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Micropile groups (MPGs) are an effective means of geological disaster prevention for small- and medium-sized landslides, with the advantages of light structures and convenient construction. However, the mechanical and deformation characteristics of MPGs are complex, and their practical application is ahead of theoretical research, which greatly limits the popularization and application of MPGs. This paper conducts a series of centrifuge model tests to investigate the mechanical and deformation characteristics and the antislip mechanism of MPGs, then compare them with those of conventional piles (CPs). In particular, MPGs with and without the platform in the strengthening process of the talus slope are compared, and monitoring the reinforcement effect of MPGs subjected to gravity loading. The results suggest that the soil pressure shows a triangular distribution pattern and is influenced by the position of the potential slip zone and the geometry of the bedrock surface. The compatibility deformation of the pile-soil leads to the stress release of the soil behind the pile, which is an important part affecting the antislip mechanism of the MPG. The platform limits 75% of the pile top displacement of the MPG and simultaneously redistributes the stress of the piles, providing a better overall antislip effect of the pile-soil composite. Key words: centrifuge modelling test, micropile group, talus slope, compatibility deformation, pile-soil interaction, antislip mechanism, 1. Introduction There are many geological disasters in China, with landslides (mainly small- and medium-sized landslides) accounting for the largest proportion (>50%)(Pei et al. 2021). As an antislip facility, micropiles [...]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for coronavirus disease 2019 (COVID-19), has evoked a global pandemic. Due to its rapid transmission rate and the severity of illness, the urgent need for the expedited design and development of effective therapeutics is evident. Computer-aided drug design (CADD) methods have been employed to accelerate the drug development process. More than 30 000 medication compounds were subjected to virtual screening for the SARS-CoV-2 main protease. The top 10 molecules based on the binding affinity scores were chosen and subjected to extra-precision docking and their pharmacokinetic properties were explored to validate whether they bound well to the SARS-CoV-2 main protease. The results indicated that the binding free energy values between Mpro and these ligands predominantly fall within the range of −7 to −8 kcal mol−1, suggesting relatively stable interactions between the ligands and the protein target. Significant contributions to the binding of most small molecules were identified through molecular dynamics simulations and MM/PBSA (molecular mechanics/Poisson–Boltzmann surface area) analyses, with residues such as His164, Glu166, and Asp187 being found to be crucial. Therefore, these residues have been recognized as potential targets for drug design. In summary, ZINC000306568896 exhibited the optimal binding free energy of −28.68 kcal mol−1 and was evaluated as the lead compound with the strongest binding affinity in this series. Its favourable pharmacokinetic properties and its stable association with the active site suggest that it is a promising lead inhibitor for SARS-CoV-2. These results demonstrate that this ligand has great potential to be an ideal lead inhibitor for SARS-CoV-2 and to expedite the development of therapeutic interventions against COVID-19. [ABSTRACT FROM AUTHOR]

Several studies reported that the expression of SIRT1 was associated with the clinical features of patients with esophageal squamous cell carcinoma (ESCC), but the function remains inconsistent. We conducted this study to illustrate the clinical value of SIRT1 expression in the early diagnosis and prediction of prognosis of ESCC. In this study, PubMed, Embase, and Web of Science were searched by two independent researchers and STATA14.0 software was used to conduct meta-analysis. The odds ratio with 95% confidence interval was used to estimate the pooled effect. Egger’s test and Begg’s funnel were used to assess publication bias. Sensitivity analysis was used to evaluate the reliability and stability of meta-analysis results. According to the inclusion and exclusion criteria, six studies were enrolled, including 811 cases of ESCC. Results of the meta-analysis indicated that SIRT1 was overexpressed in ESCC and the SIRT1 expression was closely related to the clinicopathological features of ESCC, such as tumor infiltration, tumor node metastasis (TNM) stage, and lymph node metastasis. In the survival analysis, high expression of SIRT1 represented a poor prognosis in ESCC patients. Our study demonstrated that SIRT1 was overexpressed in ESCC, and it might be a potential biomarker for progress of ESCC.

The reliable numerical simulation of the landslide process contributes to the establishment of evidence-based disaster mitigation measures in seismically active zones. To achieve this goal, a simple and unified state-dependent shear strength model of discontinuities is presented to describe the shear strength degradation in a seismic landslide process. The proposed model establishes a relationship between the shear strength parameters and the global safety factor of the slope by assuming that the slope instability (or landslide initiation) is accompanied by an instantaneous shear strength degradation of discontinuities. To realize the model numerically, the algorithms for the computation of global safety factor and the modification of shear strength parameters were incorporated into the discontinuous deformation analysis (DDA). Subsequently, the kinematic accuracy of the improved DDA method was validated by comparisons with theoretical solutions for the dynamic sliding of a block on an inclined plane. Numerical simulations of the Daguangbao landslide triggered by the Wenchuan earthquake were performed using the improved DDA method. The results illustrate that the shear strength degradation of discontinuities affect the evolution process, travel distance, and post-failure shape of the seismic landslide significantly. Key words: seismic landslide, runout analysis, shear strength degradation, numerical modelling, discontinuous deformation analysis (DDA). La simulation numerique fiable du processus de glissement de terrain contribue a l'etablissement de mesures d'attenuation des catastrophes fondees sur des donnees probantes dans les zones sismiques actives. Afin d'atteindre cet objectif, un modele simple et unifie de discontinuites de resistance au cisaillement en fonction de l'etat est presente pour decrire la degradation de la resistance au cisaillement dans un processus sismique de glissement de terrain. Le modele propose etablit une relation entre les parametres de resistance au cisaillement et le facteur de securite global de la pente en supposant que l'instabilite de la pente (ou declenchement du glissement de terrain) s'accompagne d'une degradation instantanee de la resistance au cisaillement des discontinuites. Pour realiser numeriquement le modele, les algorithmes de calcul du facteur de securite global et de modification des parametres de resistance au cisaillement ont ete integres dans l'analyse des deformations discontinues (ADD). Par la suite, la precision cinematique de la methode d'ADD amelioree a ete validee par des comparaisons avec des solutions theoriques pour le glissement dynamique d'un bloc sur un plan incline. Des simulations numeriques du glissement de terrain de Daguangbao declenche par le tremblement de terre de Wenchuan ont ete effectuees a l'aide de la methode d'ADD amelioree. Les resultats montrent que la degradation de la resistance au cisaillement des discontinuites affecte considerablement le processus d'evolution, la distance de deplacement et la forme apres rupture du glissement de terrain sismique. [Traduit par la Redaction] Mots-cles : glissement de terrain sismique, analyse du glissement, degradation de la resistance au cisaillement, modelisation numerique, analyse des deformations discontinues (ADD)., 1. Introduction During the past three decades, countless landslides induced by strong earthquakes in earthquake-prone regions and countries have occurred. These geological disasters always lead to a loss of property, [...]

Feature extraction and matching are the basic procedures of the so-called Visual Odometer (VO), Simultaneous Localization and Mapping (SLAM) and many other image processing algorithms. Oriented features from accelerated segment test (FAST) and rotated binary robust independent elementary features (ORB) algorithm are widely used since they are computationally faster. In this paper, we proposed a method to generate a value for a feature, the value is called signature. In the matching step, we only compute Hamming distances of descriptors with the same signatures. Hence, the matching time is shortened. Compared with the original ORB algorithm, features to be matched dropped 69.63% on TUM datasets and 85.7% on VGG datasets by adopting our strategy. In addition, the precision is above 85% on both VGG and TUM datasets. We design a customized hardware architecture for ORB feature extraction and matching based on the proposed method. The hardware structure is implemented on Xilinx ZCU102 evaluation board. The clock frequency is set to 150 MHz. Our Field Programmable Gate Arrays (FPGA) system achieves 193 fps on 1 2 8 0 × 7 2 0 images with 1984 features on average and 314 fps on 6 4 0 × 4 8 0 images with 700 features on average, which is more efficient compared to the state-of-the-art works. [ABSTRACT FROM AUTHOR]

Human immunodeficiency virus (HIV) reverse transcriptase (RT) works in the life cycle of HIV and is one of the key targets for anti-HIV-1 drug development. Recently, a novel series of diarylpyrimidine derivatives (DAPYs) have been reported as potent HIV-1 non-nucleoside RT inhibitors (NNRTIs), and they exhibit potent antiviral activity. Here we explored the binding interaction patterns of a set of 2,4,5-trisubstituted pyrimidine derivatives using molecular docking, three-dimensional quantitative structure–activity relationships (3D-QSAR), and molecular dynamics (MD) simulations. Molecular docking for exploring the mechanism of action of small molecule ligands with receptor proteins. Comparative molecular field (CoMFA q2 = 0.828, r2 = 0.988, r2pred = 0.981) and comparative molecular similarity index (CoMSIA q2 = 0.859, r2 = 0.968, r2pred = 0.980) were performed to build stable and reliable 3D-QSAR models. The contour plots revealed the relationship between structural features and inhibitory activities. Based on the molecular docking analysis and contour maps, some novel compounds with higher predicted activities were designed and further MD simulations and bind free energy calculations were performed. Our models results may provide an essential reference for the design and development of effective novel HIV-1 NNRTIs. [ABSTRACT FROM AUTHOR]