Disclosed are optically active high-molecular-weight compounds of the following formulaand stationary-phase materials containing the same. The linear embedding operator is determined by an affinity model comprising a first affinity parameter, a second affinity parameter, and an affinity matrix, wherein a sparsity of the affinity matrix is controlled by the first affinity parameter and the second affinity parameter. The cast strand is shaped in a dynamically variable reduction section as a result of the compressive strength that is measured on individual shaping rolls or roll segments, depending on the compressive force that can be locally applied. In a forward position, turning the knob turns a drive shaft that is coupled to the rotatable actuator of the implant, and causes the implant to expand or retract depending on the direction of rotation.