• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.19 no.1
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• pp.44-53
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• 2016

Purpose: Parenteral nutrition (PN) not only provides nutritional support but also plays a crucial role in the treatment of children with intestinal failure. The aim of this study was to evaluate the clinical significance and clinical outcomes of long-term PN. Methods: Retrospective cohort study was conducted using the medical records of patients treated at Seoul National University Children's Hospital. This study included 19 patients who received PN for over six months. Most patients received home PN. Results: The indications for PN included short bowel syndrome, chronic intestinal pseudo-obstruction, and intractable diarrhea of infancy. The median age of PN initiation was 1.3 years, and the median treatment duration was 2.9 years. Two patients were weaned from PN; 14 continued to receive PN with enteral feedings; and 3 patients died. The overall survival rates at 2 and 5 years were 93.3% and 84.0%, respectively. The incidence of catheter-related bloodstream infections was 2.7/1,000 catheter-days and was associated with younger age at PN initiation and lower initial height Z-score. Six patients developed catheter-related central vein thrombosis, with an incidence of 0.25/1,000 catheter-days. Eleven patients experienced PN-associated liver disease (PNALD), and one patient underwent multi-visceral transplant. The patients with PNALD exhibited lower final heights and body weight Z-scores. All patients experienced micronutrient deficiencies transiently while receiving PN. Conclusion: PN is an important and safe treatment for pediatric intestinal failure. PNALD was linked to final anthropometric poor outcomes. Micronutrient deficiencies were common. Anthropometric measurements and micronutrient levels must be monitored for successful PN completion.

• Archives of Pharmacal Research
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• v.22 no.2
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• pp.219-224
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• 1999

In our search for the anticonvulsant consitutent of Gastrodia elata repeated column chromatographies guided by activity assay led to isolation of an active compound, which was identified as gastrodin on the basis of spectral data. Brain succinic semialdehyde dehydrogenase (SSADH) was inactivated by preincubation with gastrodin in a time-dependent manner and the reaction was monitored by absorption and fluorescene spectroscopic methods. The inactivation followed pseudo-first-order kinetics with the second-rate order constant of $1.2{\times}10^{3} M^{-1} min^{-1}$. The time course of the reaction was significantly affected by the coenzyme NAD^{+}$, which affected complete protection against the loss of the catalytic activity, whereas substrate succinic semialdehyde failed to prevent the inactivation of the enzyme. It is postulated that the gastrodin is able to elevate the neurotransmitter GABA levels in central nervous system by inhibitory action on one of the GABA degradative enzymes, SSADH.

• Food Engineering Progress
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• v.13 no.2
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• pp.122-129
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• 2009

Ultraviolet (UV) is widely used as a sterilizing agent in restaurants and catering facilities in Korea. Efficacy of UV sterilizers (UVS) was investigated against E. coli on the inner bottom of stainless steel cups. UV intensity on the bottom of cups varied widely with the locations of cups in UVS, showing higher values at center while lower values at outskirts. The deviations in UV intensity were remarkable on top shelf, but alleviated as proceeded to middle and bottom shelves. Inactivation of E. coli was proportional to the UV intensity and treatment time, consequently to UV dose, and showed a pseudo-first-order kinetics with tailing. Initial inactivation rate constants ($K_{1}$) deviated with the locations of the cups, while final inactivation rate constants ($K_{2}$) showed comparable values. An equation for the calculation of the proposed UV treatment time was suggested.

• Bulletin of the Korean Chemical Society
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• v.18 no.10
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• pp.1061-1066
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• 1997

The complexes M(CO)4-1,2-(PPh2)2-1,2-C2B10H10 (M=Cr 2a, Mo 2b, W 2c) have been prepared in good yields from readily available bis-diphenylphosphino-o-carboranyl ligand, closo-1,2-(PPh2)2-1,2-C2B10H10 (1), by direct reaction with Group Ⅵ metal carbonyls. The infrared spectra of the complexes indicate that there is an octahedral disposition of chelate bis-diphenylphosphino-o-carboranyl ligand around the metal atom. The crystal structure of 2a was determined by X-ray diffraction. Complex 2a crystallizes in the monoclinic space group P21/n with cell parameters a = 12.2360(7), b = 17.156(1), c = 16.2040(6) Å, V = 3354.1(3) Å3, and Z =4. Of the reflections measured a total of 2514 unique reflections with F2 > 3σ(F2) was used during subsequent structure refinement. Refinement converged to R1 = 0.066 and R2 = 0.071. Structural studies showed that the chromium atom had a slightly distorted pseudo-octahedral configuration about the metal center with two phosphine groups of o-carborane occupying the equatorial plane cis-orientation to each other. These metal carbonyl complexes are rapidly converted to the corresponding metal carbene complexes, [(CO)3M=C(OCH3)(CH3)]-1,2-(PPh2)2-1,2-C2B10H10 (M= Cr 3a, Mo 3b, W 3c), via alkylation with methyllithium followed by O-methylation with CF3SO3CH3.

• Bulletin of the Korean Chemical Society
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• v.18 no.11
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• pp.1166-1172
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• 1997

[FeⅢ(BLPA)DBC]BPh4, a new functional model for the catechol dioxygenases, has been synthesized, where BLPA is bis((6-methyl-2-pyridyl)methyl)(2-pyridylmethyl)amine and DBC is 3,5-di-tert-butylcatecholate dianion. The BLPA complex has a structural feature that iron center has a six-coordinate geometry with N4O2 donor set. It exhibits EPR signals at g=5.5 and 8.0 which are typical values for the high-spin FeⅢ (S=5/2) complex with axial symmetry. The BLPA complex reacts with O2 within a few hours to afford intradiol cleavage (75%) and extradiol cleavage (15%) products which is very unique result of all [Fe(L)DBC] complexes studied. The iron-catecholate interaction of BLPA complex is significantly stronger, resulting in the enhanced covalency of the metal-catecholate bonds and low energy catecholate to FeⅢ charge transfer bands at 583 and 962 nm in CH3CN. The enhanced covalency is also reflected by the isotropic shifts exhibited by the DBC protons, which indicate increased semiquinone character. The greater semiquinone character in the BLPA complex correlates well with its high reactivity towards O2. Kinetic studies of the reaction of the BLPA complex with 1 atm O2 in CH3OH and CH2Cl2 under pseudo-first order conditions show that the BLPA complex reacts with O2 much slower than the TPA complex, where TPA is tris(2-pyridylmethyl)amine. It is presumably due to the steric effect of the methyl substituent on the pyridine ring. Nevertheless, both the high specificity and the fast kinetics can be rationalized on the basis of its low energy catecholate to FeⅢ charge transfer bands and large isotropic NMR shifts for the BLPA protons. These results provide insight into the nature of the oxygenation mechanism of the catechol dioxygenases.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.7
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• pp.875-880
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• 2019

A RC4 stream cipher is widely used for security applications such as IEEE 802.11 WEP, IEEE 802.11i TKIP and so on, because it can be simply implemented to dedicated circuits and achieve a high-speed encryption. RC4 is also used for systems with limited resources like IoT, but there are performance limitations. RC4 consists of two stages, KSA and PRGA. KSA performs initialization and randomization of S-box and K-box and PRGA produces cipher texts using the randomized S-box. In this paper, we initialize the S-box and K-box in the randomization of the KSA stage to reduce the initialization delay. In the randomization, we use clusters to process swap operation between elements of S-box in parallel and can generate two cipher texts per clock. The proposed RC4 cipher hardware can initialize S-box and K-box without any delay and achieves about 2 times to 6 times improvement in KSA randomization and key stream generation.

• The Korean Journal of Pain
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• v.32 no.1
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• pp.3-11
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• 2019

Going back to basics prior to mentioning the use of antipsychotics in patients with pain, the International Association for the Study of Pain (IASP) definition of pain can be summarized as an unpleasant experience, composed of sensory experience caused by actual tissue damage and/or emotional experience caused by potential tissue damage. Less used than antidepressants, antipsychotics have also been used for treating this unpleasant experience as adjuvant analgesics without sufficient evidence from research. Because recently developed atypical antipsychotics reduce the adverse reactions of extrapyramidal symptoms, such as acute dystonia, pseudo-parkinsonism, akathisia, and tardive dyskinesia caused by typical antipsychotics, they are expected to be used more frequently in various painful conditions, while increasing the risk of metabolic syndromes (weight gain, diabetes, and dyslipidemia). Various antipsychotics have different neurotransmitter receptor affinities for dopamine (D), 5-hydroxytryptamine (5-HT), adrenergic (${\alpha}$), histamine (H), and muscarinic (M) receptors. Atypical antipsychotics antagonize transient, weak $D_2$ receptor bindings with strong binding to the $5-HT_{2A}$ receptor, while typical antipsychotics block long-lasting, tight $D_2$ receptor binding. On the contrary, antidepressants in the field of pain management also block the reuptake of similar receptors, mainly on the 5-HT and, next, on the norepinephrine, but rarely on the D receptors. Antipsychotics have been used for treating positive symptoms, such as delusion, hallucination, disorganized thought and behavior, perception disturbance, and inappropriate emotion, rather than the negative, cognitive, and affective symptoms of psychosis. Therefore, an antipsychotic may be prescribed in pain patients with positive symptoms of psychosis during or after controlling all sensory components.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.289-296
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• 2020

BACKGROUND: There is a need for a revolutionary method to overcome the problem of biochar, which has relatively low adsorption capacity for existing anion pollutants, along with collectively recycling fallen leaves, a kind of forest by-product. Therefore, the objective of this study was to prepare iron-decorated biochar derived from fallen leaves (Fe-FLB), and to evaluate their adsorption properties to Congo red (CR) as anionic dye. METHODS AND RESULTS: The adsorption properties of CR by fallen leaves biochar (FLB) and Fe-FLB were performed under various conditions such as initial CR concentration, reaction time, pH and dosage with isotherm and kinetic models. In this study, Fe-FLB prepared through iron impregnation and pyrolysis of fallen leaves contained 56.9% carbon and 6.3% iron. Congo red adsorption by FLB and Fe-FLB was well described by Langmuir model and pseudo second order model and the maximum adsorption capacities of FLB and Fe-FLB were 1.1 mg/g and 25.6 mg/g, respectively. In particular, it was found that the adsorption of CR was occurred by chemical adsorption process by the outer boundary layer of Fe-FLB. CONCLUSION: Overall, the production of Fe-FLB using fallen leaves and using it as an anion adsorbent is considered to be a way to overcome the problem of biochar with relatively low anion adsorption in addition to the reduction effect of waste.

• Journal of the Korean Geotechnical Society
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• v.38 no.12
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• pp.29-43
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• 2022

Various underground facilities are being constructed to improve the urban environment. Therefore, it is more necessary than ever to reasonably evaluate the seismic response of underground utility tunnels, playing a significant part in urban infrastructure. In this study, the major features and differences of two types of existing pseudo-static analysis methods are reviewed. Each method uses a simplified 2D frame model to represent the seismic behavior of underground structures. Applying each method to a one-barrel rectangular utility tunnel in Korea, the suitability in predicting seismic responses, especially the racking deformation of the tunnel, is examined. In addition, several precautions and suggestions are provided in this study against the inattentive application of the methods to seismic evaluation of underground structures.

• Journal of Practical Engineering Education
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• v.16 no.2
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• pp.105-114
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• 2024

Recently, with an emphasis on software proficiency, universities are providing software education to all students regardless of their majors. However, non-majors often lack motivation for software education and perceive the unfamiliar learning content as more challenging. To address this issue, tailored software education according to the learners' characteristics is essential. Art students, for instance, with their strong visual comprehension and expressive abilities, can benefit from utilizing visual literacy to enhance the effectiveness of programming education. In this study, we propose decomposing everyday problems into flowcharts and pseudocode to construct procedural and visual images. Using the educational programming language PlayBot, we aim to analyze the effectiveness of teaching by coding to solve problems. Through this approach, students are expected to grasp programming concepts, understand problem-solving processes through computational thinking, and acquire skills to apply programming in their respective fields.