• Title/Summary/Keyword: Stress Function

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Computer-Assisted Navigation in Total Knee Arthroplasty (내비게이션 장치를 이용한 슬관절 전치환술)

  • Jeong, Hwa-Jae;Park, Yong-Beom;Lee, Han-Jun
    • Journal of the Korean Orthopaedic Association
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    • v.53 no.6
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    • pp.478-489
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    • 2018
  • Total knee arthroplasty has become a standard procedure for advanced knee arthritis to relieve pain and improve function. Computer-assisted navigation systems have been used in total knee arthroplasty to improve the mechanical axis of the limb as well as the alignment and position of the components. A computer-assisted navigation system has the advantage of real-time feedback during surgery, such as mediolateral balance in extension and flexion gap, alignment of the lower limb, and components. On the other hand, the computer-assisted navigation system requires an additional stab wound for tracker fixation, which can increase the likelihood of superficial wound infection and stress fractures and increase the operation time and cost of surgery. The clinical efficacy of computer-assisted navigation in total knee arthroplasty is also controversial. Compared to the conventional technique, computer navigation improves the accuracy of the postoperative mechanical axis within outliers of $3^{\circ}$ varus or $3^{\circ}$ valgus. This paper reviews the surgical technique, pitfalls, clinical and radiological outcomes, useful clinical cases, and future perspectives in computer-assisted navigation total knee arthroplasty.

Effects of Alismatis Rhizoma Pharmacopuncture at BL23 on Cisplatin-Induced Acute Renal Failure in Rats (신수(BL23) 택사약침이 Cisplatin으로 유발된 급성신부전 백서에 미치는 영향)

  • Kim, Myung Sik;Kim, Jae Hong;Youn, Dae Hwan;Jeong, Hyun Woo;Cho, Myoung Rae
    • Korean Journal of Acupuncture
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    • v.36 no.1
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    • pp.63-73
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    • 2019
  • Objectives : This study was designed to investigate the effects of Alismatis Rhizoma (AR) pharmacopuncture at BL23 on acute renal failure induced by cisplatin. Methods : The Sprague-Dawley rats were divided into Normal group (no injection of cisplatin and no treatment), Control group (cisplatin injection without treatment), Acu group (needling at BL23 after cisplatin injection), AR-PA1 group (treated with $0.3571mg/kg/20{\mu}l$ of AR pharmacopuncture at BL23 after cisplatin injection), and AR-PA2 group (treated with $1.7855mg/kg/20{\mu}l$ of AR pharmacopuncture at BL23 after cisplatin injection). Each treatment was given once daily for 8 days. Changes in body weight, kidney weight, tumor necrosis factor-alpha ($TNF-{\alpha}$), interleukin-6 (IL-6), Cu-Zn superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GPx), serum blood urea nitrogen (serum BUN), and serum creatinine were observed. Results : Body weight was significantly increased in AR-PA1 on $4^{th}$ and $6^{th}$ days and AR-PA2 on $2^{nd}$ day. $TNF-{\alpha}$ was significantly decreased in Acu, AR-PA1 and AR-PA2 groups. Cu-Zn SOD was significantly increased in AR-PA2 group. GPx was significantly increased in AR-PA1 and AR-PA2 groups. But kidney weight, IL-6, serum BUN and serum creatinine were not significantly changed in any groups compared to control group. Conclusions : In acute renal failure induced by cisplatin, AR pharmacopuncture has a mitigating effect on the inflammatory reaction related to the increase of $TNF-{\alpha}$ in the kidney tissue and a protective effect on the oxidative stress of the kidney tissue. However it is unlikely to restore the glomerular function or inhibit the renal swelling.

Study on the Early Detection of Mental Health Problems in the Elderly and the Utilization of Related Services (노인의 정신건강 문제의 발견과 관련서비스 이용에 관한 연구)

  • Park, Kyungsoon;Park, Yeong-Ran;Son, Duksoon;Yum, Yoosik
    • The Journal of the Korea Contents Association
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    • v.19 no.9
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    • pp.308-320
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    • 2019
  • This study aims at investigating the major symptoms that help family carers detect mental illness in elderly patients. Another purpose of this study is to empirically verify the major factors determining the utilization of mental health services with a focus on family carers. The results of this study are as follows. First, the most commonly detected symptoms that caused the family carers to suspect mental illness in the elderly patients were memory decline and other forms of cognitive function decline. Second, the determinants of the elderly's utilization of mental health services included the patient's long-term care insurance level, the age of the family carer, the period of care, the level stress associated with the provision of care felt by the carer, his understanding of geriatric mental illness, and the level of perception about community mental health services. Based on these findings, this study suggests policies and practical implications for the early detection of and response to elderly mental health problems and the utilization of related services from the viewpoint of the family carers of the elderly.

The Anti-Proliferation and Oxidative Damage-Related Mechanism of L-Carnitine in Human Colorectal Cancer Cells (L-carnitine에 의한 인간대장암세포주 증식억제 및 산화적손상 기전 규명)

  • Lee, Jooyeon;Park, Jeong-Ran;Jang, Aera;Yang, Se-Ran
    • Journal of Food Hygiene and Safety
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    • v.34 no.3
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    • pp.303-308
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    • 2019
  • L-carnitine is found in high levels in muscle tissues. It has been developed as a nutrient and dietary supplement, and also used as a therapeutic supplement in various diseases including type II diabetes, osteoporosis and metabolic neuropathies. However, it is not fully understood how it affects cellular mechanisms in colorectal cancer. Therefore, we attempted to determine the effect of L-carnitine in HCT116 human colorectal cancer cells. First, the HCT116 cells were exposed to L-carnitine for 24 hours at 0-40 mM, and then analyzed for cellular proliferation, oxidative stress and related mechanisms. In a MTT assay, L-carnitine inhibited cellular proliferation and induced reactive oxygen species (ROS) in HCT116 by DCF-DA analysis. To analyze the mechanism of L-carnitine in colorectal cancer cells, we performed a western blot analysis for pERK1/2 and pp38 MAP kinase. The western blot showed that L-carnitine significantly increased protein levels of pERK1/2 and pp38 compared with control. Taken together, we found that L-carnitine has anti-proliferative function via increased ROS and activation of ERK1/2 and p38 pathway in HCT116. These findings suggest that L-carnitine may have an anti-proliferative role on colorectal cancer.

Electrochemical performance of the flexible supercapacitor based on nanocarbon material/conductive polymer composite and all solid state electrolyte (탄소나노복합재료와 전고체 전해질 기반의 유연성 슈퍼커패시터의 전기화학적 특성 분석)

  • Kim, Chang Hyun;Kim, Yong Ryeol;Jeong, Hyeon Taek
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.1
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    • pp.200-207
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    • 2019
  • In this study, flexible supercapacitor based on the all solid state electrolyte with PVA (polyvinyl alcohol)-$H_3PO_4$, ionic liquid as a BMIMBF4 (1-buthyl-3-methylimidazolium tetrafluoroborate) and reduced graphene oxide/conductive polymer composite was fabricated and characterized electrochemical properties with function of its flexibility. In order to measure and compare that electrochemical performances (including cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and galvanostatic charge/discharge,after 0~100th bending test) of prepared flexible supercapacitor based on reduced graphene oxide/conducting polymer composite and all solid state electrolyte, we have conducted press machine with constant pressure ( 0.01/cm2) for $100^{th}$ bending test. As a result, specific capacitance of the flexible supercapacitor was 43.9 F/g which value decreased to 42.0 and 40.1 F/g after 50 and $100^{th}$ bending test, respectively. This result exhibited that decreased electrochemical property of the flexible supercapacitor effected on physical stress on the electrode after repeated bending test. In addition, we have measured that electrode surface morphology by SEM to prove its decreased electrochemical property of the flexible supercapacitor after prolonged bending test.

Verification of the Reliability of the Numerical Analysis for the Crash Impact Test of Rotorcraft Fuel Tank (회전익항공기용 연료탱크 충돌충격시험에 대한 수치해석 신뢰성 검증)

  • Kim, Sungchan;Kim, Hyun-Gi
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.918-923
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    • 2018
  • The main function of a fuel tank is to store fuel. On the other hand, the structural soundness of the fuel tank is related directly to the survival of the crew in an emergency situation, such as an aircraft crash, and the relevant performance is demonstrated by a crash impact test. Because crash impact tests have a high risk of failure due to the high impact loads, various efforts have been made to minimize the possibility of trial and error in the actual test at the beginning of the design. Numerical analysis performed before the actual test is a part of such efforts. For the results of numerical analysis to be reflected in the design, however, the reliability of numerical analysis needs to be ensured. In this study, the results of numerical analysis and actual test data were compared to ensure the reliability of numerical analysis for the crash impact test of a rotorcraft fuel tank. For the numerical analysis of a crash impact test, LS-DYNA, crash analysis software, was used and the ALE (arbitrary Lagrangian Eulerian) technique was applied as the analysis method. To obtain actual test data, strain gages were installed on the metal fittings of the fuel tank and linked to the data acquisition equipment. The strain and stress of the fuel tank fitting were calculated by numerical analysis. The reliability of the numerical analysis was enhanced by assessing the error between the strain measurement of the upper fitting obtained from an actual fuel tank and the strain calculated from numerical analysis.

Production of green tea jelly using theanine and its physiochemical characterization (녹차 theanine을 이용한 젤리 제조 및 품질특성 조사)

  • Kim, Seong Gyung;Jeong, Hana;Im, Ae Eun;Yang, Kwang-Yeol;Choi, Yong Soo;Nam, Seung-Hee
    • Korean Journal of Food Science and Technology
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    • v.53 no.5
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    • pp.553-560
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    • 2021
  • Theanine, the major amino acid and a sweet umami component of green tea, has anti-stress effects in humans. From green tea, theanine was extracted at 80℃ for 2 h using a low temperature, high pressure extractor, and caffeine was removed using an HP-20 column with 80% ethanol. Theanine extracts were applied to produce functional jelly using three kinds of gelling agents (I, II, and III) or various concentrations of theanine extracts (10-50%). Theanine jelly was characterized with respect to its physical properties, product stability, and physiological function. Gelling agent III (tamarind gum, xanthan gum, and locust bean gum=2:3:5, w/w/w) and S3 (35% theanine extracts) jelly exhibited the optimum textural properties with lower hardness and high springiness. Among theanine jellies, S3 exhibited optimum product stability, high 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, and acetylcholinesterase inhibitory activity. These results indicate that the anine extracts could be used as a neuroprotective source in the food industry.

Suppression of Lipopolysaccharide-Induced Inflammatory and Oxidative Response by 5-Aminolevulinic Acid in RAW 264.7 Macrophages and Zebrafish Larvae

  • Ji, Seon Yeong;Cha, Hee-Jae;Molagoda, Ilandarage Menu Neelaka;Kim, Min Yeong;Kim, So Young;Hwangbo, Hyun;Lee, Hyesook;Kim, Gi-Young;Kim, Do-Hyung;Hyun, Jin Won;Kim, Heui-Soo;Kim, Suhkmann;Jin, Cheng-Yun;Choi, Yung Hyun
    • Biomolecules & Therapeutics
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    • v.29 no.6
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    • pp.685-696
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    • 2021
  • In this study, we investigated the inhibitory effect of 5-aminolevulinic acid (ALA), a heme precursor, on inflammatory and oxidative stress activated by lipopolysaccharide (LPS) in RAW 264.7 macrophages by estimating nitric oxide (NO), prostaglandin E2 (PGE2), cytokines, and reactive oxygen species (ROS). We also evaluated the molecular mechanisms through analysis of the expression of their regulatory genes, and further evaluated the anti-inflammatory and antioxidant efficacy of ALA against LPS in the zebrafish model. Our results indicated that ALA treatment significantly attenuated the LPS-induced release of pro-inflammatory mediators including NO and PGE2, which was associated with decreased inducible NO synthase and cyclooxygenase-2 expression. ALA also inhibited the LPS-induced expression of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, reducing their extracellular secretion. Additionally, ALA abolished ROS generation, improved the mitochondrial mass, and enhanced the expression of heme oxygenase-1 (HO-1) and the activation of nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) in LPS-stimulated RAW 264.7 macrophages. However, zinc protoporphyrin, a specific inhibitor of HO-1, reversed the ALA-mediated inhibition of pro-inflammatory cytokines production and activation of mitochondrial function in LPS-treated RAW 264.7 macrophages. Furthermore, ALA significantly abolished the expression of LPS-induced pro-inflammatory mediators and cytokines, and showed strong protective effects against NO and ROS production in zebrafish larvae. In conclusion, our findings suggest that ALA exerts LPS-induced anti-inflammatory and antioxidant effects by upregulating the Nrf2/HO-1 signaling pathway, and that ALA can be a potential functional agent to prevent inflammatory and oxidative damage.

An Study of Pedestrian Efficiency in Apartment Complexes - Focused on Pedestrian Path in Apartment Complexes - (아파트 단지의 보행효율성에 관한 연구 - 단지 내 보행로를 중심으로 -)

  • Yang, Dongwoo;Yu, Sang-Gyun
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.11
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    • pp.85-94
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    • 2018
  • This study aims to investigate how easy pedestrians get around within/through the "Apartment Complexes (AC), " a common style of high-rise multi-family housing in Korea. Over the past six decades, the AC has been the most conventional way to provide standardized housing efficiently to address the problems of the shortage of housing and the substandard housing, due to the explosion of urban population with the rapid industrialization. The AC is a huge chunk of homeogenous multi-family housing, mostly condos with decent infrastructure, including parks, pedestrian passages, schools, ect. Both in the new town development and urban renewal programs have utilized the advantages of the AC. Since the design principals of AC tend to adopt the "protective design" to prevent cars and pedestrians coming outside from passing it, it has been criticised for dissecting the continuity of socioeconomic context in neighborhoods. The neo-traditional planning urbanists, including Jane Jacobs, emphasize that smaller blocks and grid road newtworks are the key in improving social, cultural, and economic vitality of the neighborhoods, because these design concepts allow more pedestrians and different types of people to be mixed in a neighborhood. In this study, we first adopted objective measures for pedestrian accessibility and pedestrian efficiency. These measures were used to calculate the lengths of shortest paths from residential buildings to the edges of AC. We tested the difference in shortest paths between the current pedestrian networks of AC and hypothetical grid networks on the AC, and the relative difference is considered as the pedestrian efficiency, using the network analysis function of Geographic Information Systems (GIS) and Python programming. We found from the randomly selected 30 ACs that the existing non-grid road networks in ACs are worse than the hypothesized grid networks, in terms of pedestrian efficiency. In average, pedestrians in AC with the conventional road networks have to walk than 25%, 26%, and 27% longer than the networks of $125{\times}45m$, $100{\times}45m$, and $75{\times}45m$, respectively. With the t-test analysis, we found the pedestrian efficiency of AC with the conventional network is lower than grid-networks. Many new urbanists stress, easiness of walking is one of the most import elements for community building and social bonds. With the findings from the objective measures of pedestrian accessibility and efficiency, the AC would have limitations to attract people outside into the AC itself, which would increase dis-connectivity with adjacent areas.

Effects of calcium and magnesium-balanced deep sea water on antioxidation in kidney cells (칼슘과 마그네슘이 조절된 해양심층수가 신장세포에서 항산화에 미치는 영향)

  • Jo, So Min;Nam, Jain;Park, Geonhee;Kim, Byeong Goo;Jeong, Gwi-Hwa;Hurh, Byung Serk;Kim, Ji Yeon
    • Journal of Applied Biological Chemistry
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    • v.64 no.2
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    • pp.165-170
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    • 2021
  • In this study, the antioxidant effects of mineral-containing deep sea water (DSW) on kidney function was confirmed using a cell model. DSW samples were prepared with different mineral concentrations including calcium and magnesium-the main minerals found in DSW-to derive the following sample groups: trace minerals (TM), high magnesium (HM), high magnesium, low salt (HMLS) and high magnesium, high calcium (HMHC). The purpose of this preparation was to determine the optimal calcium/magnesium ratio in DSW. Human embryonic kidney (HEK293) cells were exposed to sodium chloride (NaCl) for 2 h to induce release of reactive oxygen species (ROS). Thereafter, the cells were treated with the respective DSW samples before ROS concentrations, as well as antioxidant enzyme activity and protein levels, were measured. Among the water samples, HMLS showed the most protective effect against ROS, whereas the intracellular glutathione content was highest in cells from the HMLS- and HMHC-treated groups. However, TM- and HMHC-treated cells showed similar tendencies to the control group, in terms of mRNA expression of antioxidant genes. These results suggested that DSW may aid in preventing renal oxidative stress caused by excessive sodium intake. Furthermore, it was determined that HMLS and HMHC water samples displayed good antioxidant effects in the kidney cell model, based on the combined results of ROS concentration and antioxidant marker measurements.