Trace analysis and speciation of copper by application of an urease reactor

Summary A method for metal speciation using an enzyme reactor is described. The enzyme urease is immobilized on a polymer support. The parameters of the inhibition procedure are investigated for the determination of copper in drinking and surface water samples. The results are compared with those obtained by atomic absorption spectrometry. It has been found that the enzyme urease was inhibited only by free copper ions.Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthday     

Testing Born’s Rule in Quantum Mechanics for Three Mutually Exclusive Events

We present a new experimental approach using a three-path interferometer and find a tighter empirical upper bound on possible violations of Born’s Rule. A deviation from Born’s rule would result in multi-order interference. Among the potential systematic errors that could lead to an apparent violation we specifically study the nonlinear response of our detectors and present ways to calibrate this error in order to obtain an even better bound.     

Reaktionsprodukte aus Chlormethoxiphosphinen und Antimon(V)-chlorid. Schwingungsspektren der 1:1 Addukte aus Methoxiphosphorylverbindungen und Antimon(V)-chlorid

Reaction Products of Chloromethoxiphosphines and Antimony (V) Chloride. Vibrational Spectra of the 1:1-adducts of Methoxiphosphoryl Compounds and Antimony (V) Chloride Chloromethoxiphosphines react with antimony(V) chloride in a redox process to yield the chloromethoxiphospllonium hexachloroantimonates(V) (CH₃O)₃PCl₂⁺SbCl₆^? (II) and CH₃OPCl₃⁺SbCl₆^? (III). II, III, (CH₃O)₃PCl⁺SbCl₆^?(1) and (CH₃O)₄P⁺SbCl₆^? eliminate easily methyl chloride and give the addition compounds OP(OCH₃)₃·SbCl₅(IV), OPCl(OCH₃)₂ · SbCl₅ (V), OPCl₂(OCH₃)·SbCl₅ (VI) and OPCl₃·SbCl₅ (VII). The vibrational spectra of IV, V nnd VI are discussed.     

Addukte aus Phosphorylverbindungen und SbCl5 Darstellung und IR-Spektren der 1:1-Addukte aus Chlordimethylamino- bzw. Chlordimethylamino-methoxi-phosphorylverbindungen und Antimon(V)-chlorid

Adducts of Phosphoryl Compounds and SbCl₅ Preparation and IR Spectra of 1:1 Addition Compounds from Chlorodimethylamino- resp. Chlorodimethylaminomethoxiphosphoryl Compounds and Antimony(V) Chloride The addition compounds (CH₃O)₂[(CH₃)₂N]PO · SbCl₅ ( II ), (CH₃O)[(CH₃)₂N]₂PO · SbCl₅ ( III ), [(CH₃)₂N]₃PO · SbCl₅ ( IV ), Cl₂[(CH₃)₂N]PO · SbCl₅ ( VI ), Cl[(CH₃)₂N]₂PO · SbCl₅ ( VII ), and Cl(CH₃O)[(CH₃)₂N]PO · SbCl₅ ( VIII ) are prepared by reaction of the phosphoryl compounds with antimony(V) chloride. The influence of the Lewis acid to the bonds of the phosphoryl compounds is discussed. The ³¹P-n.m.r. data of the adducts are communicated and compared with those of the free phosphoryl compounds.     

Schwingungsspektren von Dimethylamino-methoxiphosphorylverbindungen

The Vibrational Spectra of Dimethylamino Methoxiphosphoryl Compounds The vibrational spectra of the known compounds (CH₃O)₂[(CH₃)₂N]PO ( II ), (CH₃O)[(CH₃)₂N]₂PO ( III ), and (CH₃O)[(CH₃)₂N]ClPO ( VI ) are communicated and assigned. The chemical shift of P atoms is listed.     

Isotropic proton-density-weighted high-resolution MRI for volume measurement of reconstructed orbital fractures--a comparison with multislice CT

Objective

The cause of enophthalmos as a late complication after orbital reconstruction is poorly investigated. Multislice CT (MSCT) is usually employed for its assessment, in spite of limitations regarding soft tissue depiction/imaging, as well as the implication of radiation and production of artifacts. Magnetic resonance imaging (MRI) has been shown to be a valuable alternative. The aim of this study was to establish a bony and soft tissue orbital volume calculation method based on different high-resolution MRI sequences compared to MSCT.

Materials and Methods

Thirty-seven patients were included in this prospective study investigating the origin of enophthalmos present 3–4 months after complex orbital reconstruction. Morphological and dimensional changes of the orbit, eye globes, extraocular muscles and fat content were investigated 3–4 months after surgery. To assess the site and size of bony and soft tissue changes in the traumatized orbits, we used MSCT and MR images as well as corresponding 3-D reconstructions.

Results

All enophthalmic orbits revealed a significant bony volume increase compared to the contralateral side as well as a reduced sagittal eye projection. Mean orbital volume enlargements of 1.0 cm³ lead to 0.93 mm enophthalmos (P<.05). Hardly any fatty atrophy could be depicted by the different MRI techniques.

Conclusions

For soft tissue depiction of the orbit, MRI was superior to MSCT. Particularly, proton density weighting proved to be the best sequence for soft tissue volume segmentation, allowing determination of the cause and degree of posttraumatic enophthalmos in reconstructed orbits.