Probleme bei der Flüssig-flüssig-Extraktion extrazellulärer Produkte direkt aus der Fermenterbrühe

Problems with Liquid Liquid Extraction of Extracellular Products Direct from Fermenter Broths Liquid liquid extraction is usable for separation of extracellular fermentation products. The direct extraction of products from fermenter broths which still contain the cells has important advantages compared to other methods: It shows low losses of products, high product concentrations and low flow rates. The expenditure of equipments is low and it is possible to influence the fermentation in the case of an in situ extraction. These advantages are faced to disadvantages caused by the own properties of fermenter broths. Especially the hydrodynamic behaviour of the two phase system in the extractor is affected by high viscosities and the cells. Further problems are the hindrance of the mass transfer and the selection of suitable solvents for the in situ extraction.     

Hyperinsulinism in patients with coronary artery disease

AIM: To assess the clinical impact of hyperinsulinism and major coronary risk factors in patients with angiographically documented or excluded coronary artery disease (CAD), a clinical study was carried out in 268 men admitted for left heart catheterization. METHODS: Fasting immunoreactive insulin (IRI) levels were correlated to all major cardiovascular risk factors and to the presence and degree of CAD. RESULTS: IRI levels were correlated significantly with the degree of CAD (one-vessel disease: mean IRI 9.45 microU/ml +/- 0.43 SEM; two-vessel disease: mean IRI 10.4 microU/ml +/- 0.71 SEM; three-vessel disease: mean IRI 11.88 microU/ml +/- 0.98 SEM) and inversely to the high-density lipoprotein level (P < 0.05). In patients with arterial hypertension, IRI levels were elevated, without a significant difference between those with and those without CAD, whereas the IRI levels of non-hypertensive men with CAD (n = 81; mean IRI 9.85 microU/ml +/- 0.51 SEM) differed significantly (P < 0.05) from those of non-hypertensive men without CAD (n = 59; mean IRI 7.76 microU/ml +/- 0.43 SEM). IRI levels were significantly higher (P < 0.05) in obese patients (n = 65; mean IRI 11.68 microU/ml +/- 0.70 SEM versus n = 203; mean IRI 9.32 microU/ml +/- 0.34 SEM), in patients with elevated triglycerides (n = 58 mean IRI 11.59 microU/ml +/- 0.81 SEM versus n = 210; mean IRI 9.42 microU/ml +/- 0.33 SEM), and in patients with lowered HDL cholesterol (n = 178; mean IRI 11.06 microU/ml +/- 0.63 SEM versus n = 90; mean IRI 9.29 microU/ml +/- 0.34 SEM). Diabetic patients on angiotensin converting enzyme inhibitor therapy (n = 11; mean IRI 7.91 microU/ml +/- 0.91 SEM) had significantly (P < 0.05) lower IRI levels than those not treated with ACE inhibitors (n = 25; mean IRI 12.96 microU/ml +/- 1.47 SEM). IRI levels exceeding 8 microU/ml were associated with a 1.98-fold risk for CAD compared with IRI levels below 8 microU/ml. Stepwise logistic regression showed that insulin was an independent determinant of CAD. CONCLUSION: Knowledge of the fasting insulin level is an important contribution to the identification of patients with, or at risk of, CAD.     

Technology: toys or tools?: Results of a Dutch Delphi study

The diffusion and use of Advanced Manufacturing Techniques (AMT) in Dutch factories that is expected to occur at the beginning of the next century, has been analyzed in a Delphi study with 23 Dutch experts. Four possible scenarios for ‘factories of the future’ were identified; in these special attention was paid to the role that AMT might play. It appeared that AMT would play a different role, depending on the external environment and internal condition, varying from very limited to rather extended. Introducing AMT in these ways should have a positive impact on competitive position of the enterprises, company employment, and the industrial structure.     

New Telecommunication Systems Under Development in France

This paper presents a review of the main telecommunications systems now under development in France. First, it gives the general objectives, the basic options, and the general design of the new electronic switching system E. 1 defined by CNET, with the principal characteristics of the E.10 and E.12 variants, and general planning of studies and development in process in this field. Then a summary of the new transmission systems under development such as digital systems on cables, radio relays, or circular waveguide, as well as analog systems, including submarine and space systems is given. Finally, some considerations are given to the increasing use of information processing for the telecommunication network, and to the development of specialized networks for new kinds of information.     

Evaluation of reactivity bonus due to (n, 2n) multiplication in Be/BeO-reflected 233U uranyl nitrate solution systems

Beryllium experiences (n, 2n) multiplication reaction for neutrons having energy above the threshold of ≈ 1.8 MeV. In the case of beryllium-reflected/moderated reactor assemblies these (n, 2n) neutrons contribute additional reactivity. This paper evaluates the reactivity contribution due to (n, 2n) reactions in the Be and BeO reflector of reflected ²³³U uranyl nitrate solution systems in spherical geometry in the light of the latest ⁹Be cross-section data. The results shows that the (n, 2n) reactions in a given thickness of reflector are directly proportional to the core leakage and thus very much a function of core radius. In the core radius range of 4–15 cm the reactivity bonus due to (n, 2n) reactions in a 30-cm thick Be reflector varies from 6.2 to 3.0%, which corresponds to a critical mass saving of ≈18–9%. The corresponding reactivity contributions for BeO reflected systems are ≈25% lower.     

Comparison of multicrystalline silicon surfaces after wet chemical etching and hydrogen plasma treatment: application to heterojunction solar cells

The modifications of the surface and subsurface properties of p-type multicrystalline silicon (mc-Si) after wet chemical etching and hydrogen plasma treatment were investigated. A simple heterojunction (HJ) solar cell structure consisting of front grids/ITO/(n)a-Si:H/(p)mc-Si/Al was used for investigating the conversion efficiency. It is found that the optimized wet chemical etching and cleaning processes as a last technological step before the deposition of the a-Si:H emitter are more favorable to HJ solar cells fabrication than the hydrogenation. Solar cells on p-type mc-Si were prepared without high-efficiency features (point contacts, back surface field). They exhibited efficiencies up to 13% for a cell area of 1 cm² and 12% for a cell area of 39 cm².     

Real and perceived feet orientation under fatiguing and non-fatiguing conditions in an immersive virtual reality environment

Virtual Reality - Lower limbs position sense is a complex yet poorly understood mechanism, influenced by many factors. Hence, we investigated the position sense of lower limbs through feet...