• Title/Summary/Keyword: Supply disruption

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Hazard-Consistent Ground Displacement Estimation for Seismic Input of Underground Utility Tunnels in Korea (국내 재해도에 상응하는 공동구의 지반변위 산정)

  • Kim, Dae-Hwan;Lim, Youngwoo;Chung, Yon-Ha;Lee, Hyerin
    • Journal of the Korean Geotechnical Society
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    • v.37 no.12
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    • pp.7-23
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    • 2021
  • Underground utility tunnels, which contribute to supply of electricity, communication, water and heat, are critical lifelines of an urban area. In case service is discontinued or functional disruption happens, there will be a huge socio-economic impact. For the improved seismic design and evaluation of underground structures, this study proposes a ground displacement measure when the site is subjected to a scenario earthquake based on hazard-consistent source spectra and site amplification/attenuation. This measure provides a rational estimation of ground displacement and can be an alternative to existing response displacement methods.

New proposal for skin grafts on tendon-exposed wounds

  • Um, Jung Hwan;Jo, Dong In;Kim, Soon Heum
    • Archives of Plastic Surgery
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    • v.49 no.1
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    • pp.86-90
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    • 2022
  • Performing a skin graft is not feasible for tendon-exposed defect reconstruction because tendons are fibrous connective tissues with relatively poor blood supply. This study proposes a method to effectively perform skin graft surgery in tendon-exposed wounds. A 48-year-old male patient with diabetes mellitus had a very large left dorsal foot defect (8×8 cm). The wound bed had healthy granular tissue, with tendon exposure. The tendons were turned over so that the posterior side would behave as the anterior side. The edge of the paratenon was then fixed together to the surrounding granulation tissue or dense remnant fascia using absorbable sutures, and the close granulation tissue was approximated and buried. A split-thickness skin graft was performed after 1 week. The graft site was stably taken on postoperative day 3. A small disruption was then observed at the graft site within 1 week postoperatively, but conservative treatment was continued for 1 month, after which the defect site was completely restored. This technique can increase the success rate of skin grafts for defects with tendon exposure.

On the Inflation and its Modifications in the Era of Global Pandemic: The Case of Some ADB Countries

  • CHARAIA, Vakhtang;PAPAVA, Vladimer
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.8
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    • pp.7-17
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    • 2022
  • The article discusses the problems caused by inflation in the developing Asia-Pacific region during the time of the worldwide pandemic and suggests innovative solutions to the problem. The reality is that some of the commodity groups from the consumer basket (e.g., non-seasonal fruits, electronics, furniture, hotel, and restaurant services, etc.) fail to reflect the needs of the low-income earners, which make the majority in developing countries. At the same time, the inflation targeting regime has become outdated and not reliable, because of uncontrolled exogenic factors (imported inflation, fluctuation in oil prices, supply chain disruption, Russia-Ukraine war, etc.) prevailing on endogenic factors and thus making it impossible to control the price stability, especially in developing countries. Since, the old-fashioned inflation index and inflation targeting mechanisms regrettably fail to fully reflect both the society and governmental/central banks' expectations, based on which we first should have better care and second create better policies; we propose to use a combination of already well-known indexes and policies, with the new statistical indicators, which reflects price fluctuations on the medication, utilities, and nutrition.

Updating Osteonecrosis of the Femoral Head

  • Young-Seung Ko;Joo Hyung Ha;Jung-Wee Park;Young-Kyun Lee;Tae-Young Kim;Kyung-Hoi Koo
    • Hip & pelvis
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    • v.35 no.3
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    • pp.147-156
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    • 2023
  • Osteonecrosis of the femoral head (ONFH), a condition characterized by the presence of a necrotic bone lesion in the femoral head, is caused by a disruption in the blood supply. Its occurrence is more common in young and middle-aged adults and it is the main reason for performance of total hip arthroplasty in this age group. Its incidence is increasing along with increased use of glucocorticoids for management of adjuvant therapy for treatment of leukemia as well as organ transplantation and other myelogenous diseases. Current information on etiology and pathogenesis, as well as natural history, stage system, and treatments is provided in this review. A description of the Association Research Circulation Osseous (ARCO) criteria for classification of glucocorticoids-and alcohol-associated ONFH, 2019 ARCO staging system, and 2021 ARCO classification using computed tomography for the early stages of ONFH is also provided.

A Case of Gastric Wall Hematoma and Ischemic Necrosis After Endoscopic Biopsy (상부 위장관 내시경조직검사 후 위벽에 발생한 출혈을 동반한 혈종 및 점막 괴사 1예)

  • Kim, You-Min;Lee, Jin-Sung;Kim, Dong-Hee;Sung, Young-Ho;Choi, Sun-Taek;Kim, Hyun-Tae;Lee, Hyun-Wook;Kim, Keung-Ok
    • Journal of Yeungnam Medical Science
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    • v.27 no.2
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    • pp.159-164
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    • 2010
  • Hematoma of gastric wall is very rare, and occasionally associated with coagulopathy, trauma, peptic ulcer disease, and therapeutic endoscopy. Ischemic gastric necrosis is also rare because of the abundant anastomotic supply to the stomach, and it is usually associated with surgery and disruption of the major vessels. Endoscopic submucosal injection of hypertonic saline-epinephrine (HS-E) is a safe, cost-effective, and widely used therapy for hemostasis but it may cause tissue necrosis and perforation. We describe a case of gastric wall hematoma with oozing bleeding after endoscopic gastric mucosa biopsy in 71-year old woman with chronic renal failure and angina pectoris undergoing anti-platelet medication. We injected a small dose of HS-E (7ml) for controlling oozing bleeding. Two days later, endoscopy showed huge ulcer with necrotic tissue at the site of previously hematoma. Therefore we should pay particular attention for hematoma and mucosal necrosis when performing endoscopic procedure in a patients with high bleeding and atherosclerotic risk.

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Photocatalytic Cell Disruption of Giardia lamblia in a $UV/TiO_2$ Immobilized Optical-Fiber Reactor

  • YU , MI-JIN;KIM, BYUNG-WOO
    • Journal of Microbiology and Biotechnology
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    • v.14 no.6
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    • pp.1105-1113
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    • 2004
  • Disinfection of a waterborne pathogenic protozoa, Giardia lamblia, by the conventional chlorine method has been known to be difficult. An alternative disinfection has been carried out by using a UV -light illuminating optical­fiber photoreactor. Light intensity diffused from one piece of a clad-removed optical-fiber was $1- 1.5{\mu}Em^{-2}s^{-1}$. Disinfection capability in a UV -light irradiated optical-fiber reactor suspended with 0.01 g $TiO_{2}\;dm^{-3}$ was 1.4 times that in the same reactor without $TiO_{2}$ photocatalysts. To resolve the absorption and scattering of UV light by the particles themselves as well as the difficulty of recycling particles in the slurry­type reactor, $TiO_{2}$ which was obtained by a hydrothermal method, was immobilized on clad-removed optical fibers. Such pretreatment of fiber surface resulted in an excellent transparency, which enhanced the UV light to diffuse laterally from a fiber surface. Coating time of the prepared solution by the hydrothermal method was not effective after more than two times. Disinfection capability in the $TiO_{2}$-immobilized optical-fiber reactor was $83\%$ in 1 h at $40^{\circ}C$, which was slightly higher than $76\%$ at $22^{\circ}C$ and $68\%$ at $10^{\circ}C$. Disinfection capability at $22^{\circ}C$ increased from $74\%$ at an initial pH of 3.4, through $76\%$ at pH 6.5, to $87\%$ at an initial pH of 10. Oxygen supply with air-flow rate of 5 $cm^3\;min^{-1}$ did not seem to increase the disinfection capability with UV /immobilized $TiO_2$.

Glucose Deprivation and Immunostimulation Induced Death in Rat Primary Astrocytes is Mediated by Their Synergistic Effect on the Decrease in Cellular ATP Level

  • Choi, Ji-Woong;Yoo, Byoung-Kwon;Yoon, Seo-Young;Jeon, Mi-Jin;Ko, Kwang-Ho
    • Biomolecules & Therapeutics
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    • v.12 no.1
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    • pp.25-33
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    • 2004
  • In this study we investigated whether ATP loss was involved in the potentiated death of immunostimulated rat primary astrocytes in glucose-deprived condition. Rat primary astrocytes immunostimulated with LPS plus IFN-${\gamma}$ for 48 h underwent death upon glucose deprivation, which dependent on the production of peroxynitrite. Intracellular ATP level synergistically decreased by glucose deprivation in immunostimulated astrocytes but not in control cells, and the loss of ATP occurred well ahead of the LDH release. The synergistic cell death and ATP loss by immunostimulation and glucose deprivation were inhibited by iNOS inhibitor (L-NAME and L-NNA) or peroxynitrite decomposition catalyst (also a superoxide anion scavenger), Mn(III)tetrakis(N-methyl-4'-pyridyl)porphyrin (MnTMPyP). Exogenous addition of peroxynitrite generator, SIN-l timedependently induced ATP loss and cell death in the glucose-deprived astrocytes. Depletion of intracellular glutathione (GSH) and dis겨ption of mitochondrial transmembrane potential (MTP) were also observed under same conditions. Supply cellular ATP by the addition of exogenous adenosine or ATP during glucose deprivation inhibited ATP depletion, GSH depletion, MTP disruption and cell death in SIN-l treated or immunostimulated astrocytes. This study showed that perturbation in the regulation of intracellular ATP level in immunostimulated astrocytes might make them more vulnerable to energy challenging stimuli.

Study on Optimal Real Time Pricing Model for Smart Grid in a Power Retailer Market (스마트 그리드 환경의 전력소매시장을 위한 최적의 실시간 가격결정 모형에 대한 연구)

  • Moon, Joon-Yung;Shin, Ki-Tae;Park, Jin-Woo
    • The Journal of Society for e-Business Studies
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    • v.17 no.2
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    • pp.105-114
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    • 2012
  • Recently, global warming, energy shortage, and environmental disruption have been serious problems in every nation. It became more and more important to reduce the emission of CO2 and to use of energy efficiently. Smart grid was also introduced using the rapidly developing information technology. It deployed the mutual communication concept between customers and the suppliers in the electricity supply. There were increasing demands to adopt the smart meter and to present incentive for efficient energy usage in many developed countries. The objective of this research was to develop the optimal real time pricing model which maximized the profit of the power retailer and reduced the usage of energy. The simulation study was given to show the usefulness of the model. Simulation considered the customer demand response rate and price elasticity rate. The price elasticity rate was compared in the condition of fixed value according to time and variable value according to the customers. The optimal price model could maximize the profit of the power retailer and reduce the energy usage of the consumers.

Effects of OPEC Announcements in Different Periods of Oil Price Fluctuation (사건연구 방법론을 이용한 OPEC 생산량 발표의 원유시장 영향 분석)

  • Bae, Jee Young;Heo, Eunnyeong
    • Environmental and Resource Economics Review
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    • v.26 no.3
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    • pp.451-472
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    • 2017
  • An OPEC production announcement is a major source of supply disruption that has a significant impact on the international crude oil market. In this study, the effects of OPEC's announcements are analyzed using event study methodology. Considering the oil price volatility and structural changes in the oil price, we divide the entire period into three periods and analyze the impact of OPEC's production quota announcements, including 'cut', 'hike', and 'maintain'. As a result of the analysis, we observe that the degree and direction of abnormal returns differ according to the announcements in each period. In addition, by subdividing oil price surge and plunge period into two sections, we analyze the effect of OPEC's 'maintain' announcements. During the oil price plunge period, the amount of abnormal returns was significant. This study provides policy implications for oil trading strategies and for the impact of OPEC announcements during periods of oil price fluctuation.

Effect of Propofol Preconditioning on Hypoxic-Cultured Human Osteoblast

  • Yoon, Ji Uk;Shin, Sang Wook;Park, Bong Soo;Kim, Yong Ho;Woo, Mi Na;Yoon, Ji Young;Kim, Cheul Hong
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.14 no.2
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    • pp.107-114
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    • 2014
  • Background: Angiogenesis has been recognized an essential precondition for osteogenesis. Because reduction and disruption of the blood supply to tissue cause tissue hypoxia, pathological bone loss affected by hypoxia often can occur in various clinical conditions. The effects of propofol on the process of osteogenesis have received little direct attention. Therefore, we investigated the effect of propofol on the growth and function of osteoblasts under hypoxic condition. Methods: After propofol (3, 30, $300{\mu}M$) preconditioning for 2 hours, hFOB 1.19 human osteoblast cells were cultured under 1 % oxygen tension for 48 hours. Using real time PCR and western blot analysis, we analyzed the expression of, BMP-2, TGF-${\beta}1$, type I collagen, osteocalcin, HIF-1s and Akt. Cell viability was also determined by MTT assay. Results: Propofol preconditioning on hypoxic-cultured osteoblast promoted the expressions of BMP-2, TGF-${\beta}1$, type I collagen and osteocalcin and induced hypoxia-mediated HIF-1 activation and the expression of Akt protein. Propofol with $300{\mu}M$ significant decreased cell viability compared to control. Conclusions: Clinically relevant concentrations of propofol are not cytotoxic to hypoxic osteoblasts in vitro. Propofol preconditioning on hypoxic-cultured osteoblast stimulates proliferation and differentiation of osteoblast through induced expression of BMP-2, TGF-${\beta}1$, type I collagen and osteocalcin. Propofol might promote angiogenesis and bone regeneration under hypoxic condition.