• Asian Journal of Atmospheric Environment
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• v.11 no.4
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• pp.235-253
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• 2017

This study was conducted for analyzing the contribution factors on ozone concentrations and its long term trends in each major city and province in Korea through several statistical methods such as simple linear regression, generalized linear model, KZ-filer, correlation matrix, Kringing method, and cluster analysis. The overall ozone levels in South Korea have been consistently increasing over the past 10 years. The ozone concentrations in Seoul, the biggest city in Korea, are the lowest in all areas with the highest increasing ratio for $95^{th}%$ ozone. It is thought that the active photochemical reaction could affect the higher ozone concentration increase. On the other hand, the ozone concentrations in Jeju are the highest in Korea with the highest increasing ratio for $5^{th}%$, $33^{th}%$, and $50^{th}%$ ozone. It is also thought that the weak $NO_x$ titration could be the reason of higher ozone concentrations in Jeju. In case of Jeju, transport related factors is the major factor affecting the ozone trend. Thus, it is assumed that the variation of ozone trend of Asian region affecting the ozone trend in Jeju, where domestic ozone photochemical reaction is less active than urban area. It is thought that the photochemical reaction plays the role of increasing of ozone concentrations in the urban area, even though the LRT affected on the increase of ozone concentrations in non-urban area.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.E1
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• pp.16-28
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• 2007

An improved method was developed to determine gas-phase hydrogen peroxide($H_2O_2$) and organic hydro-peroxides (ROOH) in real-time, The analytical system for $H_2O_2$ is based on formation of hydroxybenzoic acid (OHBA), a strong fluorescent compound. OHBA is formed by a sequence of reactions, photoreduction of Fe(III)-EDTA to Fe(II)-EDTA, the Fenton reaction of Fe(II)-EDTA with $H_2O_2$, and hydroxylation of benzoic acid. By use of this analytical method rather than a previous similar method, Fenton reaction time was reduced from 2 min. to 30s. Air samples were collected by a surfaceless inlet to prevent inlet line losses. With a special arrangement of the sampling apparatus, sample delivery time was drastically reduced from ${\sim}5\;min\;to\;{\sim}20\;s$. The automated system was found to be sensitive, capable of continuous monitoring, and affordable to operate. A comparison of this method with a well-established one showed an excellent linear correlation, validating applicability of this technique to $H_2O_2$ determination. The system was applied to field measurements conducted during summertime of 2004 in Gwangju, South Korea. $H_2O_2$ was found to be a predominant species of peroxides. The diurnal variation of $H_2O_2$ displayed the maximum in early afternoon and the broad minimum throughout night. $H_2O_2$ was correlated positively with ozone, photochemical age, and temperature, however, negatively with $NO_x$ and relative humidity.

• Polymer(Korea)
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• v.24 no.6
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• pp.837-844
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• 2000

The cure behavior of commercial epoxy molding compounds (EMC) commonly used for IC package was studied at constant cure temperatures as well as at constant heating rates using differential scanning calorimetry (DSC), rheometer, and dielectric analyzer (DEA). The cure kinetics were obtained using autocatalytic reaction model according to the Ryan Dutta method after assuming m+n equal to 2. The prediction of reaction rates by the model equation corresponded well to experimental data at all temperatures except for 10$0^{\circ}C$. The phase transitions such as gelation and vitrification occurred during network formation. At each isothermal cure temperature, $T_{g}$ was measured in accordance with cure time, and the vitrification point was attained when $T_{g}$ was equal to $T_{cure}$. The temperature dependence of gel points and vitrification points showed good agreement with Arrhenius relation. DEA using parallel plate electrode was effective for the monitoring of EMC cure. we knew that if the resin systems are materials of comparable quality, $_{gel}$$T_{g}$ is constant regardless of accelerator concentration in TTT (Time-Temperature-Transformation) diagram.

• The Korean journal of internal medicine
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• v.33 no.6
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• pp.1203-1209
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• 2018

Background/Aims: Adverse drug reaction (ADR) is an appreciably harmful or unpleasant reaction, resulting from an intervention related to the use of a medicinal product. The present study was conducted in order to monitor the frequency and severity of ADR during antimicrobial therapy of septicemia. Methods: A prospective, observational, and noncomparative study was conducted over a period of 6 months on patients of septicemia admitted at a university hospital. Naranjo algorithm scale was used for causality assessment. Severity assessment was done by Hartwig severity scale. Results: ADRs in selected hospitalized patients of septicemia was found to be in 26.5% of the study population. During the study period, 12 ADRs were confirmed occurring in 9, out of 34 admitted patients. Pediatric patients experienced maximum ADRs, 44.4%. Females experienced a significantly higher incidence of ADRs, 66.7%. According to Naranjo's probability scale, 8.3% of ADRs were found to be definite, 58.3% as probable, and 33.3% as possible. A higher proportion of these ADRs, 66.7% were preventable in nature. Severity assessment showed that more than half of ADRs were moderate. Teicoplanin was found to be the commonest antimicrobial agent associated with ADRs, followed by gemifloxacin and ofloxacin. Conclusions: The incidence and severity of ADRs observed in the present study was substantially high indicating the need of extra vigilant during the antimicrobial therapy of septicemia.

• Biomedical Science Letters
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• v.27 no.1
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• pp.35-43
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• 2021

Human Sapovirus (HuSaV) is one of the major causes of acute gastroenteritis in humans, and it is used as a molecular diagnostic technique based on polymerase chain reaction (PCR) from humans, food, shellfish, and aquatic environments. In this study, the HuSaV diagnosis technique was used in an aquatic environment where a number of PCR inhibitors are included and pathogens, such as viruses, are estimated to exist at low concentration levels. HuSaV-specific primers are improved to detect 38 strains registered in the National Center for Biotechnology Information (NCBI). The established optimal condition and the composition, including the RT-nested PCR primers and SL® Non-specific reaction inhibitor, were found to have 100 times higher sensitivity based on HuSaV plasmid than the previously reported methods (100 ag based on HuSaV plasmid 1 ng/μL). Through an artificial infection test, the developed method was able to detect at least 1 fg/μL of HuSaV plasmid contaminated with total nucleic acid extracted from groundwater. In addition, RT-nested PCR primer sets for HuSaV detection can react, and a positive control is developed to verify false positives. This study is expected to be used as a HuSaV monitoring method in the future and applied to the safety response to HuSaV from water environments.

• Ecology and Resilient Infrastructure
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• v.10 no.4
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• pp.125-134
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• 2023

In order to develop a backtracking technique for turbidity measurement data without discriminatory characteristics, three turbidity backtracking techniques for predicting inflow turbidity of a stream were compared using real-time turbidity data measured at automatic water quality measurement points located upstream and downstream of the stream and the Py_STPS model. Three turbidity backtracking techniques were applied: 1) simple preservation method of turbidity load considering flow time, 2) a method of using the flow rate at the upstream boundary considering the flow time as the flow rate at the downstream boundary, 3) method of introducing internal reaction rate to reflect the behavior characteristics of turbidity-causing substances. As a result of applying the three backtracking models, it was confirmed that the backtracking technique that introduced the internal reaction rate had the best results.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.108-109
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• 2013

Mitochondria play key roles in the production of cell's energy. Their dominant function is the synthesis of adenosine 5'-triphosphate (ATP) from adenosine diphosphate (ADP) and phosphate (Pi) through the oxidative phosphorylation. Evaluation of drug-induced mitochondrial toxicity has become increasingly important since mitochondrial dysfunction has recently been implicated in numerous diseases including cancer and diabetes mellitus. Mitochondrial functions have been monitored via oxygen consumption, mitochondrial membrane potential, and more importantly via ATP synthesis since ATP synthesis is the most essential function of mitochondria. Various analytical methods have been employed to investigate ATP synthesis in mitochondria, including high performance liquid chromatography (HPLC), bioluminescence technique, and pH measurement. However, most of these methods are based on destructive analysis or indirect monitoring through the enzymatic reaction. Infrared absorption spectroscopy (IRAS) is one of the useful techniques for real-time, label-free, and direct monitoring of biological reactions [1,2]. However, the strong water absorption requires very short path length in the order of several micrometers. Transmission measurements with thin path length are not suitable for mitochondrial assays because solution handlings necessary for evaluating mitochondrial toxicity, such as rapid mixing of drugs and oxygen supply, are difficult in such a narrow space. On the other hand, IRAS in the multiple internal reflection (MIR) geometry provides an ideal optical configuration to combine solution handling and aqueous-phase measurement. We have recently reportedon a real-time monitoring of drug-induced necrotic and apoptotic cell death using MIR-IRAS [3,4]. Clear discrimination between viable and damaged cells has been demonstrated, showing a promise as a label-free and real-time detection for cell-based assays. In the present study, we have applied our MIR-IRAS system to mitochondria-based assays by monitoring ATP synthesis in isolated mitochondria from rat livers. Mitochondrial ATP synthesis and hydrolysis were in situ monitored with MIR-IRAS, while dissolved oxygen level and solution pH were simultaneously monitored with O2 and pH electrodes, respectively. It is demonstrated that ATP synthesis and hydrolysis can be monitored by the IR spectral changes in phosphate groups in adenine nucleotides and MIR-IRAS is useful for evaluating time-dependent drug effects of mitochondrial toxicants.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.4
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• pp.317-326
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• 2020

Deep blocking of consciousness alone does not prevent a reaction to severe stimuli, and copious amounts of pain medication do not guarantee unconsciousness. Therefore, anesthesia must satisfy both: the loss of consciousness as well as muscle relaxation. Muscle relaxants improve the intra-bronchial intubation, surgical field of vision, and operating conditions, while simultaneously reducing the dose of inhalation or intravenous anesthesia. Muscle relaxants are also very important for breathing management during controlled mechanical ventilation during surgery. Excessive dosage of such muscle relaxants may therefore affect neurological examinations during surgery, but an insufficient dosage will result in movement of the patient during the procedure. Hence, muscle relaxation anesthesia depth and neurophysiological monitoring during surgery are closely related. Using excessive muscle relaxants is disadvantageous, since neurophysiological examinations during surgery could be hindered, and eliminating the effects of complete muscle relaxation after surgery is challenging. In the operation of neurophysiological monitoring during the operation, the anesthesiologist administers muscle relaxant based on what standard, it is hoped that the examination will be performed more smoothly by examining the trends in the world as well as domestic and global trends in maintaining muscle relaxant.

• Applied Biological Chemistry
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• v.29 no.2
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• pp.190-197
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• 1986

In order to develop a simple and effective method for determining the rate of the Maillard reaction in non-fat dry milk, the carbon dioxide content of the headspace as an indicator were used and the amount of correlation between $CO_2$ content and brown color development were determined by the gas chromatograph. There is a high correlation between brown color and $CO_2$ content. The use of gas chromatography to analyze the $CO_2$ in the headspace of samples is a quick, simple and effective method of monitoring the Maillard reaction. Volatile concentration increases with storage time and varies inversely with oxygen content. Lysine is more effective than glucose in catalyzing the Maillard reaction. Product samples can be stored at $55^{\circ}C$ and $68^{\circ}C$ to accelerate the rate of the Maillard reaction and shorten testing period, but product stored at $75^{\circ}C$ is degraded too rapidly to be of any real use.

• Journal of Hydrogen and New Energy
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• v.9 no.2
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• pp.77-84
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• 1998

Hydrogen isotope exchange in mixtures of $H_2O/D_2$, $H_2O/D_2O$, or $D_2O/H_2$ can be facilitated under electrical discharge. For example, a simple DC corona discharge through the mixture creates a plasma in which the reactants are excited energetically. The reactants in such plasma, due to increase in population of excited quantum levels or due to production of radicals or ions, undergo very rapid chemical reactions even at ambient temperature. The isotope exchange reaction of hydrogen(H) and deuterium(D) produces the third kind of heavy water(HDO) and isotopic hydrogen gas(HD), as shown in $D_2+H_2O{\rightarrow}HD$ K=11.257(at $25^{\circ}C$) The reaction products can be detected with temporal resolution using the Fourier transform infrared(FTIR) absorption spectroscopy. Since $H_2O$, $D_2O$ and HDO are all infrared active with different absorption peaks, FTIR proves to be a useful tool for monitoring the reaction. Experimental results show that the electrical method is indeed a useful means to promote the reaction, showing a better efficiency than traditional catalytic methods.