• Title/Summary/Keyword: Simon effect

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Chemical Constituents from Solenostemma argel and their Cholinesterase Inhibitory Activity

  • Demmak, Rym Gouta;Bordage, Simon;Bensegueni, Abederrahmane;Boutaghane, Naima;Hennebelle, Thierry;Mokrani, El Hassen;Sahpaz, Sevser
    • Natural Product Sciences
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    • v.25 no.2
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    • pp.115-121
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    • 2019
  • Alzheimer's disease is a chronic neurodegenerative disorder with no curative treatment. The commercially available drugs, which target acetylcholinesterase, are not satisfactory. The aim of this study was to investigate the cholinesterase inhibitory activity of Solenostemma argel aerial part. Eight compounds were isolated and identified by NMR: kaempferol-3-O-glucopyranoside (1), kaempferol (2), kaempferol-3-glucopyranosyl($1{\rightarrow}6$)rhamnopyranose (3) p-hydroxybenzoic acid (4), dehydrovomifoliol (5), 14,15-dihydroxypregn-4-ene-3,20-dione (6), 14,15-dihydroxy-pregn-4-ene-3,20-dione-$15{\beta}$-D-glucopyranoside (7) and solargin I (8). Two of them (compounds 2 and 3) could inhibit over 50 % of butyrylcholinesterase activity at $100{\mu}M$. Compound (2) displayed the highest inhibitory effect against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with a slight selectivity towards the latter. Molecular docking studies supported the in vitro results and revealed that (2) had made several hydrogen and ${\pi}-{\pi}$ stacking interactions which could explain the compound potency to inhibit AChE and BChE.

Effect of Process Parameters on Microhardness of Ni-Al2O3 Composite Coatings (Ni-Al2O3 복합코팅의 마이크로 경도에 대한 공정변수의 영향)

  • Jin, Yeung-Jun;Park, Simon
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.6_2
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    • pp.1037-1045
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    • 2022
  • In this study, nanoscale Al2O3 ceramic particles were used due its exceptionally high hardness characteristics, chemical stability, and wear resistance properties. These nanoparticles will be used to investigate the optimal process conditions for the electro co-deposition of the Ni-Al2O3 composite coatings. A Watts bath electrolytic solution of a controlled composition along with a fixed agitation speed was used for this study. Whereas the current density, the pH value, temperature and concentration of the nano Al2O3 particles of the electrolyte were designated as the manipulative variables. The experimental design method was based on the orthogonal array to find the optimum processing parameters for the electro co-deposition of Ni-Al2O3 composite coatings. The result of confirmation experimental based on the optimal processing condition through the analysis of variance ; EDX analysis found that the ratio of alumina increased to 8.65 wt.% and subsequently the overall hardness increased to 983 Hv. Specially, alumina were evenly distributed on Nickel matrix and particles were embedded more firmly and finely in Nickel matrix.

Effects of Individual Fatty Acids on Receptor-Mediated Binding, Internalization and Degradation of $[^{125}I]LDL$

  • Choue, Ryo-Won;Cho, Byung-Hee Simon
    • BMB Reports
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    • v.30 no.1
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    • pp.1-6
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    • 1997
  • The ability of Hep-G2 cells to process $[^{125}I]LDL$ under basal conditions was investigated. The receptor-binding and internalization of $[^{125}I]LDL$ increased with the time of incubation in a saturable manner. After 4 h of incubation, 31.4 ng of $[^{125}I]LDL$ was cell bound. The cells rapidly internalized $[^{125}I]LDL$ via specific, receptor-mediated endocytosis. The amount of internalized $[^{125}I]LDL$ reached a maximun of 96.7 ng at 2 h of incubation and remained constant for the next 2 h. The rate of degradation of internalized $[^{125}I]LDL$ proceeded in a linear manner over the entire 4 h of incubation after an initial lag period. The effects of individial fatty acids (C18:0. C18:1, C18:2. and C18:3), differing in their degree of unsaturation. on the receptor-binding, internalization and degradation of $[^{125}I]LDL$ were also investigated. Inclusion of 1.0 mM of each fatty acid into the culture medium significantly increased $[^{125}I]LDL$ metabolism in Hep-G2 cells. Among the fatty acids tested, stearic acid had the least effect on the receptor-binding activity. There were no significant differences among the unsaturated fatty acids in LDL-receptor binding. The effect of individual fatty acids on the $[^{125}I]LDL$ uptake was similar to that of the receptor-binding. showing a significantly lower effect with stearic acid. The amount of degraded material of internalized $[^{125}I]LDL$ was the lowest with stearic acid when it was compared with unsaturated fatty acids.

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Microfluidic Fabrication of Conjugated Polymer Sensor Fibers (미세유동을 이용한 공액 고분자 센서 섬유 제작)

  • Yoo, Imsung;Song, Simon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.10
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    • pp.853-858
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    • 2014
  • We propose a fabrication method for polydiacetylene (PDA)-embedded hydrogel microfibers on a microfluidic chip. These fibers can be applied to the detection of cyclodextrines (CDs), which are a family of sugar and aluminum ions. PDA, a family of conjugated polymers, has unique characteristics when used for a sensor, because it undergoes a blue-to-red color transition and nonfluorescence-to-fluorescence transition in response to environmental stimulation. PDAs have different sensing characteristics depending on the head group of PCDA. By taking advantage of ionic crosslinking-induced hydrogel formation and the 3D hydrodynamic focusing effect on a microfluidic chip, PCDA-EDEA-derived diacetylene (DA) monomer-embedded microfibers were successfully fabricated. UV irradiation of the fibers afforded blue-colored PDA, and the resulting blue PDA fibers underwent a phase transition to red and emitted red fluorescence upon exposure to CDs and aluminum ions. Their fluorescence intensity varied depending on the CDs and aluminum ion concentrations. This phase transition was also observed when the fibers were dried.

The effect of sociality on school adjustment among middle school students from formally broken families, focusing on the mediating role of ego-resilience (한부모가정 중학생의 사회성이 학교적응에 미치는 영향 -자아탄력성의 매개 효과를 중심으로-)

  • Kim, Hyeon-Mi
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.9
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    • pp.4421-4428
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    • 2013
  • This study was designed to find out what influences sociality on school adjustment among middle school students from formally broken families, and whether ego-resilience may have a mediating effect on the relationship between sociality and school adjustment. The participants were 147 middle school students from formally broken families in D city. Data were analyzed using the SPSS/WIN 18.0. version. As a result, both sociality(r=.716) and ego-resilience(r=.706) had significant influence on school adjustment. And also their ego-resilience played a mediating role between sociality and school adjustment. Therefore, it is necessary to develop and apply programs for improving the students' sociality and ego-resilience that can influence school adjustment.

A Critical Review on Behavioral Economics with a Focus on Prospect Theory and EBA Model (프로스펙트 이론과 속성별 제거모형을 중심으로 한 행동경제학에 대한 비판적 고찰)

  • Won, Jee-Sung
    • Journal of Distribution Science
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    • v.11 no.5
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    • pp.63-76
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    • 2013
  • Purpose - For the past several decades, behavioral economics or behavioral decision theory has undergone rapid development. This study provides a critical review of the development of behavioral economics with a focus on what are deemed to be core theories in the field. Starting from the utility function proposed by Daniel Bernoulli in the 18th century, the development history of utility functions until the emergence of the prospect theory is thoroughly reviewed. Some of the experimental results violating the traditionally assumed utility function and supporting the prospect theory value function are summarized. The most representative principles of rational choice are transitivity, independence from irrelevant alternatives (IIA), and regularity. The development of behavioral economics has been triggered by finding counter-examples to these principles. Some of the choice behaviors discussed in this study as counter-examples to the traditional theories of rational choice are the St. Petersburg paradox; the Allais paradox; gambling behavior; and the various context effects including the similarity effect, attraction effect, and the compromise effect. The Elimination-by-Aspects (EBA) model, which was proposed as an explanation for the similarity effect, is discussed in detail as well. Based on the literature review and further analysis, this study summarizes the relationship between the context effects, prospect theory, and EBA model. Research design, data, and methodology - This study provides an extensive literature review on several important theories in the field of behavioral decision theory and adds some critical comments to the theories and the relationships among them. This study first reviews the development of utility functions. Daniel Bernoulli introduced the concept of utility function to solve the St. Petersburg paradox. In the mid-20th century, Herbert Simon proposed the "satisficing" heuristic and presented a value function with a shape different from traditional utility functions. This study highlights the strengths and weaknesses of several utility functions proposed until the emergence of the prospect theory value function. Results - This study posits that prospect theory and EBA model are the two most important theories in the field of behavioral decision theory. They can explain various choice behaviors that traditional utility maximization analysis has been unable to. The application of these models to various fields is further increasing nowadays. This study explains how prospect theory and the EBA model can be used to explain the context effects. Conclusions - The traditional economic theory relies on a single variable called "utility" in explaining consumer choice. However, this study argues that, in investigating consumer choice, several other variables should also be considered. These are the similarity among alternatives, an alternative's prototypicality within the category, the dominance relationship between alternatives, and the reference point in evaluating alternatives. Due to the development of behavioral economics, we are now closer to a more complete understanding of consumer choice behavior than in the past when we had only a single tool called utility.

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Proliferative and Inhibitory Activity of Siberian ginseng (Eleutherococcus senticosus) Extract on Cancer Cell Lines; A-549, XWLC-05, HCT-116, CNE and Beas-2b

  • Cichello, Simon Angelo;Yao, Qian;Dowell, Ashley;Leury, Brian;He, Xiao-Qiong
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.11
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    • pp.4781-4786
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    • 2015
  • Siberian ginseng (Eleutherococcus senticosus) is used primarily as an adaptogen herb and also for its immune stimulant properties in Western herbal medicine. Another closely related species used in East Asian medicine systems i.e. Kampo, TCM (Manchuria, Korea, Japan and Ainu of Hokkaido) and also called Siberian ginseng (Acanthopanax senticosus) also displays immune-stimulant and anti-cancer properties. These may affect tumour growth and also provide an anti-fatigue effect for cancer patients, in particular for those suffering from lung cancer. There is some evidence that a carbohydrate in Siberian ginseng may possess not only immune stimulatory but also anti-tumour effects and also display other various anti-cancer properties. Our study aimed to determine the inhibitory and also proliferative effects of a methanol plant extract of Siberan ginseng (E. senticosus) on various cancer and normal cell lines including: A-549 (small cell lung cancer), XWLC-05 (Yunnan lung cancer cell line), CNE (human nasopharyngeal carcinoma cell line), HCT-116 (human colon cancer) and Beas-2b (human lung epithelial). These cell lines were treated with an extract from E. senticosus that was evaporated and reconstituted in DMSO. Treatment of A-549 (small cell lung cancer) cells with E. senticosus methanolic extract showed a concentration-dependent inhibitory trend from $12.5-50{\mu}g/mL$, and then a plateau, whereas at 12.5 and $25{\mu}g/mL$, there is a slight growth suppression in QBC-939 cells, but then a steady suppression from 50, 100 and $200{\mu}g/mL$. Further, in XWLC-05 (Yunnan lung cancer cell line), E. senticosus methanolic extract displayed an inhibitory effect which plateaued with increasing dosage. Next, in CNE (human nasopharyngeal carcinoma cell line) there was a dose dependent proliferative response, whereas in Beas-2 (human lung epithelial cell line), an inhibitory effect. Finally in colon cancer cell line (HCT-116) we observed an initially weak inhibitory effect and then plateau.

Difference of Ginsenoside Contents in Roots Cultivated under Blue and Red Polyethylene Shading Net in Panax ginseng C. A. Meyer (청색과 적색 해가림 재배에 따른 인삼의 진세노사이드 함량 차이)

  • Lee, Sung-Woo;Kim, Geum-Soog;Park, Chung-Heon;Simon, James E.;Kim, Kwan-Su
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.53 no.spc
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    • pp.103-107
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    • 2008
  • This study was carried out to investigate the effect of light quality on root yield and ginsenoside contents of 4-year-old ginseng by using the fourfold polyethylene shading net with different colors, blue and red color, compared to blue-black (3:1) mixed shading net as control. Control and blue shading net occurred higher root yield, especially, in tap root growth than red one, whereas transmitted quantum in red shading net was higher than those in blue one or control. However, red shading net caused the highest content of total ginsenoside, especially, Rg1 content, as compared to blue and control. We assumed that the increased content of ginsenoside is not caused by light quality such as red, but is due to the increase of relative ratio of ginsenoside in whole root tissue arising from the reduced root growth.

Construction Partnering on Alternative Project Delivery Methods: A Case Study of Construction Manager/General Contractor Partnered Transportation Projects

  • Adamtey, Simon A.;Kereri, James O.
    • Journal of Construction Engineering and Project Management
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    • v.9 no.4
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    • pp.1-15
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    • 2019
  • Since its adoption by the transportation sector in the early 1990s, partnering has been broadly used with the traditional delivery method by many agencies with significant reported benefits. During the same era, a number of transportation agencies (DOTs) started experimenting with a wide variety of alternative project delivery methods (APDMs) aimed at improving the delivery of highway construction projects. The effect of collaborative working strategies such as partnering, together with the APDMs have become somehow interrelated posing a potential challenge on how to effectively integrate partnering as a concept in the APDMs. The salient question has been if the collaborative nature of these APDMs has affected how partnering is being used by state DOTs. Through an extensive literature review, analysis of 32 CMGC RFPs/RFQs and review of three CMGC case studies, the study found that there is limited information in state DOT documents that show procedures on the usage of partnering with CMGC projects. Majority of DOTs are relying on the inherent nature of the CMGC contract to promote healthy collaborative practices and there is the need to consider partnering during preconstruction and construction separately to cater for any personnel change over. The study also revealed that partnering may become less important at the construction phase due to overlap between partnering and CMGC practices. In support of this finding, a CMGC partnering model was developed that can be adopted by DOTs. This paper contributes to both research and practice by expanding the existing knowledge on partnering on APDMs.

Improved Long-term Survival with Contralateral Prophylactic Mastectomy among Young Women

  • Zeichner, Simon Blechman;Ruiz, Ana Lourdes;Markward, Nathan Joseph;Rodriguez, Estelamari
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1155-1162
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    • 2014
  • Background: Despite mixed survival data, the utilization of contralateral prophylactic mastectomy (CPM) for the prevention of a contralateral breast cancer (CBC) has increased significantly over the last 15 years, especially among women less than 40. We set out to look at our own experience with CPM, focusing on outcomes in women less than 40, the sub-population with the highest cumulative lifetime risk of developing CBC. With an extended follow-up, we hoped to demonstrate differences in the long-term disease free survival (DFS) and overall survival (OS) among groups who underwent the procedure (CPM) versus those that did not (NCPM). Materials and Methods: We performed a retrospective review of all breast cancer patients less than age 40 diagnosed at Mount Sinai Medical Center between January 1, 1980 and December 31, 2010 (n=481). Among these patients, 42 were identified as having undergone CPM, while 195 were confirmed as being CPM-free during the observation period. A univariate and multivariate analyses were performed. Results: The CPM group had a significantly higher percentage of patients who were diagnosed between 2000 and 2010 (95.2% vs 40%, p=0.0001). The CPM group had significantly smaller tumors (0-2cm.: 41.7% vs 24.8%, p=0.04). Among the entire group of patients, the overall five- and 10-year DFS were 81.3% and 73.3%, respectively. CPM was significantly associated [HR 2.35 (1.02, 5.41); p=0.046] with 10-year OS, although a similar effect was not observed for five-year OS. Conclusions: We found that CPM has increased dramatically over the last 15 years, especially among white women with locally advanced disease. In patients less than 40, who are thought to be at greatest cumulative risk of secondary breast cancer, CPM provided an OS advantage, regardless of genetics, tumor or patient characteristics, and which was only seen after 10 years of follow-up.