96 results on '"Jiho Yoo"'
Search Results
2. Wood Pellet Driven-Biochar Characterization Produced at Different Targeted Pyrolysis Temperatures
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Irma Thya Rani, Jiho Yoo, Byung Bae Park, Wahyu Hidayat, Bangun Adi Wijaya, Sihyun Lee, Sangdo Kim, Hokyung Choi, Donghyuk Chun, Hyuk Im, and Soohyun Kim
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Forestry ,SD1-669.5 - Abstract
The imperative transition to renewable energy drives the need for innovation. Biomass, particularly wood pellets, has demonstrated poor performance in co-firing scenarios. This study employed pyrolysis to convert wood pellets into biochar with improved fuel quality. The biochar production and characterization were investigated at pyrolysis temperatures of 400°C to 500°C. The findings revealed significant improvements: the observed fixed carbon content increased from 67.2% to 78.8%, and the calorific value increased 1.2 times higher within the pyrolysis temperature increased. On the other hand, as the pyrolysis temperature increased from 400°C to 500°C, biochar yields decreased from 49% to 37%. Thermogravimetric (TG) analysis revealed distinct weight loss during heating, illuminating component volatilization and residue accumulation. Furthermore, Fourier transform infrared (FTIR) spectroscopy elucidated structural changes, demonstrating the evolution of cellulose and hemicellulose into aromatic structures. Ultimately, these insights into biochar characteristics informed the optimization of pyrolysis processes, contributing to the production of superior biochar for renewable energy applications. Keywords: biochar, biomass, carbon storage, pyrolysis, wood pellet
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- 2023
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3. Systematic analyses of the sequence conservation and ligand interaction patterns of purinergic P1 and P2Y receptors provide a structural basis for receptor selectivity
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Ri Han, Hongryul Yoon, Jiho Yoo, and Yoonji Lee
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Purinergic P1 and P2Y receptor ,Sequence conservation ,3D structures ,Clustering ,Receptor-ligand interactions ,Ligand selectivity ,Biotechnology ,TP248.13-248.65 - Abstract
Purinergic receptors are membrane proteins that regulate numerous cellular functions by catalyzing reactions involving purine nucleotides or nucleosides. Among the three receptor families, i.e., P1, P2X, and P2Y, the P1 and P2Y receptors share common structural features of class A GPCR. Comprehensive sequence and structural analysis revealed that the P1 and P2Y receptors belong to two distinct groups. They exhibit different ligand-binding site features that can distinguish between specific activators. These specific amino acid residues in the binding cavity may be involved in the selectivity and unique pharmacological behavior of each subtype. In this study, we conducted a structure-based analysis of purinergic P1 and P2Y receptors to identify their evolutionary signature and obtain structural insights into ligand recognition and selectivity. The structural features of the P1 and P2Y receptor classes were compared based on sequence conservation and ligand interaction patterns. Orthologous protein sequences were collected for the P1 and P2Y receptors, and sequence conservation was calculated based on Shannon entropy to identify highly conserved residues. To analyze the ligand interaction patterns, we performed docking studies on the P1 and P2Y receptors using known ligand information extracted from the ChEMBL database. We analyzed how the conserved residues are related to ligand-binding sites and how the key interacting residues differ between P1 and P2Y receptors, or between agonists and antagonists. We extracted new similarities and differences between the receptor subtypes, and the results can be used for designing new ligands by predicting hotspot residues that are important for functional selectivity.
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- 2023
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4. Peningkatan Kualitas Pelet Tandan Kosong Kelapa Sawit melalui Torefaksi Menggunakan Reaktor Counter-Flow Multi Baffle (COMB)
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Wahyu Hidayat, Irma Thya Rani, Tri Yulianto, Indra Gumay Febryano, Dewi Agustina Iryani, Udin Hasanudin, Sihyun Lee, Sangdo Kim, Jiho Yoo, and Agus Haryanto
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counter-flow multi baffle ,oil palm empty fruit bunches ,renewable ,torrefaction ,Chemical technology ,TP1-1185 - Abstract
Oil palm (Elaeis guineensis) empty fruit bunches (EFB) have not been utilized optimally. Currently, it is considered as a resource with low economic value. This biomass can be converted into bioenergy through a torrefaction process. Torrefaction is a mild pyrolysis at temperatures ranging between 200 and 300 °C, and it is generally performed under an inert atmosphere. The objective of this study was to evaluate the effects of torrefaction using Counter-Flow Multi Baffle (COMB) on the properties of oil palm EFB pellets. Torrefaction was conducted at 280 °C temperature with a residence time of 4 minutes. The results showed a decrease in the equilibrium moisture content and an increase in hydrophobicity after torrefaction using the COMB reactor. The change in the hygroscopic property could make the oil palm EFB pellet more stable against chemical oxidation and microbial degradation, hence self-heating and auto-ignition during storage could be prevented. The heating value of biomass increased after torrefaction. Torrefaction with the COMB reactor resulted in a heating value of 17.90 MJ/kg, which is comparable with the results of oxidative torrefaction (with longer residence time) of 18.28 MJ/kg. The results suggested that torrefaction using the COMB reactor could provide a great improvement in the quality of the bioenergetic properties of oil palm EFB pellets. However, the high ash content of the EFB pellets implied that the EFB pellets suitable for a small-scale application, but not yet for cofiring in power plants or as a feedstock for gasification. Keywords: Counter-Flow Multi Baffle; oil palm empty fruit bunches; renewable; torrefaction A B S T R A K Tandan kosong kelapa sawit (Elaeis guineensis) belum dimanfaatkan secara optimal. Saat ini bahan tersebut masih dianggap sebagai sumber daya bernilai ekonomi rendah. Tandan kosong kelapa sawit (TKKS) dapat dikonversi menjadi bioenergi melalui proses torefaksi. Torefaksi merupakan proses pirolisis ringan pada suhu berkisar antara 200 dan 300 °C dan umumnya dilakukan di bawah kondisi inert. Penelitian ini bertujuan untuk mengetahui pengaruh torefaksi dengan reaktor Counter-Flow Multi Baffle (COMB) terhadap sifat-sifat pelet TKKS. Torefaksi dilakukan pada suhu 280 °C dengan waktu tinggal 4 menit. Hasil penelitian menunjukkan bahwa torefaksi menyebabkan penurunan kadar air kesetimbangan dan menjadi hidrofobik setelah torefaksi dengan reaktor COMB. Perbaikan sifat higroskopis dapat membuat pelet TKKS lebih stabil terhadap oksidasi kimia dan degradasi mikroba, sehingga pemanasan sendiri dan pembakaran spontan selama penyimpanan dapat dicegah. Nilai kalor biomassa meningkat setelah torefaksi. Torefaksi dengan reaktor COMB menghasilkan nilai kalor 17,90 MJ/kg, yang sebanding dengan hasil torefaksi oksidatif dengan waktu tinggal lebih lama, sebesar 18,28 MJ/kg. Hasil penelitian menunjukkan bahwa torefaksi dengan reaktor COMB dapat meningkatkan kualitas energi pelet TKKS. Tetapi pelet TKKS masih memiliki kadar abu yang tinggi sehingga biomassa hasil torefaksi belum sesuai untuk cofiring di pembangkit listrik atau sebagai bahan baku untuk gasifikasi. Kata kunci: Counter-Flow Multi Baffle; tandan kosong kelapa sawit; terbarukan; torefaksi
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- 2020
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5. Pengaruh Torefaksi dengan Reaktor Counter-Flow Multi Baffle (COMB) dan Electric Furnace terhadap Pelet Kayu Jabon (Anthocephalus cadamba) (Effects of Torefaction with Counter-Flow Multi Baffle (COMB) Reactor and Electric Furnace on the Properties of Jabon (Anthocephalus cadamba) Pellets)
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Yogi Sulistio, Indra Gumay Febryano, Jiho Yoo, Sangdo Kim, Sihyun Lee, Udin Hasanudin, and Wahyu Hidayat
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Forestry ,SD1-669.5 - Abstract
The objective of this study was to improve the quality of jabon (Anthocephalus cadamba) wood pellets through torrefaction with Counter-Flow Multi-Baffle (COMB) reactor and electric furnace (EF). COMB is a reactor that can conduct torrefaction with a short residence time, approximately around 3 to 5 min. The torrefaction with COMB reactor was conducted at 260°C and 280°C C, with a residence time of 3 min. The torrefaction with EF used the temperature of 260°C and 280°C with a duration of 20 min. The pellet properties evaluated include the color changes, physical characteristics, and heating values. The result showed that the color of Jabon wood pellet was totally changed after torrefaction with COMB reactor reaching the highest overall color-change (∆E *) of 21,9 in the long pellets and 21,7 in the short pellets, while torrefaction with EF resulted in the highest ∆E* of 28,6 and 23,2, in the long and short pellets, respectively. The initial moisture content of the long and short pellets of Jabon wood were 12,41% and 12,33%. After torrefaction with COMB the moisture content decreased to 2,85% and 2,61%, while after torrefaction with EF the values decreased to 2,77% and 2,58%. The initial density of the long and short pellets were 1,05 g/cm3 and 0,97 g/cm3. The density decreased to 0,91 g/cm3 and 0,76 g/cm3 after torrefaction with COMB reactor, and decreased to 0,87 g/cm3 and 0,75 g/cm3 after torrefaction with EF. The research result also showed that the initial heating value of long and short pellets of 17,69 MJ/kg increased to 31,79 MJ/kg (long pellets) and 32.02 MJ/kg (short pellets) after torrefaction with COMB reactor, and increased to 19.74 MJ/kg (long pellets) and 19.99 MJ/kg (short pellets) after torrefaction with EF. Torrefaction with COMB reactor with shorter residence time resulted in a higher improvement in bioenergetic properties of jabon wood pellets in comparison to torrefaction with EF. Keywords: Anthocephalus cadamba, Counter-Flow Multi Baffle, torrefaction
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- 2020
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6. Efficient learning of non-autoregressive graph variational autoencoders for molecular graph generation
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Youngchun Kwon, Jiho Yoo, Youn-Suk Choi, Won-Joon Son, Dongseon Lee, and Seokho Kang
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Molecular graph ,Variational autoencoder ,Graph neural network ,Deep learning ,Information technology ,T58.5-58.64 ,Chemistry ,QD1-999 - Abstract
Abstract With the advancements in deep learning, deep generative models combined with graph neural networks have been successfully employed for data-driven molecular graph generation. Early methods based on the non-autoregressive approach have been effective in generating molecular graphs quickly and efficiently but have suffered from low performance. In this paper, we present an improved learning method involving a graph variational autoencoder for efficient molecular graph generation in a non-autoregressive manner. We introduce three additional learning objectives and incorporate them into the training of the model: approximate graph matching, reinforcement learning, and auxiliary property prediction. We demonstrate the effectiveness of the proposed method by evaluating it for molecular graph generation tasks using QM9 and ZINC datasets. The model generates molecular graphs with high chemical validity and diversity compared with existing non-autoregressive methods. It can also conditionally generate molecular graphs satisfying various target conditions.
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- 2019
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7. Meranti (Shorea sp.) Biochar Application Method on the Growth of Sengon (Falcataria moluccana) as a Solution of Phosphorus Crisis
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Bangun Adi Wijaya, Wahyu Hidayat, Melya Riniarti, Hendra Prasetia, Ainin Niswati, Udin Hasanudin, Irwan Sukri Banuwa, Sangdo Kim, Sihyun Lee, and Jiho Yoo
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biochar ,Falcataria moluccana ,phosphorus ,Shorea sp. ,Technology - Abstract
Phosphorus (P) is a limiting nutrient mined from non-renewable sources. P is needed to stimulate trees growth in a forest plantation. P-fertilizer addition in the tropical forest field causes P-leaching flux to watershed and induces eutrophication. The high C contained in meranti (Shorea sp.) biochar can avoid the P-leaching process in the soil with a strategic application method. However, the biochar application method is poorly examined. This research aimed to develop a biochar application method to sequestrate P from the environment and examine its effect on the growth of sengon (Falcataria moluccana). Shorea sp. biochar pyrolyzed at 400 °C and 600 °C were added at a dosage of 0 t ha−1, 25 t ha−1, and 50 t ha−1 for six months in the field. The biochar was placed 20 cm under topsoil without soil mixing. This application method significantly increased total P in the soil without any P-fertilizer addition. The results showed that biochar pyrolyzed at 600 °C and a dosage of 25 t ha−1 increased the total P in the soil and CEC by 192.2 mg kg−1 and 25.98 me 100 g−1, respectively. Biochar with a higher pyrolysis temperature increased higher soil pH. In contrast, the higher dosage increased organic-C higher than the lower dosage application. The most significant P-uptake, height, and diameter increments on F.moluccana were achieved using Shorea sp. biochar pyrolyzed at 600 °C with a dosage of 25 t ha−1 by 0.42 mg kg−1, 222 cm, and 2.75 cm, respectively. The total P in the soil positively correlated with the P-uptake of F. moluccana. Furthermore, using the biochar application method P could be absorbed to the biochar layer and desorbed to the topsoil. Consequently, the biochar application method together with P-fertilizer addition could increase the availability of P in the soil and decrease P-leaching to the environment.
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- 2022
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8. Low-Rank Coal Supported Ni Catalysts for CO2 Methanation
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Soohyun Kim, Yunxia Yang, Renata Lippi, Hokyung Choi, Sangdo Kim, Donghyuk Chun, Hyuk Im, Sihyun Lee, and Jiho Yoo
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carbon support ,CO2 methanation ,low-rank coal ,nickel ,ceria ,magnesia ,Technology - Abstract
As renewable energy source integration increases, P2G technology that can store surplus renewable power as methane is expected to expand. The development of a CO2 methanation catalyst, one of the core processes of the P2G concept, is being actively conducted. In this work, low-rank coal (LRC) was used as a catalyst support for CO2 methanation, as it can potentially enhance the diffusion and adsorption behavior by easily controlling the pore structure and composition. It can also improve the process efficiency owing to its simplicity (no pre-reduction step) and high thermal conductivity, compared to conventional metal oxide-supported catalysts. A screening of single metals (Ni, Co, Ru, Rh, and Pd) on LRC was performed, which showed that Ni was the most active. When Ni on the LRC catalyst was doped with a promoter (Ce and Mg), the CO2 conversion percentage increased by >10% compared to that of the single Ni catalyst. When the CO2 methanation activity was compared at 250–500 °C, the Ce-doped Ni/Eco and Mg-doped Ni/Eco catalysts showed similar or better activity than the commercial metal oxide-supported catalyst. In addition, the catalytic performance remained stable even after the test for an extended time (~200 h). The results of XRD, TEM, and TPR showed that highly efficient LRC-based CO2 methanation catalysts can be made when the metal dispersion and composition are modified.
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- 2021
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9. Valorization of Indonesian Wood Wastes through Pyrolysis: A Review
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Agus Haryanto, Wahyu Hidayat, Udin Hasanudin, Dewi Agustina Iryani, Sangdo Kim, Sihyun Lee, and Jiho Yoo
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biochar ,renewable energy ,pyrolysis ,sengon ,meranti ,rubberwood ,Technology - Abstract
The wood processing industry produces a significant amount of wood waste. Biomass valorization through pyrolysis has the potential to increase the added value of wood wastes. Pyrolysis is an important thermochemical process that can produce solid, liquid, and gas products. This paper aims to review the pyrolysis of wood wastes from Indonesia, including teak wood (Tectona grandis), meranti (Shorea sp.), sengon (Paraserianthes falcataria (L) Nielsen), and rubberwood (Hevea brasiliensis). The review is based on an in-depth study of reliable literatures, statistical data from government agencies, and direct field observations. The results showed that pyrolysis could be a suitable process to increase the added value of wood waste. Currently, slow pyrolysis is the most feasible for Indonesia, with the main product of charcoal. The efficiency of the slow pyrolysis process can be increased by harvesting also liquid and gaseous products. The use of the main product of pyrolysis in the form of charcoal needs to be developed and diversified. Charcoal is not only used for fuel purposes but also as a potential soil improvement agent.
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- 2021
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10. Synthesis and Characterization of Polycarbonate Copolymers Containing Benzoyl Groups on the Side Chain for Scratch Resistance
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Hohyoun Jang, Jaeseong Ha, Jiho Yoo, Jaeseung Pyo, Kunyoung Choi, Chaekyun Lee, Taewook Ryu, Sungkwun Lee, and Whangi Kim
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Chemical technology ,TP1-1185 - Abstract
The purpose of this study was to enhance the scratch resistance of polycarbonate copolymer by using 3,3′-dibenzoyl-4,4′-dihydroxybiphenyl (DBHP) monomer, containing benzoyl moieties on the ortho positions. DBHP monomer was synthesized from 4,4′-dihydroxybiphenyl and benzoyl chloride, followed by the Friedel-Craft rearrangement reaction with AlCl3. The polymerizations were conducted following the low-temperature procedure, which is carried out in methylene chloride by using triphosgene, triethylamine, bisphenol-A, and DBHP. The chemical structures of the polycarbonate copolymers were confirmed by 1H-NMR. The thermal properties of copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry, and also surface morphologies were assessed by atomic force microscopy. The scratch resistance of homopolymer film (100 μm) changed from 6B to 1B, and the contact angle of a sessile water drop onto the homopolymer film also increased.
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- 2016
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11. A Study on the Fuel Economy Potential of Parallel and Power Split Type Hybrid Electric Vehicles
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Hyunhwa Kim, Junbeom Wi, Jiho Yoo, Hanho Son, Chiman Park, and Hyunsoo Kim
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hybrid electric vehicle (HEV) ,transmission mounted electric device (TMED) type ,number of gear steps ,power split type ,fuel economy potential ,dynamic programming ,Technology - Abstract
What is the best number of gear steps for parallel type hybrid electric vehicles (HEVs) and what are the pros and cons of the power split type HEV compared to the parallel type have been interesting issues in the development of HEVs. In this study, a comparative analysis was performed to evaluate the fuel economy potential of a parallel HEV and a power split type HEV. First, the fuel economy potential of the parallel HEV was investigated for the number of gear steps. Four-speed, six-speed, and eight-speed automatic transmissions (ATs) and a continuously variable transmission (CVT) were selected, and their drivetrain losses were considered in the dynamic programming (DP). It was found from DP results that the power electronics system (PE) loss decreased because the magnitude of the motor load leveling power decreased as the number of gear steps increased. On the other hand, the drivetrain losses including the electric oil pump (EOP) loss increased with increasing gear step. The improvement rate from the 4-speed to the 6-speed was the greatest, while it decreased for the higher gear step. The fuel economy of the CVT HEV was rather low due to the large EOP loss in spite of the reduced PE loss. In addition, the powertrain characteristics of the parallel HEV were compared with the power split type HEV. In the power split type HEV, the PE loss was almost double compared to that of the parallel HEV because two large capacity motor-generators were used. However, the drivetrain loss and EOP loss of the power split type HEV were found to be much smaller due to its relatively simple architecture. It is expected that the power characteristics of the parallel and power split type HEVs obtained from the DP results can be used in the development of HEV systems.
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- 2018
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12. Computational design of binding proteins to EGFR domain II.
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Yoon Sup Choi, Soomin Yoon, Kyung-Lock Kim, Jiho Yoo, Parkyong Song, Minsoo Kim, Young-Eun Shin, Won Jun Yang, Jung-eun Noh, Hyun-Soo Cho, Sanguk Kim, Junho Chung, and Sung Ho Ryu
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Medicine ,Science - Abstract
We developed a process to produce novel interactions between two previously unrelated proteins. This process selects protein scaffolds and designs protein interfaces that bind to a surface patch of interest on a target protein. Scaffolds with shapes complementary to the target surface patch were screened using an exhaustive computational search of the human proteome and optimized by directed evolution using phage display. This method was applied to successfully design scaffolds that bind to epidermal growth factor receptor (EGFR) domain II, the interface of EGFR dimerization, with high reactivity toward the target surface patch of EGFR domain II. One potential application of these tailor-made protein interactions is the development of therapeutic agents against specific protein targets.
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- 2014
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13. Studies of Grafted and Sulfonated Spiro Poly(isatin-ethersulfone) Membranes by Super Acid-Catalyzed Reaction
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Lei Jin, Hohyoun Jang, Jiho Yoo, Jaeseong Ha, Kunyoung Choi, Taewook Ryu, Sungkwun Lee, and Whangi Kim
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PEM ,super acid ,spiro structure ,dimensional stability ,proton conductivity ,carbon-carbon linkage ,Organic chemistry ,QD241-441 - Abstract
Spiro poly(isatin-ethersulfone) polymers were prepared from isatin and bis-2,6-dimethylphenoxyphenylsulfone by super acid catalyzed polyhydroxyalkylation reactions. We designed and synthesized bis-2,6-dimethylphenoxyphenylsulfone, which is structured at the meta position steric hindrance by two methyl groups, because this structure minimized crosslinking reaction during super acid catalyzed polymerization. In addition, sulfonic acid groups were structured in both side chains and main chains to form better polymer chain morphology and improve proton conductivity. The sulfonation reactions were performed in two steps which are: in 3-bromo-1-propanesulfonic acid potassium salt and in con. sulfuric acid. The membrane morphology was studied by tapping mode atomic force microscope (AFM). The phase difference between the hydrophobic polymer main chain and hydrophilic sulfonated units of the polymer was shown to be the reasonable result of the well phase separated structure. The correlations of proton conductivity, ion exchange capacity (IEC) and single cell performance were clearly described with the membrane morphology.
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- 2016
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14. Synthesis and Characterization of Sulfonated Poly(Phenylene) Containing a Non-Planar Structure and Dibenzoyl Groups
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Hohyoun Jang, Sabuj Chandra Sutradhar, Jiho Yoo, Jaeseong Ha, Jaeseung Pyo, Chaekyun Lee, Taewook Ryu, and Whangi Kim
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PEMFC ,π–π interaction ,proton conductivity ,carbon-carbon coupling ,nickel catalyst ,Technology - Abstract
Polymers for application as sulfonated polyphenylene membranes were prepared by nickel-catalyzed carbon-carbon coupling reaction of bis(4-chlorophenyl)-1,2-diphenylethylene (BCD) and 1,4-dichloro-2,5-dibenzoylbenzene (DCBP). Conjugated cis/trans isomer (BCD) had a non-planar conformation containing four peripheral aromatic rings that facilitate the formation of π–π interactions. 1,4-Dichloro-2,5-dibenzoylbenzene was synthesized from the oxidation reaction of 2,5-dichloro-p-xylene, followed by Friedel-Crafts reaction with benzene. DCBP monomer had good reactivity in polymerization affecting the activity of benzophenone as an electron-withdrawing group. The polyphenylene was sulfonated using concentrated sulfuric acid. These polymers without any ether linkages on the polymer backbone were protected from nucleophilic attack by hydrogen peroxide, hydroxide anion, and radicals generated by polymer electrolyte membrane fuel cell (PEMFC) operation systems. The mole fraction of the sulfonic acid groups was controlled by varying the mole ratio of bis(4-chlorophenyl)-1,2-diphenylethylene in the copolymer. In comparison with Nafion 211® membrane, these SBCDCBP membranes showed ion exchange capacity (IEC) ranging from 1.04 to 2.07 meq./g, water uptake from 36.5% to 69.4%, proton conductivity from 58.7 to 101.9 mS/cm, and high thermal stability.
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- 2016
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15. Structural basis of Ca2+ uptake by mitochondrial calcium uniporter in mitochondria: a brief review
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Jiho Yoo
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General Medicine ,Molecular Biology ,Biochemistry - Published
- 2022
16. Understanding the structural basis of mitochondrial calcium uptake by mitochondrial calcium uniporter
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Jiho Yoo
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- 2022
17. Structure-Based Insight on the Mechanism of N-Glycosylation Inhibition by Tunicamycin
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Danbi Yoon, Ju Heun Moon, Anna Cho, Hyejoon Boo, Jeong Seok Cha, Yoonji Lee, and Jiho Yoo
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Cell Biology ,General Medicine ,Molecular Biology - Published
- 2023
18. Supplementary figure 2 from GC1118, an Anti-EGFR Antibody with a Distinct Binding Epitope and Superior Inhibitory Activity against High-Affinity EGFR Ligands
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Jonghwa Won, Hyun-Soo Cho, Dong Geon Kim, Heekyoung Yang, Do-Hyun Nam, Yeup Yoon, Yeon-Gil Kim, Se-Ho Kim, Kwang-Won Hong, YingJin Kang, Kuglae Kim, Ki Hwan Chang, Kyuhyun Lee, Tae Wook Park, Shi-Nai Lee, Jae-Chul Lee, Hyung-Suk Hur, Eun Hee Lee, Minkyu Hur, Min-Soo Kim, Jiho Yoo, and Yangmi Lim
- Abstract
Supplementary Figure 2. The EGFR-GC1118 interaction is not disrupted by excess amounts of high- or low-affinity EGFR ligands. The indicated colorectal cancer cell lines were pre-incubated with 0.1 ug/ml of cetuximab or GC1118 for 2 h prior to the addition of EGFR ligands for 10 min (EGF, HB-EGF, BTC, and TGF-�, 20~500 ng/ml; AREG and EREG, 40~1000 ng/ml). The blue and red lines indicate the relative % of cetuximab and GC1118, respectively, bound to EGFR in the presence of competing ligands compared with bound antibodies in the absence of blocking ligands. Antibody binding to EGFR was assessed by measuring the fluorescence intensity using flow cytometry. The results are expressed as the average{plus minus}SE of % maximal binding of the antibody of triplicate experiments.
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- 2023
19. Supplementary figure 1 from GC1118, an Anti-EGFR Antibody with a Distinct Binding Epitope and Superior Inhibitory Activity against High-Affinity EGFR Ligands
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Jonghwa Won, Hyun-Soo Cho, Dong Geon Kim, Heekyoung Yang, Do-Hyun Nam, Yeup Yoon, Yeon-Gil Kim, Se-Ho Kim, Kwang-Won Hong, YingJin Kang, Kuglae Kim, Ki Hwan Chang, Kyuhyun Lee, Tae Wook Park, Shi-Nai Lee, Jae-Chul Lee, Hyung-Suk Hur, Eun Hee Lee, Minkyu Hur, Min-Soo Kim, Jiho Yoo, and Yangmi Lim
- Abstract
Supplementary Figure 1. Kinetic binding interactions between GC1118 and EGFR as analyzed by SPR. SPR sensorgrams were obtained from injections of (A) GC1118 or (B) cetuximab over an EGFR-immobilized surface at a flow rate of 30 µl/min. The results of a quantitative evaluation of the experimental data are shown in Supplementary Table 2.
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- 2023
20. Supplementary table 1 from GC1118, an Anti-EGFR Antibody with a Distinct Binding Epitope and Superior Inhibitory Activity against High-Affinity EGFR Ligands
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Jonghwa Won, Hyun-Soo Cho, Dong Geon Kim, Heekyoung Yang, Do-Hyun Nam, Yeup Yoon, Yeon-Gil Kim, Se-Ho Kim, Kwang-Won Hong, YingJin Kang, Kuglae Kim, Ki Hwan Chang, Kyuhyun Lee, Tae Wook Park, Shi-Nai Lee, Jae-Chul Lee, Hyung-Suk Hur, Eun Hee Lee, Minkyu Hur, Min-Soo Kim, Jiho Yoo, and Yangmi Lim
- Abstract
Supplementary Table 1. X-ray data collection and refinement statistics.
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- 2023
21. Supplementary method from GC1118, an Anti-EGFR Antibody with a Distinct Binding Epitope and Superior Inhibitory Activity against High-Affinity EGFR Ligands
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Jonghwa Won, Hyun-Soo Cho, Dong Geon Kim, Heekyoung Yang, Do-Hyun Nam, Yeup Yoon, Yeon-Gil Kim, Se-Ho Kim, Kwang-Won Hong, YingJin Kang, Kuglae Kim, Ki Hwan Chang, Kyuhyun Lee, Tae Wook Park, Shi-Nai Lee, Jae-Chul Lee, Hyung-Suk Hur, Eun Hee Lee, Minkyu Hur, Min-Soo Kim, Jiho Yoo, and Yangmi Lim
- Abstract
Surface plasmon resonance (SPR)
- Published
- 2023
22. Methotrexate recognition by the human reduced folate carrier SLC19A1
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Nicholas J. Wright, Justin G. Fedor, Han Zhang, Pyeonghwa Jeong, Yang Suo, Jiho Yoo, Jiyong Hong, Wonpil Im, and Seok-Yong Lee
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Multidisciplinary ,Biophysics ,Article - Abstract
Folates are essential nutrients with important roles as cofactors in one-carbon transfer reactions, being heavily utilized in the synthesis of nucleic acids and the metabolism of amino acids during cell division(1,2). Mammals lack de novo folate synthesis pathways and thus rely on folate uptake from the extracellular milieu(3). The human reduced folate carrier (hRFC, also known as SLC19A1) is the major importer of folates into the cell(1,3), as well as chemotherapeutic agents such as methotrexate(4–6). As an anion exchanger, RFC couples the import of folates and antifolates to anion export across the cell membrane and it is a major determinant in methotrexate (antifolate) sensitivity as genetic variants and its depletion exhibit drug resistance(4–8). Despite its importance, the molecular basis of substrate specificity by hRFC remains unclear. Here we present cryo-electron microscopy structures of hRFC, in the apo state and captured in complex with methotrexate. Combined with molecular dynamics simulations and functional experiments, our study uncovers key determinants of hRFC transport selectivity amongst folates and antifolate drugs while shedding light on important features of anion recognition by hRFC.
- Published
- 2022
23. Untact Management of Patients with Chronic Kidney Diseases
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유승호 ( Seungho Yoo ), 서아론 ( Aaron Su ), and 유지호 ( Jiho Yoo )
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Traditional medicine ,business.industry ,Medicine ,business - Published
- 2021
24. Recent trend in thermal catalytic low temperature CO2 methanation: A critical review
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Jim Patel, Jiho Yoo, Chao’en Li, Seng Lim, Hermawan Prajitno, Yunxia Yang, and Woojin Lee
- Subjects
Power to gas ,business.industry ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,Methane ,0104 chemical sciences ,Renewable energy ,chemistry.chemical_compound ,Fuel gas ,chemistry ,Methanation ,Greenhouse gas ,Environmental science ,0210 nano-technology ,business ,Process engineering ,Polymer electrolyte membrane electrolysis ,Hydrogen production - Abstract
CO2 utilization technologies can not only provide a pathway to reduce greenhouse gas emissions but may also enable renewable energy to be incorporated into important materials used in the society such as fuel and chemicals. Power to gas (PtG) technologies, especially Power to methane has been deemed as one of the promising pathways for the conversion of CO2 into valuable gaseous fuel. Many reports have reviewed the academic literature related to CO2 methanation. While the benefits of high temperature methanation for overall process efficiency are well understood, the potential for low-temperature methanation is less understood. In particular the opportunities that arise from coupling a low-temperature methanation process with low temperature hydrogen production technologies, such as PEM electrolysis, have received little attention. It is therefore considered valuable to provide a critical review of the state of the art of this technology at low temperature conditions for the interests of broader research community. In this paper we focus on the recent work around low temperature CO2 methanation including reaction thermodynamics and kinetics, catalyst materials including supports and promoters, and suitable reactor technologies. We discuss each of these critical aspects of the technology and identify key challenges and opportunities for low temperature CO2 methanation (methanation conducted at temperatures less than 300 °C). As part of this paper, we also present the results of an ASPEN Plus simulation study based on data available from the literature to highlight the potential energy efficiency gains of a low temperature methanation process.
- Published
- 2021
25. Industrializing AI/ML during the end-to-end drug discovery process
- Author
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Jiho Yoo, Tae Yong Kim, InSuk Joung, and Sang Ok Song
- Subjects
Structural Biology ,Molecular Biology - Published
- 2023
26. Cryo-EM structure determination of the human reduced folate carrier SLC19A1 in complex with methotrexate
- Author
-
Nicholas J. Wright, Justin G. Fedor, Han Zhang, Pyeonghwa Jeong, Yang Suo, Jiho Yoo, Jiyong Hong, Wonpil Im, and Seok-Yong Lee
- Subjects
Biophysics - Published
- 2023
27. Efficient learning of non-autoregressive graph variational autoencoders for molecular graph generation
- Author
-
Youn-Suk Choi, Seokho Kang, Youngchun Kwon, Won-Joon Son, Dongseon Lee, and Jiho Yoo
- Subjects
0301 basic medicine ,Theoretical computer science ,Graph neural networks ,Computer science ,Variational autoencoder ,Library and Information Sciences ,01 natural sciences ,lcsh:Chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Reinforcement learning ,Molecular graph ,Physical and Theoretical Chemistry ,lcsh:T58.5-58.64 ,business.industry ,lcsh:Information technology ,Deep learning ,Computer Graphics and Computer-Aided Design ,Autoencoder ,Graph neural network ,Graph ,0104 chemical sciences ,Computer Science Applications ,010404 medicinal & biomolecular chemistry ,030104 developmental biology ,chemistry ,Autoregressive model ,lcsh:QD1-999 ,Learning methods ,Artificial intelligence ,business ,Research Article - Abstract
With the advancements in deep learning, deep generative models combined with graph neural networks have been successfully employed for data-driven molecular graph generation. Early methods based on the non-autoregressive approach have been effective in generating molecular graphs quickly and efficiently but have suffered from low performance. In this paper, we present an improved learning method involving a graph variational autoencoder for efficient molecular graph generation in a non-autoregressive manner. We introduce three additional learning objectives and incorporate them into the training of the model: approximate graph matching, reinforcement learning, and auxiliary property prediction. We demonstrate the effectiveness of the proposed method by evaluating it for molecular graph generation tasks using QM9 and ZINC datasets. The model generates molecular graphs with high chemical validity and diversity compared with existing non-autoregressive methods. It can also conditionally generate molecular graphs satisfying various target conditions.
- Published
- 2019
28. Deep-learning-based inverse design model for intelligent discovery of organic molecules
- Author
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Hyo Sug Lee, Youn-Suk Choi, Won-Joon Son, Sangmo Kim, Youngchun Kwon, Inkoo Kim, Young Min Nam, Jiho Yoo, Seokho Kang, Yongsik Jung, Dongseon Lee, Sunghan Kim, Kyungdoc Kim, Jhun-mo Son, Sungwoo Hwang, and Jai-Kwang Shin
- Subjects
Structure (mathematical logic) ,lcsh:Computer software ,010304 chemical physics ,Artificial neural network ,Computer science ,Process (engineering) ,business.industry ,Deep learning ,Material Design ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Computer Science Applications ,Recurrent neural network ,lcsh:QA76.75-76.765 ,Mechanics of Materials ,Modeling and Simulation ,0103 physical sciences ,lcsh:TA401-492 ,General Materials Science ,lcsh:Materials of engineering and construction. Mechanics of materials ,Artificial intelligence ,business ,Host (network) ,Machine code - Abstract
The discovery of high-performance functional materials is crucial for overcoming technical issues in modern industries. Extensive efforts have been devoted toward accelerating and facilitating this process, not only experimentally but also from the viewpoint of materials design. Recently, machine learning has attracted considerable attention, as it can provide rational guidelines for efficient material exploration without time-consuming iterations or prior human knowledge. In this regard, here we develop an inverse design model based on a deep encoder-decoder architecture for targeted molecular design. Inspired by neural machine language translation, the deep neural network encoder extracts hidden features between molecular structures and their material properties, while the recurrent neural network decoder reconstructs the extracted features into new molecular structures having the target properties. In material design tasks, the proposed fully data-driven methodology successfully learned design rules from the given databases and generated promising light-absorbing molecules and host materials for a phosphorescent organic light-emitting diode by creating new ligands and combinatorial rules. Tell your computer the materials properties you need, and it will design the molecule you are looking for. Kyungdoc Kim and colleagues from Samsung and Sungkyunkwan University, Republic of Korea, have developed two computer algorithms that work together for this purpose. The first algorithm looks at a database of known organic molecules and their properties, and finds abstract rules to describe the structure/property relationships; the second one uses these rules to design new molecular structures expected to have the same targeted properties. Using this approach, the researchers have already proposed molecules able to absorb light of a desired color, and materials for the realization of stable and efficient organic displays emitting in the blue. The technique might be applied to discover novel molecules and design rules relevant to a broader range of applications.
- Published
- 2018
29. Low-Rank Coal Supported Ni Catalysts for CO2 Methanation
- Author
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Sihyun Lee, Donghyuk Chun, Sangdo Kim, Hokyung Choi, Soo-Hyun Kim, Hyuk Im, Jiho Yoo, Yunxia Yang, and Renata Lippi
- Subjects
Control and Optimization ,Materials science ,magnesia ,Catalyst support ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,carbon support ,CO2 methanation ,low-rank coal ,nickel ,ceria ,01 natural sciences ,lcsh:Technology ,Catalysis ,Metal ,Adsorption ,Methanation ,Coal ,Electrical and Electronic Engineering ,Engineering (miscellaneous) ,Renewable Energy, Sustainability and the Environment ,business.industry ,lcsh:T ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Nickel ,Chemical engineering ,chemistry ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Dispersion (chemistry) ,business ,Energy (miscellaneous) - Abstract
As renewable energy source integration increases, P2G technology that can store surplus renewable power as methane is expected to expand. The development of a CO2 methanation catalyst, one of the core processes of the P2G concept, is being actively conducted. In this work, low-rank coal (LRC) was used as a catalyst support for CO2 methanation, as it can potentially enhance the diffusion and adsorption behavior by easily controlling the pore structure and composition. It can also improve the process efficiency owing to its simplicity (no pre-reduction step) and high thermal conductivity, compared to conventional metal oxide-supported catalysts. A screening of single metals (Ni, Co, Ru, Rh, and Pd) on LRC was performed, which showed that Ni was the most active. When Ni on the LRC catalyst was doped with a promoter (Ce and Mg), the CO2 conversion percentage increased by >10% compared to that of the single Ni catalyst. When the CO2 methanation activity was compared at 250–500 °C, the Ce-doped Ni/Eco and Mg-doped Ni/Eco catalysts showed similar or better activity than the commercial metal oxide-supported catalyst. In addition, the catalytic performance remained stable even after the test for an extended time (~200 h). The results of XRD, TEM, and TPR showed that highly efficient LRC-based CO2 methanation catalysts can be made when the metal dispersion and composition are modified.
- Published
- 2021
30. Valorization of Indonesian Wood Wastes through Pyrolysis: A Review
- Author
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Wahyu Hidayat, Jiho Yoo, Dewi Agustina Iryani, Udin Hasanudin, Sangdo Kim, Agus Haryanto, and Sihyun Lee
- Subjects
Control and Optimization ,rubberwood ,020209 energy ,Energy Engineering and Power Technology ,Biomass ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,lcsh:Technology ,Wood processing ,Biochar ,0202 electrical engineering, electronic engineering, information engineering ,biochar ,Electrical and Electronic Engineering ,Rubberwood ,Charcoal ,Engineering (miscellaneous) ,0105 earth and related environmental sciences ,biology ,Renewable Energy, Sustainability and the Environment ,business.industry ,sengon ,lcsh:T ,Building and Construction ,Pulp and paper industry ,biology.organism_classification ,pyrolysis ,renewable energy ,Renewable energy ,Tectona ,meranti ,visual_art ,visual_art.visual_art_medium ,Environmental science ,business ,Pyrolysis ,Energy (miscellaneous) - Abstract
The wood processing industry produces a significant amount of wood waste. Biomass valorization through pyrolysis has the potential to increase the added value of wood wastes. Pyrolysis is an important thermochemical process that can produce solid, liquid, and gas products. This paper aims to review the pyrolysis of wood wastes from Indonesia, including teak wood (Tectona grandis), meranti (Shorea sp.), sengon (Paraserianthes falcataria (L) Nielsen), and rubberwood (Hevea brasiliensis). The review is based on an in-depth study of reliable literatures, statistical data from government agencies, and direct field observations. The results showed that pyrolysis could be a suitable process to increase the added value of wood waste. Currently, slow pyrolysis is the most feasible for Indonesia, with the main product of charcoal. The efficiency of the slow pyrolysis process can be increased by harvesting also liquid and gaseous products. The use of the main product of pyrolysis in the form of charcoal needs to be developed and diversified. Charcoal is not only used for fuel purposes but also as a potential soil improvement agent.
- Published
- 2021
31. Product Characteristics from the Torrefaction of Bamboo Pellets in Oxidative Atmosphere
- Author
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Jiho Yoo, Christine Wulandari, Lisman Suryanegara, Udin Hasanudin, Sihyun Lee, Sangdo Kim, Jacky Michael Pah, Wahyu Hidayat, Agus Haryanto, and Dewi Agustina Iryani
- Subjects
Bamboo ,Materials science ,biology ,digestive, oral, and skin physiology ,Pellet ,Pellets ,Heat of combustion ,Dendrocalamus asper ,Relative humidity ,biology.organism_classification ,Torrefaction ,Pulp and paper industry ,Equilibrium moisture content - Abstract
Bamboo is a potential energy crop for the future and an attractive option to replace wood due to its fast growth, high productivity, and essential fuel characteristics such as low ash content, alkali index, and high heating value. This study aimed to evaluate the effects of torrefaction on the physical properties of andong (Gigantochloa pseudoarundinacea) and betung (Dendrocalamus asper) bamboo pellets. Torrefaction of bamboo pellets was conducted in an oxidative atmosphere using an electric furnace at 280°C with a residence time of 40 min. The results showed that oxidative torrefaction caused a decrease in the equilibrium moisture content of bamboo pellets. Water resistance and water adsorption test showed that the torrefied pellets are more resistant to water and relative humidity than the non-torrefied pellet, which is beneficial when the pellet is stored for a long time and in humid conditions. The results also showed that the density of bamboo pellets decreased after torrefaction.
- Published
- 2021
32. Effects of Meranti Biochar Addition on the Root Growth of Falcataria Moluccana Seedlings
- Author
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Wahyu Hidayat, Irwan Sukri Banuwa, Sangdo Kim, Ainin Niswati, Aulia Asmara Loka, Sihyun Lee, Hendra Prasetia, Jiho Yoo, Melya Riniarti, and Udin Hasanudin
- Subjects
Topsoil ,Horticulture ,biology ,Falcataria ,Germination ,Chemistry ,Biochar ,Falcataria moluccana ,Biomass ,Sowing ,Shorea ,biology.organism_classification - Abstract
The purpose of this study was to determine the effect of biochar application in growing media on the development ofthe roots of Falcataria moluccanna seedlings. Biochar from the waste of meranti wood (Shorea sp.) was produced bya slow pyrolysis process using a traditional kiln at a temperature of 600°C. The study was arranged in a completelyrandomized design with three treatments and 15 replications. The treatments were 100% topsoil (control), 5% biocharand 10% biochar addition to the planting media. F. moluccana was grown from seeds germinated in sand media. Afterone month, F. moluccana was transferred to polybags filled with planting media according to the treatment. Theobservations were conducted for four months. The parameters observed were root length, root volume, and root biomass. The results showed that the addition of biochar indicated a very significant difference in root length, root volume, and root biomass compared to the control. However, the two dosages showed no significantly different effect on root growth. This study concluded that the addition of 5% biochar meranti in the planting media could increase theroot growth of F. moluccana. Keywords: Biochar, Falcataria moluccanna, root growth.
- Published
- 2021
33. Peningkatan Kualitas Pelet Tandan Kosong Kelapa Sawit melalui Torefaksi Menggunakan Reaktor Counter-Flow Multi Baffle (COMB)
- Author
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Sangdo Kim, Sihyun Lee, Udin Hasanudin, Agus Haryanto, Indra Gumay Febryano, Tri Yulianto, Dewi Agustina Iryani, Jiho Yoo, Irma Thya Rani, Wahyu Hidayat, BPDPS, and KIER
- Subjects
torrefaction ,Materials science ,oil palm empty fruit bunches ,lcsh:TP1-1185 ,chemical engineering ,renewable ,Torrefaction ,Pulp and paper industry ,counter-flow multi baffle ,lcsh:Chemical technology ,Counter-Flow Multi Baffle - Abstract
Oil palm (Elaeis guineensis) empty fruit bunches (EFB) have not been utilized optimally. Currently, it is considered as a resource with low economic value. This biomass can be converted into bioenergy through a torrefaction process. Torrefaction is a mild pyrolysis at temperatures ranging between 200 and 300 °C, and it is generally performed under an inert atmosphere. The objective of this study was to evaluate the effects of torrefaction using Counter-Flow Multi Baffle (COMB) on the properties of oil palm EFB pellets. Torrefaction was conducted at 280 °C temperature with a residence time of 4 minutes. The results showed a decrease in the equilibrium moisture content and an increase in hydrophobicity after torrefaction using the COMB reactor. The change in the hygroscopic property could make the oil palm EFB pellet more stable against chemical oxidation and microbial degradation, hence self-heating and auto-ignition during storage could be prevented. The heating value of biomass increased after torrefaction. Torrefaction with the COMB reactor resulted in a heating value of 17.90 MJ/kg, which is comparable with the results of oxidative torrefaction (with longer residence time) of 18.28 MJ/kg. The results suggested that torrefaction using the COMB reactor could provide a great improvement in the quality of the bioenergetic properties of oil palm EFB pellets. However, the high ash content of the EFB pellets implied that the EFB pellets suitable for a small-scale application, but not yet for cofiring in power plants or as a feedstock for gasification . Keywords : Counter-Flow Multi Baffle; oil palm empty fruit bunches; renewable; torrefaction A B S T R A K Tandan kosong kelapa sawit ( Elaeis guineensis ) belum dimanfaatkan secara optimal. Saat ini bahan tersebut masih dianggap sebagai sumber daya bernilai ekonomi rendah. Tandan kosong kelapa sawit (TKKS) dapat dikonversi menjadi bioenergi melalui proses torefaksi. Torefaksi merupakan proses pirolisis ringan pada suhu berkisar antara 200 dan 300 °C dan umumnya dilakukan di bawah kondisi inert. Penelitian ini bertujuan untuk mengetahui pengaruh torefaksi dengan reaktor Counter-Flow Multi Baffle (COMB) terhadap sifat-sifat pelet TKKS. Torefaksi dilakukan pada suhu 280 °C dengan waktu tinggal 4 menit. Hasil penelitian menunjukkan bahwa torefaksi menyebabkan penurunan kadar air kesetimbangan dan menjadi hidrofobik setelah torefaksi dengan reaktor COMB. Perbaikan sifat higroskopis dapat membuat pelet TKKS lebih stabil terhadap oksidasi kimia dan degradasi mikroba, sehingga pemanasan sendiri dan pembakaran spontan selama penyimpanan dapat dicegah. Nilai kalor biomassa meningkat setelah torefaksi. Torefaksi dengan reaktor COMB menghasilkan nilai kalor 17,90 MJ/kg, yang sebanding dengan hasil torefaksi oksidatif dengan waktu tinggal lebih lama, sebesar 18,28 MJ/kg. Hasil penelitian menunjukkan bahwa torefaksi dengan reaktor COMB dapat meningkatkan kualitas energi pelet TKKS. Tetapi pelet TKKS masih memiliki kadar abu yang tinggi sehingga biomassa hasil torefaksi belum sesuai untuk cofiring di pembangkit listrik atau sebagai bahan baku untuk gasifikasi. Kata kunci: Counter-Flow Multi Baffle ; tandan kosong kelapa sawit; terbarukan; torefaksi
- Published
- 2020
34. MolFactory: Standigm integrated AI drug discovery platform
- Author
-
Sang Ok Song, Jiho Yoo, Siu Kim, Jae Hong Shin, Sanghyung Jin, Chiwon Son, Jonghwan Chae, Minkyu Ha, and Hanjo Kim
- Published
- 2020
35. Cryo-EM structure of a mitochondrial calcium uniporter
- Author
-
Gabriel C. Lander, Jiho Yoo, Mark A. Herzik, Seok-Yong Lee, Mengyu Wu, and Ying Yin
- Subjects
0301 basic medicine ,Cryo-electron microscopy ,Protein Conformation ,Amino Acid Motifs ,Biophysics ,chemistry.chemical_element ,Calcium ,Article ,Neurospora crassa ,Turn (biochemistry) ,Fungal Proteins ,03 medical and health sciences ,0302 clinical medicine ,Protein structure ,Conserved Sequence ,Ion channel ,Fungal protein ,Multidisciplinary ,biology ,Voltage-dependent calcium channel ,Cryoelectron Microscopy ,biology.organism_classification ,Transmembrane domain ,030104 developmental biology ,Models, Chemical ,chemistry ,Mitochondrial matrix ,Mutagenesis ,Calcium Channels ,Protein Multimerization ,Sequence motif ,030217 neurology & neurosurgery - Abstract
A channel for calcium Maintaining the correct balance of calcium concentrations between the cytosol and the mitochondria is essential for cellular physiology. A calcium-selective channel called the mitochondrial calcium uniporter (MCU) mediates calcium entry into mitochondria. Yoo et al. report the high-resolution structure of MCU from Neurospora crassa. The channel is formed by four MCU protomers with differing symmetry between the soluble and membrane domains. The structure, together with mutagenesis, suggests that two acidic rings inside the channel provide the selectivity for calcium. Science , this issue p. 506
- Published
- 2018
36. GlcNAc-1-P-transferase-tunicamycin complex structure reveals basis for inhibition of N-glycosylation
- Author
-
Ellene H. Mashalidis, Alvin C. Y. Kuk, Jiho Yoo, Kazuki Yamamoto, Satoshi Ichikawa, Benjamin Kaeser, and Seok-Yong Lee
- Subjects
0301 basic medicine ,Models, Molecular ,Glycosylation ,animal structures ,Transferases (Other Substituted Phosphate Groups) ,Bacterial cell structure ,Article ,Substrate Specificity ,03 medical and health sciences ,chemistry.chemical_compound ,N-linked glycosylation ,Bacterial Proteins ,Structural Biology ,Transferases ,Humans ,Magnesium ,Enzyme Inhibitors ,Molecular Biology ,chemistry.chemical_classification ,Natural product ,030102 biochemistry & molecular biology ,Endoplasmic reticulum ,Tunicamycin ,3. Good health ,Anti-Bacterial Agents ,carbohydrates (lipids) ,030104 developmental biology ,Enzyme ,chemistry ,Biochemistry ,Protein Multimerization ,Antibacterial activity ,Protein Binding - Abstract
Summary N-linked glycosylation is a predominant post-translational modification of protein in eukaryotes, and its dysregulation is the etiology of several human disorders. The enzyme UDP-N-acetylglucosamine:dolichyl-phosphate N-acetylglucosaminephosphotransferase (GlcNAc-1-P-transferase, GPT) catalyzes the first and committed step of N-linked glycosylation in the endoplasmic reticulum membrane, and it is the target of the natural product tunicamycin. Tunicamycin has potent antibacterial activity by inhibiting the bacterial cell wall synthesis enzyme MraY, but its usefulness as an antibiotic is limited by off-target inhibition of human GPT. Our understanding of how tunicamycin inhibits N-linked glycosylation and efforts to selectively target MraY are hampered by a lack of structural information. Here we present crystal structures of human GPT in complex with tunicamycin. Our structural and functional analyses reveal the difference between GPT and MraY in their mechanisms of inhibition by tunicamycin. We demonstrate that this difference could be exploited for the design of MraY-specific inhibitors as potential antibiotics.
- Published
- 2018
37. Low-rank coal and poly fatty acid distillate characterization as a preparation of coal upgrading palm oil technology
- Author
-
Sihyun Lee, Jiho Yoo, and Datin Fatia Umar
- Subjects
technology, industry, and agriculture ,otorhinolaryngologic diseases ,respiratory system ,complex mixtures ,respiratory tract diseases - Abstract
The utilization of low-rank coal is restricted by such factors as high moisture content, low heating value, high propensity to low-temperature oxidation, spontaneous combustion, etc. Some coal upgrading technologies to reduce the moisture content have been developed, one of them is coal upgrading palm oil technology using palm fatty acid distillate as an additive to keep the stability of moisture content in the coal after the process. To study the possibility of the upgrading technology application in Indonesia, some studies have been conducted. The study covered coal characterization such as proximate, ultimate and calorific value, palm fatty acid distillate for stabilization of upgraded low-rank coal and coal upgrading by coal upgrading palm oil technology in laboratory scale. By using 7 Indonesian low-rank coals and 4 palm fatty acid distillates, it is confirmed that the coal upgrading palm oil technology is effective to reduce the moisture content and increase the calorific value of low rank coal.
- Published
- 2021
38. Determination of oxygen nonstoichiometry in SrFeO3−δby solid-state Coulometric titration
- Author
-
Jiho Yoo, Chung-Yul Yoo, Allan J. Jacobson, and Ji Haeng Yu
- Subjects
Phase transition ,Materials science ,020209 energy ,Inorganic chemistry ,Solid-state ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Oxygen ,Coulometry ,chemistry ,0202 electrical engineering, electronic engineering, information engineering ,Materials Chemistry ,Ceramics and Composites ,0210 nano-technology ,Perovskite (structure) - Published
- 2017
39. Comparative Evaluation of Steam Gasification Reactivity of Indonesian Low Rank Coals
- Author
-
Paul Victor, Youngjoon Rhim, Soohyun Kim, Sangdo Kim, Jiho Yoo, Sihyun Lee, Donghyuk Chun, Hokyung Choi, and Jeonghwan Lim
- Subjects
Indonesian ,020401 chemical engineering ,Waste management ,020209 energy ,Rank (computer programming) ,0202 electrical engineering, electronic engineering, information engineering ,language ,Environmental science ,Reactivity (chemistry) ,02 engineering and technology ,0204 chemical engineering ,language.human_language ,Comparative evaluation - Published
- 2016
40. Using two dosages of biochar from shorea to improve the growth of Paraserianthes falcataria seedlings
- Author
-
Wahyu Hidayat, Ainin Niswati, Irwan Sukri Banuwa, Hendra Prasetia, Sihyun Lee, Sangdo Kim, Udin Hasanudin, Jiho Yoo, and Melya Riniarti
- Subjects
Horticulture ,biology ,Falcataria ,Dose ,Germination ,Paraserianthes falcataria ,Biochar ,Transplanting ,Shorea ,biology.organism_classification ,Scarification - Abstract
The objective of the study was to examine the effect of biochar addition on the growth of Paraserianthes falcataria seedlings. Biochar from shorea was produced using a traditional kiln at 400 °C and 600 °C. The scarification of P. falcataria seeds were conducted using hot water with temperature at 80 °C and then soaked for 24 h. The seeds were then spread on to the germination media and after germinated, the seedlings were moved to polybags contain soil and biochar. Two dosages of biochar such as 25 and 50% were applied and compared with control. The research was arranged in a completely randomized design with 15 replicates. The examination of seedlings growth was conducted one week after transplanting, then subsequently monitored every month. The results showed that the addition of biochar improved the survival rate of seedlings, height and diameter increments, root length and root volume. The results showed a potential of using biochar to improve the growth of P. falcataria seedlings in the nursery.
- Published
- 2021
41. Characteristics of biochar produced from the harvesting wastes of meranti (Shorea sp.) and oil palm (Elaeis guineensis) empty fruit bunches
- Author
-
Sihyun Lee, Jiho Yoo, Melya Riniarti, Irwan Sukri Banuwa, Wahyu Hidayat, Sangdo Kim, Hendra Prasetia, Ainin Niswati, and Udin Hasanudin
- Subjects
Horticulture ,biology ,Biochar ,Palm oil ,Shorea ,Elaeis guineensis ,biology.organism_classification - Abstract
The objective of this study was to determine the properties of biochar from meranti (Shorea sp.) and oil palm (Elaeis guineensis) empty fruit bunches (OPEFB). Biochar was produced using a traditional kiln with a temperature of 400°C and 600°C. The char yield, pH, and proximate analysis were evaluated. The results showed that the maximum char yield was obtained at 400°C, and the increase in temperature resulted in decreased char yield. At the same pyrolysis temperature, char yield was higher in meranti than OPEFB. The results revealed that the pH of meranti and OPEFB changed into basic after pyrolysis, which is essential when biochar is added to soil to neutralize soil acidity and increase the soil cation exchange capacity. The results also showed an increase of fixed carbon in meranti and OPEFB after pyrolysis at 400°C and 600°C. The higher heating values (HHV) in meranti and OPEFB increased after pyrolysis, with a remarkable increase of HHV observed in meranti than OPEFB, showing a higher potential of biochar from meranti to be used for bioenergy application than OPEFB.
- Published
- 2021
42. Deactivation Behavior of K2CO3Catalyst in the Steam Gasification of Kideco Coal
- Author
-
Jiho Yoo, Youngjoon Rhim, Paul Victor, Donghyuk Chun, Soohyun Kim, Young-Woo Rhee, Jeonghwan Lim, Hokyung Choi, Sangdo Kim, and Sihyun Lee
- Subjects
Materials science ,Chemical engineering ,business.industry ,Coal ,business ,Catalysis - Published
- 2016
43. Comparative Characterization of AFC Precipitated Using Vacuum Drying, Dilution Precipitation and Spray Drying
- Author
-
Ho Kyung Choi, Jiho Yoo, Young Joon Rhim, Young Woo Rhee, Sang Do Kim, Wan Taek Jo, Jeonghwan Lim, Ho Jung Kwon, Si Hyun Lee, and Dong Hyuk Chun
- Subjects
020401 chemical engineering ,General Chemical Engineering ,02 engineering and technology ,0204 chemical engineering ,021001 nanoscience & nanotechnology ,0210 nano-technology - Abstract
본 연구에서는 용매추출 공정 중 최종 건조 과정에서 회수방식을 달리하여 무회분석탄을 제조한 후 물리적 특성과 화학적 구조를 비교하였다. 무회분석탄 제조에는 아역청탄 등급의 Kideco coal과 극성용매인 N-methyl-2-pyrrolidone(NMP)를 사용하였으며, 회수방식으로는 감압건조, 희석침전, 분무건조 방식을 사용하였다. 제조된 무회분석탄의 물성변화를 확인하기 위해 공업분석, 원소분석, 발열량분석을 실시하였고, 화학적 구조를 알아보고자 FT-IR, NMR 분석을 하였다. 공업분석을 통해 무회분석탄의 회분함량이 원탄에 비해 줄어든 것을 확인하였다. FT-IR 분석 결과 감압건조로 회수한 샘플은 추출용매의 피크가 나타나는 반면 희석침전방식으로 제조한 무회분석탄에는 추출용매 피크가 사라지는 것을 확인하였다. 희석침전방식을 사용할 경우 다른 회수방식에 비해 저온공정이 가능하였고, 추출용매로부터 무회분석탄을 보다 확실하게 분리할 수 있었다.
- Published
- 2016
44. GC1118, an Anti-EGFR Antibody with a Distinct Binding Epitope and Superior Inhibitory Activity against High-Affinity EGFR Ligands
- Author
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Jiho Yoo, Min Soo Kim, Yeup Yoon, Tae Wook Park, Jonghwa Won, Yangmi Lim, Kwang Won Hong, Jae-Chul Lee, Yeon Gil Kim, Minkyu Hur, Do-Hyun Nam, Shi Nai Lee, Eun-Hee Lee, Se-Ho Kim, Donggeon Kim, Kyuhyun Lee, Hyung Suk Hur, Kuglae Kim, Yingjin Kang, Ki Hwan Chang, Hyun Soo Cho, and Heekyoung Yang
- Subjects
Models, Molecular ,0301 basic medicine ,Cancer Research ,medicine.drug_class ,Antineoplastic Agents ,Pharmacology ,Biology ,Antibodies, Monoclonal, Humanized ,Ligands ,Monoclonal antibody ,Epitope ,Epitopes ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Panitumumab ,Cell Proliferation ,Tumor microenvironment ,Cetuximab ,Cancer ,medicine.disease ,Xenograft Model Antitumor Assays ,ErbB Receptors ,030104 developmental biology ,Oncology ,030220 oncology & carcinogenesis ,Monoclonal ,biology.protein ,Female ,Antibody ,Colorectal Neoplasms ,Protein Binding ,medicine.drug - Abstract
The EGFR-targeted monoclonal antibodies are a valid therapeutic strategy for patients with metastatic colorectal cancer (mCRC). However, only a small subset of mCRC patients has therapeutic benefits and there are high demands for EGFR therapeutics with a broader patient pool and more potent efficacy. In this study, we report GC1118 exhibiting a different character in terms of binding epitope, affinity, mode of action, and efficacy from other anti-EGFR antibodies. Structural analysis of the EGFR–GC1118 crystal complex revealed that GC1118 recognizes linear, discrete N-terminal epitopes of domain III of EGFR, critical for EGF binding but not overlapping with those of other EGFR-targeted antibodies. GC1118 exhibited superior inhibitory activity against high-affinity EGFR ligands in terms of EGFR binding, triggering EGFR signaling, and proliferation compared with cetuximab and panitumumab. EGFR signaling driven by low-affinity ligands, on the contrary, was well inhibited by all the antibodies tested. GC1118 demonstrated robust antitumor activity in tumor xenografts with elevated expression of high-affinity ligands in vivo, whereas cetuximab did not. Considering the significant role of high-affinity EGFR ligands in modulating tumor microenvironment and inducing resistance to various cancer therapeutics, our study suggests a potential therapeutic advantage of GC1118 in terms of efficacy and a range of benefited patient pool. Mol Cancer Ther; 15(2); 251–63. ©2015 AACR.
- Published
- 2016
45. Mixed n-type electronic, oxide ion, and protonic conduction in In-doped SrTi1-xRuxO3-δ
- Author
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Allan J. Jacobson, Chan Young Park, Jiho Yoo, and Sung-Chan Nam
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Materials science ,Doping ,Analytical chemistry ,chemistry.chemical_element ,Ionic bonding ,02 engineering and technology ,Conductivity ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Thermal conduction ,01 natural sciences ,Thermal expansion ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Ionic conductivity ,Physical and Theoretical Chemistry ,0210 nano-technology ,Powder diffraction ,Indium - Abstract
As part of a study of mixed n-type electronic and ionic conductors, the conductivities of indium doped strontium ruthenium titanates were determined. The SrTi1-x-yRuxInyO3-δ (x = 0.1–0.4, y = 0–0.2) compositions were prepared by conventional solid-state synthesis. Samples were determined to be of a single phase by X-ray powder diffraction and electron probe microanalysis. The temperature and pO2 dependences of the electrical conductivities were investigated by using DC and AC four-probe methods. STRIO820 and STRIO640 have conductivity of 6.4 and 5.4 Scm−1, respectively, at 900 °C and pO2 = 1 atm. The conductivities of the In-doped samples under the same conditions were lower than that of SrTi1-xRuxO3-δ by around two orders of magnitude. For STRIO622, when pO2 was increased from 10−4 to 1 atm, the DC conductivities decreased, indicating n-type conduction. The pO2 dependence of conductivity was analyzed using the relation σT = ApO21/x + σi. STRIO622 shows significant ionic conductivity, with σi ~0.21 Scm−1 at 1000 °C. The DC conductivities of STRIO622 in reducing environments (5% H2/N2 saturated with water) show protonic conduction at low temperatures. The thermal expansion coefficients (TECs) were ~8.9–11.2 × 10−6 K−1 at 200 ≤ T ≤ 990 °C.
- Published
- 2020
46. A Study on the Fuel Economy Potential of Parallel and Power Split Type Hybrid Electric Vehicles
- Author
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Jiho Yoo, Chiman Park, Hyun-Chul Kim, Hyunhwa Kim, Junbeom Wi, and Hanho Son
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Control and Optimization ,fuel economy potential ,Powertrain ,020209 energy ,Energy Engineering and Power Technology ,Drivetrain ,power split type ,02 engineering and technology ,lcsh:Technology ,law.invention ,Oil pump ,Power split ,law ,Power electronics ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,Engineering (miscellaneous) ,Continuously variable transmission ,Mathematics ,dynamic programming ,hybrid electric vehicle (HEV) ,transmission mounted electric device (TMED) type ,number of gear steps ,Automatic transmission ,Renewable Energy, Sustainability and the Environment ,lcsh:T ,Power (physics) ,Economy ,Energy (miscellaneous) - Abstract
What is the best number of gear steps for parallel type hybrid electric vehicles (HEVs) and what are the pros and cons of the power split type HEV compared to the parallel type have been interesting issues in the development of HEVs. In this study, a comparative analysis was performed to evaluate the fuel economy potential of a parallel HEV and a power split type HEV. First, the fuel economy potential of the parallel HEV was investigated for the number of gear steps. Four-speed, six-speed, and eight-speed automatic transmissions (ATs) and a continuously variable transmission (CVT) were selected, and their drivetrain losses were considered in the dynamic programming (DP). It was found from DP results that the power electronics system (PE) loss decreased because the magnitude of the motor load leveling power decreased as the number of gear steps increased. On the other hand, the drivetrain losses including the electric oil pump (EOP) loss increased with increasing gear step. The improvement rate from the 4-speed to the 6-speed was the greatest, while it decreased for the higher gear step. The fuel economy of the CVT HEV was rather low due to the large EOP loss in spite of the reduced PE loss. In addition, the powertrain characteristics of the parallel HEV were compared with the power split type HEV. In the power split type HEV, the PE loss was almost double compared to that of the parallel HEV because two large capacity motor-generators were used. However, the drivetrain loss and EOP loss of the power split type HEV were found to be much smaller due to its relatively simple architecture. It is expected that the power characteristics of the parallel and power split type HEVs obtained from the DP results can be used in the development of HEV systems.
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- 2018
- Full Text
- View/download PDF
47. Characteristics of Binderless Briquettes for Indonesian Low-Rank Coals
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Jiho Yoo, Sihyun Lee, Jeonghwan Lim, Young Joon Rhim, Sang Do Kim, Ho Kyung Choi, and Dong Hyuk Chun
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Briquette ,Materials science ,Moisture ,business.industry ,General Chemical Engineering ,Metallurgy ,Coal ,Particle size ,Coal briquette ,business - Abstract
− The characteristics of binderless briquettes for dried low-rank coal was studied in this work. Two kinds of Indonesian coals were used to briquette after drying them in electric oven. The characteristics of briquettes have been examined by moisture contents, particle size, hydraulic force, and storing period. The optimum moisture contents of briquettes were observed at between 10 wt% and 15 wt%. The strength of coal briquette was stronger as particle size became smaller. The strength of coal briquette was proportional to the hydraulic force under 300 kN, whereas there was little difference among the briquettes made at more than 300 kN of hydraulic force. The strength of briquettes sharply decreased for a week after produced, and then showed the tendency of converging. The results from this work can be a useful guideline of manufacturing and managing upgraded coal briquettes.
- Published
- 2015
48. Evaluation of the effect of a palm acid oil coating on upgrading low rank coal
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Ho Kyung Choi, Jiho Yoo, Sang Do Kim, Sihyun Lee, Muhammad Zubair Khan, Young Joon Rhim, Jeonghwan Lim, Archi Rifella, and Dong Hyuk Chun
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Briquette ,Materials science ,Moisture ,business.industry ,General Chemical Engineering ,technology, industry, and agriculture ,Mineralogy ,General Chemistry ,Calorimetry ,respiratory system ,engineering.material ,complex mixtures ,respiratory tract diseases ,Compressive strength ,Coating ,Chemical engineering ,Volume (thermodynamics) ,otorhinolaryngologic diseases ,engineering ,Coal ,business ,Spontaneous combustion - Abstract
Indonesian low rank coal (LRC) was upgraded by the addition of palm acid oil (PAO), and the efficiency of the inhibition of spontaneous combustion, as well as the resistance to moisture readsorption, was compared with raw coal. Fluorescence microscopy images revealed that PAO was well distributed in the coal matrix during the drying process. The PAO coating the surface of coal decreased the pore volume and the surface area of the upgraded coal and improved its stability. The upgraded LRCs had higher heat calorimetry values, greater resistance to moisture readsorption, and a reduced tendency toward spontaneous combustion when compared to raw coal. In upgraded coal briquettes, PAO was present in the form of a network-like structure, which led to an increase in the compressive strength by binding the coal particles. The upgraded LRCs showed less susceptibility to isothermal oxidation due to the PAO coating on the coal particles, which suppressed the reaction of active functional groups with oxygen in the air.
- Published
- 2015
49. Differential Inhibition of Nav1.7 and Neuropathic Pain by Hybridoma-Produced and Recombinant Monoclonal Antibodies that Target Nav1.7 : Differential activities of Nav1.7-targeting monoclonal antibodies
- Author
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Jun-Ming Zhang, Di Liu, Judith A. Strong, Gang Chen, Jiho Yoo, Ma-Zhong Zhang, Qingjian Han, Yong Ho Kim, Wonseok Chang, Xin Luo, Xingrui Gong, Seok-Yong Lee, Sang-Taek Im, Sangsu Bang, and Ru-Rong Ji
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0301 basic medicine ,Male ,Sensory Receptor Cells ,Physiology ,medicine.drug_class ,Biotin ,Monoclonal antibody ,Differential inhibition ,law.invention ,NAV1.5 Voltage-Gated Sodium Channel ,Weak binding ,03 medical and health sciences ,Mice ,0302 clinical medicine ,law ,Ganglia, Spinal ,medicine ,Animals ,Humans ,Cells, Cultured ,Hybridomas ,Chemistry ,General Neuroscience ,Sodium channel ,HEK 293 cells ,NAV1.7 Voltage-Gated Sodium Channel ,Antibodies, Monoclonal ,General Medicine ,Molecular biology ,Recombinant Proteins ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,HEK293 Cells ,Hyperalgesia ,Neuropathic pain ,NAV1 ,Recombinant DNA ,Neuralgia ,Female ,Original Article ,030217 neurology & neurosurgery ,Protein Binding - Abstract
The voltage-gated Na+ channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na+ currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na+ currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na+ currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.
- Published
- 2017
50. Validation and Control Strategy to Reduce Fuel Consumption for RE-EV
- Author
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Jiho Yoo, Junbeom Wi, Wonbin Lee, Hyun-Chul Kim, Won Seok Choi, Jaewon Jung, and Hyunjong Ha
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Control (management) ,Fuel efficiency ,Environmental science ,Automotive engineering - Published
- 2017
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