• Journal of Audiology & Otology
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• 제23권4호
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• pp.210-213
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• 2019

The auricle is a three-dimensional cartilaginous frame covered with thin overlying skin. Due to its complex features, reconstructing helical rim defects after the excision of an auricular mass is challenging. Shortage of subcutaneous tissue and the presence of a tightly bound epithelium further hamper the primary closure of lateral (anterior) auricular skin defects. We present herein a case in which we used a helical rim advancement flap along with an additional postauricular skin flap. We achieved a satisfactory esthetic result with minimal loss of helical diameter and a low risk of flap necrosis by preserving the vascular network of the flap. This technique is less traumatic and will facilitate faster healing as well as improved patient recovery.

• Molecules and Cells
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• 제38권8호
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• pp.685-696
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• 2015

Rice is a model plant widely used for basic and applied research programs. Plant cell wall proteins play key roles in a broad range of biological processes. However, presently, knowledge on the rice cell wall proteome is rudimentary in nature. In the present study, the tightly-bound cell wall proteome of rice callus cultured cells using sequential extraction protocols was developed using mass spectrometry and bioinformatics methods, leading to the identification of 1568 candidate proteins. Based on bioinformatics analyses, 389 classical rice cell wall proteins, possessing a signal peptide, and 334 putative non-classical cell wall proteins, lacking a signal peptide, were identified. By combining previously established rice cell wall protein databases with current data for the classical rice cell wall proteins, a comprehensive rice cell wall proteome, comprised of 496 proteins, was constructed. A comparative analysis of the rice and Arabidopsis cell wall proteomes revealed a high level of homology, suggesting a predominant conservation between monocot and eudicot cell wall proteins. This study importantly increased information on cell wall proteins, which serves for future functional analyses of these identified rice cell wall proteins.

• 한국ITS학회 논문지
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• 제5권3호
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• pp.13-23
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• 2006

UWB(Ultra Wideband)를 이용한 시스템은 텔레메틱스의 주요기술인 무선 엑세스 기술로 Bluetooth와 함께 활발한 연구가 진행되고 있다. 고속 데이터 통신이 가능한 UWB시스템은 시스템의 복잡도가 낮고 저렴한 가격으로 구현이 가능하다는 장점을 가지고 있다. 현재 UWB 이외의 기술에 대한 타이밍 지터의 효과는 많이 분석되었으나, UWB 시스템에서는 아직 타이밍 지터에 대한 많은 연구가 이루어지지 않았다. 따라서 본 논문에서는 Hermite 펄스를 사용하는 M진 UWB 시스템에 대한 타이밍 지터 효과를 이론적으로 분석하고, 성능을 모의실험을 통해 확인하였다. 이론적인 분석을 위해 직교 Hermite 펄스의 상관함수를 closed form으로 유도하였으며, 상관함수를 이용하여 M진 직교 Hermite 펄스 시스템의 심볼 에러 확률을 수학적으로 모델링 하였다. 또한 이 수학적 모델을 이용한 결과를 모의실험과 비교하였을 때 tightly upper bound 임을 확인하였다.

• 한국융합학회논문지
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• 제10권11호
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• pp.71-77
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• 2019

본 연구에서는 다중 선택 배낭 모형의 최적해를 찾는 해법을 제시하고자 한다. 다중 선택은 동일한 집단에 소속된 구성원들이 동시에 선택되거나 동시에 배제되는 상황에서 관찰된다. 각 집단 간 관련성의 측정치인 오목 함수가 의사결정기준으로 설정되었다. 다중 선택은 비선형 제약식으로 모형화 되는데 일반 배낭 제약식으로 변환될 수 있다. 따라서 최적 해법 개발을 위해 오목함수 최소화 문제와 배낭 문제의 일반적인 해법들에서 채택하고 있는 분지 한계 접근법을 이용하였다. 단체상에서 오목함수를 가장 근접하게 하한추정하는 함수가 1차식이라는 사실이 한계 전략의 이론적 토대가 된다. 또한 하위 단계에서도 1차식 목적함수가 유일하게 결정되도록, 후보 단체를 두 개의 초평면에 투사시킴으로써 1차원 낮은 두 개의 하위 단체로 분할하는 방법이 분지 전략의 핵심이다. 앞으로 본 연구의 결과는 다양한 형태의 배낭 제약식 하에서의 오목 함수 최소화 문제의 해법을 개발하는데 응용될 수 있을 것이다.

• Biomolecules & Therapeutics
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• 제29권4호
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• pp.392-398
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• 2021

In this study, we determined the effect of 24 different synthetic 4-benzylpiperidine carboxamides on the reuptake of serotonin, norepinephrine, and dopamine (DA), and characterized their structure-activity relationship. The compounds with a two-carbon linker inhibited DA reuptake with much higher potency than those with a three-carbon linker. Among the aromatic ring substituents, biphenyl and diphenyl groups played a critical role in determining the selectivity of the 4-benzylpiperidine carboxamides toward the serotonin transporter (SERT) and dopamine transporter (DAT), respectively. Compounds with a 2-naphthyl ring were found to exhibit a higher degree of inhibition on the norepinephrine transporter (NET) and SERT than those with a 1-naphthyl ring. A docking simulation using a triple reuptake inhibitor 8k and a serotonin/norepinephrine reuptake inhibitor 7j showed that the regions spanning transmembrane domain (TM)1, TM3, and TM6 form the ligand binding pocket. The compound 8k bound tightly to the binding pocket of all three monoamine reuptake transporters; however, 7j showed poor docking with DAT. Co-expression of DAT with the dopamine D₂ receptor (D₂R) significantly inhibited DA-induced endocytosis of D₂R probably by reuptaking DA into the cells. Pretreatment of the cells with 8f, which is one of the compounds with good inhibitory activity on DAT, blocked DAT-induced inhibition of D₂R endocytosis. In summary, this study identified critical structural features contributing to the selectivity of a molecule for each of the monoamine transporters, critical residues on the compounds that bound to the transporters, and the functional role of a DA reuptake inhibitor in regulating D₂R function.

• Journal of Applied Biological Chemistry
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• 제42권1호
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• pp.19-24
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• 1999

Plants have been shown to contains $Ca^{2+}$/calmodulin-stimulated GAD and NAD kinase. To test how calmodulin and calmodulin methylation affect the activation of GAD and NAD kinase, GAD and NAD kinase were partially purified from tobacco plants. GAD was also partially purified from E. coli transformed with a plasmid carrying a cloned tobacco GAD gene. We find that GAD from the transformed E. coli showed 60-fold $Ca^{2+}$/calmodulin-dependent activation. However, GAD from tobacco plants was stimulated only about 3.8-fold by the addition of calmodulin in the presence of calcium, suggesting high background activity of the enzyme was possibly due to bound endogenous tobacco calmodulin. There were no significant differences in the tobacco GAD activator properties between calmodulins. A monoclonal antibody against petunia GAD interacted strongly with both GAD from tobacco plants and GAD from cloned gene. NAD kinase from tobacco plants showed a complete $Ca^{2+}$/calmodulin dependency for activity. Unmethylated calmodulins activated GAD in a manner similar to methylated calmodulin. However, the maximum level of NAD kinase activation obtained with unmethylated calmodulins is approximately 4-fold higher than methylated calmodutins. These data suggested that endogenous tobacco calmodulin may interact more tightly with GAD than NAD kinase and that calmodulin methylation affects the activator properties of calmodulins for tobacco NAD kinase but not for GAD.

• Journal of Microbiology and Biotechnology
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• 제9권2호
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• pp.206-212
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• 1999

The gene orf7(oxi III) was expressed using an E. coli system in anticipation that it would encode dTDP-glucose 4,6-dehydratase which is involved in the biosynthesis of the olivose moiety of chlorothricin produced from Streptomyces antibioticus Tu99. The solubility of the expressed protein increased up to 20% under optimal induction conditions. The expressed protein was purified from the E. coli BL 21(DE3) cell lysate by a 28.5-fold purification in two chromatography steps with a 38% recovery to near homogeneity. The molecular weight and N-terminal amino acid sequence of the purified protein correlated with the predicted mass and sequence deduced from the orf7 gene. The purified protein was a homodimer with a subunit relative molecular weight of 38,000 Dalton. The expressed protein was found to exhibit dTDP-glucose 4,6-dehydratase activity and be highly specific for dTDP-glucose as a substrate. The values of K'm and V'max for dTDP-glucose were 28 $\mu$M and 295 nmol $min^{-1} (mg protein)^{-1}$, respectively. dTTP and dTDP were strong inhibitors of this enzyme.$NAD^+$, the coenzyme for dTDP-glucose 4,6-dehydratase, was tightly bound to the expressed protein.

• Bulletin of the Korean Chemical Society
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• 제25권5호
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• pp.609-616
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• 2004

Complexation of cesium ion by p-tert-butylcalix[6]arene ethyl ester was studied by NMR spectroscopy in nonpolar $CDCl_3$ and polar acetone-$d_6$ and the results were compared with each other. Analysis of temperature dependent $^1H$ spectra and titration curves reveals that both solvents result in a 1 : 1 cone-form complex with nonpolar $CDCl_3$yielding a more tightly bound one than acetone-$d_6$. Unexpectedly, at very low temperature, we have found that two phenyl ring proton peaks of equal intensity appear both in $CDCl_3$and in acetone-$d_6$ solution which gradually collapse and eventually coalesce into a single line as temperature is raised. This observation could be interpreted in terms of the chemical exchange through direct and/or indirect interconversion between two equivalent conformations possible the complex in both solvents over the temperature range observed. And broadening of $^{133}Cs$ (I = 7/2) nmr line with increasing temperature has also been observed, indicating the exchange of $^{133}Cs$ ion between the complex and the solvent. From numerical fitting of lineshape changes for one-dimensional $^1H$ and $^{133}Cs$ spectra, the exchange rate constants and other relevant parameters for this conformational interconversion and the complex-solvent exchange were deduced.

• Archives of Pharmacal Research
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• 제12권3호
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• pp.186-190
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• 1989

The release rates of methotrexate (MTX) from MTX-human serum albumin (HSA) conjugate, and 5-fluorouracil (5-FU) from 5-FU acetic acid (AA)-HSA conjugate were determined after incubation of the conjugates in various conditions. The concentrations of 5-FU released from the conjugate increased monoexponentially, however those of MTX increased biexponentially in all studies. It indicated that there are two distinct types of MTX-HSA linkage, weakly and tightly bound linkages. The release rates of 5-FU were lower than those of MTX in all studies indicating that the bond of 5-FU-AA-HSA conjugate is very stable, which is supported by the higher value of activation energy (39. 9 vs 10. 7 Kcal/mole) using Arrhenius equation. The release rates of MTX and 5 -FU from the conjugates increased with incubation temperatures. Proteolytic enzyme and liver homogenates accelerated significantly the release rates of MTX and 5-FU. Approximately 1.30 and 22.0% of MTX were released after 12 hours of incubation in the absence and presence of protease, respectively. The corresponding values for 5-FU were released after 12 hours of incubation with rat liver homogenates which were diluted 6 times with phosphate buffer of pH 6.0. The MTX-HSA and 5-FU-AA-HSA conjugates were very stable in rat plasma.

• Journal of Computing Science and Engineering
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• 제7권1호
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• pp.53-66
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• 2013

Bounding the worst-case DRAM performance for a real-time application is a challenging problem that is critical for computing worst-case execution time (WCET), especially for multicore processors, where the DRAM memory is usually shared by all of the cores. Typically, DRAM commands from consecutive DRAM accesses can be pipelined on DRAM devices according to the spatial locality of the data fetched by them. By considering the effect of DRAM command pipelining, we propose a basic approach to bounding the worst-case DRAM performance. An enhanced approach is proposed to reduce the overestimation from the invalid DRAM access sequences by checking the timing order of the co-running applications on a dual-core processor. Compared with the conservative approach, which assumes that no DRAM command pipelining exists, our experimental results show that the basic approach can bound the WCET more tightly, by 15.73% on average. The experimental results also indicate that the enhanced approach can further improve the tightness of WCET by 4.23% on average as compared to the basic approach.