The time-resolved orientational anisotropies of the OD hydroxyl stretch dilute HOD in H2O confined on a nanometer length scale sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles are studied using ultrafast infrared polarization and spectrally resolved pump-probe spectroscopy, results compared to same experiments bulk water. anisotropy data for three water nanopool sizes (4.0, 2.4, 1.7nm) can be fitted well with biexponential decays. decays analyzed wobbling-in-a-cone model that...

Photosystem II (PSII) is an integral part of the photosynthesis machinery, in which several light-harvesting complexes rely on inter-complex excitonic energy transfer (EET) processes to channel reaction center. In this paper, we report a direct observation EET minimal PSII supercomplex from plants, containing trimeric complex (LHCII), monomeric CP26, and core complex. Using two-dimensional (2D) electronic spectroscopy, measure timescale 50 picoseconds for excitations LHCII-CP26 peripheral...

The dynamics of water, confined on a nanometer length scale (1.7 to 4.0 nm) in sodium bis-(2-ethylhexyl) sulfosuccinate reverse micelles, is directly investigated using frequency resolved infrared vibrational echo experiments. data are compared bulk water and salt solution data. experimentally determined frequency-frequency correlation functions show that the substantially slower than size dependent. fastest ($\ensuremath{\sim}50\text{ }\text{ }\mathrm{f}\mathrm{s}$) more similar while...

We present the theory and selection procedure of phase-cycling schemes for phase coherent multidimension optical spectroscopy. apply our to determine with least number steps needed measure two-dimensional spectra various time resolved four wave mixing processes. The scheme presented in this paper can be applied higher order nonlinear experiments involving more pulses that dimensional spectra.

The dynamics of water in nanoscopic pools 1.7−4.0 nm diameter AOT reverse micelles were studied with ultrafast infrared spectrally resolved stimulated vibrational echo and pump−probe spectroscopies. experiments conducted on the OD hydroxyl stretch low-concentration HOD H2O, providing a direct examination hydrogen-bond network dynamics. Pump−probe show that lifetime mode increases as size micelle decreases. These are also sensitive to dissociation reformation dynamics, which observed change...

Abstract Nonradiative relaxation of high-energy excited states to the lowest state in chlorophylls marks first step process photosynthesis. We perform ultrafast transient absorption spectroscopy measurements, that reveal this internal conversion dynamics be slightly slower chlorophyll B than A . Modeling with non-adiabatic molecular simulations uncovers a critical role played by different side groups two molecules governing intramolecular redistribution wavefunction, leading, turn,...

This paper examines the parallels between magnetic resonance and optical spectroscopy, with goal of determining to what extent benefits 2DNMR might be extended into regime. Precise analogues simplest sequences (collinear pulse phased laser generation, phase sensitive detection, cycling) are now feasible, we demonstrate that they do generate cross-peaks which reveal common energy levels, even when averaged over distribution flip angles expected in most experiments. One enormous difference NMR...

We analyze the effectiveness of various practical implementations time-dependent pump-probe and transient grating polarization-selective experiments. A variety optical arrangements are analyzed in Jones matrix calculus framework. The that permit correct determination orientational excited-state population dynamics delineated. It is shown magic angle experiments yield pure under certain conditions only. spectrally resolved use a monochromator to be dependent on position an analyzing polarizer...

Summary Hypotension necessitating vasopressor administration occurs commonly during caesarean section under spinal anaesthesia. We developed a novel delivery system that automatically administers phenylephrine or ephedrine based on continuous non‐invasive arterial pressure monitoring. A bolus of 50 μg was given at 30‐s intervals when systolic blood fell < 90% baseline; an 4 mg instead if baseline together with heart rate 60 beats.min −1 . The control group used manual boluses either 100 8...

We present here the first room-temperature 2D electronic spectroscopy study of energy transfer in plant light-harvesting complex II, LHCII.

We derive general expressions that incorporate finite pulse envelope effects into a coherent two-dimensional optical spectroscopy (2DOS) technique. These are simpler and less computationally intensive than the conventional triple integral calculations needed to simulate 2DOS spectra. The simplified involving multiplications of arbitrary spectra with 2D spectral response function shown be exactly equal if functions do not vary population time. With minor modifications, they also accurate for...

Summary Identifying factors associated with persistent pain after breast cancer surgery may facilitate risk stratification and individualised management. Single‐population studies have limited generalisability as socio‐economic genetic contribute to development. Therefore, this prospective multicentre cohort study aimed develop a predictive model from sample of Asian American women. We enrolled women undergoing elective at KK Women's Children's Hospital Duke University Medical Center....

We demonstrate a method to measure purely absorptive fifth-order three-dimensional (3D) electronic spectrum based on pulse-shaper assisted pump-probe beam geometry setup. The 3D spectra are measured as function of two independently controlled population times. With phase-cycling and data processing, chlorophyll obtained.

Abstract During photosynthesis, sunlight is efficiently captured by light-harvesting complexes, and the excitation energy then funneled towards reaction centre. These photosynthetic transfer (EET) pathways are complex proceed in a multistep fashion. Ultrafast two-dimensional electronic spectroscopy (2DES) an important tool to study EET processes complexes. However, can only be indirectly inferred correlating different cross peaks from series of 2DES spectra. Here we directly observe LHCII...

Excited-state relaxation dynamics and energy-transfer processes in the chlorophyll a (Chl a) manifold of light-harvesting complex II (LHCII) were examined at physiological temperature using femtosecond two-dimensional electronic spectroscopy (2DES). The experiments done under conditions free from singlet-singlet annihilation anisotropic decay. Energy transfer between different domains Chl was found to proceed on time scales hundreds femtoseconds five picoseconds, before reaching...

Photosystem I (PSI), found in all oxygenic photosynthetic organisms, uses solar energy to drive electron transport with nearly 100% quantum efficiency, thanks fast transfer among antenna chlorophylls and charge separation the reaction center. There is no complete consensus regarding kinetics of elementary steps involved overall trapping, especially rate primary separation. In this work, we employed two-dimensional coherent electronic spectroscopy follow dynamics a monomeric PSI complex from...

A complete picture of charge generation over 11 orders magnitude in time the high-performance PM6:Y6 organic-semiconductor blend from donor and acceptor excitation is obtained using ultrafast spectroscopy kinetic modeling.

Ultrafast two-dimensional electronic spectroscopy has been used to study the spectral diffusion of Qy transition chlorophyll a in methanol. The two time frequency-fluctuation correlation function (FFCF) measured using center line slope method, together with optimized fitting linear spectrum. FFCF was decay over four scales. three fastest constants which were be ∼65 fs, ∼0.5 ps, and ∼7 ps. These are assigned as inertial component solvation spectrally diffusive processes respectively. fourth...

Summary Hypotension occurs in most caesarean sections under spinal anaesthesia, necessitating vasopressor administration. However, the optimal dosing regimen remains unclear. We have developed a novel delivery system that automatically administers phenylephrine or ephedrine based on continuous non‐invasive blood pressure monitoring. This prospective cohort study recruited 55 healthy women standardised anaesthesia with 2.2 ml hyperbaric bupivacaine 0.5%, 15 μg fentanyl and 100 morphine. A...

We present the theoretical details and experimental demonstration of fifth-order three-dimensional (3D) electronic spectroscopy using a pump-probe beam geometry. This is achieved pulse shaper appropriate phase cycling schemes. show how 8-step 27-step schemes can measure purely absorptive 3D spectra as well for individual processes that contribute to spectrum. function two separate controllable waiting time periods be obtained. The peak shapes positions peaks in measurement correspond theory.