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Photocatalytic water splitting for hydrogen production (H2) is one of the main potential applications of photocatalytic technology, which can use solar energy as the energy required ...for chemical reactions to alleviate the energy crisis. In this work, zero-dimensional/two-dimensional (0D/2D) contact surface CdS/α-Fe2O3 (CF) heterojunction photocatalyst was synthesized via a simple solvothermal method. Photocatalytic hydrogen production experiments revealed that the CF-15 sample shows the optimal photocatalytic H2 rate (1806 μmol∙h−1∙g−1) and apparent quantum efficiency (AQE = 13.7% at λ = 420 nm). The enhancement of photocatalytic performance is mainly attributed to the contact of 0D/2D interface and the synergistic effect of Z-scheme electron transfer mechanism. This work provides an effective way for modified composite semiconductor photocatalyst by constructing special interface heterojunction to achieve highly efficiently catalysis.
Temperature affects the flotation of quartz in the calcium/sodium oleate (NaOL) system, while there is a lack of understanding of its potential mechanism. Therefore, in this work, the flotation ...response of quartz to temperature was investigated via micro-flotation experiments, interface property analyses, and theoretical calculations. Flotation results demonstrated that increasing temperature contributed to higher flotation recovery of quartz, which enhanced the removal of quartz from hematite. Surface tension results revealed that higher temperatures lowered the critical micelle concentration (CMC) and surface tension of the NaOL solution, and thus enhanced its surface activity. Solution chemistry calculations and X-ray photoelectron spectroscopy (XPS) measurements confirmed that the increased content of Ca(OH)+ achieved by increasing temperatures enhanced the adsorption amounts of calcium species (acting as activation sites) on the quartz surface. Dynamic light scattering (DLS) measurements verified that the association degree of RCOO− to form (RCOO)22− was strengthened. Furthermore, adsorption density measurements and molecular dynamics (MD) simulations confirmed that increasing the temperature facilitated NaOL adsorption toward the surface of the quartz, which was attributed to the stronger interaction between NaOL and the calcium-activated quartz surface at higher temperatures. As a result, quartz flotation was improved by increasing temperatures. Accordingly, a possible adsorption model was proposed.
Objective
To investigate the brain mechanism of non-correspondence between diseases severity and compression degree of the spinal cord in cervical spondylotic myelopathy (CSM) patients and to test ...the utility of brain imaging biomarkers for predicting prognosis of CSM.
Methods
We calculated voxel-wise zALFF from 54 CSM patients and 50 healthy controls using resting-state fMRI data. In analysis 1, we identified the brain regions exhibited significant differences of zALFF between CSM patients and healthy controls. In analyses 2 through 3, we investigated the zALFF differences between light-symptom CSM patients and severe-symptom CSM patients while carefully matching the degree of compression between these two groups. In analysis 4, we tested the utility of zALFF within the primary motor cortex (M1) for predicting the prognosis of CSM.
Results
We found that (1) compared with the healthy controls, CSM patients exhibited higher ALFF within left M1, bilateral superior frontal gyrus, and lower zALFF within right precuneus and calcarine, suggesting altered brain neural activity in CSM patients; (2) after matching the compression degree, the CSM patients with more severe clinical symptoms exhibited higher zALFF within M1, indicating cortical function contributes to disease’s severity of CSM; (3) taking the M1 zALFF as features in the prognosis prediction model improves the prediction accuracy, indicating that the M1 zALFF provide additional value for predicting the prognosis of CSM patients following decompression surgery.
Conclusion
The functional state of M1 contributes to the disease’s severity of CSM and can provide complementary information for predicting the prognosis of CSM following decompression surgery.
Key Points
•
Cervical spondylotic myelopathy (CSM) patients exhibited increased zALFF within the primary motor cortex (M1), bilateral superior frontal gyrus, and decreased zALFF within the right precuneus and calcarine.
•
After matching the compression degree, the CSM patients with more severe clinical symptoms exhibited higher zALFF within M1, indicating cortical function contributes to disease severity of CSM.
•
zALFF within M1 provided additional value for predicting the prognosis of CSM patients.
External disturbance poses the primary threat to robot balance in dynamic environments. This paper provides a learning-based control architecture for quadrupedal self-balancing, which is adaptable to ...multiple unpredictable scenes of external continuous disturbance. Different from conventional methods which construct analytical models which explicitly reason the balancing process, our work utilized reinforcement learning and artificial neural network to avoid incomprehensible mathematical modeling. The control policy is composed of a neural network and a Tanh Gaussian policy, which implicitly establishes the fuzzy mapping from proprioceptive signals to action commands. During the training process, the maximum-entropy method (soft actor-critic algorithm) is employed to endow the policy with powerful exploration and generalization ability. The trained policy is validated in both simulations and realistic experiments with a customized quadruped robot. The results demonstrate that the policy can be easily transferred to the real world without elaborate configurations. Moreover, although this policy is trained in merely one specific vibration condition, it demonstrates robustness under conditions that were never encountered during training.
Purpose
Plant cell wall polysaccharide composition is closely related to the occurrence of aluminum (Al) toxicity and Al resistance. Glycosyltransferases participate in cell wall polysaccharide ...biosynthesis. Our previous microarray analysis showed that Al increased the transcriptional abundance of UDP-glycosyltransferase (UGT) in soybean (
Glycine max
). The present study aimed to clarify if GmUGTs are involved in modifying the composition of cell wall polysaccharides and then alter soybean Al sensitivity.
Methods
Two soybean genes,
UGT85A111
and
UGT83R1
, were identified, and their functions were characterized by analyses of expression pattern and subcellular localization, and evaluations of carbohydrates in the cell wall and Al sensitivity by their overexpression in soybean hairy roots and
Arabidopsis
.
Results
The transcriptional expression of
UGT85A111
and
UGT83R1
was increased with different patterns and levels under Al stress. Both GmUGTs localized to the plasma membrane.
UGT85A111
-OE and
UGT83R1
-OE soybean hairy roots showed less Al absorption, which was accompanied by alterations in cell wall polysaccharide components, particularly reduced callose and/or hemicellulose contents. Monosaccharide content, including glucose and xylose in the
GmUGTs
-OE roots, was also affected. Heterologous expression of
UGT85A111
and
UGT83R1
significantly improved the plant’s Al resistance capacity.
Conclusion
GmUGTs contribute to the disruption of cell wall polysaccharide compositions and Al sensitivity in soybean. The results suggest a particularly protective role of UGTs against Al toxicity and may provide novel clues for plant Al stress adaptation.
Symmetric nonnegative matrix factorization (SNMF) is equivalent to computing a symmetric nonnegative low rank approximation of a data similarity matrix. It inherits the good data interpretability of ...the well-known nonnegative matrix factorization technique and has better ability of clustering nonlinearly separable data. In this paper, we focus on the algorithmic aspect of the SNMF problem and propose simple inexact block coordinate decent methods to address the problem, leading to both serial and parallel algorithms. The proposed algorithms have guaranteed convergence to stationary solutions and can efficiently handle large-scale and/or sparse SNMF problems. Extensive simulations verify the effectiveness of the proposed algorithms compared to recent state-of-the-art algorithms.
Plastic greenhouses (PGs) are widely built near cities in China to produce vegetables and fruits. In order to promote sustainable agriculture, rural landscape construction, and better manage water ...resources, numerous remote sensing methods have been developed to identify and monitor the distribution of PGs, of which many map PGs based on spectral responses and geometric shapes. In this study, we proposed a new fine- and coarse-scale mapping approach using two-temporal Sentinel-2 images with various seasonal characteristics and a one-dimensional convolutional neural network (1D-CNN). Having applied this approach in a pilot area study, the results were summarized as follows: (1) A time-series analysis of Sentinel-2 images showed that the reflectance of greenhouses changes during crop growth and development. In particular, the red-edge and near-infrared bands undergo a significant increase and then decrease during the whole crop growth period. Thus, two critical period images, containing a substantial difference in greenhouse reflectance, were sufficient to carry out an accurate and efficient mapping result. (2) The 1D-CNN classifier was used to map greenhouses by capturing subtle details and the overall trend of the spectrum curve. Overall, our approach showed higher classification accuracy than other approaches using support vector machines (SVM) or random forests (RF). In addition, the greenhouse area identified was highly consistent with the existing surfaces observed in very high-resolution images, with a kappa co-efficient of 0.81. (3) The narrow band feature differences (red-edge and near infrared narrow bands) in two-temporal Sentinel-2 images played a significant role in high-precision greenhouse mapping. The classification accuracy with narrow band features was much better than the maps produced without narrow band features. This scheme provided a method to digitize greenhouse precisely and publish its statistics for free, which enable advanced decision support for agriculture management.
Brain ischemia inhibits immune function systemically, with resulting infectious complications. Whether in stroke different immune alterations occur in brain and periphery and whether analogous ...mechanisms operate in these compartments remains unclear. Here we show that in patients with ischemic stroke and in mice subjected to middle cerebral artery occlusion, natural killer (NK) cells display remarkably distinct temporal and transcriptome profiles in the brain as compared to the periphery. The activation of catecholaminergic and hypothalamic-pituitary-adrenal axis leads to splenic atrophy and contraction of NK cell numbers in the periphery through a modulated expression of SOCS3, whereas cholinergic innervation-mediated suppression of NK cell responses in the brain involves RUNX3. Importantly, pharmacological or genetic ablation of innervation preserved NK cell function and restrained post-stroke infection. Thus, brain ischemia compromises NK cell-mediated immune defenses through mechanisms that differ in the brain versus the periphery, and targeted inhibition of neurogenic innervation limits post-stroke infection.
•Brain ischemia causes transient but severe suppression of cellular immunity•Natural killer (NK) cells display different profiles in the CNS versus periphery after stroke•NK cell response is shaped by organ-specific neurogenic innervation after stroke•Modulation of neurogenic innervation limits post-stroke infection
Liu and colleagues demonstrate that brain ischemia shapes innate cellular immune responses in the periphery and the brain through different neurogenic and intracellular pathways. Targeted modulation of neurogenic innervation is capable of inhibiting post-stroke infection.
•Numerical simulations with linear stability analysis are conducted to study density-driven flow with dissolution in porous media.•A multiscale approach that combines Darcy-scale linear stability ...analysis and pore-scale simulations are performed.•The transport processes are largely dominated by the interplay among density contrast, reaction rate and porosity evolution.
In the present work, a suite of numerical experiments with linear stability analysis are conducted to study density-driven flow with chemical dissolution of two reactive fluids in synthetic porous media. Linear stability analysis at the Darcy scale is first performed to predict the interfacial phenomena and instability at the initial time. Pore-scale simulations using the lattice Boltzmann method (LBM) are further conducted to capture more mechanistic information and advance the understanding of the transport processes. Under different scenarios, it is demonstrated that the transport processes exhibit distinct behaviors, which are largely dominated by the interplay among density contrast, chemical reaction rate and evolution of the porosity/permeability. All the results indicate that the interfacial instability can be triggered by the density contrast between two miscible fluids, leading to the Rayleigh-Taylor (R-T) instability. The R-T instability can be suppressed by the heterogeneous surface reaction between the fluid and solid phases, which prevents the transport of the denser fluid. Over the long term, it is found that the interfacial instability is influenced by the evolution of the porosity/permeability due to dissolution, which potentially restarts the transport of the denser fluid.
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