Scaling behavior of the reorientation kinetics of block copolymers exposed to electric fields.

We have followed the reorientation kinetics of various block copolymer solutions exposed to an external electric DC field. The characteristic time constants follow a power law indicating that the reorientation is driven by a decrease in electrostatic energy. Moreover, the observed exponent suggests an activated process in line with the expectations for a nucleation and growth process. When properly scaled, the data collapse onto a single master curve spanning several orders of magnitude both in reduced time and in reduced energy. The power law dependence of the rate of reorientation derived from computer simulations based on dynamic density functional theory agrees well with the experimental observations. First experiments in AC electric fields at sufficiently high frequencies confirm the notion that the reorientation process is dominated by differences in the dielectric constants rather than by mobile ions.

Microscopic mechanisms of electric-field-induced alignment of block copolymer microdomains.

We investigate the microscopic mechanisms responsible for microdomain alignment in block copolymer solutions exposed to an electric field. Using time-resolved synchrotron small-angle x-ray scattering, we reveal two distinct processes, i.e., grain boundary migration and rotation of entire grains, as the two dominant microscopic mechanisms. The former dominates in weakly segregating systems, while the latter is predominant in strongly segregated systems. The kinetics of the processes are followed as a function of polymer concentration and temperature and are correlated to the solution viscosity.

Moderate zinc and vitamin A deficiency in breast milk of mothers from East-Jakarta.

OBJECTIVE: To gain information about the micronutrient status of urban, middle-income, breast-feeding mothers in relation to zinc and selected fat-soluble vitamins in plasma and breast milk and to assess possible interaction between the measured micronutrients. DESIGN: Cross-sectional study. SUBJECTS: 91 mothers and their infants living in middle-income areas of Jakarta, Indonesia. RESULTS: None of the measured anthropometric data of the mothers (e.g. BMI: 22.0+/-3.1 kg/m2) and their infants (birth weight: 3.2+/-0.5 kg) gave any indication of undernutrition. The mean concentrations in blood were 124+/-18 g/l for hemoglobin, 385+/-111 microg/l for retinol, 34+/-23 microg/l for alpha-carotene, 104+/-72 microg/l for beta-carotene, 7.7+/-3.3 mg/l for alpha-tocopherol, 0.57+/-0.23 mg/l for gamma-tocopherol, 855+/-242 microg/l for zinc, and the median concentration of lycopene was 29 microg/l. The median breast milk concentrations were 420 microg/l for retinol, 7.8 microg/l for beta-carotene, and 2.7 mg/l for zinc. With increased duration of lactation, vitamin A and zinc concentrations significantly decreased in breast milk whereas plasma zinc concentration increased. Plasma alpha- and beta-carotene were positively correlated (P < 0.0001) with each other and with plasma lycopene. Breast milk beta-carotene was positively correlated with breast milk retinol and with plasma beta-carotene (P < 0.0001). There was no correlation between zinc and vitamin A in either breast milk or plasma. Forty per cent of the mothers were anemic, 29.1% had a low plasma zinc concentration, and 23.7% had a moderately low plasma vitamin A concentration. Breast milk from 70% of the women had a low concentration of vitamin A and that from 66% had a low concentration of zinc. CONCLUSIONS: Multi-micronutrient intervention should be considered to provide a sufficient supply of zinc and vitamin A for growth of exclusively breast-fed infants.

[Effectiveness of a fast culture method for mycobacteria as a therapeutic control and within the scope of diagnosis]. / Leistungsfähigkeit der Schnellanzüchtung von Mykobakterien als Therapiekontrolle und im Rahmen der Diagnostik.

A rapid method for culturing mycobacteria using a liquid medium and a rotating incubator was applied in routine examinations parallel with the conventional methods. As therapy control the rapid method appeared unsuitable, for the cultures are checked by microscopy and during therapy there is a period in which mycobacteria are visible but not multiplying. Within the diagnostics results are available somewhat earlier but the efficiency of the rapid culture is less than with the method in general use.

[Experiments concerning the value of immunoglobulin-determinations (IgG, IgM, IgA) with respect to the immunological reactions of patients suffering from malignant tumors (author's transl)]. / Untersuchungen über die Wertigkeit von Immunglobulinbestimmungen (IgG, IgM und IgA) zur Beurteilung der immunologischen Reaktivität bei Tumorerkrankungen.

The present paper is a report on the determination of G, M and A serum immunoglobulins of 177 patients (98 men and 79 women) at the age of 19 to 78 years with malignant tumors and of 100 healthy controls of the same setup with respect to age and sex. The results were evaluated by cross-section and longitudinal examinations dependent upon localization, TNM classification, histological differentiation and the therapy of the tumor. The results show that the G, M and A immunoglobulins are not suitable for statements on the situation of the reaction of the organism of tumor bearers and on the prognostic course. Neither is it possible to use the determination of the concentration of serum immunoglobulins for the regulation of a therapy.

[Behavior of serum concentrations of immunoglobulins G, M and A in the 1st week of illness in children with bacterial and viral diseases]. / Untersuchungen über das Verhalten der Serumkonzentrationen der Immunglobuline G, M und A in der ersten Krankheitswoche bei Kindern mit bakteriell und viral bedingten Erkrankungen.

The serum concentrations of the immune globulins in children with acute infection of the upper respiratory tract, angina lacunaris, mumps and acute infection of the urinary tract within the first week of illness were analysed. In the adequate age group the values (altogether 540) of healthy and diseased children were confronted and statistically compared. Here the following characteristic changes were shown: the acute infection of the upper respiratory tract was characterized by an increase of IgG. In mumps a decrease of IgA was stated. As to the infections of the urinary tract in the younger age group an increase of IgM existed, in the older age group a decrease of IgA. The results refer to the dynamics of the immune globulins in the initial phase of the individual diseases.