• Membrane and Water Treatment
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• v.10 no.2
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• pp.127-137
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• 2019

The D2EHPA/TBP co-extractants immobilized PolyHIPE membrane can be used for the selective separation of Mn (II) from Co (II). By solvent-nonsolvent method, D2EHPA/TBP co-extractants can be effectively immobilized into PolyHIPE membrane. The pore structure of PolyHIPE membrane and the presence of TBP enhance the stability of immobilized co-extractants. The optimal operating conditions for the separation of Mn (II) and Co (II) are feeding phase at pH 5.5, sulfuric acid concentration in the stripping phase of about 50 g/L and stirring speed at 400 rpm. The D2EHPA/TBP co-extractants ratio of 5:1 shows synergetic effect on Mn/Co separation factor about 22.74. The removal rate and recovery rate of Mn (II) is about 98.4 and 97.1%, respectively, while for Co (II) the transport efficiency is insignificant. The kinetic study of Mn (II) transport shows that high initial flux, $J_f^o=80.1({\mu}mol/m^2s)$, and maxima stripping flux, $J_s^{max}=20.8({\mu}mol/m^2s)$, can be achieved with D2EHPA/TBP co-extractants immobilized PolyHIPE membrane. The stability and reusability study shows that the membrane can maintain a long term performance with high efficiency. High purity of Co (II) and Mn (II) can be recovered from the feeding phase and stripping phase, respectively.

• Journal of the Korean Chemical Society
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• v.67 no.1
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• pp.54-63
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• 2023

In this study, six types of 2015 revised curriculum ChemistryII textbooks were analyzed for conditions, definitions, whether or not critical points were displayed, and real-life examples of phase diagram. In this study, it was confirmed that the problems pointed out in several previous studies were not reflected in the 2015 revised curriculum ChemistryII textbook. The same as the situation defining the phase diagram, the translation of the phase diagram into a phase equilibrium diagram, the distinction between phase and state being unclear, the critical point not being shown in the phase diagram, real life examples are very limited what is being presented as is suggested as a problem. Therefore, it is necessary to reflect the results of various previous studies in the revised curriculum ChemistryII textbook that will be made in the future, specify the conditions under which the phase diagram is drawn, newly model the situation defining the phase diagram, and translate the phase diagram as a 'phase diagram'. It is necessary to use the term, clarify the distinction between phase and state, mark the critical point in the phase diagram, and develop various real-life examples.

• The Korean Journal of Applied Statistics
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• v.32 no.1
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• pp.1-13
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• 2019

An adaptive seamless Phase II/III clinical trial design enables a reduction in the sample size (in comparison to a conventional design) that also shortens the clinical development time. It is also very effective in clinical trials since it can have higher statistical power than Phase III alone. In this study, we use extensive simulation studies to compare several multiple hypothesis testing methods that can help select the best doses in a Phase II study along with several methods to combine p-values of the Phase II and Phase III study.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.911-920
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• 2006

Phenolic antioxidant butylated hydroxyanisole (BHA) is a commonly used food preservative with broad biological activities, including protection against chemical-induced carcinogenesis, acute toxicity of chemicals, modulation of macromolecule synthesis and immune response, induction of phase II detoxifying enzymes, as well as its undesirable potential tumor-promoting activities. Understanding the molecular basis underlying these diverse biological actions of BHA is thus of great importance. Here we studied the pharmacokinetics, activation of signaling kinases and induction of phase II/III drug metabolizing enzymes/transporter gene expression by BHA in the mice. The peak plasma concentration of BHA achieved in our current study after oral administration of 200 mg/kg BHA was around $10\;{\mu}M$. This in vivo concentration might offer some insights for the many in vitro cell culture studies on signal transduction and induction of phase II genes using similar concentrations. The oral bioavailability (F) of BHA was about 43% in the mice. In the mouse liver, BHA induced the expression of phase II genes including NQO-1, HO-1, ${\gamma}-GCS$, GST-pi and UGT 1A6, as well as some of the phase III transporter genes, such as MRP1 and Slco1b2. In addition, BHA activated distinct mitogen-activated protein kinases (MAPKs), c-Jun N-terminal kinase (JNK), extracellular signal-regulated protein kinase (ERK), as well as p38, suggesting that the MAPK pathways may play an important role in early signaling events leading to the regulation of gene expression including phase II drug metabolizing and some phase III drug transporter genes. This is the first study to demonstrate the in vivo pharmacokinetics of BHA, the in vivo activation of MAPK signaling proteins, as well as the in vivo induction of Phase II/III drug metabolizing enzymes/transporters in the mouse livers.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.604-611
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• 2021

Objective: The aim of this pilot study was to investigate the potential of early-phase single-photon emission computed tomography (SPECT)/computed tomography (CT) using technetium-99m methyl diphosphonate (^99mTc-MDP) for diagnosing osteomyelitis (OM). Materials and Methods: Twenty-one patients with suspected OM were enrolled retrospectively. Three-phase bone scan (TPBS), early-phase SPECT/CT (immediately after blood pool planar imaging), and delayed-phase SPECT/CT (immediately after delayed planar imaging) were performed. The final diagnoses were established through surgery or clinical follow-up for over 6 months. We compared three diagnostic criteria based on (I) TPBS alone, (II) combined TPBS and delayed-phase SPECT/CT, and (III) early-phase SPECT/CT alone. Results: OM was diagnosed in 11 of 21 patients (nine surgically and two clinically). Of the 11 OM patients, criterion-I, criterion-II, and criterion-III were positive in six, seven, and 10 patients, respectively. Of the 10 non-OM patients, criterion-I, criterion-II, and criterion-III were negative in five, five, and seven patients, respectively. The sensitivity/specificity/accuracy of criterion-I, criterion-II, and criterion-III for diagnosing OM were 54.5%/50.0%/55.0%, 63.6%/50.0%/57.1%, and 90.9%/70.0%/87.5%, respectively. Conclusion: This pilot study demonstrated the potential of using the early-phase SPECT/CT to diagnose OM. Based on the results, prospective studies with a larger sample size should be conducted to confirm the efficacy of early-phase SPECT/CT.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.6
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• pp.641-646
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• 2004

We report the changes of the microwave reflection coefficients S$_{11}$ of copper(II)-phthalocyanine (CuPc) thin films by using a near-field microwave microscope(NSMM) in order to understand the phase transition of CuPc. For a NSMM system, a high-quality microstrip resonator coupled with a dielectric resonator was used. CuPc thin films were prepared on the pre-heated glass substrates using a thermal evaporation method. The reflection coefficients S$_{11}$ of CuPc thin films were changed by the dependence on the substrate pre-heating temperatures. By comparing reflection coefficient S$_{11}$ and crystal structures, we found the phase transition of CuPc thin films from $\alpha$-phase to $\beta$-phase at the substrate heating temperature 200 $^{\circ}C$./TEX>.

• Membrane and Water Treatment
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• v.13 no.4
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• pp.201-208
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• 2022

Emulsion Liquid Membrane (ELM) is a prominent technique for the separation of heavy metal ions from wastewater due to the fast extraction and is a single-stage operation of stripping-extraction. The selection of the components (Surfactant and Carrier) of ELM is a very significant step for its preparation. In the ELM technique, the primary water- in-oil (W/O) emulsion is emulsified in water to produce water-in-oil-in-water (W/O/W) emulsion. The water in oil emulsion was prepared by mixing the membrane phase and internal phase. To prepare the membrane phase, the extractant D2EHPA (di-2-ethylhexylphosphoric acid) was used as a mobile carrier, Span-80 as a surfactant, and Paraffin as a diluent. Moreover, the internal (receiving) phase was prepared by dissolving sulphuric acid in water. Di-(2- ethylhexyl) phosphoric acid such as surfactant concentration, carrier concentration, sulphuric acid concentration in the receiving (internal) phase, agitation time (emulsion phase and feed phase), the volume ratio of the membrane phase to the receiving phase, the volume ratio of the external feed phase to the primary water-in-oil emulsion and pH of feed were studied on the percentage extraction of metal ions at 20℃. The results show that it is possible to remove 78% for As(V), 98% for Cd(II), and 99% for Pb(II). Emulsion Liquid Membrane (ELM) is a well-known technique for separating heavy metal ions from wastewater due to the fast extraction and is a single-stage operation of stripping-extraction. The selection of ELM components (Surfactant and Carrier) is a very significant step in its preparation. In the ELM technique, the primary water-in-oil (W/O) emulsion is emulsified to produce water-in-oil-in-water (W/O/W) emulsion. The water in the oil emulsion was prepared by mixing the membrane and internal phases. The extractant D2EHPA (di-2-ethylhexylphosphoric acid) was used as a mobile carrier, Span-80 as a surfactant, and Paraffin as a diluent. Moreover, the internal (receiving) phase was prepared by dissolving sulphuric acid in water. Di-(2-ethylhexyl) phosphoric acid such as surfactant concentration, carrier concentration, sulphuric acid concentration in the receiving (internal) phase, agitation time (emulsion phase and feed phase), the volume ratio of the membrane phase to the receiving phase, the volume ratio of the external feed phase to the primary water-in-oil emulsion and pH of feed were studied on the percentage extraction of metal ions at 20℃. The results show that it is possible to remove 78% for As(V), 98% for Cd(II), and 99% for Pb(II).

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.1
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• pp.41-51
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• 2022

Purpose: Community-acquired bacterial enteritis (CABE) is a common problem in developed countries. It is important to understand the epidemiologic changes in bacterial pathogens for prevention and treatment. Therefore, we studied the epidemiologic changes in CABE in Korean children. Methods: A total of 197 hospitalized pediatric patients aged <19 years that presented with dysentery symptoms and showed positive polymerase chain reaction results for bacterial species in stool samples, were enrolled in this study for 10 years (June 2010 to June 2020). We classified patients in phase I (06, 2010-06, 2015) and phase II (07, 2015-06, 2020) and analyzed their epidemiologic and clinical characteristics. Results: The most common pathogens were Campylobacter species (42.6%) and Salmonella species were the second most common pathogens (23.9%). The abundance of pathogens decreased in the following order: Clostridium difficile (9.6%), Shigella (5.6%), and Clostridium perfringens (5.6%). Escherichia coli O157:H7 was found to be the rarest pathogen (2.0%). Campylobacter species showed an increase in the infection rate from 32.1% in phase I to 49.6% in phase II (p=0.0011). Shigella species showed a decline in the infection rate in phase I from 14.1% to 0.0% in phase II (p<0.001). C. difficile and C. perfringens showed an increase in infection rate in phase II compared to phase I, but the difference was not statistically significant. Conclusion: The infection rate of Campylobacter species in CABE has been rising more recently, reaching almost 50%. This study may help establish policies for prevention and treatment of CABE in Korean children.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.2
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• pp.107-112
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• 2016

The purpose of this study was to determine the effect of aquatic ramp walking exercise on the activity of the quadriceps, gait and activity of daily living in child with Spinal Muscular Atrophy (SMA) type II. A 5 years-old girl with SMA type II participated in this study. This study used single-subject reverse(A-B-A) design study. There are 12 sessions(4weeks 3 times a week) each during the baseline phase(A), the intervention phase(B), the follow up phase(A). During the baseline phase and the follow up phase performed general aquatic therapy, the intervention phase additional performed walking activity on ramp in pool (60m). Surface electromyogram, Timed Up and Go (TUG) test, ACTIVLIM were used as outcome. During the intervention phase, there were decrease on the activity of the quadriceps. In modified TUG test, gait time reduced during the intervention phase. The ACTIVLIM logit score increased during intervention phase by comparison with the baseline phase. These findings suggest that an aquatic ramp walking exercise activities have the therapeutic possibility on the quadriceps activity and gait ability for child with SMA type II.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.93-108
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• 2013

This study is aimed to prepare the effective detail survey methods(Phase II) of abandoned metal mines through the contamination assessment for mine types and facilities in the abandoned metal mine areas. The study sites of 12 abandoned mines are located in Gyeonggi-do and Gangwon-do and those were chosen among 310 sites that the Phase II survey was conducted from 2007 to 2009 after considering the results of Phase I for abandoned mines scattered all over the country. 12 study sites were classified into four types; Type I sites only have pit mouth. Type II sites have pit mouth and mine-waste field. Type III sites have pit mouth and tailing sorting field. Type IV sites have pit mouth, tailing sorting field and concentrator(s). In forest land, paddy soil and farm land of Type I, As and Cd were showed average concentration, and Cu and Pb were high on the pit mouth area in one mines where the pit mouth was developed within 500 m. In the mines of Type II, Cu and Pb were showed average concentration too, but As and Cd were slightly high in pit mouth and mine-waste field. The mines of Type III which had grinding particle process through physical separation milling or hitting showed similar tendency with Type II. However, mines of Type IV pit mouth, mine-waste field and showed various results depending on defining the contamination sources. For example, if contamination source was pit mouth, the mixed results of Type I, II, II were showed. In tailing sorting field which was regarded as the most important source and having high mobility, however, if there were no facilities or it was difficult to access directly, field sampling was missed occasionally during phase I and phase II survey. For that reason, the assessment for tailing sorting field is missed and it leads to completely different results. In the areas of Type I mines, the concentration of heavy metals exceeded precautionary standards of soil contamination or not within 1,000 meters of pit mouth. Nickel(Ni) was the largest factor of the heavy metal contamination in this type. The heavy metals except Arsenic(As) were shown high levels of concentration in Type II areas, where pit mouth and mine-waste field were operated for making powder in upriver region; therefore, to the areas in the vicinity of midstream and downstream, the high content of heavy metals were shown. The tendency of high level of heavy metals and toxic materials contained in flotation agent used during sorting process were found in soil around sorting and tailing field. In the abandoned-pit-mouth area, drygrinding area and tailing sorting field area, the content of Cupper(Cu) and Zinc(Zn) were higher than other areas. Also, the contaminated area were larger than mine reclamation area(2,000 m) and the location of tailing sorting field was one of the important factors to estimate contaminated area.