• 제목/요약/키워드: Modification Function

검색결과 695건 처리시간 0.029초

상백피가 개의 신장 기능에 미치는 영향 (Influence of Mori Radicis Cortex on the Renal Function of Dog)

  • 고석태;이은화
    • 약학회지
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    • 제26권4호
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    • pp.197-208
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    • 1982
  • In this study attemps were made to obtain evidence as to the action of Mori Radicis Cortex on the renal' function of anesthetized mongrel dogs. 1. A light brown powder isolated from Mori Radicis Cortex (MRC) by a slight modification of Tanemura's method, when given intravenously in doses ranging 0.5 to 5.0mg/kg, elicited diuresis with the increase of positive water clearance and amounts of $Na^{+}$ and $K^{+}$ excreted in the urine. At this time the glomerular filtration rate, renal plasma flow and osmolar clearance were not observed to have any significant changes. This diuresis was augmented in process of time and its maximum effect was exhibited about 30 minutes after administration of MRC. 2. The MRC, when administered into a intra carotid artery, responded promptly with diuresis and natriuresis at a level too small to effect renal functions when administered intravenously. In this experiment the patterns of changes of renal function were the patterns of changes of renal function were the same as those of the above intravenously administered experiment. 3. When infused directly into a renal artery, the MRC exhibited little effect on either kidney. 4. During water diuresis, the MRC did not elicit diuretic action or significant changes in renal functions. The above observations suggest that the diuresis of MRC is brought about by the inhibition of the release of antidiuretic hormone with the mechanism facilitating the excretion of $Na^{+/}$ and $K^{+}$ in urine.

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점프크기추정량에 의한 수정된 로그잔차를 이용한 불연속 로그분산함수의 추정 (Discontinuous log-variance function estimation with log-residuals adjusted by an estimator of jump size)

  • 홍혜선;허집
    • 응용통계연구
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    • 제30권2호
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    • pp.259-269
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    • 2017
  • 분산함수가 불연속점을 가지는 경우, 대부분의 비모수적 함수 추정 연구에서 분산함수가 음수 값을 갖지 않기에 잔차제곱을 이용한 Nadaraya-Watson 추정량인 국소상수항추정량을 이용하였다. 한편, Huh (2014, 2016a)는 Chen 등 (2009)과 Yu와 Jones (2004)의 연구를 바탕으로 불연속 분산함수를 로그 변환한 로그분산함수를 추정 대상으로 삼아 잔차제곱이나 로그잔차제곱으로 경계점 문제를 가지지 않는 국소선형추정량을 이용하여 비모수적으로 추정하였다. Huh (2016b)는 불연속점에서 점프크기추정량을 활용하여 잔차제곱을 분산함수가 연속인 회귀모형에서 얻어진 잔차제곱인 것처럼 수정한 후 이들을 이용하여 불연속 분산함수의 추정을 연구하였다. 본 연구에서는 불연속 로그분산함수의 점프크기추정량을 이용하여 로그잔차제곱을 수정하고 불연속 로그분산함수를 국소선형추정량을 이용하여 추정하고자 한다. 제안된 추정량의 우수성을 모의실험을 통하여 Chen 등 (2009)의 로그분산함수 추정량을 이용한 Huh (2014)의 불연속 로그분산함수 추정량과 비교하고 실제자료에 적용하고자 한다.

P62 and the Sequestosome, a Novel Mechanism for Protein Metabolism

  • Shin, Jae-Kyoon
    • Archives of Pharmacal Research
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    • 제21권6호
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    • pp.629-633
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    • 1998
  • In addition to selecting proteins for degradation by the 26S proteasome, ubiqitination appears to serve other regulatory functions, including for endosomal/lysosomal targeting, protein translocation, and enzyme modification. Currently, little is known how multiubiquitin chains are recognized by these cellular mechanisms. Within the 26S proteasome, one subunit (Mcb1/S5a) has been identified that has affinity for multiubiquitin chains and may function as a ubiquitin receptor. We recently found that a non-proteasomal protein p62 also preferentially binds multiubiquitin chains and forms a novel cytoplasmic structure "sequestosome" which serves as a storage place for ubiquitinated proteins. In the present manuscript, the role and regulation of p62 in relation to the sequestosomal function will be reviewed.

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Chemistry and Biology of Ras Farnesyltransferase

  • Cho, Kwang-Nym;Lee, Kee-In
    • Archives of Pharmacal Research
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    • 제25권6호
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    • pp.759-769
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    • 2002
  • Mutated forms of ras are found in many human tumors and the rate of incidence is significantly higher in colon and pancreatic cancers. The protein product from the ras oncogene is a small G-protein, $p21^{ras}{\;}(Ras)$ that is known to playa key role in the signal transduction cascade and cell differentiation and proliferation. Mutated Ras is unable to regulate itself and remains constantly activated, leading to uncontrolled cell growth. The function of Ras in signal transduction requires its location near the growth factor receptor at the cell membrane. However, Ras does not have a transmembrane domain. Ras requires farnesylation to increase its hydrophobicity and subsequent plasma membrane association for its transforming activity. This key post-translational modification is catalyzed by the enzyme Ras farnesyltransferase (FTase), which transfers a farnesyl group from farnesylpyrophosphate to the C-terminal cysteine of the Ras protein. The requirement has focused attention on FTase as a target for therapeutic intervention. Selective inhibition of FTase will prevent Ras protein from association with the plasma membrane, leading to a disruption of oncogenic Ras function.

Computational Prediction of Solvation Free Energies of Amino Acids with Genetic Algorithm

  • Park, Jung-Hum;Lee, Jin-Won;Park, Hwang-Seo
    • Bulletin of the Korean Chemical Society
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    • 제31권5호
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    • pp.1247-1251
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    • 2010
  • We propose an improved solvent contact model to estimate the solvation free energies of amino acids from individual atomic contributions. The modification of the solvation model involves the optimization of three kinds of parameters in the solvation free energy function: atomic fragmental volume, maximum atomic occupancy, and atomic solvation parameters. All of these atomic parameters for 17 atom types are developed by the operation of a standard genetic algorithm in such a way to minimize the difference between experimental and calculated solvation free energies. The present solvation model is able to predict the experimental solvation free energies of amino acids with the squared correlation coefficients of 0.94 and 0.93 for the parameterization with Gaussian and screened Coulomb potential as the envelope functions, respectively. This result indicates that the improved solvent contact model with the newly developed atomic parameters would be a useful tool for the estimation of the molecular solvation free energy of a protein in aqueous solution.

Separating VNF and Network Control for Hardware-Acceleration of SDN/NFV Architecture

  • Duan, Tong;Lan, Julong;Hu, Yuxiang;Sun, Penghao
    • ETRI Journal
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    • 제39권4호
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    • pp.525-534
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    • 2017
  • A hardware-acceleration architecture that separates virtual network functions (VNFs) and network control (called HSN) is proposed to solve the mismatch between the simple flow steering requirements and strong packet processing abilities of software-defined networking (SDN) forwarding elements (FEs) in SDN/network function virtualization (NFV) architecture, while improving the efficiency of NFV infrastructure and the performance of network-intensive functions. HSN makes full use of FEs and accelerates VNFs through two mechanisms: (1) separation of traffic steering and packet processing in the FEs; (2) separation of SDN and NFV control in the FEs. Our HSN prototype, built on NetFPGA-10G, demonstrates that the processing performance can be greatly improved with only a small modification of the traditional SDN/NFV architecture.

전자기파 산란을 이용한 Submicron 광학 MASK의 특성 및 최적화 (The characteristics and optimization of submicron optical mask using electromagnetic scattering effect)

  • 최준규;박정보;김유석;이성묵
    • 한국광학회지
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    • 제8권4호
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    • pp.345-352
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    • 1997
  • 최신(4GDRAM)의 MASK design에서는 전자기파의 산란에 의한 효과를 고려해 주는 것이 매우 중요하다. 이를 위하여 시간 영역에서의 요한 차분법을 도입하여 직접 마스크 함수를 계산하였다. 새롭게 도입한 마스크 함수를 사용함으로써 마스크와 렌즈의 효과뿐만 아니라, submicron 노광용 위상 변이 마스크의 식각된 옆벽에서의 산란효과를 정확하게 설명할 수 있었다. 산란효과를 줄이기 위해 변형된 마스크의 형태에 따른 특성을 살펴보았고, dual etch back에 의한 마스크 변형이 가장 좋은 공정 여유도를 제공함을 확인하였다.

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최적화된 관측 신뢰도와 변형된 HMM 디코더를 이용한 잡음에 강인한 화자식별 시스템 (A Robust Speaker Identification Using Optimized Confidence and Modified HMM Decoder)

  • ;김진영;나승유
    • 대한음성학회지:말소리
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    • 제64호
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    • pp.121-135
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    • 2007
  • Speech signal is distorted by channel characteristics or additive noise and then the performances of speaker or speech recognition are severely degraded. To cope with the noise problem, we propose a modified HMM decoder algorithm using SNR-based observation confidence, which was successfully applied for GMM in speaker identification task. The modification is done by weighting observation probabilities with reliability values obtained from SNR. Also, we apply PSO (particle swarm optimization) method to the confidence function for maximizing the speaker identification performance. To evaluate our proposed method, we used the ETRI database for speaker recognition. The experimental results showed that the performance was definitely enhanced with the modified HMM decoder algorithm.

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Regulation of a Novel Guanine Nucleotide Binding Protein Tissue Transglutaminase ($G{\alpha}_n$).

  • Im, Mie-Jae
    • BMB Reports
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    • 제34권2호
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    • pp.95-101
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    • 2001
  • Tissue transglutaminase (TGII, $G{\alpha}h$) belongs to a family of enzymes which catalyze post-translational modification of proteins by forming isopeptides via $Ca^{2+}$-dependent reaction. Although TGII-mediated formation of isopeptides has been implicated to play a role in a variety of cellular processes, the physiological function of TGII remains unclear. In addition to this Tease activity, TGII is a guanosine triphosphatase (GTPase) which binds and hydrolyzes GTP It is now well recognized that the GTPase action of TGII regulates a receptor-mediated transmembrane signaling, functioning as a signal transducer of the receptor. This TGII function signifies that TGII is a new class of GTP-binding regulatory protein (G-protein) that differs from "Classical" heterotrimeric G-proteins. Regulation of enzyme is an important biological process for maintaining cell integrity. This review summarizes the recent development in regulation of TGII that may help for the better understanding of this unique enzyme. Since activation and inactivation of GTPase of TGII are similar to the heterotrimeric G-proteins, the regulation of heterotrimeric G-protein in the transmembrane signaling is also discussed.

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질량변경에 따른 연속계의 동특성변화 예측 (Prediction of Dynamic Characteristics of Continuous Systems Due to the Mass Modification)

  • 이정윤;최상렬;박천권;오재응;정석주
    • 대한기계학회논문집
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    • 제17권2호
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    • pp.248-256
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    • 1993
  • 본 연구에서는 연속계의 진동모드를 구하여 일반질량(generalize mass)을 유 동하였으며 집중, 분포질량 변경에 따른 일반질량 변화량을 산출하여 감도계수를 구하 는 새로운 연속계 감도해석 방법을 제안하였고, 타당성을 검증하기 위해 외팔보, 계단 보에 적용하여 감도계수, 고유진동수, 진동모드, 전달함수의 변화량을 예측하고 이론 치와 비교하였다. Fig.1은 본 연구의 흐름도를 나타낸다.