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排序方式: 共有1018条查询结果,搜索用时 15 毫秒
21.
Massimo Tosolini Teresa Gianferrara Giuliana Mion Luca Dovigo Fabrizio Mancin 《Supramolecular chemistry》2020,32(2):91-105
ABSTRACTA new family of conjugates between the Hoechst minor groove binder and the TACN metal ion ligand connected through hydrophobic alkyl or more hydrophilic oxyethyl linkers of different length has been prepared. The linkers are connected to the convex side of the Hoechst skeleton thus forcing the TACN ligand to exit the minor groove and interact with the phosphate backbone of DNA. The conjugates preserve the binding mode of Hoechst with an affinity influenced by the nature of the linker, the more hydrophobic being the more efficient. Coordination of Cu(II) or Zn(II) poorly affect these parameters. Nevertheless, the Zn(II) complex bearing a C6 linear alkyl linker induced a modest but reproducible acceleration of the hydrolytic cleavage of DNA which can be ascribed to the ability of the conjugate to deliver the hydrolytic subunit close to the DNA phosphodiester bonds. 相似文献
22.
23.
Remilekun O. Lawal Fabrizio Donnarumma Kermit K. Murray 《Journal of mass spectrometry : JMS》2019,54(3):281-287
A 193‐nm wavelength deep ultraviolet laser was used for ambient laser ablation electrospray ionization mass spectrometry of biological samples. A pulsed ArF excimer laser was used to ablate solid samples, and the resulting plume of the desorbed material merged with charged electrospray droplets to form ions that were detected with a quadrupole time‐of‐flight mass spectrometer. Solutions containing peptide and protein standards up to 66‐kDa molecular weight were deposited on a metal target, dried, and analyzed. No fragmentation was observed from peptides and proteins as well as from the more easily fragmented vitamin B12 molecule. The mass spectra contained peaks from multiply charged ions that were identical to conventional electrospray. Deep UV laser ablation of tissue allowed detection of lipids from untreated tissue. The mechanism of ionization is postulated to involve absorption of laser energy by a fraction of the analyte molecules that act as a sacrificial matrix or by residual water in the sample. 相似文献
24.
Tonietto Serena Nestola Fabrizio Redhammer Gunther J. Silvestri Alberta Molin Gianmario Bruno Marco 《Applied Physics A: Materials Science & Processing》2011,103(1):207-212
The mineral inclusions of two orange glass tesserae from paleo-Christian mosaics were investigated in order to derive the
melting temperature reached during their production (sourced from Padua and Vicenza, Veneto region, Italy). In particular,
clinopyroxene crystals were studied by single-crystal X-ray diffraction and electron microprobe WDS analysis. The crystals
show C2/c symmetry, typical of disordered Ca/Na and Mg/Al distributions indicating high-temperature of formation (>700°C). The cation
site populations were obtained by combining results from the two experimental techniques enabled us to derive the following
stoichiometric formula:
lM2[Ca0.819Na0.172Mn0.006K0.003]M1[Mg0.765Fe3+0.210 Cu0.015Ti0.006Zn0.006]T[Si1.933Al0.037Sn0.024]O6\begin{array}{l}{}^{M2}[\mathrm{Ca}_{0.819}\mathrm{Na}_{0.172}\mathrm{Mn}_{0.006}\mathrm{K}_{0.003}]{}^{M1}[\mathrm{Mg}_{0.765}\mathrm{Fe}^{3+}_{0.210}\\[3pt]\quad{}\mathrm{Cu}_{0.015}\mathrm{Ti}_{0.006}\mathrm{Zn}_{0.006}]{}^{T}[\mathrm{Si}_{1.933}\mathrm{Al}_{0.037}\mathrm{Sn}_{0.024}]\mathrm{O}_{6}\end{array} 相似文献
25.
Multivariate Hierarchical Copulas with Shocks 总被引:2,自引:0,他引:2
Fabrizio Durante Marius Hofert Matthias Scherer 《Methodology and Computing in Applied Probability》2010,12(4):681-694
A transformation to obtain new multivariate hierarchical copulas, starting with an arbitrary copula, is introduced. In addition
to the hierarchical structure, the presented construction principle explicitly supports singular components. These may be
interpreted as the effect of local or global shocks to the underlying random variables. A large spectrum of dependence patterns
can be achieved by the presented transformation, which seems promising for practical applications. Moreover, copulas arising
from this construction are similarly admissible with respect to analytical tractability and sampling routines as the original
copula. Finally, several well-known families of copulas may be interpreted as special cases. 相似文献
26.
Fabrizio Cuccu Behrouz Emamizadeh Giovanni Porru 《Applied Mathematics and Optimization》2010,62(2):169-184
This paper is concerned with minimization and maximization problems of eigenvalues. The principal eigenvalue of a differential
operator is minimized or maximized over a set which is formed by intersecting a rearrangement class with an affine subspace
of finite co-dimension. A solution represents an optimal design of a 2-dimensional composite membrane Ω, fixed at the boundary,
built out of two different materials, where certain prescribed regions (patches) in Ω are occupied by both materials. We prove
existence results, and present some features of optimal solutions. The special case of one patch is treated in detail. 相似文献
27.
We study the properties of the double-frequency sine-Gordon model in the vicinity of the Ising quantum phase transition displayed by this model. Using a mapping onto a generalized lattice quantum Ashkin–Teller model, we obtain critical and nearly-off-critical correlation functions of various operators. We discuss applications of the double-sine-Gordon model to one-dimensional physical systems, like spin chains in a staggered external field and interacting electrons in a staggered potential. 相似文献
28.
Baltrusaitis RM Becker JJ Blaylock GT Brown JS Bunnell KO Burnett TH Cassell RE Coffman D Cook V Coward DH Cui H Del Papa C Dorfan DE Duncan AL Einsweiler KF Eisenstein BI Fabrizio R Gladding G Grancagnolo F Hamilton RP Hauser J Heusch CA Hitlin DG Köpke L Mockett PM Moss L Mozley RF Nappi A Odian A Partridge R Perrier J Plaetzer SA Richman JD Roehrig JR Russell JJ Sadrozinski HF Scarlatella M Schalk TL Schindler RH Seiden A Sleeman JC Spadafora AL Thaler JJ Toki W Unno Y Villa F Wattenberg A 《Physical review letters》1985,55(17):1723-1726
29.
Particularly-shaped silver nanostructures are successfully applied in many scientific fields, such as nanotechnology, catalysis, (nano)engineering, optoelectronics, and sensing. In recent years, the production of shape-controlled silver-based nanostructures and the knowledge around this topic has grown significantly. Hence, on the basis of the most recent results reported in the literature, a critical analysis around the driving forces behind the synthesis of such nanostructures are proposed herein, pointing out the important role of surface-regulating agents in driving crystalline growth by favoring (or opposing) development along specific directions. Additionally, growth mechanisms of the different morphologies considered here are discussed in depth, and critical points highlighted. 相似文献
30.
The European Physical Journal E - A common simplification used in different physical contexts by both experimentalists and theoreticians when dealing with essentially non-spherical drops is... 相似文献
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