• Korean Journal of Veterinary Research
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• v.36 no.1
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• pp.209-219
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• 1996

This study examined the effect of alcohol(AL) and/or paraquat(PQ) on serum TSH, thyroid hormones and enzyme activities, and the protective effect of selenium(SE) againse alcohol and/or paraquat-induced thyroid toxicity in guinea pigs. The experomental group consisted of control, 15% alcohol(AL), 4ppm sodium selentite(SE), 200ppm paraquat(PQ), AL+PQ, AL+SE, PQ+SE and AL+PQ+SE mixed in drinking water-fed guinea pigs for 4 weeks. The morphological changes of thyroid gland were studies on paraffin-embedded sections stained with H-E stain. Body weight losses, high serum concentration in TSH and cholesterol, and low values on triiodothyronine($T_3$), thyrozine($T_4$), free $T_4$ and alkaline phosophatase(ALP) were produced in the groups fed AL and/or PQ. We also noted that AL+PQ-fed group was marked increase in serum TSH. In AL or AL+PQ-fed groups when cpmpared to control group had increased the ratio of thyroid weight to body weight(ratio Twt/Bwt), whereas the ratio Twt/Bwt was decresed in SE or PQ-fed groups. However, the serum TSH, $T_3$,$T_4$ free $T_4$ and cholesterol values, and the ratio Twt/Bwt were reversed in groups given the combination of SE, compared with AL and/or Pq-fed groups, also ALP values were reversed in groups given the combination of SE, compared with AL or AL+PQ-fed groups. In microscope, morphological changes showed a remarkable between the AL or PQ-fed group and controls. In AL+PQ+SE-fed guinca pig, follicular colloid is high density in thyroid follicle and increased in connective tissue around the thyroid cells, and thyroidal epithelia were composed of cuboidal or columnar epithelium. The indicated that the morphological changes of thyroid were direct action in the thyroid cell. The results of this study confirmed that the toxic effect of AL or PQ on thyroid occur independently of changes in liver function, and that SE confers marked protection against AL or PQ-induced thyroid toxicity.

• Korean Journal of Materials Research
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• v.27 no.5
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• pp.255-262
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• 2017

Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environments and can completely destroy various organic pollutants in waste water. In this study, we used graphene oxide modified $Ag_2Se$ nanoparticles to enhance photochemically generated oxygen (PGO) species activity. Surface area and pore volumes of the $Ag_2Se-graphene$ ($Ag_2Se-G$) samples showed catastrophic decrease due to deposition of $Ag_2Se$. The generation of reactive oxygen species was detected through the oxidation reaction of DPCI to DPCO. The photocurrent density and the PGO effect increase in the case of the use of modified graphene. The PGO effect of the graphene modified with $Ag_2Se$ composites increased significantly due to a synergetic effect between graphene and the $Ag_2Se$ nanoparticles. The photocatalytic activity of sample was evaluated by measuring the degradation of organic pollutants such as methylene blue (MB) and industrial dyes such as Texbrite BA-L (TBA) under visible light.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.3
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• pp.267-276
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• 2000

A numerical study has been carried out to find out the optimal design condition of a solar absorption cooling system. The system was composed of solar collectors and an absorption chiller with LiBr/water The System performance with commercial single effect(SE) cycle and a new single effect/double lift(SE/DL) cycle utilizing low temperature hot water was calculated and compared. It was found that the required solar collector area grew exponentially as the overall heat loss coefficient of solar collectors increased. For instance, the required area for cooling capacity of 1 USRT was $17m^2$ if heat loss coefficient was 4 W/$m^2\;cdot\;K$. If heat loss coefficient was doubled($8\;W/m^2\;cdot\;$K), the required collector area was increased by 6 times($100m^2$) .It was also found that the SE-cycle as the heat loss coefficient of solar collectors increased. Generally, a SE/DL-cycle seems to be more advantageous than a SE-cycle if loss coefficient of solar collector is greater than 4 W/$m^2\;cdot\;K$.

• Natural Product Sciences
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• v.19 no.4
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• pp.324-328
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• 2013

Soy (Glycine max, family Leguminosae) contains isoflavones and saponins as main constituents. In our preliminary study, soybean ethanol extract (SE) ameliorated scopolamine-induced memory impairment in mice in the passive avoidance task. Therefore, to confirm its ameliorating effect for memory impairments, we measured its effect in scopolamine-induced memory-impaired mice in Morris water maze task. SE significantly prevented scopolamine-induced memory impairment in the Morris water maze task. SE also increased the swimming time within quadrant section of the platform on the day after the final training session test. SE protected the reduction of brain-derived neurotrophic factor (BDNF) expression and cAMP response element-binding protein (CREB) phosphorylation in the hippocampi of scopolamine-treated mice. However, SE did not inhibit acetylcholinesterase. To understand the possible role of soysaponins in memory impairments, we prepared soyasaponins-rich (butanol) fraction of soybean (SRF) and investigated its protective effect against in the passive avoidance and Morris water maze tasks. SRF ameliorated scopolamine-induced memory impairment in mice. The memory impairment-ameliorating effect of SRF was more effective than that of SE. Based on these findings, soybean may improve memory impairment by regulating CREB phosphorylation and BDNF expression.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.1048-1052
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• 2008

The objective of this study was to determine the effect of sodium selenite and zinc-L-selenomethionine on performance and egg Se concentration in laying hens. Two hundred and twenty-four CP Browns aged 71 weeks were divided according to a $2{\times}3$ factorial in a completely randomized design. One more group without additional Se supplementation was used as a negative control. Each treatment consisted of four replicates and each replicate contained eight laying hens. The dietary treatments were T1: basal diet; T2, T3 and T4: basal diets plus 0.3, 1.0 and 3.0 mg Se from sodium selenite/kg, respectively; T5, T6 and T7: basal diets plus 0.3, 1.0 and 3.0 mg Se from zinc-L-selenomethionine/kg, respectively. The findings revealed that feed conversion rate/kg eggs, egg production, egg weight, Haugh units and eggshell thickness were not affected by source and level of Se (p>0.05). Increasing level of dietary Se significantly increased (p<0.05 the Se content of eggs. Zinc-L-selenomethionine markedly increased p<0.05 egg Se concentration as compared with sodium selenite. The results indicated that Se source did not influence performance of laying hens. However, zinc-L-selenomethionine increased p<0.05 egg Se concentration more than sodium selenite.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.53 no.1
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• pp.28-31
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• 2004

The results of investigations of Ag2Se single crystal are presented. $Ag_2Se$ crystal was grown by the Bridgman method. The $Ag_2Se$ single crystal was an orthorhombic structure with lattice constance $a=4.333{\AA}$, $b=7.062{\AA}$, $c=7.764{\AA}$. Hall effect shows a n-type conductivity in the $Ag_2Se$ single crystal. The electrical resistivity was $1.25{\times}10^3ohm^{-1}^cm{-1}$ and electron mobility was $-5.48{\times}10^3cm^2/V{\cdot}sec$ at room temperature(RT).

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.5
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• pp.7-10
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• 1984

Generally, free carrier densities of single crystal semiconductors are indifferent to methods of measurement. Free carrier densities of CdSe thin films, however, were measured invarious values with different methods In this paper, C-V method, Seebeck effect and a.c. Hall effect were used to measure carries densities of CdSe thin films. Carrier densities of CdSe thin films were in the range of 10 - 10 carriers/㎤. And causes of different results were discussed.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.97-108
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• 2005

This study was carried out to determine effects of the feeding length of spent mushroom composts from selenium-enriched mushroom (Se-SMC) on muscular selenium deposition in finishing Hanwoo steers. A total of 30 steers were allotted to an experiment with a 3 × 2 factorial arrangement. Treatments were 2 groups of with and without Se-SMC at three different feeding lengths (2, 4, and 6 months) by body weight (BW). And then dry matter intake, body weight gain, Se concentration and/or content in blood and/or muscle were investigated. Dry matter intake was not affected by feeding length and Se-SMC supplementation. As the feeding length was prolonged, initial and final BW was significantly lowered (p<0.01) with no Se-SMC effect. However, total BW gain was significantly increased (p<0.0001) with increasing feeding length with no effect of Se-SMC. Se-SMC supplementation significantly increased Se concentration in whole blood, but there was no effect on feeding length. Se contents in muscles, especially hind-leg, were significantly increased (p<0.05) as the feeding length was increased. However, there was no difference for Se content between four and six months feeding groups of Se-SMC and also hepatic Se content was not affected by feeding length. On the contrast, hepatic Se content for Se-SMC group within each feeding length was significantly increased (p<0.001) compared with no Se-SMC supplementation. In conclusion, our results suggested that optimum feeding length of Se-SMC as a strategy for the production of Se-fortified beef might be approximately 4 months.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1907-1914
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• 2010

A novel catalytic kinetic method is proposed for the determination of Se(IV), Se(VI) and total inorganic selenium in water based on the catalytic effect of Se(IV) on the reduction of bromate by p-nitrophenylhydrazine at pH 3.0. The generated bromine, $Br_2$ or $Cl_2$ plus $Br_2$ in 0.1 M NaCl (or NaBr) environment efficiently decolorized Calmagite and the reaction was monitored spectrophotometrically at 523 nm as a function of time. In this indicator reaction, bromide acted as an activator for the catalysis of selenium (IV) and a reducing agent for selenium (VI) at pH 3.0, which allowed the determination of total selenium. The fixed time method was adopted for the determination and speciation of inorganic selenium. Under the optimum conditions, the calibration graph are linear in the range 1 - 35 ${\mu}gL^{-1}$ of Se(IV) for the fixed time method at $25^{\circ}C$. The detection limit based on statistical $3S_{blank}$/m-criterion was 0.215 ${\mu}gL^{-1}$ for the fixed time method (7 min). All of the variables that affect the sensitivity at 523 nm were investigated, and the optimum conditions were established. The interference effect of various cations and anions on the Se (IV) determination was also studied. The selectivity of the selenium determination was greatly improved with the use of the strongly cation exchange resin such as Amberlite IR120 plus. The proposed kinetic method was validated statistically and through recovery studies in natural water samples. The RSDs for ten replicate measurements of 5, 15 and 25 ${\mu}gL^{-1}$ of Se(IV) and Se(VI) was changed between 2.1 - 4.85%. Analyses of a certified standard reference material (NIST SRM 1643e) for selenium using the fixed-time method showed that the proposed kinetic method has good accuracy. Se(IV), Se(VI) and total inorganic selenium in environmental water samples have been successfully determined by this method after selective reduction of Se(VI) to Se(IV).

• Journal of the Korean Magnetics Society
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• v.17 no.3
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• pp.114-119
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• 2007

The single crystal $Nd_3Se_4$ with the $bcc-Th_3P_4$ type structure is grown and the temperature dependent magnetic susceptibilities are measured between 4 K and 300 K. The experimental data are compared with the theoretically calculated susceptibilities which depend on the splitting energies of the $Nd^{3+}$ ground state under the crystal field effect. We find that the magnetic susceptibility of the $Nd^{3+}$ ion in $Nd_3Se_4$ is not affected by the crystal field effect. The spontaneous magnetization curve below $T_c\;=\;53\;K$ of $Nd_3Se_4$ corresponds to the Brillouin function of $Nd_3Se_4$ with J=9/2.