Un nouveau theoreme d'echantillonnage pour le degre de coherence complexe en vue de la reconstitution d'une source lumineuse isotrope

We present some results obtained by using the standard technique of light scattering on so-called “microemulsions”. From the data of single-photon counting of light scattered from 0° to 90° the particle scattering factor P(θ) is obtained. Fitting with the theoretical curves gained for various kinds of particles enables us to deduce in a rather direct and simple way the shape and the size of particles.     

C-H Activation by dinuclear phosphine bridged complexes of rhodium,iridium, and ruthenium

The possibility of activation of the C-H bond by dinuclear phosphine bridged complexes of rhodium, iridium, and ruthenium is considered.This work was reported at the conference Modern Problems of Organometallic Chemistry (8–13 May, 1994, Moscow).Institut fer Technische Chemie und Petrolchemie der RWTH Aachen Worringerweg 1, 52074 Aachen, Deutschland.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 589–593, April, 1994.     

How medical quality is improved: clinical management of patients with acute cardiac ischaemia

The clinical management of patients with acute ischaemic syndromes continues to evolve. It is therefore useful to review the most common categories of such patients, with specific emphasis on the contribution of some well-known laboratory assessments. Key questions on diagnosis, prognosis and medical quality are discussed.Presented at the 9th Conference on Quality in the Spotlight, 18–19 March 2004, Antwerp, Belgium     

Large-amplitude, spatially correlated fluctuations in BOLD fMRI signals during extended rest and early sleep stages

A number of recent studies of human brain activity using blood-oxygen-level-dependent (BOLD) fMRI and EEG have reported the presence of spatiotemporal patterns of correlated activity in the absence of external stimuli. Although these patterns have been hypothesized to contain important information about brain architecture, little is known about their origin or about their relationship to active cognitive processes such as conscious awareness and monitoring of the environment. In this study, we have investigated the amplitude and spatiotemporal characteristics of resting-state activity patterns and their dependence on the subjects' alertness. For this purpose, BOLD fMRI was performed at 3.0 T on 12 normal subjects using a visual stimulation protocol, followed by a 27 min rest period, during which subjects were allowed to fall asleep. In subjects who were asleep at the end of the scan, we found (a) a higher amplitude of BOLD signal fluctuation during rest compared with subjects who were awake at the end of the scan; (b) spatially independent patterns of correlated activity that involve all of gray matter, including deep brain nuclei; (c) many patterns that were consistent across subjects; (d) that average percentage levels of fluctuation in visual cortex (VC) and whole brain were higher in subjects who were asleep (up to 1.71% and 1.16%, respectively) than in those who were awake (up to 1.15% and 0.96%) at the end of the scan and were comparable with those levels evoked by intense visual stimulation (up to 1.85% and 0.76% for two subject groups); (e) no confirmation of correlation, positive or negative, between thalamus and VC found in earlier studies. These findings suggest that resting-state activity continues during sleep and does not require active cognitive processes or conscious awareness.     

Synthetic magnetic opals

We present studies of novel nanocomposites of BiNi impregnated into the structure of opals as well as inverse opals. Atomic force microscopy and high resolution elemental analyses show a highly ordered structure and uniform distribution of the BiNi filler in the matrix. These BiNi-based nanocomposites are found to exhibit distinct ferromagnetic-like ordering with transition temperature of about 675 K. As far as we know there exists no report in literature on any BiNi compound which is magnetic.     

Asymmetric Synthesis of Spiropyrazolones by Sequential Organo‐ and Silver Catalysis

A stereoselective one‐pot synthesis of spiropyrazolones through an organocatalytic asymmetric Michael addition and a formal Conia‐ene reaction has been developed. Depending on the nitroalkene, the 5‐exo‐dig‐cyclization could be achieved by silver‐catalyzed alkyne activation or by oxidation of the intermediate enolate. The mechanistic pathways have been investigated using computational chemistry and mechanistic experiments.     

Hydrophobin purification based on the theory of CO2-nanobubbles

Purification is a critical step to obtain hydrophobin HFBII for use in positive applications. In this study, hydrophobin HFBII was produced by Trichoderma reesei via submerged fermentation. Using the CO₂-foam fractionation method yielded a fourfold increase in protein concentration. The foamate (α_L-HFBII) was dried using a nano spray-dryer under optimal temperature. The gushing activity of the dried foamate (α_S-HFBII) decreased. Addition of Tween 80 to the foamate before the drying process partially prevented the deactivation of hydrophobin HFBII. The purity of the powder was enhanced based on the theory of CO₂-nanobubbles in a CO₂-rich environment. The collected CO₂-nanobubbles were added to an apolar–polar system and the interface of these two phases was collected. After evaporation of the apolar phase, the purity of the hydrophobins assembled on the surface of the liquid was significantly improved.