• 제목/요약/키워드: $E_rC_{50}$

검색결과 392건 처리시간 0.024초

Allylisothiocyanate첨가가 Aspergillus parasiticus R-716의 배양중 효소활성에 미치는 영향 (Effect of Allylisothiocyanate on the Enzyme Activities During the Culture of Aspergillus parasiticus R-716)

  • 김성영
    • 한국식품위생안전성학회지
    • /
    • 제12권2호
    • /
    • pp.97-101
    • /
    • 1997
  • Effect of allylisothiocyanate on the enzyme activites including malate degydrogenase, isocitrate dehydrogenase, NADPH and acetyl CoA which were related to aflatoxin production of Aspergillus parasticus R-716 were invetigated. The activities of malate dehydrogenase (EC.1.1.1.37), isocitrate dehydrogenase (E.C.1.1.1.42) and NADPH oxidase (E.C.1.6.99.1) indicated relatively high in the 50 ppm allylisothiocyanate-added-culture. In contrast, the activity of acetyl CoA in the 50 ppm allylisothiocyanate-added-culture showed rather lower level through the cultivation.

  • PDF

물벼룩(Daphnia magna)에 대한 중금속의 급성 및 만성 독성 (Acute and Chronic Toxicity of heavy Metals to Daphnia magna)

  • 정재원;차미선;조순자;이상준
    • 한국환경과학회지
    • /
    • 제10권4호
    • /
    • pp.293-298
    • /
    • 2001
  • The toxicity values heavy metals were evaluated by immobilization and chronic reproduction impairment tests, using Daphnia magna. Acute tests were evaluated by the inhibition of their mobilization after 24hrs without food addition. The tests of reproductive impairment were investigated for 21 days by food addition and exchange or water. The effect of each concentration was assessed by Probit analysis and t-test. The results obtained from this study were as follows : 1) The change of pH and DO was not significant in the acute tests, while, in the reproductive tests, pH was increased by 0.3~1.4 and DO also increased. 2) The $E_iC_{50}$ values of immobilization to Daphnia magna in artificial fresh water were $0.030mg/{\ell}(Cu),\;0.054mg/{\ell}(Cd),\;0.12mg/{\ell};(Cr),\;0.74mg/{\ell}(Pb),\;3.4mg/ {\ell}(As)$ and the $NOE_iC$ values were $0.010mg/{\ell}(Cu),\;0.018mg/{\ell}(Cd),\;0.010mg/{\ell}(Cr),\;0.10mg/{\ell}(Pb),\;and\;$1.8mg/{\ell}(As)$. 3) The $E_rC_{50}$ values of reproductive impairment to Daphnia magna were $13.8\mu\textrm{g}/{\ell}(Cu),\;2.9\mu\textrm{g}/{\ell}(Cd),\;15.5\mu\textrm{g}/{\ell}(Cr),\;61.7\mu\textrm{g}/{\ell}(Pb),\;759\mu\textrm{g}/{\ell}(As)$, and $NOE_rC$ values were $0.95\mu\textrm{g}/{\ell}(Cu),\;$0.54\mu\textrm{g}/{\ell}(Cd),\;1.2\mu\textrm{g}/{\ell}(Cd),\;$7.4\mu\textrm{g}/{\ell}(Pb),\;110mu\textrm{g}/{\ell}(As)$. The results of tests using OECD artificial culture water were more sensitive than natural water for culturing. The presented data show that an artificial culture water is suitable in the experiment of bioassay for assessing the toxicity of marterials.

  • PDF

Grignard Coupling Reaction of Bis(chloromethyl)diorganosilanes with Dichloro(diorgano)silanes: Syntheses of 1,3-Disilacyclobutanes

  • 조연석;유복렬;안삼영;정일남
    • Bulletin of the Korean Chemical Society
    • /
    • 제20권4호
    • /
    • pp.427-430
    • /
    • 1999
  • The Grignard coupling reaction of bis(chloromethyl)diorganosilanes [(ClCH2)2SiR1R2: R1 = R2 = Me, la; R1 = Me, R2 = Ph, lb; R1 = R2 = Ph, lc] with diorganodichlorosilanes [(Cl2SiR3R4: R3 = R4 = Me, 2a; R3 = Me, R4 = Ph, 2b; R3 = R4 = Ph, 2c] at THE reflux temperature gave the intermolecular C-Si coupling product of 1,1,3,3-tetraorgano-1,3-disilacyclobutanes 3a-f in poor to moderate yields ranging from 7% to 50% along with polydiorganosilapropanes. The cyclization reaction of la-c with methyl-substituted dichlorosilanes 2a, b gave 1,3-disilacyclobutanes 3a-c, e, d in moderate yields (42-50%), while the same reaction with dichlorodiphenylsilane (2c) to 1,3-disilacyclobutanes 3d, f resulted in low yield (7-18%) probably due to the steric hindrance of two-phenyl groups on the silicon of 2c.

X-선에 대한 마우스의 내력 (Studies on Tolerance of Mice to X-rays)

  • 김정진
    • 한국동물학회지
    • /
    • 제6권2호
    • /
    • pp.11-15
    • /
    • 1963
  • A total of 220 adult male mice (18-20g) of the S.M. strain were divided into ten experimental and control groups. The total-body X-ray irradiation doses used were 50 r, 100r, 200r, 400r, 600r, 800r, 1,000r, 1,200r, 1,400r, and1,600r. The respiratory arrest (mortality) caused by each irradiation doses were observed for 30 days. Relationships between irradiation doses and survival time and percentage of response were examined. From this experiment, a formula was obtained to express the relationship among three factors, which may be presented as follows : {{{{{{{{P= { 10} over { SQRT { 2 pi } } INT _{ - INF }^{ p'} e-{(p'-50)^2 } over {200 }dp···(a) p'=100 LEFT { t^0.3- LEFT ( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } } / LEFT { LEFT ( { 26372.43} over {D-81.86 } RIGHT ) ^{ { 1} over {2.5 } } -( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } ···(b) p= { (D-60) t^0.75-16.9965} over {0.2186 t^0.75 +263.55434 }····(c) }} {{{{P= { 10} over { SQRT { 2 pi } } INT _{ - INF }^{ p'} e-{(p'-50)^2 } over {200 }dp···(a) p'=100 LEFT { t^0.3- LEFT ( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } } / LEFT { LEFT ( { 26372.43} over {D-81.86 } RIGHT ) ^{ { 1} over {2.5 } } -( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } ···(b) p= { (D-60) t^0.75-16.9965} over {0.2186 t^0.75 +263.55434 }····(c)

  • PDF

Antitumor Effect Of Bismuth-conjugated Anti-IL-2R Monoclonal Antibody(2E4) on a IL-2 Receptor Positive Tumor EL4J3.4

  • Kim, Sung-Hoon;Robert-W. Kozak;Chung, Kyeong-Soo;Ahn, Byung-Zun
    • Archives of Pharmacal Research
    • /
    • 제17권3호
    • /
    • pp.194-198
    • /
    • 1994
  • The antitumor effects of the 2E4 and anti--Tac, monoclonal antibodies directed to Il-2 receptor (IL-2R) conjugated with .alpha.-particle emitting radionuclide bismuth-212., were compared. The $^{212}Bi-2E4$ demonstratedspecific cytotocicity to EL4J3, 4, a I$L-2R^+$ cell line, than to EL4J, a $IL-2R^-$ cell line in thymidine incorporation assy. TEX>$^{212}Bi-2E4$ exerted the maximal antitumor effect in that % T/C in C57BL/6 mice implanted with EL4J3.4 ascitic tumor was 331% at the concentration of $50{\;}{\mu}Ci$, while that of $^{212}Bi-anti-Tac$ was 258% at $100{\;}{\mu}Ci$.

  • PDF

Musculoskeletal Health of the Adults Over 50 Years of Age in Relation to Antioxidant Vitamin Intakes

  • Namhee Kim;Yeji Kang;Yong Jun Choi;Yunhwan Lee;Seok Jun Park;Hyoung Su Park;Miyoung Kwon;Yoon-Sok Chung;Yoo Kyoung Park
    • Clinical Nutrition Research
    • /
    • 제11권2호
    • /
    • pp.84-97
    • /
    • 2022
  • As the proportion of the elderly population increases rapidly, interest in musculoskeletal health is also emerging. Here, we investigated how antioxidant vitamin intake and musculoskeletal health are related. Adults aged 50 to 80 years with a body mass index (BMI) of 18.5 to 27.0 kg/m2 were included. Bone mineral density (BMD), lean mass (LM), appendicular skeletal muscle mass index (ASMI) were measured using dual-energy X-ray absorptiometry (DXA), and the grip strength and knee extension using hand dynamometer. Nutrient intakes were measured using a 24-hour recall questionnaire. A total of 153 adults (44 men and 109 women) participated in this study. A partial correlation analysis showed a significant positive relationship between vitamin E and BMD and between vitamin C and LM/Height. Participants were classified into three groups according to whether their vitamin E and C intake met the recommended intake for Dietary Reference Intakes for Koreans (KDRIs). The prevalence of having low T-score (< -1.0) and low ASMI (< 7.0 for men and < 5.4 for women) was 51.3% and 15.4% in the group with vitamins C and E intakes below KDRIs. After adjusting for sex, smoking status and energy, protein, vitamin D, and calcium intake, the group with vitamins C and E both below the KDRIs displayed a significantly lower BMD at all test sites and LM/Height compared with vitamin C and/or E intake above the KDRIs groups. We conclude that sufficient intake of vitamin E and C is important for maintaining BMD and lean mass in Korean adults over 50 years of age.

Willemite 분말의 저온합성 (Low Temperature Synthesis of Willemite Powder)

  • 손세구;이지현;이정미;김영도
    • 한국세라믹학회지
    • /
    • 제45권7호
    • /
    • pp.401-404
    • /
    • 2008
  • Willemite ($Zn_2SiO_4$) are a wide range of applications such as a phosphor host and an important crystalline phase in glass ceramics, electrical insulators, glazes, and pigments. In this study, Willemite precursors were synthesized with zinc silicate gels from mixture of zinc nitrate solution and various sodium silicate solution by the geopolymer technique. To examine the crystallization behavior, precursors were have been monitored by the XRD. A pure willemite phase was obtained at $900^{\circ}C$. TEM investigations revealed that the sample with 50 nm particle size was obtained via heat-treated at $900^{\circ}C$ for W-3.

Functional characterization of naturally-occurring constitutively activating/inactivating mutations in equine follicle-stimulating hormone receptor

  • Byambaragchaa, Munkhzaya;Ahn, Tae-Young;Choi, Seung-Hee;Kang, Myung-Hwa;Min, Kwan-Sik
    • Animal Bioscience
    • /
    • 제35권3호
    • /
    • pp.399-409
    • /
    • 2022
  • Objective: Follicle-stimulating hormone (FSH) is the central hormone involved in mammalian reproduction, maturation at puberty, and gamete production that mediates its function by control of follicle growth and function. The present study investigated the mutations involved in the regulation of FSH receptor (FSHR) activation. Methods: We analyzed seven naturally-occurring mutations that were previously reported in human FSHR (hFSHR), in the context of equine FSHR (eFSHR); these include one constitutively activation variant, one allelic variant, and five inactivating variants. These mutations were introduced into wild-type eFSHR (eFSHR-wt) sequence to generate mutants that were designated as eFSHR-D566G, -A306T, -A189V, -N191I, -R572C, -A574V, and -R633H. Mutants were transfected into PathHunter EA-parental CHO-K1 cells expressing β-arrestin. The biological function of mutants was analyzed by quantitating cAMP accumulation in cells incubated with increasing concentrations of FSH. Results: Cells expressing eFSHR-D566G exhibited an 8.6-fold increase in basal cAMP response, as compared to that in eFSHR-wt. The allelic variation mutant eFSHR-A306T was not found to affect the basal cAMP response or half maximal effective concentration (EC50) levels. On the other hand, eFSHR-D566G and eFSHR-A306T displayed a 1.5- and 1.4-fold increase in the maximal response, respectively. Signal transduction was found to be completely impaired in case of the inactivating mutants eFSHR-A189V, -R572C, and -A574V. When compared with eFSHR-wt, eFSHR-N191I displayed a 5.4-fold decrease in the EC50 levels (3,910 ng/mL) and a 2.3-fold decrease in the maximal response. In contrast, cells expressing eFSHR-R633H displayed in a similar manner to that of the cells expressing the eFSHR-wt on signal transduction and maximal response. Conclusion: The activating mutant eFSHR-D566G greatly enhanced the signal transduction in response to FSH, in the absence of agonist treatment. We suggest that the state of activation of the eFSHR can modulate its basal cAMP accumulation.

ASTM E681-04 표준에 따른 가연성 냉매의 희박가연한계 (Lower Flammability Limits of Flammable Refrigerants According to ASTM E681-04 Standard)

  • 박기정;우승규;정동수
    • 설비공학논문집
    • /
    • 제19권10호
    • /
    • pp.726-734
    • /
    • 2007
  • In this study, lower flammability limits (LFLs) of three hydrocarbon refrigerants (R600a, R290, R1270) and two hydrofluorocarbon refrigerants (R152a, R32) and DME (RE170) are measured by the method proposed by ASTM E681-04 Standard. Flammability tests are carried out at three temperatures of $23^{\circ}C,\;60^{\circ}C\;and\;100^{\circ}C$ and relative humidity 50%. Test results show that the present data for isobutane and propane obtained at $23^{\circ}C$ are similar to those found in the literature, confirming indirectly the reliability of the present test method and facility. For propylene, R152a, and R32, LFLs found in the literature differ considerably. Especially, the deviation of LFL of propylene is more than 30% among the literature data. The present data for propylene, R152a, and R32 agree with either of the data sets available. As the temperature increases from $23^{\circ}C\;to\;100^{\circ}C$, LFLs of all refrigerants tested decrease. LFLs of most refrigerants tested in this study at $60^{\circ}C$ decrease by $0.1{\sim}0.3%$ as compared to those at $23^{\circ}C$. Also LFLs of most refrigerants tested in this study at $100^{\circ}C$ decrease by $0.1{\sim}0.3%$ as compared to those at $60^{\circ}C$.

백출의 멜라닌 생성 억제 물질 (Inhibitors of Melanogenesis from Atractylodes rhizomes)

  • 정민환;문철순;임영희;강상진;조완구;김청택
    • 생약학회지
    • /
    • 제36권1호통권140호
    • /
    • pp.60-63
    • /
    • 2005
  • One sesquiterpenoid was isolated from the methanol extract of Atractylodes rhizomes which has been used as traditional medicine for diuresis and the compound was established as selina-4(14),7(11)-dien-8-one by the spectroscopic methods. The compound$(IC_{50}<10\;ppm)$ has inhibitory effects on melanogenesis in B16 mouse melanoma.