Potential delivery system requirements

Constant use of this liquid nitrogen delivery system requires control of the environment within the X-ray enclosure to eliminate condensation of water on the phase separator located above the crystal sample. If this water were to reach the sample, the crystal would experience a temporary increase in temperature that can result in loss of crystallinity. Dehumidification of the hutch eliminates this potential problem. Removal of ambient humidity has the added benefit of reducing the formation of ice on all components that use liquid nitrogen, particularly the dewars used to store crystals before and after X-ray analysis. 

Advancing technology as well as this demonstration of potential utility of Mass Scatter able Mines led the Army to revise mine warfare doctrine and establish new requirements for a family of Scatterable Mines that could be rapidly and remotely emplaced by a variety uf delivery systems. This requirement called for both Anti-Tank and Anti-Personnel Mine Systems. To this end, two first generation systems are well ad-vandedin devebpment. These are the XM56, a helicopter delivered Anti-Tank Mine System and die XM692, an artillery delivered Anti-Personnel Mine System. Other second generation systems which add increased versatility and capability are scheduled to follow ... 

TOF-SIMS has important potentials in many areas of life science, in fundamental and applied research as well as in product development and control. This holds for the characterization of biological cells and tissues, of sensor and microplate arrays, of drug delivery systems, of implants, etc. In all these areas, relevant surfaces feature a very complex composition and structure, requiring the parallel detect ion of many different molecular species as well as metal and other elements, with high sensitivity and spatial resolution requirements, which are exactly met by TOF-SIMS. 

The potential of the chemically modified nucleic acid molecules has been proven by in vitro studies however, the in vivo therapeutic applicability of these molecules seems to be unsatisfactory because of their possible toxic effects (largely unknown) and adverse bioavailability. In this view, both antisense and transfection technologies require reliable and efficient systems for their delivery into target cells. On the basis of this consideration, the development of an efficient nucleic acid delivery system represents one of the key steps for these therapeutic agents, which are necessary for a practical clinical utilization of natural or unnatural oligonucleotides. 

The alkylglycoside vector is a kidney-specific delivery system that has recently been established [23-25].This vector is efficiently taken up from the basal side of the renal epithelium in a blood flow-limited manner and it can be used with several types of therapeutic molecules. The following sections summarize and discuss, first, how the novel kidney-specific alkylglycoside vector was identified, second, its structural and size requirements and third, the potential limitations of delivery to the kidney and the characterization of its binding sites on kidney cell membranes. 

Table 12.3 Some modem drug delivery systems and suggestions as to their potential use in battlefield situations Requirement...

As an example of a potential limitation, the drugs listed in Figure 1 have rather low molecular weights and relatively similar in molecular size. However, their skin permeation rates vary as much as 100 folds (2 mcg/cm /hr for fentanyl vs. 200 mcg/cm /hr for ephedrine). This difference in skin permeability will be reflected in the size of TDD system required to deliver the effective daily dose (Table I). A TDD system having a drug-releasing surface area of 90 cm is expected to be required for the delivery of diethylcarbamazine at a daily dose of 215 mg/day. From the standpoint of practical applications, a TDD system of this size would not be neither desirable nor economical. 

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