• Journal of Advanced Navigation Technology
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• v.25 no.3
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• pp.177-184
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• 2021

This paper proposes an assessment method using probability-based index for safe and successful underwater docking of autonomous underwater vehicles(AUVs) to the docking stations(DSs). The proposed method assesses the probability of docking according to the degree to which the state of the AUV is consistent with the state criteria for docking. The assessment is performed within a specific area considering the kinematic constraints and docking plans of the AUV. The assessment process is defining probability density function, calculating probabilities for reaching the docking station according to the difference to position and heading criteria, and computing the probability-based index in real-time. We verify the validity of the proposed method through analyzing the data acquired on operation test.

• Korean Journal of Biological Psychiatry
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• v.6 no.2
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• pp.176-188
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• 1999

Objective : The purpose of this study was to evaluate the effects of alcohol on neurocognitive function, psychomotor performance and subjective response in healthy Korean adults with different ALDH2 genotypes. Method : A total of 24 males, half with active $ALDH2^*1/2^*1$ and the other with inactive $ALDH2^*1/2^*2$, was selected through genotyping using restriction fragment length polymorphism. In a double-blind, placebo-controlled cross-over design, each subject consumed 0.5g/kg dose of alcohol, given as a mixture of 40% vodka and orange juice, and placebo(orange juice) on two separate occasions on an average of weekly intervals. The blood alcohol concentrations(BACs) were measured using a breath analyzer at baseline and at 30, 60 minutes after drinking. P300s were measured at baseline and at 30 minutes after alcohol and placebo intake. Vital signs and psychomotor performance[Critical Flicker Fusion Threshold(CFFT), Choice Reaction Time (CRT), Digit Symbol Substitution(DSS)] were measured at baseline and at 60 minutes after alcohol and placebo intake. Subjective responses were measured at the end of the study. The statistical analysis focused on whether there were any differences between groups with different ALDH2 genotypes. Results : The major results are as follows. 1) BACs in the inactive group were overall equivalent to those in the active group. Only in terms of time, BACs were significantly higher overall at 30 minutes than at 60 minutes after alcohol intake. 2) Pulse rates were significantly increased after alcohol intake compared with placebo, and the increase was greater in the inactive than in the active group. 3) P300 latencies in leads Fz(frontal), Cz(cental) and Pz(parietal) were significantly increased after alcohol intake compared to placebo, and the increase was greater in the inactive than in the active group. P300 amplitudes in leads Cz and Pz were significantly decreased overall after alcohol intake compared to placebo. 4) Compared with placebo, alcohol produced significant effect on the psychomotor performance : impairment in the inactive group, improvement in the active group. 5) Compared with placebo, alcohol significantly induced a negative or an intense effect on the subjective responses in the inactive group, but little negative and even a somewhat positive effect in the active group. Conclusions : These results suggest that ALDH isozyme variance might be an important factor to determine the effects of acute dose of alcohol on the various psychobehavioural functions and also to determine the alcohol use pattern and to predict the future development of alcohol overuse and/or abuse.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1446-1451
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• 2016

Clostridium difficile toxin A causes acute gut inflammation in animals and humans. It is known to downregulate the tight junctions between colonic epithelial cells, allowing luminal contents to access body tissues and trigger acute immune responses. However, it is not yet known whether this loss of the barrier function is a critical factor in the progression of toxin A-induced pseudomembranous colitis. We previously showed that NADH:quinone oxidoreductase 1 (NQO1) KO (knockout) mice spontaneously display weak gut inflammation and a marked loss of colonic epithelial tight junctions. Moreover, NQO1 KO mice exhibited highly increased inflammatory responses compared with NQO1 WT (wild-type) control mice when subjected to DSS-induced experimental colitis. Here, we tested whether toxin A could also trigger more severe inflammatory responses in NQO1 KO mice compared with NQO1 WT mice. Indeed, our results show that C. difficile toxin A-mediated enteritis is significantly enhanced in NQO1 KO mice compared with NQO1 WT mice. The levels of fluid secretion, villus disruption, and epithelial cell apoptosis were also higher in toxin A-treated NQO1 KO mice compared with WT mice. The previous and present results collectively show that NQO1 is involved in the formation of tight junctions in the small intestine, and that defects in NQO1 enhance C. difficile toxin A-induced acute inflammatory responses, presumably via the loss of epithelial cell tight junctions.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.269-277
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• 2010

Selenium is an essential micronutrient for normal body function and functions as an essential constituent of selenoproteins. This study was carried out to investigate effect of selenium on the formation of colonic aberrant crypt foci (ACF) and tumor formation in a mouse model. Five-week old ICR mice were acclimated for one week and fed different selenium diet (0.02, 0.1, and 0.5 ppm) for 12 weeks. Animals received three intraperitoneal injections of azoxymethane (10 mg/kg B.W. in saline for 3 weeks), followed by 2% dextran sodium sulfate in the drinking water for a week. There were four experimental groups, including a normal control group and three different selenium levels groups. After sacrifice, the total numbers of aberrant crypt (AC) and ACF were measured in the colonic mucosa after methylene blue staining. The number of tumors was noted for tumor incidence. Liver selenium concentration was measured using ICP-AES method. Gutathione peroxidase (GPx) activity was determined using a GPx assay kit in the liver and colon. TUNEL assay and proliferating cell nuclear antigen (PCNA) staining were performed to examine the cell apoptosis and cell proliferation, respectively. Immunohistochemistry of $\beta$-catenin was also performed on the mucous membrane tissue of colon. The activity of GPx in the liver and colon was decreased in the selenium-deficient diet group while it was increased in the selenium-overloaded diet group. Apoptotic positive cells were increased in the selenium-overloaded diet group but decreased in the selenium-deficient diet group. PCNA staining area was decreased in the selenium-overloaded diet group. In addition, the $\beta$-catenin protein level in the selenium-deficient diet group was increased but decreased in the selenium-overloaded diet group. These results indicate that dietary selenium might exert a modulating effect on colon cancer by inhibiting the development of ACF and colon tumor formation in this mouse model.

• BMB Reports
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• v.52 no.5
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• pp.318-323
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• 2019

Mesenchymal stem cells (MSCs) are multipotent adult stem cells that present immunosuppressive effects in experimental and clinical trials targeting various rare diseases including inflammatory bowel disease (IBD). In addition, recent studies have reported tryptophanyl-tRNA synthetase (WRS) possesses uncanonical roles such as angiostatic and anti-inflammatory effects. However, little is known about the function of WRS in MSC-based therapy. In this study, we investigated if a novel factor, WRS, secreted from MSCs has a role in amelioration of IBD symptoms and determined a specific mechanism underlying MSC therapy. Experimental colitis was induced by administration of 3% DSS solution to 8-week-old mice and human umbilical cord blood-derived MSCs (hUCB-MSCs) were injected intraperitoneally. Secretion of WRS from hUCB-MSCs and direct effect of WRS on isolated $CD4^+$ T cells was determined via in vitro experiments and hUCB-MSCs showed significant therapeutic rescue against experimental colitis. Importantly, WRS level in serum of colitis induced mice decreased and recovered by administration of MSCs. Through in vitro examination, WRS expression of hUCB-MSCs increased when cells were treated with interferon-${\gamma}$ ($IFN-{\gamma}$). WRS was evaluated and revealed to have a role in inhibiting activated T cells by inducing apoptosis. In summary, $IFN-{\gamma}$-mediated secretion of WRS from MSCs has a role in suppressive effect on excessive inflammation and disease progression of IBD and brings new highlights in the immunomodulatory potency of hUCB-MSCs.

• Journal of Microbiology and Biotechnology
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• v.34 no.6
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• pp.1287-1298
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• 2024

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that is currently difficult to treat effectively. Both Bacillus natto (BN) and ginseng-soluble dietary fiber (GSDF) are anti-inflammatory and helps sustain the intestinal barrier. In this study, the protective effects and mechanism of the combination of B. natto JLCC513 and ginseng-soluble dietary fiber (BG) in DSS-induced UC mice were investigated. Intervention with BG worked better than taking BN or GSDF separately, as evidenced by improved disease activity index, colon length, and colon injury and significantly reduced the levels of oxidative and inflammatory factors (LPS, ILs, and TNF-α) in UC mice. Further mechanistic study revealed that BG protected the intestinal barrier integrity by maintaining the tight junction proteins (Occludin and Claudin1) and inhibited the LPS/TLR4/NF-κB pathway in UC mice. In addition, BG increased the abundance of beneficial bacteria such as Bacteroides and Turicibacter and reduced the abundance of harmful bacteria such as Allobaculum in the gut microbiota of UC mice. BG also significantly upregulated genes related to linoleic acid metabolism in the gut microbiota. These BG-induced changes in the gut microbiota of mice with UC were significantly correlated with changes in pathological indices. In conclusion, this study demonstrated that BG exerts protective effect against UC by regulating the LPS/TLR4/NF-κB pathway and the structure and metabolic function of gut microbiota. Thus, BG can be potentially used in intestinal health foods to treat UC.