• Korean Journal of Radiology
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• 제24권10호
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• pp.996-1005
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• 2023

Objective: To compare the incidence of aspiration pneumonia, nausea, and vomiting after intravascular administration of nonionic iodinated contrast media (ICM) between patients who fasted before contrast injection and those who did not. Materials and Methods: Ovid-MEDLINE and Embase databases were searched from their inception dates until September 2022 to identify original articles that met the following criteria: 1) randomized controlled trials or observational studies, 2) separate reports of the incidence of aspiration pneumonia, nausea, and vomiting after intravascular injection of non-ionic ICM, and 3) inclusion of patients undergoing radiological examinations without fasting. A bivariate beta-binomial model was used to compare the risk difference in adverse events between fasting and non-fasting groups. The I² statistic was used to assess heterogeneity across the studies. Results: Ten studies, encompassing 308013 patients (non-fasting, 158442), were included in this meta-analysis. No cases of aspiration pneumonia were reported. The pooled incidence of nausea was 4.6% (95% confidence interval [CI]: 1.4%, 7.8%) in the fasting group and 4.6% (95% CI: 1.1%, 8.1%) in the non-fasting group. The pooled incidence of vomiting was 2.1% (95% CI: 0.0%, 4.2%) in the fasting group and 2.5% (95% CI: 0.7%, 4.2%) in the non-fasting group. The risk difference (incidence in the non-fasting group-incidence in the fasting group) in the incidence of nausea and vomiting was 0.0% (95% CI: -4.7%, 4.7%) and 0.4% (95% CI: -2.3%, 3.1%), respectively. Heterogeneity between the studies was low (I² = 0%-13.5%). Conclusion: Lack of fasting before intravascular administration of non-ionic ICM for radiological examinations did not increase the risk of emetic complications significantly. This finding suggests that hospitals can relax fasting policies without compromising patient safety.

• Bulletin of the Korean Chemical Society
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• 제24권7호
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• pp.937-942
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• 2003

The relaxation phenomena of ionic currents through the charged membrane under the constant applied potentials has been studied. The formulation was obtained for the non stationary current by assuming that the ion mobility is independent of concentration and the potential gradient is a constant within membrane, and it was applied to the experimental results with the sulfonated polystyrene collodion base membrane. It has been shown that the initial ion distributions in the membrane play a predominant role in the relaxation phenomena.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.80.2-80.2
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• 2010

The development of high temperature-proton exchange fuel cell (HT-PEFC) is a key in solving the problem of carbon monoxide poisoning of the platinum at anode as well as water management in PEFCs operated below $90^{\circ}C$. In order to overcome these main issues, PEFCs must be operated at high temperature above $120^{\circ}C$. Ionic liquids are available for HT-PEFC due to exhibiting non-volatility and thermal stability. Ionic liquids are however leached out from polymeric matrix resulting in the increase of gas permeability. In this study, we have prepared and characterized the composite membranes with the ionic liquids consisting of 1-(4-vinylbenzyl)-3-butyl imidazolium chloride immobilized by the cross-linkers in pore-filling membrane to prevent to be leached out from the membrane. We confirmed that cross-linked ionic liquids were not leached out from the composite membranes through the various characteristic analyses. It was also verified that the prepared membranes are thermally stable from the result of TG analysis. The pore-filling membranes with the immobilized ionic liquids have a high proton conductivity over $10^{-2}$ S/cm at high temperature (> $120^{\circ}C$).

• 대한방사선기술학회지:방사선기술과학
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• 제44권4호
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• pp.335-342
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• 2021

Studies on the side effects of contrast agents are being discussed based on various cases, but studies analyzing the chemical structure of the underlying contrast agents are difficult to understand as the manufacturers have not disclosed them. Therefore, in this study, the chemical structure of the contrast medium was analyzed using ¹H-NMR spectrometer for Omnipaque contrast medium prepared from Iohexol, which is a nonionic iodide contrast medium, Xenetix contrast medium from Iobitridol, and Iomeron contrast medium from Iomeprol. As a result, it was found that the Omnipaque contrast medium of Iohexol had 6 carboxyl groups, 3 carbonyl groups, 4 amine groups, 1 methyl group, and 2 cyano groups. It was found that the Xenetix contrast medium of the iobitridol formulation had 6 carboxyl groups, 3 carbonyl groups, 2 amine groups, and 4 cyano groups. It was found that the Iomeron contrast agent of the Iomeprol formulation had 5 carboxyl groups, 3 carbonyl groups, 4 amine groups, 1 methyl group, and 2 cyano groups. As shown in this study, the chemical structure of the non-ionic monomer contrast agent increases its affinity with water by binding a number of hydroxyl groups (OH) to the carboxyl group. It is necessary to accurately identify each of these factors and analyze the physical and chemical changes of the contrast medium according to various environmental factors.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제24회 KOSCO SYMPOSIUM 논문집
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• pp.179-184
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• 2002

Interaction between flames and non-thermal plasmas of DBD type has been experimentally investigated. Vigorous streamers were observed under flame conditions because of the increase of reduced field (electrical) at high temperature as well as the seeding of free electrons and ions generated inside the flame. Flame lengths were significantly shortened as the applied voltage increased on account of intense mixing by ionic winds and soot-induced flows. Flame luminosities severely decreased under plasma conditions, which means the reduction of soot, since the residence time was reduced because of the flame shortening. Temperature and major species concentrations measured by FTIR were not changed despite the plasma generation. which shows overall chemistries were not affected by non-thermal plasmas.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.608-612
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• 2012

We investigated the cycling behavior of $Li_4Ti_5O_{12}$ electrode in a cross-linked gel polymer electrolyte based on non-flammable ionic liquid consisting of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide and vinylene carbonate. The $Li_4Ti_5O_{12}$ electrodes in ionic liquid-based gel polymer electrolytes exhibited reversible cycling behavior with good capacity retention. Cycling data and electrochemical impedance spectroscopy analyses revealed that the optimum content of the cross-linking agent necessary to ensure both acceptable initial discharge capacity and good capacity retention was about 8 wt %.

• Applied Science and Convergence Technology
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• 제26권1호
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• pp.6-10
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• 2017

We investigated the stability of ionic configurations of the tip of the cantilever in non-contact AFM.; For this, we used a computational model that couples the ionic motion of the MgO surface and the oscillating cantilever. The motion of ions was connected to the oscillating cantilever using a coupling method that had been recently developed. The adhesive process on the ionic MgO surface leads to energy dissipation of the cantilever. It is shown that limited types of ionic configurations of the tip are stable during the adhesive process. Based on the present computational model, we discuss the adhesive mechanism leading to energy dissipation.

• Elastomers and Composites
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• 제56권3호
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• pp.117-123
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• 2021

Electronic skin (or E-skin) is an artificial smart skin composed of one or more than two sensors. E-skins detect external stimuli and convert them into electrical signals. Various types of E-skin sensors exist, including mechanical, physical, and chemical, depending on the detection signals involved. For wearable E-skins with superior sensitivity and reliability, developing conductors that possess both good elasticity and sensitivity is essential. Typical electrical conductors used in these sensors show very high sensitivity, but they have drawbacks such as non-linearity, irreversibility, and a narrow sensing range. To address these issues, stretchable and lightweight ionic conductors have been actively used in E-skin applications. This study summarizes the recent progress on various types of ionic conductors and ionic-conductor-based E-skin sensors.

• 한국미생물·생명공학회지
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• 제45권1호
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• pp.51-56
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• 2017

목질계 바이오 매스 전처리에 사용되는 ionic liquid는 전처리 후 100% 회수되지 않아 잔존하는 ionic liquid의 독성이 직접적으로 미생물 균주의 생육에 나쁜 영향을 미쳐 에탄올 발효의 수율 및 생산성을 저해하는 문제를 가지고 있다. 본 연구에서는 ionic liquid에 저해를 받지 않으며 높은 ethanol 생산 효율을 가진 균주를 얻고자 유도적 돌연변이 유발 실험을 진행하였다. 선별된 돌연변이 균주 D452-B2와 D452-S3는 3% [EMIM][Ac]가 포함된 배지에서 glucose 소비속도는 $4.5g{\cdot}l^{-1}{\cdot}h^{-1}$와 $4.4g{\cdot}l^{-1}{\cdot}h^{-1}$로 모균주인 S. cerevisiae D452-2 균주에 비해 6배 가량 증가하였으며, ethanol 생산성은 각각 $1.99g{\cdot}l^{-1}{\cdot}h^{-1}$와 $2.0g{\cdot}l^{-1}{\cdot}h^{-1}$로 27배 가량 증가하였다.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1616-1622
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• 2022

Selenium has been identified as an element of interest for the safety assessment of a deep geological repository (DGR) for used nuclear fuel. In Canada, groundwaters at DGR depths in sedimentary rocks have been observed to have a high ionic strength. This paper examines the sorption behavior of Se(-II) onto illite, MX-80 bentonite, Queenston shale, and argillaceous limestone in Na-Ca-Cl solutions of varying ionic strength (0.1-6 mol/kgw (m)) and across a pH range of 4-9. Little ionic strength dependence for Se(-II) sorption onto all solids was observed except that sorption at high ionic strength (6 m) was generally slightly lower than sorption at low ionic strength (0.1 m). Illite and MX-80 exhibited the expected results for anion sorption, while shale and limestone exhibited more constant sorption across the pH range tested. A non-electrostatic surface complexation model successfully predicted sorption of Se(-II) onto illite and MX-80 using the formation of an inner-sphere surface complex and an outer-sphere surface complex. Optimized values for the formation reactions of these surface species were proposed.