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排序方式: 共有993条查询结果,搜索用时 15 毫秒
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Simone Zanella Dr. Michele Mingozzi Alberto Dal Corso Dr. Roberto Fanelli Dr. Daniela Arosio Prof. Dr. Marco Cosentino Dr. Laura Schembri Dr. Franca Marino Dr. Marta De Zotti Prof. Dr. Fernando Formaggio Dr. Luca Pignataro Prof. Dr. Laura Belvisi Prof. Dr. Umberto Piarulli Prof. Dr. Cesare Gennari 《ChemistryOpen》2015,4(5):633-641
A dual-action ligand targeting both integrin αVβ3 and vascular endothelial growth factor receptors (VEGFRs), was synthesized via conjugation of a cyclic peptidomimetic αVβ3 Arg-Gly-Asp (RGD) ligand with a decapentapeptide. The latter was obtained from a known VEGFR antagonist by acetylation at the Lys13 side chain. Functionalization of the precursor ligands was carried out in solution and in the solid phase, affording two fragments: an alkyne VEGFR ligand and the azide integrin αVβ3 ligand, which were conjugated by click chemistry. Circular dichroism studies confirmed that both the RGD and VEGFR ligand portions of the dual-action compound substantially adopt the biologically active conformation. In vitro binding assays on isolated integrin αVβ3 and VEGFR-1 showed that the dual-action conjugate retains a good level of affinity for both its target receptors, although with one order of magnitude (10/20 times) decrease in potency. The dual-action ligand strongly inhibited the VEGF-induced morphogenesis in Human Umbilical Vein Endothelial Cells (HUVECs). Remarkably, its efficiency in preventing the formation of new blood vessels was similar to that of the original individual ligands, despite the worse affinity towards integrin αVβ3 and VEGFR-1. 相似文献
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Mechanism of Thyroxine Deiodination by Naphthyl‐Based Iodothyronine Deiodinase Mimics and the Halogen Bonding Role: A DFT Investigation 下载免费PDF全文
Mariagrazia Fortino Prof. Dr. Tiziana Marino Prof. Nino Russo Prof. Dr. Emilia Sicilia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(23):8554-8560
This paper deals with a systematic density functional theory (DFT) study aiming to unravel the mechanism of the thyroxine (T4) conversion into 3,3′,5‐triiodothyronine (rT3) by using different bio‐inspired naphthyl‐based models, which are able to reproduce the catalytic functions of the type‐3 deiodinase ID‐3. Such naphthalenes, having two selenols, two thiols, and a selenol–thiol pair in peri positions, which were previously synthesized and tested in their deiodinase activity, are able to remove iodine selectively from the inner ring of T4 to produce rT3. Calculations were performed including also an imidazole ring that, mimicking the role of the His residue, plays an essential role deprotonating the selenol/thiol moiety. For all the used complexes, the calculated potential energy surfaces show that the reaction proceeds via an intermediate, characterized by the presence of a X?I?C (X=Se, S) halogen bond, whose transformation into a subsequent intermediate in which the C?I bond is definitively cleaved and the incipient X?I bond is formed represents the rate‐determining step of the whole process. The calculated trend in the barrier heights of the corresponding transition states allows us to rationalize the experimentally observed superior deiodinase activity of the naphthyl‐based compound with two selenol groups. The role of the peri interactions between chalcogen atoms appears to be less prominent in determining the deiodination activity. 相似文献
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Frontispiece: Gd‐DTPA‐Dopamine‐Bisphytanyl Amphiphile: Synthesis,Characterisation and Relaxation Parameters of the Nanoassemblies and Their Potential as MRI Contrast Agents 下载免费PDF全文
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Prof. Dr. A. Campo 《Heat and Mass Transfer》1982,17(1):1-9
A method of analysis is described which yields quasianalytical solutions for one and multidimensional unsteady heat conduction problems with linearly dependent thermal properties, such as thermal conductivity and volumetric specific heat. The method accomodates rather general thermal boundary conditions including arbitrary variations in surface temperature or in surface heat flux or a convective exchange with a fluid having even varying temperature. Once the solution for the identical problem but with constant properties has been developed, its practical realization is rather direct, being facilitated by a reduced number of iterations. The four applied examples given in this work show that a wide variety of nonlinear heat conduction problems can be tackled by this procedure without much difficulty. These simple solutions compare favorably with more laborious results reported in the archival heat transfer literature.
Nomenclature a side of square bar - B i0 reference Biot number,hR/k0 - B i0 T transformed Biot number, equation (16) - c geometric parameter, equation (8) - h convective coefficient - k thermal conductivity - k 0 value ofk atT 0 - K dimensionless thermal conductivity,k/k 0 - K i value ofK at i - K i+1 value ofK at i+1 - m k slope of theK- line, equation (3) - m s slope of theS- line, equation (4) - R characteristic length - s volumetric specific heat - s 0 value of s at T0 - S dimensionless volumetric specific heat, s/s0 - S i value ofS at i - S i+1 value of S at i+1 - t time - T temperature - T 0 reference temperature - x, y cartesian coordinates - X, Y dimensionless cartesian coordinates,x/a andy/a - thermal diffusivity - k transformed time, equation (11) - s transformed time, equation (37) - k dimensionless time for variable conductivity, equation (8) - s dimensionless time for variable specific heat, equation (34) - dimensionless temperature,T/T 0 - dimensionless coordinate,r/R - 0 value of at T0 - i lower value of the interval (i, i+1) - i+1 upper value of the interval (i, i+1 相似文献
Berechnung nichtstationärer Wärmeleitvorgänge mit linear temperaturabhängigen Stoffwerten aus der Lösung für konstante Stoffwerte
Zusammenfassung Es werden quasi-analytische Lösungen für ein- und mehrdimensionale nichtstationäre Wärmeleitprobleme mit linear temperaturabhängigen Stoffwerten, wie Wärmeleitfähigkeit und volumetrische Wärmekapazität, mitgeteilt. Die Methode gilt für recht allgemeine Randbedingungen wie beliebige Veränderungen der Oberflächentemperatur, der Wärmestromdichte oder auch konvektiven Wärmeaustausch mit veränderlicher Fluidtemperatur. Ist die Lösung für das identische Problem mit konstanten Stoffwerten bekannt, kann die Methode direkt mit einer begrenzten Zahl von Iterationen angewandt werden. Die vier hier mitgeteilten Beispiele zeigen, daß eine große Zahl nichtlinearer Wärmeleitprobleme auf diese Weise ohne Schwierigkeit angepackt werden können. Die einfachen Lösungen stimmen befriedigend mit komplizierteren Ergebnissen aus der Literatur überein.
Nomenclature a side of square bar - B i0 reference Biot number,hR/k0 - B i0 T transformed Biot number, equation (16) - c geometric parameter, equation (8) - h convective coefficient - k thermal conductivity - k 0 value ofk atT 0 - K dimensionless thermal conductivity,k/k 0 - K i value ofK at i - K i+1 value ofK at i+1 - m k slope of theK- line, equation (3) - m s slope of theS- line, equation (4) - R characteristic length - s volumetric specific heat - s 0 value of s at T0 - S dimensionless volumetric specific heat, s/s0 - S i value ofS at i - S i+1 value of S at i+1 - t time - T temperature - T 0 reference temperature - x, y cartesian coordinates - X, Y dimensionless cartesian coordinates,x/a andy/a - thermal diffusivity - k transformed time, equation (11) - s transformed time, equation (37) - k dimensionless time for variable conductivity, equation (8) - s dimensionless time for variable specific heat, equation (34) - dimensionless temperature,T/T 0 - dimensionless coordinate,r/R - 0 value of at T0 - i lower value of the interval (i, i+1) - i+1 upper value of the interval (i, i+1 相似文献
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