrain in the south of Jianshi on the cold pool, and the merging of convective cells moving northward, are the reasons for the formation of quasi-stationary merging of the MCS. (4) The complex terrain plays an important role in the evolution of the MCS. The canyon wind effect and the topographic lifting effect of windward slope result in the enhanced development of the MCS. The cold outflow guided by the slope terrain of Jianshi Canyon quickly descends the mountain to form the convergence zone with the southerly lifted by the windward slope at front of the mountain, which speeds up the backward propagation of the MCS. The γ-mesoscale topography in the south of Jianshi Canyon blocks the downhill cold outflow and makes it move slowly southward, resulting in the propagation speed of the MCS to slow down and show a quasi-stationary state.

Platostoma palustre (or Mesona chinensis Benth) is an important medicinal and edible plant in China and Southeast Asian countries. To study the effects of different processing methods on the quality, nutrition, and flavor of P. palustre, we adopted the LC-MS and HS-GC-MS to compare the influences of tedding (S), sweating (M), and drying (H) on the metabolites and volatile substances of P. palustre. Biochemical determinations revealed that the M treatment could promote the accumulation of the contents of total sugar, soluble sugar, and total pectin compared with the H and S treatments but decrease the total flavonoid contents. LC-MS and HS-GC-MS uncovered 98 differential metabolites and 27 differential volatile substances among the three treatments, respectively. Overall, the M treatment facilitated the stabilization and improvement of the quality of polysaccharides and volatile substances, while the H treatment could promote the level of amino acids in P. palustre. The current study provided a theoretical reference for establishing standardized processing methods and sustaining the quality stability of P. palustre in future.

Summary: N6-adenine DNA methylation (6mA), a rediscovered epigenetic mark in eukaryotic organisms, diversifies in abundance, distribution, and function across species, necessitating its study in more taxa. Paramecium bursaria is a typical model organism with endosymbiotic algae of the species Chlorella variabilis. This consortium therefore serves as a valuable system to investigate the functional role of 6mA in endosymbiosis, as well as the evolutionary importance of 6mA among eukaryotes. In this study, we report the first genome-wide, base pair-resolution map of 6mA in P. bursaria and identify its methyltransferase PbAMT1. Functionally, 6mA exhibits a bimodal distribution at the 5′ end of RNA polymerase II-transcribed genes and possibly participates in transcription by facilitating alternative splicing. Evolutionarily, 6mA co-evolves with gene age and likely serves as a reverse mark of endosymbiosis-related genes. Our results offer new insights for the functional diversification of 6mA in eukaryotes as an important epigenetic mark.

ObjectiveTo explore the influence of the type of anterior clinoidal meningioma on surgical strategy planning, surgical approach selection, and postoperative efficacy.Patients and methodsWe conducted a retrospective analysis of the clinical data of 63 cases, including data on visual function, extent of tumor resection, and postoperative follow-up. Grade I and II approaches were selected according to the type of tumor. A univariate analysis of the factors influencing the extent of tumor resection, postoperative visual function, and postoperative relapse and complications was conducted.ResultsSimpson Grade I–II total resection was seen in 48 cases (76.2%), with an overall relapse/progression rate of 12.7%. The tumor type and texture and the relationship between the tumors and adjacent structures were the main factors influencing total tumor resection (P < 0.01). The overall postoperative visual acuity improvement, stabilization rate, and deterioration rate were 76.2, 15.9, and 7.9%, respectively. Postoperative visual acuity level was significantly correlated with preoperative visual acuity level and tumor type (P < 0.01).ConclusionsDetermining the type of tumor at a preoperative level and whether the optic canal and cavernous sinus are invaded can aid in the planning of detailed individualized surgical strategies.

Mesona chinensis Benth (MCB) (or Platostoma palustre or Platostoma chinense) is an important edible and medicinal plant in China. However, the mitochondrial genome (mitogenome, or mtDNA) of MCB has not been characterized or reported yet. In this study, we first sequenced and characterized the complete mitogenome of MCB. The MCB mitogenome was 494,599 bp in length and encoded 59 genes containing 37 protein-coding genes (PCGs), 19 tRNAs, and 3 rRNAs. Gene transfer analysis revealed that a total of 12 transfer segments with more than 93% identity (total length of 25,427 bp) were detected in the MCB mitogenome. Simple sequence repeats (SSR) analysis showed that 212 simple sequence repeats (SSR) were identified. Repeat sequence analysis revealed 305 repeat sequences (158 forward and 147 palindromic repeats) ranging from 30 bp to 48,383 bp and the 30–39 bp repeats were the majority type. Relative synonymous codon usage (RSCU) analysis uncovered that in total, 9,947 codons were encoding the protein-coding genes (PCGs). Serine (909, 9.1%) and leucine (879, 8.8%) were the two most abundant amino acids, while terminator (32, .3%) was the least abundant amino acid. Ka/Ks analysis indicated that almost all genes were subject to purification selection, except ccmB. Analysis of Lamiaceae mitogenomes constitution revealed that atpB and atpE were unique to the Rotheca serrata and Salvia miltiorrhiza mitogenomes. mttB gene loss was unique to the Boea hygrometrica mitogenome. The core fragments of the Lamiaceae mitogenomes harbored a higher GC content than the specific and variable fragments. In addition, phylogenetic analysis revealed that MCB was closely related to Salvia miltiorrhiza based on the mitogenomes. The current study provided valuable genomic resources for understanding and utilizing this important medicinal plant in the future.

Accumulating evidence indicated that oxidative stress is closely related to inflammation and the progression of multiple chronic diseases, which seriously threaten the host health. Currently, multiple plant-derived polysaccharides have been demonstrated to ameliorate the negative effects of oxidative stress on the host, but the potential protective effect of radix paeoniae alba polysaccharide (RPAP) on host have not been well characterized. Here, we investigated whether different doses of RPAP administration could alleviate lipopolysaccharide (LPS)-induced intestinal injury and gut microbial dysbiosis in mice. Results indicated that RPAP administration effectively alleviated LPS-induced intestinal damage in dose dependent. Additionally, amplicon sequencing showed that RPAP administration reversed the significant decrease in gut microbial diversity caused by LPS exposure and restored the alpha-diversity indices to normal levels. Microbial taxonomic investigation also indicated that LPS exposure resulted in significant changes in the gut microbial composition, characterized by a decrease in the abundances of beneficial bacteria (Lactobacillus, Alistipes, Bacillus, Rikenellaceae_RC9_gut_group, etc.) and an increase in the contents of pathogenic bacteria (Klebsiella, Helicobacter, Enterococcus, etc.). However, RPAP administration, especially in high doses, could improve the composition of the gut microbiota by altering the abundance of some bacteria. Taken together, this study demonstrated that RPAP administration could ameliorate LPS-induced intestinal injury by regulating gut microbiota. Meanwhile, this also provides the basis for the popularization and application of RPAP and alleviating oxidative stress from the perspective of gut microbiota.

Objective: This study aimed to fully develop and utilize the resources of passion fruits. Methods: The volatile flavor compounds at different brewing stages were analyzed by GC-IMS technology. Results: A total of 63 kinds of flavor compounds were identified, including 26 kinds of esters, 10 kinds of alcohols, 9 kinds of aldehydes, 7 kinds of ketones, 6 kinds of alkanes, 2 kinds of acids, 2 kinds of furans and 1 kinds of ether. Principal components analysis （PCA） showed that the cumulative difference contribution rate of the first two principal components （PC1 and PC2） was 81.2%, indicating that the volatile flavor substances changed significantly during the brewing process. The differential metabolites with VIP ＞ 1 obtained by orthogonal partial least squares-discriminant analysis （OPLS-DA） combined with the relative odor activity value （ROAV ≥ 1） suggested that the critical flavor substances contributing to the aroma of passion beer included hexyl acetate （apple, cherry flavor）, isoamyl acetate （banana flavor）, ethyl butyrate （banana, pineapple flavor）, 1-penten-3-one, acetic acid isobutyl ester （floral）, 3-methylbutyraldehyde （almond almond）, ethyl 3-methylbutyrate （apple flavor） and dimethyl sulfide （seafood flavor）. Conclusion: Passion beer is rich in nutrition and with unique flavor, and has broad prospects for future market.

Abstract Background Sophora tonkinensis Gagnep is a traditional Chinese medical plant that is mainly cultivated in southern China. Drought stress is one of the major abiotic stresses that negatively impacts S. tonkinensis growth. However, the molecular mechanisms governing the responses to drought stress in S. tonkinensis at the transcriptional and posttranscriptional levels are not well understood. Results To identify genes and miRNAs involved in drought stress responses in S. tonkinensis, both mRNA and small RNA sequencing was performed in root samples under control, mild drought, and severe drought conditions. mRNA sequencing revealed 66,476 unigenes, and the differentially expressed unigenes (DEGs) were associated with several key pathways, including phenylpropanoid biosynthesis, sugar metabolism, and quinolizidine alkaloid biosynthesis pathways. A total of 10 and 30 transcription factors (TFs) were identified among the DEGs under mild and severe drought stress, respectively. Moreover, small RNA sequencing revealed a total of 368 miRNAs, including 255 known miRNAs and 113 novel miRNAs. The differentially expressed miRNAs and their target genes were involved in the regulation of plant hormone signal transduction, the spliceosome, and ribosomes. Analysis of the regulatory network involved in the response to drought stress revealed 37 differentially expressed miRNA-mRNA pairs. Conclusion This is the first study to simultaneously profile the expression patterns of mRNAs and miRNAs on a genome-wide scale to elucidate the molecular mechanisms of the drought stress responses of S. tonkinensis. Our results suggest that S. tonkinensis implements diverse mechanisms to modulate its responses to drought stress.

By using network radar, national gridded real-time observation datasets and the hourly precipitation observation data at the automatic weather stations in the Yangtze River Basin, the radar extrapolation precipitation forecast product of the Yangtze River Basin based on the variational optical flow method is established. The results of threat score in 39 sub-basins and deviation analysis in the whole basin for 17 flood weather events in the Yangtze River Basin in 2020 were analyzed. The results show that: 1) 0-3 h rainfall nowcasting with the variational optical flow method has a positive correlation with the radar distribution range. The denser the distribution is, the better the prediction result is. 2) 0-3 h rainfall nowcasting with the variational optical flow method can better track the movement and evolution of the weather system. The precipitation concentration area is also in a relatively high zone for threat score of rainfall nowcasting. 3) Threat score of 0-3 h rainfall nowcasting with the optical flow method is the highest in the first hour, and the prediction skill decreases exponentially with the change of prediction time. 4) Comparing 0-3 h rainfall nowcasting and the gridded real-time observation datasets of precipitation, it is found that the absolute error rate of the precipitation forecast of the variational optical flow method is less than 5% when the precipitation is less than 10.0 mm. When the precipitation is over 10.0 mm, the absolute error rate is 6-11%. 5) The result of 0-3 h rainfall nowcasting with the variational optical flow method is applied to the quantitative precipitation forecast of the Yangtze River Basin replacing the output results of the current direct numerical model, which has a strong practical significance to improve the accuracy of flood forecast.