Theory of electroporation: A review

The past twenty five years have seen an explosion in the creation and discovery of new medicinal agents. Related innovations in drug delivery systems have not only enabled the successful implementation of many of these novel pharmaceuticals, but have also permitted the development of new medical treatments with existing drugs. The creation of transdermal delivery systems has been one of the most important of these innovations, offering a number of advantages over the oral route. In this article, we discuss the already significant impact this field has made on the administration of various pharmaceuticals; explore limitations of the current technology; and discuss methods under exploration for overcoming these limitations and the challenges ahead.

Current status and future potential of transdermal drug delivery

We characterize high-performance streaming applications as a new and distinct domain of programs that is becoming increasingly important. The StreamIt language provides novel high-level representations to improve programmer productivity and program robustness within the streaming domain. At the same time, the StreamIt compiler aims to improve the performance of streaming applications via stream-specific analyses and optimizations. In this paper, we motivate, describe and justify the language features of StreamIt, which include: a structured model of streams, a messaging system for control, a re-initialization mechanism, and a natural textual syntax.

/pdf/streamit-a-language-for-streaming-applications-il2k3rjwwy.pdf

StreamIt: A Language for Streaming Applications

http://drugdelivery.chbe.gatech.edu/Papers/1998/Henry%20J%20Pharm%20Sci%201998.pdf

Microfabricated microneedles: a novel approach to transdermal drug delivery.

Novel mechanisms and devices to enable successful transdermal drug delivery.

Mammalian skin owes its remarkable barrier function to its outermost and dead layer, the stratum corneum. Transdermal transport through this region occurs predominantly through intercellular lipids, organized largely in bilayers. Electroporation is the creation of aqueous pores in lipid bilayers by the application of a short (microseconds to milliseconds) electric pulse. Our measurements suggest that electroporation occurs in the intercellular lipid bilayers of the stratum corneum by a mechanism involving transient structural changes. Flux increases up to 4 orders of magnitude were observed with human skin in vitro for three polar molecules having charges between -1 and -4 and molecular weights up to slightly more than 1000. Similar flux increases were observed in vivo with animal skin. These results may have significance for drug delivery and other medical applications.

https://www.pnas.org/content/pnas/90/22/10504.full.pdf

Electroporation of mammalian skin: a mechanism to enhance transdermal drug delivery

Conventional software radios take advantage of vastly improved analog to digital converters (ADCs) and digital signal processing (DSP) hardware. Our approach, which we refer to as virtual radios, also depends upon high performance ADCs. However, rather than use DSPs, we have chosen to ride the curve of rapidly improving workstation hardware. We use wideband digitization and then perform all of the digital signal processing in user space on a general purpose workstation. This approach allows us to experiment with new approaches to signal processing that exploit the hardware and software resources of the workstation. Furthermore, it allows us to experiment with different ways of structuring systems in which the radio component of communication devices is integrated with higher-level applications. This paper describes the design and performance of an environment we have constructed that facilitates building virtual radios and of two applications built using that environment. The environment consists of an input/output (I/O) subsystem that provides high bandwidth low latency user-level access to digitized signals and a programming environment that provides an infrastructure for building applications. The applications, which exemplify some of the benefits of virtual radios, are a software cellular receiver and a novel wireless network interface.

http://ieeexplore.ieee.org/iel4/49/16463/00761038.pdf

Virtual radios

This dissertation presents the design, implementation and evaluation of a novel software radio architecture based on wideband digitization, a general purpose processor and application level software. The system is designed to overcome the many challenges and exploit the advantages of performing real-time signal processing in a general purpose environment. The main challenge was overcoming the uncertainty in execution times and resource availability. The main advantages are faster clock speeds, large amounts of memory and better development environments. In addition it is possible to optimize the signal processing in conjunction with the application program, since they are running on the same platform. 
The system has been used to implement a virtual radio, a wireless communication system in which all of the signal processing from the air interface through the application is performed in software. The only functions performed by dedicated hardware are the down conversion and digitization of a wide band of the RF spectrum. The flexibility enabled by this system provides the means for overcoming many limitations of existing communication systems. Taking a systems design approach, the virtual radio exploits the flexibility of software signal processing coupled with wideband digitization to realize a system in which any aspect of the signal processing can be dynamically modified. The work covers several areas, including: the design of an I/O system for digitizing wideband signals as well as transporting the sample stream in and out of application memory; the design of a programming environment supporting real-time signal processing applications in a general purpose environment; a performance evaluation of software radio applications on a general purpose processor; and the design of applications and algorithms suited for a software implementation. Several radio applications including an AMPS cellular receiver and a network link employing frequency hopping with FSK modulation have been implemented and measured. 
This work demonstrates that it is both useful and feasible to implement real-time signal processing systems on a general purpose platform entirely in software. The virtual radio platform allows new approaches to both system and algorithm design that result in greater flexibility, better technology tracking and improved average performance. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Design and implementation of software radios using a general purpose processor

The SpectrumWare project is applying a software oriented approach to wireless communication and distributed signal processing. Advances in processor and analog-to-digital conversion technology have made it possible to implement virtual radios that directly sample wide bands of the RF spectrum and process these samples in application software. The elimination of dedicated hardware introduces tremendous flexibility into a wireless communication system. Our approach goes further than the software implementation of traditional signal processing functions. We use processor and network memory to temporally decouple the sample streams from the software modules so that the bulk of the processing can be realized within virtual time programming environments. Decoupling relaxes the temporal constraints on the processing algorithms and their execution. This paper describes the SpectrumWare concept, our experimental approach, and the implications that this approach has for wireless signal processing algorithms.

The SpectrumWare approach to wireless signal processing

The SpectrumWare project is applying a software oriented approach to wireless communication and distributed signal processing. Advances in processor and analog-to-digital conversion technology have made it possible to implement virtual radios that directly sample wide bands of the RF

Vanu G. Bose

Papers

Electroporation of mammalian skin: a mechanism to enhance transdermal drug delivery

Virtual radios

Design and implementation of software radios using a general purpose processor

The SpectrumWare approach to wireless signal processing

SpectrumWare: a software-oriented approach to wireless signal processing