Mn-MOF derived manganese sulfide as peroxymonosulfate activator for levofloxacin degradation: An electron-transfer dominated and radical/nonradical coupling process.

Recently, transition metal sulfides have attracted much attention due to their better catalytic capacities as peroxymonosulfate (PMS) activator than their metal oxide counterparts. However, the systematic studies on PMS activation using transition metal sulfides are still lacking. In this work, manganese sulfide (MnS) materials were synthesized via a MOFs-derived method and utilized for PMS activation to degrade levofloxacin (LVF) in water for the first time. As expected, MnS exhibited remarkable LVF degradation efficiency by PMS activation, which was distinctly higher than Mn2O3. The results of quenching experiments, electro spin resonance identification and electrochemical tests indicated that electron-transfer progress was the dominant mechanism in α-MnS/PMS system. Meanwhile, the presence of 1O2 and radicals further became the removal of LVF by α-MnS/PMS system into a radical/nonradical coupling process. The superior electrical conductivity of α-MnS than α-Mn2O3 was revealed by DFT calculations, which resulted in the higher catalytic capacity of α-MnS. The result of XPS also indicated the S species in MnS accelerated the recycle of Mn(IV)/Mn(II) and then promoted the generation of radicals. Furthermore, the influence of various environmental conditions on LVF removal and the reusability of α-MnS were also investigated, which demonstrated the high application potential of α-MnS/PMS system. Finally, six possible pathways of LVF oxidation in the system were proposed based on the identified byproducts and their ecotoxicity was evaluated with ECOSAR method. This work promotes the fundamental understanding of PMS activation by α-MnS and provides useful information for practical application of manganese sulfide in water treatment.

The steroid hormone 20-hydroxyecdysone binds to dopamine receptor to repress lepidopteran insect feeding and promote pupation.

Holometabolous insects stop feeding at the final larval instar stage and then undergo metamorphosis; however, the mechanism is unclear. In the present study, using the serious lepidopteran agricultural pest Helicoverpa armigera as a model, we revealed that 20-hydroxyecdysone (20E) binds to the dopamine receptor (DopEcR), a G protein-coupled receptor, to stop larval feeding and promote pupation. DopEcR was expressed in various tissues and its level increased during metamorphic molting under 20E regulation. The 20E titer was low during larval feeding stages and high during wandering stages. By contrast, the dopamine (DA) titer was high during larval feeding stages and low during the wandering stages. Injection of 20E or blocking dopamine receptors using the inhibitor flupentixol decreased larval food consumption and body weight. Knockdown of DopEcR repressed larval feeding, growth, and pupation. 20E, via DopEcR, promoted apoptosis; and DA, via DopEcR, induced cell proliferation. 20E opposed DA function by repressing DA-induced cell proliferation and AKT phosphorylation. 20E, via DopEcR, induced gene expression and a rapid increase in intracellular calcium ions and cAMP. 20E induced the interaction of DopEcR with G proteins αs and αq. 20E, via DopEcR, induced protein phosphorylation and binding of the EcRB1-USP1 transcription complex to the ecdysone response element. DopEcR could bind 20E inside the cell membrane or after being isolated from the cell membrane. Mutation of DopEcR decreased 20E binding levels and related cellular responses. 20E competed with DA to bind to DopEcR. The results of the present study suggested that 20E, via binding to DopEcR, arrests larval feeding and promotes pupation.

Multi-Model- and Soft-Transition-Based Height Soft Sensor for an Air Cushion Furnace.

The floating height of the strip in an air cushion furnace is a key parameter for the quality and efficiency of production. However, the high temperature and high pressure of the working environment prevents the floating height from being directly measured. Furthermore, the strip has multiple floating states in the whole operation process. It is thus difficult to employ a single model to accurately describe the floating height in different states. This paper presents a multi-model soft sensor to estimate the height based on state identification and the soft transition. First, floating states were divided using a partition method that combined adaptive k-nearest neighbors and principal component analysis theories. Based on the identified results, a hybrid model for the stable state, involving a double-random forest model for the vibration state and a soft-transition model, was created to predict the strip floating height. In the hybrid model for the stable state, a mechanistic model combined thick jet theory and the equilibrium equation of force to cope with the lower floating height. In addition, a novel soft-transition model based on data gravitation that further reflects the intrinsic process characteristic was developed for the transition state. The effectiveness of the proposed approach was validated using a self-developed air cushion furnace experimental platform. This study has important value for the process prediction and control of air cushion furnaces.

The Steroid Hormone 20-Hydroxyecdysone Enhances Gene Transcription through the cAMP Response Element-binding Protein (CREB) Signaling Pathway.

Animal steroid hormones regulate gene transcription through genomic pathways by binding to nuclear receptors. These steroid hormones also rapidly increase intracellular calcium and cyclic adenosine monophosphate (cAMP) levels and activate the protein kinase C (PKC) and protein kinase A (PKA) nongenomic pathways. However, the function and mechanism of the nongenomic pathways of the steroid hormones are unclear, and the relationship between the PKC and PKA pathways is also unclear. We propose that the steroid hormone 20-hydroxyecdysone (20E) activates the PKA pathway to enhance 20E-induced gene transcription in the lepidopteran insect Helicoverpa armigera The expression of the catalytic subunit 1 of PKA (PKAC1) increased during metamorphosis, and PKAC1 knockdown blocked pupation and repressed 20E-responsive gene expression. 20E regulated PKAC1 phosphorylation at threonine 200 and nuclear translocation through an ecdysone-responsive G-protein-coupled receptor 2. PKAC1 induced cAMP response element-binding protein (CREB) phosphorylation at serine 143, which bound to the cAMP response element on DNA to enhance 20E-responsive gene transcription. Through ecdysone-responsive G-protein-coupled receptor 2, 20E increased cAMP levels, which induced CREB PKA phosphorylation and 20E-responsive gene expression. This study demonstrates that the PKA/CREB pathway tightly and critically regulates 20E-induced gene transcription as well as its relationship with the 20E-induced PKC pathway.

HDAC4 stabilizes SIRT1 via sumoylation SIRT1 to delay cellular senescence.

The nicotinamide adenine dinucleotide-dependent protein deacetylase silent information regulator 2 (Sir2) regulates cellular lifespan in several organisms. Histone deacetylase 4 (HDAC4) belongs to the class IIa group of HDACs; this class of HDACs is composed of proteins that are important regulators of gene expression that control pleiotropic cellular functions. However, the role of HDAC4 in cellular senescence is still unknown. This study shows that the expression patterns of HDAC4 and Sirtuin 1 (SIRT1; the mammalian homolog of Sir2) are positively correlated during cellular senescence. Moreover, the overexpression of HDAC4 delays senescence, whereas the knockdown of HDAC4 leads to premature senescence in human fibroblasts. Furthermore, it is demonstrated that HDAC4 increases endogenous SIRT1 expression by enhancing its sumoylation modification levels, thereby stabilizing its protein levels. This study, therefore, provides a new molecular mechanism for the regulation of cellular senescence.

Removal of 2-ClBP from soil-water system using activated carbon supported nanoscale zerovalent iron.

We explored the feasibility and removal mechanism of removing 2-chlorobiphenyl (2-ClBP) from soil-water system using granular activated carbon (GAC) impregnated with nanoscale zerovalent iron (reactive activated carbon or RAC). The RAC samples were successfully synthesized by the liquid precipitation method. The mesoporous GAC based RAC with low iron content (1.32%) exhibited higher 2-ClBP removal efficiency (54.6%) in the water phase. The result of Langmuir-Hinshelwood kinetic model implied that the different molecular structures between 2-ClBP and trichloroethylene (TCE) resulted in more difference in dechlorination reaction rates on RAC than adsorption capacities. Compared to removing 2-ClBP in the water phase, RAC removed the 2-ClBP more slowly in the soil phase due to the significant external mass transfer resistance. However, in the soil phase, a better removal capacity of RAC was observed than its base GAC because the chemical dechlorination played a more important role in total removal process for 2-ClBP. This important result verified the effectiveness of RAC for removing 2-ClBP in the soil phase. Although reducing the total RAC removal rate of 2-ClBP, soil organic matter (SOM), especially the soft carbon, also served as an electron transfer medium to promote the dechlorination of 2-ClBP in the long term.

Effects of metalloprotease anthrax lethal factor on its peptide-based inhibitor R9LF-1.

The metalloprotease lethal factor (LF) from Bacillus anthracis plays a vital role in anthrax toxin action, and thus becomes a target for anti-anthrax therapy. Following the guidelines based on existing metalloprotease inhibitors, we designed a 'first-generation' LF inhibitor R9LF-1. This inhibitor was shown to be very stable by itself in a wide range of pH and temperature and able to inhibit LF activity in vitro. However, as we reported previously in the presence of LF, this inhibitor was degraded to a small molecular weight species, resulting in a significantly decreased ability to protect MAPKK from cleavage by LF as well as to protect murine macrophages from lethal toxin. In order to elucidate this unusual phenomenon to build solid basis for high-efficiency LF inhibitor development, we performed extensive research to study the effect of LF on its peptide-based inhibitor. Effects of temperature and incubation period of time on generation of the smaller peptide (short version R9LF-1) by LF as well as its catalytic domain were analyzed. We found that LF degraded R9LF-1 with maximum efficiency in the pH range of 7.0-8.5, which correlates well with the range of LF enzymatic activity with its native substrate. The degradation showed a deviation from normal hyperbolic kinetics but a similarity to the kinetics profile of an enzyme-catalyzed reaction with positive cooperativity. The short version R9LF-1 had decreased inhibitory activity toward LF; surprisingly, BIAcore results suggested a better affinity for its binding to LF. In addition, R9LF-1 was not hydrolyzed by other common proteases, such as chymotrypsin and pepsin, suggesting hydrolysis of the bond between amino acid and hydroxamate groups is unique to LF. This study calls for caution when designing peptide-based LF inhibitors and when interpreting effects of these types of inhibitors.

[Study on Chemical Constituents in Seeds of Datura metel from Xinjiang].

OBJECTIVE: To study the chemical constituents in the seeds of Datura metel from Xinjiang Province. METHODS: The constituents were isolated and purified by silica gel, ODS and Sephadex LH-20 column chromatographic methods. Their chemical structures were analyzed and identified on the basis of physical and chemical properties and spectral data. RESULTS: Ten compounds were isolated and identified as Isofraxidin (1), Scopatone (2), Daturadiol (3),1,4-Benzenediol (4), Arenarine D (5), Vanillin (6), N-trans-Feruloyl-tyramine (7), Scopoletin (8), G-Sitosterol (9) and Hyoscyamilactol (10). CONCLUSION: Compounds 1 and 2 are firstly isolated from the plants in Solanaceae, compounds 3-8 are firstly isolated from this plant.

Understanding cadherin EGF LAG seven-pass G-type receptors.

The cadherin epidermal growth factor (EGF) laminin G (LAG) seven-pass G-type receptors (CELSRs) are a special subgroup of adhesion G protein-coupled receptors, which are pivotal regulators of many biologic processes such as neuronal/endocrine cell differentiation, vessel valve formation, and the control of planar cell polarity during embryonic development. All three members of the CELSR family (CELSR1-3) have large ecto-domains that form homophilic interactions and encompass more than 2000 amino acids. Mutations in the ecto-domain or other gene locations of CELSRs are associated with neural tube defects and other diseases in humans. Celsr knockout (KO) animals have many developmental defects. Therefore, specific agonists or antagonists of CELSR members may have therapeutic potential. Although significant progress has been made regarding the functions and biochemical properties of CELSRs, our knowledge of these receptors is still lacking, especially considering that they are broadly distributed but have few characterized functions in a limited number of tissues. The dynamic activation and inactivation of CELSRs and the presence of endogenous ligands beyond homophilic interactions remain elusive, as do the regulatory mechanisms and downstream signaling of these receptors. Given this motivation, future studies with more advanced cell biology or biochemical tools, such as conditional KO mice, may provide further insights into the mechanisms underlying CELSR function, laying the foundation for the design of new CELSR-targeted therapeutic reagents. The cadherin EGF LAG seven-pass G-type receptors (CELSRs) are a special subgroup of adhesion G protein-coupled receptors (GPCRs), which have large ecto-domains that form homophilic interactions and encompass more than 2000 amino acids. Recent studies have revealed that CELSRs are pivotal regulators of many biological processes, such as neuronal/endocrine cell differentiation, vessel valve formation and the control of planar cell polarity during embryonic development.

Mitochondria-Targeting and Oxygen Self-Supplying Eccentric Hollow Nanoplatform for Enhanced Breast Cancer Photodynamic Therapy.

Photodynamic therapy (PDT) has received increasing attention for tumor therapy due to its minimal invasiveness and spatiotemporal selectivity. However, the poor targeting of photosensitizer and hypoxia of the tumor microenvironment limit the PDT efficacy. Herein, eccentric hollow mesoporous organic silica nanoparticles (EHMONs) are prepared by anisotropic encapsulation and hydrothermal etching for constructing PDT nanoplatforms with targeting and hypoxia-alleviating properties. The prepared EHMONs possess a unique eccentric hollow structure, a uniform size (300 nm), a large cavity, and ordered mesoporous channels (2.3 nm). The EHMONs are modified with the mitochondria-targeting molecule triphenylphosphine (CTPP) and photosensitizers chlorin e6 (Ce6). Oxygen-carrying compound perfluorocarbons (PFCs) are further loaded in the internal cavity of EHMONs. Hemolytic assays and in vitro toxicity experiments show that the EHMONs-Ce6-CTPP possesses very good biocompatibility and can target mitochondria of triple-negative breast cancer, thus increasing the accumulation of photosensitizers Ce6 at mitochondria after entering cancer cells. The EHMONs-Ce6-CTPP@PFCs with oxygen-carrying ability can alleviate hypoxia after entering in the cancer cell. Phantom and cellular experiments show that the EHMONs-Ce6-CTPP@PFCs produce more singlet oxygen reactive oxygen species (ROSs). Thus, in vitro and in vivo experiments demonstrated that the EHMONs-Ce6-CTPP@PFCs showed excellent treatment effects for triple-negative breast cancer. This research provides a new method for a targeting and oxygen-carrying nanoplatform for enhancing PDF effectiveness.

Nucleus-Spike 3D Hierarchical Superstructures via a Lecithin-Mediated Biomineralization Approach.

3D hierarchical superstructures (3DHSs) are key products of nature's evolution and have raised wide interest. However, the preparation of 3DHSs composed of building blocks with different structures is rarely reported, and regulating their structural parameters is challenging. Herein, a simple lecithin-mediated biomineralization approach is reported for the first time to prepare gold 3DHSs composed of 0D nucleus and 1D protruding dendritic spikes. It is demonstrated that a hydrophobic complex by coordination of disulfiram (DSF) with a share of chloroauric acid is the key to forming the 3DHSs. Under the lecithin mediation, chloroauric acid is first reduced to form the 0D nucleus, followed by the spike growth through the reduction of the hydrophobic complex. The prepared 3DHSs possess well-defined morphology with a spike length of ≈95 nm. Notably, the hierarchical spike density is systematically manipulated from 38.9% to 74.3% by controlling DSF concentrations. Moreover, the spike diameter is regulated from 9.2 to 12.9 nm by selecting different lecithin concentrations to tune the biomineralization process. Finite-difference time-domain (FDTD) simulations reveal that the spikes form "hot spots". The dense spike structure endows the 3DHSs with sound performance in surface-enhanced Raman scattering (SERS) applications.

Phosphatidate phosphatase Lipin1 involves in diabetic encephalopathy pathogenesis via regulating synaptic mitochondrial dynamics.

Diabetic encephalopathy (DE) is a common central nervous system complication of diabetes mellitus without effective therapy currently. Recent studies have highlighted synaptic mitochondrial damages as a possible pathological basis for DE, but the underlying mechanisms remain unclear. Our previous work has revealed that phosphatidate phosphatase Lipin1, a critical enzyme involved with phospholipid synthesis, is closely related to the pathogenesis of DE. Here, we demonstrate that Lipin1 is significantly down-regulated in rat hippocampus of DE. Knock-down of Lipin1 within hippocampus of normal rats induces dysregulation of homeostasis in synaptic mitochondrial dynamics with an increase of mitochondrial fission and a decrease of fusion, then causes synaptic mitochondrial dysfunction, synaptic plasticity deficits as well as cognitive impairments, similar to that observed in response to chronic hyperglycemia exposure. In contrast, an up-regulation of Lipin1 within hippocampus in the DE model ameliorates this cascade of dysfunction. We also find that the effect of Lipin1 that regulating mitochondrial dynamics results from maintaining appropriate phospholipid components in the mitochondrial membrane. In conclusion, alterations in hippocampal Lipin1 contribute to hippocampal synaptic mitochondrial dysfunction and cognitive deficits observed in DE. Targeting Lipin1 might be a potential therapeutic strategy for the clinical treatment of DE.

Liquiritin attenuates advanced glycation end products-induced endothelial dysfunction via RAGE/NF-κB pathway in human umbilical vein endothelial cells.

Advanced glycation end products (AGEs)-induced vasculopathy, including oxidative stress, inflammation and apoptosis responses, contributes to the high morbidity and mortality of coronary artery diseases in diabetic patients. The present study was conducted to evaluate the protective activity of liquiritin (Liq) on AGEs-induced endothelial dysfunction and explore its underlying mechanisms. After pretreatment with Liq, a significant reduction in AGEs-induced apoptosis, as well as reactive oxygen species generation and malondialdehyde level in human umbilical vein endothelial cells (HUVECs) were observed via acridine orange/ethidium bromide fluorescence staining test. Notably, Liq also significantly increased AGEs-reduced superoxide dismutase activity. Furthermore, the pretreatment with receptor for advanced glycation end products (RAGE)-antibody or Liq remarkably down-regulated TGF-beta1 and RAGE protein expressions and significantly blocked NF-κB activation which were proved by immunocytochemistry or immunofluorescence assays. These results indicated that Liq held potential for the protection on AGEs-induced endothelial dysfunction via RAGE/NF-κB pathway in HUVECs and might be a promising agent for the treatment of vasculopathy in diabetic patients.

Long period fiber grating transverse load effect-based sensor for the omnidirectional monitoring of rebar corrosion in concrete.

From the angle of sensitivity of the long period fiber grating (LPFG) resonant transmission spectrum, we demonstrate the sensitivity of LPFG resonance peak amplitude changing with transverse loads. The design of a resonant peak modulation-based LPFG rebar corrosion sensor is described by combining the spectral characteristics of LPFG with the expansion state monitoring of rebar corrosion. LPFG spectrum curves corresponding with different rebar corrosion status of the environment under test are captured by the monitoring technique of LPFG transmission spectra, and the relationship between the resonance peak amplitude change and the state of rebar corrosion is obtained, that is, the variation of LPFG resonance peak amplitude increases with the intensifying of the degree of rebar corrosion. The experimental results numerically show that the sensor response has good regularity for a wide range of travel.

Performance and mechanism of simultaneous Sb(III) and Cd(II) removal from water by Fe-Mn binary oxide/bone char.

A novel Fe-Mn binary oxide (FMBO)/bone char composite (FMBC) was synthesized and utilized to simultaneously adsorb Sb(III) and Cd(II) from aqueous phase in this study. The successful loading of Fe-Mn binary oxide on the bone char surface was revealed by the results of scanning electron microscope, X-ray diffraction patterns, and energy dispersive spectroscopy of FMBC. The FMBC exhibited remarkable ability of simultaneous removing Sb(III) and Cd(II) from aqueous, and the presence of Cd(II) enhanced Langmuir theoretical maximum adsorption capacity for Sb(III) significantly from 67.8 to 209.0 mg/g. Besides, FMBC could efficiently remove Sb(III) and Cd(II) in the wide initial pH range of 2-7. The influences of ionic strength, co-existing anions, humic acid, and temperature on the adsorption of Sb(III) and Cd(II), and the application potential of FMBC in actual groundwater were investigated. The main mechanisms of Sb(III) and Cd(II) adsorption onto FMBC involved redox, electrostatic interaction, surface complexation, ion exchange, and precipitation. The result of X-ray photoelectron spectroscopy and mapping spectrum analysis revealed that Mn(III) on FMBC played the key role in the Sb(III) oxidation, while FeOOH worked as the adsorption sites of FMBC. Meanwhile, the hydroxyapatite on FMBC also contributed to the removal of Cd(II). The presence of Cd(II) not only increased the positive charge on the surface of FMBC but also formed the Fe-Sb-Cd ternary complex, promoting the removal of Sb. This work provides valuable information for the application of FMBO/bone char as a cost-effective adsorbent to remediate co-pollution of Sb(III) and Cd(II) in aqueous environment.

Lipin2 ameliorates diabetic encephalopathy via suppressing JNK/ERK-mediated NLRP3 inflammasome overactivation.

OBJECTIVES: Diabetic encephalopathy (DE) is a common complication of diabetes in the central nervous system, which can cause cognitive dysfunction in patients. However, its pathophysiological mechanism has not been elucidated, and thus effective prevention and treatment methods are still lacking.Previous studies reported that neuroinflammation involved in the central neuropathy, while lipin2 plays an important role in inflammatory response.Therefore, we aimed to investigate the effects of lipin2 on regulating inflammatory response in the pathogenesis of DE. METHODS: BV2 cells were treated with high glucose and infected with lipin2 overexpression or knockdown virus to observe the cell viability. Then, we constructed a mouse model of DE, and constructed a lipin2 knockdown or overexpression model by injecting lentivirus into the brain with stereotaxis. The expression of lipin2 in inflammatory bodies and related inflammatory factor signaling pathway-related proteins were examined by western blot and quantitative real-time PCR. Morris water maze was used to evaluate the spatial learning and memory of mice. RESULTS: High glucose decreased the expression of lipin2 in BV2 cells, while overexpression of lipin2 in BV2 cells significantly suppressed the inflammatory response and apoptosis induced by high glucose. Meanwhile, the expression of lipin2 was down-regulated in the hippocampus in a DE mice model. Up-regulation of lipin2 in the hippocampus of DE mice inhibited JNK/ERK signaling pathway, reduced NLRP3 inflammasome-mediated inflammatory response, down-regulated IL-1/TNF-α expression, and improved synaptic plasticity and cognitive dysfunction in mice. Conversely, knockdown of lipin2 increased NLRP3 inflammasome overactivation, caused neuronal abnormalities and cognitive impairment in mice. CONCLUSIONS: Lipin2 may play a neuroprotective role in DE by inhibiting JNK/ERK-mediated NLRP3 inflammasome overactivation and subsequent inflammatory responses. It may be a potential therapeutic target for DE therapy.

Genetic mutation signature for relapse prediction in normal karyotype acute myeloid leukemia.

Risk stratification for normal karyotype acute myeloid leukemia (NK-AML) remains unsatisfactory, which is reflected by the high incidence of leukemia relapse. This study aimed to evaluate the role of gene mutations and clinical characterization in predicting the relapse of patients with NK-AML. A prognostic system for NK-AML was constructed. A panel of gene mutations was explored using next-generation sequencing. A nomogram algorithm was used to build a genomic mutation signature (GMS) nomogram (GMSN) model that combines GMS, measurable residual disease, and clinical factors to predict relapse in 347 patients with NK-AML from four centers. Patients in the GMS-high group had a higher 5-year incidence of relapse than those in the GMS-low group (p < 0.001). The 5-year incidence of relapse was also higher in patients in the GMSN-high group than in those in the GMSN-intermediate and -low groups (p < 0.001). The 5-year disease-free survival and overall survival rates were lower in patients in the GMSN-high group than in those in the GMSN-intermediate and -low groups (p < 0.001) as confirmed by training and validation cohorts. This study illustrates the potential of GMSN as a predictor of NK-AML relapse.

2-Cyano-N'-[1-(pyridin-2-yl)ethyl-idene]acetohydrazide.

In the title compound, C(10)H(10)N(4)O, the dihedral angle between the pyridine ring and the -C=O(CH(2))CN group is 24.08 (12)°. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R(2) (2)(8) loops.

Data Augmentation Using Bitplane Information Recombination Model.

The performance of deep learning heavily depend on the quantity and quality of training data. But in many fields, well-annotated data are so difficult to collect, which makes the data scale hard to meet the needs of network training. To deal with this issue, a novel data augmentation method using the bitplane information recombination model (termed as BIRD) is proposed in this paper. Considering each bitplane can provide different structural information at different levels of detail, this method divides the internal hierarchical structure of a given image into different bitplanes, and reorganizes them by bitplane extraction, bitplane selection and bitplane recombination, to form an augmented data with different image details. This method can generate up to 62 times of the training data, for a given 8-bits image. In addition, this generalized method is model free, parameter free and easy to combine with various neural networks, without changing the original annotated data. Taking the task of target detection for remotely sensed images and classification for natural images as an example, experimental results on DOTA dataset and CIFAR-100 dataset demonstrated that, our proposed method is not only effective for data augmentation, but also helpful to improve the accuracy of target detection and image classification.

Atmospheric deposition of microplastics in the megalopolis (Shanghai) during rainy season: Characteristics, influence factors, and source.

Urban areas are the hardest hit by microplastic pollution, and deposition is an important part of microplastic migration and transport in the atmosphere, therefore, the study of microplastics in an urban atmospheric deposition is of great significance. This study aims to investigate the deposition characteristics of atmospheric microplastics in megapolis, to clarify the influence of meteorological and anthropogenic factors, and to analyze the sources of atmospheric microplastics. Six sampling sites in Shanghai were selected to collect atmospheric deposition samples during the rainy season. The mean deposition flux of microplastics was 3261.22 ± 2847.99 P·m-2·d-1 (median: 2559.70 P·m-2·d-1), and the types were mainly polyamide (PA, 27.79 %), polyethylene terephthalate (PET, 27.29 %), polypropylene (PP, 16.95 %), and polyvinyl fluoride (PVF, 12.88 %). The microplastic with the particle size of <1000 µm accounted for 88.23 %, and the shape was mainly fiber (73.55 %). The results of correlation analysis and variance analysis of microplastic characteristics with meteorological and anthropogenic factors (land-use, atmospheric pollutants, and urban indicators) showed that wind and precipitation had effects on deposition flux, size and shape, and were more significant at small scales (individual cities), while at large scales, the population was the main influence of microplastics. Atmospheric microplastics in Shanghai may be dominated by exogenous sources, through a combination of microplastic characteristics, wind and backward trajectories. This study further reveals the fate of urban atmospheric microplastics, which has implications for the study of global microplastic pollution.