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Redox-active organic compounds gather significant attention for their potential application as electrodes in alkali ion batteries, owing to the structural versatility, environmental friendliness, and cost-effectiveness. However, their practical applications of such compounds are impeded by insufficient active sites with limited capacity, dissolution in electrolytes, and sluggish kinetics. To address these issues, a naphthol group-containing triarylamine polymer, namely poly[6,6'-(phenylazanediyl)bis(naphthol)] (poly(DNap-OH)) is rationally designed and synthesized, via oxidative coupling polymerization. It is capable of endowing favorable steric structures that facilitate fast ion diffusion, excellent chemical stability in organic electrolytes, and additional redox-active sites that enable a bipolar redox reaction. By exploiting these advantages, poly(DNap-OH) cathodes demonstrate remarkable cycling stability in both lithium-ion batteries (LIBs) and potassium-ion batteries (PIBs), showcasing enhanced specific capacity and redox reaction kinetics in comparison to the conventional poly(4-methyltriphenylamine) cathodes. Overall, this work offers insights into molecular design strategies for the development of high-performance organic cathodes in alkali-ion batteries.
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BACKGROUND: Recent studies have demonstrated that long-term exposure to particulate matter (PM) is associated with poor sleep quality. However, no studies have linked PM constituents, particularly heavy metals, to sleep quality. OBJECTIVE: This study investigated the association between exposure to heavy metals in PM and sleep quality. METHODS: We obtained nationwide data from the Korean Community Health Survey conducted in 2018 among adults aged 19-80 years. Sleep quality was evaluated using Pittsburgh Sleep Quality Index (PSQI). Poor sleep quality was defined as PSQI ≥5. One-year and three-month average concentrations of heavy metals (lead, manganese, cadmium, and aluminum) in PM with diameter ≤10 µm were obtained from nationwide air quality monitoring data and linked to the survey data based on individual district-level residential addresses. Logistic regression analyses were performed after adjusting for age, gender, education level, marital status, smoking status, alcohol consumption, history of hypertension, and history of diabetes mellitus. RESULTS: Of 32,050 participants, 17,082 (53.3%) reported poor sleep quality. Increases in log-transformed one-year average lead (odds ratio, 1.14; 95% confidence interval, 1.08-1.20), manganese (1.31; 1.25-1.37), cadmium (1.03; 1.00-1.05), and aluminum concentrations (1.17; 1.10-1.25) were associated with poor sleep quality. Increases in log-transformed three-month average manganese (odds ratio, 1.13; 95% confidence interval, 1.09-1.17) and aluminum concentrations (1.28; 1.21-1.35) were associated with poor sleep quality. CONCLUSION: We showed for the first time that exposure to airborne lead, manganese, cadmium, and aluminum were associated with poor sleep quality. This study may be limited by self-reported sleep quality and district-level exposure data.
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Contaminantes Atmosféricos , Metales Pesados , Adulto , Humanos , Material Particulado/análisis , Manganeso/análisis , Cadmio/análisis , Calidad del Sueño , Aluminio , Exposición a Riesgos Ambientales/análisis , Metales Pesados/toxicidad , Metales Pesados/análisis , Contaminantes Atmosféricos/toxicidad , Contaminantes Atmosféricos/análisisRESUMEN
Cloud point temperature (Tcp) is a thermal index used to define the phase transition of thermoresponsive polymers. In this study, we used electrochemical techniques to obtain an electrochemical cloud point temperature (Tecp) that exhibits the more accurate phase transition temperature and can replace Tcp. Thermoamperometry on an ultramicroelectrode was conducted with a poly(arylene ether sulfone) (PES10) as a model system to obtain a current-temperature (i-T) curve in real time; the Tecp of the PES10 was determined from the i-T curve. The i-T curve shows an unprecedented current decrease in the PES10 solution despite increasing temperature; on the other hand, the current increased linearly with increasing temperature in the solution without PES10. This phenomenon was analyzed by considering the characteristics of PES10 during phase transition, such as dynamic viscosity, temperature of the solution, and electrode impedance. It was confirmed that the current drops shown in the i-T curves were mainly due to the decrease of real electrode area. The comparison of Tecp and Tcp showed that both depended similarly on the concentrations of the thermoresponsive polymer and the supporting electrolyte. The results reveal that by adjusting the concentration of polymer and electrolyte in an organic solution, Tecp, as a new analytical method, can be used in electric circuit-based energy storage appliances such as Li-ion batteries and supercapacitors.
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Herein, a study on a new lower critical solution temperature (LCST) polymer in an organic solvent by an electrochemical technique has been reported. The phase-transition behavior of poly(arylene ether sulfone) (PAES) was examined on 1,2-dimethoxyethane (DME). At a temperature above the LCST point, polymer molecules aggregated to create polymer droplets. These droplets subsequently collided with an ultramicroelectrode (UME), resulting in a new form of staircase current decrease. The experimental collision frequency and collision signal were analyzed in relation to the concentration of the polymer. In addition, the degree of polymer aggregation associated with temperature change was also observed.
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Acinetobacter baumannii, a strictly aerobic, non-fermentative, Gram-negative coccobacillary rod-shaped bacterium, is an opportunistic pathogen in humans. We recently isolated a multidrug-resistant A. baumannii strain KBN10P02143 from the pus sample drawn from a surgical patient in South Korea. We report the complete genome of this strain, which consists of 4,139,396 bp (G + C content, 39.08%) with 3,868 protein-coding genes, 73 tRNAs and six rRNA operons. Identification of the genes related to multidrug resistance from this genome and the discovery of a novel conjugative plasmid will increase our understanding of the pathogenicity associated with this species.
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Acinetobacter baumannii/genética , Farmacorresistencia Bacteriana Múltiple/genética , Genoma Bacteriano/genética , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/aislamiento & purificación , ADN Bacteriano/genética , Humanos , República de Corea , Análisis de Secuencia de ADNRESUMEN
We have developed a simple and selective method for the electrochemical detection of hydrazine (HZ) using poly(dopamine) (pDA)-modified indium tin oxide (ITO) electrodes. Modification with pDA was easily achieved by submerging the ITO electrode in a DA solution for 30 min. The electrocatalytic oxidation of HZ on the pDA-modified ITO electrode was measured by cyclic voltammetry. In buffer solution, the concentration range for linear HZ detection was 100 µM-10 mM, and the detection limit was 1 µM. The proposed method was finally used to determine HZ in tap water to simulate the analysis of real samples. This method showed good recovery (94%-115%) and was not affected by the other species present in the tap water samples.
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We report here the electrochemistry of emulsion droplets by observing single emulsion droplet collisions with selective electrochemical reduction on an ultramicroelectrode (UME). With appropriately applied potentials at an UME, we can observe the electrochemical effects of single collision signals from the complete electrolysis of single emulsion droplets, or selective electrolysis of redox species in single emulsion droplets. This was observed with nitrobenzene (NB), 7,7,8,8-tetracyanoquinodimethane (TCNQ), and ionic liquid. The NB, TCNQ, and ionic liquid act as emulsion material, redox specie, and emulsifier (and electrolyte), respectively. NB emulsions and NB (TCNQ) emulsions were made by ultrasonic processing. During the amperometric current-time (i-t) curve measurement with NB/water emulsion at -0.65 V, reduction of NB emulsion droplets was measured. In the case of less negative potentials, e.g., at -0.45 V with a NB (TCNQ) emulsion, selective reduction of TCNQ in NB droplet was measured. Spike-like responses from electrolysis of NB or TCNQ in each experiment were observed. From these single-particle collision results of NB and NB (TCNQ) emulsions, the collision frequency, size distribution, i-t decay behavior of emulsion droplets, and possible mechanisms are discussed.
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We describe a method to produce electrogenerated chemiluminescence (ECL) in water using a family of highly hydrophobic polycyclic aromatic hydrocarbon (PAH) luminophores and boron dipyrromethene (BODIPY). This method is based on an oil-in-water emulsion system. Various PAHs (rubrene, 9,10-diphenylanthracene, pyrene, or perylene) and BODIPY were trapped in a toluene and tri-n-propylamine mixed oil-in-water emulsion using an ionic liquid as the supporting electrolyte and emulsifier. ECL was observed for all the aforementioned PAHs and BODIPY, and the rubrene and BODIPY emulsion systems showed adequate light to record an ECL spectrum. ECL was also observed using oxalate as the co-reactant, which was dissolved in the aqueous continuous phase. The emulsions were stable for hours and showed a droplet size distribution that ranged from 275 to 764 nm, in accordance with dynamic light scattering data.
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We describe the fabrication of a nanometer-size electrode based on an insulating TiO2 film and a metal nanoparticle (NP). The TiO2 film is deposited on the conducting Pt surface of an ultramicroelectrode (UME) to block electron transfer (ET) to solution species. The film thickness is, however, thin enough to enable tunneling to Pt NPs; thus, the subsequent contact of metal NP to the TiO2 film restores the ET to solution species solely on the NP surface via facile electron tunneling. Consequently, the composite of UME/metal oxide film/NP offers nm-scale active area. The TiO2 film is electrochemically deposited on the Pt UME (Pt UME/TiO2), monitoring the cyclic voltammetry (CV) of ferrocenemethanol until the oxidation wave just disappears. A single Pt NP is captured in a collision experiment by observing the current increase upon contact of the Pt NP with the Pt UME/TiO2 by means of Pt NP-mediated electrochemical reduction of Fe(CN)6(3-). The resultant Pt UME/TiO2/Pt NP (or tunneling UME, T-UME) showed long-term stability and robustness with well-defined electrochemical response, suggesting applicability as a novel nm-size electrode for CV and steady-state measurements such as those with scanning electrochemical microscopy (SECM). Here, we employed the T-UME to measure SECM approach curves and showed remarkable approach capability for a nm-size SECM probe.
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We report an electrochemical study of the collisions of single droplets in an emulsion by two methods. In the first method, an electroactive redox species, for example, ferrocene, inside a toluene-in-water emulsion droplet (but not in the continuous phase) is measured by chronoamperometry during a collision with an ultramicroelectrode (UME). Here, a blip or spike type of collision signal is observed, representing electrolysis of the droplet contents. In the second method, electrochemical oxidation of an electroactive redox species in the continuous aqueous phase is hindered by a droplet blocking collision. In this case, a staircase current decrease is observed. From an analysis of single soft particle collision data, one can find the emulsion droplet size distribution and the droplet contents.
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Four Gram-stain-negative, aerobic, rod-shaped bacterial strains, MM-124, MM-126, NB-68 and NB-77, were isolated from the coastal seawater or a region with a bloom of sea sparkle around Geoje island in Korea. The sequence similarity values of the 16S rRNA gene between the isolates and Sulfitobacter mediterraneus DSM 12244(T) ranged from 97.7 to 98.2%, and phylogenetic relationships suggested that they belong to a phylogenetic branch that includes the genera Sulfitobacter and Roseobacter. The isoprenoid quinone of all three novel strains was ubiquinone-10 and the major fatty acid was cis-vaccenic acid, as in other species of the genus Sulfitobacter. However, there were several differences in the morphological, physiological and biochemical characteristics among the four strains and the reference species of the genus Sulfitobacter. Moreover, the average nucleotide identity values between the three sequenced isolates and the reference strains were below 76.33, indicating that genomic variation exists between the isolates and reference strains. Chemotaxonomic characteristics together with phylogenetic affiliations and genomic distances illustrate that strains MM-124, NB-68 and NB-77 represent novel species of the genus Sulfitobacter, for which the names Sulfitobacter geojensis sp. nov. (type strain MM-124(T)â=KCTC 32124(T)â=JCM 18835(T)), Sulfitobacter noctilucae sp. nov. (type strain NB-68(T)â=KCTC 32122(T)â=JCM 18833(T)) and Sulfitobacter noctilucicola sp. nov. (type strain NB-77(T)â=KCTC 32123(T)â=JCM 18834(T)) are proposed.
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Filogenia , Rhodobacteraceae/clasificación , Agua de Mar/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Ácidos Oléicos/química , ARN Ribosómico 16S/genética , República de Corea , Rhodobacteraceae/genética , Rhodobacteraceae/aislamiento & purificación , Análisis de Secuencia de ADN , Ubiquinona/análogos & derivados , Ubiquinona/químicaRESUMEN
BACKGROUND: Helicobacter pylori (H. pylori) infection plays an important role in the early stage of cancer development. However, various bacteria that promote the synthesis of reactive oxygen and nitrogen species may be involved in the later stages. We aimed to determine the microbial composition of gastric mucosa from the patients with chronic gastritis, intestinal metaplasia, and gastric cancer using 454 GS FLX Titanium. METHODS: Gastric mucosal biopsy samples were collected from 31 patients during endoscopy. After the extraction of genomic DNA, variable region V5 of the 16S rRNA gene was amplified. PCR products were sequenced using 454 high-throughput sequencer. The composition, diversity, and richness of microbial communities were compared between three groups. RESULTS: The composition of H. pylori-containing Epsilonproteobacteria class appeared to be the most prevalent, but the relative increase in the Bacilli class in the gastric cancer group was noticed, resulting in a significant difference compared with the chronic gastritis group. By analyzing the Helicobacter-dominant group at a family level, the relative abundance of Helicobacteraceae family was significantly lower in the gastric cancer group compared with chronic gastritis and intestinal metaplasia groups, while the relative abundance of Streptococcaceae family significantly increased. In a UPGMA clustering of Helicobacter-dominant group based on UniFrac distance, the chronic gastritis group and gastric cancer group were clearly separated, while the intestinal metaplasia group was distributed in between the two groups. The evenness and diversity of gastric microbiota in the gastric cancer group was increased compared with other groups. CONCLUSIONS: In Helicobacter predominant patients, the microbial compositions of gastric mucosa from gastric cancer patients are significantly different to chronic gastritis and intestinal metaplasia patients. These alterations of gastric microbial composition may play an important, as-yet-undetermined role in gastric carcinogenesis of Helicobacter predominant patients.
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Bacterias/aislamiento & purificación , Mucosa Gástrica/microbiología , Gastritis/microbiología , Enfermedades Intestinales/microbiología , Microbiota , Adulto , Anciano , Bacterias/clasificación , Bacterias/genética , Técnicas de Tipificación Bacteriana , Biodiversidad , Femenino , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Helicobacter pylori/aislamiento & purificación , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Enfermedades Intestinales/patología , Masculino , Metaplasia/microbiología , Persona de Mediana Edad , Estudios Prospectivos , Neoplasias Gástricas/microbiologíaRESUMEN
We provide evidence of single attoliter oil droplet collisions at the surface of an ultra-microelectrode (UME) by the observation of simultaneous electrochemical current transients (i-t curves) and electrogenerated chemiluminescent (ECL) transients in an oil/water emulsion. An emulsion system based on droplets of toluene and tri-n-propylamine (2:1 v/v) emulsified with an ionic liquid and suspended in an aqueous continuous phase was formed by ultrasonification. When an ECL luminophore, such as rubrene, is added to the emulsion droplet, stochastic events can be tracked by observing both the current blips from oxidation at the electrode surface and the ECL blips from the follow-up ECL reaction, which produces light. This report provides a means of studying fundamental aspects of electrochemistry using the attoliter oil droplet and offers complementary analytical techniques for analyzing discrete collision events, size distribution of emulsion systems, and individual droplet electroactivity.
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Electrochemical measurements involving single nanoparticles have attracted considerable research attention. In recent years, various studies have been conducted on single-entity electrochemistry (SEE) for the in-depth analyses of catalytic reactions. Although, several electrocatalysts have been developed for H2 energy production, designing innovative electrocatalysts for this purpose remains a challenging task. Stochastic collision electrochemistry is gaining increased attention because it has led to new findings in the SEE field. Importantly, it facilitates establishing structure activity relationships for electrocatalysts by monitoring transient signals. This article reviews the recent achievements related to hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) using different electrocatalysts at the nanoscale level. In particular, it discusses the electrocatalytic activities of noble metal nanoparticles, including Ag, Au, Pt, and Pd nanoparticles, at the single-particle level. Because heterogeneity is a key factor affecting the catalytic activity of nanostructures, our work focuses on the influence of heterogeneities in catalytic materials on the OER and HER activities. These results may help to achieve a better understanding of the fundamental processes involved in the water splitting reaction.
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The complete mitochondrial genome of Marphysa victori Lavesque, Daffe, Bonifácio & Hutchings, 2017, was 15,891 bp in length with a GC content of 41%, comprising 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes. The maximum-likelihood tree showed the closest relationship between M. victori and M. sanguinea.
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Given the recognized involvement of the gut microbiome in the development of obesity, considerable efforts are being made to discover probiotics capable of preventing and managing obesity. In this study, we report the discovery of Lactiplantibacillus plantarum GBCC_F0227, isolated from fermented food, which exhibited superior triglyceride catabolism efficacy compared to L. plantarum WCSF1. Molecular analysis showed elevated expression levels of α/ß hydrolases with lipase activity (abH04, abH08_1, abH08_2, abH11_1, and abH11_2) in L. plantarum GBCC_F0227 compared to L. plantarum WCFS1, demonstrating its enhanced lipolytic activity. In a high-fat-diet (HFD)-induced mouse obesity model, the administration of L. plantarum GBCC_F0227 mitigated weight gain, reduced blood triglycerides, and diminished fat mass. Furthermore, L. plantarum GBCC_F0227 upregulated adiponectin gene expression in adipose tissue, indicative of favorable metabolic modulation, and showed robust growth and low cytotoxicity, underscoring its industrial viability. Therefore, our findings encourage the further investigation of L. plantarum GBCC_F0227's therapeutic applications for the prevention and treatment of obesity and associated metabolic diseases.
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Various R/Ar-functionalized tin 5,10,15-tris(pentafluorophenyl)corrolate derivatives are reported herein including the first ferrocenyltin corrolate species. The isopropyl, sec-butyl-, 2-methyl-n-butyl-, phenyl-, 2-thienyl-, and ferrocenyltin species have been prepared and characterized through (1)H, (13)C, and (119)Sn HMQC NMR spectroscopy, mass spectrometry, UV-vis and photoluminescent spectroscopy, and cyclic voltammetry studies. J(C/H-Sn) NMR spectroscopic couplings and ring-current effects (upfield shifting) were determined for the R-Sn axial hydrogen and carbon atoms. This report adds to older conceptually similar reports, by, i.e., Janson et al. (J. Am. Chem. Soc. 1969, 91, 5210) and Walker et al. (J. Am. Chem. Soc.1983, 105, 6923-6929), as discussed herein. Such NMR spectroscopic aspects are discussed for these model systems. Compound Sn-Ph bond cleavage was achieved by treatment with I(2).
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Técnicas Electroquímicas , Compuestos Orgánicos de Estaño/química , Porfirinas/química , Estaño/química , Isótopos , Espectroscopía de Resonancia Magnética , Estructura Molecular , Compuestos Orgánicos de Estaño/síntesis química , Porfirinas/síntesis químicaRESUMEN
Kluyveromyces marxianus is a thermotolerant yeast that has been explored for potential use in biotechnological applications, such as production of biofuels, single-cell proteins, enzymes, and other heterologous proteins. Here, we present the high-quality draft of the 10.9-Mb genome of K. marxianus var. marxianus KCTC 17555 (= CBS 6556 = ATCC 26548).
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Genoma Fúngico , Kluyveromyces/genética , Secuencia de Bases , Bases de Datos Genéticas , Datos de Secuencia MolecularRESUMEN
Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.
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Alteromonadaceae/genética , Genoma Bacteriano , Agar/metabolismo , Alteromonadaceae/aislamiento & purificación , Alteromonadaceae/metabolismo , Composición de Base , Secuencia de Bases , ADN Bacteriano/genética , Glicósido Hidrolasas/genética , Datos de Secuencia Molecular , Plásmidos , Agua de Mar/microbiología , Análisis de Secuencia de ADN , Sulfatasas/genéticaRESUMEN
Burkholderia pyrrocinia CH-67 was isolated from forest soil as a biocontrol agent to be utilized in agriculture. Here, we report the 8.05-Mb draft genome sequence of this bacterium. Its genome contains genes involved in biosynthesis of secondary metabolites and plant growth promotion, which may contribute to probiotic effects on plants.