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排序方式: 共有1204条查询结果,搜索用时 31 毫秒
1.
2.
Functional Binding Surface of a β‐Hairpin VEGF Receptor Targeting Peptide Determined by NMR Spectroscopy in Living Cells 下载免费PDF全文
Dr. Donatella Diana Anna Russomanno Dr. Lucia De Rosa Dr. Rossella Di Stasi Dr. Domenica Capasso Dr. Sonia Di Gaetano Dr. Alessandra Romanelli Dr. Luigi Russo Dr. Luca D. D'Andrea Prof. Roberto Fattorusso 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):91-95
In this study, the functional interaction of HPLW peptide with VEGFR2 (Vascular Endothelial Growth Factor Receptor 2) was determined by using fast 15N‐edited NMR spectroscopic experiments. To this aim, 15N uniformly labelled HPLW has been added to Porcine Aortic Endothelial Cells. The acquisition of isotope‐edited NMR spectroscopic experiments, including 15N relaxation measurements, allowed a precise characterization of the in‐cell HPLW epitope recognized by VEGFR2. 相似文献
3.
Zero-schemes on smooth complex projective varieties, forcing all elements of ample and free linear systems to be reducible, are studied. Relationships among the minimal length of such zero-schemes, the positivity of the line bundle associated with the linear system, and the dimension of the variety are established. Bad linear spaces are also investigated. 相似文献
4.
We consider a charged particle following the boundary of a two dimensional domain because a homogeneous magnetic field is
applied. We develop the basic scattering theory for the corresponding quantum mechanical edge states. The scattering operator
attains a limit for large magnetic fields which preserves Landau bands. We interpret the corresponding scattering phases in
terms of classical trajectories.
Communicated by Yosi Avron
submitted 23/02/05, accepted 3/05/05 相似文献
5.
DFT computational study of the mechanism of allyl halides carbonylation catalyzed by nickel tetracarbonyl 总被引:1,自引:0,他引:1
Bottoni A Miscione GP Novoa JJ Prat-Resina X 《Journal of the American Chemical Society》2003,125(34):10412-10419
A theoretical investigation at the DFT(B3LYP) level on the carbonylation reaction of allyl bromide catalyzed by nickel tetra-carbonyl Ni(CO)(4) is discussed. The computational results show the following: (i) Three main steps characterize the catalytic cycle: (a) an oxidative addition step, (b) a carbonylation step, and (c) a reductive elimination step where the acyl product is obtained and the catalyst is regenerated. (ii) Both Ni(CO)(3) and Ni(CO)(4) complexes can behave as "active" catalytic species. (iii) The oxidative addition leads to the formation of either eta(3) or eta(1)-allyl nickel complexes, which are involved in a fast equilibrium. (iv) The carbonylation occurs much more easily on the eta(1) than on the eta(3) intermediates. 相似文献
6.
Lucarini M Franchi P Pedulli GF Gentilini C Polizzi S Pengo P Scrimin P Pasquato L 《Journal of the American Chemical Society》2005,127(47):16384-16385
ESR spectroscopy has been used to study the interaction of para-pentylbenzyl hydroxyalkyl nitroxide with the monolayer of water-soluble protected gold clusters having a core diameter ranging from 1.6 to 5.3 nm. The solubilization of the nitroxide probe in the more hydrophobic environment of the monolayer strongly depends on the size of the gold core. In particular, the partition equilibrium constant increases as the nanoparticle diameter decreases. These results have been attributed to the different packing of the chains in the monolayer resulting from the different radius of curvature of the investigated nanoparticles. This represents, to the best of our knowledge, the first report demonstrating that the core size of metallic nanoparticles affects the solvating properties of the protective organic monolayer. 相似文献
7.
Raquel Peña-Alonso Gian Domenico Sorarù 《Journal of Sol-Gel Science and Technology》2007,43(3):313-319
The sol–gel method has been used for the synthesis of borosilicate gels from mixtures of methyltriethoxysilane (MTES) and
dimethyldiethoxysilane (DMDES) and boric acid. The use of boric acid, B(OH)3 allows the hydrolysis and condensation of hybrid silicon alkoxides without further addition of water or catalyst. The use
of difunctional silicon units, –(CH3)2SiO– promote the formation, during the sol–gel process, of linear oligomers which facilitate fiber drawing before gelation.
Gel characterization performed by FT-IR, XRD, TG-DTA and DCS analysis indicates the formation of a mixed network with incorporation
of the boron units via =B-O-Si≡ bridges. The formation of borosiloxane bonds seems favored by the presence of DMDES. SiBOC
glasses were obtained after pyrolysis of the borosilicate gels in argon atmosphere at 1000 °C. TG-DTA study indicates that
the ceramic yield decreases by increasing the amount of DMDES. Gel fibers were successfully prepared from convenient partially-aged
solutions by hand drawing. Pyrolysis of the obtained gel fibers under argon atmosphere at 1000 °C open the possibility to
produce SiBOC homogeneous glass fibers with diameter as low as 10 μm. 相似文献
8.
Gian Luigi Bendazzoli 《Theoretical chemistry accounts》2007,118(1):135-142
We present and discuss a variational single-product approximation to the van der Waals dispersion interaction leading to a
simple formula for C
6 that seems capable to give more than 99% of the ‘exact’ value. The formula is derived from Hylleraas’ variational principle
in the tensor product space of the interacting molecules and therefore enjoys bounding properties. The formula has been tested
by computing the C
6 dispersion constants of H–H, and, at Full CI level, of the following systems: He–He, He–Li, Li–Li, LiH–LiH, HF–HF. Connections
with the London formula are discussed.
Contribution to the Fernando Bernardi Memorial Issue. 相似文献
9.
The bond dissociation enthalpies (BDE) of several phenols containing electron-withdrawing substituents in the para position have been determined by means of the EPR radical equilibration technique. It has been found that CN, NO(2), CHO, COOR, and COOH induce an increase of the BDE value of the O-H bond, thus producing a worsening of the antioxidant activity of phenols, while Cl, Ph, and CH[double bond]CHPh show an opposite effect. The contributions of these substituents for the calculation of the BDE values in polysubstituted phenols by using the group additivity rule have also been derived. It is shown that this rule provides quite reliable predictions of bond strengths, so that the method can be conveniently used to estimate new data on substituted phenols. 相似文献
10.
Angela Lopedota Adriana Trapani Annalisa Cutrignelli Valentino Laquintana Nunzio Denora Massimo Franco Giuseppe Trapani Gaetano Liso 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):425-432
The objective of this work was to develop a novel microparticulate system based on the mucoadhesive polymer Eudragit-RS 100
and cyclodextrins (CDs), potentially useful for the oral administration of Glutathione (γ–glutamylcysteinylglycine, GSH).
For this purpose, an oil-in-oil (O/O) emulsion-solvent evaporation method was used for the preparation of microparticles (MPs)
containing GSH alone or together with one of the following CDs: α-, β-, γ-, methyl-β-(Me-β-), hydroxypropyl-β-(HP-β-) or sulfobutylether-β-cyclodextrin
(SBE7m-β-CD). MPs were obtained by emulsifying a mixture of Eudragit RS 100, GSH, CD and magnesium stearate in acetone or acetonitrile
with a mixture of liquid paraffin and Span 80. Size, encapsulation efficiency, and drug release of the prepared MPs were evaluated.
The results clearly indicated that all the examined properties were dependent on the water-miscible solvents and CD used.
In particular, MPs prepared by using acetone or acetonitrile showed different size distributions with mean diameters in the
ranges 82–350 and 15–22 μm, respectively. Moreover, encapsulation efficiency values were found to be high in all cases (71–99%)
and was significantly affected by the CD type. The GSH release rates were evaluated employing dissolution media with different
pH values (1.2, 6.8 and 7.4) and the following rank order was obtained for MPs prepared using acetone: MPs incorporating Me-β-CD > MPs
without CD > MPs incorporating the remaining CDs. On the other hand, MPs prepared using acetonitrile gave the highest GSH
release rate. Finally, stability of GSH encapsulated in MPs containing HP-β-CD to enzymatic attack by pepsin A, α-chymotrypsin,
and γ-glutamyltranspeptidase was also investigated. 相似文献