• 전자공학회논문지B
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• 제33B권8호
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• pp.60-67
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• 1996

In this paper, we propose a new temporal interpolation method based on spatial filtering. Compared with the conventional method, the proposed one may use a few adjacent frames and apply temporal lowpass filtering. To develop this method, we follow the basic approach of sampling rate conversion. Additionally, we use some assumption of video sequence : moving object has constant velocity rigid translational motion. From them, spatial filtering for temporal sampling rate conversion is described. This method has a lot of noise immunity on a motion vector and doesn't make a great difference from the original frame. The interpolated frame shows moderate change even there is a great time difference. This method has exactly same description of motion adaptive spatial filter which has an efficient temporal band-limiting characteristics. It imposes the possibility to make video sequence with good pictural quality.

• Allergy, Asthma & Respiratory Disease
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• 제6권6호
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• pp.279-283
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• 2018

Asthma is considered a chronic inflammatory airway disease. Mounting evidence reports that patients with asthma are at significantly higher risk of developing communicable diseases such as invasive pneumococcal disease, Haemophilus influenza, varicella, measles, pertussis and tetanus. While impaired innate immunity may play a role in increased risk of developing these infections, suboptimal adaptive immune responses have also been reported to play a role in asthmatic subjects with regard to increased risk of infections. This review discusses the currently underrecognized immunological effect of asthma on antibody to vaccines and recommends that clinicians be aware of less optimal antibody production in response to vaccines in subjects with asthma.

• 한국자기공명학회논문지
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• 제25권3호
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• pp.39-44
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• 2021

The CRISPR-Cas system provides adaptive immunity for bacteria and archaea against invading phages and foreign plasmids. In the Class 1 CRISPR-Cas system, multi-subunit Cas proteins assemble with crRNA to bind to DNA targets. To disarm the bacterial defense system, bacteriophages evolved anti-CRISPR (Acr) proteins that actively inhibit the host CRISPR-Cas function. Here we report the backbone resonance assignments of AcrIF7 protein that inhibits the type I-F CRISPR-Cas system of Pseudomonas aeruginosa using triple-resonance nuclear magnetic resonance spectroscopy. We employed various computational methods to predict the structure and binding interface of AcrIF7, and assessed the model with experimental data. AcrIF7 binds to Cas8f protein via flexible loop regions to inhibit target DNA binding, suggesting that conformational heterogeneity is important for the Cas-Acr interaction.

• 대한이식학회지
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• 제28권3호
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• pp.113-120
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• 2014

Two-signal models are useful in explaining various types of immune responses. In particular, secondary, so-called costimulatory, signals are critically required for the process of T-cell activation, survival, differentiation, and memory formation. Early studies in rodent models showed that targeting T-cell costimulatory pathways elicits immunological tolerance, providing a basis for development of costimulatory therapeutics in allograft rejection. However, as the classic definition of T-cell costimulation continues to evolve, simple blockade of costimulatory pathways has limitations in prevention of allograft rejection. Furthermore, functions of costimulatory molecules are much more diverse than initially anticipated and beyond T cells. In this mini-review, we will discuss CD137-CD137L bidirectional signals as examples showing that two-signals can be applicable to multiple phases of immune responses.

• IMMUNE NETWORK
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• 제21권1호
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• pp.1.1-1.16
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• 2021

The emergence of a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has become a significant health concern worldwide. Undoubtedly, a better understanding of the innate and adaptive immune responses against SARS-CoV-2 and its relationship with the coronavirus disease 2019 (COVID-19) pathogenesis will be the sole basis for developing and applying therapeutics. This review will summarize the published results that relate to innate immune responses against infections with human coronaviruses including SARS-CoV-1 and SARS-CoV-2 in both humans and animal models. The topics encompass the innate immune sensing of the virus to the dysregulation of various innate immune cells during infection and disease progression.

• IMMUNE NETWORK
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• 제16권1호
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• pp.44-51
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• 2016

Dendritic cells (DCs) are professional antigen presenting cells, and play an important role in the induction of antigen-specific adaptive immunity. However, some DC populations are involved in immune regulation and immune tolerance. These DC populations are believed to take part in the control of immune exaggeration and immune disorder, and maintain immune homeostasis in the body. Tolerogenic DCs (tolDCs) can be generated in vitro by genetic or pharmacological modification or by controlling the maturation stages of cytokine-derived DCs. These tolDCs have been investigated for the treatment of rheumatoid arthritis (RA) in experimental animal models. In the last decade, several in vitro and in vivo approaches have been translated into clinical trials. As of 2015, three tolDC trials for RA are on the list of ClinicalTrial.gov (www.clinicaltrials.gov). Other trials for RA are in progress and will be listed soon. In this review, we discuss the evolution of tolDC-based immunotherapy for RA and its limitations and future prospects.

• Journal of Power Electronics
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• 제16권4호
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• pp.1513-1525
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• 2016

Rapid and accurate phase synchronization is critical for the reliable control of grid-tied inverters. However, the commonly used software phase-locked loop methods do not always satisfy the need for high-speed and accurate phase synchronization under severe grid imbalance conditions. To address this problem, this study develops a novel open-loop phase locking scheme based on a synchronous reference frame. The proposed scheme is characterized by remarkable response speed, high accuracy, and easy implementation. It comprises three functional cascaded blocks: fast orthogonal signal generation block, fast fundamental-frequency positive sequence component construction block, and fast phase calculation block. The developed virtual orthogonal signal generation method in the first block, which is characterized by noise immunity and high accuracy, can effectively avoid approximation errors and noise amplification in a wide range of sampling frequencies. In the second block, which is the foundation for achieving fast phase synchronization within 3 ms, the fundamental-frequency positive sequence components of unsymmetrical grid voltages can be achieved with the developed orthogonal signal construction strategy and the symmetrical component method. The real-time grid phase can be consequently obtained in the third block, which is free from self-tuning closed-loop control and thus improves the dynamic performance of the proposed scheme. The proposed scheme is adaptive to severe unsymmetrical grid voltages with sudden changes in magnitude, phase, and/or frequency. Moreover, this scheme is able to eliminate phase errors induced by harmonics and random noise. The validity and utility of the proposed scheme are verified by the experimental results.

• 약학회지
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• 제52권1호
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• pp.73-78
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• 2008

Immune system can protect host attacking from a variety of microorganism and virus through innate and adaptive immunities. The innate immune system can be activated by recognition of conserved carbohydrates on the cell surface of pathogen resulting in protection, immunity regulation and inflammation. Immunostimulating and anti-tumor ${\beta}$-glucan, major cell wall component of many fungi, could be recognized as pathogen associated molecular pattern (PAMP) by C-type lectin such as pathogen recognition receptor (PRR) of host innate immunity cells. In spite of many studies of basidiomycetes ${\beta}$-glucan on immunostimulation, little is known about the precise mechanism as molecular-level. Among C-type lectins, dectin-1 was cloned and reported as a ${\beta}$-glucan receptor. In this report, we demonstrated induction of cytokine gene transcription by Ganoderma lucidum ${\beta}$-glucan in the absence or presence of lipopolysaccharide (LPS) by RT-PCR analysis. The expression of murine dectin-1 (MD-1) on RAW264.7 macrophage by RT-PCR showing both the full length, 757 bp $(MD-1{\alpha})$ and alternative spliced form, 620 bp $(MD-1{\beta})$. Both $MD-1{\alpha}$ and $MD-1{\beta}$ mRNAs were induced by ${\beta $-glucan both in the absence and presence of LPS. To explore expression of inflammatory cytokines by ${\beta}$-glucan, RAW264.7 cells were treated with ${\beta}$-glucan for 12 hours. As a result, the expressions of IL-1 IL-6, IL-l0 and $TNF-{\alpha}$ were increased by ${\beta}$-glucan treatment in a dose-dependent fashion. From these results, ${\beta}$-glucan induced transcriptions of dectin-1 and immune activating cytokine genes, indicating induction of immune allertness by expressing dectin-1 and secreting inflammatory cytokines.

• IMMUNE NETWORK
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• 제8권2호
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• pp.59-65
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• 2008

Background: Toll-like receptors (TLRs) detect microbial infection and can directly induce innate host defense responses, which are thought to play critical roles in protecting the tubotympanum from infection. However, little is known about the relationship between TLRs, which are related to innate immunity, and immunoglobulins, which are related to adaptive immunity, in recurrent otitis media with effusion (OME). We therefore investigated the expression of TLR2 and TLR4 and immunoglobulin in children with OME. Methods: The study population consisted of 72 children with OME, 31 with more than 4 episodes in 12 months or more than 3 episodes in 6 months (otitis-prone group), and 41 with fewer than 3 episodes in 12 months (non-otitis prone group). The expression in middle ear effusion of TLR2 and TLR4 mRNA, as determined by Real time- -polymerase chain reaction (RT-PCR), and the concentrations of IgG, IgA, and IgM, as determined by Enzyme-linked immunosorbent assay(ELISA), were compared between the two groups. Results: Expression of TLR2 and TLR4 mRNA was lower in the otitis prone than in the non-otitis prone group, but the difference was not statistically significant (p>0.05). Between group differences in the concentrations of IgG, IgA and IgM in effusion fluid were not significant (p>0.05), and there were no correlations between immunoglobulin concentration and the expression of TLR2 and TLR4. Conclusion: Although there was a trend toward lower expression of TLR2 and TLR4 in the otitis-prone group, the differences, and those in immunoglobulin concentration, did not differ significantly between the otitis-prone and non-prone groups.

• BMB Reports
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• 제54권5호
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• pp.278-283
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• 2021

Our understanding of the differential effects between specific omega-3 fatty acids is incomplete. Here, we aimed to evaluate the effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on T-helper type 1 (Th1) cell responses and identify the pathways associated with these responses. Naïve CD4⁺ T cells were co-cultured with bone marrow-derived dendritic cells (DCs) in the presence or absence of palmitate (PA), DHA, or EPA. DHA or EPA treatment lowered the number of differentiated IFN-γ-positive cells and inhibited the secretion of IFN-γ, whereas only DHA increased IL-2 and reduced TNF-α secretion. There was reduced expression of MHC II on DCs after DHA or EPA treatment. In the DC-independent model, DHA and EPA reduced Th1 cell differentiation and lowered the cell number. DHA and EPA markedly inhibited IFN-γ secretion, while only EPA reduced TNF-α secretion. Microarray analysis identified pathways involved in inflammation, immunity, metabolism, and cell proliferation. Moreover, DHA and EPA inhibited Th1 cells through the regulation of diverse pathways and genes, including Igf1 and Cpt1a. Our results showed that DHA and EPA had largely comparable inhibitory effects on Th1 cell differentiation. However, each of the fatty acids also had distinct effects on specific cytokine secretion, particularly according to the presence of DCs.