Quantum feedback control and classical control theory

We introduce and discuss the problem of quantum feedback control in the context of established formulations of classical control theory, examining conceptual analogies and essential differences. We describe the application of state-observer-based control laws, familiar in classical control theory, to quantum systems and apply our methods to the particular case of switching the state of a particle in a double-well potential

The effect of a calorie controlled diet containing walnuts on substrate oxidation during 8-hours in a room calorimeter

Objective Dietary macronutrient proportions affect substrate utilization, but in practice people consume foods. We hypothesized that in overweight adults, a calorie controlled diet based on core foods and including walnuts may be advantageous in promoting greater use of fat stores. Methods This crossover study tested the effects of diet-related energy expenditure and fat oxidation in 16 overweight individuals over an 8-hour period. The 2 diets included breakfast and lunch meals during the measurement period and an evening meal the night before. They comprised core foods of bread/cereals, fruit, vegetables, milk/yogurt, and meat, and either walnuts (walnut diet) or olive oil (control diet). There was no difference in the energy and macronutrient composition of the diets in the measurement period. Energy expenditure, respiratory quotient (RQ), and macronutrient oxidation were assessed during two 8-hour stays in a room calorimeter facility. Results During the 8-hour measurement period, no difference in energy expenditure was noted between the diets, but a significant difference in RQ was observed between diets (control 0.908 ± 0.046 vs. walnut 0.855 ± 0.036, p = 0.029). Carbohydrate oxidation was lower and fat oxidation was higher during the walnut period than during the control period. Conclusions A calorie controlled diet of core foods including walnuts may be advantageous in promoting the use of body fat stores, at least under acute conditions

The effect of a calorie controlled diet containing walnuts on substrate oxidation during 8-hours in a room calorimeter

Objective Dietary macronutrient proportions affect substrate utilization, but in practice people consume foods. We hypothesized that in overweight adults, a calorie controlled diet based on core foods and including walnuts may be advantageous in promoting greater use of fat stores. Methods This crossover study tested the effects of diet-related energy expenditure and fat oxidation in 16 overweight individuals over an 8-hour period. The 2 diets included breakfast and lunch meals during the measurement period and an evening meal the night before. They comprised core foods of bread/cereals, fruit, vegetables, milk/yogurt, and meat, and either walnuts (walnut diet) or olive oil (control diet). There was no difference in the energy and macronutrient composition of the diets in the measurement period. Energy expenditure, respiratory quotient (RQ), and macronutrient oxidation were assessed during two 8-hour stays in a room calorimeter facility. Results During the 8-hour measurement period, no difference in energy expenditure was noted between the diets, but a significant difference in RQ was observed between diets (control 0.908 ± 0.046 vs. walnut 0.855 ± 0.036, p = 0.029). Carbohydrate oxidation was lower and fat oxidation was higher during the walnut period than during the control period. Conclusions A calorie controlled diet of core foods including walnuts may be advantageous in promoting the use of body fat stores, at least under acute conditions

Chinese herbal medicine for infertility with anovulation: a systematic review.

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Impact of adsorption on scanning electrochemical microscopy voltammetry and implications for nanogap measurements

Scanning electrochemical microscopy (SECM) is a powerful tool that enables quantitative measurements of fast electron transfer (ET) kinetics when coupled with modeling predictions from finite-element simulations. However, the advent of nanoscale and nanogap electrode geometries that have an intrinsically high surface area-to-solution volume ratio realizes the need for more rigorous data analysis procedures, as surface effects such as adsorption may play an important role. The oxidation of ferrocenylmethyl trimethylammonium (FcTMA+) at highly oriented pyrolytic graphite (HOPG) is used as a model system to demonstrate the effects of reversible reactant adsorption on the SECM response. Furthermore, the adsorption of FcTMA2+ species onto glass, which is often used to encapsulate ultramicroelectrodes employed in SECM, is also found to be important and affects the voltammetric tip response in a nanogap geometry. If a researcher is unaware of such effects (which may not be readily apparent in slow to moderate scan voltammetry) and analyzes SECM data assuming simple ET kinetics at the substrate and an inert insulator support around the tip, the result is the incorrect assignment of tip–substrate heights, kinetics, and thermodynamic parameters. Thus, SECM kinetic measurements, particularly in a nanogap configuration where the ET kinetics are often very fast (only just distinguishable from reversible), require that such effects are fully characterized. This is possible by expanding the number of experimental variables, including the voltammetric scan rate and concentration of redox species, among others

(2 Z )-3-Hydroxy-1-(pyridin-2-yl)-3-(pyridin-3-yl)prop-2-en-1one: crystal structure and Hirshfeld surface analysis

The title compound, C13H10N2O2 [also called 1-(pyridin-2-yl)-3-(pyridin-3-yl)propane-1,3-dione], features an almost planar (r.m.s. deviation = 0.0095 Å) central C3O2 core consolidated by an intra­molecular hy­droxy-O-H...O(carbon­yl) hydrogen bond. Twists are evident in the mol­ecule, as seen in the dihedral angles between the central core and the 2- and pyridin-3-yl rings of 8.91 (7) and 15.88 (6)°, respectively. The conformation about the C=C bond [1.3931 (17) Å] is Z, and the N atoms lie to the same side of the mol­ecule. In the mol­ecular packing, supra­molecular chains along the a axis are mediated by [pi](pyridin-2-yl)-[pi](pyridin-3-yl) inter­actions [inter-centroid distance = 3.7662 (9) Å]. The observation that chains pack with no directional inter­actions between them is consistent with the calculated electrostatic potential, which indicates that repulsive inter­actions dominate

Reconstruction of the joint state of a two-mode Bose-Einstein condensate

We propose a scheme to reconstruct the state of a two-mode Bose-Einstein condensate, with a given total number of atoms, using an atom interferometer that requires beam splitter, phase shift and non-ideal atom counting operations. The density matrix in the number-state basis can be computed directly from the probabilities of different counts for various phase shifts between the original modes, unless the beamsplitter is exactly balanced. Simulated noisy data from a two-mode coherent state is produced and the state is reconstructed, for 49 atoms. The error can be estimated from the singular values of the transformation matrix between state and probability data.Comment: 4 pages (REVTeX), 5 figures (PostScript

Al0.52In0.48P avalanche photodiodes for soft X-ray spectroscopy

The performance of Al0.52In0.48P avalanche photodiodes was assessed as soft X-ray detectors at room temperature. The effect of the avalanche gain improved the energy resolution and an energy resolution (FWHM) of 682 eV is reported for 5.9 keV X-rays

Lowering Low-Density Lipoprotein Particles in Plasma Using Dextran Sulphate Co-Precipitates Procoagulant Extracellular Vesicles

Plasma extracellular vesicles (EVs) are lipid membrane vesicles involved in several biological processes including coagulation. Both coagulation and lipid metabolism are strongly associated with cardiovascular events. Lowering very-low- and low-density lipoprotein ((V)LDL) particles via dextran sulphate LDL apheresis also removes coagulation proteins. It remains unknown, however, how coagulation proteins are removed in apheresis. We hypothesize that plasma EVs that contain high levels of coagulation proteins are concomitantly removed with (V)LDL particles by dextran sulphate apheresis. For this, we precipitated (V)LDL particles from human plasma with dextran sulphate and analyzed the abundance of coagulation proteins and EVs in the precipitate. Coagulation pathway proteins, as demonstrated by proteomics and a bead-based immunoassay, were over-represented in the (V)LDL precipitate. In this precipitate, both bilayer EVs and monolayer (V)LDL particles were observed by electron microscopy. Separation of EVs from (V)LDL particles using density gradient centrifugation revealed that almost all coagulation proteins were present in the EVs and not in the (V)LDL particles. These EVs also showed a strong procoagulant activity. Our study suggests that dextran sulphate used in LDL apheresis may remove procoagulant EVs concomitantly with (V)LDL particles, leading to a loss of coagulation proteins from the blood