Effects of train vibration load on the structure and hydraulic properties of soils.

Investigating the impact of train-induced vibration loads on soil hydraulic properties, this study conducted experiments using a self-designed indoor soil seepage platform that incorporates vibration loads. The experiments were complemented with scanning electron microscopy to analyze the influence of train-induced vibration loads on soil hydraulic conductivity and its evolutionary characteristics under different vibration frequencies. The experimental results indicated that as the vibration frequency increases from no vibration (0 Hz) to 20 Hz, the time required for the soil volumetric moisture content to reach its peak and stabilize decreases rapidly. However, after the vibration frequency exceeds 20 Hz, the rate at which the time required for the volumetric moisture content to reach its peak and stabilize decreases slows down. Furthermore, the soil pore water pressure increases with the increase in vibration frequency. At a vibration frequency of 80 Hz, the peak value of pore water pressure increases by 105% compared to the non-vibration state, suggesting that higher vibration frequencies promote the development and acceleration of soil pore moisture migration. Additionally, as the vibration frequency increases, the soil hydraulic conductivity initially experiences a rapid increase, with a growth rate ranging from 40.1 to 47.4%. However, after the frequency exceeds 20 Hz, this growth rate significantly decreases, settling to only 18.6% to 7.8%. When the soil was subjected to a vibration load, the scanning electron microscopy test revealed alterations in its pore structure. Micropores and small pores transformed into macropores and mesopores. Additionally, the microstructural parameters indicated that vibration load decreased the complexity of soil pores, thereby speeding up the hydraulic conduction process. This, in turn, affected the hydraulic properties of the soil and established a relationship between pore structure complexity and soil hydraulic properties.

Higher temperature sensitivity of retrogressive thaw slump activity in the Arctic compared to the Third Pole.

Climate change exacerbates permafrost thawing, resulting exceptionally intense retrogressive thaw slump (RTS) activity in the Arctic and Third Pole. However, comparative assessments of permafrost characteristics and RTS sensitivity under warming climate at both poles are still lacking. Here, the severity and temperature sensitivity of RTS were presented and compared using Tasselled Cap (TC) trend analysis of time-series Landsat images and Interferometric Synthetic Aperture Radar (InSAR) measurement. RTS has a more severe growth trend in the Arctic cold permafrost region, also with a deformation rate of approximately 70 mm/year and cumulative displacement up to 120 mm. In comparison, the deformation rate in the Third Pole is approximately 50 mm/year. The RTS severity in the Arctic is about 1.5 times higher than in the Third Pole, primarily owing to different sensitivities of cold and warm permafrost under warming climate. The intensification and vulnerability of RTS have global implications on climatological processes, hydrology, carbon release and ground stability, thus calling for attention and effective governance action.

Solving the Static Resource-Allocation Problem in SDM-EONs via a Node-Type ILP Model.

Space division multiplexing elastic optical networks (SDM-EONs) are one of the most promising network architectures that satisfy the rapidly growing traffic of the internet. However, different from traditional wavelength division multiplexing (WDM)-based networks, the problems of resource allocation become more complicated because SDM-EONs have smaller spectrum granularity and have to consider several novel network resources, such as modulation formats and spatial dimensions. In this work, we propose an integer linear programming (ILP) model without space lane change (SLC) that provides theoretically exact solutions for the problem of routing, modulation format, space, and spectrum assignment (RMSSA). Moreover, to more efficiently solve our model which is difficult to solve directly, we propose three exact algorithms based on model decomposition and evaluate their performance via simulation experiments, and we find that two of our exact algorithms can solve the model effectively in small-scale instances.

Hydrochemical characteristics and formation mechanisms of groundwater in west Zoucheng City, Shandong Province, China.

Groundwater is an important water source for domestic, industrial, and agricultural use in the western part of Zoucheng, China. Understanding its hydrochemical characteristics and formation mechanisms is important for the sustainable development and utilization of groundwater. In this study, 36 water samples were collected during the wet and dry seasons, respectively, and the hydrochemical components such as K+, Na+, Ca2+, Mg2+, Cl-, SO42-, HCO3-, NO3-, F-, TH, and TDS were analyzed. A graphical method, correlation analysis, and principal component analysis were applied to explore the hydrochemical characteristics and evolution mechanisms of groundwater in the study area. The results show that the orders of the anion and cation concentrations of karst groundwater and pore groundwater are Ca2+ > Na+ > Mg2+ > K+ and HCO3- > SO42- > Cl- > NO3- > F-, respectively. On the whole, the karst groundwater quality is better than the pore groundwater quality, which in turn is better than the surface water quality. In addition, water quality in the dry season is better than water quality in the wet season for all the three water sources. The hydrochemical types of groundwater are complex and changeable. Compared with dry seasons, HCO3 and SO4 type water increase during the wet seasons, while the Cl type and Mg type water decrease. Na type is significantly more prevalent in pore groundwater than in karst groundwater. The chemical formations of karst groundwater and pore groundwater in the dry and wet seasons are mainly affected by water-rock interactions and human activities.

Targeted delivery of celastrol to glomerular endothelium and podocytes for chronic kidney disease treatment.

The etiology of chronic kidney disease (CKD) is complex and diverse, which could be briefly categorized to glomerular- or tubular-originated. However, the final outcomes of CKD are mainly glomerular sclerosis, endothelial dysfunction and injury, and chronic inflammation. Thus, targeted delivery of drugs to the glomeruli in order to ameliorate glomerular endothelial damage may help alleviate CKD and help enrich our knowledge. The herb tripterygium wilfordii shows therapeutic effect on kidney disease, and celastrol (CLT) is one of its active ingredients but with strong toxicity. Therefore, based on the unique structure and pathological characteristics of the glomerulus, we designed a targeted delivery system named peptides coupled CLT-phospholipid lipid nanoparticles (PC-PLNs) to efficiently deliver CLT to damaged endothelial cells and podocytes in the glomerulus for CKD treatment and research. PC-PLNs could effectively inhibit inflammation, reduce endothelial damage, alleviate CKD severity, and reduce the toxicity of CLT. We also studied the mechanism of CLT in the treatment of nephropathy and found that CLT can increase the level of NO by increasing eNOS while inhibiting the expression of VCAM-1, thus provides an anti-inflammatory effect. Therefore, our study not only offered an efficient CKD drug formulation for further development, but also provided new medical knowledge about CKD. Electronic Supplementary Material: Supplementary material (attached with all the supporting tables and figures mentioned in this work) is available in the online version of this article at 10.1007/s12274-021-3894-x.

Collagenase-loaded pH-sensitive nanocarriers efficiently remodeled tumor stroma matrixes and improved the enrichment of nanomedicines.

The dense extracellular matrix (ECM) in tumor tissue severely hinders the penetration and enrichment of antitumor nanomedicines, which could significantly affect their efficiency. In this study, we used pH-sensitive nanocarriers loaded with collagenase (Col) to remold the tumor microenvironment (TME). Furthermore, we combined the collagenase delivery system with a nanomedicine to improve its penetration and enrichment in the tumor, thereby improving efficacy. We synthesized acetalated dextran (Ace-DEX) with an ideal pH-sensitivity as the carrier material of collagenase. Under mild preparation conditions, collagenase was loaded into Ace-DEX nanoparticles (NPs) with a high loading capacity (>4%) and remained highly active (>90%). Col-carrying NPs (Col-NPs) significantly reduced the tumor collagen content by 15.1%. Pretreatment with Col-NPs increased the accumulation of doxorubicin (DOX)-loaded liposome (DOX-Lipo) in the tumor by 2.8-fold. There were no safety concerns as the Col-NP showed no significant toxicity and reduced Col-induced damage to healthy tissues. Additionally, the number of circulating tumor cells remained unchanged after Col-NP treatment, suggesting no increased risk of tumor metastasis. Because the Col-NP acts essentially independent of the subsequent treatment, it has considerable potential for enhancing many existing delivery systems and drugs for cancer treatment. It may also be used for treating other collagen-related diseases.

Assessment of the impact of natural and anthropogenic activities on the groundwater chemistry in Baotou City (North China) using geochemical equilibrium and multivariate statistical techniques.

The rapid development of urbanization and agriculture poses serious impacts on groundwater in arid and semi-arid areas, which typically have high groundwater depletion rates. In this study, chemical and isotopic analyses combined with different data interpretation methods (diagrams, bivariate analyses, principal component analysis (PCA), and hierarchical cluster analysis (HCA)) were used to identify the major factors controlling groundwater chemistry in an arid and semi-arid region of North China. Sixty-four groundwater samples (35 from unconfined aquifer, 29 from confined aquifer) were collected in Baotou City, North China, and 17 chemical variables were detected for each sample. The complex hydrochemical types in unconfined groundwater (e.g., HCO3-Ca·Mg, HCO3·Cl-Na·Mg, SO4-Na·Mg, and Cl·SO4-Na types) may be related to anthropogenic activities, while the main hydrochemical types in confined groundwater are HCO3-Ca·Mg, HCO3-Na·Mg, HCO3·Cl-Na·Ca, SO4·HCO3-Na·Mg, and Cl·SO4-Na types. Three component models for unconfined and confined groundwater were revealed using PCA, which explained approximately 79.69% and 80.68% of the data variance, respectively, providing a deeper insight into groundwater composition controlled by geochemistry and anthropogenic activities. Three clusters were yielded from HCA. The factors and identified clusters were verified with hydrochemical investigations. Among the natural factors, the main hydrochemical processes involve the dissolution of various minerals (halite, gypsum, feldspar, fluorite, mirabilite, biotite, dolomite, and calcite), cation exchange, evaporation, and mixing. The anthropogenic factors include domestic sewage intrusion and agricultural activities, which are most likely to lead to further declines in groundwater quality. These findings may be useful for improving groundwater resource management for sustainable development in arid and semi-arid areas.

Gas and liquid permeability in the variably saturated compacted loess used as an earthen final cover material in landfills.

Landfill final covers are crucial to mitigating both the emission of landfill gases and surface water infiltration into solid wastes. Loess that is widely distributed in Northwest China has been transformed into earthen final cover (EFC), although not yet on a large scale. There remains a need for laboratory bench-testing in assessing the performance of this loess as an EFC material, particularly with respect to gas and liquid permeability. To evaluate gas and liquid permeability in the variably saturated loess at the laboratory scale, loess specimens with various resultant dry densities and post-compaction water contents were prepared. Laboratory tests were performed including constant gas pressure-gradient tests and wetting tests in a step-wise fashion to measure gas and liquid permeability as well as water retention behaviours. Large differences were found between intrinsic permeability to gas and liquid, and an empirical power relationship was proposed to characterize the measured intrinsic permeability to gas and liquid relative to the void ratio. The data of relative gas permeability as a function of liquid saturation plotted nearly along a single curve for all dry densities; this was also the case for the relative liquid permeability. Based on the regression results of water retention curves, the measured relative gas permeability values were well described by the van Genuchten-Mulaem (vG-M) model, and a certain difference between the relative liquid permeability evaluated by the vG-M model and the modified Childs and Collis-George equation. An unique relationship was found between the ratio of liquid to gas permeability and liquid saturation for all dry densities, in a range of residual liquid to gas saturation. An empirical model was proposed to efficiently describe gas and liquid permeability of the compacted loess at various liquid saturations and dry densities as well as the data of the loam from another experimental program.

Co-delivery of p38α MAPK and p65 siRNA by novel liposomal glomerulus-targeting nano carriers for effective immunoglobulin a nephropathy treatment.

Glomerulonephritis related renal failure is a frequent cause of end-stage renal disease, and immunoglobulin A nephropathy (IgAN) is the most frequent type of primary glomerulonephritis. As damage induced by IgAN mostly attributes to inflammation responses, inhibiting inflammation in glomerulus can protect normal renal function and delay the onset of renal failure. Hence, reducing levels of p38 MAPK and p65 which are essential regulators in p38 MAPK and NF-κB related inflammation responses could be effective against IgAN. Here, we rationally designed and constructed size- and surface charge- dependent glomerulus-targeting liposomal nanoparticles which are loaded with both p38α MAPK and p65 siRNA. Experiments show that our nanoparticles successfully crossed fenestrated endothelium, accumulated in mesangial cells and endothelial cells, efficiently silenced p38α MAPK and p65 genes, and eventually alleviated proteinuria, inflammation and excessive extracellular matrix deposition in mouse IgAN models. This siRNA co-delivery system thus represents a promising treatment option for IgAN and offers a versatile platform for other glomerular problems. Our work also highlights a novel strategy of glomerulus-targeting and an encouraging therapeutic route for other inflammatory diseases.

Geochemical factors controlling the occurrence of high-fluoride groundwater in the western region of the Ordos basin, northwestern China.

Hydrogeochemistry and isotope hydrology were carried out to investigate the spatial distribution of fluoride (F-) and the mechanisms responsible for its enrichment in the western region of the Ordos basin, northwestern China. Sixty-two groundwater samples from the unconfined aquifer and fifty-six from confined aquifer were collected during the pre-monsoon (June 2016). Over 77% of groundwater samples from the unconfined aquifer (F- concentration up to 13.30 mg/L) and approximately 66% from confined aquifer (with a maximum F- concentration of 3.90 mg/L) exhibit F- concentrations higher than the Chinese safe drinking limit (1.0 mg/L). High-F- groundwater presents a distinctive hydrochemical characteristic: a high pH value and HCO3- concentration with Ca-poor and Na-rich. Mineral dissolution (e.g., feldspar, calcite, dolomite, fluorite), cation exchange and evaporation in the aquifers predominate the formation of groundwater chemistry, which are also important for F- enrichment in groundwater. Mixing with unconfined groundwater is a significant mechanism resulting in the occurrence of high-F- groundwater in confined aquifer. These findings indicate that physicochemical processes play crucial roles in driving F- enrichment and that may be useful for studying F- occurrence in groundwater in arid and semi-arid areas.