Standard-Nutzungsbedingungen:Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden.Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen.Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. This paper provides a new data set of regional income inequalities within countries based on satellite nighttime light data. We first empirically study the relationship between luminosity data and regional incomes for those countries where regional income data are available. We subsequently use our estimation results for an out-ofsample prediction of regional incomes based on the luminosity data, which allows us to investigate regional income differentials in developing countries as well, where official income data are lacking. Based on the predicted incomes, we calculate commonly used measures of regional inequality within countries. Investigating changes in the dispersion of regional incomes over time reveals that approximately 71-80% of all countries face sigma-convergence. Finally, we study different major determinants of the level of regional inequality based on cross-section data. Panel regressions investigate the within-country changes in inequality, i.e., the determinants of the convergence process. We find evidence for an N-shaped relationship between development and regional inequality. Geography, mobility and trade openness are also highly important. Terms of use: Documents inJEL-Code: D300, E010, E230, O110, O150, O570, R100.
Additive Manufacturing (AM) addresses various benefits as the build-up of complex shaped parts, the possibility of functional integration, reduced lead times or the use of difficult machinable materials compared to conventional manufacturing possibilities. Beside these advantages, the use of more than one material in a component would strongly increase the field of applications in typical AM branches as energy, aerospace or medical technology.By means of multi-material build-ups, cost-intensive alloys could be only used in high-loaded areas of the part, whereas the remaining part could be fabricated with cheaper compositions. The selection of combined materials strongly depends on the requested thermophysical but also mechanical properties. Within this contribution, examples (e. g. used in the turbine business) show how alloys can be arranged to fit together, e. g. in terms of a well-chosen coefficient of thermal expansion (CTE).As can be seen in nature, the multi-material usage can be characterized by sharp intersections from one material to the other (e. g. in case of a thin corrosion protection), but also by graded structures enabling a smoother material transition (e. g. in case of dissimilar materials which are joined together without defects). The latter is shown for an example from aerospace within this paper.Another possibility is the simultaneous placement of several materials, e.g. hard carbide particles placed in a more ductile matrix composition. These particles can be varied in size (e.g. TiC vs. WC). Also the ratio between carbides and matrix alloy can be adjusted depending on its application.Especially nozzle-based free form fabrication technologies, e.g. Laser Metal Deposition (LMD), enable the utilization of more than one material. Within this contribution, possibilities to feed more than one filler material are demonstrated. In addition, results of multi-material processes are shown. Finally, this work focuses on different (potential) applications, mainly in power generation but also for medical technology or wear resistant components.
In the human gastric carcinoma cell line EPG85-257P (parent) induction of resistance to daunorubicin (DAU) was achieved by selection with stepwise increased concentrations of the drug. The new variant was named EPG85-257DAU and was shown to overexpress the mdr1 gene product 170 kDa P-glycoprotein (P-Gp) as demonstrated by immunocytochemistry and mdr1-specific RT-PCR. To investigate the intracellular pathway of DAU the subcellular distribution of this autofluorescent drug was studied in the resistant cells and compared to its chemosensitive counterpart EPG85-257P. When sensitive cells were exposed to DAU the drug rapidly accumulated in the nucleus until cell death. No redistribution of DAU to the cytoplasm was observed. In resistant cells exposed to the drug DAU also accumulated in the nucleus but to a lesser extent than in parent cells. Following exposure, nuclear fluorescence was observed to decrease over a time period of up to 48 h. Six hours after DAU exposure formation of fluorescent vesicle formation started in the perinuclear region and increased continuously. After 48 h nuclear fluorescence was no longer detectable and DAU was located exclusively in vesicles. During this period the vesicles moved from the region of origin to the cell periphery. A pulse chase experiment showed, that vesicles may contain DAU derived from the nucleus. Treatment of EPG85-257DAU cells with DAU in conjunction with the chemosensitizer cyclosporin A (CsA) increased nuclear fluorescence without impairing vesicle formation. Disruption of microtubules by nocodazole led to an accumulation of vesicles in the perinuclear region indicating that microtubules are involved in vesicular transport. Treatment of EPG85-257DAU cells with the actin disruptor cytochalasin B led to accumulation of vesicles in the cell periphery indicating that actin may be involved in exocytosis. Uptake and efflux of DAU and rhodamin (RH) were determined in sensitive and resistant cells using a fluorescence activated cell sorter. Uptake of both compounds was distinctly lower in resistant than in sensitive cells. When resistant cells preloaded for 2 h with RH subsequently were incubated in drug free medium the substance was rapidly released indicating transmembrane transport by P-Gp. In contrast, despite expression of P-Gp in resistant cells no considerable release of DAU was observed for up to 2 h under the same experimental protocol. This indicates that in resistant cells intracellular DAU at least in part may be inaccessible for P-Gp and that vesicular drug transport appears to contribute to DAU resistance by removing intracellular DAU via exocytosis.
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