N-Aminierung von Isochinolinbasen

N-Amination of Isoquinoline Bases 3, 3-Pentamethylene oxaziridine 1 forms an N N-bond with secondary isoquinoline bases 2a – f to give the cyclohexylidene hydrazines 3a – f . In some cases nitrogen elimination yielding indane derivatives 13b, 13e competes with hydrazone formation. The cyclic Schiff'base 14 and the β-carboline derivative 16 can also be aminated.     

Ringöffnungs- und SubstitutionsReaktionen von 4,4-Dihalogen-pyrazolin-5-onen durch Nucleophile

Ring Opening and Substitution Reactions of 4,4-Dihalo-pyrazolin-5-ones with Nucleophiles 1-Aryl-4,4-dihalo-3-methyl-pyrazolin-5-ones ( 1a – c ) undergo ring opening with alkoxides and form alkyl 3-arylazo-2-halo-2-butenoats ( 2a – d ). Analogous reactions take place with ammonia and amines. 4-Nitro-phenoxide reacts with substitution of both halogens to the 4,4-bis(4-nitro-phenyl)-compound ( 5 ). Phenols are selectively orthobrominated by the title compounds 1a and b .     

Analysis of the Temperature and Strain-Rate Dependences of Strain Hardening

A classical constitutive modeling-based Ansatz for the impact of thermal activation on the stress–strain response of metallic materials is compared with the state parameter-based Kocks–Mecking model. The predicted functional dependencies suggest that, in the first approach, only the dislocation storage mechanism is a thermally activated process, whereas, in the second approach, only the mechanism of dynamic recovery is. In contradiction to each of these individual approaches, our analysis and comparison with experimental evidence shows that thermal activation contributes both to dislocation generation and annihilation.     

Plasma viscosity and the risk of coronary heart disease: results from the MONICA-Augsburg Cohort Study, 1984 to 1992

Plasma viscosity is determined by various macromolecules, eg, fibrinogen, immunoglobulins, and lipoproteins. It may therefore reflect several aspects involved in cardiovascular diseases, including the effects of classic risk factors, hemostatic disturbances, and inflammation. We examined the association of plasma viscosity with the incidence of a first major coronary heart disease event (CHD; fatal and nonfatal myocardial infarction and cardiac death; n=50) in 933 men aged 45 to 64 years of the MONICA project of Augsburg, Germany. The incidence rate was 7.23 per 1000 person-years (95% confidence interval [CI], 5.37 to 9.53), and the subjects were followed up for 8 years. All suspected cases of an incident CHD event were classified according to the MONICA protocol. There was a positive and statistically significant unadjusted relationship between plasma viscosity and the incidence of CHD. The relative risk of CHD events associated with a 1-SD increase in plasma viscosity (0.070 mPa x s) was 1.60 (95% CI, 1.25 to 2.03). After adjustment for age, total cholesterol, high density lipoprotein cholesterol, smoking, blood pressure, and body mass index, the relative risk was reduced only moderately (1.42; 95% CI, 1.09 to 1.86). The relative risk of CHD events for men in the highest quintile of the plasma viscosity distribution in comparison with the lowest quintile was 3.31 (95% CI, 1.19 to 9.25) after adjustment for the aforementioned variables. A large proportion of events (40%) occurred among men in the highest quintile. These findings suggest that plasma viscosity may have considerable potential to identify subjects at risk for CHD events.     

Identification of the Sex Pheromone of the Currant Shoot Borer Lampronia capitella

Under an artificial light:dark cycle, females of Lampronia capitella were observed calling, with extended terminal abdominal segments, during the first 2 hr of the photoperiod. Extracts of terminal abdominal segments from females elicited large electroantennographic responses from male antennae. Gas chromatography with electroantennographic detection revealed three active peaks. Based on comparison of retention times and mass spectra of synthetic standards, these compounds were identified as (Z,Z)-9,11-tetradecadienol and the corresponding acetate and aldehyde. The electroantennographic activity of the four geometric isomers of all three compounds was investigated, and the respective (Z,Z)-isomer was found to be the most active in all cases. Aldehydes generally elicited larger antennal responses than alcohols, whereas acetates were the least active compounds. A subtractive trapping assay in the field, based on a 13:26:100 micrograms mixture of (Z,Z)-9,11-tetradecadienal, (Z,Z)-9,11-tetradecadienyl acetate, and (Z,Z)-9,11-tetradecadienol confirmed that all three compounds are pheromone components. Subtraction of (Z,Z)-9,11-tetradecadienol from the blend completely eliminated its attractiveness, whereas the other two-component blends showed reduced activity. This is the first pheromone identification from the monotrysian superfamily Incurvarioidea, confirming that the common pheromones among ditrysian moths (long-chain fatty acid derivatives comprising alcohols, acetates, and aldehydes with one or more double bonds) is not an autapomorphy of Ditrysia, but a synapomorphy of the more advanced heteroneuran lineages.     

Effect of ultrasound on thermoset polyurethane: NMR relaxation and diffusion measurements

Recycling of rubber-based materials is of increasing industrial environmental importance. In order to characterize the effect of ultrasound on polymer networks, nuclear magnetic resonance (NMR) relaxation and pulsed-gradient diffusion measurements were made at 70.5 °C in polyurethane rubber (PUR) and foam after subsequent treatment by intense ultrasound. The proton transverse relaxation decay was analyzed in terms of molecular and segmental mobilities of all motional species, a chemical and physical network as well as diffusing sol. The diffusivity spectrum, measurable in foams, reflected the changing molecular weight distribution of low-molecular weight sol and oligomers. It was observed that the effect of ultrasound was less pronounced in PUR than rubbers like SBR, PDMS and BR owing to its low degree of unsaturation. The investigation on the foams is the first of its kind to be reported.     

Design and demonstration of an experimental membrane reactor set-up for oxidative coupling of methane

In this experimental research, the performance of the oxidative coupling of methane (OCM) reactions in a porous packed bed membrane reactor was investigated. A commercially available porous alpha-alumina membrane was modified to obtain the characteristics needed for a stable and catalytically inert OCM membrane reactor. The silica-sol impregnation–calcination method and a new silicon oxycarbide (SiOC) coating-calcination approach were applied to modify the membrane. The characteristics of the resulted membrane and its typical performance as OCM membrane reactor are reported.