166 research outputs found
Celiac axis infusion chemotherapy in advanced nonresectable pancreatic cancer
Summary: Conclusion: Based on these data we suggest that regional intra-arterial chemotherapy for advanced pancreatic cancer seems not to be superior to common treatment modalities, such as combined radiochemotherapy. Background: The prognosis for advanced pancreatic cancer is very poor. No standard treatment is available. Recently, better survival and quality of life was reported from regional cancer treatment via celiac axis infusion. In an attempt to confirm these results we conducted a phase II study of intra-arterial chemotherapy for nonresectable pancreatic cancer. Methods: From May 1994 to February 1995, 12 consecutive patients with biopsy-proven advanced ductal carcinoma of the exocrine pancreas were given intra-arterial infusions consisting of Mitoxantrone, 5-FU+ folinic acid, and Cisplatin via a transfemorally placed catheter in the celiac axis. Six patients were classified as UICC stage III and six as stage IV with the liver as the sole site of distant metastasis. Nine patients had primary and three had recurrent pancreatic carcinoma after a Whipple procedure. Nonresectability of primary tumors was assessed in all patients by laparotomy or laparoscopy. Results: A total of 31 cycles of chemotherapy (mean 2.6 cycles/patient) was administered. Catheter placement was technically feasible in all cycles. A groin hematoma was the only catheter complication. The follow-up by CT sans at 2-mo intervals revealed partial remission in 1 patient (8%), temporary stable disease in 4 patients (33%), and disease progression in 7 patients (58%). The same response was obtained after analyzing the CA 19-9 course. Median survival in stage III patients was 8.5 mo (3-12 mo) and in stage IV patients 5 mo (2-11 mo). Toxicity according to WHO criteria consisted of grade III (4 events), grade II (10 events), and grade I (17 events), mainly resulting from leucopenia and diarrhea/vomiting. Nine of 11 patients experienced temporary relief of pain immediately after regional treatmen
Dissimilar Metal Joining
Magnetic pulse welding (MPW) can offer unique advantages over other joining techniques
when applied correctly. Especially for dissimilar metal welding it has several advantages
due to its very low heat input and short process times. Due to the high demands of the
process on the welding system properties, it is vital to understand the process as detailed
as possible to reduce system-related challenges and costs.
The paper discusses similarities and dissimilarities to other high velocity joining
processes like explosion welding. Specific aspects of MPW, like its special transient
nature are presented and their impact on welding parameters are explained. Using results
of example welds on similar and dissimilar metal joints, microscopic and macroscopic
effects of part geometry, metallurgical behaviour and pulse parameters are shown.
Concerning microscopic effects, the question is discussed whether interfaces of
dissimilar metals can fully be free of intermetallics. This is a relevant question in relation to
achievable joint strength, joint ductility and even electric conductivity. Here evidence of
recent SEM and TEM analysis is presented. Conclusions are drawn with respect to
optimal process conditions and practical geometric relations on the macroscopic scale
A lithium–sulfur full cell with ultralong cycle life: influence of cathode structure and polysulfide additive
Lithium–sulfur batteries are highly attractive energy storage systems, but suffer from structural anode and cathode degradation, capacity fade and fast cell failure (dry out). To address these issues, a carbide-derived carbon (DUT-107) featuring a high surface area (2088 m² g⁻¹), high total pore volume (3.17 cm³ g⁻¹) and hierarchical micro-, meso- and macropore structure is applied as a rigid scaffold for sulfur infiltration. The DUT-107/S cathodes combine excellent mechanical stability and high initial capacities (1098–1208 mA h gs ⁻¹) with high sulfur content (69.7 wt% per total electrode) and loading (2.3–2.9 mgs cm⁻²). Derived from the effect of the electrolyte-to-sulfur ratio on capacity retention and cyclability, conducting salt is substituted by polysulfide additive for reduced polysulfide leakage and capacity stabilization. Moreover, in a full cell model system using a prelithiated hard carbon anode, the performance of DUT-107/S cathodes is demonstrated over 4100 cycles (final capacity of 422 mA h gs ⁻¹), with a very low capacity decay of 0.0118% per cycle. Application of PS additive further boosts the performance (final capacity of 554 mA h gs ⁻¹), although a slightly higher decay of 0.0125% per cycle is observed
Decreased CD90 expression in human mesenchymal stem cells by applying mechanical stimulation
BACKGROUND: Mesenchymal stem cells (MSC) are multipotent cells which can differentiate along osteogenic, chondrogenic, and adipogenic lineages. The present study was designed to investigate the influence of mechanical force as a specific physiological stress on the differentiation of (MSC) to osteoblast-like cells. METHODS: Human MSC were cultured in osteoinductive medium with or without cyclic uniaxial mechanical stimulation (2000 μstrain, 200 cycles per day, 1 Hz). Cultured cells were analysed for expression of collagen type I, osteocalcin, osteonectin, and CD90. To evaluate the biomineral formation the content of bound calcium in the cultures was determined. RESULTS: After 14 days in culture immunfluorescence staining revealed enhancement of collagen type I and osteonectin expression in response to mechanical stimulation. In contrast, mechanically stimulated cultures stained negative for CD90. In stimulated and unstimulated cultures an increase in the calcium content over time was observed. After 21 days in culture the calcium content in mechanical stimulated cultures was significantly higher compared to unstimulated control cultures. CONCLUSION: These results demonstrate the influence of mechanical force on the differentiation of human MSC into osteoblast-like cells in vitro. While significant enhancement of the biomineral formation by mechanical stimulation is not detected before 21 days, effects on the extracellular matrix became already obvious after 14 days. The decrease of CD90 expression in mechanically stimulated cultures compared to unstimulated control cultures suggests that CD90 is only transiently expressed expression during the differentiation of MSC to osteoblast-like cells in culture
Measurement of P T -weighted Sivers asymmetries in leptoproduction of hadrons
The transverse spin asymmetries measured in semi-inclusive leptoproduction of hadrons, when weighted
with the hadron transverse momentum PT , allow for the extraction of important transverse-momentumdependent distribution functions. In particular, the weighted Sivers asymmetries provide direct information
on the Sivers function, which is a leading-twist distribution that arises from a correlation between the transverse momentum of an unpolarised quark in a transversely polarised nucleon and the spin of the nucleon.
Using the high-statistics data collected by the COMPASS Collaboration in 2010 with a transversely polarised proton target, we have evaluated two types of PT -weighted Sivers asymmetries, which are both
proportional to the product of the first transverse moment of the Sivers function and of the fragmentation
function. The results are compared to the standard unweighted Sivers asymmetries and used to extract the
first transverse moments of the Sivers distributions for u and d quark
Feilke revisited : 60 Stellenbesuche
Weitere Hrsg.: Thorsten Pohl, Sara Rezat, Torsten Steinhoff, Martin SteinseiferAnlässlich des 60. Geburtstags des Linguisten und Sprachdidaktikers Helmuth Feilke wurden Wegbegleiterinnen und Wegbegleiter gebeten, einzelne Stellen in seinen wissenschaftlichen Schriften erneut zu besuchen.
Entstanden sind pointierte Kommentare, kurze wissenschaftliche Abhandlungen und Analysen, Varianten auch des kritischen und kontroversen Nach- und Weiterdenkens und Ansätze zur Neu- oder Re-Kontextualisierung.
Je nach wissenschaftlicher Vita der Autorinnen und Autoren kann es sich um Stellen handeln, deren Rezeption zeitlich weit zurückliegt, oder um Passagen, die ganz aktuelle Fragen der eigenen Forschungsarbeit tangieren. Abgesehen davon, dass ein kurzes Format für die Beiträge gewählt und die Autorinnen und Autoren gebeten wurden, die ausgewählte Stelle knapp zu verorten und zu erläutern, war die Bearbeitungsform gänzlich freigestellt.
So sind Texte in einer Bandbreite von pointierten Kommentaren, kurzen wissenschaftlichen Abhandlungen und Analysen, Varianten des Nach- und Weiterdenkens, Ansätze zur Neu- oder Re-Kontextualisierung bis hin zu Formen des kritischen Hinterfragens und der kontroversen Auseinandersetzung entstanden
Significance of established TEM analysis for industry-related research on inhomogeneous and / or inside boundaries and interfaces
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