• Title/Summary/Keyword: Depletion effect

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Mechanisms of Contraction Induced by Sodium Depletion in the Rabbit Renal Artery

  • Kim, Se-Hoon;Chang, Seok-Jong
    • The Korean Journal of Physiology
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    • v.25 no.2
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    • pp.159-170
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    • 1991
  • In the rabbit renal artery, mechanisms of contraction by sodium depletion were investigated. The helical strips of isolated renal artery were immersed in the Tris-buffered salt solution. The contractions were recorded isometrically using a strain-gauge transducer. Na-free solution (Na was substituted by Li, choline or sucrose) produced contractions which were dependent on the nature of the Na substitutes. Na-free solution (choline) produced the contraction in ouabain-pretreated artery (Na loaded artery) even in the presence of verapamil. The amplitude of the contraction was dependent on the duration of the pretreatment with ouabain $(10\;^5M)$. Monensin potentiated the effect of ouabain on the contraction. Removal of Ca from bathing solution abolished the contraction and the substitution of Sr for Ca produced the contraction. Divalent cations such as Mg, Mn blocked the depolarization-induced contraction, while they had little effect on the Na-free contraction in Na loaded artery. These results suggest that the contraction induced by Na removal is dependent on the cellular Na content and may be caused by Ca influx via the Na-Ca exchange carrier.

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The analysis of students' ideas about the greenhouse effect (온실효과에 대한 학생들의 개념 분석)

  • Je, Kwi-Youn;An, Hui-Soo
    • Journal of The Korean Association For Science Education
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    • v.19 no.4
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    • pp.585-594
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    • 1999
  • The purpose of this study is to examine the concept of Greenhouse Effect as understood by middle school high school university students using a closed-form questionnaire. Based on results of the questionnaire which was administered to 619, the extent to which alternative concepts were held was quantified and compared the difference of various group based on grade level. gender, text and major. Also, subjects were divided into two groups, one is middle school students and the other is high school university students and common themes within conceptual framework of each group were identified by factor analysis. The result showed that students confused Greenhouse Effect with ozone layer depletion in stratosphere and linked familiar contamination around everyday life. acid rain. radioactive contamination, nuclear arsenal to Greenhouse Effect. These trends were more appreciable in female than male, biology major than any other major and text did not make any significant difference. In addition, the result of factor analysis showed that two groups linked familiar contamination around everyday life to Greenhouse Effect and high school university students understand the consequences of an increase in the Greenhouse Effect more systematically than middle school student, perceived the relation between the origin of an increase in the Greenhouse Effect and human activity but confused Greenhouse Effect with ozone layer depletion in stratosphere.

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Spatial Assessment of Effects of Near-Stream Groundwater Pumping on Streamflow Depletion (하천변 지하수 양수로 인한 하천수 감소 영향의 공간적 평가 - 죽산천 유역을 중심으로 -)

  • Lee, Jeongwoo;Kim, Nam Won;Chung, Il Moon;Lee, Min Ho
    • Journal of Korea Water Resources Association
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    • v.48 no.7
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    • pp.545-552
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    • 2015
  • The objective of this study is to spatially assess the streamflow depletion due to groundwater pumping near the main stream of Juksanchoen watershed. The surface water and groundwater integrated model, SWAT-MODFLOW, in this study, was used to simulate streamflow responses to each groundwater pumping from wells located within 500m from the stream. The simulated results showed that the streamflow depletion rate divided by the pumping rate for each well location ranges from 20% to 96%. In particular, the streamflow depletion exceeds 60% of pumping rate if the distance between stream and well is lower than 100 m, hydraulic diffusivity is higher than $500m^2/d$, and streambed hydraulic conductance is above 25m/d. The simulated results were also presented in the form of spatial distribution maps that indicate the fraction of the well pumping rate in order to show the effect of a single well more comprehensively and easily. From the developed areal distribution of stream depletion, higher and more rapid responses to pumping occur near middle-downstream reach, and the spatially averaged percent depletion is about 66.7% for five years of pumping. The streamflow depletion map can provide objective information for the near-stream groundwater permission and management.

Depletion of Nitrite by Lactic Acid Bacteria Isolated from Kimchi(II) (김치에서 분리한 유산균에 의한 아질산염 소모(II))

  • 오창경;오명철;현재석;최우정;이신호;김수현
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.4
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    • pp.556-562
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    • 1997
  • Depletion of nitrite by lactic acid bacteria isolated from Kimchi and the effects of pH and temperature on depletion of nitrite in Lactobacillus MRS broth were investigated. Depletion of nitrite by Lactobacillus plantarum and Lactobacillus sake was low in initial stage of growth but increased during growth at 15 and 2$0^{\circ}C$. L. plantarum and L. sake depleted than 90 and 75% of nitrite(250$\mu\textrm{g}$/$m\ell$) in 1 day of growth at 25 and 3$0^{\circ}C$, respectively, but depleted almost all of nitrite in 2 days. While the effect of Leuconostoc mesenteroides (150$\mu\textrm{g}$/$m\ell$) was lower compared to Lactobacillus(250$\mu\textrm{g}$/$m\ell$). In addition, even high concentrations(600 and 900 $\mu\textrm{g}$/$m\ell$) of nitrite was depleted at 2 days of growth by L. plantarum. pH of growing broth decreased as the increase of growth time and temperature, and depletion of nitrite in- creased as the decrease of pH of growing culture. However, pH of broth related with the decrease of depletion of nitrite at 25 and 3$0^{\circ}C$, but not at 15 and 2$0^{\circ}C$. Therefore, depletion of nitrite was greatly affected by growth temperature rather than by pH.

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Effect of Polyamine Biosynthesis InhibItion on the Microbicidai and Jumoriddal Activities in Mouse Macrophage (생쥐 대식세포의 감염균 치사활성과 종양 치사활성에 미치는 Polyamine 생합성 억제의 영향)

  • 이준백;정노팔
    • The Korean Journal of Zoology
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    • v.34 no.2
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    • pp.173-180
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    • 1991
  • The objective of this experiment was to examine the effect of polyamine depletion by polyamine biosynthesis inhibitors on microbicidal activity and tumoricidal activity in mouse mac-rophages. $\alpha$ -Difluoromethylomithine (DFMO), inhibitor of putrescine and spernidine biosynthesis, treatment in vivo for 6-8 days reduced chemiluminescence levels in thioglycollate-, lipo-polysaccharide (LPS), and BCG-treated mouse macrophages. An DFMO treatment in vitro inhibited production of tumor necrosis factor (TNF), in dose-dependent manner, and tumoricidal activity by macrophages. The effect of polyamine depletion by MO on ThF production and tumoricidal activity could be reversed by the addition of exogenous putrescine. These result indicated that the obserbed effect of DFMO on macrophage activities were mediated through inhibition of polyamines are, must be, required for optimal activities of macrophages.

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Effects of workplace bullying on turnover intentions - Mediated effects of emotional depletion moderate by organizational Justice (직장 내 괴롭힘이 이직 의도에 미치는 영향 - 조직 공정성이 조절하는 정서적 고갈의 매개 효과)

  • Jeong, Hae Suk;Kim, hyun;Hyeon, byung Hwan
    • Journal of Digital Convergence
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    • v.19 no.10
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    • pp.209-220
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    • 2021
  • This study sought to examine the impact relationship of the mediated effects of organizational justice on the effects of workplace bullying on turnover intentions. The research hypothesis was verified using SPSS 24 and smartPLS 3 by analyzing 400 surveys of small and medium enterprise workers. Studies have shown that increasing bullying in the workplace also increases emotional depletion and turnover intentions. Emotional depletion has been shown to significantly mediate the impact relationship between workplace bullying and turnover intentions, and organizational justice has laid a theoretical foundation for significantly moderating the impact relationship between workplace bullying and emotional depletion. Therefore, it presented practical implications to increase competitiveness through the well-being and growth of individuals and businesses by increasing respect and sensitivity for workers through compulsory bullying prevention education and various programs. Future research requires research using various variables to prevent bullying.

The function of zinc in the primary vascular smooth muscle cell proliferation in rats (아연의 1차혈관평활근세포 증식에 대한 기능)

  • Cho, Young-Eun;Kwun, In-Sook
    • Journal of Nutrition and Health
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    • v.53 no.6
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    • pp.563-569
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    • 2020
  • Purpose: The vascular smooth muscle cells (VSMCs) in mature animals have implicated to play a major role in the progression of cardiovascular diseases such as atherosclerosis. This study aimed at optimizing the protocol in culturing primary VSMCs (pVSMCs) from rat thoracic aorta and investigating the effect of cellular zinc (Zn) deficiency on cell proliferation of the isolated pVSMCs. Methods: The thoracic aorta from 7-month-old Sprague Dawley rats was isolated, minced and digested by the enzymatic process of collagenase I and elastase, and then inoculated with the culture Dulbecco Modified Eagle Medium (DMEM) at 37℃ in an incubator. The primary cell culture morphology was observed using phase-contrast microscopy and cellular Zn was depleted using Chelex-100 resin (extracellular zinc depletion only) or 3 µM N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN) (extracellular and intracellular zinc depletion). Western blot analysis was used for the detection of SM22α and calponin as smooth muscle cell marker proteins and von Willebrand factor as endothelial cell marker protein to detect the culture purity. Cell proliferation by Zn depletion (1 day) was measured by MTT assay. Results: A primary culture protocol for pVSMCs from rat thoracic aorta was developed and optimized. Isolated cultures exhibited hill and valley morphology as the major characteristics of pVSMCs and expressed the smooth muscle cell protein markers, SM22α and calponin, while the endothelial marker von Willebrand factor was hardly detected. Zn deprivation for 1 day culture decreased rat primary vascular smooth muscle cell proliferation and this pattern was more prominent under severe Zn depletion (3 µM TPEN), while less prominent under mild Zn depletion (Chelexing). Conclusion: Our results suggest that cellular Zn deprivation decreased pVSMC proliferation and this may be involved in phenotypic modulation of pVSMC in the aorta.

Zero Cerenkov Radiation Angle Effect in Optical Parametric Amplification in the Cerenkov-idler Configuration (Cerenkov-idler configuration 광 매개증폭에서의 0° 체렌코프 복사각도 효과)

  • Suh, Zung-Shik
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.1
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    • pp.225-232
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    • 2014
  • Optical parametric amplification has been analyzed for the Cerenkov-idler configuration in planar waveguides. The coupled-mode theory is employed for the analysis. The coupled-mode equations are derived and the approximate analytic solution is obtained for no pump depletion. From the analytic solution, it is shown that the signal power gain can be enhanced as the Cerenkov radiation angle of the idler approaches to zero. The numerical example is also shown for the effect of the Cerenkov radiation angle approaching zero.

Correlation between Capacitance and Structure-optical Properties of Semiconductor with Zero Leakage Current (누설전류 Zero인 반도체 물질의 구조적 광학적 특성과 전도성과의 상관성)

  • Yun, Tae Hwan;Oh, Teresa
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.3
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    • pp.27-31
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    • 2015
  • It was the electrical properties of ZnS treated by the annealing in a vaccum and an atmosphere conditions to reseached the leakage current effect of semiconductor devices. Most samples were shown the non-linear with unipolar properties, but the ZnS annealed at $100^{\circ}C$ in a vaccum was only observed no leakage current in a range of -20 V< voltage < 15 V. The crystallinity of ZnS with no leakage current was improved and optical property was also improved. Because the ambipolar characteristics and low leakage currents originated from the extension effect of a depletion width by electron-hole combination in the depletion layer.