Search results for "spheres"

Attachment of Marine Sponge Cells of Hymeniacidon perleve on Microcarriers

2003

Toward the development of an in vitro cultivation of marine sponge cells for sustainable production of bioactive metabolites, the attachment characteristics of marine sponge cells of Hymeniacidon perleve on three types of microcarriers, Hillex, Cytodex 3, and glass beads, were studied. Mixed cell population and enriched cell fractions of specific cell types by Ficoll gradient centrifugation (6%/8%/15%/20%) were also assessed. Cell attachment ratio (defined as the ratio of cells attached on microcarrier to the total number of cells in the culture) on glass beads is much higher than that on Cytodex 3 and Hillex for both mixed cell population and cell fraction at Ficoll 15-20% interface. The h…

Formation of hierarchically ordered silicas prepared by spray drying of nanosized spheres

2002

We report on our strategy to synthesise defined arrangements of macro- and mesopores in one single material with spherical morphology using the spray drying technique. As starting materials, nano-sized silica spheres and colloidal suspensions were chosen. The intra-particle as well as inter-particle pore size was independently controlled which allowed to obtain materials with varied bimodal pore networks. The spherical agglomerates were characterised regarding their pore structural parameters and are potential adsorbents in liquid chromatographic separations.

The Role of Ciphering in Phenomenology of Life

2004

Contemporary philosophy is inseparable from the general tendencies of spiritual life that have dominated over the past centuries. The ruling tendency of European-type philosophy has been the affirmation of a democratic life style, liberal values and human individuality and creative activity. The testimony to this is the proportional growth of the philosophy of subjectivism since modern times, the division of pure practical reason and reasoning into separate spheres to substantiate fundamental human abilities, to analyse the ways of grasping the world — such as cognition, understanding, intuition, deciphering, experience — and describe man’s correlation with beingness (cosmos). Epistemology …

Direct formation of highly tunable and biocompatible protein microparticles

Highly tunable protein microspheres for drug delivery

2019

Traditionally protein aggregation has been related to several neurodegenerative diseases, however in the past few years there has been a grown interest to use them as biomaterials. Among the very broad range of different amyloid structures a special focus has been developed on protein particulates, spherical protein aggregates formed at a pH near the isoelectric point of the protein they are made of, whose radius ranges from hundreds of nm to few um. They are a generic feature for all globular proteins and besides, they have never been related to any disease. Among the years different methods for the functionalization of amyloid fibrils or microspheres have been unravelled, but normally the…

Molecular characterization of tunable microscale protein-based biomaterials

2019

Particulate Matter Contamination of Intravenous Antibiotics Aggravates Loss of Functional Capillary Density in Postischemic Striated Muscle

2002

Through the increased use of less expensive and counterfeit medicines, the contamination of parenteral fluids and drugs by particulate matter poses an increasing health hazard worldwide. However, the mechanism of action of such contamination has never been conclusively demonstrated. We have systemically injected the particles contained in three different 1-g preparations of the antibiotic cefotaxime into hamsters and visualized the functional capillary density in striated skin muscle, using intravital fluorescence microscopy. Injection of particles from either of the three preparations did not affect capillary perfusion in normal muscle (n = 3 hamsters, each). However, injection of particle…

On exotic affine 3-spheres

2014

Every A 1 \mathbb {A}^{1} -bundle over A ∗ 2 , \mathbb {A}_{\ast }^{2}, the complex affine plane punctured at the origin, is trivial in the differentiable category, but there are infinitely many distinct isomorphy classes of algebraic bundles. Isomorphy types of total spaces of such algebraic bundles are considered; in particular, the complex affine 3 3 -sphere S C 3 , \mathbb {S}_{\mathbb {C}}^{3}, given by z 1 2 + z 2 2 + z 3 2 + z 4 2 = 1 , z_{1}^{2}+z_{2}^{2}+z_{3}^{2}+z_{4}^{2}=1, admits such a structure with an additional homogeneity property. Total spaces of nontrivial homogeneous A 1 \mathbb {A}^{1} -bundles over A ∗ 2 \mathbb {A}_{\ast }^{2} are classified up to G m \mathbb {G}_{m}…

Blending canal surfaces along given circles using Dupin cyclides

2013

We study blends between canal surfaces using Dupin cyclides via the space of spheres. We have already studied the particular case where it is possible to blend two canal surfaces using one piece of Dupin cyclide bounded by two characteristic circles, but this is not possible in the general case. That is why we solve this problem using two pieces of different cyclides, which is always possible. To get this conclusion and give the algorithms allowing to obtain such a result, we study, at first, the blend between two circles by a piece of cyclide. We impose to the cyclide to be tangent to a given sphere containing one of the circles. We give the existence condition on the previous circles to h…

Iterative construction of Dupin cyclides characteristic circles using non-stationary Iterated Function Systems (IFS)

2012

International audience; A Dupin cyclide can be defined, in two different ways, as the envelope of an one-parameter family of oriented spheres. Each family of spheres can be seen as a conic in the space of spheres. In this paper, we propose an algorithm to compute a characteristic circle of a Dupin cyclide from a point and the tangent at this point in the space of spheres. Then, we propose iterative algorithms (in the space of spheres) to compute (in 3D space) some characteristic circles of a Dupin cyclide which blends two particular canal surfaces. As a singular point of a Dupin cyclide is a point at infinity in the space of spheres, we use the massic points defined by J.C. Fiorot. As we su…