Strategien zur gezielten Verbesserung des anodenseitigen Elektronentransfers in mikrobiellen Brennstoffzellen

The concept of the microbial fuel cell (MFC) has existed for over 100 years, but only since the last decade its practical implementation in waste water treatment has been realized in scales up to 1000 L. This review article shows available strategies to increase the limiting extracellular electron transfer (EET) for anode space of MFCs. Therefore, organism‐based improvements as well as the effect of (bio)polymers and redox mediators on ETT will be demonstrated.     

Selective expansion of alveolar macrophages in vivo by adenovirus-mediated transfer of the murine granulocyte-macrophage colony-stimulating factor cDNA

Based on the hypothesis that genetic modification of freshly isolated alveolar macrophages (AM) with the granulocyte-macrophage colony-stimulating factor (GM-CSF) cDNA would induce AM to proliferate, this study focuses on the ability of adenoviral (Ad) vectors to transfer and efficiently express the murine (m) GM-CSF cDNA in murine AM with consequent expansion in the number of AM in vitro and in vivo. To demonstrate that an Ad vector can effectively transfer and express genes in AM, murine AM recovered by bronchoalveolar lavage from the lung of Balb/c mice were infected with an Ad vector coding for green fluorescent protein (GFP) in vitro and expressed GFP in a dose-dependent fashion. Infection of AM with an Ad vector containing an expression cassette coding for mGM-CSF led to GM-CSF expression and to AM proliferation in vitro. When AM infected with AdGFP were returned to the respiratory tract of syngeneic recipient mice, GFP-expressing cells could still be recovered by bronchoalveolar lavage 2 weeks later. In vitro infection of AM with AdmGM-CSF and subsequent transplantation of the genetically modified AM to the lungs of syngeneic recipients led to GM-CSF expression in vivo. Strikingly, the AM recovered by lavage 5 weeks after transplantation demonstrated an increased rate of proliferation, and the total number of alveolar macrophages was 1. 9-fold greater than controls. Importantly, the increase in the numbers of AM was selective (ie, other inflammatory cell numbers were unchanged), and there was no modification to the lung architecture. Thus, it is feasible to genetically modify AM with Ad vectors and to use this strategy to modify the behavior of AM in vivo. Based on the importance of AM in the primary defense of the respiratory epithelial surface, this strategy may be useful in enhancing pulmonary defenses in immunodeficiency states.     

Bürokratieabbau versus betrieblicher Datenschutz?

Zusammenfassung  Eine neue Variante, sich in den Unternehmen den Datenschutz vom Leib zu halten, ist der Vorwurf der Bürokratisierung. Nach einem Vorschlag der L?nder Niedersachen und Hessen aus dem Herbst 20051 sollte die Bestellungspflicht von 5 auf 20 EDVMitarbeiter heraufgesetzt werden. Eine abgeschw?chte Variante enth?lt nun der Gesetzentwurf der Bundesregierung mit einem Quorum von 10 Personen. Ob diese Regelung den gewünschten Effekt bringen wird, ist zweifelhaft. Sicher ist nur, dass die betriebliche Selbstregulierung geschw?cht und die Erwartungen an die Kontrollt?tigkeit der Aufsichtsbeh?rden steigen werden. Vorteile birgt der Entwurf aber in anderer Hinsicht: Externe Datenschutzbeauftragte k?nnen zukünftig auch für Bereiche t?tig werden, die durch § 203 StGB geschützt sind.     

Neue Netzzugangstechnologien — Schlüssel zu Multimedia-Anwendungen

World-wide, telecommunication is marked by three basic conditions:

1. the market demand of new services;
2. the politically stimulated liberalization of the telecommunication market and
3. the technical possibilities of new telecommunication technologies.

Network operators are confronted with the task to yield high interests within a short time with limited investment possibilities. Therefore, the access network and the technologies linked to it have an increasing importance for the economic success on a liberalized telecom market. This article describes the most distinguishing aspects of an access network, its positioning within a telecom system, and the most important technological developments in this field: use of fibres in the access area, FITL systems, multimedia transfer via the copper twisted pair by means of xDSL technologies and via CATV networks by means of HFC technologies.     

Chromized Layers Produced on Steel Surface by Means of CVD

DIFFUSION CHROMIZING is one of many types ofthermochemical treatment employed today forimproving properties of steel surface such as hardness,wear and corrosion resistance[144].In this paper,anovel CVD method that combines the low cost of packmetallization and the advantage of vacuum techniquewas investigated[5].The coating process was based onthe formation of chromium chlorides atmosphere in situduring the processing.A metallic chromium powdermixture with a halide activator(NRiCl)we…     

Selektivitätsstudien: OH-, NH- und SH-gruppenspezifische Reagentien – ihre Anwendung in der organischen Analytik und als Schutzgruppen in der Synthese

Selectivity: OH-, NH- and SH-Groupspecific Reagents. The Application in Organic Analysis and as Protective Groups Phosphylhalides and -pseudohalides R¹R²P(O)X (X = Cl, F, CN, N₃, OC₆H₄NO₂(p)) reactdepending on X- with a different selectivity with OHNH- and SH-groups. Vinylsulfones ArSO₂CH = CH₂ are SH-selective. Silanes R₃SiH are OH-selective. By exchange of one ligand bound on P, SO₂ or Si by the 5-dimethylamino resp. the 5-methoxynaphthalinogroup reagents are formed, which combine group selectivity with fluorescence. The fluorescence is quenched if a ligand or the leaving group is substituted by a NO₂-group. The fluorescence appears again if after the group selective fixation the ligand with the nitrogroup is split off. In serine enzymes (α-chymotrypsine, trypsin, butyryl- and acetylcholinesterase, subtilisine) and insuline (after the reductive opening of the S-S bridges) the primary OH-groups in the active site in the enzymes resp. the SH groups in the reduced insuline were substituted with fluorescing groups using group selective fluorescing reagents.     

Multimodal Spectroscopic Imaging of Pea Root Nodules to Assess the Nitrogen Fixation in the Presence of Biofertilizer Based on Nod-Factors

Multimodal spectroscopic imaging methods such as Matrix Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI MSI), Fourier Transform Infrared spectroscopy (FT-IR) and Raman spectroscopy were used to monitor the changes in distribution and to determine semi quantitatively selected metabolites involved in nitrogen fixation in pea root nodules. These approaches were used to evaluate the effectiveness of nitrogen fixation by pea plants treated with biofertilizer preparations containing Nod factors. To assess the effectiveness of biofertilizer, the fresh and dry masses of plants were determined. The biofertilizer was shown to be effective in enhancing the growth of the pea plants. In case of metabolic changes, the biofertilizer caused a change in the apparent distribution of the leghaemoglobin from the edges of the nodule to its centre (the active zone of nodule). Moreover, the enhanced nitrogen fixation and presumably the accelerated maturation form of the nodules were observed with the use of a biofertilizer.     

Scheduling saves in fault-tolerant computations

Computer users with very long computations run the risk of losing work because of machine failures. Such losses can often be reduced by scheduling saves on secure storage devices of work successfully done. In the model studied here, the user leaves the computation unattended for extended periods of time, after which he or she returns to check whether a machine failure occurs. When a check reveals a failure, the user resets the computation so that it resumes from the point of the last successful save.Saves are themselves time consuming, so that any strategy for scheduling saves must strike a balance between the computing time lost during saves and the computing time that is occasionally lost, because of a failure since the last successful save.For a given time to the next check and given constant save times, this paper computes schedules that maximize the expected amount of work successfully done before the next check, under the uniform and exponential failure laws. Explicit formulas are obtained for the uniform law. A recurrence leads to routine numerical calculations for the more difficult system with an exponential failure law.     

The effect of cream and ointment bases on the steady state penetration of permeants through intact skin: the reciprocal of the onset time of a pharmacodynamic effect as parameter of response

To characterize cream or ointment bases for cosmetic or pharmaceutical purposes with regard to their effect on permeant penetration through intact healthy skin, the measurement of the pharmacodynamic response of a suitable model drug incorporated in these bases has been shown to be a promising approach. In general, it may be distinguished between thermodynamic vehicle effects owing to different permeant escaping tendencies from the vehicles and penetration-enhancing vehicle effects resulting from a change of the stratum corneum structure, which manifests itself in an increase of the permeant diffusion coefficient and/or its solubility in this barrier. As the latency time of onset of a pharmacodynamic effect, usually used as reciprocal value, represents a suitable response parameter under certain circumstances, this study was done to further evaluate this parameter with regard to the determination of relative bioavailability and penetration enhancement data obtained from simulated dose- and activity-response curves assuming infinite dose conditions, i.e. zero order penetration kinetics and considering varying lag times of drug penetration. The results indicate that bioavailability and enhancement factors may be determined accurately from the horizontal distance between dose- or activity-response curves of a standard and a test preparation as long as the curves are parallel to each other, as it is the case with uniform lag times of permeant penetration. Non-parallel curves observed with varying lag times indicate an influence of the vehicles on the permeant diffusion coefficient in the barrier. Enhancement factors from these curves may be obtained after determination of the lag times from the plateau region of the curves, subsequent subtraction of these values from the measured latency time data, and finally plotting of the reciprocal data as a function of the drug activity. Enhancement factors then correspond to the inverse logarithm of the horizontal distances between the resulting parallel curves.