• International Journal of Aeronautical and Space Sciences
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• 제18권1호
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• pp.129-137
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• 2017

When the micro-Doppler (MD) image of a ballistic missile is derived, the translational motion compensation (TMC) method is usually applied to the inverse synthetic aperture radar (ISAR) image, but yields poor results because of the micro-motion of the ballistic missile. This paper proposes an efficient TMC method to obtain a focused MD image of a ballistic missile engaged in complicated micro-motion. During range alignment, range profiles (RPs) are coarsely aligned by using the 1D entropy cost function of RPs as a mark, then the coarsely-aligned RPs are fine-aligned by using the minimum 2D entropy of the MD image. During phase adjustment, the gradient of the phase error is appropriately weighted and added to the previous phase error to further fine-tune the aligned RPs. In simulations using the point scatterer model and the measured data from the real missile model, the proposed method provided better image focus than the existing method.

• 생물정신의학
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• 제15권4호
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• pp.254-264
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• 2008

Objectives : The neural substrate of fear is thought to be highly conserved among species including human. The purpose of this review was to address the neural substrates of fear based on recent findings obtained from animal and human studies. Methods : Recent studies on brain regions related to fear, particularly fear conditioning in rodents and humans, were extensively reviewed. Results : This paper suggests high consistency in anatomical structure and physiological mechanisms for fear perception, response, learning and modulation in animals and humans. Conclusions : Fear is manifested and modulated by well conserved neural circuits among species interconnected with the amygdala, such as the hippocampus and the ventromedial prefrontal cortex. Further research is required to incorporate findings from animal studies into a better understanding of neural circuitry of fear in human in a translational approach.

• Molecules and Cells
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• 제39권8호
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• pp.581-586
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• 2016

Post-translational modifications (PTMs) of proteins are essential to increase the functional diversity of the proteome. By adding chemical groups to proteins, or degrading entire proteins by phosphorylation, glycosylation, ubiquitination, neddylation, acetylation, lipidation, and proteolysis, the complexity of the proteome increases, and this then influences most biological processes. Although small RNAs are crucial regulatory elements for gene expression in most eukaryotes, PTMs of small RNA microprocessor and RNA silencing components have not been extensively investigated in plants. To date, several studies have shown that the proteolytic regulation of AGOs is important for host-pathogen interactions. DRB4 is regulated by the ubiquitin-proteasome system, and the degradation of HYL1 is modulated by a de-etiolation repressor, COP1, and an unknown cytoplasmic protease. Here, we discuss current findings on the PTMs of microprocessor and RNA silencing components in plants.

• 전자공학회논문지S
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• 제35S권3호
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• pp.176-184
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• 1998

We present a sequential factorization method using singular value decomposition (SVD) for recovering both the three-dimensional shape of an object and the motion of camera from a sequence of images. We employ paraperpective projection [6] for camera model to handle significant translational motion toward the camera or across the image. The proposed mthod not only quickly gives robust and accurate results, but also provides results at each frame becauseit is a sequential method. These properties make our method practically applicable to real time applications. Considerable research has been devoted to the problem of recovering motion and shape of object from image [2] [3] [4] [5] [6] [7] [8] [9]. Among many different approaches, we adopt a factorization method using SVD because of its robustness and computational efficiency. The factorization method based on batch-type computation, originally proposed by Tomasi and Kanade [1] proposed the feature trajectory information using singular value decomposition (SVD). Morita and Kanade [10] have extenened [1] to asequential type solution. However, Both methods used an orthographic projection and they cannot be applied to image sequences containing significant translational motion toward the camera or across the image. Poleman and Kanade [11] have developed a batch-type factorization method using paraperspective camera model is a sueful technique, the method cannot be employed for real-time applications because it is based on batch-type computation. This work presents a sequential factorization methodusing SVD for paraperspective projection. Initial experimental results show that the performance of our method is almost equivalent to that of [11] although it is sequential.

• Biomolecules & Therapeutics
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• 제14권2호
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• pp.75-82
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• 2006

Synaptic plasticity, which is a long lasting change in synaptic efficacy, underlies many neural processes like learning and memory. It has long been acknowledged that new protein synthesis is essential for both the expression of synaptic plasticity and memory formation and storage. Most of the research interests in this field have focused on the events regulating transcriptional activation of gene expression from the cell body and nucleus. Considering extremely differentiated structural feature of a neuron in CNS, a neuron should meet a formidable task to overcome spatial and temporal restraints to deliver newly synthesized proteins to specific activated synapses among thousands of others, which are sometimes several millimeters away from the cell body. Recent advances in synaptic neurobiology has found that almost all the machinery required for the new protein translation are localized inside or at least in the vicinity of postsynaptic compartments. These findings led to the hypothesis that dormant mRNAs are translationally activated locally at the activated synapse, which may enable rapid and delicate control of new protein synthesis at activated synapses. In this review, we will describe the mechanism of local translational control at activated synapses focusing on the role of cytoplasmic polyadenylation of dormant mRNAs.

• 제어로봇시스템학회논문지
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• 제6권9호
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• pp.777-785
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• 2000

This paper provides a guideline for the determination of compliance characteristics and the proper location of the compliance center in typical peg-in-hole and peg-out-hole tasks using hands. We first observe the fact that some of coupling stiffness elements cannot be planned arbitrarily. The given peg-in/out-hole tasks are classified into two contact styles. Then, we analyze concluded of the operational siffness matrix, which achieve the give peg-in/out-hole tasks effectively for each case. It is concluded that the location of the compliance center on the peg and the coupling stiffness element existing between the translational and the rotational direction play ompliance on the peg and the coupling siffness element existing between the translational and the rotational direction play important roles for successful peg-in/out-hole tasks. The analytic results verified through simulations.

• Journal of Gastric Cancer
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• 제16권1호
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• pp.1-7
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• 2016

Epstein-Barr virus-associated gastric carcinoma (EBVaGC) is one of the four subtypes of gastric carcinoma (GC), as defined by the novel classification recently proposed by The Cancer Genome Atlas. EBVaGC has several clinicopathological features such as longer survival and higher frequency of lymphoepithelioma-like carcinoma (LELC) and carcinoma with Crohn's disease-like lymphoid reaction that distinguish it from EBV-negative GC. The intensity and pattern of host cellular immune response in GC have been found to significantly correlate with the prognosis of patients with GC, suggesting that immune reaction and tumor microenvironment have critical roles in the progression of GC, and in particular, EBVaGC. Here, we reviewed the cellular and molecular mechanisms underlying prominent immune reactions in patients with EBVaGC. In EBVaGC, deregulation of the expression of immune response-related genes promotes marked intra-or peritumoral immune cell infiltration. The expression of programmed death receptor-ligand 1 is known to be increased in EBVaGC, and therefore, it has been proposed as a favorable prognostic factor for patients with EBVaGC, albeit some data supporting this claim are controversial. Overall, the underlying mechanisms and clinical significance of the host cellular immune response in patients with EBVaGC have not been thoroughly elucidated. Therefore, further research is necessary to better understand the role of tumor microenvironment in EBVaGC.

• Molecules and Cells
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• 제37권1호
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• pp.66-73
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• 2014

Myeloid-derived suppressor cells (MDSCs) play an important role in impairing the function of T cells. We characterized MDSCs in two chronic hepatitis C (CHC) cohorts: a cross-sectional group that included 61 treatment-naive patients with CHC, 14 rapid virologic response (RVR) cases and 22 early virologic response (EVR) cases; and a longitudinal group of 13 cases of RVR and 10 cases of EVR after pegylated-interferon-${\alpha}$/ribavirin treatment for genotype 1b HCV infection. Liver samples from 32 CHC patients and six healthy controls were subjected to immunohistochemical analysis. MDSCs frequency in treatment-naive CHC was significantly higher than in RVR, EVR, or healthy subjects and was positively correlated with HCV RNA. Patients infected with HCV genotype 2a had a significantly higher frequency of MDSCs than those infected with genotype 1b. Decreased T cell receptor (TCR) ${\zeta}$ expression on $CD8^+$ T cells was significantly associated with an increased frequency of MDSCs in treatment-naive CHC patients and was restored by L-arginine treatment in vitro. Increased numbers of liver arginase-$1^+$ cells were closely associated with the histological activity index in CHC. The TCR ${\zeta}$ chain was significantly downregulated on hepatic $CD8^+$ T cells in CHC. During antiviral follow up, MDSCs frequency in peripheral blood mononuclear cells was directly correlated with the HCV RNA load in the plasma and inversely correlated with TCR ${\zeta}$ chain expression in $CD8^+$ T cells in both RVR and EVR cases. Notably, the RVR group had a higher frequency of MDSCs at baseline than the EVR group. Collectively, this study provides evidence that MDSCs might be associated with HCV persistence and downregulation of CD8 ${\zeta}$ chain expression.

• Experimental and Molecular Medicine
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• 제50권11호
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• pp.3.1-3.11
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• 2018

This study aimed to verify the effects of estrogen on the onset and development of adolescent idiopathic scoliosis and the mechanisms associated with these effects by constructing a pubescent bipedal rat model. Experiments were conducted to investigate whether scoliosis progression was prevented by a Triptorelin treatment. One hundred twenty bipedal rats were divided into female, OVX (ovariectomy), OVX + E2, Triptorelin, sham, and male groups. According to a spinal radiographic analysis, the scoliosis rates and curve severity of the female and OVX + E2 groups were higher than those in the OVX, Triptorelin, and male groups. The measurements obtained from the sagittal plane of thoracic vertebrae CT confirmed a relatively slower growth of the anterior elements and a faster growth of the posterior elements between T11 and T13 in the female and OVX + E2 groups than in the OVX and Triptorelin groups. Histomorphometry and immunohistochemistry revealed a significantly longer hypertrophic zone of the vertebral cartilage growth plates that expressed more type X collagen and less type II collagen in the OVX and Triptorelin groups than in the female and OVX + E2 groups. Ki67 immunostaining confirmed an increase in the proliferation of vertebral growth plate chondrocytes in the OVX group compared with the female and OVX + E2 groups. In conclusion, estrogen obviously increased the incidence of scoliosis and curve severity in pubescent bipedal rats. The underlying mechanism may be a loss of coupling of the endochondral ossification between the anterior and posterior columns. Triptorelin decreased the incidence of scoliosis and curve magnitudes in bipedal female rats.

• 한국가금학회지
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• 제48권2호
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• pp.81-90
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• 2021

조류 인플루엔자 바이러스는 다양한 숙주 단백질을 이용해야만 증식이 가능하다. 포유류 (사람, 쥐) Fragile X mental retardation protein (FMRP)는 최근 인플루엔자 A 바이러스 viral RNP (vRNP)의 조립을 돕고, 이를 핵에서 세포질로 운반시켜 바이러스 증식에 도움을 준다. 하지만, 조류 인플루엔자 바이러스의 주요 숙주인 닭에서는 FMRP translational regulator 1 (FMR1) 유전자의 기능이 규명되지 않았다. 본 연구는 CRISPR/Cas9 (Clustered regularly interspaced short palindromic repeats/Cas9) 유전자 가위를 이용해 정확히 닭 FMR1 유전자를 제거하여 닭 FMR1 유전자가 조류 인플루엔자 바이러스 증식에 어떤 영향을 끼치는지 연구하였다. 닭 FMR1 유전자는 닭 배아섬유아세포 (DF1세포)에서 초기 조류 인플루엔자 바이러스의 유전자 발현을 촉진하나, 감염 후 24시간 뒤에는 바이러스 생산 및 바이러스 중합효소 (Polymerase)의 활성에 영향을 끼치지 않았다. 또한, 야생형 닭 FMR1 유전자를 과발현 함에도 불구하고, 조류 인플루엔자 바이러스의 생산량에는 변화가 없었다. 위 결과들은 닭 FMR1은 포유류 FMR1 유전자에 비해 조류 인플루엔자 바이러스의 증식에 큰 영향을 주지 못하는 숙주인자임을 시사한다. 또한, 닭 FMR1처럼 기존에 포유류에서 알려진 숙주 인자를 목표로 하는 조류 인플루엔자 바이러스 저항성 치료제 및 형질전환 동물을 생산할 때, 조류 시스템에서 위 숙주 인자의 기능이 보존돼 있는지 고찰할 필요가 있다고 사료된다.