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101.
Sarah W. Kamau Chapman Paul O. Hassa Sabine Koch-Schneidemann Brigitte von Rechenberg Margarethe Hofmann-Amtenbrink Benedikt Steitz Alke Petri-Fink Heinrich Hofmann Michael O. Hottiger 《Journal of magnetism and magnetic materials》2008
Primary cell lines are more difficult to transfect when compared to immortalized/transformed cell lines, and hence new techniques are required to enhance the transfection efficiency in these cells. We isolated and established primary cultures of synoviocytes, chondrocytes, osteoblasts, melanocytes, macrophages, lung fibroblasts, and embryonic fibroblasts. These cells differed in several properties, and hence were a good representative sample of cells that would be targeted for expression and delivery of therapeutic genes in vivo. The efficiency of gene delivery in all these cells was enhanced using polyethylenimine-coated polyMAG magnetic nanoparticles, and the rates (17–84.2%) surpassed those previously achieved using other methods, especially in cells that are difficult to transfect. The application of permanent and pulsating magnetic fields significantly enhanced the transfection efficiencies in synoviocytes, chondrocytes, osteoblasts, melanocytes and lung fibroblasts, within 5 min of exposure to these magnetic fields. This is an added advantage for future in vivo applications, where rapid gene delivery is required before systemic clearance or filtration of the gene vectors occurs. 相似文献
102.
103.
104.
In this paper we give upper and lower bounds for each eigenvalue λ
n
of Hill's differential equation. We apply the results to toroidal surfaces of revolution in order to get estimates for the
eigenvalues of the Laplacian in terms of curvature expressions; they are sharp for the flat torus. As an example, we investigate
the standard torus in IR3; here, the bounds depend on the radii only. 相似文献
105.
The influence of hydroxy-functionalized hyperbranched poly(ester-amide) (HBP) of different molecular weight on the curing process of diglycidylether of bisphenol A (DGEBA) was studied using methyltetrahydrophthalic anhydride (MTHPA) as curing agent. By Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR) the curing reaction was monitored and the covalent incorporation of the modifier in the matrix was proved. By thermomechanical analysis (TMA) the reduction of the contraction after gelation on changing the HBP proportion was observed. The incorporation of HBP increased the glass transition temperature (Tg) and reduced the overall shrinkage. The modified materials showed a higher thermal degradability than neat DGEBA thermosets allowing reworkability. Thermal expansion coefficient, Young’s modulus, impact strength and microhardness were improved. The water uptake behavior was also evaluated. 相似文献
106.
Chlorophyll a and, in particular, bacteriochlorophyll a derivatives are promising candidates for photosensitizers in photodynamic therapy. The distribution of 21 (bacterio)chlorophyll derivatives among human blood plasma fractions was studied by iodixanol gradient ultracentrifugation and in situ absorption spectroscopy. Modifications of the natural pigments involved the central metal (Mg2+ , Zn2+ , Pd2+ , none), the isocyclic ring (closed, open and taurinated), substituents at C-3 (vinyl, acetyl, 1-hydroxyethyl) and C-173 (phytyl ester, free acid). Cellular blood components bound only a small fraction of the pigments. Distribution among low-density lipoproteins (LDL), high-density lipoproteins (HDL) and high-density proteins (HDP) of the plasma was influenced as follows: (1) application in Cremophor® EL slightly altered pigment distribution by lipoprotein modification, (2) only very polar pigments with multiple hydrophilic substituents showed substantial HDP binding, (3) the presence of the esterifying alcohol at C-173 caused enrichment in LDL, this was more pronounced with bacteriochlorophylls than with chlorophylls, (4) substituents at C-3 had only little influence on the distribution, (5) Zn2+ -complexes were enriched in HDL compared to Mg2+ and Pd2+ complexes, indicating specific binding of the former. Equilibration of pigments among the different fractions was largely complete within 3 h. 相似文献
107.
Brigitte E. Breckner 《Archiv der Mathematik》2016,106(2):183-188
We show that harmonic functions are not zero divisors in the algebra of real-valued continuous functions on the Sierpinski fractal. 相似文献
108.
F. Guerin 《Physics letters. [Part B]》2002,530(1-4):142-146
The effective amplitudes for gluon momenta pgT in hot QCD exhibit damping as a result of collisions. The whole set of n-point amplitudes is shown to be generated from one functional
, in addition to the induced current jμ(X;A). 相似文献
109.
110.
Jochen Schölhammer Brigitte Baretzky Wolfgang Gust Eric Mittemeijer Boris Straumal 《Interface Science》2001,9(1-2):43-53
The atomic force microscopy (AFM) was used to study the grain boundary (GB) groove profiles far away from the melting temperature T
m. It is shown that AFM allows one to measure the temperature dependence of the GB energy in a rather broad temperature interval (from 0.85 T
m to T
m). The GB energy and GB segregation of Bi were measured at 1123 K in the interval of the Bi bulk concentration x
v
Bi from 5 to 140 ppm Bi. The transition from monolayer to multilayer adsorption is observed for the 19a GB at 1123 K and x
v
Bi = 60 at. ppm Bi. At the same point (1123 K and x
v
Bi = 60 at. ppm Bi) a discontinuity of the first derivative of the GB energy is observed. These features were explained using the model of GB prewetting phase transformation developed previously. 相似文献