• BMB Reports
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• v.32 no.4
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• pp.331-338
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• 1999

Ethanol catabolism is thought to produce metabolic disorders resulting in alcoholic liver disease. To investigate the mutual effects of ethanol catabolism and cholestasis induced by common bile duct ligation on the activities of carboxylesterase, we have determined the enzyme activities in rat hepatic (cytosolic, mitochondrial, and microsomal) preparations as well as in rat serum using ten animal models: normal rats (group 1), sham-operated rats (group 2), common bile duct-ligated rats (group 3), ethanol-intoxicated rats (group 4), sham-operation plus chronic ethanol-intoxicated rats (group 5), common bile duct-ligated plus chronic ethanol-intoxicated rats at 1.5h and 24h (groups 7A and 7B), and duct-ligated and acute ethanol intoxicated rats at 1.5 h and 24 h (groups 8A and 8B). The $K_m$ and $V_{max}$ values of carboxylesterase from these hepatic preparations of cholestatic rat liver combined with chronic ethanol intoxication were also measured by using ethyl valerate as the substrate from the 14th day post-ligation. Carboxylesterase activities of all hepatic preparations and rat serum (group 3) showed significant decreases compared to the activities from the sham-operated control (group 2). Enzyme kinetic parameters indicated that $V_{max}$ of carboxylesterase from all the hepatic preparations in cholestatic rats (group 3) decreased significantly, although the $K_m$ values were about the same as in the sham-operated control (group 2). When cholestasis was combined with chronic ethanol intoxication (group 6), carboxylesterase activities showed further decrease in all the hepatic preparations and serum compared to the control activity (group 5). The $V_{max}$ also decreased significantly, although $K_m$ values did not change. When common bile duct ligation was combined with acute ethanol intoxication (group 8), the enzyme activities in the rat liver and serum showed significant decrease compared to the activity from acute ethanol-intoxicated rats (group 7). However, quite contrary to this, the activities of serum from acute ethanol intoxication 1.5 h (group 7A) increased significantly compared to the activities in the normal control (group 1). These results, therefore, suggest that the biosynthesis of hepatic carboxyl-esterase seems to decrease when cholestasis is combined with chronic and acute ethanol intoxication, and the decrease in activity is more significant than from cholestasis alone.

• Korean Journal of Materials Research
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• v.10 no.5
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• pp.375-381
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• 2000

Aluminium foil for electrolytic capacitors was anodized at the voltage of 100V and 140V for 10 minutes in ammonium adipate solution to form aluminum oxide layer on aluminum substrate as an dielectric film. The thickness, the stoichiometry and the crystal structure of the layer were investigated by using RBS and TEM . In addition EIS technique was employed to study the effects of addition of sulfuric acid on the increment of the foil surface area. It was found that the thickness values of the layers anodized at 100V and 140V were about 130 nm and 190 nm respectively and the stoichiometry of the elements of aluminum and oxygen was 2:3. The anodic oxide layer was shown to be amorphous. but the structure irradiated with electron beam resulted in the transformation into crystalline structure of $${\gamma}$-Al_2$$O_3$ . From a comparison of the impedance results and the capacitance variation to investigate the ef- fects of sulfuric acid addition to the etching bath of hydrochloric acid, the EIS techinque could be useful to analyze the capacitance variation.

• Journal of the Korean Vacuum Society
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• v.20 no.1
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• pp.50-56
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• 2011

In this study, the effects of ZnO buffer layer thickness and annealing temperature on the heterojunction diode, ZnO/b-ZnO/p-Si(111), were reported. The effects of those on the structural and electrical properties of zinc oxide (ZnO) films on ZnO buffered p-Si (111) substrate were also studied. Structural properties of ZnO thin films were studied by X-ray diffraction and I-V characteristics were measured by a semiconductor parameter analyzer. ZnO thin films with 70 nm thick buffer layer and annealing temperature of $700^{\circ}C$ showed the best c-axis preferred orientation. The best electrical property was found at the condition of buffer layer annealing temperature of $700^{\circ}C$ and 50nm thick ZnO buffer layer (resistivity: $2.58{\times}10^{-4}[{\Omega}-cm]$, carrier concentration: $1.16{\times}1020[cm^{-3}]$). The I-V characteristics for ZnO/b-ZnO/p-Si(111) heterojunction diode were improved with increasing buffer layer thickness at buffer layer annealing temperature of $700^{\circ}C$.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.1
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• pp.35-42
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• 2018

Ascorbic acid is one of the most well-known nutritional supplement and antioxidant found in fruits and vegetables. Calcium ascorbate has been developed to mitigate the gastric irritation caused by the acidity of ascorbic acid. The aim of this study was to compare calcium ascorbate and ascorbic acid, focusing on their antioxidant activity and effects on gastric juice pH, total acid output, and pepsin secretion in an in vivo rat model, as well as pharmacokinetic parameters. Calcium ascorbate and ascorbic acid had similar antioxidant activity. However, the gastric fluid pH was increased by calcium ascorbate, whereas total acid output was increased by ascorbic acid. In the rat pylorus ligation-induced ulcer model, calcium ascorbate increased the gastric fluid pH without changing the total acid output. Administration of calcium ascorbate to rats given a single oral dose of 100 mg/kg as ascorbic acid resulted in higher plasma concentrations than that from ascorbic acid alone. The area under the curve (AUC) values of calcium ascorbate were 1.5-fold higher than those of ascorbic acid, and the $C_{max}$ value of calcium ascorbate (91.0 ng/ml) was higher than that of ascorbic acid (74.8 ng/ml). However, their $T_{max}$ values were similar. Thus, although calcium ascorbate showed equivalent antioxidant activity to ascorbic acid, it could attenuate the gastric high acidity caused by ascorbic acid, making it suitable for consideration of use to improve the side effects of ascorbic acid. Furthermore, calcium ascorbate could be an appropriate antioxidant substrate, with increased oral bioavailability, for patients with gastrointestinal disorders.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.103-103
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• 2018

Oenothera biennis, commonly known as evening primrose, a potential source of natural bioactive substances: flavonoids, steroids, tannins, fatty acids and terpenoids responsible for a diverse range of pharmacological functions. However, whether extract prepared from aerial part of O. biennis (APOB) protects skin against oxidative stress remains unknown. To investigate the protective effects of APOB against oxidative stress-induced cellular damage and elucidated the underlying mechanisms in the HaCaT human skin keratinocytes. Our results revealed that treatment with APOB prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased viability, and the highest DPPH radical-scavenging activities and reducing power of HaCaT cells. APOB also effectively attenuated H2O2-induced comet tail formation and inhibited the $H_2O_2$-induced phosphorylation levels of the histone ${\gamma}H2AX$, as well as the number of apoptotic bodies and Annexin V-positive cells. In addition, APOB exhibited scavenging activity against intracellular reactive oxygen species (ROS) accumulation and restored the mitochondrial membrane potential loss by $H_2O_2$. Moreover, $H_2O_2$ enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)-polymerase (PARP), a typical substrate protein of activated caspase-3, as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with APOB. Furthermore, APOB increased the levels of heme oxygenase-1 (HO-1), which is a potent antioxidant enzyme, associated with the induction of nuclear factor-erythroid 2-related factor 2 (Nrf2). According to our data, APOB is able to protect HaCaT cells from $H_2O_2$-induced DNA damage and cell death through blocking cellular damage related to oxidative stress through a mechanism that would affect ROS elimination and activating the Nri2/HO-1 signaling pathway.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.2
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• pp.47-53
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• 2015

The effects of electroless nickel immersion gold (ENIG) and organic solderability preservative (OSP) surface finishes on the in-situ intermetallics reaction and the electromigration (EM) reliability of Sn-3.0Ag-0.5Cu (SAC305) solder bump were systematically investigated. After as-bonded, $(Cu,Ni)_6Sn_5$ intermetallic compound (IMC) was formed at the interface of the ENIG surface finish at solder top side, while at the OSP surface finish at solder bottom side,$ Cu_6Sn_5$ and $Cu_3Sn$ IMCs were formed. Mean time to failure on SAC305 solder bump at $130^{\circ}C$ with a current density of $5.0{\times}10^3A/cm^2$ was 78.7 hrs. EM open failure was observed at bottom OSP surface finish by fast consumption of Cu atoms when electrons flow from bottom Cu substrate to solder. In-situ scanning electron microscope analysis showed that IMC growth rate of ENIG surface finish was much lower than that of the OSP surface finish. Therefore, EM reliability of ENIG surface finish was higher than that of OSP surface finish due to its superior barrier stability to IMC reaction.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.4
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• pp.105-110
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• 2014

It is required to improve the efficiency and the reliability of the polymer solar cells (PSCs) as the energy saving optical device for the future application of the smart farm facilities. In this study, we fabricated the bulk hetero junction PSCs with organic passivation film layer for the reliability improvement of the devices. The effects of the passivation layer on the electrical properties of the PSCs were studied. The materials of passivation layer are composed of poly vinyl alcohol (PVA) and ammonium dichromate, and the passivation films were fabricated by the spin coating method on the P3HT:$PC_{61}BM$/LiF/Al substrate. The prepared structure of the device is the glass/ITO/PEDOT:PSS/P3HT:$PC_{61}BM$/LiF/Al/passivation layer. The performances of the PSCs with the organic passivation film showed better electrical properties compared with the PSCs without passivation layers. The power conversion efficiency (PCE) values of passivated PSCs decreased from 3.0 to 1.3% after air exposure for 140 hrs. In contrast, the PCE values for the devices without passivation decreased sharply from 3.5 to 0.1% under the same exposure condition.

• Journal of Life Science
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• v.25 no.11
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• pp.1255-1264
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• 2015

Cnidium officinale, a traditional herb, has diverse beneficial pharmacological activities, such as anti-inflammatory, antioxidant, anticancer, and antiangiogenesis effects. However, the cellular and molecular mechanisms of apoptosis by C. officinale are poorly defined. The present study investigated the proapoptotic effects of water, ethanol, and methanol extract of C. officinale (WECO, EECO, and MECO, respectively) in human leukemia U937 cells. The antiproliferative activity of EECO was higher than that of WECO and MECO. The antiproliferative effect of EECO treatment in U937 cells was associated with the induction of apoptotic cell death, including increased populations of annexin-V positive cells, the formation of apoptotic bodies, DNA fragmentation, and increased numbers of cells with a loss of mitochondrial membrane potential (MMP, Δψm). EECO-induced apoptotic cell death was associated with upregulation of death receptor 4 (DR4) and down-regulation of cellular inhibitor of apoptosis protein-1 (cIAP-1), Bcl-2, and total Bid. The EECO treatment also induced the proteolytic activation of caspases (-3, -8, and -9), and degradation of caspase-3 substrate proteins, such as poly(ADP-ribose) polymerase (PARP), β-catenin, and phospholipase C-γ1 (PLCγ1). In addition, the EECO treatment effectively activated the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. However, compound C, a specific inhibitor of AMPK, significantly reduced EECO-induced apoptosis. These results indicate that AMPK is a key regulator of apoptosis in response to EECO in human leukemia U937 cells.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.2
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• pp.263-271
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• 2010

This trial was conducted to determine the effects of feeding a diet containing solid-state fermented rapeseed meal on performance, nutrient digestibility, intestinal ecology and intestinal morphology of broiler chickens. A mixed liquid culture, containing approximately 5 log cfu/ml Lactobacillus fermentum, Enterococcus faecium, Saccharomyces cerevisae and Bacillus subtilis was prepared in a 1:1:1:1 ratio. A basal substrate (BS) containing 75% rapeseed, 24% wheat bran and 1% brown sugar was mixed with the liquid culture in a ratio of 10:3. Over the 30-day fermentation, isothiocyanates were reduced from 119.6 to 14.7 mmol/kg. A total of 168, day-old male Arbor Acres broiler chicks were assigned to one of three dietary treatments including a corn-soybean meal based control diet as well as two experimental diets in which the control diet was supplemented with 10% of the BS containing unfermented rapeseed meal or 10% of the BS containing rapeseed meal subjected to solid state fermentation. There were 8 pens per treatment and 7 birds per pen. From days 19-21 and days 40-42, uncontaminated excreta were collected from each pen for digestibility determinations. In addition, digesta from the colon and ceca were collected to determine the number of lactobacilli, enterobacteria and total aerobes. The middle sections of the duodenum, jejunum, and ileum were collected for intestinal morphology. Over the entire experimental period (d 1-42), the weight gain and feed conversion of birds fed fermented rapeseed meal were superior (p<0.05) to that of birds fed nonfermented rapeseed meal and did not differ from the soybean control. On day 42, birds fed fermented rapeseed meal had higher (p<0.05) total tract apparent digestibility coefficients for dry matter, energy, and calcium than birds fed non-fermented rapeseed meal. Colon and ceca digesta from broilers fed the fermented feed had higher (p<0.05) lactobacilli counts than birds fed the control and non-fermented rapeseed meal diets on day 21 and 42. Fermentation also improved (p<0.05) villus height and the villus height:crypt depth ratio in the ileum and jejunum on day 21 and 42. The results indicate that solid-state fermentation of rapeseed meal enhanced performance and improved the intestinal morphology of broilers and may allow greater quantities of rapeseed meal to be fed to broilers potentially reducing the cost of broiler production.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1426-1435
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• 2014

Saponins have been considered as promising natural substances for mitigating methane emissions from ruminants. However, studies reported that addition of saponin-rich sources often arrived at contrasting results, i.e. either it decreased methane or it did not. The aim of the present study was to assess ruminal methane emissions through a meta-analytical approach of integrating related studies from published papers which described various levels of different saponin-rich sources being added to ruminant feed. A database was constructed from published literature reporting the addition of saponin-rich sources at various levels and then monitoring ruminal methane emissions in vitro. Accordingly, levels of saponin-rich source additions as well as different saponin sources were specified in the database. Apart from methane, other related rumen fermentation parameters were also included in the database, i.e. organic matter digestibility, gas production, pH, ammonia concentration, short-chain fatty acid profiles and protozoal count. A total of 23 studies comprised of 89 data points met the inclusion criteria. The data obtained were subsequently subjected to a statistical meta-analysis based on mixed model methodology. Accordingly, different studies were treated as random effects whereas levels of saponin-rich source additions or different saponin sources were considered as fixed effects. Model statistics used were p-value and root mean square error. Results showed that an addition of increasing levels of a saponin-rich source decreased methane emission per unit of substrate incubated as well as per unit of total gas produced (p<0.05). There was a decrease in acetate proportion (linear pattern; p<0.001) and an increase in propionate proportion (linear pattern; p<0.001) with increasing levels of saponin. Log protozoal count decreased (p<0.05) at higher saponin levels. Comparing between different saponin-rich sources, all saponin sources, i.e. quillaja, tea and yucca saponins produced less methane per unit of total gas than that of control (p<0.05). Although numerically the order of effectiveness of saponin-rich sources in mitigating methane was yucca>tea>quillaja, statistically they did not differ each other. It can be concluded that methane mitigating properties of saponins in the rumen are level- and source-dependent.