The present invention provides an anionic group-containing amphiphilic block copolymer that is biocompatible and biodegradable and, when used as a drug carrier for a cationic drug, provides several advantages such as increased blood concentration and improved stability of the drug. The method and system comprise minimizing redundancy within the plurality of email messages to provide a minimized email thread and displaying the minimized email thread. The echo received at each aspect is multiplied by the transform of the point spread function of each of the other preselected aspects. Each transistor of the first plurality has a source coupled to a source voltage bus, and each transistor of the second plurality has a source not coupled to the source voltage bus, through use of a programmable contact window during fabrication. The top part of the head may include a resilient actuation portion formed integrally thereon and adapted to be depressed by a user and an actuation member disposed on an internal surface of the resilient actuation portion of the head for contacting the nozzle actuation member receiving portion.