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BACKGROUND: Patients with sepsis resulting in acute lung injury (ALI) usually have increased mortality. Ferroptosis is a vital regulator in sepsis-induced ALI. Exploring the association of ferroptosis and sepsis-induced ALI is crucial for the management of sepsis-induced ALI. METHODS: Whole blood was collected from sepsis patients. Mice were treated with cecal ligation and puncture (CLP) to model sepsis. Primary murine pulmonary microvascular endothelial cells were treated with lipopolysaccharide as a cell model. Ferroptosis was evaluated by analyzing levels of iron, malonaldehyde, glutathione, nonheme iron, ferroportin, ferritin, and GPX4. Hematoxylin and eosin and Masson's trichrome staining were applied to examine lung injury and collagen deposition. Cell apoptosis was analyzed by caspase-3 activity and TUNEL assays. Gene regulatory relationship was verified using RNA pull-down and immunoprecipitation assays. RESULTS: CircEXOC5 was highly expressed in sepsis patients and CLP-treated mice, in which knockdown alleviated CLP-induced pulmonary inflammation and injury, and ferroptosis. CircEXOC5 recruited IGF2BP2 to degrade ATF3 mRNA. The demethylase ALKBH5 was responsible for circEXOC5 upregulation through demethylation. CircEXOC5 silencing significantly improved sepsis-induced ALI and survival rate of mice by downregulating ATF3. CONCLUSIONS: ALKBH5-mediated upregulation of circEXOC5 exacerbates sepsis-induced ALI by facilitating ferroptosis through IGF2BP2 recruitment to degrade ATF3 mRNA.
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Lesão Pulmonar Aguda , Ferroptose , Sepse , Humanos , Camundongos , Animais , Células Endoteliais/metabolismo , Lesão Pulmonar Aguda/etiologia , Pulmão/metabolismo , Sepse/metabolismo , Ferro/metabolismo , RNA Mensageiro/metabolismo , Lipopolissacarídeos , Proteínas de Ligação a RNA/metabolismo , Fator 3 Ativador da Transcrição/metabolismoRESUMO
BACKGROUND: Sepsis is a systemic inflammatory response which is frequently associated with acute lung injury (ALI). Activating transcription factor 3 (ATF3) promotes M2 polarization, however, the biological effects of ATF3 on macrophage polarization in sepsis remain undefined. METHODS: LPS-stimulated macrophages and a mouse model of cecal ligation and puncture (CLP)-induced sepsis were generated as in vitro and in vivo models, respectively. qRT-PCR and western blot were used to detect the expression of ATF3, ILF3, NEAT1 and other markers. The phenotypes of macrophages were monitored by flow cytometry, and cytokine secretion was measured by ELISA assay. The association between ILF3 and NEAT1 was validated by RIP and RNA pull-down assays. RNA stability assay was employed to assess NEAT1 stability. Bioinformatic analysis, luciferase reporter and ChIP assays were used to study the interaction between ATF3 and ILF3 promoter. Histological changes of lung tissues were assessed by H&E and IHC analysis. Apoptosis in lungs was monitored by TUNEL assay. RESULTS: ATF3 was downregulated, but ILF3 and NEAT1 were upregulated in PBMCs of septic patients, as well as in LPS-stimulated RAW264.7 cells. Overexpression of ATF3 or silencing of ILF3 promoted M2 polarization of RAW264.7 cells via regulating NEAT1. Mechanistically, ILF3 was required for the stabilization of NEAT1 through direct interaction, and ATF3 was a transcriptional repressor of ILF3. ATF3 facilitated M2 polarization in LPS-stimulated macrophages and CLP-induced septic lung injury via ILF3/NEAT1 axis. CONCLUSION: ATF3 triggers M2 macrophage polarization to protect against the inflammatory injury of sepsis through ILF3/NEAT1 axis.
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Fator 3 Ativador da Transcrição , Macrófagos , RNA Longo não Codificante , Sepse , Animais , Humanos , Camundongos , Fator 3 Ativador da Transcrição/genética , Fator 3 Ativador da Transcrição/metabolismo , Lipopolissacarídeos , Macrófagos/metabolismo , Proteínas do Fator Nuclear 90/genética , Proteínas do Fator Nuclear 90/metabolismo , Células RAW 264.7 , Sepse/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismoRESUMO
In analogy to the cell microenvironment in biology, understanding and controlling the active-material microenvironment (ME@AM) microstructures in battery electrodes is essential to the successes of energy storage devices. However, this is extremely difficult for especially high-capacity active materials (AMs) like sulfur, due to the poor controlling on the electrode microstructures. To conquer this challenge, here, a semi-dry strategy based on self-assembled nano-building blocks is reported to construct nest-like robust ME@AM skeleton in a solvent-and-stress-less way. To do that, poly(vinylidene difluoride) nanoparticle binder is coated onto carbon-nanofibers (NB@CNF) via the nanostorm technology developed in the lab, to form self-assembled nano-building blocks in the dry slurry. After compressed into an electrode prototype, the self-assembled dry-slurry is then bonded by in-situ nanobinder solvation. With this strategy, mechanically strong thick sulfur electrodes are successfully fabricated without cracking and exhibit high capacity and good C-rate performance even at a high AM loading (25.0 mg cm-2 by 90 wt% in the whole electrode). This study may not only bring a promising solution to dry manufacturing of batteries, but also uncover the ME@AM structuring mechanism with nano-binder for guiding the design and control on electrode microstructures.
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Photo-responsive materials have garnered significant interest for their ability to react to non-contact stimuli, though achieving self-healing under gentle conditions remains an elusive goal. In this research, an innovative and straightforward approach for synthesizing silicone elastomers is proposed that not only self-heal at room temperature but also possess unique photochromic properties and adjustable mechanical strength, along with being both transparent and reprocessable. Initially, aldehyde-bifunctional dithiophene-ethylene molecules with dialdehyde groups (DTEM) and isocyanurate (IPDI) is introduced into the aminopropyl-terminated polydimethylsiloxane (H2N-PDMS-NH2) matrix. Subsequently, palladium is incorporated to enhance coordination within the matrix. These silicone elastomers transition to a blue state under 254 nm UV light and revert to transparency under 580 nm light. Remarkably, they demonstrate excellent thermal stability at temperatures up to 100 °C and show superior fatigue resistance. The optical switching capabilities of the silicone elastomers significantly affect both their mechanical characteristics and self-healing abilities. Notably, the PDMS-DTEM-IPDI-@Pd silicone elastomer, featuring closed-loop photo-switching molecules, exhibits a fracture toughness that is 1.3 times greater and a room temperature self-healing efficiency 1.4 times higher than its open-loop counterparts. This novel photo-responsive silicone elastomer offers promising potential for applications in data writing and erasure, UV protective coatings, and micro-trace development.
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Although family and school experiences play an important role in adolescents' adjustment during the transition to high school, most prior studies investigated the effects of these experiences in isolation; their joint implications for both adolescents' concurrent and long-term adjustment outcomes are less clear, and the potential role of individual characteristics within such associations remains understudied. Based on 525 10th graders (Mage = 15.48, SDage = 0.71, 43.6% boys) who participated in a longitudinal study, the present research aimed to identify distinct family and school experience profiles among first-year high school students and examine their associations with adolescents' internalizing problems and externalizing problems, both concurrently and 18 months later. Latent profile analysis revealed four distinctive profiles: thriving, low resources-moderate family risk, developmental stress-high parental conflicts, and developmental stress-high peer victimization profiles. The other three profiles (vs. the thriving profile) reported significantly higher levels of concurrent internalizing problems; while these differences diminished after 18 months. However, the enduring impacts of these profiles on internalizing problems persisted among adolescents with higher levels of environmental sensitivity. Additionally, adolescents characterized by two developmental stress profiles (vs. the thriving profile) exhibited significantly higher levels of externalizing problems both currently and longitudinally. Findings underscore the importance of identifying at-risk populations among adolescents during the transition to high school by including both family and school experiences when examining environmental influence on their adjustment, as well as the necessity to take individual environmental sensitivity into account when examining these associations.
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Animals create high-performance fibers at natural ambient conditions via a unique spinning process. In contrast, the spinning technologies developed by human beings are usually clumsy and require sophisticated skills. Here, inspired by adhesion-based silkworm spinning, we report a microadhesion guided (MAG) spinning technology for instant and on-demand fabrication of micro/nanofibers. Enabled by the adhesion between the spinning fluids and the microneedles, the MAG spinning can generate micro/nanofibers with programmable morphology. By further mimicking the head movement of the silkworm spinning, the MAG technology is extended with three different modes: straight, vibratory, and twisted spinning, which generate oriented fibers, hierarchical cross-linked fibers, and all-in-one fibers, respectively. Due to the prevalence of microadhesion and its unprecedented flexibility in operation, equipment-free MAG spinning is finally realized for instant fiber fabrication by only polymeric foams. Finally, the MAG spinning is demonstrated as a promising instant technology for emergent applications, such as wound dressing.
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Bombyx , Nanofibras , Animais , Humanos , Biomimética , PolímerosRESUMO
High-voltage lithium metal batteries (LMBs) are a promising high-energy-density energy storage system. However, their practical implementations are impeded by short lifespan due to uncontrolled lithium dendrite growth, narrow electrochemical stability window, and safety concerns of liquid electrolytes. Here, a porous composite aerogel is reported as the gel electrolyte (GE) matrix, made of metal-organic framework (MOF)@bacterial cellulose (BC), to enable long-life LMBs under high voltage. The effectiveness of suppressing dendrite growth is achieved by regulating ion deposition and facilitating ion conduction. Specifically, two hierarchical mesoporous Zr-based MOFs with different organic linkers, that is, UiO-66 and NH2 -UiO-66, are embedded into BC aerogel skeletons. The results indicate that NH2 -UiO-66 with anionphilic linkers is more effective in increasing the Li+ transference number; the intermolecular interactions between BC and NH2 -UiO-66 markedly increase the electrochemical stability. The resulting GE shows high ionic conductivity (≈1 mS cm-1 ), high Li+ transference number (0.82), wide electrochemical stability window (4.9 V), and excellent thermal stability. Incorporating this GE in a symmetrical Li cell successfully prolongs the cycle life to 1200 h. Paired with the Ni-rich LiNiCoAlO2 (Ni: Co: Al = 8.15:1.5:0.35, NCA) cathode, the NH2 -UiO-66@BC GE significantly improves the capacity, rate performance, and cycle stability, manifesting its feasibility to operate under high voltage.
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Lítio , Estruturas Metalorgânicas , Fontes de Energia Elétrica , Eletrólitos , Ácidos FtálicosRESUMO
Frequently-occurred secondary organic aerosols (SOAs) under low-NOx conditions contribute to the winter haze episodes and remain unclear in the abundant presence of NH3. Here, the effects of CaCl2 seed particles on the photooxidation of low-molecular-weight C3H6 with co-existing NO2 and NH3 were highlighted and investigated through a chamber-simulation study equipped with high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS). The influences of NH3 are often overestimated to exclusively enhance SOA yields under a low-[NO2]0 condition. Instead, the seeds played a central role in the heterogeneous formation of SOAs in this reaction with two orders of magnitudes higher than that in the absence of seeds at relative humidity (RH) of 82%. Interestedly, the O3 production was unchanged whether the seeds existed or not, small changes in the production of O3 were observed whether the seeds existed or not, indicating that the gas-phase conversions of C3H6 and NOx into C1-C3 oxygenated volatile organic compounds (OVOCs) and nitrogen-containing compounds (NOCs) were not affected by seed particles. Given that the ensuing formation of these low-volatile compounds was condensed into nucleation on the seeds, the explosive growth of C3H6 SOAs was then stimulated in the addition of NH3. Besides NO2 photolysis, the producing O3 was related to the formation of secondary carbonyls such as formaldehyde and then was consumed in the ·OH generation of approximately 3.40 × 10-12 molecules cm-3. This study provides a new insight to better understand the new gas-to-particle formation mechanisms when the haze pollution outbreaks in the complex air mixture.
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Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Aerossóis , Poluentes Atmosféricos/análise , Dióxido de Nitrogênio , FotóliseRESUMO
The shuttling of polysulfides is the most detrimental contribution to degrading the capacity and cycle stability of lithium-sulfur (Li-S) batteries. Adding a carbon interlayer to prevent the polysulfides from migrating is feasible, and a rational design of the structures and surface properties of the carbon layer is essential to increasing its effectiveness. Herein, we report a hierarchical porous carbon (HPC) created by carbonization of bis(phenoxy)phosphazene and in-situ doping of triple heteroatoms into the carbon lattice to fabricate an effective polysulfide-trapping interlayer. The generated carbon integrates the advantages of a hierarchical porous structure, a high specific area and rich dopants (N, O and P), to yield chemisorption and physical confinement for polysulfides and fast ion-transport synergistically. The HPC interlayer significantly improves the electrochemical performance of Li-S batteries, including an exceptional discharge capacity of 1509â mA h/g at 0.06â C and a high capacity retention of 83.7 % after 250â cycles at 0.3â C. This work thus proposes a facile in-situ synthesis of heteroatom-doped carbon with rational porous structures for suppressing the shuttle effect.
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Nitrous acid (HONO) is an important photochemical precursor to hydroxyl radicals particularly in an urban atmosphere, yet its primary emission and secondary production are often poorly constrained. Here, we measured HONO and nitrogen oxides (NOx) at both the inlet and the outlet in a busy urban tunnel (>30â¯000 vehicles per day) in south China. Multiple linear regression revealed that 73.9% of the inlet-outlet incremental HONO concentration was explained by NO2 surface conversion, while the rest was directly emitted from vehicles with an average HONO/NOx ratio of 1.31 ± 0.87%, which was higher than that from previous tunnel studies. The uptake coefficient of NO2, γ(NO2), on the tunnel surfaces was calculated to be (7.01 ± 0.02) × 10-5, much higher than that widely used in models. As tunnel surfaces are typical of urban surfaces in the wall and road materials, the dominance of HONO from surface reactions in the poorly lit urban tunnel demonstrated the importance of NO2 conversion on urban surfaces, instead of NO2 conversion on the aerosol surface, for both daytime and night-time HONO even in polluted ambient air. The higher γ(NO2) on urban surfaces and the elevated HONO/NOx ratio from this study can help explain the missing HONO sources in urban areas.
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Ácido Nitroso , Emissões de Veículos , Aerossóis , Atmosfera , Dióxido de NitrogênioRESUMO
Design and fabrication of bimodal structures are essential for successful development of advanced air filters with ultralow airflow resistance. To realize this goal, simplified processing procedures are necessary for meeting the practical needs. Here, a bimodal protein fabric with high-performance air filtration, and effectively lowered airflow resistance is reported. The various functional groups of proteins provide versatile interactions with pollutants. By utilizing a novel and cost-effective "cross-axial" configuration with an optimized condition (75° of contacting angle between solution nozzle and cospinning solvent nozzle), the diffusion in Taylor cone is in situ controlled, which results in the successful production of bimodal protein fabric. The bimodal protein fabric (16.7 g/m2 areal density) is demonstrated to show excellent filtration performance for removing particulate matter (PM) pollutants and only causes 17.1 Pa air pressure drop. The study of multilayered protein fabric air filters shows a further improvement in filtration performance of removing 97% of PM0.3 and 99% of PM2.5 with a low airflow resistance (34.9 Pa). More importantly, the four-layered bimodal protein fabric shows an exceptional long-term performance and maintains a high removal efficiency in the humid environment. This study presents an effective and viable strategy for fabricating bimodal fibrous materials for advanced air filtration.
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Filtros de Ar , Difusão , Filtração , Material ParticuladoRESUMO
Incorporating nanofillers is one of the promising approaches for simultaneously boosting the ionic conductivity and mechanical properties of solid polymer electrolytes (SPEs). However, effectively creating faster ion-conduction pathways via nanofillers still remains a big challenge. Herein, core-shell protein-ceramic nanowires for more efficiently building fast ion-conduction networks in SPEs are reported. The core-shell protein-ceramic nanowires are fabricated via in situ growth of protein coating on the electrospun TiO2 nanowires in a subtly controlled protein-denaturation process. It is demonstrated that the core-shell protein@TiO2 nanowires effectively facilitate ion-conduction. As a result, the ionic conductivity, mechanical properties, electrochemical stability, and even Li+ transference number of the SPEs with core-shell protein@TiO2 nanowires are significantly enhanced. The contributions from the 1D morphology of the protein@TiO2 nanowires, and more importantly, the favorable protein structure for further promoting ion-conduction at the polymer-filler interfaces are analyzed. It is believed that the protein plays a pivotal role in dissociating lithium salts, which benefits from the strong interactions between protein and ions, making the protein serve as a unique "natural channel" for rapidly conducting Li+ . This study initiates an effective method of promoting ionic conductivity and constructing faster ion-conduction networks in SPEs via combining bio- and nanotechnology.
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Different types of childhood maltreatment have negative effects on individual mental and behavioural outcomes. However, most of previous studies investigated their effects separately. Little is known about the effects of co-occurring maltreatment profiles on adolescents' developmental outcomes and the potential protective factor. The current study sought to identify distinct profiles of childhood maltreatment and examine the effects of profiles of childhood maltreatment on internalising and externalising problems and the protective role of resilience based on two-wave longitudinal data, which was collected from a sample of 670 Chinese adolescents (Mage = 15.50, SDage = 0.75, 48.4% boys). Four profiles of childhood maltreatment, that is, No maltreatment (67.9%), High neglect (23.0%), High abuse and neglect/Low sexual abuse (5.0%), and Multi-maltreatment (4.1%), were identified. Adolescents in High neglect, High abuse and neglect/Low sexual abuse, and Multi-maltreatment profiles were more likely to report internalising and externalising problems. Further, significant moderating effects of resilience only emerged for the association between the High neglect profile and internalising problems, such that high levels of resilience may weaken the association between the High neglect profile and internalising problems. Our findings revealed the importance and utility of identifying maltreatment profiles to tailor treatment based on specific maltreatment experiences. Resilience-oriented intervention could be considered for Chinese adolescents who have experienced high neglect.
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Maus-Tratos Infantis , Transtornos do Comportamento Infantil , Resiliência Psicológica , Masculino , Adolescente , Humanos , Criança , FemininoRESUMO
Accumulating evidence has indicated an increased risk of acute pancreatitis in individuals with inflammatory bowel disease (IBD); however, the establishment of a clear and direct causal connection between IBD and acute pancreatitis remains uncertain. Utilizing genetic data from publicly accessible genome-wide association studies (GWAS), we conducted a 2-sample MR analysis to identify the associations between IBD, ulcerative colitis (UC), Crohn disease (CD), and acute pancreatitis risk. Rigorous quality control steps ensured the selection of eligible single nucleotide polymorphisms (SNPs) with strong associations to IBD. The primary estimation used the inverse-variance weighted method. We also assessed heterogeneity, potential pleiotropy, and conducted sensitivity analyses. The direction of causality was confirmed using the Steiger test. The MR analysis showed that IBD increased the risk of acute pancreatitis (IVW: OR = 1.032, 95% CI: 1.006-1.06, P = .015). Among the subgroup of IBD, CD (IVW: OR = 1.034, 95% CI: 1.008-1.06, P = .007) indicates a significant increase in the risk of acute pancreatitis compared to UC (IVW: OR = 1.02, 95% CI: 0.99-1.051, P = .189). The MR analysis assessing the association between CD and acute pancreatitis showed no evidence of heterogeneity or horizontal pleiotropy. Likewise, the leave-one-out (LOO) method indicated no significant influence of any individual SNP on the overall findings. In addition, the Steiger direction test revealed that CD was the cause for increased risk of acute pancreatitis, but not vice versa. In summary, this research pioneers in proposing a causal relationship between CD and acute pancreatitis among the European population.
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Colite Ulcerativa , Doença de Crohn , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Pancreatite , Polimorfismo de Nucleotídeo Único , Humanos , Colite Ulcerativa/genética , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/complicações , Doença de Crohn/genética , Doença de Crohn/epidemiologia , Pancreatite/genética , Pancreatite/epidemiologia , Pancreatite/etiologia , Predisposição Genética para Doença , Fatores de Risco , Doença AgudaRESUMO
Advanced solid electrolytes with strong adhesion to other components are the key for the successes of solid-state batteries. Unfortunately, traditional solid electrolytes have to work under high compression to maintain the contact inside owing to their poor adhesion. Here, a concept of high-entropy tape electrolyte (HETE) is proposed to simultaneously achieve tape-like adhesion, liquid-like ion conduction, and separator-like mechanical properties. This HETE is designed with adhesive skin layer on both sides and robust skeleton layer in the middle. The significant properties of the three layers are enabled by high-entropy microstructures which are realized by harnessing polymer-ion interactions. As a result, the HETE shows high ionic conductivity (3.50 ± 0.53 × 10-4 S cm-1 at room temperature), good mechanical properties (toughness 11.28 ± 1.12 MJ m-3, strength 8.18 ± 0.28 MPa), and importantly, tape-like adhesion (interfacial toughness 231.6 ± 9.6 J m-2). Moreover, a compression-free solid-state tape battery is finally demonstrated by adhesion-based assembling, which shows good interfacial and electrochemical stability even under harsh mechanical conditions, such as twisting and bending. The concept of HETE and compression-free solid-state tape batteries may bring promising solutions and inspiration to conquer the interface challenges in solid-state batteries and their manufacturing.
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A polymer separator plays a pivotal role in battery safety, overall electrochemical performance, and cell assembly process. Traditional separators are separately produced from the electrodes and dominated by porous polyolefin thin films. In spite of their commercial success, today's separators are facing growing challenges with the increasing demand on the device safety and performance. As an attempt to address this urgent need, here, we propose a concept of in situ separator technology by manipulating the two-dimensional (2D) microfluid nanophase separation (2D-MFPS) of a poly(vinylidene difluoride)/lithium salt solution during drying. Particularly, nanophase separation is effectively regulated by low humidity, salt type, and compositions. For application studies, this 2D-MFPS is directly performed onto commercial electrodes under drying conditions with low humidity to fabricate a high-performance in situ separator with thickness and porous structures comparable to those of commercial Celgard separators. This in situ separator shows superior performance in high-temperature stability and wetting capability to a variety of liquid electrolytes. Finally, pouch cells with this in situ separator technology are successfully assembled with an extremely simplified separator-stacking-free process and demonstrate stable cycle performance due to the well-controlled porous structures and electrode-separator interface.
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Stable inversion represents a classic approach to achieve the exact inverse input for non-minimum-phase (NMP) systems. Solutions deduced based on state-space equations and transfer functions have been frequently proposed, however they are basically developed in the infinite-time horizon and are inherently time-domain computation methods. Considering the practical finite-time tracking tasks, this paper investigates the finite-time stable inversion problem. In particular, the discrete-frequency-domain solution which enables frequency-domain computation is studied. As the main contribution of the paper, the accuracy issues of the discrete-frequency-domain solution are revealed and an easy-to-use procedure is provided to improve the inversion accuracy by utilizing pre-actuation and post-actuation methods. Simulation and experiment both verify the effectiveness of the developed discrete-frequency-domain stable inversion technique.
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Nitrated aromatic compounds (NACs) are important components of brown carbon (BrC), and their health and climate effects are of wide concern. Biomass burning is a major contributor to NACs in the atmosphere, yet NACs emitted from biomass burning are poorly constrained. In this study particulate NACs from open burning of corn straws were characterized in terms of their compositions, light absorption and toxic equivalents. 1, 6-dinitropyrene was the most abundant species among the measured nitropolycyclic aromatic hydrocarbons (NPAHs) with a share of 13.4% in total NPAHs, while 4-nitrocatechol was the most abundant nitrophenol (NP) species and accounted for 25.4% of measured NPs. 2-nitropyrene, widely used as a marker of secondary formation of NPAHs, was found to be the second most abundant NPAHs (13.3% of the total NPAHs) in the particulate matter (PM) primarily emitted from corn straw burning, and thus is inappropriate to be an indicator of the secondary formation. The measured primary NACs could only explain a negligible part (0.2%) of the light absorption by BrC. Although the concentrations of 9 toxic NACs were less than one-third of the 16 USEPA priority PAHs, their benzo(a)pyrene toxic equivalency quotients however were approximately 10 times that of the 16 PAHs. This study suggests that in comparison of PAHs from straw burning, NACs should be given greater attention due to their potentially higher toxic effects.
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Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Atmosféricos/análise , Nitrocompostos , Zea mays , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poeira , Carvão Mineral/análise , Monitoramento Ambiental , ChinaRESUMO
A diabetic wound is a typical chronic wound with a long repair process and poor healing effects. It is an effective way to promote diabetic wound healing to design electrospinning nanofiber films with drug-assisted therapy, good air permeability and, a multilayer functional structure. In this paper, a diabetic wound dressing with a "sandwich-like" structure was designed. Metformin hydrochloride, loaded in the hydrophilic PVA inner layer, could effectively promote diabetic wound healing. The drug release was slowed down by osmosis. The laminate film dressing had good mechanical properties, with tensile strength and elongation at break reaching 5.91 MPa and 90.47 %, respectively, which was close to human skin. The laminate film loaded with erythromycin and puerarin in the hydrophobic PLA outer layer had good antibacterial properties. In addition, due to the high specific surface of the electrostatic spun film, it exhibited high water vapor permeability. It facilitates the gas exchange between the wound and the outside world. The cell experiments proved that the laminate film dressing had good biocompatibility. There was no toxic side effect on cell proliferation. In the diabetic animal wound model, it was shown that the closure rate of diabetic wound repair by laminate film reached 91.11 % in the second week. Our results suggest that the "sandwich-like" nanofiber film dressing could effectively promote the healing process and meet the various requirements of diabetic wound dressing as a promising candidate for future clinical application of chronic wound dressings.
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Diabetes Mellitus , Metformina , Nanofibras , Animais , Humanos , Cicatrização , Álcool de Polivinil/química , Nanofibras/química , Metformina/farmacologia , Eletricidade Estática , Bandagens , Poliésteres/química , Antibacterianos/farmacologiaRESUMO
Bacterial and fungal contamination have become major factors in fruit spoilage and damage, posing a potential risk to human health. In this work, polylactic acid (PLA) nanofibers combined with Ag2O-hemp fibers for a good antimicrobial effect were developed and applied to antimicrobial fruit fresh-keeping packages. The results of molecular simulation calculations showed that the strength of hydrogen bonds between Ag2O and hemp fibers reached 45.522 kJ·mol-1, which proved that Ag2O and with hemp fibers formed a stable deposition. The Ag2O-hemp fibers modified electrospun polylactic acid nanofibrous composite film exhibited favorable mechanical properties. The tensile strength reached 5.23 ± 0.05 MPa and the elongation at break reached 105.56 ± 3.95 %. The obtained nanofibrous composite film has good antibacterial activity against E. coli, S. aureus, A. niger, and Penicillium, which indicated that they could effectively inhibit the growth of bacteria and fungi. The cell experiments proved that the nanofibrous composite film had good biocompatibility with a cell survival rate of 100 %. The experimental results on the fresh-keeping of red grapes showed that the PLA nanofibrous composite film modified by the Ag2O-hemp fibers could effectively prolong the spoilage time of red grapes at room temperature. Compared with the blank group, the freshness period of PLA nanofiber film modified by Ag2O-hemp fibers could be extended for more than 5 days. The hardness of 15 days (1.94 ± 0.19 × 105 Pa) was basically the same as that of 1 day (2.05 ± 0.06 × 105 Pa). The results were superior to commercially available PE preservation films. The above research results indicated that the Ag2O-hemp fibers modified PLA nanofibrous composite film had potential application prospects in the field of fruit fresh-keeping package.