Gate measurements

Attractive for the use of QDs are their long lifetimes (typically 5 ns to hundreds of nanoseconds), compared to organic dyes, that are typically insensitive to the presence of oxygen. In conjunction with time-gated measurements, this provides the basis for enhanced sensitivity [69]. This property can be also favorable for time-resolved applications of FRET. The complicated size-, surface-, and wavelength-dependent, bi- or multi-exponential QD decay behavior (Fig. 2) can complicate... 

Acri JB, Morse DE, Popke EJ, Grunberg NE. (1994). Nicotine increases sensory gating measured as inhibition of the acoustic startle reflex in rats. Psychopharmacology (Berlin). 114(2) 369-74. 

In addition, the luminescence lifetime of quantum dots is approximately one order of magnitude longer than that of their organic counterparts.30 Thus, the autofluorescence of biological samples can effectively be filtered, for example, with time-gated measurements, in the case of these inorganic luminophores. Moreover, QDs are also particularly interesting for multiplexed analysis because of two of their inherent... 

A measurement of the Kerr relaxation times in succinoni-trile(SN)as a function of temperature is shown in Fig. 2. The Kerr relaxation times measured show the effect of temperature on the rotational motion of the SN molecules as they undergo a change from the liquid to the plastic crystal phase. The data obtained from the Kerr gate measurement is shown along with a best fit curve from depolarized Rayleigh scattering (dotted line), and a best fit curve from dielectric relaxation measure-... 

TR-FRET measurements present interesting alternatives to the FRET quench format to minimize compound interference. Time-gated measurements allow the exclusion of compound auto-fluorescence from the detection. The technology is very popular due to its sensitivity, ease of use, and simplicity of assay development. The high costs for the reagents are the major disadvantage of... 

On each experimental day, the Repeatable Battery for Assessment of Neuropsychological Status (RBANS) was administered (Randolph, 1998). It assesses attention, immediate memory, visuospatial/ construction, language, and delayed memory (Gold et al., 1999). Schizophrenics score significantly lower than normal subjects the decrement is correlated with diminished psychosocial status. Compared to placebo, the DMXB-A significantly improved overall performance and specifically improved function on the Attention subscale. Inhibition of the P50 response to repeated stimulus, the sensory gating measure that led to identification of nicotinic receptor deficits in schizophrenia, also improved (Olincy et al., 2006). 

NMDA antagonists reliably induce deficits in sensory gating measures, such as prepulse inhibition (PPI) that closely mimic the deficits seen in schizophrenia in both rodent (de Bruin et al., 1999 ... 

Corry B, Rigby P, Martinac B. Conformational changes involved in MscL channel gating measured using ERET spectroscopy. Biophys. J. 2005 91 1032-1045. 

This technique utilizes a pulse pump-probe experiment and monitors the absorption of a weak probe beam in the presence of a strong pump beam. Fig. 8 depicts the experimental set-up for a two-beam pump-probe experiment, which includes homodyne and heterodyne Kerr gate measurements and polarization-controlled transient absorption measurement. Generally, the input beam is produced from an amplified pulse laser system with 1 KHz repetition rate, which can produce picosecond or femtosecond pulses. This pumping light beam is divided into two beams by a beam-splitter with an intensity ratio of 30 1 therefore, the one with the stronger intensity will act as the pump and the weaker one will be the probe. The position of the sample is where these two beams focus and overlap spatially. The time delay between the pulses from these two beams is controlled by a retroreflec-... 

FIGURE 49.8. Schematics of experimental arrangement of the optical Kerr gate measurement. 

Figure 6.6 Schematic depiction of source and drain currents versus average of source and drain potentials (gate potential) when the source and drain potentials are changed simultaneously while maintaining a fixed potential offset between them (source-drain voltage) calculated using Equation 6.10 (i.e., gate measurement) [7], Lines labeled a-g indicate source and drain current for different gate potentials. The source-drain voltage used here to calculate the source and drain current is 0.1 V.

Figure 6.8 depicts and Ig plotted versus Eq for various values of V calculated on the basis of Equation 6.10, indicating that the maximum source-drain current for gate measurements occurs when Eq = E° and V is sufficiently large (>0.25 V at room temperature), yielding I = nFAk d /w. 

Here, G, conductance, characterizes the dependency of source-drain current on source-drain voltage for gate measurements when V is sufficiently small to yield a linear (ohmic) dependency. G specifically applies to the box geometry depicted in Figure 6.1. Figure 6.9 depicts /d and Is plotted versus V for various values of Eq calculated using Equation 6.10, where G is the slope of the line tangent to the curve when V < 0.05 V per Equation 6.14. The purpose of G is that it enables a standardized comparison of different materials of their ability to conduct... 

D.N. Fittinghoff, K.W. DeLong, and R. Trebino, Noise Sensitivity in Frequency-Resolved Optical-Gating Measurements of Ultrashort Pulses , J. Opt. Soc. Am. B 12, 1955 (1995). 

Pal R., A. Beeby, D. Parker. Analysis of citrate in low-volume seminal fluid samples using a time-gated measurement of europium luminescence, J. Pharm. Biomed. Anal., 56, 352-358 (2011). 

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