118 research outputs found
Unsteady Characteristics of Sediment Transport Under Non-harmonic Waves
AbstractSediment transport under waves is one of the key dynamic processes of coastal sediment motion. Previous studies for this issue are mainly based on linear wave theory and quasi-steady simplification. However, waves in real circumstance are always irregular, generally with a certain degree of asymmetry and/or velocity-leaning especially in shallow water. It is envisaged that sediment movement under non-harmonic waves is different from sinusoidal waves. Based on large eddy simulation of turbulent flows in wave boundary layer, a modified method is proposed to calculate sediment transport rate under non-harmonic waves. It is further used to explore the influences of flow acceleration and the phase lead between the free stream velocity and bed shear stress on sediment transport rate in different phases of one wave cycle for forth-leaning. The net transport rate is found to increase with the degree of asymmetry and velocity-leaning index. Both the acceleration and the phase lead have a great influence on average transport rate in each phase
Effect of rosuvastatin and benazepril on matrix metalloproteinase-2, matrix metalloproteinase-9 and leukotriene B4 of patients with acute myocardial infarction
Purpose: To investigate the effects of rosuvastatin and benazepril on matrix metalloproteinase-2 (MMP-2), MMP-9 and leukotriene B4 (LTB4) of patients with acute myocardial infarction (AMI).
Methods: Fifty-six patients with AMI were selected. They were randomly divided into control and study groups. Thirty healthy people were used in the normal group. On the basis of conventional therapy, patients in the control group were given rosuvastatin orally, while those in the study group received rosuvastatin and benazepril orally. The duration of treatment in both groups was 3 months. Serum levels of MMP-2, MMP-9 and LTB4, and incidence of left ventricular remodelling and recurrence of cardiovascular events were determined before and after treatment for both groups.
Results: MMP-2, MMP-9 and LTB4 levels in serum were significantly lower for the two groups after treatment, when compared to pre-treatment values, and significantly lower in the study group (p < 0.05). Left ventricular remodelling was lower in the study group than in the control group (p < 0.05). Recurrence of cardiovascular events declined significantly in the study group, relative to control (p > 0.05).
Conclusion: Rosuvastatin and benazepril significantly reduce serum levels of MMP-2, MMP-9 and LTB4 in AMI patients, and thus can potentially prevent ventricular remodelling, improve prognosis and reduce recurrence rate
Experiment Study on Local Scouring Depth around Pile Permeable Spur Dikes
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Experimental Study on the Characteristics of Three-Dimensional Flow Structures with Changing Condition in Bifurcation Area
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Experimental Investigation on the Vertical Distribution of Cohesive Sediment Concentration in Weak Dynamical Flow
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Protein-ligand binding representation learning from fine-grained interactions
The binding between proteins and ligands plays a crucial role in the realm of
drug discovery. Previous deep learning approaches have shown promising results
over traditional computationally intensive methods, but resulting in poor
generalization due to limited supervised data. In this paper, we propose to
learn protein-ligand binding representation in a self-supervised learning
manner. Different from existing pre-training approaches which treat proteins
and ligands individually, we emphasize to discern the intricate binding
patterns from fine-grained interactions. Specifically, this self-supervised
learning problem is formulated as a prediction of the conclusive binding
complex structure given a pocket and ligand with a Transformer based
interaction module, which naturally emulates the binding process. To ensure the
representation of rich binding information, we introduce two pre-training
tasks, i.e.~atomic pairwise distance map prediction and mask ligand
reconstruction, which comprehensively model the fine-grained interactions from
both structure and feature space. Extensive experiments have demonstrated the
superiority of our method across various binding tasks, including
protein-ligand affinity prediction, virtual screening and protein-ligand
docking
Observation of two splitting processes in a partial filament eruption on the sun: the role of breakout reconnection
Partial filament eruptions have often been observed, however, the physical
mechanisms that lead to filament splitting are not yet fully understood. In
this study, we present a unique event of a partial filament eruption that
undergoes two distinct splitting processes. The first process involves vertical
splitting and is accompanied by brightenings inside the filament, which may
result from internal magentic reconnection within the filament. Following the
first splitting process, the filament is separated into an upper part and a
lower part. Subsequently, the upper part undergoes a second splitting, which is
accompanied by a coronal blowout jet. An extrapolation of the coronal magnetic
field reveals a hyperbolic flux tube structure above the filament, indicating
the occurrence of breakout reconnection that reduces the constraning field
above. Consequently, the filament is lifted up, but at a nonuniform speed. The
high-speed part reaches the breakout current sheet to generate the blowout jet,
while the low-speed part falls back to the solar surface, resulting in the
second splitting. In addition, continuous brightenings are observed along the
flare ribbons, suggesting the occurrence of slipping reconnection process. This
study presents, for the first time, the unambiguous observation of a two-stage
filament splitting process, advancing our understanding of the complex dynamics
of solar eruptions.Comment: 12 pages, 8 figure
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