This study was aimed to investigate the direction and magnitude of soil organic carbon (SOC) dynamics and the underlying mechanisms following agricultural abandonment in a subtropical karst area, ...southwest China. Two post-agriculture succession sequences including grassland (~10 years), shrubland (~29 years), secondary forest (~59 years) and primary forest with cropland as reference were selected. SOC and other soil physicochemical variables in the soil depth of 0-15 cm (representing the average soil depth of the slope in the studied area) were measured. SOC content in the grassland was not significantly elevated relative to the cropland (42.0 ± 7.3 Mg C ha
). SOC content in the shrubland reached the level of the primary forest. On average, SOC content for the forest was 92.6 ± 4.2 Mg C ha
, representing an increase of 120.4 ± 10.0% or 50.6 ± 4.2 Mg ha
relative to the cropland. Following agricultural abandonment, SOC recovered to the primary forest level in about 40 years with a rate of 1.38 Mg C ha
yr
. Exchangeable Ca and Mg were found to be the strongest predictors of SOC dynamics. Our results suggest that SOC content may recover rapidly following agricultural abandonment in the karst region of southwest China.
•The FE analysis with real corroded surface and monotonic tensile test to estimate the corrosion effects.•Quantitatively characterized the pitting parameters of the corroded steel surface.•Strain ...information on the corroded specimen surface was measured by using DIC technology.•The size parameter and its spatial parameter of critical pits to discuss the initiation law of the ductile cracks.
To study the effects of corrosion on the mechanical property of corroded steel, the standard monotonic tensile tests and corresponding finite element (FE) simulations with a modified fracture criterion to analyze the ductility degradation and fracture behaviour are systematically conducted on corroded steel specimens. The results showed that the degeneration of the mechanical property of corroded steel is mainly affected by the presence of single or double critical pits, the pit sizes (a or c), as well as the spatial distance (S) between the adjacent critical pits; the spatial parameter must be ignored during the interaction of the adjacent critical pits. The strength and deformation of the corroded steel rapidly degenerated because the critical pit led to the prematurely initiated ductile cracks, which were enhanced by the presence of double critical pits, as their interactions facilitated a faster accumulation of local plastic strains on the specimen; The initiation and propagation of local ductile cracks were closely associated with the critical pits because of the loss of sectional stiffness near the critical pits. By increasing the pit size and reducing the spatial parameter, the effect of the critical pit on local ductile crack evolution gradually increased, and the stress triaxiality was continuously elevated; thus, the equivalent deformation capacity defined by the equivalent plastic fracture strain (εplf) was reduced. Finally, an all-encomplete concept, including fracture initiation and propagation, was employed with the FE analysis to distinguish between the contributions of different pitting parameters on the ductility degradation of corroded steel.
Display omitted
•A non-invasive imaging technique was developed for real-time bacterial observation.•Depth for maximum bacterial retention shifted with time under unsaturated flow.•Bacterial ...retention decreased exponentially with travel distance at lower velocity.•Bacterial retention decreased multi-exponentially with distance at higher velocity.
This study investigated the transport and retention of bioluminescent Escherichia coli strain 652T7 under different pore water velocities (8.7 cm h−1 and 13.0 cm h−1) and pore water saturations (85% and 100%) utilizing a non-invasive, real-time bioluminescent imaging technique. Under saturated flow conditions, the concentrations of retained bioluminescent E. coli 652T7 decreased exponentially with distance from the source at the lower velocity but decreased non-exponentially at the higher velocity. Under unsaturated flow conditions, pore water velocity had no significant effect on bacterial breakthrough concentration; however, the concentrations of retained cells were maximal at a significant distance from the source (non-monotonic). The distance from source of the maximum concentration increased from 2.4-cm at 1.05 pore volumes to 4.3-cm at 3.15 pore volumes, indicating slow translation of bacterial down-gradient under unsaturated flow conditions. That conditions were modestly unfavorable to attachment at the solid-water interface (SWI) was indicated by deposition rate coefficients being greater (by a factor of four) for simulations versus experiments, and by significant repulsive barriers to attachment at both the SWI (260 kT) and the air–water interface (AWI, fully repulsive). The inferred slow translation under unsaturated flow conditions therefore reflects either accumulation without arrest in the secondary minimum at the SWI and/or capillary interaction at the AWI. This non-invasive bioluminescence method yielded real-time quantitative observation of bacterial distribution from source and demonstrated contrasting transport behaviors previously obtained solely via more laborious methods with limited spatio-temporal observation.
Abstract
As immune checkpoint inhibitors (ICIs) continue to advance, more evidence has emerged that anti-PD-1/PD-L1 immunotherapy is an effective treatment against cancers. Known as the programmed ...death ligand-1 (PD-L1), this co-inhibitory ligand contributes to T cell exhaustion by interacting with programmed death-1 (PD-1) receptor. However, cancer-intrinsic signaling pathways of the PD-L1 molecule are not well elucidated. Therefore, the present study aimed to evaluate the regulatory network of PD-L1 and lay the basis of successful use of anti-PD-L1 immunotherapy in acute myeloid leukemia (AML). Data for AML patients were extracted from TCGA and GTEx databases. The downstream signaling pathways of PD-L1 were identified via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The key PD-L1 related genes were selected by weighted gene co-expression network analysis (WGCNA), MCC algorithm and Molecular Complex Detection (MCODE). The CCK-8 assay was used to assess cell proliferation. Flow cytometry was used to determine cell apoptosis and cell cycle. Western blotting was used to identify the expression of the PI3K-AKT signaling pathway. PD-L1 was shown to be elevated in AML patients when compared with the control group, and high PD-L1 expression was associated with poor overall survival rate. The ECM-receptor interaction, as well as the PI3K-AKT signaling pathway, were important PD-L1 downstream pathways. All three analyses found eight genes (ITGA2B, ITGB3, COL6A5, COL6A6, PF4, NMU, AGTR1, F2RL3) to be significantly associated with PD-L1. Knockdown of PD-L1 inhibited AML cell proliferation, induced cell apoptosis and G2/M cell cycle arrest. Importantly, PD-L1 knockdown reduced the expression of PI3K and p-AKT, but PD-L1 overexpression increased their expression. The current study elucidates the main regulatory network and downstream targets of PD-L1 in AML, assisting in the understanding of the underlying mechanism of anti-PD-1/PD-L1 immunotherapy and paving the way for clinical application of ICIs in AML.
, as an indicator of fecal contamination, can move from manure-amended soil to groundwater under rainfall or irrigation events. Predicting its vertical transport in the subsurface is essential for ...the development of engineering solutions to reduce the risk of microbiological contamination. In this study, we collected 377 datasets from 61 published papers addressing
transport through saturated porous media and trained six types of machine learning algorithms to predict bacterial transport. Eight variables, including bacterial concentration, porous medium type, median grain size, ionic strength, pore water velocity, column length, saturated hydraulic conductivity, and organic matter content were used as input variables while the first-order attachment coefficient and spatial removal rate were set as target variables. The eight input variables have low correlations with the target variables, namely, they cannot predict target variables independently. However, using the predictive models, input variables can effectively predict the target variables. For scenarios with higher bacterial retention, such as smaller median grain size, the predictive models showed better performance. Among six types of machine learning algorithms, Gradient Boosting Machine and Extreme Gradient Boosting outperformed other algorithms. In most predictive models, pore water velocity, ionic strength, median grain size, and column length showed higher importance than other input variables. This study provided a valuable tool to evaluate the transport risk of
in the subsurface under saturated water flow conditions. It also proved the feasibility of data-driven methods that could be used for predicting other contaminants' transport in the environment.
•Establishing a synthetic approach to show the corrosive effect on corroded steel.•Fractal character of the critical pit to analyze the performance degradation of corroded steel.•Proposing the ...influence of the oxide passivation layer on material property of corroded steel.•The changes of corroded morphology and material property to study the fracture behaviors of corroded steel.
To analyze the effects of morphological characteristics on fracture behaviors of corroded steel, the morphology analysis, tensile test and corresponding finite element (FE) simulation were systematically performed to investigate the morphological evolution and the degradation of mechanical property of corroded steel. The results indicated that the size parameters (C and W) followed the Chi-square distribution, and the fractal character was obviously observed on corroded steel, especially for critical corrosion pit. The fractal dimension of critical corrosion pit (D*) was a key factor influencing the mechanical property and fracture behavior for corroded steel due to the advantage in systematacially reflecting the morphological characteristics, the agreement with the various mechanical parameters was obvious more than C or W of critical corrosion pit. Comparing the toughness parameters (α and η) among different corroded specimens, the effect of the oxide passivation layer on fracture toughness properties of corroded steel was revealed, and modified. Finally, the characterization of D* on fracture toughness parameters (α, η, effective plastic strain εpcritical and stress triaxiality T) of corroded steel was discussed
Early research indicates that cancer patients are more vulnerable to adverse outcomes and mortality when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Nonetheless, the ...specific attributes of SARS-CoV-2 in lung Adenocarcinoma (LUAD) have not been extensively and methodically examined.
We acquired 322 SARS-CoV-2 infection-related genes (CRGs) from the Human Protein Atlas database. Using an integrative machine learning approach with 10 algorithms, we developed a SARS-CoV-2 score (Cov-2S) signature across The Cancer Genome Atlas and datasets GSE72094, GSE68465, and GSE31210. Comprehensive multi-omics analysis, including assessments of genetic mutations and copy number variations, was conducted to deepen our understanding of the prognosis signature. We also analyzed the response of different Cov-2S subgroups to immunotherapy and identified targeted drugs for these subgroups, advancing personalized medicine strategies. The expression of Cov-2S genes was confirmed through qRT-PCR, with GGH emerging as a critical gene for further functional studies to elucidate its role in LUAD.
Out of 34 differentially expressed CRGs identified, 16 correlated with overall survival. We utilized 10 machine learning algorithms, creating 101 combinations, and selected the RFS as the optimal algorithm for constructing a Cov-2S based on the average C-index across four cohorts. This was achieved after integrating several essential clinicopathological features and 58 established signatures. We observed significant differences in biological functions and immune cell statuses within the tumor microenvironments of high and low Cov-2S groups. Notably, patients with a lower Cov-2S showed enhanced sensitivity to immunotherapy. We also identified five potential drugs targeting Cov-2S.
experiments revealed a significant upregulation of GGH in LUAD, and its knockdown markedly inhibited tumor cell proliferation, migration, and invasion.
Our research has pioneered the development of a consensus Cov-2S signature by employing an innovative approach with 10 machine learning algorithms for LUAD. Cov-2S reliably forecasts the prognosis, mirrors the tumor's local immune condition, and supports clinical decision-making in tumor therapies.
Dental pulp stem cells (DPSCs) are mesenchymal stem cells (MSCs) derived from dental pulp tissue, which have high self-renewal ability and multi-lineage differentiation potential. With the discovery ...of the immunoregulatory ability of stem cells, DPSCs have attracted much attention because they have similar or even better immunomodulatory effects than MSCs from other sources. DPSCs and their exosomes can exert an immunomodulatory ability by acting on target immune cells to regulate cytokines. DPSCs can also migrate to the lesion site to differentiate into target cells to repair the injured tissue, and play an important role in tissue regeneration. The aim of this review is to summarize the molecular mechanism and target cells of the immunomodulatory effects of DPSCs, and the latest advances in preclinical research in the treatment of various immune-mediated diseases, providing new reflections for their clinical application. DPSCs may be a promising source of stem cells for the treatment of immune-mediated diseases.
Bioretention technology, a low-impact development stormwater management measure, was evaluated for its ability to remove heavy metals (specifically cadmium, Cd) from urban stormwater runoff. Fine ...sand, zeolite, sand and quartz sand were selected as composite bioretention media. The effects of these materials on the removal efficiency, chemical forms, and accumulation and migration characteristics of Cd were examined in laboratory scale bioretention columns. Heretofore, few studies have examined the removal of Cd by bioretention. A five-step sequential extraction method, a single-contamination index method, and an empirical migration equation were used in the experiments. The average Cd removal efficiency of quartz sand approached 99%, and removal by the other media all exceeded 90%. The media types markedly affected the forms of Cd found in the columns as well as its vertical migration rate. The Cd accumulated in the four media was mainly in residual form; moreover, accumulation of Cd occurred mainly in the surface layer of the bioretention column. The migration depth of Cd in the four media increased with elapsed time, in the following sequence: zeolite>quartz sand>fine sand>sand. In contrast, the migration rate decreased with elapsed time, and the migration rate of Cd was lowest in sand (0.015m per annum over the first ten years). The comprehensive risk index analysis indicated that the risk arising from Cd discharge to surface water was “intermediate”, and that the degree of risk was lowest in sand, then quartz sand, zeolite, and fine sand in sequence. These results indicate that the adsorption and accumulation of Cd in the four media are more significant than the migration of Cd. In addition, the results of Cd risk assessment for the effluent indicate that each of the four media can serve as long-term adsorption material in a bioretention facility for purifying stormwater runoff.
•The bioretention media were adopted.•The variation of Cd were investigated.•The risk of Cd effluent was evaluated.
Transport of pathogenic bacteria from land surface to groundwater is largely influenced by rainfall intensity and geochemical and structural heterogeneities of subsurface sediments at different ...depths. It has been assumed that the change in rainfall intensity has different effects on bacterial transport as a function of soil depth. In this study, repacked and intact column systems were used to investigate the influences of pore water velocity on the transport of
652T7 through a loamy soil collected from varying soil depths. The soils differed in geochemical properties and soil structures. The concentrations of bacteria in soil and liquid samples were measured using plate counting method. The breakthrough percentages of
652T7 increased with pore water velocity at each depth in both intact and disturbed soils. Among the different soil depths, the largest velocity effect was observed for the transport through the top soil (0-5 cm) of both disturbed and intact soil profiles. This depth-dependent effect of pore water velocity was attributed to down gradients of soil organic matter (SOM) and iron oxide contents with depth because SOM and iron oxides were favorable for bacterial attachment on soil surfaces. In addition, less bacteria broke through the disturbed soil than through the intact soil at the same depth, and the pore water velocity effect was stronger with the disturbed than intact soils. Specifically, the maximum C/C
(i.e., ratio of effluent to influent concentration) doubled (i.e., from 0.36 to 0.76) in the 0-5 cm intact soil columns and tripled (i.e., from 0.16 to 0.43) in the 0-5 cm repacked soil columns. This structure-dependent effect of pore water velocity was attributed to larger pore tortuosity and a narrower range of pore sizes in the disturbed soil than in the intact soil. These findings suggest that change in pore water velocity could trigger bacterial remobilization especially in surface soils, where more bacteria are retained relative to deep soils.
PDF
