• Journal of electromagnetic engineering and science
• /
• v.15 no.3
• /
• pp.123-128
• /
• 2015

Previously, we investigated extremely low-frequency magnetic fields (ELF-MFs) on diverse DNA damage responses, such as phosphorylated H2AX (${\gamma}H2AX$), comet tail moments, and aneuploidy production in several non-tumorigenic epithelial or fibroblast cell lines. However, the effect of ELF-MF on DNA damage responses in neuronal cells may not be well evaluated. Here, we investigated the effects of ELF-MF on the DNA damage responses in HT22 non-tumorigenic mouse neuronal cells. Exposure to a 60-Hz, 2 mT ELF-MF did not produce any increased ${\gamma}H2AX$ expression, comet tail moments, or aneuploidy formation. However, 2 mT ELF-MF transiently increased the cell number. From the results, ELF-MF could affect the DNA damage responses differently, depending on the cell lines.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.29 no.12 s.243
• /
• pp.1335-1343
• /
• 2005

The calibration technique of Time Resolved Laser Induced Incandescence was investigated both experimentally and numerically by using standard-sized carbon black particles for the instantaneous soot measurement at exhaust tail pipe in engine. The carbon black particles (19nm, 25nm, 45nm and 58nm) used in this study are similar, though not identical, to soot particle generated from flame not only in morphology but also in micro-structure. The amount of soot loading in flow was controled by a diluted gas (nitrogen) and was measured by the gravimetric method at exhaust pipe in calibrator. The successful calibrations of primary particle size and soot mass fraction were carried out at the range from 19nm to 58nm and from $0.25mg/m^3$ to $37mg/m^3$ respectively. And based on these results the numerical simulation of LII signal was tuned and the effect of an exhaust temperature variation on the decay rate of LII signal was corrected.

• Advances in Traditional Medicine
• /
• v.9 no.3
• /
• pp.232-237
• /
• 2009

The effect of arogh, a polyherbal formulation-PHF [each 3 g powder contained Nelumbo nucifera G. (0.24 g), Hemidesmus indicus R. (0.24 g), Zingiber officinale R. (0.24 g), Terminalia chebula R. (0.24 g), Quercus infectoria O. (0.12 g), Hibiscus rosa-sinensis L. (0.24 g), Rosa damascene M.(0.24 g), Eclipta alba H.(0.24 g), Glycyrrhiza glabra L. (0.24 g)] was investigated in various experimental models of pain and inflammation. Analgesic activity of PHF was studied in mice using acetic acid induced writhing, tail immersion and hot plate methods. Anti-inflammatory activity of PHF was studied in rats using carrageenan induced hind paw edema and formalin induced rat paw edema methods. PHF significantly (P < 0.05) reduced the number of writhings, increased latency to flick tail in tail immersion method and elevated the mean basal reaction time in hot plate method. PHF significantly (P < 0.05) inhibited carrageenan induced hind paw edema and formalin induced rat paw edema. The PHF was tested at dose of 30, 100, 300 and 500 mg/kg.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.1
• /
• pp.226-229
• /
• 2004

We investigated the comparative effect with different frequency and duration time of electroacupuncture(EA) for suppression of pain. Inflammation was induced by an intraplantar injection of 1 % carrageenan into the right hind paw. Bilateral EA stimulation with 2 Hz, 15 Hz and 120 Hz were delivered at those acupoints corresponding to Zusanli and Sanyinjiao in man via the needles in carrageenan-injected rats. The paw and tail thermal hyperalgesia were measured in 30-minute intervals after carrageenan injection using hot plate and tail flick analgesia meter, respectively. The significant difference was found between the control and any of EA frequencies examined. Especially 2 Hz EA presented more effective inhibitory effects compared with other frequency of EA in tail flick latency. The hyperalgesia induced by carrageenan was strongly inhibited by 2 Hz EA from 5 min post and reached sufficient effects from 20 min post EA treatment. These results suggest that EA treatment might be a useful therapy for mitigation of inflammatory pain.

• IMMUNE NETWORK
• /
• v.6 no.2
• /
• pp.67-75
• /
• 2006

Background: Cytotoxic function of killer cells is inhibited by specific recognition of class I MHC molecules on target cells by inhibitory killer Ig-like receptors (KIR) expressed on NK cells and some cytotoxic T cells. The inhibitory effect of KIR is accomplished by recruitment of SH2-containing protein tyrosine phosphatase (SHP) to the phosphotyrosine residues in the cytoplasmic tail. Methods: By in vitro coprecipitation experiments and transfection analysis, we investigated the association of KIR with an adaptor protein Shc in Jurkat T cells. Results: The cytoplasmic tail of KIR appeared to associate with an adaptor protein Shc in Jurkat T celilysates. Similar in vitro experiments showed that phosphorylated KIR cytoplasmic tail bound SHP-1 and Shc in Jurkat T cell lysates. The association of KIR with Shc was further confirmed by transfection analysis in 293T cells. Interestingly, however, Shc appeared to be replaced by SHP-2 upon engagement of KIR in 293T cells. Conclusion: Our data indicate that KIR associate with an adaptor protein Shc in Jurkat T cells, and suggest that KIR might have an additional role which is mediated by this adaptor protein.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.20 no.3
• /
• pp.63-67
• /
• 2012

Spaceflight induces a number of cardiovascular physiological alterations. To study adaptations to microgravity on Earth, the tail-suspended, hindlimb-unloaded rat model has been used to simulate the effects of microgravity. Despite the extensive use of this model to infer physiological adaptations of many organs to microgravity, little information has been obtained on the effect of tail suspension(TS) on cardiac adaptations in the rat. This study was aimed to investigate the effects of simulated microgravity on the rat myocardium using the TS model. Twenty-four male Sprague-Dawley rats were randomly assigned to 3 experimental groups(1, 7 and 14 days of TS) and a control group. A microscopic examination was performed to assess histopathological changes in the myocardial morphology. The hearts from the control group, the 1 day-TS rats and the 7 day-TS rats revealed no evident abnormalities in cardiomyocyte size and morphology. At day 14 of TS, in contrast, the ventricular cardiomyocytes appeared more separated from each other and were slightly smaller in size compared with those of the control group. Also seen were scattered areas exhibiting focal disorganization of muscle fibers and some degenerating cardiomyocytes, of which the nuclei had become pyknotic or disappeared. In this study, we demonstrated that the ventricular cardiomyocytes underwent degeneration and atrophy at the microscopic level during exposure to simulated microgravity in TS rats.

• Asia-Pacific Journal of Business
• /
• v.11 no.4
• /
• pp.37-48
• /
• 2020

Purpose - This study empirically investigates whether the risk property included in fat-tails of return distributions is systematic or unsystematic based on the devised statistical methods. Design/methodology/approach - This study devised empirical designs based on two traditional methods: principal component analysis (PCA) and the testing method of portfolio diversification effect. The fatness of the tails in return distributions is quantitatively measured by statistical probability. Findings - According to the results, the risk property in the fat-tails of return distributions has the economic meanings of eigenvalues having a value greater than 1 through PCA, and also systematic risk that cannot be removed through portfolio diversification. In other words, the fat-tails of return distributions have the properties of the common factors, which may explain the changes of stock returns. Meanwhile, the fatness of the tails in the portfolio return distributions shows the asymmetric relationship of common factors on the tails of return distributions. The negative tail in the portfolio return distribution has a much closer relation with the property of common factors, compared to the positive tail. Research implications or Originality - This empirical evidence may complement the existing studies related to tail risk which is utilized in pricing models as a common factor.

• International Journal of Oral Biology
• /
• v.34 no.3
• /
• pp.137-142
• /
• 2009

Whole-body $\gamma$-irradiation(WBI), which produces an oxidative stress, is reported to attenuate the acute antinociceptive action of morphine (a $\mu$-opioid receptor agonist), but not DPLPE (a $\delta$-opioid receptor agonist), in mice. Recently, we also reported that antinociceptive effect of morphine, but not $\beta$-endorphin (a novel $\varepsilon$-opioid receptor agonist), was attenuated by oxidative stress. These findings prompted us to investigate the effect of WBI on the antinociception of morphine and $\beta$-endorphin in mice. Mice were exposed to WBI (5 Gy) from a $^{60}Co$ gamma-source and tested 2 hours later for antinociception produced by intracerebroventricular administration of morphine or $\beta$-endorphin using the hot water tail-immersion and the writhing tests. WBI significantly attenuated the antinociception produced by morphine only in the hot water tail-immersion test, whereas the antinociception of $\beta$-endorphin was significantly potentiated by WBI in both tests. These results demonstrate a differential sensitivity of $\mu$- and $\varepsilon$-opioid receptors to WBI, and support the hypothesis that morphine and $\beta$-endorphin administered supraspinally produce antinociception by different neuronal mechanisms.

• Journal of Veterinary Clinics
• /
• v.18 no.4
• /
• pp.311-314
• /
• 2001

To elucidate the effect of dorsal acupoints for canine electroacupuncture anesthesia, mongrel dogs(6 heads: 2.6-10.5kg, 3 males and 3 females) were used. After needling perpendicularly to Tian-Ping(GV-5) and Bai-Hui(GV-20), the electrodes were connected with positive to Tian-Ping and negative to Bi-hui, respectively using with veterinary electroacupuncture apparatus(TEC AM-3000). The electric conditions were 2-4V and 30 Hz. The pain of body surface was checked by hemostatic forceps. The effect of electroacupuncture andesthesia was appreciated by application of laparotomy(2 heads), ear trimming and tail amputation(1 head), castration(2 heads) and enterotomy(1 head), respectively. Induction time, clinical findings and operation findings were investigated under the electroacupuncture anesthesia. The induction time of electroacupuncture anesthesia was very rapid, approximately 1 minute and the pain of body surface including the extremities was not detected. As for clinical findings during electroacupuncture anesthesia, consciousness was evident, pupil reflex was weak and blepharoreaction was existed. As for operation findings, pain was not detected during incision and suture, and bleeding was relatively small volume. The grade of electroacupuncture anesthesia was excellent in all cases applied with ear trimming and tail amputation, laparatomy, castration and enterotomy. Considering above all findings, it was thought that electroacupuncture stimulation at Tian-Ping and Bai-hui examined in the present study induced excellent electroacupuncture anesthesia for dogs.

• Journal of the Korean Applied Science and Technology
• /
• v.8 no.2
• /
• pp.183-189
• /
• 1991

This study aimed to find out the effect of freeze-drying leek against cholesterol feeding rats on the cholesterol and lipid in serum, hemolysis in erythrocyte and blood pressure in rats tall. In this experiment, male rats of Wistar strain were used. The rats were divided into 3 groups in 8 weeks : basal diet, 1% cholesterol and 1% cholesterol and 1% leek. The followings are the results of this experiment. 1. In vitro, leek-ext, reduced the hemolysis. 2. Leek reduced VLDL, LDL/HDL-cholesterol in serum. 3. Leek reduced the blood pressure in rat's tail. 4. Leek reduced the fatty change in liver caused by cholesterol treatment. This experiment showed that leek-addition group had portective effect against cholesterol fed and decresed VLDL, LDL/HDL-cholesterol in serum, Leek alleviated hemolysis in erythrocyte, blood pressure in rat's tail and fatty change in liver. Therefore, this experiment concluded that leek has defensive power against cholesterol.