• Journal of information and communication convergence engineering
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• 제19권4호
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• pp.205-213
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• 2021

The properties of a scale-free network are little known; its node degree following a power-law distribution is among its few known properties. By selecting real-field scale-free networks from a network dataset and comparing them to other networks, such as random and non-scale-free networks, the topology characteristics of scale-free networks are identified. The assortative coefficient is identified as a key metric of a scale-free network. It is also identified that most scale-free networks have negative assortative coefficients. Traditional generation models of scale-free networks are evaluated based on the identified topology characteristics. Most representative models, such as BA and Holme&Kim, are not effective in generating real-field scale-free networks. A link-rewiring method is suggested that can control the assortative coefficient while preserving the node degree sequence. Our analysis reveals that it is possible to effectively reproduce the assortative coefficients of real-field scale-free networks through link-rewiring.

• Journal of Chest Surgery
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• 제49권5호
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• pp.366-373
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• 2016

Background: The aim of the study was to test the hypothesis that in patients with chronic complex sternum dehiscence, the use of muscle flap repair minimizes the occurrence of paradoxical motion of the chest wall (CWPM) when compared to sternal rewiring, eventually leading to better respiratory function and clinical outcomes during follow-up. Methods: In a propensity score matching analysis, out of 94 patients who underwent sternal reconstruction, 20 patients were selected: 10 patients underwent sternal reconstruction with bilateral pectoralis muscle flaps (group 1) and 10 underwent sternal rewiring (group 2). Eligibility criteria included the presence of hemisternum diastases associated with multiple (${\geq}$3) bone fractures and radiologic evidence of synchronous chest wall motion (CWSM). We compared radiologically assessed (volumetric computed tomography) ventilatory mechanic indices such as single lung and global vital capacity (VC), diaphragm excursion, synchronous and paradoxical chest wall motion. Results: Follow-up was 100% complete (mean $85{\pm}24months$). CWPM was inversely correlated with single lung VC (Spearman R=-0.72, p=0.0003), global VC (R=-0.51, p=0.02) and diaphragm excursion (R=-0.80, p=0.0003), whereas it proved directly correlated with dyspnea grade (Spearman R=0.51, p=0.02) and pain (R=0.59, p=0.005). Mean CWPM and single lung VC were both better in group 1, whereas there was no difference in CWSM, diaphragm excursion and global VC. Conclusion: Our study suggests that in patients with complex chronic sternal dehiscence, pectoralis muscle flap reconstruction guarantees lower CWPM and greater single-lung VC when compared with sternal rewiring and it is associated with better clinical outcomes with less pain and dyspnea.

• Biomolecules & Therapeutics
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• 제26권1호
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• pp.45-56
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• 2018

Cancer is the leading cause of human deaths worldwide. Understanding the biology underlying the evolution of cancer is important for reducing the economic and social burden of cancer. In addition to genetic aberrations, recent studies demonstrate metabolic rewiring, such as aerobic glycolysis, glutamine dependency, accumulation of intermediates of glycolysis, and upregulation of lipid and amino acid synthesis, in several types of cancer to support their high demands on nutrients for building blocks and energy production. Moreover, oncogenic mutations are known to be associated with metabolic reprogramming in cancer, and these overall changes collectively influence tumor-microenvironment interactions and cancer progression. Accordingly, several agents targeting metabolic alterations in cancer have been extensively evaluated in preclinical and clinical settings. Additionally, metabolic reprogramming is considered a novel target to control cancers harboring un-targetable oncogenic alterations such as KRAS. Focusing on lung cancer, here, we highlight recent findings regarding metabolic rewiring in cancer, its association with oncogenic alterations, and therapeutic strategies to control deregulated metabolism in cancer.

• 한국항공우주학회지
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• 제50권11호
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• pp.809-817
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• 2022

무인 로봇과 UAV의 발달로 경로 계획 알고리즘의 필요성이 높아지고 있으며 다양한 환경에서 잘 작동하는 RRT^* 알고리즘이 여러 분야에서 유용하게 활용되고 있다. RRT^* 알고리즘에 다양한 변형을 통해 더 좋은 경로를 생성하기 위한 많은 연구가 진행되고 있으며, 이러한 노력 덕분에 알고리즘의 성능 향상은 거듭되는 중이다. 본 논문은 이러한 연구의 연장선에서 샘플링 범위의 제한을 이용하여 효율적인 경로를 생성하는 방법을 제안한다. 장애물이 있는 환경에서 경로가 장애물에 근접할수록 최적의 경로에 가까워진다는 발상에 근거하여 더 짧은 경로를 얻기 위해 장애물 근처에 노드를 생성한다. 또한 경로가 장애물을 휘감는 경우 변경된 재연결 방법을 통해 빠르게 직선화된 경로를 얻는다. 기존의 알고리즘과 제안하는 방법을 비교 분석하여 성능을 검증하고, 무인항공기의 운동학 모델을 도입하여 생성된 경로를 추적할 수 있음을 확인한다.

• BMB Reports
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• 제52권6호
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• pp.360-372
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• 2019

Macrophages play an essential role not only in mediating the first line of defense but also in maintaining tissue homeostasis. In response to extrinsic factors derived from a given tissue, macrophages activate different functional programs to produce polarized macrophage populations responsible for inducing inflammation against microbes, removing cellular debris, and tissue repair. However, accumulating evidence has revealed that macrophage polarization is pivotal in the pathophysiology of metabolic syndromes and cancer, as well as in infectious and autoimmune diseases. Recent advances in transcriptomic and metabolomic studies have highlighted the link between metabolic rewiring of macrophages and their functional plasticity. These findings imply that metabolic adaption to their surrounding microenvironment instructs activation of macrophages with functionally distinct phenotypes, which in turn probably leads to the pathogenesis of a wide spectrum of diseases. In this review, we have introduced emerging concepts in immunometabolism with focus on the impact on functional activation of macrophages. Furthermore, we have discussed the implication of macrophage plasticity on the pathogenesis of metabolic syndromes and cancer, and how the disease microenvironment manipulates macrophage metabolism with regard to the pathophysiology.

• BMB Reports
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• 제44권1호
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• pp.1-10
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• 2011

Inter-cellular communication via diffusible small molecules is a defining character not only of multicellular forms of life but also of single-celled organisms. A large number of bacterial genes are regulated by the change of chemical milieu mediated by the local population density of its own species or others. The cell density-dependent "autoinducer" molecules regulate the expression of those genes involved in genetic competence, biofilm formation and persistence, virulence, sporulation, bioluminescence, antibiotic production, and many others. Recent innovations in recombinant DNA technology and micro-/nano-fluidics systems render the genetic circuitry responsible for cell-to-cell communication feasible to and malleable via synthetic biological approaches. Here we review the current understanding of the molecular biology of bacterial intercellular communication and the novel experimental protocols and platforms used to investigate this phenomenon. A particular emphasis is given to the genetic regulatory circuits that provide the standard building blocks which constitute the syntax of the biochemical communication network. Thus, this review gives focus to the engineering principles necessary for rewiring bacterial chemo-communication for various applications, ranging from population-level gene expression control to the study of host-pathogen interactions.

• Journal of Chest Surgery
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• 제45권2호
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• pp.127-130
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• 2012

Sternal dehiscence is one of the most troublesome complications following cardiac surgery. Treatment failure and consequent lethal results are very common, even with all the efforts to resolve sternal dehiscence such as removal of infectious tissue, muscle flap interposition, and sternal rewiring. We report on a case of sternal osteomyelitis following coronary artery bypass grafting that was successfully treated with wide sternal resection, titanium plate fixation, and pectoralis muscle flap interposition.

• BMB Reports
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• 제45권2호
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• pp.59-70
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• 2012

Carbon catabolite repression (CCR) is a key regulatory system found in most microorganisms that ensures preferential utilization of energy-efficient carbon sources. CCR helps microorganisms obtain a proper balance between their metabolic capacity and the maximum sugar uptake capability. It also constrains the deregulated utilization of a preferred cognate substrate, enabling microorganisms to survive and dominate in natural environments. On the other side of the same coin lies the tenacious bottleneck in microbial production of bioproducts that employs a combination of carbon sources in varied proportion, such as lignocellulose-derived sugar mixtures. Preferential sugar uptake combined with the transcriptional and/or enzymatic exclusion of less preferred sugars turns out one of the major barriers in increasing the yield and productivity of fermentation process. Accumulation of the unused substrate also complicates the downstream processes used to extract the desired product. To overcome this difficulty and to develop tailor-made strains for specific metabolic engineering goals, quantitative and systemic understanding of the molecular interaction map behind CCR is a prerequisite. Here we comparatively review the universal and strain-specific features of CCR circuitry and discuss the recent efforts in developing synthetic cell factories devoid of CCR particularly for lignocellulose-based biorefinery.

• Molecules and Cells
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• 제39권9호
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• pp.692-698
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• 2016

Advances in next generation sequencing (NGS) technologies have enabled population-level studies for many animals to unravel the relationships between genotypic differences and traits of specific populations. The objective of this study was to perform evolutionary analysis of single nucleotide polymorphisms (SNP) in genes of Korean native cattle Hanwoo in comparison to SNP data from four other cattle breeds (Jersey, Simmental, Angus, and Holstein) and four related species (pig, horse, human, and mouse) obtained from public databases through NGS-based resequencing. We analyzed population structures and differentiation levels for the five cattle breeds and estimated species-specific SNPs with their origins and phylogenetic relationships among species. In addition, we identified Hanwoo-specific genes and proteins, and determined distinct changes in protein-protein interactions among five species (cattle, pig, horse, human, mouse) in the STRING network database by additionally considering indirect protein interactions. We found that the Hanwoo population was clearly different from the other four cattle populations. There were Hanwoo-specific genes related to its meat trait. Protein interaction rewiring analysis also confirmed that there were Hanwoo-specific protein-protein interactions that might have contributed to its unique meat quality.

• Journal of Chest Surgery
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• 제36권8호
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• pp.583-589
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• 2003

흉골절개술 후에 발생하는 흉골 감염과 종격동염의 유의한 위험인자를 확인하기 위해 지난 2년간 본원에서 개심술을 시행한 환자들을 대상으로 후향적 분석을 시행하였다. 방법 뜻 대상: 2001년 3월부터 2003년 3월까지 본원 흉부외과에서 정중 흉골 절개술을 이용하여 개심술을 시행받은 123명의 환자 중 12명의 환자에게서 흉골 감염 및 종격동염이 발생하였으며 이에 대한 위험인자들을 분석하였다. 환자들을 연령, 성별, 당뇨, 만성 폐쇄성 폐질환, 비만의 유무로 나누었고 입원 후 수술까지의 기간, 수술 술기의 종류, 응급 수술의 여부, 재수술의 여부. 수술 시간, 체외 순환 시간, 수혈량, 수술 후 출혈량, 응급 재개흉의 여부, 흉골 재봉합의 여부, 기계 호흡 보조 시간, 그리고 중환자실 재원일수를 분석하였다 결과: 분석 결과 환자의 나이, 성별, 당뇨의 유무, 수술 술기의 종류, 재수술의 여부, 수술 시간이나 체외 순환 시간, 그리고 입원 후 수술까지의 기간 등은 창상 감염과는 유의한 연관이 없었다. 그 외 다른 변인들은 p-value가 .05 이하로 유의한 인자로서 나타났다. 조기에 응급 재개흉을한 경우, 흉골의 재봉합, 환자가 비만이거나 만성 페쇄성 폐질환을 진단 받은 경우, 수술 후 출혈량과 수혈량, 기계호흡 보조시간과 중환자실 재원일수 등의 나머지 인자들은 수술 후 감염과 유의한 연관이 있었다. 결론: 창상오염은 수술 전, 수술 중 그리고 수술 후에 발생할 수 있으며, 수술 후 환자에게 부수적인 수술적 처치를 시행하는 것은 환자의 수술 후 창상 감염에 유발 인자로 작용한다고 할 수 있다.