• Asian-Australasian Journal of Animal Sciences
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• v.31 no.5
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• pp.658-671
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• 2018

Objective: Nandrolone decanoate (ND) is an anabolic-androgenic steroid frequently used for clinical treatment. However, the inappropriate use of ND results in the reduction of serum testosterone level and sperm production. The suppressive effect of ND on testosterone production has not been investigated in detail. The present study was designed to examine the effect of ND on the expression of steroidogenic enzymes in the rat testis. Methods: Male Sprague Dawley rats at 50 days of age were subcutaneously administrated with either 2 or 10 mg of ND/kg body weight/week for 2 or 12 weeks. The changes of transcript and protein levels of steroidogenic enzymes in the testis were determined by real-time polymerase chain reaction and western blotting analyses, respectively. Moreover, immunohistochemical analysis was employed to determine the changes of immunostaining intensity of these enzymes. The steroidogenic enzymes investigated were steroidogenic acute regulatory protein, cytochrome P450 side chain cleavage enzyme, $17{\alpha}-hydroxylase$, $3{\beta}-hydroxysteroid$ dehydrogenase, and cytochrome P450 aromatase. Results: The treatment of ND resulted in depletion of Leydig cells and sloughing of germ cells in the testis. The ND treatment caused significant expressional decreases of steroidogenic enzymes at transcript and protein levels, and the destructive effects of ND on the testis were more apparent with a higher dose and a longer period of the treatment. Evident reduction of immunostaining intensity present in Leydig cells was clearly detected by the ND treatment. Conclusion: The exposure to ND in young male results not only in histological changes of the testis but also in aberrant gene expression of testicular steroidogenic enzymes, consequently leading into the reduction of testosterone production in the testis and thus likely disruption of spermatogenesis.

• Korean Journal of Optics and Photonics
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• v.14 no.1
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• pp.85-91
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• 2003

Intracavity frequency doubling of a single-mode Nd:YAG laser by using a nonplanar ring cavity is demonstrated. The nonplanar ring cavity consists of a Brewster-angled Nd:YAG crystal placed in a magnetic field, a KTP crystal, and two spherical mirrors. In this design the Nd:YAG block acts as both a nonreciprocal polarization rotator and a partial polarizer, and the nonplanar portion of the ring cavity, which is formed by a relative twist angle between the Brewster-angled end surfaces of the Nd:YAG block, serves as a reciprocal polarization rotator. An eigenpolarization theory for the cavity configuration is presented and suitable values of the relative twist angle for unidirectional operation are estimated. A single-mode output power of 22 ㎽ at 532 nm and an optical to optical conversion efficiency of 1.8% are obtained with a 1.2 W diode laser at 809 nm.

• Journal of the Korean Magnetics Society
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• v.5 no.1
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• pp.34-37
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• 1995

$Nd_{x}Fe_{77}B_{23-x}(x=4,\;6,\;8,\;11,\;13)$ alloys were prepared by rapid quenching technique. They were crystallized at higher than $650^{\circ}C$ and subsequently the magnetic properties were investigated The melt-spun alloy of x=8 consisted of nearly single metastable compound $Nd_{2}Fe_{23}B_{3}$ and showed the soft magnetic property. In $8{\leq}x{\leq}13$ alloys, the coercivities were increased according to the increase of Nd content but the remanences decreased. In $4{\leq}x{\leq}6$ alloys, the coercivities and the remanences were increased by lowering Nd content. In x=4 alloy, the ratio of soft to hard magnetic phase was 70:30 and the energy product was $96kJ/m^{3}(12MG.Oe)$.

• Transactions of the Korean hydrogen and new energy society
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• v.10 no.3
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• pp.177-184
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• 1999

The charge-discharge characteristics of the $Mg_2Ni-x$ wt.%Nd (x = 0~3) electrodes were investigated. The electrodes were prepared by the mechanical grinding of the induction-melted $Mg_2Ni$ alloy powders with Ni and/or Nd using planetary ball mill apparatus. The discharge capacity of the $Mg_2Ni$ alloy increased with the increase in the nickel content. The electrode possessing 100 wt.% nickel powder showed the initial capacity of 760 mAh/g and the capacity decay with the cycle number was less than that of the 55 wt.% nickel powder. The Nd was added to this composition. It was found that the $Mg_2Ni-100$ wt.%Ni -0.2 wt.%Nd alloy showed an excellent charge-discharge cycle characteristics compared with the other reported Mg-Ni alloy system. The discharge capacity was 400 mAh/g after 70 cycles. Such an improved cycle life seems to be attributed to the improvement in the corrosion characteristics of the alloy. The anodic polarization curve of the $Mg_2Ni-100$ wt.%Ni-0.2 wt.%Nd alloy exhibited better passivating behavior than that of the $Mg_2Ni-100$ wt.%Ni.

• Korean Journal of Agricultural Science
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• v.40 no.2
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• pp.87-91
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• 2013

The major characteristics of the developed corn hybrids were compared at each different planting time; 1st time(April 28) and 2nd time(August 20), respectively. Among traits surveyed, stem height showed highly at 1st time than 2nd, while ear height, stem diameter and ear length were similar at two times. Sugar content of the used hybrids showed highly at 2nd planting time than 1st. Pericarp thickness was also high at 2nd planting time. Especially, among hybrids CNU99 was the highest in stem height and ear length, CNU11 and CNU56 were high in sugar content, and CNU51 and CNU124 were thiner than other hybrids in pericarp thickness. Accordingly, these hybrids will be planted and recognized in 2nd yield trial for superior corn hybrid selection.

• Electrical & Electronic Materials
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• v.7 no.4
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• pp.306-311
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• 1994

In this study, the influence of the powder sintering, the 2nd sinteiing and the grinding time on the Superconducting properties in the Bi(Pb)SiCaCuO Superconductor has been studied. From the analysis of SEM and XRD patterns, it was known that the sample prepared by the process of powder sintering has a porous microstructure with the critical temperature(Tc) below 77K, while the sample prepared by the 2nd sintering has a highly oriented microstructure with the Tc above 100K. The Critical Current Density(Jc) of the sample prepared by the 2nd sintering was better than the sample prepared by the process of powder sinteiing, but it's Jc, was low in practical use. Also, the effect of grinding time from 0[min] to 120[min] was investigated. As the grinding time is increased, the samples degraded from high-Tc phase to low-Tc phase and nonsuperconducting phases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05a
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• pp.42-45
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• 2003

The phase transformation of $REBa_2Cu_3O_{7-x}$ (RE=Nd, Gd, Dy) was investigated using isothermal heat-treatment and continuous cooling in air. During continuous cooling, the $REBa_2Cu_3O_{7-x}$ (RE=123) superconducting phase with well-distributed $REBa_2Cu_3O_{7-x}$ (RE-211) was obtainde at a cooling rate of $0.001^{\circ}C$/s. Single phase RE-123 (Nd, Gd, Dy) was stable at $1050^{\circ}C$, $1050^{\circ}C$, and $950^{\circ}C$ during isothermal heat-treatment, respectively. Above these temperatures the RE-211 phase existed within the RE-123 grains. The RE-123, RE-211, $BaCu_2Od_2$, and CuO phases coexisted at $50^{\circ}C$ below the partial melting temperature for each respective rare-earth RE-123.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.672-675
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• 2010

Spray characteristics for the modulation with a pulsed spray in low-frequency region were investigted by performing with additional internal pulsed injection. The 1st perturbative flow was generated by rotating-type pulsed device and the 2nd pulse source generated by the magnetic valve was used to modulate the 1st flow. A pattern of the modulated spray was observed through FFT result and visualization. In case of modulated spray with the 2nd pulse control, the width of up and down motion of the modulated spray is smaller than that of the spray without the 2nd pulse. Also, the depth of penetration of the down stream is higher than that of spray without the 2nd pulse.

• Journal of Food Hygiene and Safety
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• v.2 no.3
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• pp.121-136
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• 1987

As a part of continuing monitoring program since 1983, a study on pesticide residues on Korean agricultural products has been conducted to offer the tolerance of pesticide residues suiting Korean reality. The samples used in this experiment were collected from four areas in five provinces of Korea. The residue, levels of organochlorine pesticide (two kinds), organophosphoric pesticide (eight kinds) and carbamate pesticide (three kinds) on lettuce, garland chrysanthemum, radish Korean, potato, egg plant, green onion, persimmon and sweet potato, and the residue levels of captan and captafol on tomato, green pepper fresh, apple, peach, soybean, cucumber and cabbage Korean were determined by GC-NPD and ECD.

• Journal of Environmental Health Sciences
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• v.43 no.2
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• pp.103-110
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• 2017

Objectives: This study was performed to provide basic data for the re-establishment of standards (criteria) and analytical methods for hazardous metals in nail enamel. Methods: Ten metals (lead; Pb, arsenic; As, cadminum; Cd, antimony: Sb, cobalt; Co, nikel; Ni, copper; Cu, chromium; Cr, aluminum; Al, and mercury; Hg) were measured in 67 commercial nail enamels containing glitter and/or pearls. The content of hazardous metals (excepting Hg) was determined by using an inductively coupled plasma-optical emission spectrophotometer (ICP-OES) after microwave digestion. Mercury content was measured by a mercury analyzer without any preparation. Results: The detected ranges of the intact samples were as follows: $ND-1.756{\mu}g/g$ for Pb, $ND-1.24{\mu}g/g$ for As, ND for Cd, $ND-20.41{\mu}g/g$ for Sb, $ND-12.36{\mu}g/g$ for Co, $ND-7.908{\mu}g/g$ for Ni, $0.088-79.27{\mu}g/g$ for Cu, $0.281-18.54{\mu}g/g$ for Cr, $13.78-3563{\mu}g/g$ for Al, and $ND-0.044{\mu}g/g$ for Hg. After centrifugation, the detected ranges of supernatant were as follows: $ND-0.435{\mu}g/g$ for Pb, $ND-0.504{\mu}g/g$ for As, ND for Cd, $ND-0.035{\mu}g/g$ for Sb, $ND-13.17{\mu}g/g$ for Co, $ND-0.232{\mu}g/g$ for Ni, $0.117-90.07{\mu}g/g$ for Cu, $0.174-2.787{\mu}g/g$ for Cr, and $9.459-1565{\mu}g/g$ for Al. The results of this analysis showed that the levels of heavy metals such as Pb, As, and Sb were much higher in the intact samples than those of supernatant. Conclusion: In the present study, we found that the levels of hazardous metals were significantly different depending on the status of the presence of glitter. Based on the results, we recommend that the product consumer refrain from prolonged application of nail enamel, avoid biting or chewing the nails, and wear gloves during cooking and washing dishes.