Channeling measurements

Smith, J.S., Coronado, R., Meissner, G. (1986). Single channel measurements of the calcium release charmel from skeletal muscle sarcoplasmic reticulum. J. Gen. Physiol. 88, 573-588. 

Khakh, B. S., Fisher, J. A., Nashmi, R., Bowser, D. N. and Lester, H. A. (2005). An angstrom scale interaction between plasma membrane ATP-gated P2X2 and alpha4beta2 nicotinic channels measured with fluorescence resonance energy transfer and total internal reflection fluorescence microscopy. J. Neurosci. 25, 6911-20. 

Extensive channeling measurements on 2H implanted into silicon have been published by Bech Nielsen (1988). These measurements also use the 3He-induced nuclear reaction in conjunction with extensive modeling using the statistical equilibrium model already described. The 2H implants were done at 30 K, and lattice location of the 2H was done as a function of annealing. 

Bech Nielsen et al. (1988) also made a channeling study of the 2H in B-2H complexes that was similar in principle to that just described but differed in details of technique and in some of the conclusions arrived at. Also, they did not investigate the position of the boron atoms. They used Si uniformly doped with a high (1 x 1019 B/cm3) boron concentration, rather than implanted boron. The surface was etched off after hydrogenation, but no SIMS data was presented to confirm the uniform hydrogen concentration assumed. The penetration depth of the H was given as —7000 A. The channeling measurements were performed at 30 K. For analysis of their data Bech Nielsen et al. used the same model, based on the assumption of statistical equilibrium (SE) of the channeled ions, already described in connection with the measurements of implanted deutrium... 

The description of channeling measurements on hydrogen-passivated boron-doped layers has shown that there is broad agreement on the main features of the experimental data from the different groups, if we leave aside data that is strongly influenced by radiation damage caused by the... 

Figure 30. Water mole fraction profiles along the anode gas channel measured by a microGC in a cathode underhumidified PEEC using 30 / m membrane (EW < 1000).

The OH radicals are trapped by reaction with benzoic acid, forming hydroxybenzoic acid, which is measured by fluorescence. Organic peroxides ROOH form RO + OH-, but the derivatives of benzoic acid formed by the reaction of the RO radicals do not fluoresce under the conditions chosen to measure H202. Thus, in principle, this second channel measures H202. However, in practice, it was found to give about a 30% response to hydroxymethyl hydroperoxide as well, so that the results from this channel must be corrected for this contribution (Lee et al., 1993). 

The duration of action of a local anaesthetic is proportional to the time that the drug remains bound to the sodium channels. Measures that prolong contact time will prolong the duration of the local anaesthetic effect. Cocaine has a vasoconstricting effect on blood vessels and prevents its own absorption. Many local anaesthetics are prepared with adrenaline (epinephrine) in order to achieve this effect. Concentrations are usually of the order of 1 200000 or more dilute than this. Care should be exercised when using adrenaline-containing solutions in the presence of halothane as it is known to sensitise the myocardium to the effects of catecholamines. 

Fig. 29.3. The Palmsens hand-held potentiostat equipped with the dedicated multiplexer for eight-channel measurements.

Atmospheric Infrared Sounder (AIRS) It has 2,382 high-resolution channels, 2,378 channels measuring IR radiation in the range 3.7 pm to 15.4 pm, other channels cover visible and near-IR regions (0.4 pm-0.94 pm). 

Clouds and the Earth s Radiant Energy System (CERES) CERES is a broadband three-channel scanning radiometer. One channel measures reflected solar radiation in the range 0.3 pm-5.0 pm. Two other channels (0.3 pm-100 pm and 8 pm-12 pm) measure reflected and emitted radiant energy at the top of the atmosphere. 

Fig. 37 Topography of two conductive graphitic channels, measured with an intact tip (foreground) and with a tip which has lost its conductivity at the very end. Scan width 65 nm, corrugation 3 nm. The local current density was encoded in greyscale colour, where white represents the highest current, and dark grey the current below the detection level. The excitation voltage is 100 mV at 51 kHz, the current is several 10 nA...

Wiegand G, Neumaier KR, Sackmann E (2000) Fast impedance spectroscopy general aspects and performance study for single ion channel measurements. Rev Sci Instrum 71 2309-20... 

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