• The Journal of Internal Korean Medicine
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• v.25 no.4
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• pp.129-139
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• 2004

Objectives : This study was done to examine the antioxidant actions of free radicals caused by Banryong-hwan in blood.. Methods : Twelve week-old SD rats were divied into normal group, control group and HTG group. Control and HTG groups were age-induced with D-galactose, and extract of Banryong-hwan(BRH) was administerd to BRH group for six weeks. After then, blood was taken, and activities of SOD and GSH-px in erythrocytes were measured, as well as TBARS levels and concentrations of total lipid tryglyceride in plasma. Results : 1. The activities of SOD and GSH-px in erythrocytes were significantly increased in the BRH group compared with control group. 2. The concentration of total lipid was significantly decreased in the BRH group compared with control group. The values of TBARS and the concentrations of tryglyceride in plasma showed a tendency to decrease but they were not remarkable. Conclusions : Judging from the above findings, it is suggested that Banryong-hwan decrease the activities of free radical, the concentrations of lipid in plasma and generate enzyme which form lipid peroxide.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.119-129
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• 2014

This work undertook to prepare nanofibers of cellulose nanofibrils (CNF)/polyvinyl alcohol (PVA) composite by electrospinning, and characterize the electrospun composite nanofibers. Different contents of CNFs isolated from hardwood bleached kraft pulp (HW-BKP) by 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO)-mediated oxidation were suspended in aqueous polyvinyl alcohol (PVA) solution, and then electrospun into CNF/PVA composite nanofibers. The morphology and dimension of CNFs were characterized by transmission electron microscopy (TEM), which revealed that CNFs were fibrillated form with the diameter of about $7.07{\pm}0.99$ nm. Morphology of the electrospun nanofiber observed by field-emission scanning electron microscopy (FE-SEM) showed that uniform CNF/PVA composite nanofibers were manufactured at 1~3% CNF contents while many beads were observed at 5% CNF level. Both the viscosity of CNF/PVA solution and diameter of the electrospun nanofiber decreased with an increase in CNF content. The diameter and its distribution of the electrospun nanofibers helped explain the differences observed in their morphology. These results show that the electrospinning method was successful in preparing uniform CNF/PVA nanofibers, indicating a great potential for manufacturing consistent and reliable cellulose-based nanofibrils for scaffolds in future applications.

• Journal of Applied Biological Chemistry
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• v.49 no.3
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• pp.82-85
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• 2006

Eucommia ulmoides bark extracts by cold water, boiling water, 100% EtOH, 70% EtOH, 100% MeOH, 70% MeOH and $CHCl_3$ were assayed for their medicinal effects. The antioxidant activity of the extracts ranged from $IC_{50}$ 125.2 to $IC_{50}\;872.7{\mu}g/ml$ in the 1,1-diphenyl-2-picrylhydrazyl (DDPH) free radical-scavenging assay, and cold water extracts had the highest antioxidant activity. $CHCl_3$ extracts had the highest inhibitory effect on angiotensin I-converting enzyme (ACE) giving inhibition of up to 56.4% at a concentration of 1 mg/ml. Extracts in 100% EtOH had the greatest inhibitory effect on $\acute{a}-amylase$ activity ($IC_{50}=174.6{\mu}g/ml$), and 70% MeOH extracts had the greatest inhibitory effect on ${\alpha}-glucosidase$ activity ($IC_{50}=14.0{\mu}g/ml$). Taken together, these results provided the in vitro evidence on the ACE, amylase and glucosidase inhibitory actions of E. ulmoides bark that form the pharmacological basis for its antihypertensive and antidiabetic action.

• Korean Journal of Head & Neck Oncology
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• v.29 no.2
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• pp.54-57
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• 2013

Malignant triton tumor(MTT) is a rare type of malignant peripheral nerve sheath tumor(MPNST) with focal rhabdomyoblastic differentiation. MTT constitutes about 5% of all MPNSTs and described the first case of a MTT in a patient with Von Recklinghausen disease by Masson in 1932. MTT is commonly seen in the head, neck, extremities and trunk. It can occur in sporadic form or over a setting of neurofibromatosis-1(NF-1). The diagnosis can be confirmed based on morphologic grounds supported by an immunostain such as S-100 protein. Desmin, myo-D1 and myogenin are immunostains positive for rhabdomyoblasts. MTT has an aggressive biological behavior so prognosis of this rare and highly malignant tumor is poor and optimal treatment remains unclear. But modern treatment consisted of radical excision and postoperative radiotherapy has improved the prognosis of such cases.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.117-122
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• 2014

As a Chinese herbal medicine used in East Asia for thousands years, Cortex Magnoliae Officinalis (CMO) was observed to possess a protective effect against OH-induced DNA damage in the study. To explore the mechanism, the antioxidant effects and chemical contents of five CMO extracts were determined by various methods. On the basis of mechanistic analysis, and correlation analysis between antioxidant effects & chemical contents, it can be concluded that CMO exhibits a protective effect against OH-induced DNA damage, and the effect can be attributed to the existence of phenolic compounds, especially magnolol and honokiol. They exert the protective effect via antioxidant mechanism which may be mediated via hydrogen atom transfer (HAT) and/or sequential electron proton transfer (SEPT). In the process, the phenolic-OH moiety in phenylpropanoids is oxidized to the stable quinine-like form and the stability of quinine-like can be ultimately responsible for the antioxidant.

• Journal of the Korean Chemical Society
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• v.34 no.3
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• pp.255-259
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• 1990

The nitrogen-laser flash photolysis apparatus has been set up to detect directly the transient produced from the excited Benoxaprofen (BXP). The function of the instrument has been tested by using anthracene as a standard sample. The laser photoexcitation of BXP in ethanol has been carried out under a constant stream of $N_2$ gas and a transient absorption spectrurn has been recorded over the 400-600 nm. The effects of oxygen and ${\beta}-carotene$ on the transient spectrum reveal that thee maximum transient absorption at 415 nm is attributed to the triplet state of BXP and the triplet energy of BXP is above 22 Kcal/mole. In addition to the triplet state, another transient species has been observed to be produced, which is probably a radical form of BXP. The photosensitization mechanism of BXP is discussed based on these results.

• Journal of the Korean Society of Combustion
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• v.5 no.2
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• pp.37-50
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• 2000

In the present study, a systematic chemical kinetic calculations were made to investigate the augmentation of $NO-NO_2$ conversion due to the addition of various hydrocarbons (methane, ethylene, ethane, propylene, propane) in the nonthermal plasma treatment. It is included in the present conclusion that the reaction between hydrocarbon and oxygen radicals induced by electron collision, is believed to be a primarily process for triggering the overall NO oxidation and the eventual NOx reduction. Upon the completion of the initiating step, various radicals (OH, $HO_2$ etc.) successively are produced by hydrocarbon decomposition form the primary path of $NO-NO_2$ conversion. When the initiating step is not activated, hydrocarbon consumption rate appeared to be very low, thereby the targeted level of NO conversion can only be achieved by the addition of more input energy. Present study showed ethylene and propylene to have higher affinity with O radical under all conditions, thereby both of these hydrocarbons show very fast and efficient $NO-NO_2$ oxidation. It was also shown that propylene is superior to ethylene in the aspect of NOx removal.

• Journal of the Korean Society of Combustion
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• v.11 no.1
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• pp.19-26
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• 2006

Structure of edge flame established in a mixing layer, formed between two uniformly flowing pure $CH_4$ and pure $O_2$ streams, is numerically investigated by employing a detailed methane-oxidation mechanism. The numerical results exhibited the most outstanding distinction of using pure oxygen in the fuel-rich premixed-flame front, through which the carbon-containing compound is found to leak mainly in the form of CO instead of HC compounds, contrary to the rich $CH_4-air$ premixed flames in which $CH_4$ as well as $C_2H_m$ leakage can occur. Moreover, while passing through the rich premixed flame, a major route for CO production, in addition to the direct $CH_4$ decomposition, is found to be $C_2H_m$ compound formation followed by their decomposition into CO. Beyond the rich premixed flame front, CO is further oxidized into $CO_2$ in a broad diffusion-flame-like reaction zone located around moderately fuel-rich side of the stoichiometric mixture by the OH radical from the fuel-lean premixed-flame front. Since the secondary CO production through $C_2H_m$ decomposition has a relatively strong reaction intensity, an additional heat-release branch appears and the resulting heat-release profile can no longer be seen as a tribrachial structure.

• Bulletin of the Korean Chemical Society
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• v.24 no.9
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• pp.1276-1280
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• 2003

Thermal behavior of bromphenols was investigated by direct pyrolysis at high temperature. The thermal degradation products formed by the pyrolysis of mono-bromophenols (o-, m-, and p-) were identified by gas chromatography-mass spectrometry. During the pyrolysis reactions, several kinds of dioxins and furans were produced, and the relative ratio of pyro-products was dependent on the substituted position of bromine in phenolic structure due to the effect of symmetry and steric hindrance. The formation of dioxins can be explained by the phenoxy radical addition and Br atom elimination at an ortho-carbon site on phenolic structure. On the other hand, the formation of furans can be explained by the ortho-ortho carbon coupling of phenoxy radicals at unsubstituted sites to form o, o'-dihydroxydiphenyl intermediate via its keto-tautomer, followed by $H_2O$ elimination. The pyrolysis temperature has also a substantial effect on the dimerized products quantities but little effect on the type of pyro-products. Moreover, the formation mechanism of pyro-products was suggested on the basis of products identified.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.989-998
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• 2010

The titled dye of DBPI gives amplified spontaneous emission (ASE) with maximum at 580 nm upon pumping by nitrogen laser (${\lambda}_{ex}\;=\;337.1\;nm$). The ground state absorption cross section (${\sigma}_A$) and emission cross section (${\sigma}_E$) as well as effective emission cross section(${\sigma}^*_E$) have been determined. The electronic absorption spectra of DBPI were measured in ethanol and tetrahydrofuran at room and low temperature. DBPI displays molecular aggregation in water. The photochemical reactivity of DBPI was also studied in carbon tetrachloride upon irradiation with 525 nm light. The electrochemical investigation of DBPI dye has been carried out using cyclic voltammetry and convolution deconvolution voltammetry combined with digital simulation technique at a platinum electrode in 0.1 mol/L tetrabutyl ammonium perchlorate (TBAP) in two different solvents acetonitrile ($CH_3CN$) and dimethylformamide (DMF). The species were reduced via consumption of two sequential electrons to form radical anion and dianion (EE mechanism). In switching the potential to positive direction, the compound was oxidized by loss of two sequential electrons, which were followed by a fast dimerization and/or aggregation process i.e $EC_{dim1}EC_{dim2}$ mechanism. The electrode reaction pathway and the chemical and electrochemical parameters of the investigated compound were determined using cyclic and convolutive voltammetry. The extracted electrochemical parameters were verified and confirmed via digital simulation method.