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The primary light-induced charge separation in reaction centers from Rhodopseudomonas sphaeroides R-26 has been investigated after excitation with laser pulses of 150 fsec duration within the longwave absorption band of the primary donor at 850 nm. An excited state of the primary donor, characterized by a broad absorption spectrum extending over the whole(More)
Reaction centers from the photosynthetic bacterium Rhodopseudomonas viridis have been excited within the near-infrared absorption bands of the dimeric primary donor (P), of the "accessory" bacteriochlorophylls (B), and of the bacteriopheophytins (H) by using laser pulses of 150-fsec duration. The transfer of excitation energy between H, B, and P occurs in(More)
Kinetics of sarcomere movement were studied in real-time by laser diffraction. Instantaneous sarcomere shortening was measured during afterloaded twitches simultaneously with instantaneous shortening and tension of the whole trabecula excised from rat right ventricle. Resting sarcomere length at optimal length was 2.20 +/- 0.02 micron (mean +/- SEM).(More)
The primary electron transfer processes in isolated reaction centers of Rhodopseudomonas sphaeroides have been investigated with subpicosecond and picosecond spectroscopic techniques. Spectra and kinetics of the absorbance changes following excitation with 0.7-ps 610-nm pulses, absorbed predominantly by bacteriochlorophyll (BChl), indicate that the radical(More)
We have measured spectral and kinetic differences in protoheme, sperm whale or horse heart myoglobin and human hemoglobin following photodissociation induced by optical pulses of 80 fs duration. Full ligation was performed with oxygen or carbon monoxide. Femtosecond kinetics and transient difference spectra revealed the appearance of a deoxy species with(More)
Developing access control extensions for operating systems is an expensive and time-consuming task. Mechanisms available for access control extension lag behind industry standard extension solutions for file systems, process schedulers, and device drivers, and suffer from a number of serious flaws in modern multi-processor, multi-threaded kernels. In this(More)
Pulses of 20-TW peak power have been generated at 1064 nm using the chirped-pulse-amplification technique with a 90-mm output-aperture Nd:silicate glass amplification line. This system delivers 60 J of energy in a chirped pulse of 600-psec duration, with a capacity to maintain a 3.5-nm output bandwidth. These chirped pulses are compressed to 1.2 psec with(More)
We demonstrate correction of laser wave-front distortions by use of an adaptive-optical technique based on a light valve. The setup consists of an achromatic and adjustable-sensitivity wave-front sensor and a wave-front corrector relying on an optically addressed liquid-crystal spatial light modulator. Experimental results with strongly aberrated beams(More)
Photolysis of HbCO, MbCO, and CO-protoheme has been investigated by measuring transient differential spectra and kinetics of induced absorption after excitation with a 250-fsec laser pulse at 307 nm. Probing was performed by a part of a continuum pulse between 395 and 445 nm. Photodissociation of the three liganded species occurred within the pulse(More)
We demonstrate efficient generation of picosecond narrow-bandwidth pulses by frequency mixing of broadband opposite chirped pulses in a type I doubling crystal. This procedure allows us to produce picosecond pulses that are perfectly synchronized with femtosecond pulses. The experiment shows a decrease of the initial bandwidth by a factor of more than 30,(More)