• Title/Summary/Keyword: life testing

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Development and application of stent-based image guided navigation system for oral and maxillofacial surgery (구강외과 수술용 스텐트 기반 영상유도 수술 시스템의 개발)

  • Lee, Woo-Jin;Kim, Dae-Seung;Yi, Won-Jin;Lee, Sam-Sun;Choi, Soon-Chul;Heo, Min-Suk;Huh, Kyung-Hoe;Kim, Myung-Jin;Lee, Jee-Ho
    • Imaging Science in Dentistry
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    • v.39 no.3
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    • pp.149-156
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    • 2009
  • Purpose : The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. Materials and Methods : We devised a patient-specific stent for patient-to-image registration and navigation. Three-dimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. Results : The accuracy over 8 anatomical landmarks showed an overall mean of $0.56{\pm}0.16\;mm$. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. Conclusion : The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites.

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Evaluation of Hydrogen Properties on Mg2NiHx-Graphene Composites by Mechanical Alloying (기계적 합금화법으로 제조한 Mg2NiHx-Graphene 복합재료의 수소화 특성 평가)

  • Lee, Young-Sang;Lee, Soo-Sun;Lee, Byung-Ha;Jung, Seok;Hong, Tae-Whan
    • Transactions of the Korean hydrogen and new energy society
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    • v.25 no.1
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    • pp.19-27
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    • 2014
  • Mg hydride has a high hydrogen capacity (7.6%), at high temperature, and is a lightweight and low cost material, thus it a promising hydrogen storage material. However, its high operation temperature and very slow reaction kinetics are obstacles to practical application. In order to overcome these disadvantages of Mg hydride, graphene powder was added to it. The addition of graphene has been shown to reduce the operating temperature of dehydrogenation. Moreover, in this report the environmental aspects of $MgH_x$-Graphene composites are investigated by means of the environmental life cycle assessment (LCA) method. $MgH_x$-Graphene mixture was prepared by hydrogen induced mechanical alloy (HIMA). The synthesized powder was characterized by XRD(X-ray Diffraction). The hydrogenation behaviors were evaluated by using a Sievert's type automatic PCT apparatus. Such evaluation of Materials also conducted in the LCA. From the result of P-C-T(Pressure-Composition-Temperature) curves, the $MgH_x$-3wt.% graphene composite was evaluated as having a 5.86wt.% maximum hydrogen storage capacity, at 523K. From absorption kinetic testing, the $MgH_x$-7wt.% graphene composite was evaluated as having a maximum 6.94wt.%/ms hydrogen absorption rate, at 573K. Environment evaluation results for the $MgH_x$-graphene composites and other materials indicated environmental impact from the electric power used and from the materials themselves.

Immuno-chromatographic Analysis for HPV-16 and 18 E7 Proteins as a Biomarker of Cervical Cancer Caused by Human Papillomavirus

  • Kim, Joo-Ho;Cho, Il-Hoon;Seo, Sung-Min;Kim, Ji-Sook;Oh, Kyu-Ha;Kang, Heun-Soo;Kim, In-Gyu;Paek, Se-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.30 no.12
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    • pp.2999-3005
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    • 2009
  • Among the more than 120 different types of human papillomavirus (HPV), types 16 and 18 have been known to be high risk agents that cause cervical cancer. We examined, in an immuno-chromatographic analysis, the potential of using the early gene product, E7 protein, as a diagnostic marker of cervical cancer caused by HPV. We developed monoclonal antibodies specific to HPV-16 and 18 E7 proteins that were produced from bacterial cells using gene recombinant technology. For each E7 protein, the optimal antibody pair was selected using the immuno-chromatographic sandwichtype binding system based on the lateral flow through membrane pores. Under these conditions, this rapid testing assay had a detection capability as low as 2 ng/mL of E7 protein. Furthermore, since viral analysis required the host cell to be lysed using chemicals such as detergents, it was possible that the E7 protein was structurally damaged during this process, which would result in a decrease in detection sensitivity. Therefore, we examined the detrimental effects caused by different detergents on the E7 protein using HeLa cells as the host. In these experiments, we found that the damage caused by the detergent, nonylphenylpolyethylene glycol (NP-40), was minimal relative to Triton X-100 commonly used for the cell lysis. Temperature also affected the stability of the E7 protein, and we found that the E7 protein was stabilized at 4$^{\circ}C$ for about 2 h, which was 4 times longer than at room temperature. Finally, a HPV-infected cervical cancer cell line, which was used as a real sample model, was treated using the optimized conditions and the presence of E7 proteins were analyzed by immuno-chromatography. The results of this experiment demonstrated that this rapid test could specifically detect HPV-infected samples.

Evaluate efficacy of fermented soybean(Bio-Peptone)cream in pruritus : Randomized, double-blinded, placebo-controlled, parallel-group clinical experiment study (피부 가려움증에 대한 대두(大豆) 발효물(Bio-Peptone)크림의 유효성 평가 : 무작위 배정, 양측 눈가림, 위약크림 대조, 평행 설계 연구)

  • An, Jae-Hyun;Jung, Hyun-A;Kim, Eun-Ju;Kim, Ae-Jung
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.33 no.3
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    • pp.27-44
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    • 2020
  • Objectives : The authors conducted randomized, Double-blinded, and placebo-controlled parallel-group clinical experiment study to evaluate efficacy of fermented soybean(Bio-Peptone)cream in pruritus. Methods : The research had been conducted for 4 months from the date of IRB approval(May 26 in 2017) to Sept 2017. The experiment started by randomly distributing 25 subjects with pruritus into experimental group and control group, respectively. The experimental group applied fermented soybean(Bio-Peptone)cream twice a day, in the morning and evening, for one week on itchy area. The effect of the product was evaluated by comparing the PSS(Patient subjective score), moisture level by measuring skin moisture content(Corneometer) and transepidermal water loss(Tewameter), and the Korean version of Skindex-29(index of quality of life improvement) before applying the cream, after applying the cream for one week and after stop applying the cream for one week. The control group conducted identical experiment with the experimental group, except the control group applied placebo instead of the fermented soybean(Bio-Peptone)cream. Results : Pruritus, criterion of the first validation testing, indicates fermented soybean(Bio-Peptone)cream tend to reduce pruritus compare to placebo, although the result is not statistically noticeable. Significant difference in reduction of prutitus, the second validation test was not discovered in both groups. Corneometer and life quality tend to be improved with soy cream than placebo, but not statistically effective and both groups did not show any difference in terms of Tewameter measurement. Conclusions : The result of clinical experiment didn't prove that the fermented soybean(Bio-Peptone)cream is more effective in reducing pruritus than placebo, statistically. The clinical use of soybean product for pruritus requires further studies to be verified.

Acute Toxicity of the BKCa Channel Opener LDD175

  • Choi, Ji-Young;Choi, Jong-Hyun;Lee, Geum-Seon;Ko, Hong-Sook;Park, Chul-Seung;Kim, Yong-Chul;Cheong, Jae-Hoon
    • Biomolecules & Therapeutics
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    • v.14 no.4
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    • pp.253-258
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    • 2006
  • LDD175(4-choloro-7-trifluoromethyl-10H-benzo[4,5]furo[3,2-b]indole-l-carboxylic acid) is one of benzofuroindole derivatives that act as a potent $BK_{Ca}$ channel openers. In the process of testing LDD175 as a new drug candidate, an acute toxicity study was carried out in mice. The mice were administered LDD175 intraperitoneally at dose of 0.2, 1, 10, 50, 100, 200, 400, 800mg/kg and orally at dose of 10, 100, 400, 800mg/kg body weight. After administering LDD175, the vital organs such as the liver, kidney and spleen were carefully observed for any significant pathological features or differences from the norm over a l4-day period. LDD175 did not induce any short-term toxicity at doses less than 100mg/kg. A $LD_{50}$ of LDD175 was 2493mg/kg in male mice and 4908mg/kg in female mice. Weight reduction was observed at a dose of 800mg/kg in male, and 400 and 800mg/kg in female. The kidney weight decreased in females after an intraperitoneal injection of LDD175 high dose(>400mg/kg, i.p.), and the spleen weight increased in the male(800mg/kg, i.p.) and female(400mg/kg, i.p.) mice. Inspite of the change in organ weights, there were neither histopathological changes nor any gross morphological abnormalities detected in any organ. LDD175 did not produce significant changes in the general behavior at doses of <200mg/kg, but decreased locomotor activity was observed at an intraperitoneal dose of 400mg/kg. Its effects on the locomotor activity and activity on the rotarod were tested and compared with the effects of diazepam 5mg/kg. The decrement in the locomotor activity and the activity on the rotarod induced by LDD175 was less serious than it by diazepam.

Investigation of Porcine Melanocortin-4 Receptor (MC4R) Polymorphism on Economic Traits (돼지 melanocortin-4 receptor (MC4R) 유전자의 경제형질과의 연관성에 관한 연구)

  • Kim Kwan-Suk;Shin Hee Young;Lee Joong-Jae;Hong Sung-Kwang;Choi Bong-Hwan;Kim Tae-Hun;Lee Hak-Kyo;Cho Byung-Wook
    • Journal of Life Science
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    • v.15 no.6 s.73
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    • pp.968-971
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    • 2005
  • The Melanocortin-4 receptor gene (MC4R) regulates the energy balance and the genetic basis of obesity. A polymorphism in the porcine melanocortin-4 receptor has previously shown to be associated with growth, fat deposition and feed intake. In this study, the polymorphism of the gene was studied in several pig breeds of Duroc, Landrace, Berkshire, and Yorkshire. The results showed that the frequencies of MC4R genotype varied among those breeds. Association analyses were also performed between the MC4R polymorphism and average daily gain, feed conversion ratio, backfat thickness and lean percentage phenotypes. The results strongly support that the MC4R polymorphism can be used DNA marker selection indicator for economically important traits for pig breeding program in Korea.

A Study on the Growth and Disease of Chondrus ocellatus in Korea (한국산 진두발, Chondrus ocellatus의 생장과 질병에 대한 연구)

  • Lee, Soon Jeong;Park, Myoung-Ae;Ogandaga-Maranguy, Cyr Abel;Park, Seo Kyoung;Kim, Hoikyung;Kim, Young Sik;Choi, Han Gil
    • Journal of fish pathology
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    • v.26 no.3
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    • pp.265-274
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    • 2013
  • The growth, reproduction, gametophyte(G)/tetrasporophyte(T) ratio, and diseases of Chondrus ocellatus populations were examined at 3 sites (Samcheok, Youngduk, Pohang) of East coast and at 2 sites (Hakampo, Manripo) of West coast in between July and August, 2013. Average plant lengths were 6.10~9.69 cm and it was minimum at Manripo and maximum at Pohang population. In general, average plant length and weight of C. ocellatus were greater on East coast than West coast populations. The proportion of vegetative plant was between 26.7~66.7 %, and G/T ratio of total plants including vegetative plants after testing resorcinol method was 3:2 on the East coast where is gametophyte dominant area. However, G/T ratio was 1:1 at Hakampo and 1:2.3 at Manripo representing tetrasporophyte dominance. In the present study, Korean C. ocellatus have various diseases (white colour and green colour), an endophytic alga(Ulvella sp.), and many epiphytic macroalgae and diatoms. Healthy C. ocellatus plants were about 20~40 % in summer population and most of plants had disease. Chondrus ocellatus had a filamentous green alga, endophytic Ulvella sp. which was not identified. The endophyte is easily observed in C. crispus growing in Europe and Canada and it is recognised as a pathogen destroying population and reducing yield of C. crispus. Thus more interest and research on the endophytic algae and disease of C. ocellatus are required.

Population genetic structure of Sedum polytrichoides (Crassulaceae): Insights into barriers to gene flow (바위채송화(돌나물과)집단의 유전적 구조: 유전자 이동과 물리적 장벽에 관한 통찰)

  • Chung, Mi Yoon;Lopez-Pujol, Jordi;Chung, Myong Gi
    • Korean Journal of Plant Taxonomy
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    • v.46 no.4
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    • pp.361-370
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    • 2016
  • An area comprising Juwangsan National Park and its adjacent mountains (southeastern Korean Peninsula) is a good model system for testing the effects of physical barriers to gene flows in plant populations. We predicted that plant species consisting of isolated populations are genetically more differentiated than those that are rather continuously distributed. Most populations of Sedum polytrichoides occur in four isolated valleys, and we assessed the genetic variability and structures using twelve allozyme loci in ten populations. We also compared the present results to earlier findings pertaining to the two co-occurring herbs Hylotelephium ussuriense (${\equiv}$ Sedum ussuriense) (growing only in the four isolated valleys) and S. kamtschaticum (rather continuously distributed). We found moderate levels of within-population genetic variation in S. polytrichoides ($H_{e}=0.112$). Estimates of among-population divergence in S. polytrichoides were also moderate ($F_{ST}=0.250$) and, as expected, very similar to that of H. ussuriense (0.261) but considerably higher than the variation in S. kamtschaticum (0.165). An analysis of molecular variance (AMOVA) revealed that S. polytrichoides and H. ussuriense had higher percentages of among-valley variation (19% each) than S. kamtschaticum (4%). Most of this variation, as also indicated by the STRUCTURE program, was due to differences in genetic profiles between the two central valleys. We concluded that the genetic differences observed between species (S. kamtschaticum vs. S. polytrichoides and H. ussuriense) are mainly due to differences in their distribution within the study area.

Characterization of Potential Plant Growth-promoting Rhizobacteria as Biological Agents with Antifungal Activity, Plant Growth-promoting Activity, and Mineral Solubilizing Activity (항진균 활성, 식물 생장촉진 활성, 미네랄 가용화능을 가진 생물학적 제제로서 잠재적 식물 생장촉진 근권세균의 특성조사)

  • Lee, Song Min;Kim, Ji-Youn;Kim, Hee Sook;Oh, Ka-Yoon;Lee, Kwang Hui;Lee, Sang-Hyeon;Jang, Jeong Su
    • Journal of Life Science
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    • v.31 no.7
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    • pp.641-653
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    • 2021
  • The purpose of this study was to confirm the antifungal activity, plant growth-promoting activity, and mineral solubilizing activity of 18 types of bacteria isolated purely from rhizosphere soil. The potential of isolates of the genus Bacillus and Pseudomonas as biocontrol agents was confirmed through the antifungal activity of these isolates. This activity has been determined to be due to various hydrolytic enzymes on the cell wall of plant pathogenic fungi and the production of siderophores in isolates. In addition, most of the isolates have been found to have aminocyclopropane-1-carboxylate deaminase production activity, indole-3-acetic acid production activity, and nitrogen fixation activity. These characteristics are believed to have a positive effect on root development, growth, and the productivity of crops via a reduction in the concentration of ethylene under conditions of environmental stress, to which plants are commonly exposed. In addition, on testing for the solubilizing activity of the isolates for phosphoric acid, silicon, calcium carbonate, and zinc, some isolates were found to have mineral solubilizing activities. Inoculation of these isolates during plant growth is expected to assist plant growth by converting nutrients necessary for growth into usable forms that can be absorbed by plants. The 18 isolated strains can be used as biocontrol agents due to their antifungal activity, plant growthpromoting activity, and mineral solubilizing activity.

Effect of Repeated Laundry on Shrinkage Rate of Chainsaw Protective Pants (반복세탁이 산림작업복 하의의 수축률에 미치는 영향)

  • Jeong, Eung-Jin;Park, Su-Gyu;Han, Sang-Kyun;Cha, Du-Song
    • Journal of Korean Society of Forest Science
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    • v.108 no.3
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    • pp.341-348
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    • 2019
  • In order to reduce the safety risk of forestry operations, this research was conducted to examine the suitability of chainsaw protective pants after repeated laundering, testing four different products that are currently used in hand-held chainsaw operations. Laundering was repeated 10, 20, 30, 40, and 50 times. After washing, we measured the shrinkage ratio of 17 measurement positions mostly affecting the safety of forest operations and suggested the expected safety life cycle of chainsaw protective clothes. The results showed that most of the products have only one measurement position where the standard shrinkage ratio (<6%) was exceeded after 20 washings, and that the lateral direction of measurement positions shrank more than the vertical one. The numbers of repeated launderings and measurement positions were found to be significant factors influencing the shrinkage ratio (p<0.05). In the shrinkage rates for 17 measurement positions, there were significant correlations between five of the measurement positions (a, b, g, j, and n) and the number of repeated launderings (p<0.05). Therefore, the results suggest that about 10 months would be suitable for an adequate safety lifetime for chainsaw protective pants. The relationship between the number of repeated launderings and the measurement positions will be further analyzed in detail to examine the durability of chainsaw protective pants.