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711.
712.
Emanuela S. Fioretta Joost O. Fledderus Ewelina A. Burakowska‐Meise Frank P. T. Baaijens Marianne C. Verhaar Carlijn V. C. Bouten 《Macromolecular bioscience》2012,12(5):577-590
In situ vascular tissue engineering has been proposed as a promising approach to fulfill the need for small‐diameter blood vessel substitutes. The approach comprises the use of a cell‐free instructive scaffold to guide and control cell recruitment, differentiation, and tissue formation at the locus of implantation. Here we review the design parameters for such scaffolds, with special emphasis on differentiation of recruited ECFCs into the different lineages that constitute the vessel wall. Next to defining the target properties of the vessel, we concentrate on the target cell source, the ECFCs, and on the environmental control of the fate of these cells within the scaffold. The prospects of the approach are discussed in the light of current technical and biological hurdles.
713.
Daziano JP Günther WH Krieg M Tsujino I Miyagi K Anderson GS Sampson RW Ostrowski MD Muir SA Bula RJ Sieber F 《Photochemistry and photobiology》2012,88(2):448-460
The objective of this study was to determine if and how photoproducts contribute to the antitumor effect of merocyanine-mediated PDT. A panel of barbituric, thiobarbituric and selenobarbituric acid analogues of Merocyanine 540 was photobleached, and the resulting photoproducts were characterized by absorption, fluorescence emission, mass, energy dispersive X-ray, and X-ray photoelectron spectroscopy and tested for cytotoxic activity against tumor cell lines and freshly explanted bone marrow cells. While all dyes were readily photobleached, only photoproducts of selone dyes showed cytotoxic activity. One-hour incubations with micromolar concentrations of selone-derived photoproducts were sufficient to reduce leukemia/lymphoma cells ≥10 000 fold, whereas preserving virtually all normal CD34-positive bone marrow cells. Of six multidrug-resistant tumor cell lines tested, five were as sensitive or more sensitive to photoproducts than the corresponding wild-type lines. Physicochemical characterizations of the cytotoxic activity indicated that it consisted of conjugates of subnano particles of elemental selenium and (lipo)proteins. The discovery of cytotoxic Se-protein conjugates provides a rare example of photoproducts contributing substantially to the antitumor effect of PDT and challenges the long-held view that Se in oxidation state zero is biologically inert. Agents modeled after our Se-protein conjugates may prove useful for the treatment of leukemia. 相似文献
714.
Falsig H Gross A Kongsted J Osted A Sloth M Mikkelsen KV Christiansen O 《The journal of physical chemistry. A》2006,110(2):660-670
We present a study of the interaction between a phenol molecule and an aerosol particle. The aerosol particle is represented by a cluster of 128 water molecules. Using a classical approach, we present interaction energy surfaces for different relative distances and for three orientations of phenol relative to the particle. From the energy surfaces we find the reaction pathways with the largest interaction between the molecule and the particle. We use a quantum mechanics/molecular mechanics (QM/MM) method to calculate a potential energy curve for each reaction path. Coupled cluster methods are used for the part of the system described by quantum mechanics, while the part described by molecular mechanics is represented by a polarizable force field. We compare results obtained from the classical approach with the QM/MM results. Furthermore, we use the QM/MM results to calculate mass accommodation coefficients using a quantum-statistical (QM-ST) model and show how the mass accommodation coefficient depends on the relative orientation of phenol with respect to the aerosol particle. 相似文献
715.
Manson JL Conner MM Schlueter JA Lancaster T Blundell SJ Brooks ML Pratt FL Papageorgiou T Bianchi AD Wosnitza J Whangbo MH 《Chemical communications (Cambridge, England)》2006,(47):4894-4896
[Cu(HF2)(pyz)2]BF4 consists of rare mu(1,3) bridging HF2- anions and micro-pyrazine ligands leading to a 3D pseudo-cubic framework that antiferromagnetically orders below 1.54(1) K. 相似文献
716.
Nicolas Dietl Marianne Engeser Dr. Helmut Schwarz Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(26):4861-4863
No need for a metal : A combination of mass spectrometry and computational studies (density functional theory and coupled‐cluster methods) shows that [P4O10].+ is the first polynuclear nonmetal oxide cation that is capable of activating the C? H bond of methane at room temperature (see picture). This process represents a further example in the reactivity of oxygen‐centered radicals.
717.
N-chlorination of aryl substituted azabicycloheptanes and subsequent rearrangement provided the endo arylated azabicyclo[2.2.1]heptanes. 相似文献
718.
719.
The synthesis of NaA-type zeolite from superalkaline reaction mixtures by influence on the formation- and transformation rate of the polymorphous phases according to the Ostwald step rule is discussed. The appearence time of NaA as a single crystallization product is described in dependence on the reaction conditions. The kinetics of the zeolite crystallization and the property alterations of the reaction products in dependence on the time are investigated in the pilot scale. 相似文献