By employing molecular dynamics simulations, a family of graphyne heterojunctions (GYHJs) made by two different graphynes (GYs) have been designed and prepared. The dependence of tunable properties ...of GYHJs, such as thermal conductivity, mechanical properties, interfacial thermal resistance and rectification, on the composition and type of GYHJs is determined. Upon changing the composition of a GYHJ, one can keep a constant value of its fracture strength (and/or Young's modulus), while tuning its thermal conductivity. The thermal conductivities of GYHJs in the zigzag direction are larger than those in the armchair direction, indicating GYHJs are anisotropic. By decreasing the percentage of γ-GY, the thermal conductivities of GYHJs γ-GY/6,6,12-GY/γ-GY and γ-GY/14-GY/γ-GY decrease linearly in the armchair direction, whereas they undergo three stages (first decrease, then keep a constant value, and finally increase) in the zigzag direction. Regarding the mechanical response, by increasing the percentage of the graphyne in the GYHJ which possesses smaller Young's modulus, the Young's modulus of the GYHJ decreases. These findings would provide significant insights into the potential applications of graphyne-family materials in nanodevices.
Groundwater is considered the best candidate for drinking water supply in the karst area. The groundwater water resources, however, are vulnerable to pathogenic microorganism contamination because of ...the typically thin soil layers overlying aquifers and the high permeability of the aquifer host rock, resulting in short residence times and low natural attenuation capacities. Until now, little attention has been paid to the critical environmental factors affecting the pathogenic microorganism contamination in soil-groundwater systems in the karst area.
In the study, orthogonality column experiments with controlling ambient temperatures, pH values of inlet water, and soil porosities were carried out to investigate the transport and lifespan of pathogenic microorganisms in the leachate of agricultural soils in the karst area of Yunnan province, China. The pathogenic indicators, i.e., total bacteria count (TBC) and total coliforms count (TCC), and hydrochemical parameters, i.e., pH and permanganate index (COD
) in the leaching water, were systematically monitored.
The results showed that bacteria including coliforms can survive for prolonged periods of time in karst soils. The soils overlying the karst rocks were unable to impede the bacteria from seeping into the groundwater. The soils, in turn, likely served as both reservoirs and incubators for pathogenic bacteria. The ambient temperature was the most predominant influential factor affecting both TBC and TCC. The bacteria concentrations were proportional to the temperature in the leachate. Therefore, more attention should be paid to temperature variations in protecting the water supply, particularly in the high-temperature period, such as during the summer months.
The connexin protein family consists of approximately 20 members, and is well recognized as the structural unit of the gap junction channels that perforate the plasma membranes of coupled cells and, ...thereby, mediate intercellular communication. Gap junctions are assembled by two preexisting hemichannels on the membranes of apposing cells. Non-junctional connexin hemichannels (CxHC) provide a conduit between the cell interior and the extracellular milieu, and are believed to be in a protectively closed state under physiological conditions. The development and characterization of the peptide mimetics of the amino acid sequences of connexins have resulted in the development of a panel of blockers with a higher selectivity for CxHC, which have become important tools for defining the role of CxHC in various biological processes. It is increasingly clear that CxHC can be induced to open by pathogen-associated molecular patterns. The opening of CxHC facilitates the release of damage-associated molecular patterns, a class of endogenous molecules that are critical for the pathogenesis of inflammatory diseases. The blockade of CxHC leads to attenuated inflammation, reduced tissue injury and improved organ function in human and animal models of about thirty inflammatory diseases and disorders. These findings demonstrate that CxHC may contribute to the intensification of inflammation, and serve as a common target in the treatments of various inflammatory diseases. In this review, we provide an update on the progress in the understanding of CxHC, with a focus on the role of these channels in inflammatory diseases.
Immune cells are present within the central nervous system and play important roles in neurological inflammation and disease. As relatively new described immune cell population, Innate Lymphoid Cells ...are now increasingly recognized within the central nervous system and associated diseases. Innate Lymphoid Cells are generally regarded as tissue resident and early responders, while conversely within the central nervous system at steady-state their presence is limited. This review describes the current understandings on Innate Lymphoid Cells in the central nervous system at steady-state and its borders plus their involvement in major neurological diseases like ischemic stroke, Alzheimer's disease and Multiple Sclerosis.
Cytoplasmic membrane-bound connexin 43 (Cx43) proteins oligomerize into hexameric channels (hemichannels) that can sometimes dock with hemichannels on adjacent cells to form gap junctional (GJ) ...channels. However, the possible role of Cx43 hemichannels in sterile and infectious inflammatory diseases has not been adequately defined due to the lack of selective interventions. Here we report that a proinflammatory mediator, the serum amyloid A (SAA), resembled bacterial endotoxin by stimulating macrophages to up-regulate Cx43 expression and double-stranded RNA-activated protein kinase R (PKR) phosphorylation in a TLR4-dependent fashion. Two well-known Cx43 mimetic peptides, the GAP26 and TAT-GAP19, divergently affected macrophage hemichannel activities in vitro, and differentially altered the outcome of lethal sepsis in vivo. By screening a panel of Cx43 mimetic peptides, we discovered that one cysteine-containing peptide, P5 (ENVCYD), effectively attenuated hemichannel activities, and significantly suppressed endotoxin-induced release of ATP and HMGB1 in vitro. In vivo, the P5 peptide conferred a significant protection against hepatic ischemia/reperfusion injury and lethal microbial infection. Collectively, these findings have suggested a pathogenic role of Cx43 hemichannels in sterile injurious as well as infectious inflammatory diseases possibly through facilitating extracellular ATP efflux to trigger PKR phosphorylation/activation.
The functional significance of extracellular Niemann-Pick disease type C2 protein (NPC2) is poorly defined. It is not known whether there is an association between plasma NPC2 and sepsis. Our ...exploratory, quantitative proteomic analysis showed a significant increase in the level of plasma NPC2 in moribund sepsis patients. Thus, we subsequently determined NPC2 concentration in plasma from healthy subjects, pneumonia patients and sepsis patients with comorbid pneumonia; and analyzed the association of plasma NPC2 with organ dysfunction and prognosis of sepsis patients. Our data shows that plasma NPC2 concentration was significantly higher in pneumonia and sepsis patients than healthy subjects, and was further increased in sepsis patients when the SOFA score reached 14. In addition, NPC2 concentration was significantly higher in patients that subsequently developed septic shock or died within 30 days. Moreover, NPC2 level showed the strongest association with the degree of renal dysfunction in sepsis patients. In moribund sepsis patients, however, NPC2 had highest correlation coefficient with indicators of coagulation anomaly. Based on these results, we conclude that the increase in plasma NPC2 in sepsis patients is associated with multiple organ failure, possibly results from a deficiency in renal clearance, and may serve as a prognostic marker for sepsis.
FOXP3
Regulatory T (Treg) cells play a key role in the maintenance of immune homeostasis and tolerance. Disruption of Foxp3 expression results in the generation of instable Treg cells and acquisition ...of effector T-cell-like function. Here we report that the E3 deubiquitinase USP21 prevents the depletion of FOXP3 at the protein level and restricts the generation of T-helper-1-like Treg cells. Mice depleted of Usp21 specifically in Treg cells display immune disorders characterized by spontaneous T-cell activation and excessive T-helper type 1 (Th1) skewing of Treg cells into Th1-like Treg cells. USP21 stabilizes FOXP3 protein by mediating its deubiquitination and maintains the expression of Treg signature genes. Our results demonstrate how USP21 prevents FOXP3 protein depletion and controls Treg lineage stability in vivo.
The Xiaojiang watershed in Luxi, Yunnan, is a typical rocky desertification area, in which karst groundwater pollution is severe and water resources are scarce. This article takes the watershed as an ...example and investigates the response mechanisms of surface karst spring water quality to agricultural pollution in rocky desertification areas. Specifically, the study was conducted as follows: (I) A total of 108 water samples from 54 sources were collected during the dry and wet seasons for analysis. (i) Principal component and correlation analyses identified the main pollution indicators in the soil surface karst zone of the area, including total bacterial count, total coliforms, COD, pH, and redox potential. (ii) It was also discovered that surface soil, impacted by agricultural activities, directly contributes to groundwater pollution in the soil surface karst zone. (II) Local soil was used to prepare soil columns under various conditions for simulation. The findings indicate: (i) Temperature significantly affects the surface karst springs, with higher temperatures leading to more pronounced water quality responses, increased enrichment of pathogen-microbiota indicators, and degraded water quality. (ii) Soil porosity substantially influences the water quality of surface karst springs. Increased porosity results in looser soil, more oxidizing conditions in the storage matrix, reduced pathogen-microbiota development, and consequently, less water pollution. This study offers theoretical and technical references for evaluating, monitoring, and issuing early warnings for pathogenic bacteria-microbiota pollution in groundwater in rocky desertification areas.
The frequent occurrence of urban flood disasters is a major and persistent problem threatening the safety of cities in China and elsewhere in the world. As this issue is so pervasive, exploring new ...methods for more effective risk prevention and urban flood disaster control is now being prioritized. Taking the case of the city of Zhengzhou as an example, this paper proposes using geological, hydrogeological, ecological, and environmental conditions together with appropriate engineering designs to address the problem of urban flooding. The strategy includes integrating urban sponge–hydrogeological conditions, ecological engineering, and the construction of deep underground water storage facilities. Field investigations, data collection and analysis, in situ observations, testing, and laboratory experiments, are analyzed to explain the formation mechanism and means to mitigate flood disasters in Zhengzhou. Our results suggest that the appropriate use of geological, ecological, and hydrogeological aspects, combined with effective engineering practices, can significantly improve the city’s flood control capacity. These measures can solve the problem of the “once-in-a-millennium” occurrence of torrential rain disasters such as the “720” torrential rainstorm that has affected the city of Zhengzhou.
To gain insight into the mechanical properties of crushed sugarcane tail leaves during stress relaxation, a self-made compression equipment was used in this study. The variation law of different ...factors on the stress relaxation process of crushed cane tail was explored and a stress relaxation model was established. The three-element and five-element generalized Maxwell models were selected to fit the regression analysis of the stress relaxation curve of the crushed cane tail. The comparison showed that the determination coefficient R2 of the five-element stress relaxation model was higher, and a three-factor and three-level response surface test was designed. Following the quadratic regression polynomial of the stress rapid decay time and the equilibrium elastic modulus, the final optimization results obtained are as follows: The moisture content was 60.8%, the crushing particle size was 45 mm, the feeding amount was 150 g, and the stress rapid decay time was 14.0 s. The equilibrium elastic modulus was 129 kPa.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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