Abstract: Grooved metal tubes, with a groove-bottom thickness Tf and outside diameter De, internally grooved with N helical ribs having an apex angle ?, height H, base width LN, and helix angle ?, two consecutive ribs being separated by a groove, generally flat-bottomed, having a width LR, with a pitch P equal to LR+LN, are characterized in that: a) the thickness Tf of the tube is such that Tf/De is equal to 0.023±0.005, Tf and De being expressed in mm, with De ranging between 4 and 14.5 mm; b) the ribs have a height H such that H/De is equal to 0.028±0.005, H and De being expressed in mm; c) the number N of ribs is such that N/De is equal to 2.1±0.4, and the corresponding pitch P is equal to p·Di/N, with Di equal to De?2·Tf, and De being expressed in mm; d) the base widths LN and LR are such that LN/LR is between 0.20 and 0.80; e) the apex angle ? ranges from 10° to 50°; and f) the helix angle ? ranges from 20° to 50°.

Abstract: Two-dimensional microcarriers for culture of anchorage dependent cells are formed having two opposed and parallel anchorage surfaces and a thickness so thin that cells attach only to the surfaces and not between the surfaces. Preferably, each of the surfaces is less than about 500 microns in each of its two dimensions, the thickness is not more than about 35 microns, the microcarriers have a shape resulting from the orthogonal or oblique intersection of two parallel planes separated by a distance of not more than 35 microns with a solid cylinder and the microcarriers are made from a hydrophobic polymeric material such as polystyrene, polycarbonate or polyterephthalate. The microcarriers can be microdisks having a density of between 0.90 and 1.10 g/cm.sup.3. The anchorage surfaces may be treated to enable cell attachment by applying a thin metallic deposit such as a titanium deposit or by electrical corona discharge. The microcarriers may be transparent to light waves and capable of withstanding sterilization.

Abstract: A method comprising the steps of (a) preparing a divided copper oxide dispersion (4) including a solvent and a selected binder, (b) applying said dispersion to a non-conductive substrate (1) to form a film (5), (c) forming a Cu film (9) with a suitable reagent, and (d) electrolytically depositing at least one metal film (11) on said film (9).