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31.
Mechanics of Composite Materials - Experimental results are presented on the onset and propagation of local delaminations caused by the interaction between specimen edges and intralaminar cracks in... 相似文献
32.
In the present paper we introduce the notion of a positive linear relation and we investigate the class of such operators. As well as placing the theory of positive operators in a natural setting, this structure seems to be interesting for the study of abstract boundary value problems. 相似文献
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Highly transparent, n-type conducting ZnO thin films were obtained by low temperature magnetron sputtering of (Co, Al) co-doped ZnO nanocrystalline aerogels. The nanoparticles of ∼30 nm size were synthesized by a sol-gel method using supercritical drying in ethyl alcohol. The structural, optical and electrical properties of the films were investigated. The ZnO films were polycrystalline textured, preferentially oriented with the (0 0 2) crystallographic direction normal to the film plane. The films show within the visible wavelength region an optical transmittance of more than 90% and a low electrical resistivity of 3.5 × 10−4 Ω cm at room temperature. 相似文献
35.
Leila Ayadi Damien Forget Alain Martelli Jean-François Constant Martine Demeunynck Christian Coulombeau 《Theoretical chemistry accounts》2000,104(3-4):284-289
We use molecular modeling calculations to study the structure and the flexibility of abasic (AP sites) and for the design
of anticancer drugs targeted against AP sites. For either adenine or cytosine on the opposing strand within the same sequence
context, the results are in line with experimental data which show that the two unpaired bases lead to intrahelical forms,
but with differences in induced curvature. Results on flexibility, indicate that the two duplexes have the same bending rigidity
for cytosine. In previous work a series of polyfunctional molecules, such as ATAc, were designed to selectively recognize
and cleave abasic sites in DNA. The nitrobenzamide group which was added to the ATAc molecule to obtain a new molecule, termed
ATAc4, can induce a second lesion under irradiation in close proximity to the abasic site. The different conformations of
ATAc4 interacting with a DNA oligomer containing a stable analog of the abasic site were compared to the photoinduced cleavage
pattern observed experimentally.
Received: 16 September 1999 / Accepted: 3 February 2000 / Published online: 12 May 2000 相似文献
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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
39.
We prove real Paley-Wiener type theorems for the Dunkl transform ℱ
D
on the space
of tempered distributions. Let T∈S′(ℝ
d
) and Δ
κ
the Dunkl Laplacian operator. First, we establish that the support of ℱ
D
(T) is included in the Euclidean ball
, M>0, if and only if for all R>M we have lim
n→+∞
R
−2n
Δ
κ
n
T=0 in S′(ℝ
d
). Second, we prove that the support of ℱ
D
(T) is included in ℝ
d
∖B(0,M), M>0, if and only if for all R<M, we have lim
n→+∞
R
2n
ℱ
D
−1(‖y‖−2n
ℱ
D
(T))=0 in S′(ℝ
d
). Finally, we study real Paley-Wiener theorems associated with
-slowly increasing function.
相似文献
40.
K. Nahdi M. Férid Malika Trabelsi Ayadi 《Journal of Thermal Analysis and Calorimetry》2009,96(2):455-461
The aim of this work is to highlight the importance of controlling the residual water vapour pressure above the sample as
well as the rate of the thermal decomposition during the thermal dehydration of cerium cyclotriphosphate trihydrate CeP3O9·3H2O.
For this reason, the dehydration of the titled compound was followed by both techniques: the constant rate thermal analysis
at P
H2O = 5 hPa and the conventional TG-DTA in air. 相似文献