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991.
Giuseppe Fiume Annalisa Rossi Emanuela Di Salle Carmen Spatuzza Massimo Mallardo Giuseppe Scala Ileana Quinto 《Computational Biology and Chemistry》2009,33(6):434-439
MicroRNAs (miRNAs) are small single-stranded RNA molecules that play an essential role in the regulation of gene expression and cell physiology. Gene rearrangements occurring in the miRNA sequence are associated with cancer. The IBTK genetic locus is located in the genomic sequence 6q14.1 that undergoes chromosomal aberration in lymphoproliferative disorders. The IBTK gene encodes the proteins IBtk-α, β and γ that regulate the B cell receptor signalling through Bruton's tyrosine kinase, which promotes B cell survival and differentiation. Pro-MirII-based analysis predicted four precursors of microRNAs (pre-miR) encoded by introns 17, 21, 26 and the 3′ un-translated region of the IBTK gene. Pre-miR-IBTK3, which was encoded by intron 26, was the effective substrate of RNase III Dicer in vitro as well as the precursor of an IBtk miRNA generated in vivo. By CLUSTALW-based analysis, pre-miR-IBTK3 homologues were found in Pan troglodytes, Pongo pygmaeus and Macaca mulatta, suggesting an evolutionary conserved function in primates. 相似文献
992.
Summary: In this work the analysis of an accident in transport of dangerous goods is proposed. The objective of this study is to contribute to the determination of the causes that brought about the self-polymerization of commercial divinylbenzene (DVB 63%) contained in an iso-container, in order to prevent this accident to happen in the future. Time and conditions during transport and storage of monomers (in particular the storage temperature) are very important factors, that affect the self-polymerization aptitude of these substances. To stabilize this monomer, usually 4-tert-Butylcatechol (TBC) is added at a level of 900–1200 ppm by weight to act as an inhibitor to prevent the self-initiated autopolymerization of the material. In particular one hypothesis has been investigated: probably the quantity of oxygen in the tanker was insufficient to activate properly the inhibition mechanism of TBC. From this consideration the self-polymerization of DVB and the inhibition mechanism of TBC have been studied as a function of temperature and monomer exposure to air. Different calorimetric techniques have been applied, in particular Differential Scanning Calorimetry and Adiabatic Calorimetry, to investigate the causes of the accident. 相似文献
993.
Diego Venegas-Yazigi Patricio Hermosilla-Ibáñez Juan Costamagna Evgenia Spodine Andrés Vega Verónica Paredes-García Eric Le Fur 《Macromolecular Symposia》2011,304(1):80-86
Summary: A novel coordination polymer[{Cu(en)2}(V10O28)]n · 2n[Cu(en)2(H2O)] · 2n(H3BO3) · 2n(H2O) was obtained by hydrothermal reaction. The compound crystallizes in the monoclinic crystal system, in the C2/c space group, with a = 26.490 (3) Å; b = 11.6558 (11) Å; c = 19.8426 (19) Å; β = 124.011 (1)°; V = 5078.6(8) Å3. The solid structure is formed by polymeric chains, [Cu(en)2(H2O)]2+ cations, and boric acid and water solvate molecules, stabilized through a multiple hydrogen bond network. 相似文献
994.
Pedro Aguirre Kareen Brown Diego Venegas-Yazigi Verónica Paredes-García Evgenia Spodine 《Macromolecular Symposia》2011,304(1):65-71
Summary: The search of new inorganic materials with better catalytic properties is an important field of research. Reusability, efficiency and atom economy correspond to the main parameters to characterize a catalyst. In this work, we inform the effectiveness of [Cu(H2btec)(bipy)]∞ (H4btec = 1,2,4,5-benzenetetracarboxylic acid) as an heterogeneous coordination polymer catalyst for the oxidation of olefins. The catalyst exhibits good atom economy, high turnover numbers and good selectivity for a ratio of 4000/1 substrate/catalyst for cyclohexene and styrene oxidation. Furthermore, the catalyst was recycled and reused for seven consecutive cycles, retaining the structural integrity and effectiveness as catalyst in all the performed experiments. 相似文献
995.
Antonello Santini Rosalia Ferracane Giuseppe Meca Alberto Ritieni 《Analytical and bioanalytical chemistry》2009,395(5):1253-1260
In recent years consumers and the scientific community have become increasingly interested in food safety, making it a major
focus among the objectives of the international institutions responsible for food safety monitoring, e.g. the European Union
or the EFSA. Aspects attracting much attention are the colonization of food by microscopic fungi which, under aerobic conditions,
produce toxic secondary metabolites known as mycotoxins, and the accumulation of these toxins in the food chain. Numerous
studies of surveillance, detoxification, prevention, and toxicological aspects reported in the literature mostly concentrate
on major mycotoxins such as aflatoxins, ochratoxin A, trichothecenes, and fumonisins; studies on toxic secondary metabolites
of mycotoxins are less common or are only just beginning. Among the molecules of interest, the family of beauvericin and fusaproliferin
is certainly the most interesting. The objective of this review is to summarize reported data and the methods used to extract
and quantify beauvericin and fusaproliferin in food matrices. 相似文献
996.
We give dimension-free regularity conditions for a class of possibly degenerate sub-elliptic equations in the Heisenberg group exhibiting super-quadratic growth in the horizontal gradient; this solves an issue raised in [J.J. Manfredi, G. Mingione, Regularity results for quasilinear elliptic equations in the Heisenberg group, Math. Ann. 339 (2007) 485-544], where only dimension dependent bounds for the growth exponent are given. We also obtain explicit a priori local regularity estimates, and cover the case of the horizontal p-Laplacean operator, extending some regularity proven in [A. Domokos, J.J. Manfredi, C1,α-regularity for p-harmonic functions in the Heisenberg group for p near 2, in: Contemp. Math., vol. 370, 2005, pp. 17-23]. In turn, using some recent techniques of Caffarelli and Peral [L. Caffarelli, I. Peral, On W1,p estimates for elliptic equations in divergence form, Comm. Pure Appl. Math. 51 (1998) 1-21], the a priori estimates found are shown to imply the suitable local Calderón-Zygmund theory for the related class of non-homogeneous, possibly degenerate equations involving discontinuous coefficients. These last results extend to the sub-elliptic setting a few classical non-linear Euclidean results [T. Iwaniec, Projections onto gradient fields and Lp-estimates for degenerated elliptic operators, Studia Math. 75 (1983) 293-312; E. DiBenedetto, J.J. Manfredi, On the higher integrability of the gradient of weak solutions of certain degenerate elliptic systems, Amer. J. Math. 115 (1993) 1107-1134], and to the non-linear case estimates of the same nature that were available in the sub-elliptic setting only for solutions to linear equations. 相似文献
997.
Nadia?Benhalima Khaled?Toubal Abdelkader?ChouaihEmail author Giuseppe?Chita Sabino?Maggi Ayada?Djafri Fodil?Hamzaoui 《Journal of chemical crystallography》2011,41(11):1729-1736
Abstract
We report here the synthesis of (Z)-5-(4-nitrobenzyliden)-3-N(2-ethoxyphenyl)-2-thioxo-thiazolidin-4-one (ARNO) compound. The crystal structure has been determined by X-ray diffraction. The compound crystallizes in the triclinic system with space group P[`1] P\bar{1} and cell parameters: a = 9.1289(19), b = 9.3717(7), c = 12.136(3) ?, α = 102.133(11)°, β = 90.99(2)°, γ = 117.165(9)°, V = 895.4(3) ?3 and Z = 2. The structure has been refined to a final R = 0.05 for 2591 observed reflections. The refined structure was found to be significantly non planar. The molecule exhibits intermolecular hydrogen bond of type C–H⋯O and C–H⋯S. ab initio calculations were also were performed at Hartree–Fock and density functional theory levels. The full HF and DFT geometry optimization was carried out using LANL2DZ, 6-31G* and B3LYP/6-31+G** basis sets. The optimized geometry of the title compound was found to be consistent structure determined by X-ray diffraction. The minimum energy of geometrical structure is obtained by using level HF/LANL2DZ basis sets. 相似文献998.
Diego Dominici 《Journal of Computational and Applied Mathematics》2009,233(3):708-718
We analyze the Bell polynomials Bn(x) asymptotically as n→∞. We obtain asymptotic approximations from the differential-difference equation which they satisfy, using a discrete version of the ray method. We give some examples showing the accuracy of our formulas. 相似文献
999.
Giuseppe Borrelli 《manuscripta mathematica》2009,130(4):523-531
We prove that if the bicanonical map of a minimal surface of general type S with p
g
= q = 1 and KS2=8{K_{S}^2=8} is nonbirational, then it is a double cover onto a rational surface. An application of this theorem is the complete classification
of minimal surfaces of general type with pg=q=1, KS2=8{p_{g}=q=1, K_{S}^2=8} and nonbirational bicanonical map. 相似文献
1000.
Paolo Boggiatto Giuseppe De Donno Alessandro Oliaro 《Mathematische Nachrichten》2009,282(12):1656-1663
We study boundedness and compactness properties for the Weyl quantization with symbols in Lq (?2d ) acting on Lp (?d ). This is shown to be equivalent, in suitable Banach space setting, to that of the Wigner transform. We give a short proof by interpolation of Lieb's sufficient conditions for the boundedness of the Wigner transform, proving furthermore that these conditions are also necessary. This yields a complete characterization of boundedness for Weyl operators in Lp setting; compactness follows by approximation. We extend these results defining two scales of spaces, namely L*q (?2d ) and L?q (R2d ), respectively smaller and larger than the Lq (?2d ),and showing that the Weyl correspondence is bounded on L*q (R2d ) (and yields compact operators), whereas it is not on L?q (R2d ). We conclude with a remark on weak‐type Lp boundedness (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献