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( Changshin Kang ),( Soo Hyun Han ),( Jung Soo Park ),( Dae Eun Choi ) 대한신장학회 2023 Kidney Research and Clinical Practice Vol.42 No.3
Background: This study compares the incidence of post-contrast acute kidney injury (PC-AKI) in patients who received a single administration of iodine-based contrast medium (ICM) with that in patients who received a sequential administration of ICM and gadolinium-based contrast agents (GBCA) in a single visit to an emergency department (ED) to determine the risk factors for PC-AKI. Methods: Patients who received one or more contrast media in the ED from 2016 to 2021 were included in this retrospective study. They were divided into the ICM alone and ICM + GBCA groups, and the incidence of PC-AKI was compared between the groups. The risk factors were assessed using a multivariable analysis after propensity score matching (PSM). Results: Overall, 6,318 patients were analyzed, of whom 139 were in the ICM + GBCA group. The incidence of PC-AKI was significantly higher in the ICM + GBCA group than in the ICM alone group (10.9% vs. 27.3%, p < 0.001). In the multivariable analysis, sequential administration was a risk factor for PC-AKI, and single administration was not (adjusted odds ratio [95% confidence interval] in the 1:1, 2:1, and 3:1 PSM cohorts: 2.38 [1.25-4.55], 2.13 [1.26-3.60], and 2.28 [1.39-3.72], respectively). In subgroup analyses of the ICM + GBCA group, osmolality (1.05 [1.01-1.10]) and estimated glomerular filtration rate (eGFR, 0.93 [0.88-0.98]) were associated with PC-AKI. Conclusion: Compared with a single administration of ICM alone, sequential administration of ICM and GBCA during a single ED visit might be a risk factor for PC-AKI. Osmolality and eGFR might be associated with PC-AKI after sequential administration.
Jo, Changshin,Hwang, Ilkyu,Lee, Jinwoo,Lee, Chul Wee,Yoon, Songhun American Chemical Society 2011 The Journal of Physical Chemistry Part C Vol.115 No.23
<P>Herein, a pseudocapacitive charging behavior of highly conductive ordered mesoporous tungsten oxide (m-WO<SUB>3-X</SUB>) is investigated. For this purpose, various electrochemical analysis methods such as cyclic voltammetry (CV), galvanostatic charge–discharge experiment and electrochemical impedance spectroscopy (EIS) were employed. From CV experiment, a relationship analysis between voltammetric charge and scan rate resulted in total (67 C g<SUP>–1</SUP>), outer (61 C g<SUP>–1</SUP>) and inner charge (6 C g<SUP>–1</SUP>), which was related with the well-developed crystalline structure of m-WO<SUB>3-X</SUB>. In galvanostatic charge–discharge profiles with change of applied current, a more severe decrease of cathodic capacity than the anodic one was observed, which was attributed to larger cathodic resistance. This resistance dependency on potential was clarified with EIS fitting analysis. Here, the charge transfer resistance and Warburg diffusion resistance became larger with increasing potential, which was relevant to the change of oxidation state during redox reaction. Using these electrochemical analysis results, a schematic illustration of the pseudocapacitive charging mechanism was proposed.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2011/jpccck.2011.115.issue-23/jp2036982/production/images/medium/jp-2011-036982_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp2036982'>ACS Electronic Supporting Info</A></P>
Jo, Changshin,Park, Yuwon,Jeong, Jooyoung,Lee, Kyu Tae,Lee, Jinwoo American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.22
<P>Ordered meso- or macro-porous carbons (OMCs) were applied as anodes in Na ion battery (NIB) systems. Three different block copolymers (BCPs) enabled us to control the pore sizes (6, 33, and 60 nm) while maintaining the same 2-D hexagonal structure. To exclude other effects, the factors including precursors, particle sizes, and degrees of graphitization were controlled. The structures of OMCs were characterized by nitrogen physisorption, Raman spectroscopy, X-ray analyses (XRD and SAXS), and microscopies (TEM and SEM). With a galvanostatic charge/discharge, we confirmed that OMC electrode with medium pore size (OMC-33) exhibited a higher reversible capacity of 134 mA h g<SUP>–1</SUP> (at 20th cycle) and faster rate capability (61% retention, current densities from 50 to 5000 mA g<SUP>–1</SUP>) than those of OMC-6, and OMC-60 electrodes. The high performance of OMC-33 is attributed to the combined effects of pore size and wall thickness which was supported by charge/discharge and electrochemical impedance spectroscopy (EIS) analyses.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-22/acsami.5b03186/production/images/medium/am-2015-03186z_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b03186'>ACS Electronic Supporting Info</A></P>
Jo, Changshin,Hwang, Jongkook,Song, Hannah,Dao, Anh Ha,Kim, Yong‐,Tae,Lee, Sang Hyup,Hong, Seok Won,Yoon, Songhun,Lee, Jinwoo WILEY‐VCH Verlag 2013 Advanced functional materials Vol.23 No.30
<P>A study by S. Yoon, J. Lee, and co‐workers on the improvement of rate performance highlights an important issue for pseudocapacitor electrode materials. On page 3747, the synthesis of an ordered mesoporous tungsten oxide–carbon nanocomposite is presented via a ‘one‐pot’ soft‐template method. The ordered mesoporous structure, partial reduction of the metal oxide, and the nanosized mixing of the metal oxide/carbon result in both high power and energy density. </P>
Jo, Changshin,Hwang, Jongkook,Song, Hannah,Dao, Anh Ha,Kim, Yong‐,Tae,Lee, Sang Hyup,Hong, Seok Won,Yoon, Songhun,Lee, Jinwoo WILEY‐VCH Verlag 2013 Advanced functional materials Vol.23 No.30
<P><B>Abstract</B></P><P>An ordered mesoporous tungsten‐oxide/carbon (denoted as m‐WO<SUB>3−<I>x</I></SUB>‐C‐s) nanocomposite is synthesized using a simple one‐pot method using polystyrene‐<I>block</I>‐poly(ethylene oxide) (PS‐<I>b</I>‐PEO) as a structure‐directing agent. The hydrophilic PEO block interacts with the carbon and tungsten precursors (resol polymer and WCl<SUB>6</SUB>), and the PS block is converted to pores after heating at 700 °C under a nitrogen flow. The m‐WO<SUB>3−<I>x</I></SUB>‐C‐s nanocomposite has a high Brunauer–Emmett–Teller (BET) surface area and hexagonally ordered pores. Because of its mesoporous structure and high intrinsic density of tungsten oxide, this material exhibits a high average volumetric capacitance and gravimetric capacitance as a pseudocapacitor electrode. In comparison with reduced mesoporous tungsten oxide (denoted as m‐WO<SUB>3−<I>x</I></SUB>‐h), which is synthesized by a tedious hard template approach and further reduction in a H<SUB>2</SUB>/N<SUB>2</SUB> atmosphere, m‐WO<SUB>3−<I>x</I></SUB>‐C‐s shows a high capacitance and enhanced rate performance, as confirmed by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The good performance of m‐WO<SUB>3−<I>x</I></SUB>‐C‐s is attributed to the high surface area arising from the mesoporous structure, the large interconnected mesopores, and the low internal resistance from the well‐dispersed reduced tungsten oxide and amorphous carbon composite structure. Here, the amorphous carbon acts as an electrical pathway for effective pseudocapacitor behavior of WO<SUB><I>3‐x</I></SUB>.</P>
Jo, Changshin,An, Sunhyung,Kim, Younghoon,Shim, Jongmin,Yoon, Songhun,Lee, Jinwoo The Royal Society of Chemistry 2012 Physical chemistry chemical physics Vol.14 No.16
<P>Mesocellular carbon foam (MSU-F-C) is functionalized with hollow nanographite by a simple solution-phase method to enhance the intrapenetrating electrical percolation network. The electrical conductivity of the resulting material, denoted as MSU-F-C-G, is increased by a factor of 20.5 compared with the pristine MSU-F-C. Hollow graphite nanoparticles are well-dispersed in mesocellular carbon foam, as confirmed by transmission electron microscopy (TEM), and the <I>d</I> spacing of the (002) planes is 0.343 nm, which is only slightly larger than that of pure graphite (0.335 nm), suggesting a random combination of graphitic and turbostratic stacking. After nanographitic functionalization, the BET surface area and total pore volume decreased from 928 m<SUP>2</SUP> g<SUP>−1</SUP> and 1.5 cm<SUP>3</SUP> g<SUP>−1</SUP> to 394 m<SUP>2</SUP> g<SUP>−1</SUP> and 0.7 cm<SUP>3</SUP> g<SUP>−1</SUP>, respectively. Thermogravimetric analysis in air shows that the thermal stability of MSU-F-C-G is improved relative to that of MSU-F-C, and the one-step weight loss indicates that the nanographite is homogeneously functionalized on the MSU-F-C particles. When the resulting mesocellular carbon materials are used as electrode materials for an electric double layer capacitor (EDLC), the specific capacitances (<I>C</I><SUB>sp</SUB>) of the MSU-F-C and MSU-F-C-G electrodes at 4 mV s<SUP>−1</SUP> are 109 F g<SUP>−1</SUP> and 93 F g<SUP>−1</SUP>, respectively. The MSU-F-C-G electrode exhibited a very high area capacitance (<I>C</I><SUB>area</SUB>, 23.5 μF cm<SUP>−2</SUP>) compared with that of the MSU-F-C electrode (11.7 μF cm<SUP>−2</SUP>), which is attributed to the enhanced intraparticle conductivity by the nanographitic functionalization. MSU-F-C-G exhibited high capacity retention (52%) at a very high scan rate of 512 mV s<SUP>−1</SUP>, while only a 23% capacity retention at 512 mV s<SUP>−1</SUP> was observed in the case of the MSU-F-C electrode. When applied as an anode in a lithium ion battery, a significant increase in the initial efficiency (44%), high reversible discharge capacity (580 mA h g<SUP>−1</SUP>) in the lower voltage region, and a higher rate capability were observed. The high rate capability of the MSU-F-C-G electrode as charge storage was due to the low resistance derived from the nanographitic functionalization.</P> <P>Graphic Abstract</P><P>Nano-graphite functionalized mesocellular carbon foam exhibits advanced electrochemical performances as electrode materials in EDLC and LIB due to the role of graphite as an intrapenetrating electrical network. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cp40657h'> </P>
Jo, Changshin,Kim, Youngsik,Hwang, Jongkook,Shim, Jongmin,Chun, Jinyoung,Lee, Jinwoo American Chemical Society 2014 Chemistry of materials Vol.26 No.11
<P>In order to achieve high-power and -energy anodes operating above 1.0 V (vs Li/Li<SUP>+</SUP>), titanium-based materials have been investigated for a long time. However, theoretically low lithium charge capacities of titanium-anodes have required new types of high-capacity anode materials. As a candidate, TiNb<SUB>2</SUB>O<SUB>7</SUB> has attracted much attention due to the high theoretical capacity of 387.6 mA h g<SUP>–1</SUP>. However, the high formation temperature of the TiNb<SUB>2</SUB>O<SUB>7</SUB> phase resulted in large-sized TiNb<SUB>2</SUB>O<SUB>7</SUB> crystals, thus resulting in poor rate capability. Herein, ordered mesoporous TiNb<SUB>2</SUB>O<SUB>7</SUB> (denoted as m-TNO) was synthesized by block copolymer assisted self-assembly, and the resulting binary metal oxide was applied as an anode in a lithium ion battery. The nanocrystals (∼15 nm) developed inside the confined pore walls and large pores (∼40 nm) of m-TNO resulted in a short diffusion length for lithium ions/electrons and fast penetration of electrolyte. As a stable anode, the m-TNO electrode exhibited a high capacity of 289 mA h g<SUP>–1</SUP> (at 0.1 C) and an excellent rate performance of 162 mA h g<SUP>–1</SUP> at 20 C and 116 mA h g<SUP>–1</SUP> at 50 C (= 19.35 A g<SUP>–1</SUP>) within a potential range of 1.0–3.0 V (vs Li/Li<SUP>+</SUP>), which clearly surpasses other Ti-and Nb-based anode materials (TiO<SUB>2</SUB>, Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB>, Nb<SUB>2</SUB>O<SUB>5</SUB>, etc.) and previously reported TiNb<SUB>2</SUB>O<SUB>7</SUB> materials. The m-TNO and carbon coated m-TNO electrodes also demonstrated stable cycle performances of 48 and 81% retention during 2,000 cycles at 10 C rate, respectively.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2014/cmatex.2014.26.issue-11/cm501011d/production/images/medium/cm-2014-01011d_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm501011d'>ACS Electronic Supporting Info</A></P>
Kim, Younghoon,Jo, Changshin,Lee, Jinwoo,Lee, Chul Wee,Yoon, Songhun The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.4
<P>An ordered nanocomposite of polyethylene glycol–organic radical polymer–mesocellular carbon foam (PEG–ORP–MCF) was prepared by incorporation of ORP into acidified MCF and following PEG coating. The prepared nanocomposite was employed as the cathode material in lithium ion batteries. The nanocomposite electrode exhibited an improvement of high-temperature cycling performance (70% capacity retention after 50 cycles at 50 °C) with a high capacity (111 mA h g<SUP>−1</SUP>), a good rate performance (67% under 20 C current rate) and a smaller polarization under ambient conditions. This improved cathode performance was ascribed to the protective effect of PEG polymer that prevented the ORP from being dissolved in the electrolyte and the high electrical percolation network by the MCF carbon framework.</P> <P>Graphic Abstract</P><P>An ordered nanocomposite electrode of polyethylene glycol–organic radical polymer–mesocellular carbon foam exhibited a high discharge capacity (111 mA h g<SUP>−1</SUP>), a good rate capability (67% retention at 20 C) under ambient temperature and a greatly improved cycle performance at 50 °C (70 retention at 50 cycles) due to the protective effect of PEG layer. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1jm15053g'> </P>