• Journal of the Korean Magnetics Society
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• v.17 no.3
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• pp.128-132
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• 2007

The thermal and magnetic properties of amorphous (FeCo)SiBNb ribbon alloys with high glass forming ability have been investigated. The glass forming ability was enhanced by Co substitution in amorphous ($Fe_{1-X}Co_X)_{72}Si_4B_{20}Nb_4$ alloys with the thickness of about $40{\mu}m$. With the increase in Co content, the temperature range of supercooled liquid phase increased indicating the high glass forming ability of the Co-added alloys. Further the ac permeability increased, and the core loss decreased considerably by Co substitution, while small change in $B_8$ (magnetic flux density at 800 A/m) was observed. The frequency characteristics of permeability deteriorated as compared to conventional amorphous ribbon alloys with the thickness of about $20\;{\mu}m$ due to the increased skin effect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.236-243
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• 2018

The purpose of this study was to investigate the mediating effects of parental attachment and ego resiliency in the tendency toward social networking site (SNS) addiction in college students. For this purpose, 382 college students in the Jeju area were surveyed and their responses analyzed. To analyze the collected data, structural equations were implemented using SPSS Statistics version 18.0. According to the results of the study, there is a significant negative correlation between attachment formation and SNS intoxication in college students, and a negative correlation between ego resiliency and SNS addiction. Also, there is a significant positive correlation between formation of parental attachment and ego resiliency in college students, indicating that parental attachment and ego resiliency are significant factors in lowering SNS addiction. Second, in order to examine the mediating effects of ego resiliency in the relationship between the formation of parental attachment and SNS addiction in college students, a research model and a competition model were established and verified. As a result, the relationship between parent attachment and SNS addiction was mediated completely, and the research model is more appropriate. These findings suggest that ego resiliency is of practical significance in seeking ways to improve the problem of SNS addiction in the future. In other words, overuse of SNSs by university students can lead to addiction, but strengthening ego resiliency enables sound SNS use.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.3
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• pp.351-359
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• 1996

We have investigated the effect of hydrogen plasma on the formation of InAs QDs (quantum dots) structure by using a CBE (chemical beam epitaxy)system equipped with ECR (electron cyclotron resonance) plasma source. It is confirmed that the formation of self-organized InAs-QDs on GaAs is started after the growth of InAs layer up to 2.6 ML (monolayer) with the irradiation of hydrogen plasma while it is started after 1.9 ML without hydrogen gas and hydrogen plasma through the observation of RHEED patterns. Density and size of the QDs formed at $T_{sub}=370^{\circ}C$ are $1.9{\times}10^{11}cm^{-2}$ and 17.7 nm without hydrogen plasma, and $1.3{\times}10^{11}cm^{-2}$ and 19.4 nm with hydrogen plasma, respectively. It is also observed from the PL(photoluminescence) measurement on InAs-QDs that red shift in PL peak energy and broadening in FWHM (full width at half maximum)of PL peak caused by the effects of hydrogen plasma on the increment of size and its distribution. These effects of hydrogen plasma are considered as a act of atomic hydrogen which enhances the layer-growth of InAs on GaAs resulted from the relief of misfit strain between GaAs substrate and InAs.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.626-636
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• 2003

Pediococcus pentosaceus K1270 was isolated from naturally fermented kimchi and identified based on the 16S rDNA sequence as well as cultural and biochemical characteristics. This strain strongly inhibited the formation of biofilm by Streptococcus mutans Ingbritt. K1270 also showed antibacterial activity against S. mutans Ingbritt. It was observed that K1270 strain produced hydrogen peroxide on MRS agar supplemented with 3, 3, 5, 5-tetramethylbenzidine (TMB) and peroxidase and the inhibitory effect of K1270 strain on the biofilm formation was reversed by the addition of catalase in part. Culture supernatant of K1270 inhibited the biofilm formation and the multiplication of S. mutans Ingbritt. This inhibitory effect of culture supernatant was decreased slightly by the addition of catalase and abolished by heat or trypsin treatment. Thus, this study suggests that P. pentosaceus K1270 inhibit the biofilm formation through the inhibition of the replication of S. mutans Ingbritt by producing hydrogen peroxide and bacteriocin.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.3
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• pp.211-218
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• 2018

Instant face lifting cosmetics contain various film forming agents for stretching the wrinkles on the skin surface. But, most of the film-forming polymers have sticky feels. And they are easily scrubbed out when skin is rubbed on. In this study, we focused on the influence of sodium silicate that has rapid film forming effect on skin surface and immediate wrinkle reducing effect. Sodium silicate, also known as water glass or soluble glass, is a compound containing sodium oxide and silica. Sodium silicate is a white powder that is readily soluble in water, producing an alkaline solution. Sodium silicate is stable in neutral and alkaline solutions. The sodium silicate solution hardens by drying in air and rapidly forms a thin film. When the solution is applied to the skin, the fine membrane coating is formed by water evaporation and ionic bond re-formation. It also makes the strong siloxane (Si-O) bonding on the skin surface. When these fixation properties are applied to cosmetics, they can give remarkable skin tightening effect. The sodium silicate solution can provide the lifting effect by forming a film on skin at a proper concentration. But, skin irritation may be caused with too high concentration of sodium silicate. We studied a desirable range of the sodium silicate concentration and combination with other fixatives for skin care formulation that has no sticky feels and no scrubbing out phenomenon. Immediate lifting gel was developed by using sodium silicate and various thickening systems. Among of the various thickeners, aluminum magnesium silicate showed the best compatibility with sodium silicate for rapid lifting effect. This instant physical lifting gel was confirmed as a low stimulating formula by skin clinical test.

• Journal of Acupuncture Research
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• v.26 no.1
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• pp.153-162
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• 2009

목적 : 한의학 분야에서 육계(CCE: Cinnamomum cassia)는 혈류 순환이 저하된 상태에 널리 쓰이는 약재이다. 이 연구에서는 CCE와 그 활성 혼합물인 cinnamic acid가 in vitro와 in vivo에서 발휘하는 신생혈관 형성 작용에 대해 알아보고자 한다. 방법 : CCE와 CA의 신생혈관형성 작용을 알아보기 위하여 Human unbilical endothelial cells(HUVECs)와 Bovine arterial endothelial cells(BAECs) 그리고 Matrigel assay를 이용하였다. 결과 : In vitro에서 CCE와 그 활성 혼합물은 HUVEC 증식, 이동, 모세혈관-유사 관 형성을 유도한다. CCE에서의 25-50% 증가(1 또는 10ng/ml 용량에서)는 CA에서 증식과 유사하게 나타났다. HUVEC에서는 증식이 뚜렷하게 나타났으나 BAEC에서는 증식이 뚜렷하게 나타나지 않아 증식 효과는 내피세포의 기원에 따라 다른 것으로 나타났다. BAEC는 CCE와 CA에서 증식은 보이지 않았지만 이동과 모세혈관-유사 관 형성 또는 분화를 보였다. 또한 CCE와 CA는 HUVEC에서 VEGF 발현과 Flk-1/KDR 발현을 각각 2.2배와 2.5배 증가시켰다. 결론 : CCE와 그 활성 혼합물은 in vivo와 in vitro에서 혈관 내피세포의 VEGF 발현을 통하여 신생혈관 형성 작용을 유도하며 이는 앞으로 다른 한약 추출물의 신생혈관형성 촉진 작용 연구에 모델을 제시할 것으로 보인다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.29-29
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• 2002

참오갈피(Acanthopanax pedunculus)는 국내 고유한 자생 종이며 현재 몇 그루 만이 존재하는 것으로 추정된다. 이 수종은 대체적으로 다른 오갈피 수종에 비해 잎 및 열매는 물론 식물 전체 부위가 다소 커서 경제성이 높다고 판단된다. 본 실험에서는 참오갈피의 세포배양 기술을 이용한 묘목 및 약용원료의 산업적 대량 생산 기술을 개발하고자 수행 하였다. 참오갈피 접합자배를 적출하여 무균적으로 배양한 다음 자엽단계로 성숙한 이들 접합자배를 1 mg/1 2,4-D가 첨가된 MS 배지에 배양하여 배형성 캘러스를 유도하였다. 배형성 세포의 유도율은 약 72%에 달했다. 유도된 배형성 캘러스는 2,4-D가 첨가된 같은 고체 및 액체 배지에서 계대배양하여 배형성 캘러스 및 세포를 유지하였다. 배형성 캘러스를 2,4-D가 첨가되지 않은 배지에 옮겨주면 이들 세포로부터 체세포배가 발생되었다. 약 2개월의 기간을 거쳐 자엽단계로 성숙된 체세포 배는 발아되지 않기 때문에 5 mg/1 GA$_3$가 첨가된 1/2 MS 배지에 옮겨 발아 및 식물체로 재생 시켰다. 약 7 cm 크기로 재생된 식물체를 인공토양에 옮겨 1달간 순화시키고 난 후 토양에 옮겼을 경우 87%가 생존하였다. 기내에서 유도된 참오갈피 식물체는 특별한 처리를 하여주지 않아도 뿌리로부터 배발생 세포를 형성 할 수 있었다. 따라서 이들 식물체로부터 배발생세포 유도는 세포주의 보존 및 증식에 효과적으로 이용될 수 있었다. 한편 참오갈피 세포는 5-10 리터 바이오리엑터 배양을 통하여 배형성세포, 자엽단계의 배, 유식물의 대량생산의 가능성을 확인하였다.

• Korean Journal of Environmental Biology
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• v.28 no.1
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• pp.14-19
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• 2010

Angiogenesis is an important event involved in cell growth and wound healing process. However, the imbalance of growth factors causes diseases, such as ocular, inflammatory diseases. One of treatment of these diseases is to suppress the formation of blood vessels. Function and mechanism of gold nanoparticles (AuNPs) in the formation of blood vessels is not yet proved. Pigment epithelium derived factor (PEDF) is currently being offered anti-angiogenic materials. In this study, we postulated that AuNPs might have the ability to inhibit angiogenesis, the pivotal step in tumor growth, invasion and metastasis. We have demonstrated that AuNPs could inhibit vascular endothelial growth factor (VEGF) induced cell proliferation, angiogenesis in bovine retinal endothelial cells.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.23-30
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• 2019

Fiber-Reinforced Cement Composite (FRCC) is known to be effective in mechanical effects such as cracking width control as well as steel anticorrosive effect. In this study, we examined about steel anticorrosive effect by using metal fibers including zinc fibers by accelerated corrosion test. Moreover, it was examined for salt penetration, sacrificial anode effect and formation of electric circuit that was significant effect on the steel anticorrosive effect. As a result, Steel anticorrosive effect was confirmed with mixed metal fibers on FRCC. Especially, In the case of zinc fibers with a high sacrificial anode effect, it was confirmed that the suppression of penetration and corrosion resistance were improved.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.210-214
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• 2000

대기 중 에어로졸은 지구표면에 도달하는 태양복사에너지를 흡수 또는 산란시키는 직접 효과 및 대기물리작용에 의한 구름의 형성 및 구름 수명에 영향을 미치는 간접 효과를 통해 지구복사 평형에 불균형을 초래함으로써 전지구적인 기후변화에 영향을 미친다(Toon, 1995). 이들 에어로졸은 온실기체와는 달리 -0.4~-3.0 W/$m^2$ 의 지구 평균 복사강제력을 나타내면서(IPCC, 1995) 대기 중에 냉각 효과(whitehouse effect)를 일으킨다(Schwartz, 1996). (중략)