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1.
Ines Belhaj-Ben Romdhane Zamen Ben Romdhane Maha Bouzid Ali Gargouri Hafedh Belghith 《Applied biochemistry and biotechnology》2013,171(8):1986-2002
Waste frying oil, which not only harms people’s health but also causes environmental pollution, can be a good alternative to partially substitute petroleum diesel through transesterification reaction. This oil contained 8.8 % of free fatty acids, which cause a problem in a base-catalyzed process. In this study, synthesis of biodiesel was efficiently catalyzed by the covalently immobilized Talaromyces thermophilus lipase and allowed bioconversion yield up to 92 % after 24 h of reaction time. The optimal molar ratio was four to six parts of methanol to one part of oil with a biocatalyst loaded of 25 wt.% of oil. Further, experiments revealed that T. thermophilus lipase, immobilized by a multipoint covalent liaison onto activated chitosan via a short spacer (glutaraldehyde), was sufficiently tolerant to methanol. In fact, using the stepwise addition of methanol, no significant difference was observed from the one-step whole addition at the start of reaction. The batch biodiesel synthesis was performed in a fixed bed reactor with a lipase loaded of 10 g. The bioconversion yield of 98 % was attained after a 5-h reaction time. The bioreactor was operated successfully for almost 150 h without any changes in the initial conversion yield. Most of the chemical and physical properties of the produced biodiesel meet the European and USA standard specifications of biodiesel fuels. 相似文献
2.
Hafedh Hajlaoui Soumaya Arraouadi Emira Noumi Kaïss Aouadi Mohd Adnan Mushtaq Ahmad Khan Adel Kadri Mejdi Snoussi 《Molecules (Basel, Switzerland)》2021,26(12)
Herbs and spices have been used since antiquity for their nutritional and health properties, as well as in traditional remedies for the prevention and treatment of many diseases. Therefore, this study aims to perform a chemical analysis of both essential oils (EOs) from the seeds of Carum carvi (C. carvi) and Coriandrum sativum (C. sativum) and evaluate their antioxidant, antimicrobial, anti-acetylcholinesterase, and antidiabetic activities alone and in combination. Results showed that the EOs mainly constitute monoterpenes with γ-terpinene (31.03%), β-pinene (18.77%), p-cymene (17.16%), and carvone (12.20%) being the major components present in C. carvi EO and linalool (76.41%), γ-terpinene (5.35%), and α-pinene (4.44%) in C. sativum EO. In comparison to standards, statistical analysis revealed that C. carvi EO showed high and significantly different (p < 0.05) antioxidant activity than C. sativum EO, but lower than the mixture. Moreover, the mixture exhibited two-times greater ferric ion reducing antioxidant power (FRAP) (IC50 = 11.33 ± 1.53 mg/mL) and equipotent chelating power (IC50 = 31.33 ± 0.47 mg/mL) than the corresponding references, and also potent activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50 = 19.00 ± 1.00 mg/mL), β-carotene (IC50 = 11.16 ± 0.84 mg/mL), and superoxide anion (IC50 = 10.33 ± 0.58 mg/mL) assays. Antimicrobial data revealed that single and mixture EOs were active against a panel of pathogenic microorganisms, and the mixture had the ability to kill more bacterial strains than each EO alone. Additionally, the anti-acetylcholinesterase and α-glucosidase inhibitory effect have been studied for the first time, highlighting the high inhibition effect of AChE by C. carvi (IC50 = 0.82 ± 0.05 mg/mL), and especially by C. sativum (IC50 = 0.68 ± 0.03 mg/mL), as well as the mixture (IC50 = 0.63 ± 0.02 mg/mL) compared to the reference drug, which are insignificantly different (p > 0.05). A high and equipotent antidiabetic activity was observed for the mixture (IC50 = 0.75 ± 0.15 mg/mL) when compared to the standard drug, acarbose, which is about nine times higher than each EO alone. Furthermore, pharmacokinetic analysis provides some useful insights into designing new drugs with favorable drug likeness and safety profiles based on a C. carvi and C. sativum EO mixture. In summary, the results of this study revealed that the combination of these EOs may be recommended for further food, therapeutic, and pharmaceutical applications, and can be utilized as medicine to inhibit several diseases. 相似文献
3.
Zied Zarai Houda Gharsallah Adnane Hammami Hafedh Mejdoub Sofiane Bezzine Youssef-Talel Gargouri 《Applied biochemistry and biotechnology》2012,168(4):877-886
In order to report pharmacological characterization of marine snail (Hexaplex trunculus) hepatopancreatic phospholipase A2 (mSDPLA2), we have talked for the first time the antimicrobial activity against different pathogenic bacterial strains, anti-chlamydial activity as well as its cytotoxic activity against McCoy cell lines. mSDPLA2, showed a high level of activity towards Gram-positive bacteria as Staphylococcus aureus and Staphylococcus epidermidis. Whereas Gram-negative bacteria, unfortunately, exhibited a higher resistance, mSDPLA2 was also found to have a strong cytotoxic activity, causing significant morphological alterations of the McCoy cell lines surfaces and to be a hinder to the proliferation. Moreover, mSDPLA2 proved to have a very potent anti-chlamydial activity. Over 95?% inhibition of chlamydial inclusions were obtained at a concentration of 10???g/ml of mSDPLA2 after 24?h postinfection. Interestingly, at a concentration of 10???g/ml of mSDPLA2, the proliferation of McCoy cells was not affected. Approximately 50?% inhibition of cell growth was obtained with a concentration of 37???g/mL of mSDPLA2. mSDPLA2 could be considered as an excellent candidate for the development of a new anti-infective agent. This enzyme showed significant antimicrobial activities. 相似文献
4.
Genetic diversity and haplotype structure of 21 Y‐STRs,including nine noncore loci,in South Tunisian Population: Forensic relevance 下载免费PDF全文
Faten Makki‐Rmida Arwa Kammoun Nadia Mahfoudh Adnene Ayadi Abdullah Ahmed Gibriel Bakhta Mallek Leila Maalej Zouheir Hammami Samir Maatoug Hafedh Makni Saber Masmoudi 《Electrophoresis》2015,36(23):2908-2913
Y chromosome STRs (Y‐STRs) are being used frequently in forensic laboratories. Previous studies of Y‐STR polymorphisms in different groups of the Tunisian population identified low levels of diversity and discrimination capacity (DC) using various commercial marker sets. This definitely limits the use of such systems for Y‐STRs genotyping in Tunisia. In our investigation on South Tunisia, 200 unrelated males were typed for the 12 conventional Y‐STRs included in the PowerPlex® Y System. Additional set of nine noncore Y‐STRs including DYS446, DYS456, DYS458, DYS388, DYS444, DYS445, DYS449, DYS710, and DYS464 markers were genotyped and evaluated for their potential in improving DC. Allele frequency, gene diversity, haplotype diversity (HD), and DC calculation revealed that DYS464 was the most diverse marker followed by DYS710 and DYS449 markers. The standard panel of 12 Y‐STRs (DC = 80.5%) and the nine markers were combined to obtain DC of 99%. Among the 198 different haplotypes observed, 196 haplotypes were unique (HD = 99.999). Out of the nine noncore set, six Y‐STRs (DYS458, DYS456, DYS449, DYS710, DYS444, and DYS464) had the greatest impact on enhancing DC. Our data provided putative Y‐STRs combination to be used for genetic and forensic applications. 相似文献
5.
Hafedh Ben Belgacem Sergio Conti Antonio DeSimone Stefan Müller 《Archive for Rational Mechanics and Analysis》2002,164(1):1-37
We derive an optimal scaling law for the energy of thin elastic films under isotropic compression, starting from three-dimensional nonlinear elasticity. As a consequence we show that any deformation with optimal energy scaling must exhibit fine-scale oscillations along the boundary, which coarsen in the interior. This agrees with experimental observations of folds which refine as they approach the boundary. We show that both for three-dimensional elasticity and for the geometrically nonlinear Föppl-von Kármán plate theory the energy of a compressed film scales quadratically in the film thickness. This is intermediate between the linear scaling of membrane theories which describe film stretching, and the cubic scaling of bending theories which describe unstretched plates, and indicates that the regime we are probing is characterized by the interplay of stretching and bending energies. Blistering of compressed thin films has previously been analyzed using the Föppl-von Kármán theory of plates linearized in the in-plane displacements, or with the scalar eikonal functional where in-plane displacements are completely neglected. The predictions of the linearized plate theory agree with our result, but the scalar approximation yields a different scaling. 相似文献
6.
Kamoun F Fguira IB Hassen NB Mejdoub H Lereclus D Jaoua S 《Applied biochemistry and biotechnology》2011,165(1):300-314
This study reports on the identification, characterization and purification of a new bacteriocin, named Bacthuricin F103,
from a Bacillus thuringiensis strain BUPM103. Bacthuricin F103 production began in the early exponential phase and reached a maximum in the middle of the
same phase. Two chromatographic methods based on high performance liquid chromatography and fast protein liquid chromatography
systems were used to purify Bacthuricin F103. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed that this
bacteriocin had a molecular weight of approximately 11 kDa. It also showed a wide range of thermostability of up to 80 °C
for 60 min and a broad spectrum of antimicrobial activity over a pH range of 3.0–10.0. This bacteriocin was noted, and for
the first time, to exhibit potent antimicrobial activity against Agrobacterium subsp. strains, the major causal agents of crown gall disease in tomato and vineyard crops, and against several challenging
organisms in food, such as Listeria monocytogenes and Bacillus cereus. Complete killing with immediate impact on cells was observed within a short period of time. The sequence obtained for Bacthuricin
F103 by direct N-terminal sequencing shared considerable homology with hemolysin. Bacthuricin F103 was noted to act through
the depletion of intracellular ions, which suggest that the cell membrane was a possible target to Bacthuricin F103. 相似文献
7.
In situ heating experiments using high-energy, high-intensity synchrotron radiation, can be successfully designed to study structural evolution with temperature of glassy materials. Coherent diffraction from glassy materials forms a succession of halos or diffraction maxima in reciprocal space and the variation with temperature, of the wave-vector Qmax or angular position of the first diffracted intensity I(Qmax) maximum below Tg can be used to determine the iso-structural volume expansion. In the present work we have obtained synchrotron X-ray diffraction patterns in transmission during in situ heating of a B2O3 glass. Samples were obtained by melting the B2O3 glass rods which were then air-cooled or liquid nitrogen-cooled. The evolution with temperature (and time) of the position of the first diffraction maximum of the diffraction pattern accurately reflected the thermal expansion coefficient and the relaxation behavior of the B2O3 glass. Such results allowed determination by diffraction of the glass transition temperature, Tg, at 580 K, as well as information on the structural relaxation during thermal annealing. The total volume changes due to relaxation were measured to be about 1.5 vol.% and 2.5 vol.%, for the air-cooled and the liquid nitrogen-cooled B2O3 glass, respectively. 相似文献
8.
R. Dhahri M. Hajlaoui M.A. Valente 《Journal of magnetism and magnetic materials》2009,321(11):1735-1738
Electrical conductance and X-ray diffraction (XRD) measurements of lanthanum-deficiency La1−x□xMnO3 (x=0.05, 0.10 and 0.20) polycrystalline samples were performed to examine the effect of the internal pressure at B-site on the conduction mechanism. The structural study reveals that all samples crystallize in the rhombohedral system. The electronic conduction appears to be thermally activated at high temperature, which indicates the presence of semiconductor behaviour. The increase of the x content converts 3x Mn3+ to 3x Mn4+ ions with smaller ionic radius, which reduces the internal pressure and leads to the increase of the one-electron bandwidth W. This increase causes the appearance of metallic behaviour at low temperature for x=0.10 and 0.20 content. 相似文献
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10.
Hafedh Rguigui 《Complex Analysis and Operator Theory》2018,12(7):1637-1656
This paper reports on the characterization of the quantum white noise (QWN) Gross Laplacian based on nuclear algebra of white noise operators acting on spaces of entire functions with \(\theta \)-exponential growth of minimal type. First, we use extended techniques of rotation invariance operators, the commutation relations with respect to the QWN-derivatives and the QWN-conservation operator. Second, we employ the new concept of QWN-convolution operators. As application, we study and characterize the powers of the QWN-Gross Laplacian. As for their associated Cauchy problem it is solved using a QWN-convolution and Wick calculus. 相似文献