Redox Active Zn@MOFs as Spontaneous Reactive Oxygen Species Releasing Antimicrobials.

The rapid development of antimicrobial resistance (AMR) among infectious pathogens has become a major threat and challenge in healthcare systems globally. A strategy distinct from minimizing the overuse of antimicrobials involves the development of novel antimicrobials with a mode of action that prevents the development of AMR microbial strains. Reactive oxygen species (ROS) are formed as a natural byproduct of the cellular aerobic metabolism. However, it becomes pathological when ROS is produced at excessive levels. Exploiting this phenomenon, research on redox-active bactericides has been demonstrated to be beneficial. Materials that release ROS via photodynamic, thermodynamic, and photocatalytic interventions have been developed as nanomedicines and are used in various applications. However, these materials require external stimuli for ROS release to be effective as biocides. In this paper, we report novel zinc-based metal organic framework (Zn@MOF) particles that promote the spontaneous release of active ROS species. The synthesized Zn@MOF spontaneously releases superoxide anions and hydrogen peroxide, exhibiting a potent antimicrobial efficacy against various microbes. Zn@MOF-incorporated plastic films and coatings show excellent, long-lasting antimicrobial potency even under continuous microbial challenge and an aging process. These disinfecting surfaces maintain their antimicrobial properties even after 500× surface wipes. Zn@MOF is also biocompatible and safe on the skin, illustrating its broad potential applications in medical technology and consumer care applications.

Self-Promoted Hydroxyl Radical Releasing Magnetic Zn@Fe Particles.

Semiconductor photocatalysts, such as TiO2 and ZnO, have garnered significant attention for their ability to generate hydroxyl radicals, offering various practical applications. However, the reliance on UV light to facilitate electron-hole separation for hydroxyl radical production poses limitations. In this study, a novel approach is presented utilizing Zn@Fe core/shell particles capable of generating hydroxyl radicals without external energy input. The generation process involves electron donation from Zn to O2, resulting in the formation of radical species .O2 -/H2O2, followed by Fe-catalyzed conversion of H2O2 into hydroxyl radicals through the Fenton reaction. The release of .OH imparts good antimicrobial and antiviral properties to the Zn@Fe particles. Furthermore, the inclusion of Fe confers magnetic properties to the material. This dual functionality holds promise for diverse potential applications for the Zn@Fe particles.

Multi-ecosystem services differently affected by over-canopy and understory nitrogen additions in a typical subtropical forest.

Obtaining a holistic understanding of the impacts of atmospheric nitrogen deposition on multiple ecosystem services of forest is essential for developing comprehensive and sustainable strategies, particularly in heavy N deposition regions such as subtropical China. However, such impacts remain incompletely understood, with most previous studies focus on individual ecosystem function or service via understory N addition experiments. To address this knowledge gap, we quantified the effects of over-canopy and understory N additions on multiple ecosystem services based on a 7-year large-scale field experiment in a typical subtropical forest. Our results showed continued over-canopy N addition with 50 kg ha-1 year-1 over a period of 4-7 years significantly increased plant nutrient retention, but did not affect the services of soil nutrient accumulation, water yield, C sequestration (in plants and soil), or oxygen release. There were trade-offs between the soil and plant on providing the services of nutrient accumulation/retention and C sequestration under over-canopy N addition. However, without uptake and retention of tree canopy, the trade-off between soil and plant were more weaken under the understory N addition with 50 kg ha-1 year-1 , and their relationships were even synergetic under the understory N addition with 25 kg ha-1 year-1 . The results suggest that understory N addition cannot accurately simulate the effects of atmospheric N deposition on multiple services, along with mutual relationships. Interestingly, the services of plant N, P retention, and C sequestration exhibited a synergetic increase under the over-canopy N addition but a decrease under the understory N addition. Our results also found tree layer plays a primary role in providing plant nutrient retention service and is sensitive to atmospheric N deposition. Further studies are needed to investigate the generalized effects of forest canopy processes on alleviating the threaten of global change factors in different forest ecosystems.

A Self-Immolative DNA Nanogel Vaccine toward Cancer Immunotherapy.

The development of precisely engineered vehicles for intracellular delivery and the controlled release of payloads remains a challenge. DNA-based nanomaterials offer a promising solution based on the A-T-G-C alphabet-dictated predictable assembly and high programmability. Herein, we present a self-immolative DNA nanogel vaccine, which can be tracelessly released in the intracellular compartments and activate the immune response. Three building blocks with cytosine-rich overhang domains are designed to self-assemble into a DNA nanogel framework with a controlled size. Two oligo agonists and one antigen peptide are conjugated to the building blocks via an acid-labile chemical linker. Upon internalization into acidic endosomes, the formation of i-motif configurations leads to dissociation of the DNA nanogel vaccine. The acid-labile chemical linker is cleaved, releasing the agonists and antigen in their traceless original form to activate antigen-presenting cells and an immune response. This study presents a novel strategy for constructing delivery platforms for intracellularly stimuli-triggered traceless release of therapeutics.

Spatial variation of soil seed banks along a gradient of anthropogenic disturbances in tropical forests on coral islands.

Poor regeneration of natural vegetation is a major factor contributing to the degradation of tropical coral islands. Soil seed banks (SSB) are important for maintaining the resilience of plant communities. However, the community characteristics and spatial distribution of SSBs and the controlling factors along human disturbance on coral islands are unclear. To fill this gap, we measured the community structure and spatial distributions of forest SSBs on three coral islands in the South China Sea, with varying degrees of human disturbance. The results showed that strong human disturbance increased the diversity, richness, and density of SSBs, as well as increased the richness of invasive species. With increased human disturbance, the heterogeneity pattern of SSBs spatial distribution changed from difference between forest east and west to forest center and edge. The similarity between the SSBs and above-ground vegetation also increased, and the distribution of invasive species extended from the edge to the central area of the forests, demonstrating that human disturbance limited the outward dispersal of seeds of resident species but increased the inward dispersal of seeds of invasive species. Interaction between soil properties, plant characteristics, and human disturbance explained 23-45% of the spatial variation of forest SSBs on the coral islands. However, human disturbance reduced the correlations of plant communities and spatial distribution of SSBs with soil factors (i.e., available phosphorus and total nitrogen) and increased the correlations of the community characteristics of SSB with landscape heterogeneity index, road distance, and shrub and litter cover. Resident seed dispersal on tropical coral islands might be enhanced by reducing building height, constructing buildings in down-wind locations, and preserving corridors that support animal movement among forest fragments.

Acid-Resistant and Physiological pH-Responsive DNA Hydrogel Composed of A-Motif and i-Motif toward Oral Insulin Delivery.

An acid-resistant DNA hydrogel that is stable in an extremely acidic environment with pH as low as 1.2 has not been reported before, largely due to the instability of DNA-hybridized structures. To achieve this, adenine (A)-rich and cytosine (C)-rich oligonucleotides are rationally designed and integrated to form copolymers with acrylamide monomers via free-radical polymerization. In an acidic environment (pH 1.2-6.0), the generated copolymers form a hydrogel state, which is cross-linked by parallel A-motif duplex configurations (pH 1.2-3.0) and quadruplex i-motif structures (pH 4.0-6.0) due to the protonation of A and C bases, respectively. Specifically, the protonated A-rich sequences under pH 1.2-3.0 form a stable parallel A-motif duplex cross-linking unit through reverse Hoogsteen interaction and electrostatic attraction. Hemi-protonated C bases under mildly acidic pH (4.0-6.0) form quadruplex i-motif cross-linking configuration via Hoogsteen interaction. Under physiological pH, both A and C bases deprotonated, resulting in the separation of A-motif and i-motif to A-rich and C-rich single strands, respectively, and thereby the dissociation of the DNA hydrogel into the solution state. The acid-resistant and physiological pH-responsive DNA hydrogel was further developed for oral drug delivery to the hostile acidic environment in the stomach (pH 1.2), duodenum (pH 5.0), and small intestine (pH 7.2), where the drug would be released and absorbed. As a proof of concept, insulin was encapsulated in the DNA hydrogel and orally administered to diabetic rats. In vitro and in vivo studies demonstrated the potential usage of the DNA hydrogel for oral drug delivery.

A hybrid multi-objective optimizer-based model for daily electricity demand prediction considering COVID-19.

Electricity consumption has been affected due to worldwide lockdown policies against COVID-19. Many countries have pointed out that electricity supply security during the epidemic is critical to ensuring people's livelihood. Accurate prediction of electricity demand would act a more important role in ensuring energy security for all the countries. Although there have been many studies on electricity forecasting, they did not consider the pandemic, and many works only considered the prediction accuracy and ignored the stability. Driven by the above reasons, it is necessary to develop an electricity consumption prediction model that can be well applied in the pandemic. In this work, a hybrid prediction system is proposed with data processing, modelling, and optimization. An improved complete ensemble empirical mode decomposition with adaptive noise is used for data preprocessing, which overcomes the shortcomings of the original method; a multi-objective optimizer is adopted for ensuring the accuracy and stability; support vector machine is used as the prediction model. Taking daily electricity demand of US as an example, the results prove that the proposed hybrid models are superior to benchmark models in both prediction accuracy and stability. Moreover, selection of input parameters is discussed, and the results indicate that the model considering the daily infections has the highest prediction accuracy and stability, and it is proved that the proposed model has great potential in real-world applications.

Dynamics of community structure and bio-thermodynamic health of soil organisms following subtropical forest succession.

Soil organisms play essential roles in maintaining multiple ecosystem processes, but our understanding of the dynamics of these communities during forest succession remains limited. In this study, the dynamics of soil organism communities were measured along a 3-step succession sequence of subtropical forests (i.e., a conifer forest, CF; a mixed conifer and broad-leaved forest, MF; and a monsoon evergreen broad-leaved forest, BF). The eco-exergy evaluation method was used as a complement to the classic community structure index system to reveal the holistic dynamics of the bio-thermodynamic health of soil organism communities in a forest succession series. Association between the self-organization of soil organisms, soil properties, and plant factors were explored through redundancy analyses (RDA). The results indicated that the biomass of soil microbes progressively increased in the dry season, from 0.75 g m-2 in CF to 1.75 g m-2 in BF. Microbial eco-exergy showed a similar pattern, while the community structure and the specific eco-exergy remained constant. Different trends for the seasons were observed for the soil fauna community, where the community biomass increased from 0.72 g m-2 to over 1.97 g m-2 in the dry season, but decreased from 3.94 g m-2 to 2.36 g m-2 in the wet season. Faunal eco-exergies followed a similar pattern. Consequently, the average annual biomass of the soil faunal community remained constant (2.17-2.39 g m-2) along the forest succession sequence, while the significant seasonal differences in both faunal biomass and eco-exergy observed at the early successional stage (CF) were insignificant in the middle and late forest successional stages (MF and BF). Both the dynamics of soil microbes and soil fauna were tightly correlated with tree biomass and with soil physicochemical properties, especially soil pH, moisture, total nitrogen, nitrate nitrogen, and organic matter content.

Identification of microRNAs in developing wheat grain that are potentially involved in regulating grain characteristics and the response to nitrogen levels.

BACKGROUND: MicroRNAs (miRNAs) play crucial roles in the regulation of plant development and growth, but little information is available concerning their roles during grain development under different nitrogen (N) application levels. Our objective was to identify miRNAs related to the regulation of grain characteristics and the response to different N fertilizer conditions. RESULTS: A total of 79 miRNAs (46 known and 33 novel miRNAs) were identified that showed significant differential expression during grain development under both high nitrogen (HN) and low nitrogen (LN) treatments. The miRNAs that were significantly upregulated early in grain development target genes involved mainly in cell differentiation, auxin-activated signaling, and transcription, which may be associated with grain size; miRNAs abundant in the middle and later stages target genes mainly involved in carbohydrate and nitrogen metabolism, transport, and kinase activity and may be associated with grain filling. Additionally, we identified 50 miRNAs (22 known and 28 novel miRNAs), of which 11, 9, and 39 were differentially expressed between the HN and LN libraries at 7, 17, and 27 days after anthesis (DAA). The miRNAs that were differentially expressed in response to nitrogen conditions target genes involved mainly in carbohydrate and nitrogen metabolism, the defense response, and transport as well as genes that encode ubiquitin ligase. Only one novel miRNA (PC-5p-2614_215) was significantly upregulated in response to LN treatment at all three stages, and 21 miRNAs showed significant differential expression between HN and LN conditions only at 27 DAA. We therefore propose a model for target gene regulation by miRNAs during grain development with N-responsive patterns. CONCLUSIONS: The potential targets of the identified miRNAs are related to various biological processes, such as carbohydrate/nitrogen metabolism, transcription, cellular differentiation, transport, and defense. Our results indicate that miRNA-mediated networks, via posttranscriptional regulation, play crucial roles in grain development and the N response, which determine wheat grain weight and quality. Our study provides useful information for future research of regulatory mechanisms that focus on improving grain yield and quality.

An AP2/ERF Gene, HuERF1, from Pitaya (Hylocereus undatus) Positively Regulates Salt Tolerance.

Pitaya (Hylocereus undatus) is a high salt-tolerant fruit, and ethylene response factors (ERFs) play important roles in transcription-regulating abiotic tolerance. To clarify the function of HuERF1 in the salt tolerance of pitaya, HuERF1 was heterogeneously expressed in Arabidopsis. HuERF1 had nuclear localization when HuERF1::GFP was expressed in Arabidopsis protoplasts and had transactivation activity when HuERF1 was expressed in yeast. The expression of HuERF1 in pitaya seedlings was significantly induced after exposure to ethylene and high salinity. Overexpression of HuERF1 in Arabidopsis conferred enhanced tolerance to salt stress, reduced the accumulation of superoxide (O2∙) and hydrogen peroxide (H2O2), and improved antioxidant enzyme activities. These results indicate that HuERF1 is involved in ethylene-mediated salt stress tolerance, which may contribute to the salt tolerance of pitaya.

Molecular Swings as Highly Active Ion Transporters.

Ions are transported across membrane mostly via carrier or channel mechanisms. Herein, a unique class of molecular-machine-inspired membrane transporters, termed molecular swings is reported that utilize a previously unexplored swing mechanism for promoting ion transport in a highly efficient manner. In particular, the molecular swing, which carries a 15-crown-5 unit as the ion-binding and transporting unit, exhibits extremely high ion-transport activities with EC50 values of 46 nm (a channel:lipid molar ratio of 1:4800 or 0.021 mol % relative to lipid) and 110 nm for K+ and Na+ ions, respectively. Remarkably, such ion transport activities remain high in a cholesterol-rich environment, with EC50 values of 130 (0.045 mol % relative to lipid/cholesterol) and 326 nm for K+ and Na+ ions, respectively.

Bamboo vs. crops: an integrated emergy and economic evaluation of using bamboo to replace crops in south Sichuan Province, China.

Based on long-term monitoring conducted in Chang-ning county, a pilot site of the 'Grain for Green Program' (GFGP), an integrated emergy and economic method was applied to evaluate the dynamic ecological-economic performance of 3 kinds of bamboo systems planted on sloping farmland. The results confirmed the positive effects of all 3 kinds of bamboo systems on water conservation and soil erosion control. The benefits gained progressively increased during the first 8 years after conversion, going from 4639 to 16127 EMyuan/ha/yr on average. All three bamboo plantations were much more sustainable than common agricultural crops planted on sloping land (CP) on both the short and long-term scales with their Emergy Sustainability Index (ESI) and Emergy Index for Sustainable Development (EISD), respectively, being 14.07-325.71 and 80.35-265.80 times that of CP. However, all 3 bamboo plantations had a Net Economic Benefit (NEB) less than that of CP during the first 8 years after conversion. Even with the government-mandated ecological compensation applied, the annual NEBECs of the Bambusa rigida (BR) and Phyllostachys pubescense (PP) plantations were, respectively, 3922.03 and 7422.77 yuan/ha/yr lower than the NEB of CP. Emergy-based evaluation of ecosystem services provides an objective reference for applying ecological compensation in strategy-making, but it cannot wholly solve the economic viability problem faced by all bamboo plantations. Inter-planting annual herbs or edible fungus, such as Dictyophora echinovolvata, within bamboo forests, especially in young bamboo plantations, might be a direction for optimizing bamboo cultivation that would improve its economic viability.

TNF-α promotes extracellular vesicle release in mouse astrocytes through glutaminase.

BACKGROUND: Extracellular vesicles (EVs) are membrane-contained vesicles shed from cells. EVs contain proteins, lipids, and nucleotides, all of which play important roles in intercellular communication. The release of EVs is known to increase during neuroinflammation. Glutaminase, a mitochondrial enzyme that converts glutamine to glutamate, has been implicated in the biogenesis of EVs. We have previously demonstrated that TNF-α promotes glutaminase expression in neurons. However, the expression and the functionality of glutaminase in astrocytes during neuroinflammation remain unknown. We posit that TNF-α can promote the release of EVs in astrocytes through upregulation of glutaminase expression. RESULTS: Release of EVs, which was demonstrated by electron microscopy, nanoparticle tracking analysis (NTA), and Western Blot, increased in mouse astrocytes when treated with TNF-α. Furthermore, TNF-α treatment significantly upregulated protein levels of glutaminase and increased the production of glutamate, suggesting that glutaminase activity is increased after TNF-α treatment. Interestingly, pretreatment with a glutaminase inhibitor blocked TNF-α-mediated generation of reactive oxygen species in astrocytes, which indicates that glutaminase activity contributes to stress in astrocytes during neuroinflammation. TNF-α-mediated increased release of EVs can be blocked by either the glutaminase inhibitor, antioxidant N-acetyl-L-cysteine, or genetic knockout of glutaminase, suggesting that glutaminase plays an important role in astrocyte EV release during neuroinflammation. CONCLUSIONS: These findings suggest that glutaminase is an important metabolic factor controlling EV release from astrocytes during neuroinflammation.

Integrated emergy and economic evaluation of lotus-root production systems on reclaimed wetlands surrounding the Pearl River Estuary, China.

Lotus (Newnbo nucifera, Gaertn) is the most important aquatic vegetable in China, with a cultivation history of over 3000 years. The emergy, energy, material, and money flows of three lotus root cultivation modes in Wanqingsha, Nansha District, Guangzhou, China were examined using Energy Systems Language models and emergy evaluation to better understand their ecological and economic characteristics on multiple spatial and temporal scales. The natural resource foundations, economic characteristics and sustainability of these modes were evaluated and compared. The results showed that although all three modes were highly dependent on purchased emergy inputs, their potential impacts as measured by the local (ELRL) and global (ELRW) environmental loading ratios were less than 1.2 and 0.7, respectively. The lotus-fish mode was the most sustainable with its emergy index of sustainable development (EISD) 2.09 and 2.13 times that of the pure lotus and lotus-shrimp modes, respectively. All three lotus-root production modes had superior economic viability, since their Output/Input ratio ranged from 2.56 to 4.95. The results indicated that agricultural systems may have different environmental impacts and sustainability characteristics at different spatial and temporal scales, and that these impacts and characteristics can be simultaneously explored using integrated emergy and economic evaluations.

The contact force between lunar-based equipment and lunar soil.

Lunar-based equipment plays a vital role in the exploration of the moon because it undertakes the tasks of moving, transporting, digging, and so on. In order to control the gait of lunar-based equipment more precisely and guarantee mobile stability, the contact mechanism between its foot and lunar soil is worthy of in-depth study. In this paper, a contact model is proposed to predict the stress, strain, and displacement both on the contact surface and in the lunar soil when the foot is under vertical load. The axial stress in the proposed contact model is verified through the experiment and its accuracy in the lunar equipment is verified through simulation. The error is in a reasonable range and the influence depth of load conforms to the experiment results. This paper provides a relatively accurate model to describe the contact force between the lunar-based equipment's foot and the lunar soil and will promote the research of lunar exploration.

Environmental risk of oil pipeline accidents.

Oil spills from pipeline accidents, caused by either material degradation or improper operation, can result in long-lasting environmental damage to soil and water. Assessing the potential environmental risks of these accidents is crucial for effective pipeline integrity management. This study calculates the accident rate using Pipeline and Hazardous Materials Safety Administration (PHMSA) data and estimates the environmental risk of pipeline accidents by factoring in the cost of environmental remediation. Results show that crude oil pipelines in Michigan pose the highest environmental risk, while Texas has the highest environmental risk for product oil pipelines. On average, crude oil pipelines have a higher environmental risk (56,533.6 US dollars·times·mile-1·year-1) compared to product oil pipelines (13,395.6 US dollars·times·mile-1·year-1). Factors affecting pipeline integrity management are also analyzed, including diameter, diameter-thickness ratio, and design pressure. The study finds that larger pipelines with higher pressures receive more attention during maintenance and thus pose a lower environmental risk. Furthermore, underground pipelines pose a much higher environmental risk than pipelines in other environments, and pipelines are more vulnerable in the early and mid-stages of operation. The leading causes of environmental risk in pipeline accidents are material failure, corrosion, and equipment failure. By comparing environmental risks, managers can better understand the strengths and weaknesses of their integrity management efforts.

An inventory of greenhouse gas emissions due to natural gas pipeline incidents in the United States and Canada from 1980s to 2021.

Natural gas is believed to be a critical transitional energy source. However, natural gas pipelines, once failed, will contribute to a large amount of greenhouse gas (GHG) emissions, including methane from uncontrolled natural gas venting and carbon dioxide from flared natural gas. However, the GHG emissions caused by pipeline incidents are not included in the regular inventories, making the counted GHG amount deviate from the reality. This study, for the first time, establishes an inventory framework for GHG emissions including all natural gas pipeline incidents in the two of the largest gas producers and consumers in North America (United States and Canada) from 1980s to 2021. The inventory comprises GHG emissions resulting from gathering and transmission pipeline incidents in a total of 24 states or regions in the United States between 1970 and 2021, local distribution pipeline incidents in 22 states or regions between 1970 and 2021, as well as natural gas pipeline incidents in a total of 7 provinces or regions in Canada between 1979 and 2021. These datasets can improve the accuracy of regular emission inventories by covering more emission sources in the United States and Canada and provide essential information for climate-oriented pipeline integrity management.

Greenhouse gas emissions from U.S. crude oil pipeline accidents: 1968 to 2020.

Crude oil pipelines are considered as the lifelines of energy industry. However, accidents of the pipelines can lead to severe public health and environmental concerns, in which greenhouse gas (GHG) emissions, primarily methane, are frequently overlooked. While previous studies examined fugitive emissions in normal operation of crude oil pipelines, emissions resulting from accidents were typically managed separately and were therefore not included in the emission account of oil systems. To bridge this knowledge gap, we employed a bottom-up approach to conducted the first-ever inventory of GHG emissions resulting from crude oil pipeline accidents in the United States at the state level from 1968 to 2020, and leveraged Monte Carlo simulation to estimate the associated uncertainties. Our results reveal that GHG emissions from accidents in gathering pipelines (~720,000 tCO2e) exceed those from transmission pipelines (~290,000 tCO2e), although significantly more accidents have occurred in transmission pipelines (6883 cases) than gathering pipelines (773 cases). Texas accounted for over 40% of total accident-related GHG emissions nationwide. Our study contributes to enhanced accuracy of the GHG account associated with crude oil transport and implementing the data-driven climate mitigation strategies.

Differential regulation of alternative promoters emerges from unified kinetics of enhancer-promoter interaction.

Many eukaryotic genes contain alternative promoters with distinct expression patterns. How these promoters are differentially regulated remains elusive. Here, we apply single-molecule imaging to quantify the transcriptional regulation of two alternative promoters (P1 and P2) of the Bicoid (Bcd) target gene hunchback in syncytial blastoderm Drosophila embryos. Contrary to the previous notion that Bcd only activates P2, we find that Bcd activates both promoters via the same two enhancers. P1 activation is less frequent and requires binding of more Bcd molecules than P2 activation. Using a theoretical model to relate promoter activity to enhancer states, we show that the two promoters follow common transcription kinetics driven by sequential Bcd binding at the two enhancers. Bcd binding at either enhancer primarily activates P2, while P1 activation relies more on Bcd binding at both enhancers. These results provide a quantitative framework for understanding the kinetic mechanisms of complex eukaryotic gene regulation.