Elucidation of a reaction mechanism is the most critical aspect for designing electrodes for highperformance secondary batteries.Herein,we investigate the sodium insertion/extraction into an iron fluoride hydrate(FeF_...Elucidation of a reaction mechanism is the most critical aspect for designing electrodes for highperformance secondary batteries.Herein,we investigate the sodium insertion/extraction into an iron fluoride hydrate(FeF_(3)·0.5H_(2)O)electrode for sodium-ion batteries(SIBs).The electrode material is prepared by employing an ionic liquid 1-butyl-3-methylimidazolium-tetrafluoroborate,which serves as a reaction medium and precursor for F^(-)ions.The crystal structure of FeF_(3)·0.5H_(2)O is observed as pyrochlore type with large open 3-D tunnels and a unit cell volume of 1129A^(3).The morphology of FeF_(3)·0.5H_(2)O is spherical shape with a mesoporous structure.The microstructure analysis reveals primary particle size of around 10 nm.The FeF_(3)·0.5H_(2)O cathode exhibits stable discharge capacities of 158,210,and 284 mA h g^(-1) in three different potential ranges of 1.5-4.5,1.2-4.5,and 1.0-4.5 V,respectively at 0.05 C rate.The specific capacities remained stable in over 50 cycles in all three potential ranges,while the rate capability was best in the potential range of 1.5-4.5 V.The electrochemical sodium storage mechanism is studied using X-ray absorption spectroscopy,indicating higher conversion at a more discharged state.Ex-situ M?ssbauer spectroscopy strengthens the results for reversible reduction/oxidation of Fe.These results will be favorable to establish high-performance cathode materials with selective voltage window for SIBs.展开更多
PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula...PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic parameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of Pr BSCF < Nd BSCF < Gd BSCF. To elucidate the close relationship between hydration properties and electrochemical performances in LnBSCF cathodes, PCFC single cell measurements and analysis of the distribution of relaxation time were further investigated.展开更多
Solidif ication and f luid f low analysis using computer simulation is a current common practice. There is also a high demand for thermal stress analysis in the casting process because casting engineers want to contro...Solidif ication and f luid f low analysis using computer simulation is a current common practice. There is also a high demand for thermal stress analysis in the casting process because casting engineers want to control the defects related to thermal stresses, such as large deformation and crack generation during casting. The riser system is an essential part of preventing the shrinkage defects in the casting process, and it has a great inf luence on thermal phenomena. The analysis domain is dramatically expanded by attaching the riser system to a casting product due to its large volume, and it makes FEM mesh generation diff icult. However, it is diff icult to study and solve the above proposed problem caused by riser system using traditional analysis methods which use single numerical method such as FEM or FDM. In this paper, some research information is presented on the effects of the riser system on thermal stress analysis using a FDM/FEM hybrid method in the casting process simulation. The results show the optimal conditions for stress analysis of the riser model in order to save computation time and memory resources.展开更多
We present near-infrared spectroscopic and photometric observations of nova V5584 Sgr taken during the first 12 d following its discovery on Oct. 26.439 UT2009. The evolution of the spectra is shown from the initial P...We present near-infrared spectroscopic and photometric observations of nova V5584 Sgr taken during the first 12 d following its discovery on Oct. 26.439 UT2009. The evolution of the spectra is shown from the initial P Cygni phase to an emission line phase. The prominent carbon lines seen in the JHK spectra closely match those observed in an Fe II class nova outburst. The spectra show first-overtone CO bands in emission between 2.29-2.40 μm. By examining WISE and other publicly available data, we show that the nova underwent a pronounced dust formation phase between February- April 2010.展开更多
Extracellular matrix(ECM)undergoes dynamic inflation that dynamically changes ligand nanospacing but has not been explored.Here we utilize ECM-mimicking photocontrolled supramolecular ligand-tunable Azo^(+)self-assemb...Extracellular matrix(ECM)undergoes dynamic inflation that dynamically changes ligand nanospacing but has not been explored.Here we utilize ECM-mimicking photocontrolled supramolecular ligand-tunable Azo^(+)self-assembly composed of azobenzene derivatives(Azo^(+))stacked via cation-πinteractions and stabilized with RGD ligand-bearing poly(acrylic acid).Near-infrared-upconverted-ultraviolet light induces cis-Azo^(+)-mediated inflation that suppresses cation-πinteractions,thereby inflating liganded self-assembly.This inflation increases nanospacing of“closely nanospaced”ligands from 1.8 nm to 2.6 nm and the surface area of liganded selfassembly that facilitate stem cell adhesion,mechanosensing,and differentiation both in vitro and in vivo,including the release of loaded molecules by destabilizing water bridges and hydrogen bonds between the Azo^(+)molecules and loaded molecules.Conversely,visible light induces trans-Azo^(+)formation that facilitates cation-πinteractions,thereby deflating self-assembly with“closely nanospaced”ligands that inhibits stem cell adhesion,mechanosensing,and differentiation.In stark contrast,when ligand nanospacing increases from 8.7 nm to 12.2 nm via the inflation of self-assembly,the surface area of“distantly nanospaced”ligands increases,thereby suppressing stem cell adhesion,mechanosensing,and differentiation.Long-term in vivo stability of self-assembly via real-time tracking and upconversion are verified.This tuning of ligand nanospacing can unravel dynamic ligand-cell interactions for stem cell-regulated tissue regeneration.展开更多
The direct reductive amination of 2,5-diformylfuran (DFF) with ammonia to 2,5-bis(aminomethyl)furan (BAF) was demonstrated, for the first time, over the commercial type Nickel-Raney and acid treated Nickel-Raney catal...The direct reductive amination of 2,5-diformylfuran (DFF) with ammonia to 2,5-bis(aminomethyl)furan (BAF) was demonstrated, for the first time, over the commercial type Nickel-Raney and acid treated Nickel-Raney catalysts. The effects of reaction parameters such as reaction medium, temperature and hydrogen pressure were described. The acid treated Nickel-Raney catalyst exhibited the highest BAF yield in the THF-water mixed reaction medium. The relatively higher Ni0 species composition and larger surface area of the acid treated Nickel-Raney catalyst with specific reaction conditions contributed greatly to the BAF formation. The oligomeric species, such as furanic imine trimers and tetramers confirmed by MALDI-MS analysis were presented as the intermediates of DFF reductive amination.展开更多
The low-temperature physical vapor deposition process of atomically thin two-dimensional transition metal dichalcogenide(2D TMD) has been gaining attention owing to the cost-effective production of diverse electrochem...The low-temperature physical vapor deposition process of atomically thin two-dimensional transition metal dichalcogenide(2D TMD) has been gaining attention owing to the cost-effective production of diverse electrochemical catalysts for hydrogen evolution reaction(HER) applications. We, herein, propose a simple route toward the cost-effective physical vapor deposition process of 2D WSe2 layered nanofilms as HER electrochemical catalysts using RF magnetron sputtering at room temperature(<27℃). By controlling the variable sputtering parameters, such as RF power and deposition time, the loading amount and electrochemical surface area(ECSA) of WSe2 films deposited on carbon paper can be carefully determined. The surface of the sputtered WSe2 films are partially oxidized, which may cause spherical-shaped particles. Regardless of the loading amount of WSe2, Tafel slopes of WSe2 electrodes in the HER test are narrowly distributed to be ~120–138 mV dec-1, which indicates the excellent reproducibility of intrinsic catalytic activity. By considering the trade-off between the loading amount and ECSA, the best HER performance is clearly observed in the 200 W-15 min sample with an overpotential of 220 mV at a current density of 10 mA cm-2. Such a simple sputtering method at low temperature can be easily expanded to other 2D TMD electrochemical catalysts, promising potentially practical electrocatalysts.展开更多
Abstinence from prolonged psychostimulant use prompts stimulant withdrawal syndrome.Molecular adaptations within the dorsal striatum have been considered the main hallmark of stimulant abstinence. Here we explored str...Abstinence from prolonged psychostimulant use prompts stimulant withdrawal syndrome.Molecular adaptations within the dorsal striatum have been considered the main hallmark of stimulant abstinence. Here we explored striatal miRNA-target interaction and its impact on circulating miRNA marker as well as behavioral dysfunctions in methamphetamine(MA) abstinence. We conducted miRNA sequencing and profiling in the nonhuman primate model of MA abstinence, followed by miRNA qPCR,LC-MS/MS proteomics, immunoassays, and behavior tests in mice. In nonhuman primates, MA abstinence triggered a lasting upregulation of miR-137 in the dorsal striatum but a simultaneous downregulation of circulating miR-137. In mice, aberrant increase in striatal miR-137-dependent inhibition of SYNCRIP essentially mediated the MA abstinence-induced reduction of circulating miR-137. Pathway modeling through experimental deduction illustrated that the MA abstinence-mediated downregulation of circulating miR-137 was caused by reduction of SYNCRIP-dependent miRNA sorting into the exosomes in the dorsal striatum. Furthermore, diminished SYNCRIP in the dorsal striatum was necessary for MA abstinence-induced behavioral bias towards egocentric spatial learning. Taken together, our data revealed circulating miR-137 as a potential blood-based marker that could reflect MA abstinence-dependent changes in striatal miR-137/SYNCRIP axis, and striatal SYNCRIP as a potential therapeutic target for striatum-associated cognitive dysfunction by MA withdrawal syndrome.展开更多
Highly immunosuppressive tumor microenvironment containing various protumoral immune cells accelerates malignant transformation and treatment resistance.In particular,tumor-associated macrophages(TAMs),as the predomin...Highly immunosuppressive tumor microenvironment containing various protumoral immune cells accelerates malignant transformation and treatment resistance.In particular,tumor-associated macrophages(TAMs),as the predominant infiltrated immune cells in a tumor,play a pivotal role in regulating the immunosuppressive tumor microenvironment.As a potential therapeutic strategy to counteract TAMs,here we explore an exosome-guided in situ direct reprogramming of tumor-supportive M2-polarized TAMs into tumor-attacking M1-type macrophages.Exosomes derived from M1-type macrophages(M1-Exo)promote a phenotypic switch from anti-inflammatory M2-like TAMs toward pro-inflammatory M1-type macrophages with high conversion efficiency.Reprogrammed M1 macrophages possessing protein-expression profiles similar to those of classically activated M1 macrophages display significantly increased phagocytic function and robust cross-presentation ability,potentiating antitumor immunity surrounding the tumor.Strikingly,these M1-Exo also lead to the conversion of human patient-derived TAMs into M1-like macrophages that highly express MHC class II,offering the clinical potential of autologous and allogeneic exosome-guided direct TAM reprogramming for arming macrophages to join the fight against cancer.展开更多
Fibers are low-cost substrates that are abundantly used in our daily lives. This review highlights recent advances in the fabrication and application of multifunctional fibers to achieve fibers with unique functions f...Fibers are low-cost substrates that are abundantly used in our daily lives. This review highlights recent advances in the fabrication and application of multifunctional fibers to achieve fibers with unique functions for specific applications ranging from textile electronics to biomedical applications. By incorporating various nanomaterials such as carbon nanomaterials, metallic nanomaterials, and hydrogel-based biomaterials, the functions of fibers can be precisely engineered. This review also highlights the performance of the functional fibers and electronic materials incorporated with textiles and demonstrates their practical application in pressure/tensile sensors,chemical/biosensors, and drug delivery. Textile technologies in which fibers containing biological factors and cells are formed and assembled into constructions with biomimetic properties have attracted substantial attention in the field of tissue engineering. We also discuss the current limitations of functional textile-based devices and their prospects for use in various future applications.展开更多
Engineering of the orbital angular momentum(OAM)of light due to interaction with photonic lattices reveals rich physics and motivates potential applications.We report the experimental creation of regularly distributed...Engineering of the orbital angular momentum(OAM)of light due to interaction with photonic lattices reveals rich physics and motivates potential applications.We report the experimental creation of regularly distributed quantized vortex arrays in momentum space by probing the honeycomb and hexagonal photonic lattices with a single focused Gaussian beam.For the honeycomb lattice,the vortices are associated with Dirac points.However,we show that the resulting spatial patterns of vortices are strongly defined by the symmetry of the wave packet evolving in the photonic lattices and not by their topological properties.Our findings reveal the underlying physics by connecting the symmetry and OAM conversion and provide a simple and efficient method to create regularly distributed multiple vortices from unstructured light.展开更多
Fibroblast growth factor 23(FGF23)is an osteocyte-and osteoblast-derived hormone that primarily regulates phosphate and vitamin D metabolism.Circulatory FGF23 levels are abnormally increased in pathological conditions...Fibroblast growth factor 23(FGF23)is an osteocyte-and osteoblast-derived hormone that primarily regulates phosphate and vitamin D metabolism.Circulatory FGF23 levels are abnormally increased in pathological conditions like acute or chronic kidney injury,resulting in disease progression as well as increased rates of morbidity and mortality.^(1) However,FGF23 production in acute liver injury is not fully investigated.In this study.展开更多
In the last few decades,adverse reactions to pharmaceuticals have been evaluated using 2D in vitro models and animal models.However,with increasing computational power,and as the key drivers of cellular behavior have ...In the last few decades,adverse reactions to pharmaceuticals have been evaluated using 2D in vitro models and animal models.However,with increasing computational power,and as the key drivers of cellular behavior have been identified,in silico models have emerged.These models are time-efficient and cost-effective,but the prediction of adverse reactions to unknown drugs using these models requires relevant experimental input.Accordingly,the physiome concept has emerged to bridge experimental datasets with in silico models.The brain physiome describes the systemic interactions of its components,which are organized into a multilevel hierarchy.Because of the limitations in obtaining experimental data corresponding to each physiome component from 2D in vitro models and animal models,3D in vitro brain models,including brain organoids and brain-on-a-chip,have been developed.In this review,we present the concept of the brain physiome and its hierarchical organization,including cell-and tissue-level organizations.We also summarize recently developed 3D in vitro brain models and link them with the elements of the brain physiome as a guideline for dataset collection.The connection between in vitro 3D brain models and in silico modeling will lead to the establishment of cost-effective and time-efficient in silico models for the prediction of the safety of unknown drugs.展开更多
Neuromodulation by ultrasound has recently received attention due to its noninvasive stimulation capability for treating brain diseases.Although there have been several studies related to ultrasonic neuromodulation,th...Neuromodulation by ultrasound has recently received attention due to its noninvasive stimulation capability for treating brain diseases.Although there have been several studies related to ultrasonic neuromodulation,these studies have suffered from poor spatial resolution of the ultrasound and low repeatability with a fixed condition caused by conventional and commercialized ultrasound transducers.In addition,the underlying physics and mechanisms of ultrasonic neuromodulation are still unknown.To determine these mechanisms and accurately modulate neural circuits,researchers must have a precisely controllable ultrasound transducer to conduct experiments at the cellular level.Herein,we introduce a new MEMS ultrasound stimulation system for modulating neurons or brain slices with high spatial resolution.The piezoelectric micromachined ultrasonic transducers(pMUTs)with small membranes(submm membranes)generate enough power to stimulate neurons and enable precise modulation of neural circuits.We designed the ultrasound transducer as an array structure to enable localized modulation in the target region.In addition,we integrated a cell culture chamber with the system to make it compatible with conventional cell-based experiments,such as in vitro cell cultures and brain slices.In this work,we successfully demonstrated the functionality of the system by showing that the number of responding cells is proportional to the acoustic intensity of the applied ultrasound.We also demonstrated localized stimulation capability with high spatial resolution by conducting experiments in which cocultured cells responded only around a working transducer.展开更多
The convective heat transfer coefficient and surface emissivity before and after flame occurrence on a wood specimen surface and the flame heat flux were estimated using the repulsive particle swarm optimization algor...The convective heat transfer coefficient and surface emissivity before and after flame occurrence on a wood specimen surface and the flame heat flux were estimated using the repulsive particle swarm optimization algorithm and cone heater test results. The cone heater specified in the ISO 5660 standards was used, and six cone heater heat fluxes were tested. Preservative-treated Douglas fir 21 mm in thickness was used as the wood specimen in the tests. This study confirmed that the surface temperature of the specimen, which was calculated using the convective heat transfer coefficient, surface emissivity and flame heat flux on the wood specimen by a repulsive particle swarm optimization algorithm, was consistent with the measured temperature. Considering the measurement errors in the surface temperature of the specimen, the applicability of the optimization method considered in this study was evaluated.展开更多
The pathological origin of Alzheimer’s disease(AD)is still shrouded in mystery,despite intensive worldwide research efforts.The selective visualization ofβ-amyloid(Aβ),the most abundant proteinaceous deposit in AD,...The pathological origin of Alzheimer’s disease(AD)is still shrouded in mystery,despite intensive worldwide research efforts.The selective visualization ofβ-amyloid(Aβ),the most abundant proteinaceous deposit in AD,is pivotal to reveal AD pathology.To date,several small-molecule fluorophores for Aβspecies have been developed,with increasing binding affinities.In the current work,two organic small-molecule dioxaborine-derived fluorophores were rationally designed through tailoring the hydrophobicity with the aim to enhance the binding affinity for Aβ_(1-42) fibrils-while concurrently preventing poor aqueous solubility-via biannulate donor motifs in D-π-A dyes.An unprecedented sub-nanomolar affinity was found(K_(d)=0.62±0.33 nM)and applied to super-sensitive and red-emissive fluorescent staining of amyloid plaques in cortical brain tissue ex vivo.These fluorophores expand the dioxaborine-curcumin-based family of Aβ-sensitive fluorophores with a promising new imaging agent.展开更多
Viral infections cause damage to various organ systems by inducing organ-specific symptoms or systemic multi-organ damage.Depending on the infection route and virus type,infectious diseases are classified as respirato...Viral infections cause damage to various organ systems by inducing organ-specific symptoms or systemic multi-organ damage.Depending on the infection route and virus type,infectious diseases are classified as respiratory,nervous,immune,digestive,or skin infections.Since these infectious diseases can widely spread in the com-munity and their catastrophic effects are severe,identification of their causative agent and mechanisms un-derlying their pathogenesis is an urgent necessity.Although infection-associated mechanisms have been studied in two-dimensional(2D)cell culture models and animal models,they have shown limitations in organ-specific or human-associated pathogenesis,and the development of a human-organ-mimetic system is required.Recently,three-dimensional(3D)engineered tissue models,which can present human organ-like physiology in terms of the 3D structure,utilization of human-originated cells,recapitulation of physiological stimuli,and tight cell–cell interactions,were developed.Furthermore,recent studies have shown that these models can recapitulate infection-associated pathologies.In this review,we summarized the recent advances in 3D engineered tissue models that mimic organ-specific viral infections.First,we briefly described the limitations of the current 2D and animal models in recapitulating human-specific viral infection pathology.Next,we provided an overview of recently reported viral infection models,focusing particularly on organ-specific infection pathologies.Finally,a future perspective that must be pursued to reconstitute more human-specific infectious diseases is presented.展开更多
Developing efficient separation materials for recovering metal resources from aqueous environments is crucial for the sustainable water–food–energy nexus,which addresses the interdependence between energy production...Developing efficient separation materials for recovering metal resources from aqueous environments is crucial for the sustainable water–food–energy nexus,which addresses the interdependence between energy production,water production,and energy consumption.Various material-based separation processes have demonstrated outstanding performance.However,electric energy and chemicals are used to frequently replace the separation materials used in such processes owing to their short life span.This study presents a methodology for designing the self-regenerable fiber(SRF)according to the types of metals through a self-regeneration model.The SRF can semi-permanently recover the metal resources from water through a repetitive adsorption–crystallization–detachment process of metal ions on its surface.The ionic metal resources are adsorbed and crystallized with the counter-anions on the SRF surface.Next,the metal crystals are self-detached from the SRF surface by the collision between the crystals and curvature and non-sticky surface of the SRF.Thus,a module containing the SRF maintains its metal recovery capability even during continuous injection of the metal solution without its replacement.These findings highlight the significance of interfacial engineering and further guide the rational design of energy/environmentally friendly resource recovery modules.展开更多
Realizing highly immersive tactile interactions requires a skin-integrated,untethered,high-definition tactile transducer devices that can record and generate tactile stimuli.However,the rigid and bulky form factor,and...Realizing highly immersive tactile interactions requires a skin-integrated,untethered,high-definition tactile transducer devices that can record and generate tactile stimuli.However,the rigid and bulky form factor,and insufficient resolution of existing actuators are hindering the reproduction of sophisticated tactile sensations and immersive user experiences.Here,we demonstrate an ultraflexible tactile interface with high spatial resolution of 1.8 mm for telehaptic communication on human skin.Dual mechanism sensors and sub-mm scale piezoceramic actuators are designed to record and generate the static and dynamic pressures in a wide frequency range(1 Hz to 1 kHz).Moreover,actuators are integrated on ultra-flexible substrate with chessboard pattern to minimize stress during mechanical deformations.Finally,remote transmissions of various tactile stimuli,such as shapes,textures,and vibration patterns were demonstrated by the telehaptic system with low latency(<1.55 ms)and high fidelity as proven by the shorttime Fourier-transform analysis.展开更多
Dear Editor,Since the COVID-19 demonstrated a remarkable transmission speed and a high mortality risk,COVID-19 is currently declared as a pandemic by the World Health Organization.This is the first time that the WHO h...Dear Editor,Since the COVID-19 demonstrated a remarkable transmission speed and a high mortality risk,COVID-19 is currently declared as a pandemic by the World Health Organization.This is the first time that the WHO has declared a pandemic since H1N1 in 2009.As of 6 September 2020,the total number of COVID-19 patients is 26,763,217(876,616 deaths),and it continues to rise(https://covid19.who.int/).In spite of the urgent demand for the vaccines and therapeutics,global efforts are primarily focused on the utilization of the existing anti-viral drugs,such as remdesivir,hydroxychloroquine,and dexamethasone,to relieve the symptoms due to the limited development of renovative therapeutics.展开更多
基金supported by the Basic Science Research Program of the National Research Foundation(NRF)of South Koreafunded by the Ministry of Science&ICT and Future Planning(NRF-2020M3H4A3081889)KIST Institutional Program of South Korea(Project Nos.2E31860)。
文摘Elucidation of a reaction mechanism is the most critical aspect for designing electrodes for highperformance secondary batteries.Herein,we investigate the sodium insertion/extraction into an iron fluoride hydrate(FeF_(3)·0.5H_(2)O)electrode for sodium-ion batteries(SIBs).The electrode material is prepared by employing an ionic liquid 1-butyl-3-methylimidazolium-tetrafluoroborate,which serves as a reaction medium and precursor for F^(-)ions.The crystal structure of FeF_(3)·0.5H_(2)O is observed as pyrochlore type with large open 3-D tunnels and a unit cell volume of 1129A^(3).The morphology of FeF_(3)·0.5H_(2)O is spherical shape with a mesoporous structure.The microstructure analysis reveals primary particle size of around 10 nm.The FeF_(3)·0.5H_(2)O cathode exhibits stable discharge capacities of 158,210,and 284 mA h g^(-1) in three different potential ranges of 1.5-4.5,1.2-4.5,and 1.0-4.5 V,respectively at 0.05 C rate.The specific capacities remained stable in over 50 cycles in all three potential ranges,while the rate capability was best in the potential range of 1.5-4.5 V.The electrochemical sodium storage mechanism is studied using X-ray absorption spectroscopy,indicating higher conversion at a more discharged state.Ex-situ M?ssbauer spectroscopy strengthens the results for reversible reduction/oxidation of Fe.These results will be favorable to establish high-performance cathode materials with selective voltage window for SIBs.
基金supported by the National Research Foundation (NRF) grant funded by the Korea government (NRF2022R1C1C1007619, NRF-2021M3H4A1A01002921, NRF2021M3I3A1084292)supported by the KIST Institutional Program (Project No. 2E32592-23-069)。
文摘PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic parameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of Pr BSCF < Nd BSCF < Gd BSCF. To elucidate the close relationship between hydration properties and electrochemical performances in LnBSCF cathodes, PCFC single cell measurements and analysis of the distribution of relaxation time were further investigated.
文摘Solidif ication and f luid f low analysis using computer simulation is a current common practice. There is also a high demand for thermal stress analysis in the casting process because casting engineers want to control the defects related to thermal stresses, such as large deformation and crack generation during casting. The riser system is an essential part of preventing the shrinkage defects in the casting process, and it has a great inf luence on thermal phenomena. The analysis domain is dramatically expanded by attaching the riser system to a casting product due to its large volume, and it makes FEM mesh generation diff icult. However, it is diff icult to study and solve the above proposed problem caused by riser system using traditional analysis methods which use single numerical method such as FEM or FDM. In this paper, some research information is presented on the effects of the riser system on thermal stress analysis using a FDM/FEM hybrid method in the casting process simulation. The results show the optimal conditions for stress analysis of the riser model in order to save computation time and memory resources.
基金funded by the Department of Space, Government of India
文摘We present near-infrared spectroscopic and photometric observations of nova V5584 Sgr taken during the first 12 d following its discovery on Oct. 26.439 UT2009. The evolution of the spectra is shown from the initial P Cygni phase to an emission line phase. The prominent carbon lines seen in the JHK spectra closely match those observed in an Fe II class nova outburst. The spectra show first-overtone CO bands in emission between 2.29-2.40 μm. By examining WISE and other publicly available data, we show that the nova underwent a pronounced dust formation phase between February- April 2010.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.RS-2023-00208427,2021R1I1A1A01046207,2021R1A2C2005418,2022R1A2C2005943,and 2022M3H4A1A03076638)supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.RS-2023-00271399 and RS-2023-00275654)+1 种基金supported by a Korea University Grant and KIST intramural programHAADF-STEM was conducted with the support of the Seoul center in Korea Basic Science Institute(KBSI).
文摘Extracellular matrix(ECM)undergoes dynamic inflation that dynamically changes ligand nanospacing but has not been explored.Here we utilize ECM-mimicking photocontrolled supramolecular ligand-tunable Azo^(+)self-assembly composed of azobenzene derivatives(Azo^(+))stacked via cation-πinteractions and stabilized with RGD ligand-bearing poly(acrylic acid).Near-infrared-upconverted-ultraviolet light induces cis-Azo^(+)-mediated inflation that suppresses cation-πinteractions,thereby inflating liganded self-assembly.This inflation increases nanospacing of“closely nanospaced”ligands from 1.8 nm to 2.6 nm and the surface area of liganded selfassembly that facilitate stem cell adhesion,mechanosensing,and differentiation both in vitro and in vivo,including the release of loaded molecules by destabilizing water bridges and hydrogen bonds between the Azo^(+)molecules and loaded molecules.Conversely,visible light induces trans-Azo^(+)formation that facilitates cation-πinteractions,thereby deflating self-assembly with“closely nanospaced”ligands that inhibits stem cell adhesion,mechanosensing,and differentiation.In stark contrast,when ligand nanospacing increases from 8.7 nm to 12.2 nm via the inflation of self-assembly,the surface area of“distantly nanospaced”ligands increases,thereby suppressing stem cell adhesion,mechanosensing,and differentiation.Long-term in vivo stability of self-assembly via real-time tracking and upconversion are verified.This tuning of ligand nanospacing can unravel dynamic ligand-cell interactions for stem cell-regulated tissue regeneration.
文摘The direct reductive amination of 2,5-diformylfuran (DFF) with ammonia to 2,5-bis(aminomethyl)furan (BAF) was demonstrated, for the first time, over the commercial type Nickel-Raney and acid treated Nickel-Raney catalysts. The effects of reaction parameters such as reaction medium, temperature and hydrogen pressure were described. The acid treated Nickel-Raney catalyst exhibited the highest BAF yield in the THF-water mixed reaction medium. The relatively higher Ni0 species composition and larger surface area of the acid treated Nickel-Raney catalyst with specific reaction conditions contributed greatly to the BAF formation. The oligomeric species, such as furanic imine trimers and tetramers confirmed by MALDI-MS analysis were presented as the intermediates of DFF reductive amination.
基金supported by the Fundamental Research Program of the Korean Institute of Materials Science(Grant PNK6130)the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT,Ministry of Science and ICT)(No.2017R1C1B1005076)+1 种基金financially supported by the Ministry of Trade,Industry and Energy(MOTIE)Korea Institute for Advancement of Technology(KIAT)through the National Innovation Cluster R&D program(P0006704_Development of energy saving advanced parts)。
文摘The low-temperature physical vapor deposition process of atomically thin two-dimensional transition metal dichalcogenide(2D TMD) has been gaining attention owing to the cost-effective production of diverse electrochemical catalysts for hydrogen evolution reaction(HER) applications. We, herein, propose a simple route toward the cost-effective physical vapor deposition process of 2D WSe2 layered nanofilms as HER electrochemical catalysts using RF magnetron sputtering at room temperature(<27℃). By controlling the variable sputtering parameters, such as RF power and deposition time, the loading amount and electrochemical surface area(ECSA) of WSe2 films deposited on carbon paper can be carefully determined. The surface of the sputtered WSe2 films are partially oxidized, which may cause spherical-shaped particles. Regardless of the loading amount of WSe2, Tafel slopes of WSe2 electrodes in the HER test are narrowly distributed to be ~120–138 mV dec-1, which indicates the excellent reproducibility of intrinsic catalytic activity. By considering the trade-off between the loading amount and ECSA, the best HER performance is clearly observed in the 200 W-15 min sample with an overpotential of 220 mV at a current density of 10 mA cm-2. Such a simple sputtering method at low temperature can be easily expanded to other 2D TMD electrochemical catalysts, promising potentially practical electrocatalysts.
基金funded by Korea Institute of Science and Technology Intramural Funding (2E26640,2E30952Republic of Korea)+7 种基金National Research Council of Science & Technology (NST) grant by Korean government (MSIP) (CRC-15-04-KISTRepublic of Korea)Center for Women In Science,Engineering,and Technology (WISET) grant by Korean government (WISET2020-525Republic of Korea)National Research Foundation of Korea (2017R1A2B2003993,2020R1A2C2004610Republic of Korea)UST Young Scientist Research Program through Korea University of Science and Technology (UST) (2017YS03Republic of Korea)。
文摘Abstinence from prolonged psychostimulant use prompts stimulant withdrawal syndrome.Molecular adaptations within the dorsal striatum have been considered the main hallmark of stimulant abstinence. Here we explored striatal miRNA-target interaction and its impact on circulating miRNA marker as well as behavioral dysfunctions in methamphetamine(MA) abstinence. We conducted miRNA sequencing and profiling in the nonhuman primate model of MA abstinence, followed by miRNA qPCR,LC-MS/MS proteomics, immunoassays, and behavior tests in mice. In nonhuman primates, MA abstinence triggered a lasting upregulation of miR-137 in the dorsal striatum but a simultaneous downregulation of circulating miR-137. In mice, aberrant increase in striatal miR-137-dependent inhibition of SYNCRIP essentially mediated the MA abstinence-induced reduction of circulating miR-137. Pathway modeling through experimental deduction illustrated that the MA abstinence-mediated downregulation of circulating miR-137 was caused by reduction of SYNCRIP-dependent miRNA sorting into the exosomes in the dorsal striatum. Furthermore, diminished SYNCRIP in the dorsal striatum was necessary for MA abstinence-induced behavioral bias towards egocentric spatial learning. Taken together, our data revealed circulating miR-137 as a potential blood-based marker that could reflect MA abstinence-dependent changes in striatal miR-137/SYNCRIP axis, and striatal SYNCRIP as a potential therapeutic target for striatum-associated cognitive dysfunction by MA withdrawal syndrome.
基金This work was supported by the Samsung Research Funding&Incubation Center of Samsung Electronics(SRFC-MA1901-10)and the Intramural Research Program of KIST.
文摘Highly immunosuppressive tumor microenvironment containing various protumoral immune cells accelerates malignant transformation and treatment resistance.In particular,tumor-associated macrophages(TAMs),as the predominant infiltrated immune cells in a tumor,play a pivotal role in regulating the immunosuppressive tumor microenvironment.As a potential therapeutic strategy to counteract TAMs,here we explore an exosome-guided in situ direct reprogramming of tumor-supportive M2-polarized TAMs into tumor-attacking M1-type macrophages.Exosomes derived from M1-type macrophages(M1-Exo)promote a phenotypic switch from anti-inflammatory M2-like TAMs toward pro-inflammatory M1-type macrophages with high conversion efficiency.Reprogrammed M1 macrophages possessing protein-expression profiles similar to those of classically activated M1 macrophages display significantly increased phagocytic function and robust cross-presentation ability,potentiating antitumor immunity surrounding the tumor.Strikingly,these M1-Exo also lead to the conversion of human patient-derived TAMs into M1-like macrophages that highly express MHC class II,offering the clinical potential of autologous and allogeneic exosome-guided direct TAM reprogramming for arming macrophages to join the fight against cancer.
基金supported by the Priority Research Centers Program(No.2012-0006689)through the National Research Foundation(NRF)of Korea funded by the Ministry of Education,Science and Technology(MEST)the R&D program of MOTIE/KEIT[10064081,Devclopment of fiber-based flexible multimodal pressure sensor and algorithm for gesture/posture-recognizable wearable devices]+3 种基金partial support from the National Research Foundation of Korea(No.NRF-2017K2A9A2A06013377,NRF-2017M3A7B4049466)the Yonsei University Future-leading Research Initiative and Implantable artificial electronic skin for an ubiquitous healthcare system of 2016-12-0050supported by KIST Project(Nos.2E26900,2E27630)supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2016R1A6A3A03006491)
文摘Fibers are low-cost substrates that are abundantly used in our daily lives. This review highlights recent advances in the fabrication and application of multifunctional fibers to achieve fibers with unique functions for specific applications ranging from textile electronics to biomedical applications. By incorporating various nanomaterials such as carbon nanomaterials, metallic nanomaterials, and hydrogel-based biomaterials, the functions of fibers can be precisely engineered. This review also highlights the performance of the functional fibers and electronic materials incorporated with textiles and demonstrates their practical application in pressure/tensile sensors,chemical/biosensors, and drug delivery. Textile technologies in which fibers containing biological factors and cells are formed and assembled into constructions with biomimetic properties have attracted substantial attention in the field of tissue engineering. We also discuss the current limitations of functional textile-based devices and their prospects for use in various future applications.
基金supported by the National Key R&D Program of China(Grant Nos.2018YFA0307500 and 2023YFA1407100)the Key Scientific and Technological Innovation Team of Shaanxi Province(Grant No.2021TD-56)+7 种基金the National Natural Science Foundation of China(Grant Nos.12074303,62022066,12074306,and 11804267)the IBS Young Scientist Fellowship(Grant No.IBS-R024-Y3)the Basis Foundation(Grant No.21-1-3-30-1)the support of the European Union’s Horizon 2020 program,through an FET Open research and innovation action(Grant No.964770)(Topo Light)he ANR projects Labex Ga NEXT(Grant No.ANR-11-LABX0014)“NEWAVE”(Grant No.ANR-21-CE24-0019)the ANR program“Investissements d’Avenir”through the IDEX-ISITE initiative 16-IDEX-0001(Grant No.CAP 20-25)support by the Russian Science Foundation(Grant No.22-12-00144)
文摘Engineering of the orbital angular momentum(OAM)of light due to interaction with photonic lattices reveals rich physics and motivates potential applications.We report the experimental creation of regularly distributed quantized vortex arrays in momentum space by probing the honeycomb and hexagonal photonic lattices with a single focused Gaussian beam.For the honeycomb lattice,the vortices are associated with Dirac points.However,we show that the resulting spatial patterns of vortices are strongly defined by the symmetry of the wave packet evolving in the photonic lattices and not by their topological properties.Our findings reveal the underlying physics by connecting the symmetry and OAM conversion and provide a simple and efficient method to create regularly distributed multiple vortices from unstructured light.
基金supported by the National Research Foundation(NRF)basic science research program Korean government(Ministry of Science and ICT),Republic of Korea(No.2020R1A6A3A01096145,2020)(No.NRF-2019R1C1C1005319,2019)(No.NRF-2017R1A6A3A04006167,2017)(No.NRF-2020R1A2C3006952,2020)and(No.NRF-2021R1A2C3004923,2021)The Federal Ministry of Education and Research-Liver Systems Medicine Program of the Stiftung für Biomedizinische Alkoholforschung,Germany(No.PTJ-031L0043).
文摘Fibroblast growth factor 23(FGF23)is an osteocyte-and osteoblast-derived hormone that primarily regulates phosphate and vitamin D metabolism.Circulatory FGF23 levels are abnormally increased in pathological conditions like acute or chronic kidney injury,resulting in disease progression as well as increased rates of morbidity and mortality.^(1) However,FGF23 production in acute liver injury is not fully investigated.In this study.
基金This work was supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(grant nos.2020R1A6A3A01098991 and 2020R1A6A3A01099935)by the National Research Foundation of Korea(NRF)funded by the Korean Government(MSIT)(grant nos.2021R1A2B5B02086828,2018M3C7A1056896,and 2020M3E5D907974412)+4 种基金by a grant(grant no.20172MFDS196)funded by the Ministry of Food and Drug SafetyThe funder did not play any role in study designin the collection,analysis,and interpretation of datain the writing of the reportand in the decision to submit the article for publication.
文摘In the last few decades,adverse reactions to pharmaceuticals have been evaluated using 2D in vitro models and animal models.However,with increasing computational power,and as the key drivers of cellular behavior have been identified,in silico models have emerged.These models are time-efficient and cost-effective,but the prediction of adverse reactions to unknown drugs using these models requires relevant experimental input.Accordingly,the physiome concept has emerged to bridge experimental datasets with in silico models.The brain physiome describes the systemic interactions of its components,which are organized into a multilevel hierarchy.Because of the limitations in obtaining experimental data corresponding to each physiome component from 2D in vitro models and animal models,3D in vitro brain models,including brain organoids and brain-on-a-chip,have been developed.In this review,we present the concept of the brain physiome and its hierarchical organization,including cell-and tissue-level organizations.We also summarize recently developed 3D in vitro brain models and link them with the elements of the brain physiome as a guideline for dataset collection.The connection between in vitro 3D brain models and in silico modeling will lead to the establishment of cost-effective and time-efficient in silico models for the prediction of the safety of unknown drugs.
基金This work was supported by the Brain Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(NRF-2017M3C7A1028854)Bio&Medical Technology Development Program of the National Research Foundation(NRF)funded by the Ministry of Science&ICT(NRF-2017M3A9B3061319)This work was also supported by the KIST Institutional Program(2E29200).
文摘Neuromodulation by ultrasound has recently received attention due to its noninvasive stimulation capability for treating brain diseases.Although there have been several studies related to ultrasonic neuromodulation,these studies have suffered from poor spatial resolution of the ultrasound and low repeatability with a fixed condition caused by conventional and commercialized ultrasound transducers.In addition,the underlying physics and mechanisms of ultrasonic neuromodulation are still unknown.To determine these mechanisms and accurately modulate neural circuits,researchers must have a precisely controllable ultrasound transducer to conduct experiments at the cellular level.Herein,we introduce a new MEMS ultrasound stimulation system for modulating neurons or brain slices with high spatial resolution.The piezoelectric micromachined ultrasonic transducers(pMUTs)with small membranes(submm membranes)generate enough power to stimulate neurons and enable precise modulation of neural circuits.We designed the ultrasound transducer as an array structure to enable localized modulation in the target region.In addition,we integrated a cell culture chamber with the system to make it compatible with conventional cell-based experiments,such as in vitro cell cultures and brain slices.In this work,we successfully demonstrated the functionality of the system by showing that the number of responding cells is proportional to the acoustic intensity of the applied ultrasound.We also demonstrated localized stimulation capability with high spatial resolution by conducting experiments in which cocultured cells responded only around a working transducer.
基金support from the research fund of the National Emergency Management Agency.(NEMA- Infra-2014-103)
文摘The convective heat transfer coefficient and surface emissivity before and after flame occurrence on a wood specimen surface and the flame heat flux were estimated using the repulsive particle swarm optimization algorithm and cone heater test results. The cone heater specified in the ISO 5660 standards was used, and six cone heater heat fluxes were tested. Preservative-treated Douglas fir 21 mm in thickness was used as the wood specimen in the tests. This study confirmed that the surface temperature of the specimen, which was calculated using the convective heat transfer coefficient, surface emissivity and flame heat flux on the wood specimen by a repulsive particle swarm optimization algorithm, was consistent with the measured temperature. Considering the measurement errors in the surface temperature of the specimen, the applicability of the optimization method considered in this study was evaluated.
基金This research was supported by the National Research Foundation of Korea(CRI project no.2018R1A3B1052702,NRF-2019M3E5D1A01068998,J.S.Kim)the Korea University Graduate School Junior Fellow Research Grant(J.An)+3 种基金the National Research Council of Science&Technology(NST)granted by the Ministry of Science,ICT&Future Planning(MSIP)(No.CRC-15-04-KIST)the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI)and Korea Dementia Research Center(KDRC)the Ministry of Health&Welfare and Ministry of Science and ICT,Republic of Korea(No.HI20C1234)P.V.acknowledges support from Interne Fondsen KU Leuven/Internal Funds KU Leuven(STG/19/029).
文摘The pathological origin of Alzheimer’s disease(AD)is still shrouded in mystery,despite intensive worldwide research efforts.The selective visualization ofβ-amyloid(Aβ),the most abundant proteinaceous deposit in AD,is pivotal to reveal AD pathology.To date,several small-molecule fluorophores for Aβspecies have been developed,with increasing binding affinities.In the current work,two organic small-molecule dioxaborine-derived fluorophores were rationally designed through tailoring the hydrophobicity with the aim to enhance the binding affinity for Aβ_(1-42) fibrils-while concurrently preventing poor aqueous solubility-via biannulate donor motifs in D-π-A dyes.An unprecedented sub-nanomolar affinity was found(K_(d)=0.62±0.33 nM)and applied to super-sensitive and red-emissive fluorescent staining of amyloid plaques in cortical brain tissue ex vivo.These fluorophores expand the dioxaborine-curcumin-based family of Aβ-sensitive fluorophores with a promising new imaging agent.
基金National Research Foundation of Korea(NRF)grant(Nos.2021R1A2B5B02086828 and 2022M3A9B6082678)(H.N.K)funded by the Korean Government(MSIT)Korea Environment Industry&Technology Institute(KEITI)through Technology Development Project for Biological Hazards Management in Indoor Air Program(or Project),funded by Korea Ministry of Environment(MOE)(No.2021003370005).
文摘Viral infections cause damage to various organ systems by inducing organ-specific symptoms or systemic multi-organ damage.Depending on the infection route and virus type,infectious diseases are classified as respiratory,nervous,immune,digestive,or skin infections.Since these infectious diseases can widely spread in the com-munity and their catastrophic effects are severe,identification of their causative agent and mechanisms un-derlying their pathogenesis is an urgent necessity.Although infection-associated mechanisms have been studied in two-dimensional(2D)cell culture models and animal models,they have shown limitations in organ-specific or human-associated pathogenesis,and the development of a human-organ-mimetic system is required.Recently,three-dimensional(3D)engineered tissue models,which can present human organ-like physiology in terms of the 3D structure,utilization of human-originated cells,recapitulation of physiological stimuli,and tight cell–cell interactions,were developed.Furthermore,recent studies have shown that these models can recapitulate infection-associated pathologies.In this review,we summarized the recent advances in 3D engineered tissue models that mimic organ-specific viral infections.First,we briefly described the limitations of the current 2D and animal models in recapitulating human-specific viral infection pathology.Next,we provided an overview of recently reported viral infection models,focusing particularly on organ-specific infection pathologies.Finally,a future perspective that must be pursued to reconstitute more human-specific infectious diseases is presented.
基金the National R&D program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(MSIT)(No.2020M3H4A3106366 and RS-2023-00209565)by an institutional program grant(2E32442)From the Korea Institute of Science and Technology.
文摘Developing efficient separation materials for recovering metal resources from aqueous environments is crucial for the sustainable water–food–energy nexus,which addresses the interdependence between energy production,water production,and energy consumption.Various material-based separation processes have demonstrated outstanding performance.However,electric energy and chemicals are used to frequently replace the separation materials used in such processes owing to their short life span.This study presents a methodology for designing the self-regenerable fiber(SRF)according to the types of metals through a self-regeneration model.The SRF can semi-permanently recover the metal resources from water through a repetitive adsorption–crystallization–detachment process of metal ions on its surface.The ionic metal resources are adsorbed and crystallized with the counter-anions on the SRF surface.Next,the metal crystals are self-detached from the SRF surface by the collision between the crystals and curvature and non-sticky surface of the SRF.Thus,a module containing the SRF maintains its metal recovery capability even during continuous injection of the metal solution without its replacement.These findings highlight the significance of interfacial engineering and further guide the rational design of energy/environmentally friendly resource recovery modules.
基金supported by the Institute for Information&Communications Technology Promotion (IITP) grant funded by the Korean government (MSIT) (Grant No.2020-0-00003,Development of High Piezoelectric Coefficient Composite and Ultra-low Power Multi-layered Piezoelectric Sensor/Actuator Multi-functional Module and Grant No.2017-0-00048,Development of Core Technologies for Tactile Input/Output Panels in Skintronics).
文摘Realizing highly immersive tactile interactions requires a skin-integrated,untethered,high-definition tactile transducer devices that can record and generate tactile stimuli.However,the rigid and bulky form factor,and insufficient resolution of existing actuators are hindering the reproduction of sophisticated tactile sensations and immersive user experiences.Here,we demonstrate an ultraflexible tactile interface with high spatial resolution of 1.8 mm for telehaptic communication on human skin.Dual mechanism sensors and sub-mm scale piezoceramic actuators are designed to record and generate the static and dynamic pressures in a wide frequency range(1 Hz to 1 kHz).Moreover,actuators are integrated on ultra-flexible substrate with chessboard pattern to minimize stress during mechanical deformations.Finally,remote transmissions of various tactile stimuli,such as shapes,textures,and vibration patterns were demonstrated by the telehaptic system with low latency(<1.55 ms)and high fidelity as proven by the shorttime Fourier-transform analysis.
基金supported by a grant from the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2020R1A4A4079817(to W.L.)and 2019R1C1C1004022(to D.K.)。
文摘Dear Editor,Since the COVID-19 demonstrated a remarkable transmission speed and a high mortality risk,COVID-19 is currently declared as a pandemic by the World Health Organization.This is the first time that the WHO has declared a pandemic since H1N1 in 2009.As of 6 September 2020,the total number of COVID-19 patients is 26,763,217(876,616 deaths),and it continues to rise(https://covid19.who.int/).In spite of the urgent demand for the vaccines and therapeutics,global efforts are primarily focused on the utilization of the existing anti-viral drugs,such as remdesivir,hydroxychloroquine,and dexamethasone,to relieve the symptoms due to the limited development of renovative therapeutics.
