Hyperbranched polyesters (HBP) with different end groups (P-OH, P-COOH, P-OAc) were prepared as thin films. Their surface properties were investigated using zeta potential and contact angle measurements. The differences in surface properties between P-OH and P-COOH, on the one hand, and P-OAc, on the other hand, predicted different behavior in sensoric applications. Therefore, the vapor of the homologous series of alcohols from methanol to pentanol was exposed to the thin films. Changes in thickness were observed with reflectometric interference spectroscopy (RIfS). First investigations in a current analytical problem for the detection and discrimination of refrigerants (freons) using P-OH as sensitive layer have been shown. Polydimethylsiloxane (PDMS) and poly(ether urethane) (PUT) were used as reference sensor materials for the RIfS measurements.

Comparative membrane phenotypes of normal T and B lymphocytes, of normal myeloid cells, and of various leukemic cell types were established by the use of specific Ia‐type alloantisera and ‘classical’ immunological surface markers, including complement receptors. 4%–8% of lymphocytes taken from mixed leukocyte cultures on day 4 showed Ia alloantigens of responder‐type specificity, in addition to two known T‐cell markers on the same cell surface. Together with Ia antiserum inhibition studies, this subpopulation would appear to present a human mixed leukocyte culture (MLC)‐related suppressor T‐cell population. Whilst such cells could not be detected in normal peripheral blood by double fluorescence, a small percentage could readily be demonstrated among cell populations from patients with systemic lupus erythematosus and rheumatoid arthritis (joint fluid). Specific Ia alloantigens were further detected on the immature myeloid cells from bone marrow but not on the more mature myeloid cell types. This establishes the Ia alloantigen system as a valuable cell surface differentiation marker in man. The appearance of complement receptors on myeloid cells was Later than that of Ia alloantigens. Ia alloantigens are expressed on various numbers of leukemic myelo‐ and lympho‐blasts of the so‐called ‘non‐T, non‐B’ cell types. After discontinuous Ficoll gradients to enrich specific density cell groups, mainly the Ia alloantigens and the complement receptors allow a discrimination between acute (AML) and chronic myelocytic leukemia (CML) blasts, inclucling blasts crisis cells. AML cells appear to present a less differentiated cell type than CML blasts crisis cells. For the Latter disease, a more complex picture is obtained since at least three different membrane phenotypes of blasts cells can be identified: an Ia‐positive and an Ia‐negative myeloid blasts and an Ia‐positive lymphoid blasts. The relative quantities of these three elements can vary considerably within even a small group of patients.

The aim of this study was the quantification of vapors of the ozone-depleting refrigerant R22 in the presence of its most important substitute R134a, by the use of the reflectometric interference spectroscopy and polymers as sensitive layers. First, the sorption characteristic of different types of polymers exposed to the vapors of the two analytes was investigated. Then, binary mixtures of the two refrigerants were measured with an array set-up on the basis of six polymer sensors. The measurements were evaluated by the use of neural networks, whereby low limits of detection of 0.45 percentage volume (vol. %)for R22 and 1.45 vol. % for R134a could be established. Additionally, one polar polymer and one microporous polymer were selected for the measurements with a low-cost set-up. The quantification of R22 in the presence of R134a with this low-cost set-up was possible with a limit of detection of 0.44 vol. %, which would enable a fast and economical monitoring at recycling stations.