• Title/Summary/Keyword: 산 저항성

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A Study on the Fracture Resistance Characteristics of Post-Installed Anchor (후설치 앵커볼트의 파괴저항 특성에 관한 연구)

  • Kim, Doo Hwan;Hwang, Yun Sung;Cha, Young Min;Song, Kwan Kwon;Choi, Kyung Gyp
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.156-156
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    • 2011
  • 중량물 혹은 철골구조물 등을 고정시키는데, 건축구조물의 철골기둥, 터빈 제네레이터 기기등을 콘크리트 구조물에 부착시키기 위해 널리 쓰인다. 1990년대 들어 국내 건물의 리모델링, 보수 및 유지관리의 증가에 따라 앵커의 사용량도 현저히 증가하고 있으나 대부분 고가의 외국산제품을 수입하고 있다. 현재 국내외에 주로 시행되는 앵커타입은 마찰형 앵커이나 마찰형 앵커와 달리 지압형 앵커의 경우, 외국에서는 이미 그 유효성에 대한 인식이 널리 퍼져있으며 각국의 지반조건에 적합한 설계법이 개발되었다. 그러나 국내의 경우 이러한 연구가 미진한 실정이며 이에 대한 연구가 절실한 상황이다. 본 연구에서는 중량물앵커(Heavy Duty Anchor)의 인장시험을 실시하여 내력을 규명하고 도출한 결과를 기존 시험연구 결과와 비교분석하여 기 제안된 이론식들과 사업경제성에대해 보다 깊이있고 정확한 적용성을 입증하는데 본 연구를 수행하였다. 시험을 통한 저강도 파괴시험의 결과 구조부재의 접합부에서 각 시험체마다 뽑힘파괴가 발생하였으며, 뽑힘파괴가 발생한 시험체는 앵커강재의 파괴력 또는 콘크리트의 콘파괴를 발생시키기에는 앵커슬리브의 확장력이 작게 작용되었다. 그 결과, 콘파괴 대신 구조부재의 접합부에서 뽑힘파괴가 발생되었으며 이를 통해 설계시, 앵커의 안정성을 증가시키기 위해 구조부재의 접합부를 연성적이며, 부가여력을 충분히 지니도록 설계하는 것이 효과적인 것으로 나타났다. 고강도 파괴시험의 결과 콘파괴가 발생되었음을 알 수 있는데, 본 시험에 사용된 앵커의 경우 정착위치가 구조물의 연단 모서리 거리와 너무 근접하여 앵커의 내력이 감소하게 되어 콘크리트의 콘강도가 발생되기 전에 먼저 파괴되었다. 따라서 설계시, 앵커의 파괴강도를 증가시키기 위해 앵커의 정착위치를 고려한 설치를 통해 앵커체결과정에서 적정 연단거리를 확보하는 것이 효과적인 것으로 나타났다. 앵커볼트 최소간격과 연단거리에 따른 파괴시험결과 앵커볼트의 간격이 허용범위 내에서 넓어질수록 불균등 부반력의 차는 감소하였으며, 최대 부반력도 감소하였다. 따라서 앵커의 파괴저항강도를 증가시키기 위해서는 허용범위 내에서 앵커볼트의 설치간격을 증가시키는 것이 효과적인 것으로 나타났다.

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Blockade of Thromboxane Influences Does Not Affect Renal Blood Flow Deficit in Anesthetized Diabetic Rats (마취된 당뇨 흰쥐의 신혈류량 감소에 관여하는 기전 : 내인성 쓰롬복산계의 무관성)

  • Ha, Hun-Joo;Dunham, Earl W.
    • The Korean Journal of Pharmacology
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    • v.24 no.2
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    • pp.221-232
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    • 1988
  • Studies were conducted to determine whether reduced renal blood flow (RBF) exhibited by rats with uncontrolled, streptozotocin (STZ)-induced diabetes is attributable to diabetes-associated, enhanced renal vasoconstrictor influence of endogenous thromboxane $(TX)A_2$. Rats which were injected with STZ after pretreatment with 3-O-methyl glucose (3OMG), an agent which prevents STZ-induced hyperglycemia, were also studied. Basal values of total RBF (RBF; ml $min^{-1}$ $gKw^{-1}$; electromagnetic flow probe), systemic arterial pressure (BP; mm Hg) and renal vascular resistance (RVR;BP $RBF^{-1})$in pentobarbital-anesthetized rats during a control period were $5.9{\pm}0.3$(P<0.1_{VS}. CR), $115{\pm}3$ and $20.3{\pm}1.0$(P<0.1_{VS}. CR) for STZR (n=15), and $8.4{\pm}0.4$, $123{\pm}3$ and $15.1{\pm}0.8$ for age-matched control rats (CR; n= 15), respectively. Basal values of RBF, BP and RVR in 3OMG pretreated STZR were identical to CR. In preparations shown capable of renal vasodilatation, OKY 1581 (1 mg/kg, i.v. followed by 0.4 mg/kg min infusion) abolished arachidonate-induced $(TX)A_2$ synthesis, but did not alter basal BP, RBF or RVR in either STZR or CR (n=4/group). Similarly, i.r.a. infusion of SQ29548 (100 ng/ml RBF) abolished renal vasoconstriction induced by a TX/prostaglandin endoperoxide mimic, U46619, but had no discern able affect on RVR in either STZR (n=8) or CR (n=8). The data indicates that $TXA_2$ does not participate in the elevated basal RVR of STZR which are associated with the diabetic state.

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Generation of Bacterial Blight Resistance Rice with Transcription Factor OsNAC69-overexpressing (전사인자 OsNAC69-과발현을 통한 흰잎마름병 저항성 벼 제작)

  • Park, Sang Ryeol;Cha, Eun-Mi;Moon, Seok Jun;Shin, Dongjin;Hwang, Duk-Ju;Ahn, Il-Pyung;Bae, Shin-Chul
    • Korean Journal of Breeding Science
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    • v.43 no.5
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    • pp.457-463
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    • 2011
  • Plant specific gene family, NAC (NAM, ATAF, and CUC) transcription factors have been characterized for their roles in plant growth, development, and stress tolerance. In this study, we isolated OsNAC69 gene and analyzed expression level by inoculation of bacterial leaf blight pathogen, Xanthomonas oryzae pv. oryzae (Xoo). NAC transcription factor family can be divided into five groups (I-V). On the basis of phylogenetic analysis, OsNAC69 was fall into group II. OsNAC69 was strongly induced 1 hr after infected with Xoo. To investigate its biological function in the rice, we constructed vector for overexpression in rice, and then generated transgenic rice lines. Gene expression of OsNAC69-overexpressed transgenic rice lines were analyzed by northern blot. Analysis of disease resistance to pathogen Xoo, nine OsNAC69-overexpressed transgenic rice lines showing high expression level of OsNAC69 were shown more resistant than wild type. These results suggest that OsNAC69 gene may play regulatory role during pathogen infection.

Studies on the Varietal Resistance of Rice to the Green Rice Leafhopper, Nephotettix cincticeps UHLER (끝동매미충에 대한 벼의 품종저항성에 관한 연구(1))

  • Choi S. Y.;Song Y. H.;Park J. S.;Son B. I.
    • Korean journal of applied entomology
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    • v.12 no.1
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    • pp.47-53
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    • 1973
  • Experiments were conducted to study resistance of rice varieties originated from Korea·and IRRI-sources to the green rice leafhopper, Nephotettix cincticeps UHLER. The nature of varietal resistance to the insect was evaluated from the viewpoints of ovipositional and feeding preferences and antibiosis. A trial was also made to survey local biotypes o( the green rice leafhopper possible to show different reaction for the rice varieties. The varieties resistant to the green rice leafhopper were mostly IRRI sources such as Bir-tsan-3, MTU-15, DK-1, DV-139, H105, ASD-7, MGL-2, PTB-18, Muthumanikam, Vellanlangalayan, and the domestic commercial varieties were generally susceptible, but only the reaction of Tong-il and its lines were moderate. Ovipositional and feeding preferences were significantly different among the varieties, but no correlation was observed between the two preferences. The nature of varietal resistance to the insect seemed to be related with the feeding preference, not ovipositional preference. The green rice leafhoppers confined on the resistant varieties such as PTB-18, Muthumanikam, H105 etc. suffered higher nymphal mortality than the susceptible varieties such as T(N) 1 and Jinheung. Though the varieties Mudgo and Suweon 214 were moderately resistant and moderate in plant reaction, the insects confned on two varieties suffered relatively higher nymphal mortality. No local biotypes of green rice leafhoppers with respect to plant reaction were found.

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Induction of Nitric Oxide and Cytokines in Macrophages by Codonopsis lanceolata (대식세포에서 산더덕에 의한 NO 생성 및 싸이토카인 유도효과)

  • So, Mi-Sun;Lee, Jin-Sil;Yi, Seh-Yoon
    • Korean Journal of Food Science and Technology
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    • v.36 no.6
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    • pp.986-990
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    • 2004
  • The immunomodulatory effect of Codonopsis lanceolata based on the production of cytokines and the activation of macrophage was studied. The mRNA expression of nitric oxide synthase (iNOS) was gradually induced after 24 hr treatment of Codonopsis lanceolata, and NO production was a maximum after 24 hr treatment with 1 mg/mL. RAW 264.7 cell on in vitro treatment with Codonopsis lanceolata induced mRNA of cytokines such as interleukin-1(IL-1)${\beta}$, interleukin-6(IL-6), tumor necrosis $factor(TNF)-{\alpha}\;and\;interferon(IFN)-{\gamma}$; $IL-1{\beta}$ and IL-6 mRNA were gradually induced up to 24 hr, $TNF-{\alpha}\;mRNA$ was regularly induced up to 24 hr, and $IFN-{\gamma}\;mRNA$ level was a maximum within 1 hr. These results suggest that Codonopsis lanceolata exerts as an effective immunomodulator and enhances antitumor activity of macrophages.

A High Essential Amino Acid Properties Rice Cultivar 'Haiami' (필수아미노산 고함유 신품종 '하이아미')

  • Hong, Ha-Cheol;Kim, Yeon-Gyu;Yang, Chang-Ihn;Hwang, Hung-Goo;Lee, Jeom-Ho;Lee, Sang-Bok;Choi, Yong-Hwan;Kim, Hong-Yeol;Lee, Kyu-Seong;Yang, Sae-Jun;Kim, Myeong-Ki;Jeong, O-Young;Cho, Young-Chan;Jeon, Yong-Hee;Choi, Im-Soo;Jeong, Eung-Gi;Oh, Sea-Kwan;O, Myeong-Gyu;Yea, Jong-Du;Shin, Young-Seoup;Kim, Jeong-Ju
    • Korean Journal of Breeding Science
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    • v.43 no.6
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    • pp.543-548
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    • 2011
  • Haiami is a new Japonica rice variety developed from a cross between 'Jinmibyeo' TR treated with ethyl methane sulfonate (EMS) EMS and 5-methytryptophan, and 'Gyehwabyeo' in order to develop a new premium quality rice variety by a rice breeding team of National Institute of Crop Science, Rural Development Administration in 2008. This variety has about 138 days of growth duration from transplanting to harvesting in central plain area of Korea. The heading date of this vareity was on $15^{th}$, August. The 'Haiami' has good semi-elect plant type and resistant to lodging with strong culm. The number of panicles/hill of 'Haiami' is more than that of 'Hwaseongbyeo'. This variety shows slow leaf senescence and considerable tolerance to viviparous germination. It is susceptible to leaf blast, bacterial blight, and insect pests, but resistance to rice stripe virus. The milled rice of this variety exhibited translucent, clear non-glutinous endosperm and short grain shape. The essential amino acid properties of 'Haiami' have more than 31% that of 'Hwaseongbyeo' in polished rice. This variety has premium palatability of cooked rice. The yield performance of this rice cultivar was about 5.38 MT/ha in milled rice in local adaptability test for three years from 2006 to 2008. 'Haiami' is adaptable to central and southern plain areas of Korea.

Association of Serum Vitamin D with Insulin Resistance and Beta Cell Function in Korean Health Checkup Examinees (건강검진 수검자에서 혈청 Vitamin D 수준과 인슐린저항성 및 β-세포 기능과의 관련성)

  • Kim, Han-soo;Ryu, So Yeon;Park, Jong;Han, Mi-Ah;Choi, Seong-Woo;Shin, Min-Ho
    • Journal of agricultural medicine and community health
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    • v.43 no.1
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    • pp.18-30
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    • 2018
  • Objectives: This study was conducted to examine the association of serum Vitamin D with insulin resistance and ${\beta}-cell$ function in Korean health checkup examinees. Methods: This study subjects were 374 healthy adults (199 males, 175 females) over the age of 20, who visited a general hospital medical center located in Haenam-gun, Jeollanam-do. To find the association of Vitamin D with HOMA-IR and $HOMA-{\beta}$, the used statistical analysis were ANOVA and ANCOVA. Results: Of the study subjects, the level of serum Vitamin D defined by deficient group, insufficient group and sufficient group was 38.5%, 48.1% and 13.4%, respectively. According to the level of serum Vitamin D, the mean values of HOMA-IR were $1.92{\pm}1.08$ in sufficient group, $1.99{\pm}1.04$ in the insufficient group and $2.91{\pm}1.05$ in deficient group and there were statistically significant different(p<0.001). The mean values of $HOMA-{\beta}$ were $84.69{\pm}1.07$ in sufficient group, $78.41{\pm}1.04$ in the insufficient group and $80.48{\pm}1.04$ in deficient group, and there were not significant. As a result of ANCOVA, adjusted mean of HOMA-IR were statistically significant different (p<0.001), but those of $HOMA-{\beta}$ were not statistically significant according to the level of serum Vitamin D. Conclusion: The insufficient level of serum Vitamin D was relatively high in healthy adults who live in rural area, and it was found that HOMA-IR significantly increased when Vitamin D was deficient. To prevent insulin resistance or diabetes, it is necessary to provide sufficient information related to sufficient production of Vitamin D such as Vitamin D supplement, sun exposure, food intake and etc.

Effect of structural variation of medium chain fatty acids on antibacterial activities against pathogenic bacteria (중쇄지방산의 구조적 차이에 따른 병원성 세균에 대한 항균활성 변화)

  • Ju-Hyeon Choi;Su-Hyeon Son;Hak-Ryul Kim
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.73-80
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    • 2023
  • Broad range of fatty acids were reported to show antimicrobial activities against broad range of microorganisms. However, possible changes of the antibacterial activity of a fatty acid based on structural variations are largely unknown. This study was focused on determination and comparison of the antimicrobial activities of the medium chain fatty acids, based on the position of carboxyl groups on either terminal end, against the representative food-pathogenic bacteria. Over all, mono-carboxyl medium chain fatty acids (MC-MCFA) presented stronger antimicrobial activities against the food-pathogenic bacteria tested including methicillin-resistant Staphylococcus aureus (MRSA) than di-carboxyl medium chain fatty acid (DC-MCFA). In addition, some of MC-MCFA and DC-MCFA showed high possibility to be used as a synergistic adjuvant for both the commercial β-lactam family antibiotics and aminoglycoside family antibiotics against MRSA.

Cloning and Characterization of a 5-Enolpyruvyl Shikimate 3-Phosphate Synthase (EPSPS) Gene from Korean Lawn Grass (Zoysia japonica) (들잔디 5-Enolpyruvyl Shikimate 3-Phosphate Synthase(EPSPS) 유전자 클로닝 및 특성)

  • Lee, Hye-Jung;Lee, Geung-Joo;Kim, Dong-Sub;Kim, Jin-Beak;Ku, Ja-Hyeong;Kang, Si-Yong
    • Horticultural Science & Technology
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    • v.28 no.4
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    • pp.648-655
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    • 2010
  • This study is the first comprehensive report on the molecular cloning, structural characterization, sequence comparison between wild and mutant types, copy number in the genome, expression features and activities of a gene encoding 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in Korean lawn grass ($Zoysia$ $japonica$). The full length cDNA of the EPSPS from Korean lawn grass ($zj$EPSPS) obtained from a 3' and 5' RACE method was 1540 bp, containing a 1176 bp ORF, a 144 bp leader sequence (5' UTR) and a 220 bp 3' UTR, which was eventually decoded 391 amino acid residues with a molecular mass of 41.74 kDa. The Southern blot detection of the $zj$EPSPS showed that the gene exists as a single copy in the Korean lawn grass genome. Sequence comparison of the $zj$EPSPS gene demonstrated that the glyphosate-tolerant mutant (GT) having a Pro-53 to Ser substitution in the gene seems to have a preferred binding activity of the enzyme to phosphoenol pyruvate(PEP) over glyphosate, which allows the continuous synthesis of aromatic amino acids in the shikimate pathway. From the Northern blotting analysis, the $zj$EPSPS was found to be highly expressed, with continuous increase until 36 hours after 0.5% glyphosate treatment in both wild and mutant samples, but 1.5-fold higher EPSP synthase activity was observed in the tolerant mutant when exposed to the glyphosate treatment. The molecular information of the $zj$EPSPS gene obtained from this study needs to be further dissected to be more effectively applied to the development of gene-specific DNA markers and zoysiagrass cultivars; nevertheless, the glyphosate-tolerant mutant having the featured $zj$EPSPS gene can be provided to turfgrass managers for weed problems with timely adoptable management options.

Effects of Simulated Acid Rain on Stomatal Resistance, Wettability and Anatomical Changes in Quercus acutissima and Ginkgo biloba Seedlings (인공산성우가 상수리나무와 은행나무 유묘의 기공저항성, 엽의 Wettability 및 해부학적 변화에 미치는 영향)

  • Lee, Kye Han;Chung, Gap Chae;Lee, Jyung Seuk
    • Journal of Korean Society of Forest Science
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    • v.82 no.4
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    • pp.337-346
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    • 1993
  • Experiments were performed to find out the effects of simulated acid rain(SAR) of pH 4.0 or pH 2.5 for 12 weeks on stomatal resistance, wettability and anatomical changes in Quercus acutissima and Ginkgo biloba seedlings. As a control, distilled water with a pH 6.5 was also sprayed. Stomatal resistance of Q. acutissima and of G. biloba remarkably increased after exposure to SAR. SAR increased the wettability of Q. acutissima leaves measured with water blue solution and of G. biloba leaves measured by leaf contact angle method. Anatomical changes in the leaves of Q. acutissima affected by SAR were the partial damage of epidermis and parenchymatous cells. Scanning electron microscopical observation showed that the number of trichomes in the leaves of Q. acutissima treated with SAR markedly decreased and the erosion of epicuticular wax was significant. No distinct damage was found in the G. biloba leaves at pH 4.0, while epidermis and vascular tissue were collapsed at pH 2.5. No significant alteration of surface structures in this tree species was observed.

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