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Rapid dynamic loads, such as those caused by earthquakes or traffic, induce medium strain rates in expansive soil, impacting its mechanical properties, which are vital for geotechnical engineering design. This study aims to deepen understanding of the rate effect on expansive clay under plane strain conditions. It conducts various isotropic triaxial and plane strain shearing tests at different medium strain rates. Post-testing, the microstructures of the clay, affected by varying shearing rates, are examined using scanning electron microscope and nuclear magnetic resonance. The experimental findings revealed that the strength at higher strain rates surpasses that at lower ones. In addition, the strength under plane strain at the same consolidation stress level exceeds that under triaxial loading. The strain rate effect is more pronounced in the clay studied under low consolidation pressure, which is more significant in the triaxial state than under plane strain. Excess pore water pressure initially peaks at low strain rates before decreasing but increases at higher strain rates. The specimen’s intermediate principal stress coefficient (b) rises with the increase in consolidation pressure and strain rate. In addition, the expansion of fissures and changes in internal structure account for the strain rate effect in undisturbed expansive soil under specific loading rates. These new insights aid in better understanding the behavior of expansive clay under medium strain rates, enabling engineers to establish appropriate design parameters and criteria. This ensures the safety and stability of structures under dynamic loading. [ABSTRACT FROM AUTHOR]

An important characteristic of some clays is their abundance of fissures. In the case study reported here, to investigate how the fissure inclination angle affects the deformation and strength of fissured clay, samples of undisturbed fissured clay with different inclination angles of its inherent fissures (0°, 45°, and 90°) were subjected to consolidated undrained plane-strain shear tests using a true triaxial apparatus. Moreover, consolidated undrained triaxial tests were carried out on samples with the same inclination angles for comparison. The results showed that compared with the triaxial state, the degree of fissure influence on samples with different fissure angles is different under plane strain, which weakens the influence of the fissure inclination angle on the soil's mechanical behavior. Under the designed consolidation pressures, the peak stress of the 45° fissured soil samples was the smallest, with a stress–strain curve that exhibits strain softening. The 0° fissured soil samples exhibited the highest peak stress, with a stress–strain curve that exhibits strain hardening. The 90° fissured soil samples fell in between, with a stress–strain curve that exhibits a relatively stable trend. The intermediate principal stress coefficient b-value showed different trends at different fissure angles, which also reflects the influence of fissure dip angle. According to the von Mises and Lade–Duncan strength criteria, the generalized plane-strain criterion for fissured soil was obtained. The dip angle of the shear band was calculated from Mohr–Coulomb theory, and the difference between the calculated and measured dip angles was found to be small. [ABSTRACT FROM AUTHOR]

It is of great significance to investigate the shear mechanical behavior of pile–structural soil interface (PSSI) for guiding the design and construction of pile foundations in structural soft soil areas. The available studies rarely consider the effect of shear rate on the shear behavior of the PSSI under large deformation, and a relevant constitutive model is still lacking. In this paper, the effect of shear rate on the shear behavior of the PSSI under large deformation is investigated using a series of ring shear tests with different shear rates. Based on the test results, damage theory is introduced to analyze the mechanism of shear damage of the PSSI, and an interface damage constitutive model is proposed to describe the shear mechanical behavior of the PSSI under large deformation. Finally, a method for calculating the brittleness index of the PSSI is proposed based on the interface constitutive model. The evolution of the shear stress of the PSSI is analyzed, and the shear mechanical behavior of the PSSI under any normal stress is evaluated. The results show that the PSSI subjected to large deformation exhibits strain softening and has stable residual strength. The shear strength of the interface first decreases and then increases with increasing shear rate. The interface constitutive model can accurately reflect the shear behavior of the PSSI under large deformation. The shear rate has a positive effect on the brittleness index of the PSSI, and the normal stress amplifies this effect. The interface constitutive model can also predict the effect of normal stress on the brittleness index. [ABSTRACT FROM AUTHOR]

Patients with systemic lupus erythematosus (SLE) often suffer from chronic pain. Little is known about the peripheral mechanisms underlying the genesis of chronic pain induced by SLE. The aim of this study was to investigate whether and how membrane properties in nociceptive neurons in the dorsal root ganglions (DRGs) are altered by SLE. We found elevation of resting membrane potentials, smaller capacitances, lower action potential thresholds and rheobases in nociceptive neurons in the DRGs from MRL/lpr mice (an SLE mouse model) with thermal hyperalgesia. DRGs from MRL/lpr mice had increased protein expressions in TNFα, IL-1β, and phosphorylated ERK but suppressed AMPK activity, and no changes in sodium channel 1.7 protein expression. We showed that intraplantar injection of Compound C (an AMPK inhibitor) induced thermal hyperalgesia in normal mice while intraplantar injection of AICAR (an AMPK activator) reduced thermal hyperalgesia in MRL/Lpr mice. Upon inhibition of AMPK membrane properties in nociceptive neurons from normal control mice could be rapidly switched to those found in SLE mice with thermal hyperalgesia. Our study indicates that increased excitability in peripheral nociceptive sensory neurons contributes to the genesis of thermal hyperalgesia in mice with SLE, and AMPK regulates membrane properties in nociceptive sensory neurons as well as thermal hyperalgesia in mice with SLE. Our study provides a basis for targeting signaling pathways regulating membrane properties of peripheral nociceptive neurons as a means for conquering chronic pain caused by SLE. [ABSTRACT FROM AUTHOR]

Highlights: Imine groups in covalent organic framework (COF) films act as dual-active sites for humidity sensing, inducing an intrinsic enhanced mechanism of reversible protonated tautomerism via water molecule-induced hydrogen bonding. The cis-ketoimine reciprocal isomerization induces a stretching vibration effect for the ordered conjugated conductive frame of COF films, realizing fast response, wide range, and high sensitivity characteristics for humidity detection. Resistance changes of COF film-based sensors keep a strong linear relationship with low-range relative humidity, reflecting the quantitative sensing mechanism at the molecular level. Human metabolite moisture detection is important in health monitoring and non-invasive diagnosis. However, ultra-sensitive quantitative extraction of respiration information in real-time remains a great challenge. Herein, chemiresistors based on imine-linked covalent organic framework (COF) films with dual-active sites are fabricated to address this issue, which demonstrates an amplified humidity-sensing signal performance. By regulation of monomers and functional groups, these COF films can be pre-engineered to achieve high response, wide detection range, fast response, and recovery time. Under the condition of relative humidity ranging from 13 to 98%, the COFTAPB-DHTA film-based humidity sensor exhibits outstanding humidity sensing performance with an expanded response value of 390 times. Furthermore, the response values of the COF film-based sensor are highly linear to the relative humidity in the range below 60%, reflecting a quantitative sensing mechanism at the molecular level. Based on the dual-site adsorption of the (–C=N–) and (C–N) stretching vibrations, the reversible tautomerism induced by hydrogen bonding with water molecules is demonstrated to be the main intrinsic mechanism for this effective humidity detection. In addition, the synthesized COF films can be further exploited to effectively detect human nasal and oral breathing as well as fabric permeability, which will inspire novel designs for effective humidity-detection devices. [ABSTRACT FROM AUTHOR]

The cyclic stresses in subgrade soil induced by traffic loads are three-dimensional—cyclic major, intermediate, and minor principal stresses. To investigate the permanent deformation of natural undisturbed clay under three-dimensional cyclic stresses, a series of undrained true triaxial tests was carried out, using a true triaxial apparatus that could apply cyclic major, intermediate, and minor principal stresses simultaneously. The emphasis was on the effects of the cyclic stress ratio (CSR), the coefficient of cyclic intermediate principal stress (bcyc), and the reciprocal slope of the stress path in the p–q plane (ξ) on the permanent deformation characteristics. The test results show that bcyc reduces the accumulation of permanent major principal strain (ε1p) remarkably. For given values of the number of loading cycles (N), CSR, and ξ, ε1p decreases approximately linearly with increasing bcyc. ξ also limits the accumulation of ε1p. Furthermore, the ratio of ε1p for a given value of ξ to ε1p for ξ = 1 decreases from 1.095 to 0.887 when ξ increases from 0.67 to 1.5, and the relationship between ε1p(ξ)/ε1p(ξ=1) and ξ is described by a linear formula. A critical value of bcyc is observed at which ε2p changes from tension to compression, that is, ε2p is zero at the critical value of bcyc. The difference among the critical values of bcyc in all the tests is relatively small, and the mean critical value of bcyc is 0.328. Moreover, an empirical formula is established for predicting the permanent major principal strain under three-dimensional cyclic stresses. [ABSTRACT FROM AUTHOR]

Shale is often encountered during rock engineering. The inherent anisotropy of shale and the loading and unloading path affect the failure characteristics of this material. In this study, shale specimens with seven different bedding orientations were used to carry out cyclic loading and unloading experiments to explore the anisotropy of the mechanical properties of shale and the energy evolution of its failure. The experimental results indicate that with an increasing number of cycles, the secant modulus of shale with bedding orientations of 0°, 15°, 45°, and 90° decreases; however, for bedding orientations of 0°, 30°, and 75°, the secant modulus increases or becomes constant. During cyclic loading, hysteresis and irrecoverable strain are clearly observed. The irrecoverable deformation with a bedding orientation of 45° is the largest. The energy evolution during cyclic loading clearly presents anisotropic characteristics. Under the same axial stress, the elastic energy storage capacity, which nonlinearly increases with the axial stress, is the largest for the bedding orientation of 15° and the smallest for the bedding orientations of 60° and 90°. The dissipated energy is much larger for bedding orientations of 45° and 75° than for other bedding orientations. A comparison of the damage evolutions defined by the damage energy release rate suggests that the damage evolution trends are the same for all bedding orientations, but damage is more easily generated with bedding orientations of 60° and 75°. To theoretically describe the energy evolution, an elastic energy evolution model that considers the external incentive effect, self-promotion effect, and self-inhibition effect of energy was established. An energy release dispersion coefficient and fabric tensor were defined to consider the effect of confining pressure and inherent anisotropy. Then, a modified energy-based strength criterion for anisotropic sedimentary rocks was proposed. The results show that both the energy evolution model and the strength criterion have good correlations with experimental data. [ABSTRACT FROM AUTHOR]

Objective: Gastric carcinoma is the most common malignant tumour of the human digestive system worldwide. CD44 serves as a marker for several tumour stem cells, including gastric cancer. However, the prognostic value of CD44 and its correlation with immune infiltration in gastric cancer remain unclear. Methods: The relative expression level of CD44 RNA in gastric cancer was analysed in the TCGA and GEPIA2 databases and validated in the GEO database. Differences in CD44 between gastric cancer cell lines and normal cells were detected by real-time PCR, and the HPA database was used to analyse the differential expression of CD44 protein in gastric cancer and normal tissues. The effect of CD44 on the proliferation and migration of gastric cancer cells was detected by CCK8 and transwell assays. UALCAN was used to analyse the relationship between CD44 expression and clinical parameters, and the Kaplan‒Meier Plotter was used to evaluate the prognostic value, including overall survival (OS), progression-free survival (PFS) and post-progression survival (PPS). The CD44 gene and protein interaction network was constructed by using the Linked Omics, GeneMANIA, STRING and DisGeNET databases. GO and KEGG analyses and GSEA of CD44 were performed by using R language. The correlation between CD44 and immune infiltration was explored by using the TIMER, CIBERSORT and GEPIA databases. Results: CD44 is highly expressed in gastric cancer compared with normal tissues. Inhibition of proliferation and migration of gastric cancer cells after CD44 knockdown was observed. The UALCAN database showed that CD44 was independent of sex in gastric cancer but correlated with cancer stage and lymph node metastasis. Kaplan‒Meier Plotter online analysis showed that OS, PFS and PPS were prolonged in the CD44 low-expression group. GO and KEGG analyses and GSEA results showed that CD44 was mainly located in the endoplasmic reticulum and the extracellular matrix containing collagen, which was mainly involved in protein digestion and absorption. TIMER, CIBERSORT and GEPIA showed that CD44 was associated with infiltrating immune cells and thereby affected survival prognosis. Conclusion: CD44 is highly expressed in gastric cancer and is an independent prognostic factor associated with immune invasion, which can be used as a candidate prognostic biomarker to determine the prognosis associated with gastric immune invasion. [ABSTRACT FROM AUTHOR]

To investigate the small-strain stiffness characteristics of highly weathered granite (HWG), a resonance column test system was used to conduct resonance column tests on highly weathered granite taken from the Lincang City, Yunnan Province, China. The effects of effective consolidation stress and structural changes is caused by remodeling process and initial dry density on the small-strain stiffness of HWG. Furthermore, the difference between the test data and other geotechnical materials were compared and analyzed. The test results show that the maximum dynamic shear modulus G max of remodeled highly weathered granite samples is greater than that of undisturbed samples once the effective consolidation stress is smaller than 300 kPa, but the opposite result is observed once the effective consolidation stress exceeds 300 kPa, and the phenomenon was also explained from a microscopic perspective based on the scanning electron microscopy (SEM). The G max of remodeled highly weathered granite gradually increases with the increase in dry density and effective consolidation stress. At an identical effective consolidation stress, the dynamic shear modulus ratio G / G max − γ curves of remodeled highly weathered granites at different initial dry densities are nearly consistent. Additionally, according to the test data, the mathematical model of G max for remodeled highly weathered granite considering effective consolidation pressure and initial dry density was established and agrees well with the test results of practical engineering cases. The range of variation in G / G max was given by the research results, which were compared with the G / G max of weathered granite obtained from the existing research, and the results in this work can provide a valuable reference for analyzing dynamic stability of buildings in the engineering construction of weathered granite sites. [ABSTRACT FROM AUTHOR]

Plastics originate from the synthesis of chemical products, and the regeneration of chemical products from waste plastics through catalytic pyrolysis helps to reduce the dependence on fossil resources and improve the treatment of waste, which is an important aspect of current sustainable social development. In this study, metasequoia was used as a biomass precursor and three porous char-supported nanocatalysts (Fe-MEC, Ni-MEC, and Co-MEC) were synthesized via a simple and feasible microwave heating method, which were then used as catalysts for the preparation of high-quality liquid oil from polystyrene powder via an ex-situ catalytic pyrolysis method. The results indicate that Fe-MEC, Ni-MEC, and Co-MEC possessed good pore structures due to the microwave-heating and catalytic effect of these metals, and metal nanoparticles are generated and uniformly anchored on the matrix of the char support. Using these catalysts, the yield of liquid product from polystyrene pyrolysis decreased slightly, while the gas yield increased slightly. Fe-MEC catalysis reached the highest liquid yield of 91% among the three catalysts. The catalysts can improve the yield of a series of high-value liquid products such as toluene, ethylbenzene, and α-methyl styrene. The catalysts also exhibited excellent cycle stability, and carbon nanotubes were formed which are less prone to deactivation. [Display omitted] • Biomass char-supported nanocatalysts were prepared via microwave heating method. • The catalysts exhibit porous structure with well-dispersed metal NPs on the matrix. • Fe-MEC catalysis reached a high liquid yield of 91.15% from polystyrene pyrolysis. • The yields of high-value oil products are significantly improved. • The catalysts exhibit excellent stability with carbon nanotubes generated the surface. [ABSTRACT FROM AUTHOR]

Determining the evolution characteristics of cracks and shear bands is important for understanding the damage mechanisms of geotechnical materials. However, there are few experimental studies on the mesoscopic evolution characteristics of cracks in shear bands. In this study, micro-chromatography (micro-CT) is used to evaluate the triaxial test processes of granite residual soil samples under confining pressures of 50 kPa, 100 kPa, 200 kPa and 300 kPa. Then, advanced digital volume correlation (DVC) is used to obtain three-dimensional strain fields and shear bands at different test loading stages, the evolution characteristics of cracks inside and outside the shear band are further measured basis on this. The results indicate that, if the maximum gradient region of the crack distribution in the initial state of the sample can form a trend surface similar to the "interface", then the shear band may be generated in this region. After the formation of the shear band, the penetration degrees of the shear bands are similar to an S curve with the increasing axial strain. The crack volume densities of the shear bands are obviously smaller than those of whole specimens. The crack volume densities on the shear bands first decrease rapidly and then increase gradually with increasing axial strain, and the increasing rate decreases with increasing confining pressure. Among the various crack types on the shear bands, the volume contents of brand-new cracks increase the fastest and exceed half, indirectly reflecting the severe deformation characteristics on the shear bands. • Measurement of crack evolution law in shear bands by micro-CT. • Quantitative calculation of spatial connectivity of shear bands. • The relationship between initiation of shear bands and the distribution of cracks. • The crack density in the shear band is smaller than that of the whole sample. [ABSTRACT FROM AUTHOR]

Nowadays, the high cost and poor durability of commercial catalyst Pt/C for methanol oxidation reaction have impeded the further development of direct methanol fuel cells. Herein, we firstly introduced a delafossite CuCoO2 to act as the support of noble metal Pt. The strong metal support interaction between Pt and CuCoO2, abundant hydroxide species and active sites on the surface of catalyst may be the key factors for enhanced performances of methanol oxidation. Pt‐CuCoO2/C achieved a mass activity of 1.16 A mgPt−1, which obtained 3.02 times enhancement compared with commercial Pt/C (0.38 A mgPt−1). The If/Ib value of Pt‐CuCoO2/C is 1.96, much higher than that of Pt/C (0.76), demonstrating favorable anti‐poisoning ability. After 200 times cycling, Pt‐CuCoO2/C still maintained 77.1 % of its initial activity, exhibiting superior COads intermediate tolerance and stability. Low cost, better performances and stability of Pt‐CuCoO2/C reveal that it can be seen as a hopeful catalyst. [ABSTRACT FROM AUTHOR]

Background: Osteosarcoma (OS) is a malignant bone tumour of mesenchymal origin. These tumours are characterised by rich vascularisation, therefore promoting rapid proliferation and facilitating metastasis. CD44 has been reported to be involved in OS, but its role and molecular mechanisms in the pathogenesis of the disease are not fully determined. Methods: In this study, we investigated the antitumor effect of CD44 on the development of OS and further explored the molecular mechanisms. The expression of CD44, cathepsin S and MMP-9 was detected by Western blot (WB) and reverse transcription-polymerase chain reaction (RT-qPCR) in different cell lines (MG63, U2OS OS and hFOB 1.19). To elucidate the role of CD44 in OS, MG63 and U2OS cells were treated with small interference RNA (siRNA) to knock down CD44, and the knockdown efficiency was validated with GFP and RT-qPCR. Furthermore, cell proliferation was assayed using Cell Counting Kit‑8 (CCK-8) and colony formation assays, and cell migration and invasion were assayed by transwell and wound-healing assays. Results: We found that CD44 expression in the MG63 and U2OS OS cell lines was markedly increased compared to that of the human osteoblast hFOB 1.19 cell line. Knockdown of CD44 inhibited proliferation, migration and invasion of MG63 and U2OS cells. Cathepsin S expression in the MG63 and U2OS OS cell lines was increased compared to that of the human osteoblast hFOB 1.19 cell line. When CD44 was knocked down, its expression level went down. Conclusion: Taken together, our data reinforced the evidence that CD44 knockdown inhibited cell proliferation, migration and invasion of OS cells accompanied by altered expression of cathepsin S. These findings offer new clues for OS development and progression, suggesting CD44 as a potential therapeutic target for OS. [ABSTRACT FROM AUTHOR]

This study conducts several triaxial cyclic and plane strain cyclic impact tests on fissured soil under varying effective consolidation pressures, impact peak loads, and frequencies through the true triaxial test system to investigate the mechanical response characteristics. The results indicated that, under plane strain conditions, the specimens' shear resistance increases compared to that under triaxial loading. Moreover, the influence of fissures is challenging to quantify under triaxial loading compare to the mechanical response to fissure failure under the plane strain condition. As a result of the lateral confinement under plane strain conditions, the excess pore pressure, stress path, and lateral stress coefficient exhibit changes in sensitivity due to fissure damage, facilitating the analysis of the fissures' influence. Lower consolidation stress tends to increase the likelihood of fissure failure. As the peak impact stress escalates, the specimen deformation and excess pore pressure rise. When the impact peak stress reaches a critical value, the sample undergoes substantial deformation and fails rapidly. The impact of the frequency on specimen deformation correlates with the peak impact stress. Under low-impact peak stress, higher frequencies result in smaller deformations. However, under high-impact peak stress, a critical frequency exists. As the frequency increases, the difference between the maximum and minimum pore water pressure expands, with the change in this difference relating to fissure damage. Inherently, fissures in the soil significantly affect the mechanical properties under the impact load in the plane strain condition. The findings from this study can provide technical support for determining and evaluating the mechanical parameters of the fissured soil layer in light of the impact load. • The plane strain condition enhance the sensitivity of fissures to mechanical property effects. • The relationship between fissure rapture and maximum principal strain is not proportional. • Both the frequency and the peak impact stress have critical values. • A effective method is proposed to quantitatively determine the initial failure of fissures. [ABSTRACT FROM AUTHOR]

To examine the effect of drying-wetting cycles on the damage patterns of microstructural and mechanical properties of granite residual soils, nuclear magnetic resonance scans, triaxial shear tests and scanning electron microscopy measurements were performed on undisturbed samples. The correlation between pore distributions and shear strength parameters were then examined and the microscopic mechanism of the drying-wetting cycles was revealed. The pore volume distribution curve of granite residual soil showed a major peak and a secondary peak, which represented micro pores and macro pores, respectively. As the number of drying-wetting cycles increased, the distributed proportions of micro pores remained almost constant, whereas those of macro pores increased dramatically. The NMR-based porosity was nonlinearly related to drying-wetting cycles in a positive manner. Moreover, the weakening trend of mechanical properties evolved synchronously with the development of microstructure damage during continuous drying-wetting cycles. The damage patterns of microstructure and mechanical properties of soils were attributed to expansive forces in pore walls and losses of fine clay particle due to periodic drying-wetting cycles. [ABSTRACT FROM AUTHOR]

Fully convolutional neural networks (FCNs) have shown great effects in the saliency detection task. In this paper, we present an FCN based model to aggregate multi-level convolutional features for salient object detection. The main contribution of this work is to make full use of the information extracted by the network while preserving the characteristics of each level. We first propose a novel Intra-stage Feature Aggregating (IFA) module to enhance the detailed information by integrating feature maps from different layers within the same stage of the ResNet-50. We then design an Inter-stage Feature Fusion (IFF) module which exploits contextual information by combining the features from neighboring stages to make each feature map more discriminative. Finally, we propose a Deeply Supervised Group Recursive Prediction (DGR) module to refine the details of the predicted saliency maps and generate the final saliency map. Our approach performs favorably against state-of-the-art methods on five popular datasets and achieves a real-time speed of 30 fps. [ABSTRACT FROM AUTHOR]

A major concern for direct methanol fuel cells is the deactivation of irreplaceable Pt-based anode catalysts. Herein, a simple cerium nitrate hydrothermal treatment was employed to fabricate a copper-cerium hybridized interface that efficiently utilized the characteristic of Cu release from layered Cu-based delafossite. Remarkably, the construction of hybridized interface considerably utilized ligand effect, strain effect, and bifunctional effect of loaded Pt, yielding the mass activity of 1268.6 mA/mg Pt and specific activity of 1.57 mA/cm2, which were 3.69, 1.54 times higher than commercial Pt/C, respectively. Meanwhile, nitrate-treated CeT-rGO-Pt achieved a satisfactory anti-CO poisoning ability as evidenced by a high I f / I b ratio (1.86) and a low CO oxidation onset potential (less than Pt/C 55 mV). Density functional theory calculations further confirmed that the formation of hybridized interface optimized the geometry and electronic structure of Pt, which was favorable for inhibiting carbon monoxide adsorption. This straightforward and effective hybridized interface fabricated strategy provided insight into the design of delafossite-based composite catalysts for the high performance of the methanol oxidation reaction. [Display omitted] • A simple nitrate treatment method was applied to fabricate copper-cerium hybridized interface. • The hybridized interface in CeT-rGO-Pt optimized the geometric and electronic structure of Pt. • The MOR activity, durability and anti-CO poisoning ability were enhanced due to the formation of hybridized interface. [ABSTRACT FROM AUTHOR]

An experimental study was conducted to investigate the physical and mechanical properties of an intensely weathered mudstone from Northeast China after wetting–drying (W–D), freezing–thawing (F–T), and wetting–drying–freezing–thawing (W–D–F–T) cycles. These cyclic climatic processes have significant effects on the volume, microstructure, stress–strain behaviour, shear strength, electrical resistivity, and P-wave velocity of the samples. The variation in electrical resistivity exhibits an inverse correlation with the volume change, and a strong relationship can be observed between the electrical resistivity and porosity. The cohesion decreases with increasing number of cycles, while the internal friction angle slightly increases; these relationships can be caused by the presence of cracks and large voids and by the increase in the aggregate size and density during the drying and freezing processes, respectively. Moreover, the W–D–F–T cycles have a greater influence on the shear strength than do either the W–D or F–T cycles. This phenomenon is similar to that observed in the P-wave velocity, and the relationships between the shear strength parameters and P-wave velocity are also explored. This study provides nondestructive methods of predicting the deformation and shear strength of mudstones in seasonally frozen regions. [ABSTRACT FROM AUTHOR]

This paper advances the present understanding of the nonlinear characteristic of Poisson's ratio in seasonal frozen regions. The influence of freeze-thaw cycles, confining pressure and shear strain is investigated on the basis of extensive resonant column tests. It is demonstrated that the Poisson's ratio increases with increasing shear strain and decreases with increasing confining pressure. A new empirical equation is formulated to describe the strain-dependency of Poisson's ratio. With the fitting parameters, the influence of freeze-thaw cycles on Poisson's ratio is discussed. Based on the Hardin-Drnevich model, an effective method for estimating the Poisson's ratio in seasonal frozen regions is developed. It is found that the comprehensive effects of the parameters are adequately represented by maximum shear modulus, normalized shear modulus and confining pressure, which makes the method simple and facile for use. [ABSTRACT FROM AUTHOR]

Gassy sediments have often been encountered in the marine seabed, and they have different features from common saturated and unsaturated soil. By developing and improving an effective methodology, triaxial gassy sand specimens with different initial gas content (saturation ≥85%) were prepared in the laboratory. Their state parameters can be controlled in real time. A series of undrained dynamic triaxial tests by a Global Digital System (GDS) dynamic testing apparatus were conducted to investigate the liquefaction characteristics of gassy sand sediments. The results show that the gassy sand can liquefy the same as the fully saturated sand, but gas existence monotonically increases the sand liquefaction resistance. The occluded gas bubbles have significant influences on sand liquefaction properties. The dynamic pore pressure of gassy sand shows obvious features of slower accumulation, greater amplitude fluctuation, and deeper groove shape in time history curves of pore water, resulting from the effects of gas compression/expansion, migration, and dissolution/exsolution. By introducing a parameter of saturation, a modified model was proposed to describe the evolution of dynamic pore pressure of gassy sands. It was found that the model parameter θ is linearly dependent on the initial gas content (or initial saturation degree Sr). [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to develop an appropriate machine learning model for predicting soil compaction degree while also examining the contribution rates of three influential factors: moisture content, electrical conductivity and temperature, towards the prediction of soil compaction degree. Design/methodology/approach: Taking fine-grained soil A and B as the research object, this paper utilized the laboratory test data, including compaction parameter (moisture content), electrical parameter (electrical conductivity) and temperature, to predict soil degree of compaction based on five types of commonly used machine learning models (19 models in total). According to the prediction results, these models were preliminarily compared and further evaluated. Findings: The Gaussian process regression model has a good effect on the prediction of degree of compaction of the two kinds of soils: the error rates of the prediction of degree of compaction for fine-grained soil A and B are within 6 and 8%, respectively. As per the order, the contribution rates manifest as: moisture content > electrical conductivity >> temperature. Originality/value: By using moisture content, electrical conductivity, temperature to predict the compaction degree directly, the predicted value of the compaction degree can be obtained with higher accuracy and the detection efficiency of the compaction degree can be improved. [ABSTRACT FROM AUTHOR]

To explore the anti-tumor effects of Radix Astragali on osteosarcoma and its mechanism. We analyzed the PPI network of Radix Astragali’s potential targets for treating osteosarcoma and got the hub targets. We used KM curves to screen hub targets that could prolong sarcoma patients’ survival time. We performed GO and KEGG enrichment analysis of Radix Astragali’s potential targets and predicted Radix Astragali's molecular mechanism and function in treating osteosarcoma. The binding process between the hub targets, which could prolong sarcoma patients' survival time, and Radix Astragali was simulated through molecular docking. PPI network analysis of potential therapeutic targets discriminated 25 hub targets. The KM curves of the hub targets showed there were 13 hub targets that were effective in improving the 5-year survival rate of sarcoma patients. GO and KEGG enrichment demonstrated that Radix Astragali regulates multiple signaling pathways of osteosarcoma. Molecular docking results indicated that Radix Astragali could bind freely to the hub target, which could prolong the sarcoma patient's survival time. Radix Astragali act on osteosarcoma by regulating a signaling network formed by hub targets connecting multiple signaling pathways. Radix Astragali has the potential to become a drug for treating osteosarcoma and prolonging the sarcoma patient's survival time. [ABSTRACT FROM AUTHOR]

Because of the weathering pedogenesis of natural granite residual soil (GRS), its mechanical responses are dominated by the parent rock and weathering process, a situation that differs fundamentally from that of sedimentary soil. Natural GRS is characterized by inherent anisotropy and anisotropic in situ stress conditions, but how this affects its stiffness behavior is not well understood. In this study, systematic bender-element and modified Hardin-type resonant-column tests were performed under various stress conditions (isotropic or anisotropic), thereby enabling the shear wave velocities and shear modulus in different directions to be measured. The degree of inherent stiffness anisotropy of natural GRS is quantified and compared with those of well-studied soils. Natural GRS is found to have apparent stiffness anisotropy, with the shear wave velocity in the vertical direction being higher than that in the horizontal direction. This unique stiffness anisotropy behavior can be attributed to the unique structural characteristics of natural GRS, in which cementation and minor fissures play important roles. Under stress anisotropy, natural GRS has the same shear wave velocity hierarchy as that under isotropic conditions, but vertical loading alters the soil structure as reflected by the change of soil fabric constants. In addition, a higher stress ratio corresponds to a larger shear modulus of both natural and reconstituted GRS, but it affects them differently, with cementation again playing an important role. This study provides a fundamental dataset regarding the stiffness anisotropy of natural residual soil and improves the understanding of its stiffness behavior. [ABSTRACT FROM AUTHOR]

Due to the formational environment and climatic variability, granite residual soils with grain-size distribution ranging from gravel to clay undergo multiple drying-wetting cycles. The influences of multiple drying-wetting cycles on the soil-water characteristic curve (SWCC) and pore-size distribution (POSD) of undisturbed granite residual soils are investigated using the pressure plate test and nuclear magnetic resonance (NMR) spin-spin relaxation time ( T2) distribution measurement, respectively. Results show that the water-retention capacity and air-entry value decrease and pores become more uniform with increasing drying-wetting cycles. After four drying-wetting cycles, the soil reaches a nearly constant state. The POSD change of multiple drying-wetting cycle samples is consistent with the SWCC of the soils. Furthermore, a modified van Genuchten model in terms of cumulative pore volume is used to obtain the best-fit POSD of the drying-wetting cycle samples. The shape and changing tendency of both curves of SWCC and POSD are quite similar and achieved a better correlation. It can be concluded that the SWCC is strongly dependent on the POSD of the soil and NMR T2 relaxometry can be used as an alternative to the assessment of microstructural variation of residual soils subjected to the periodic drying and wetting process. [ABSTRACT FROM AUTHOR]

Cracks and potholes around manholes on carriageways have long been a problem for municipal asphalt concrete roads. The traditional repairing method not only requires a long period of traffic interruption, but also does not meet the requirements of durability and aesthetic appearance. A black rapid repair fibre concrete (BRRFC) was developed for asphalt concrete pavement rehabilitation around manholes, based on a series of optimisation and scaled tests. As a super high-early-strength concrete, BRRFC has capacity to carry normal traffic loads after pavement manholes repairs for 8 h. Meanwhile, it offers other advantages such as uniform and stable black colour, good performance in dry-shrinkage and wear resistance, low-cost, and easy construction. Applications of BRRFC in numerous municipal maintenance works showed that rehabilitated manhole areas were still intact and no obvious colour difference between the new and old pavement concrete after several years of service, achieving significant social and economic benefits for sustainability. [ABSTRACT FROM AUTHOR]

It is of great significance to study the nonlinear evolution law of the small strain shear modulus of expansive soil for analyzing the deformation behavior of soil or geotechnical structure and the seismic site response. Existing studies rarely discuss the damage mechanism of the small strain shear modulus of expansive soil, and the corresponding damage model describing the small strain stiffness decay law is lacking. In this study, a series of resonance column tests were carried out to investigate the effects of mean effective stress, loading and unloading stress paths and vibration cycles on the nonlinear decay law of small strain shear modulus of expansive soil, and the damage mechanism was discussed in detail. Subsequently, a novel damage model describing the decay law of small strain shear modulus of expansive soil was proposed and verified by the results of resonant column tests. The results show that the decay process of the small strain shear modulus with the shear strain is essentially the damage of the soil structure, which can be characterized mathematically by damage model. The mean effective stress and the larger overconsolidation ratio caused by the unloading process can inhibit the damage, while the vibration cycles can cause small reduction in small strain shear modulus and promote the damage. The proposed damage model with clear physical meaning can well describe the evolution law of small strain shear modulus of expansive soil, and has higher accuracy than the traditional model. • The effects of various factors on the small strain shear modulus of expansive soil are investigated. • The damage mechanism of small strain shear modulus of expansive soil is analyzed. • A novel damage model describing the decay law of small strain shear modulus of expansive soil is proposed. [ABSTRACT FROM AUTHOR]

• Advantages of microplane and micromechanics are utilized to propose a new model for capturing the coupling effect of quasi-brittle materials' damage and plasticity. • Tensile damage mechanism, friction energy dissipation mechanism, unilateral effect of microcracks, directional damage mechanism and strain softening can be well considered. • A novel return mapping algorithm for efficient numerical calculation of the proposed new model is detailed derived. • The failure of quasi-brittle geomaterial under tensile, compressive, shear or true triaxial compressive loading path can be captured by the proposed model. • Directional multi-scale deformation and failure characteristics of rock are well visualized through microplane configuration. Quasi-brittle materials exhibit significant heterogeneity due to their complex mesoscopic components and microdefects, and their macroscopic mechanical behavior depends strongly on crack initiation, propagation and friction-slip. In this study, by coupling microplane and micromechanics, a new constitutive model that can consider the mesoscopic damage and plasticity mechanisms of quasi-brittle materials is proposed. The microplane is used throughout the whole construction process for the model: first, a representative volume element (RVE) is established to characterize the mesoscopic structure of quasi-brittle materials, and the advantages of microplanes are fully exploited to characterize the equivalent cracks‒matrix system. Then, the relationship between macroscopic and microplane strains (stresses) is elucidated. Second, considering the unilateral effect for cracks, the expressions for the free energy potential functions for a microplane and for the RVE are established. Third, for each microplane, the damage criterion characterized by the damage driving force is constructed for the open and closed cracks, and in particular, a new plasticity criterion characterizing the static friction property coupled damage and dilatancy behavior during strain softening deformation is constructed. By considering the characteristics of the microplane to relate macroscopic and mesoscopic stress and strain, an efficient return mapping algorithm based on the Newton‒Raphson method is derived. Finally, the stress‒strain curves and the evolution of damage and plasticity are simulated under conventional triaxial compression, uniaxial tensile, direct shear and true triaxial compression stress paths, and the effectiveness of the model is verified by comparison to the experimental data. To better reflect the inherent correlation between mesoscopic damage and macroscopic mechanical behavior, a microplane configuration that can visually characterize the mesoscopic evolution characteristics of damage is established, and it is shown that the simulated results correspond well to the macroscopic deformation and failure pattern of granite samples under different loading paths. [ABSTRACT FROM AUTHOR]

While the anisotropy of sedimentary soil—particularly the underlying role of soil structure—is well understood, similar knowledge about granite residual soil formed by weathering is scarce. In particular, the evolution of soil structure during the hollow cylinder torsional shear tests (among the most appropriate for studying soil strength anisotropy) remains largely unknown. This study systematically investigates the multiscale structural properties of granite residual soil using stereo microscopy, scanning electron microscopy, energy-dispersive spectrometry, and computed tomography. Furthermore, the structural evolution during hollow cylinder torsional shear tests is traced. Results indicate the strength anisotropy of residual soil is associated with horizontal fissures which cause low shear strength when the soil is sheared with a principal stress direction of 45°. The cementation via Fe is characterized by a uniform distribution. Different evolutionary patterns are observed for soils within the shear band, inside the necking area, and in other regions. It is not always the case that particles are rearranged with their long axis perpendicular to the major principal stress. This study improves the understanding of natural residual soil structure and provides some insights into its anisotropic behavior. [ABSTRACT FROM AUTHOR]

A multicolor switching was achieved via simple reversible coordinationand acetalation reaction between aldehydes, tri(pentafluorophenyl)borane (BCF) and methanol. The coordination [HPB → BCF] of 4,4′-[(1E,3E)-1,2,3,4-tetraphenylbuta-1,3-diene-1,4-diyl]- dibenzaldehyde ( E,E- HPB) to tri(pentafluorophenyl)borane can change the emissive wavelength from 550 to 630 nm, while transformation of the aldehyde into acetal can change the emissive wavelength from 550 to 530 nm in the presence of methanol. More important, these reactions can access reversibility easily and tune the emission color repeatedly between cyan, yellow and red. All of these dyes show typical aggregation-induced emission (AIE) or aggregation-enhanced emission (AEE) characteristics. In addition, a tunable photoluminescence mechanism is proposed based on the characterization data including NMR, XRD, MS and IR. The result may provide a new design strategy for the multicolor switches and their related applications. [ABSTRACT FROM AUTHOR]

• Micro and macro anisotropy of LDHs-NS guide the anisotropic growth of PVK crystals. • Efficient charge transport and low trap-state density are achieved. • The optimized device yields a significant enhancement in stability and PCE. The anisotropy of perovskite (PVK) crystals is important for charge carrier transport and light absorption. In this regard, organic small molecules are most commonly used to induce the orientation growth of PVK. However, the high volatility and high diffusion coefficient of small molecules hinders its practical application. Here, inorganic layered double hydroxide nanosheets (LDHs-NS) is introduced into the PVK solution, where both micro and macro anisotropy of LDHs-NS guide the anisotropic growth of PVK crystals. Based on this, the efficiency of assembled perovskite solar cells (PSC) in an all-air environment can reach 12.26% with excellent thermal stability. The orderly arrangement of –OH on LDHs-NS surfaces can induce orderly growth of PVK crystals by interacting with Pb2+; the anisotropy stacking of LDHs-NS ensured the orderly growth of PVK crystals on a large scale. Our work has important guiding implications for the anisotropy growth of PVK crystal, resulting in more efficient PSCs. In this paper, hydroxide nanosheets (LDHs-NS) is used as an additive to the perovskite absorbent layer, because the micro and macro anisotropic of LDHs-NS guides the anisotropic growth of perovskite crystals, the optimized device significantly improves stability and photoelectric conversion efficiency. [Display omitted] [ABSTRACT FROM AUTHOR]

Soils beneath railway embankments can be considered under the plane strain condition. Excessive settlement has been observed on structured clays beneath railway embankments in the coastal areas of China. Compared with the cyclic behaviors of structured clay under the axisymmetric condition, the dynamic responses under the plane strain condition have been less studied. In this study, several one-way undrained cyclic true triaxial and cyclic plane strain tests were conducted on undisturbed structured clay. The test results show that the permanent major principal strain obtained from cyclic plane strain tests is smaller than that obtained from cyclic true triaxial tests under the same conditions, implying that the permanent major principal strain obtained from the cyclic true triaxial test is overestimated. Moreover, the cyclic minor principal stress has a significant influence on the permanent deformation and excess pore pressure in cyclic plane strain tests. Compared to the results of cyclic plane strain tests with the constant minor principal stress, the permanent major principal strain is lower by 9.2% and 20.1% when the ratios of the amplitude of the cyclic minor principal stress to that of the cyclic major principal stress (η) are 0.3 and 0.5, respectively. As η increases, the maximum excess pore pressure increases markedly, whereas the change in the minimum excess pore pressure is almost negligible. Furthermore, an empirical formula for predicting the permanent major principal strain under the plane strain condition considering the impacts of bidirectional cyclic loadings was established. • A dynamic true triaxial apparatus that can realize the plane strain state is used. • The plane strain condition restricts the permanent major principal strain. • The cyclic σ 3 limits the accumulation of permanent major principal strain. • The cyclic σ 3 significantly promotes the development of minimum pore pressure. • A formula for permanent major principal strain in plane strain state is proposed. [ABSTRACT FROM AUTHOR]

Clogging has attracted increasing attention as one of the key problems affecting the development and application of constructed wetland (CW) technology. However, there is a lack of systematic research on the evolution history, hot spots, frontiers and direction classification of CW clogging, lack of research papers on how to effectively solve clogging, and some mixed use in methods and concepts. To bridge these research gaps, this systematic and in-depth review was conducted using published references and analyses and the visualization software CiteSpace based on 15 years of literature research. Keyword cluster and reference co-cited analyses were conducted. Hotspot directions and cutting-edge development trends of CW clogging fields were obtained. Some methods discussed in this review could not only be used to monitor but also evaluate CW clogging. The boundaries and usage of monitoring and evaluation have not been studied before, which can lead to potential inconsistencies in classification standards in the future. Therefore, the differences and definitions are based on comprehensive and in-depth analyses and considerations. The existing literature is classified based on three aspects: mechanism, monitoring and evaluation, and solutions. Specific analyses and assessments were also conducted on the progress and cutting-edge development trends in these three directions. • "CiteSpace" is used to conduct a comprehensive study on clogging occurs in constructed wetland (CW). • Knowledge structure, historical evolution, and cutting-edge trends of CW clogging are revealed based on a 15-year analysis. • Wastewater treatment, solids accumulation, and flow, etc., are the hotspots of CW clogging research in recent years. • The mechanism, monitoring and evaluation, and solutions to solve CW clogging was discussed, respectively. • A new type of promising modular CW is proposed for the first time, which can effectively solve the clogging problem. [ABSTRACT FROM AUTHOR]

As a result of weathering, the mechanical behavior of granite residual soil differs from that of sedimentary soil. Although the mechanical properties of granite residual soil have been studied extensively, its strength anisotropy is yet to be established. Previous work has revealed the association between the principal stress direction α and soil shear strength, but little is known about how the intermediate principal stress affects the soil strength. This paper presents the shear-strength parameters under various combinations of α and the intermediate principal stress factor b as obtained through undrained hollow-cylinder torsional shear tests performed on samples of natural granite residual soil. The test results confirmed the considerable effect of b on the shear strength and highlighted the differences between the soil studied here and those studied previously. It was found that b affects the undrained strength and mobilized frictional angle (or ultimate stress ratio) differently, with increasing b leading to lower undrained strength but higher frictional angle. In addition, the degrees to which b affects undrained strength and frictional angle are not the same and depend on the α value at which the soil is sheared. Therefore, two parameters are proposed to quantify that difference. This study extends the understanding of the strength anisotropy of granite residual soil and provides data for soil behavior under various values of b. [ABSTRACT FROM AUTHOR]

A new type of AIE molecules based on hexaphenyl-1,3-butadienes was reported with respect to the synthesis and characterization. This material exhibited different maximum emission wavelength and enhanced emission intensity at different aggregate state (amorphous and crystalline state). [ABSTRACT FROM AUTHOR]

Detecting salient objects in complicated scenarios is a challenging problem. Except for semantic features from the RGB image, spatial information from the depth image also provides sufficient cues about the object. Therefore, it is crucial to rationally integrate RGB and depth features for the RGB-D salient object detection task. Most existing RGB-D saliency detectors modulate RGB semantic features with absolution depth values. However, they ignore the appearance contrast and structure knowledge indicated by relative depth values between pixels. In this work, we propose a depth-induced network (DIN) for RGB-D salient object detection, to take full advantage of both absolute and relative depth information, and further, enforce the in-depth fusion of the RGB-D cross-modalities. Specifically, an absolute depth-induced module ( A D I M ) is proposed, to hierarchically integrate absolute depth values and RGB features, to allow the interaction between the appearance and structural information in the encoding stage. A relative depth-induced module ( R D I M ) is designed, to capture detailed saliency cues, by exploring contrastive and structural information from relative depth values in the decoding stage. By combining the A D I M and R D I M , we can accurately locate salient objects with clear boundaries, even from complex scenes. The proposed DIN is a lightweight network, and the model size is much smaller than that of state-of-the-art algorithms. Extensive experiments on six challenging benchmarks, show that our method outperforms most existing RGB-D salient object detection models. [ABSTRACT FROM AUTHOR]

Noncoaxiality is critical for predicting accurately the constitutive relationships of soils. Although the noncoaxiality of sand and clay has been studied extensively, such information for residual soil is far from sufficient. The mechanical behavior of residual soil differs from that of sedimentary soil, thus the applicability of the existing results is yet to be confirmed. This paper reports systematic undrained hollow-cylinder torsional shear tests performed on specimens of natural granite residual soil (GRS). The tests involve shear paths of monotonic shear with fixed principal-stress direction (fixed-α) as well as rotation of the principal-stress direction at constant deviator stress (α-rotation). The results show that the noncoaxial behavior of GRS depends on the principal-stress direction as well as the deviator stress. In the fixed-α tests, the soil tends to become more coaxial when approaching an ultimate state. The higher deviator stress during the α-rotation tests results in reduced noncoaxiality, but no obvious reduction in noncoaxiality is induced by α-rotation. This paper correlates soil's inherent anisotropy with its noncoaxial behavior. For sand, the initial and maximum noncoaxiality degree correlate well with the initial anisotropy, and two corresponding empirical relationships are proposed. However, they do not apply to natural GRS and soft clay. The ultimate noncoaxiality degree correlates poorly with the inherent anisotropy because of the damage to the latter. For GRS, the inherent anisotropy declines when soil particles rearrange during shear, which damages the bridge-form iron-bearing minerals. [ABSTRACT FROM AUTHOR]

Cold rolling the CC AA 5754 aluminum alloy to different reductions was followed by an hour of annealing at 537 °C under varied pressures. The changes in microstructure and texture were studied. According to the findings, high-pressure heat treatment restricts recrystallization, and the restriction effect is stronger as pressure rises. The refining impact of high-pressure heat treatment can refine recrystallized grains, and it becomes stronger as the rolling reduction gets higher. The variation of recrystallization texture is significantly affected by high-pressure heat treatment. The sheet with a 19.6% reduction is found to have a weak cube texture at atmospheric pressure and 2 GPa, but the sheet that has been annealed at 4 GPa and 6 GPa has a strong cube texture and a weak β fiber rolling texture. High-pressure heat treatment improves the intensities of the cube and R textures in the fully recrystallized sheets with the same reduction. The strengthening impact of R texture from high-pressure heat treatment improves with increasing rolling reduction. [ABSTRACT FROM AUTHOR]

Abstract: Electroless Ni-P alloy coating was deposited on carbon fibers (CFs) reinforced polyether ether ketone (PEEK), and a transparent passive film was formed on it. Effects of passivation on the oxidation behavior and electromagnetic interference shielding effectiveness (EMI SE) of Ni-P alloy coatings were investigated. The phase structure of the Ni-P coating was investigated by X-ray diffractometry (XRD). Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) showed that dense and uniform nodules presented in the coating, and chromate (VI) passive film formed onto Ni-P alloy coating. Electrochemical tests showed that passivation improved the corrosion resistance and delayed the oxidation of the Ni-P alloy coating. The EMI SE test proved that the passivation enhanced EMI SE greatly because passive film effectively restrained the oxidation of the Ni-P alloy coating. All the data proved that the passivated Ni-P alloy coating to be potential shielding material under oxidation environment. [Copyright &y& Elsevier]

As indicated by the theory of a clay-water-electrolyte system, the dispersive mechanism of cohesive soil involves three aspects: low clay content, high sodium ion percentage, and strongly alkaline pH. Accordingly, an empirical equation was established with an associated procedure and criteria proposed for evaluating the dispersivity of cohesive soil. The equation consists of four soil physical and chemical indicators: liquid limit ( WL), clay content ( PC), sodium percentage in the pore water ( PS), and pH. The equation is F = 4 − 0.01(2 WL + PC − PS) + 0.1 pH, where F is the soil dispersivity value. Compared with the evaluation based on laboratory tests, the empirical equation had higher accuracy for the evaluation of the dispersivity of cohesive soil, and was thus conducive to greater engineering safety. This indicates that the proposed empirical equation is applicable for evaluating the dispersivity of cohesive soil in general engineering. [ABSTRACT FROM AUTHOR]

The micropile-cantilever retaining wall (CRW) combined retaining structures are widely used in slope reinforcement design. While the landslide thrust distributed between the micropiles and the CRW remains unclear. In this work, the seismic response of a micropile-reinforced cut slope behind a CRW are studied by means of a centrifuge shaking-table model test. The proportion of slope sliding force borne by CRW and micropiles under multistage earthquakes is revealed. When the backfill has a large slope angle and loads are applied to the upper part of the slope crest, the dynamic earth pressure coefficient is much larger than that when the backfill surface is horizontal and no additional loads are applied. The current data show that the residual bending moment accumulates significantly on the CRW and micropiles after an earthquake, which must be considered during the seismic design of the micropile-CRW combined retaining structures. • By means of a centrifuge shaking-table model test, the seismic response of a CRW-micropile-supported slope are studied. • The proportion of slope sliding force borne by CRW and micropiles under multistage earthquakes is revealed. • Dynamic earth pressure coefficient increases with backfill slope angle. [ABSTRACT FROM AUTHOR]

The expansive soil in seasonally frozen areas is vulnerable to repeated freezing and thawing. When exposed to freeze–thaw cycles, this soil may pose a danger to civil engineering structures and cause serious economic losses. Using a closed-system freeze–thaw test, the deformation characteristics of expansive soil under freeze–thaw cycles with different loads were studied. Nuclear magnetic resonance (NMR) and SEM technology were used to study the microstructure characteristics of the soils after the freeze–thaw cycles. The test results show that the soils under different load conditions have different deformation characteristics. The pre-freezing stage of soils under loads is significantly longer than that for soil without a load. Loads play a key role in the deformation caused by freeze–thaw cycles. There exists also a freezing load (p F) and melting load (p T), under which the soil volume change is zero in the frozen and melted state after the soil reaches equilibrium. NMR and SEM tests showed that the pore structure characteristics of the soils under different loads are significantly different. When a low load is applied during the freeze–thaw cycles, the freeze–thaw cycles will damage the structure of the soil, forming new cracks and hence resulting in a loose pore structure. However, if there is a high load, the freeze–thaw cycles contribute to the formation of a dense pore structure. A backfilled soil thickness of 1.5–2.5 m is proposed without considering the gravity of the supporting structure. • The deformation characteristics and pore structure of expansive soil under freeze–thaw cycles with loads were studied. • The unfrozen water content and the evolutions in the sizes of pores containing unfrozen water during the freezing process of frozen soils under different temperatures were studied. • The backfill thickness of the slope in the canal was suggested experimentally. [ABSTRACT FROM AUTHOR]

Highlights: [•] Transcript and protein of rKirre are increased in postnatal cerebellar development. [•] rKirre mRNA is expressed in migrating granule cells and developing Purkinje cells. [•] rKirre protein is co-localized with a neuron marker NF-200 in Purkinje cells. [•] rKirre may contribute to the granule cell migration and Purkinje cell development. [ABSTRACT FROM AUTHOR]

Tetraamido-oxacalix[4]arene derivatives have been synthesized via the reactions of tetraamino-oxacalix[4]arene with excess butyryl chloride, octanoyl chloride, benzoyl chloride and p-toluenesulfonyl chloride, respectively. 1H NMR results suggest that these oxacalix[4]arene derivatives preferentially adopt the 1,3-alternate (saddle-like) conformation in solution, which were also the case in the solid state as demonstrated by single crystal X-ray analysis. A dimerized slipped capsule could be formed by tetra-butyramido-oxacalix[4]arene in the solid state via intermolecular hydrogen bond interactions under the assistance of two encapsulated methanol molecules. On the other hand, a molecular cavity was formed by tetra- p-toluenesulfonamido-oxacalix[4]arene which can encapsulate a solvent molecule of ethyl acetate. [ABSTRACT FROM AUTHOR]

It is widely accepted that residual soils (RSs) form very differently from sedimentary soils. While there have been extensive advances regarding sedimentary soil, little is known about the strain stiffness decay in RS. This study considers granite residual soil (GRS) from Taishan in China, where stiffness behaviors are established using in situ and laboratory investigations. Variability in the soil stiffness is due to its current state, including the depth, test method, and strain. This is established via systematic resonant-column and in situ tests. In situ tests include the seismic dilatometer Marchetti test (SDMT) and the self-boring pressuremeter test (SBPT). The degree of weathering of the test soil varies significantly along the depth direction, and the top layer of the soil has a hardening shell due to severe weathering. The laboratory G-γ decay curves of GRS were determined from the resonant column. A comparison of the shear modulus (from SBPT) obtained by different analysis methods gives the shear modulus from nonlinear analyses. An approach is proposed to properly describe the trends in typical in situ G-γ decay curves based on data from the tests. The G-γ curve obtained from the resonant-column test of GRS was compared with the in situ curves. The shear modulus G, as obtained from laboratory tests, is smaller than the curves of the in situ tests, which reflects the processes of sampling, transportation, and preparation of soil specimens. [ABSTRACT FROM AUTHOR]

Background: Interleukin-lβ (IL-lβ) is associated with vascular smooth muscle cell (VSMC) migration during neointimal formation following arterial injury, of which matrix metalloproteinase-2 (MMP-2) may have an important role. We investigated whether IL-lβ stimulated migration and MMP-2 production in VSMC, and, if so, whether migration correlated with MMP-2 activity. Materials and Methods: Modified Boyden chamber assay quantified cultured rat aorta VSMC migration. Methyl-thiazolyl-tetrazolium assay assessed cell growth. Gelatin zymography and Western blotting determined MMP-2 activity and protein levels, respectively. Results: IL-lβ (0.1 - 10 ng/mL) induced migration of VSMC in a concentration-dependent manner without cell proliferation. VSMC released increasing levels of active MMP-2 in a dose-response fashion at IL-1β 1–10 ng/mL (P < 0.05) while significantly increased levels of latent MMP-2 (pro-MMP-2) were attained more gradually (10 ng/mL, P < 0.05). There was a dose-dependent increase in the ratio of active MMP-2 to pro-MMP-2 in response to IL-1β (1–10 ng/mL, P < 0.05), suggesting extracellular activation of pro-MMP-2. Protein levels on Western blot paralleled enzyme activity, with the synthesis of more active MMP-2 than pro-MMP-2 in response to IL-1β. IL-lβ-stimulated VSMC migration was significantly attenuated by both the pan-selective MMP inhibitor GM6001 and cis-9-octadecenoyl-N-hydroxylamide, a MMP-2-selective inhibitor. Conclusions: IL-lβ increases MMP-2 activity in VSMC through increased protein synthesis and activation of pro-MMP-2. VSMC migration induced by IL-lβ requires active MMP-2. IL-lβ may play a role in arterial remodeling following injury. [ABSTRACT FROM AUTHOR]

Abstract: Aims: Immunoglobulin superfamily (IgSF) proteins play a critical role in development of the nervous system. Here, a new member of IgSF gene family was cloned from rat brain, which was subsequently identified as rat homolog of Drosophila Kirre. This new molecule was named as rat Kirre (rKirre). We aimed to reveal the developmental expression of rKirre, both at mRNA and protein levels, in the central nervous system. The deduced amino acid sequence of rKirre showed a putative PDZ binding motif at the C-terminus, which provided a rationale for analyzing the co-localization of rKirre and post-synaptic density protein 95 (PSD-95) in cultured rat cortical neurons. Main methods: cDNA library screening was used in the isolation of cDNA. Northern blotting and Western blotting were used to reveal the levels of rKirre expression. In situ hybridization and immuno-fluorescent staining were used to determine the localization of rKirre. Key findings: The rKirre gene was found to be highly expressed in the cerebrum, hippocampus, cerebellum, brain stem and spinal cord of adult rats. In parallel, the protein level of rKirre was also increased in a developing cerebral cortex. In cultured rat cortical neurons, the amount of rKirre was significantly increased during neuronal differentiation. Immuno-cytofluorescent staining indicated that rKirre was present along the neurites of cortical neurons, and was co-localized with PSD-95. Significance: These results suggested that rKirre might play an essential role in neuronal differentiation and development in the central nervous system. [Copyright &y& Elsevier]

Abstract: Generation of thrombin is associated with vascular remodeling that involves proliferation of vascular smooth muscle cells (SMCs) and activation of pro-matrix metalloproteinases (pro-MMPs). The present study was to investigate whether thrombin would induce mitogenesis and activation of pro-MMPs in cerebrovascular SMCs (CSMCs), and if so, whether MMP activity would contribute to the CSMC mitogenesis. CSMCs were cultured from pig middle cerebral arteries and stimulated with thrombin. Thrombin (0.1–5U/ml), in a dose-dependent fashion, stimulated mitogenesis in CSMCs as detected by bromo-2′-deoxy-uridine (BrdU) incorporation. Additionally, zymographic analyses showed that thrombin stimulated the appearance of the active form of MMP-2 (MMP-2) in a concentration-dependent manner, but not the release of pro-MMP-2. Thrombin did not affect expression of cell-associated pro-MMP-2 protein as evaluated by Western blot analysis. Treatment with the synthetic MMP inhibitor GM6001 or antibodies to MMP-2 significantly reduced thrombin-induced BrdU incorporation in CSMCs. In conclusion, thrombin activates pro-MMP-2 in the absence of elevated pro-MMP-2 expression and secretion in CSMCs, and thrombin induces CSMC mitogenesis involving its action on MMP-2. These findings suggest that thrombin may have relevance in cerebrovascular remodeling associated with brain atherosclerosis and atherothrombotic ischemic stroke through a mechanism involving MMP-dependent CSMC mitogenesis. [Copyright &y& Elsevier]

Granite residual soil (GRS) is sensitive to variations in humidity and regularly experiences wetting–drying (D-W) cycles in naturally seasonal climates. It is therefore necessary to explore the effects of D-W cycles on the basic properties of GRS for both engineering safety and scientific research. Triaxial shear tests, computed tomography, nuclear magnetic resonance, and scanning electron microscopy were performed to study the mechanical behavior and structural damage of GRS samples from 0 to 8 D-W cycles. The failure stress, cohesion, and internal friction angle of the GRS samples decreased to different extents with an increase in the number of D-W cycles. The cohesion and internal friction angle of the GRS decreased from 55.95 to 26.93 kPa and 23.28° to 22.65° after eight D-W cycles. Based on computed tomography, the development of mesoscopic cracks can be divided into a crack-generating stage (0–1 D-W cycles), a crack-propagating stage (2–5 D-W cycles), and a crack-stable stage (> 5 D-W cycles). Pore volume distribution curves showed that the pores could be classified into three types (micropores, mesopores, and macropores). The proportion of micropores and mesopores decreased with an increase in the number of D-W cycles, whereas the proportions of macropores and fractures increased. The microstructure in clay particles gradually disintegrated and the pores increased in size and formed connected fractures. The deterioration in the macroscopic mechanical properties of the GRS is the external manifestation of irreversible damage to its microscopic and mesoscopic structure due to the effects of D-W cycles. [ABSTRACT FROM AUTHOR]

Most previous studies have focused on the small strain stiffness of sedimentary soil, while little attention has been given to residual soils with different properties. Most studies also neglected the effects of the deviator stress, which is extensively involved in civil engineering. This note considers the effects of the deviator stress on the small strain stiffness of natural granite residual soil as established from resonant column tests performed under various stress ratios. Although increasing the stress ratio results in a greater maximum shear modulus for both natural and remolded residual soils, remolded soil is more sensitive to changes in the stress ratio, which highlights the effects of soil cementation. The data herein offers new insights to understand the stiffness of residual soil and other weathered geomaterials. [ABSTRACT FROM AUTHOR]