• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1158-1158
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• 2001

Fast and dynamic biochemical, enzymatic and morphological changes occur during the so-called generative development and during the vegetative processes in seeds. The most characteristic biochemical and compositional changes of this period are the formation and decline of storage components or their precursors, the change of their degree in polymerization and an extensive change in water content. The aim of the present study was to detect the maturation processes in seed nondestructively and to verify the applicability of near infrared spectroscopic methods in the measurement of physiological, chemical and biochemical changes in wheat seed. The amount and variation of different water “species” has been changed intensively during maturation. Characteristic changes of three water absorption bands (1920, 1420 and 1150 nm) during maturation were analysed. It was concluded that the free/bound transition of water molecules could be followed sensitively in different region of NIR spectra. Kinetic changes of carbohydrate reserves were characteristic during maturation. An intensive formation and decline of carbohydrate reserves were observed during early stage of maturation (0 -13 days, high energy demand). An accelerated formation of storage carbohydrates (starch) was detected in the second phase of maturation. Five characteristic absorption bands were analysed which were sensitive indicators the changes of carbohydrates occurred during maturation. Precursors of protein synthesis and the synthesis of reserve proteins and their kinetic changes during maturation were followed from NIR spectra qualitative and qualitatively. Dynamic formation of amino acids and the changes of N forms were detected by spectroscopic, chromatographic and by capillary electrophoresis methods. Calibration equations were developed and validated in order to measure the optimal maturation time protein and moisture content of developing wheat seeds. The spectroscopic methods are offering chance and measurement potential in order to detect fine details of physiological processes. The spectra have many hidden details, which can help to understand the biochemical background of processes.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2981-2987
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• 2011

A comparative study of the photodynamic and antioxidant activities of methyl pheophorbide-a (MPa, 1) and its transition metal(II) complexes (2-5) is described. Four transition metal complexes (palladium(II): 2, zinc(II): 3, cobalt(II): 4 and copper(II): 5) of MPa were prepared by reaction between the corresponding transition metal and 1, respectively, and were characterized by $^1H$-NMR and UV-vis spectroscopic and mass spectrometric analyses. In vitro results show a photodynamic therapy (PDT) efficacy with A549 cells might be attributed to a heavy atom effect of the transition metal complexes of MPa. Among them, 4 and 5 showed higher photodynamic activity than that of 1 at the concentration of 5 ${\mu}M$ at 24 h incubation after photoirradiation. The images of morphological change for 2-5 show evidence for the PDT effect with A549 cells. And the all transition metal complexes of MPa showed higher antioxidant activity than that of MPa, in which 4 showed the highest antioxidant activity.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.769-774
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• 2011

Porous carbon nanofibers(CNF) were synthesized via NaOH activation at 700~$900^{\circ}C$, and the porous CNF-supported PtRu catalysts were evaluated for the anode in direct methanol fuel cells. The change of surface characteristics by NaOH activation was examined by analyses of the specific surface area and pore size distribution. The morphological and structural modification was investigated under scanning electron microscopy. The activity of catalysts supported on porous CNFs was examined by cyclic voltammograms and single cell tests. The pore formation on CNF by the NaOH activation was discussed, concerning the catalyst activity, when they were applied as catalyst supports.

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.12-20
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• 1996

A multipotential hematopojetic cell line, 1(562 cell, was differentiated into megakaryocyte by a chemical inducer, PMA, with an enhanced expression of gpIlla accompaning with a distinct morphological change. On the other hand, 1(562 cells were differentiated into erythrocytes by other chemical inducers, DMSO or butyrate, with a concomitant increase in hemoglobin accumulation. An antigen of apparent molecular weight of 61 kDa was identified on the surface of 1(562 cells by using monoclonal antibody raised against 1(562 cells. The antigen was considered to be a glycoprotein molecule rich in sialic acids and the epitope of antigen was sensitive to neuraminidase digestion or peroxidase oxidation, but resistant to heat treatment. The 61 kDa surface antigen was increased or decreased in its expression along differentiation of 1(562 cells into megakaryocytes or erythrocytes, respedively.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.727-733
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• 2009

Effects of $Ca(OH)_2$ concentration(0.16~0.64 wt%), total volumetric flow rate(3~6 L/min) and $CO_2$ volume fraction(0.3~0.6) on morphology of the precipitated $CaCO_3$ and the mean particle size of the precipitated $CaCO_3$ were investigated in the slurry bubble column reactor. Experiments were carried out in acrylic reactor($0.11m-ID{\times}1.0m-high$) with a internal tube($0.04m-ID{\times}1.0m-high$). The calibration curve on the mass ratio of $CaCO_3$ to $Ca(OH)_2$ was obtained by FT-IR for the conversion of $Ca(OH)_2$ with the reaction time. The reaction rate of $Ca(OH)_2$ increased with increasing the volumetric flow rate of $CO_2$. From SEM images, the crystal size of $CaCO_3$ increased with increasing the reaction rate in the saturated concentration of $Ca(OH)_2$ (0.16 wt%). In addition, the crystal size of precipitated $CaCO_3$ decreased with increasing the concentration of $Ca(OH)_2$, but the mean particle size of precipitated $CaCO_3$ increased with increasing the concentration of $Ca(OH)_2$.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.320-326
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• 2013

In this study, various polyimide films were synthesized via low temperature cure in order to understand changes in their physical properties when using 4,4'-oxydianiline (ODA) as a diamine and dianhydride molecules with different backbones on a single diamine such as 4,4'-Oxydiphthalic anhydride (ODPA), 4,4-hexafluoroisopropylidene diphthalic dianhydride (6FDA), and 3,3', 4,4'-benzophenone tetracarboxylic dianhydride (BTDA). After the synthesis of poly(amic acid), polyimide films were fabricated by adding 1,4-diazabicyclo [2.2.2]octane (DABCO), a low-temperature catalyst, at various wt% to poly(amic acid)s. Changes of optical and thermal properties were compared and analyzed between polyimide films without catalyst and polyimide films with catalyst by FT-IR, UV-Vis transmittance, DSC/TGA, and WAXD analysis. Wide-angle X-ray diffraction (WAXD) analysis revealed that the mean intermolecular distance decreased with the use of a catalyst by the type of dianhydride. Thus, while the optical properties of the films improve by a low-temperature cure performed using a catalyst, their thermal properties decrease. These changes can be explained by the changes in the morphological structure of the films triggered by a catalyst-induced reduction in the mean intermolecular distance. Moreover, the results show that the type of dianhydride determines the degree of change in the optical and thermal properties in each types of polyimide, demonstrating that changes in the optical and thermal properties are directly associated with the backbone of the polyimide structure.

• Polymer(Korea)
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• v.29 no.3
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• pp.282-287
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• 2005

A novel ice particle leaching method for fabrication of porous and biodegradable PLGA scaffold has been proposed for the application to tissue engineering. After uniform mixing of poly(L-lactide-co-glycolide) (PLGA) and bovine serum albumin-fluorescein isothiocyanate (FITC-BSA), the FITC-BSA loaded scaffold was fabricated by adding various ratio of ice particle. The release profiles of FITC-BSA were examined using pH 7.4 PBS for 28 days at $37^{circ}$. The release amount was determined by fluorescence intensity by using the fluorescence spectrophotometer and the morphological change of the scaffolds was observed by scanning electron microscope. The release initial burst of BSA containing scaffolds was lower than that of simple dipping scaffolds resulting in constant release aspect. Although the BSA concentration increased. the initial burst was not increased. As a result of this study, it can be suggested that ice particle leaching method for the tissue engineered scaffold miff be very useful and it is possible to impregnate with water soluble factors like cytokine. We suggest that ice particle leaching method may be useful to tissue engineered organ regeneration.

• Journal of the Korean Chemical Society
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• v.65 no.4
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• pp.249-253
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• 2021

Litter and manure were obtained at a cow house of a livestock farm in Andondg city. We examined the change of formation of nitrogen and phosphorous from these samples and tried to suggest a more useful and realistic way for removing them. Constituent and its content of sample were identified by XRF. NO₂^-, NO₃^-, and PO₄^3- ions and NH₄⁺, T-P and T-N released from sample were analyzed using ion chromatograph and UV/Vis spectrometry, respectively. As the results of this study, the ammonia nitrogen in the early stage of cow excretion is a need to make an ammonia gas state that can be immediately volatile by increasing the pH. Nitrogen and phosphorous, the main source of nutrition in green algal bloom can be removed by transforming insoluble salts such as calcium phosphate (CaHPO₄·3H₂O) and struvite (NH₄MgPO₄·6H₂O), respectively, with addition of Ca and Mg after stimulating fermentation of manure.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.397-403
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• 2018

The leaves of Spiraea prunifolia were extracted with 80% aqueous MeOH and the concentrates were partitioned into EtOAc, n-BuOH, and $H_2O$ fractions. The repeated $SiO_2$ or ODS column, and medium pressure liquid chromatographies for the n-BuOH fraction led to isolation of two phenolic glucosides. The chemical structures of these compounds were determined as isosalicin (1) and crenatin (2) based on spectroscopic analyses including Nuclear magnetic resonance and MS. Extracts were analyzed using UPLC-MS/MS providing a short analysis time within 5 min using MRM technique. The concentration of crenatin was higher as 9.53 mg/g and isosalicin was lower as 0.65 mg/g. Neuroprotective effects of these compounds against hydrogen peroxide ($H_2O_2$)-induced neurotoxicity were evaluated. The results showed that exposure to $H_2O_2$ induced morphological changes, cell death and neurotoxicity in SK-N-MC cells. However, pretreatment with crenatin resulted in inhibition of morphological change, reduction of loss of cell viability and attenuation of neuronal damage. These results suggested that neuroprotective effect of crenatin isolated from S. prunifolia can be a good candidate for the development of health beneficial foods which can ameliorate the degenerative neuronal disease caused by oxidative stress.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.39-48
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• 2020

The present study investigates the chemical reaction and performance of ternary blended binders by mixing ferronickel slag. Cement was replaced using ground granulated blast furnace slag and ferronickel slag, combined up to 50% of the replacement rate. The blended cements were tested by setting times, length change, compressive strength at 1, 3, 7, 28 days. X-ray diffraction and scanning electron microscope were conducted for detecting hydration products while the MIP and microhydation heat were used for examining morphological characteristics. The results showed that by adding ferronickel slag, Pozzolanic reaction occurred, forming a dense pore structure and the effect of reducing hydration heat and dry shrinkage was also found. The compressive strength at 28 days was lower than that of 100% OPC control specimen (OSP0), but ternary blended cements showed no significant difference compared to binary blended (OSP50). If the optimal mix is derived later and used for the purpose, the potential for use as a cement binder is expected.