• Korean Journal of Materials Research
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• v.27 no.12
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• pp.699-704
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• 2017

Recently, the use of an aluminum nitride(AlN) buffer layer has been actively studied for fabricating a high quality gallium nitride(GaN) template for high efficiency Light Emitting Diode(LED) production. We confirmed that AlN deposition after $N_2$ plasma treatment of the substrate has a positive influence on GaN epitaxial growth. In this study, $N_2$ plasma treatment was performed on a commercial patterned sapphire substrate by RF magnetron sputtering equipment. GaN was grown by metal organic chemical vapor deposition(MOCVD). The surface treated with $N_2$ plasma was analyzed by x-ray photoelectron spectroscopy(XPS) to determine the binding energy. The XPS results indicated the surface was changed from $Al_2O_3$ to AlN and AlON, and we confirmed that the thickness of the pretreated layer was about 1 nm using high resolution transmission electron microscopy(HR-TEM). The AlN buffer layer deposited on the grown pretreated layer had lower crystallinity than the as-treated PSS. Therefore, the surface $N_2$ plasma treatment on PSS resulted in a reduction in the crystallinity of the AlN buffer layer, which can improve the epitaxial growth quality of the GaN template.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.651-665
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• 2020

Hydrolysis of biomass for the production of fermentable sugar can be improved by the addition of surfactants. In pulp and paper mills, lignin, which is a by-product of the pulping process, can be utilized as a fine chemical. In the hydrolysis process, lignin is one of the major inhibitors of the enzymatic breakdown cellulose into sugar monomer. Therefore, the conversion of lignin into a biosurfactant offers the opportunity to solve the waste problem and improve hydrolysis efficiency. In this study, lignin derivatives, a biosurfactant, was applied to enzymatic hydrolysis of various lignocellulosic biomass. This Biosurfactant can be prepared by reacting lignin with a hydrophilic polymer such as polyethylene glycol diglycidylethers (PEDGE). In this study, the effect of biosurfactants on the enzymatic hydrolysis of pretreated sweet sorghum bagasse (SSB), oil palm empty fruit bunch, and sugarcane trash with different lignin contents was investigated. The results show that lignin derivatives improve the enzymatic hydrolysis of the pretreated biomass with low lignin content, however, it has less influence on the enzymatic hydrolysis of other pretreated biomass with lignin content higher than 10% (w/w). The use of biosurfactant on SSB kraft pulp can increase the sugar yield from 45.57% to 81.49%.

• Korean Journal of Clinical Pharmacy
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• v.13 no.1
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• pp.29-39
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• 2003

Neurodegenerative disorders are associated with apoptosis as a causing factor or an inducer. On the other hand, it has been reported that epigallocatechin gallate (EUG), one of antioxidants and flavonoids, and z-VAD-fmk, a nonselective caspase inhibitor, suppress oxidative-radical-stress-induced apoptosis. However, it is not yet known what is the effects of EGCG and z-VAD-fmk on the apoptotic pathway is through phosphoinositide 3-kinase (PI3K), Akt and glycogen synthase kinase-3 (GSK-3) as well as mitochondria, caspase-3 and poly (ADP-ribose) polymerase (PARP). We investigated the effects of EGCG by using $H_2O_2$ treated N18D3 cells, mouse DRG hybrid neurons. Methods: Following 30 min $100\;{\mu}m\;H_2O_2$ exposure, the viability of N18D3 cells (not pretreated vs. EGCG or z-VAD-fmk pretreated) was evaluated by using MTT assay. The effect of EGCG on immunoreactivity (IR) of cytochrome c, caspase-3, PARP, PI3K/Akt and GSK-3 was examined by using Western blot, and was compared with that of z-Y4D-fmk. Results: EGCG or z-VAD-fmk pretreated N18D3 cells showed increased viability. Dose-dependent inhibition of caspase-3 activation accompanied by PARP cleavage were demonstrated by pretreatment of both agents. However, inhibition of cytochrome c release was only detected in EGCG pretreated N18D3 cells. On the pathway through PI3K/Akt and GSK-3, however, the result of Western blot in EGCG pretreated N18D3 cells showed decreased IR of Akt and GSK-3 and increased IR of p85a PI3K, phosphorylated Akt and GSK-3, and contrasted with that in z-VAD-fmk pretreated N18D3 cells showing no changes on each molecule. Conclusion: These data show that EGCG affects apoptotic pathway through upstream signal including PI3K/Akt and GSK-3 pathway as well as downstream signal including cytochrome c and caspase-3 pathway. Therefore, these results suggest that EGCG mediated activation of PI3K/Akt and inhibition GSK-B could be new potential therapeutic strategy for neurodegenerative diseases associated with oxidative injury.

• The Korean Journal of Pharmacology
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• v.6 no.1
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• pp.45-55
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• 1970

It is well known that the uterine contractility is affected by sexual hormone. In this experiment, the authors attempted to study the influences of testosterone and estrogen or the uterine contractility to oxytocics. The contractile sensitivity of the excised uterine muscle of non-castrated and castrated rabbits with testosterone and estrogen 24 hours before experiment is observed respectively. And the cholinesterase activity and electrolytes (Na, K, Ca and Mg) in the uterine muscle are measured in order to study the relationship with contractile sensitivity and those changes. The results obtained were summarized as follows: 1. The contractile effect of spareng on the excised uterine muscle of non-castrated rabbits pretreated with estrogen was markedly increased in small dose, but that of rabbits pretreated with testosterone was significantly increased in large dose, comparing with that of the control group. In castrated rabbits, the contractile sensitivity of the uterine muscle to spareng was significantly increased by pretreatment with estrogen in large dose but it was markedly decreased by pretreatment with testosterone in small dose. 2. The contractile effect of quinine on the excised uterine muscle of non-castrated rabbits pretreated with estrogen was significantly decreased but that of castrated rabbits pretreated with both estrogen and testosterone were markedly increased comparing with that of the control group. 3. The cholinesterase activity in the uterine muscle of non-castrated rabbits was significantly increased by pretreatment with small dose of estrogen or large dose of testosterone, but that of castrated rabbits was markedly decreased by pretreatment with large dose of estrogen. 4. Na and K contents in the uterine muscle of non-castrated rabbits were markedly increased by pretreatment with both estrogen and testosterone, but that of castrated rabbits was significantly increased by pretreatment with small dose of estrogen. 5. Ca content in uterine muscle of non-castrated rabbits was significantly decreased by pretreatment with both large dose of estrogen and testosterone but increased by pretreatment of testosterone. In castrated rabbits, Ca content was significantly decreased by pretreatment with both estrogen and testosterone. 6. Mg content in the uterine muscle of non-castrated rabbits was markedly increased by pretreatment with estrogen and small dose of testosterone, but that of castrated rabbits was significantly decreased by pretreatment with both large dose of estrogen and testosterone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.34-40
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• 2004

The purpose of this study was to measure the changes of regional cerebral blood flow (rCBF) and blood pressure (BP) in rats, following the intravenous injection of Schizandrae fructus water extract. The measurement was continually monitored by laser-doppler flowmeter and pressure tranducer in anesthetized adult Sprague-Dawley rats for 2 hours to 2 hours and a half through the data acquisition system composed of MacLab and Macintosh computer. The result of this experiment was as followed. Schizandrae fructus increased the changes of rCBF in rats significantly. The rCBF of Schizandrae fructus did not change by pretreated propranolol, atropine, L-NNA and indomethacin. But the rCBF of Schizandrae fructus was increased by pretreated methylene blue. Schizandrae fructus decreased the changes of BP, significantly. The BP of Schizandrae fructus did not change by pretreated propranolol, atropine, L-NNA and indomethacin. But the BP of Schizandrae fructus was decreased by pretreated methylene blue. There results indicated that Schizandrae fructus can increase the rCBF and decrease the BP, that is related to guanylyl cyclase activity.

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.531-536
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• 2014

Recently, the amounts of dredge sea soil in south Korea have been increasing because of various maintenance works at harbors and rivers. Dredged sea soil contains various contaminants. Hence, prior to recycling the dredged sea soil, the various contaminants should be removed to prevent a secondary contamination due to the leaching of hazardous chemicals. Pretreated dredged sea soil can be buried under the ground or used for land reclamation. In this study, however, pretreated dredged sea soil was used to investigate the level of pozzolanic activity. The properties of pretreated dredged sea soil were investigated, the method for heat treatment was determined, and the compressive strength of mortar using dredged sea soil was examined. According to the XRF result, the main components of dredged sea soil were $SiO_2$ of over 55%, and $Al_2O_3$ and $SO_3$ of some amounts. Results from XRD and TG/DTA showed that pretreated dredged sea soil can be used as a pozzolanic material. When dredged sea soil was thermally treated for 90 min at $550^{\circ}C$, a compressive strength result was similar to that of control mortar.

• Korean journal of food and cookery science
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• v.11 no.1
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• pp.37-43
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• 1995

Effect of the pretreatment with acetic acid(0.01%, 0.05%, 0.1%) on the fermentation of Chinese cabbage Kimchi, and differences in the degree of maturity between Chinese cabbage blades and midribs were observed. To estimate the degree of maturity, correlation analysis was used with several variables such as pH, titratable acidity, volatile acidity, ascorbic acid content, resazurin test value and pH/acidity ratio. Based on the pH and titratable acidity, the degree of maturity of Chinese cabbage midribs fermented at 10$^{\circ}C$ until the optimum stage of fermentation increased more rapidly than those of the blades. The stage of maturity of Kimchi pretreated with 0.01% acetic acid were slightly prolonged, compared to those pretreated with acetic acid at the higher levels. The pH of Chinese cabbage midribs and blades pretreated with acetic acid was lower than those of control between 2nd and l0th day of fermentation. The volatile acidity of Chinese cabbage midribs and blades increased proportionally with the concentration of acetic acid. The ascorbic acid contents of Chinese cabbage midribs showed higher than those of Chinese cabbage blades. During the fermentation, the higher concentration of acetic acid was used, the less ascorbic acid content was remained. The pH/acidity ratio, volatile acidity, ascorbic acid content and resazurin test value of Chinese cabbage midribs and blades during Kimchi fermentation at 10$^{\circ}C$ showed good correlations with the pH and titratable acidity.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7959-7965
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• 2015

Background: Identification of predictive markers for the efficacy of platinum-based chemotherapy is necessary to improve the quality of the life of cancer patients. Materials and Methods: We detected proteins recognized by autoantibodies in pretreated sera from patients with lung adenocarcinoma (AC) evaluated as showing progressive disease (PD) or a partial response (PR) after cisplatin-based chemotherapy by proteomic analysis. Then, the levels of the candidate autoantibodies in the pretreated serum were validated by dot-blot analysis for 22 AC patients who received platinum-based chemotherapy, and the expression of identified proteins was immunohistochemically analyzed in 40 AC biopsy specimens. Results: An autoantibody against galectin-3 (Gal-3) was detected in pretreated sera from an AC patient with PD. Serum IgG levels of anti-Gal-3 autoantibody were significantly higher in patients evaluated with PD than in those with PR and stable disease (SD) (p = 0.0084). Furthermore, pretreated biopsy specimens taken from patients evaluated as showing PD following platinumbased chemotherapy showed a tendency to have a higher positive rate of Gal-3 than those with PR and SD (p = 0.0601). Conclusions: These results suggest that serum IgG levels of anti-Gal-3 autoantibody may be useful to predict the efficacy of platinum-based chemotherapy for patients with lung AC.

• Applied Microscopy
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• v.25 no.3
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• pp.51-62
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• 1995

It has been well known that ischemia and reperfusion injury to skeletal muscle following an acute arterial occlusion causes significant morbidity and mortality. The skeletal muscle, which contains high energy phosphate compounds, has ischemic tolerance. During the ischemia, the ATP is catalyzed to hypoxanthine anaerobically and hypoxanthine dehydrogenase is converted to xanthine oxidase. During reperfusion, the hypoxanthine is catalyzed to xanthine by xanthine oxidase under $O_2$, presence and that results in production of cytotoxic oxygen free radicals. These cytotoxic free radicals, $O_2^-,\;H_{2}O_2,\;OH^-$, are toxic and make lesions in skeletal muscle during reperfusion. The authors perform the present study to investigate the effects of allopurinol, the inhibitor of xanthine oxidase, on reperfused ischemic skeletal muscles by observing the ultrastructural changes of the muscle fibers. A total of 48 healthy Sprague-Dawley rats weighing from 200 g to 250 g were used as experimental animals. Under urethane(3.0mg/kg., IP) anesthesia, lower abdominal incision was done and the left common iliac artery were ligated by using vascular clamp for 1, 2 and 6 hours. The left rectus femoris muscles were obtained at 6 hours after the removal of vascular clamp. In the allopurinol pretreated group, 50mg/kg of allopurinol was administered once a day for 2 days and before 2 hours of ischemia. The specimens were sliced into $1mm^3$ and prepared by routine methods for electron microscopic observations. All preparations were stained with uranyl acetate and lead citrate, and then observed with Hitachi -600 transmission electron microscope. The results were as follows: 1. In 1 hour ischemia/6 hours reperfused rectus femoris muscles of rats, decreased glycogen particles and electron density of mitochondrial matrix and dilated terminal cisternae are seen. In 2 hours ischemia/6 hours repersed rectus femoris muscles of rats, mitochondria with electron lucent matrix, irregularly dilated triad and spheromembranous bodies are observed. In 6 hours ischemia/6 hours reperfused rectus femoris muscles of rats, irregularly arranged myofibrils, and many spheromembranous bodies, fat droplets and lysosome are seen. 2. In 1 hour ischemia/6 hours reperfused rectus femoris muscles of rats pretreated with allopurinol, decreased glycogen particle and dilated cisternae of sarcoplasmic reticulum and triad are observed. In 2 hours ischemia/6 hours reperfused rectus femoris muscles of rats pretreated with allopurinol decreased electron density of mitochondrial matrix and spheromembranous bodies are seen. In 6 hours ischemia/6 hours reperfused rectus femoris muscles of rats pretreated with allopurinol, mitochondria with electron lucent matrix, spheromembranous bodies and dilated cisternae of sarcoplasmic reticulum and terminal cistern are observed. The results suggest that the allopurinol attenuates the damages of the skeletal muscles of rats during ischemia and reperfusion.

• The Korean Journal of Pharmacology
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• v.21 no.2
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• pp.99-110
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• 1985

Majarine that was isolated from Berberis Koreasra Palibin (Berberidaceae) is the isoquinoline alkaloid. The effects of dopaminergic and serotonergic antagonists on majarine induced changes in body temperature were studied in the mouse. Intraperitoneal administration of majarine produced dose-dependent hypothermia. At a dose of 0.1 mg/kg, majarine caused a slight increase in body temperature. Majarine-induced hyperthermia was attenuated by the 5-HT antagonist, cyproheptadine However, it caused hyothermia in mice pretreated with the DA antagonist, haloperidol, and hyperthermia in mice pretreated with haloperidol and cyproheptadine in comparision with haloperidol pretreatment. At a dose of 2.0 mg/kg, majarine-induced hypothermia was attenuated by haloperidol and cyproheptadine, respectively. In reserpine pretreated mice, majarine produced dose-dependent hypothermia. At a dose of 0.1 mg/kg, majarine pretreated with haloperidol caused no significant effect in body temperature. At a dose of 2.0 mg/kg, majarine-induced hypothermia was attenuated by haloperidol pretreatment in mice treated with reserpine and ${\alpha}$-methyl-p-tyrosine. These data suppose that both dopaminergic and serotonergic mechanisms in the brain mediate the effects of majarine on body temperature. We propose that majarine directly stimulate DA receptor, which secondarilly activate 5-HT neurons to cause changes in body temperature.