211 results on '"Jung Heon Lee"'
Search Results
2. Alveolar macrophage phagocytosis-evading inhaled microgels incorporating nintedanib-PLGA nanoparticles and pirfenidone-liposomes for improved treatment of pulmonary fibrosis
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Woo Tak Lee, Hyunjun Lee, Juho Kim, Yujin Jung, Eojin Choi, Ji Hoon Jeong, Jee-Heon Jeong, Jung Heon Lee, and Yu Seok Youn
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Aerosolizable microgel ,Lung retention ,Extracellular matrix ,Pro-inflammatory cytokines ,Idiopathic pulmonary fibrosis ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Biology (General) ,QH301-705.5 - Abstract
Idiopathic pulmonary fibrosis (IPF) is a chronic inflammatory and fibrotic response-driven lung disease that is difficult to cure because it manifests excessive profibrotic cytokines (e.g., TGF-β), activated myofibroblasts, and accumulated extracellular matrix (ECM). In an attempt to develop an inhalation formulation with enhanced antifibrotic efficacy, we sought to fabricate unique aerosolizable inhaled microgels (μGel) that contain nintedanib-poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs; n-PN) and pirfenidone-liposomes (p-LP). The aero-μGel was ∼12 μm, resisted phagocytosis by alveolar macrophages in vitro and in vivo, and protected inner-entrapped n-PN and p-LP. The n-PN/p-LP@aero-μGel caused enhanced/extended antifibrotic efficacy in a bleomycin-induced pulmonary fibrosis mouse presumably due to prolonged lung residence. Consequently, the results obtained by intratracheal aerosol insufflation of our n-PN/p-LP@aero-μGel twice a week were much better than those by as many as seven doses of single or mixed applications of n-PN or p-LP. The antifibrotic/pharmacokinetic results for the n-PN/p-LP@aero-μGel included reduced fibrosis progression, restored lung physiological functions, deactivated myofibroblasts, inhibited TGF-β progression, and suppressed ECM component production (collagen I and α-SMA) along with prolonged lung retention time. We believe that our n-PN/p-LP@aero-μGel increased the local availability of both nintedanib and pirfenidone due to evasion of alveolar macrophage phagocytosis and prolonged lung retention with reduced systemic distribution. Through this approach, our inhalation formulation subsequently attenuated fibrosis progression and improved lung function. Importantly, these results hold profound implications in the therapeutic potential of our n-PN/p-LP@aero-μGel to serve as a clinically promising platform, providing significant advancements for improved treatment of many respiratory diseases including IFP.
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- 2024
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3. Scanning Electron Microscopy Imaging of Large DNA Molecules Using a Metal‐Free Electro‐Stain Composed of DNA‐Binding Proteins and Synthetic Polymers
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Chanyoung Noh, Yoonjung Kang, Sujung Heo, Taesoo Kim, Hayeon Kim, Junhyuck Chang, Priyannth Ramasami Sundharbaabu, Sanghee Shim, Kwang‐il Lim, Jung Heon Lee, and Kyubong Jo
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DNA binding protein ,polyvinylpyrrolidone ,quantum dot labeling ,SEM DNA imaging ,SEM optical DNA mapping ,Science - Abstract
Abstract This paper presents the first scanning electron microscopy (SEM)‐based DNA imaging in biological samples. This novel approach incorporates a metal‐free electro‐stain reagent, formulated by combining DNA‐binding proteins and synthetic polymers to enhance the visibility of 2‐nm‐thick DNA under SEM. Notably, DNA molecules stain with proteins and polymers appear as dark lines under SEM. The resulting DNA images exhibit a thickness of 15.0±4.0 nm. As SEM is the primary platform, it integrates seamlessly with various chemically functionalized large surfaces with the aid of microfluidic devices. The approach allows high‐resolution imaging of various DNA structures including linear, circular, single‐stranded DNA and RNA, originating from nuclear and mitochondrial genomes. Furthermore, quantum dots are successfully visualized as bright labels that are sequence‐specifically incorporated into DNA molecules, which highlights the potential for SEM‐based optical DNA mapping. In conclusion, DNA imaging using SEM with the novel electro‐stain offers electron microscopic resolution with the ease of optical microscopy.
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- 2024
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4. Co-Estimating State of Charge and Capacity of Automotive Lithium-Ion Batteries Under Deep Degradation Using Multiple Estimators
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Min Young Yoo, Jung Heon Lee, Hyunjoon Lee, Joo-Ho Choi, Jae Sung Huh, and Woosuk Sung
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lithium-ion battery ,battery management system ,battery aging ,enhanced self-correcting model ,dual extended Kalman filter ,state of charge ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Since battery systems typically account for over 40% of the cost of an electric vehicle, their mid-life replacements are exceptional. Therefore, the battery’s lifespan must exceed that of the vehicle. To ensure long-term and safe use, accurate state-of-charge (SOC) estimation must be maintained throughout the battery’s lifespan. This requires appropriate updates to parameters, such as capacity, in the battery model. In this context, dual extended Kalman filters, which simultaneously estimate both states and parameters, have gained interest. While existing reports on simultaneous estimators seemed promising, our study found that they performed well under low levels of battery aging but encountered issues at higher levels. Accurately reflecting the actual physicochemical changes of the parameters in aging cells is challenging for two reasons: the limited number of measurements of terminal voltage available for numerous parameters, and the weak observability of the capacity. Therefore, we combined the simultaneous estimator with a capacity estimator operated separately during charging and a sequential estimator specialized for an enhanced self-correcting model, achieving SOC accuracy within 5% even when the SOH decreased by 30%. However, there is still much work to be carried out to implement sequential estimators in battery management systems operating in real time with limited computational resources.
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- 2024
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5. Structural understanding of SARS-CoV-2 virus entry to host cells
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Kim Le, Shrute Kannappan, Truc Kim, Jung Heon Lee, Hye-Ra Lee, and Kyeong Kyu Kim
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cryo-EM ,SARS-CoV-2 ,structure-guided drug design ,virus entry ,membrane fusion ,Biology (General) ,QH301-705.5 - Abstract
Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a major global health concern associated with millions of fatalities worldwide. Mutant variants of the virus have further exacerbated COVID-19 mortality and infection rates, emphasizing the urgent need for effective preventive strategies. Understanding the viral infection mechanism is crucial for developing therapeutics and vaccines. The entry of SARS-CoV-2 into host cells is a key step in the infection pathway and has been targeted for drug development. Despite numerous reviews of COVID-19 and the virus, there is a lack of comprehensive reviews focusing on the structural aspects of viral entry. In this review, we analyze structural changes in Spike proteins during the entry process, dividing the entry process into prebinding, receptor binding, proteolytic cleavage, and membrane fusion steps. By understanding the atomic-scale details of viral entry, we can better target the entry step for intervention strategies. We also examine the impacts of mutations in Spike proteins, including the Omicron variant, on viral entry. Structural information provides insights into the effects of mutations and can guide the development of therapeutics and vaccines. Finally, we discuss available structure-based approaches for the development of therapeutics and vaccines. Overall, this review provides a detailed analysis of the structural aspects of SARS-CoV-2 viral entry, highlighting its significance in the development of therapeutics and vaccines against COVID-19. Therefore, our review emphasizes the importance of structural information in combating SARS-CoV-2 infection.
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- 2023
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6. Digital colorimetric sensing for real‐time gas monitoring for smart green energy system
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Hui Hun Cho, Riya Dutta, Jang‐Kyun Kwak, Changgyun Moon, Min‐Jae Kim, Su‐Jeong Suh, Dong‐Hwan Kim, Jung Heon Lee, and Sunkook Kim
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digital colorimetric sensing ,gas‐insulated switchgear ,IoT ,real‐time gas monitoring ,smart green energy system ,SO2 gas ,Renewable energy sources ,TJ807-830 ,Environmental sciences ,GE1-350 - Abstract
Abstract In this study, we demonstrate that a digital colorimetric sensor platform can transform a conventional energy system, such as gas‐insulated switchgear (GIS) into a smart green energy system. Our sensor platform consists of a colorimetric sensor film (CSF), an array of silicon photodiodes, and a low‐power‐driven fiber optical photodiode with a wireless communication protocol integrated into an information network. The photodiode measures the transmitted light of the color‐variable CSF when exposed to sulfur dioxide (SO2) gas, a decomposition by‐product of the sulfur hexafluoride (SF6) gas in GIS. We report the electrical photocurrent measurement through the CSF can measure the concentration of SO2 gas via remote and real‐time monitoring and shows a comparable behavior to UV–Vis absorption measurement. The limit of detection of the sensor, 0.78 ppm is sufficient to analyze the GIS insulation deterioration allowing green energy systems.
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- 2023
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7. Structurally Engineered Silica Shells on Gold Nanorods for Biomedical Applications
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Min Jeong Kim, Do Hyeon Jung, Chae Yeon Lee, Seungpyo Hong, Jun Hyuk Heo, and Jung Heon Lee
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biomedical applications ,cetyltrimethylammonium bromide ,gold nanorods ,silica coatings ,toxicity ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Owing to their unique optical and chemical properties, gold nanorods (AuNRs) are among the most frequently used nanomaterials for biomedical applications, including cancer therapy, imaging, and drug delivery. In particular, the longitudinal dipole plasmon wavelength of AuNRs can be verified from the visible to the near‐infrared (NIR) region, allowing AuNRs to be used as photodynamic/photothermal and imaging contrast agents. At the same time, the silica shell is important as it enhances stability and facilitates the functionalization and biocompatibility of AuNRs, offering numerous advantages in biomedical applications. In this review, silica‐coated AuNRs from a bioapplication perspective are focused. First, the importance of AuNRs for biomedical applications is explained and the purpose of silica coating on AuNRs is discussed. Then, recent studies on the development of silica‐coated AuNRs from a biomedical perspective are reviewed. Subsequently, various strategies for engineering silica coatings and their properties in the biomedical field are reviewed. This review is expected to promote further research on next‐generation silica‐coated AuNRs for biomedical applications.
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- 2023
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8. Biomineralization of bone tissue: calcium phosphate-based inorganics in collagen fibrillar organic matrices
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Min-Ho Hong, Jung Heon Lee, Hyun Suk Jung, Heungsoo Shin, and Hyunjung Shin
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Biomineralization ,Hierarchical structure ,Bone growth ,Bone regeneration ,Nucleation and crystallization ,Collagen matrix ,Medical technology ,R855-855.5 - Abstract
Abstract Background Bone regeneration research is currently ongoing in the scientific community. Materials approved for clinical use, and applied to patients, have been developed and produced. However, rather than directly affecting bone regeneration, these materials support bone induction, which regenerates bone. Therefore, the research community is still researching bone tissue regeneration. In the papers published so far, it is hard to find an improvement in the theory of bone regeneration. This review discusses the relationship between the existing theories on hard tissue growth and regeneration and the biomaterials developed so far for this purpose and future research directions. Mainbody Highly complex nucleation and crystallization in hard tissue involves the coordinated action of ions and/or molecules that can produce different organic and inorganic composite biomaterials. In addition, the healing of bone defects is also affected by the dynamic conditions of ions and nutrients in the bone regeneration process. Inorganics in the human body, especially calcium- and/or phosphorus-based materials, play an important role in hard tissues. Inorganic crystal growth is important for treating or remodeling the bone matrix. Biomaterials used in bone tissue regeneration require expertise in various fields of the scientific community. Chemical knowledge is indispensable for interpreting the relationship between biological factors and their formation. In addition, sources of energy for the nucleation and crystallization processes of such chemical bonds and minerals that make up the bone tissue must be considered. However, the exact mechanism for this process has not yet been elucidated. Therefore, a convergence of broader scientific fields such as chemistry, materials, and biology is urgently needed to induce a distinct bone tissue regeneration mechanism. Conclusion This review provides an overview of calcium- and/or phosphorus-based inorganic properties and processes combined with organics that can be regarded as matrices of these minerals, namely collagen molecules and collagen fibrils. Furthermore, we discuss how this strategy can be applied to future bone tissue regenerative medicine in combination with other academic perspectives.
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- 2022
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9. Toward Visualizing Genomic DNA Using Electron Microscopy via DNA Metallization
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Xuelin Jin, Shrute Kannappan, Natalia Diyah Hapsari, Yu Jin, Kyeong Kyu Kim, Jung Heon Lee, and Kyubong Jo
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DNA–peptide/protein interactions ,electron microscope ,genomic DNA visualizations ,heavy metal staining ,nanoparticle staining ,nanowire metallization ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Electron microscopy‐based DNA imaging is a powerful tool that provides a high resolution for observing genomic structures involved in biochemical processes. The first method, heavy metal shadow casting, was developed in 1948. Uranyl acetate has been widely used for DNA electron microscopic imaging since the 1960s. However, for this method, scientists must deal with government regulations for the safety and disposal. Additionally, sample preparation is often complicated and time‐consuming. Recently, nanoparticles and nanowires have emerged as a new way of imaging DNA molecules under both transmission and scanning electron microscopes. However, as this technology is still in its early stages, there is room for further development. In this review, heavy metal staining, nanoparticle staining, and nanowire growth for DNA visualization are introduced. The applications of shadow casting and uranyl acetate staining in the visualization of DNA structures and protein–DNA complexes are discussed. Then, nanomaterial‐based DNA staining methods are covered, including electrostatic interactions, DNA chain modification, reducing‐group‐modified DNA ligands and DNA–peptide/protein interactions. This review provides up‐to‐date information on different DNA staining approaches and their applications in DNA studies. Ultimately, it offers a new direction for genome analysis through DNA visualization.
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- 2023
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10. Interface‐Controlled Biomimetic Intrafibrillar Mineralization of Collagen: Effect of Ca2+/[PO4]3− Concentration Ratio
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Urasawadee Amornkitbamrung, Yongjae In, Jung Heon Lee, Zhen Wang, Sang Ho Oh, Heungsoo Shin, Dae Sung Yoon, and Hyunjung Shin
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collagen ,crystallization kinetics ,hydroxyapatite ,interface control ,intrafibrillar mineralization ,Physics ,QC1-999 ,Technology - Abstract
Abstract Mineralized fibrils are important building blocks in bone tissue, formed by the hierarchical assembly of collagen molecules and crystalline hydroxyapatite (HAp). The mineralization pathway of HAp is reported as a nonclassical‐crystallization, but the nanoconfined crystallization in collagen fibrils remains poorly understood. The mechanism of intrafibrillar mineralization of collagen‐PDA fibrils in modified‐simulated body fluid (m‐SBF) solution is studied. Collagen‐amorphous calcium phosphate (ACP) fibrils are obtained by assembling collagen‐PDA fibrils with polyaspartic acid (pAsp) as a stabilizer. The ACP undergoes a phase transformation to HAp within the fibrils upon adjusting the phosphate concentration. It is found that the phase transformation of ACP to HAp in collagen fibrils can be accelerated with a 12 h incubation with 1/10 ratio of Ca2+ to [PO4]3−. A lower ratio of 1/1 and 1/5 results in a much slower phase transformation. This finding suggests that an elevated concentration of [PO4]3− is crucial for faster phase transformation. The relationship between the crystallization rate of HAp in the fibrils and the degree of mineralization is found to be linear in all cases, indicating an interface‐controlled process. This gives a better understanding of the mechanism of HAp mineralization in collagen fibrils, providing an effective approach to material design.
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- 2023
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11. Sensor design strategy for environmental and biological monitoring
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Jun Hyuk Heo, Minchul Sung, Tran Quang Trung, Yullim Lee, Do Hyeon Jung, Hajeong Kim, Sandeep Kaushal, Nae‐Eung Lee, Jin Woong Kim, Jung Heon Lee, and Soo‐Yeon Cho
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analytics ,design ,ecosystem ,interface ,monitoring ,sensor ,Renewable energy sources ,TJ807-830 ,Environmental sciences ,GE1-350 - Abstract
Abstract Rapid industrial growth has severely impacted ecosystems and aggravated economic and health risks to society. Monitoring of ecosystems is fundamental to our understanding of how ecosystem change impacts resources and is critical for developing data‐based sustainability. Thus, the design and development of optimized sensors for ecosystem monitoring have received increasing attention. This review provides a comprehensive overview of systematic sensor design strategies for ecosystem monitoring from the material level to the form factor level. We discuss the fundamental transducing mechanisms of a representative sensor system including optical, electrical, and electrochemical sensors. We then review the sensor interfacing strategy for achieving stable and real‐time monitoring of environmental biochemical factors from air, water, soil, and living organisms. Finally, we provide a summary of the current performance and prospects of this state‐of‐the‐art sensor technology and an outlook on opportunities for possible future research directions in this emerging field.
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- 2023
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12. Natural bone-mimicking nanopore-incorporated hydroxyapatite scaffolds for enhanced bone tissue regeneration
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Chansong Kim, Jin Woong Lee, Jun Hyuk Heo, Cheolhyun Park, Dai-Hwan Kim, Gyu Sung Yi, Ho Chang Kang, Hyun Suk Jung, Hyunjung Shin, and Jung Heon Lee
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Natural bone-mimicking ,Nanopore ,Hydroxyapatite ,Scaffold ,Bone graft material ,Medical technology ,R855-855.5 - Abstract
Abstract Background A considerable number of studies has been carried out to develop alloplastic bone graft materials such as hydroxyapatite (HAP) that mimic the hierarchical structure of natural bones with multiple levels of pores: macro-, micro-, and nanopores. Although nanopores are known to play many essential roles in natural bones, only a few studies have focused on HAPs containing them; none of those studies investigated the functions of nanopores in biological systems. Method We developed a simple yet powerful method to introduce nanopores into alloplastic HAP bone graft materials in large quantities by simply pressing HAP nanoparticles and sintering them at a low temperature. Results The size of nanopores in HAP scaffolds can be controlled between 16.5 and 30.2 nm by changing the sintering temperature. When nanopores with a size of ~ 30.2 nm, similar to that of nanopores in natural bones, are introduced into HAP scaffolds, the mechanical strength and cell proliferation and differentiation rates are significantly increased. The developed HAP scaffolds containing nanopores (SNPs) are biocompatible, with negligible erythema and inflammatory reactions. In addition, they enhance the bone regeneration when are implanted into a rabbit model. Furthermore, the bone regeneration efficiency of the HAP-based SNP is better than that of a commercially available bone graft material. Conclusion Nanopores of HAP scaffolds are very important for improving the bone regeneration efficiency and may be one of the key factors to consider in designing highly efficient next-generation alloplastic bone graft materials.
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- 2022
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13. Development of a highly sensitive lateral flow strip device for nucleic acid detection using molecular beacons
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Youngkwang Moon, Hyeokgyun Moon, Junhyuck Chang, Harold D. Kim, Jung Heon Lee, and Jinkee Lee
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paper-based diagnostic device ,molecular beacon (MB) ,nucleic acid detection ,point-of-care (POC) ,lateral flow strip (LFS) ,Biotechnology ,TP248.13-248.65 - Abstract
Extensive research is focused on the development of highly sensitive, rapid on-site diagnostic devices. The lateral flow strip (LFS) is a paper-based point-of-care diagnostic device, which is highly promising because of its ease of use and low cost. Despite these advantages, LFS device is still less popular than other methods such as enzyme-linked immunosorbent assay (ELISA) or real-time polymerase chain reaction (qPCR) due to its low sensitivity. Here, we have developed a fluorescence-based lateral flow strip (f-LFS) device for DNA detection using a molecular beacon (MB), a short hairpin-forming DNA strand tagged with a fluorophore-quencher pair. Each paper and membrane component of f-LFS device was carefully selected based on their physicochemical properties including porosity, surface functionality, and autofluorescence. The limit of detection (LOD) of this device was substantially improved to 2.1 fg/mL by adding MgCl2 to the reaction buffer and narrowing the test membrane dimension. Also, a portable fluorescence detection system for f-LFS was developed using a multi-pixel photon counter (MPPC), a sensitive detector detecting the signal on site. We anticipate that this highly sensitive paper-based diagnostic device can be utilized for on-site diagnosis of various diseases.
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- 2022
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14. State-of-Charge Estimation of Batteries for Hybrid Urban Air Mobility
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Min Young Yoo, Jung Heon Lee, Joo-Ho Choi, Jae Sung Huh, and Woosuk Sung
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lithium-ion battery ,urban air mobility ,charge-sustaining ,equivalent circuit model ,extended kalman filter ,state-of-charge (SOC) ,Motor vehicles. Aeronautics. Astronautics ,TL1-4050 - Abstract
This paper proposes a framework for accurately estimating the state-of-charge (SOC) and current sensor bias, with the aim of integrating it into urban air mobility (UAM) with hybrid propulsion. Considering the heightened safety concerns in an airborne environment, more reliable state estimation is required, particularly for the UAM that uses a battery as its primary power source. To ensure the suitability of the framework for the UAM, a two-pronged approach is taken. First, realistic test profiles, reflecting actual operational scenarios for the UAM, are used to model the battery and validate its state estimator. These profiles incorporate variations in battery power flow, namely, charge-depleting and charge-sustaining modes, during the different phases of the UAM’s flight, including take-off, cruise, and landing. Moreover, the current sensor bias is estimated and corrected concurrently with the SOC. An extended Kalman filter-based bias estimator is developed and experimentally validated using actual current measurements from a Hall sensor, which is prone to noise. With this correction, a SOC estimation error is consistently maintained at 2% or lower, even during transitions between operational modes.
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- 2023
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15. A study on the bio-applicability of aqueous-dispersed van der Waals 1-D material Nb2Se9 using poloxamer
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Sudong Chae, Seungbae Oh, Kyung Hwan Choi, Jin Woong Lee, Jiho Jeon, Zhixiang Liu, Cong Wang, Changmo Lim, Xue Dong, Chaeheon Woo, Ghulam Asghar, Liyi Shi, Joohoon Kang, Sung Jae Kim, Si Young Song, Jung Heon Lee, Hak Ki Yu, and Jae-Young Choi
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Medicine ,Science - Abstract
Abstract In this research, dispersion of a new type of one-dimensional inorganic material Nb2Se9, composed of van der Waals bonds, in aqueous solution for bio-application study were studied. To disperse Nb2Se9, which exhibits hydrophobic properties in water, experiments were carried out using a block copolymer (poloxamer) as a dispersant. It was confirmed that PPO, the hydrophobic portion of Poloxamer, was adsorbed onto the surface of Nb2Se9, and PEO, the hydrophilic portion, induced steric hinderance to disperse Nb2Se9 to a size of 10 nm or less. To confirm the adaptability of muscle cells C2C12 to the dispersed Nb2Se9 using poloxamer 188 as dispersant, a MTT assay and a live/dead assay were performed, demonstrating improvement in the viability and proliferation of C2C12 cells.
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- 2021
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16. Polysaccharide from Hizikia Fusiformis Enhances the Immunomodulatory Activity of Macrophages
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Jieun Lee, Moon Hee Choi, Eun-su Jang, Hyun-Jae Shin, and Jung Heon Lee
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sargassum ,polysaccharides ,nf-kappa b ,inflammation ,immunity ,Medicine ,Otorhinolaryngology ,RF1-547 - Abstract
Background and Objectives Hizikia fusiformis is widely used in oriental health food in Japan, China, and Korea, and is known for its anti-oxidation properties. Materials and Method In this study, we investigated the anti-inflammatory and immune-modulatory effects and mechanisms of Hizikia fusiformis (H. fusiformis) extracts in lipopolysaccharide (LPS)-treated RAW 264.7 cells. RAW 264.7 cells were incubated in the presence of different concentrations of the viscozyme component of H. fusiformis (1, 2, 5, and 10 μg/mL), and changes in expression of pro-inflammatory cytokines (GM-CSF, iNOS, VEGF, and COX-2) were evaluated by real-time PCR and immunoblotting. In addition, the associated signaling pathway including phospho (p)-pNF-κB 65, p-pIkBa, p-p38, and p-p44/42 was also evaluated. Results The viscozyme component of H. fusiformis downregulated the expression of GM-CSF, iNOS, VEGF, and COX-2 mRNA. The augmented NO and ROS production was decreased by administration of H. fusiformis. The signal intensity of p-pNF-κB 65, p-pIkBa, p-p38, and p-p44/42 protein activated by LPS was ameliorated by administration of the viscozyme fraction in RAW 264.7 cells. Conclusion These results suggest that H. fusiformis has potential as a therapeutic agent for inflammatory diseases.
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- 2020
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17. Antimicrobial Activity of Various Parts of Tomato Plants Varied with Different Solvent Extracts
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Dong Sub Kim, Yurina Kwack, Jung Heon Lee, and Changhoo Chun
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caffeic acid ,linolenic acid ,Rhizoctonia solani ,Plant culture ,SB1-1110 - Abstract
The antimicrobial activity of acetone, hexane, dichloromethane, and methanol extracts from leaves, stems, immature green fruits, and red fruits of tomato plants was examined against six phytopathogens. The minimum inhibitory concentration (MIC) of the acetonic extracts from these four plant parts was lower than that of the other solvents. Among the acetonic extracts, tomato leaves had a lower MIC than the other tomato parts. The acetonic extract from tomato leaves was therefore selected as a source of antimicrobial substances. The acetonic extract from tomato leaves inhibited mycelial growth of Fusarium oxysporum f. sp. lycopersici, Glomerella cingulata, and Rhizoctonia solani. Mycelial growth of R. solani treated with acetone extract from leaves showed more susceptibility than the other phytopathogens. Using 0.31 mg/ml of the acetonic extract from leaves, mycelial growth of R. solani on days 1, 2, and 3 decreased by 50.0, 52.1, and 64.0%, respectively, compared with acetone solvent treatment. The antimicrobial compounds effective against R. solani were identified as linolenic acid and caffeic acid by bioautography and GC-MS. These two compounds were used to treat six phytopathogens to confirm their antimicrobial activities. Linolenic acid inhibited mycelial growth of R. solani, while caffeic acid showed only slight antimicrobial activity. Results : indicated that we propose extracts from tomato leaves which included antimicrobial compounds may provide a new lead in the pursuit of new biological sources of agrochemical candidates.
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- 2019
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18. Author Correction: A study on the bio-applicability of aqueous-dispersed van der Waals 1-D material Nb2Se9 using poloxamer
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Sudong Chae, Seungbae Oh, Kyung Hwan Choi, Jin Woong Lee, Jiho Jeon, Zhixiang Liu, Cong Wang, Changmo Lim, Xue Dong, Chaeheon Woo, Ghulam Asghar, Liyi Shi, Joohoon Kang, Sung Jae Kim, Si Young Song, Jung Heon Lee, Hak Ki Yu, and Jae‑Young Choi
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Medicine ,Science - Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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- 2021
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19. Hierarchical Surface Texturing of Hydroxyapatite Ceramics: Influence on the Adhesive Bonding Strength of Polymeric Polycaprolactone
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Jonas Biggemann, Philipp Müller, David Köllner, Swantje Simon, Patrizia Hoffmann, Paula Heik, Jung Heon Lee, and Tobias Fey
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hierarchical surface texturing ,surface functionalization ,hydroxyapatite ,polycaprolactone ,acid etching ,tartaric acid ,Biotechnology ,TP248.13-248.65 ,Medicine (General) ,R5-920 - Abstract
The tailored manipulation of ceramic surfaces gained recent interest to optimize the performance and lifetime of composite materials used as implants. In this work, a hierarchical surface texturing of hydroxyapatite (HAp) ceramics was developed to improve the poor adhesive bonding strength in hydroxyapatite and polycaprolactone (HAp/PCL) composites. Four different types of periodic surface morphologies (grooves, cylindric pits, linear waves and Gaussian hills) were realized by a ceramic micro-transfer molding technique in the submillimeter range. A subsequent surface roughening and functionalization on a micron to nanometer scale was obtained by two different etchings with hydrochloric and tartaric acid. An ensuing silane coupling with 3-aminopropyltriethoxysilane (APTES) enhanced the chemical adhesion between the HAp surface and PCL on the nanometer scale by the formation of dipole–dipole interactions and covalent bonds. The adhesive bonding strengths of the individual and combined surface texturings were investigated by performing single-lap compressive shear tests. All individual texturing types (macro, micro and nano) showed significantly improved HAp/PCL interface strengths compared to the non-textured HAp reference, based on an enhanced mechanical, physical and chemical adhesion. The independent effect mechanisms allow the deliberately hierarchical combination of all texturing types without negative influences. The hierarchical surface-textured HAp showed a 6.5 times higher adhesive bonding strength (7.7 ± 1.5 MPa) than the non-textured reference, proving that surface texturing is an attractive method to optimize the component adhesion in composites for potential medical implants.
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- 2020
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20. Revealing the Presence of a Symbolic Sequence Representing Multiple Nucleotides Based on K-Means Clustering of Oligonucleotides
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Byoungsang Lee, So Yeon Ahn, Charles Park, James J. Moon, Jung Heon Lee, Dan Luo, Soong Ho Um, and Seung Won Shin
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representative nucleotide ,hybridization profile ,K-means clustering ,multiple equilibria ,sociogram ,Organic chemistry ,QD241-441 - Abstract
In biological systems, a few sequence differences diversify the hybridization profile of nucleotides and enable the quantitative control of cellular metabolism in a cooperative manner. In this respect, the information required for a better understanding may not be in each nucleotide sequence, but representative information contained among them. Existing methodologies for nucleotide sequence design have been optimized to track the function of the genetic molecule and predict interaction with others. However, there has been no attempt to extract new sequence information to represent their inheritance function. Here, we tried to conceptually reveal the presence of a representative sequence from groups of nucleotides. The combined application of the K-means clustering algorithm and the social network analysis theorem enabled the effective calculation of the representative sequence. First, a “common sequence” is made that has the highest hybridization property to analog sequences. Next, the sequence complementary to the common sequence is designated as a ‘representative sequence’. Based on this, we obtained a representative sequence from multiple analog sequences that are 8–10-bases long. Their hybridization was empirically tested, which confirmed that the common sequence had the highest hybridization tendency, and the representative sequence better alignment with the analogs compared to a mere complementary.
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- 2019
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21. Gold Nanoparticles as Exquisite Colorimetric Transducers for Water Pollutant Detection
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Hui Hun Cho, Do Hyeon Jung, Jun Hyuk Heo, Chae Yeon Lee, Sang Yun Jeong, and Jung Heon Lee
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General Materials Science - Published
- 2023
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22. DNA-Wrapped CNT Sensor for Small Nucleic Acid Detection: Influence of Short Complementary Sequence
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Shrute Kannappan, Junhyuck Chang, Priyannth Ramasami Sundharbaabu, Jun Hyuk Heo, Won-kee Sung, Jae Chul Ro, Kyeong Kyu Kim, John Bosco Balaguru Rayappan, and Jung Heon Lee
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Biomedical Engineering ,Bioengineering ,Electrical and Electronic Engineering ,Biotechnology - Published
- 2022
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23. Nanoparticles as Next-Generation Tooth-Whitening Agents: Progress and Perspectives
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Dai-Hwan Kim, Jina Bae, Jun Hyuk Heo, Cheol Hyun Park, Eun Bi Kim, and Jung Heon Lee
- Subjects
Bleaching Agents ,General Engineering ,Urea ,Nanoparticles ,General Physics and Astronomy ,General Materials Science ,Hydrogen Peroxide ,Tooth Bleaching Agents ,Peroxides - Abstract
Whitening agents, such as hydrogen peroxide and carbamide peroxide, are currently used in clinical applications for dental esthetic and dental care. However, the free radicals generated by whitening agents cause pathological damage; therefore, their safety issues remain controversial. Furthermore, whitening agents are known to be unstable and short-lived. Since 2001, nanoparticles (NPs) have been researched for use in tooth whitening. Importantly, nanoparticles not only function as abrasives but also release reactive oxygen species and help remineralization. This review outlines the historical development of several NPs based on their whitening effects and side effects. NPs can be categorized into metals or metal oxides, ceramic particles, graphene oxide, and piezoelectric particles. Moreover, the status quo and future prospects are discussed, and recent progress in the development of NPs and their applications in various fields requiring tooth whitening is examined. This review promotes the research and development of next-generation NPs for use in tooth whitening.
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- 2022
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24. Tannic acid modified antifreezing gelatin organohydrogel for low modulus, high toughness, and sensitive flexible strain sensor
- Author
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Syed Farrukh Alam Zaidi, Yun Ah Kim, Aiman Saeed, Nasir Sarwar, Nae-Eung Lee, Dae Ho Yoon, Byungkwon Lim, and Jung Heon Lee
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Ions ,Wearable Electronic Devices ,Structural Biology ,Electric Conductivity ,Gelatin ,Hydrogels ,General Medicine ,Tannins ,Molecular Biology ,Biochemistry - Abstract
Current hydrogel strain sensors have met assorted essential requirements of wearing comfort, mechanical toughness, and strain sensitivity. However, an increment in the toughness of a hydrogel usually leads to an increase in elastic moduli that could be unfavorable for wearing comfort. In addition, traits of biofriendly and sustainability require synthesis of the hydrogels from natural polymer-based networks. We propose a novel strategy to fabricate an ionic conductive organohydrogel from natural biological macromolecule "gelatin" and polyacid "tannic acid" to resolve these challenges. Tannic acid modified the structure of the gelatin network in the ionic conductive organohydrogels, that not only led to an increase in toughness accompanying a decrease in elastic moduli but also headed to higher strain sensitivity and tunability. The proposed methodology exhibited tunable tensile modulus from 27 to 13 kPa, tensile strength from 287 to 325 kPa, elongation at fracture from 510 to 620%, toughness from 500 to 550 kJ/m
- Published
- 2022
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25. Progress and perspectives of metal-ion-substituted hydroxyapatite for bone tissue engineering: comparison with hydroxyapatite
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Si Hyun Kim, Cheol Hyun Park, Jun Hyuk Heo, and Jung Heon Lee
- Subjects
Ceramics and Composites - Published
- 2022
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26. Synergistic Adenosine Triphosphate/Chitosan Bio-coatings on Polyurethane Foam for Simultaneously Improved Flame Retardancy and Smoke Suppression
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Hyewon Song, Cheol Hyun Park, Sun Hwan Jeong, Jun Hyuk Heo, and Jung Heon Lee
- Subjects
Polymers and Plastics ,Process Chemistry and Technology ,Organic Chemistry - Published
- 2023
- Full Text
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27. Comparison of Functional Flavonoid Components and Contents from Domestic Propolis Extracts
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Chan-Gun Yun, Sehee Cho, Seong-Jun Kim, Jung-Heon Lee, Gang-Hyeon Jung, Jee-In Kim, In-Seop So, Young-Hyeon Park, and Jae-Hwan Lim
- Published
- 2021
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28. Developments of GABA Process for the Mass Production
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Eui Jin Kim, Hyun-Jae Shin, and Jung-Heon Lee
- Published
- 2021
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29. Multifunctional Small Biomolecules as Key Building Blocks in the Development of Hydrogel-Based Strain Sensors
- Author
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Syed Farrukh Alam Zaidi, Aiman Saeed, Jun Hyuk Heo, and Jung Heon Lee
- Subjects
Renewable Energy, Sustainability and the Environment ,General Materials Science ,General Chemistry - Abstract
Hydrogels are three-dimensional polymer networks that are considered a promising option for developing strain sensors due to their stretchability, mechanical robustness, and high water content. These attributes make hydrogel-based sensors...
- Published
- 2023
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30. Portable Au Nanoparticle-Based Colorimetric Sensor Strip for Rapid On-Site Detection of Cd2+ Ions in Potable Water
- Author
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Kwon Hoon Han, Su-Jeong Suh, So Hui Kim, Do Hyeon Jung, Jung Heon Lee, Hui Hun Cho, and Jun Hyuk Heo
- Subjects
Detection limit ,Materials science ,Polyvinylpyrrolidone ,Biomedical Engineering ,Analytical chemistry ,Nanoparticle ,Bioengineering ,Contamination ,medicine.disease_cause ,chemistry.chemical_compound ,chemistry ,Tap water ,Mold ,Polyethylene terephthalate ,medicine ,Water blue ,Electrical and Electronic Engineering ,Biotechnology ,medicine.drug - Abstract
Simple, rapid, and instrument-free detection of cadmium ions (Cd2+) with a portable device is essential to prevent the contamination of potable water. Herein, we propose a simple, fast, and low-cost method for the real-time/on-site detection of Cd2+ using glutathione-modified Au nanoparticles (GSH-AuNPs) deposited on a polyethylene terephthalate (PET) sensor strip. To fabricate the sensor strip, a paint composed of GSH-AuNPs and polyvinylpyrrolidone was prepared. Subsequently, the GSH-AuNP paint was deposited on a mold fixed on the PET substrate and dried in ambient air. The GSH-AuNPs deposited on the PET substrate quickly redispersed in water, turning the water red. However, the GSH-AuNPs aggregated in water samples containing Cd2+, turning the water blue. The limit of detection of this Cd2+ sensor strip is 18.8 nM, which is comparable to the maximum contamination level of 44.5 nM Cd2+ in potable water stipulated by the US Environmental Protection Agency. Finally, we demonstrate that the GSH-AuNP-based sensor strip can be used in the on-site detection of Cd2+ in real samples such as tap water.
- Published
- 2021
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31. Surface Polarity-Insensitive Organosilicasome-Based Clustering of Nanoparticles with Intragap Distance Tunability
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Wan Ki Bae, Jung Heon Lee, Seokyoung Yoon, Min Jeong Kim, Byoungsang Lee, Kyung Eun Lee, Chansong Kim, Hyung Bin Bae, and Jun Hyuk Chang
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Surface (mathematics) ,Materials science ,Chemical physics ,Polarity (physics) ,General Chemical Engineering ,Materials Chemistry ,Nanoparticle ,General Chemistry ,Cluster analysis - Published
- 2021
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32. Bioinspired Adenosine Triphosphate as an 'All-In-One' Green Flame Retardant via Extremely Intumescent Char Formation
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Cheol Hyun Park, Jun Hyuk Heo, Jin Woong Lee, Min Jeong Kim, S.H. Jeong, and Jung Heon Lee
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Materials science ,Flame test ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Limiting oxygen index ,chemistry.chemical_compound ,fluids and secretions ,Chemical engineering ,chemistry ,Blowing agent ,General Materials Science ,Char ,0210 nano-technology ,Intumescent ,Fire retardant ,Flammability ,Polyurethane - Abstract
The development of eco-friendly flame retardants is crucial due to the hazardous properties of most conventional flame retardants. Herein, adenosine triphosphate (ATP) is reported to be a highly efficient "all-in-one" green flame retardant as it consists of three essential groups, which lead to the formation of char with extreme intumescence, namely, three phosphate groups, providing an acid source; one ribose sugar, working as a char source; and one adenine, acting as a blowing agent. Polyurethane foam was used as a model flammable material to demonstrate the exceptional flame retardancy of ATP. The direct flammability tests have clearly shown that the ATP-coated polyurethane (PU) foam almost did not burn upon exposure to the torch flame. Importantly, ATP exhibits an extreme volume increase, whereas general phosphorus-based flame retardants show a negligible increase in volume. The PU foam coated with 30 wt % of ATP (PU-ATP 30 wt %) exhibits a significant reduction in the peak heat release rate (94.3%) with a significant increase in the ignition time, compared to bare PU. In addition, PU-ATP 30 wt % exhibits a high limiting oxygen index (LOI) value of 31% and HF-1 rating in the UL94 horizontal burning foamed material test. Additionally, we demonstrated that ATP's flame retardancy is sufficient for other types of matrices such as cotton, as confirmed from the results of the standardized ASTM D6413 test; cotton-ATP 30 wt % exhibits an LOI value of 32% and passes the vertical flame test. These results strongly suggest that ATP has great potential to be used as an "all-in-one" green flame retardant.
- Published
- 2021
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33. Graphene Quantum Dots – Hydrothermal Green Synthesis, Material Characterization and Prospects for Cervical Cancer Diagnosis Applications: A Review
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Raghavv Raghavender Suresh, Arockia Jayalatha Kulandaisamy, Noel Nesakumar, Saisubramanian Nagarajan, Jung Heon Lee, and John Bosco Balaguru Rayappan
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General Chemistry - Published
- 2022
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34. A study on the bio-applicability of aqueous-dispersed van der Waals 1-D material Nb2Se9 using poloxamer
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Jiho Jeon, Jin Woong Lee, Liyi Shi, Si Young Song, Cong Wang, Kyung Hwan Choi, Zhixiang Liu, Ghulam Asghar, Sung Jae Kim, Sudong Chae, Seungbae Oh, Xue Dong, Jung Heon Lee, Changmo Lim, Jae-Young Choi, Hak Ki Yu, Chaeheon Woo, and Joohoon Kang
- Subjects
Steric effects ,Science ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Dispersant ,Article ,symbols.namesake ,Adsorption ,Copolymer ,Multidisciplinary ,Aqueous solution ,Chemistry ,Synthesis and processing ,Poloxamer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Tissues ,Chemical engineering ,symbols ,Medicine ,van der Waals force ,0210 nano-technology ,Dispersion (chemistry) - Abstract
In this research, dispersion of a new type of one-dimensional inorganic material Nb2Se9, composed of van der Waals bonds, in aqueous solution for bio-application study were studied. To disperse Nb2Se9, which exhibits hydrophobic properties in water, experiments were carried out using a block copolymer (poloxamer) as a dispersant. It was confirmed that PPO, the hydrophobic portion of Poloxamer, was adsorbed onto the surface of Nb2Se9, and PEO, the hydrophilic portion, induced steric hinderance to disperse Nb2Se9 to a size of 10 nm or less. To confirm the adaptability of muscle cells C2C12 to the dispersed Nb2Se9 using poloxamer 188 as dispersant, a MTT assay and a live/dead assay were performed, demonstrating improvement in the viability and proliferation of C2C12 cells.
- Published
- 2021
35. The Effect of Audit Committee Expertise on Accounting Transparency
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Yeol In Chang, Jung Heon Lee, and Sung Won Park
- Subjects
business.industry ,Audit committee ,Accounting ,business ,Transparency (behavior) - Published
- 2020
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36. Statistical Characterization of the Morphologies of Nanoparticles through Machine Learning Based Electron Microscopy Image Analysis
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Byoungsang Lee, Yunchul Kim, Junhyuck Chang, Jin Woong Lee, Jae Chul Ro, Jaesub Yun, Jung Heon Lee, Seokyoung Yoon, and Jongmin Lee
- Subjects
False discovery rate ,Materials science ,General Engineering ,General Physics and Astronomy ,Nanoparticle ,Total population ,Image (mathematics) ,Characterization (materials science) ,law.invention ,law ,Transmission electron microscopy ,General Materials Science ,Electron microscope ,Representation (mathematics) ,Biological system - Abstract
Although transmission electron microscopy (TEM) may be one of the most efficient techniques available for studying the morphological characteristics of nanoparticles, analyzing them quantitatively in a statistical manner is exceedingly difficult. Herein, we report a method for mass-throughput analysis of the morphologies of nanoparticles by applying a genetic algorithm to an image analysis technique. The proposed method enables the analysis of over 150,000 nanoparticles with a high precision of 99.75% and a low false discovery rate of 0.25%. Furthermore, we clustered nanoparticles with similar morphological shapes into several groups for diverse statistical analyses. We determined that at least 1,500 nanoparticles are necessary to represent the total population of nanoparticles at a 95% credible interval. In addition, the number of TEM measurements and the average number of nanoparticles in each TEM image should be considered to ensure a satisfactory representation of nanoparticles using TEM images. Moreover, the statistical distribution of polydisperse nanoparticles plays a key role in accurately estimating their optical properties. We expect this method to become a powerful tool and aid in expanding nanoparticle-related research into the statistical domain for use in big data analysis.
- Published
- 2020
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37. High-Throughput Characterization and In Situ Control of Three-Dimensional Orientations of Single Gold Nanorods Coated with Spherical Mesoporous Silica Shell
- Author
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Geun Wan Kim, Jaeran Lee, Jung Heon Lee, Ji Won Ha, and Seokyoung Yoon
- Subjects
In situ ,Materials science ,Shell (structure) ,Flow cell ,Nanotechnology ,02 engineering and technology ,Mesoporous silica ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Characterization (materials science) ,General Energy ,Glass slide ,Nanorod ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Anisotropic gold nanorods (AuNRs) are widely used as orientation probes in many biological and physical studies. However, the in situ control of the spatial orientation of AuNRs having various thre...
- Published
- 2020
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38. Polysaccharide from Hizikia Fusiformis Enhances the Immunomodulatory Activity of Macrophages
- Author
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Choi Moon Hee, Hyun-Jae Shin, Jung Heon Lee, Eun-su Jang, and Jieun Lee
- Subjects
0301 basic medicine ,nf-kappa b ,polysaccharides ,lcsh:Medicine ,Inflammation ,Polysaccharide ,Microbiology ,03 medical and health sciences ,0302 clinical medicine ,Immunity ,sargassum ,Medicine ,chemistry.chemical_classification ,biology ,business.industry ,lcsh:R ,NFKB1 ,biology.organism_classification ,lcsh:Otorhinolaryngology ,immunity ,lcsh:RF1-547 ,030104 developmental biology ,chemistry ,inflammation ,030220 oncology & carcinogenesis ,Sargassum ,Hizikia fusiformis ,medicine.symptom ,business - Abstract
Background and Objectives: Hizikia fusiformis is widely used in oriental health food in Japan, China, and Korea, and is known for its anti-oxidation properties.Materials and Method: In this study, we investigated the anti-inflammatory and immune-modulatory effects and mechanisms of Hizikia fusiformis (H. fusiformis) extracts in lipopolysaccharide (LPS)-treated RAW 264.7 cells. RAW 264.7 cells were incubated in the presence of different concentrations of the viscozyme component of H. fusiformis (1, 2, 5, and 10 μg/mL), and changes in expression of pro-inflammatory cytokines (GM-CSF, iNOS, VEGF, and COX-2) were evaluated by real-time PCR and immunoblotting. In addition, the associated signaling pathway including phospho (p)-pNF-κB 65, p-pIkBa, p-p38, and p-p44/42 was also evaluated.Results: The viscozyme component of H. fusiformis downregulated the expression of GM-CSF, iNOS, VEGF, and COX-2 mRNA. The augmented NO and ROS production was decreased by administration of H. fusiformis. The signal intensity of p-pNF-κB 65, p-pIkBa, p-p38, and p-p44/42 protein activated by LPS was ameliorated by administration of the viscozyme fraction in RAW 264.7 cells.Conclusion: These results suggest that H. fusiformis has potential as a therapeutic agent for inflammatory diseases.
- Published
- 2020
39. Chitosan-reinforced gelatin composite hydrogel as a tough, anti-freezing, and flame-retardant gel polymer electrolyte for flexible supercapacitors
- Author
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Syed Farrukh Alam Zaidi, Aiman Saeed, Van-Chuong Ho, Jun Hyuk Heo, Hui Hun Cho, Nasir Sarwar, Nae-Eung Lee, Junyoung Mun, and Jung Heon Lee
- Subjects
Structural Biology ,General Medicine ,Molecular Biology ,Biochemistry - Published
- 2023
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40. Carbon Nanotubes and Nucleic Acids
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Priyannth Ramasami Sundharbaabu, Junhyuck Chang, and Jung Heon Lee
- Published
- 2022
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41. Automatic quantification of living cells via a non-invasive achromatic colorimetric sensor through machine learning-assisted image analysis using a smartphone
- Author
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Do Hyeon Jung, Yunchul Kim, Hui Hun Cho, Byoungsang Lee, Su-Jeong Suh, Jun Hyuk Heo, and Jung Heon Lee
- Subjects
History ,Polymers and Plastics ,General Chemical Engineering ,Environmental Chemistry ,General Chemistry ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
- Full Text
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42. High-throughput in-focus differential interference contrast imaging of three-dimensional orientations of single gold nanorods coated with a mesoporous silica shell
- Author
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Jung Heon Lee, Seokyoung Yoon, Ji Won Ha, and Geun Wan Kim
- Subjects
Materials science ,business.industry ,General Chemical Engineering ,Shell (structure) ,General Chemistry ,Mesoporous silica ,law.invention ,Lens (optics) ,Cardinal point ,Differential interference contrast microscopy ,law ,Microscopy ,Optoelectronics ,Nanorod ,business ,Plasmon - Abstract
Plasmonic gold nanorods (AuNRs) have been widely applied as optical orientation probes in many biophysical studies. However, characterizing the various three-dimensional (3D) orientations of AuNRs in the same focal plane of the objective lens is a challenging task. To overcome this challenge, we fabricated single AuNRs (10 nm × 30 nm) coated with either an elliptical or spherical mesoporous silica shell (AuNRs@mSiO2). Unlike bare AuNRs and elliptical AuNRs@mSiO2, spherical AuNRs@mSiO2 contained randomly oriented AuNR cores in 3D space, which could be observed on the same focal plane within a single frame by differential interference contrast (DIC) microscopy. The spherical AuNRs@mSiO2 thus achieved high-throughput detection. The proposed approach can overcome the limitations of the current gel-matrix method, which requires vertical scanning of the embedded AuNRs to capture different focal planes.
- Published
- 2020
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43. Biologically Benign Multi-functional Mesoporous Silica Encapsulated Gold/Silver Nanorods for Anti-bacterial Applications by On-demand Release of Silver Ions
- Author
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Seokyoung Yoon, Jung Heon Lee, Junhyuck Chang, Jeon G. Han, Younghwan Chung, and Jin Woong Lee
- Subjects
Biocompatibility ,Chemistry ,Biomedical Engineering ,Nanoparticle ,Bioengineering ,engineering.material ,Mesoporous silica ,Coating ,engineering ,Electrical and Electronic Engineering ,Surface plasmon resonance ,Cytotoxicity ,Bimetallic strip ,Biotechnology ,Nuclear chemistry ,Antibacterial agent - Abstract
Although silver (Ag)-based nanoparticles (NPs) are frequently used for bactericidal purposes, they have critical issues including excessive release of Ag+, severe oxidation, and cytotoxicity. In this study, we designed a multifunctional, on-demand antibacterial agent by successively encapsulating bimetallic gold/silver nanorods (Ag/AgNRs) with mesoporous silica (mSiO2) shells. Au/AuNRs were synthesized by coating Ag on AuNRs in a controlled manner, so that they exhibited a localized surface plasmon resonance peak in the near-infrared (NIR) region. When Au/AgNR@mSiO2 NPs were irradiated with an NIR laser under optimal conditions (0.4 W/cm2), they generated a small amount of heat (40–45 oC), which successively triggered the release of Ag+ and induced bacterial cell death. Here, mSiO2 shells play critical roles because they not only protect Ag from oxidation but also prevent the burst release of Ag+ and improve biocompatibility of the antibacterial agent against normal cells. We found that this multifunctional bacterial agent effectively kills gram-negative Escherichia coli and gram-positive Staphylococcus aureus without significantly increasing the temperature of the medium. Au/AgNR@mSiO2 NPs were also biologically benign with high biocompatibility against mammalian cells.
- Published
- 2019
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44. Significant Enhancement of the Adhesion Properties of Chemically Functionalized Polypropylene
- Author
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Jung Heon Lee, Jin Woong Lee, Jun Hyuk Heo, Hui Hun Cho, and Byoungsang Lee
- Subjects
Polypropylene ,chemistry.chemical_compound ,Materials science ,Chemical engineering ,chemistry ,General Materials Science ,Adhesion - Abstract
Organosilicon compounds have been actively used with nano- and micro-fillers to improve the adhesion and mechanical properties. However, studies on the adhesion properties of polymeric materials, such as polypropylene (PP), functionalized with organosilicon compounds are limited. Here, we investigated the adhesion of organosilanized PP substrates, functionalized using (3-glycidoxypropyl)trimethoxysilane (GPTMS) and (3-aminopropyl)trimethoxysilane (APTMS) as coupling agents, with epoxy adhesives. The curing of epoxy-functionalized PP (PP-EPOXY) with triethylenetetramine (TETA) hardener led to the chemical crosslinking of TETA with PP-EPOXY, as determined by X-ray photoelectron spectroscopy and vacuum Fourier-transform infrared spectroscopy. Similarly, the curing of amine-functionalized PP (PP-NH2) with bisphenol A diglycidyl ether (DGEBA) epoxy resin led to the chemical crosslinking of the resin with PP-NH2. Finally, we measured the adhesion properties of the functionalized PP substrates using an adhesive composed of DGEBA and TETA based on ASTM D3163 and observed that the shear strength of PP-EPOXY and PP-NH2 increased significantly up to 580% and 506% as compared with that of bare PP. These results strongly suggest that the functionalization of PP significantly contributes to the improvement of adhesion with an adhesive.
- Published
- 2019
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- View/download PDF
45. Enhancement in the adhesion properties of polycarbonate surfaces through chemical functionalization with organosilicon coupling agents
- Author
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Jun Hyuk Heo, Jin Woong Lee, Byoungsang Lee, Hui Hun Cho, Jung Heon Lee, and Tae-Kyung Kim
- Subjects
010302 applied physics ,Materials science ,Epoxy ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,visual_art ,0103 physical sciences ,visual_art.visual_art_medium ,Surface modification ,Adhesive ,Electrical and Electronic Engineering ,Fourier transform infrared spectroscopy ,Polycarbonate ,Bisphenol A diglycidyl ether ,Curing (chemistry) ,Organosilicon - Abstract
Although polycarbonate (PC) materials are well known to have poor adhesion to other surfaces, few studies have been conducted on the improvement of their adhesive properties via surface chemical functionalization. Herein, we report the enhancement in the adhesion properties of PC by adapting two silane coupling agents, namely (3-glycidoxypropyl) methyldiethoxysilane (GPTMS) and (3-aminopropyl) trimethoxysilane (APTMS), on the surface. We tested the adhesion with an epoxy-based adhesive consisting of bisphenol A diglycidyl ether (BADGE) and trientine (trien). The chemical interaction between the amine groups of the hardener (trien) and the epoxy rings of an epoxy-functionalized PC (PC-GPTMS) sample surface was observed with X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. We found that the amine-functionalized PC (PC-APTMS) can also form crosslinked polymeric structures with the BADGE after curing. Compared to the bare PC, an increase in the shear strength of up to 168% and 163% was observed from the PC-GPTMS and PC-APTMS, respectively. In contrast, the ultraviolet-ozone (UVO) and O2 plasma-treated samples showed a negligible increase in adhesion strength. These results strongly suggest that the chemical functionalization of PC substrates with coupling agents significantly enhances the adhesion properties of PCs.
- Published
- 2019
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46. Exceptional Mechanical Properties of Phase-Separation-Free Mo3Se3–-Chain-Reinforced Hydrogel Prepared by Polymer Wrapping Process
- Author
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Liyi Shi, Si Hyun Kim, Sudong Chae, Jung Heon Lee, Jongwha Chang, Jin Woong Lee, Jae-Young Choi, Kyung Eun Lee, Kyung Hwan Choi, and Seungbae Oh
- Subjects
chemistry.chemical_classification ,food.ingredient ,Materials science ,Mechanical Engineering ,Composite number ,Nanowire ,Bioengineering ,02 engineering and technology ,General Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Gelatin ,food ,Fracture toughness ,chemistry ,Self-healing hydrogels ,Ultimate tensile strength ,General Materials Science ,Composite material ,0210 nano-technology ,Elastic modulus - Abstract
As Mo3Se3- chain nanowires have dimensions comparable to those of natural hydrogel chains (molecular-level diameters of ∼0.6 nm and lengths of several micrometers) and excellent mechanical strength and flexibility, they have large potential to reinforce hydrogels and improve their mechanical properties. When a Mo3Se3--chain-nanowire-gelatin composite hydrogel is prepared simply by mixing Mo3Se3- nanowires with gelatin, phase separation of the Mo3Se3- nanowires from the gelatin matrix occurs in the micronetwork, providing only small improvements in their mechanical properties. In contrast, when the surface of the Mo3Se3- nanowire is wrapped with the gelatin polymer, the chemical compatibility of the Mo3Se3- nanowire with the gelatin matrix is significantly improved, which enables the fabrication of a phase-separation-free Mo3Se3--reinforced gelatin hydrogel. The composite gelatin hydrogel exhibits significantly improved mechanical properties, including a tensile strength of 27.6 kPa, fracture toughness of 26.9 kJ/m3, and elastic modulus of 54.8 kPa, which are 367%, 868%, and 378% higher than those of the pure gelatin hydrogel, respectively. Furthermore, the amount of Mo3Se3- nanowires added in the composite hydrogel is as low as 0.01 wt %. The improvements in the mechanical properties are significantly larger than those for other reported composite hydrogels reinforced with one-dimensional materials.
- Published
- 2019
- Full Text
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47. Multifunctional Nanomaterial-alginate Drug Delivery and Imaging System for Cancer Therapy
- Author
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Kwon Hoon Han, Byungkwon Lim, Youngmin Park, Junhyuck Chang, Nayoung Kwon, Jung Heon Lee, Seokhoon Moon, and Seokyoung Yoon
- Subjects
Gold nanorod ,Materials science ,Superparamagnetic iron oxide nanoparticles ,Biomedical Engineering ,Thermal effect ,Cancer therapy ,Bioengineering ,Nanomaterials ,Drug delivery ,medicine ,Doxorubicin ,Electrical and Electronic Engineering ,Nir laser ,Biotechnology ,Biomedical engineering ,medicine.drug - Abstract
Although chemotherapy is mostly performed by direct injection of the chemotherapeutic agents systemically, this approach can cause undesirable side effects in normal tissues and lacks targeting efficiency. In this study, we have developed a micron-sized, bead-type multifunctional anticancer-drug carrier that can be injected in the vicinity of a lesion using a syringe. The multifunctional anticancer-drug carrier bead was fabricated by incorporating functional nanomaterials, such as near-infrared (NIR)-responsive gold nanorod (GNR) and superparamagnetic iron oxide nanoparticles (IONP) that work as a magnetic resonance imaging (MRI) contrast agent, into an alginate hydrogel bead. The carrier bead containing GNR and IONP was spherical, with an average size of 362.2 ± 22.7 µm. These multifunctional anticancer-drug carrier beads could successfully release doxorubicin (Dox) into the external environment upon irradiation with an NIR laser. The laser responsive on-demand release profile demonstrated well-controlled and sustained release of Dox, and the effectiveness of this drug delivery system can be confirmed in vitro by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. Additionally, the control experiments evidenced that the thermal effect of GNR was insignificant and the cytotoxic action of Dox was expressed only after irradiation with the NIR laser. The multifunctional anticancer-drug carrier beads can be precisely monitored with the MRI T2 imaging mode.
- Published
- 2019
- Full Text
- View/download PDF
48. Systematic Review and Meta-analysis of Pharmacist-Led Transitions of Care Services on the 30-Day All-Cause Readmission Rate of Patients with Congestive Heart Failure
- Author
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Chanhyun Park, Jongwha Chang, Sean Hyungwoo Kim, Connor McKay, Jae-Young Choi, Marcia L. Brackbill, and Jung Heon Lee
- Subjects
medicine.medical_specialty ,business.industry ,education ,MEDLINE ,Pharmacist ,Pharmacy ,General Medicine ,030204 cardiovascular system & hematology ,Cochrane Library ,030226 pharmacology & pharmacy ,03 medical and health sciences ,0302 clinical medicine ,Meta-analysis ,Health care ,Emergency medicine ,medicine ,Pharmacology (medical) ,Transitional care ,business ,Cohort study - Abstract
A systematic review and meta-analysis were performed to determine the cumulative effect of pharmacist-led transitions of care on the 30-day all-cause readmission rates of patients with congestive heart failure with the objective to isolate and assess the effect of pharmacy intervention to a condition-specific service. Previous studies that review pharmacist-led transitional care services involve multiple condition-specific services or a pharmacy service integrated into the healthcare team that presents complications in interpreting the independent effectiveness of component services by pharmacy professionals. A systematic review was conducted using articles identified from MEDLINE, CINAHL, Web of Science, Embase, the Cochrane Library, and clinicaltrials.gov databases for studies on congestive heart failure readmission rates based on transitions of care pharmacist services using detailed inclusion and exclusion criteria. Abstracts were screened for outcome of interest and appropriate transitions of care program structure. Practice and patient characteristics were described and compared to identify current practice trends. A meta-analysis was then performed utilizing previously identified studies from systematic analysis that reported the required data to calculate the effect size. Evidence was reviewed and appraised according to the Newcastle-Ottawa Scale for cohort studies. The database search produced 443 potential articles for inclusion. Six articles were identified for inclusion in the systematic review based on abstract screening. Of the six articles included in the systematic review, three studies met inclusion criteria for a meta-analysis. Two studies in the meta-analysis stated a significant reduction in the 30-day all-cause readmission rate for patients with congestive heart failure, while the third depicted a reduction in readmission that was found to be non-significant. The pooled effect of the included articles found that pharmacist-led transitions of care services for patients with congestive heart failure had an increased odds to have lower all-cause readmission rates of patients with congestive heart failure (odds ratio = 2.19, 95% confidence interval 1.50–3.20). Based on the meta-analysis of three studies, pharmacist-led transitions of care services significantly reduced the odds of 30-day all-cause readmission rates in patients with congestive heart failure compared with standard-of-care discharge protocols. Results of the meta-analysis demonstrate the capacity for pharmacist-led transitions of care programs to reduce 30-day all-cause readmission rates in patients with congestive heart failure compared with non-pharmacist discharge care. The financial implications of transitions of care pharmacist involvement have yet to be validated. In general, existing database search results highlight the lack of evidence detailing specific clinical outcomes of pharmacist-led transitions of care services in distinct chronic conditions. Future studies may serve to compare patient-centered outcomes between condition-specific services or across disciplines to provide the most cost-effective delivery of care.
- Published
- 2019
- Full Text
- View/download PDF
49. Antiallergic Effect of Hizikia fusiformis in an Ovalbumin-Induced Allergic Rhinitis Mouse Model
- Author
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Yu-Lian Zhang, Jung-Heon Lee, Hyun-Jae Shin, and Ji Eun Lee
- Subjects
Allergic Rhinitis ,medicine.medical_treatment ,Mucous membrane of nose ,Immunoglobulin E ,Allergic inflammation ,Mice ,03 medical and health sciences ,Th2 Cells ,0302 clinical medicine ,Splenocyte ,Medicine ,030223 otorhinolaryngology ,Inflammation ,biology ,business.industry ,respiratory system ,Eosinophil ,Ovalbumin ,Cytokine ,medicine.anatomical_structure ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Immunology ,biology.protein ,Original Article ,Surgery ,Nasal administration ,business - Abstract
Objectives The extract of Hizikia fusiformis is known to exhibit anticancer, antiatopic and antioxidant activities. We aimed to investigate the extract of H. fusiformis on allergic rhinitis inflammation in a mouse model. Methods The 4-week-old BALB/c mice were randomly assigned into four groups: group A, control group (n=9); group B, allergic rhinitis group (n=10); group C (n=10) received 300 mg/kg of H. fusiformis during nasal challenging period; group D (n=10) received 600 mg/kg of H. fusiformis during general sensitization period and 300 mg/kg of H. fusiformis during nasal challenging period. Allergic inflammation was made with ovalbumin (OVA) and alum then challenged intranasally with OVA. H. fusiformis was intraperitoneally administered 3 hours before the OVA administration. Allergic symptom score and the levels of immunoglobulin G1 (IgG1), IgG2a, OVA-specific IgE antibodies, levels of cytokines in the nasal mucosa and in spleen cell culture supernatant, such as tumor necrosis factor alpha (TNF-α), interleukin 4 (IL-4), IL-5, IL-13, and IL-10 were assessed. The percentage of regulatory T cell was analyzed by flow cytometry. Eosinophilic infiltration and goblet cell hyperplasia were also evaluated. Results H. fusiformis administered groups C and D showed significant inhibitory effects on nasal symptoms, IL-13 mRNA expression and eosinophil infiltration/goblet cell hyperplasia in the nasal tissue; OVA-specific IgE production in serum (P
- Published
- 2019
- Full Text
- View/download PDF
50. New Photosensitive Poly(amic acid ester) with BTDA-BBPA Unit : Synthesis, Photopatterning, and Imidization
- Author
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Yu Kyoung Moon, Yun Ho Kim, Jong Chan Won, Jung Heon Lee, Young Beom Seo, Yu Jin Park, and Jinsoo Kim
- Subjects
Materials science ,Polymers and Plastics ,General Chemical Engineering ,Polymer chemistry ,Materials Chemistry - Published
- 2019
- Full Text
- View/download PDF
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