Publications by authors named "Won-Il Lee"

Hierarchically porous materials containing sub-nm ultramicropores with molecular sieving abilities and microcavities with high gas diffusivity may realize energy-efficient membranes for gas separations. However, rationally designing and constructing such pores into large-area membranes enabling efficient H separations remains challenging. Here, we report the synthesis and utilization of hybrid carbon molecular sieve membranes with well-controlled nano- and micro-pores and single zinc atoms and clusters well-dispersed inside the nanopores via the carbonization of supramolecular mixed matrix materials containing amorphous and crystalline zeolitic imidazolate frameworks.

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Nanoparticles (NPs) at high loadings are often used in mixed matrix membranes (MMMs) to improve gas separation properties, but they can lead to defects and poor processability that impede membrane fabrication. Herein, it is demonstrated that branched nanorods (NRs) with controlled aspect ratios can significantly reduce the required loading to achieve superior gas separation properties while maintaining excellent processability, as demonstrated by the dispersion of palladium (Pd) NRs in polybenzimidazole for H /CO separation. Increasing the aspect ratio from 1 for NPs to 40 for NRs decreases the percolation threshold volume fraction by a factor of 30, from 0.

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Rapid, yet accurate and sensitive testing has been shown to be critical in the control of spreading pandemic diseases such as COVID-19. Current methods which are highly sensitive and can differentiate different strains are slow and cannot be conveniently applied at the point of care. Rapid tests, meanwhile, require a high titer and are not sufficiently sensitive to discriminate between strains.

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Rapid, sensitive and accurate point-of-care-testing (POCT) of bacterial load from a variety of samples can help prevent human infections caused by pathogenic bacteria and mitigate their spreading. However, there is an unmet demand for a POCT device that can detect extremely low concentrations of bacteria in raw samples. Herein, we introduce the 'count-on-a-cartridge' (COC) platform for quantitation of the food-borne pathogenic bacteria Staphylococcus aureus.

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Biosensor systems for wearable continuous monitoring are desired to be developed into conformal patch platforms. However, developing such patches is very challenging owing to the difficulty of imparting materials and components with both high stretchability and high performance. Herein, we report a fully stretchable microfluidics-integrated glucose sensor patch comprised of an omnidirectionally stretchable nanoporous gold (NPG) electrochemical biosensor and a stretchable passive microfluidic device.

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A key challenge for realizing mobile device-based on-the-spot environmental biodetection is that a biosensor integrated with a fluid handling sensor cartridge must have acceptable accuracy comparable to that of conventional standard analytical methods. Furthermore, the user interface must be easy to operate, technologically plausible, and concise. Herein, we introduced an advanced smartphone imaging-based fluorescence microscope designed for Hg2+ monitoring by utilizing a biosensor cartridge that reduced user intervention via time-sequenced passive fluid handling.

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Adult hippocampal neural (HCN) stem cells promptly undergo irreversible autophagic cell death (ACD) if deprived of insulin in culture. Small, non-coding microRNAs (miRNA) play an important role in regulating biological processes, including proliferation and cell death. However, there have been no reports thus far regarding miRNA involvement in the induction of adult HCN stem cell death under insulin-deprived conditions, for which we performed a microarray-based analysis to examine the expression signature of miRNAs in adult rat HCN stem cells.

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A critical unmet need in the diagnosis of bacterial infections, which remain a major cause of human morbidity and mortality, is the detection of scarce bacterial pathogens in a variety of samples in a rapid and quantitative manner. Herein, we demonstrate smartphone-based detection of Staphylococcus aureus in a culture-free, rapid, quantitative manner from minimally processed liquid samples using aptamer-functionalized fluorescent magnetic nanoparticles. The tagged S.

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The accuracy of a bioassay based on smartphone-integrated fluorescent biosensors has been limited due to the occurrence of false signals from non-specific reactions as well as a high background and low signal-to-noise ratios for complementary metal oxide semiconductor image sensors. To overcome this problem, we demonstrate dual-wavelength fluorescent detection of biomolecules with high accuracy. Fluorescent intensity can be quantified using dual wavelengths simultaneously, where one decreases and the other increases, as the target analytes bind to the split capture and detection aptamer probes.

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Probe-mediated fluorescence biosensing methods based on spectrophotometry still have limitations such as detection inaccuracy caused by the occurrence of false signals and lack of simultaneous qualitative and quantitative read-outs with an ultra-low detection limit. Herein, we describe a novel seesawed fluorescence detection strategy based on dual-colour imaging-based quantitation in which the green fluorescence of the capture aptamer decreases and the red fluorescence of the detection aptamer increases simultaneously upon their respective interactions with the target biomolecule. This approach enhances detection accuracy through facilitating identification of probable false-positives in biological samples.

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Background: It is widely accepted that cervical interlaminar steroid injection (CIESI) is more effective in treating radicular pain than axial neck pain, but without direct comparison. And the differences of effect after CIESI according to MRI findings are inconsistent. In this retrospective study, we evaluated the therapeutic response of CIESI according to pain sites, durations, MRI findings, and other predictive factors altogether, unlike previous studies, which evaluated them separately.

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Although real-time label-free fluorescent aptasensors based on nanomaterials are increasingly recognized as a useful strategy for the detection of target biomolecules with high fidelity, the lack of an imaging-based quantitative measurement platform limits their implementation with biological samples. Here we introduce an ensemble strategy for a real-time label-free fluorescent graphene (Gr) aptasensor platform. This platform employs aptamer length-dependent tunability, thus enabling the reagentless quantitative detection of biomolecules through computational processing coupled with real-time fluorescence imaging data.

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The realization of a high-throughput biosensor platform with ultrarapid detection of biomolecular interactions and an ultralow limit of detection in the femtomolar (fM) range or below has been retarded due to sluggish binding kinetics caused by the scarcity of probe molecules on the nanostructures and/or limited mass transport. Here, as a new method for the highly efficient capture of biomolecules at extremely low concentration, we tested a three-dimensional (3D) platform of a bioelectronic field-effect transistor (bio-FET) with vertically aligned and highly dense one-dimensional (1D) ZnO nanorods (NRs) as a sensing surface capped by an ultrathin TiO2 layer for improved electrolytic stability on a chemical-vapor-deposited graphene (Gr) channel. The ultrarapid detection capability with a very fast response time (∼1 min) at the fM level of proteins in the proposed 3D bio-FET is primarily attributed to the fast binding kinetics of the probe-target proteins due to the small diffusion length of the target molecules to reach the sensor surface and the substantial number of probe molecules available on the largely increased surface area of the vertical ZnO NRs.

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Background: We investigated the correction methods following wrong-settings of emulsion concentrations of propofol as a countermeasure against erroneous target-controlled infusions (TCI).

Methods: TCIs were started with targeting 4.0 µg/ml of effect-site concentration (Ceff) of propofol, and the emulsion concentrations were selected for 2.

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Background: Gabapentin is a safe and well-tolerated anticonvulsant with a wide therapeutic index, and it is used for neuropathic pain. The aim of this study was to compare previous dosing methods with the administration of four different doses of gabapentin while maintaining the same maximum daily dose for the safe administration of high doses of the medication.

Methods: THE SUBJECTS WERE OUTPATIENTS WITH VARIOUS NEUROPATHIC PAIN SYNDROMES, WITH AT LEAST TWO OF THE FOLLOWING SYMPTOMS: allodynia, burning pain, shooting pain, or hyperalgesia.

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Cholinergic urticaria with acquired generalized hypohidrosis, and its pathophysiology is not well known. Autoimmunity to sweat glands or to acetylcholine receptors on sweat glands has been mentioned as one of the possible etiologies. Systemic steroid therapy, antihistamines, anticholinergics, and avoidance of the stimulatory situations are recommended for treatment.

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Recombinant adeno-associated virus serotype 5 (rAAV5) is considered to be a promising gene transfer vehicle. However, preferential gene delivery to the tumor remains a requirement for cancer treatment. We generated rAAV5 mutants bearing tumor marker-binding peptides and analyzed their properties as viral vectors, as well as their transduction efficiencies and preferential antitumoral potencies.

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Ethnopharmacological Relevance: The dried flowers of Lonicera japonica, also known as Japanese honeysuckle, and the dried root of Anemarrhena asphodeloides, the component herbs of WIN-34B, are traditionally used in Eastern medicine to treat various inflammatory conditions including arthritis.

Objective: To study the acute and chronic toxicities of WIN-34B and to compare its effects on gastric mucosa with those of diclofenac, a widely used NSAID, and celecoxib, a selective COX-2 inhibitor.

Materials And Methods: To investigate acute toxicity, we orally administered a single dose of 5,000 mg/kg WIN-34B to rats.

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Objectives: Our aim was to verify neural regulation of submucous gland mucus secretions in the Eustachian tubes of guinea pigs.

Study Design: Prospective animal study.

Methods: Eustachian tubes harvested from 12 guinea pigs were used for this study.

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Article Synopsis
  • Otogenic pneumocephalus is characterized by the presence of air in the cranial cavity due to issues with the middle ear or mastoid air cells, often linked to trauma.
  • A case study highlights a patient who developed tinnitus 29 months after brain tumor surgery, with imaging revealing a significant air cavity in the left posterior fossa.
  • A surgical procedure successfully sealed the defect using a muscle plug and bone dust, addressing the unusual cause of the patient's symptoms.
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Background: Recent studies show that transcriptional activation of GTP cyclohydrolase I (GCH1) in dorsal root ganglia (DRG) is significantly involved in the development and persistency of pain symptoms. We thus hypothesize that neuropathic pain may be attenuated by down-regulation of GCH1 expression, and propose a gene silencing system for this purpose.

Results: To interrupt GCH1 synthesis, we designed a bidirectional recombinant adeno-associated virus encoding both a small hairpin RNA against GCH1 and a GFP reporter gene (rAAV-shGCH1).

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Zero-valent iron nanoparticles (nano-Fe0) in aqueous solution rapidly inactivated Escherichia coli. A strong bactericidal effect of nano-Fe0 was found under deaerated conditions, with a linear correlation between log inactivation and nano-Fe0 dose (0.82 log inactivation/mg/L nano-Fe0 x h).

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Background: Effective gene delivery techniques are required to genetically manipulate dendritic cells (DCs). We therefore investigated the feasibility of using various self-complementary recombinant adeno-associated virus (scAAV) serotypes to deliver genes to human DCs.

Methods: Monocytes isolated from healthy volunteers were differentiated to immature DCs (iDC) by incubation with interleukin (IL)-4 and granulocyte macrophage colony-stimulating factor.

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The feasibility of various self-complementary AAV (scAAV) serotypes as efficient gene delivery vehicles in human cancer cells was evaluated. To dissect the transduction characteristics, we infected a variety of human cancer cells with scAAV1-6 or scAAV8 expressing GFP. scAAV2 led to the best transduction efficiency with nearly complete transgene expression at 1000 MOI in most cancer cells, regardless of cell/tissue origins.

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