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ConspectusIn recent years, significant efforts have been directed toward achieving efficient and mild lignocellulosic biomass conversion into valuable chemicals and fuels, aiming to address energy and environmental concerns and realize the goal of carbon neutrality. Lignin is one of the three primary building blocks of lignocellulose and the only aromatic renewable feedstock. However, the complex and diverse nature of lignin feedstocks, characterized by their three-dimensional, highly branched polymeric structure and intricate C-O/C-C chemical bonds, results in substantial challenges. To tackle these challenges, we carried out extensive research on selectively activating and transforming chemical bonds in lignin for chemical synthesis. In this Account, we discuss our recent progress in catalytic lignin conversion.Our work is focused on two main objectives: (i) achieving precise and selective transformation of C-O/C-C bonds in lignin (and its model compounds) and (ii) fully utilizing the aromatic nuclei and side chains present in lignin to produce valuable chemicals. Lignin consists of interconnected phenylpropanoid subunits linked by interlaced C-C/C-O bonds. To unlock the full potential of lignin, we propose the concept of "the full utilization of lignin", which encompasses both the aromatic nuclei and the side chains (e.g., methoxyl and polyhydroxypropyl groups).For the conversion of aromatic nuclei, selective activation of C-O and/or C-C bonds is crucial in synthesizing targeted aromatic products. We begin with model compounds (such as anisole, phenol, guaiacol, etc.) and then transition to protolignin feedstocks. Various reaction routes are developed, including self-supported hydrogenolysis, direct Caryl-Csp3 cleavage, coupled Caryl-Csp3 cleavage and Caryl-O hydrogenolysis, and tandem selective hydrogenation and hydrolysis processes. These tailored pathways enable high-yield and sustainable production of a wide range of aromatic (and derived) products, including arenes (benzene, toluene, alkylbenzenes), phenols, ketones, and acids.In terms of side chain utilization, we have developed innovative strategies such as selective methyl transfer, coupling depolymerization-methyl shift, selective acetyl utilization, and new activation methods such as amine-assisted prefunctionalization. These strategies enable the direct synthesis of methyl-/alkyl-derived products, such as acetic acid, 4-ethyltoluene, dimethylethylamine, and amides. Additionally, aromatic residues can be transformed into chemicals or functionalized ingredients that can serve as catalysts or functional biopolymer materials. These findings highlight promising opportunities for harnessing both the aromatic nuclei and side chains of lignin in a creative manner, thereby improving the overall atom economy of lignin upgrading.Through innovative catalyst engineering and reaction route strategies, our work achieves the sustainable and efficient production of various valuable chemicals from lignin. By integrating side chains and aromatic rings, we have successfully synthesized methyl-/alkyl-derived and aromatic-derived products with high yields. The full utilization of lignin not only minimizes waste but also opens up new possibilities for generating chemical products from lignin. These novel approaches unlock the untapped potential of lignin, expand the boundaries of lignin upgrading, and enhance the efficiency and economic viability of lignin biorefining.
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Electrochemical production of hydrogen peroxide (H2 O2 ) via two-electron oxygen reduction reaction (ORR) process is emerging as a promising alternative method to the conventional anthraquinone process. To realize high-efficiency H2 O2 electrosynthesis, robust and low cost electrocatalysts have been intensively pursued, among which Co-based catalysts attract particular research interests due to the earth-abundance and high selectivity. Here, we provide a comprehensive review on the advancement of Co-based electrocatalyst for H2 O2 electroproduction. The fundamental chemistry of 2-electron ORR is discussed firstly for guiding the rational design of electrocatalysts. Subsequently, the development of Co-based electrocatalysts involving nanoparticles, compounds and single atom catalysts is summarized with the focus on active site identification, structure regulation and mechanism understanding. Moreover, the current challenges and future directions of the Co-based electrocatalysts are briefly summarized in this review.
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Cyclohexanone and benzoquinone are important chemicals in chemical and manufacturing industries. The simultaneous production of cyclohexanone and benzoquinone by the reaction of phenol and water is an ideal route for the economical production of the two chemicals. In principle, this can be achieved in an electrochemical reaction system that couples the cathodic reduction of phenol to cyclohexanone and the anodic oxidation of phenol to benzoquinone, which has not been realized. Here, we report the first work on this integration strategy, where nitrogen-doped hierarchically porous carbon (NHPC)-supported NiPt and FeRu designed in this work are very efficient and selective cathode and anode catalysts, affording >99.9% selectivities to both cyclohexanone and benzoquinone. The excellent electrocatalytic performance of the catalysts can be ascribed to the poor absorption capability of the NiPt alloy nanoparticles (NPs) for cyclohexanone and Fe single-atom decorated Ru NPs for benzoquinone, which avoids the excessive reduction and oxidation of the desired products. The reaction pathway is proposed on the basis of control experiments, in which two phenol molecules react with one H2O molecule with 100% atom-efficiency. In the scale-up experiment at the 1 g scale, NiPt/NHPC and FeRu/NHPC exhibit excellent durability and stability, which enables this integrated system to afford 645.3 mg of cyclohexanone and 691.7 mg of benzoquinone synchronously in an operating time of 90 h.
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Cyclohexanols are widely used chemicals, which are mainly produced by oxidation of fossil feedstocks. Selective hydrodeoxygenation of lignin derivatives has great potential for producing these chemicals but is challenging to obtain high yields. Here, we report that CeO2-supported Ru single-atom catalysts (SACs) enabled the hydrogenation of the benzene ring and catalyzed etheric C-O(R) bond cleavage without changing the C-O(H) bond, which could afford 99.9% yields of cyclohexanols. As far as we know, this is the first to report that SACs catalyze hydrogenation of the aromatic ring. The reaction mechanism was studied by control experiments and density functional theory calculations. In the catalysts, the Ru-O-Ce sites were formed and one Ru atom was coordinated with about four O atoms. These catalytic sites could realize both the hydrogenation and deoxygenation reactions efficiently, and thus desired cyclohexanols were generated. This work pioneers the single-atom catalysis in aromatic transformation and provides a novel route for synthesis of cyclohexanols.
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Antibiotic-resistant bacteria are a serious threat to human and animal health. Metabolite-enabled eradication of drug-resistant pathogens is an attractive strategy, and metabolite adjuvants, such as fumarate, are used for restoring the bactericidal ability of antibiotics. However, we show that metabolites in the TCA cycle increase the viability of Edwardsiella tarda against chloramphenicol (CAP), based on the survival assay of differential metabolites identified by LC-MS/MS. Furthermore, NADPH promotes CAP resistance in the CAP-resistant strain, while oxidants restore the bactericidal ability. Finally, we show that the intracellular redox state determines the sensitivity to CAP, and the total antioxidative capacity is decreased significantly in the antibiotic-resistant strain. Considering that the metabolites promote CAP resistance, metabolite adjuvants should be applied very cautiously. Overall, our research expands on the knowledge that the redox state is related to the bactericidal ability of CAP.
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Edwardsiella tarda , Doenças dos Peixes , Animais , Antibacterianos/farmacologia , Cloranfenicol/farmacologia , Cromatografia Líquida , Humanos , Espectrometria de Massas em TandemRESUMO
The polymeric immunoglobulin receptor (pIgR) plays an important role in mediating the transcytosis of polymeric immunoglobulins (pIgs) to protect organisms against pathogen invasion. Here, a polyclonal antibody against grass carp (Ctenopharyngodon idellus) recombinant pIgR was developed by immunizing New Zealand white rabbit, and the responses of pIgR, IgM and IgZ were analyzed after bath immunization and intraperitoneal administration with Flavobacterium columnare. The results showed that pIgR transcription level was similar to IgM and IgZ, but pIgR rose much faster and peaked earlier than IgM and IgZ; the pIgR mRNA levels were higher in the skin and spleen for both immunized groups, while IgM and IgZ mRNA expression were higher in skin, gills, and intestines in bath immersion group, or spleen and head kidney in intraperitoneal immunization group. ELISA revealed that the IgM, IgZ and pIgR protein levels were up-regulated in skin mucus, gill mucus, gut mucus and bile, reaching a higher peak level earlier in skin mucus and gill mucus in bath immersion group, but a higher peak level in bile in injection group. Moreover, secretory component molecules were detected in grass carp's skin, gill and intestine mucus and bile, but not in serum, which molecular mass was near the theoretical mass obtained from the sequence of grass carp pIgR. These results demonstrated that bath and intraperitoneal immunization up-regulated pIgR and secretory Ig expression in secretions, which provided more insights into the role of pIgR in immunity and offer insight into ways of protecting teleost against pathogen invasion.
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Carpas/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/imunologia , Infecções por Flavobacteriaceae/imunologia , Flavobacterium , Imunoglobulinas/imunologia , Animais , Bile/imunologia , Carpas/microbiologia , Infecções por Flavobacteriaceae/veterinária , Brânquias/imunologia , Muco/imunologia , Coelhos , Proteínas Recombinantes/imunologia , Pele/imunologiaRESUMO
Proton-exchange membrane fuel cells (PEMFCs) are limited by their extreme sensitivity to trace-level CO impurities, thus setting a strict requirement for H2 purity and excluding the possibility to directly use cheap crude hydrogen as fuel. Herein, we report a proof-of-concept study, in which a novel catalyst comprising both Ir particles and Ir single-atom sites (IrNP @IrSA -N-C) addresses the CO poisoning issue. The Ir single-atom sites are found not only to be good CO oxidizing sites, but also excel in scavenging the CO molecules adsorbed on Ir particles in close proximity, thereby enabling the Ir particles to reserve partial active sites towards H2 oxidation. The interplay between Ir nanoparticles and Ir single-atom centers confers the catalyst with both excellent H2 oxidation activity (1.19â W cm-2 ) and excellent CO electro-oxidation activity (85â mW cm-2 ) in PEMFCs; the catalyst also tolerates CO in H2 /CO mixture gas at a level that is two times better than that of the current best PtRu/C catalyst.
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Neuroblastoma (NB) is a common intracranial solid tumor with high mortality. Small nucleolar RNA host gene 16 (SNHG16), one of the long noncoding RNAs (lncRNAs), has been reported to be linked to the poor prognosis of NB. However, the mechanisms of SNHG16 in regulating NB progression remain poorly understood. The expression level of SNHG16 was measured by quantitative real time polymerase chain reaction (qRT-PCR). The starBase was employed to predict the interaction of miR-128-3p and SNHG16 or HOXA7, which was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Cell proliferation and apoptosis were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry, respectively. Transwell assay was used to detect cell invasion or migration. The mRNA and protein levels of homeobox protein A7 (HOXA7) were determined by qRT-PCR and western blot, respectively. The levels of SNHG16 and HOXA7 were conspicuously increased in NB tissues and cells, while the expression of miR-128-3p was obviously declined, compared with corresponding normal tissues and cells. SNHG16 silencing inhibited proliferation, migration and invasion and induced apoptosis of NB cells. We identified that SNHG16 directly interacted with miR-128-3p, and miR-128-3p could target the 3'UTR of HOXA7 in NB cells. Simultaneously, miR-128-3p expression was negatively associated with SNHG16 or HOXA7. Further studies indicated that SNHG16 overexpression rescued the effects of miR-128-3p-mediated on inhibiting proliferation, migration, invasion and promoting apoptosis of NB cells. Moreover, SNHG16 could modulate HOXA7 by sponging miR-128-3p in NB cells. Besides, SNHG16 silencing suppressed tumor growth in vivo. Knockdown of SNHG16 impeded proliferation, migration, invasion and induced apoptosis through the SNHG16/miR-128-3p/HOXA7 axis in NB cells.
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Proteínas de Homeodomínio/metabolismo , MicroRNAs/metabolismo , Neuroblastoma/fisiopatologia , RNA Longo não Codificante/metabolismo , Animais , Apoptose/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos Endogâmicos BALB C , Neuroblastoma/metabolismo , RNA Longo não Codificante/antagonistas & inibidoresRESUMO
Transcranial magnetic stimulation (TMS) is one of the most widely used noninvasive brain stimulation method. It has been utilized for both treatment and diagnosis of many neural diseases, such as neuropathic pain and loss of function caused by stroke. Existing TMS tools cannot deliver focused electric field to targeted penetration depth even though many important neurological disorders are originated from there. A breakthrough is needed to achieve noninvasive, focused brain stimulation. We demonstrated using magnetic shield to achieve magnetic focusing without sacrificing significant amount of throughput. The shield is composed of multiple layers of copper ring arrays, which utilize induced current to generate counter magnetic fields. We experimentally set up a two-pole stimulator system to verify device simulation. A transient magnetic field probe was used for field measurements. The focusing effect highly depends on the geometric design of shield. A tight focal spot with a diameter of smaller than 5mm (plotted in Matlab contour map) can be achieved by using copper ring arrays. With properly designed array structures and rings locations, the combined original and induced counter fields can produce a tightly focused field distribution with enhanced field strength at a depth 7.5mm beyond the shield plane, which is sufficient to reach many deep and critical parts of a mouse brain.
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It was found that nanodomains existed in the ionic liquid (IL)-based ternary system containing IL 1-ethyl-3-methylimidazole tetrafluoroborate (EmimBF4 ), IL 1-decyl-3-methylimidazole nitrate (DmimNO3 ) and water, and the size distribution of the domains varied continuously with the composition of the solution. A strategy to synthesize hierarchical porous metals using IL-based media as solvent and template is proposed, and the hierarchical porous Ru and Pt metals were prepared by the assembly of metal clusters of about 1.5â nm using this new method. It is demonstrated that the metals have micropores and mesopores, and the size distribution is tuned by controlling the composition of the solution. Porous Ru was used for a series of hydrogenation reactions. It has an outstanding catalytic performance owing to its special morphology and structure.
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Selective transformation of lignin into a valuable chemical is of great importance and challenge owing to its complex structure. Herein, we propose a strategy for the transformation of methoxy group (-OCH3 ) which is abundant in lignin into pure highly valuable chemicals. As an example to apply this strategy, a route to produce acetic acid with high selectivity by conversion of methoxy group of lignin was developed. It was demonstrated that the methoxy group in lignin could react with CO and water to generate acetic acid over RhCl3 in the presence of a promoter. The conversions of methoxy group in the kraft lignin and organosolv lignin reached 87.5 % and 80.4 %, respectively, and no by-product was generated. This work opens the way to produce pure chemicals using lignin as the feedstock.
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Flavobacterium columnare (FC) has caused worldwide fish columnaris disease with high mortality and great economic losses in cultured fish, including Topmouth culter (Culter alburnus). However, the knowledge about the host factors involved in FC infection is little known. In this study, the transcriptomic profiles of the head kidney from Topmouth culter with or without FC infection were obtained using HiSeq™ 2500 (Illumina). Totally 79,641 unigenes with high quality were obtained. Among them, 4037 differently expressed genes, including 1217 up-regulated and 2820 down-regulated genes, were identified and enriched using databases of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The differently expressed genes were mainly associated with pathways such as immune response, carbohydrate metabolism, amino acid metabolism, and lipid metabolism. Since phagocytosis is a central mechanism of innate immune response by host cells to defense against infectious agents, genes related to the phagosome pathway were scrutinized and 9 differently expressed phagosome-related genes were identified including 3 up-regulated and 6 down-regulated genes. Five of them were further validated by quantitative real-time polymerase chain reaction (qRT-PCR). This transcriptomic analysis of host genes in response to FC infection provides data towards understanding the infection mechanisms and will shed a new light on the prevention of columnaris.
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Cyprinidae , Doenças dos Peixes/genética , Proteínas de Peixes/genética , Infecções por Flavobacteriaceae/veterinária , Flavobacterium/fisiologia , Imunidade Inata , Transcriptoma , Animais , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Proteínas de Peixes/metabolismo , Flavobacteriaceae , Infecções por Flavobacteriaceae/genética , Infecções por Flavobacteriaceae/imunologia , Infecções por Flavobacteriaceae/microbiologia , Rim Cefálico/imunologia , Fagossomos/imunologiaRESUMO
MicroRNAs (miRNAs) play important roles in regulation of many biological processes in eukaryotes, including pathogen infection and host interactions. Flavobacterium columnare (FC) infection can cause great economic loss of common carp (Cyprinus carpio) which is one of the most important cultured fish in the world. However, miRNAs in response to FC infection in common carp has not been characterized. To identify specific miRNAs involved in common carp infected with FC, we performed microRNA sequencing using livers of common carp infected with and without FC. A total of 698 miRNAs were identified, including 142 which were identified and deposited in the miRbase database (Available online: http://www.mirbase.org/) and 556 had only predicted miRNAs. Among the deposited miRNAs, eight miRNAs were first identified in common carp. Thirty of the 698 miRNAs were differentially expressed miRNAs (DIE-miRNAs) between the FC infected and control samples. From the DIE-miRNAs, seven were selected randomly and their expression profiles were confirmed to be consistent with the microRNA sequencing results using RT-PCR and qRT-PCR. In addition, a total of 27,363 target genes of the 30 DIE-miRNAs were predicted. The target genes were enriched in five Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, including focal adhesion, extracellular matrix (ECM)-receptor interaction, erythroblastic leukemia viral oncogene homolog (ErbB) signaling pathway, regulation of actin cytoskeleton, and adherent junction. The miRNA expression profile of the liver of common carp infected with FC will pave the way for the development of effective strategies to fight against FC infection.
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Carpas/genética , Carpas/microbiologia , Doenças dos Peixes/genética , Infecções por Flavobacteriaceae/veterinária , Flavobacterium/fisiologia , MicroRNAs/genética , Animais , Doenças dos Peixes/microbiologia , Infecções por Flavobacteriaceae/genética , Perfilação da Expressão Gênica , Fígado/metabolismo , Fígado/microbiologiaRESUMO
The effect of water on CO2 hydrogenation to produce higher alcohols (C2-C4) was studied. Pt/Co3O4, which had not been used previously for this reaction, was applied as the heterogeneous catalyst. It was found that water and the catalyst had an excellent synergistic effect for promoting the reaction. High selectivity of C2-C4 alcohols could be achieved at 140 °C (especially with DMI (1,3-dimethyl-2-imidazolidinone) as co-solvent), which is a much lower temperature than reported previously. The catalyst could be reused at least five times without reducing the activity and selectivity. D2O and (13)CH3OH labeling experiments indicated that water involved in the reaction and promoted the reaction kinetically, and ethanol was formed via CH3OH as an intermediate.
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Hydrogenation of CO(2) to alcohols is of great importance, especially when producing higher alcohols. In this work, we synthesized heterogeneous PtRu/Fe(2)O(3), in which the Pt and Ru bimetallic catalysts were supported on Fe(2)O(3). The catalyst was used to catalyse CO(2) hydrogenation to alcohols. It was demonstrated that the activity and selectivity could be tuned by the bimetallic composition, and the catalyst with a Pt to Ru molar ratio of 1:2 (Pt(1)Ru(2)/Fe(2)O(3)) had high activity and selectivity at 200°C, which is very low for heterogeneous hydrogenation of CO(2) to produce higher alcohols. The conversion and the selectivity increased with increasing pressures of CO(2) and/or H(2). The catalyst could be reused at least five times without any obvious change in activity or selectivity.
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The utilization of compounds from natural sources to prepare functional materials is of great importance. Herein, we describe for the first time the preparation of organic-inorganic hybrid catalysts by using natural phytic acid as building block. Zirconium phosphonate (Zr-PhyA) was synthesized by reaction of phytic acid and ZrCl4 and was obtained as a mesoporous material with pore sizes centered around 8.5â nm. Zr-PhyA was used to catalyze the mild and selective Meerwein-Ponndorf-Verley (MPV) reduction of various carbonyl compounds, e.g., of levulinic acid and its esters into γ-valerolactone. Further studies indicated that both Zr and phosphate groups contribute significantly to the excellent performance of Zr-PhyA.
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Owing to population growth and environmental pollution, freshwater aquaculture has been rapidly shrinking in recent years. Aquaculture in saline-alkaline waters is a crucial strategy to meet the increasing demand for aquatic products. The Chinese mitten crab is an important economic food in China, but the molecular mechanism by which it tolerates carbonate alkalinity (CA) in water remains unclear. Here, we found that enzyme activities of the tricarboxylic acid (TCA) cycle in the gills, such as citrate synthase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, and malate dehydrogenase, were markedly reduced under CA stress induced by 40 mM NaHCO3. Secondly, the TCA cycle in the gills is inhibited under acute CA stress, according to proteomic and metabolomic analyses. The expressions of six enzymes, namely aconitate hydratase, isocitrate dehydrogenase, 2-oxoglutarate dehydrogenase, dihydrolipoyl dehydrogenase, succinate-CoA ligase, and malate dehydrogenase, were downregulated, resulting in the accumulation of phosphoenolpyruvic acid, citric acid, cis-aconitate, and α-ketoglutaric acid. Finally, we testified that if the TCA cycle is disturbed by malonate, the survival rate increases in CA water. To our knowledge, this is the first study to show that the TCA cycle in the gills is inhibited under CA stress. Overall, the results provide new insights into the molecular mechanism of tolerance to saline-alkaline water in crabs, which helped us expand the area for freshwater aquaculture and comprehensively understand the physiological characteristics of crab migration.
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Braquiúros , Carbonatos , Ciclo do Ácido Cítrico , Brânquias , Estresse Fisiológico , Animais , Ciclo do Ácido Cítrico/efeitos dos fármacos , Brânquias/metabolismo , Brânquias/efeitos dos fármacos , Braquiúros/metabolismo , Braquiúros/fisiologia , Braquiúros/efeitos dos fármacos , Carbonatos/farmacologiaRESUMO
Urea electrosynthesis under ambient conditions is emerging as a promising alternative to conventional synthetic protocols. However, the weak binding of reactants/intermediates on the catalyst surface induces multiple competing pathways, hindering efficient urea production. Herein, we report the synthesis of defective Co3O4 catalysts that integrate dual-functional sites for urea production from CO2 and nitrite. Regulating the reactant adsorption capacity on defective Co3O4 catalysts can efficiently control the competing reaction pathways. The urea yield rate of 3361 mg h-1 gcat-1 was achieved with a corresponding faradaic efficiency (FE) of 26.3% and 100% carbon selectivity at a potential of -0.7 V vs. the reversible hydrogen electrode. Both experimental and theoretical investigations reveal that the introduction of oxygen vacancies efficiently triggers the formation of well-matched adsorption/activation sites, optimizing the adsorption of reactants/intermediates while decreasing the C-N coupling reaction energy. This work offers new insights into the development of dual-functional catalysts based on non-noble transition metal oxides with oxygen vacancies, enabling the efficient electrosynthesis of essential C-N fine chemicals.
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Objective.Accurate modeling of transcranial magnetic stimulation (TMS) coils with the magnetic core is largely an open problem since commercial (quasi) magnetostatic solvers do not output specific field characteristics (e.g. induced electric field) and have difficulties when incorporating realistic head models. Many open-source TMS softwares do not include magnetic cores into consideration. This present study reports an algorithm for modeling TMS coils with a (nonlinear) magnetic core and validates the algorithm through comparison with finite-element method simulations and experiments.Approach.The algorithm uses the boundary element fast multipole method applied to all facets of a tetrahedral core mesh for a single-state solution and the successive substitution method for nonlinear convergence of the subsequent core states. The algorithm also outputs coil inductances, with or without magnetic cores. The coil-core combination is solved only once i.e. before incorporating the head model. The resulting primary TMS electric field is proportional to the total vector potential in the quasistatic approximation; it therefore also employs the precomputed core magnetization.Main results.The solver demonstrates excellent convergence for typical TMS field strengths and for analyticalB-Happroximations of experimental magnetization curves such as Froelich's equation or an arctangent equation. Typical execution times are 1-3 min on a common multicore workstation. For a simple test case of a cylindrical core within a one-turn coil, our solver computed the small-signal inductance nearly identical to that from ANSYS Maxwell. For a multiturn rodent TMS coil with a core, the modeled inductance matched the experimental measured value to within 5%.Significance.Incorporating magnetic core in TMS coil design has advantages of field shaping and energy efficiency. Our software package can facilitate model-informed design of more efficiency TMS systems and guide selection of core material. These models can also inform dosing with existing clinical TMS systems that use magnetic cores.
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Software , Estimulação Magnética Transcraniana , Estimulação Magnética Transcraniana/métodos , Análise de Elementos Finitos , Algoritmos , Fenômenos Magnéticos , Encéfalo/fisiologiaRESUMO
As a probiotic, enterococcus faecium (E. faecium) has the characteristics of high temperature resistance, gastric acid resistance, bile salt resistance, etc. It can also effectively improve animal performance and immunity and improve the animal's intestinal environment, so in recent years it has been more widely used in the livestock industry. However, due to the improper use of antibiotics and the growing environmental stress of strains, the drug resistance of enterococcus faecium has become more and more serious, and because some enterococcus faecium carry virulence genes, leading to the emergence of pathogenic strains, its safety issues have been widely concerned. This paper focuses on the biological characteristics of enterococcus faecium, the application of this bacterium in animal husbandry and the safety issues in its use, with a view to providing a reference for the application of enterococcus faecium in the development of animal husbandry.