Metabolic Nanoregulator Remodels Gut Microenvironment for Treatment of Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is strongly related to the occurrence of accumulation of toxic reactive oxygen species (ROS), inflammation of the mucosa, and an imbalance of intestinal microbes. However, current treatments largely focus on a single factor, yielding unsatisfactory clinical outcomes. Herein, we report a biocompatible and IBD-targeted metabolic nanoregulator (TMNR) that synergistically regulates cellular and bacterial metabolism. The TMNR comprises a melanin-gallium complex (MNR) encapsulated within a thermosensitive and colitis-targeting hydrogel, all composed of natural and FDA-approved components. The TMNR confers superior broad-spectrum antioxidant properties, effectively scavenging reactive oxygen species (ROS) and blocking inflammatory signaling pathways. The presence of Ga3+ in TMNR selectively disrupts iron metabolism in pathogenic microorganisms due to its structural resemblance to the iron atom. Additionally, incorporating a thermosensitive injectable hydrogel enables targeted delivery of TMNR to inflammatory regions, prolonging their retention time and providing a physical barrier function for optimizing IBD treatment efficacy. Collectively, TMNR effectively modulates the redox balance of inflamed colonic epithelial tissue and disrupts iron metabolism in pathogenic microorganisms, thereby eliminating inflammation and restoring intestinal homeostasis against IBD. Hence, this work presents a comprehensive approach for precise spatiotemporal regulation of the intestinal microenvironmental metabolism for IBD treatment.

Experimental study of CO2 capture by nanoparticle-enhanced 2-amino-2-methyl-1-propanol aqueous solution.

2-Amino-2-methyl-1-propanol (AMP) is often used as a moderator to enhance the CO2 capture capacity of absorbents due to its unique spatial site resistance structure, and relatively few studies have been conducted on the enhancement of AMP aqueous solutions by nanoparticles for CO2 capture. In order to investigate the effect of nanoparticles on the CO2 capture performance of AMP aqueous solution, different nanofluids were formulated in this paper using a two-step method, and a bubbling reactor and an oil bath were used as the experimental setup for absorption/desorption, and through comparative experiments, it was found that the type of nanoparticles, the solid content, and the different parameters have great influences on the CO2 absorption load and desorption rate. The experimental results show that the addition of TiO2 nanoparticles to the AMP base solution can accelerate the absorption-desorption mass transfer rate of CO2, and there exists an optimal solid content of 1 g L-1 (±1.0%, ±2.5%); after multiple absorption-desorption experiments, good cycling performance can still be achieved. The experimental results of the nanofluid-promoted mass transfer mechanism are also illustrated and analyzed in this paper.

Quantitative assessment of the risk of human activities on landscape fragmentation: A case study of Northeast China Tiger and Leopard National Park.

Risk assessment of human activities on landscape fragmentation in nature reserves can effectively balance the conflict between wildlife conservation and human development. However, previous studies had been unable to quantitatively assess the risk of human activities on landscape fragmentation. Thus, we constructed a risk assessment methodology to quantitatively assess the risk of different human activities on the Landscape Fragmentation Composite Index (LFCI) in the Northeast China Tiger and Leopard National Park (NCTLNP). First, we fitted the relationship curve between LFCI and different human activity factors based on the Generalized Additive Model (GAM) to determine the impact patterns of each factor on LFCI. Secondly, we identified impact risk areas of each human activity factor on LFCI by the location of threshold points in the curve and analyzed their spatiotemporal variation characteristics from 2015 to 2020. The results show that the relationship between LFCI and Land Use Intensity (LUI) showed an inverted "U" shape, the relationship with Population Density (POPD) showed a "rising-flat-rising" trend, and the relationship with Traffic Accessibility (TA) and Industrial and Mining Activity (IMA) showed a positive correlation after a flat interval. In addition, we found that the LUI and IMA impact risk areas were widely distributed and remained stable for five years. But the POPD impact risk area was mainly distributed around settlements and expanded by 6.6 % from 2015 to 2020. The TA impact risk area was distributed in strips and expanded by 16.38 % from 2015 to 2017 due to the construction of the G331 national road. And the joint impact risk area of these four factors expanded by 1.55 times in five years. Our research can provide a reference for ecological risk assessment under the impact of human activities on other nature reserves in the world.

Co-pyrolysis characteristics and kinetics of low metamorphic coal and pine sawdust.

Co-pyrolysis experiments with low metamorphic coal (LC) and pine sawdust (PS) were carried out in a fixed-bed pyrolysis reactor. The effect of biomass addition on the yield distribution and composition of the coal pyrolysis products was investigated. The pyrolysis behavior was studied by thermogravimetric analysis. The Coats-Redfern integral and Achar differential methods were used to study the mechanism functions and the kinetic parameters of the pyrolysis process of each sample. The results show that there is a synergistic effect on the co-pyrolysis and it is most pronounced at a PS mixing ratio of 30%, and it results in improved tar and gas yields. Part of the polycyclic aromatic hydrocarbons (PAHs) in the co-pyrolysis tar are converted into phenolic substances with a simple structure, which improves the quality of the tar. At the same time, the alcohols and acids in the PS and LC react to generate a large number of esters. The addition of PS shifted the LC pyrolysis process towards the low temperature region, lowering the pyrolysis temperature of the coal sample and increasing the pyrolysis rate of the sample. The main pyrolysis process of LC conforms to the second-order chemical reaction law with an activation energy of 35.93 kJ mol-1, and the main pyrolysis process of PS conforms to the one-dimensional diffusion parabolic law with an activation energy of 63.84 kJ mol-1, and the main pyrolysis process of LC and PS co-pyrolysis conforms to a second-order chemical reaction law with an activation energy of 86.19 kJ mol-1.

Application of biological activated carbon as a low pH biofilter medium for gas mixture treatment.

Packing material is a crucial component of a bioreactor as it is the microbial population's habitat. This study assessed potential improvements to current biofiltration processes by investigating use of a novel support medium. Biological activated carbon (BAC) with microorganisms growing on granular activated carbon can produce a novel medium in which both adsorption and biodegradation contribute to pollutants removal. Investigation of carbon characteristics demonstrated that BAC was an ideal packing medium for biofiltration. The application of the novel packing medium for gas mixture treatment was evaluated in a low pH biofilter. Results demonstrated that BAC biofilter obtained high removal efficiency for both H(2)S and toluene. The removal mechanisms of BAC were investigated after the biofilter operation and it demonstrated that the performance of the BAC system was mainly controlled by the additive contributions of two removal mechanisms - adsorption and biodegradation. This study also indicated the potential for simultaneous treatment of hydrogen sulfide and toluene at low pH condition.