Genome-Wide Association Study Discovers Novel Germplasm Resources and Genetic Loci with Resistance to Gibberella Ear Rot Caused by Fusarium graminearum.

Gibberella ear rot (GER) in maize caused by Fusarium graminearum is one of the most devastating maize diseases reducing grain yield and quality worldwide. The genetic bases of maize GER resistance remain largely unknown. Using artificial inoculation across multiple environments, the GER severity of an association panel consisting of 316 diverse inbred lines was observed with wide phenotypic variation. In the association panel, a genome-wide association study using a general linear model identified 69 single-nucleotide polymorphisms (SNPs) significantly associated with GER resistance at the threshold of 2.04 × 10-5, and the average phenotypic variation explained (PVE) of these SNPs was 5.09%. We also conducted a genome-wide association study analysis using a mixed linear model at a threshold of 1.0 × 10-4, and 16 significantly associated SNPs with an average PVE of 4.73% were detected. A combined general linear model and mixed linear model method obtained 10 co-localized significantly associated SNPs linked to GER resistance, including the most significant SNP (PZE-105079915) with the greatest PVE value, 9.07%, at bin 5.05 following 10 candidate genes. These findings are significant for the exploration of the complicated genetic variations in maize GER resistance. The regions and genes identified herein provide a list of candidate targets for further investigation, in addition to the elite germplasm resources that can be used for breeding GER resistance in maize.

A Combination of QTL Mapping and GradedPool-Seq to Dissect Genetic Complexity for Gibberella Ear Rot Resistance in Maize Using an IBM Syn10 DH Population.

Gibberella ear rot (GER) caused by Fusarium graminearum (teleomorph Gibberella zeae) is one of the most devastating maize diseases that reduces grain yield and quality worldwide. Utilization of host genetic resistance has become one of the most suitable strategies to control GER. In this study, a set of 246 diverse inbred lines derived from the intermated B 73 × Mo 17 doubled haploid population (IBM Syn10 DH) were used to detect quantitative trait loci (QTL) associated with resistance to GER. Meanwhile, a GradedPool-Seq (GPS) approach was performed to identify genomic variations involved in GER resistance. Using artificial inoculation across multiple environments, GER severity of the population was observed with wide phenotypic variation. Based on the linkage mapping, a total of 14 resistant QTLs were detected, accounting for 5.11 to 14.87% of the phenotypic variation, respectively. In GPS analysis, five significant single nucleotide polymorphisms (SNPs) associated with GER resistance were identified. Combining QTL mapping and GPS analysis, a peak-value SNP on chromosome 4 from GPS was overlapped with the QTL qGER4.2, suggesting that the colocalized region could be the most possible target location conferring resistance to GER. Subsequently, seven candidate genes were identified within the peak SNP, linking them to GER resistance. These findings are useful for exploring the complicated genetic variations in maize GER resistance. The genomic regions and genes identified herein provide a list of candidate targets for further investigation, in addition to the combined strategy that can be used for quantitative traits in plant species.

[Research on the Time-Histories of Exited Radicals during the Combustion of Methylcyclohexane by Emission Spectroscopy].

By using three monochromator! detecting systems, the light emissions of excited-state OH*, CH* and C* radicals during the transient combustion of methylcyclohexane at high temperatures behind the reflected shock wave have been measured. The dependence of the time-history and the relative intensity of excited radicals on the temperature have been obtained. The reflected shock temperatures are 1 200-1 700 K, the shock pressure is 1.5 atm, the mole fraction of methylcyclohexane is 0.1% and the equivalence ratio is 1.0. At the beginning of the combustion process, these three radicals were produced at the same time. The durations of these radicals became shorter when the temperature increases. At the same ignition temperature, the durations of CH* and OH* are longer than that of C2*. The C2* signal disappears below 1 400 K. The emission intensities of OH* and CH* are not sensitive to the temperature at T < 1 400 K. However, at high temperature (T > 1 400 K), the peak intensity of CH* increases rapidly as temperature increases, while C2* and OH* increase slowly. Current results were compared to the simulation results of corresponding chemical reaction mechanism. The obtained time-history of OH* radical matches well with the prediction of mechanism at low temperatures, but shows difference at high temperatures. The time-history of CH* radical matches well between experimental and simulated results at high temperatures, however, the simulated durations of CH* are longer than the experimental results at low temperatures. Current work provides experimental data to validate and optimize corresponding chemical reaction mechanism containing excited-state species.

[Measurement of Soot Yield from the Pyrolysis of Toluene at High Temperatures by Laser Extinction Method].

The measurement system for the detection of soot production as high-temperature pyrolysis of hydrocarbon fuels behind the reflected shock wave was established. By using the laser extinction method, the soot yields of toluene/argon mixtures were measured at high temperatures. The mole fractions of toluene were 0.25% and 0.5% while the pressures were approximate 2 and 4 atm. The temperatures ranged from 1 630 to 2 273 K. The dependence of soot yield on the temperature, pressure and fuel concentration was obtained. With the changes of temperature, the soot yield is a Gauss distribution. The soot yield increases as the pressure or fuel concentration increases. The maximum of soot yield was as high as 55%. The peak temperature of soot yield was not changed dramatically with the pressure. However, it changed from 1 852 to 1 921 K as the concentration of toluene increase from 0.25% to 0.5%. Moreover, we compared the soot yield between toluene and methylcyclohexane at pressure of 4 atm with fuel concertation of 0.5%. During the pyrolysis of methylcyclohexane, the peak temperature of soot yield was 2 045 K, which is about 135 K higher than that of toluene. However, the maximum soot yield of methylcyclohexane is only 1/8 of toluene. This work provides experimental reference for the research of soot particle emission in the engines and the mechanism of soot formation.

The HANTS-fitted RSEI constructed in the vegetation growing season reveals the spatiotemporal patterns of ecological quality.

Yuxi, located in China's central plateau of Yunnan, is grappling with ecological and environmental challenges as it continues to develop its economy. While ecological quality assessment serves as the foundation for ecological protection, it is pivotal to have reliable and long-term methods for assessing the ecological status to support informed decision-making in ecological protection. Reliable and long-term methods for assessing ecological status in order to facilitate informed decision-making in ecological protection are applied. This study utilized Landsat data to reconstruct four indices (greenness, wetness, dryness, and heat) during the vegetation growth in Yuxi from 2000 to 2020 that employs Harmonic Analysis of Time Series (HANTS) method. Subsequently, the annual Remote Sensing Ecological Index (RSEI) was computed by using the reconstructed indices to evaluate ecological quality in Yuxi. Additionally, spatiotemporal patterns and determinants of Yuxi's ecological quality are unveiled through Sen's slope estimator and Mann-Kendall test (Sen + MK) trend analysis, spatial auto-correlation analysis, and geographical detectors applied to year-by-year RSEI data. The findings in the paper indicate that the accuracy of the RSEI is significantly influenced by the vegetation season, suggesting that constructing the RSEI model with data from the vegetation growth season is crucial. Moreover, the HANTS optimization method effectively enhances the ecological indices used in the RSEI model, leading to smoother and more continuous filling of missing data. The difference between the reconstructed RSEI and the original RSEI falls within the range of - 0.15 to 0.15. Yuxi has an average RSEI of 0.54 to emphasis a moderate level of comprehensive ecological quality. Compared with river valley plains, the ecological quality of mountainous areas is higher, and the ecological quality of Yuxi presents a distinct center-edge pattern. From 2000 to 2020, Yuxi's ecological quality exhibited fluctuations, with a slight overall improvement. Land use patterns, particularly in forestry land and impervious surfaces, are identified as the main drivers of these changes. The research offers valuable insights for scientific decision-making related to sustainable development and ecological protection.

Green tissue-targeted expression of the Cry1Ab/c gene in transgenic maize using the Cre/loxP system as an alternative strategy against lepidopteran pests.

Genetically modified (GM) proteins in edible tissues of transgenic maize are of intense public concern. We provided a Cre/loxP-based strategy for manipulating the expression of transgenes in green tissues while locking them in nongreen tissues. First, the Cre gene was driven by the green tissue-specific promoter Zm1rbcS to generate transgenic maize KEY. Meanwhile, a gene cassette containing a Nos terminator (NosT) in front of the Cry1Ab/c gene was driven by the strong promoter ZmUbi to generate another transgenic maize LOCK. By crossing KEY and LOCK plants, the expressed Cre recombinase under the control of the Zm1rbcS promoter from KEY maize accurately removed the NosT of LOCK maize. Consequently, the expression of blocked Cry1Ab/c was enabled in specific green tissues in their hybrids. The expression level and concentration of Cry1Ab/c were observed using a strategy with high specific accumulation in green tissues (leaf and stem). Still, only a small or absent amount was observed in root and kernel tissues. Furthermore, we assessed the bioactivity of transgenic maize against 2 common lepidopteran pests, Ostrinia furnacalis and Spodoptera frugiperda, in the laboratory and field. The transgenic plants showed high plant resistance levels against the 2 pests, with mortality rates above 97.2% and damage scales below 2.2 compared with the control group. These findings are significant for exploring novel genetic engineering techniques in GM maize and providing a feasible strategy for transgenes avoiding expression in edible parts. In addition, implementing the Cre/loxP-mediated system could relieve public sentiment toward the biosafety of GM plants.

A Deep Learning Method for Intelligent Analysis of Sports Training Postures.

With the further research of artificial intelligence technology, motion recognition technology is widely used in posture analysis of sports training. However, the interference of light, Angle, and distance in real life makes the existing model unable to focus on the expression of human movements. Aiming at the above problems, this paper proposes a motion training attitude analysis method based on a multiscale spatiotemporal graph convolution network. Firstly, the spatiotemporal image of the skeleton is constructed, and then the convolution operation is performed on the spatiotemporal image of the skeleton. Finally, the convolution results are linearly weighted and fused to capture the characteristics of action types with different time lengths. At the same time, the algorithm increases the processing of some important information loss and increases the randomness of the data set. Experimental results show that the proposed algorithm can adapt to the behavior changes of different complexity, and the model performance and recognition accuracy are significantly improved.

Protective effects of corni fructus extract in mice with potassium oxonate-induced hyperuricemia.

Corni fructus is consumed as food and herbal medicine in Chinese culture. Studies have revealed that corni fructus exhibits potent antioxidant activity; however, few studies have investigated the ability of corni fructus to lower uric acid concentrations. In this study, the xanthine oxidase (XO) inhibition and uric acid-lowering effect of corni fructus extract (CFE) were evaluated in mice with potassium oxonate-induced hyperuricemia. Hyperuricemia is a chronic disease prevalent worldwide and is associated with high recurrence rates. In addition, drugs used to treat hyperuricemia induce side effects that discourage patient compliance. Hyperuricemia induces metabolic imbalances resulting in accumulative uric acid deposition in the joints and soft tissues. Hyperuricemia not only induces gout but also interrupts hepatic and renal function, thereby trigging severe inflammation and various complications, including obesity, nonalcoholic fatty liver disease, diabetes, and metabolic diseases. In this study, the ethyl acetate fraction (EAF) of CFE resulted in yields of antioxidant photochemical components significantly higher than those of CFEs formed using other substances. The EAF of CFE exhibited high free radical scavenging activity and XO inhibition and effectively lowered uric acid concentrations in the animal model of chemically induced hyperuricemia. The results of this study can serve as a reference for the prevention of preclinical gout as well as for functional food research.

Urban Public Sports Information-Sharing Technology Based on Internet of Things.

With the continuous development of social economy, sports has become one of the important ways of physical exercise, and the demand for corresponding sports facilities is also increasing. The Internet of Things technology is introduced in this paper. Through combining the current status of urban public sports, an urban public sports sharing system is built by trial, to promote the sharing of urban public sports information through the continuous development of new technologies such as the Internet and improve the publicity and popularization of public sports information. Simulation experiments prove that the Internet of Things technology is effective and can effectively support the sharing of urban public sports information.

Preparation and characterization of bionic bone structure chitosan/hydroxyapatite scaffold for bone tissue engineering.

Three-dimensional oriented chitosan (CS)/hydroxyapatite (HA) scaffolds were prepared via in situ precipitation method in this research. Scanning electron microscopy (SEM) images indicated that the scaffolds with acicular nano-HA had the spoke-like, multilayer and porous structure. The SEM of osteoblasts which were polygonal or spindle-shaped on the composite scaffolds after seven-day cell culture showed that the cells grew, adhered, and spread well. The results of X-ray powder diffractometer and Fourier transform infrared spectrometer showed that the mineral particles deposited in the scaffold had phase structure similar to natural bone and confirmed that particles were exactly HA. In vitro biocompatibility evaluation indicated the composite scaffolds showed a higher degree of proliferation of MC3T3-E1 cell compared with the pure CS scaffolds and the CS/HA10 scaffold was the highest one. The CS/HA scaffold also had a higher ratio of adhesion and alkaline phosphate activity value of osteoblasts compared with the pure CS scaffold, and the ratio increased with the increase of HA content. The ALP activity value of composite scaffolds was at least six times of the pure CS scaffolds. The results suggested that the composite scaffolds possessed good biocompatibility. The compressive strength of CS/HA15 increased by 33.07% compared with the pure CS scaffold. This novel porous scaffold with three-dimensional oriented structure might have a potential application in bone tissue engineering.

Dual stimuli-responsive N-phthaloylchitosan-graft-(poly(N-isopropylacrylamide)-block-poly(acrylic acid)) copolymer prepared via RAFT polymerization.

In order to develop stimuli-responsive hydrogel, chitosan graft copolymer with chitosan back-bone and poly(N-isopropylacrylamide)-block-poly(acrylic acid) (PNIPAAm-b-PAA) branch chains was prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization in DMF. The chain transfer agent was obtained by modification of chitosan with 3-benzylsulfanyl thiocarbonylsulfanyl propionic acid (BPATT) with 68% the degree of substitute. The graft polymerizations possessed controlled/living characteristics. The behavior of the graft copolymer in aqueous solution was investigated by dynamic light scattering, transmission electron microscopy, and UV-visible spectrophotometer. N-Phthaloylchitosan-graft-(poly(N-isopropylacrylamide)-block-poly(acrylic acid)) copolymer (N-phthaloylchitosan-g-(PNIPAAm-b-PAA)) could assemble to micelles in aqueous solution in range of 200-300 nm with narrow size distribution, and the hydrodynamic diameter could be controlled dependent on length of branch chains and temperature. The LCST values of micelle could be modulated from 34 to 40 °C by controlling the constitution of branch chains, pH, and concentration.

Modification of chitosan membrane with poly(vinyl alcohol) and biocompatibility evaluation.

This work aimed to overcome chitosan (CS) membrane' drawbacks: mainly stiffness and hydrophobic surface by adding poly(vinyl alcohol) (PVA) and evaluate their biocompatibility. The chemical structure, crystalline and thermal properties were studied by FT-IR, XRD and DSC. The mechanical properties and wettability of CS/PVA membranes were studied by tensile test and static contact angle measurement. In vitro biocompatibility was also evaluated by MTS cytotoxicity assay and SEM examination. The results suggest that adding PVA into CS membrane could greatly improve CS membrane's flexibility and wettability. All the membranes prepared were biocompatible and have potential applications in GTR technology.

One-pot synthesis of chitosan-g-(PEO-PLLA-PEO) via "click" chemistry and "SET-NRC" reaction.

For the development of biocompatible and degradable biomaterials, a kind of well-defined graft copolymer consisting of chitosan back-bone and amphiphilic PEO-PLLA-PEO branch chains was synthesized by Cu(0) catalyzed one-pot strategy combining "click" chemistry and single electron transfer-nitroxide radical coupling (SET-NRC) reaction. First, the precursors of 6-azide-N-phthaloyl-chitosan, TEMPO-PEO-alkyne and mPEO-PLLA-Br were designed and produced. Then, the one-pot coupling reactions between these precursors were performed in the presence of nanosized Cu and PMDETA. The efficiencies of the coupling reactions were greater than 90% determined by the FTIR and ESR spectra. The structure of graft copolymer with 43% of the grafting ratio was confirmed by the spectral analysis. This work provided a route to prepare chitosan graft copolymer.

The preparation and characterization of chitosan rods modified with Fe3+ by a chelation mechanism.

Chitosan composite rods (CS-Fe(3+)) were prepared via an in situ precipitation method. The relationships among the preparation, structures, and properties of the CS-Fe(3+) composite rods have been investigated. The results of Fourier-transform infrared spectroscopy (FTIR) and core electron X-ray photoelectron spectroscopy (XPS) indicate that the CS and Fe(3+) are coordinated via a chelation mechanism. The content of Fe(3+) in the complex was determined by atomic absorption spectrometry (AAS) and elemental analysis (EA), the results of which suggested that the content of Fe(3+) in the complex can be controlled by the concentration of the ferric salts during coordination. The changes in thermal stability and crystallization properties were measured by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) patterns, respectively. Scanning electron microscopy (SEM) was used to observe the morphological change of the CS-Fe(3+) complex rod. After coordination with Fe(3+), the CS rod had a denser, layered structure. However, the layered structure cannot remain intact when the ratios of -NH(2)/Fe(3+) are 100/15 and 100/20. Moreover, its thermal stability decreased, and its bending strength was improved significantly (from 86 MPa to more than 210 MPa), despite the remarkable decrease in the degree of crystallinity.

[Experimental study on p53 gene mutation in keloid fibroblasts].

OBJECTIVE: To explore the significance and the role of the p53 gene mutation in the exon 4 to 8 in keloid fibroblasts. METHODS: Tissue samples from twelve patients with keloid and twelve hyperplastic scar respectively were harvested for in vitro culture of fibroblasts, and normal skin samples from the same patients were employed as the control. Polymerase chain reaction-based single-strained conformational polymorphism (PCR-SSCP) and DNA sequencing were employed to detect p53 gene mutations of the fibroblasts. RESULTS: The points and frameshift mutations in the exon 4, 5, 6, 7 of p53 gene were identified in 9 of the 12 keloid tissue samples. No p53 gene mutation was detected in all hyperplastic scar and normal skin samples. CONCLUSION: p53 gene mutation might play an important role in the formation and development of keloids.