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81.
《Macromolecular bioscience》2018,18(5)
A method is developed that can rapidly produce blood vessel‐like structures by bonding cell‐laden electrospinning (ES) films layer by layer using fibrin glue within 90 min. This strategy allows control of cell type, cell orientation, and material composition in separate layers. Furthermore, ES films with thicker fibers (polylactic‐co‐glycolic acid, fiber diameter: ≈3.7 µm) are used as cell‐seeding layers to facilitate the cell in‐growth; those with thinner fibers (polylactic acid, fiber diameter: ≈1.8 µm) are used as outer reinforcing layers to improve the mechanical strength and reduce the liquid leakage of the scaffold. Cells grow, proliferate, and migrate well in the multilayered structure. This design aims at a new type of blood vessel substitute with flexible control of parameters and implementation of functions. 相似文献
82.
Najwa Sbei Belen Batanero Fructuoso Barba Beya Haouas Mohamed Lamine Benkhoud Isidoro Barba 《Tetrahedron》2018,74(16):2068-2072
A new series of 3,4-disubstituted quinazolin-2-ones, with potential T-type calcium channel antagonist activity, and new 4-methylene-quinazolin-2-ones, promising catalysts as N-heterocyclic olefins, have been prepared in good yield by a simple reaction between 2-aminobenzophenone, or 2-aminoacetophenone, and cyanomethyl anion electrogenerated by acetonitrile reduction at a graphite electrode, followed by the addition of different organic isocyanates and subsequent heterocyclization. 相似文献
83.
Atomic layer deposition (ALD) of the pyrite‐type metal disulfides FeS2, CoS2, and NiS2 is reported for the first time. The deposition processes use iron, cobalt, and nickel amidinate compounds as the corresponding metal precursors and the H2S plasma as the sulfur source. All the processes are demonstrated to follow ideal self‐limiting ALD growth behavior to produce fairly pure, smooth, well‐crystallized, stoichiometric pyrite FeS2, CoS2, and NiS2 films. By these processes, the FeS2, CoS2, and NiS2 films can also be uniformly and conformally deposited into deep narrow trenches with aspect ratios as high as 10:1, which thereby highlights the broad and promising applicability of these ALD processes for conformal film coatings on complex high‐aspect‐ratio 3D architectures in general. 相似文献
84.
多相催化剂是极为重要的一类催化剂,在许多重要工业反应中扮演关键角色。然而,传统的湿化学合成手段在很多情况下难以做到对催化剂活性位点的结构、组成以及其周围局部环境的原子级精细调控,继而给优化催化剂性能、理解多相催化机理带来较大的挑战。原子层沉积(ALD)是一种气相催化剂合成技术,其原理是基于两种前驱体蒸汽交替进样并在载体表面上发生分子层面上的“自限制”反应,实现目标材料在载体表面上的精准沉积。利用其分子层面上的“自限制”反应特性,并通过改变沉积周期数、次序和种类等方法可以实现对催化剂活性位结构的原子级精细控制,进而为人们提供了一种催化剂“自下而上”精细可控合成的新策略。在本文中,我们总结了利用ALD方法在负载型单金属和双金属催化剂精细设计方面的进展,讨论了ALD方法在设计高效催化剂方面的特点与优势。特别地,我们总结了利用ALD方法制备单原子和双原子结构金属催化剂的方法与策略。此外,我们总结了利用氧化物可控沉积精准调控金属催化活性中心周围的微环境,从而实现提升催化剂活性、选择性和稳定性的方法。最后我们展望了ALD技术在催化剂制备领域中应用的潜力。 相似文献
86.
The assembly of alternating DNA and positively charged poly‐(dimethyldiallylammonium chloride) (PDDA) multilayer films by electrostatic layer‐by‐layer adsorption has been studied. Real time surface plasmon resonance (BIAcore) technique was used to characterize and monitor the formation of multilayer films in solution in real time continuously. The results indicate that the uniform multilayer can be obtained on the poly‐(ethylenimine) (PEI) coated substrate surface. The kinetics of the adsorption of DNA on PDDA surface was also studied by real‐time BIAcore technique, and the observed rate constant was calculated using a Langmuir model (kobs = (1.28 ± 0.08) × 10?2s?1). 相似文献
87.
The reaction of CuCl2 · 2 H2O, 1,10‐phenanthroline (phen), suberic acid and Na2CO3 in a CH3CN–H2O solution yielded blue needle‐like crystals of [Cu2(phen)2(C8H12O4)2] · 3 H2O. The crystal structure (monoclinic, P21/n, a = 10.756(2) Å, b = 9.790(2) Å, c = 18.593(4) Å, β = 91.15(3)°, Z = 2, R = 0.043, wR2 = 0.1238) consists of suberato‐bridged [Cu2(phen)2(C8H12O4)4/2] layers and hydrogen bonded H2O molecules. The Cu atoms are coordinated by two N atoms from one bidentate chelating phen ligand and three carboxyl O atoms from different suberato ligands to form distorted [CuN2O3] square‐pyramids with one carboxyl O atom at the apical position (d(Cu–N) = 2.017(2), 2.043(3) Å, basal d(Cu–O) = 1.936(2), 1.951(2) Å and axial d(Cu–O) = 2.389(2) Å). Two [CuN2O3] square‐pyramids are condensed via a common O–O edge to a centrosymmetric [Cu2N4O4] dimer with the Cu…Cu distance of 3.406(1) Å indicating no interaction between Cu atoms. The resultant [Cu2N4O4] dimers are interlinked by the tridentate suberato ligands to form [Cu2(phen)2(C8H12O4)4/2] layers parallel to (101). These are assembled via π‐π stacking interactions into 3D network with H2O molecules in the tunnels extending in the [010] direction. 相似文献
88.
89.
A model is presented for the potential distribution across a charged membrane. The membrane-fixed charges are assumed to be distributed through a surface layer of non-zero thickness on the membrane. We treat the surface layer as a different phase from the surrounding solution phase. The potential arises from the membrane-fixed charges and from different solubilities of positive and negative electrolyte ions in the two phases. Equations are presented for the potential distribution, which involve the partition coefficients of electrolyte ions and the relative permittivity of the surface layer. 相似文献
90.
In our former investigations, the phenomenon high temperature corrosion (HTC) was described exemplarily on selected materialcoating combinations for blades of stationary gas turbines, mainly in the temperature region of up to 750° C. To answer the question, in which manner higher gas inlet and/or higher material surface temperature would influence the HTC behaviour, a special analytical technique—the integral layer profile analysis—was introduced to ameliorate concentration profile methods. By examining IN 738 LC specimens with CoCrAlY plasma spray coating, stressed by hot gas at 900° C, the limits of this system are shown by explaining the corrosion mechanism; the method is also used for other systems, e.g. U 520 with NiCrAlY coating at 750° C. 相似文献