Abstract
In Arabidopsis, secondary cell walls (SCW) are formed in fiber cells and vessel cells in vascular tissue for providing plants with mechanical strength and channels for the long distance ...transportation of water and nutrients. NAC SECONDARY WALL THICKENING PROMOTING FACTOR1 (NST1) acts as a key gene for the initiation of SCW formation through a hierarchical transcription network. In this study, we report that NST activity is modulated by the NAC domain transcription factor XYLEM NAC DOMAIN1 (XND1) during plant growth. Using yeast two-hybrid screening and in vivo protein interaction analysis, XND1 was identified as an NST-interacting protein that modulates NST1 activity. XND1 and NST1 were co-localized in the nucleus and the interaction of XND1 with NST1 resulted in inhibition of NST1 transactivation activity. In the process of inflorescence growth, XND1 was expressed with a similar pattern to NST1. Up-regulation of XND1 in fiber cells repressed SCW formation. The study demonstrates that NST1 activity is modulated by XND1 in the regulation of secondary cell walls formation.
NAC transcription factor NST1 serves as a check-point in regulation of secondary cell wall formation during plant growth. Transcription factor XND1 binds to it to repress its activity.
An experimental and numerical study on laminar burning characteristics of the premixed methane–hydrogen–air flames was conducted at room temperature and atmospheric pressure. The unstretched laminar ...burning velocity and the Markstein length were obtained over a wide range of equivalence ratios and hydrogen fractions. Moreover, for further understanding of the effect of hydrogen addition on the laminar burning velocity, the sensitivity analysis and flame structure were performed. The results show that the unstretched laminar burning velocity is increased, and the peak value of the unstretched laminar burning velocity shifts to the richer mixture side with the increase of hydrogen fraction. Three regimes are identified depending on the hydrogen fraction in the fuel blend. They are: the methane-dominated combustion regime where hydrogen fraction is less than 60%; the transition regime where hydrogen fraction is between 60% and 80%; and the methane-inhibited hydrogen combustion regime where hydrogen fraction is larger than 80%. In both the methane-dominated combustion regime and the methane-inhibited hydrogen combustion regime, the laminar burning velocity increases linearly with the increase of hydrogen fraction. However, in the transition regime, the laminar burning velocity increases exponentially with the increase of hydrogen fraction in the fuel blends. The Markstein length is increased with the increase of equivalence ratio and is decreased with the increase of hydrogen fraction. Enhancement of chemical reaction with hydrogen addition is regarded as the increase of H, O and OH radical mole fractions in the flame. Strong correlation is found between the burning velocity and the maximum radical concentrations of H and OH in the reaction zone of the premixed flames.
Abstract
The precise and efficient construction of axially chiral scaffolds, particularly toward the aryl-alkene atropoisomers with impeccably full enantiocontrol and highly structural diversity, ...remains greatly challenging. Herein, we disclose an organocatalytic asymmetric nucleophilic aromatic substitution (S
N
Ar) reaction of aldehyde-substituted styrenes involving a dynamic kinetic resolution process via a hemiacetal intermediate, offering a novel and facile way to significant axial styrene scaffolds. Upon treatment of the aldehyde-containing styrenes bearing (
o
-hydroxyl)aryl unit with commonly available fluoroarenes in the presence of chiral peptide-phosphonium salts, the S
N
Ar reaction via an exquisite bridged biaryl lactol intermediate undergoes smoothly to furnish a series of axially chiral aldehyde-containing styrenes decorated with various functionalities and bioactive fragments in high stereoselectivities (up to >99% ee) and complete
E
/
Z
selectivities. These resulting structural motifs are important building blocks for the preparation of diverse functionalized axial styrenes, which have great potential as efficient and privileged chiral ligands/catalysts in asymmetric synthesis.
Accurately predicting traffic flow is crucial for optimizing traffic conditions, reducing congestion, and improving travel efficiency. To explore spatiotemporal characteristics of traffic flow in ...depth, this study proposes the MFSTBiSGAT model. The MFSTBiSGAT model leverages graph attention networks to extract dynamic spatial features from complex road networks, and utilizes bidirectional long short-term memory networks to capture temporal correlations from both past and future time perspectives. Additionally, spatial and temporal information enhancement layers are employed to comprehensively capture traffic flow patterns. The model aims to directly extract original temporal features from traffic flow data, and utilizes the Spearman function to extract hidden spatial matrices of road networks for deeper insights into spatiotemporal characteristics. Historical traffic speed and lane occupancy data are integrated into the prediction model to reduce forecasting errors and enhance robustness. Experimental results on two real-world traffic datasets demonstrate that MFSTBiSGAT successfully extracts and captures spatiotemporal correlations in traffic networks, significantly improving prediction accuracy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Experimental and numerical study on hydrogen–air flames at elevated pressures and temperatures was conducted. Meanwhile, the calculation is extended to initial pressure and temperature up to 8.0
MPa ...and 950
K, respectively. Laminar burning velocities and Markstein lengths were obtained at the elevated pressures and temperatures. Sensitivity analysis and flame structure were also analyzed. The results show good agreement between the computed results and experimental data. The study shows that laminar burning velocities are increased with the increase of initial temperature, and they decrease with the increase of initial pressure. With the increase of initial pressure, advancement of the onset of cellular instability is presented and Markstein length is decreased, indicating an increase of flame instability with the increase of initial pressure. The study shows insensitivity of flame instability to initial temperature. Laminar burning velocity is depended on the competition between the main chain branching reactions and chain termination reaction. The chain branching reactions are the temperature-sensitive reaction, while the termination reaction is the temperature-insensitive reaction. Through the extraction of the overall reaction orders, it is demonstrated that with increasing pressure, the overall reaction orders give a decreasing trend and then increasing trend. This behavior suggests an analogy to three explosion limits of hydrogen/oxygen mixtures. Numerical study also shows that the suppression (or enhancement) of overall chemical reaction with the increase of initial pressure (or temperature) is closely linking to the decrease (or increase) of H, O and OH mole fractions in the flames. Strong correlation is existed between burning velocity and maximum radical concentrations of H and OH radicals in the reaction zone of premixed flames. On the basis of the numerical data, an empirical formula for laminar burning velocity is correlated for the hydrogen–air premixed mixture at elevated pressures and temperatures. The correlated laminar burning velocities are in good agreement with the known experimental results and simulated results with CHEMKIN. The correlation can be used in the calculation of laminar burning velocities at evaluated pressures and temperatures.
The endoplasmic reticulum-mitochondria encounter structure (ERMES) complex creates contact sites between the endoplasmic reticulum and mitochondria, playing crucial roles in interorganelle ...communication, mitochondrial fission, mtDNA inheritance, lipid transfer, and autophagy. The mechanism regulating the number of ERMES foci within the cell remains unclear. Here, we demonstrate that the mitochondrial membrane protein Emr1 contributes to regulating the number of ERMES foci. We show that the absence of Emr1 significantly decreases the number of ERMES foci. Moreover, we find that Emr1 interacts with the ERMES core component Mdm12 and colocalizes with Mdm12 on mitochondria. Similar to ERMES mutant cells, cells lacking Emr1 display defective mitochondrial morphology and impaired mitochondrial segregation, which can be rescued by an artificial tether capable of linking the endoplasmic reticulum and mitochondria. We further demonstrate that the cytoplasmic region of Emr1 is required for regulating the number of ERMES foci. This work thus reveals a crucial regulatory protein necessary for ERMES functions and provides mechanistic insights into understanding the dynamic regulation of endoplasmic reticulum-mitochondria communication.
Digital economy is regarded as the main economic form following agricultural economy and industrial economy. And the digital transformation has given enterprises new development momentum. Can it ...reduce the equity capital cost? This paper uses text analysis obtained by crawling the annual reports from 2010 to 2021 and investigates the impact of digital transformation on the corporate equity capital cost. The results show that: 1) Digital transformation will reduce the equity capital cost; 2) The digital transformation has a heterogeneous impact on the equity capital cost of enterprises with different scales, natures and levels of leverage, which is more significant for large-scale enterprises, state-owned enterprises and highly leveraged enterprises; 3) Digital transformation mainly affects the equity capital cost by improving enterprise value, rather than by increasing analysts' attention and influencing the level of corporate risk bearing.
We present light curve solution of V458 Mon firstly by using the Wilson-Devinney code. The total eclipse and deep minima of the light curves of V458 Monenable us to determine reliable orbital ...parameters of the binary system. The solution suggests that V458 Monis a low mass ratio binary system with about 0.2 possessing a moderate degree of contact. The long-term period investigation showed that the period of V458 Monis increasing at dP/dt=+2.59×10−7days/yr, which could be the reason of mass transfer from the less massive component to more massive primary one, together with a periodic change. The oscillation in orbital period may be due to an unseen tertiary companion with the mass about M3=1.8M⊙ . After removing these change, there is still a weak cyclic change maybe due to magnetic activity. With the increase in orbital period of binary, the separation increases and mass ratio decreases which eventually leads V458 Montowards merger.
•The first light curves from TESS were analyzed by using Wilson-Devinney code.•The Photometric solution discovered V458 Mon is a low mass-ratio contact binary.•The orbital period is extended to more than 100 years by using DASCH. A long-term increasing together with two periodic changes were determined.•The mass transfer due to period increasing is calculated and the third body infer from main periodic change are estimated to be a compact star and magnetic activity may be the reason of weak cyclic change.
► Pro-and anti-inflammatory cytokine expressions were assayed in brain of CMS-treated depression-like animals. ► The imbalance of pro-and anti-inflammatory cytokines was involved in depression of ...rat. ► The dysregulation of cytokines was correlated with low neurogenesis.
The association between pro-inflammatory cytokines and depression has been reported by many studies. However, the mechanisms by which inflammation affects mood are only partially understood. In this study, we detected depression-like behavior in a rat animal model which was induced inflammation in the spleen and brain by chronic mild stress (CMS). Wistar rats receiving CMS treatment for four weeks showed a variety of depression-like behavioral changes, including a significant reduction in sucrose preference and locomotion. Real-time RT-PCR was used to analyze the transcriptional regulation of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6, and IL-18) and anti-inflammatory cytokines (IL-10, IL-4 and TGF-β) in hippocampus, cortex, hypothalamus and spleen. The result showed high expression of pro-inflammatory cytokines IL-1β, TNF-α and IL-6, and low expression of anti-inflammatory cytokines TGF-β and IL-10, thus higher ratio of TNF-α/IL-10 and IL-6/IL-10 in the brain of animal exposed to CMS. Simultaneously, brain derived neurotrophic factor mRNA decreased significantly in the hippocampus and hypothalamus of stressed rats. Immunofluorescence found that the BrdU Positive cells after CMS treatment significantly decreased in the hippocampus. These data suggested a crucial role of dysregulation between pro- and anti-inflammatory in CMS-induced depression, possibly because the imbalance of cytokines affects regeneration of neurons.
Population migration continues to reshape the spatial pattern of China’s population and regional economic development. During this internal migration process, production and consumption patterns ...often change, ultimately leading to changes in green total factor productivity. This paper, based on the Chinese population census data and 1% sampling survey data from 2005 to 2015, utilizes social network analysis methods to measure the labor mobility network indicators of 284 prefecture-level cities. Further, this paper analyzes the impact and mechanisms of regional network status on green total factor productivity using a panel fixed effects model. We find that as network density increases, the interpersonal connections between regions become closer, and the network exhibits a clear pattern of “concentrated inflows” and “dispersed outflows”, with the trend of forming strong alliances becoming increasingly apparent. Regions positioned centrally either in terms of network in-degree or out-degree exhibit higher green total factor productivity. Among these, the labor mobility network plays a crucial role in enhancing green total factor productivity through the channel of technology diffusion effects, which improve investment efficiency via knowledge exchange and material capital accumulation. The promotive effect of labor network status on green total factor productivity is more pronounced in the eastern regions, where talent quality is higher, and in areas with fewer restrictions from the household registration system.
PDF
