• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.466-468
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• 1998

This paper designs a robust controller with improved stability of a system. Robust control theory has been developed by many researchers. The controller derived in that using robust control theory has an assumption that it will be exactly implementation. But, It is very hard because of truncation errors, D-A, A-D transformation, and finite resolution, etc. Such perturbations would make problems in the stability of the system. Recently, Keel's paper presents some examples which shows controllers based on the robust controller design method are very fragile on its own perturbation. In this paper, we try to improve the stability of the closed-loop system in which there exist perturbation in the plant as well as in the controller. The results shows that the stability is improved and the performance is still satisfied.

• 한국동물생명공학회지
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• 제35권4호
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• pp.289-296
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• 2020

Spermatogonial stem cells are self-renewal and differentiate into sperm in post-pubertal mammals. There exists a balance between the self-renewal and differentiation in the testes. Spermatogonial stem cells make up only 0.03% of testicular cells in adult mice. These cells maintain sperm production by differentiating after puberty. Therefore, analyzing the expression of genes associated with spermatogenesis is critical for understanding differentiation. The present study aimed to establish the postnatal period of cells in relation to spermatogenesis. To study the expression of differentiated and undifferentiated marker genes in enriched spermatogonial stem cells, in vitro culture was performed and cells from pup (6-8-day-old) and adult (4-months-old) testicular tissues were isolated. As a result, undifferentiated genes, Pax7, Plzf, GFRa1, Etv5 and Bcl6b, were highly increased in cultured spermaotogonial stem cells compared with pup and adult testicular cells. On the other hands, differentiated gene, c-kit was highly increased in adult testicular cells, Also Stra8 gene was highly increased in pup and adult testicular cells. This study provides a better understanding of spermatogenesis-associated gene expression during postnatal periods.

• 한국축산식품학회지
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• 제42권5호
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• pp.775-799
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• 2022

The purpose of this review is to summarize studies that investigate blood and the main components of fetal bovine serum (FBS) in vertebrates, including major livestock, and review the current research on commercializing cultured meat. Detailed research on FBS is still lacking; however, some studies have shown that FBS consists of proteins, carbohydrates, growth factors, cytokines, fats, vitamins, minerals, hormones, non-protein nitrogen, and inorganic compounds. However, there are few studies on how the composition of FBS differs from blood or serum composition in adult animals, which is probably one of the main reasons for not successfully replacing FBS. Moreover, recent studies on the development of FBS replacers and serum-free media have shown that it is difficult to conclude whether FBS has been completely replaced or serum-free media have been developed successfully. Our review of the industrialization of cultured meat reveals that many basic studies on the development of cultured meat have been conducted, but it is assumed that the study to reduce or replace ingredients derived from fetuses such as FBS has not yet been actively developed. Therefore, developing inexpensive and edible media is necessary for the successful industrialization of cultured meat.

• Journal of Applied Biological Chemistry
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• 제57권3호
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• pp.211-218
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• 2014

Polymethoxyflavones (PMFs) are a group of polymethoxylated bioactive flavones with diverse biological activities, including anticancer, anti-inflammatory, antibacterial, and antiviral activities. PMFs are found from various plants such as orange, tangerine, and krachaidum. To establish the simple quantitative analytical methods for PMFs, chromatographic analysis was applied to the selected krachaidum foods because krachaidum contains diverse PMFs compared to other PMF-containing foods. Krachaidum is the rhizome of Kaempferia parviflora, and many commercial krachaidum products, such as tea, juice and wine, are commercially available and consumed as health functional foods in Asian countries. Apart from the claimed health promoting benefits, reliable quality assurance and legal guideline for the registration of these products are not available yet. Twelve PMFs were analyzed from the commercial krachaidum foods by GC-FID and HPLC-DAD. No single chromatographic method could not analyze 12 PMFs simultaneously. HPLC-DAD method was found more sensitive to detect PMFs. Based on our analysis data, we proposed 5,7-dimethoxyflaone and 5,7,4'-trimethoxyflavone as index components for the food products.

• 한국식품영양과학회지
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• 제37권1호
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• pp.66-71
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• 2008

반응표면분석법을 통하여 홍차의 침출 온도와 시간에 따른 침출물의 기능성 성분과 항산화성을 모니터링하고 최적 침출조건을 예측하였다. 수용성 성분의 침출수율, 환원당, 총 페놀, 총 플라보노이드 함량 등은 침출온도가 높아지고 침출시간이 길어짐에 따라 증가되는 경향을 보였고, $78.28{\sim}87.08^{\circ}C$와 $3.97{\sim}4.27$분으로 침출할 경우 최대값을 얻을 수 있었다. 비타민 C는 침출온도가 높거나 낮고 침출시간이 길거나 짧을 경우에 감소하였으며 $61.29^{\circ}C$와 2.68분에서 가장 높았다. 전자공여능은 침출온도가 높거나 낮고 침출시간이 길어짐에 따라 감소하였고 $68.30^{\circ}C$와 0.54분에서 최대값을 나타내었다. 이로써 홍차 티백의 기능성 관련 성분을 고려한 최적 침출조건은 침출온도 $63{\sim}79^{\circ}C$와 침출시간 $1.5{\sim}2.1$분으로 예측되었다.

• 한방재활의학과학회지
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• 제34권2호
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• pp.165-172
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• 2024

Objectives This study aims to report current status and strategies of thread embedding acupuncture (TEA) on face through survey of Korean medicine doctors. Methods The survey was conducted online via e-mail to certified Korean medicine doctors. The questionnaire is developed by Korean medicine doctors in Kyung-Hee Korean Medicine Hospital at Gangdong. The survey mainly consisted with multiple-choice questions on the current status, cost, and adverse reactions. Results TEA was predominantly utilized for cosmetic purposes, and the billing cost was commonly determined based on the number of threads used. The reported incidence of adverse reactions during TEA was 69.9%. The most frequent self-resolving adverse reaction was bruising, while the most common adverse reaction requiring medical intervention or resulting in sequelae was the 'dimple phenomenon'. According to the questionnaire, the primary factor associated with adverse reactions was the treatment area. Conclusions This study provided insights into the practical use of TEA on face in Korean medical clinic.

• The Korean Journal of Physiology and Pharmacology
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• 제13권5호
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• pp.393-400
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• 2009

NO released by myenteric neurons controls the off contraction induced by electrical field stimulation (EFS) in distal esophageal smooth muscle, but in the presence of nitric oxide synthase (NOS) inhibitor, L-NAME, contraction by EFS occurs at the same time. The authors investigated the intracellular signaling pathways related with G protein and ionic channel EFS-induced contraction using cat esophageal muscles. EFS-induced contractions were significantly suppressed by tetrodotoxin ($1\;{\mu}M$) and atropine ($1\;{\mu}M$). Furthermore, nimodipine inhibited both on and off contractions by EFS in a concentration dependent meaner. The characteristics of 'on' and 'off contraction and the effects of G-proteins, phospholipase, and $K^+$ channel on EFS-induced contraction in smooth muscle were also investigated. Pertussis toxin (PTX, a $G_i$ inactivator) attenuated both EFS-induced contractions. Cholera toxin (CTX, $G_s$ inactivator) also decreased the amplitudes of EFS-induced off and on contractions. However, phospholipase inhibitors did not affect these contractions. Pinacidil (a $K^+$ channel opener) decreased these contractions, and tetraethylammonium (TEA, ${K^+}_{Ca}$ channel blocker) increased them. These results suggest that EFS-induced on and off contractions can be mediated by the activations Gi or Gs proteins, and that L-type $Ca^{2+}$ channel may be activated by G-protein ${\alpha}$ subunits. Furthermore, ${K^+}_{Ca^-}$ channel involve in the depolarization of esophageal smooth muscle. Further studies are required to characterize the physiological regulation of $Ca^{2+}$ channel and to investigate the effects of other $K^+$ channels on EFS-induced on and off contractions.

• The Korean Journal of Physiology and Pharmacology
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• 제12권2호
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• pp.73-77
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• 2008

Recent studies have documented that testosterone relaxes several smooth muscles by modulating $K^+$ channel activities. Smooth muscles of seminal vesicles playa fundamental role in ejaculation, which might involve testosterone. This study was aimed to assess the role of testosterone in seminal vesicular motility by studying its effects on contractile agents and on the ion channels of single vesicular myocytes in a rabbit model. The contractile responses of circular smooth muscle strips of rabbit seminal vesicles to norepinephrine ($10{\mu}M$), a high concentration of KCI (70 mM), and testosterone ($10{\mu}M$) were observed. Single vesicular myocytes of rabbit were isolated using proteolytic enzymes including collagenase and papain. Inside-out, attached, and whole-cell configurations were examined using the patch clamp technique. The applications of $10{\mu}M$ norepinephrine or 70 mM KCl induced tonic contractions, and $10{\mu}M$ testosterone (pharmacological concentration) evoked dose-dependent relaxations of these precontracted strips. Various $K^+$ channel blockers, such as tetraethylammonium (TEA; $10{\mu}M$), iberiotoxin ($0.1{\mu}M$), 4-aminopyridine (4-AP, $10{\mu}M$), or glibenclamide ($10{\mu}M$) rarely affected these relaxations. Single channel data (of inside-out and attached configurations) of BK channel activity were also hardly affected by testosterone ($10{\mu}M$). On the other hand, however, testosterone reduced L-type $Ca^{2+}$ currents significantly, and found to induce acute relaxation of seminal vesicular smooth muscle and this was mediated, at least in part, by $Ca^{2+}$ current inhibition in rabbit.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.781-783
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• 2000

1bit full adder have 3 input (including carry_in) and 2 outputs(Sum and Carry_out). Because of 1 bit full adder's propagation delay. We usually use 4-bit binary full adder with fast carry, 74LS283. The 74LS283 is positive logic circuit chip. But the logic function of binary adder is symmetrical, so it can be possible to use it not only positive logic but also the negative logic. This thesis use symmetrical property. such as $C_{i+1}(\bar{a_i}\bar{b_i}\bar{c_i})=C_{i+1}{\bar}(a_i,\;b_i,\;c_i)$ and $S_i(\bar{a_i}\bar{b_i}\bar{c_i})=\bar{S_i}(a_i,\;b_i,\;c_i)$. And prove this property with logic operation. Using these property, the 74LS283 adder is possile as the negation logic circuit. It's very useful to use the chip in negative logic. because many system chip is negative logic circuit. for example when we have negative logic chip with 74LS283. we don't need any not gate for 74LS283 input, and just use output of adder(74LS283) as the negation of original output.

• 한국식품위생안전성학회지
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• 제25권1호
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• pp.43-48
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• 2010

침출차와 소스류, 전분류의 각 품목에 대하여 PSL과 TL의 적용 가능성을 검토하기 위하여 각 품목별로 다른 선량으로 방사선 조사를 실시하여 PSL과 TL 분석을 하였다. 침출차 2종은 0, 2, 7kGy, 소스류 2종은 0, 5, 7, 10 kGy, 전분류 3종은 0, 2, 5 kGy로 조사를 실시하였다. PSL의 분석 결과, 침출차는 비조사구에서는 threshold value $T_1$(700) 이하의 낮은 값을 나타내었고 2kGy 이상의 조사구에서는 $T_2$(5000) 이상의 높은 값을 나타내어 방사선 조사 여부 확인이 가능하였다. 이에 비해 소스류는 비조사구에서는 $T_1$ 이하의 값이 나타났지만, 5kGy 이상의 조사구에서 1173, 1773의 $T_1$보다 높고 $T_2$보다 낮은 photon count를 나타내어 중간시료로 나타났다. 또한 전분류에서는 비조사구에서 $T_1$보다 높고 $T_2$보다 낮은 중간값을 나타내어 TL 확인 시험을 필요로 하였다. TL 분석에서는 3가지 품목 모두 비조사구에서는 $300^{\circ}C$ 부근에서 최고의 peak를 가지는 glow curve를 나타내거나 특정적인 TL glow curve를 나타내지 않았다. 그리고 조사구에서는 $150{\sim}250^{\circ}C$ 부근에서 비조사구에서 보이지 않았던 특유의 glow curve를 나타내었고, 조사선량에 따른 intensity의 차이도 보이고 있었다 한편 TL 결과를 검증하기 위하여 재조사에 의한 TL ratio를 산출한 결과 비조사구에서는 0.08 이하를 나타내었으나, 각 선량별 조사구에서는 전분류의 경우 0.07 이상의 낮은 값을 나타내기도 하였으나 TL온도범 위와 glow curve의 형태에 따라서 방사선 조사된 것을 확인할 수 있었다. 따라서 PSL과 TL 분석법의 적용 가능성이 확인되었다.