Phase-locked ultrashort pulse trains at separate and independently tunable wavelengths

The generation and characterization of femtosecond pulses at three independently tunable visible wavelengths is reported. Selected spectral portions of a common continuum generated in sapphire are amplified in noncollinear optical parametric amplifiers. The phase relation of the pulse trains is analyzed with a nonlinear interferometer based on coherent anti-Stokes Raman scattering and is found to be locked to better than 250 mrad rms. Small spectral shifts of the pulses lead to interference behavior that is consistent with 1 kHz frequency combs.     

The EC networking on elemental speciation revisited

In Europe, the EC-funded Thematic Network Speciation 21 was instrumental in disseminating the existing knowledge about chemical speciation of trace elements. It created a forum in which analytical chemists working in method development were mixed with potential users from industry and representatives of legislative bodies. This endeavour is continuing in the currently established European Virtual Institute for Speciation Analysis (EVISA). Although there already exists substantial know-how in Europe for the speciation of a number of substances, such as organo-arsenic, organo-tin and organo-mercury compounds, to name just these three groups, there is an urgent need to enforce the analytical potential in speciation analysis on a much wider scope of compounds capable of providing data of a suitable quality. The ensuing need for quality assurance of the analytical procedures requires the analysis of representative reference materials, certified for the relevant species. Last but not least, where applicable, the European-wide legislation should be adapted to focus on toxic species of the elements, rather than the total element.Presented at BERM-9—Ninth International Symposium on Biological and Environmental Reference Materials, June 15–19, 2003, Berlin, Germany. Disclaimer The opinions expressed in the present article are entirely those of the authors. They do not represent the opinion of the European Community.     

A Novel Stereoselective Synthesis of <Emphasis Type="Italic">cis</Emphasis>-Configured Erythrinane and Erythrinane Type Analogues

Summary. N-Alkylation of certain angularly substituted heterocycles by C₂- and C₃-units provided appropriate precursors to construct stereoselectively the erythrinanone and several erythrinanone type analogues by intramolecular Friedel-Crafts acylation. The resulting aromatic ketones were catalytically reduced affording the corresponding parent frameworks including the hitherto unknown tetracyclus A-norschelhammerane. On the other hand, the stereoselective reduction of the carbonyl moiety offered a convenient approach to 11-hydroxylated erythrinanes with the natural occurring -configuration. The structures and the stereochemistry of the target compounds were proved by NMR spectroscopy.Part of PhD thesis, LMU München, D     

A Convenient Synthesis of 1-Benzyl-1,2,3,4-tetrahydroisoquinolines by Combined Strecker/Bruylants Reaction

Summary. Strecker reaction of iodophenethylamines with phenylacetaldehydes afforded the corresponding -aminonitriles, which on treatment with i-propyl magnesium chloride underwent a Bruylants reaction to give the title compounds. Their structures were deduced by NMR and by an independent preparation starting from papaverine. The educts were easily available by standard procedures.     

Weak spectral synthesis for the projective tensor product of commutative Banach algebras

Let and be regular commutative Banach algebras and their projective tensor product, and suppose that is semisimple. We investigate the relation between weak spectral synthesis properties of and those of and .

     

F-18-FDG uptake is a reliable predictory of functional recovery of akinetic but viable infarct regions as defined by magnetic resonance imaging before and after revascularization

Identification of akinetic but viable myocardium is important for the selection of patients for coronary revascularization. In order to assess predictive values of end-diastolic wall thickness and dobutamine induced wall thickening obtained by magnetic resonance imaging (MRI) and [18F]Fluorodeoxyglucose uptake assessed by positron emission tomography (F-18-FDG-PET), these parameters were compared to recovery of left ventricular function after successful revascularization. Forty patients with chronic myocardial infarction and regional a- or dyskinesia by ventriculography underwent rest- and dobutamine-MRI studies (10 microg dobutamine/kg body weight/min) and F-18-FDG-PET. Viability of the infarct region was considered to be present if; 1) end-diastolic wall thickness was > or =5.5 mm; 2) dobutamine induced wall thickening > or =2 mm could be measured; and 3) normalized F-18-FDG-uptake was > or =50% in > or =50% of akinetic segments. Preserved end-diastolic wall thickness was found in 32/40 patients, functional improvement during dobutamine infusion in 26/40 patients and preserved F-18-FDG-uptake in 29/40 patients. After revascularization regional left ventricular function improved in 25/40 patients. Positive and negative predictive values and diagnostic accuracy were 78%, 100%, and 83% for preserved end-diastolic wall thickness, 92%, 93%, and 93% for dobutamine inducible contraction reserve and 86%, 100%, and 90% for preserved F-18-FDG-uptake. Quantitative assessment of dobutamine induced systolic wall thickening by MRI and F-18-FDG-uptake by PET are highly accurate techniques for the identification of viable myocardium and prediction of functional recovery after successful revascularization. Preserved end-diastolic wall thickness results in an overestimation of viable myocardium compared to functional improvement, but wall thickness <5.5 mm excludes recovery of regional function.     

Analysis of class I phosphoinositide 3-kinase autophosphorylation sites by mass spectrometry

This article describes the identification of the autophosphorylation sites of the G protein-sensitive class I phosphoinositide 3-kinase isoforms beta and gamma by mass spectrometry. Since discrimination and suppression effects prevented the immediate detection and sequencing of phosphopeptides in complex mixtures, a strategy was applied that involved (32)P-radiolabeling of the phosphoproteins, cleavage of the phosphoproteins with several proteases and/or cyanogen bromide, separation of the resulting peptide mixtures by micro-reversed-phase liquid chromatography, and mass spectrometric analysis of fractions containing phosphopeptides. As a result the primary autophosphorylation sites of phosphoinositide 3-kinase p110beta and p110gamma subunits could be unambiguously assigned to the C-terminal Ser 1070 and Ser 1101, respectively.     

Bounded point evaluations and cyclic polynomials on the spaces $$\hat F$$

LetF be aBK space withAK and denote the set of all formal power series with such that ε F for the sequence of coefficients of . We give a necessary and sufficient condition for a point to be a bounded point evaluation on , and for a polynomial to be cyclic in . As special cases, we obtain the results for the space ℓ _p (β) in [7]. Research of the authors supported under the research project #1232 of the Serbian Ministry of Sciences and Tecnology and, in the case of the second author, also by the DAAD foundation (German Academic Exchange Service), grant 911 103 102 8.     

Effects of Professional Singing Education on Vocal Vibrato—A Longitudinal Study

Vocal vibrato is regarded as one of the essential characteristics of voice quality in classical singing. Professional singers seem to develop vibrato automatically, without actively striving to acquire it. In this longitudinal investigation, the vocal vibrato of 22 singing students was examined at the beginning of and after 3 years of professional singing education. Subjects sang an ascending-descending triad pattern in slow tempo on vowel [a:] at a comfortable pitch level twice at soft (piano) and twice at medium (mezzoforte) loudness. The top note of the triad pattern was sustained for approximately 5s. The mean and the standard deviation (SD) of the vibrato rate were measured for this note. Results revealed that after 3 years of training, voices with vibrato slower than 5.2 Hz were found to have a faster vibrato, and voices with vibrato faster than 5.8 Hz were found to have a slower vibrato. Standard deviation of vibrato rate was higher in soft than in medium loudness, particularly before the education. Also high values of SD of vibrato rate, exceeding 0.65 Hz, had decreased after the education. These findings confirm that vibrato characteristics can be affected by singing education.