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61.
The roots ofAchillea depressa afforded in addition to known sesquiterpene-isofraxidine ethers three new derivatives: the bicyclic drimenol derived albartol and the monocyclic derivatives deparnol and acetyldeparnol. The compounds were characterized by1H-NMR, MS, UV, IR, and CD data.Herrn Prof. Dr.U. Schmidt mit den besten Wünschen zum 60. Geburtstag gewidmet. 相似文献
62.
The lanthanide induced shift (LIS) data of 10 polysubstituted 2,2-spirobiindanes with a carbonyl group in conjugation to an aromatic ring were simulated using theMcConnell-Robertson equation. In the case of oxomethylene-bridged derivates (with CO incorporated in a more or less rigid ring) the classical one site or two site models gave reasonable results. For sterically hindered acetyl or formyl derivates (bothortho positions alkyl-substituted) a new model was developed: the carbonyl group was found to be 30° out of the aromatic plane and the possible 4 positions (±30° and ±150°) turned out to be populated differently depending on theortho substituents. The LIS programme had to be modified to account for this situation.Dedicated to Prof. Dr.A. Neckel on the occasion of his 60th birthday. 相似文献
63.
In recent years there has been growing interest in replacing (genetically modified) soya by lupin. Lupin seeds, flours and lupin containing food have been analyzed in order to assess the relevance of a potential health hazard given by mycotoxins and/or naturally occurring alkaloids. Since not all important alkaloids used for quantitation were commercially available, isolation of lupanine, 13alpha-hydroxylupanine and angustifoline from lupin flours of high alkaloid contents was performed. Alkaloids were analyzed by GC-MS/GC-FID in parallel, while the phomopsin mycotoxins were analyzed by ELISA, since chromatographic methods were not sensitive enough and required time-consuming sample cleanup. The analyzed lupin containing foods were free of phomopsins. In foods where lupin was only a minor constituent the alkaloid content was of no concern. However, roasted lupin beans intended as coffee surrogate had alkaloid contents close to the Australian intervention limit of 200 microg/g. 相似文献
64.
Otto?H?nninen Irene?Brüske-Hohlfeld Miranda?Loh Tobias?Stoeger Wolfgang?Kreyling Otmar?Schmid Annette?Peters 《Journal of nanoparticle research》2010,12(1):91-99
Several studies have reported laser printers as significant sources of nanosized particles (<0.1 μm). Laser printers are used
occupationally in office environments and by consumers in their homes. The current work combines existing epidemiological
and toxicological evidence on particle-related health effects, measuring doses as mass, particle number and surface area,
to estimate and compare the potential risks in occupational and consumer exposure scenarios related to the use of laser printers.
The daily uptake of laser printer particles was estimated based on measured particle size distributions and lung deposition
modelling. The obtained daily uptakes (particle mass 0.15–0.44 μg d−1; particle number 1.1–3.1 × 109 d−1) were estimated to correspond to 4–13 (mass) or 12–34 (number) deaths per million persons exposed on the basis of epidemiological
risk estimates for ambient particles. These risks are higher than the generally used definition of acceptable risk of 1 × 10−6, but substantially lower than the estimated risks due to ambient particles. Toxicological studies on ambient particles revealed
consistent values for lowest observed effect levels (LOELs) which were converted into equivalent daily uptakes using allometric
scaling. These LOEL uptakes were by a factor of about 330–1,000 (mass) and 1,000–2,500 (particle surface area) higher than
estimated uptakes from printers. This toxicological assessment would indicate no significant health risks due to printer particles.
Finally, our study suggests that particle number (not mass) and mass (not surface area) are the most conservative risk metrics
for the epidemiological and toxicological risks presented here, respectively. 相似文献
65.
In the context of convex variational regularization, it is a known result that, under suitable differentiability assumptions, source conditions in the form of variational inequalities imply range conditions, while the converse implication only holds under an additional restriction on the operator. In this article, we prove the analogous result for polyconvex regularization. More precisely, we show that the variational inequality derived by the authors in 2017 implies that the derivative of the regularization functional must lie in the range of the dual-adjoint of the derivative of the operator. In addition, we show how to adapt the restriction on the operator in order to obtain the converse implication. 相似文献
66.
Let
J (\mathbb M2){{\mathcal J}\,(\mathbb M^2)} denote the σ-ideal associated with two-dimensional Miller forcing. We show that it is relatively consistent with ZFC that the additivity
of
J (\mathbb M2){{\mathcal J}\,(\mathbb M^2)} is bigger than the covering number of the ideal of the meager subsets of
ω
ω. We also show that Martin’s Axiom implies that the additivity of
J (\mathbb M2){{\mathcal J}\,(\mathbb M^2)} is 2
ω
.Finally we prove that there are no analytic infinite maximal antichains in any finite product of
\mathfrakP(w)/fin{\mathfrak{P}{(\omega)}/{\rm fin}} . 相似文献
67.
Doz. Dr. Heinz Falk Otmar Hofer Alfred Leodolter 《Monatshefte für Chemie / Chemical Monthly》1975,106(2):571-574
A slightly modified ring current model can be used for pyrrole derivatives. This is demonstrated for a model compound of the bornene series. 相似文献
68.
Ramsey and Freeness Properties of Polish Planes 总被引:2,自引:0,他引:2
Suppose that X is a Polish space which is not -compact. We provethat for every Borel colouring of X2 by countably many colours,there exists a monochromatic rectangle with both sides closedand not -compact. Moreover, every Borel colouring of [X]2 byfinitely many colours has a homogeneous set which is closedand not -compact. We also show that every Borel measurable functionf:X2 X has a free set which is closed and not -compact. Ascorollaries of the proofs we obtain two results: firstly, theproduct forcing of two copies of superperfect tree forcing doesnot add a Cohen real, and, secondly, it is consistent with ZFCto have a closed subset of the Baire space which is not -compactand has the property that, for any three of its elements, noneof them is constructible from the other two. A similar proofshows that it is consistent to have a Laver tree such that noneof its branches is constructible from any other branch. Thelast four results answer questions of Goldstern and Brendle.2000 Mathematics Subject Classification: 03E15, 26B99, 54H05. 相似文献
69.
70.