Fabrication, characterisation and performance of hydrophilic and super-hydrophilic silica as cell culture surfaces

We demonstrate a straightforward procedure for the controlled formation of silica films on tissue culture polystyrene (PS) surfaces. The films were formed by sequentially treating PS with polyaniline, glutaric dialdehyde and protein prior to silica formation. The films could be tailored to exhibit superhydrophilicity (contact angle < 5°) which was retained for more than two months under ambient conditions. Both hydrophilic and super-hydrophilic silica coated surfaces were suitable for the culture of an adherent human melanoma cell line. Proliferation, toxicity and adhesion assays were used to compare cell behaviour. Cells on the silica surfaces showed enhanced adhesion and comparable rates of cell proliferation as compared to cells grown on conventional tissue culture plastic. The results obtained can be understood by considering the surface properties of the different materials and the ability of the silica coated surfaces to adsorb significantly higher levels of serum proteins from the growth medium. One of the outcomes of this study is a re-evaluation of the hydrophobicity/hydrophilicity characteristics required for good cell growth and the possibility of designing new tissue culture materials capable of greater control over cell populations

Elliptical flux vortices in YBa2Cu3O7

The most energetically favorable vortex in YBa2Cu3O7 forms perpendicular to an anisotropic plane. This vortex is elliptical in shape and is distinguished by an effective interchange of London penetration depths from one axis of the ellipse to another. By generalizing qualitatively from the isotropic to the anisotropic case, we suggest that the flux flow resistivity for the vortex that forms perpendicular to an anistropic plane should have a preferred direction. Similar reasoning indicates that the Kosterlitz-Thouless transition temperature for a vortex mediated transition should be lower if the vortex is elliptical in shape

Sex differences in the language development rates of two-year olds

The purpose of this study was to examine and compare the language development rate of male and female children, 24 to 30 months of age, during a three month time period

Design considerations for lunar base photovoltaic power systems

A survey was made of factors that may affect the design of photovoltaic arrays for a lunar base. These factors, which include the lunar environment and system design criteria, are examined. A photovoltaic power system design with a triangular array geometry is discussed and compared to a nuclear reactor power systems and a power system utilizing both nuclear and solar power sources

In Memoriam-Jo Ann Boydston (1924–2011)

Jo Ann Boydston enjoyed a distinguished career as general editor of the Collected Works of John Dewey and director of the Center for Dewey Studies at Southern Illinois University Carbondale. Born in Poteau, Oklahoma, of Choctaw Indian heritage, she graduated summa cum laude from Oklahoma State University in 1944. She received an M.A. from Oklahoma State in 1947, a Ph.D. from Columbia University in 1950, and honorary doctorates from Indiana University (1994) and Southern Illinois University (2004)

Dewey’s Logic: Reviews and Criticisms

I draw attention to some common misunderstandings among Dewey’s critics, as well as to some significant interpretive clarifications by commentators who viewed his work in a positive light. I have found it instructive to look back at two sources as an aid to understanding what his critics found so puzzling about his work. First, there are the reviews in professional journals that appeared in the wake of the publication of the Logic. Second, there are essays by some of his critics included in the Library of Living Philosophers volume published as a part of the celebration of his 80th birthday in 1939. In addition, I occasionally call on ancillary remarks and interpretations from other sources when I think they will help to clarify a point.En este artículo señalo algunos malentendidos comunes en los críticos de Dewey al igual que algunas aclaraciones interpretativas significativas de comentadores que contemplaron su trabajo bajo una luz más favorable. He considerado que sería esclarecedor recordar dos fuentes que ayudarían a comprender lo que sus críticos veían tan desconcertante en su trabajo. Primero, están las reseñas en revistas profesionales que aparecieron tras la publicación de la Lógica. Segundo, hay ensayos de algunos de sus críticos incluidos en el volumen de la Library of Living Philosophers que fue publicado como parte de la celebración de su 80º cumpleaños en 1939. Además, en ocasiones recurro a argumentos e interpretaciones adicionales que provienen de otras fuentes cuando creo que ayudarán a dejar más clara una idea

Ultrabroad-bandwidth multifrequency Raman generation

We report on the modeling of transient stimulated rotational Raman scattering in H2 gas. We predict a multifrequency output, spanning a bandwidth greater than the pump frequency, that may be generated without any significant delay with respect to the pump pulses. The roles of dispersion and transiency are quantified