Publications by authors named "Min Yong Lee"

Addressing the high cost and long cycle associated with the multistep digital restoration process involving 3D printing technology, we proposed the 3D pen as an innovative strategy for rapid bone repair. Capitalizing on the low melting point characteristic of polycaprolactone (PCL), we introduced, for the first time, the novel concept of directly constructing scaffolds at bone defect sites using 3D pens. In this in vitro study, we meticulously evaluated both the mechanical and biological properties of 3D pen-printed PCL scaffolds with six distinct textures: unidirectional (UNI) (0°, 45°, 90°), bidirectional (BID) (-45°/45°, 0°/90°), and concentric (CON).

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  • * A new palladium-palladium oxide (Pd-PdO) heterostructure demonstrates exceptional performance, with a significantly higher catalytic efficiency for converting toxic chlorophenols into phenol compared to conventional catalysts.
  • * The success of this Pd-PdO system hinges on optimized interactions between two types of palladium sites that enhance hydrogen generation and its role in the dechlorination process, facilitating both detoxification and resource recovery.
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  • * This study developed a 1D convolution neural network (1D-CNN) model to predict cyanobacterial alert levels a week in advance using 11 years of data, aiming for better decision-making.
  • * By addressing data imbalance through adaptive synthetic sampling, the model achieved high training accuracy (97.3%) and reasonable testing accuracy (85.0%), which supports the creation of management strategies against HABs.
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  • The KrCl-excimer lamp emits far-UVC light at 222 nm, which is more effective than conventional UVC light at 254 nm for degrading and detoxifying harmful organic pollutants, specifically chlorophenols.
  • UV222 demonstrated significantly higher efficiencies in photolyzing chlorophenols, being 1.4 to 34.1 times faster than UV254, particularly with protonated versions due to better light absorption and quantum yields.
  • The study found UV222 to enhance dechlorination rates to 95% compared to 60% with UV254, although the presence of radical sensitizers could complicate the process, producing toxic intermediates but also aiding in detoxification.
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  • The KrCl* excimer lamp (UV222) is a mercury-free alternative to low-pressure mercury lamps (UV254) for UV-based advanced oxidation processes, offering higher photon energy and better performance.
  • A comprehensive study was conducted on various oxidants like hydrogen peroxide and persulfate, revealing that UV222 significantly enhances oxidant activation, with increased efficacy for degrading micropollutants compared to UV254.
  • PDS proved to be the most effective oxidant under UV222, achieving much higher rates of micropollutant elimination and requiring less energy, despite some interference from other water constituents.
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  • The study examined how different cleaning solutions affect the properties of 3D-printed zirconia, focusing on factors like geometry, roughness, gloss, hardness, and flexural strength.
  • Solutions included isopropyl alcohol (IPA), ethyl alcohol (EtOH), and tripropylene glycol monomethyl ether (TPM), all tested at 70% concentration, leading to significant findings regarding the thickness and weight of the TPM groups.
  • Results showed that while the surface roughness varied between solutions, surface gloss, hardness, and flexural strength remained generally unaffected, suggesting IPA70, TPM97, and EtOH could be effective alternatives to the more traditional IPA99.
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  • Vacuum-UV (VUV), specifically at 185 nm, is effectively used to purify reverse osmosis permeate water, crucial for electronics-grade ultrapure water production.
  • The study revealed that various anions present in low concentrations significantly impact the VUV oxidation of acetaldehyde, a common contaminant in this water.
  • Bicarbonate minimally affects the process, while nitrate and chloride notably hinder acetaldehyde removal rates and mineralization, highlighting the need for deeper research into how these anions alter VUV photochemistry in water.
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Vital pulp therapy (VPT) has gained prominence with the increasing trends towards conservative dental treatment with specific indications for preserving tooth vitality by selectively removing the inflamed tissue instead of the entire dental pulp. Although VPT has shown high success rates in long-term follow-up, adverse effects have been reported due to the calcification of tooth canals by mineral trioxide aggregates (MTAs), which are commonly used in VPT. Canal calcification poses challenges for accessing instruments during retreatment procedures.

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  • The study explores the use of mineral trioxide aggregate (MTA) as a barrier membrane in guided bone regeneration (GBR) due to its beneficial properties like biocompatibility and antimicrobial effects.
  • Researchers created electrospun membranes using different MTA formulations and assessed their physicochemical characteristics, including fiber structure and mechanical strength, as well as their effects on cell behavior and gene expression related to bone formation.
  • Results showed that while all membranes supported cell attachment and were biocompatible, the 4MTA formulation had the best potential for osteogenic activity, enhancing the expression of bone-related genes over time.
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Background/purpose: The retrograde filling material, particularly mineral trioxide aggregate (MTA) employed in apicoectomy, should possess high antibacterial efficacy and osteogenic potential. We evaluated the antibacterial efficacy, biocompatibility, and osteogenic potential following the addition of silver nanoparticles (AgNPs) and calcium fluoride (CaF) in retrograde filling material of MTA.

Materials And Methods: MTA was mixed with four different solvents.

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Brominated byproducts and toxicity generation are critical issues for ozone application to wastewater containing bromide. This study demonstrated that ultraviolet/ozone (UV/O, 100 mJ/cm, 1 mg-O/mg-DOC) reduced the cytotoxicity of wastewater from 14.2 mg of pentol/L produced by ozonation to 4.

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Wound healing involves a complex and dynamic interplay among various cell types, cytokines, and growth factors. Macrophages and transforming growth factor-β1 (TGF-β1) play an essential role in different phases of wound healing. Cold atmospheric plasma has a wide range of applications in the treatment of chronic wounds.

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  • * UV222 and UV254 show similar effectiveness in inactivating E. coli, but UV222 treatment prevents reactivation by causing extensive damage to the bacteria's DNA and cell membrane.
  • * Overall, using UV222 for disinfection may be a better option for water treatment as it minimizes the chance of bacterial recovery after treatment.
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  • * The study found that while VUV shows better performance in activating hydroxyl radicals (HO) for contaminant degradation, its effectiveness varies greatly with the depth of water, whereas UV/HO maintains a more consistent performance regardless of conditions.
  • * Environmental factors like chloride and nitrate concentrations significantly inhibit the VUV process due to competitive absorbance, though some hydroxyl radicals are still generated from the photolysis of these substances, impacting the overall oxidation efficiency.
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  • - The study investigates how well different oxidants—ozone (O), peroxymonosulfate (PMS), and hydrogen peroxide (HO)—can inactivate the MS2 coliphage virus in water, which is important for preventing viral disease spread.
  • - Results showed that to achieve a significant 4-log reduction in virus levels, all three oxidants needed specific doses and a contact time of 30 minutes, but ozone was the fastest, requiring only 0.5 minutes.
  • - In secondary effluent, all three oxidants effectively inactivated the virus and removed dissolved organic matter, but ozone was found to be the most efficient option overall for disinfection.
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Co-processing recycled waste during cement production, i.e., using alternative materials such as secondary raw materials or secondary raw fuels, is widely practiced in developed countries.

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Dental bases require low thermal conductivity and good mechanical properties, such as bonding with composite resins. This study aims to elucidate the physicochemical properties of premixed mineral trioxide aggregate (MTA) for its suitability as a dental base and to explore the optimal adhesive strategy with composite resin. The thermal conductivity and compressive strength of this premixed MTA are 0.

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  • Microwave discharge electrodeless lamp (MDEL) produces UV light and, when combined with ozone (O), offers enhanced disinfection of bacteria such as E. coli and Bacillus subtilis.
  • The dual treatment (MWUV/O) significantly outperformed individual treatments with either MWUV or ozone alone, achieving a high inactivation rate of 5.52 log for E. coli.
  • Additionally, the MWUV/O treatment not only reduced the likelihood of bacteria reactivating post-disinfection but also improved disinfection efficiency in real domestic wastewater scenarios.
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  • Vacuum ultraviolet (VUV) irradiation effectively oxidizes pollutants but doesn't necessarily reduce their toxicity, highlighting the need for more research in real wastewater scenarios.
  • In this study, VUV irradiation was found to significantly decrease the cytotoxicity and genotoxicity of secondary effluents when tested on Chinese hamster ovary cells, with reductions of 57%-63% and 56%-61% respectively after 36 minutes.
  • Hydroxyl radicals generated during VUV irradiation contributed largely to these reductions in toxicity, while the overall removal of dissolved organic carbon (DOC) was only 15.8%-20.0%, indicating that VUV treatment primarily affects smaller molecular weight compounds and alters chemical properties associated with toxicity.
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Some individuals with mild traumatic brain injury (mTBI), also known as concussion, have neuropsychiatric and physical problems that last longer than a few months. Symptoms following mTBI are not only impacted by the kind and severity of the injury but also by the post-injury experience and the individual's responses to it, making the persistence of mTBI particularly difficult to predict. We aimed to identify prognostic blood-based protein biomarkers predicting 6-month outcomes, in light of the clinical course after the injury, in a longitudinal mTBI cohort (N = 42).

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Background: In workers with moderate to severe work-related traumatic brain injury (wrTBI), this study aimed to investigate the effect of the timing of rehabilitation therapy initiation on the length of hospital stay and the factors that can influence this timing.

Methods: We used data obtained from the Republic of Korea's nationwide Workers' Compensation Insurance. In the Republic of Korea, between the years 2010 and 2019, a total of 26,324 workers filed a claim for compensation for moderate to severe wrTBI.

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  • - The study analyzed the rate and impact of work-related traumatic spinal cord injuries (wrTSCI) in Korea from 2010 to 2019 using workers' compensation data.
  • - The average annual incidence of wrTSCI was 22.8 cases per million workers, with the highest rates occurring in the cervical region, particularly among workers in the construction industry.
  • - The information gathered can assist in pinpointing high-risk groups and aid in creating targeted prevention strategies for these injuries.
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This study aimed to examine the frequency of worker injuries by affected body part(s) and the associated costs. Methods : We performed a secondary analysis of national workers' compensation claims data from the Korean workers' compensation insurance. The main outcome measures were frequency and cost of claims by injury type.

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  • The study aimed to assess the incidence of traumatic spinal cord injuries (TSCI) in South Korea using three different databases: NHIS, AUI, and IACI, over various years.
  • Results showed that the TSCI incidence in the NHIS database significantly increased from 2009 to 2018, while the AUI database showed a significant decrease during the same period.
  • Interestingly, all databases indicated higher incidences of TSCI in individuals aged 60 and above, particularly those over 70, with the NHIS and IACI databases showing dramatic increases in this age group.
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Introduction: This study aimed to investigate alterations in whole-brain functional connectivity after a concussion using graph-theory analysis from global and local perspectives and explore the association between changes in the functional network properties and cognitive performance.

Methods: Individuals with mild traumatic brain injury (mTBI, n = 29) within a month after injury, and age- and sex-matched healthy controls (n = 29) were included. Graph-theory measures on functional connectivity assessed using resting state functional magnetic resonance imaging data were acquired from each participant.

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