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111.
Repeated fractionation of the acetylated methanol extract of Prasium majus afforded acetylated derivatives of a new iridoid glycoside hamighriprasin (1), myoporoside (2), beta-D-glycopyranose (3) and saccharose (4). The structures of 1 and 2 were established by interpretation of 1D and 2D NMR data of their corresponding acetylated derivatives and by comparison with the literature. 相似文献
112.
The flowers of Pulicaria laciniata (Coss. et Kral.) Thell. (Asteraceae) afforded a new sesquiterpene acid 1, named lacitemzine together with the three known compounds, 4-hydroxy-3-methoxypyridine 2, β-sitosterol-3-O-β-d-glucoside 3 and 1,3,5-trimethoxybenzene 4. The structure of compound 1, 2-(2,6-dimethyl-3,4,5,6,7,8,9,10-octahydro-5,8-oxaazulen-9-yl)acrylic acid, contains a guaiane skeleton and was elucidated by spectroscopic procedures including 2D-NMR and X-ray diffraction. 相似文献
113.
The pooling layer is at the heart of every convolutional neural network (CNN) contributing to the invariance of data variation. This paper proposes a pooling method based on Zeckendorf’s number series. The maximum pooling layers are replaced with Z pooling layer, which capture texels from input images, convolution layers, etc. It is shown that Z pooling properties are better adapted to segmentation tasks than other pooling functions. The method was evaluated on a traditional image segmentation task and on a dense labeling task carried out with a series of deep learning architectures in which the usual maximum pooling layers were altered to use the proposed pooling mechanism. Not only does it arbitrarily increase the receptive field in a parameterless fashion but it can better tolerate rotations since the pooling layers are independent of the geometric arrangement or sizes of the image regions. Different combinations of pooling operations produce images capable of emphasizing low/high frequencies, extract ultrametric contours, etc. 相似文献
114.
Hichem Hajaiej 《Annali di Matematica Pura ed Applicata》2010,189(3):395-401
For a large class of supermodular integrands, we establish conditions under which balls are the unique (up to translations)
maximizers of the Riesz-type functionals with constraints. 相似文献
115.
Inhibition of Fungi and Gram-Negative Bacteria by Bacteriocin BacTN635 Produced by Lactobacillus plantarum sp. TN635 总被引:1,自引:0,他引:1
Slim Smaoui Lobna Elleuch Wacim Bejar Ines Karray-Rebai Imen Ayadi Bassem Jaouadi Florence Mathieu Hichem Chouayekh Samir Bejar Lotfi Mellouli 《Applied biochemistry and biotechnology》2010,162(4):1132-1146
The aim of this study was to evaluate 54 lactic acid bacteria (LAB) strains isolated from meat, fermented vegetables and dairy products for their capacity to produce antimicrobial activities against several bacteria and fungi. The strain designed TN635 has been selected for advanced studies. The supernatant culture of this strain inhibits the growth of all tested pathogenic including the four Gram-negative bacteria (Salmonella enterica ATCC43972, Pseudomonas aeruginosa ATCC 49189, Hafnia sp. and Serratia sp.) and the pathogenic fungus Candida tropicalis R2 CIP203. Based on the nucleotide sequence of the 16S rRNA gene of the strain TN635 (1,540 pb accession no FN252881) and the phylogenetic analysis, we propose the assignment of our new isolate bacterium as Lactobacillus plantarum sp. TN635 strain. Its antimicrobial compound was determined as a proteinaceous substance, stable to heat and to treatment with surfactants and organic solvents. Highest antimicrobial activity was found between pH 3 and 11 with an optimum at pH?=?7. The BacTN635 was purified to homogeneity by a four-step protocol involving ammonium sulfate precipitation, centrifugal microconcentrators with a 10-kDa membrane cutoff, gel filtration Sephadex G-25, and C18 reverse-phase HPLC. SDS-PAGE analysis of the purified BacTN635, revealed a single band with an estimated molecular mass of approximately 4 kDa. The maximum bacteriocin production (5,000 AU/ml) was recorded after a 16-h incubation in Man, Rogosa, and Sharpe (MRS) medium at 30?°C. The mode of action of the partial purified BacTN635 was identified as bactericidal against Listeria ivanovii BUG 496 and as fungistatic against C. tropicalis R2 CIP203. 相似文献
116.
Dr. Mohammed Hichem Mortad 《Integral Equations and Operator Theory》2009,64(3):399-408
We give a spectral analysis of some unbounded normal product HK of two self-adjoint operators H and K (which appeared in [7]) and we say why it is not self-adjoint even if the spectrum of one of the operators is sufficiently
“asymmetric”. Then, we investigate the self-adjointness of KH (given it is normal) for arbitrary self-adjoint H and K by giving a counterexample and some positive results and hence finishing off with the whole question of normal products of
self-adjoint operators (appearing in [1, 7, 12]).
The author was supported in part by CNEPRU: B01820070020 (Ministry of Higher Education, Algeria). 相似文献
117.
Two new phytochemical compounds, Tetranins A and B, 1-(3,5'-dihydroxy-4'-méthoxyphenyl)-2-phenylethanol 1 and 5,2'-dihydroxy-5'-methoxy-6,7-methylenedioxy-isoflavone 2, were isolated from the EtOAc extract of Salsola tetrandra roots. They exhibited a significant antioxidant effect in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assays. Their structures were elucidated by extensive spectroscopic methods including 1-D-((1)H and (13)C) and 2-D-NMR experiments (CHcorr, HMBC, (1)H-(1)H COSY and NOESY) as well as high-resolution ES-MS and they were found to be quite active as antioxidants in the DPPH and ABTS assays. 相似文献
118.
Michel Cristofol Patricia Gaitan Hichem Ramoul Masahiro Yamamoto 《Applicable analysis》2013,92(11):2073-2081
In this article, we consider a nonlinear parabolic system with two components and prove a stability estimate of Lipschitz type in determining two coefficients of the system by data of only one component. The main idea for the proof is a Carleman estimate. 相似文献
119.
Hichem Mrabet Author Vitae Iyad Dayoub Author Vitae Rabah Attia Author Vitae Walaa Hamouda Author Vitae 《Optics Communications》2010,283(21):4234-4241
In this paper, we report the modal dispersion of silica graded-index optical fibers as a function of the input mode parameters and lunching conditions in local area network (LAN) context. In that, we examine the mode-depending parameters, namely, modal delay, modal attenuation and mode-coupling effects as a function of wavelength. We show that the number of excited mode groups depends strongly on the spot beam radius when the fiber is excited with an axial Gaussian beam where we find an optimal axial diameter exciting only two mode groups. We present a comparison of the number of excited mode groups, the optimal spot radius beam, the signal penalty and the 3-dB baseband bandwidth enhancement for the optimal axial launching compared with full mode excitation, offset launching and mode-field matched axial launching. 相似文献
120.
In this Note, we consider the problem of the existence of conformal metrics with prescribed scalar curvature on the standard sphere , . We give new existence and multiplicity results based on a new Euler–Hopf formula type. Our argument also has the advantage of extending the well known results due to Y. Li (1995) [10]. 相似文献