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In this study, a novel synthesis of ultrathin, highly uniform colloidal bismuth sulfohalide (BiSX where X = Cl, Br, I) nanowires (NWs) and NW bundles (NBs) for room-temperature and solution-processed flexible photodetectors are presented. High-aspect-ratio bismuth sulfobromide (BiSBr) NWs are synthesized via a heat-up method using bismuth bromide and elemental S as precursors and 1-dodecanethiol as a solvent. Bundling of the BiSBr NWs occurs upon the addition of 1-octadecene as a co-solvent. The morphologies of the BiSBr NBs are easily tailored from sheaf-like structures to spherulite nanostructures by changing the solvent ratio. The optical bandgaps are modulated from 1.91 (BiSCl) and 1.88 eV (BiSBr) to 1.53 eV (BiSI) by changing the halide compositions. The optical bandgap of the ultrathin BiSBr NWs and NBs exhibits blueshift, whose origin is investigated through density functional theory-based first-principles calculations. Visible-light photodetectors are fabricated using BiSBr NWs and NBs via solution-based deposition followed by solid-state ligand exchanges. High photo-responsivities and external quantum efficiencies (EQE) are obtained for BiSBr NW and NB films even under strain, which offer a unique opportunity for the application of the novel BiSX NWs and NBs in flexible and environmentally friendly optoelectronic devices.
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This corrects the article on p. 446 in vol. 41, PMID: 36649918.
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Compared to traditional cooling systems, radiative cooling (RC) is a promising cooling strategy in terms of reducing energy consumption enormously and avoiding severe environmental issues. Radiative cooling materials (RCMs) reduce the temperature of objects without using an external energy supply by dissipating thermal energy via infrared (IR) radiation into the cold outer space through the atmospheric window. Therefore, RC has a great potential for various applications, such as energy-saving buildings, vehicles, water harvesting, solar cells, and personal thermal management. Herein, we review the recent progress in the applications of inorganic nanoparticles (NPs) and microparticles (MPs) as RCMs and provide insights for further development of RC technology. Particle-based RCMs have tremendous potential owing to the ease of engineering their optical and physical properties, as well as processibility for facile, inexpensive, and large area deposition. The optical and physical properties of inorganic NPs and MPs can be tuned easily by changing their size, shape, composition, and crystals structures. This feature allows particle-based RCMs to fulfill requirements pertaining to passive daytime radiative cooling (PDRC), which requires high reflectivity in the solar spectrum and high emissivity within the atmospheric window. By adjusting the structures and compositions of colloidal inorganic particles, they can be utilized to design a thermal radiator with a selective emission spectrum at wavelengths of 8-13 µm, which is preferable for PDRC. In addition, colloidal particles can exhibit high reflectivity in the solar spectrum through Mie-scattering, which can be further engineered by modifying the compositions and structures of colloidal particles. Recent advances in PDRC that utilize inorganic NPs and MPs are summarized and discussed together with various materials, structural designs, and optical properties. Subsequently, we discuss the integration of functional NPs to achieve functional RCMs. We describe various approaches to the design of colored RCMs including structural colors, plasmonics, and luminescent wavelength conversion. In addition, we further describe experimental approaches to realize self-adaptive RC by incorporating phase-change materials and to fabricate multifunctional RC devices by using a combination of functional NPs and MPs.
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PURPOSE: Testosterone hormonal replacement is the most commonly prescribed solution for men with reproductive issues; however, this treatment has various drawbacks. Hence, the identification of a natural product that promotes steroidogenesis is urgently needed. Ginseng is a popular traditional medicine. This study aimed to investigate steroidogenic effects of Korean ginseng berry extract (GBE; Panax ginseng C.A. Meyer) in vitro and in vivo. MATERIALS AND METHODS: In vitro model, mouse Leydig cells were treated with varying concentrations of GBE, and the levels of steroidogenesis-related genes and proteins and testosterone were measured using western blotting, qRT-PCR, and enzyme-linked immunosorbent assay (ELISA). Similarly, in an in vivo model using lipopolysaccharide-injected C57BL/6J mice, expression of steroidogenesis-related genes and proteins and testosterone levels were analyzed. Additionally, sleep deprivation was used to simulate common life stressors related to late-onset hypogonadism (LOH) and the natural effects of aging. Mice were fed sham or GBE before being subjected to paradoxical sleep deprivation. RESULTS: In vitro, GBE induced steroidogenic effects by increasing the levels of enzymes associated with steroidogenesis, steroidogenic acute regulatory protein (STAR), CYP11A1, and CYP17A1. In vivo, GBE significantly increased mRNA and protein levels of steroidogenic enzymes. Furthermore, the synthetic testosterone levels in mouse Leydig cell supernatants and blood sera were increased. In the sleep deprivation study, mice fed GBE showed increased testosterone production and survival under such stressful conditions. CONCLUSIONS: GBE increased mRNA and protein levels of steroidogenesis-related enzymes STAR, CYP11A1, and CYP17A1. These key enzymes induced the increased production of testosterone both in vivo and in vitro. Thus, GBE might be a promising therapeutic or additive nutritional agent for improving men's health by increasing steroidogenesis or improving LOH.
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In this work, the effectiveness of pyrite/sodium hypochlorite (FeS2/NaClO) treatment to eliminate arsenic (As) from fractured-bedrock groundwater via oxidative adsorption was evaluated. The As concentration in the tested reactors decreased sharply during the initial 5 min, as the addition of NaClO effectively increased the As removal efficiency, attaining 98.6% removal within 60 min in the presence of 0.05 M NaClO. There was no coexisting anion effect (Cl-, CO3-, HCO3-, NO3-, and F-) on the As removal capacity of FeS2/NaClO, except for the PO43- which resulted in less removal of As. X-ray spectroscopy analysis of As(III)-sorbed FeS2 surfaces revealed that a portion of As(III) was oxidized into As(V) during the adsorption process. Scanning electron microscopy-energy-dispersive spectrometer results of FeS2 exhibited the distribution of adsorbed As on the newly formed iron (oxy) hydroxide surfaces, with an As element ratio of 1.27%. A continuous flow-bed column study further demonstrated the efficiency of FeS2/NaClO treatment to lower the contamination level of As at the removal rates of 0.66-3.02 mg/L·day for 160 h. These results suggest that FeS2/NaClO treatment can be considered an effective strategy for removing As in groundwater of bedrock aquifers.
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Arsênio , Água Subterrânea , Poluentes Químicos da Água , Purificação da Água , Arsênio/análise , Hipoclorito de Sódio , Poluentes Químicos da Água/análise , Ferro/química , Água Subterrânea/química , Purificação da Água/métodos , AdsorçãoRESUMO
Paralichthys olivaceus (olive flounder) is widely cultivated in Korea. However, data on the antibiotic susceptibility of bacterial pathogens that infect olive flounders in Korea are limited. The susceptibility of 84 strains of 3 pathogenic bacteria (Streptococcus spp., Vibrio spp., and Edwardsiella piscicida) to 18 antibiotics was tested using the minimum inhibitory concentration (MIC) panels, and the distribution of the MIC values for each species was confirmed. Among the panel antibiotics, nine commonly used antibiotics were selected, and the multiple antibiotic resistance (MAR) index and antibiotic resistance pattern were indicated using the disk diffusion method. It was confirmed that most of the isolates had a MAR index greater than 0.2, indicating a high-risk source. The distribution patterns of the MIC values and resistance pattern between gram-positive and gram-negative bacteria showed slightly different results. Ampicillin, erythromycin, and clindamycin were more effective against gram-positive bacteria than gram-negative bacteria. However, the MIC values of flumequine for gram-positive bacteria were higher than those of gram-negative bacteria. Through the distribution patterns of the MIC values and resistance patterns presented in this study, the need for monitoring the multidrug-resistant bacteria in aquaculture is emphasised.
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Linguado , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias , Linguado/microbiologia , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Testes de Sensibilidade MicrobianaRESUMO
In this paper, the N,N-dimethylformamide (DMF)-assisted shape evolution of highly uniform and shape-pure copper nanocrystals (Cu NCs) is presented for the first time. Colloidal Cu NCs are synthesized via the disproportionation reaction of copper (I) bromide in the presence of a non-polar solvent mixture. It is observed that the shape of Cu NCs is systematically controlled by the addition of different amounts of DMF to the reaction mixture in high-temperature reaction conditions while maintaining a high size uniformity and shape purity. With increasing amount of DMF in the reaction mixture, the morphology of the Cu NCs change from a cube enclosed by six {100} facets, to a sphere with mixed surface facets, and finally, to an octahedron enclosed by eight {111} facets. The origin of this shape evolution is understood via first-principles density functional theory calculations, which allows the study of the change in the relative surface stability according to surface-coordinating adsorbates. Further, the shape-dependent plasmonic properties are systematically investigated with highly uniform and ligand-exchanged colloidal Cu NCs dispersed in acetonitrile. Finally, the facet-dependent electrocatalytic activities of the shape-controlled Cu NCs are investigated to reveal the activities of the highly uniform and shape-pure Cu NCs in the methanol oxidation reaction.
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Cobre , Nanopartículas , Dimetilformamida , OxirreduçãoRESUMO
In this study, the natural attenuation potential and biogeochemical analysis of nitrate contaminated bedrock aquifers by injection of carbon sources was evaluated. The denitrification capacity was assessed by injecting different carbon sources (succinate, acetate, fumarate) into the groundwater. Acetate was identified as the optimum source of electron donors for microbial metabolic processes, as it improved the effect of nitrate removal and microbial activity in the groundwater. In addition, when acetate was injected with a C/N ratio = 2.1:1, the ratio of denitrifying bacteria was the greatest (C/N 2.1 (2.1%) > C/N 4.2 (1.9%) > C/N 7.0 (0.9%) > control (0.7%)). Reflecting the geochemical characteristics of the bedrock aquifer environment, acetate was injected into groundwater at the research site to activate biological heterotrophic denitrification. As a result, the nitrate reduction rate was 0.377 g-N/day (YP-3), while the rate in groundwater unaffected by acetate was significantly lower, at 0.028 g-N/day (YP-4) over the same reaction time. In particular, the ratio of Dechloromonas denitrificans sp., which is a representative denitrification bacteria involved in anaerobic reduction of nitrate, increased (before injection: 0.0089%, after injection: 1.3067%). Expression of the nosZ gene, which is involved in the denitrification pathway (N2O â N2), increased from 4.82 Log (gene copies L-1) to 9.71 Log (gene copies L-1). Together, these results demonstrate that denitrification in bedrock aquifers can be activated by injection of carbon sources and identified the genetic reason for that denitrification.
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Água Subterrânea , Nitratos , Betaproteobacteria , Carbono , Desnitrificação , Nitratos/análiseRESUMO
In this study, we demonstrate the colloidal synthesis of nearly monodisperse, sub-100-nm phase change material (PCM) nanobeads with an organic n-paraffin core and poly(methylmethacrylate) (PMMA) shell. PCM nanobeads are synthesized via emulsion polymerization using ammonium persulfate as an initiator and sodium dodecylbenzenesulfonate as a surfactant. The highly uniform n-paraffin/PMMA PCM nanobeads are sub-100 nm in size and exhibit superior colloidal stability. Furthermore, the n-paraffin/PMMA PCM nanobeads exhibit reversible phase transition behaviors during the n-paraffin melting and solidification processes. During the solidification process, multiple peaks with relatively reduced phase change temperatures are observed, which are related to the phase transition of n-paraffin in the confined structure of the PMMA nanobeads. The phase change temperatures are further tailored by changing the carbon length of n-paraffin while maintaining the size uniformity of the PCM nanobeads. Sub-100-nm-sized and nearly monodisperse PCM nanobeads can be potentially utilized in thermal energy storage and drug delivery because of their high colloidal stability and solution processability.
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OBJECTIVES: Multidrug-resistant (MDR) Acinetobacter baumannii as well as MDR Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and other Enterobacteriaceae ('ESKAPE' pathogens) currently present a major public-health problem. These bacteria are associated with opportunistic infections in intensive care units as well as in immunocompromised patients. There is an urgent need for new alternative antibacterials to control these MDR bacteria. Here we describe the antibacterial action of a novel peptidoglycan hydrolase that targets the bacterial cell wall, identified in the genome of clinical isolate A. baumannii 1656-2. METHODS: We generated a recombinant protein from a sequence encoding a lysozyme-like protein identified in the genome of A. baumannii 1656-2. We named it Ablysin and tested its antibacterial activity and biofilm removal ability targeting ESKAPE pathogens. RESULTS: In vitro application of Ablysin resulted in growth inhibition of the six aforementioned bacterial species, with a highest activity against A. baumannii. Electron microscopy revealed the concentration-dependent (250-2000 µg/mL) rupture of A. baumannii bacterial cells accompanied by elimination of the associated biofilm. CONCLUSIONS: Ablysin represents a potential new class of antibacterial proteins that can be used to target MDR A. baumannii as well as other bacterial species.
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Acinetobacter baumannii , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Biofilmes , Farmacorresistência Bacteriana Múltipla , Humanos , Muramidase/farmacologiaRESUMO
OBJECTIVES: Multidrug-resistant (MDR) bacteria are a major public-health concern. Bacteriophage endolysins (lysins) can be used as novel antimicrobial agents against bacterial infections. In this study, a novel endolysin (LysSS) containing a lysozyme-like domain was evaluated for its antibacterial activity against various species of bacteria. METHODS: The LysSS-encoding gene was analyzed and cloned and the LysSS recombinant protein was expressed and purified. Purified LysSS was used to determine its antimicrobial activity against various bacterial species in vitro and to measure its protection rate against Acinetobacter baumannii systemic infection in an in vivo murine model. RESULTS: Recombinant LysSS showed activity against MDR A. baumannii, MDR Escherichia coli, MDR Klebsiella pneumoniae, MDR Pseudomonas aeruginosa and Salmonella sp. without pre-treatment with an outer membrane permeabiliser. Moreover, LysSS inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentration (MIC) of LysSS against 16 MDR A. baumannii strains ranged from 0.063-0.25mg/mL. LysSS had no cytotoxic effect on A549 human lung cells below 250µg/mL. In an animal model, mice infected with A. baumannii were protected (40% survival rate with 125µg LysSS) by intraperitoneal injection of LysSS. CONCLUSION: The current results demonstrate that LysSS may be a novel and promising antimicrobial agent against MRSA and MDR Gram-negative bacteria, including A. baumannii and P. aeruginosa.