Analysis of 5-fluorouracil in plasma by precolumn derivatization with 4-bromomethyl-7-methoxycoumarin, followed by multi-dimensional high-performance liquid chromatography

An assay for 5-fluorouracil (5-FU) has been developed that utilizes a double extraction with ethyl acetate, followed by precolumn derivatization with 4-bromo-methyl-7-methoxycoumarin. The reaction mixture was quenched with 5% acetic acid, extracted with hexane, and analyzed by multi-dimensional high-performance liquid chromatography. Derivatized 5-FU was injected into a cyanopropyl column and a heart cut containing the analyte was then switched to an octadecyl column and quantitated by fluorescence detection. The assay had a limit of detection of 0.5 ng 5-FU/ml plasma and was linear to 20 micrograms/ml. It was shown to be free of interferences from the other anticancer agents commonly used in combination with 5-FU. This assay should have the sensitivity needed to measure the low levels that occur after low-dose, continuous infusion of 5-FU.     

Physical registration: configuring electronic directories using handheld devices

An important problem in pervasive computing is how to create and maintain manageable collections of pervasive resources appropriate for disparate and typically nomadic users. This article describes physical registration, a new, human-centric mechanism for constructing collections of resources in the form of electronic directories. Users identify physical objects using sensor-equipped wirelessly networked handheld devices to build directories of virtual "entities" associated with those objects. The entities can be Web resources accessible over a network, like printers, projectors, picture frames, or storage devices. They can also be Web resources correlated with objects like books or telephones that are not themselves accessible over a network. This article describes and motivates the method, then compares two implementations we have constructed.     

People,Places, Things: Web Presence for the Real World

The convergence of Web technology, wireless networks, and portable client devices provides new design opportunities for computer/communications systems. In the HP Labs' Cooltown project we have been exploring these opportunities through an infrastructure to support web presence for people, places and things. We put web servers into things like printers and put information into web servers about things like artwork; we group physically related things into places embodied in web servers. Using URLs for addressing, physical URL beaconing and sensing of URLs for discovery, and localized web servers for directories, we can create a location-aware but ubiquitous system to support nomadic users. On top of this infrastructure we can leverage Internet connectivity to support communications services. Web presence bridges the World Wide Web and the physical world we inhabit, providing a model for supporting nomadic users without a central control point.