• 제목/요약/키워드: Potential barrier

검색결과 645건 처리시간 0.027초

Breast abscess caused by Staphylococcus aureus in 2 adolescent girls with atopic dermatitis

  • Park, Sung Man;Choi, Won Sik;Yoon, YoonSun;Jung, Gee Hae;Lee, Chang Kyu;Ahn, So Hyun;Yoon, Wonsuck;Yoo, Young
    • Clinical and Experimental Pediatrics
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    • 제61권6호
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    • pp.200-204
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    • 2018
  • Atopic dermatitis (AD) is a chronic inflammatory skin disease in children. Patients with AD experience a high rate of colonization of the skin surface by Staphylococcus aureus. Because of a skin barrier defect, there is a potential risk of staphylococcal invasive infection in patients with AD. Here, we present 2 cases of breast abscess caused by S. aureus in 2 adolescent girls with severe AD. Methicillin-sensitive S. aureus was identified from the breast abscess material. They were treated with appropriate antibiotics, however surgical drainage of the abscess was needed in case 1. Identical strains were found from the breast abscess material as well as the lesional and the nonlesional skin of the patients through matrix-assisted laser desorption/ionization time-of-flight analysis. We characterized the differential abundance of Firmicutes phylum in patients' skin in microbiota analysis. In particular, S. aureus, a member of Firmicutes, differed significantly between the lesional and the normal-appearing skin. Our cases demonstrate the potential severity of bacterial deep tissue infection in AD and the dysbiosis of skin microbiota may be involved in inflammation in AD.

단순 유전 알고리즘에서 단속평형의 지속시간에 대한 연구 (The Duration of Punctuated Equilibria in Simple Genetic Algorithms)

  • 오상엽
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제32권11호
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    • pp.1059-1070
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    • 2005
  • 유전 알고리즘에서 개체군은 지역 최적치에 빠질 수 있지만 긴 지속시간이 지난 후에는 여기에서 빠져나을 수 있으며 이러한 현상을 단속평형 (punctuated equilibrium)이라고 한다. 자연계나 컴퓨터 생태계 (computational ecosystems) 에서 관찰되는 단속평형은 확산 방정식 (diffusion equation)으로 잘 설명된다. 본 연구에서는 단순 유전 알고리즘을 이론적으로 분석하여 개체군의 움직임이 확산 방정식으로 표현될 수 있다는 것을 보인다. 또한 적합도 (fitness) 함수를 단위화 (unitation) 함수로 국한하면 이 분석을 더 구체화하여 유전 알고리즘의 주요 변수들이 이 방정식에 나타나도록 할 수 있다. 이 경우 확산 방정식에 대한 이론적 결과를 이용하면 지역 최적치에서 빠져 나오기까지의 지속시간이 개체군의 크기, 1/(돌연변이 확률), 그리고 지역 최적치의 깊이에 대해 지수적으로 증가한다는 것을 알 수 있다. 이러한 이론적 결과는 이중안정 지형 (bistable landscapes)에서의 시뮬레이션 결과와 일치한다.

중성염이 견의 반응염색에 미치는 영향 (Ⅱ) - 음이온의 영향 - (Effect of Neutral Salts on the Reactive Dyeing of Silk (Ⅱ) - Effect of Anions -)

  • 도성국;박찬헌;권지윤
    • 한국염색가공학회지
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    • 제13권2호
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    • pp.28-28
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    • 2001
  • Four kinds of neutral sodium salts with different anions, NaF, NaCl, NaBr, and NaI, were added to the dye bath to accurately understand the effect of anions on the reactive dyeing of silk with C. I. Reactive Black 5. The sodium cation lowered the negative surface potential of the silk and increased the dye-uptake on fille fabric as reported previously. However, because of the discrepancy in the anions′inhibition power from cation′s lowering the surface negative potential the amount of the dye on the silk fiber was different from each other in the order of $F^-\;>\;Cl^-\;>\; Br^-\;>\;I^-$. The activation energy($E_a$) for the dyeing was in the order of $F^-\;>\;Cl^-\;>\; Br^-\;>\;I^-$ but the dye-uptake on the fabric and the activation free energy(Δ$G^*$), the real energy barrier for the reaction, were in the order of $F^-\;>\;Cl^-\;>\; Br^-\;>\;I^-$ because the strength of the interaction of the anions with sodium cations was the same as the order of the latter. In other words $F^-$ exerted the weakest electrostatic force on $Na^+$and competed with the dyestuff anions least of all. The decrease in Δ$S^*$may be due to the looesly bonded activated complex of dyestuff anions, sodium cations and fiber molecules at transition state. It was clarified from the Bronsted equation that sodium salts with different anions also had fille ionic strength effect and the specific salt effect on the reactive dyeing.

The biological effect of cyanoacrylate-combined calcium phosphate in rabbit calvarial defects

  • Chang, Yun-Young;Dissanayake, Surangi;Yun, Jeong-Ho;Jung, Ui-Won;Kim, Chang-Sung;Park, Kyeong-Jun;Chai, Jung-Kiu;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • 제41권3호
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    • pp.123-130
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    • 2011
  • Purpose: The purpose of this study was to determine the biological effects of cyanoacrylate-combined calcium phosphate (CCP), in particular its potential to act as a physical barrier - functioning like a membrane - in rabbit calvarial defects. Methods: In each animal, four circular calvarial defects with a diameter of 8 mm were prepared and then filled with either nothing (control group) or one of three different experimental materials. In the experimental conditions, they were filled with CCP alone (CCP group), filled with biphasic calcium phosphate (BCP) and then covered with an absorbable collagen sponge (ACS; BCP/ACS group), or filled with BCP and then covered by CCP (BCP/CCP group). Results: After 4 and 8 weeks of healing, new bone formation appeared to be lower in the CCP group than in the control group, but the difference was not statistically significant. In both the CCP and BCP/CCP groups, inflammatory cells could be seen after 4 and 8 weeks of healing. Conclusions: Within the limits of this study, CCP exhibited limited osteoconductivity in rabbit calvarial defects and was histologically associated with the presence of inflammatory cells. However, CCP demonstrated its ability to stabilize graft particles and its potential as an effective defect filler in bone augmentation, if the biocompatibility and osteoconductivity of CCP were improved.

Photoprotective effects of topical ginseng leaf extract using Ultraflo L against UVB-induced skin damage in hairless mice

  • Hong, Yang Hee;Lee, Hyun-Sun;Jung, Eun Young;Han, Sung-Hee;Park, Yooheon;Suh, Hyung Joo
    • Journal of Ginseng Research
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    • 제41권4호
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    • pp.456-462
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    • 2017
  • Background: Abnormal activation of matrix metalloproteinases (MMPs) plays an important role in UV-induced wrinkle formation, which is a major dermatological problem. This formation occurs due to the degeneration of the extracellular matrix (ECM). In this study, we investigated the cutaneous photoprotective effects of Ultraflo L treated ginseng leaf (UTGL) in hairless mice. Methods: SKH-1 hairless mice (6 weeks of age) were randomly divided into four groups (8 mice/group). UTGL formulation was applied topically to the skin of the mice for 10 weeks. The normal control group received nonvehicle and was not irradiated with UVB. The UV control (UVB) group received nonvehicle and was exposed to gradient-UVB irradiation. The groups (GA) receiving topical application of UTGL formulation were subjected to gradient-UVB irradiation on $0.5mg/cm^2$ [GA-low (GA-L)] and $1.0mg/cm^2$ [(GA-high (GA-H)] of dorsal skin area, respectively. Results: We found that topical treatment with UTGL attenuated UVB-induced epidermal thickness and impairment of skin barrier function. Additionally, UTGL suppressed the expression of MMP-2, -3, and -13 induced by UVB irradiation. Our results show that topical application of UTGL protects the skin against UVB-induced damage in hairless mice and suggest that UTGL can act as a potential agent for preventing and/or treating UVB-induced photoaging. Conclusion: UTGL possesses sunscreen properties and may exhibit photochemoprotective activities inside the skin of mice. Therefore, UTGL could be used as a potential therapeutic agent to protect the skin against UVB-induced photoaging.

Warfarin 및 Digoxin 정제의 처방 용량 실태 및 조제 양식의 고찰 (Study on the Prescribed Doses and Dispensing Patterns of Warfarin and Digoxin Tablets)

  • 김윤숙;이승미;천부순
    • 약학회지
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    • 제58권1호
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    • pp.40-46
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    • 2014
  • Drugs with a narrow therapeutic index (NTI) require very precise dosing. Warfarin and digoxin are the examples of NTI-drugs and dosing of them varies widely for different patients. However, in South Korea, only two strengths of warfarin and one of digoxin are commercially available. This is a big barrier for the precise dispensing and has potential safety risks to patients, particularly to elderly patients. To find a potential solution to the problem, an analysis of the prescribed doses and dispensing patterns of those drugs was performed. Data were collected by computer-facilitated prescription review in a university hospital. The period screened was from May 1st, 2012 to April 30th, 2013. All the prescriptions with either warfarin or digoxin tablets were selected for this study and dispensing patterns were analyzed according to the prescribed doses. A total of 17,017 warfarin prescriptions were analyzed; 8,148 for inpatient prescriptions, 8,869 for outpatient prescriptions, respectively. Of the 23 kinds of prescribed doses, 2 mg (19.9%) was most frequent, followed by 3 mg (13.2%) and 2.5 mg (11.7%). By analyzing the dispensing patterns, 60.3% (10,253) of the prescriptions required pill splitting and 72.0% of them were for the patients 65 years old and over. On the other hand, 4,350 digoxin prescriptions were included in this study. Of the 6 kinds of prescribed doses, 0.125 mg (71.2%) was most frequent, followed by 0.0625 mg (20.2%). Among the prescriptions for digoxin, 92.0% (3,998) should be split and 65.7% of them were for the patients aged 65 years and over. Despite limitations of strengths, various doses of warfarin and digoxin were prescribed. Furthermore, more than half of the prescriptions that required pill splitting were for elderly patients. The results from this study suggest that different strengths of warfarin and digoxin should be provided for accuracy of dispensing and safety for patients receiving them.

뇌경색 전임상 연구 후보 약재 선정을 위한 네트워크 약리학 분석법의 활용과 치자(梔子)의 적용 가능성 검토 (Network pharmacological analysis for identifying herbal medicine candidate for cerebral infarction focusing on Gardeniae Fructus)

  • 정주현;박희준;임세현;조수인
    • 대한한의학방제학회지
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    • 제31권3호
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    • pp.145-156
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    • 2023
  • Objectives : This study aimed to select candidate herbal medicines to be used in preclinical studies of cerebral infarction using the network pharmacology research method. Methods : Oral bioavailability (OB), drug likeness (DL), Caco-2, and blood-brain barrier (BBB) permeability were employed in this study's network pharmacology analysis method to choose compounds with potential efficacy. The following formulas were utilized for the values of each variable used in this study: OB ≥ 20%, DL ≥ 0.18, Caco-2 ≥ 0, and BBB ≥ -0.3. The relationships between target proteins and diseases that are assumed to be involved in the chosen bioavailable chemicals were built in a network manner using the aforementioned factors, and proteins thought to play a significant role were identified. Results : Sudan III was obtained as a result of selecting compounds related to ischemic stroke in consideration of pharmacokinetic characteristics such as digestion and absorption and practicality using the TCMSP database. Medicinal herbs Gardeniae Fructus (GF) contains sudan III, and it was confirmed that compounds in GF were highly related to brain diseases, and the mechanism involved through the KEGG pathway was confirmed. GF, which has sudan III related to ischemic stroke and is also involved in other neurological diseases, is expected to be used for ischemic stroke treatment. Conclusions : GF has been predicted to have potential for ischemic stroke treatment, and can be used for future preclinical studies.

Establishing porcine jejunum-derived intestinal organoids to study the function of intestinal epithelium as an alternative for animal testing

  • Bo Ram Lee;Sun A Ock;Mi Ryung Park;Min Gook Lee;Sung June Byun
    • 한국동물생명공학회지
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    • 제39권1호
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    • pp.2-11
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    • 2024
  • Background: The small intestine plays a crucial role in animals in maintaining homeostasis as well as a series of physiological events such as nutrient uptake and immune function to improve productivity. Research on intestinal organoids has recently garnered interest, aiming to study various functions of the intestinal epithelium as a potential alternative to an in vivo system. These technologies have created new possibilities and opportunities for substituting animals for testing with an in vitro model. Methods: Here, we report the establishment and characterisation of intestinal organoids derived from jejunum tissues of adult pigs. Intestinal crypts, including intestinal stem cells from the jejunum tissue of adult pigs (10 months old), were sequentially isolated and cultivated over several passages without losing their proliferation and differentiation using the scaffold-based and three-dimensional method, which indicated the recapitulating capacity. Results: Porcine jejunum-derived intestinal organoids showed the specific expression of several genes related to intestinal stem cells and the epithelium. Furthermore, they showed high permeability when exposed to FITC-dextran 4 kDa, representing a barrier function similar to that of in vivo tissues. Collectively, these results demonstrate the efficient cultivation and characteristics of porcine jejunum-derived intestinal organoids. Conclusions: In this study, using a 3D culture system, we successfully established porcine jejunum-derived intestinal organoids. They show potential for various applications, such as for nutrient absorption as an in vitro model of the intestinal epithelium fused with organ-on-a-chip technology to improve productivity in animal biotechnology in future studies.

n-Si(111) 기판 위에 전기증착에 의한 Fe 박막의 성장과 구조적 특성 (Growth and Structural Properties of Fe Thin Films Electrodeposited on n-Si(111))

  • 김현덕;박경원;이종덕
    • 한국정보통신학회논문지
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    • 제10권9호
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    • pp.1663-1670
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    • 2006
  • 펄스 전기증착법에 의해 단결정 Fe 박막을 n-Si(111) 기판위에 직접 성장시켰다. CV 분석 을 통해 $Fe^{2+}n-Si(111)$ 계면은 쇼트키 장벽 형성에 따른 다이오드 특성을 가진다는 사실을 알 수 있었다. 또한 인가 전압에 따른 전기용량의 변화를 보여주는 Mott-Schottky chottky(MS) 관계식을 이용하여 전해질 내에서 n-Si(111) 기판의 flat-band potential(EFB)을 조사하였으며, 0.1M $FeCl_2$ 전해질 내에서 EFB와 산화-환원 전위는 각각 -0.526V 과 -0.316V 임을 알 수 있었다. Fe/n-Si(111) 계면반응 시, Fe 증착 초기 단계에서의 핵 형성과 성장 운동학은 과도전류 특성을 이용하여 조사하였으며, 과도전류 특성을 통해 Fe 박막의 성장모드는 "instantaneous nucleation and 3-dimensional diffusion limited growth"임을 알 수 있었다. 주파수가 300Hz, 최대 전압이 1.4V인 펄스 전압을 이용하여 n-Si(111) 기판위에 Fe를 직접 전기 증착 시켰으며, 형 성 된 Fe 박막은 단결정 ${\alpha}-Fe$로 Si 기판위에 ${\alpha}-Fe(110)/Si(111)$의 격자 정합성을 가지고 성장하였음을 XRD 분석을 통해 확인하였다.

한국과 걸프협력회의(GCC)국가 간의 교역구조분석에 관한 연구 (A Study on Trade Structure Analysis between Korea and GCC(Gulf Cooperation Council) Countries)

  • 정태원
    • 디지털융복합연구
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    • 제14권11호
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    • pp.135-142
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    • 2016
  • 최근 중동의 주요 국가들의 경제 성장과 맞물려 우리나라와의 다양한 분야에서의 경제협력 및 교류의 가능성에도 불구하고 그동안 이 지역과 경제협력과 관련된 연구와 자료가 부족했으며 특히, 이 지역과의 교역구조 및 동향과 관련된 논문은 거의 찾아 볼 수 없었다. 이에 본 연구는 우리나라와 주요 GCC(Gulf Cooperation Council) 국가(사우디아라비아, 아랍에미레이트, 카타르) 간에 최근 5년 동안 무역결합도 지수 분석과, 무역보완도, 국별편향도 지수 분석을 통해 향후 GCC 국가로의 한국의 수출 및 교류의 확대의 가능성을 살펴보고, 더 나아가 FTA 체결에 대한 시사점을 검토해 보는 것을 목적으로 하였다. 분석결과 중동의 주요 3개 국가 모두 산업구조상 한국과 상호보완 관계가 이루어져 있어 국가 간 자본이동을 점증적으로 증가시키거나 무역장벽을 낮추도록 노력한다면 향후 무역보완도와 국별편향도를 더욱 증가 시킬 수 있을 것으로 나타났다. 특히 한국과 사우디 간의 무역 및 교역 구조는 3국 중에서 가장 상호 보완관계가 높아 미래 FTA의 체결을 통해 우리나라의 수출증대와 더불어 양국 간 교역을 활성화 할 수 있는 새로운 기회를 창출할 수 있을 것으로 기대된다.