• 음성과학
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• 제8권3호
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• pp.201-208
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• 2001

The purpose of the study was to examine a method most pertinent to measure subglottic air pressure. Subglottic air pressure and loudness analyses were performed on vowels /a/, /i/ and consonant /p/ in 12 normal subjects using. Aerophone II voice function. The experimental contexts were, therefore, /i:pi:pi:/ and /a:pa:pa:/. The subjects produced the intervocalic /p/ in 4 different situations: 1) /i:pi:pi:/ with voiceless /p/, 2) /i:pi:pi:/ with voiced /p/, 3) /a:pa:pa:/ with voiceless /p/, and 4) /a:pa:pa:/ with voiced /p/. A t-test and a correlation analysis revealed the following results. First, when we measured subglottic air pressure by /i:pi:pi:/, voiceless /p/ was significantly different from voiced /p/. Second, when we measured subglottic air pressure by /a:pa:pa:/, voiceless /p/ was significantly different from voiced /p/. Therefore, it was concluded that voiceless /p/ produced more accurate subglottic air pressure and clinicians needed to have patients produce accurate /p/ when measuring subglottic air pressure using Aerophone II.

• Molecules and Cells
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• 제39권4호
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• pp.322-329
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• 2016

Voltage-gated $Ca^{2+}$ ($Ca_V$) channels are dynamically modulated by Gprotein-coupled receptors (GPCR). The $M_1$ muscarinic receptor stimulation is known to enhance $Ca_V2.3$ channel gating through the activation of protein kinase C (PKC). Here, we found that $M_1$ receptors also inhibit $Ca_V2.3$ currents when the channels are fully activated by PKC. In whole-cell configuration, the application of phorbol 12-myristate 13-acetate (PMA), a PKC activator, potentiated $Ca_V2.3$ currents by ~two-fold. After the PMA-induced potentiation, stimulation of $M_1$ receptors decreased the $Ca_V2.3$ currents by $52{\pm}8%$. We examined whether the depletion of phosphatidylinositol 4,5-bisphosphate ($PI(4,5)P_2$) is responsible for the muscarinic suppression of $Ca_V2.3$ currents by using two methods: the Danio rerio voltage-sensing phosphatase (Dr-VSP) system and the rapamycin-induced translocatable pseudojanin (PJ) system. First, dephosphorylation of $PI(4,5)P_2$ to phosphatidylinositol 4-phosphate (PI(4)P) by Dr-VSP significantly suppressed $Ca_V2.3$ currents, by $53{\pm}3%$. Next, dephosphorylation of both PI(4)P and $PI(4,5)P_2$ to PI by PJ translocation further decreased the current by up to $66{\pm}3%$. The results suggest that $Ca_V2.3$ currents are modulated by the $M_1$ receptor in a dual mode-that is, potentiation through the activation of PKC and suppression by the depletion of membrane $PI(4,5)P_2$. Our results also suggest that there is rapid turnover between PI(4)P and $PI(4,5)P_2$ in the plasma membrane.

• Molecules and Cells
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• 제22권1호
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• pp.97-103
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• 2006

Phosphoinositides are critical regulators of ion channel and transporter activity. There are multiple isomers of biologically active phosphoinositides in the plasma membrane and the different lipid species are non-randomly distributed. However, the mechanism by which cells impose selectivity and directionality on lipid movements and so generate a non-random lipid distribution remains unclear. In the present study we investigated which structural elements of phosphoinositides are responsible for their subcellular location and movement. We incubated phosphatidylinositol (PI), phosphatidylinositol 4-monophosphate (PI(4)P) and phosphatidylinositol 4,5-bisphosphate ($PI(4,5)P_2$) with short or long acyl chains in CHO and HEK cells. We show that phosphate number and acyl chain length determine cellular location and translocation movement. In CHO cells, $PI(4,5)P_2$ with a long acyl chain was released into the cytosol easily because of a low partition coefficient whereas long chain PI was released more slowly because of a high partition coefficient. In HEK cells, the cellular location and translocation movement of PI were similar to those of PI in CHO cells, whereas those of $PI(4,5)P_2$ were different; some mechanism restricted the translocation movement of $PI(4,5)P_2$, and this is in good agreement with the extremely low lateral diffusion of $PI(4,5)P_2$. In contrast to the dependence on the number of phosphates of the phospholipid head group of long acyl chain analogs, short acyl chain phospholipids easily undergo translocation movement regardless of cell type and number of phosphates in the lipid headgroup.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2011년도 추계학술발표회
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• pp.31-45
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• 2011

The amyloid ${\beta}$-peptide ($A{\beta}$), which originates from the proteolytic cleavage of amyloid precursor protein (APP), plays a central role in the pathogenesis of Alzheimer's disease (AD). Mounting evidence indicates that different species of $A{\beta}$, such as $A{\beta}$ oligomers and fibrils, may contribute to AD pathogenesis via distinct mechanisms at different stages of the disease. Importantly, elevation and accumulation of soluble $A{\beta}$ oligomers closely correlate with cognitive decline and/or disease progression in animal models of AD. In agreement with these studies, oligomers of $A{\beta}$ have been shown to directly affect synaptic plasticity, a neuronal process that is known to be essential for memory formation. Our previous studies showed that $A{\beta}$ induces the breakdown of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), a phospholipid that regulates key aspects of neuronal function. PI(4,5)P2 breakdown was found to be a key step toward synaptic and memory dysfunction in a mouse model of AD. To this end, we seek to identify small molecules that could elevate the levels of PI(4,5)P2 and subsequently block $A{\beta}$ oligomer-induced breakdown of PI(4,5)P2 and synaptic dysfunction.. We found that (20S)Rg3, an active triterpene glycoside from heat-processed ginseng, serves as an agonist for phosphatidylinositol 4-kinase IIalpha (PI4KIIalpha), which is a lipid kinase that mediates a rate-limiting step in PI(4,5)P2 synthesis. Consequently, (20S)Rg3 stimulates PI(4,5)P2 synthesis by directly stimulating the activity of PI4KIIalpha. Interestingly, treatment of a mouse model of AD with (20S)Rg3 leads to reversal of memory deficits. Our data suggest that the PI(4,5)P2-promoting effects of (20S)Rg3 may help mitigate the cognitive symptoms associated with AD.

• Korean Journal of Radiology
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• 제22권7호
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• pp.1100-1109
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• 2021

Objective: To compare the diagnostic performance between Prostate Imaging-Reporting and Data System version 2.0 (PI-RADSv2.0) and version 2.1 (PI-RADSv2.1) for clinically significant prostate cancer (csPCa) in the peripheral zone (PZ). Materials and Methods: This retrospective study included 317 patients who underwent multiparametric magnetic resonance imaging and targeted biopsy for PZ lesions. Definition of csPCa was International Society of Urologic Pathology grade ≥ 2 cancer. Area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for csPCa were analyzed by two readers. The cancer detection rate (CDR) for csPCa was investigated according to the PI-RADS categories. Results: AUC of PI-RADSv2.1 (0.856 and 0.858 for reader 1 and 2 respectively) was higher than that of PI-RADSv2.0 (0.795 and 0.747 for reader 1 and 2 respectively) (both p < 0.001). Sensitivity, specificity, PPV, NPV, and accuracy for PI-RADSv2.0 vs. PI-RADSv2.1 were 93.2% vs. 88.3% (p = 0.023), 52.8% vs. 76.6% (p < 0.001), 48.7% vs. 64.5% (p < 0.001), 94.2% vs. 93.2% (p = 0.504), and 65.9% vs. 80.4% (p < 0.001) for reader 1, and 96.1% vs. 92.2% (p = 0.046), 34.1% vs. 72.4% (p < 0.001), 41.3% vs. 61.7% (p < 0.001), 94.8% vs. 95.1% (p = 0.869), and 54.3% vs. 78.9% (p < 0.001) for reader 2, respectively. CDRs of PI-RADS categories 1-2, 3, 4, and 5 for PI-RADSv2.0 vs. PI-RADSv2.1 were 5.9% vs. 5.9%, 5.8% vs. 12.5%, 39.8% vs. 56.2%, and 88.9% vs. 88.9% for reader 1; and 4.5% vs. 4.1%, 6.1% vs. 11.1%, 32.5% vs. 53.4%, and 85.0% vs. 86.8% for reader 2, respectively. Conclusion: Our data demonstrated improved AUC, specificity, PPV, accuracy, and CDRs of category 3 or 4 of PI-RADSv2.1, but decreased sensitivity, compared with PI-RADSv2.0, for csPCa in PZ.

• Applied Biological Chemistry
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• 제34권2호
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• pp.117-124
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• 1991

기주 식물에 대한 인산공급이 근류의 인산 형태와 bacteroid의 인산흡수에 미치는 영향을 살펴보고자 B. japonicum MN 110을 접종한 대두식물을 1.0, 0.25, 0.05 mM-P 조건에서 재배하였다. 1.0, 0.25, 0.05 mM-P 조건에서 재배한 대두식물의 근류 Pi 농도는 각각 4.1, 2.5, 2.0 mM이었으며 인산공급이 근류의 Pi, SOP, lOP의 분포에는 유의성 있는 영향을 미치지 못하였다. 0.25, 0.05 mM-P 조건에서 재배한 대두식물의 유엽 Pi 농도는 대조구(1.0 mM-P)의 각각 33%, 20%이었으며 노엽 Pi 농도는 대조구의 각각 16%, 7%였다. 잎에서는 인산 결핍이 전인산에 대한 Pi의 분포를 감소시켰으나 lOP의 분포는 증가시켰다. 근류내의 bacteroid의 수는 $0.87-1.30{\times}10^{11}\;/GFW\;nodule$이었으며, 인산흡수도는 15-16 pmoles /min/$10^8$ bacteroid로 기주식물의 인산공급에는 영향을 받지 않았다 이러한 결과는 인산결핍 대두식물의 근류내 Pi농도는 bacteroid의 생육과 번식에 충분하며 인산결핍에 의하여 기주식물의 생육이 저해될 때에도 bacteroid의 인산흡수는 억제상태에 있음을 나타낸다.

• BMB Reports
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• 제47권7호
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• pp.361-368
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• 2014

Lipid components in biological membranes are essential for maintaining cellular function. Phosphoinositides, the phosphorylated derivatives of phosphatidylinositol (PI), regulate many critical cell processes involving membrane signaling, trafficking, and reorganization. Multiple metabolic pathways including phosphoinositide kinases and phosphatases and phospholipases tightly control spatio-temporal concentration of membrane phosphoinositides. Metabolizing enzymes responsible for PI 4,5-bisphosphate (PI(4,5)P2) production or degradation play a regulatory role in Toll-like receptor (TLR) signaling and trafficking. These enzymes include PI 4-phosphate 5-kinase, phosphatase and tensin homolog, PI 3-kinase, and phospholipase C. PI(4,5)P2 mediates the interaction with target cytosolic proteins to induce their membrane translocation, regulate vesicular trafficking, and serve as a precursor for other signaling lipids. TLR activation is important for the innate immune response and is implicated in diverse pathophysiological disorders. TLR signaling is controlled by specific interactions with distinct signaling and sorting adaptors. Importantly, TLR signaling machinery is differentially formed depending on a specific membrane compartment during signaling cascades. Although detailed mechanisms remain to be fully clarified, phosphoinositide metabolism is promising for a better understanding of such spatio-temporal regulation of TLR signaling and trafficking.

• 한국자원식물학회지
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• 제36권4호
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• pp.275-281
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• 2023

본 연구에서 우리는 작약 뿌리 추출물이 TLR4/PI3K/Nrf2 신호전달을 통해 p62/SQSTM1을 증가시켜 대식세포에서 자가포식을 유도한다는 것을 확인하였다. 대식세포의 자가포식 유도는 선천성과 적응성 면역 반응 간의 연결을 강화해 백신 보조제 개발에 있어서 중요한 표적으로 사용되기 때문에, 작약 뿌리 추출물은 백신개발에 필수적인 백신보조제로의 활용이 가능할 것으로 생각된다.

• 충청수학회지
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• 제21권3호
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• pp.371-376
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• 2008

Let $P(M,G,{\pi})=:P$ be a principal fibre bundle with structure Lie group G over a base manifold M. In this paper we get the following facts: 1. The tangent bundle TG of the structure Lie group G in $P(M,G,{\pi})=:P$ is a Lie group. 2. The Lie algebra ${\mathcal{g}}=T_eG$ is a normal subgroup of the Lie group TG. 3. $TP(TM,TG,{\pi}_*)=:TP$ is a principal fibre bundle with structure Lie group TG and projection ${\pi}_*$ over base manifold TM, where ${\pi}_*$ is the differential map of the projection ${\pi}$ of P onto M. 4. for a Lie group $H,\;TH=H{\circ}T_eH=T_eH{\circ}H=TH$ and $H{\cap}T_eH=\{e\}$, but H is not a normal subgroup of the group TH in general.

• Bulletin of the Korean Chemical Society
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• 제4권4호
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• pp.157-161
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• 1983

Ab initio calculations were performed on systems containing various basic ${\pi}$ fragments and glycines to generalize the ${\pi}$-nonbonded interaction (${\pi}$-NBI) method of determining relative conformational and configurational stability of organic molecules. It was found that the relative stability of conformational isomers can be determined in general by the simple application of the ${\pi}$-NBI method, but the method is not applicable to the geometrical isomerism in which stronger structural factors are involved. The ${\pi}$-NBI effect of a crowded ${\pi}$-structure ($n{\pi}/m$) is maximum for the system in which n is equal to m. In crowded structures containing heteroatoms, ${P^{\pi}}_{ij}$ values of 4N+1 system may become negative, but this sign reversal does not invalidate the predictions based on the ${\pi}$-NBI method.