<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wang, Jianping</style></author><author><style face="normal" font="default" size="100%">El-Sayed, Mostafa A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Time-resolved long-lived infrared emission from bacteriorhodopsin during its photocycle</style></title><secondary-title><style face="normal" font="default" size="100%">Biophysical Journal</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Sep</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">3</style></number><volume><style face="normal" font="default" size="100%">83</style></volume><pages><style face="normal" font="default" size="100%">1589-1594</style></pages><isbn><style face="normal" font="default" size="100%">0006-3495</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The infrared emission observed below 2000 cm(-1) upon exciting retinal in bacteriorhodopsin (bR) is found to have a rise time in the submicrosecond time regime and to relax with two exponential components on the submillisecond to millisecond time scale. These time scales, together with the assignment of this emission to hot vibrations from the all-trans retinal (in bR) and the 13-cis retinal (in the K intermediate), support the recent assignment of the J-intermediate as an electronically excited species (Atkinson et al., J. Phys. Chem. A. 104:4130-4139, 2000) rather than a vibrationally hot K intermediate. A discussion of these time scales of the observed infrared emission is given in terms of the competition between radiative and nonradiative relaxation processes of the vibrational states involved.</style></abstract><accession-num><style face="normal" font="default" size="100%">WOS:000177774500033</style></accession-num><notes><style face="normal" font="default" size="100%">Wang, JP El-Sayed, MA</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wang, Jianping</style></author><author><style face="normal" font="default" size="100%">Gan, D. J.</style></author><author><style face="normal" font="default" size="100%">Lyon, L. A.</style></author><author><style face="normal" font="default" size="100%">El-Sayed, Mostafa A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Temperature-jump investigations of the kinetics of hydrogel nanoparticle volume phase transitions</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of the American Chemical Society</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2001</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Nov</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">45</style></number><volume><style face="normal" font="default" size="100%">123</style></volume><pages><style face="normal" font="default" size="100%">11284-11289</style></pages><isbn><style face="normal" font="default" size="100%">0002-7863</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The dynamics of the deswelling and swelling processes in thermoresponsive poly-N-isopropylacrylamide (pNIPAm) hydrogel nanoparticles have been studied by using time-resolved transmittance measurements, in combination with a nanosecond laser-induced temperature-jump (T-jump) technique. A decrease in the solution transmittance associated with deswelling of the particles has been observed as the solution temperature traverses the volume phase transition temperature of the particles. Upon inducing the T-jump, the deswelling transition only occurs in a small percentage (&lt; 10%) of the particle volume, which was found to be a thin periphery layer of the particles. The particle deswelling occurs on the microsecond time scale, and as shown previously, the collapse time can be tuned via adding small amounts of hydrophobic component to the particle shell. In contrast, the reswelling of the particles was thermodynamically controlled by bath equilibration, and only small differences in particle reswelling kinetics were found due to sluggish heat dissipation (millisecond time scale) from the sample cell.</style></abstract><accession-num><style face="normal" font="default" size="100%">WOS:000172239900018</style></accession-num><notes><style face="normal" font="default" size="100%">Wang, JP Gan, DJ Lyon, LA El-Sayed, MA</style></notes><electronic-resource-num><style face="normal" font="default" size="100%">10.1021/ja016610w</style></electronic-resource-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wang, Jianping</style></author><author><style face="normal" font="default" size="100%">El-Sayed, Mostafa A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Time-resolved Fourier transform infrared spectroscopy of the polarizable proton continua and the proton pump mechanism of bacteriorhodopsin</style></title><secondary-title><style face="normal" font="default" size="100%">Biophysical Journal</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2001</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Feb</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">2</style></number><volume><style face="normal" font="default" size="100%">80</style></volume><pages><style face="normal" font="default" size="100%">961-971</style></pages><isbn><style face="normal" font="default" size="100%">0006-3495</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Nanosecond-to-microsecond time-resolved Fourier transform infrared (FTIR) spectroscopy in the 3000-1000-cm(-1) region has been used to examine the polarizable proton continua observed in bacteriorhodopsin (bR) during its photocycle. The difference in the transient FTIR spectra in the time domain between 20 ns and 1 ms shows a broad absorption continuum band in the 2100-1800-cm(-1) region, a bleach continuum band in the 2500-2150-cm(-1) region, and a bleach continuum band above 2700 cm(-1). According to Zundel (G. Zundel, 1994, J. Mol. Struct. 322.33-42), these continua appear in systems capable of forming polarizable hydrogen bonds. The formation of a bleach continuum suggests the presence of a polarizable proton in the ground state that changes during the photocycle. The appearance of a transient absorption continuum suggests a change in the polarizable proton or the appearance of new ones. It is found that each continuum has a rise time of less than 80 ns and a decay time component of similar to 300 mus. In addition, it is found that the absorption continuum in the 2100-1800-cm(-1) region has a slow rise component of 190 ns and a fast decay component of similar to 60 mus. Using these results and those of the recent x-ray structural studies of bR(570) and M-412 (H. Luecke, B. Schobert, H.T. Richter, J.-P. Cartailler, and J. K. Lanyi, 1999, Science 286:255-260), together with the already known spectroscopic properties of the different intermediates in the photocycle, the possible origins of the polarizable protons giving rise to these continua during the bR photocycle are proposed. Models of the proton pump are discussed in terms of the changes in these polarizable protons and the hydrogen-bonded chains and in terms of previously known results such as the simultaneous deprotonation of the protonated Schiff base (PSB) and Tyr185 and the disappearance of water molecules in the proton release channel during the proton pump process.</style></abstract><accession-num><style face="normal" font="default" size="100%">WOS:000166765100038</style></accession-num><notes><style face="normal" font="default" size="100%">Wang, JP El-Sayed, MA</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wang, Jianping</style></author><author><style face="normal" font="default" size="100%">El-Sayed, Mostafa A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Temperature jump-induced secondary structural change of the membrane protein bacteriorhodopsin in the premelting temperature region: A nanosecond time-resolved Fourier transform infrared study</style></title><secondary-title><style face="normal" font="default" size="100%">Biophysical Journal</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year><pub-dates><date><style  face="normal" font="default" size="100%">May</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">5</style></number><volume><style face="normal" font="default" size="100%">76</style></volume><pages><style face="normal" font="default" size="100%">2777-2783</style></pages><isbn><style face="normal" font="default" size="100%">0006-3495</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The secondary structural changes of the membrane protein, bacteriorhodopsin, are studied during the premelting reversible transition by using laser-induced temperature jump technique and nanosecond time-resolved Fourier transform infrared spectroscopy. The helical structural changes are triggered by using a 15 degrees C temperature jump induced from a preheated bacteriorhodopsin in D2O solution at a temperature of 72 degrees C. The structural transition from alpha(II)- to alpha(I)-helices is observed by following the change in the frequency of the amide I band from 1667 to 1651 cm(-1) and the shift in the frequency of the amide II vibration from 1542 cm(-1) to 1436 cm(-1) upon H/D exchange. It is found that although the amide I band changes its frequency on a time scale of &lt;100 ns, the H/D exchange shifts the frequency of the amide II band and causes a complex changes in the 1651-1600 cm(-1) and 1530-1430 cm(-1) frequency region on a longer time scale (&gt;300 ns). Our result suggests that in this &quot;premelting transition&quot; temperature region of bacterioriorhodopsin, an intrahelical conformation conversion of the alpha(II) to alpha(I) leads to the exposure of the hydrophobic region of the protein to the aqueous medium.</style></abstract><accession-num><style face="normal" font="default" size="100%">WOS:000080278600043</style></accession-num><notes><style face="normal" font="default" size="100%">Wang, JP El-Sayed, MA</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wang, Jianping</style></author><author><style face="normal" font="default" size="100%">Song, Li</style></author><author><style face="normal" font="default" size="100%">Zou, Bingsuo</style></author><author><style face="normal" font="default" size="100%">El-Sayed, Mostafa A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Time-resolved Fourier-transform infrared and visible luminescence spectroscopy of photoexcited porous silicon</style></title><secondary-title><style face="normal" font="default" size="100%">Physical Review B</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Feb</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">7</style></number><volume><style face="normal" font="default" size="100%">59</style></volume><pages><style face="normal" font="default" size="100%">5026-5031</style></pages><isbn><style face="normal" font="default" size="100%">0163-1829</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In order to identify the luminescent centers in aged porous silicon, both the time-resolved vibration spectra in the 750-2000-cm(-1) region and the visible luminescence spectra are studied for the same sample in the 0-440-mu s time domain. Laser excitation gives rise to emission characteristics of the porous silicon as well as strong bleach in the infrared spectrum in the region of the ground-stale silicon-oxygen stretching vibration frequencies at 1100 and 1235 cm(-1). In addition, new transient absorption bands appear in this region as a result of the laser excitation. Three characteristic Lifetimes in the decay of the bleach band at 1235 cm(-1) are observed on the 1-, 10-, and 100-mu s time scale. These are similar to the observed decay times of the photoluminescence from porous silicon. These results suggest that the emitting centers in aged porous silicon are trapped excitation sites in an inhomogeneously defected oxidized silicon surface. [S0163-1829(99)09207-3].</style></abstract><accession-num><style face="normal" font="default" size="100%">WOS:000078778800080</style></accession-num><notes><style face="normal" font="default" size="100%">Wang, JP Song, L Zou, BS El-Sayed, MA</style></notes><electronic-resource-num><style face="normal" font="default" size="100%">10.1103/PhysRevB.59.5026</style></electronic-resource-num></record></records></xml>