Amyotrophic lateral sclerosis(ALS),also known as Lou Geh rig's disease,is a progressive neurodegenerative disorder that affects motor neurons in the brain and spinal cord.This leads to muscle weakness,paralysis,an...Amyotrophic lateral sclerosis(ALS),also known as Lou Geh rig's disease,is a progressive neurodegenerative disorder that affects motor neurons in the brain and spinal cord.This leads to muscle weakness,paralysis,and ultimately,respiratory failure(Cha and Kim,2022).展开更多
Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disorder characterized by the degeneration of motor neurons in the brain and spinal cord,leading to muscle weakness,paralysis,and ultimately death(C...Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disorder characterized by the degeneration of motor neurons in the brain and spinal cord,leading to muscle weakness,paralysis,and ultimately death(Cleveland and Rothstein,2001).Frontotemporal lobar degeneration(FTLD)is a neurodegenerative disease affecting the frontal and temporal lobes of the brain,leading to changes in behavior,personality,and language(Van Langenhove et al.,2012).Both ALS and FTLD are classified as proteinopathies in which abnormal protein aggregation and accumulation in neurons contribute to the disease pathogenesis.Fused in sarcoma(FUS)is a DNA/RNA-binding protein involved in various cellular processes,including transcriptional regulation,RNA splicing,and DNA repair.Mutations in the FUS gene have been linked to familial ALS,highlighting the importance of FUS in the disease pathogenesis(Vance et al.,2009).In ALS and FTLD,aberrant post-translational modifications(PTMs)of FUS,such as phosphorylation,acetylation,and methylation,have been implicated in the promotion of FUS aggregation and neurotoxicity(Choi et al.,2023).Therefore,understanding the regulatory mechanisms of FUS PTMs is crucial for developing targeted therapies against these diseases.展开更多
Development of electrodes with high electrocatalytic activity and stability is essential for solving problems that still restrict the extensive application of vanadium redox flow batteries(VRFBs).Here,we designed a no...Development of electrodes with high electrocatalytic activity and stability is essential for solving problems that still restrict the extensive application of vanadium redox flow batteries(VRFBs).Here,we designed a novel negative electrode with superior electrocatalytic activity by tailoring nitrogen functional groups,such as newly formed nitro and pyridinic-N transformed to pyridonic-N,from the prenitrogen-doped electrode.It was experimentally confirmed that an electrode with pyridonic-N and nitro fuctional groups(tailored nitrogen-doped graphite felt,TNGF) has superior electrocatalytic acivity with enhanced electron and mass transfer.Density functional theory calulations demonstrated the pyridonic-N and nitro functional groups promoted the adsorption,charge transfer,and bond formation with the vanadium species,which is consistent with expermental results.In addition,the V2+/V3+redox reaction mechanism on pyridonic-N and nitro functional groups was estabilised based on density functional theory(DFT) results.When TNGF was applied to a VRFB,it enabled enhanced-electrolyte utilization and energy efficiencies(EE) of 57.9% and 64.6%,respectively,at a current density of 250 mA cm^(-2).These results are 18.6% and 8.9% higher than those of VRFB with electrode containing graphitic-N and pyridinicN groups.Interestingly,TNGF-based VRFB still operated with an EE of 59% at a high current density of300 mA cm^(-2).The TNGF-based VRFB exhibited stable cycling performance without noticeable decay of EE over 450 charge-discharge cycles at a current density of 250 mA cm^(-2).The results of this study suggest that introducing pyridonic-N and nitro groups on the electrode is effective for improving the electrochemical performance of VRFBs.展开更多
Porosity is a main defect in aluminum alloy castings, which is also thought to be severe in aluminum alloy castings produced by lost foam process due to the pyrolysis of the polystyrene foam pattern during pouring. Fu...Porosity is a main defect in aluminum alloy castings, which is also thought to be severe in aluminum alloy castings produced by lost foam process due to the pyrolysis of the polystyrene foam pattern during pouring. Fundamental experiments were carried out to evaluate the effect of process parameters such as the melt treatment, the cooling rate and the density of expanded polystyrene （EPS） foam on porosity in A356.2 bar casting. The effect of melt treatment including degassing and refining was investigated. The effect of cooling rate was also evaluated by changing the mold packing material such as the silica sand, the zircon sand and the steel shots. Gas entrapment due to the turbulent metal flow during mold filling in conventional molding process results in porosity. Mold filling sequence in lost foam process is different from that in conventional molding process. The effect of molten metal flow was estimated by comparing the density of the casting by conventional sodium silicate molding with that by lost foam process. Density measurement was conducted to analyze the extent of porosity in the casting. Source of the porosity in lost foam process can be divided into two factors, i.e. turbulence in molten metal flow and entraining residue or gas from the pattern during pouring.展开更多
Porosity is thought to be severe in aluminum alloy castings produced by lost foam process due to the pyrolysis of the polystyrene foam pattern during pouring, which results in detrimental effect in mechanical property...Porosity is thought to be severe in aluminum alloy castings produced by lost foam process due to the pyrolysis of the polystyrene foam pattern during pouring, which results in detrimental effect in mechanical property. The slow solidification rate promotes the formation of gassing pin holes, and relative weakness of the thermal gradients can cause micro-shrinkage if the outline of the part complicates feeding in the lost foam casting. One of the methods to eliminate the porosity is to apply high pressure to the molten metal like an isostatic forging during solidification. Fundamental experiments were carried out to evaluate the effect of the external pressure on the porosity and mechanical properties of A356.2 alloy bar in the lost foam casting. Solidification time and porosity decreased with increasing the applied pressure during solidification. Applying external pressure was effective in decreasing the porosity and increasing the elongation of the lost foam casting.展开更多
NEDD8 conjugation of Cullin has an important role in ubiquitin-mediated protein degradation. The COP9 signalosome, of which CSN5 is the major catalytic subunit, is a major Cullin deneddylase, Another deneddylase, Dene...NEDD8 conjugation of Cullin has an important role in ubiquitin-mediated protein degradation. The COP9 signalosome, of which CSN5 is the major catalytic subunit, is a major Cullin deneddylase, Another deneddylase, Deneddylase 1, has also been shown to process the Nedd8 precursor. In Drosophila, the DEN1 mutants do not have increased levels of Cullin neddylation, but instead show a significant decrease in neddylated Cullin. This characteristic decrease in neddylated Cullins in the DEN1^null background can be rescued by UAS-dDEN1^WT overexpression but not by overexpression of mature NEDDS, indicating that this phenotype is distinct from the NEDD8-processing function of DENI. We examined the role of DEN 1-CSN interaction in regulating Cullin neddylation. Overexpression of DEN1 in a CSN5^hypo background slightly reduced unneddylated Cullin levels. The CSN5, DEN1 double mutation partially rescues the premature lethality associated with the CSN5 single mutation. These results suggest that DEN1 regulates Cullin neddylation by suppressing CSN deneddylase activity.展开更多
基金supported by the BK21 FOUR(Fostering Outstanding Universities for Research)the Basic Science Research Program through the National Research Foundation of Korea(NRF)+2 种基金the Regional Innovation Mega Project Program through the Korea Innovation Foundation funded by the Ministry of Education(MOE)the Ministry of Science and ICT(MSIT)(NRF-2022R1A2C1004204,RS-2023-00219563,2023-DD-UP-0007)the Soonchunhyang University Research Fund(to KK)。
文摘Amyotrophic lateral sclerosis(ALS),also known as Lou Geh rig's disease,is a progressive neurodegenerative disorder that affects motor neurons in the brain and spinal cord.This leads to muscle weakness,paralysis,and ultimately,respiratory failure(Cha and Kim,2022).
基金supported by the BK21 FOUR(Fostering Outstanding Universities for Research)and the Basic Science Research Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Education(MOE)and the Ministry of Science and ICT(MSIT)(NRF-2022R1A2C1004204,RS-2023-00219563,2023-DD-UP-0007)by the Soonchunhyang University Research Fund(to KK)。
文摘Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disorder characterized by the degeneration of motor neurons in the brain and spinal cord,leading to muscle weakness,paralysis,and ultimately death(Cleveland and Rothstein,2001).Frontotemporal lobar degeneration(FTLD)is a neurodegenerative disease affecting the frontal and temporal lobes of the brain,leading to changes in behavior,personality,and language(Van Langenhove et al.,2012).Both ALS and FTLD are classified as proteinopathies in which abnormal protein aggregation and accumulation in neurons contribute to the disease pathogenesis.Fused in sarcoma(FUS)is a DNA/RNA-binding protein involved in various cellular processes,including transcriptional regulation,RNA splicing,and DNA repair.Mutations in the FUS gene have been linked to familial ALS,highlighting the importance of FUS in the disease pathogenesis(Vance et al.,2009).In ALS and FTLD,aberrant post-translational modifications(PTMs)of FUS,such as phosphorylation,acetylation,and methylation,have been implicated in the promotion of FUS aggregation and neurotoxicity(Choi et al.,2023).Therefore,understanding the regulatory mechanisms of FUS PTMs is crucial for developing targeted therapies against these diseases.
基金financially supported by the Research Program from Korea Institute of Industrial Technology(EM220011)the Technology Innovation Program(20020229,Development of technology for manufacturing catalysts and electrode parts by use of low contents precious metals of rare metals) funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)+2 种基金the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT)(2022R1F1A1072569)supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science,ICT & Future Planning(NRF2020R1C1C1010493)“Regional Innovation Strategy(RIS)” through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(MOE)(2021RIS-004)。
文摘Development of electrodes with high electrocatalytic activity and stability is essential for solving problems that still restrict the extensive application of vanadium redox flow batteries(VRFBs).Here,we designed a novel negative electrode with superior electrocatalytic activity by tailoring nitrogen functional groups,such as newly formed nitro and pyridinic-N transformed to pyridonic-N,from the prenitrogen-doped electrode.It was experimentally confirmed that an electrode with pyridonic-N and nitro fuctional groups(tailored nitrogen-doped graphite felt,TNGF) has superior electrocatalytic acivity with enhanced electron and mass transfer.Density functional theory calulations demonstrated the pyridonic-N and nitro functional groups promoted the adsorption,charge transfer,and bond formation with the vanadium species,which is consistent with expermental results.In addition,the V2+/V3+redox reaction mechanism on pyridonic-N and nitro functional groups was estabilised based on density functional theory(DFT) results.When TNGF was applied to a VRFB,it enabled enhanced-electrolyte utilization and energy efficiencies(EE) of 57.9% and 64.6%,respectively,at a current density of 250 mA cm^(-2).These results are 18.6% and 8.9% higher than those of VRFB with electrode containing graphitic-N and pyridinicN groups.Interestingly,TNGF-based VRFB still operated with an EE of 59% at a high current density of300 mA cm^(-2).The TNGF-based VRFB exhibited stable cycling performance without noticeable decay of EE over 450 charge-discharge cycles at a current density of 250 mA cm^(-2).The results of this study suggest that introducing pyridonic-N and nitro groups on the electrode is effective for improving the electrochemical performance of VRFBs.
文摘Porosity is a main defect in aluminum alloy castings, which is also thought to be severe in aluminum alloy castings produced by lost foam process due to the pyrolysis of the polystyrene foam pattern during pouring. Fundamental experiments were carried out to evaluate the effect of process parameters such as the melt treatment, the cooling rate and the density of expanded polystyrene （EPS） foam on porosity in A356.2 bar casting. The effect of melt treatment including degassing and refining was investigated. The effect of cooling rate was also evaluated by changing the mold packing material such as the silica sand, the zircon sand and the steel shots. Gas entrapment due to the turbulent metal flow during mold filling in conventional molding process results in porosity. Mold filling sequence in lost foam process is different from that in conventional molding process. The effect of molten metal flow was estimated by comparing the density of the casting by conventional sodium silicate molding with that by lost foam process. Density measurement was conducted to analyze the extent of porosity in the casting. Source of the porosity in lost foam process can be divided into two factors, i.e. turbulence in molten metal flow and entraining residue or gas from the pattern during pouring.
文摘Porosity is thought to be severe in aluminum alloy castings produced by lost foam process due to the pyrolysis of the polystyrene foam pattern during pouring, which results in detrimental effect in mechanical property. The slow solidification rate promotes the formation of gassing pin holes, and relative weakness of the thermal gradients can cause micro-shrinkage if the outline of the part complicates feeding in the lost foam casting. One of the methods to eliminate the porosity is to apply high pressure to the molten metal like an isostatic forging during solidification. Fundamental experiments were carried out to evaluate the effect of the external pressure on the porosity and mechanical properties of A356.2 alloy bar in the lost foam casting. Solidification time and porosity decreased with increasing the applied pressure during solidification. Applying external pressure was effective in decreasing the porosity and increasing the elongation of the lost foam casting.
文摘NEDD8 conjugation of Cullin has an important role in ubiquitin-mediated protein degradation. The COP9 signalosome, of which CSN5 is the major catalytic subunit, is a major Cullin deneddylase, Another deneddylase, Deneddylase 1, has also been shown to process the Nedd8 precursor. In Drosophila, the DEN1 mutants do not have increased levels of Cullin neddylation, but instead show a significant decrease in neddylated Cullin. This characteristic decrease in neddylated Cullins in the DEN1^null background can be rescued by UAS-dDEN1^WT overexpression but not by overexpression of mature NEDDS, indicating that this phenotype is distinct from the NEDD8-processing function of DENI. We examined the role of DEN 1-CSN interaction in regulating Cullin neddylation. Overexpression of DEN1 in a CSN5^hypo background slightly reduced unneddylated Cullin levels. The CSN5, DEN1 double mutation partially rescues the premature lethality associated with the CSN5 single mutation. These results suggest that DEN1 regulates Cullin neddylation by suppressing CSN deneddylase activity.
