Kongzhuang coal mine of Shanghai Datun Energy Resources Co., Ltd. is a typical deep coal mine in eastern China. The mining disturbance of working face in deep coal mine leads to the fracture and ...movement of overlying strata and the damage of the aquifer in overlying strata, thereby causing water inrush disaster and posing a serious threat to the safety production in coal mine. Therefore, the temporal and spatial evolution mechanism of the water-conducting fractured zone of overlying strata in the Kongzhuang coal mine is researched systematically in this paper. Especially, the hydro-geological conditions and mining conditions in the Kongzhuang coal mine are analyzed; on this basis, the fracture and movement of overlying strata are simulated by physical similarity simulation test, and the temporal and spatial evolution rule of overlying strata in the Kongzhuang coal mine is obtained. Besides, the development height of “two zones” is measured by double-end water shutoff detection method, and the risk assessment for the water inrush disaster of the coal seam roof is carried out in the Kongzhuang coal mine. The research achievements in this paper indicate that the water-conducting channel formed in the mining process of #7 coal seam is the most important water-filling channel. Quaternary aquifer water recharges the mine indirectly through the bedrock aquifer, and the sandy mudstone with large thickness is the key layer to control the development of a water-conducting fracture zone. Meanwhile, the height of the caving zone is 26.7 m, about 8.3 times of mining height, and the height of the fracture zone is 68.3 m, approximately equal to 16.26 of the mining height. The results of #1 and #2 borehole leakages in the double-end water shutoff detection method show that the height of the water-conducting fractured zone is 63.70 m-65.27 m, and the split-to-mining ratio is 15.17-15.54. The water inrush risk of the coal seam roof shows that most of the 7436 working face is in the transition zone, and a small area around the cutting hole of the working face is in the relatively dangerous zone. Therefore, the innovation of this paper is that the temporal and spatial evolution mechanism of the water-conducting fractured zone of overlying strata in the Kongzhuang coal mine is revealed, which provides the theoretical guidance for the prediction and prevention of water inrush disaster in the coal mine with the similar mining conditions.
ABSTRACT
High salt is a major environmental factor that threatens plant growth and development. Increasing evidence indicates that histone acetylation is involved in plant responses to various ...abiotic stress; however, the underlying epigenetic regulatory mechanisms remain poorly understood. In this study, we revealed that the histone deacetylase OsHDA706 epigenetically regulates the expression of salt stress response genes in rice (Oryza sativa L.). OsHDA706 localizes to the nucleus and cytoplasm and OsHDA706 expression is significantly induced under salt stress. Moreover, oshda706 mutants showed a higher sensitivity to salt stress than the wild‐type. In vivo and in vitro enzymatic activity assays demonstrated that OsHDA706 specifically regulates the deacetylation of lysines 5 and 8 on histone H4 (H4K5 and H4K8). By combining chromatin immunoprecipitation and mRNA sequencing, we identified the clade A protein phosphatase 2 C gene, OsPP2C49, which is involved in the salt response as a direct target of H4K5 and H4K8 acetylation. We found that the expression of OsPP2C49 is induced in the oshda706 mutant under salt stress. Furthermore, the knockout of OsPP2C49 enhances plant tolerance to salt stress, while its overexpression has the opposite effect. Taken together, our results indicate that OsHDA706, a histone H4 deacetylase, participates in the salt stress response by regulating the expression of OsPP2C49 via H4K5 and H4K8 deacetylation.
Histone acetylation plays important roles in plant growth and development, but its roles in regulating plant salt stress responses remain unclear. The rice histone deacetylase OsHDA706 regulates the expression of OsPP2C49 via H4K5 and H4K8 deacetylation, which further increases the tolerance to salt stress.
The cross-corrugated triangular duct is a common flow channel in plate heat exchangers. To further improve the heat transfer in the cross-corrugated triangular duct, trapezoidal baffles were inserted ...in the flow channel in this study. The apex angle and baffle position on heat and flow characteristics of the flow channel are investigated. The flow fields, velocity contours, and temperature contours were obtained through calculation. Numerical results of friction factor (f), Nusselt number (Nu), and Performance Evaluation Criterion (PEC) for various channel structures were analyzed. The variations of apex angle and baffle position make the field more complex in the flow channel than that of without baffles. For various apex angles, the f of flow channels with an apex angle of 60° or 90° are close in value, higher than that of 120°. The same trend is found for Nu. When the baffles are in the center of the upper half of the channel, the flow duct owns the highest f, Nu, and PEC values. When the Reynolds number is less than 1000, the PEC value for the flow channel with a particular baffle position at the apex angle of 120° may be lower than that of without baffles.
Aneuploid refers to the gene dosage imbalance due to copy number alterations. Aneuploidy is generally harmful to the growth, development and reproduction of organisms according to the numerous ...research. However, it has rarely been reported on whether aneuploid have a relevant pattern of genome expression between the parental and its offspring generations. In this study, mRNA sequencing analysis was performed on rice (
Oryza sativa
L.) primary trisomes 11 and 12, same primary trisomes and normal individuals in their filial generation. We systematically summarized the changes in gene expression patterns that occur on
cis
genes and on
trans
genes between parental and filial generations. In T11 and T12, the ratio of
cis
-gene expression showed intermediate type in parents and dosage compensation in filial generations, which maybe due to more genes being downregulated. The
trans
genes were also affected by aneuploidy and manifested as
cis
-related. The strains with normal chromosomes in filial generations, there are still aneuploid-sensitive genes differentially expressed in their genomes, indicating that the effect of aneuploidy is far-reaching and could not be easily eliminated. Meanwhile, among these differentially expressed genes, genes with low-expression level were more likely to be upregulated, while genes with medium- and high-expression level were easy to be downregulated. For the different types of rice aneuploid, upregulated genes were mainly associated with genomic imbalance while downregulated genes were mainly influenced by the specific added chromosome. In conclusion, our results provide new insights into the genetic characterization and evolution of biological aneuploidy genomes.
Among the various scanning techniques, spot and raster scanning are the most frequently adopted. Raster scanning turns off the beam only when each isoenergy slice irradiation is completed. This ...feature intrinsically solves the leakage dose and frequent beam-switching problems encountered during spot scanning. However, to shorten the delivery time of raster scanning, a sophisticated dose control strategy is required to guarantee dose distribution. In this study, a real-time compensation method with raster scanning for synchrotron systems was designed. It is characterized by a small spot-spacing planning strategy and real-time subtraction of the transient number of particles delivered between two planning-spot positions from the planned number of particles of the subsequent raster point. The efficacy of the compensation method was demonstrated by performing accurate raster scanning simulations with an in-house simulation code and accurate final dose evaluations with a commercial treatment planning system. Given the similar dose evaluation criteria under a practical high scanning speed, compared with the spot scanning method, the total delivery time of the compensated raster scanning method was significantly shortened by 53.3% in the case of irradiating a cubical target and by 28.8% in a pelvic case. Therefore, it can be concluded that real-time compensated raster scanning with a fast scanning configuration can significantly shorten the delivery time compared to that of spot scanning. It is important to reduce the pressure on patients caused by prolonged immobilization and to improve patient throughput capacity at particle therapy centers.
A class of iodobenzoyldiazenido-functionalized POMs (TBA)
Mo
O
(=N=NCOAr) (Ar = Ph-
-I
; Ph-
-I
; Ph-
-I
; Ph-3,4-I
; Ph-2,3,5-I
(TBA = tetrabutylammonium) were prepared
the refluxing reaction of
...-octamolybdates, DCC, and corresponding hydrazides in dry acetonitrile. Their structures were determined by Fourier-transform infrared spectroscopy, ultraviolet-visible spectra, X-ray photoelectron spectroscopy, hydrogen-1 nuclear magnetic resonance, and high-resolution mass spectrometry. Research on the biological activity of title compounds shows that
,
, and
demonstrate potent inhibitory activity against coxsackievirus B3 and low
cytotoxic activity against Hep-2 cell lines. The covalent linkage between the iodobenzoyldiazenido components and POMs can enhance the molecular inhibitory efficiency of iodobenzohydrazides.
The first example of highly efficient kinetic resolution of exo-3-oxodicyclopentadienes and endo-3-oxodicyclopentadiene has been developed by means of Cu(I)-catalyzed asymmetric 1,3-dipolar ...cycloaddition of azomethine ylide. Compared with the existing methodologies for those synthetically important optically active convex molecules, the current protocol provides an alternative but more practical approach from the readily available racemic starting materials, which is free from the repetitive reduction/oxidation steps in the enzymatic resolution or the indispensable stoichiometric amount of chirality-induction reagents.
Abstract
The colour gamut, a two-dimensional (2D) colour space primarily comprising hue and saturation (HS), lays the most important foundation for the colour display and printing industries. ...Recently, the metasurface has been considered a promising paradigm for nanoprinting and holographic imaging, demonstrating a subwavelength image resolution, a flat profile, high durability, and multi-functionalities. Much effort has been devoted to broaden the 2D HS plane, also known as the CIE map. However, the brightness (B), as the carrier of chiaroscuro information, has long been neglected in metasurface-based nanoprinting or holograms due to the challenge in realising arbitrary and simultaneous control of full-colour HSB tuning in a passive device. Here, we report a dielectric metasurface made of crystal silicon nanoblocks, which achieves not only tailorable coverage of the primary colours red, green and blue (RGB) but also intensity control of the individual colours. The colour gamut is hence extruded from the 2D CIE to a complete 3D HSB space. Moreover, thanks to the independent control of the RGB intensity and phase, we further show that a single-layer silicon metasurface could simultaneously exhibit arbitrary HSB colour nanoprinting and a full-colour hologram image. Our findings open up possibilities for high-resolution and high-fidelity optical security devices as well as advanced cryptographic approaches.
•High temperature background reflection affects the selection of emissivity model.•BP neural network can distinguish different emissivity models effectively.•Radiation temperature calculation method ...based on INSGA-II has better performance.•Adaptive emissivity model can improve the accuracy of temperature measurement.
When the object surface temperature in high temperature environment is measured by multi-spectral temperature measurement method, the radiation generated by the reflection of the high temperature background on the surface of the object and the radiation emitted by the object itself are both received by the pyrometer. For one thing, the amount of radiation received by the pyrometer increases. On the other hand, the surface emissivity model may change. So a large temperature measurement error may occur. In order to accurately measure the true surface temperature of an object in a high temperature environment, a multi-spectral temperature measurement method based on adaptive emissivity model is proposed in this paper. First, BP neural network is used to identify the shape of spectral data and obtain the correspondence between spectral data and emissivity model, then output the emissivity model that conforms to the measured target and specific environment. Moreover, the traditional NSGA-II algorithm (Non-dominant sorting genetic algorithm-II) is prone to falling into local optimal solutions and the numerical values obtained are not accurate enough. In this paper, the concepts of clustering algorithm, difference operator and symmetrical solution are introduced in the process of crossover and mutation, and then the new algorithm of INSGA-II (Improved Non-dominant sorting genetic algorithm-II)) is proposed. On the basis of this algorithm, the emissivity model of BP network is combined to solve the target true temperature. The experimental results show that the maximum temperature measurement error can reach 60 K if the influence of high temperature background is ignored. After removing the influence of high temperature background, the non-adaptive emissivity model was used to obtain the maximum temperature error of 30 K, and the fluctuation between adjacent temperature points was large. The multi-spectral temperature measurement method based on adaptive emissivity model proposed in this paper can obtain more accurate temperature measurement results with the maximum error of 8 K.
SUMMARY
Neocentromeres develop when kinetochores assemble de novo at DNA loci that are not previously associated with CenH3 nucleosomes, and can rescue rearranged chromosomes that have lost a ...functional centromere. The molecular mechanisms associated with neocentromere formation in plants have been elusive. Here, we developed a Xian (indica) rice line with poor growth performance in the field due to approximately 272 kb deletion that spans centromeric DNA sequences, including the centromeric satellite repeat CentO, in the centromere of chromosome 8 (Cen8). The CENH3‐binding domains were expanded downstream of the original CentO position in Cen8, which revealed a de novo centromere formation in rice. The neocentromere formation avoids chromosomal regions containing functional genes. Meanwhile, canonical histone H3 was replaced by CENH3 in the regions with low CENH3 levels, and the CenH3 nucleosomes in these regions became more periodic. In addition, we identified active genes in the deleted centromeric region, which are essential for chloroplast growth and development. In summary, our results provide valuable insights into neocentromere formation and show that functional genes exist in the centromeric regions of plant chromosomes.
Significance Statement
The mechanisms underlying neocentromere formation in plants have been elusive. In this study, we demonstrate that CentO deletion led to the expansion of the CENH3‐binding domain and neocentromere formation in rice. Our findings also provide valuable insights into neocentromere formation and show that functional genes exist in the centromeric regions of plant chromosomes.
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