Polymere Procyanidine, die pr?genden Bestandteile der Mandel-Samenschale

Zusammenfassung Die Samenschale der Mandel (Prunus amygdalus Batsch) besteht neben fettem Öl, Lignin, Polysacchariden und Cutin zu ca. 30% aus Procyanidinen der verschiedensten Polymerisationsgrade. Monomer-Einheiten der Dimere bis Tetracosamere sind (–)-Epicatechin und (+)-Catechin. Prodelphinidine waren nicht nachzuweisen. Die Dimere B-1, B-3, B-4, Trimere und Oligomere sind in Aceton/Wasser löslich. Der Hauptanteil ist hochpolymer und wird in Thioglykolsäure durch Thiolyse gespalten. Die hochpolymeren Procyanidine prägen Struktur und Eigenschaften der Samenschale.

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Procyanidin polymers crucial to the structure of the almond seedcoat

Summary The seedcoat of almond (Prunus amygdalus Batsch) contains up to 30% procyanidins with different degrees of polymerisation and, in addition, fatty oils, lignin, polysaccharides and cutin. Monomer units of dimers to tetracosamers are (–)-epicatechin and (+)-catechin. Prodelphinidins could not be detected. The dimers B-1, B-3, B-4, trimers and oligomers are soluble in acetone/water. The bulk material is large polymer, that is only soluble, by thiolysis, in thioglycolic acid. The large polymer procyanidins are crucial to the structure and attributes of the seedcoat.

     

Phosphorescence and fluorescence of poly(vinyl alcohol) films

Luminescence properties of poly(vinyl alcohol) (PVA) films were investigated at room and low (103 K) temperatures. It was estimated that the PVA films can be regarded as luminescentless matrices when excited by radiation of wavelengths greater than 420 nm (λ_exc ≥ 420 nm).     

The magnetic compass mechanisms of birds and rodents are based on different physical principles.

Recently, oscillating magnetic fields in the MHz-range were introduced as a useful diagnostic tool to identify the mechanism underlying magnetoreception. The effect of very weak high-frequency fields on the orientation of migratory birds indicates that the avian magnetic compass is based on a radical pair mechanism. To analyse the nature of the magnetic compass of mammals, we tested rodents, Ansell's mole-rats, using their tendency to build their nests in the southern part of the arena as a criterion whether or not they could orient. In contrast to birds, their orientation was not disrupted when a broad-band field of 0.1-10MHz of 85nT or a 1.315MHz field of 480nT was added to the static geomagnetic field of 46000nT. Even increasing the intensity of the 1.315MHz field (Zeeman frequency in the local geomagnetic field) to 4800nT, more than a tenth of the static field, the mole-rats remained unaffected and continued to build their nests in the south. These results indicate that in contrast to that of birds, their magnetic compass does not involve radical pair processes; it seems to be based on a fundamentally different principle, which probably involves magnetite.     

Client attachment style and the psychotherapist's interpersonal stance.

Attachment style is proposed as an important client variable that psychotherapists may need to assess in order to tailor their interpersonal stance in psychotherapy. The authors draw on J. Bowlby's (1969, 1973, 1978) attachment theory and describe the therapeutic implications of 3 adult attachment styles: Anxious/Ambivalent, Avoidant, and Secure. Results are summarized from a psychotherapy research program, including the finding that attachment style was related to symptomatology and to therapists' perceptions of the therapeutic alliance. Case illustrations of clients displaying the 3 types of attachment style are presented to illustrate how therapists can productively alter their interpersonal stance to enhance treatment outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mrp1 multidrug resistance-associated protein and P-glycoprotein expression in rat brain microvessel endothelial cells

Two membrane glycoproteins acting as energy-dependent efflux pumps, mdr-encoded P-glycoprotein (P-gp) and the more recently described multidrug resistance-associated protein (MRP), are known to confer cellular resistance to many cytotoxic hydrophobic drugs. In the brain, P-gp has been shown to be expressed specifically in the capillary endothelial cells forming the blood-brain barrier, but localization of MRP has not been well characterized yet. Using RT-PCR and immunoblot analysis, we have compared the expression of P-gp and Mrp1 in homogenates, isolated capillaries, primary cultured endothelial cells, and RBE4 immortalized endothelial cells from rat brain. Whereas the mdr1a P-gp-encoding mRNA was specifically detected in brain microvessels and mdr1b mRNA in brain parenchyma, mrp1 mRNA was present both in microvessels and in parenchyma. However, Mrp1 was weakly expressed in microvessels. Mrp1 expression was higher in brain parenchyma, as well as in primary cultured brain endothelial cells and in immortalized RBE4 cells. This Mrp1 overexpression in cultured brain endothelial cells was less pronounced when the cells were cocultured with astrocytes. A low Mrp activity could be demonstrated in the endothelial cell primary monocultures, because the intracellular [3H]vincristine accumulation was increased by several MRP modulators. No Mrp activity was found in the cocultures or in the RBE4 cells. We suggest that in rat brain, Mrp1, unlike P-gp, is not predominantly expressed in the blood-brain barrier endothelial cells and that Mrp1 and the mdr1b P-gp isoform may be present in other cerebral cells.     

The analysis of change: Issues, fallacies, and new ideas.

In this special section of The Journal of Consulting and Clinical Psychology, new ideas about how to analyze change are presented in a format that is accessible to clinicians and clinical researchers. D. Rogosa's (1988) myths of longitudinal research are reviewed in an attempt to familiarize psychologists with the dangers of assuming (1) that regression toward the mean is unavoidable, (2) that difference scores are unreliable, (3) that analysis of covariance is the way to analyze change, (4) that 2 points are adequate to measure change, and (5) that the correlation between change and initial level is always negative. An overview of the articles emphasizes what is new and improved in the design and analysis of change. The articles are preceded with a conceptual discussion of how to measure change over time when the stability of the criterion construct is high and there is little variance to predict. Other articles discuss the form of change over time and how this can be an important tool in testing specific hypotheses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expression of alpha-D-mannosidase in man-hamster somatic cell hybrids

Two types of alpha-D-mannosidase isozymes are present in human white blood cells, human diploid fibroblasts, and HeLa cells. One of these (the S isozyme) constitutes the major alpha-D-mannosidase of the human cells, has a pH optimum of 4.4, and is associated with lysosomes. The other (the F isozyme) is most active at pH 6, is acid labile, and is located in the soluble portion of the cytoplasm. The expression of human lysosomal alpha-D-mannosidase was examined in man-hamster hybrid clones, and was found to be concordant with that of phosphohexose isomerase in 54 of 55 primary clones. A locus specifying human lysosomal alpha-D-mannosidase has therfore been assigned to chromosome 19.     

Einfluß der Versuchsparameter auf die Abschreckgeschwindigkeiten beim Laseroberflächenumschmelzen am Beispiel ledeburitischer Stähle

Influence of the Process Parameters on Quenching Rates in Laser Melting of Ledeburitic Steels On quenching, surface melted ledeburitic steels solidify dendritically. The secondary arm separation can be used to estimate the cooling rate and hence enables the effect of the operating conditions on the cooling rate to be assessed. In general, the residual melt solidifies as an eutectic or as chromium carbide or a mixture of chromium carbide and iron. The resultant carbide net and the resultant grain refinement change the hardness of the surface. The hardness can be controlled by varying the quenching rate in surface melting and if necessary a subsequent heat treatment.