• 제목/요약/키워드: complex potential function

검색결과 157건 처리시간 0.027초

하전된 멤브레인 미세기공에서의 계면동전기적 유동에 의한 흐름전위: 비선형 Poisson-Boltzmann 전기장을 갖는 경우 (Electrokinetically Flow-Induced Streaming Potential Across the Charged Membrane Micropores: for the Case of Nonlinear Poisson-Boltzmann Electric Field)

  • Myung-Suk Chun
    • 멤브레인
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    • 제13권1호
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    • pp.37-46
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    • 2003
  • 하전된 멤브레인 미세기공으로 유체가 흐르는 경우는 계면동전기 효과가 작용하게 된다. 비선형 Poisson-Boltzmann 전기장과 흐름에 의해 유발되는 전기장 사이의 정전상호작용을 운동방정식의 외부작용 힘으로 고려하였다. 유한차분법으로 정전위 분포를 우선 산출하고, 이어서 Green 함수로 슬릿형 기공에 대한 Navier-Stokes 식의 해석해를 구하였다. 계면동전기적 유동에 의한 흐름전위를 관련된 물리화학적 인자들의 함수로 유도되는 해석적인 명확한 표현으로 제시하였다. 전기이중층, 표면전위, 그리고 기공벽면의 하전조건의 영향에 따른 유속분포와 흐름전위 변화를 고찰하였다 계산결과, 전기이중층 두께나 표면전위가 증가함에 따라 평균유속은 감소하는 반면에 흐름전위는 증가하였다.

The acute and sub-acute toxicity of C60/PVP complex in vivo

  • Dumpis, Marina A.;Iljin, Viktor V.;Litasova, Elena V.;Nikolaev, Dmitry N.;Bulion, Valentina V.;Krylova, Irina B.;Okunevich, Irina V.;Rodionova, Olga M.;Safonova, Albina F.;Selina, Elena N.;Piotrovsky, Levon B.
    • Advances in nano research
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    • 제4권3호
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    • pp.167-179
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    • 2016
  • The detailed study of acute and sub-acute toxicity of the complex polyvinylpyrrolidon (PVP 20 kDa)-wrapped fullerene $C_{60}$ after intraperitoneal (ip) administration was carried out on adult male Wistar rats. The $LD_{50}$ value of $C_{60}/PVP$ complex was found to be 7, 8 g/kg. In sub-acute study which lasted for 30 days the rats were exposed to daily administration of the complex in the doses of 350 or 700 mg/kg. All animals survived during the study and had no significant changes in clinical signs, organ weight, hematological and biochemical parameters of blood. The electrophysiological properties of myocardium and the excretory function of kidneys remained normal. Histological analysis of liver, kidney and spleen at the end of the study also did not demonstrate toxic alterations. It was thus established that intraperitoneal administration of complex $C_{60}/PVP$ has no toxic effect. These results suggest that $C_{60}/PVP$ has no acute and sub-acute toxicity and is a perspective substance for potential application in biology and medicine.

Classification, Structure, and Bioactive Functions of Oligosaccharides in Milk

  • Mijan, Mohammad Al;Lee, Yun-Kyung;Kwak, Hae-Soo
    • 한국축산식품학회지
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    • 제31권5호
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    • pp.631-640
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    • 2011
  • Milk oligosaccharides are the complex mixture of six monosaccharides namely, D-glucose, D-galactose, N-acetyl-glucosamine, N-acetyl-galactosamine, L-fucose, and N-acetyl-neuraminic acid. The mixture is categorized as neutral and acidic classes. Previously, 25 oligosaccharides in bovine milk and 115 oligosaccharides in human milk have been characterized. Because human intestine lacks the enzyme to hydrolyze the oligosaccharide structures, these substances can reach the colon without degradation and are known to have many health beneficial functions. It has been shown that this fraction of carbohydrate can increase the bifidobacterial population in the intestine and colon, resulting in a significant reduction of pathogenic bacteria. The role of milk oligosaccharides as a barrier against pathogens binding to the cell surface has recently been demonstrated. Milk oligosaccharides have the potential to produce immuno-modulation effects. It is also well known that oligosaccharides in milk have a significant influence on intestinal mineral absorption and in the formation of the brain and central nervous system. Due to its structural resemblance, bovine milk is considered to be the most potential source of oligosaccharides to produce the same effect of oligosaccharides present in human milk. This review describes the characteristics and potential health benefits of milk oligosaccharides as well as the prospects of oligosaccharides in bovine milk for use in functional foods.

소분자 도킹에서의 평가함수의 개발 동향 (Recent Development of Scoring Functions on Small Molecular Docking)

  • 정환원;조승주
    • 통합자연과학논문집
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    • 제3권1호
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    • pp.49-53
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    • 2010
  • Molecular docking is a critical event which mostly forms Van der waals complex in molecular recognition. Since the majority of developed drugs are small molecules, docking them into proteins has been a prime concern in drug discovery community. Since the binding pose space is too vast to cover completely, many search algorithms such as genetic algorithm, Monte Carlo, simulated annealing, distance geometry have been developed. Proper evaluation of the quality of binding is an essential problem. Scoring functions derived from force fields handle the ligand binding prediction with the use of potential energies and sometimes in combination with solvation and entropy contributions. Knowledge-based scoring functions are based on atom pair potentials derived from structural databases. Forces and potentials are collected from known protein-ligand complexes to get a score for their binding affinities (e.g. PME). Empirical scoring functions are derived from training sets of protein-ligand complexes with determined affinity data. Because non of any single scoring function performs generally better than others, some other approaches have been tried. Although numerous scoring functions have been developed to locate the correct binding poses, it still remains a major hurdle to derive an accurate scoring function for general targets. Recently, consensus scoring functions and target specific scoring functions have been studied to overcome the current limitations.

Mitochondrial transplantation: an overview of a promising therapeutic approach

  • Ji Soo Kim;Seonha Lee;Won-Kon Kim;Baek-Soo Han
    • BMB Reports
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    • 제56권9호
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    • pp.488-495
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    • 2023
  • Mitochondrial transplantation is a promising therapeutic approach for the treatment of mitochondrial diseases caused by mutations in mitochondrial DNA, as well as several metabolic and neurological disorders. Animal studies have shown that mitochondrial transplantation can improve cellular energy metabolism, restore mitochondrial function, and prevent cell death. However, challenges need to be addressed, such as the delivery of functional mitochondria to the correct cells in the body, and the long-term stability and function of the transplanted mitochondria. Researchers are exploring new methods for mitochondrial transplantation, including the use of nanoparticles or CRISPR gene editing. Mechanisms underlying the integration and function of transplanted mitochondria are complex and not fully understood, but research has revealed some key factors that play a role. While the safety and efficacy of mitochondrial transplantation have been investigated in animal models and human trials, more research is needed to optimize delivery methods and evaluate long-term safety and efficacy. Clinical trials using mitochondrial transplantation have shown mixed results, highlighting the need for further research in this area. In conclusion, although mitochondrial transplantation holds significant potential for the treatment of various diseases, more work is needed to overcome challenges and evaluate its safety and efficacy in human trials.

Effects of proteinate complex zinc on growth performance, hepatic and splenic trace elements concentrations, antioxidative function and immune functions in weaned piglets

  • She, Yue;Huang, Qiang;Li, Defa;Piao, Xiangshu
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권8호
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    • pp.1160-1167
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    • 2017
  • Objective: To assess the effects of proteinate complex zinc (PC-Zn) on growth performance, antioxidative function, trace element concentrations and immune function in weaned piglets. Methods: Three hundred newly weaned barrows ($Duroc{\times}Landrace{\times}Yorkshire$), 28 days of age, were randomly allotted to 3 dietary groups of 5 replicate pens per group for 4 weeks of feeding. Experimental diets were: i) zinc deficient diet (ZnD, 24 mg/kg Zn supplementation from $ZnSO_4$), ii) inorganic Zn diet supplemented with 120 mg/kg of Zn from Zn sulfate ($ZnSO_4$), and iii) organic Zn diet supplemented with 120 mg/kg of Zn from PC-Zn. The body weight of pigs were recorded at the beginning, at the middle and at the end of the experiment, and the amount of feed supplied each day was recorded. Five barrows from each dietary treatment group were selected to be anesthetized and euthanized at the end of the trial to determine the Zn, Cu, Fe, and Mn concentrations, the hepatic metallothionein content, the levels of methane dicarboxylic aldehyde (MDA), Mn, and Cu/Zn superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in the spleen, the levels of interleukin (IL)-2, IL-4, IL-10, interferon $(IFN)-{\gamma}$, $CD3^+$, $CD4^+$, and $CD8^+$ T lymphocyte. Results: The accumulation of Zn in the spleen, levels of SOD, GSH-Px, IL-4, IL-10, the proportions of $CD3^+$ and $CD4^+$ T lymphocyte, and the ratio of $CD4^+/CD8^+$ T lymphocyte were increased by organic Zn supplementation compared to ZnD, while the levels of MDA, $IFN-{\gamma}$, and proportion of $CD8^+$ T lymphocyte were lowered. Conclusion: These findings indicate that Zn can improve the antioxidant potential and immune functions of weaned piglets.

위암에서 새로운 종양원인 유전자 Nemo-like Kinase의 발현 증가 (The Overexpression of Oncogenic Nemo-like Kinase in Gastric Cancer)

  • 김민규;정광화;남석우
    • 약학회지
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    • 제56권6호
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    • pp.358-363
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    • 2012
  • Nemo-like kinase (NLK), an evolutionarily conserved serine/threonine protein kinase, plays an important role in wide variety of developmental events. NLK phosphorylates T-cell factor/lymphoid enhancer factor (TCF/LEF) transcriptional complex and suppresses wnt signaling pathway through inhibition of ${\beta}$-catenin/TCF complex interaction. However, the function of NLK in gastric carcinogenesis has not been investigated. In the present study, we have examined whether the NLK gene is involved in the development and/or progression of gastric cancers. NLK expression was analyzed by immunohistochemical staining in 153 advanced gastric cancer specimens. Immunhistochemical analysis showed increased expression of NLK in 91 (59.5%) out of 153 gastric cancer specimens. Statistically, there was no significant relationship between altered expression of NLK protein and clinicopathological parameters, including tumor differentiation, location, lymph node metastasis. We identified that mRNA and protein expression of NLK was significantly up-regulated in human gastric cancer tissues compare to corresponding normal gastric tissues. In addition, we found that human gastric cancer cell lines exhibited relatively high expression of NLK, as compared with normal gastric cells. The results of this study suggest that aberrant regulation of NLK may contribute to the development or progression of gastric cancers and serve as a potential biomarker for advanced gastric cancer patients.

Quantitative Frameworks for Multivalent Macromolecular Interactions in Biological Linear Lattice Systems

  • Choi, Jaejun;Kim, Ryeonghyeon;Koh, Junseock
    • Molecules and Cells
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    • 제45권7호
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    • pp.444-453
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    • 2022
  • Multivalent macromolecular interactions underlie dynamic regulation of diverse biological processes in ever-changing cellular states. These interactions often involve binding of multiple proteins to a linear lattice including intrinsically disordered proteins and the chromosomal DNA with many repeating recognition motifs. Quantitative understanding of such multivalent interactions on a linear lattice is crucial for exploring their unique regulatory potentials in the cellular processes. In this review, the distinctive molecular features of the linear lattice system are first discussed with a particular focus on the overlapping nature of potential protein binding sites within a lattice. Then, we introduce two general quantitative frameworks, combinatorial and conditional probability models, dealing with the overlap problem and relating the binding parameters to the experimentally measurable properties of the linear lattice-protein interactions. To this end, we present two specific examples where the quantitative models have been applied and further extended to provide biological insights into specific cellular processes. In the first case, the conditional probability model was extended to highlight the significant impact of nonspecific binding of transcription factors to the chromosomal DNA on gene-specific transcriptional activities. The second case presents the recently developed combinatorial models to unravel the complex organization of target protein binding sites within an intrinsically disordered region (IDR) of a nucleoporin. In particular, these models have suggested a unique function of IDRs as a molecular switch coupling distinct cellular processes. The quantitative models reviewed here are envisioned to further advance for dissection and functional studies of more complex systems including phase-separated biomolecular condensates.

21C 종합항만을 위한 부산항의 추진과제 평가 (An Evaluation of Action Plan for Busan Port to grow as Complex Port in 21st Century)

  • 허윤수;김율성
    • 한국항해항만학회지
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    • 제32권1호
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    • pp.57-63
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    • 2008
  • 최근 미국 LA항과 LB항, 로테르담항을 중심으로 친환경적인 항만을 개발하기 위한 Green Port 추진사업이 본격화되고 있다. 이와 동시에 싱가포르항, 상하이항, 두바이항 등은 화물, 사람, 정보의 중심지 역할을 수행하는 진정한 의미의 종합항만이 되기 위해 노력하고 있다. 이제 항만은 더 이상 여객이나 화물을 실어 나르는 단순한 역할만을 수행하지는 않는다. 21C 종합항만은 항만 그 자체가 여객이나 화물, 정보, 금융의 집결지가 되고, 항만주변의 물류배후부지가 화물을 창출할 수 있는 공간으로 변화되고 있다. 따라서 본 연구에서는 AHP 분석을 통해 21C 종합항만으로 성장하기 위한 부산항의 추진과제를 각 분야별로 도출하고, 도출된 추진과제를 정량요인(지역내 사업비중, 특화정도, 산업연관효과)과 정성요인(미래성장성, 경쟁력확보, 혁신역량)으로 평가하고자 한다. 추진과제별 평가값을 바탕으로 사업의 우선순위 도출의 기초자료로 활용될 수 있을 것이다.

다발성 안면골절환자의 교합회복 증례 (Full mouth rehabilitation of a panfacial fracture patient with bilateral condylar fracture)

  • 박고운;차민상;김대곤;박찬진;조리라
    • 구강회복응용과학지
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    • 제30권2호
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    • pp.159-169
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    • 2014
  • 다발성 안면골절 시 연조직 및 경조직의 소실로 인해 적절한 과두-디스크의 기능을 회복할 위치를 찾는데 어려움이 있다. 다발성 안면골절 및 양측 과두골절과 부족한 수직고경 및 안면비대칭을 가진 환자가 내원하였다. 교합안정장치를 이용하여 골절된 과두를 정복하고 과두-디스크 복합체에 새로운 기능적 위치를 선정하였다. 추적조사를 통해 과두의 위치가 편안감과 안정성이 적절하다고 판단한 뒤 임플란트와 고정성 보철물을 이용한 완전구강회복을 시행하였다. 환자는 심미성과 기능에 만족하였으며 안정적 교합상태를 보였지만 추가적인 교합변화의 가능성을 배제할 수 없기 때문에 야간안정장치 및 정기적인 관리가 필요할 것으로 사료된다.