In situ screening of 3-arylcoumarin derivatives reveals new inhibitors of mast cell degranulation

Marcela de Souza Santos,Maria Perpe´tua Freire de Morais Del Lama,Laila Aparecida Deliberto,Fla´vio da Silva Emery,Moˆnica Tallarico Pupo,Rose Mary Zumstein Georgetto Naal 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.6

Due to the severity and high prevalence ofallergic diseases, there is growing interest in the developmentof inhibitors of such conditions. 3-Arylcoumarinderivatives emerge as promising compounds for thetreatment of allergic disorders, in particular due to theirclose structural similarity to flavonoids, whose anti-allergicactivity has been extensively reported. The aim of this workwas to perform a screening of a set of 3-arylcoumarins aspotential inhibitors of mast cell degranulation, a key eventfor the development of allergic reactions. For that purpose, itwas utilized a biosensor model based on mast cells, whosein vitro assay allows for such screening, in a high throughputfashion, and also permits bringing to attention some coumarinstructural features that are important for their biologicalactivity. The mast cell-based biosensor was shown todiscriminate, with high sensitivity and reproducibility,between coumarins that did not affect or caused differentdegrees of inhibition of degranulation. Among activecoumarins, some substituents could be accounted for theirinhibitory activity, such as the hydroxylation of positions 6and 20 of 3-phenylcoumarins, in addition to catechol, aminoand thiophene moieties. In summary, 3-arylcoumarins couldbe suggested as potential candidates for the developmentof new anti-allergic drugs.

Dynamic Simulation and Aircraft Level Assessment of CMC Implementation on GTF Engine

Da Mo,Ioannis Roumeliotis,Yixiong Liu,Christos Mourouzidis,Sajal Kissoon 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.3

This paper dynamically simulated the geared turbofan engine with CMC turbine components, including impacts of fuel schedule, shaft inertia, volume packing, BOV schedule. Deliberated comparisons were performed between CMC engine and Inconel engine on aircraft level performance and transient behaviour. Heat load examination is included in flight mission analysis, which lays the basis on the gearbox efficiency map related to torque and rotational speed. Results indicate that IPC surge margin of the CMC case slightly fall 0.15% but maintain steady. The mitigated T4 overshooting phenomenon has offered a 30 K drop and thus extended turbine life. More importantly, Fan shaft inertia dominantly affects engine operability, whereas the blow-off air fraction severely impacts the low power setting operation. Further investigation of heat load reveals that power loss at take-off segment accounts for 1.1% of IP shaft input power, which is 3.98% higher than Inconel case. The thermal management system needs to be redesigned to absorb extra heat. On assessment of aircraft level performance, CMC engine provides superior profits in maximizing airline revenue. The predicted annual fuel cost saving is about 0.08 million dollars coming from block fuel reduction. NOx, noise and CO2 demonstrate obvious decline, approaching 5.9%, 1.0% and 4.9%, respectively.

Medicinal Chemistry : RESEARCH ARTICLE ; Chemical constituents from the leaves of Juglans mandshurica

( Da Lei Yao ),( Chang Hao Zhang ),( Jie Luo ),( Mei Jin ),( Ming Shan Zheng ),( Jiong Mo Cui ),( Jong Keun Son ),( Gao Li ) 영남대학교 약품개발연구소 2015 영남대학교 약품개발연구소 연구업적집 Vol.25 No.-

Two new (1 and 3) two known diarylhep-tanoids (2 and 4), along with two tetralones (5 and 6), one naphthoquinone (7), four phenylpropanoids (8-11), and phenol (12) were isolated from the leaves of Juglans mandshurica. Their structures were elucidated on the basis of spectral and chemical data. Compounds 2 and 10 are firstly isolated from this plant and 8 and 12 were isolated from the Juglans genus for the first time. Among these compounds, only 7 cxhibitcd moderate cytotoxicities against cultured Mgc-803, A549, K562, and Hela tumor cell lines with IC50 values of 25.90, 28.60, 39.06, 44.90 LLM, respectively.

Chemical constituents from the leaves of Juglans mandshurica

Da Lei Yao,Chang Hao Zhang,Jie Luo,Mei Jin,Ming Shan Zheng,Jiong Mo Cui,손종근,Gao Li 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.4

Two new (1 and 3) and two known diarylheptanoids(2 and 4), along with two tetralones (5 and 6), onenaphthoquinone (7), four phenylpropanoids (8–11), andone phenol (12) were isolated from the leaves of Juglansmandshurica. Their structures were elucidated on the basisof spectral and chemical data. Compounds 2 and 10 arefirstly isolated from this plant and 8 and 12 were isolatedfrom the Juglans genus for the first time. Among thesecompounds, only 7 exhibited moderate cytotoxicitiesagainst cultured MGC-803, A549, K562, and HeLa tumorcell lines with IC50 values of 25.90, 28.60, 39.06,44.90 lM, respectively.

Hypoxia-dependent mitochondrial fission regulates endothelial progenitor cell migration, invasion, and tube formation

Da Yeon Kim,Seok Yun Jung,Yeon Ju Kim,Songhwa Kang,Ji Hye Park,Seung Taek Ji,Woong Bi Jang,Shreekrishna Lamichane,Babita Dahal Lamichane,Young Chan Chae,Dongjun Lee,Joo Seop Chung,Sang-Mo Kwon 대한생리학회-대한약리학회 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.2

Tumor undergo uncontrolled, excessive proliferation leads to hypoxic microenvironment. To fulfill their demand for nutrient, and oxygen, tumor angiogenesis is required. Endothelial progenitor cells (EPCs) have been known to the main source of angiogenesis because of their potential to differentiation into endothelial cells. Therefore, understanding the mechanism of EPC-mediated angiogenesis in hypoxia is critical for development of cancer therapy. Recently, mitochondrial dynamics has emerged as a critical mechanism for cellular function and differentiation under hypoxic conditions. However, the role of mitochondrial dynamics in hypoxia-induced angiogenesis remains to be elucidated. In this study, we demonstrated that hypoxiainduced mitochondrial fission accelerates EPCs bioactivities. We first investigated the effect of hypoxia on EPC-mediated angiogenesis. Cell migration, invasion, and tube formation was significantly increased under hypoxic conditions; expression of EPC surface markers was unchanged. And mitochondrial fission was induced by hypoxia time-dependent manner. We found that hypoxia-induced mitochondrial fission was triggered by dynamin-related protein Drp1, specifically, phosphorylated DRP1 at Ser637, a suppression marker for mitochondrial fission, was impaired in hypoxia timedependent manner. To confirm the role of DRP1 in EPC-mediated angiogenesis, we analyzed cell bioactivities using Mdivi-1, a selective DRP1 inhibitor, and DRP1 siRNA. DRP1 silencing or Mdivi-1 treatment dramatically reduced cell migration, invasion, and tube formation in EPCs, but the expression of EPC surface markers was unchanged. In conclusion, we uncovered a novel role of mitochondrial fission in hypoxia-induced angiogenesis. Therefore, we suggest that specific modulation of DRP1-mediated mitochondrial dynamics may be a potential therapeutic strategy in EPC-mediated tumor angiogenesis.

Correlation Study Between Material Parameters and Mechanical Properties of Iron–Carbon Compacts Using Sensitivity Analysis and Regression Model

Da Seul Shin,Suk Hyun Kim,Joo Won Oh,Im Doo Jung,Woo Seok Yang,Chi Hun Lee,Hyeok Joon Kwon,Jin Mo Koo,Seong Jin Park 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.5

Changing the material parameters such as powder characteristics and additives affects the final properties of an iron–carbonalloy. This study investigated the influences of three typical material parameters, iron particle size, graphite addition, andpowder lubricant addition, on the density and mechanical properties of an iron–carbon alloy formed via powder compactionand sintering. Each material parameter was designed with five levels, and all of the powder mixtures were compactedunder 500 MPa and sintered at 1120 °C for 30 min. The microstructure of the samples was observed for the green part andsintered part. Through the tensile test, yield strength, ultimate tensile strength, and elongation were measured. The tensilefracture surface was also examined to understand the changes in mechanical properties according to the parameters. Thecorrelations between mechanical properties and material parameters were characterized by the mapping functions, and asensitivity analysis was carried out to investigate which parameter had the larger influence on the mechanical properties. The results showed that graphite addition has the greatest influence on the mechanical properties due to the microstructuralchanges from hypoeutectoid structure to hypereutectoid structure. Further, a regression model was developed to describethe mechanical response of the iron–carbon alloy depending on the material conditions.

Explaining International Expansion Through Export-Venture Market Orientation: A Perspective of Resource-Advantage Theory

Da-Som Kim,Han-Mo Oh 강원대학교 경영경제연구소 2017 Asia-Pacific Journal of Business Vol.8 No.1

The present study aims to examine the role of market orientation as an international partnership property. This property, labeled export-venture market orientation, is at the inter-firm level and is related to the new market development (NMD) activities of export-ventures. Specifically, this article is to define the export-venture market orientation; to argue that it is a major factor in NMD export-venture success; and to argue that the resource-advantage (R-A) theory of competition can provide a theoretical foundation for this concept and explain its contribution to export-ventures’ international expansion success. This manuscript is conceptual in approach. In their efforts to strengthen relationships, export-ventures may tend to focus so much time on the partnership factors that they miss market opportunities. As a spanning process, NMD should be informed by both external and internal activities. In an export-venture, market orientation helps guide NMD activities from outside to inside and vice versa. As a dynamic and disequilibrium provoking process, the R-A theory can theoretically ground the concept of export-venture market orientation and explain its role in NMD export-venture success. The current study contributes to business marketing theory in three ways: it extends the concept of intra-organizational market orientation to an inter-organizational context; contributes to understanding the role of idiosyncratic resources in export-ventures; and theoretically explains the concept of export-venture market orientation. The present study is the first to extend the concept of market orientation into inter-organizational NMD framework and to examine the role of export-venture market orientation in NMD export-venture success.

The Colonoscopist's Expertise Affects the Characteristics of Detected Polyps

Da Kyoung Jung,Tae Oh Kim,Mi Seon Kang,Mo Se Kim,Min Sik Kim,Young Soo Moon 대한소화기내시경학회 2016 Clinical Endoscopy Vol.49 No.1

Background/Aims: The influence of the endoscopist on the polyp detection rate (PDR) is underappreciated in clinical practice. Moreover, flat lesions or lesions of the proximal colon are more difficult to detect. Here, we evaluated the differences in the PDR and the characteristics of detected polyps according to the experience of the colonoscopist. Methods: We collected data on 2,549 patients who underwent screening colonoscopy performed by three fellows. The PDR was calculated according to the percentage of patients who had at least one polyp (method A) and according to the percentage of detected lesions (method B). The primary outcome included the change in the PDR, and the secondary outcome included the change in the characteristics of the detected polyps with increasing experience of the colonoscopist. Results: No proportional correlation was found between the PDR and increasing experience in colonoscopy with method A; however, with method B, the PDR increased after 400 colonoscopies (p=0.0209). With method B, the detection rates of small polyps (<5 mm) (p=0.0015) and polyps in proximal sites (p=0.0050) increased after 300 colonoscopies. Conclusions: Our study demonstrated that the quality of a colonoscopy, measured by using the PDR, may increase when performed by experienced fellows.

Development and Application of Group IV Transition Metal Oxide Precursors

Da Hye Kim,Bo Keun Park,Dong Ju Jeone,Chang Gyoun Kim,Seung Uk Son,Taek-Mo Chung 한국진공학회 2014 한국진공학회 학술발표회초록집 Vol.2014 No.2

Peptide Nucleic Acid Probe-Based Analysis as a New Detection Method for Clarithromycin Resistance in Helicobacter pylori

( Da Hyun Jung ),( Jie-hyun Kim ),( Su Jin Jeong ),( Soon Young Park ),( Il-mo Kang ),( Kyoung Hwa Lee ),( Young Goo Song ) 대한소화기학회 2018 Gut and Liver Vol.12 No.6

Background/Aims: Helicobacter pylori eradication rates are decreasing because of increases in clarithromycin resistance. Thus, finding an easy and accurate method of detecting clarithromycin resistance is important. Methods: We evaluated 70 H. pylori isolates from Korean patients. Duallabeled peptide nucleic acid (PNA) probes were designed to detect resistance associated with point mutations in 23S ribosomal ribonucleic acid gene domain V (A2142G, A2143G, and T2182C). Data were analyzed by probe-based fluorescence melting curve analysis based on probe-target dissociation temperatures and compared with Sanger sequencing. Results: Among 70 H. pylori isolates, 0, 16, and 58 isolates contained A2142G, A2143G, and T2182C mutations, respectively. PNA probe-based analysis exhibited 100.0% positive predictive values for A2142G and A2143G and a 98.3% positive predictive value for T2182C. PNA probe-based analysis results correlated with 98.6% of Sanger sequencing results (κ-value=0.990; standard error, 0.010). Conclusions: H. pylori clarithromycin resistance can be easily and accurately assessed by dual-labeled PNA probe-based melting curve analysis if probes are used based on the appropriate resistance-related mutations. This method is fast, simple, accurate, and adaptable for clinical samples. It may help clinicians choose a precise eradication regimen. (Gut Liver 2018;12:641-647)