Increased microtubule stability and alpha tubulin acetylation in cells transfected with microtubule

A rail construction for mounting and tensioning an electrically heated screen on and between a pair of longitudinally extending, spaced frame members. The rail preferably is formed as an aluminum extrusion having a relatively large metal mass in cross section. The rail has a modified channel shape in cross section with an upper curved flange, a lower angled flange and an intervening projection. The upper curved flange is enclosed with electrical insulation and is adapted to engage a vertical wall of one of the frame members when mounted thereon. The lower angled flange has a hook shape complementary to a hook shape formed on the edge of the screen cloth. The intervening projection forms a wedge-shaped channel in combination with the lower hook-shaped flange of the rail. The wedge-shaped channel has an angled surface against which a complementary wedge-shaped clamping bar clamps the hooked screen edge. A series of bolts extending through the rail from the outside surface clamp the wedge bar, and interposed hooked screen edge, against the angled surface of the wedge-shapedchannel. A plurality of bolts extend through the rail and are engageable wih a vertical wall of the frame member and are adapted to draw the rail toward the wall to tension the screen which is clamped to the rail by the wedge bar. Electrical insulators are mounted on the rail bolts, and are located between the frame member and bottom of the rail to electrically insulate the rail from its associated frame member. One or both surfaces of the opposed clamping surfaces of the wedge bar and wedge-shape channel may be serrated to provide increased gripping contact between the wedge clamp and the screen edge.