Untersuchung von Bier, Bierroh- und Zwischenerzeugnissen

Ohne Zusammenfassung     

Nanometrization of Lanthanide‐Based Coordination Polymers

Heteronuclear lanthanide‐based coordination polymers are microcrystalline powders, the luminescence properties of which can be precisely tuned by judicious choice of the rare‐earth ions. In this study, we demonstrate that such materials can also be obtained as stable solutions of nanoparticles in non‐toxic polyols. Bulk powders of the formula [Ln_2?2xLn′_2x(bdc)₃ ? 4 H₂O]_∞ (where H₂bdc denotes 1,4‐benzene‐dicarboxylic acid, 0≤x≤1, and Ln and Ln′ denote lanthanide ions of the series La to Tm plus Y) afford nanoparticles that have been characterized by dynamic light‐scattering (DLS) and transmission electron microscopy (TEM) measurements. Their luminescence properties are similar to those of the bulk materials. Stabilities versus time and versus dilution with another solvent have been studied. This study has revealed that it is possible to tune the size of the nanoparticles. This process offers a reliable means of synthesizing suspensions of nanoparticles with tunable luminescence properties and tunable size distributions in a green solvent (glycerol). The process is also extendable to other coordination polymers and other solvents (ethylene glycol, for example). It constitutes a new route for the facile solubilization of lanthanide‐based coordination polymers.     

Methyl proton contacts obtained using heteronuclear through-bond transfers in solid-state NMR spectroscopy

A two-dimensional proton-mediated carbon-carbon correlation experiment that relies on through-bond heteronuclear magnetization transfers is demonstrated in the context of solid-state NMR of proteins. This new experiment, dubbed J-CHHC by analogy to the previously developed dipolar CHHC techniques, is shown to provide selective and sensitive correlations in the methyl region of 2D spectra of crystalline organic compounds. The method is then demonstrated on a microcrystalline sample of the dimeric protein Crh (2 x 10.4 kDa). A total of 34 new proton-proton contacts involving side-chain methyl groups were observed in the J-CHHC spectrum, which had not been observed with the conventional experiment. The contacts were then used as additional distance restraints for the 3D structure determination of this microcrystalline protein. Upon addition of these new distance restraints, which are in large part located in the hydrophobic core of the protein, the root-mean-square deviation with respect to the X-ray structure of the backbone atom coordinates of the 10 best conformers of the new ensemble of structures is reduced from 1.8 to 1.1 A.     

The modeling of small scales in two-dimensional turbulent flows: A statistical mechanics approach

In previous work we have defined statistical equilibrium states for 2D incompressible Euler equations. We study here the relaxation process toward equilibrium. This leads to a natural modeling of the small scales in turbulent flows, which might be relevant for meteorological and oceanographic applications. Numerical simulations illustrating the performance of these new models are presented.     

The effects of time constraints on phonatory stability in normally speaking adult women

Forty normally speaking women sustained /a/ five times in two conditions,untimed and timed. In the untimed condition, phonation began whenever the subject felt ready. The timed task required subjects to begin phonation as quickly as possible after the examiner's signal. Conditions were counterbalanced across subjects. Jitter and shimmer values were obtained on a Kay Elemetrics Computerized Speech Lab (Pine Brook, NJ). Three distinct patterns of change emerged for fitter and shimmer from the untimed to the timed condition, reflecting either decreases, increases, or no change in values. These changes in jitter and shimmer values across conditions are related to a reaction time model of “bias toward accuracy.”     

Arytenoid Cartilage Dislocation: A 20-year Experience

SUMMARY: Arytenoid cartilage dislocation is an infrequently diagnosed cause of vocal fold immobility. Seventy-four cases have been reported in the literature to date. Intubation is the most common origin, followed by external laryngeal trauma. Decreased volume and breathiness are the most common presenting symptoms. We report on 63 patients with arytenoid cartilage dislocation treated by the senior author (RTS) since 1983. Significantly more posterior than anterior dislocations were represented. Although reestablishing joint mobility is difficult, endoscopic reduction should be considered to align the heights of the vocal processes. This process may result in significant voice improvement even long after the dislocation. Strobovideolaryngoscopy, laryngeal electromyography, and laryngeal computed tomography (CT) imaging are helpful in the evaluation of patients with vocal fold immobility to help distinguish arytenoid cartilage dislocation from vocal fold paralysis. Familiarity with signs and symptoms of arytenoid cartilage dislocation and current treatment techniques improves the chances for optimal therapeutic results.     

Facile synthesis of a cis-syn thymine dimer building block and its incorporation into oligodeoxynucleotides

The synthesis of a building block containing the photobiologically relevant cis-syn thymine cyclobutane photoproduct and its incorporation into oligonucleotides by the phosphoramidite-based solid-phase synthesis is reported. Compared to previous syntheses, this route is extremely short and allows such modified oligonucleotides to be easily available for biological studies.     

Cracking in polylactide spherulites

A polylactide of high optical purity was crystallized between 100 and 140 °C, in‐between two glass slides, and its morphology was investigated by polarizing optical microscopy, scanning electron microscopy, and atomic force microscopy, during subsequent heating and cooling cycles between ?15 °C and the crystallization temperature. It was found that dark circular rings show up on cooling on top of the spherulites and represent cracks of about 300 nm in width. This phenomenon is completely reversible, and the heating–cooling curves are centered at about 56 °C, which coincide with the T_g of polylactide. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3308–3315, 2005     

Spasmodic dysphonia symptoms as initial presentation of amyotrophic lateral sclerosis

A patient initially diagnosed with adductor-type spasmodic dysphonia was referred for botulinum toxin (Botox) injections, but found on subsequent evaluation to have amyotrophic lateral sclerosis, and therefore Botox was not administered. This unique case underscores the need to delay botulinum toxin treatments in any patient with recent onset symptoms, and to obtain thorough motor speech and voice, otolaryngologic, and neurologic evaluation in all patients prior to consideration for injection.