• 제목/요약/키워드: ${\Delta}C_p$

검색결과 805건 처리시간 0.034초

Enzymatic Characteristics of steroid $\Delta^1$-dehydrogenase from Arthrobacter simplex

  • Lee, Mi-Kyung;Bae, Moo
    • Journal of Microbiology and Biotechnology
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    • 제4권2호
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    • pp.119-125
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    • 1994
  • Steroid $\Delta^1$-dehydrogenase purified from hydrocortisone-induced cells of Arthrobacter simplex converted various 3-ketosteroids into their corresponding $\Delta^1$-dehydrogenated products. The transformation efficiencies depend upon the chemical structure of the steroids, especially length of the side chain at 17 position and hydroxyl groups at 11 and 17 positions. The Km values for androstenedione, the most favorable substrate examined, and hydrocortisone were 74 ${\mu}M$ and 294 ${\mu}M$, respectively. The optimum temperature and pH of the enzyme reaction were 35$^{\circ}C$ and pH 9, respectively, and the enzyme was relatively stable at the range from 20 to 35$^{\circ}C$ and from pH 5 to 10 after one hour of incubation. The enzyme activity was markedly inhibited in the presence of $Cu^{2+},\;Fe^{3+},\;Hg^{2+},\;Mo^{6+}$ ions, and somewhat inhibited by $Zn^{2+}$ and $Fe^{2+}$. $\alpha,\alpha'$-Dipyridyl that inhibits 9$\alpha$-hydroxylase and accumulates 1,4-androstadiene-3,17-dione from sterols revealed no inhibitory effect on this enzyme. EGTA showed inhibitory effect. $\beta$-Estradiol competitively inhibited the enzyme activity. Chemical modifications of the enzyme were attempted with several reagents. p-Hydroxymer-curibenzoate showed inhibition of the enzyme activity and protection of the substrate. This suggests that cysteine residue may be involved in the active site of the enzyme.

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a-Si:H TFT의 누설전류 및 문턱전압 특성 연구 (Leakage Current and Threshold Voltage Characteristics of a-Si:H TFT Depending on Process Conditions)

  • 양기정;윤도영
    • Korean Chemical Engineering Research
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    • 제48권6호
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    • pp.737-740
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    • 2010
  • 높은 누설 전류와 문턱 전압의 이동은 비정질 실리콘(a-Si:H) 트랜지스터(TFT)의 단점이다. 이러한 특성은 게이트 절연체와 활성층 박막의 막 특성, 표면 거칠기와 공정 조건에 따라 영향을 받는다. 본 연구의 목적은 누설 전류와 문턱 전압의 특성을 개선하는데 목적이 있다. 게이트 절연체의 공정 조건에 대해서는 질소를 증가한 증착 공정 조건을 적용하였고, 활성층의 공정 조건에 대해서는 산소를 증가한 공정 조건을 적용하여 전자 포획을 감소시키고 박막의 밀도를 증가시켰다. $I_{off}$$65^{\circ}C$ 조건하에서 1.01 pA에서 0.18pA로, ${\Delta}V_{th}$는 -1.89 V에서 -1.22V로 개선되었다.

저체온 체외순환시 혈액가스분석의 판독과 체온과의 상관관계 (Interpretation of Blood Gas Analysis During Hypothermic Cardiopulmonary Bypass)

  • 송선옥
    • Journal of Yeungnam Medical Science
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    • 제6권1호
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    • pp.121-131
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    • 1989
  • 건강한 성인 83명을 무작위로 선정하여 실시한 신경전도속도 검사에서 다음과 같은 결과를 얻었다. 1) 상지의 정중신경에서는 운동신경의 TL이 3.0-4.2msec 이고, MNCV는 각각 52.1-70.3m/sec(W-E), 44.6-71.0m/sec(E-Ax), 56.6-70.8m/sec(W-E), 50.5-75.1m/sec(E-Ax)이며, CNAP의 진폭은 $6.5-46.1{\mu}V$였다. 2) 척골신경에서는 운동신경의 TL이 2.4-3.4msec이고, MNCV는 각각 54.6-72.8m/sec(W-E), 41.1-64.9m/sec(E-Ax)1987년 3월부터 동년 12월까지 영남대학교 의과대학 부속병원에서 시행된 개심술마취 40례를 대상으로 저체온 체외순환시 저체온상태의 동맥혈과 정맥혈을 동시에 각각 채혈하여 $37^{\circ}C$ 혈액가스분석기로 측정한 비보정치와 환자의 실제 저체온으로 보정한 보정치를 각각 얻어 이를 비교하여 보았던 바 보정치가 비보정치에 비하여 pH는 높았고 이산화탄소분압과 산소분압은 낮았으며 $HCO_{3^-}$, 염기과잉, 이산화탄소분압 및 산소포화도는 온도보정에 영향을 받지 않았다. 이상의 결과로 미루어 보아 저체온상태의 혈액가스분석시 pH와 이산화탄소분압에 대한 온도보정의 영향은 크며, 저온상태에서의 pH 중심점이동과 산염기가 환자상태에 미치는 영향을 고려한다면 환자실제 저체온으로의 온도보정은 필요치 않을 것 같으며 오히려 $37^{\circ}C$ 비보정치로 판독하여 환자상태를 판정하는 것이 임상적으로는 더 타당한 방법이라 사료된다.

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소풍순기원(疏風順氣元)이 mouse의 NMu2Li 간세포와 C2C12 골격근세포에서 PPARs 조절의 분자기전에 미치는 영향 (A Molecular Study of Sopungsungi-won(Shufengshunqiyuan) about Regulation of PPARs in Mouse NMu2Li Liver Cells and C2C12 Skeletal Muscle Myogenic Progenital Cells)

  • 오영진;신순식;윤미정;김보경
    • 동의신경정신과학회지
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    • 제20권1호
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    • pp.147-164
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    • 2009
  • Objectives : We investigated the effects of Sopungsungi-won(Shu!engshunqiyuan) (SSEx1, SSEx2) to treat the metabolic syndrome by the molecular mechanism of regulation of PPAR and modulation of mitochondrial MCAD, VLCAD mRNA expression. Methods : Mouse NMu2Li liver cells and C2C12 skeletal muscle myogenic progenital cells were transiently transfected with expression plasmids for PPAR(PPAR${\alpha}$, PPAR${\delta}$), a luciferase reporter gene construct containing 3 copies of the PPRE from the rat acyl-CoA oxidase gene and ${\beta}$-galactosidase gene. Cells were treated with several concentrated kinds of SSEx1, SSEx2 at the initial time of culture and analyzed PPAR${\alpha}$, PPAR${\delta}$ reporter gene activity using spectrophotometer (405 nm). Total RNA was extracted from SSEx1, SSEx2 and measured mRNA levels of mitochondrial MCAD, VLCAD. Representative RT-PCR bands are shown. Results : 1. SSEx1 increased the expression of PPAR${\alpha}$ reporter gene activities at 0.1 ${\mu}$g/ml (p${\mu}$g/ml (p<0.05), SSEx2 at 0.1 ${\mu}$g/ml (p${\mu}$g/ml (p<0.05) significantly in NMu2Li liver cell lines. 2. SSEx1 increased the expression of PPAR${\alpha}$ reporter gene activities at 1 ${\mu}$g/ml (p${\mu}$g/ml (p${\alpha}$ reporter gene activities in C2C12 skeletal muscle cells. 4. SSEx1 increased the modulation of mitochondrial MCAD mRNA expression (p<0.05) significantly in NMu2Li liver cell lines. 5. SSEx1, SSEx2 both increased the modulation of mitochondrial MCAD mRNA expression (p<0.05) significantly in C2C12 skeletal muscle cells. Conclusions : These results show the SSEx1, SSEx2 can be used as therapeutic agent for metabolic syndrome and it's molecular mechanisms of PPAR more contribute to the activation of PPAR${\alpha}$ then PPAR${\delta}$ reporter gene activities and it's total RNA more contribute to the modulation of mitochondrial MCAD then VLCAD mRNA expression.

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순수 티타늄 판재의 피로균열 전파거동에 관한 연구 (A Study on Fatigue Crack Propagation Behavior with Pure-Ti Plate)

  • 오세욱;김태형;김득진;임만배
    • 한국해양공학회지
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    • 제9권1호
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    • pp.92-100
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    • 1995
  • The effect of different anisotropy and stress ratio on fatigue crack propagation behavior was investigated under various stress ratio(R=-0.4, -0.2, 0.2, 0.2, 0.4) using pure titanium sheet used in aerospace, chemical and food industry. The rack closure behavior under constant load amplitude fatigue crack propagation test was examined. Fatigue crack propagation rate da/dN was estimated in terms of effective stress intensity factor range, $\Delta$K$_{eff}$, regardless of various stress ratio but was influenced by anisotropy. Also, it was found that the effect of anisotropy was considerably decreased but still not negligible when he da/dN was evaluated by a conventional parameter, $\Delta$$K_{eff}$/E and when the modified da/dN.$\sqrt{\varepsilon}_f$ was evaluated by $\Delta$$K_{eff}$/E. On the other hand, da/dN could be evaluated uniquely by effective new parameter, $\Delta$K$_{eff}$/$sigma_{ys}$, regardless of anisotropy, as int he following equation da/dN=C''[\frac{{\Delta}K_{eff}}{{\sigma}_{ys}}]^{n''}. And effective stress intensity factor range ratio, U was estimated by the following equation with respect to the ratio of reversed plastic zone size, $\Delta r_{p}$ to monotonic plastic zone size, $r_p$ regardless of stress ratio and anisotropy. U=-4.45$(\Delta r_{p}/r_{p})^{2}$+4.1$(\Delta r_{p}/r_{p})$+0.245_{p})$+0.245

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Some Difference Paranormed Sequence Spaces over n-normed Spaces Defined by a Musielak-Orlicz Function

  • Raj, Kuldip;Sharma, Sunil K.;Gupta, Amit
    • Kyungpook Mathematical Journal
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    • 제54권1호
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    • pp.73-86
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    • 2014
  • In the present paper we introduce difference paranormed sequence spaces $c_0(\mathcal{M},{\Delta}^n_m,p,u,{\parallel}{\cdot},{\cdots},{\cdot}{\parallel})$, $c(\mathcal{M},{\Delta}^n_m,p,u,{\parallel}{\cdot},{\cdots},{\cdot}{\parallel})$ and $l_{\infty}(\mathcal{M},{\Delta}^n_m,p,u,{\parallel}{\cdot},{\cdots},{\cdot}{\parallel})$ defined by a Musielak-Orlicz function $\mathcal{M}$ = $(M_k)$ over n-normed spaces. We also study some topological properties and some inclusion relations between these spaces.

BIHARMONIC-KIRCHHOFF TYPE EQUATION INVOLVING CRITICAL SOBOLEV EXPONENT WITH SINGULAR TERM

  • Tahri, Kamel;Yazid, Fares
    • 대한수학회논문집
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    • 제36권2호
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    • pp.247-256
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    • 2021
  • Using variational methods, we show the existence of a unique weak solution of the following singular biharmonic problems of Kirchhoff type involving critical Sobolev exponent: $$(\mathcal{P}_{\lambda})\;\{\begin{array}{lll}{\Delta}^2u-(a{\int}_{\Omega}{\mid}{\nabla}u{\mid}^2dx+b){\Delta}u+cu=f(x){\mid}u{\mid}^{-{\gamma}}-{\lambda}{\mid}u{\mid}^{p-2}u&&\text{ in }{\Omega},\\{\Delta}u=u=0&&\text{ on }{\partial}{\Omega},\end{array}$$ where Ω is a smooth bounded domain of ℝn (n ≥ 5), ∆2 is the biharmonic operator, and ∇u denotes the spatial gradient of u and 0 < γ < 1, λ > 0, 0 < p ≤ 2# and a, b, c are three positive constants with a + b > 0 and f belongs to a given Lebesgue space.

TENS와 SSP가 전류지각역치 및 통증역치에 미치는 효과 (The Effect of Current Perception Threshold and Pain Threshold through Transcutaneous Electrical Nerve Stimulation and Silver Spike Point Therapy)

  • 윤미정;이완희
    • The Journal of Korean Physical Therapy
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    • 제23권2호
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    • pp.53-59
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    • 2011
  • Purpose: This study was designed to compare the effects of transcutaneous electrical nerve stimulation (TENS) and silver spike point (SSP) therapy on current perception threshold (CPT) and mechanical pain threshold (MPT). Methods: Forty-five healthy adult male and female subjects were studied. Fourteen of them were males and twenty-one were females. Subject were randomly assigned to receive; (1) TENS (80/120 Hz alternating frequency), (2) SSP (3 Hz), or (3) no treatment (control group). Electric stimulation was applied over LI4 and LI11 on acupuncture points of the left forearm for 30 minutes. CPT and MPT were recorded before and after electrical stimulation. The data were analyzed using linear mixed models, with group treated as a between subject factor and time a within-subject factor. Results: At 30 minutes after cessation of electrical stimulation the CPT of C fibers and A${\delta}$fibers was reduced in the TENS group that of C fibers was reduced in the SSP group (p<0.05). After cessation of electrical stimulation, the MPT of C fibers and A${\delta}$fibers increased in the TENS group, and that of A${\delta}$fibers increased in the SSP group (p<0.05). Conclusion: After TENS and SSP stimulation, MPT of C fibers and A${\delta}$fibers were selectively increased. In particular, the TENS group showed increases in both C and A${\delta}$fibers, while the SSP group showed increases only in A${\delta}$fibers.

The Effect of Pressure on the Solvolysis of Benzylchlorides(Ⅰ). p-Methylbenzyl Chloride in Ethanol-Water Mixtures

  • Kwun, Oh-Cheun;Kyong, Jin-Burm
    • Bulletin of the Korean Chemical Society
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    • 제6권5호
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    • pp.259-263
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    • 1985
  • Rate Constants for the solvolysis of p-methylbenzyl chloride in various ethanol-water mixtures were studied at 30 and $40^{\circ}C$ under various pressures up to 1600 bar. The rates of reaction were increased with increasing temperature and pressure, and decreased with increasing solvent composition of ethanol mole fraction. From the rate constants, the values of the activation parameters (${\Delta}V^{\neq},{\Delta}{\beta}^{\neq},{\Delta}H^{\neq}\;and\;{\Delta}S^{\neq}$) were evaluated. The values of ${\Delta}V^{\neq}\;and\;{\Delta}{\beta}^{\neq}$ exhibit the extremum behavior at about 0.30 mole fraction of ethanol. This behavior is discussed in terms of solvent structure variation (electrostriction). From the relation between the reaction rate and the dielectric constant of solvent or the number of water molecule participated in the transition state, it could be postulated that the reaction proceeds through $S_N1$ mechanism.

δ-Catenin Increases the Stability of EGFR by Decreasing c-Cbl Interaction and Enhances EGFR/Erk1/2 Signaling in Prostate Cancer

  • Shrestha, Nensi;Shrestha, Hridaya;Ryu, Taeyong;Kim, Hangun;Simkhada, Shishli;Cho, Young-Chang;Park, So-Yeon;Cho, Sayeon;Lee, Kwang-Youl;Lee, Jae-Hyuk;Kim, Kwonseop
    • Molecules and Cells
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    • 제41권4호
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    • pp.320-330
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    • 2018
  • ${\delta}$-Catenin, a member of the p120-catenin subfamily of armadillo proteins, reportedly increases during the late stage of prostate cancer. Our previous study demonstrates that ${\delta}$-catenin increases the stability of EGFR in prostate cancer cell lines. However, the molecular mechanism behind ${\delta}$-catenin-mediated enhanced stability of EGFR was not explored. In this study, we hypothesized that ${\delta}$-catenin enhances the protein stability of EGFR by inhibiting its lysosomal degradation that is mediated by c-casitas b-lineage lymphoma (c-Cbl), a RING domain E3 ligase. c-Cbl monoubiquitinates EGFR and thus facilitates its internalization, followed by lysosomal degradation. We observed that ${\delta}$-catenin plays a key role in EGFR stability and downstream signaling. ${\delta}$-Catenin competes with c-Cbl for EGFR binding, which results in a reduction of binding between c-Cbl and EGFR and thus decreases the ubiquitination of EGFR. This in turn increases the expression of membrane bound EGFR and enhances EGFR/Erk1/2 signaling. Our findings add a new perspective on the role of ${\delta}$-catenin in enhancing EGFR/Erk1/2 signaling-mediated prostate cancer.