In this paper we compare the value of different molecular modeling techniques for the prediction of vibrational
modes, especially in the mid- and far-infrared region. There is a wide range of different levels of theory available
for molecular modelling - the choice depending on the kind of system to be investigated. For our calculations
we use different theoretical approaches such as Hartree-Fock and Density functional theory. We also compare
the performances of two available electronic structure programs-Gamess-US and Gaussian03. As examples,
we use two different retinoids - all-<i>trans</i> retinal and all-<i>trans</i> retinoic acid - derivatives of Vitamin A.
Terahertz spectroscopy, which investigates the electromagnetic spectrum of samples between 0.1 and 10 THz, allows not only for exploration of molecular structures but also of molecular dynamics. One difficulty in performing THz spectroscopy is that the data can be noisy and difficult to interpret. Ab initio molecular modelling has recently become more and more useful in the prediction of, for example, molecular structures, dynamic states and isomeric forms. Since the structure of biomolecules is closely related to their functionality there are broad ranging applications in biomedicine, for example in DNA sensing. An a priori knowledge of the expected THz spectra allows for improved experimentation. There is a growing and recognised need for THz spectroscopic databases to be created and made available along with classifiers that are able to effectively
detect a specific substance. We show, for a specific example, the 9-cis and all-trans retinal isomers, how ab initio molecular orbital calculations and quantum chemical modelling programs, such as Gamess, can aid in this endeavour.
This paper focuses on the future of RFID systems for biomedical
applications. It discusses current technology, restrictions and
applications and also illustrates possible future development for
the technology. This report gives the reader an idea of what
research has been done to date and draws some conclusions about
where further development is needed. We focus mainly on actuator
devices and introduce some of the concepts for RFID sensors. Radio
Frequency Identification or RFID is a technology that has evolved
from the development of magnetic bar code systems. Unlike magnetic
bar codes, passive RFID can be used in extreme climatic conditions
and unlike conventional bar coding does not require wiring or the
tags to be within close proximity of the reader. In RFID
technology there are two main components, they are an Interrogator
and a label/transponder. The interrogator sends coded RF signals
to the label in the form of radio frequency waves. The label
receives this RF energy and uses it to power its circuit as well
as interpreting the energy as some form of instruction. In this
report we focus mainly on the label/transponder and assume that
the relevant RF energy has been correctly encoded and sent.
The application of biotelemetry in the case of a RF controllable microvalve is discussed. Biotelemetry implies the contactless measurement of different electrical and nonelectrical parameters measured on human or animal subjects. A biotelemetry system consists of a transmitter and a receiver with a transmission link in-between. Transmitted information can be a biopotential or a nonelectric value like arterial pressure, respiration, body temperature or pH value. Transducers convert nonelectrical values into electrical signals. Radio frequency (RF) telemetry allows a patient greater mobility. Above all, the application of wireless communication becomes more and more popular in microinvasive surgery. Battery powered implants are most commonly used, but batteries must be changed after a period of time. To avoid this, wireless transcutaneous radio frequency (RF) communication is proposed for the powering and control of medical implants.