• Structural Monitoring and Maintenance
• /
• v.7 no.4
• /
• pp.295-317
• /
• 2020

Investigation of the stability of arch dam abutments is one of the most important aspects in the analysis of this type of dams. To this end, the Bakhtiari dam, a doubly curved arch dam having six wedges at each of its abutments, is selected. The seismic safety of dam abutments is studied through time history analysis using the design-based earthquake (DBE) and maximum credible earthquake (MCE) hazard levels. Londe limit equilibrium method is used to calculate the stability of wedges in abutments. The thrust forces are obtained using ABAQUS, and stability of wedges is calculated using the code written within MATLAB. Effects of foundation flexibility, grout curtain performance, vertical component of earthquake, nonlinear behavior of materials, and geometrical nonlinearity on the safety factor of the abutments are scrutinized. The results show that the grout curtain performance is the main affecting factor on the stability of the abutments, while nonlinear behavior of the materials is the least affecting factor amongst others. Also, it is resulted that increasing number of the contraction joints can improve the seismic stability of dam. A cap is observed on the number of joints, above which the safety factor does not change incredibly.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.19 no.6
• /
• pp.343-351
• /
• 2019

Background: Preterm labor and miscarriage may occur in stressful situations, such as a surgical operation or infection during pregnancy. Pharyngeal and buccal abscess and facial bone fractures are inevitable dental surgeries in pregnant patients. Remifentanil is an opioid analgesic that is commonly used for general anesthesia and sedation. Nonetheless, no study has investigated the effects of remifentanil on amniotic epithelial cells. This study evaluated the effects of remifentanil on the factors related to uterine contraction and its mechanism of action on amniotic epithelial cells. Methods: Amniotic epithelial cells were preconditioned at various concentrations of remifentanil for 1 h, followed by 24-h lipopolysaccharide (LPS) exposure. MTT assays were performed to assess the cell viability in each group. The effects of remifentanil on factors related to uterine contractions in amniotic epithelial cells were assessed using a nitric oxide (NO) assay, western blot examinations of the expression of nuclear factor-kappa B (NF-κB), cyclooxygenase 2 (COX2), and prostaglandin E2 (PGE₂), and RT-PCR examinations of the expression of the proinflammatory cytokines interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α). Results: Remifentanil did not affect viability and nitric oxide production of amniotic epithelial cells. Western blot analysis revealed that remifentanil preconditioning resulted in decreased expressions of NF-κB and PGE2 in the cells in LPS-induced inflammation, and a tendency of decreased COX2 expression. The results were statistically significant only at high concentration. RT-PCR revealed reduced expressions of IL-1β and TNF-α. Conclusions: Preconditioning with remifentanil does not affect the viability of amniotic epithelial cells but reduces the expression of factors related to uterine contractions in situations where cell inflammation is induced by LPS, which is an important inducer of preterm labor. These findings provide evidence that remifentanil may inhibit preterm labor in clinical settings.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.2
• /
• pp.277-290
• /
• 2008

The process of wound repair involves an ordered sequence of events such as overlapping biochemical and cellular events that, in the best of circumstances, result in the restoration of both the structural and functional integrity of the damaged tissue. An important event during wound healing is the contraction of newly formed connective tissues by fibroblasts. The polypeptide growth factors, like transforming growth factor-${\beta}$(TGF-${\beta}$, insulin-like growth factor I (IGF- I) and epidermal growth factor (EGF), play very important mediator roles in the process of wound contraction. Deer antlers, as models of mammalian regeneration, are cranial appendages that develop after birth as extensions of a permanent protuberance (pedicle) on the frontal bone. Antlers contain various growth factors which stimulate dermal fibroblast growth. They are involved in digestion and respiration and are necessary for normal wound healing and skin health. In order to investigate and evaluate the effects of red deer antlers on skin wound site, the speed of full-thickness skin wound healing and the expression of IGF-I, TGF-${\beta}$ and EGF in skin wounds, three groups of skin full-thickness rat models with a high concentration of antler ointment, a low concentration of antler ointment and without antler ointment were compared. At post-injury days 0, 2, 4, 8, 16, 20, 32, 40 and 60, the skin wound area was measured, the expressions of IGF-I, TGF- ${\beta}$ and EGF mRNA were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and collagen formation by sirius red dye and the localization of IGF-I, TGF-${\beta}$ and EGF peptides were inspected by histological immunohistochemical techniques. Wound healing was significantly more rapid in antler treated skins. In addition, the wound treated with a high concentration antler ointment, a low concentration antler ointment, and the control closed completely at post-injury day 40, day 44 and day 60, respectively. Via RT-PCR, the expressions of IGF-I (day 8 and day 16), TGF-${\beta}$(day 8, day 16 and day 20) and EGF (day 4, day 8, day 16, and day 32) were obviously up-regulated in high concentration antler-treated skins compared to control skins. Similar results could be seen in the histological detection of collagen dye and immunohistochemical methods using the corresponding polyclone antibodies of IGF-I, TGF-${\beta}$ and EGF. These results illustrate that antlers stimulate and accelerate the repair of cutaneous wounds.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.1
• /
• pp.92-99
• /
• 2002

Transient in an electric distribution system are mainly generated by switching. This paper presents analysis of switching surge and means of limiting the voltage magnification transient for high voltage power systems by using the EDSA's EMTAP software package. One means of limiting the voltage magnification transient is to convert the end-user power factor contraction capacitor banks to harmonics filters. An inductance in series with the capacitor bank was used to decrease the transient voltage at the customer bus to acceptable levels. And also simulation results used the EDSA harmonics analysis program show the effect of harmonics reduction.

• Journal of Advanced Marine Engineering and Technology
• /
• v.21 no.1
• /
• pp.49-58
• /
• 1997

The membrane type LNG tank is non self-supporting tank which consists of both primary and secondary membrane supported through the insulation boxes by the adjacent hull struc¬ture. Although the membranes are not structural member. They are subject to periodical cyclic loads due to the thermal expansion and other expansions or contraction of membrane. At the design stage of the tank, an analytical and experimental approach on the fatigue strengths of membrane and its welds is necessary in order to assist the designer and the inpector. In this study the evaluation method of fatigue strength of membrane type LNG tank is pre¬sented with FEM analysis and fatigue test of lap welds and it contains the following:1) The fatigue tests and preparation of design S - N curve for lap welds 2) FEM analysis of test specimens 3) Estimation of cumulative damage factor of lap welds 4) Guideline for inspection of lap welds of membrane type LNG tank As the results of analytical and experimental approaches in this study, the evaluation method of fatigue strengths of membrane type LNG tank is proposed, which is expected to be useful for design and inspection of membrane type LNG tank.

• The Korean Journal of Physiology and Pharmacology
• /
• v.5 no.1
• /
• pp.47-53
• /
• 2001

Drinking excessive alcohol has been recognized as a risk factor for hypertension. However, the mechanism by which alcohol intake causes hypertension still remains elusive. We tested the hypothesis that ethanol itself acts as a stress factor on vasculature and indirectly modulates vascular contractility. After end of exposure to 1, 2.5 and 5% ethanol for 45 min, rat aortic strips were subjected to contractile responses, immunoblot for Hsp70 and the measurement of levels of myosin light chain phosphorylation. Exposure to 5% ethanol not only augmented contractions to KCl or phenylephrine, but also increased expression of Hsp70 and the levels of myosin light chain phosphorylation. There were no significant differences in contractions produced by $1\;{\mu}mol/L$ phorbol 12,13-dibutyrate, a protein kinase C activator, whether the tissues were exposed to 5% ethanol or not. This is the first report to show that even short exposure to ethanol has a delayed effect to increase vascular smooth muscle contractility through a modulation of thick filament regulation. It may be a mechanism by which ingestion of alcohol induces hypertension.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.12
• /
• pp.955-961
• /
• 2011

We investigated the physical properties of stoichiometric and non-stoichiometric oxide doped complex perovskite, $Ba(Zn_{1/3}Ta_{2/3})O_3$ ceramics and their impacts on the microwave dielectric performances using various characterization techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and network analyzer. According to the measurement of lattice constant changes, anomalous lattice volume contraction of $ZrO_2$ doped $Ba(Zn_{1/3}Ta_{2/3})O_3$ sample only showed the dielectric quality factor enhancements, which was due to the lattice volume contraction as well as the 1:2 B-site cation ordering. In addition, NiO doping was useful to the stabilization of temperature coefficient of resonance frequency.

• Physical Therapy Rehabilitation Science
• /
• v.6 no.4
• /
• pp.170-175
• /
• 2017

Objective: The anti-inflammatory effects of low-level laser in burn wound model in rats were investigated. Design: Randomized controlled trial. Methods: The rats were assigned to three experimental groups. Group I received second-degree burn wounds; Group II received dressing film and low-level laser ($1.2J/cm^2$) treatment after a burn wound; Group III received dressing film and low-level laser ($2.3J/cm^2$) treatment after a burn wound. After inducing a deep second-degree burn wound, the wound was observed every day and the burn area diameter and retraction quantification at 1, 7, and 14 days were evaluated. Low-level laser was investigated on hematological parameters after 14 days. Effects of low-level laser on the inflammatory cytokines (tumor necrosis $factor-{\alpha}$ [$TNF-{\alpha}$] and interleukin-6 [IL-6]) concentrations in the serum were evaluated using immunosorbent assay kits. Results: Group III showed a significant difference in wound size on days 7 and 14 compared to Group I (p<0.05). Group II showed a significant difference in wound size on day 14 compared to Group I (p<0.05). For wound contraction percentage, both laser therapy treatment groups showed a significant difference compared with Group I (p<0.05). There was also a significant difference in wound contraction percentage in Group III compared to Group II (p<0.05). Compared with the model control group, decreased $TNF-{\alpha}$ and IL-6 levels in the serum was observed at 14 days after burn wound induction. Conclusions: The results of this study suggest that low-level laser therapy can assist in burn wound healing, which might be associated with decreased concentrations of $TNF-{\alpha}$ and IL-6 related proinflammatory cytokines.

• The Journal of Internal Korean Medicine
• /
• v.18 no.1
• /
• pp.69-85
• /
• 1997

This study was designed to elucidate the anti-inflammatory, cardiovascular, anti-thrombotic and analgesic effects of Shintongchugeotang. The anti-inflammatory effect was measured by the method of carragenin induced edema, protein leakage test using CMC-pouch, and the analgesic effect was measured by the acetic acid method and hot plate method, and the effect of Shintongchugeotang on the cardiovascular system was observed by the change of flow rate of Ringer solution in the vascular system in the ear of rabbit, and the contraction and dilatation of rat tail artery. Death rate, platelet aggregation, plasma coagulation activity was observed for the measurement of the anti-coagurative effect of Shintongchugeotang. The result was as follows : 1. After the administration of Shintongchugeotang extract, Carragenin induced edema and CMC-pouch protein leakage were significantly decreased. 2. The slight analgesic effect of Shintongchugeotang extract was confirmed by the observation of writhing syndrome, paw licking time, and escape time. 3. The drug increased the auricular blood flow in rabbit. 4. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 5. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 6. The drug inhibited the platelet aggregation in rat. 7. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable.

• The Journal of Internal Korean Medicine
• /
• v.19 no.2
• /
• pp.88-106
• /
• 1998

This study was designed to elucidate the antiinflammatory, cardiovascular, antithrombotic, and analgesic effect of Sambitang. The antiinflammatory effects was measured by the method of carrageenin induced edema, protein leakage test using CMC-pouch, and the effect of Sambitang on the cardiovascular system was observed by the change of flow rate of Ringer solution in the vascular system in the ear of rabbit, and the contraction and dilatation of rat tail artery. Death rate, platelet aggregation, plasma coagulation activity was observed for the measurement of the anticoagurative effect of Sambitang, and the analgesic effect was measured by the acetic acid method and hot plate method. The result was as follows: 1. Sambitang administration, edema and protein leakage was significantly decreased. 2. The drug increased the auricular blood flow in rabbit. 3. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 4. The drug inhibited the death rate of mouse which was led to thromboembo- lism by serotonin and collagen. 5. The drug inhibited the platelet aggregation in rat. 6. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 7. The slight anagesic effect of Sambitang extract was confirmed by the observation of writhing syndrome, paw licking time, and escape time.