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Weon KY, Kim MG, Shin S, Kim TH, Joo SH, Ma E, Jeong SW, Yoo SD, Youn YS, Shin BS. Alterations of Gefitinib Pharmacokinetics by Co-administration of Herbal Medications in Rats. Chin J Integr Med 2018; 24:460-466. [PMID: 29335861 DOI: 10.1007/s11655-017-2907-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To evaluate the potential pharmacokinetic interactions of the anticancer agent gefitinib (Iressa®) and the oriental medications Guipi Decoction (, GPD, Guibi-tang in Korean) and Bawu Decoction (, BWD, Palmul-tang in Korean). METHODS Methylcellulose (MC, control), GPD (1,200 mg/kg), or BWD (6,000 mg/kg) was orally administered to rats either as a single dose or multiple doses prior to gefitinib administration. To examine the effects of a single dose of the herbal medicines, gefitinib (10 mg/kg) was orally administered after 5 min or 1 h of MC or the herbal medicine pretreatments. To examine the effects of the multiple doses of the herbal medicines, gefitinib (10 mg/kg) was orally administered following 7 consecutive days of the administration of MC or each herbal medicine. The plasma concentrations of gefitinib were determined with liquid chromatography-tandem mass spectrometry assay. The plasma concentration-time profiles of gefitinib were analyzed with a noncompartmental analysis. RESULTS Gefitinib was rapidly absorbed and showed a monoexponential decline with an elimination half-life of 3.7-4.1 h. The pharmacokinetics of gefitinib was not affected by GPD pretreatment. However, a significantly lower maximum plasma concentration (Cmax, P<0.05) and area under the curve (P<0.05), and a delayed time to reach Cmax (Tmax, P<0.01) were observed in both single- and multipledose BWD-pretreated rats compared with the control rats. CONCLUSIONS BWD and not GPD might delay and interfere with gefitinib absorption. Further evaluations of the clinical significance of these findings are needed.
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Hwang H, Kwon T, Kim HY, Park J, Oh A, Kim B, Baik H, Joo SH, Lee K. Ni@Ru and NiCo@Ru Core-Shell Hexagonal Nanosandwiches with a Compositionally Tunable Core and a Regioselectively Grown Shell. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:1702353. [PMID: 29171686 DOI: 10.1002/smll.201702353] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/19/2017] [Indexed: 06/07/2023]
Abstract
The development of highly active electrocatalysts is crucial for the advancement of renewable energy conversion devices. The design of core-shell nanoparticle catalysts represents a promising approach to boost catalytic activity as well as save the use of expensive precious metals. Here, a simple, one-step synthetic route is reported to prepare hexagonal nanosandwich-shaped Ni@Ru core-shell nanoparticles (Ni@Ru HNS), in which Ru shell layers are overgrown in a regioselective manner on the top and bottom, and around the center section of a hexagonal Ni nanoplate core. Notably, the synthesis can be extended to NiCo@Ru core-shell nanoparticles with tunable core compositions (Ni3 Cox @Ru HNS). Core-shell HNS structures show superior electrocatalytic activity for the oxygen evolution reaction (OER) to a commercial RuO2 black catalyst, with their OER activity being dependent on their core compositions. The observed trend in OER activity is correlated to the population of Ru oxide (Ru4+ ) species, which can be modulated by the core compositions.
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Kim J, Jin H, Oh A, Baik H, Joo SH, Lee K. Synthesis of compositionally tunable, hollow mixed metal sulphide Co xNi yS z octahedral nanocages and their composition-dependent electrocatalytic activities for oxygen evolution reaction. NANOSCALE 2017; 9:15397-15406. [PMID: 28975945 DOI: 10.1039/c7nr04327a] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Hollow nanostructures such as nanocages and nanoframes can serve as advanced catalysts with their enlarged active surface areas, and hence they have been of widespread interest. Despite the recent progress in the synthesis of this class of nanomaterials, hollow nanostructures with tunable compositions and controlled morphologies have rarely been reported. Here, we report a facile synthetic route to a series of compositionally tunable, hollow mixed metal sulphide (CoxNiySz) octahedral nanocages. The sulfidation of CoO octahedral nanoparticles generates CoO@CoxSy core-shell octahedra, and the in situ etching of the CoO core and annealing yield Co9S8 (pentlandite) octahedral nanocages (ONC). The addition of a Ni precursor during the etching/annealing process of CoO@CoxSy core-shell octahedra progressively yields hollow ONC structures of Co9-xNixS8, Ni9S8, Ni9S8/β-NiS, and Ni3S2/β-NiS via cation exchange reactions. Mixed cobalt/nickel sulphide, Co9-xNixS8 ONC, shows superior oxygen evolution reaction activity to monometallic sulphide ONC structures, demonstrating the synergy between different metal species.
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Sa YJ, Kim JH, Joo SH. Recent Progress in the Identification of Active Sites in Pyrolyzed Fe−N/C Catalysts and Insights into Their Role in Oxygen Reduction Reaction. J ELECTROCHEM SCI TE 2017. [DOI: 10.33961/jecst.2017.8.3.169] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Lee KR, Jeong JW, Hyun HC, Jang E, Ahn S, Choi S, Joo SH, Kim S, Koo TS. Pharmacokinetics of tafamidis, a transthyretin amyloidosis drug, in rats. Xenobiotica 2017; 48:831-838. [PMID: 28803538 DOI: 10.1080/00498254.2017.1366575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
1. We characterized the pharmacokinetics of tafamidis, a novel drug to treat transthyretin-related amyloidosis, in rats after intravenous and oral administration at doses of 0.3-3 mg/kg. In vitro Caco-2 cell permeability and liver microsomal stability, as well as in vivo tissue distribution and plasma protein binding were also examined. 2. After intravenous injection, systemic clearance (CL), volumes of distribution at steady state (Vss) and half-life (T½) remained unaltered as a function of dose, with values in the ranges of 6.41-7.03 mL/h/kg, 270-354 mL/kg and 39.5-46.9 h, respectively. Following oral administration, absolute bioavailability was 99.7-104% and was independent of doses from 0.3 to 3 mg/kg. In the urine and faeces, 4.36% and 48.9% of tafamidis, respectively, were recovered. 3. Tafamidis was distributed primarily in the liver and not in the brain, kidney, testis, heart, spleen, lung, gut, muscle, or adipose tissue. Further, tafamidis was very stable in rat liver microsomes, and its plasma protein binding was 99.9%. 4. In conclusion, tafamidis showed dose-independent pharmacokinetics with intravenous and oral doses of 0.3-3 mg/kg. Tafamidis undergoes minimal first-pass metabolism, distributes mostly in the liver and plasma, and appears to be eliminated primarily via biliary excretion.
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Yoon D, Lee J, Seo B, Kim B, Baik H, Joo SH, Lee K. Cactus-Like Hollow Cu 2-x S@Ru Nanoplates as Excellent and Robust Electrocatalysts for the Alkaline Hydrogen Evolution Reaction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1700052. [PMID: 28594433 DOI: 10.1002/smll.201700052] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 04/26/2017] [Indexed: 05/28/2023]
Abstract
The development of Pt-free electrocatalysts for the hydrogen evolution reaction (HER) recently is a focus of great interest. While several strategies are developed to control the structural properties of non-Pt catalysts and boost their electrocatalytic activities for the HER, the generation of highly reactive defects or interfaces by combining a metal with other metals, or with metal oxides/sulfides, can lead to notably enhanced catalytic performance. Herein, the preparation of cactus-like hollow Cu2-x S@Ru nanoplates (NPs) that contain metal/metal sulfide heterojunctions and show excellent catalytic activity and durability for the HER in alkaline media is reported. The initial formation of Ru islands on presynthesized Cu1.94 S NPs, via cation exchange between three Cu+ ions and one Ru3+ , induces the growth of the Ru phase, which is concomitant with the dissolution of the Cu1.94 S nanotemplate, culminating in the formation of a hollow nanostructure with numerous thin Ru pillars. Hollow Cu2-x S@Ru NPs exhibit a small overpotential of 82 mV at a current density of -10 mA cm-2 and a low Tafel slope of 48 mV dec-1 under alkaline conditions; this catalyst is among state-of-the-art HER electrocatalysts in alkaline media. The excellent performance of hollow Cu2-x S@Ru NPs originates from the facile dissociation of water in the Volmer step.
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Seo B, Joo SH. Recent advances in unveiling active sites in molybdenum sulfide-based electrocatalysts for the hydrogen evolution reaction. NANO CONVERGENCE 2017; 4:19. [PMID: 28798900 PMCID: PMC5524877 DOI: 10.1186/s40580-017-0112-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 07/07/2017] [Indexed: 05/25/2023]
Abstract
Hydrogen has received significant attention as a promising future energy carrier due to its high energy density and environmentally friendly nature. In particular, the electrocatalytic generation of hydrogen fuel is highly desirable to replace current fossil fuel-dependent hydrogen production methods. However, to achieve widespread implementation of electrocatalytic hydrogen production technology, the development of highly active and durable electrocatalysts based on Earth-abundant elements is of prime importance. In this context, nanostructured molybdenum sulfides (MoS x ) have received a great deal of attention as promising alternatives to precious metal-based catalysts. In this focus review, we summarize recent efforts towards identification of the active sites in MoS x -based electrocatalysts for the hydrogen evolution reaction (HER). We also discuss recent synthetic strategies for the engineering of catalyst structures to achieve high active site densities. Finally, we suggest ongoing and future research challenges in the design of advanced MoS x -based HER electrocatalysts.
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Park J, Sa YJ, Baik H, Kwon T, Joo SH, Lee K. Iridium-Based Multimetallic Nanoframe@Nanoframe Structure: An Efficient and Robust Electrocatalyst toward Oxygen Evolution Reaction. ACS NANO 2017; 11:5500-5509. [PMID: 28599106 DOI: 10.1021/acsnano.7b00233] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nanoframe electrocatalysts have attracted great interest due to their inherently high active surface area per a given mass. Although recent progress has enabled the preparation of single nanoframe structures with a variety of morphologies, more complex nanoframe structures such as a double-layered nanoframe have not yet been realized. Herein, we report a rational synthetic strategy for a structurally robust Ir-based multimetallic double-layered nanoframe (DNF) structure, nanoframe@nanoframe. By leveraging the differing kinetics of dual Ir precursors and dual transition metal (Ni and Cu) precursors, a core-shell-type alloy@alloy structure could be generated in a simple one-step synthesis, which was subsequently transformed into a multimetallic IrNiCu DNF with a rhombic dodecahedral morphology via selective etching. The use of single Ir precursor yielded single nanoframe structures, highlighting the importance of employing dual Ir precursors. In addition, the structure of Ir-based nanocrystals could be further controlled to DNF with octahedral morphology and CuNi@Ir core-shell structures via a simple tuning of experimental factors. The IrNiCu DNF exhibited high electrocatalytic activity for oxygen evolution reaction (OER) in acidic media, which is better than Ir/C catalyst. Furthermore, IrNiCu DNF demonstrated excellent durability for OER, which could be attributed to the frame structure that prevents the growth and agglomeration of particles as well as in situ formation of robust rutile IrO2 phase during prolonged operation.
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Ko HM, Joo SH, Jo JH, Park WS, Jung WY, Shin JH, Ahn HJ. Liver-Wrapping, Nitric Oxide-Releasing Nanofiber Downregulates Cleaved Caspase-3 and Bax Expression on Rat Hepatic Ischemia-Reperfusion Injury. Transplant Proc 2017; 49:1170-1174. [PMID: 28583550 DOI: 10.1016/j.transproceed.2017.03.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Hepatic ischemia-reperfusion injury (IRI) is an important determinant of the outcome of hepatic surgery, including re-section and transplantation. Previous studies have shown that nitric oxide (NO) has a protective effect against IRI. Therefore, many studies have examined methods for supplying NO. In this study, we investigated the effect of NO-releasing nanofibers on hepatic IRI in a rat model. METHODS Male Sprague-Dawley rats were divided into 4 groups: control, IRI only (n = 3); group 1, hepatic IRI and liver-wrapping with nanofiber lacking NO (n = 4); group 2, hepatic IRI and liver-wrapping with NO rapid-releasing nanofiber (n = 4); and group 3, hepatic IRI and liver-wrapping with NO slow-releasing nanofiber (n = 5). RESULTS The levels of aspartate aminotransferase and alanine aminotransferase were not significantly different between groups. On the basis of Western blots, Bax/β-actin levels were significantly lower in group 2 than in group 3 (P < .01). Cleaved Caspase-3/β-actin levels were significantly lower in group 2 than in the control, group 1, and group 3 (P < .05, .01, and .01, respectively). However, there were no significant differences in Bcl-2/β-actin between groups. CONCLUSIONS The liver-wrapping NO rapid-releasing nanofiber downregulated cleaved Caspase-3 and Bax expression. It has a protective effect by reducing apoptosis in hepatic IRI in rats.
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Kang SW, Kim K, Chun DH, Yang JI, Lee HT, Jung H, Lim JT, Jang S, Kim CS, Lee CW, Joo SH, Han JW, Park JC. High-performance Fe 5 C 2 @CMK-3 nanocatalyst for selective and high-yield production of gasoline-range hydrocarbons. J Catal 2017. [DOI: 10.1016/j.jcat.2017.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Kim JJ, Joo SH, Lee KS, Yoo JH, Park MS, Kwak JS, Lee J. Improved design for a low temperature scanning tunneling microscope with an in situ tip treatment stage. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:043702. [PMID: 28456260 DOI: 10.1063/1.4979928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The Low Temperature Scanning Tunneling Microscope (LT-STM) is an extremely valuable tool not only in surface science but also in condensed matter physics. For years, numerous new ideas have been adopted to perfect LT-STM performances-Ultra-Low Vibration (ULV) laboratory and the rigid STM head design are among them. Here, we present three improvements for the design of the ULV laboratory and the LT-STM: tip treatment stage, sample cleaving stage, and vibration isolation system. The improved tip treatment stage enables us to perform field emission for the purpose of tip treatment in situ without exchanging samples, while our enhanced sample cleaving stage allows us to cleave samples at low temperature in a vacuum without optical access by a simple pressing motion. Our newly designed vibration isolation system provides efficient space usage while maintaining vibration isolation capability. These improvements enhance the quality of spectroscopic imaging experiments that can last for many days and provide increased data yield, which we expect can be indispensable elements in future LT-STM designs.
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Lee S, Jang WJ, Choi B, Joo SH, Jeong CH. Comparative metabolomic analysis of HPAC cells following the acquisition of erlotinib resistance. Oncol Lett 2017; 13:3437-3444. [PMID: 28529573 PMCID: PMC5431587 DOI: 10.3892/ol.2017.5940] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/17/2017] [Indexed: 12/30/2022] Open
Abstract
Pancreatic cancer is one of the most lethal types of cancer, due to difficulty in early detection and the limited efficacy of available treatments. Erlotinib is used to inhibit the epidermal growth factor receptor for the treatment of pancreatic cancer; however, erlotinib resistance is a major issue and the mechanisms underlying the development of erlotinib resistance remain unclear. To better understand the alterations in tumor metabolism by acquired resistance to erlotinib, an erlotinib-resistant pancreatic cancer cell line (HPAC-ER) was established, followed by a comparison of the metabolic characteristics between these cells and their erlotinib-sensitive parental cells (HPAC). This comparison was accomplished through mass spectrometry-based targeted metabolic profiling. Five metabolite groups (acylcarnitines, amino acids and biogenic amines, glycerophospholipids, sphingolipids and monosaccharides) were semi-quantified and compared statistically. These results revealed significant differences between the two groups of cells. A significant increase in the level of short-chain acylcarnitines and selected lysophosphatidylcholines, and a significant decrease in the level of acyl-alkyl-phosphatidylcholines and one sphingolipid, were observed in the HPAC-ER cells compared with the HPAC cells. The metabolic changes observed in the present study support the theory that there are increased metabolic demands in erlotinib-resistant cancer, reflecting the changes in acetyl-CoA-associated and choline phospholipid metabolism. These findings will aid in elucidating the changes that occur in pancreatic cancer metabolism through the acquired resistance to erlotinib, and in the identification of biomarkers for the early detection of pancreatic cancer.
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Chaudhari NK, Oh A, Sa YJ, Jin H, Baik H, Kim SG, Lee SJ, Joo SH, Lee K. Morphology controlled synthesis of 2-D Ni–Ni 3S 2 and Ni 3S 2 nanostructures on Ni foam towards oxygen evolution reaction. NANO CONVERGENCE 2017; 4:7. [PMCID: PMC6141903 DOI: 10.1186/s40580-017-0101-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/17/2017] [Indexed: 05/30/2023]
Abstract
Catalysts for oxygen evolution reactions (OER) are at the heart of key renewable energy technologies, and development of non-precious metal catalysts with high activity and stability remain a great challenge in this field. Among various material candidates, metal sulfides are receiving increasing attention. While morphology-dependent catalytic performances are well established in noble metal-based catalysts, relatively little is known for the morphology‒catalytic performance relationship in metal sulfide catalysts. In this study, uniform spider web-like Ni nanosheets–Ni3S2 and honeycomb-like Ni3S2 structures are deposited on nickel foam (Ni3S2/NF) by a facile one-step hydrothermal synthetic route. When used as an oxygen evolution electrode, the spider web-like Ni–Ni3S2/NF with the large exposed surface area shown excellent catalytic activity and stability with an overpotential of ~310 mV to achieve at 10 mA/cm2 and a Tafel slope of 63 mV/dec in alkaline media, which is superior to the honeycomb-like structure without Ni nanosheet. The low Tafel slope of the spider web-like Ni–Ni3S2/NF represents one of the best OER kinetics among nickel sulfide-based OER catalysts. The results point to the fact that performance of the metal sulfide electrocatalysts might be fine-tuned and optimized with morphological controls.
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Kim JH, Sa YJ, Jeong HY, Joo SH. Roles of Fe-N x and Fe-Fe 3C@C Species in Fe-N/C Electrocatalysts for Oxygen Reduction Reaction. ACS APPLIED MATERIALS & INTERFACES 2017; 9:9567-9575. [PMID: 28244305 DOI: 10.1021/acsami.6b13417] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Iron and nitrogen codoped carbons (Fe-N/C) have emerged as promising nonprecious metal catalysts for the oxygen reduction reaction (ORR). While Fe-Nx sites have been widely considered as active species for Fe-N/C catalysts, very recently, iron and/or iron carbide encased with carbon shells (Fe-Fe3C@C) has been suggested as a new active site for the ORR. However, most of synthetic routes to Fe-N/C catalysts involve high-temperature pyrolysis, which unavoidably yield both Fe-Nx and Fe-Fe3C@C species, hampering the identification of exclusive role of each species. Herein, in order to establish the respective roles of Fe-Nx and Fe-Fe3C@C sites we rationally designed model catalysts via the phase conversion reactions of Fe3O4 nanoparticles supported on carbon nanotubes. The resulting catalysts selectively contained Fe-Nx, Fe-Fe3C@C, and N-doped carbon (C-Nx) sites. It was revealed that Fe-Nx sites dominantly catalyze ORR via 4-electron (4 e-) pathway, exerting a major role for high ORR activity, whereas Fe-Fe3C@C sites mainly promote 2 e- reduction of oxygen followed by 2 e- peroxide reduction, playing an auxiliary role.
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Shim Y, Sa YJ, Shin Y, Oh J, Ju H, Joo SH, Park S. Electrocatalysts composed of a Co(acetylacetonate)2 molecule and refluxed graphene oxide for an oxygen reduction reaction. NEW J CHEM 2017. [DOI: 10.1039/c7nj00311k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Co-Based organometallic species, Co-O4-O, on the graphene-based materials showed electrocatalytic activity for ORR.
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Park MS, Joo SH, Kim BS, Lee JW, Kim YI, Hong MK, Ahn HJ. Remote Preconditioning on Rat Hepatic Ischemia-Reperfusion Injury Downregulated Bax and Cleaved Caspase-3 Expression. Transplant Proc 2016; 48:1247-50. [PMID: 27320597 DOI: 10.1016/j.transproceed.2015.12.125] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 12/30/2015] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Hepatic ischemia-reperfusion injury (IRI) is considered a major cause of hepatic damage in liver surgery. The aim of this study was to investigate the effect of the remote ischemic perconditioning method on hepatic IRI in a rat model. METHODS Seventeen rats underwent hepatic IRI for 30 minutes followed by reperfusion, and were divided into 3 groups: group I, only hepatic IRI (n = 5); group II, hepatic IRI with remote perconditioning (n = 7); and group III, hepatic IRI with remote postconditioning (n = 5). RESULTS For Bax/β-actin, mean values of the 3 groups (±standard deviation) were 1.29 ± 0.26 (group I), 0.89 ± 0.15 (group II), and 1.02 ± 0.23 (group III). The level of Bax/β-actin in group II was significantly lower than in group I (P < .01). The cleaved Caspase-3/β-actin ratio for groups I, II, and III was 0.93 ± 0.22, 0.46 ± 0.16, and 0.63 ± 0.22, respectively. The level of cleaved Caspase-3/β-actin in groups II and III were significantly lower than in group I (P < .01 and P < .05, respectively). The Bcl-2/β-actin ratio for groups I, II, and III was 1.01 ± 0.09, 1.19 ± 0.39, and 1.20 ± 0.12, respectively. However, there were no significant difference between groups II and III and group I. CONCLUSIONS The remote perconditioning on rat hepatic IRI downregulated the Bax and cleaved Caspase-3 expression.
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Sa YJ, Seo DJ, Woo J, Lim JT, Cheon JY, Yang SY, Lee JM, Kang D, Shin TJ, Shin HS, Jeong HY, Kim CS, Kim MG, Kim TY, Joo SH. A General Approach to Preferential Formation of Active Fe–Nx Sites in Fe–N/C Electrocatalysts for Efficient Oxygen Reduction Reaction. J Am Chem Soc 2016; 138:15046-15056. [DOI: 10.1021/jacs.6b09470] [Citation(s) in RCA: 550] [Impact Index Per Article: 68.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Shim Y, Han J, Sa YJ, Lee S, Choi K, Oh J, Kim S, Joo SH, Park S. Electrocatalytic performances of heteroatom-containing functionalities in N-doped reduced graphene oxides. J IND ENG CHEM 2016. [DOI: 10.1016/j.jiec.2016.07.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kim HY, Cho S, Sa YJ, Hwang SM, Park GG, Shin TJ, Jeong HY, Yim SD, Joo SH. Self-Supported Mesostructured Pt-Based Bimetallic Nanospheres Containing an Intermetallic Phase as Ultrastable Oxygen Reduction Electrocatalysts. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:5347-5353. [PMID: 27515995 DOI: 10.1002/smll.201601825] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 06/29/2016] [Indexed: 06/06/2023]
Abstract
Developing highly active and stable cathode catalysts is of pivotal importance for proton exchange membrane fuel cells (PEMFCs). While carbon-supported nanostructured Pt-based catalysts have so far been the most active cathode catalysts, their durability and single-cell performance are yet to be improved. Herein, self-supported mesostructured Pt-based bimetallic (Meso-PtM; M = Ni, Fe, Co, Cu) nanospheres containing an intermetallic phase are reported, which can combine the beneficial effects of transition metals (M), an intermetallic phase, a 3D interconnected framework, and a mesoporous structure. Meso-PtM nanospheres show enhanced oxygen reduction reaction (ORR) activity, compared to Pt black and Pt/C catalysts. Notably, Meso-PtNi containing an intermetallic phase exhibits ultrahigh stability, showing enhanced ORR activity even after 50 000 potential cycles, whereas Pt black and Pt/C undergo dramatic degradation. Importantly, Meso-PtNi with an intermetallic phase also demonstrated superior activity and durability when used in a PEMFC single-cell, with record-high initial mass and specific activities.
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Spisni E, Seo S, Joo SH, Su C. Release and toxicity comparison between industrial- and sunscreen-derived nano-ZnO particles. INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY : IJEST 2016; 13:2485-2494. [PMID: 32632346 PMCID: PMC7336526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Many consumer products containing ZnO have raised concern for safety in regard to environmental impact and the public health. Widely used sunscreens for protecting against UV and avoiding sunburns represent a great exposure to nano-ZnO, one of the ingredients commonly applied in sunscreens. Applying nanoproducts on beaches may release nanoparticles unintentionally into the ocean. Despite the accumulation of such nanoproducts in the ocean harming or being detrimental to critical marine organisms, few studies have investigated the release and potential toxicity of nanoparticles extracted from products and compared them with those from industrial-type nanoparticles. Results show that the cytotoxicity of both industrial- and sunscreen-derived nano-ZnO to the marine diatom algae, Thalassiosira pseudonana, increased as exposure increases over time, as measured by growth inhibition (%) of the algae at a constant concentration of nano-ZnO (10 mg/L). The extent of toxicity appeared to be higher from industrial-type nano-ZnO compared with sunscreen-extracted nano-ZnO, though the extent becomes similar when concentrations increase to 50 mg/L. On the other hand, at a fixed exposure time of 48 h, the cytotoxicity increases as concentrations increase with the higher toxicity shown from the industrial-type compared with sunscreen-induced nano-ZnO. Results indicate that while industrial-type nano-ZnO shows higher toxicity than sunscreen-derived nano-ZnO, the release and extent of toxicity from nano-ZnO extracted from sunscreen are not trivial and should be monitored for the development of safe manufacturing of nanomaterials-induced products.
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Oh A, Sa YJ, Hwang H, Baik H, Kim J, Kim B, Joo SH, Lee K. Rational design of Pt-Ni-Co ternary alloy nanoframe crystals as highly efficient catalysts toward the alkaline hydrogen evolution reaction. NANOSCALE 2016; 8:16379-16386. [PMID: 27714051 DOI: 10.1039/c6nr04572c] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The rational design of highly efficient electrocatalysts for the hydrogen evolution reaction (HER) is of prime importance for establishing renewable and sustainable energy systems. The alkaline HER is particularly challenging as it involves a two-step reaction of water dissociation and hydrogen recombination, for which platinum-based binary catalysts have shown promising activity. In this work, we synthesized high performance platinum-nickel-cobalt alloy nanocatalysts for the alkaline HER through a simple synthetic route. This ternary nanostructure with a Cartesian-coordinate-like hexapod shape could be prepared by a one-step formation of core-dual shell Pt@Ni@Co nanostructures followed by a selective removal of the Ni@Co shell. The cobalt precursor brings about a significant impact on the control of size and shape of the nanostructure. The PtNiCo nanohexapods showed a superior alkaline HER activity to Pt/C and binary PtNi hexapods, with 10 times greater specific activity than Pt/C. In addition, the PtNiCo nanohexapods demonstrated excellent activity and durability for the oxygen reduction reaction in acidic media.
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97
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Joo SH, Chung HS. Crystal structure and activity of Francisella novicida UDP-N-acetylglucosamine acyltransferase. Biochem Biophys Res Commun 2016; 478:1223-9. [PMID: 27545601 DOI: 10.1016/j.bbrc.2016.08.098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 08/17/2016] [Indexed: 01/26/2023]
Abstract
The first step of lipid A biosynthesis in Escherichia coli (E. coli) is catalyzed by LpxA (EcLpxA), an acyltransferase selective for UDP-N-acetylglucosamine (UDP-GlcNAc) and R-3-hydroxymyristoyl-acyl carrier protein (3-OH-C14-ACP), and is an essential step in majority of Gram-negative bacteria. Since the majority of lipid A species isolated from F. novicida contains 3-OH-C16 or 3-OH-C18 at its C3 and C3' positions, FnLpxA was thought to be selective for longer acyl chain (3-OH-C16 and 3-OH-C18) over short acyl chain (3-OH-C14, 3-OH-C12, and 3-OH-C10). Here we demonstrate that Francisella novicida (F. novicida) lpxA functionally complements an E. coli lpxA knockout mutant and efficiently transfers 3-OH-C14 as well as 3-OH-C16 in E. coli. Our results implicate that the acyl chain length of lipid A is determined by several factors including acyl chain selectivity of LpxA and downstream enzymes, as well as the composition of the acyl-ACP pool in vivo. We also report the crystal structure of F. novicida LpxA (FnLpxA) at 2.06 Å. The N-terminal parallel beta-helix (LβH) and C-terminal alpha-helical domain are similar to other reported structures of LpxAs. However, our structure indicates that the supposed ruler residues for hydrocarbon length, 171L in one monomer and 168H in the adjacent monomer in a functional trimer of FnLpxA, are located just 3.8 Å apart that renders not enough space for binding of 3-OH-C12 or longer acyl chains. This implicates that FnLpxA may have an alternative hydrophobic pocket, or the acyl chain may bend while binding to FnLpxA. In addition, the FnLpxA structure suggests a potential inhibitor binding site for development of antibiotics.
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98
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Yang Y, Jin H, Kim HY, Yoon J, Park J, Baik H, Joo SH, Lee K. Ternary dendritic nanowires as highly active and stable multifunctional electrocatalysts. NANOSCALE 2016; 8:15167-15172. [PMID: 27507777 DOI: 10.1039/c6nr04305d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Multimetallic nanocatalysts with a controlled structure can provide enhanced catalytic activity and durability by exploiting electronic, geometric, and strain effects. Herein, we report the synthesis of a novel ternary nanocatalyst based on Mo doped PtNi dendritic nanowires (Mo-PtNi DNW) and its bifunctional application in the methanol oxidation reaction (MOR) at the anode and the oxygen reduction reaction (ORR) at the cathode for direct methanol fuel cells. An unprecedented Mo-PtNi DNW structure can combine multiple structural attributes of the 1D nanowire morphology and dendritic surfaces. In the MOR, Mo-PtNi DNW exhibits superior activity to Pt/C and Mo doped Pt dendritic nanowires (Mo-Pt DNW), and excellent durability. Furthermore, Mo-PtNi DNW demonstrates excellent activity and durability for the ORR. This work highlights the important role of compositional and structural control in nanocatalysts for boosting catalytic performances.
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Kim TH, Kim MG, Shin S, Chi YH, Paik SH, Lee JH, Yoo SD, Youn YS, Bulitta JB, Joo SH, Jeong SW, Weon KY, Shin BS. Placental transfer and mammary excretion of a novel angiotensin receptor blocker fimasartan in rats. BMC Pharmacol Toxicol 2016; 17:35. [PMID: 27459959 PMCID: PMC4962410 DOI: 10.1186/s40360-016-0080-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 07/19/2016] [Indexed: 12/02/2022] Open
Abstract
Background Fimasartan (FMS) is a potent angiotensin receptor blocker for the treatment of mild to moderate hypertension. This study aimed to evaluate the transfer of FMS to fetus and breast milk in rats. Methods In order to study the transfer to the fetus and nursing pup, pregnant and nursing maternal rats were administered with FMS by a constant intravenous infusion to reach target plasma concentrations of 200 ng/mL and 100 ng/mL. The concentrations of FMS in plasma, placenta, amniotic fluid, fetus, and milk were determined by a validated LC-MS/MS assay. Results Upon constant intravenous infusion, the plasma FMS concentration reached the target steady state concentrations (Css = 200 ng/mL and 100 ng/mL) in 24 h. The tissue-to-plasma partition coefficients (Kp) for placenta, amniotic fluid, and milk were obtained based on the observed FMS concentrations in the tissues and Css. The Kp values for all tissues were not different between high (Css = 200 ng/mL) and low (Css = 100 ng/mL) dose groups. While the mean Kp of the placenta was 44.6–59.0 %, the mean Kp was 1.3–1.7 % for the amniotic fluid and 14.9–17.0 % for fetus. The mean Kp of milk was 10.4–15.2 %. Conclusions Placental transfer and milk excretion of FMS was relatively lower compared to other angiotensin receptor blockers.
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100
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Seo B, Sa YJ, Woo J, Kwon K, Park J, Shin TJ, Jeong HY, Joo SH. Size-Dependent Activity Trends Combined with in Situ X-ray Absorption Spectroscopy Reveal Insights into Cobalt Oxide/Carbon Nanotube-Catalyzed Bifunctional Oxygen Electrocatalysis. ACS Catal 2016. [DOI: 10.1021/acscatal.6b00553] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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