Highlights? CPYPP binds to DOCK2 DHR-2 domain and inhibits its catalytic activity ? CPYPP inhibits DOCK2-mediated Rac activation in cells ? The structural features of CPYPP required for its inhibitory effect were revealed ? CPYPP inhibits lymphocyte migration and activation in vitro and in vivo 相似文献
We predict the elastic properties of mixed amphiphilic monolayers in the swollen state within the blob model using scaling
arguments. First the elastic moduli and the spontaneous curvature of a bimodal brush are determined as a function of the composition
and the relative chain length. We obtain simple and useful scaling functions which interpolate between the elastic moduli
of a pure short-chain brush and a pure long-chain brush. By using the analogy between block copolymer interfaces and polymeric
brushes, the effect of mixing on self-assembled diblock copolymer monolayers is investigated in the swollen state. We calculate
various interfacial properties, such as the equilibrium surface coverage, interface curvature, and the mixing free energy
as a function of the composition. In general, we find a nonlinear dependence on the composition, which deviates from the simple
linear averaging of the properties of pure components. Our results are used to discuss a recent experiment on the effect of
amphiphilic block copolymers on the efficiency of microemulsions.
Received 29 December 2000 and Received in final form 19 March 2001 相似文献
We have investigated 3-substituted-2-phenylimidazo[2,1-b]benzothiazole derivatives and herein we have discussed their pharmaceutical activities. We found that some 2-phenyl-5,6,7,8-tetrahydroimidazo[2,1-b]-benzothiazoles could overcome multidrug resistance for tumor cells. Among them, 2-phenyl-3-(N-methyl-3-piperidyl)carbonylammomiinomemyl-5,6,7,8-tetrahydVoimidazo[2,1-b]benzothiazole [N276-12] demonstrated the most potent activity for overcoming multidrug resistance. 相似文献
Enzymatic hydrolysis of poly(butylene succinate) (PBS) and poly(butylene succinate‐co‐L ‐lactate) (PBSL) has been studied by using a lipase originated from Pseudomonascepacia. It has been found that the drawn fibers of PBSL are readily hydrolyzed by the action of the lipase, while those of PBS undergo little enzymatic hydrolysis. Since the polymer films of PBS and PBSL are readily hydrolyzed under the same conditions, the enzymatic hydrolysis should depend not only on the crystallinity but also on the molecular orientation. The molecular weight of the samples gradually decreases with incubation time, because nonspecific hydrolysis occurs on the main chains of both PBS and PBSL even in the absence of lipase. The enzymatic hydrolysis of PBS and PBSL gives 4‐hydroxybutyl succinate (HBS) as the main product with traces of succinic acid and butane‐1,4‐diol together with L ‐lactic acid in the case of PBSL. In addition, the hydrolysis rate of the carboxyl end‐capped PBS is much slower than that of the original or hydroxyl end‐capped PBS. These results imply a hydrolysis mechanism involving the preferential exo‐type chain scission from the carboxyl terminals.
A neutral tetradentate ligand L1 [L1?=?3,6-bis(pyrazol-1-yl)-pyridazine] reacts with Ni(ClO4)2·6H2O and undergoes counterion exchange with PF?6 to give di- and tetranuclear complexes [Ni2(L1)2(CH3CN)4](PF6)4·4H2O (1) and [Ni4(L1)4(µ-OH)4](ClO4)4·2H2O (2), respectively. The presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as base controls the nuclearity of the complex formation. Both complexes were structurally characterized by physicochemical and spectroscopic techniques. Their crystal structures revealed that both complexes are centrosymmetric and adopt slightly distorted octahedral geometry. Complex 1 crystallizes in monoclinic space group C2/c as the Ni(II) center is octahedrally bound to L1 in a trans-isomer arrangement. Complex 2 crystallizes in tetragonal space group I41/amd with four L1 and four hydroxy bridging ligands linked to Ni(II) center in cis-isomer arrangement. Cyclic voltammograms of complexes 1 and 2 were measured under Ar and CO2. Under CO2, the quasireversible peaks of both complexes become irreversible and a current enhancement occurs under reduction.
Optical absorption spectra of one-electron reduced species of copper(II) and oxovanadium(IV) tetraphenylporphyrins. Cu(II)TPP and V(IV)OTPP, in 2-methyltetrahydrofuran at 77 K reveal that not the central metal but the porphyrin ligand is reduced by an excess electron. The triplet ESR spectrum resulting from the spin-spin interaction between two odd electrons located on the porphyrin ligand and the central metal is observed for the one-electron reduced species of V(IV)OTPP while not for that of Cu(II)TPP. 相似文献
Irradiation of an aldehyde dithioacetal S-oxide gives the corresponding aldehyde. The mechanism of this photochemical transformation is discussed and its application to organic synthesis is also described. 相似文献
A new basic framework for solid–fluid mixture flow simulation was developed using moving particle methods. The interactions between solid and fluid were modeled by the finite volume particle (FVP) method. The distinct element method (DEM) together with a multi-time-step algorithm was introduced into the FVP method to calculate the effects of contact between solid bodies and between solid bodies and walls. The introduced DEM model was verified by experimental analyses for the collapse of multiple solid cylinder layers. The proposed algorithm using the optimized DEM model was then applied to a water dam breaking, involving multiple solid cylinder layers. A comparison between experiments and simulations demonstrated the DEM model introduced into the FVP method is effective in representing solid–fluid mixture flows reasonably well. 相似文献