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The identification of host factors with antiviral potential is important for developing effective prevention and therapeutic strategies against SARS-CoV-2 infection. Here, by using immortalized cell lines, intestinal organoids, ex vivo intestinal tissues and humanized ACE2 mouse model as proof-of-principle systems, we have identified lipolysis-stimulated lipoprotein receptor (LSR) as a crucial host defense factor against SARS-CoV-2 infection in the small intestine. Loss of endogenous LSR enhances ACE2-dependent infection by SARS-CoV-2 Spike (S) protein-pseudotyped virus and authentic SARS-CoV-2 virus, and exogenous administration of LSR protects against viral infection. Mechanistically, LSR interacts with ACE2 both in cis and in trans, preventing its binding to S protein, and thus inhibiting viral entry and S protein-mediated cell-cell fusion. Finally, a small LSR-derived peptide blocks S protein binding to the ACE2 receptor in vitro. These results identify both a previously unknown function for LSR in antiviral host defense against SARS-CoV-2, with potential implications for peptide-based pan-variant therapeutic interventions.
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2-Alkyl chromanone scaffold has become prominent in pharmaceuticals and natural compounds. Consequently, devising robust strategies for synthesizing 2-alkyl chromanones remains crucial. Here, multicomponent reactions were employed to synthesize 2-alkyl chromanones containing an oxazole moiety using 3-formylchromones, amines, and N-propargylamides as reactants. This method utilizes readily available feedstocks with a catalytic amount of Zn(OTf)2 and exhibits an impressive substrate scope compared to existing methods. Importantly, the synthesized compounds demonstrated highly selective anticancer activity against the DU145 cell line.
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Antineoplásicos , Cromonas , Ácidos de Lewis , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/síntesis química , Humanos , Cromonas/química , Cromonas/farmacología , Cromonas/síntesis química , Línea Celular Tumoral , Ácidos de Lewis/química , Estructura Molecular , Ensayos de Selección de Medicamentos Antitumorales , Proliferación Celular/efectos de los fármacos , Catálisis , Relación Estructura-ActividadRESUMEN
Macrophorins H (4) and L (5), two rare HMG-conjugate macrophorins along with three known macrophorins (1-3), three DMOA-derived meroterpenoids (6-8) and two ergosterol derivates (9-10) were isolated from sterilized rice medium cultured Penicillium sp. NX-05-G-3. Their structures were elucidated by 1D and 2D NMR. The cytotoxicities of all compounds were evaluated, and compounds 1 and 2 showed extensive cytotoxicity against human cancer cell lines Hela, SCC15, MDA-MB-453 and A549, with IC50 values ranging from 17.6 to 32.8 µM.
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Ensayos de Selección de Medicamentos Antitumorales , Penicillium , Penicillium/química , Humanos , Estructura Molecular , Células HeLa , Antineoplásicos/farmacología , Antineoplásicos/química , Línea Celular Tumoral , Terpenos/farmacología , Terpenos/químicaRESUMEN
An unexpected Ugi cascade reaction was developed for the facile construction of γ-lactam-fused pyridone derivatives with high tolerance of substrates. A C(sp3)-N bond and a C(sp2)-C(sp2) bond were formed together, accompanied by a chromone ring-opening in Ugi adducts, under the basic conditions without any metal catalyst for the whole process. Screening data of several difficult-to-inhibit cancer cell lines demonstrated that 7l displayed a high cytotoxicity against HCT116 cells (IC50 = 5.59 ± 0.78 µM). Taken together, our findings revealed new insights into the molecular mechanisms underlying compound 7l and provided potential usage of this scaffold for cancer therapeutics.
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Compuestos Heterocíclicos , Lactamas , Lactamas/farmacología , Piridonas/farmacología , Piridonas/química , MetalesRESUMEN
Operation lifetime, as an important parameter, determines the performance of phosphorescent organic light-emitting diodes (OLEDs). Unveiling the intrinsic degradation mechanism of emission material is crucial for improving the operation's lifetime. In this article, the photo-stabilities of tetradentate transition metal complexes, the popular phosphorescent materials, are explored by means of density functional theory (DFT) and time-dependent (TD)-DFT, aiming to illustrate the geometric signatures as important factors to control the photo-stabilities. Results indicate that for the tetradentate Ni(II), Pd(II), and Pt(II) complexes, the coordinate bonds of the Pt(II) complex exhibit stronger strength. It seems that the strengths of coordinate bonds are closely related to the atomic number of the metal center in the same group, which could be attributed to the various electron configurations. The effect of intramolecular and intermolecular interactions on ligand dissociation is also explored here. The large intramolecular steric hindrance and strong π-π interaction between the Pd(II) complexes caused by aggregation could effectively raise the energy barriers of the dissociation reaction, leading to an unfeasible reaction pathway. Moreover, the aggregation of Pd(II) complex can change the photo-deactivation mechanism as compared to that of monomeric Pd(II) complex, which is favored for avoiding the TTA (triplet-triplet annihilation) process.
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A practical one-pot protocol has been developed to synthesize diarylacetylenes from arylaldehydes by treatment with 1-(arylmethyl)benzotriazoles and LiN(SiMe3)2. The reaction proceeded through imine formation, Mannich-type addition and double elimination to deliver products in up to 99% yields with broad substrate scope. In addition, gram-scale synthesis of 1-bromo-4-(phenylethynyl)benzene has been demonstrated.
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Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tuberculosis) is a fatal infectious disease to human health, and the drug tolerance and immune evasion of M. tuberculosis were reported to be related to its biofilm formation; however, the difficulty of M. tuberculosis biofilm culture and its unknown global mechanism impede its further research. Here, we developed a modified in vitro M. tuberculosis biofilm model with shorter culture time. Then we used Illumina RNA-seq technology to determine the global gene expression profile of M. tuberculosis H37Rv biofilms. Over 437 genes are expressed at significantly different levels in biofilm cells than in planktonic cells; among them, 153 were downregulated and 284 were upregulated. Go enrichment analysis and KEGG pathway analysis showed that genes involved in biosynthesis and metabolism of sulfur metabolism, steroid degradation, atrazine degradation, mammalian cell entry protein complex, etc. are involved in M. tuberculosis biofilm cells. Especially, ATP-binding cassette (ABC) transporters Rv1217c and Rv1218c were significantly upregulated in biofilm, whereas efflux pump inhibitors (EPIs) piperine and 1-(1-naphthylmethyl)-piperazine (NMP) inhibited biofilm formation and the expression of the Rv1217c and Rv1218c genes in a concentration-dependent manner, respectively, indicating Rv1217c and Rv1218c are potential target genes of M. tuberculosis biofilm. This study is the first RNA-Seq-based transcriptome profiling of M. tuberculosis biofilms and provides insights into a potential strategy for M. tuberculosis biofilm inhibition. KEY POINTS: ⢠Characterize M. tuberculosis transcriptomes in biofilm cells by RNA-seq. ⢠Inhibit the expression of Rv1217c and Rv1218c repressed biofilm formation.
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Mycobacterium tuberculosis , Tuberculosis , Biopelículas , Perfilación de la Expresión Génica , Estudios de Asociación Genética , Humanos , Mycobacterium tuberculosis/genética , TranscriptomaRESUMEN
Diabetes mellitus (DM) affects bone metabolism and leads to osteoporosis; however, its pathogenetic mechanisms remain unknown. We found that high glucose (HG) conditions induced the production of reactive oxygen species (ROS) and the expression of proteins related to MAPKs [phosphorylated (p)-ERK, p-JNK, and p-p38], NF-κB (NF-κB, p-IκB, and IKK), and NACHT-LRR-PYD domains-containing protein 3 (NALP3) (NLRP3) [apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), caspase-1, IL-18, IL-1ß, and NLRP3] in osteoclasts (OCs) in vitro. Further analysis showed that in HG-induced OCs, ROS is an upstream signal for MAPKs, NF-κB, and the NLRP3 inflammasome. Moreover, MAPKs mediated the activation of NF-κB and NLRP3, whereas NF-κB up-regulated the NLRP3 inflammasome response. Interestingly, HG inducement enhanced the bone resorption of OCs but inhibited their efferocytosis, whereas insulin and lipoxin A4 (4) treatment reversed this phenomenon. In streptozotocin-induced diabetic rats in vivo, the numbers and the bone-resorption capacity of OCs as well as the serum levels of TRACP-5b were significantly increased, and the expression of MAPK-, NF-κB-, and NLRP3 inflammasome-related proteins in the proximal tibia were also significantly elevated; however, treatment with insulin and LXA4 reversed this elevation. Together, these results demonstrated that the activation of ROS/MAPKs/NF-κB/NLRP3 and the inhibition of efferocytosis in OCs are the main causes of osteoporosis in DM.-An, Y., Zhang, H., Wang, C., Jiao, F., Xu, H., Wang, X., Luan, W., Ma, F., Ni, L., Tang, X., Liu, M., Guo, W., Yu, L. Activation of ROS/MAPKs/NF-κB/NLRP3 and inhibition of efferocytosis in osteoclast-mediated diabetic osteoporosis.
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Complicaciones de la Diabetes/metabolismo , Diabetes Mellitus Experimental/metabolismo , Sistema de Señalización de MAP Quinasas , Osteoclastos/metabolismo , Osteoporosis/metabolismo , Animales , Complicaciones de la Diabetes/genética , Complicaciones de la Diabetes/patología , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patología , Quinasas MAP Reguladas por Señal Extracelular/genética , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Masculino , FN-kappa B/genética , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Osteoclastos/patología , Osteoporosis/genética , Osteoporosis/patología , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Previous studies have demonstrated that insulin-like growth factor-I (IGF-1) and reactive oxygen species (ROS) are involved in the development and progression of various cancers. However, their regulatory mechanism remains unknown. In this study, we treated cancer cells (HeLa, HepG2 and SW1116 cells) and normal cells (NCM-460) with IGF-1 at different concentrations and for different times and found that cancer cells produced large amounts of cytoplasmic ROS in cancer cells but not in normal cells. Further mechanistic analysis demonstrated that IGF-1 activated NFκB and NLRP3 inflammatory signalling in HeLa cells; systematic analysis indicated that IGF-1 activates NFκB and NLRP3, and the activation was cytosolic ROS- and NADPH oxidase 2 (NOX2)-dependent. Additionally, through coimmunoprecipitation experiments, we found that the IRS-1/COX2/mPGES-1/MAPKs/RAC2/NOX2 pathway nexus was involved in IGF-1-induced NFκB and NLRP3 production. Finally, we validated the regulatory mechanisms through IRS-1, mPGES-1 or NOX2 inhibition using their respective selective inhibitors or shRNA knockdown. Taken together, this is the first report on the mechanism by which IGF-1 activates NFκB and NLRP3 inflammatory signalling via ROS. These findings pave the way for an in-depth study of the role of IGF-1 and ROS in inflammation associated with the development and progression of cancer.
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Inflamación/patología , Factor I del Crecimiento Similar a la Insulina/metabolismo , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Línea Celular Tumoral , Ciclooxigenasa 2/metabolismo , Humanos , Proteínas Sustrato del Receptor de Insulina/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Prostaglandina-E Sintasas/metabolismo , Proteínas de Unión al GTP rac/metabolismo , Proteína RCA2 de Unión a GTPAsunto(s)
Proteínas Morfogenéticas Óseas , Túbulos Renales Proximales , Lipólisis , Transducción de Señal , Animales , Humanos , Ratones , Proteínas Morfogenéticas Óseas/metabolismo , Enfermedades Renales/metabolismo , Túbulos Renales Proximales/metabolismo , Receptores de Lipoproteína/metabolismo , Receptores de Lipoproteína/genética , Proteínas Smad/metabolismoRESUMEN
Tuberculosis is a highly infectious disease and of high incidence in low-income countries that is caused by Mycobacterium tuberculosis (M. tuberculosis). M. tuberculosis can form biofilms in vitro and in vivo, and the cells in the biofilm can survive at high concentrations of antibiotics. CwlM is a peptidoglycan hydrolase (amidase) and can hydrolyze bacterial cell walls, and the effects of CwlM on autolysis and biofilms is worthy of in-depth study. In this study, we successfully constructed an in vitro biofilm model of M. tuberculosis and Mycobacterium smegmatis (M. smegmatis). Reverse transcription followed by real-time quantitative PCR (qPCR) revealed that the expression of cwlM in M. tuberculosis and M. smegmatis was significantly up-regulated during the middle stage of biofilm formation. Treatment with recombinant CwlM enhanced the autolytic ability of M. tuberculosis and M. smegmatis and reduced the formation of their biofilms. As M. smegmatis is a model bacterium of M. tuberculosis, we built the M. smegmatis cwlM-deletion strain MSΔ6935, whose autolytic ability, biofilm production, and eDNA and eRNA content were determined to be lower than those of its parental strain. In conclusion, the cwlM gene plays a key regulatory role in biofilm formation in M. tuberculosis and M. smegmatis. This study provided a theoretical basis for using peptidoglycan hydrolase as a target for the inhibition of biofilms.
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Bacteriólisis/genética , Biopelículas/crecimiento & desarrollo , Mycobacterium smegmatis/genética , Mycobacterium tuberculosis/genética , N-Acetil Muramoil-L-Alanina Amidasa/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Pared Celular/metabolismo , Humanos , Infecciones por Mycobacterium no Tuberculosas/microbiología , Mycobacterium smegmatis/enzimología , Mycobacterium tuberculosis/enzimología , N-Acetil Muramoil-L-Alanina Amidasa/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Eliminación de Secuencia , Tuberculosis/microbiologíaRESUMEN
Tuberculosis is highly persistent and displays phenotypic resistance to high concentrations of antimicrobials. Recent reports exhibited that Mycobacterium tuberculosis biofilm was implicated to its pathogenicity and drug resistance. In this study, there were 47 kinds of differential proteins in the biofilm of M. tuberculosis H37Rv cells compared with the planktonic bacteria, and 37 proteins were nonredundant and identified by proteomics approach, such as 2DE and LC-MS/MS. Moreover, six kinds of proteins were identified as HspX, which were conservative and highly expressed in biofilm. Note that 47 differential proteins were divided into seven categories, such as cell wall and cell processes, conserved hypotheticals, intermediary metabolism and respiration, and so on by TUBERCULIST. The Gene Ontology classification results showed that the largest protein group involved in metabolism, binding proteins, and catalytic function accounts for 30% and 57% of all identified proteins, respectively. Moreover, the protein interaction network analyzed by STRING showed that the minority proteins such as RpoA, SucC, Cbs, Tuf, DnaK, and GroeL in the interaction network have high network connectivity. These results implied that the proteins involved in metabolic process and catalytic function and the minority proteins mentioned above may play an important role in M. tuberculosis biofilm formation. To our knowledge, this is the first report about differential proteins between biofilm and planktonic M. tuberculosis, which provided the potential antigens for vaccines and target proteins for anti-mycobacterial drugs.
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Proteínas Bacterianas/análisis , Biopelículas , Mycobacterium tuberculosis , Proteoma/análisis , Proteómica/métodos , Proteínas Bacterianas/metabolismo , Mycobacterium tuberculosis/química , Mycobacterium tuberculosis/citología , Mycobacterium tuberculosis/metabolismo , Mycobacterium tuberculosis/fisiología , Mapas de Interacción de Proteínas/fisiología , Proteoma/metabolismoRESUMEN
BACKGROUND: An increasing number of studies have shown that obesity is the key etiological agent of cardiovascular diseases, nonalcoholic fatty liver disease, type 2 diabetes and several kinds of cancer and that gut microbiota change was one of the reasons suffering from obesity. At present, the gut microbiota has gained increased attention as a potential energy metabolism organ. Our recent study reported that cordycepin, a major bioactive component separated from Cordyceps militaris, prevented body weight gain in mice fed a high-fat diet directly acting to adipocytes, however, the effect of cordycepin regulating gut microbiota keeps unknown. METHODS: In this research, we synthesized cordycepin (3-deoxyadenosine) by chemical methods and verified that cordycepin reduces body weight gain and fat accumulation around the epididymis and the kidneys of rats fed a high-fat diet. Furthermore, we used high-throughput sequencing on a MiSeq Illumina platform to test the species of intestinal bacteria in high-fat-diet-induced obese rats. RESULTS: We found that cordycepin modifies the relative abundance of intestinal bacteria in high-fat-diet-induced obese rats. However, cordycepin did not alter the variety of bacteria in the intestine. Cordycepin treatment dramatically reversed the relative abundance of two dominant bacterial phyla (Bacteroidetes and Firmicutes) in the high-fat-diet-induced obese rats, resulting in abundance similar to that of the chow diet group. CONCLUSION: Our study suggests that cordycepin can reduce body weight and microbiome done by cordycepin seems be a result among its mechanisms of obesity reduction.
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Cordyceps/química , Desoxiadenosinas/administración & dosificación , Obesidad/tratamiento farmacológico , Pérdida de Peso/efectos de los fármacos , Animales , Peso Corporal/efectos de los fármacos , Desoxiadenosinas/síntesis química , Desoxiadenosinas/química , Dieta Alta en Grasa/efectos adversos , Microbioma Gastrointestinal/efectos de los fármacos , Humanos , Ratones , Obesidad/etiología , Obesidad/microbiología , Obesidad/fisiopatología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Ratas , Pérdida de Peso/fisiologíaRESUMEN
Staphylococcus aureus is one of the most important pathogens in humans and animals. The formation of biofilm by S. aureus is considered an important mechanism of antimicrobial resistance. Therefore, finding effective drugs against the biofilm produced by S. aureus has been a high priority. Licochalcone A (LAA), a natural plant product, was reported to have antibacterial activities and showed good activity against all 21 tested strains of S. aureus biofilm and planktonic cells. To detect the possible molecular mechanism of LAA against S. aureus biofilm or planktonic cells, Affymetrix GeneChips were used to determine the global comparative transcription of S. aureus biofilm and planktonic cells triggered by treatment with sub-bactericidal and sub-inhibitory concentrations of LAA, respectively. LAA significantly altered (greater than a 2- or less than -2-fold change) the expression of 693 genes in planktonic cells and 817 genes in biofilm. The levels of genes encoding autolysis-associated proteins, cell wall proteins, pathogenic factors, protein synthesis genes, and enzymes involved in capsule synthesis were significantly altered in LAA-treated S. aureus. Furthermore, some differences observed in the microarray analysis were verified by real-time RT-PCR. To our knowledge, this is the first observation of phenotype and expression profiles of S. aureus biofilm and planktonic cells in response to LAA treatment.
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Antibacterianos/metabolismo , Biopelículas/efectos de los fármacos , Chalconas/metabolismo , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Perfilación de la Expresión Génica , Genotipo , Análisis por Micromatrices , Fenotipo , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Staphylococcus aureus/genéticaRESUMEN
To investigate the antimicrobial activity of imipenem and rifampicin alone and in combination against clinical isolates of Acinetobacter baumannii grown in planktonic and biofilm cultures. Minimum inhibitory concentrations were determined for each isolate grown in suspension and in biofilm using a microbroth dilution method. Chequerboard assays and the agar disk diffusion assay were used to determine synergistic, indifferent or antagonistic interactions between imipenem and rifampicin. We used the tissue culture plate method for A. baumannii biofilm formation to measure the percentage of biofilm inhibition and the amount of extracellular DNA after the treatment. To understand the synergistic mechanisms, we conducted hydroxyl radical formation assays. The results were verified by confocal laser scanning microscopy. Imipenem and rifampicin showed effective antimicrobial activity against suspensions and biofilm cultures of A. baumannii, respectively. Synergistic antimicrobial effects between imipenem and rifampicin were observed in 13 and 17 of the 20 clinical isolates when in suspension and in biofilms, respectively. Imipenem and rifampicin alone and in combination generated hydroxyl radicals, which are highly reactive oxygen forms and the major components of bactericidal agents. Furthermore, treatment with imipenem and rifampicin individually or in combination has obvious antibiofilm effects. The synergistic activity of imipenem and rifampicin against clinical isolates of A. baumannii (in suspension and in biofilms) was observed in vitro. Therefore, we conclude that imipenem combined with rifampicin has the potential to be used as a combinatorial therapy for the treatment of infectious diseases caused by A. baumannii.
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Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/fisiología , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Imipenem/farmacología , Rifampin/farmacología , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/aislamiento & purificación , Interacciones Farmacológicas , Humanos , Radical Hidroxilo/análisis , Pruebas de Sensibilidad Microbiana , Microscopía ConfocalRESUMEN
Lipolysis-stimulated lipoprotein receptor (LSR) is a multi-functional protein that is best known for its roles in assembly of epithelial tricellular tight junctions and hepatic clearance of lipoproteins. Here, we investigated whether LSR contributes to intestinal epithelium homeostasis and pathogenesis of intestinal disease. By using multiple conditional deletion mouse models and ex vivo cultured organoids, we find that LSR elimination in intestinal stem cells results in the disappearance of Paneth cells without affecting the differentiation of other cell lineages. Mechanistic studies reveal that LSR deficiency increases abundance of YAP by modulating its phosphorylation and proteasomal degradation. Using gain- and loss-of-function studies, we show that LSR protects against necrotizing enterocolitis through enhancement of Paneth cell differentiation in small-intestinal epithelium. Thus, this study identifies LSR as an upstream negative regulator of YAP activity, an essential factor for Paneth cell differentiation, and a potential therapeutic target for necrotizing enterocolitis.
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Enterocolitis Necrotizante , Receptores de Lipoproteína , Ratones , Animales , Células de Paneth/metabolismo , Receptores de Lipoproteína/metabolismo , Diferenciación Celular , Intestinos , Mucosa Intestinal/metabolismoRESUMEN
Magnetic chitosan hydrogel has aroused immense attention in recent years due to their biomedical significance and magnetic responsiveness. Here, A new electrodeposition method is reported for the fabrication of a novel CuNi-based magnetic chitosan freestanding film (MCFF) in an acidic chitosan plating bath containing SDS-modified CuNi NPs. Contrary to chitosan's anodic and cathodic deposition, which typically involves electrochemical oxidation, the synthetic process is triggered by coordination of chitosan with Cu and Ni ions in situ generated by the controlled surface dissolution of the suspended NPs with the acidic plating bath. The NPs provide not only the ions required for chitosan growth but also become entrapped during electrodeposition, thereby endowing the composite with magnetic properties. The obtained MCFF offers a wide range of features, including good mechanical strength, magnetic properties, homogeneity, and morphological transparency. Besides the fundamental interest of the synthesis itself, sufficient mechanical strength ensures that the hydrogel can be used by either peeling it off of the electrode or by directly building a complex hydrogel electrode. Its fast and easy magnetic steering, separation and recovery, large surface area, lack of secondary pollution, and strong chelating capability could lead to it finding applications as an electrochemical detector or adsorbent.
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Understanding the pollution characteristics and assessing the ecological risk of toxic metals in mine soil are crucial to controlling and managing risks in abandoned mine areas. In this study, the profile soil pollution characteristics and modified ecological risk of As, Cd, Hg, Pb, Sb, and Tl for both the different mining functional areas and the downstream impacted areas at a large-scale abandoned arsenic-containing mine were studied. Results showed that both the profile soils at the mining functional areas and the surface layer in downstream sites are heavily polluted by As, Cd, Hg, Sb, and Tl. As, Hg, Sb, and Tl mainly accumulated on soils with a depth of 0-1.5â¯m. In contrast, these metals in the mining site were gradually increased with soil depth above the bedrock strata. Cd and Pb were mainly concentrated at depth of 2.5-3.5â¯m in the smelting with by-product processing site. The speciation of metals in the profile soils mainly occurred in residual fraction. However, high levels of potential mobile As and Sb were found in mining soils and smelting surface soils, as well as Tl in deep soils at mining functional sites and top soils at downstream sites, with their mean contents in these areas arrived to 2950â¯mgâ¯kg-1, 9.64â¯mgâ¯kg-1, and 0.98â¯mgâ¯kg-1, respectively. In addition, the modified ecological risk assessment (NIRIm) values revealed a substantial ecological risk of As, Cd, Hg, and Sb in both the entire profile soils at the mining, smelting sites and topsoil (0-1.5â¯m) at the adjacent downstream site. In summary, the pollution characteristics and potential ecological risk of toxic metals in profile soils from the different functional sites at arsenic-containing mine were significantly different and suitable control strategies for available toxic elements should be adopted in the different functional sites of mine.
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Arsénico , Mercurio , Metales Pesados , Contaminantes del Suelo , Cadmio , China , Monitoreo del Ambiente/métodos , Contaminación Ambiental , Plomo , Mercurio/análisis , Metales Pesados/análisis , Minería , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisisRESUMEN
Novel porous magnetic soft materials (pMSMs) based on a poly (vinyl alcohol) (PVA) porous matrix filled with CuNi nanoparticles (NPs) of around 70 nm were synthesized. Initially, magnetic CuNi NPs were fabricated by the reduction of Ni and Cu ions with hydrazine hydrate in ethylene glycol medium in the absence of other capping agents. The pMSMs are subsequently fabricated by mixing CuNi NPs and PVA through freezing-drying process. The as-obtained pMSMs can respond to a magnetic field, i.e., the compressive modulus increase under a magnetic field of 0.23 T. The experimental results indicate that CuNi NPs can easily move to form chain-like structures under the application of a magnetic field. A combination of direct observation and finite element modeling has shown that under the influence of a magnetic field, chain-like aggregates of CuNi NPs lead to self-reinforcement of the pMSMs and, thus, to the increased compressive modulus. From a technological point of view, these materials with good magnetic responsiveness and moderate mechanical strength have potential applications in artificial muscle, soft actuators and drug release, to name a few.
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The lithium (Li)-metal anode offers a promising solution for high-energy-density lithium-metal batteries (LMBs). However, the significant volume expansion of the Li metal during charging results in poor cycling stability as a result of the dendritic deposition and broken solid electrolyte interphase. Herein, a facile one-step roll-to-roll fabrication of a zero-volume-expansion Li-metal-composite anode (zeroVE-Li) is proposed to realize high-energy-density LMBs with outstanding electrochemical and mechanical stability. The zeroVE-Li possesses a sandwich-like trilayer structure, which consists of an upper electron-insulating layer and a bottom lithiophilic layer that synergistically guides the Li deposition from the bottom up, and a middle porous layer that eliminates volume expansion. This sandwich structure eliminates dendrite formation, prevents volume change during cycling, and provides outstanding flexibility to the Li-metal anode even at a practical areal capacity over 3.0 mAh cm-2 . Pairing zeroVE-Li with a commercial NMC811 or LCO cathode, flexible LMBs that offer a record-breaking figure of merit (FOM, 45.6), large whole-cell energy density (375 Wh L-1 , based on the volume of the anode, separator, cathode, and package), high-capacity retention (> 99.8% per cycle), and remarkable mechanical robustness under practical conditions are demonstrated.