Search

Groups of connected ramets produced by clonal growth in plants are particularly susceptible to fragmentation in aquatic ecosystems. Both clonal fragment size and nutrient availability are likely to affect the competitive ability of clonal aquatic plants, but the effects of fragment size, nutrients, and competition on plant performance have rarely been studied in combination. We hypothesized that larger fragments have greater competitive ability and that this effect is greater when nutrients are lower. To test this and other interactive effects, we grew fragments of the widespread, floating, clonal pteridophyte Salvinia natans initially containing 1, 2, 3, or 6 ramets at two levels of nutrients with and without a co-occurring, floating pteridophyte, Azolla pinnata, for 7 weeks. Floating mass of S. natans was mostly higher and submerged mass lower at high than at low nutrients, summing to a 0–30 % increase in total mass with higher nutrients at different initial fragment sizes. The presence of A. pinnata reduced total mass of S. natans by 30–60%. In partial agreement with the hypotheses, response of S. natans to competition was less negative in larger fragments in the low nutrient treatment but did not vary consistently with initial fragment size in the high nutrient treatment. Results show that growth of aquatic clonal plants can be determined by complex interactions and suggest that eutrophication may increase the competitive ability of very small clonal fragments.

Colloid transfusion during surgical decompressive hemicraniectomy (DHC) to treat space-occupying cerebral infarction induced by middle cerebral artery (MCA) is controversial. A multicenter retrospective study was conducted to determine whether an increased colloid transfusion during surgery is associated with a lower incidence of postoperative pneumonia and better long-term outcomes after space-occupying cerebral infarction.Data from surgical DHC within 48 hours to treat space-occupying cerebral infarction that took place between November 30, 2013, and March 30, 2016, were collected in a multicenter chart. Univariate analysis, Spearman correlation, χUnivariate analysis showed that surgical duration and mRS were significantly different between the subjects older and younger than 60 years who underwent surgical DHC (P0.05). In the entire population studied, increased National Institutes of Health Stroke Scale was associated with a greater incidence of postoperative pneumonia (odds ratio [OR] 1.255, P = 0.003) and increased mRS (OR 1.229, P = 0.014). In the population older than 60 years, it was revealed that increased colloid transfusion was associated with a lower incidence of postoperative pneumonia (OR 0.761, P = 0.030) or better outcomes, as indicated with lower mRS (OR 0.837, P = 0.045).Our retrospective study demonstrated that there is a robust association between increased perioperative colloid transfusion and lower incidence of postoperative pneumonia and better outcomes among the patients older than 60 years after space-occupying cerebral infarction.

Clonal integration, i.e. resource sharing between interconnected ramets, can help clonal plants tolerate abiotic stress. However, few studies have directly examined the ecological significance of clonal integration in the ability of clonal plants to tolerate biotic stress such as herbivory. We grew clonal fragments of an invasive clonal plant Alternanthera philoxeroides, each consisting of an apical part (relatively young) and a basal part (relatively old), at two levels (low and high) of soil nitrogen (N). For each fragment, the apical part was subjected to either no herbivory or herbivory for 2 weeks by a specialist insect, Agasicles hygrophila, and was either connected with or disconnected from the basal part not subjected to herbivory. Herbivory in the apical part severely reduced leaf growth (leaf mass, leaf number or leaf area) and ramet production of both apical and basal parts, and increased root to shoot ratio of the apical part. Irrespective of herbivory and soil N, stem connection between the apical and the basal part decreased root to shoot ratio of the apical part, but did not change its growth measures. Meanwhile, connection increased stem N concentration of the apical part growing under high-N supply and decreased stem carbon (C) concentration of the apical part under low-N supply. By contrast, connection increased root to shoot ratio of the basal part, but reduced its leaf and ramet production. Connection also increased leaf and stem C concentrations of the basal part under low-N supply. Thus, clonal integration can be beneficial for the early development of young A. philoxeroides ramets, but not for their local adaptation to herbivory damage by A. hygrophila.

While valence-pure copper alkynyl nanoclusters show near-infrared TADF, the mixed-valence ones exhibit semiconductivity., We report herein that copper alkynyl nanoclusters show metal-core dependent properties via a charge-transfer mechanism, which enables new understanding of their structure–property relationship. Initially, nanoclusters 1 and 2 bearing respective Cu(i)15 (C1) and Cu(i)28 (C2) cores were prepared and revealed to display near-infrared (NIR) photoluminescence mainly from the mixed alkynyl → Cu(i) ligand-to-metal charge transfer (LMCT) and cluster-centered transition, and they further exhibit thermally activated delayed fluorescence (TADF). Subsequently, a vanadate-induced oxidative approach to in situ generate a nucleating Cu(ii) cation led to assembly of 3 and 4 featuring respective [Cu(ii)O6]@Cu(i)47 (C3) and {[Cu(ii)O4]·[VO4]2}@Cu(i)46 (C4) cores. While interstitial occupancy of Cu(ii) triggers inter-valence charge-transfer (IVCT) from Cu(i) to Cu(ii) to quench the photoluminescence of 3 and 4, such a process facilitates charge mobility to render them semiconductive. Overall, metal-core modification results in an interplay between charge-transfer processes to switch TADF to semiconductivity, which underpins an unusual structure–property correlation for designed synthesis of metal nanoclusters with unique properties and functions.

Copper-Nickel alloy pipes in marine engineering have been suffering severe seawater corrosion and erosion-corrosion. In this work, six kinds of Cu-Ni alloy pipes with different service lives delivered by two manufacturers were used to clarify the relationship between corrosion resistance and microstructure. The corrosion behaviors of the samples in 3.5 wt.% NaCl solution were studied by electrochemical measurements. Chemical composition, grain size distribution, crystallographic orientation, and grain boundary characterization distribution (GBCD) were investigated by energy-dispersive spectrometry (EDS), metallography and electron backscattered diffraction (EBSD) technology. There were no obvious differences in chemical composition and GBCD in contrast with size and uniformity of grains. Pipes with large grains and a broader grain size distribution had better corrosion resistance. It was also found that the accuracy of experimental data greatly depended on the quality of the sample surface in EBSD analysis. The scratches and contamination during sample preparation have a strong impact on the imaging quality and the calculation of GBCD.

The return of post-hemorrhagic shock mesenteric lymph (PHSML) induces pulmonary vascular endothelial barrier dysfunction, which results in acute lung injury. Activation of the apoptosis signal-regulated kinase 1 (ASK1) and p38 mitogen-activated protein kinase (p38 MAPK) pathway has been shown to trigger inflammatory responses. However, whether the ASK1-p38 MAPK pathway is involved in the PHSML-induced pulmonary endothelial barrier dysfunction remains unclear. In the present study, permeability changes of pulmonary capillaries were found in vivo, and activation of the ASK1-p38 MAPK pathway was determined in vitro. PMVEC barrier dysfunction was determined by measuring TEER. Furthermore, junctional and cytoskeletal protein expressions were analyzed. The results showed that hemorrhagic shock led to a marked increase in the permeability of pulmonary capillaries in vivo, which was markedly alleviated by PHSML drainage. In cultured pulmonary microvascular endothelial cells (PMVECs), PHSML reduced the endothelial barrier function accompanied by upregulated p-ASK1 and p-p38 MAPK protein expression, impaired the cytoskeletal protein structure, and down-regulated junction protein expression. These adverse effects were eliminated by applying either Trx1 (ASK1 inhibitor) or SB203580 (p38 MAPK inhibitor). These results indicated that the ASK1-p38 MAPK pathway mediates PHSML-induced pulmonary vascular endothelial barrier dysfunction during hemorrhagic shock.

We aimed to determine whether heart rate variability (HRV) was correlated to long-term outcome in patients who received mechanical thrombectomy (MT) under general anesthesia for emergent large vessel occlusion (ELVO). Data from 106 patients receiving MT under general anesthesia to treat ELVO between January 1, 2017 and December 31, 2019 were collected in a multicenter chart review. Univariate analysis, Chi-square test, and bivariate logistic regression were performed to assess the correlations between preoperative risk factors such as HRV and long-term outcome (as indicated by the modified Rankin score [mRS] at 90 days after MT). Bivariate logistic regression revealed that decreased LF/HF (low frequency/high frequency in HRV) ratio was correlated with unfavorable functional outcome as indicated by mRS ≥ 2 (odds ratio [OR], 0.650; 95% confidence interval [CI], 0.157–0.839; p = 0.018), and functionally dependent outcome as indicated by mRS ≥ 3 (OR, 0.704; 95% CI, 0.360–0.914; p = 0.021). It was also found that ELVO in the right anterior circulation was correlated with lower LF/HF ratio, as compared with ELVO in the contralateral side (p < 0.05). Our retrospective study demonstrated that worse outcome in patients with ELVO who received MT under general anesthesia induced autonomic changes and that decreased LF/HF ratio.

B cell hyperactivities are involved in the development of systemic lupus erythematosus (SLE). Toll-like receptor 7 (TLR7) in the B cells plays a pivotal role in the pathogenesis of SLE. Previous studies have focused on the intrinsic role of B cells in TLR7/MyD88 signaling and consequently on immune activation, autoantibody production, and systemic inflammation. However, a feasible treatment for this immune disorder remains to be discovered. The in vitro cellular response that have been studied likely plays a central role in the production of some important autoantibodies in SLE. We successfully used R848 to build a lupus-like B cell model in vitro; these B cells were overactivated, differentiated into plasma cells, escaped apoptosis, massively proliferated, and produced large amounts of autoantibodies and cytokines. In the present study, we found that TJ-M2010-5, a novel MyD88 inhibitor previously synthesized in our lab, seemed to inhibit the lupus-like condition of B cells, including overactivation, massive proliferation, differentiation into plasma cells, and overproduction of autoantibodies and cytokines. TJ-M2010-5 also induce B cells apoptosis. Furthermore, TJ-M2010-5 was found to remarkably inhibit NF-κB and MAPK signaling. In summary, TJ-M2010-5 might correct R848-induced lupus-like immune disorders of B cells by blocking the TLR7/MyD88/NF-κB and TLR7/MyD88/MAPK signaling pathways.

A catastrophic debris flow occurred in Zhouqu County, Gansu Province, Northwestern China, at midnight on 7 August 2010, resulting in damage to >390 buildings. Assessment of the vulnerability of buildings to debris flow hazards is essential to quantify the risk of debris flows. This paper presents a new family of physical vulnerability curves to assess the damage to buildings by debris flows based on extensive observed data of building damage and simulated debris flow intensity. A database of damaged buildings in the affected area of the Zhouqu debris flow was reconstructed. Numerical simulations using FLO-2D were conducted to determine the intensity of debris flows. A series of physical vulnerability empirical models for assessing the building damage has been proposed using various hazard intensity measures. Since buildings of different structural types have different resistances to debris flows, the vulnerability functions were developed for two typical types of structures, i.e. brick-concrete structures and reinforced concrete-frame structures. The proposed vulnerability functions are comparable with those for debris flows in Switzerland, Italy and Austria. The buildings may be completely destroyed when the debris flow depth is more than one half of the building height for both types of building structures.

Most dynamic response analyses of rock slopes only consider the vertical incidence of seismic waves. However, obliquely incident waves dominate in near-field seismic areas. This paper presents a new seismic input method that considers near-field oblique incidence based on mechanisms of artificial viscous boundaries and the influence of incident angle on the dynamic response of rock slopes. Three numerical model slopes with different slope angles of 30°, 45° and 60° are excited with the El Centro earthquake record assuming varying incident angles from 0° to 90°. The results show that the incident angle significantly affects the dynamic response of the slopes. The most damaging incident directions are approximately perpendicular to the slope surface, rather than in the vertical direction. The dynamic response of the slopes will be underestimated if only the vertical incidence is considered. The incident angle affects the reflection wave field in the slope and the areas affected by the reflection waves decrease with increasing slope angle. However, the predominant period of the response spectrum of the rock slopes is not sensitive to the incident angle and location. This study unveils the dynamic mechanism of earthquake-induced rock slides, which is of significance for earthquake hazard prevention.

New sensing and wireless technologies generate massive data. This paper proposes an efficient Bayesian network to evaluate the slope safety using large-quantity field monitoring information with underlying physical mechanisms. A Bayesian network for a slope involving correlated material properties and dozens of observational points is constructed. Keywords: Slope reliability, Monitoring information, Bayesian networks, Risk management, Value of information, Big data

This study evaluates the effects of root morphology and depth on the enhancement of induced suctions in soil grounds due to transpiration. Root morphology is idealized as uniform, triangular, parabolic and exponential distributions based on observations and the transpiration process is governed by the modified Richards equation. The study reveals that the exponential and triangular root networks enhance soil suctions more remarkably than the uniform and parabolic patterns. With the same total root amount, a root network with most of root amount concentrated in the superficial zone can induce significantly higher suction values than a root system distributed deeply.

The tidal volume setting as well as colloid transfusion during the peri-operative period after intracranial aneurysm is controversial. A multicenter retrospective study was conducted to determine whether or not an increased tidal volume setting and colloid transfusion are associated with poor outcomes and postoperative pulmonary complications after intracranial aneurysm.Data from endovascular coiling to treat intracranial aneurysms that took place between 30 March 2014 and 30 March 2016 were collected in a multicenter chart. The primary outcomes were better (defined as a Modified Rankin scores [MRS] ≤2) and worse outcomes (MRS ≥3). Secondary outcomes included pneumonia and non-pneumonia in patients with intracranial aneurysms. Univariate analysis, bivariate logistic regression, Spearman correlation, and a linear regression model were performed to account for the association between peri-operative risk factors and different outcomes.Bivariate logistic analysis showed that worse outcomes were correlated with height, Hunt and Hess scores (HHS), and Fisher grade (P 0.05). There was no significant association between colloid transfusion and worse outcomes and postoperative pneumonia (P 0.05). Postoperative pneumonia incidence was associated with increased height in a population with intracranial aneurysms (P 0.05). The Spearman correlation and a linear regression model suggested that increased height was significantly correlated with lower tidal volume setting (per unit of body weight; P 0.05).Decreased tidal volume with increased height, but not colloid transfusion, was independently associated with worse outcomes and postoperative pneumonia across a spectrum of risk profiles. These findings may help to improve practice decisions regarding tidal volume settings.

An assessment of soil properties at unsampled locations is a common requirement during the design of a geotechnical structure/system. Such an assessment is challenging due to inherent soil variability and the limited number of in situ tests currently available. Here we present a three-dimensional conditioned random field approach for the estimation of anisotropic soil resistance at unsampled locations based only on data from a limited number of cone penetration tests (CPT). The novelty of this work is that the measured CPT data at arbitrary locations can be combined with random field theory to update the estimated soil properties in three dimensions. The accuracy of the estimation can be improved significantly using the proposed method. A case study in Australia is conducted to illustrate the procedure and to assess the capability of the method. The results indicate that the mean values of the conditioned random fields are good estimates of the soil resistance at unsampled locations. The prediction error of the normalized cone penetration resistance is about 0.08 when there are only six CPT tests. A unique feature of this method is its ability to obtain high-resolution results of soil properties in three-dimensional space using a limited number of CPT tests.

In this work, 3D discrete element method modeling of drained shearing tests with gap-graded soils after internal erosion is carried out based on published experimental results. The erosion in the model is achieved by randomly deleting fine particles, mimicking the salt dissolving process in the experiments. The present model successfully simulates the stress–strain behavior of the physical test by employing the roll resistance and lateral membrane. The case without erosion shows a strain-softening and dilative response, while strain-hardening and contractive response starts to occur as the degree of erosion increases. The dilative to contractive transition is mainly caused by the increase in void ratio due to the loss of fine particles. The change from dilative behavior to contractive behavior is more abrupt for the specimen with larger fine particle percentage because the soil skeleton is mainly controlled by the fine particles instead of by the coarse soil particles. The transition from “fines in sand” to “sand in fines” might be associated with the rapid increasing in the contacts associated with fine particles in the specimen as the percentage of fine content increases. The erosion scenario based on the hydraulic gradient is also modeled by deleting the fine particles based on the ranking of the contact force. Compared with the scenario based on random deletion, the remaining fine particles for the erosion scenario based on the ranking of contact force are more dispersedly distributed, which might benefit the small strain stiffness but result in a smaller strength. This work provides some insights for better understanding the mechanism behind the internal erosion and the associated stress–strain behavior of soil. The gradient of the critical state line increases with more loss of fine particles denoting that the fine particles are helpful for holding the structure of the soils from larger deformation.

With global warming, glacial collapse chain disasters have frequently occurred in high-mountain areas. In particular, the ice avalanche-glacial debris flow/landslide-barrier lake-flood burst chain disaster caused the most serious consequences. Different from the general landslide dam consisted of rocks and soils, the landslide dam initiated by ice avalanches contains a considerable amount of ice. The appearance of ice will influence the overall performance of the landslide dam by melting, which may cause differential settlements, local weak zones, a more porous structure, and a lower erosion resistance of the landslide dam. Such changes in the erodibility and geometry of the landslide dam will further affect the dam overtopping and flood routing process, which have not been investigated yet and urgently require further study. Therefore, in this study, a preliminary study of the effects of different ice fractions of the landslide dam is conducted, which mainly involves changes in the dam erodibility, the dam geometry, the overtopping development, the final breach size, the process of downstream flood routing, etc. Results show that with the increasing amount of ice melting, the coefficient of soil erodibility and the soil void ratio increase significantly, implying a more erodible dam material and a looser dam structure. The melting of ice can also induce obvious dam settlement, which further results in an earlier dam burst and a shorter rescue time. With the increasing initial ice amount in the landslide dam, the overtopping process develops more rapidly, the breach expands greater both horizontally and vertically, the subsequent flood becomes larger, and the peak arrival time comes earlier.

The 2008 Wenchuan earthquake in Sichuan, China triggered numerous landslides in the stricken area. The loose landslide materials retained on mountain slopes and in gullies are prone to reactivation and may transform into debris flows in the rainy season. Nine years after the Wenchuan earthquake, debris flows are still active in Gaojiagou Ravine 16.5 km north of the epicentre. On 14 August 2010, 3 July 2011, 13 July 2013, and 6 July 2016, four large-scale debris flows were triggered by heavy storms in Gaojiagou Ravine. The four debris flows blocked the Minjiang River twice and caused severe damage to nearby villages and reconstruction sites. Several questions arise from these repeated debris flows. Did the level of triggering rainfall change in the four debris flow events? How did the initiation mechanism evolve over time? What are the differences in the runout characteristics in the four events? How did the check dams constructed in 2012 function in the subsequent debris flows? In this paper, we evaluated the loose deposit volumes in Gaojiagou Ravine before and after each of the four debris flows and the runout volumes, and analysed the triggering rainfall intensities, initiation mechanisms and runout characteristics of the four debris flows. The rainfall threshold for the debris flows in Gaojiagou Ravine increased over time, and the initiation mechanisms evolved from landslides to channel-bed failure, and subsequently to channel-bank erosion. The mobility of the debris flows decreased from 2010 to 2016 as the initiation positions moved lower and the particle size of the runout materials became coarser.

Interstitial cells of Cajal (ICC), especially myenteric interstitial cells of Cajal (ICC-MY), are key to gastrointestinal motility. However, their role in the pathogenesis of functional dyspepsia (FD) is unclear. Therefore, autophagy and differentiation of ICC-MY were investigated to elucidate the pathogenesis of gastric motility disorder in FD. FD model was induced by chronic stress via tail clamping in rats, which was assessed by the vital signs of rats, gastric emptying rate result, and histology. The ultrastructure of ICC-MY was examined using transmission electron microscope. In ICC-MY, changes in autophagic biomarkers (Beclin1 and LC3B) and differentiation biomarkers (c-kit and SCF) were evaluated with in situ hybridization, quantitative real time PCR, immunofluorescence, and Western blot, respectively. The FD model was successfully induced in rats, as evidenced by the abnormal vital signs (such as loss of appetite, liquid excreta, less activity, and slower weight gain), the decrease in gastric emptying rates, and little pathological change in gastric antrum tissue. Compared with the control group, FD caused increased organelle denaturation or reduction and increase in vacuolization. FD also promoted generation of autophagosomes in ICC-MY. Moreover, increased the expression of Beclin1 and LC3B, but decreased expression of c-kit and SCF. Excessive autophagy and abnormal differentiation of ICC-MY may contribute to the pathogenesis of gastric motility disorder in FD.

This paper presents a stochastic seismic analysis of geosynthetic-reinforced soil slopes (GRSS) using the probability density evolution method (PDEM). The combination of the uncertainties of seismic ground motions (SGM), soil properties and reinforcement parameters was considered. The stochastic SGM was generated from a random function based on the spectral representation method. The present method is proved to be more precise than the pseudo-static method and pseudo-dynamic method due to the consideration of the uncertainty of frequency spectrum of seismic excitations, and more efficient than the Monte Carlo simulation method for reducing the number of samples by 39 times. Without involving the stochastic earthquake, the result of the estimated performance would incur large errors since it greatly depends on the selected earthquakes, which may be one of the major reasons for GRSS failure. The slope displacement and the reinforcement strain occur at a relatively narrow region at the beginning, then increase and fluctuate intensively with large uncertainty, and finally become steady in the earthquake decay phase. The reinforcement length has a more substantial influence on the failure probability of the reinforcement than other parameters in the studied ranges. The reinforcement strain increases but the slope displacement decreases with the reinforcement length because of the variation of failure mechanisms.

Tapered piles have superior benefits over traditional cylindrical piles in resisting axial and lateral loads, being an economical alternative to cylindrical piles. When designing the tapered pile in soft or liquefiable soil, it is necessary to identify its buckling strengths. Notwithstanding, the buckling analysis of tapered piles considering nonlinear pile-soil interactions with geometric imperfections under combined loads has not been well established. This paper presents a non-prismatic beam-column element for nonlinear buckling analysis, considering nonlinear pile-soil interactions, combined external loads, and geometric imperfections, to robustly and efficiently simulate the buckling response of tapered piles. Unlike the discrete-spring stepped element (DSSE) model using an approximate stepwise modeling approach, analytical expressions for considering the axial and flexural rigidity of tapered section members are derived in the proposed element formulations to explicitly model the tapered sections. Several examples of buckling analysis are provided to validate the accuracy and efficiency of the proposed method. Parametric studies are performed to investigate the influences of Young’s modulus, taper ratio, initial geometric imperfection, and horizontal load on the buckling behavior of tapered piles with different boundary conditions. The critical buckling load of tapered piles is found to increase with increasing Young’s modulus and decreasing initial geometric imperfection and horizontal load. An optimal taper ratio of the tapered pile can be determined to carry the maximum axial load.

Study region Hong Kong, China. Study focus This paper aims to develop a flood analysis model to integrate the effects of multiple flooding triggers (i.e. rainfall, high sea levels and wave overtopping) during powerful tropical cyclones and investigate coastal flood hazards in an urban area at the street scale. The process of wave overtopping is properly estimated and integrated in a dual-drainage model in a maneuverable way as an inflow discharge hydrograph. The inundation during Typhoon Mangkhut, 2018, in Tseung Kwan O town center, a coastal community of Hong Kong, is taken as a case study. New hydrological insights for the region The inundation scenario in Tseung Kwan O town center during Tyhpoon Mangkhut is reproduced and comparison between different drainage conditions demonstrates the key role of drainage facilities in the mitigation of flooding induced by wave overtopping, although the varying sea level boundary could partly reduce the drainage efficiency. In addition, possible flood scenarios and pedestrian stability in flowing water upon the unfavorable combination of storm surge and astronomical tide, as well as the effectiveness of a 1.1 m wave wall are evaluated. The overtopping discharge, flooding severity and dangerous zones for pedestrian can be markedly reduced by the wave wall.

Landslides pose threats to the safety and property of people living in mountainous areas like Hong Kong. Dependence of landslide travel distance on initial conditions and travel routes has broad implications for assessing the landslide risks. In this study, the controlling topographic and geologic factors for travel distances of open hillslope landslides and channelized debris flows are examined based on the Enhanced Natural Terrain Landslide Inventory (ENTLI) in Hong Kong with 11,622 records during the period of 1984–2013. The mean values of the horizontal travel distances of open hillslope landslides and channelized debris flows are 24.1 and 86.3 m, respectively. Correlations combining horizontal travel distances, volumes and fall heights of open hillslope landslides have been derived. The horizontal travel distances (L) and fall heights (H) are closely related for both types of landslides. The use of the L/H ratio alone as a representation of natural terrain landslide mobility is not suggested. Because of the entrainment of loose materials, the travel distances of channelized debris flows are enlarged significantly on colluvium lands (with mean value of 142.6 m), compared with those on weathered mantles (with mean value of 74.2 m).

In the comproportionation reaction of CuII X2 and Cu0 with isopropylacetylene (iPr-C≡C-H), the ethynediide species C22- is generated via concomitant C-H/C-C bond cleavage of the iPr-C≡C-H precursor under moderate temperature to direct the formation of CuI mixed ethynediide/isopropylethynide nanoclusters (potentially explosive). The active ethynediide dianion C22- exhibits chameleon-like templating behavior to form C2 @Cum (m=6 (3, 4), 7 (2, 4), 8 (1)) central structural units for successive formation of {C22- ⊂Cu24 } (1, 2), {6 C22- ⊂Cu48 } (3), and {18 C22- ⊂Cu92 } (4) complexes. Bearing the highest C22- content, complex 4 features an unprecedented nanoscale Cu2 C2 kernel. Furthermore, 1-3 exhibit structure-controlled photoluminescence in the solid state.

This paper presents a coupled air–water flow analysis to evaluate the performance of a three-layer capillary barrier for controlling water infiltration into and gas emission from a waste containment system in a high precipitation environment, and to optimize combinations of local soil layers for barrier construction. A multi-phase flow model is proposed considering the movements of the gas and water phases simultaneously. The governing partial differential equations are solved in COMSOL Multiphysics software. Several combinations of lean clay with sand (CL), clayey sand with gravel (SC), silty sand with gravel (SM), sandy silt (ML), and well-graded gravel with silt (GW–GM) are examined. The rates of percolation water and gas emission are used as indicators to compare the performance of different combinations. A fine-grained surface soil layer reduces both water infiltration and gas emission due to its low desaturation rate and high water-retention capacity. The coarse middle layer plays a critical role, promoting capillary effects and hindering water infiltration during rainfall as well as draining any infiltrated water or percolated gas.

Rain-induced landslides are recognized as one of the most catastrophic hazards on hilly terrains. To develop strategies for landslide risk assessment and management, it is necessary to estimate not only the rainfall threshold for the initiation of landslides, but also the likely magnitudes of landslides triggered by a storm of a given intensity. In this study, the frequency distributions of both open hillside landslides and channelized debris flows in Hong Kong are established on the basis of the Enhanced Natural Terrain Landslide Inventory (ENTLI) with 19,763 records in Hong Kong up to 2013. The landslide magnitudes are measured in terms of the number, scar area, volume, or density of landslides. The mean values of the scar areas and volumes are 55.2 m2 and 102.0 m3, respectively, for the open hillside landslides and 91.3 m2 and 166.5 m3, respectively, for the channelized debris flows. Empirical correlations between the numbers, scar areas, and volumes of hillside landslides or channelized debris flows and the maximum rolling rainfall intensities of different periods have been derived. The maximum rolling 4- to 24-h rainfall amounts provide better predictions compared with those with the maximum rolling 1-h rainfall. Maximum rolling rainfall intensity-duration thresholds identifying the likely rainfall conditions that yield natural terrain landslides or debris flows of different magnitudes are also proposed. The initiation rainfall thresholds are identified as 75, 90, 100, 120, 150, 180, and 200 mm for the maximum rolling 1-, 2-, 4-, 6-, 8-, 12-, and 24-h rainfall, respectively.

We successfully employed bisphenol A and several different formyl-containing monomers as useful building blocks to construct a series of hydroxy-group-containing porous organic polymers in a sealed tube at high temperature. Fourier transform infrared and solid-state 13C CP/MAS NMR spectroscopy are utilized to characterize the possible structure of the obtained polymers. The highest Brunauer–Emmet–Teller specific surface area of the phenolic-resin porous organic polymers (PPOPs) is estimated to be 920 m2 g–1. The PPOPs exhibit a highest carbon dioxide uptake (up to 15.0 wt % (273 K) and 8.8 wt % (298 K) at 1.0 bar), and possess moderate hydrogen storage capacities ranging from 1.28 to 1.04 wt % (77 K) at 1.0 bar. Moreover, the highest uptake of methane for the PPOPs is measured as 4.3 wt % (273 K) at 1.0 bar.

A series of seven new complexes including silver-thiolate molecular clusters and their covalent supramolecular frameworks have been assembled from the silver carbide precursor Ag2 C2 using a C22- pre-templated approach. Herein, two prototype clusters Ag14 (SR)6 and CO3 @Agm (SR)10 (R=isopropyl, cyclohexyl or tert-butyl; m=18 or 20) are employed to construct cluster-based metal-organic frameworks of different dimensions. In particular, both new ellipsoidal tetradecanuclear molecular cluster compounds, namely, Ag14 (S-iPr)6 (CO2 CF3 )8 ⋅(DMSO)6 (two polymorphic forms 1, 2) and [Ag14 (S-Cy)6 (CO2 CF3 )8 (DMSO)4 ]⋅(DMSO)3 (3), and a cluster-based metal-organic framework {Ag3 [Ag14 (S-iPr)6 (CO2 CF3 )11 (H2 O)3 CH3 OH]⋅(H2 O)2.5 }n (4) have been isolated and structurally characterized. Furthermore, increased acidity of the reaction mixture afforded three carboxylate-templated cluster based frameworks: a chain-like compound {[HN(CH3 )2 CO]⋅[CO3 @Ag18 (S-tBu)10 (NO3 )7 (DMF)4 ]⋅DMF}n (5), as well as two layer-type compounds, namely, {Ag[CO3 @Ag20 (S-iPr)10 (CO2 CF3 )9 (CO2 HCF3 )(CH3 OH)2 ]}n (6) and {Ag2 [CO3 @Ag20 (S-Cy)10 (CO2 CF3 )10 (CO2 HCF3 )2 (H2 O)2 ]⋅(H2 O)3 ⋅(CH3 OH)3 }n (7) exhibiting sql-net characteristics. It is demonstrated that the C≡C2- pre-template, which draws several Ag+ ions together to form the C2 @Agn entity, plays an indispensable role in the syntheses of these compounds. Furthermore, covalent linkage of these nano-sized silver thiolate clusters from one- to three-dimensions revealed enormous potential for the future development of silver cluster-based frameworks.

Coastal wetlands soil organic carbon (SOC) plays an important role in global carbon sequestration, and exotic S. alterniflora affects the coastal ecosystem’s functions including SOC storage (SOCS). We investigated the vertical deep soil SOC distribution (0–300 cm) in Jiangsu salt marsh and estimated its changes. The results show that (1) exotic S. alterniflora increases the SOC, with higher densities (g kg −1 ) in both topsoil and deep soil in its colonized area, and subsequently increases the SOCS vertical depth (cm) distribution. Such influences become more prominent with time since the introduction of S. alterniflora . The deepest SOC distribution (180 cm) and the highest SOC content (2.14 ± 0.19 g kg −1 ) in the deep layer (50–300 cm) were found in the zones where S. salsa – S. alterniflora co-exist (SSI). The vertical SOC distribution in zones where multi-species co-exists is deeper than that in mono-species dominated zones; (2) The deep soil (100–300 cm) SOC accounts more than 50% of 0–300 cm SOC in Jiangsu salt marsh, suggesting that SOC content of deep soil should not be ignored when calculating the global soil carbon stock; (3) Total SOCS within 0–300 cm in Jiangsu salt marshes (107.84 × 10 6 m 2 ) is 84.90 × 10 10 g, of which 0–100 cm, 100–200 cm and 200–300 cm layer accounts for 38.25%, 30.72% and 31.03%, respectively. The size of the SOCS (0–300 cm) in the Jiangsu salt marshes relatively to the global biome (0.36 × 10 −6 ) is in a lower proportion of the range of salt marsh area to global biome area (0.89 × 10 −6 ). The S. alterniflora salt marsh contributes most of the SOCS in the 0–300 cm and 0–100 cm soils.

Heavy rainfall is a key cause of shallow landslides in red-bed terrains with steep topography and residual soils of degradable strength. In this study, laboratory model tests were carried out to examine the characteristics of rainfall infiltration, deformation, and failures of slopes in the red-bed area of Sichuan. The hydrological response and deformation of the slope soil during rainfall are addressed. Based on a modified Green–Ampt infiltration model, ponding along the bedrock surface is incorporated. A physically based model for shallow landslides caused by rainfall is developed. The theoretical analysis and the model test results indicate that the slope failures are related to erosion in the shallow soil layer and rainwater infiltration, particularly along preferential seepage channels. The process of rainfall-induced shallow landslides can be separated into three stages: erosion at the slope toe, tension crack formation at the slope crest, and shallow sliding. When initial underground water level is located at the bedrock surface or the preferential seepage flow quickly reaches the bedrock surface, it is easier for the soil slopes to slide along the bedrock surface than along the wetting front.

This paper presents a computational scheme for simulating debris-flow impact pressures on buildings in urban areas. The debris flow mobility is described using depth-averaged mass and momentum equations considering the erosion and deposition processes and changing solid concentrations. The total impact pressure consists of a dynamic impact pressure from the moving debris flow mixture and a static pressure from the deposited debris material. A target analysis area on Hong Kong Island, including a large number of buildings in that area, is characterized precisely using a three-dimensional high-resolution digital elevation model, and discretized into a grid of 5 m square cells with different bed material parameters. Using the model, the flow patterns of a large debris flow around nearly 20 buildings along the flow path and the impact pressures against the facades of these buildings are simulated. The buildings increase the flow depth and flow velocity as the debris tends to run up and deposit in front of the buildings and the flow path tends to be narrowed due to building blockage. The impact pressures are high on the building facades that face the main traversing path of the debris flow. Deposition of debris in front of the buildings increases the impact pressure.

Based on the Hilbert–Huang Transform and its marginal spectrum, an energy-based method is proposed to analyse the dynamics of earthquake-induced landslides and a case study is presented to illustrate the proposed method. The results show that the seismic Hilbert energy in the sliding mass of a landslide is larger than that in the sliding bed when subjected to seismic excitations, causing different dynamic responses between the sliding mass and the sliding bed. The seismic Hilbert energy transits from the high-frequency components to the low-frequency components when the seismic waves propagate through the weak zone, causing a nonuniform seismic Hilbert energy distribution in the frequency domain. Shear failure develops first at the crest and toe of the sliding mass due to resonance effects. Meanwhile, the seismic Hilbert energy in the frequency components of 3–5 Hz, which is close to the natural frequency of the slope, is largely dissipated in the initiation and failure processes of the landslide. With the development of dynamic failure, the peak energy transmission ratios in the weak zone decrease gradually. This study offers an energy-based interpretation for the initiation and progression of earthquake-induced landslides with the shattering-sliding failure type.

A geotechnical problem that involves several spatially correlated parameters can be best described using multivariate cross-correlated random fields. The joint distribution of these random variables cannot be uniquely defined using their marginal distributions and correlation coefficients alone. This paper presents a generic methodology for generating multivariate cross-correlated random fields. The joint distribution is rigorously established using a copula function that describes the dependence structure among the individual variables. The cross-correlated random fields are generated through Cholesky decomposition and conditional sampling based on the joint distribution. The random fields are verified regarding the anisotropic scales of fluctuation and copula parameters.

The aim of the present study was to identify whether sepsis-induced vascular hyporeactivity is associated with microcirculation disturbance and multiple organ injuries. The current study assessed the impact of resveratrol (Res) treatment on lipopolysaccharide (LPS) challenge mediated vascular hyporeactivity. Effects of Res treatment (30 mg/kg; i.m.) at 1 h following LPS stimulation (5 mg/kg; i.v.) on the survival time, mean arterial pressure (MAP), and maximal difference of MAP (ΔMAP) to norepinephrine (NE; 4.2 µg/kg) in mice were observed. The reactivity to gradient NE of isolated mesenteric arterioles and the association with the RhoA-RhoA kinase (ROCK)-myosin light chain phosphatase (MLCP) pathway were investigated by myography, and the signaling molecule protein levels were assessed using ELISA. Res treatment prolonged the survival time of mice subjected to LPS challenge, but did not prevent the LPS-induced hypotension and increase in ΔMAP. Res treatment and RhoA agonist U-46619 incubation prevented LPS-induced vascular hyporeactivity ex vivo, which were suppressed by incubation with ROCK inhibitor Y-27632. LPS-induced vascular hyporeactivity was not affected by the MLCP inhibitor okadaic acid incubation, but was further downregulated by the co-incubation of OA plus Y-27632. The inhibiting effect of Y-27632 on Res treatment was eradicated by incubation with U-46619. Furthermore, RhoA inhibitor C3 transferase did not significantly inhibit the enhancing role of Res treatment, which was further increased by U-46619 plus C3 transferase co-incubation. In addition, Res treatment eradicated the LPS-induced decreases in p-RhoA and p-Mypt1 levels and increases in MLCP levels. The results of the present study indicate that post-treatment of Res significantly ameliorates LPS-induced vascular hyporeactivity, which is associated with the activation of the RhoA-ROCK-MLCP pathway.

Root length, position and orientation on a soil slope are random but key elements when evaluating the stability of the vegetated slope. The main objectives of this note are to understand the effects of natural characteristics of vegetation on slope stability and to investigate how the variability in root features propagates to the variability in slope stability. A batch of randomly sized roots at given root densities are randomly positioned over a slope, and the stability of the slope for each combination of roots is evaluated. Traditional analysis considering uniform identical roots overestimates the factor of safety of the slope.

Although the Early Pleistocene Sus lydekkeri has been uncovered from several localities in northern China, the fragmental state of the specimens results the discussion on its taxonomic status and its relationship with European Sus strozzii . A nearly complete skull with mandible was unearthed in situ from upper Nihewan Formation at the horizon paleomagnetically dated 1.6 Ma during the excavation conducted in 2013 at Yangshuizhan in the Nihewan Basin in North China. The skull is better preserved than that from the Middle Pleistocene of the Peking Man Site, the type locality of S. lydekkeri . As the best preserved skull of S. lydekkeri , it bears some key characters previously little known, e.g. the developed canine flange, small and flattened tympanic bulla, and rather weak hamulus pterygoideus of pterygoid. The morphology and metric analyses show that the material from Nihewan belongs to S. lydekkeri instead of S. strozzii and the latter is a distinct species different from S. lydekkeri . The interaction between early human and suid started at least as early as the Early Pleistocene based on the fact that S. lydekkeri is present in many early human or Palaeolithic sites.

Carbon monoxide‑releasing molecule‑3 (CORM‑3), which is an exogenous carbon monoxide (CO) compound, slowly releases CO under physiological conditions; this exerts neuroprotective effects against incomplete ischemia/reperfusion injury. The objective of the present study was to investigate whether the administration of CORM‑3 protects against nucleotide‑binding oligomerization domain‑like receptor pyrin domain‑3 (NLRP3) inflammasome formation and neuronal pyroptosis in the hippocampus following hemorrhagic shock and resuscitation (HSR). To establish this, an HSR model was created. Hemorrhagic shock was induced in adult male Sprague‑Dawley rats under sevoflurane anesthesia by bleeding using a heparinized syringe to maintain a mean arterial pressure of 30±5 mmHg for 60 min. Resuscitation was performed by reperfusion of the blood and, if necessary, administering sterile saline to achieve the baseline arterial pressure. Following resuscitation, CORM‑3 (4 mg/kg) was injected via the femoral vein. Neuronal pyroptosis in the hippocampus, mitochondrial morphology, mitochondrial DNA (mtDNA), brain magnetic resonance imaging, expression levels of NLRP3 and the interaction of pro‑caspase‑1 and apoptosis‑associated speck‑like protein containing a CARD domain (ASC) were examined 12 h after HSR; locomotor activity was assessed 7 days after HSR. Compared with HSR‑treated rats, CORM‑3 administration resulted in a lower level of neuronal pyroptosis in the hippocampus, improved mitochondrial morphology, a lower mtDNA level, steadier levels of metabolites, decreased expression levels of NLRP3 and pro‑caspase‑1 interacting with ASC and enhanced locomotor activity. In conclusion, treatment with CORM‑3 ameliorated impairments of locomotor and exploratory activities in a rat model of HSR. The mechanism may be associated with the inhibition of mitochondrial DNA‑induced pyroptosis via improvements in cell metabolism.

Landslides threaten the safety of vehicles on highways. Nevertheless, a rigorous quantitative highway landslide risk assessment seems difficult. Using a case study in Hong Kong, this paper presents a method for quantitative risk assessment for highway landslides. The suggested method consists of three parts, i.e., analysis of annual failure probability of the slope, the spatial impact analysis and the consequence analysis. In the case study, the annual failure probability of the slope is analyzed based on historical failure data in Hong Kong. The spatial impact of the landslides is estimated based on empirical correlations with the geometry of the slope. The consequence is assessed based on probabilistic modeling of the traffic on the highway. Based on the suggested method, the annual failure probability of the slope, the distance from the slope and the road and the density of vehicles on the road can significantly affect the landslide risk and the suggested method can be used to quantify the effects of these factors. The suggested method can be also potentially used to analyze the highway landslide risk in other regions.

Barriers are commonly used to intercept landslide flows or debris flows. The presence of a barrier changes the flow condition and leads to a buildup of earth pressure in a zone behind the b...

Objective. To explore the ability of asiatic acid to interfere with the invasion and proliferation of breast cancer cells by inhibiting WAVE3 expression and activation through the PI3K/AKT signaling pathway. Methods. The MDA-MB-231 cells with strong invasiveness were screened by transwell assay, and plasmids with high expression of WAVE3 were constructed for transfection. The transfection effect and protein expression level of plasmids were verified by PCR and WB. The effects of asiatic acid on cell proliferation and invasion were investigated by flow cytometry. The xenografted tumor models in nude mice were established to study the antitumor activity of asiatic acid. Results. Asiatic acid significantly inhibited the activity of MDA-MB-231 cells, and the expression level of WAVE3 increased significantly in the tissue of ductal carcinoma in situ and was lower than that in the metastasis group. After plasmid transfection, the mRNA and protein expression of WAVE3 increased significantly in the cells. Asiatic acid at different concentrations had an impact on cell apoptosis and invasion and could significantly inhibit the expression of WAVE3, P53, p-PI3K, p-AKT, and other proteins. The T/C(%) of asiatic acid (50 mg/kg) for MDA-MB-231(F10) xenografted tumor in nude mice was 46.33%, with a tumor inhibition rate of 59.55%. Asiatic acid could significantly inhibit the growth of MDA-MB-231 (F10) xenografted tumors in nude mice (p<0.05). Conclusions. Asiatic acid interferes with the ability of breast cancer cells to invade and proliferate by inhibiting WAVE3 expression and activation and the mechanism of action may be related to the PI3K/AKT signaling pathway.

Flood damage has been extremely severe in recent decades and is responsible for a greater number of damaging events than any other type of natural hazard. Floods are anticipated to happen more frequently in the future because of climate change, unplanned rapid urbanization, change in land use pattern, poor watershed management and declining recharge of groundwater by extension of impermeable surfaces in urban areas. Therefore, assessment of flood consequence under large storms is an important issue. This paper quantifies the elements at risk in Hong Kong under large storm scenarios with rain intensities of 29 and 85% of the 24-h Probable Maximum Precipitation (PMP). The buildings affected were obtained by overlaying flood maps and building maps in a GIS environment. The numbers of buildings of all types and exposed individuals affected by the flood under the two storm scenarios were also quantified. The results indicate that residential buildings appear to be the most vulnerable among all structures and facilities in Hong Kong and thereby may lead to the highest affected population under the two rainfall scenarios. The western part of Hong Kong Island is more susceptible to flooding as a result of its steeper slope terrain and densely populated infrastructures. Enhanced flood risk assessment methods and improved understanding about flood risk will support decision makers in decreasing damage and fatalities.

The break of large landslide dam will trigger catastrophic flood hazard to the downstream area. To manage the flood risk, multiple mitigation measures are required, such as evacuation and removal of obstacles in the river channel. Design of these mitigation measures relies on the estimation of critical flood parameters, namely, peak discharges and stages along the river. However, uncertainties in outburst flood prediction and flood routing analysis have significant influence on the estimation of these flood parameters. Ignoring these uncertainties will undermine the reliability of the estimated flood parameters, which might lead to insufficient design of risk mitigation measures. To enhance the reliability of landslide dam break risk management, we quantify the influence of uncertainties in both landslide dam material erodibility and river channel roughness on the estimation of flood parameters. Successive Baige landslide dams on the Jinsha River in 2018 are investigated to show how the uncertainty quantification facilitates robust decision making for risk management.

A drum centrifuge accommodates a long soil model in its drum, hence models distributed geotechnical problems better than a beam centrifuge. A modular package has been designed for the HKUST 870 g-ton drum centrifuge to simulate overtopping and erosion of embankment dams. For the sake of space-saving and convenient operation, 1/6 of the drum model channel is designed as a fluid storage tank. The fluid storage tank is sealed by a top cover, and controlled by a fixed baffle and a movable baffle driven by a three-dimensional centrifuge actuator. After the drum centrifuge spins to the design speed, the movable baffle can be lifted by the actuator to release the fluid into the reservoir of the embankment. The rising rate of the water level can be controlled by adjusting the lifted height of the baffle. The embankment can then be overtopped. High-speed cameras and a PICV system will be employed to monitor the erosion or break process of the embankment. Pore pressure sensors are installed inside the embankment to measure the pore pressure response.

Landslide dams are typically formed by loose landslide deposits which can be vulnerable to overtopping failure. Subsequent flash flood can pose great threat to downstream area. Hong Kong is subject to subtropical weather and the terrain is hilly. Due to the changing climate, extreme rainfall is becoming more and more frequent which can cause a large number of landslides. Therefore, it is essential to evaluate possible landslide dam formation and failure process, especially on Hong Kong Island which is densely populated. In this paper, a physically-based distributed cell model, EDDA 2.0, is adopted which is capable to predict rainfall-induced landslides, debris flows, erosion and deposition process, and flash floods. Possible landslide dam formation and failure are predicted under an extreme rainfall condition (65% of the 24-h PMP, Probable Maximum Precipitation). Although the magnitude of the landslide and the landslide dam is not very large, the subsequent flash flood can pose much greater threat to people’s lives and properties especially in urban area such as Hong Kong Island where the population density is rather high.

Loss of fine particles or suffusion in soils induced by seepage is an important problem that may cause dam or dike failures. This paper aims to study the evolution mechanisms of suffusion i...

In shallow eutrophic lakes, benthic bioclastic deposits accumulate abundant organic carbon derived from macrophyte detritus. Taking the typical macrophyte-dominated Xukou Bay as the study area, field investigations were performed using sediment cores to evaluate benthic phytodetritus accumulation. Specifically, nutrient contents, TOC/TN ratios, pigmentation, and biodegradable compounds were measured as descriptive parameters. The results show that the benthic bioclastic deposit had accumulated abundant pigments, nutrients, and biodegradable compounds derived from macrophytes detritus. These were mainly localized in the top 15 cm of sediments. Nitrogen loading in the sediments was significantly higher than phosphorous loading, with a distinct spatial difference; the total nitrogen content ranged from 127.2-2092.8 mg·kg

Oxidative stress mediates the nerve injury during the pathogenesis of Alzheimer's disease (AD). Protecting against oxidative stress damage is an important strategy to prevent and treat AD. Di-Huang-Yi-Zhi (DHYZ) is a Chinese medicine used for the treatment of AD, but its mechanism remains unknown. This study is aimed to investigate the effect of DHYZ on HPC12 cells were treated with HThe results showed that DHYZ antagonized HThe present study suggested that DHYZ protected PC12 cells from H