• Analytical Science and Technology
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• v.34 no.1
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• pp.23-35
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• 2021

In order to measure the volatile organic compounds (VOCs) of a sample which is too large to use commercially available chamber, a stainless steel vacuum chamber (VC) (with an internal diameter of 205 mm and a height of 50 mm) was manufactured and the temperature of the chamber was controlled using an oven. After concentrating the volatiles of the sample in the chamber by helium gas, it was made possible to remove residual volatile substances present in the chamber under reduced pressure ((2 ± 1) × 10-2 mmHg). The chamber was connected to a purge & trap (P&T) using a 6 port valve to concentrate the VOCs, which were analyzed by gas chromatography-mass spectrometry (GC-MS) after thermal desorption (VC-P&T-GC-MS). Using toluene, the toluene recovery rate of this device was 85 ± 2 %, reproducibility was 5 ± 2 %, and the detection limit was 0.01 ng L-1. The method of removing VOCs remaining in the chamber with helium and the method of removing those with reduced pressure was compared using Korean drinking water regulation (KDWR) VOC Mix A (5 μL of 100 ㎍ mL-1) and butylated hydroxytoluene (BHT, 2 μL of 500 ㎍ mL-1). In case of using helium, which requires a large amount of gas and time, reduced pressure ((2 ± 1) × 10-2 mmHg) only during the GC-MS running time, could remove VOCs and BHT to less than 0.1 % of the original injection concentration. As a result of analyzing volatile substances using VC-P&T-GC-MS of six types of cell phone case, BHT was detected in four types and quantitatively analyzed. Maintaining the chamber at reduced pressure during the GC-MS analysis time eliminated memory effect and did not affect the next sample analysis. The volatile substances in a cell phone case were also analyzed by dynamic headspace (HT3) and GC-MS, and the results of the analysis were compared with those of VC-P&T-GC-MS. Considering the chamber volume and sample weight, the VC-P&T configuration was able to collect volatile substances more efficiently than the HT3. The VC-P&T-GC-MS system is believed to be useful for VOCs measurement of inhomogeneous large sample or devices used inside clean rooms.

• Clean Technology
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• v.27 no.2
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• pp.168-173
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• 2021

The treatment of plated wastewater is subject to various and complex processes depending on the pH, heavy metal, and cyanide content of the wastewater. Alkali chlorine treatment using NaOCl is commonly used for cyanide treatment. However, if ammonia and cyanide are present simultaneously, NaOCl is consumed excessively to treat ammonia. To solve this problem, this study investigated 1) the consumption of NaOCl according to ammonia concentration in the alkaline chlorine method and 2) whether ferrate (VI) could selectively treat the cyanide. Experiments using simulated wastewater showed that the higher the ammonia concentration, the lower the cyanide removal rate, and the linear increase in NaOCl consumption according to the ammonia concentration. Removal of cyanide using ferrate (VI) confirmed the removal of cyanide regardless of ammonia concentration. Moreover, the removal rate of ammonia was low, so it was confirmed that the ferrate (VI) selectively eliminated the cyanide. The cyanide removal efficiency of ferrate (VI) was higher with lower pH and showed more than 99% regardless of the ferrate (VI) injection amount. The actual application to plated wastewater showed a high removal ratio of over 99% when the input mole ratio of ferrate (VI) and cyanide was 1:1, consistent with the molarity of the stoichiometry reaction method, which selectively removes cyanide from actual wastewater containing ammonia and other pollutants like the result of simulated wastewater.

• Journal of IKEEE
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• v.25 no.4
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• pp.782-785
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• 2021

In this paper, we propose a personalized cooling management system with thermal imaging camera. The proposed equipment uses a thermal imaging camera to control the amount of cold air and the system according to the difference between the user's skin temperature before and after the procedure. When the skin temperature is abnormally low, the cold air supply is cut off to prevent the possibility of a safety accident. It is economical by replacing the skin temperature sensor with a thermal imaging camera temperature measurement, and it can be visualized because the temperature can be checked with the thermal image. In addition, the proposed equipment improves the sensitivity of the sensor that measures the distance to the skin by calculating the focal length by using a dual laser pointer for the safety of a personalized cooling management system to which a thermal imaging camera is applied. In order to evaluate the performance of the proposed equipment, it was tested in an externally accredited testing institute. The first measured temperature range was -100℃~-160℃, indicating a wider temperature range than -150~-160℃(cryo generation/USA), which is the highest level currently used in the field. In addition, the error was measured to be ±3.2%~±3.5%, which showed better results than ±5%(CRYOTOP/China), which is the highest level currently used in the field. The second measured distance accuracy was measured as below ±4.0%, which was superior to ±5%(CRYOTOP/China), which is the highest level currently used in the field. Third, the nitrogen consumption was confirmed to be less than 0.15 L/min at the maximum, which was superior to the highest level of 6 L/min(POLAR BEAR/USA) currently used in the field. Therefore, it was determined that the performance of the personalized cooling management system applied with the thermal imaging camera proposed in this paper was excellent.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.4
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• pp.265-275
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• 2021

Findings of microplastics and nanoplastics from diverse natural environments have increased demand for research of the fate and transport of the potentially toxic plastic particles in soils and groundwater. Weathering of microplastics would generate a significant amount of nanoplastics, but nanoplastics research is scarce because of technical difficulties in detecting nanoplastics in environments and analyzing nanoplastics adsorption to mineral surfaces. In the current study, we tested a possibility using quartz crystal microbalance (QCM) for application to nanoplastics adsorption analysis on mineral surfaces. In silica (SiO₂)-packed column experiments, a measurable adsorption capacity for polystyrene nanoparticles often requires injection of unrealistically high ionic strengths or concentrated nanoplastic particles. The current test shows that QCM can measure polystyrene nanoplastics adsorbed onto SiO₂ surface under the low ionic strengths and nanoplastics concentrations, where typical column experiments cannot. QCM is a promising tool for understanding the interaction between nanoplastics and mineral surfaces and thus transport of nanoplastics in soils and groundwater.

• The Korea Journal of Herbology
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• v.34 no.5
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• pp.21-28
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• 2019

Objectives : In present study, we investigated a therapeutic effect and optimum dose of Socheongryong-Tang (SCT) on LPS-induced lung inflammation rats model. Methods : Male Sprague-Dawley rats ($260{\pm}10g$) were divided into 12 groups : Group 1 included the normal rats, and Group 2-12 were administrated LPS by intranasal injection to induce experimental lung inflammation. After 1 day of LPS administration, Group 3-9 were treated with SCT ${\times}1/4$, ${\times}1/2$, ${\times}1$, ${\times}3$, ${\times}6$, ${\times}12$ or ${\times}18$, respectively. Group 10-12 (positive control) were treated with dexamethasone 1 mg/kg or acetylcystein 1.5 mg/kg or diclofenac sodium 0.4 mg/kg, respectively. After sacrifice, bronchoalveolar lavage fluid (BALF) was isolated. The levels of IL-$1{\beta}$, TNF-${\alpha}$, mucin glycoprotein 5AC (MUG5AC) were measured in BALF using enzyme-linked immunosorbent assay (ELISA). Results : LPS injected rats exhibited outstanding lung inflammation manifestations, including increased amount of total cells and neutrophil, and upregulated inflammatory cytokines level in BALF. However, the administration of SCT ${\times}1/4$, ${\times}1/2$ and ${\times}1$ decreased total cells and neutrophil, and suppressed the production of inflammatory cytokines, including $IL-1{\beta}$ and TNF-${\alpha}$, and MUG5AC in BALF. Notably, inhibitory effect of SCT ${\times}1/2$ and ${\times}1$ on the level of TNF-${\alpha}$ was markedly better than that of positive controls, dexamethasone and acetylcystein. Conclusions : Taken together, these results suggest that SCT ${\times}1/2$ and ${\times}1$ has therapeutic effects on LPS-induced lung inflammation rats model.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.1
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• pp.19-28
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• 2023

Background: Fearful and anxious patients who find dental treatment intolerable without sedative and analgesic support may benefit from moderate sedation. Target controlled infusion (TCI) pumps are superior to bolus injection in maintaining low plasma and effect-site concentration variability, resulting in stable, steady-state drug concentrations. We evaluated the safety and efficacy of moderate sedation with remifentanil and propofol using TCI pumps in non-hospital dental settings. Methods: A prospective chart review was conducted on 101 patients sedated with propofol and remifentanil using TCI pumps. The charts were completed at two oral surgeons and one general dentist's office over 6 months. Hypoxia, hypotension, bradycardia, and over-sedation were considered adverse events and were collected using Tracking and Reporting Outcomes of Procedural Sedation (TROOPS). Furthermore, patient recovery time, sedation length, drug dose, and patient satisfaction questionnaires were used to measure sedation effectiveness. Results: Of the 101 reviewed sedation charts, 54 were of men, and 47 were of women. The mean age of the patients was 40.5 ±18.7 years, and their mean BMI was 25.6 ± 4.4. The patients did not experience hypoxia, bradycardia, and hypotension during the 4694 min of sedation. The average minimum Mean Arterial Pressure (MAP) and heartbeats were 75.1 mmHg and 60.4 bpm, respectively. 98% of patients agreed that the sedation technique met their needs in reducing their anxiety, and 99% agreed that they were satisfied with the sedation 24 hours later. The average sedation time was 46.9 ± 55.6 min, and the average recovery time was 12.4 ± 4.4 min. Remifentanil and propofol had mean initial effect-site concentration doses of 0.96 µ/.ml and 1.0 ng/ml respectively. The overall total amount of drug administered was significantly higher in longer sedation procedures compared to shorter ones, while the infusion rate decreased as the procedural stimulus decreased. Conclusion: According to the results of this study, no patients experienced adverse events during sedation, and all patients were kept at a moderate sedation level for a wide range of sedation times and differing procedures. The results showed that TCI pumps are safe and effective for administering propofol and remifentanil for moderate sedation in dentistry.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.589-595
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• 2023

If complete coronary artery occlusion occurs due to severer coronary spasm, malignant arrhythmias can lead to death. Therefore, early screening for coronary artery spasm angina is essential. Among the test methods, the drug injection test through coronary angiography is generally performed. Therefore, the purpose of this study was to evaluate the advantages of ergonovine drug test for vasospasitc angina examination during coronary angiography, such as the relationship between the procedure time, contrast medium usage, and radiation exposure effects of coronary angiography. Follow-up data of 142 patients who underwent coronary angiography and variant angina examination from september 2021 to february 2023 were used. As a result of analyzing contrast usage dose and dose area product and air kerma dose and number of imaging series and procedure time, variant angina examination was statistically significantly higher than coronary angiography. (p<0.001) In conclusion, variant angina examination other than coronary artery angiography are radiologically negative. Therefore, we think it is better to avoid excessive inspection. Nevertheless, in the case of the provocation test, the longer the examination time, the higher the fluoroscopy time and the amount of contrast medium used, so it is better to conduct the test as quickly as possible or shorten it.

• Clinical Pain
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• v.18 no.1
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• pp.24-30
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• 2019

Objective: Greater occipital nerve block (GONB) is a widely accepted treatment of primary headaches. Two ultrasound (US)-guided blockade techniques exist: 1) the classical distal nerve block technique performed medial to the occipital artery at the superior nuchal line, and 2) the new proximal nerve block technique performed at the obliquus capitis inferior muscle at the level of C2. Our study aim was to perform a head-to-head comparative study of these two US-guided techniques. Method: Forty-nine patients with primary headache treated in our university hospital were recruited. Patients were randomized into two groups of the classical nerve block and the new proximal nerve block techniques. The headache questionnaire was made to assess the intensity of the pain of headache attacks, number of days they experience headache, duration of headache, and amount of pain medication they consumed. Results: In both groups, a decrease in the severity and frequency of the headache was observed. There was no measurable difference in outcome between the two groups. Conclusion: Our study showed that the classic and new proximal techniques are equally effective in decreasing the headache severity and frequency.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.4
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• pp.221-232
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• 2023

Carbon neutrality requires carbon dioxide reduction technology and alternative green energy sources. Palygorskite is a clay mineral with a ribbon structure and possess a large surface area due to the nanoscale pore size. The clay mineral has been proposed as a potential material to capture carbon dioxide (CO₂) and possibly to store eco-friendly hydrogen gas (H2). We report our preliminary results of grand canonical Monte Carlo (GCMC) simulations that investigated the adsorption isotherms and mechanisms of CO₂ and H₂ into palygorskite nanopores at room temperature. As the chemical potential of gas increased, the adsorbed amount of CO₂ or H₂ within the palygorskite nanopores increased. Compared to CO₂, injection of H₂ into palygorskite required higher energy. The mean squared displacement within palygorskite nanopores was much higher for H₂ than for CO₂, which is consistent with experiments. Our simulations found that CO₂ molecules were arranged in a row in the nanopores, while H₂ molecules showed highly disordered arrangement. This simulation method is promising for finding Earth materials suitable for CO₂ capture and H₂ storage and also expected to contribute to fundamental understanding of fluid-mineral interactions in the geological underground.

• Animal Bioscience
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• v.37 no.1
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• pp.131-141
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• 2024

Objective: This experiment aimed to explore the protective action of dietary supplementation with isoquinoline alkaloids (IA) from Macleaya cordata on lipopolysaccharide (LPS)-induced liver injury in broilers. Methods: Total 216 healthy broilers were selected in a 21-d trial and assigned randomly to the following 3 treatments: control (CON) group, LPS group, and LPS+IA group. The CON and LPS groups were provided with a basal diet, whereas the LPS+IA group received the basal diet supplemented with 0.6 mg/kg Macleaya cordata IA. Broilers in LPS and LPS+IA groups were intraperitoneally injected with LPS (1 mg/kg body weight) at 17, 19, and 21 days of age, while those in CON group were injected with equivalent amount of saline solution. Results: Results showed LPS injection caused systemic and liver inflammation in broilers, inhibited immune function, and ultimately lead to liver injury. By contrast, supplementation of IA ameliorated LPS-induced adverse change in serum parameters, boosted immunity in LPS+IA group. Furthermore, IA suppressed the elevation of hepatic inflammatory cytokines and caspases levels induced by LPS, as well as the expressions of genes related to the toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor-kappa B (NF-κB) pathway. Conclusion: Dietary inclusion of 0.6 mg/kg Macleaya cordata IA could enhance immune function of body and inhibit liver damage via inactivating TLR4/MyD88/NF-κB signaling pathway in broilers.