Transducer mechanisms

Hair cells are specialized mechanoreceptors located in the inner ear these cells transduce mechanical forces transmitted by sound and head movement, and permit an organism to sense features of the external world. Well-characterized biophysically, a molecular description of hair-cell transduction has finally begun to emerge. 

The molecules that transduce noxious heat or cold are members of the transient receptor potential (TRP) receptor family 929 Receptors that transduce mechanical stimuli are members of the Degenerin family 930... 

Primary sensory neurons sense pain and convey it to the spinal cord. Nociceptors have unmyelinated (C fiber) or thinly myelinated (AS) axons, while the low-threshold Ap-fiber mechanoreceptors involved in tactile and proprioceptive perception have large myelinated sensory neurons (Table 57-1). The peripheral terminals of primary sensory neurons convert changes in the environment into neuronal activity by transducing mechanical (Ch. 51), thermal or chemical stimuli into ion fluxes across their... 

Recently, a very practical bubble pressure tensiometer was developed using elegant pressure transducer mechanics which only needs one capillary made from a high-tech polymer [51, 52]. The tensiometer is able to measure at different immersion depths but needs calibration in order to make the resulting data comparable to surface tension values from other sources. It was shown in a series of measure-... 

Hoefer, U. Bottner, H. Wagner, E. Kohl, C.-D. Highly Sensitive N02 Sensor Device Featuring a JFET-like Transducer Mechanism. Sensors and Actuators B 47 (1-3) (1998), p. 212-216. 

Knowles, R. G., Palacios, M., Palmer, R. M. J., and Moncada, S. (1989). Formation of nitric oxide from L-arginine in the central nervous system A transducer mechanism for stimulation of the soluble guanylate cyclase. Proc. Natl. Acad. Sci. U.S.A. 86, 5159-5162. 

The application of semiconductor luminescence to chemical sensing can rely on the chemical, electrical, and optical properties of II-VI and III-V semiconductors [1]. These properties provide the binding capability, transducing mechanism, and signal required for chemical sensing. The diverse chemical compositions of semiconductor materials provide a range of surfaces for molecular binding. 

The transducing mechanism of semiconductor luminescence involves the modification of the semiconductors surface electrical properties through molecular adsorption. Changes in solid-state electro-optical properties result from adsorption of the molecule of interest onto the semiconductor surface. 

All cells have specific and highly sensitive signal-transducing mechanisms, which have been conserved during evolution. 

With regard to the signal transducing mechanisms coupled to histamine H3 receptors, we performed an extensive investigation in our lab on the guinea pig duodenum. Poli et al., (1993)... 

Poli, E., Pozzoli, C., Coruzzi, G., Bertaccini., G., 1994a. Signal transducing mechanisms coupled to histamine H3 receptors and alpha-2 adrenoceptors in the guinea pig duodenum possible involvement of N-type Ca++ channels. J. Pharmacol. Exp. Ther. 270, 788-794. 

There is a continuing demand for the application of electrochemical sensors with a good quality/cost performance not only in comparison to sensors based on other transducer mechanisms but also to some standard analytical methods. Electrochemical Sensor Analysis (ECSA) presents novel theoretical considerations along with detailed applications of electrochemical (bio)sensors. The combination of both theoretical and practical aspects provides a comprehensive forum that integrates interdisciplinary research and development, presenting the most recent advances in applications in various important areas related to everyday life. Additionally ECSA reflects that electrochemical sensor analysis is already a well established research and applied area of analytical chemistry. 

Berridge MJ. 1981 Phosphatidylinositol hydrolysis a multifunctional transducing mechanism. Mol Cell Endocrinol 24, 115-140. 

The best investigated systems use H202 producing oxidases. The subsequent oxidation of H202 on the working electrodes at a potential from +400 mV to 650 mV versus an Ag/AgCl reference electrode serves as the transducing mechanism. 

The testing concepts described so far make explicit use of the fact that additional drive electrodes, together with those used to capacitively sense a primary sensor input signal, may be used for built-in tests. Design for test concepts therefore appear to be limited to the class of sensors employing reversible transducer mechanisms (i.e., capacitance or piezoelectricity) and to their processing sequences. 

A few typical instruments are briefly described, but the naming of a particular company does not imply any preference by the author for this instrument over any other (named or unnamed). These have been chosen merely to show the different transducer mechanisms employed. 

E. Racker, Energy Transducing Mechanisms, Butterworths, London, 1974. 

Lancy ME (1984) Phonon-Electron Coupling as a Possible Transducing Mechanism in Bioelectronic Process Involving Neuromelanin. J Theor Biol 111 201... 

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