Formation Potential Research Articles

Licochalcone A decreases cancer cell proliferation and enhances ferroptosis in acute myeloid leukemia through suppressing the IGF2BP3/MDM2 cascade.

Licochalcone A (Lico A), a naturally bioactive flavonoid, has shown antitumor activity in several types of cancers. However, few studies have focused on its effect on acute myeloid leukemia (AML). Cell viability and colony formation potential were detected by CCK-8 assay and colony formation assay, respectively. Cell cycle distribution and apoptosis were assessed by flow cytometry. Ferroptosis was assessed by measuring reactive oxygen species (ROS), lipid ROS, malondialdehyde (MDA), and glutathione (GSH). Protein expression levels were determined by immunoblotting and immunohistochemistry (IHC), and mRNA expression was detected by real-time qPCR. The m6A modification of MDM2 mRNA was verified by methylated RNA immunoprecipitation (MeRIP) assay, and the interaction of IGF2BP3 and MDM2 mRNA was analyzed by RIP assay. Actinomycin D was used to evaluate mRNA stability. The efficacy of Lico A in vivo was examined by a murine xenograft model. Lico A suppressed cell proliferation and induced ferroptosis in MOLM-13 and U-937 in vitro, and slowed the growth of xenograft tumors in vivo. IGF2BP3 was highly expressed in human AML specimens and cells, and Lico A suppressed IGF2BP3 expression in AML cells. Lico A exerted the anti-proliferative and pro-ferroptosis effects by downregulating IGF2BP3. Moreover, IGF2BP3 enhanced the stability and expression of MDM2 mRNA through an m6A-dependent manner. Downregulation of IGF2BP3 impeded AML cell proliferation and enhanced ferroptosis via repressing MDM2. Furthermore, Lico A could affect the MDM2/p53 pathway by downregulating IGF2BP3 expression. Lico A exerts the anti-proliferative and pro-ferroptosis activity in AML cells by affecting the IGF2BP3/MDM2/p53 pathway, providing new evidence for Lico A as a promising agent for the treatment of AML.

Mechanistic studies on defective hBN-supported metal-nonmetal synergistic catalysis for urea electrosynthesis

This study explores electrocatalytic urea synthesis promoted by a newly-designed bimetallic-tricenter catalyst consisting of defective hexagonal boron nitride (hBN) and embedded dimerized 3d metal, by means of density functional theory calculations. Among all candidates, Mn was proved to be the most feasible catalytic center originating from its unique electronic structure and metal-support interactions. The metal-nonmetal synergistic effects of the Mn2N center effectively drive site-selective co-adsorption of CO and NO, spontaneous C-N coupling, low-energy-demand NO hydrogenation, and adequate protection of the carbonyl group, achieving highly active and selective urea production. The calculated limiting potential of urea formation is as low as −0.19 V, making it more favorable energetically compared to other competing reactions such as hydrogen evolution and NO reduction reactions.

Role of Organic Vapor Precursors in Secondary Organic Aerosol Formation: Concurrent Observations of IVOCs and VOCs in Guangzhou

AbstractSecondary organic aerosol (SOA) formed through the atmospheric transformation of organic vapors constitutes a significant portion of fine particulate matter or PM2.5. While recent laboratory studies underscore the importance of intermediate‐volatility organic compounds (IVOCs) as key precursors to SOA, field observations that recognize the role of both volatile organic compounds (VOCs) and IVOCs in SOA formation remain scarce. In this study, we conducted concurrent measurements of VOCs and IVOCs in ambient air at urban and suburban sites in Guangzhou during a PM2.5 pollution event in winter 2021. The results reveal that between 12:00–15:00 local time, the photochemically adjusted initial concentrations of VOCs at both sites were approximately 7 times higher than that of IVOCs. However, the SOA formation potential (SOAFP) of primary hydrocarbon IVOCs exceeded that of VOCs by over 3–4 times. Receptor modeling results further indicated that while ship emissions contributed to less than 10% of the C2–C22 primary hydrocarbons concentration (VOCs + primary carbonaceous IVOCs), they accounted for the most significant source (approximately 40%) of SOA formation. This study highlights the substantial role of IVOCs in SOA formation and emphasizes the importance of future PM2.5 pollution control measures targeting major IVOCs contributors, such as ship emissions in harbor cities.

Enhancement of Biocrude Quality Using Fecal Sludge and Organic Solid Waste Through Two-Stage Hydrothermal Liquefaction Technique

The escalating global challenge of managing unmanaged fecal sludge (250-300 million tonnes/year) and organic solid waste (600-700 million tonnes/year) necessitates innovative and sustainable waste-to-energy solutions. Hydrothermal liquefaction (HTL) of FS & OSW to produce biocrude has been seen as a double-edged sword to substitute fossil fuel and address the issues relating to unmanaged waste (GHG emission, global warming, climate change). Through this study, an approach was taken to improve the biocrude production and enhance the biocrude quality by introducing a two-stage heating in HTL of FS and OSW separately. Four different runs were comprised in this study where one run was in conventional one stage, at 320℃ for 60 min. In terms of the other three runs, in the first stage, 100, 200, and 300℃ were retained for 30 min respectively and the second stage was conducted at 320℃ for 30 min. Results indicate a substantial improvement in biocrude yield of 15% &18% through two-stage heating during HTL (30 min at 200℃, and then 30 min at 320℃) compared to conventional single-stage HTL processes of FS & OSW respectively with a biomass conversion rate of 70%. From the analysis of biocrude maturity & intensity of oil we observe a high potential for crude oil formation being classified as Kerogen type I. GC-FID shows that increasing heat in the first stage tends to produce a lighter fraction (at 300℃ in the first stage produces biocrude with a lighter fraction>80% from FS & OSW feedstocks) in biocrude. In addition to improving the overall efficiency of converting organic waste to biocrude, the two-stage system offers a more flexible platform that allows the biofuel composition to be customized to match the needs of individual applications. The results show that a two-stage HTL process is a feasible and effective technique for converting difficult waste streams into biofuels, with implications for both environmental sustainability and energy security. Journal of Engineering Science 15(1), 2024, 95-105

A Cost-Effective Approach for Single-Stranded DNA Amplification Using Primer-Blocked Asymmetric PCR.

In vitro amplification of single-stranded oligonucleotide libraries presents a significant challenge due to the potential for excessive byproduct formation. This phenomenon largely affects the quality of the ssDNAs created using the most commonly used methods, e.g., asymmetric PCR, biotin-streptavidin separation, or lambda exonuclease digestion of dsDNA. Here, we describe an improved protocol that combines primer-blocked asymmetric PCR (PBA-PCR) with emulsion PCR and a cost-effective downstream process that altogether alleviates byproduct formation without distorting the sequence space of the ssDNA library. In PBA-PCR, the reaction mixture is complemented with a 3'-phosphate-blocked limiting primer that decreases mispriming, thus reducing polymerization of DNA byproducts. The downstream process includes mixing of the PBA-PCR product with excess reverse complement of the 3'-phosphate-blocked limiting primer and removal of dsDNA strands via biotin-streptavidin separation, yielding purified ssDNAs. In conclusion, we have devised a universally applicable approach for simple and cost-effective production of ssDNA libraries and unique ssDNA sequences with on-demand labeling. Our protocol could be beneficial for a variety of uses, such as generating aptamer libraries for SELEX, creating unique molecular identifiers for a wide range of sequencing applications, providing donor DNA for CRISPR-Cas9 systems, developing scaffold nanostructures, and enabling DNA-based data storage. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Amplification of ssDNA libraries using PBA-PCR Alternate Protocol 1: Amplification of ssDNA libraries using emulsion PBA-PCR with a simplified extraction of PBA-PCR products Basic Protocol 2: Purification of PBA-PCR products to remove dsDNA and conversion of 3'-blocked primer to double-stranded complexes Alternate Protocol 2: Purification of PBA-PCR products to remove both dsDNA and blocking primers from the reaction mixture Support Protocol: Analysis of PBA-PCR products by gel electrophoresis.

Seasonal natural organic matter removal and implications for disinfection by-product formation at the Koka water treatment plant: Upper Awash, Ethiopia

ABSTRACT This study evaluated the seasonal performance of the Koka water treatment plant in removing natural organic matter (NOM) and the implications for disinfection by-product (DBP) formation potential. Raw and treated water samples were collected during the dry and wet seasons and analyzed using physicochemical parameters and fluorescence spectroscopy. The results revealed significant seasonal variations in raw water (RW) quality, with higher turbidity, pH, temperature, conductivity, total organic carbon (TOC), dissolved organic carbon (DOC), and UV254 absorbance during both seasons and across treatment processes. The NOM removal efficiency of the treatment plant was poor, with mean TOC removal of 46 and 43% and DOC removal of 15.8 and 15.2% during dry and wet seasons, respectively. The sedimentation unit demonstrated negative TOC removal, indicating NOM accumulation likely due to biochemical reactions in the unit. Fluorescence analysis and the correlation between specific ultraviolet absorbance (SUVA) and DBP formation potential suggest a higher risk of DBP formation in chlorinated drinking water. These findings highlight the influence of seasonal variations, RW quality, and the treatment process dynamics on the plant's performance in removing NOM. There is a need to implement adaptable strategies to enhance NOM removal, accounting for seasonal fluctuations in RW quality.

High entropy alloys for hydrogen storage applications: A machine learning-based approach

Hydrogen is a clean energy carrier and has potential applications in energy storage, power generation, and transportation. This study explores the efficient and safe storage of hydrogen, particularly through solid-state methods using high entropy alloys (HEAs). HEAs have garnered attention for their versatility in tailoring properties for hydrogen storage. The integration of Machine Learning (ML) in designing HEAs offers an expedited approach, analyzing datasets and predicting material properties to enhance storage capacity, kinetics, and stability. Despite significant progress, the study acknowledges certain research limitations, particularly its relatively narrow focus on applying ML to HEAs for hydrogen storage. One of the biggest challenges with HEAs is their complexity, which.necessitates larger datasets to develop accurate predictive models. Collecting and analyzing existing HEA data for hydrogen storage using ML techniques is the main objective. Using algorithms like support vector regression (SVR), K-nearest (KNN), and random forest (RF), hydrogen-to-metal ratio (H/M) and valence electron configuration (VEC) are accurately predicted. The study proposes alloys with potential for HEA formation, identifying 741 with quaternary and 631 with quinary HEAs. These compositions are newly proposed and do not yet exist. Out of these, 774 HEAs are identified as potential candidates for hydrogen storage applications. Applying ML techniques, the selection process is more efficient, reducing the dependency on time-consuming experiments and making it easier to discover promising candidates.

Hydrocarbon potential and depositional environment of the Middle Miocene Balikpapan Formation, lower Kutai Basin, Indonesia: Sedimentology, calcareous nannofossil, organic geochemistry, and organic petrography integrated approach

The Middle Miocene Balikpapan Formation is exposed in the Samarinda Anticlinorium, which forms part of the Lower Kutai Basin situated on East Kalimantan, Indonesia. The Balikpapan Formation is considered the main source rock for oil and gas fields in Lower Kutai Basin. This study integrates sedimentology, organic geochemistry, organic petrography and calcareous nannofossil analysis to characterize the depositional environment, to determine the source of the organic matter, and to assess the hydrocarbon potential of the Balikpapan Formation. The studied sections contain at one locality calcareous nannofossil assemblages with low diversity including Sphenolithus heteromorphus, suggesting nannofossil zones NN4 – NN5 (upper Burdigalian - Langhian-lower Serravallian) are restricted to the Air Putih section in the northeastern part of the study area. Six facies associations were identified in the study area, comprising eleven lithofacies, interpreted as fluvial-deltaic to shallow marine in origin. The fine-grained lithofacies include shale, coaly shale and coal while the coarse-grained facies include sandstone and sandy conglomerates. The geochemical results (TOC) indicate that the analyzed samples have strongly varying total organic carbon (TOC) contents. The organic matter is composed of type III (gas-prone) and type II-III (mixed oil and gas prone) kerogen, with HI values ranging from 32 to 252 mg HC/g TOC. The Rock-Eval parameter Tmax 409–441 °C and vitrinite reflectance values (0.40–0.67 %Rr) indicate that the sediments are immature to marginal mature. The rank of coal in the Balikpapan Formation ranges from the sub-bituminous to the high-volatile bituminous B stage.

Elevated level of extracellular vimentin is associated with an increased fibrin formation potential in sepsis: ex vivo swine study

BackgroundSepsis can lead to coagulopathy and microvascular thrombosis. Prior studies, including ours, reported an increased level of extracellular vimentin in blood derived from septic patients. Moreover, we identified the contribution of extracellular vimentin to fibrin formation and to the fibrin clot structure ex vivo in plasma from septic patients. Here, we tested the status of plasma vimentin and its impact on fibrin clots using our recently described swine model of methicillin-resistant Staphylococcus aureus (MRSA) sepsis-induced coagulopathy.ResultsWe employed ELISA, size-exclusion chromatography, vimentin antibodies, confocal microscopy, and turbidity assays on piglet plasma obtained at pre- and post-MRSA inoculation. Plasma vimentin level at 70 h post-MRSA inoculation was on average twofold higher compared to pre-infection (0 h) level in the same animal. Anti-vimentin antibody effectively reduced fibrin formation ex vivo and increased porosity in the fibrin clot structure generated from septic piglet plasma. In contrast to plasma at 0 h, the size-exclusion chromatography revealed that phosphorylated vimentin was in-complex with fibrinogen in septic piglet plasma.ConclusionsThus, our swine model of sepsis-induced coagulopathy, reproduced increased extracellular circulating vimentin and subsequent potentiation of fibrin formation, often observed in septic patient. These outcomes validate the use of large animal models to investigate the dysregulated host immune response to infection leading to coagulopathy, and to develop new therapies for sepsis-induced disseminated microvascular thrombosis.

Responses of plant volatile emissions to increasing nitrogen deposition: A pilot study on Eucalyptus urophylla

Biogenic volatile organic compounds (BVOCs) significantly impact atmospheric chemistry, with emissions potentially influenced by nitrogen (N) deposition. The response of BVOC emissions to increasing N deposition remains debated. In this study, we examined Eucalyptus urophylla (E. urophylla) using three N treatments: N0, N50, and N100 (0, 50, and 100 kg N hm−2 yr−1 N addition). These treatments were applied to mature E. urophylla trees in a plantation subjected to over 10 years of soil N addition in southern China, a region with severe N deposition. Seventeen BVOCs were measured, with isoprene (36.99 %), α-pinene (38.80 %), and d-limonene (14.27 %) being the predominant compounds under natural conditions. Total BVOC emissions under N50 were nearly double those under N0 and N100, with leaf net CO2 assimilation identified as the most critical photosynthetic parameter. Isoprene and α-pinene emissions significantly increased under N50 compared to N0, while d-limonene emission decreased under N100. Stronger correlations for individual BVOCs under N50 and N100 compared to N0 might be due to differences in BVOC biosynthetic pathways and storage structures. The localized canopy-scale emission factors (EFs) under N50 were significantly higher than the default values in the Model of Emissions of Gases and Aerosols from Nature (MEGAN), suggesting the model might underestimate BVOC emissions from Eucalyptus in southern China under increased N deposition. Additionally, the secondary pollutant formation potentials of BVOCs were evaluated, identifying isoprene and monoterpenes as primary precursors of ozone and secondary organic aerosols. This study provides insights into the impacts of increased N deposition on BVOC emissions and their contribution to secondary atmospheric pollution. Updating localized BVOC EFs for subtropical tree species in southern China is crucial to reduce uncertainties in BVOC estimations under current and future N deposition scenarios.

Molecular Evaluation of Aminoglycoside Resistance and Biofilm Formation Potential in Escherichia coli Isolates Collected from Hospitalized Patients

Background: Resistance to antibiotics and the ability to develop biofilms, two main virulence determinants of Escherichia coli, play a crucial role in the persistence of infections. Objectives: The aim of this study was to evaluate aminoglycoside resistance and biofilm formation potential in E. coli isolates collected from hospitalized patients in the Southwest of Iran. Methods: A total of 70 E. coli clinical isolates from different specimens were collected from Ahvaz teaching hospitals affiliated with Ahvaz Jundishapur University of Medical Sciences. All the isolates were identified as E. coli using conventional microbiological tests. Susceptibility to antibiotics was determined using the Kirby–Bauer disk diffusion method. Biofilm formation was assessed using the microtiter plate method. Finally, PCR was conducted to detect virulence gene determinants, including fimbrial genes, aminoglycoside modifying enzymes (AMEs), and 16S rRNA methylase (RMTase) genes. Results: Among aminoglycoside antibiotics, E. coli isolates showed the highest and lowest resistance rates to tobramycin (TOB; 51.4%) and gentamicin (GEN; 24.2%), respectively. Simultaneous resistance to GEN, amikacin, and TOB was observed in 28.5% of the isolates, representing the most common antibiotic resistance pattern. The prevalence of strong biofilm producers was higher in the extensively drug-resistant (XDR) phenotype group compared to the multiple drug-resistant (MDR) group (76.1% vs. 23.8%). Among the 36 isolates resistant to at least one of the aminoglycoside antibiotics, 36.1% had AME-related genes, either alone or in various combinations. Most isolates harboring AME genes were also positive for the presence of biofilm-related genes, including ecpA and fimA. Conclusions: The most frequent AME-related genes were ant(2”)-Ia and aph(3’)-Ia, followed by aac(3’)-IIa. The findings of the present study provide probable evidence that GEN is an effective aminoglycoside against biofilm-producing and antibiotic-resistant E. coli isolates.

Different impacts of natural and anthropogenic factors on dissolved organic matter chemistry in coastal rivers: Implications for water management

The chemical composition of dissolved organic matter (DOM) exerts significant influence on aquatic energy dynamics, pollutant transportation, and carbon storage, thereby playing pivotal roles in the local water quality and regional-global biogeochemical cycling. However, the effects of natural climate change and local human activities on watershed characteristics and in-river processes have led to uncertainties regarding their contributions to DOM chemistry in coastal rivers, creating challenges for effective water management and the study of organic matter cycling. In this investigation, we employed a combination of stable isotopic analysis, optical techniques, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) to elucidate the sources, optical properties, and molecular composition of DOM in three South China coastal rivers. Our results suggest that terrestrial DOM entering the three rivers through natural or anthropogenic pathways is gradually diluted by in situ primary production as it moves downstream, ultimately being influenced by seawater intrusion near the estuary. Additionally, terrestrial processes influenced by temperature likely govern DOC concentration, while seawater intrusion promotes the natural production of S-containing organic compounds. In contrast, human-altered landcover significantly impacts DOM molecular composition. Increased water areas lead to the enrichment of lignins with high disinfection byproduct formation potential, and agricultural residue burning appears to be the dominant source of pyrogenic DOM in these coastal rivers. Our distinct results suggest that the development of specific water management plans that consider the combined effects of temperature, seawater intrusion, landcover changes, and agricultural practices will be essential to ensure sustainable water resource.

The Emission Characteristics of VOCs and Environmental Health Risk Assessment in the Plywood Manufacturing Industry: A Case Study in Shandong Province

The current emission characteristics of volatile organic compounds (VOCs) in the plywood manufacturing industry are not yet clearly understood, and their impact on occupational health warrants attention. This study examines VOC concentrations in adhesive-coating and hot-pressing workshops, aiming to discern the emission characteristics and evaluate the health risks to workers. The calculated VOC emission factors range from 1.5 to 3.6 g/m3 for plywood, and an average total VOC concentration of 954.17 μg/m3 is observed. Hot pressing (336.63 μg/m3) and adhesive coating (276.24 μg/m3) substantially contribute to organized and unorganized emissions, respectively. Oxygenated VOCs (OVOCs) (50.79%) predominate, followed by alkanes (16.22%) and halohydrocarbons (15.81%). Formaldehyde, acetone, and acetaldehyde are most prevalent in organized emissions, while dichloromethane, formaldehyde, and methyl methacrylate are dominant in unorganized emissions. Ozone formation potential (OFP) values range from 905.04 to 1822.35 μg/m3, with notable contributions from formaldehyde, methyl methacrylate, and acetaldehyde. Health risk assessments using the total lifetime cancer risk (T-LCR) values suggest potential cancer risks for identified VOCs, particularly formaldehyde in the hot-pressing process. These findings will contribute valuable insights for regional-scale VOC pollution control and offer guidance for minimizing environmental impact and improving occupational health and safety within the plywood manufacturing industry.

A step to microplastic formation: Microcracking and associated surface transformations of recycled LDPE, LLDPE, HDPE, and PP plastics exposed to UV radiation

Plastics when exposed to UV radiation start to degrade via photooxidative aging including free radical formation, oxidation, chain scission and/or crosslinking reactions. These chemical changes can cause loss in mechanical strength, surface embrittlement, and eventually surface erosion. The eroded particles are microplastics (MPs), which have been identified as a potentially serious threat to the environment and its inhabitants. In general, photodegradation of virgin plastics has been studied extensively, but there is not much literature on the degradation of recycled plastics. The goal of the study was to investigate the changes caused by photodegradation in recycled plastics and assess the potential risks of MPs formation. And eventually, knowing the chemical and physical transformations occurring on the surface understand the mechanism behind surface microcracking, which is the first step of MPs formation. Pellets of five industrially recycled plastics (low-density polyethylene (rLDPE), linear low-density polyethylene (rLLDPE), high-density polyethylene (rHDPE), and two polypropylenes (rPP)) from different waste sources were analysed. UV irradiation was performed in an accelerated weathering chamber for milled (< 400 µm) plastic powder to ensure homogeneous changes throughout the sample. The properties were investigated by ATR-FTIR, HT-SEC, XPS and DSC. Formation of microcracks was studied on plastic pellets by SEM. The results showed that the degradation significantly differed between the recycled plastics, and the waste source was more important than the plastic type. rLDPE and one of the rPP samples showed a significant increase in carbonyl index as well as decrease in molar mass during the first 500 h of UV exposure. The other rPP and rHDPE samples showed first considerable signs of degradation only after 1000 h of UV exposure. Minor changes were observed for the rLLDPE sample during the whole test. The SEM revealed microcracking on the surface of all samples, which also had noticeable degradation identified by other methods. These recycled plastics can be considered the ones with the highest potential of MPs formation. From the chemical and physical transformations identified on the surface, the mechanism leading to microcracking, which is the first step in the formation of MPs, is proposed.

Natural vs. anthropogenic sources of N-Nitrosodimethylamine precursors in surface water

N-nitrosodimethylamine (NDMA) is a carcinogenic disinfection byproduct formed from reactions between dichloramine and organic nitrogen-containing precursors. It is unclear if NDMA precursors in surface water intakes originate in anthropogenic (i.e., wastewater) or natural sources. The Truckee River has a single point source release of treated wastewater effluent, making it an ideal system to study the relative importance of precursor sources. Three Lagrangian sampling events were conducted. NDMA formation potential (FP, a measurement of precursors) above the wastewater outfall indicated that the natural background of NDMA precursors was 2-28 ng/L. NDMA FP increased to 18-31 ng/L immediately downstream of the wastewater outfall, but decreased rapidly in a first order manner, and were not statistically different from the upstream samples in only ∼6 km. This suggests that the dominant source of NDMA precursors may be wastewater derived only near wastewater outfalls and deviates from the previous belief that wastewater-derived precursors are responsible for NDMA formation in drinking water sources located further downstream. Additionally, given the rapid loss of the wastewater precursors in this study, precursors which are slow to biodegrade/photolyze/adsorb to sediment are likely to be poor surrogates for the overall wastewater NDMA precursor pool. To understand temporal changes in the wastewater impact on environmental NDMA precursor loading, two 24-hour sampling events were conducted near (<3 km) the wastewater outfall and demonstrated that temporal changes in the NDMA precursors directly downstream of the wastewater outfall are directly linked to the wastewater flow contribution.

The assembly of neutrophil inflammasomes during COVID-19 is mediated by type I interferons.

The severity of COVID-19 is linked to excessive inflammation. Neutrophils represent a critical arm of the innate immune response and are major mediators of inflammation, but their role in COVID-19 pathophysiology remains poorly understood. We conducted transcriptomic profiling of neutrophils obtained from patients with mild and severe COVID-19, as well as from SARS-CoV-2 infected mice, in comparison to non-infected healthy controls. In addition, we investigated the inflammasome formation potential in neutrophils from patients and mice upon SARS-CoV-2 infection. Transcriptomic analysis of polymorphonuclear cells (PMNs), consisting mainly of mature neutrophils, revealed a striking type I interferon (IFN-I) gene signature in severe COVID-19 patients, contrasting with mild COVID-19 and healthy controls. Notably, low-density granulocytes (LDGs) from severe COVID-19 patients exhibited an immature neutrophil phenotype and lacked this IFN-I signature. Moreover, PMNs from severe COVID-19 patients showed heightened nigericin-induced caspase1 activation, but reduced responsiveness to exogenous inflammasome priming. Furthermore, IFN-I emerged as a priming stimulus for neutrophil inflammasomes. These findings suggest a potential role for neutrophil inflammasomes in driving inflammation during severe COVID-19. Altogether, these findings open promising avenues for targeted therapeutic interventions to mitigate the pathological processes associated with the disease.

Experimental Study of the Effect of CO/H2 Ratio and Release Pressure on Syngas Jet Flame Propagation and Overpressure.

Syngas, composed of hydrogen and carbon monoxide, serves as an alternative fuel for hydrogen energy and a key raw material for chemical synthesis. However, due to its flammable nature, syngas poses risks of forming explosive mixtures in the event of a leak. This study explores potential accident scenarios in coal chemical environments involving syngas reaction vessels. Experimental investigations focus on the overpressure and propagation dynamics of jet flames resulting from syngas leakage, with CO volume fractions ranging from 50 to 80% and release pressures between 2 and 5 MPa. Results reveal that maximum flame overpressure occurs within a CO volume fraction range of 55-65%, with no consistent relationship observed between overpressure and CO fraction at fixed release pressures. During our experiments, the maximum recorded overpressure of 28.4 kPa was reached during vented explosions. Additionally, ignition outcomes categorize into three types based on flame propagation speed: combustion/flare, resembling normal deflagration; and high-velocity deflagration, characterized by rapid propagation and potential for steady jet fire formation. While shockwave-like features may be observed, these do not indicate true detonation. These findings offer insights for the safe handling and storage of syngas.

Evidence for sustainably reducing secondary pollutants in a typical industrial city in China: Co-benefit from controlling sources with high reduction potential beyond industrial process

Under China’s strict industrial control measures, the reduction of secondary pollutants (O3 and secondary organic aerosols [SOA]) and precursors (volatile organic compounds [VOCs] and NOx) caused by industrial processes has encountered bottlenecks. In this study, the net O3 formation rate (Net [O3]) in summer and the self-reaction rate between peroxy radicals (Self-Rnxs) in winter are used to characterize the formation potentials of O3 and SOA, respectively. Assuming that the precursor reduction ratio based on emission inventories is approximately equal to that based on observed concentrations, this study combines emission inventory and observation-based model (OBM) methods to indicate the potential source of secondary pollutants reduction. The findings show that strict control measures implemented by local governments, particularly those targeting industrial processes and fossil fuel combustion, are effective in reducing VOCs and NOx emissions during summer, and the two sources result in 3.8 % and 5.3 % decrease in the Net (O3), respectively. Similarly, control measures focusing on industrial processes help to significantly reduce VOCs emissions during winter, resulting in an 8.0 % decrease in Self-Rnxs. However, current measures for industrial processes are stringent and have little potential for further reduction. Therefore, additional sources with higher reduction potentials beyond industrial processes should be subject to stringent controls in industrial cities. Given the limited emission reduction potential associated with industrial processes, this study provides perspectives for sustained reduction of secondary pollutants in industrial cities.

Role of magnesium ions in modifying oxide growth rate on Zircaloy under breakaway corrosion regimes

General corrosion of nuclear reactor in core material like Zircaloy-2 and breakaway corrosion in particular are of great importance in ensuring its smooth long term operation. Metal ions like Mg2+ added to the coolant, to mitigate corrosion of other structural materials like Carbon steel, can get incorporated in the corrosion product oxide on Zircaloy-2 and alter its corrosion behavior. Plasma Electrolytic Oxidation (PEO) method was employed to investigate the effect of Mg2+ ions during breakaway corrosion of Zircaloy-2. The main objective was to understand the morphology, protectiveness, semiconducting properties of the Mg modified oxide films on Zircaloy-2 surface. DC potentials 300, 400 and 500 V were used to accelerate corrosion kinetics and form oxide mimicking the breakaway corrosion regime. Borate buffer (pH 9.8) was used as the electrolyte, and Mg acetate was added as Mg source for probing the effect of Mg2+ ions. Oxide morphology depended largely on the formation potentials. The presence of magnesium resulted in thinner oxides with lower defect densities. GIXRD of the oxide showed stabilization of tetragonal phase in presence of Mg at 300 and 400 V. Oxide resistance and charge transfer resistances measured by EIS were observed to be higher due to Mg incorporation at these potentials. Mg addition facilitated formation of t-ZrO2. The electrochemical measurements suggested that the presence of Mg in ZrO2 could reduce the connected porosity in the oxide thereby stifling the diffusion paths. These factors lead to improved corrosion protectiveness of the oxide formed in the presence of Mg.

Emissions of Oxygenated Volatile Organic Compounds and Their Roles in Ozone Formation in Beijing

Oxygenated volatile organic compound (OVOC) emissions play a critical role in tropospheric ozone (O3) formation. This paper aims to establish an emission inventory and source profile database for OVOCs in Beijing, utilizing revised and reconstructed data from field measurements and existing literature. The study also assesses their potential impact on the O3 base on the ozone formation potential (OFP). Results indicate that OVOC emissions in Beijing predominantly originate from natural and residential sources, encompassing commercial solvent usage, cooking, residential combustion, construction adhesives, and construction coatings. OVOCs contributed 5.6% to OFP, which is significantly less than their emission contribution of 20.1%. Major OFP contributors include plant sources (26.2%), commercial solvent use (21.0%), cooking (20.5%), and construction adhesives (8.4%). The primary OVOC species contributing to OFP for OVOCs are acetaldehyde, methanol, hexanal, ethanol, and acetone, collectively contributing 59.0% of the total OFP. Natural sources exhibit significant seasonal variability, particularly in summer when plant emissions peak, constituting 78.9% of annual emissions and significantly impacting summer ozone pollution (OFP of 13,954 t). Conversely, emissions from other OVOC sources remain relatively stable year-round. Thus, strategies to mitigate summer ozone pollution in Beijing should prioritize plant sources while comprehensively addressing residential sources in other seasons. District-specific annual OVOC emissions are from Fangshan (3967 t), Changping (3958 t), Daxing (3853 t), and Chaoyang (3616 t), which reflect year-round forested areas in these regions and high populations.