Modeling the spreading and remediation efficiency of slow-release oxidants in a fractured and contaminated low-permeability stratum.

Traditional remediation technologies cannot well remediate the low permeability contaminated stratums due to the limitation in the transport capacity of solute. The technology that integrates the fracturing and/or slow-released oxidants can be a new alternative, and its remediation efficiency remains unknown. In this study, an explicit dissolution-diffusion solution for the oxidants in control release beads (CRBs) was developed to describe the time-varying release of oxidants. Together with advection, diffusion, dispersion and the reactions with oxidants and natural oxidants, a two-dimensional axisymmetric model of solute transport in a fracture-soil matrix system was established to compare the removal efficiencies of CRB oxidants and liquid oxidants and to identify the main factors that can significantly affect the remediation of fractured low-permeability matrix. The results show that CRB oxidants can achieve a more effective remediation than liquid oxidants under the same condition due to the more uniform distribution of oxidants in the fracture and hence a higher utilization rate. Increasing the dose of the embedded oxidants can benefit the remediation to some extent, while at small doses the release time over 20 d has little impact. For extremely low-permeability contaminated stratums, the remediation effect can be significantly improved if the average permeability of the fractured soil can be enhanced to more than 10-7 m/s. Increasing the injection pressure at a single fracture during the treatment can enlarge the influence distance of the slow-released oxidants above the fracture (e.g., 0.3-0.9 m in this study) rather than below the fracture (e.g., 0.3 m in this study). In general, this work is expected to provide some meaningful guidance for the design of fracturing and remediating low permeability contaminated stratums.

Influence mechanism of thermally enhanced phase change on heat transfer and soil vapour extraction.

Thermal enhanced soil vapour extraction (T-SVE) is a remedial technique involving gas, aqueous, solid and nonaqueous phases along with mass and heat transfer. Interphase mass transfer of contaminants and water evaporation/condensation will cause the redistribution of phase saturation, eventually affecting the performance of T-SVE. In this study, a multiphase, multicompositional and nonisothermal model was developed to simulate the T-SVE treatment of contaminated soil. The model was calibrated using published data from the SVE laboratory and T-SVE field experiments. The temporal and spatial distributions of the contaminant concentrations in the four different phases, the mass transfer rates and the temperatures are presented to reveal the coupling interactions that occur between multiple fields during T-SVE. A series of parametric studies were carried out to investigate the effect of water evaporation and adsorbed/dissolved contaminants on the T-SVE performance. It was found that endothermic evaporation, exothermic condensation and the interaction between different removal paths of a contaminant played critical roles in the thermal enhancement of SVE. Ignoring them can result in significant differences in the removal efficiency values.

Comparative Study on International Research Hotspots and National-Level Policy Keywords of Dynamic Disaster Monitoring and Early Warning in China (2000-2021).

For more than 20 years, disaster dynamic monitoring and early warning have achieved orderly and sustainable development in China, forming a systematic academic research system and top-down policy design, which are inseparable from the research of China's scientific community and the promotion of government departments. In the past, most of the research on dynamic disaster monitoring and early warning focused on specific research in a certain field, scene, and discipline, while a few studies focused on research review or policy analysis, and few studies combined macro and meso research reviews in academia with national policy analysis for comparative analysis. It is necessary and urgent to explore the interaction between scholars' research and policy deployment, which can bring theoretical contributions and policy references to the top-down design, implementation promotion, and academic research of China's dynamic disaster monitoring and early warning. Based on 608 international research articles on dynamic disaster monitoring and early warning published by Chinese scholars from 2000-2021 and 187 national policy documents published during this period, this paper conducts a comparative analysis between the knowledge maps of international research hotspots and the co-occurrence maps of policy keywords on dynamic disaster monitoring and early warning. The research shows that in the stage of initial development (2000-2007), international research articles are few and focused, and research hotspots are somewhat alienated from policy keywords. In the stage of rising development (2008-2015), after the Wenchuan earthquake, research hotspots are closely related to policy keywords, mainly in the fields of geology, engineering disasters, meteorological disasters, natural disasters, etc. Meanwhile, research hotspots also focus on cutting-edge technologies and theories, while national-level policy keywords focus more on overall governance and macro promotion, but the two are gradually closely integrated. In the stage of rapid development (2016-2021), with the continuous attention and policy promotion of the national government, the establishment of the Ministry of Emergency Management, and the gradual establishment and improvement of the disaster early warning and monitoring system, research hotspots and policy keywords are integrated and overlapped with each other, realizing the organic linkage and mutual promotion between academic research and political deployment. The motivation, innovation, integration, and transformation of dynamic disaster monitoring and early warning are promoted by both policy and academic research. The institutions that issue policies at the national level include the State Council and relevant departments, the Ministry of Emergency Management, the Ministry of Water Resources, and other national ministries and commissions. The leading affiliated institutions of scholars' international research include China University of Mining and Technology, Chinese Academy of Sciences, Wuhan University, Shandong University of Science and Technology, and other institutions. The disciplines involved are mainly multidisciplinary geosciences, environmental sciences, electrical and electronic engineering, remote sensing, etc. It is worth noting that in the past two to three years, research and policies focusing on COVID-19, public health, epidemic prevention, environmental governance, and emergency management have gradually increased.

The relationship between dyslipidemia and inflammation among adults in east coast China: A cross-sectional study.

Objective: Dyslipidemia is one of the major public health problems in China. It is characterized by multisystem dysregulation and inflammation, and oxidant/antioxidant balance has been suggested as an important factor for its initiation and progression. The objective of this study was to determine the relationship between prevalence of dyslipidemia and measured changes in the levels of proinflammatory cytokines (IL-6, TNF-a, and MCP-1), thiobarbituric acid-reactant substances (TBARS), and serum total antioxidant capacity (TAC) in serum samples. Study design: A cross-sectional survey with a purposive sampling of 2,631 enrolled participants (age 18-85 years) was performed using the adult population of long-term residents of the municipality of east coast China in Fujian province between the years 2017 and 2019. Information on general health status, dyslipidemia prevalence, and selected mediators of inflammation was collected through a two-stage probability sampling design according to socioeconomic level, sex, and age. Methods: The lipid profile was conducted by measuring the levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) with an autoanalyzer. Dyslipidemia was defined according to National Cholesterol Education Program Adult Treatment Panel III diagnostic criteria, and patients with it were identified by means of a computerized database. Serum parameters including IL-6/TNF-a/MCP-1, TBARS, and TAC were measured in three consecutive years. Familial history, education level, risk factors, etc. were determined. The association between dyslipidemia and serum parameters was explored using multivariable logistic regression models. Sociodemographic, age, and risk factors were also investigated among all participants. Results: The mean prevalence of various dyslipidemia in the population at baseline (2017) was as follows: dyslipidemias, 28.50%; hypercholesterolemia, 26.33%; high LDL-C, 26.10%; low HDL-C, 24.44%; and hypertriglyceridemia, 27.77%. A significant effect of aging was found among all male and female participants. The mean levels of serum Il-6/TNF-a/MCP-1 were significantly higher in all the types of dyslipidemia among male participants. Female participants with all types of dyslipidemia but low HDL-C showed an elevation of IL-6 and MCP-1 levels, and those with dyslipidemias and hypercholesterolemia presented higher levels of TNF-a compared to the normal participants. The oxidative stress marker TBARS increased among all types of dyslipidemia except hypertriglyceridemia. All participants with different types of dyslipidemia had a lower total antioxidant capacity. Correlation analysis showed that cytokines and TBARS were positively associated with age, obesity, and diabetes mellitus, but not sex, sedentary leisure lifestyle, hypertension, and CVD/CHD history. The activity of TAC was negatively associated with the above parameters. Conclusions: The correlation between the prevalence of dyslipidemia and the modification of inflammation status was statistically significant. The levels of proinflammatory cytokines, oxidative stress, and antioxidant capacity in serum may reflect the severity of the lipid abnormalities. These promising results further warrant a thorough medical screening in enhanced anti-inflammatory and reduced oxidative stress to better diagnose and comprehensively treat dyslipidemia at an early stage.

Transient migration behavior of VOC vapor in layered unsaturated soils subjected to multiple time-dependent point pollution sources: Analytical study.

Predicting the migration behavior of volatile organic compounds (VOCs) vapor is essential for the remediation of subsurface contamination such as soil vapor extraction. Previous analytical prediction models of VOCs migration are mostly limited to constant-concentration nonpoint sources in homogeneous soil. Thus, this study presents a novel analytical model for two-dimensional transport of VOCs vapor subjected to multiple time-dependent point sources involving transient diffusion, sorption and degradation in layered unsaturated soils. Two representative time-dependent sources, i.e., an instantaneous source and a finite pulse source, are used to describe the short-term and long-term leakage. Results reveal that soil heterogeneity can cause pollution accumulation, especially in low-diffusivity capillary fringe. The assumption of an equivalent plane source from multiple point sources would significantly overestimate the vapor concentration and the contaminated range. The previous single point source model is no longer inapplicable when the relative distance and/or the release interval between sources is small, giving a strong interaction between multiple sources. Moreover, a faster vapor degradation rate or a higher groundwater level will reduce the area of vapor plume linearly. Hence, close attention should be paid to the time-variation characteristics of multiple sources, the vapor degradation and the groundwater level fluctuation in practice to facilitate soil remediation. The proposed model is a promising tool for addressing the above issue.

An analytical model for one-dimensional diffusion of degradable contaminant through a composite geomembrane cut-off wall.

A one-dimensional analytical model is proposed to analyze contaminant diffusion through a composite geomembrane cut-off wall (CGCW) composed of a geomembrane (GMB) and a bentonite cut-off wall (BCW). The model considers degradation process of contaminant and time-dependent inlet boundary condition which are common in engineering practices. Moreover, two limiting scenarios of the exit boundary condition (EBC) of CGCW for field conditions are taken into account, including the flushing and non-advective semi-infinite aquifer EBCs. The influence of boundary conditions and performance of CGCW are comprehensively investigated. The results show that the upper and lower limits of the mass flux of the exit face of CGCW can be obtained by the models with flushing EBC and the model with non-advective semi-infinite aquifer EBC, respectively. In addition, degradation has substantial influence on the contaminant migration, and smaller half-life in BCW results in smaller contaminant leakage. The performance of CGCW can be improved by embedding GMB at a proper location which is related to the type of contaminant and EBC. Furthermore, thickening HDPE GMB or adopting a coextruded EVOH GMB is efficient to improve the performance of CGCW. The present model can be used as an applicable tool for rational design of CGCW.

Is AAV-delivered IL-27 a potential immunotherapeutic for cancer?

Cytokines are one of the first immunotherapeutics utilized in trials of human cancers with significant success. However, due to their significant toxicity and often lack of efficacy, cytokines have given their spotlight to other cancer immunotherapeutics such as immune checkpoint inhibitors. Nevertheless, only a subset of cancer patients respond to checkpoint inhibitors. Therefore, developing a novel cytokine-based immunotherapy is still necessary. Among an array of cytokine candidates, IL-27 is a unique one that exhibits clear anti-tumor activity with low toxicity. Systemically delivered IL-27 by adeno-associated virus (AAV-IL-27) is very well tolerized by mice and exhibits potent anti-tumor activity in a variety of tumor models. AAV-IL-27 exerts its anti-tumor activity through directly stimulation of immune effector cells and systemic depletion of Tregs, and is particularly suitable for delivery in combination with checkpoint inhibitors or vaccines. Additionally, AAV-IL-27 can also be delivered locally to tumors to exert its unique actions. In this review, we summarize the evidence that support these points and propose AAV-delivered IL-27 as a potential immunotherapeutic for cancer.