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71.
Hadji I Marzouki MN Ferraro D Fasano E Majdoub H Pani G Limam F 《Applied biochemistry and biotechnology》2007,143(2):129-141
Crude garlic extract contains one Mn-superoxide dismutase designated as SOD1 and two Cu,Zn superoxide dismutases as SOD2 and
SOD3. The major isoform SOD2 was purified to homogeneity by Sephacryl S200-HR gel filtration, DEAE Sepharose ion exchange
chromatography, and chromatofocusing using PBE 94. SOD2 was purified 82-fold with a specific activity of 4,960 U/mg protein.
This enzyme was stable in a broad pH range from 5.0 to 10.0 and at various temperatures from 25 to 60°C. The native molecular
mass of SOD2 estimated by high performance liquid chromatography on TSK gel G2000SW column was 39 kDa. Sodium dodecyl sulfate–polyacrylamide
gel electrophoresis analysis showed a single band near 18 kDa, suggesting that native enzyme was homodimeric. The isoelectric
point as determined by chromatofocusing was 5. Analysis of its N terminal amino acid sequence revealed high sequence homology
with several other cytosolic Cu,Zn-SODs from plants. Exposure of cancer cell lines to garlic Cu,Zn-SOD2 led to a significant
decrease in superoxide content with a concomitant rise in intracellular peroxides, indicating that the enzyme is active in
mammalian cells and could, therefore, be used in pharmacological applications. 相似文献
72.
Mongi Saoudi Riadh Badraoui Ahlem Chira Mohd Saeed Nouha Bouali Salem Elkahoui Jahoor M. Alam Choumous Kallel Abdelfattah El Feki 《Molecules (Basel, Switzerland)》2021,26(16)
In our study, Allium subhirsutum L. (AS) was investigated to assess its phenolic profile and bioactive molecules including flavonoids and organosulfur compounds. The antioxidant potential of AS and wound healing activity were addressed using skin wound healing and oxidative stress and inflammation marker estimation in rat models. Phytochemical and antiradical activities of AS extract (ASE) and oil (ASO) were studied. The rats were randomly assigned to four groups: group I served as a control and was treated with simple ointment base, group II was treated with ASE ointment, group III was treated with ASO ointment and group IV (reference group; Ref) was treated with a reference drug “Cytolcentella® cream”. Phytochemical screening showed that total phenols (215 ± 3.5 mg GAE/g) and flavonoids (172.4 ± 3.1 mg QE/g) were higher in the ASO than the ASE group. The results of the antioxidant properties showed that ASO exhibited the highest DPPH free radical scavenging potential (IC50 = 0.136 ± 0.07 mg/mL), FRAP test (IC50 = 0.013 ± 0.006 mg/mL), ABTS test (IC50 = 0.52 ± 0.03 mg/mL) and total antioxidant capacity (IC50 = 0.34 ± 0.06 mg/mL). In the wound healing study, topical application of ASO performed the fastest wound-repairing process estimated by a chromatic study, percentage wound closure, fibrinogen level and oxidative damage status, as compared to ASE, the Cytolcentella reference drug and the untreated rats. The use of AS extract and oil were also associated with the attenuation of oxidative stress damage in the wound-healing treated rats. Overall, the results provided that AS, particularly ASO, has a potential medicinal value to act as effective skin wound healing agent. 相似文献
73.
Study of a Generalized Nonlinear Euler-Poisson-Darboux System: Numerical and Bessel Based Solutions
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In this paper a nonlinear Euler-Poisson-Darboux system is considered. In a first part, we proved the genericity of the hypergeometric functions in the development of exact solutions for such a systemin some special cases leading to Bessel type differential equations. Next, a finite difference scheme in two-dimensional case has been developed. The continuous system is transformed into an algebraic quasi linear discrete one leading to generalized Lyapunov-Sylvester operators. The discrete algebraic system is proved to be uniquely solvable, stable and convergent based on Lyapunov criterion of stability and Lax-Richtmyer equivalence theorem for the convergence. A numerical example has been provided at the end to illustrate the efficiency of the numerical scheme developed in section 3. The present method is thus proved to be more accurate than existing ones and lead to faster algorithms. 相似文献
74.
On probabilistic constraints induced by rectangular sets and multivariate normal distributions 总被引:1,自引:0,他引:1
Wim Van Ackooij René Henrion Andris Möller Riadh Zorgati 《Mathematical Methods of Operations Research》2010,71(3):535-549
In this paper, we consider optimization problems under probabilistic constraints which are defined by two-sided inequalities
for the underlying normally distributed random vector. As a main step for an algorithmic solution of such problems, we prove
a derivative formula for (normal) probabilities of rectangles as functions of their lower or upper bounds. This formula allows
to reduce the calculus of such derivatives to the calculus of (normal) probabilities of rectangles themselves thus generalizing
a similar well-known statement for multivariate normal distribution functions. As an application, we consider a problem from
water reservoir management. One of the outcomes of the problem solution is that the (still frequently encountered) use of
simple individual probabilistic constraints can completely fail. By contrast, the (more difficult) use of joint probabilistic
constraints, which heavily depends on the derivative formula mentioned before, yields very reasonable and robust solutions
over the whole time horizon considered. 相似文献
75.
In this paper, the smoothed particle hydrodynamics (SPH) method is applied to the solution of shallow water equations. A brief review of the method in its standard form is first described then a variational formulation using SPH interpolation is discussed. A new technique based on the Riemann solver is introduced to improve the stability of the method. This technique leads to better results. The treatment of solid boundary conditions is discussed but remains an open problem for general geometries. The dam‐break problem with a flat bed is used as a benchmark test. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
76.
Aymen Ezzine Myriam Moussaoui Emna El Hammi Mohamed Nejib Marzouki Laura Baciou 《Applied biochemistry and biotechnology》2014,173(5):1023-1037
Flavohemoglobins (FlavoHb) play a key role in bacterial resistance to nitrosative stress and NO signaling modulation. In this study, we cloned, expressed, and characterized the flavoHb from the opportunistic pathogen, Staphylococcus aureus. The higher amino-acid sequence homology is shared with that from Saccharomyces cerevisiae which was therefore used to build a model structure by homology modeling. Interestingly, the high sequence homology with S. cerevisiae did not correlate with the enzymatic and kinetic properties which are much similar to those of Escherichia coli. In vitro and aerobically, we showed that S. aureus and Ralstonia eutropha flavoHbs accept cytochrome c and oxygen as substrates. Based on this feature, we investigated the preferences for both substrates depending on miconazole or econazole addition and found that the inhibitor chemical composition is determinant. 相似文献
77.
Riadh Kefi Erwann Jeanneau Frdric Lefebvre Cherif Ben Nasr 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(5):m126-m129
A new noncentrosymmetric organic–inorganic hybrid material, (C8H12N)2[ZnCl4], has been synthesized as single crystals at room temperature and characterized by X‐ray diffraction and solid‐state NMR spectroscopy. Its novel structure consists of two 4‐methylbenzylammonium cations and one [ZnCl4]2− anion connected by N—H...Cl and C—H...Cl hydrogen bonds, two of which are three‐centre interactions. The ZnII metal centre has a slightly distorted tetrahedral coordination geometry. Results from 13C CP–MAS NMR spectroscopy are in good agreement with the X‐ray structure. Density functional theory calculations allow the assignment of the carbon peaks to the independent crystallographic sites. 相似文献
78.
Rim Ben Mansour Raja Serairi Beji Hanen Wasli Sami Zekri Riadh Ksouri Wided Megdiche-Ksouri Susana M. Cardoso 《Molecules (Basel, Switzerland)》2022,27(5)
Myrtus communis L. essential oil (EO), mainly composed of myrtenyl acetate (30.6%), linalool (14.9%), α-pinene (11.10%) and 1,8-cineole or eucalyptol (9.9%), was microencapsulated with maltodextrin by emulsification and spray-drying, reaching a yield and efficiency of 43.7 and 48.7%, respectively. The microencapsulated myrtle EO (MMEO) was then evaluated regarding its gastroprotective activity in a model of ethanol/HCl-induced acute gastric ulcer in Wistar rats. Pretreatment with MMEO induced a remarkable inhibition of gastric lesions and acidity, correlated to high healing and protection percentages. Moreover, it exerted a potent anti-inflammatory effect on the gastric mucosa, counteracting EtOH-induced gastric lipoperoxidation and preventing the depletion of the antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Taken together, the gastroprotective action of encapsulated MMEO may be multi-factorial, and ascribable, at least in parts, to its anti-inflammatory and antioxidant properties. 相似文献
79.
80.
Purification and characterization of an alkaline protease prot 1 frombotrytis cinerea 总被引:1,自引:0,他引:1
Alkaline thiol protease named Prot 1 was isolated from a culture filtrate ofBotrytis cinerea. The enzyme was purified by ammonium sulfate fractionation, gel filtration, and ion-exchange chromatography. Thus, the enzyme
was purified to homogeneity with specific activity of 30-fold higher than that of the crude broth. The purified alkaline protease
has an apparent molecular mass of 43 kDa under denaturing conditions as estimated by sodium dodecyl sulfate-polyacrylamide
gel electrophoresis. The native molecular mass (45 kDa), determined by gel filtration, indicated that the alkaline protease
has a monomeric form. The purified protease was biochemically characterized. The enzyme is active at alkaline pH and has a
suitable and high thermostability. The optimal pH and temperature for activity were 9.0–10.0 and 60°C, respectively. This
protease was stable between pH 5.0 and 12.0. The enzyme retained 85% of its activity by treatment at 50°C over 120 min; it
maintained 50% of activity after 60 min of heating at 60°C. Furthermore, the protease retained almost complete activity after
4 wk storage at 25°C. The activity was significantly affected by thiol protease inhibitors, suggesting that the enzyme belongs
to the alkaline thiol protease family. With the aim on industrial applications, we focused on studying the stability of the
protease in several conditions. Prot 1 activity was not affected by ionic strength and different detergent additives, and,
thus, the protease shows remarkable properties as a biodetergent catalyst. 相似文献