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Sensing Probe (sensing + probe)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

ChemInform Abstract: Design and Synthesis of Hg2+ Sensing Probe Based on Spirobenzopyran Derivatives.

CHEMINFORM, Issue 3 2008
Tian Tian
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Blood Flow in Snake Infrared Organs: Response-Induced Changes in Individual Vessels

MICROCIRCULATION, Issue 2 2007
RICHARD C. GORIS
ABSTRACT Objective: In the past the microkinetics of blood flow in the infrared pit organs of pit vipers has been studied with Doppler flowmetry using various infrared stimuli such as a human hand or soldering iron at various distances, lasers of various wavelengths, etc. Quick-acting variations in blood flow were recorded, and interpreted as a cooling mechanism for avoiding afterimage in the infrared receptors. However, the Doppler measurements provided only the summation of blood flow in a number of vessels covered by the sensing probe, but did not give data on flow in individual vessels. Methods: In the present work the authors introduced into the bloodstream of Gloydius and Trimeresurus pit vipers fluorescent microspheres labeled with fluorescein isothiocyanate (FITC) contained in a solution of FITC-dextran in physiological saline. They observed the passage of the microspheres through individual pit organ vessels with a fluorescent microscope to which was attached a high-speed video camera and image intensifier. Output of the camera was recorded before, during, and after stimulus with a 810-nm diode laser. Recording was done at 250 frames/s on high-speed video apparatus and downloaded to a hard disk. Disk files were loaded into proprietary software and particles were tracked and average velocities calculated. The data were then tested for significance by ANOVA with post hoc tests. Results: A significant (p < .05) increase in blood velocity was found at the focal point of the stimulus laser, but not anywhere removed from this point. Proximal severing of the pit sensory nerves caused degeneration of the pit receptor terminals and abolished stimulus-induced blood flow changes, but did not affect normal blood flow. Conclusions: The authors conclude that the receptors themselves are directly and locally controlling the smooth muscle elements of the blood vessels, in response to heating of the receptors by infrared radiation. They speculate that the heavy vascularization constitutes a cooling system for the radiation-encoding receptors, and further that the agent of control may be a volatile neuromediator such as nitric oxide. [source]

Nanofibrous polyaniline thin film prepared by plasma-induced polymerization technique for detection of NO2 gas

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2010
Ashutosh Tiwari
Abstract A nanofibrous polyaniline (PANI) thin film was fabricated using plasma-induced polymerization method and explored its application in the fabrication of NO2 gas sensor. The effects of substrate position, pressure, and the number of plasma pulses on the PANI film growth rate were monitored and an optimum condition for the PANI thin film preparation was established. The resulting PANI film was characterized with UV,visible spectrophotometer, FTIR, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The PANI thin film possessed nanofibers with a diameter ranging from 15 to 20 nm. The NO2 gas sensing behavior was studied by measuring the change in electrical conductivity of PANI film with respect to NO2 gas concentration and exposure time. The optimized sensor exhibited a sensitivity factor of 206 with a response time of 23 sec. The NO2 gas sensor using nanofibrous PANI thin film as sensing probe showed a linear current response to the NO2 gas concentration in the range of 10,100 ppm. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Methodological aspects of in vitro sensing of L -glutamate in acute brain slices

THE CHEMICAL RECORD, Issue 6 2007
Masao Sugawara
Abstract L -Glutamate is a major amino acid neurotransmitter in the central neuronal system of the mammalian brain and plays a vital role in brain development, synaptic plasticity, neurotoxicity, and neuropathological disorders. Despite technical limitations, progress is being made in sensing L -glutamate in vivo and in vitro. Sophisticated microsensors with the necessary spatial and temporal resolution have recently been emerging, which enable us to discern regional distribution, concentration levels, and temporal changes of L -glutamate in acute brain slices. The L -glutamate sensors for in vitro sensing have different structures and sizes, such as glass capillary-based enzyme sensors, polymer-coated enzyme sensors, and patch sensors based on natural sensing probes. The concentration of L -glutamate released in brain slices by chemical stimulation is markedly dependent on neuronal regions, types of stimulation, and sensing methods. Real- and long-time monitoring of L -glutamate in acute hippocampal slices is beginning to shed light on L -glutamate release related to the molecular mechanisms of long-term potentiation. Progress is also being made toward the visualization of L -glutamate release in acute hippocampal slices. The methodological aspects of in vitro sensing of L -glutamate are discussed. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 317,325; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20126 [source]