1,083 research outputs found

    Development of a Chaff Dispense Program for Target Tracking Radar Deception

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    This study aims to develop an appropriate chaff dispensing program to deceive the target tracking radar (TTR) effectively. Chaff is a countermeasure commonly used by fighter aircraft to deceive TTR. However, there has been a lack of methodology for calculating chaff dispense programs that take into account the specific characteristics of the fighter, chaff, and TTR. This study proposes a methodology that considers these variables to calculate chaff dispense programs and addresses this gap. The proposed method is demonstrated through TESS engagement, which shows its effectiveness in various engagement situations

    Development of a Chaff Dispense Program for Target Tracking Radar Deception

    Get PDF
    This study aims to develop an appropriate chaff dispensing program to deceive the target tracking radar (TTR) effectively. Chaff is a countermeasure commonly used by fighter aircraft to deceive TTR. However, there has been a lack of methodology for calculating chaff dispense programs that take into account the specific characteristics of the fighter, chaff, and TTR. This study proposes a methodology that considers these variables to calculate chaff dispense programs and addresses this gap. The proposed method is demonstrated through TESS engagement, which shows its effectiveness in various engagement situations

    Revisiting the Concept of Targeting NFAT to Control T Cell Immunity and Autoimmune Diseases

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    The nuclear factor of activated T cells (NFAT) family of transcription factors, which includes NFAT1, NFAT2, and NFAT4, are well-known to play important roles in T cell activation. Most of NFAT proteins are controlled by calcium influx upon T cell receptor and costimulatory signaling results increase of IL-2 and IL-2 receptor. NFAT3 however is not shown to be expressed in T cells and NFAT5 has not much highlighted in T cell functions yet. Recent studies demonstrate that the NFAT family proteins involve in function of lineage-specific transcription factors during differentiation of T helper 1 (Th1), Th2, Th17, regulatory T (Treg), and follicular helper T cells (Tfh). They have been studied to make physical interaction with the other transcription factors like GATA3 or Foxp3 and they also regulate Th cell signature gene expressions by direct binding on promotor region of target genes. From last decades, NFAT functions in T cells have been targeted to develop immune modulatory drugs for controlling T cell immunity in autoimmune diseases like cyclosporine A, FK506, etc. Due to their undesirable side defects, only limited application is available in human diseases. This review focuses on the recent advances in development of NFAT targeting drug as well as our understanding of each NFAT family protein in T cell biology. We also discuss updated detail molecular mechanism of NFAT functions in T cells, which would lead us to suggest an idea for developing specific NFAT inhibitors as a therapeutic drug for autoimmune diseases

    Alleviating psoriatic skin inflammation through augmentation of Treg cells via CTLA-4 signaling peptide

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    Psoriasis is a chronic inflammatory skin disease characterized by hyperplasia of keratinocytes and immune cell infiltration. The IL-17-producing T cells play a key role in psoriasis pathogenesis, while regulatory T (Treg) cells are diminished during psoriatic inflammation. Current psoriasis treatments largely focus on IL-17 and IL-23, however, few studies have explored therapeutic drugs targeting an increase of Treg cells to control immune homeostasis. In this study, we investigated the effects of a cytotoxic T lymphocyte antigen-4 (CTLA-4) signaling peptide (dNP2-ctCTLA-4) in Th17, Tc17, γδ T cells, Treg cells in vitro and a mouse model of psoriasis. Treatment with dNP2-ctCTLA-4 peptide showed a significant reduction of psoriatic skin inflammation with increased Treg cell proportion and reduced IL-17 production by T cells, indicating a potential role in modulating psoriatic skin disease. We compared dNP2-ctCTLA-4 with CTLA-4-Ig and found that only dNP2-ctCTLA-4 ameliorated the psoriasis progression, with increased Treg cells and inhibited IL-17 production from γδ T cells. In vitro experiments using a T cell-antigen presenting cell co-culture system demonstrated the distinct mechanisms of dNP2-ctCTLA-4 compared to CTLA-4-Ig in the induction of Treg cells. These findings highlight the therapeutic potential of dNP2-ctCTLA-4 peptide in psoriasis by augmenting Treg/Teff ratio, offering a new approach to modulating the disease

    Prevalence, Distribution, and Concomitance of Whole-Spine Ossification of the Posterior Longitudinal Ligament and Ossification of the Ligament Flavum in South Koreans: A Whole-Spine-CT-Based Cross-Sectional Study

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    Objective No studies assessing the prevalence of ossification of the spinal ligament were conducted using whole-spine positron emission tomography and computed tomography (PET-CT) in healthy Koreans. We aimed to determine the prevalence of ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligament flavum (OLF) in healthy Koreans using whole-body PET-CT. Methods We reviewed whole-body PET-CT images captured during general health checkups at the General Health Promotion Center of our institution from January 2015 to 2020. OPLL and OLF were identified by the presence of heterotopic ossification in the posterior longitudinal ligament and ligament flavum on axial and sagittal PET-CT images. Results A total of 1,934 adults (1,645 men, 289 women) were included. The mean age was 48.05 years (range, 28–86 years). Among the 1,934 patients, 173 had OPLL (8.9%). The most commonly involved cervical vertebra levels arranged according to frequency were C4, C5, C3, and C6. OLF was observed in 125 patients (6.5%). The most commonly involved thoracic levels were T10, T11, and T5. The prevalence of OPLL and OLF was the highest in patients aged 60–69 years. Among the C-OPLL patients, 15.1% had T-OPLL, 5.0% had L-OPLL, and 25.8% had T-OLF. Conclusion Our study revealed the prevalence of OPLL and OLF in healthy Korean subjects. It was consistent with that in other Asian countries. The presence of OPLL and OLF at most locations correlated with the presence or absence of spinal ossification at other locations

    Health-Related Quality of Life Using the EuroQol 5D Questionnaire in Korean Patients with Type 2 Diabetes

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    We aimed; 1) to determine the validity of the EuroQol 5D (EQ-5D) for the health-related quality of life (HRQOL) of Korean patients with type 2 diabetes, and 2) to identify associated factors of the HRQOL of these patients. Follow-up surveys were conducted for consecutive patients with type 2 diabetes. HRQOL was assessed using the EQ-5D and the Short Form-36 (SF-36). The validity of EQ-5D was assessed with the perspectives of known group, convergent and discriminant validity. Additionally, a linear mixed model using a backward elimination was used for identify associated factors. Of the 1,072 patients included in the first survey, 858 (80.0%) completed the questionnaires in the follow-up. In the known group validity, the problem rates in each EQ-5D dimension were highest among women, elderly people, and less-educated subjects. The Spearman's ρ between the EQ-5D and the SF-36 scales were larger in the comparable dimensions than those in the less comparable dimensions. In the final model, we found that sex, age, education, body mass index, atrial fibrillation, stroke, and retinopathy were statistically significant. Our data suggest that the EQ-5D is a valid tool for Korean patients with type 2 diabetes and that various factors could affect their HRQOL

    Paroxysmal atrial fibrillation developed during incomplete epidural anesthesia -A case report-

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    Atrial fibrillation (AF) is the most common sustained tachyarrhythmia, and occurs in organic heart disease such as rheumatic, atherosclerotic and hypertensive heart disease. In recent studies, the sympathetic and parasympathetic nervous systems have been shown to have important roles in initiating paroxysmal AF. We report here a patient who developed paroxysmal AF that might be a result of an imbalance of the sympathetic-parasympathetic systems due to epidural anesthesia, and that was potentiated by pain with inadequate analgesia. A 69-year-old woman was scheduled for operation of a right-sided ankle fracture. Twenty minutes after epidural drug injection, paroxysmal AF occurred. Even after intravenous administration of esmolol and digoxin, AF continued. After transfer to the intensive care unit, her heart rate gradually decreased and AF disappeared. During perioperative anesthetic management, the proper preoperative prevention and intraoperative treatment are needed in AF high-risk patients
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