Growth hormone, but not insulin-like growth factor I, induces a serum protease activity for insulin-like growth factor binding protein-3 in hypophysectomized rats in vivo

AbstractInsulin-like growth factor binding proteins (IGFBPs) modulate IGF action. Proteolytic cleavage of IGFBPs yields lower molecular forms with reduced ability to bind IGFs, thereby increasing IGF bioavailability. In serum from normal adult rats, we found a proteolytic activity for IGFBP-3, presumably a cation-dependent serine protease. It is lacking in serum from hypophysectomized rats and restored by infusion of growth hormone (GH), but not IGF I. Thus, IGF I does not appear to mediate the GH effect on IGFBP-3 proteolysis. Rather, GH seems to modulate IGF action indirectly via alteration of IGFBP-3 structure

Die Rolle alternativer Wohlstandsindikatoren bei der Begutachtung der gesamtwirtschaftlichen Entwicklung. Reprint eines Gutachtens für den Sachverständigenrat zur Begutachtung der gesamtwirtschaftlichen Entwicklung vom September 1972

Der Deutsche Bundestag hat Ende 2010 eine Enquete-Kommission zum Thema „Wachstum, Wohlstand und Lebensqualität“ eingerichtet, die ihre Arbeit Anfang 2011 aufgenommen hat und die bis zum Ende der Legislaturperiode einen Bericht und Empfehlungen abgeben soll. Eine wesentliche Aufgabe dieser Kommission, der 17 Abgeordnete und 17 sachverständige Mitglieder angehören, ist die Diskussion und Erarbeitung „alternativer Wohlstands-Indikatoren“, die das Bruttoinlandsprodukt (BIP, im Englischen: GDP) als politische Zielgröße ergänzen oder ersetzen können. Damit ist die Thematik dieser Enquete-Kommission eng mit der Weiterentwicklung der amtlichen Statistik und der gesamten Forschungs-Infrastruktur in den Sozial-, Verhaltens- und Wirtschaftswissenschaften verbunden. Die Arbeitspapier-Reihe des RatSWD, die insbesondere der Diskussion der konzeptionellen und organisatorischen Weiterentwicklung von Statistik und Forschungsinfrastruktur dient, wurde deswegen ausdrücklich für Beiträge geöffnet, die sich mit methodischorganisatorischen Fragen alternativer Wohlstandsindikatoren beschäftigen. Das erste Arbeitspapier zur Indikatoren-Thematik wurde von Sonja C. Kassenböhmer und Christoph M. Schmidt (RatSWD Working Paper Nr. 167: Beyond GDP and Back: What is the Value-Added by Additional Components of Welfare Measurement?) geschrieben. Christoph Schmidt ist Präsident des RWI Essen, Mitglied im Sachverständigenrat zur Beurteilung der gesamtwirtschaftlichen Entwicklung und auch sachverständiges Mitglied in der Enquete-Kommission. Das hier vorliegende Arbeitspapier ist ein Nachdruck eines Gutachtens für den Sachverständigenrat zur Begutachtung der gesamtwirtschaftlichen Entwicklung aus dem Jahr 1972. Das ursprüngliche Manuskript ist also nahezu 40 Jahre alt. Aber der Nachdruck dieses Gutachtens lohnt sich, da es sich mit methodischen und organisatorischen Fragen „alternativer Wohlstandsindikatoren“ beschäftigt, die heute noch bzw. wieder aktuell sind. Verwiesen sei in diesem Zusammenhang auch auf ein Gutachten, das Wolfgang Zapf 1975 für die „Kommission für wirtschaftlichen und sozialen Wandel“ schrieb (W. Zapf, Sozialberichterstattung: Möglichkeiten und Probleme, Göttingen 1976: Verlag Otto Schwartz & Co). Der hier abgedruckte Text wurde nie in der Original-Form des Gutachtens veröffentlicht. Er wurde von zwei Pionieren der Sozialindikatoren-Bewegung in Deutschland geschrieben: Hans-Jürgen Krupp und Wolfgang Zapf, die 1972 als Professoren für Volkswirtschaftslehre (an der Johann Wolfgang Goethe Universität in Frankfurt am Main) und Soziologie (an der Universität Mannheim) tätig waren. Beide waren Leiter des SPES-Projektes; einem hoffnungsvollen DFGProjekt über ein „SozialPolitisches Entscheidungs- und Indikatoren-System“. Aus dem SPES-Projekt ist der DFG-Sonderforschungsbereich „Mikroanalytische Grundlagen der Gesellschaftspolitik“ (1979 bis 1990) hervorgegangen, der wiederum u. a. die Grundlagen für den RatSWD legte. Und Hans-Jürgen Krupp und Wolfgang Zapf haben auf verschiedene Art und Weise zu den Gründern des „Rats für Sozial- und Wirtschaftsdaten“ gehört.

Technikfolgen für Haushaltsorganisation und Familienbeziehungen

Die Autoren diskutieren einige theoretische und empirische Ausgangspunkte eines Forschungsprojekts, in welchem sie die Zusammenhänge von Technikausstattung, Techniknutzung, Haushaltsorganisation, Familienbeziehungen, Innovationsverhalten und individuellem Wohlbefinden untersuchen. Sie gehen hierzu auf den unterschätzten Umfang der Haushalts- und Alltagstechnik, auf die kontroverse Beurteilung der sozialen Folgen der Haushaltstechnik sowie auf die Zukunft der Privathaushalte und der Haushaltstechnik ein. Ihre Ausführungen lassen sich in drei Thesen zusammenfassen: (1) Umfang, Aufwand und Erträge der Alltagstechnik haben ein so großes Gewicht, dass sie die Einstellung der Bevölkerung zur Technik vermutlich stärker prägen als die medienvermittelten Wahrnehmungen der Rüstungstechnologie, der industriellen Automation oder der Umweltbedrohung; (2) Die moderne Haushaltstechnik hat die Haushaltsorganisationen und die Familienbeziehungen der Kernfamilie nicht revolutioniert, aber sie hat die Pluralisierung der Lebensformen und Lebensstile gefördert; (3) Weder Stagnation noch Roboterisierung werden die künftige Alltagstechnik auszeichnen, aber eine Fülle neuer, geplanter und ungeplanter, funktionaler und symbolischer Verwendungen. Die Kollektivierung von Haushaltsfunktionen ist unwahrscheinlich, aber soziale Innovationen sind in Richtung auf kooperative Lösungen absehbar. (ICI2

The effect of hypophysectomy on pancreatic islet hormone and insulin-like growth factor I content and mRNA expression in rat

The growth arrest after hypophysectomy in rats is mainly due to growth hormone (GH) deficiency because replacement of GH or insulin-like growth factor (IGF) I, the mediator of GH action, leads to resumption of growth despite the lack of other pituitary hormones. Hypophysectomized (hypox) rats have, therefore, often been used to study metabolic consequences of GH deficiency and its effects on tissues concerned with growth. The present study was undertaken to assess the effects of hypophysectomy on the serum and pancreatic levels of the three major islet hormones insulin, glucagon, and somatostatin, as well as on IGF-I. Immunohistochemistry (IHC), in situ hybridization (ISH), radioimmunoassays (RIA), and Northern blot analysis were used to localize and quantify the hormones in the pancreas at the peptide and mRNA levels. IHC showed slightly decreased insulin levels in the β cells of hypox compared with normal, age-matched rats whereas glucagon in α cells and somatostatin in δ cells showed increase. IGF-I, which localized to α cells, showed decrease. ISH detected a slightly higher expression of insulin mRNA and markedly stronger signals for glucagon and somatostatin mRNA in the islets of hypox rats. Serum glucose concentrations did not differ between the two groups although serum insulin and C-peptide were lower and serum glucagon was higher in the hypox animals. These changes were accompanied by a more than tenfold drop in serum IGF-I. The pancreatic insulin content per gram of tissue was not significantly different in hypox and normal rats. Pancreatic glucagon and somatostatin per gram of tissue were higher in the hypox animals. The pancreatic IGF-I content of hypox rats was significantly reduced. Northern blot analysis gave a 2.6-, 4.5-, and 2.2-fold increase in pancreatic insulin, glucagon, and somatostatin mRNA levels, respectively, in hypox rats, and a 2.3-fold decrease in IGF-I mRNA levels. Our results show that the fall of serum IGF-I after hypophysectomy is accompanied by a decrease in pancreatic IGF-I peptide and mRNA but by partly discordant changes in the serum concentrations of insulin and glucagon and the islet peptide and/or mRNA content of the three major islet hormones. It appears that GH deficiency resulting in a "low IGF-I state” affects translational efficiency of these hormones as well as their secretory responses. The maintenance of normoglycemia in the presence of reduced insulin and elevated glucagon serum levels, both of which would be expected to raise blood glucose, may result mainly from the enhanced insulin sensitivity, possibly due to GH deficiency and the subsequent decrease in IGF-I productio

Insulin-like growth factor I (IGF-I) in a growth-enhanced transgenic (GH-overexpressing) bony fish, the tilapia ( Oreochromis niloticus ): indication for a higher impact of autocrine/paracrine than of endocrine IGF-I

Several lines of growth hormone (GH)-overexpressing fish have been produced and analysed for growth and fertility parameters. However, only few data are available on the growth-promoting hormone insulin-like growth factor I (IGF-I) that mediates most effects of GH, and these are contradictory. Using quantitative real-time RT-PCR, radioimmunoassay, in situ hybridization, immunohistochemistry, and radiochromatography we investigated IGF-I and IGF binding proteins (IGFBPs) in an adult (17 months old) transgenic (GH-overexpressing) tilapia (Oreochromis niloticus). The transgenics showed an around 1.5-fold increase in length and an approximately 2.3-fold higher weight than the non-transgenics. Using radioimmunoassay, the serum IGF-I levels were lower (6.22±0.75ng/ml) in transgenic than in wild-type (15.01±1.49ng/ml) individuals (P=0.0012). Radioimmunoassayable IGF-I in transgenic liver was 4.2-times higher than in wild-type (16.0±2.21 vs. 3.83±0.71ng/g, P=0.0017). No hepatocytes in wild-type but numerous hepatocytes in transgenic liver contained IGF-I-immunoreactivity. RT-PCR revealed a 1.4-times higher IGF-I mRNA expression in the liver of the transgenics (10.51±0.82 vs. 7.3±0.49pg/μg total RNA, P=0.0032). In correspondence, in situ hybridization showed more IGF-I mRNA containing hepatocytes in the transgenics. A twofold elevated IGF-I mRNA expression was determined in the skeletal muscle of transgenics (0.33±0.02 vs. 0.16±0.01pg/μg total RNA, P<0.0001). Both liver and serum of transgenics showed increased IGF-I binding. The increased IGFBP content in the liver may lead to retention of IGF-I, and/or the release of IGF-I into the circulation may be slower resulting in accumulation of IGF-I in the hepatocytes. Our results indicate that the enhanced growth of the transgenics likely is due to enhanced autocrine/paracrine action of IGF-I in extrahepatic sites, as shown here for skeletal muscl

Unified model for laser doping of silicon from precursors

Laser doping of silicon with the help of precursors is well established in photovoltaics. Upon illumination with the constant or pulsed laser beam, the silicon melts and doping atoms from the doping precursor diffuse into the melted silicon. With the proper laser parameters, after resolidification, the silicon is doped without any lattice defects. Depending on laser energy and on the kind of precursor, the precursor either melts or evaporates during the laser process. For high enough laser energies, even parts of the silicon’s surface evaporate. Here, we present a unified model and simulation program, which considers all these cases. We exemplify our model with experiments and simulations of laser doping from a boron oxide precursor layer. In contrast to previous models, we are able to predict not only the width and depth of the patterns on the deformed silicon surface but also the doping profiles over a wide range of laser energies. In addition, we also show that the diffusion of the boron atoms in the molten Si is boosted by a thermally induced convection in the silicon melt: the Gaussian intensity distribution of the laser beam increases the temperature-gradient-induced surface tension gradient, causing the molten Si to circulate by Marangoni convection. Laser pulse energy densities above H > 2.8 J/cm2 lead not only to evaporation of the precursor, but also to a partial evaporation of the molten silicon. Without considering the evaporation of Si, it is not possible to correctly predict the doping profiles for high laser energies. About 50% of the evaporated materials recondense and resolidify on the wafer surface. The recondensed material from each laser pulse forms a dopant source for the subsequent laser pulses.Die Forschungs- und Entwicklungsaktivitäten des Bundesministeriums für Wirtschaft und Energie (BMWi

Laser activation for highly boron-doped passivated contacts

Passivated, selective contacts in silicon solar cells consist of a double layer of highly doped polycrystalline silicon (poly Si) and thin interfacial silicon dioxide (SiO2). This design concept allows for the highest efficiencies. Here, we report on a selective laser activation process, resulting in highly doped p++-type poly Si on top of the SiO2. In this double-layer structure, the p++-poly Si layer serves as a layer for transporting the generated holes from the bulk to a metal contact and, therefore, needs to be highly conductive for holes. High boron-doping of the poly Si layers is one approach to establish the desired high conductivity. In a laser activation step, a laser pulse melts the poly Si layer, and subsequent rapid cooling of the Si melt enables electrically active boron concentrations exceeding the solid solubility limit. In addition to the high conductivity, the high active boron concentration in the poly Si layer allows maskless patterning of p++-poly Si/SiO2 layers by providing an etch stop layer in the Si etchant solution, which results in a locally structured p++-poly Si/SiO2 after the etching process. The challenge in the laser activation technique is not to destroy the thin SiO2, which necessitates fine tuning of the laser process. In order to find the optimal processing window, we test laser pulse energy densities (Hp) in a broad range of 0.7 J/cm2 ≤ Hp ≤ 5 J/cm2 on poly Si layers with two different thicknesses dpoly Si,1 = 155 nm and dpoly Si,2 = 264 nm. Finally, the processing window 2.8 J/cm2≤ Hp ≤ 4 J/cm2 leads to the highest sheet conductance (Gsh) without destroying the SiO2 for both poly Si layer thicknesses. For both tested poly Si layers, the majority of the symmetric lifetime samples processed using these Hp achieve a good passivation quality with a high implied open circuit voltage (iVOC) and a low saturation current density (J0). The best sample achieves iVOC = 722 mV and J0 = 6.7 fA/cm2 per side. This low surface recombination current density, together with the accompanying measurements of the doping profiles, suggests that the SiO2 is not damaged during the laser process. We also observe that the passivation quality is independent of the tested poly Si layer thicknesses. The findings of this study show that laser-activated p++-poly Si/SiO2 are not only suitable for integration into advanced passivated contact solar cells, but also offer the possibility of maskless patterning of these stacks, substantially simplifying such solar cell production.Bundesministerium für Wirtschaft und Klimaschutz (BMWK

Size- and surface-dependent solubility of cadmium telluride in aqueous solutions

Due to the toxicity of cadmium (Cd) and the scarcity of telluride (Te), CdTe-based photovoltaic modules have been under discussion during the last few years. In particular, the stability of CdTe in aqueous solutions is under debate. Here we show that the stability of CdTe depends not only on the pH of water-based solutions but also on size and surface treatment of CdTe particles. We compare milled module pieces with CdTe powders of different particle size. The leaching of CdTe is conditioned by the outdiffusion of Cd and Te at the interface between CdTe particles and the aqueous solution. The smaller the particle size, the faster the leaching. Therefore, milled module pieces decompose faster than CdTe powders with relatively large grains. We observe a dependence on time t according to t0.43. The room temperature diffusion coefficients are calculated as DCd ≈ 3 × 10-17 cm2/s for Cd, and DTe ≈ 1.5 × 10−17 cm2/s for Te in pH4. The chemical instability in aqueous solutions follows thermodynamic considerations. The solution behavior of Cd and Te depends on the pH value and the redox potential of the aqueous solutions. Chemical treatments such as those used in solar cell production modify the surface of the CdTe particles and their leaching behavior.Bundesministerium für Wirtschaft und Technologi