http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
( Shaheen Amna ),( Geun Young Nam ),( Jae Kweon Park ) 한국키틴키토산학회 2018 한국키틴키토산학회지 Vol.23 No.2
The aim of this study is to elucidate the relationship between the chemical composition and antioxidant activity of water soluble compounds derived from the degradation of microalgal biomass. Since some of particular species of microalgae are promising source for biofuel production, a vast amount of wastes after extracting lipids are treated as trash. To address the potent utilization as a bio-resource, water soluble compounds (WSC) were isolated by the enzymatic and chemical degradation of microalgal biomasses. To test biological activities of WSC, antioxidant activity was determined by DPPH, ABTS, and FRAP based on free radical-scavenging assay. As the result, we found that WSC obtained after enzymatic or chemical treatments have been shown difference in chemical composition and relative antioxidant activities. Although WSC has shown the less significant antioxidant activities, our data suggest that technical development for the extraction and utilization of WSC from microalga are very important to make a good understanding the correlation between the chemical compositions and biological activity.
Enzymatically Hydrolyzed Water-Soluble Chitosan as a Potent Anti-Microbial Agent
Shaheen Amna Kashif,박제권 한국고분자학회 2019 Macromolecular Research Vol.27 No.6
Biological activities of chitosan depend upon its degree of polymerization (DP), fraction of acetylation (FA), and possibly on their pattern of acetylation (PA). Active molecular weight chitosan (AMC) was obtained from water soluble chitosan (WSC) by enzymatic hydrolysis over 600 h of time period. By the end of hydrolysis WSC was hydrolyzed to AMC with final concentration of 14 mM of reducing sugars with lowest viscosity (1.99 mm2/sec). Matrix assisted laser desorption/ionizationtime of flight mass spectrometer (MALDI-TOF) analysis has shown homo- and hetero- oligomers in the reaction mixture. Intense infra-red (IR) bands appeared through 500-3700cm-1 were assigned to be asymmetric and symmetric stretching of common sugars. WSC-AMC has inhibited 80% growth of Candida albicans and Penicillium italicum with highest zone of inhibition of 22 and 25 mm respectively. Mechanism of action for cellular growth inhibition involves the reactive oxygen species (ROS) elimination beyond the normal levels along with inactivation of β-lactamase like enzymes. Our results demonstrated that after hydrolysis the biological activities of WSC improved along with its flow properties and other biological activities.
Purunusides A-C, α-Glucosidase Inhibitory Homoisoflavone Glucosides from Prunus domestica
Shaheen Kosar,Itrat Fatima,Azhar Mahmood,Rehana Ahmed,Abdul Malik,Muhammad Iqbal Chouhdary,Sumaira Talib 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.12
Purunusides A-C (1-3), new homoisoflavone glucosides together with the known compounds β-sitosterol (4) and 6,7-methylenedioxy-8-methoxycoumarin (5) have been isolated from nbutanol and ethyl acetate soluble fractions of Prunus domestica. Their structures were assigned on the basis of spectral studies. The compounds 1-3 showed potent inhibitory activity against the enzyme α-glucosidase.
Structural performance of ferrocement beams reinforced with composite materials
Shaheen, Yousry B.I.,Eltaly, Boshra A.,Abdul-Fataha, Samer G. Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.6
An experimental program was designed in the current work to examine the structural behavior of ferrocement beams reinforced with composite materials under three point loadings up to failure. The experimental program comprised casting and testing of twelve ferrocement beams having the dimensions of 120 mm width, 200 mm depth and 1600 mm length. The twelve beams were different in the type of reinforcements; steel bars, traditional wire meshes (welded and expanded wire meshes) and composite materials (fiberglass wire meshes and polypropylene wire meshes). The flexural performances of the all tested beams in terms of strength, ductility, cracking behavior and energy absorption were investigated. Also all the tested beams were simulated using ANSYS program. The results of the experimental tests concluded that the beam with fiber glass meshes gives the lowest first crack load and ultimate load. The ferrocement beam reinforced with four layers of welded wire meshes has better structural behavior than those beams reinforced with other types of wire meshes. Also the beams reinforced with metal wire meshes give smaller cracks width in comparing with those reinforced with non-metal wire meshes. Also the Finite Element (FE) simulations gave good results comparing with the experimental results.
Current Researches and Future Research Directions in Textile Supply Chain Management
Shaheen Sardar,Young Hae Lee 대한산업공학회 2012 대한산업공학회 추계학술대회논문집 Vol.2012 No.11
Textile industry has played a significant role in the growth of the global economy. Textile products are among the basic needs of human beings. Textile supply chain has a very complex structure. Synchronization in the activities of all participants of the textile supply chain is a challenging task. Textile industry has been sadly neglected by the researchers from the supply chain management perspective. Awareness of the existing situation of the textile supply chain is essential from the optimization point of view. The objective of this study is to investigate the current researches and explore the future research directions in textile supply chain management. A systematic literature review was conducted through maximum possible sources. Then, outcomes of relevant literature were categorized into various groups. Finally, potential areas of future research were highlighted on the basis of literature review, evaluation, and our observations at different textile organizations.
Shaheen, Sabry M.,Kwon, Eilhann E.,Biswas, Jayanta K.,Tack, Filip M.G.,Ok, Yong Sik,Rinklebe, Jö,rg Elsevier 2017 CHEMOSPHERE - Vol.180 No.-
<P><B>Abstract</B></P> <P>The fractionation and potential mobilization of As, Cr, Mo, and Se in four floodplain soil profiles collected along the Nile (Egypt) and Wupper (Germany) Rivers were assessed using the BCR sequential extraction procedure. The concentrations of total and the geochemical fractions (acid soluble (F1), reducible (F2), oxidizable (F3), and residual (F4) fraction) of the elements were determined. The Wupper soils had the highest total concentrations (mg kg<SUP>−1</SUP>) of As (378) and Cr (2,797) while the Nile soils contained the highest total Mo (12) and Se (42). The residual fraction of As, Cr, Mo, and Se was dominant in the Nile soils suggesting the geogenic source of the elements in these soils. The residual fraction of As and Mo and the oxidizable fraction of Cr and Se were dominant in the Wupper soils. Among the non-residual fractions (potential mobile fractions; PMF = ∑F1−F3), the oxidizable fraction was dominant for Cr, Mo, and Se in the Nile soils and for Mo in the Wupper soils, while the reducible fraction was dominant for As in both soils. The PMF of As, Cr, and Se was higher in the Wupper than in the Nile soils which might reflect the anthropogenic sources of these elements in the Wupper soils, while the opposite was the case for the PMF of Mo. The high PMF of Se (87%), Cr (87%), and As (21%) in the Wupper soils suggested that a release of these toxic elements may happen which increase the potential environmental risks in the anthropogenically polluted soils.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Selenium showed the highest potential mobilization followed by Cr, Mo, and As. </LI> <LI> Potential mobilization of As, Cr, and Se was high in the Wupper soils. </LI> <LI> Potential mobilization of Mo was high in the Nile soils. </LI> <LI> Residual fraction of As, Cr, Mo, and Se was dominant in the Nile soils. </LI> <LI> Oxidizable fraction of Cr and Se was dominant in the Wupper soils. </LI> </UL> </P>
( Shaheen Amna ),( Ah Young Yoo ),( Jae Kweon Park ) 한국키틴키토산학회 2018 한국키틴키토산학회지 Vol.23 No.3
The aim of this study was to isolate and characterize the extracellular polysaccharides (EPS) from defatted microalga Tetraselmis KCTC 12236 BP (T1) and Tetraselmis KCTC 12432 BP (T2), both were isolated and used microalgal biomasses for the production of biodiesel. The difference of molecular diversity of EPS in T1 were obviously observed from each sample based on MALDI-TOF mass spectra analysis. Higher productivity and significant antioxidant activity were only observed from the EPS isolated from T1 than that of T2. Therefore, EPS from T1 were used for further study to elucidate the relationship between the EPS and its biological activity. These results suggest the importance of the understanding of primary structure to address the biological role of EPS in microalgal species.
Degradation of Polysaccharide in Fenton Oxidative Cleavage Reaction and Their Antioxidant Activity
( Shaheen Amna ),( Bo Mi Lee ),( Choon Geun Lee ),( You Jin Hwang ),( Jae Kweon Park ) 한국키틴키토산학회 2016 한국키틴키토산학회지 Vol.21 No.1
One of well known methods for degrading polysaccharide is to use the reactive oxygen species. The fenton reaction can produce aggressive OH-radical, which is one of potential species of ROS, from hydrogen peroxide in the presence of catalytic metal ions. Ascorbic acid acts as a potent antioxidant necessary to cope up these oxidative damages. We found that ascorbic acid also exhibits pro-oxidant characteristics in the presence of catalytic metal ions, which can reduce the redox-active metal ions. Active size of molecules was obtained via degradation of higher molecular weight chitosan and hyaluronic acid, to obtain such active molecules, fast digestion was performed based on fenton reaction to determine the anti-oxidant activity of these molecules. Our results indicated that lysates from both the parental polysaccharides possess significant radical scavenging activity which proves that chitosan and hyaluronic acid are good anti-oxidants in terms of scavenging free radicals.