Publications by authors named "Seung Goo Lee"

The improper handling and uncontrolled discharge of toxic organic dyes result in significant adverse effects on both human health and the environment. This study investigates the fabrication of SnO₂, yttrium and cobalt dual-doped SnO₂ (YCSn), chitosan-capped SnO₂ (CS*Sn), and chitosan-capped yttrium and cobalt dual-doped SnO₂ (CS*YCSn) nanoparticles using a one-step coprecipitation method for the photocatalytic degradation of methylene blue (MB) under visible light irradiation. Characterization techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), and ultraviolet-visible (UV-Vis) spectrophotometry confirm the successful synthesis of biodegradable CS*YCSn nanoparticles.

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Rodent whiskers are a distinct class of tactile sensors that work in conjunction with the biological skin to discern airstreams and obstacles with remarkable sensitivity, facilitating navigation around proximate objects. In this study, a flexible artificial skin is developed comprising sensory active units, including electronic skin (e-skin) and an artificial whisker, inspired by the sensory capabilities of rodent skin and whiskers. As a novel strategy, unique congruent air pockets are introduced within the e-skin to enhance the sensitivity.

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A halotolerant consortium between microalgae and methanotrophic bacteria could effectively remediate in situ CH and CO, particularly using saline wastewater sources. Herein, Methylomicrobium alcaliphilum 20Z was demonstrated to form a mutualistic association with Chlorella sp. HS2 at a salinity level above 3.

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Soft piezoresistive pressure sensors play an underpinning role in enabling a plethora of future Internet of Things (IoT) applications such as human-robot interaction (HRI) technologies, wearable devices, and metaverse ecosystems. Despite significant attempts to enhance the performance of these sensors, existing sensors still fall short of achieving high strain tolerance and linearity simultaneously. Herein, we present a low-cost, facile, and scalable approach to fabricating a highly strain-tolerant and linearly sensitive soft piezoresistive pressure sensor.

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  • The study focuses on a key group of bacteria in the human gut microbiome that has potential for creating treatments for gut diseases through microbiome engineering and live biotherapeutics.
  • Researchers identified new signal peptides that improve protein transport within these bacteria, which is crucial for developing therapeutics.
  • They also created an improved episomal plasmid system that enhances protein delivery and stability, while addressing the demand for antibiotic-free selection methods in clinical applications.
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Isoprene has numerous industrial applications, including rubber polymer and potential biofuel. Microbial methane-based isoprene production could be a cost-effective and environmentally benign process, owing to a reduced carbon footprint and economical utilization of methane. In this study, Methylococcus capsulatus Bath was engineered to produce isoprene from methane by introducing the exogenous mevalonate (MVA) pathway.

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Natural sharkskin features staggered-overlapped and multilayered architectures of riblet-textured anisotropic microdenticles, exhibiting drag reduction and providing a flexible yet strong armor. However, the artificial fabrication of three-dimensional (3D) sharkskin with these unique functionalities and mechanical integrity is a challenge using conventional techniques. In this study, it is reported on the facile microfabrication of multilayered 3D sharkskin through the magnetic actuation of polymeric composites and subsequent chemical shape fixation by casting thin polymeric films.

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  • * After treating the filler, the researchers created composites through melt-mixing and extrusion-injection molding to assess compatibility and migration behavior.
  • * Results showed that using butyl acrylate and maleic anhydride improved filler migration issues while preserving mechanical properties, but too much hydrophobicity from lauric acid decreased compatibility, indicating a balance is needed for effective automotive applications.
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  • * The study optimized nutrient levels, particularly calcium and phosphorus, during bioreactor operations, leading to a notable increase in cell density and mevalonate production from methane.
  • * Results indicate that the methanotroph HCDC approach could be a viable strategy for sustainable development, achieving high production levels of valuable synthetic biochemicals.
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Levulinic acid (LA) is a valuable chemical used in fuel additives, fragrances, and polymers. In this study, we proposed possible biosynthetic pathways for LA production from lignin and poly(ethylene terephthalate). We also created a genetically encoded biosensor responsive to LA, which can be used for screening and evolving the LA biosynthesis pathway genes, by employing an LvaR transcriptional regulator of KT2440 to express a fluorescent reporter gene.

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Antibiotics have been widely used for plasmid-mediated cell engineering. However, continued use of antibiotics increases the metabolic burden, horizontal gene transfer risks, and biomanufacturing costs. There are limited approaches to maintaining multiple plasmids without antibiotics.

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Stretchable pressure sensors are important components of multimodal electronic skin needed for potentializing numerous Internet of Things applications. In particular, to use pressure sensors in various wearable/skin-attachable electronics, both high deformability and strain-independent sensitivity must be realized. However, previously reported stretchable pressure sensors cannot meet these standards because they exhibit limited stretchability and nonuniform sensitivity under deformation.

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Miniaturized untethered soft robots are recently exploited to imitate multi-modal curvilinear locomotion of living creatures that perceive change of surrounding environments. Herein, the use of Caenorhabditis elegans (C. elegans) is proposed as a microscale model capable of curvilinear locomotion with mechanosensing, controlled by magnetically reconfigured 3D microtopography.

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Recent advances in nanolithography, miniaturization, and material science, along with developments in wearable electronics, are pushing the frontiers of sensor technology into the large-scale fabrication of highly sensitive, flexible, stretchable, and multimodal detection systems. Various strategies, including surface engineering, have been developed to control the electrical and mechanical characteristics of sensors. In particular, surface wrinkling provides an effective alternative for improving both the sensing performance and mechanical deformability of flexible and stretchable sensors by releasing interfacial stress, preventing electrical failure, and enlarging surface areas.

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This study presents a novel DNA part characterization technique that increases throughput by combinatorial DNA part assembly, solid plate-based quantitative fluorescence assay for phenotyping, and barcode tagging-based long-read sequencing for genotyping. We confirmed that the fluorescence intensities of colonies on plates were comparable to fluorescence at the single-cell level from a high-end, flow-cytometry device and developed a high-throughput image analysis pipeline. The barcode tagging-based long-read sequencing technique enabled rapid identification of all DNA parts and their combinations with a single sequencing experiment.

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Article Synopsis
  • * The growing demand for wearable electronics, like e-skins for health monitoring, highlights the need for "green" materials that are biodegradable, self-healing, and biocompatible.
  • * The text reviews the characteristics of both biological and artificial e-skins, emphasizes biodegradable materials for new applications, and discusses future challenges and prospects in developing environmentally friendly e-skins.
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The alignment of nanowires (NWs) has been actively pursued for the production of electrical devices with high-operating performances. Among the generally available alignment processes, spin-coating is the simplest and fastest method for uniformly patterning the NWs. During spinning, the morphology of the aligned NWs is sensitively influenced by the resultant external drag and inertial forces.

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In the current work, we combined different physical and chemical modifications of carbon nanofibers through the creation of micro-, meso-, and macro-pores as well as the incorporation of nitrogen groups in cyclic polyacrylonitrile (CPAN) using gas-assisted electrospinning and air-controlled electrospray processes. We incorporated them into electrode and interlayer in Li-Sulfur batteries. First, we controlled pore size and distributions in mesoporous carbon fibers (mpCNF) via adding polymethyl methacrylate as a sacrificial polymer to the polyacrylonitrile carbon precursor, followed by varying activation conditions.

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As the design of genetic circuitry for synthetic biology becomes more sophisticated, diverse regulatory bioparts are required. Despite their importance, well-characterized 3'-untranslated region (3'-UTR) bioparts are limited. Thus, transcript 3'-ends require further investigation to understand the underlying regulatory role and applications of the 3'-UTR.

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Enantiomerically pure d-amino acids are important intermediates as chiral building blocks for peptidomimetics and semisynthetic antibiotics. Here, a transcriptional factor-based screening strategy was used for the rapid screening of d-stereospecific amino acid amidase via an enzyme-specific amidophenol substrate. We used a d-threonine amidophenyl derivative to produce 2-aminophenol that serves as a putative enzyme indicator in the presence of d-threonine amidases.

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Background: The gut microbiota is associated with diverse age-related disorders. Several rejuvenation methods, such as probiotic administration and faecal microbiota transplantation, have been applied to alter the gut microbiome and promote healthy ageing. Nevertheless, prolongation of the health span of aged mice by remodelling the gut microbiome remains challenging.

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  • A new strategy was developed to create low-cost stretchable electrodes that maintain high stretchability and conductivity while being easy to manufacture.
  • The electrodes were made using a bridged square-shaped (BSS) AgNW bundle mesh and a stretchable polymer matrix with a microcavity array, allowing for effective strain distribution during stretching.
  • This method enables the production of complex patterns without extra processes and is suitable for industrial techniques like spray and bar coating, paving the way for the commercialization of stretchable electronics like displays and electronic skin.
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The microbial conversion of glycerol into value-added commodity products has emerged as an attractive means to meet the demands of biosustainability. However, glycerol is a non-preferential carbon source for productive fermentation because of its low energy density. We employed evolutionary and metabolic engineering in tandem to construct an Escherichia coli strain with improved GABA production using glycerol as the feedstock carbon.

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Bacteroides thetaiotaomicron represents a major symbiont of the human gut microbiome that is increasingly viewed as a promising candidate strain for microbial therapeutics. Here, we engineer B. thetaiotaomicron for heterologous production of non-native butyrate as a proof-of-concept biochemical at therapeutically relevant concentrations.

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Dual-sizing effects with either epoxy or polyurethane (PU) on the thermal, mechanical, and impact properties of carbon fiber/acrylonitrile-butadiene-styrene (ABS) composites produced by extrusion and injection molding processes were investigated. The heat deflection temperature, dynamic mechanical, tensile, flexural, and impact properties of the composites reinforced with either (epoxy + epoxy) or (epoxy + PU) dual-sized carbon fiber were higher than those commercially single-sized with epoxy. The result indicated that the dual-sized carbon fiber significantly contributed not only to improving the heat deflection temperature and the storage modulus, but also to improving the tensile, flexural, and impact properties of carbon fiber/ABS composites.

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