• The Korean Journal of Physiology and Pharmacology
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• 제21권4호
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• pp.423-428
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• 2017

Vestibular compensation is a recovery process from vestibular symptoms over time after unilateral loss of peripheral vestibular end organs. The aim of the present study was to observe time-dependent changes in long-term potentiation (LTP) at Schaffer collateral-CA1 synapses in the CA1 area of the hippocampus during vestibular compensation. The input-output (I/O) relationships of fEPSP amplitudes and LTP induced by theta burst stimulation to Schaffer's collateral commissural fibers were evaluated from the CA1 area of hippocampal slices at 1 day, 1 week, and 1 month after unilateral labyrinthectomy (UL). The I/O relationships of fEPSPs in the CA1 area was significantly reduced within 1 week post-op and then showed a non-significant reduction at 1 month after UL. Compared with sham-operated animals, there was a significant reduction of LTP induction in the hippocampus at 1 day and 1 week after UL. However, LTP induction levels in the CA1 area of the hippocampus also returned to those of sham-operated animals 1 month following UL. These data suggest that unilateral injury of the peripheral vestibular end organs results in a transient deficit in synaptic plasticity in the CA1 hippocampal area at acute stages of vestibular compensation.

• Journal of Magnetics
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• 제14권1호
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• pp.1-6
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• 2009

The magnetic properties of ${Bi_x}{Ca_{1-x}}{MnO_3}$ for x = 0.12, 0.13, 0.14, 0.15, and 0.16 were examined by measuring magnetic susceptibility, resistivity and electron magnetic resonance at different temperatures. ${Bi_x}{Ca_{1-x}}{MnO_3}$ showed complicated magnetic structure that varies with temperature and composition, particularly around Bi composition x. 0.15. The aim of this study was to determine how the magnetic and physical properties of ${Bi_x}{Ca_{1-x}}{MnO_3}$ change in this region. In addition, first principles calculations of the magnetic phase of ${Bi_x}{Ca_{1-x}}{MnO_3}$ for x = 0, 0.125, 0.25 were carried out, and the spin state, electric and magnetic characteristics are discussed.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.30.1-30
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• 2002

• Journal of Nutrition and Health
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• 제43권4호
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• pp.351-356
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• 2010

본 연구는 칼슘고갈식이와 칼슘회복식이를 급여한 SD 종 흰쥐에서 골격대사 지표와 골밀도를 측정함으로써 어린소재 Ca (Tilapia mossambica 비늘을 이용한 칼슘소재)의 유용성을 $CaCO_3$와 비교 평가하였다. 1) 칼슘고갈식이인 LoCa군에 비해 칼슘회복식이를 먹인 AdCa군과 AdFa군에서 체중증가, 사료섭취량이 유의하게 높았고, 이는 어린소재 Ca의 식이효율이 적정수준에 있다고 할 수 있다. 2) 혈청 PTH와 칼시토닌은 실험군 사이에 차이가 없었다. 3) 혈청 ALP와 오스테오칼신은 LoCa군에서 유의하게 증가하였고, AdCa와 AdFa군에서 저하되었다. 뇨의 DPD는 LoCa군에서 현저히 높은 수치를 보인 반면, AdCa와 Ad-Fa군에서 낮은 수치를 보임으로써 뼈의 형성지표와 흡수지표는 칼슘회복식이에 의해 개선되었다. 4) 대퇴골의 습윤무게, 건조무게, 체중 100g 단위당 중량이 모두 AdFa > AdCa > LoCa 순으로 높았고, 대퇴골의 회분함량과 칼슘함량도 모두 같은 순서를 보임으로써 뼈의 형성과 칼슘 축적에 AdCa군과 마찬가지로 AdFa군에서도 효과적이었음을 시사한다. 5) 대퇴골의 골밀도는 AdCa군과 AdFa군에서 LoCa군에 비해 25~26%의 유의하게 높은 수치를 보였다. 이상에서와 같이 칼슘회복식이 (AdCA와 AdFa)는 ALP, 오스테오칼신, DPD의 지표를 개선하였고, 대퇴골의 중량과 회분함량의 증가와 함께 골밀도를 향상시키는 것으로 나타났다. 따라서 어린소재 칼슘은 대조 칼슘급원으로 많이 사용되는 $CaCO_3$에 비교하여 뼈 건강에 대등한 효과를 보이므로, 칼슘 소재로서 개발될 가치가 있을 것으로 평가된다.

• 자원리싸이클링
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• 제11권4호
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• pp.27-36
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• 2002

생활폐기물의 소각으로 발생되는 바닥재(bottom ash)로 calcium-chloroaluminate($l1CaOㆍ7Al_2$$O_3$ㆍ$CaCl_2$)가 함유된 클링커를 제조한 후 이들 클링커의 수화반응성 및 보통 포틀랜드 시멘트와 혼합 사용할 때의 압축강도 및 중금속 용출특성을 연구하였다. 시약으로 calcium-chloroaluminate를 제조한 결과. calcium-chloroaluminate는 80$0^{\circ}C$부터 생성되며, $CaSO_4$ 및 $Ca(OH)_2$ 와의 수화반응에 의해 ettringite($3CaOㆍAl_2$$O_3$ㆍ$3CaSO_4$ㆍ$32H_2$O)가 생성된다. 4 mesh 이하의 바닥재를 분쇄하지 않고 온도별로 1시간 소성한 결과, 80$0^{\circ}C$부터 calcium-chloroaluminate가 30 mesh 이하의 입도에서 합성되었다. $1,000^{\circ}C$에서 소성한 30 mesh 이하의 바닥재에 무수석고($CaSO_4$)를 10 : 6의 중량비로 혼합한 후 이들 혼합물을 보통 포틀랜드 시멘트에 3～13 wt.% 첨가하여 제조한 모르타르의 압축강도를 측정한 결과, 이들 혼합물의 치환량이 11 wt.%까지 증가됨에 따라 보통 포틀랜드 시멘트의 압축강도보다 높았다. 각 모르타르 공시체를 1 mm 이하로 분쇄하여 중금속 용출시험 결과, 용출된 중금속의 농도는 환경규제치보다 낮았다.

• Bulletin of the Korean Chemical Society
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• 제20권7호
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• pp.791-795
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• 1999

The crystal structure of a cyclopropane sorption complex of dehydrated fully Ca (2+) -exchanged zeolite X, Ca46Si100Al92O384· 30C3H6 (a = 24.988(4) Å), has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21(1)℃. The crystal was prepared by ion exchange in a flowing stream of 0.05M aqueous Ca(NO3)2 for four days, followed by dehydration at 460℃ and 2×10 (-6) Torr for two days, and exposure to 100 Torr of cyclopropane gas at 21(1)℃. The structure was determined in this atmosphere and refined to the final error indices R1 = 0.068 and R2 = 0.082, with 373 reflections for which I > 3σ (I). In this structure, Ca 2+ ions are located at two crystallographic sites. Sixteen Ca 2+ ions fill the octahedral sites I at the centers of the hexagonal prisms (Ca-O = 2.412(9)Å). The remaining 30 Ca 2+ ions are at sites Ⅱ; each extends 0.46Å into the supercage (an increase of 0.16Å upon C3H6 sorption) where it coordinates to three trigonally arranged framework oxygens at 2.311(8)Å. Each of the 30 cyclopropane molecules was found to complex to Ca 2+ ions at site II by the induced dipole interaction (Ca-C = 2.99(4)Å). All carbon atoms in each cyclopropane molecule are equivalent and equidistant from Ca 2+ ions at site II with which they are associated.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.110-110
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• 2003

It is well-documented that decreased antioxidant defense system by ultraviolet(UV) irradiation is the most important reason to induce the skin aging, especially photoaging. Chlorogenic acid(CA), a nonflavonoid catecholic compound, is present in the diet as part of fruits, tea, coffee and wine and has been reported to have anti-inflammatory, antimutagenic and anticarcinogenic activities. In this study, we examined the effects of CA on the UV -induced photoaging. Firstly, we investigated the protective effect of CA on antioxidant defense system in HaCaT human keratinocytes after UV irradiation treatment. UV irradiation decreased antioxidant defence enzyme activities of superoxide dismutase, catalase and GSH contents, which were restored by CA. To elucidate the effect of CA, 1% of CA and vehicle were applied to human buttock skin before and after UV irradiation (2MED). CA prevented UV -induced matrix metalloproteinase-1 mRNA expression and procollagen mRNA depression. And CA also increased CD1a(Langerhans cell) expression significantly. Our results suggest that CA has protective effects on UV -induced photoaging by increasing cellular antioxidant defense system. Therefore, CA may be a useful anti-aging agent for cosmetic purpose.

• 한국전기전자재료학회논문지
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• 제19권6호
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• pp.524-530
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• 2006

$xCa(Li_{1/4}Nb_{3/4})O_{3}-(1-x)CaTiO_{3}$ ceramics were sintered under the presence of zinc-borosilicate(ZBS) glass and resultant microwave dielectric properties were investigated with a view to applying the composition to low-temperature co-fired ceramic(LTCC) technology. The addition of $5{\sim}15wt%$ ZBS glass ensured successful sintering below $900\;^{\circ}C$. In general, increased addition of ZBS glass increased sinterability but it decreased the quality factor($Q{\times}f_{0}$) significantly due to the formation of an excessive liquid and second phases. As for the addition of $CaTiO_3$, the dielectric constant(${\epsilon}_r$) and temperature coefficient of resonant frequency(${\tau}_f$) increased, while the quality factor($Q{\times}f_{0}$) did not show an apparent change. The sintered $0.9Ca(Li_{1/4}Nb_{3/4})O_{3}-0.1CaTiO_{3}$ specimen at $900\;^{\circ}C$ with 10 wt% ZBS glass demonstrated 39.6 in dielectric constant(${\epsilon}_r$), 4,400 in quality factor$(Q{\times}f_{0}),\;and\;-11ppm/^{\circ}C$ in temperature coefficient of resonant frequency(${\tau}_f$).

• Animal Bioscience
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• 제36권7호
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• pp.1044-1058
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• 2023

Objective: The objective of this study was to characterize physiochemical and nutrient profiles of feedstock and co-products from canola bio-oil processing that were impacted by source origin. The feedstocks and co-products (mash, pellet) were randomly collected from five different bio-oil processing plants with five different batches of samples in each bio-processing plant in Canada (CA) and China (CH). Methods: The detailed chemical composition, energy profile, total digestible nutrient (TDN), protein and carbohydrate subfractions, and their degradation and digestion (CNCPS6.5) were determined. Results: The results showed that TDN_1x was similar in meals between CA and CH. CH meals and feedstock had higher, truly digestible crude protein (tdCP) and neutral detergent fiber (tdNDF) than CA while CA had higher truly digestible non-fiber carbohydrate (tdNFC). The metabolizable energy (ME_3x), net energy (NE_Lp3x, NE_m3x, and NE_g3x) were similar in meals between CA and CH. No differences were observed in energy profile of seeds between CA and CH. The protein and carbohydrate subfractions of seeds within CH were similar. The results also showed that pelleting of meals affected protein sub-fractionation of CA meals, except rapidly degradable fractions (PB1), rumen degradable (RDPB1) and undegrdable PB1 (RUPB1), and intestinal digestible PB1 (DIGPB1). Canola meals were different in the soluble (PA2) and slowly degradable fractions (PB2) between CA and CH. The carbohydrate fractions of intermediately degradable fraction (CB2), slowly degradable fraction (CB3), and undegradable fraction (CC) were different among CH meals. CH presented higher soluble carbohydrate (CA4) and lower CB2, and CC than CA meals. Conclusion: The results indicated that although the seeds were similar within and between CA and CH, either oil-extraction process or meal pelleting seemed to have generated significantly different aspects in physiochemical and nutrient profiles in the meals. Nutritionists and producers need to regularly check nutritional value of meal mash and pellets for precision feeding.

• 원예과학기술지
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• 제33권4호
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• pp.525-534
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• 2015

The effects of aqueous calcium oxide (CaO) treatment on the quality characteristics and shelf life of mulberry (Morus alba L.) were investigated. Mulberry fruits were immersed in 0, 0.5, 1, and $2g{\cdot}L^{-1}$ CaO solutions for 0, 1, 3, 6, and 12 min. Mulberries were then rinsed with potable tap water for 1 min and stored at $-1^{\circ}C$ for 14 days. CaO treatment was effective at promoting the retention of titratable acid, pH, and ascorbic acid as well as total flavonoid contents. CaO concentration and treatment time were significant factors affecting the sensory qualities of the fruits, including off-odor, flavor, and texture. For shelf life determinations, the total bacterial count was reduced by CaO treatment so that the samples treated with $1g{\cdot}L^{-1}$ CaO for 12 min had bacterial levels at 14 days comparable to those of the control at 4 day, and no coliform group was detected after CaO treatment. These results indicate that calcium oxide treatment is a promising approach for the preservation of mulberry fruit.