Two-time quantum transport and quantum diffusion.

Based on the nonequilibrium Green's function technique, a unified theory is developed that covers quantum transport and quantum diffusion in bulk semiconductors on the same footing. This approach, which is applicable to transport via extended and localized states, extends previous semiphenomenological studies and puts them on a firm microscopic basis. The approach is sufficiently general and applies not only to well-studied quantum-transport problems, but also to models, in which the Hamiltonian does not commute with the dipole operator. It is shown that even for the unified treatment of quantum transport and quantum diffusion in homogeneous systems, all quasimomenta of the carrier distribution function are present and fulfill their specific function. Particular emphasis is put on the double-time nature of quantum kinetics. To demonstrate the existence of robust macroscopic transport effects that have a true double-time character, a phononless steady-state current is identified that appears only beyond the generalized Kadanoff-Baym ansatz.

Influence of an electric field on the spin polarization in semiconductor superlattices.

The influence of a quantizing electric field on the spin polarization is treated for semiconductor superlattices with a Rashba spin-orbit interaction. For weakly coupled superlattices, the quantum kinetic equation for the canonically transformed density matrix is analytically solved. The spin polarization, which is induced by a magnetic field via the Zeeman splitting, exhibits a sharp minimum at the cyclotron-Stark tunnelling resonance. This electric-field-induced resonant tunnelling mixes different spin states and leads to a strong spin depolarization.

Filter paper cards contaminated with EMLA cream produce artefacts on acylcarnitine analysis.

Electrospray ionization tandem mass spectrometry is a widely applied method for the analysis of acylcarnitines in blood samples spotted on filter paper cards (Guthrie cards). When the filter paper cards are contaminated by EMLA cream, highly intense signals at m/z 221 and 235 are detected under ESI-MS/MS conditions, monitoring for precursors of m/z 85. These signals correspond to the active ingredients prilocaine and lidocaine in EMLA and overlap with the signals from the isotopically labelled internal standards (2H3)propionyl carnitine and (2H3)butyrylcarnitine. This interference prevents the proper quantification of the two short-chain acylcarnitines when samples are analysed without derivatization.

Comparison of combined and separated biological aerated filter (BAF) performance for pre-denitrification/nitrification of municipal wastewater.

The performance of two systems of semi-industrial up-flow biological aerated filters (BAF) with pre-denitrification followed by nitrification was studied and compared under various operating and loading conditions. The first system consisted of two separate reactors for the denitrification and the nitrification step, whereas in the second system the aerobic nitrification zone was packed on top of the anoxic denitrification zone in one reactor. The second system potentially offers substantial savings in investment costs and space requirements for a large scale treatment plant. Regarding the elimination of carbonaceous pollution and denitrification the systems did not show significant differences. However, nitrification in the combined system suffered from the mixing of different biocenosis by daily backwashing and was reduced to 50-70% of the separated system's performance. Factors such as oxygen concentration, raw water composition and loading rates affected both systems' nitrification rates in similar ways. Since it is impossible to optimise the nitrification and denitrification processes separately, the combined system should only be considered for large scale applications if space is very scarce and if a stable raw water composition can be expected. If strict limit values for nitrate have to be met in the effluent, a combination of pre- and post-denitrification is advantageous and advisable.

Platelet Survival in Healthy Volunteers After Storage with N-(2-mercaptopropionyl)-glycine.

The sulphhydryl group containing drug N-(2-mercaptopropionyl)-glycine (MPG) was tested as a cytoprotective substance for storage of human platelets for transfusion. Autologous platelets stored for 48 h at 21 ± 1°C in the absence (control-platelets) or in the presence (MPG-platelets) of MPG, respectively, were labelled with Indium-III oxine and retransfused into the healthy donors. Significantly higher survival and a higher spleen/liver-ratio were obtained using stored MPG-platelets compared to stored control-platelets. Additionally, a very strong correlation was found between the percentage of discocytes counted after incubation of stored platelets in fresh plasma in vitro and the survival of stored platelets after retransfusion in vivo.

[The evaluation of the adhesive properties of dental materials by using radioactive-labelled bacteria]. / Die Bewertung adhäsiver Eigenschaften von Dentalmaterialien mit Hilfe radioaktiv markierter Bakterien.

Dental materials with different surfaces were incubated with 111In-oxine-labelled bacteria Streptococcus mutans 20 min respectively 2 h, 6 h and 24 h. To determine the amount of the bacteria accumulated on the specimens we measured the radioactivity with a scintillation counter. The same measuring was done after decontamination by the help of ultrasonication. The comparison of activities shows that different dental material surfaces adhere different amounts of bacteria. The adhesive properties are material and time dependent, but the surface processing has a lower influence on the bacterial adherence. The lowest degree of bacterial adherence has the cobalt base alloy Gisadent KCM 83. On the other hand the highest remaining activity was found after decontamination of cobalt base alloy and PMMA resin Kallocryl A.

[Fc-receptor mediated immune complex clearance function of the mononuclear phagocyte system in systemic lupus erythematosus]. / Untersuchungen zur Fc-Rezeptor vermittelten Immunkomplex-Clearancefunktion des mononukleär-phagozytären Systems beim systemischen Lupus erythematodes.

Fc receptor mediated immune complex clearance function was measured in patients with systemic lupus erythematosus. Autologous erythrocytes were sensitized by human IgG anti-Rh(D) and used as immune complex model. An impaired Fc receptor function was demonstrable in 20 of 25 investigated patients. We have found a significant correlation between the seriousness of the defect and the step of the immunologic activity of the patients, but not between the impaired Fc receptor function and clinical activity and renal manifestation in our SLE patients. Further studies are necessary to determine the relevance of this phenomenon and to clear the possibility of therapeutical influence.

99mTc-labelling of leucocytes with 99mTc-DPO: a complex developed for myocardial imaging.

The lipophilic 99mTc-DPO complex, developed as a myocardial imaging radiopharmaceutical, was used to label leucocytes. After an incubation of 0.1 ml 99mTc-DPO (8 micrograms DMPE*2HCl) with mixed leucocytes in plasma, the labelling efficiency was over 70%. During incubation in 5 ml plasma, a loss of activity was found between 20% (1 h) and 35% (3 h) caused by elution. Disturbances of cell viability could not be found with the help of the chemiluminescence test. The in vivo recovery was determined in three dogs and was 45%-50% (0.5 h), 30%-36% (1 h), and 18%-24% (3 h). Autologous 99mTc-DPO-leucocytes were used on seven patients with suspected osteomyelitis, there were four true negative and three true positive results. The target/nontarget ratio determined by ROI in the positive cases was 1.8 to 2.5 at 3 h after injection.

The use of N-(2-mercaptopropionyl)-glycine (MPG) for preparation and storage of platelets.

The SH group containing drug MPG which inhibits platelet aggregation in a reversible manner was used as a cytoprotective substance in some experiments on preparation and storage of human platelets for transfusion. In vitro (n = 6): concentration, morphology score, HSR and aggregation of stored platelets were measured after simulating in vitro the post transfusional conditions by resuspension of stored platelets in fresh drawn plasma (pH 7.4, 37 degrees C). In vivo (n = 2): Autologous platelets stored for 48 h at 22 degrees C were labelled with 111In and retransfused. The results obtained from platelets prepared and stored in plasma containing MPG were compared with those obtained from control platelets without MPG.

[111Indium-thrombocyte scintigraphy and percutaneous transluminal dilatation (angioplasty) of supra-aortic vascular stenoses. A new method for deciding therapy and for follow-up control]. / 111Indium-Thrombozytenszintigraphie und perkutane transluminale Dilatation (Angioplastik) von supraaortalen Gefässstenosen. Eine neue Methode zur Therapieentscheidung und Verlaufskontrolle.

Scintigraphy with 111indium-marked autologous platelets has been used during percutaneous transluminal dilatation of supra-aortic arterial stenoses; there were 14 successful dilatations and one attempted dilatation. The material consisted of nine stenoses of the internal carotid artery, two stenoses at the origin of the vertebral artery and four stenoses of the first part of the left subclavian artery. Deposition of thrombi could be demonstrated by scintigraphy, both before and after catheter dilatation. The value of this method for deciding on the type of treatment and for observing the course of percutaneous dilatation of cerebral vessels is discussed.