Abstract: A hydrophilic soft gas permeable contact lens having substantially improved clinical performance by the provision of a sufficient higher proportion of hydroxy acrylic units to silicon units in the lens surface layer, as compared to that existing in the lens core, by the surface treatment of the lens, such as by reacting of the lens surface with polyols and base or acid or by radiation treatment of the base lens to graft, deposit or coat thereon hydroxy acrylic units.

Abstract: A reproduction camera for the production of contact screen prints from an original is provided with sensing means, such as a photoelectric cell, for obtaining a measure of the light reflected by the original under conditions of an imagewise main exposure through the contact screen and a signal representing the obtained measure is inputted to a computerized control system through which, by taking into account the effect of stray light caused by reflection from the original during the main exposure, a non-imagewise additional exposure through the contact screen is effected so as to reproduce the minimum and maximum optical densities of the original with the correct dot sizes.

Abstract: An amorphous silicon based photoconductive element for use in electrophotographic copying processes, which exhibits a suitably low dark discharge rate with other good photoelectric properties, is composed of an electrically conductive support having applied thereto, in sequence, a barrier layer consisting essentially of a doped hydrogen-containing amorphous silicon, an intermediate layer consisting essentially of substantially undoped hydrogen-containing amorphous silicon, an intermediate barrier layer consisting essentially of doped hydrogen-containing amorphous silicon and a main, charge receiving layer consisting essentially of substantially undoped hydrogen-containing amorphous silicon.

Abstract: A process for the extraction of an anthocyanin-type color from a natural product which comprises bringing the natural product containing said color into contact with a sulfite ion-containing aqueous solution at a temperature of 85.degree. C. or higher for 30 minutes or less, at which time the sulfite ion content of said aqueous solution firstly contacting the natural product is adjusted to at least 10,000 ppm in terms of SO.sub.2.