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1.
Purification,structural data and biological properties of polysaccharide from Prunus amygdalus gum 下载免费PDF全文
Fatma Bouaziz Mohamed Koubaa Claire Boisset Helbert Fatma Kallel Dorra Driss Imen Kacem Raoudha Ghorbel Semia Ellouz Chaabouni 《International Journal of Food Science & Technology》2015,50(3):578-584
This work demonstrates the efficiency of almond gum polysaccharides (AGPs) as bioactive compounds. AGPs were first extracted using H2O2, in the presence of NaOH, at different times and temperatures. The optimal extraction conditions were 4% H2O2 and 2 N NaOH, for 7 h at 50 °C, leading to an extraction yield of 58.2% (w/w). After a purification step, the retained AGPs were characterised using high‐performance liquid chromatography showing a molecular weight of 99.3 kDa. The monosaccharide composition of AGPs were assessed using gas chromatography–mass spectrometry. AGPs were found to be a complex heteropolysaccharide with a repeating unit mainly composed of galactose, arabinose, xylose, mannose, rhamnose, and glucuronic acid with the respective ratios: 45:26:7:10:1:11. The acidic nature of the polysaccharide is due to the presence of glucuronic acid. Total antioxidant activity, free radical‐scavenging activity and reducing power assay of AGPs were investigated. The obtained results showed high antioxidant activities of AGPs. Furthermore, beyond 60 mg mL?1, AGPs exhibited bacterial growth inhibition for five pathogenic strains: Escherichia coli, Staphylococcus aureus, Enterococcus feacalis, Pseudomonas aeruginosa and Salmonella typhimurium. 相似文献
2.
H. Petite K. Kacem J. T. Triffitt 《Journal of materials science. Materials in medicine》1996,7(11):665-671
Bone marrow contains stromal fibroblastic stem cells which have the potential to differentiate into bone-forming cells. Therefore addition of bone marrow to porous bone substitutes such as coral or coralline hydroxyapatite may be expected to enhance bone ingrowth into these implants. This study was designed to evaluate the possibility of growing human bone marrow stromal fibroblastic cells (HBMC) on a calcium carbonate substrate. For this purpose, HBMC were cultured for 20 days on plastic or calcium carbonate and cell adhesion, growth, and differentiation were studied. It was concluded that calcium carbonate is a highly compatible material for the growth of HBMC. Cells were capable of adhesion within 30 min and were spread within 24 h on this material. However, plating efficiency was decreased in comparison to plastic. Population doubling times (PDT) showed that they were similar when the cells were grown on plastic or calcium carbonate as substratum (PDT=4, 5.5 days). Early protein synthesis included collagen I, collagen III, osteopontin and bone sialoprotein. To induce differentiation of HBMC on plastic and calcium carbonate the influence of dexamethasone (Dex) and 1,25dihydroxyvitamin D3 (1,25(OH)2D3) on alkaline phosphatase (ALP) expression was studied. Basic ALP activity was similar when cells were grown on plastic or calcium carbonate. However, Dex and 1,25(OH)2D3 increased ALP activity of HBMC which could be driven best towards osteogenesis in the presence of Dex and 1,25(OH)2D3. 相似文献
3.
Spatial bound whale optimization algorithm: an efficient high-dimensional feature selection approach
Too Jingwei Mafarja Majdi Mirjalili Seyedali 《Neural computing & applications》2021,33(23):16229-16250
Neural Computing and Applications - Selecting a subset of candidate features is one of the important steps in the data mining process. The ultimate goal of feature selection is to select an optimal... 相似文献
4.
This paper is the first attempt to successfully design efficient approximation algorithms for the single-machine weighted
flow-time minimization problem when jobs have different release dates and weights equal to their processing times under the
assumption that one job is fixed (i.e., the machine is unavailable during a fixed interval corresponding to the fixed job).
Our work is motivated by an interesting algorithmic application to the generation of valid inequalities in a branch-and-cut
method. Our analysis shows that the trivial FIFO sequence can lead to an arbitrary large worst-case performance bound. Hence,
we modify this sequence so that a new 2-approximation solution can be obtained for every instance and we prove the tightness
of this bound. Then, we propose a fully polynomial-time approximation algorithm with efficient running time for the considered
problem. Especially, the complexity of our algorithm is strongly polynomial. 相似文献
5.
In this paper, we present a new sufficient condition for absolute stability of Lure system with two additive time-varying delay components. This criterion is expressed as a set of linear matrix inequalities (LMIs), which can be readily tested by using standard numerical software. We use this new criterion to stabilize a class of nonlinear time-delay systems. Some numerical examples are given to illustrate the applicability of the results using standard numerical software. 相似文献
6.
In this paper, we present a new sufficient condition for absolute stability of Lure system with two additive time-varying
delay components. This criterion is expressed as a set of linear matrix inequalities (LMIs), which can be readily tested by
using standard numerical software. We use this new criterion to stabilize a class of nonlinear time-delay systems. Some numerical
examples are given to illustrate the applicability of the results using standard numerical software. 相似文献
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