•The effects of raindrop impact and runoff detachment on soil aggregate loss were investigated.•The contribution of raindrop impact to soil erosion was 78.3% to 95.2%.•The contribution of raindrop ...impact to the.•2, 1–2, 0.5–1, 0.25–0.5 and <0.25mm soil aggregate loss was 79.1% to 89.7%.
Soil aggregates profoundly influence soil fertility and soil erosion. A large number of studies have showed that soil aggregate loss was mainly affected by raindrop impact and runoff detachment during hillslope erosion process; however, few attempts have been made to investigate which one plays the dominant role in soil aggregate loss. Therefore, a laboratory study was conducted to quantify the effects of raindrop impact and runoff detachment on soil erosion and soil aggregate loss during hillslope erosion processes. A soil pan (8m long, 1.5m wide, and 0.6m deep and with an adjustable slope gradient of 0–35°) was subjected to rainfall simulation experiments under two soil surface conditions: with and without raindrop impact through placing nylon net over soil pan. Two rainfall intensities (50 and 100mmh−1) of representative erosive rainfall and two slope gradients (5 and 10°) in the Mollisol region of Northeast China were subjected to two soil surface conditions. The results showed that raindrop impact played the dominant role in hillslope soil erosion and soil aggregate loss. Soil loss caused by raindrop impact was 3.6–19.8 times higher than that caused by runoff detachment. The contributions of raindrop impact to hillslope soil erosion were 78.3% to 95.2%. As rainfall intensity and slope gradient increased, soil loss caused by raindrop impact and runoff detachment both increased. The loss of each size aggregate was greatly reduced by 46.6–99.4% after eliminating raindrop impact. Meanwhile, the contributions of raindrop impact to the >2, 1–2, 0.5–1, 0.25–0.5 and <0.25mm soil aggregate loss were 79.1% to 89.7%. Eliminating raindrop impact reduced rainfall intensity effect and increased slope gradient impact on aggregate loss.
The hierarchical self‐assembly process opens up great potential for the construction of nanostructural superlattices. Precise regulation of self‐assembled superlattices, however, remains a challenge. ...Even when the primary molecules are precise, the supramolecular motifs (or secondary building blocks) can vary dramatically. In the present work, we propose the concept of unimolecular nanoparticles (UMNPs). The UMNPs act as the supramolecular motif and directly pack into the superlattices. A highly branched giant molecule is presented. We systematically explore its conformations and the superlattice of this giant molecule. Moreover, intriguing complex phases are discovered when blending this UMNP with other conventional giant molecules. These binary mixtures provide direct evidence to support our previously proposed self‐sorting process in the self‐assembly of “soft alloys”. The concept of UMNPs offers a unique approach toward more precise regulation of self‐assembled superlattices in soft matter.
With the precisely synthesized giant molecule βCD‐O21 the concept of soft unimolecular nanoparticles (UMNPs) has been realized. Upon self‐assembly or assembly with other giant molecules, βCD‐O21 directly participates in superlattice formation, giving rise to various complex superlattices with fast dynamics and enhanced ordering.
The quasiperiodic structures in metal alloys have been known to depend on the existence of icosahedral order in the melt. Among different phases observed in intermetallics, decagonal quasicrystal ...(DQC) structures have been identified in many glass-forming alloys yet remain inaccessible in bulk-state condensed soft matters. Via annealing the mixture of two giant molecules, the binary system assemblies into an axial DQC superlattice, which is identified comprehensively with meso-atomic accuracy. Analysis indicates that the DQC superlattice is composed of mesoatoms with an unusually broad volume distribution. The interplays of submesoatomic (molecular) and mesoatomic (supramolecular) local packings are found to play a crucial role in not only the formation of the metastable DQC superlattice but also its transition to dodecagonal quasicrystal and Frank-Kasper σ superlattices.
Core Ideas
Directional components of splash erosion and effects of raindrop kinetic energy were investigated.
Lateral splash erosion played a significant role in supplying detached particles to ...adjacent areas.
We fit equations for total and net splash erosion to rainfall physical parameters.
We used cross‐validation to test the equations.
Splash erosion is an important process of hillslope erosion. However, there is little information available in the literature to show how rainfall physical parameters affect the directional components of splash erosion. Therefore, the objectives of this study were to investigate the effects of rainfall physical parameters (rainfall intensity RI, raindrop kinetic energy KE, and raindrop diameter) on the directional components (upslope, lateral, downslope) of splash erosion characteristics in the Chinese Mollisol region. A specially designed soil pan, which can measure the directional components of splash erosion, was subjected to designed rainfall intensities of 50 and 100 mm h−1 and varying raindrop KE. The results showed that the total splash erosion (downslope plus upslope plus lateral splash erosion), directional components of splash erosion, and net splash erosion (downslope minus upslope erosion) on hillslopes significantly increased as RI and raindrop KE increased (p < 0.05). Furthermore, splash erosion from downslope, lateral slope, and upslope contributed 32.2, 26.3, and 14.5%, respectively, of total splash erosion. Additionally, raindrop KE and raindrop median volume diameter (D50) were the key indicators affecting both total and net splash erosion. The equations between total and net splash erosion with both parameters of raindrop KE and raindrop D50 were fitted. The cross validation results showed that the two equations had acceptable accuracy. Therefore, preventing raindrop impact by using conservation tillage methods, such as retaining crop residue or mulch cover, can effectively reduce splash erosion in the Mollisol region of Northeast China.
Di-(2-ethylhexyl) phthalate (DEHP), an extensively used plasticizer, can cause environmental pollution and organ injury. Lycopene (LYC) is a natural carotene that has the potential to prevent chronic ...diseases. To reveal the effect of DEHP and/or LYC on the kidney, male mice were treated with LYC (5 mg/kg) and/or DEHP (500 mg/kg or 1000 mg/kg) by gavage for 28 days. The study indicated that DEHP caused glomerular atrophy, tubular expansion, disappearance of the mitochondrial membrane, and cristae rupture. DEHP exposure can increase the expression of aquaporin (AQP) subunits and the activity of Ca2+-Mg2+-ATPase and decrease the activity of Na+-K+-ATPase, which results in ion disorder. However, LYC can relieve kidney injury by regulating the activity of ATPase, the expression of ATPase subunits, and AQP subunit expression. The results indicated that AQP was a target for LYC in antagonizing the disturbance of DEHP-induced renal damage.
The present results indicated that AQP was a target for LYC to antagonize the disturbance of DEHP-induced renal ion homeostasis and renal injury. This research might provide a feasible molecular mechanism for LYC cotreatment of renal toxicity caused by DEHP. Display omitted
•DEHP exposure induced nephrotoxicity.•DEHP can cause the ions homeostasis imbalance.•DEHP caused the expression of AQP and ATPase activity disorder.•LYC can protect the organism from DEHP-induced nephrotoxicity.
Abstract
The selective removal and immobilization of uranyl ions from aqueous solutions is essential for the sustainable development of nuclear energy. Herein, a robust lanthanide‐organic framework ...material (
IHEP‐24
) is developed for simultaneous fluorescence sensing, selective adsorption, and photocatalytic reduction of uranium, integrating three different functions in one material. The confined space formed by the coordination assembly of viologen derivative ligands and metal‐oxygen clusters can act as precise recognition sites for uranyl, allowing
IHEP‐24
to efficiently detect and capture uranyl ions. In addition, the presence of a viologen‐based radical ligand enables
IHEP‐24
to a further photocatalytic reduction of the adsorbed uranyl to amorphous UO
2
. The mechanisms of adsorption and photocatalysis are revealed by batch experiments, photoelectrochemical characterizations, and theoretical calculations. This study provides a reference for the construction of robust multi‐functional MOF materials and also provides support for the deep removal and immobilization of radionuclides from aqueous solution.
The Thomsen-Friedenreich (TF or T) antigen, Galβ1-3GalNAcα1-O-Ser/Thr, is the core 1 structure of O-linked mucin type glycans appearing in tumor-associated glycosylation. The TF antigen occurs in ...about 90% of human cancer cells and is a potential ligand for the human endogenous galectins. It has been reported that human galectin-1 (Gal-1) and galectin-3 (Gal-3) can perform their cancer-related functions via specifically recognizing TF antigen. However, the detailed binding properties have not been clarified and structurally characterized. In this work, first we identified the distinct TF-binding abilities of Gal-1 and Gal-3. The affinity to TF antigen for Gal-3 is two orders of magnitude higher than that for Gal-1. The structures of Gal-3 carbohydrate recognition domain (CRD) complexed with TF antigen and derivatives, TFN and GM1, were then determined. These structures show a unique Glu-water-Arg-water motif-based mode as previously observed in the mushroom galectin AAL. The observation demonstrates that this recognition mode is commonly adopted by TF-binding galectins, either as endogenous or exogenous ones. The detailed structural comparisons between Gal-1 and Gal-3 CRD and mutagenesis experiments reveal that a pentad residue motif ((51)AHGDA(55)) at the loop (g1-L4) connecting β-strands 4 and 5 of Gal-1 produces a serious steric hindrance for TF binding. This motif is the main structural basis for Gal-1 with the low affinity to TF antigen. These findings provide the intrinsic structural elements for regulating the TF-binding activity of Gal-1 in some special conditions and also show certain target and approach for mediating some tumor-related bioactivities of human galectins.
Time series forecasting is ubiquitous in various scientific and industrial domains. Powered by recurrent and convolutional and self-attention mechanism, deep learning exhibits high efficacy in time ...series forecasting. However, the existing forecasting methods are suffering some limitations. For example, recurrent neural networks are limited by the gradient vanishing problem, convolutional neural networks cost more parameters, and self-attention has a defect in capturing local dependencies. What’s more, they all rely on time invariant or stationary since they leverage parameter sharing by repeating a set of fixed architectures with fixed parameters over time or space. To address the above issues, in this paper we propose a novel time-variant framework named Self-Attention-based Time-Variant Neural Networks (SATVNN), generally capable of capturing dynamic changes of time series on different scales more accurately with its time-variant structure and consisting of self-attention blocks that seek to better capture the dynamic changes of recent data, with the help of Gaussian distribution, Laplace distribution and a novel Cauchy distribution, respectively. SATVNN obviously outperforms the classical time series prediction methods and the state-of-the-art deep learning models on lots of widely used real-world datasets.
Rhodium nanoparticles (Rh NPs) stabilized by natural cinchona alkaloids were synthesized in imidazolium-based ionic liquids using H
2
as the reductant. Characterization showed well-dispersed Rh NPs ...of about 1.96 nm (TEM and HRTEM) and confirmed the ionic liquid and cinchona alkaloid stabilization to the Rh(0) NPs (XPS). When modified by chiral diamine, including (1
R
,2
R
)-diphenylethylenediamine ((1
R
,2
R
)-DPEN) or cinchona alkaloid derivatives, the Rh NPs catalysts exhibited good activity, chemoselectivity and enantioselectivity in the heterogeneous enantioselective hydrogenation of aromatic ketones. Synergistic effect between (
1R,2R
)-DPEN and cinchonidine was also observed, which significantly accelerated the reaction rate and enhanced the enantioselectivity. 63.0% enantioselectivity and 98.9% chemoselectivity could be achieved in the acetophenone enantioselective hydrogenation; up to 70.2% enantioselectivity and 100% chemoselectivity was obtained in the isobutyrylbenzene catalytic enantioselective hydrogenation. Catalytic system could be reused several times without significant loss in activity, chemoselectivity as well as enantioselectivity. This catalytic protocol opens the door to heterogeneous enantioselective hydrogenation of aromatic ketones with metal Rh NPs immobilized in ionic liquid.
Graphical Abstract
Cinchona alkaloid and ionic liquid stabilized Rh NPs catalyst, when modified by chiral diamine like (1R,2R)-DPEN, exhibited high activity, high chemoselectivity and good enantioselectivity in the challenging heterogeneous enantioselective hydrogenation of aromatic ketones to corresponding aromatic alcohols under mild conditions. Synergistic effect between (1R,2R)-DPEN and cinchonidine was also observed, which significantly accelerated the reaction rate and enhanced the enantioselectivity. 63.0% enantioselectivity and 98.9% chemoselectivity could be achieved in the acetophenone enantioselective hydrogenation; up to 70.2% enantioselectivity and 100% chemoselectivity was obtained in the isobutyrylbenzene catalytic enantioselective hydrogenation. Catalytic system could be reused several times without significant loss in activity, chemoselectivity as well as enantioselectivity. This catalytic protocol opens the door to heterogeneous enantioselective hydrogenation of aromatic ketones with metal Rh NPs immobilized in ionic liquid.
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