• 제목/요약/키워드: 03-03

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Streptomyces sp. DMCJ-49 균주가 생산하는 Alpha-Amylase 저해제 MB4-03의 분리와 구조분석 (Isolation and Structural Analysis of MB4-03, an $\alpha$-Amylase Inhibitor Produced by Streptomyces sp. DMCJ-49)

  • 염대현;최응철;김병각;김진웅
    • 한국미생물·생명공학회지
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    • 제18권4호
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    • pp.338-343
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    • 1990
  • Streptomyces sp. DMCJ-49 균주의 배양액으로부터 분리된 $\alpha$-amylase 저해물질 MB4-03은 구조상 질소원자와 methyl기를 포함하는 일종의 직선형 Alpha(1-4) 결합으로 연결된 glucose의 변형된 oligomer 형태로서 구성 단당류는 12 정도로 추정된다.

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La2NiO4+δ세라믹스의 유전이완 및 전기전도특성 (Dielectric Relaxation and Electrical Conduction Properties of La2NiO4+δ Ceramics)

  • 정우환
    • 한국재료학회지
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    • 제21권7호
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    • pp.377-383
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    • 2011
  • Thermoelectric power, dc conductivity, and the dielectric relaxation properties of $La_2NiO_{4.03}$ are reported in the temperature range of 77 K - 300 K and in a frequency range of 20 Hz - 1 MHz. Thermoelectric power was positive below 300K. The measured thermoelectric power of $La_2NiO_{4.03}$ decreased linearly with temperature. The dc conductivity showed a temperature variation consistent with the variable range hopping mechanism at low temperatures and the adiabatic polaron hopping mechanism at high temperatures. The low temperature dc conductivity mechanism in $La_2NiO_{4.03}$ was analyzed using Mott's approach. The temperature dependence of thermoelectric power and dc conductivity suggests that the charge carriers responsible for conduction are strongly localized. The relaxation mechanism has been discussed in the frame of the electric modulus and loss spectra. The scaling behavior of the modulus and loss tangent suggests that the relaxation describes the same mechanism at various temperatures. The logarithmic angular frequency dependence of the loss peak is found to obey the Arrhenius law with activation energy of ~ 0.106eV. At low temperature, variable range hopping and large dielectric relaxation behavior for $La_2NiO_{4.03}$ are consistent with the polaronic nature of the charge carriers.

The influence of magnetic field on the alignment of steel fiber in fresh cementitious composites

  • Li, Hui;Li, Lu;Li, Lin;Zhou, Jian;Mu, Ru;Xu, Mingfeng
    • Computers and Concrete
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    • 제30권5호
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    • pp.323-337
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    • 2022
  • This paper proposes a numerical model to simulate the rotational behavior of steel fiber in fresh cement-based materials in the presence of a magnetic field. The results indicate that as the aspect ratio of fiber increases, the required minimum magnetic field intensity to make fiber rotate in viscous fluid increases. The optimal magnetic field intensity is 0.03 T for aligning steel fiber in fresh cement-based materials to ensure that the applying time of the magnetic field can be conducted concurrently with the vibrating process to increase the aligning efficiency. The orientation factor of steel fiber in cement mortar can exceed 0.85 after aligning by 0.03 T of the uniform magnetic field. When the initial angle of the fiber to the magnetic field direction is less than 10°, the magnetic field less than 0.03 T cannot make the fiber overcome the yield stress of fluid to rotate. The coarse aggregate in steel fiber-reinforced concrete is detrimental to the rotation and alignment of the steel fiber. But the orientation factor of ASFRC under the 0.03T of the magnetic field can also exceed 0.8, while the orientation factor of SFRC without magnetic field application is around 0.6.

Formalin으로 유도된 통증모델에서 제돈과(齊墩果)약침의 진통효과 (Analgesic Effect of Styrax Japonica Pharmacopuncture on Formalin-Induced Pain in Rats)

  • 박무섭;이현종;이윤규;김미려;박해진;김재수
    • Journal of Acupuncture Research
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    • 제33권2호
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    • pp.97-108
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    • 2016
  • Objectives : This study was performed to investigate the analgesic effect of Styrax japonica pharmacopuncture on formalin induced pain in rats and to figure out efficient extraction method. Methods : The subjects were divided into 5 groups ; normal group(treated with normal saline at KI03, and injected normal saline at right hindpaw after 35 minutes), control group(treated with normal saline at KI03, and injected with formalin at right hindpaw after 35 minutes), water group(treated by hot water extraction pharmacopuncture at KI03, and injected with formalin at right hindpaw after 35 minutes), ethanol group(treated with ethanol extraction pharmacopuncture at KI03, and injected with formalin at right hindpaw after 35 minutes), and ultrasound group(treated with ultrasound extraction pharmacacupuncture and injected with fromalin formalin at right hindpaw after 35 minutes). We conducted a formalin test with ultrasonic vocalization( USV), and after the test checked for substance P, Aspartate aminotransferase(AST), and Alanine aminotransferase(ALT) concentration in the blood for each of the groups. Results : There was a significant analgesic effect of Styrax japonica pharmacopuncture in the early phase of the formalin test, and pharmacopuncture made with an ultrasound extracting method was observed to have a better analgesic effect than other extracting methods in early phases. The substance P concentration decreased significantly in the Styrax japonica pharmacopuncture treated group and no difference was found in the AST and ALT concentration of each group. Conclusion : These results demonstrated that Styrax japonica pharmacopuncture had analgesic effects in noxious nociceptors stimulation. Also pharmacopuncture made with an ultrasound extracting method had a better analgesic effect than others.

올리빈형 $LiFePO_4$ 분말의 전기전도도와 입도 크기에 미치는 도핑의 영향 (Effects of doping on the electrical conductivity and particle size in olivine type $LiFePO_4$ powders)

  • 백진도;하정수;김창삼
    • 한국결정성장학회지
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    • 제18권6호
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    • pp.248-252
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    • 2008
  • 전기전도성이 우수하면서 입자 크기가 작은 $LiFePO_4$ 분말을 얻기 위해서, 이종원소(Cr+B 또는 Cr+Al) 도핑이 $LiFePO_4$의 전기전도도에 미치는 영향과 열처리 조건이 입자 크기에 미치는 영향에 대해서 조사하였다. 조성이 $LiFe_{0.965}Cr_{0.03}B_{0.005}PO_4$ and $LiFe_{0.065}Cr_{0.03}Al_{0.005}PO_4$인 두 종류의 분말을 기계화학적 밀링법으로 혼합 후 $675{\sim}759^{\circ}C$에서 $5{\sim}10$시간 열처리하여 합성하였다. 이종원소 도핑은 입자성장을 촉진하였고 전기전도도를 높이는 효과가 있었다. $LiFe_{0.065}Cr_{0.03}Al_{0.005}PO_4$의 전기전도도는 $1{\times}10^{-8}S/cm$로 도핑하지 않은 것의 $5{\times}10^{-10}S/cm$보다 높았다.

Biological control efficacy on Sclerotinia rot(Sclerotinia sclerotiorum) by the use of antifungal agent some Bacillus sp.

  • Hong, Yeon-Kyu;Lee, Bong-Choon;Shin, Dong-Beom;Hyun, Jong-Nae;Kang, Hang-Won;Park, Sung-Tae
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.106-107
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    • 2003
  • The effect of biological control agent Bacillus sp. (BAC03-3-1, BAC03-3-2, BAC02-4) on pre- and postemergence Sclerotinia rot of perilla (Perilla frutescens var. japonica) caused by Sclerotinia sclerotiorum was determined from greenhouse field trials. The ability of this antagonist to reduce germination of sclerotia of S. sclerotiorum was also evaluated. In the greenhouse, suspension of BAC03-3-1 application as root drench of perilla, which provided as little as 10$\^$7/ cells/ $m\ell$ per gram of soil, significantly increased plant stand in pathogen-infested soil over that in the untreated control. All three isolates reduced the germination of sclerotia of S. sclerotiorum in loamy sand soils in the greenhouse. In loamy sand amended with rice bran the sclerotial germination was inversely correlated (r = -0.79) with perilla stand in the greenhouse. However, a higher rate of bacterial suspension with rice bran(Ig dwt./100g soil) than that applied with bacterial suspensions only was necessary to achieve a comparable reduction in sclerotial germination. In field study, all three isolates added to soil to provide 10$\^$7/ cells/$m\ell$ per gram significantly prevented Sclerotinia rot (73-85%) after 35 days of growth. The isolate BAC02-4, BAC03-3-1 and BAC03-3-2 gave final stands of 65 to 75, 60 to 70, and 55 to 60%, respectively. The addition of rice bran(1 %) to loamy sand in the field resulted in a 10-fold increase in propagule numbers of the three isolates within 10 days of application.

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Isolation and Characterization of Kimchi Starters Leuconostoc mesenteroides PBio03 and Leuconostoc mesenteroides PBio104 for Manufacture of Commercial Kimchi

  • Lee, Kang Wook;Kim, Geun Su;Baek, A Hyong;Hwang, Hyun Sun;Kwon, Do Young;Kim, Sang Gu;Lee, Sang Yun
    • Journal of Microbiology and Biotechnology
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    • 제30권7호
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    • pp.1060-1066
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    • 2020
  • This study was focused on developing and obtaining a kimchi starter for use in commercial kimchi production. Kimchi varieties made with selected starters are of high quality, have high levels of mannitol, and extended shelf life. The starters were screened for properties such as mannitol production, low gas/acid production, and acid resistance. Finally, kimchi fermentation testing was performed using selected LAB starters. Kimchi samples were prepared with lactic acid bacteria (LAB) starters, including Leuconostoc mesenteroides PBio03 and Leuconostoc mesenteroides PBio104. The LAB starters are isolated from kimchi and can grow under pH 3.0 and low temperature conditions of 5℃. Four kimchi samples were fermented and stored for 28 days at 5℃. The kimchi samples made with starters (PBio03 and PBio104) had better quality (production of mannitol and maintenance of heterofermentative LAB dominance) than the non-starter kimchi samples. In the starter kimchi, Leu. mesenteroides was the dominant LAB, comprising 80% and 70% of total LAB counts at 7 and 21 days, respectively. Mannitol content of the kimchi with Leu. mesenteroides PBio03 was 1,423 ± 19.1 mg/100 g at 28 days, which was higher than that of the non-starter kimchi sample (1,027 ± 12.2 mg/100 g). These results show the possibility of producing kimchi with improved qualities using Leu. mesenteroides PBio03 and PBio104 as starters.

Effect of anesthetics and diuretics on Doppler measurements of intrarenal resistive index in dogs

  • Choi, Ho-jung;Yoon, Jung-hee;Eom, Ki-dong;Lee, Hee-chon;Choi, Ji-hye;Sung, Jae-ki
    • 대한수의학회지
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    • 제39권4호
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    • pp.832-837
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    • 1999
  • lntrarenal resistive index (RI) was determined in normal, sedated and diuretic kidneys. The mean RI values of normal dogs were $0.64{\pm}0.03$ without statistically significant difference between left and right kidney. Interrenal RI difference (${\Delta}RI$) was $0.03{\pm}0.01$. No significant relationship was found between mean intrarenal RI versus body weight. The mean intrarenal RI values after administration of acepromazine, xylazine, thiopental, and ketamine were $0.66{\pm}0.03$, $0.64{\pm}0.03$, $0.56{\pm}0.05$, and $0.50{\pm}0.05$, respectively. After administration of acepromazine or xylazine, a significant change of the RI was not found. But, a significant decrease of the RI following thiopental or ketamine administration could be observed as compared with the normal RI. The mean intrarenal RI values were $0.63{\pm}0.06$ and $0.62{\pm}0.04$ at 10 minutes and 30 minutes after injection of furosemide, respectively. No significant change of intrarenal RI was found after administration of furosemide. But, mannitol significantly decreased mean intrarenal RI to $0.57{\pm}0.02$ and $0.58{\pm}0.03$ at 30 minutes and 60 minutes, respectively. Based on the obtained results, values of 0.72 and 0.05 may be proposed as the reasonable upper limits of RI and ${\Delta}RI$ of normal average. Acepromazine or xylazine are recommended as anesthetics for renal diseases because they have less effect on the RI. Further study using mannitol injection to increase ${\Delta}RI$ may be suggested in unilateral urinary tract obstruction since mannitol more effectively changed mean RI than furosemide.

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Electrokinetic Process의 효율 향상을 위한 전극교환 방식과 혼합용매 적용 가능성 평가 (Applicability Evaluation of Electrodes Exchange and Mixed Solution for Enhanced Electrokinetic Process)

  • 이노섭;박성수;남궁완
    • 공업화학
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    • 제18권4호
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    • pp.391-395
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    • 2007
  • 본 연구는 electrokinetic process (EK process)를 이용하여 20000 mg/kg의 납(Pb)으로 오염된 토양을 처리하는 과정에서 중금속이 오염토양 내부에 수산화물 형태로 침전되는 현상을 억제할 수 있는 방법을 찾기 위하여 전극교환(EK-Exchange, EK-E)과 혼합용매(0.3 M acetic acid and 0.03 M EDTA, EK-Mixed Solution, EK-M)를 사용하는 방법을 적용하였다. 혼합용매를 사용하는 경우(EK-M)에는 EDTA 0.03 M을 단독으로 사용하는 경우(EK-Blank, EK-B)보다는 약 2% 정도 낮은 제거효율을 나타내었다. 그러나, 비싼 EDTA 약품 값을 절약할 수 있다는 측면에서 보면, 이 방법도 충분히 적용 가능한 방법이다. 전극교환을 하는 경우(EK-E)에는 EDTA 0.03 M을 사용하는 경우(EK-B)보다 2% 높은 제거효율을 나타내었다. 그러나 더욱 중요한 사항은 다른 운전조건(EK-B, EK-M)과는 달리 토양 내부의 pH가 7~8 사이로 중성 부근에서 유지되었다는 점이다. 특히, 중금속의 축적이 우려되는 EK-B와 EK-M과는 달리 중금속이 특정 부위(오염토양 중앙부 또는 음극부)에 축적되지 않는다는 장점을 나타내었다.

Fenugreek seeds reduce aluminum toxicity associated with renal failure in rats

  • Belaid-Nouira, Yosra;Bakhta, Hayfa;Haouas, Zohra;Flehi-Slim, Imen;Cheikh, Hassen Ben
    • Nutrition Research and Practice
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    • 제7권6호
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    • pp.466-474
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    • 2013
  • Despite the reports on safety concerns regarding the relationship between aluminum salts and neurological and bone disease, many countries continue to use aluminum as phosphate binders among patients with renal failure. In search for a diet supplement that could reduce aluminum toxicity related to renal failure, we carried out this prospective animal study in which the fenugreek seeds were assessed for their effects on rats nephrotoxicity induced by aluminum chloride ($AlCl_3$). Oral $AlCl_3$ administration during 5 months (500 mg/kg bw i.g for one month then 1600 ppm via drinking water) led to plasma biochemical changes, an inhibition of alkaline phosphatase (ALP), a decrease of total antioxidant status (TAS), and an induction of lipid peroxidation (LPO) in the blood and brain, in addition to kidney atrophy and morphological alterations at the level of Bowman's capsule, the glomerulus and different sorts of tubules, reminiscent of some known kidney disease. The treatment with the whole fenugreek seed powder (FSP) (5% in the diet) during the last 2 months showed its effectiveness in restoring normal plasma values of urea, creatinine, ALP and glucose, as well as re-increasing the TAS, inhibiting LPO and alleviating histopathological changes in the injured kidneys. This study highlights the induced nephrotoxicicity, as well as the related toxicity in the brain and bone, by chronic oral ingestion of the aluminum salts. However, the maintenance of a diet supplemented with fenugreek seeds could offer protection for the kidney, bone and brain, at the same time.