40 research outputs found
Accurate prediction of X-ray pulse properties from a free-electron laser using machine learning
Free-electron lasers providing ultra-short high-brightness pulses of X-ray radiation have great potential for a wide impact on science, and are a critical element for unravelling the structural dynamics of matter. To fully harness this potential, we must accurately know the X-ray properties: intensity, spectrum and temporal profile. Owing to the inherent fluctuations in free-electron lasers, this mandates a full characterization of the properties for each and every pulse. While diagnostics of these properties exist, they are often invasive and many cannot operate at a high-repetition rate. Here, we present a technique for circumventing this limitation. Employing a machine learning strategy, we can accurately predict X-ray properties for every shot using only parameters that are easily recorded at high-repetition rate, by training a model on a small set of fully diagnosed pulses. This opens the door to fully realizing the promise of next-generation high-repetition rate X-ray lasers
Poly[ADP-Ribose] Polymerase-1 Expression Is Related To Cold Ischemia, Acute Tubular Necrosis, and Delayed Renal Function In Kidney Transplantation
Cold ischemia time especially impacts on outcomes of expanded-criteria donor (ECD) transplantation. Ischemia-reperfusion (IR) injury produces excessive poly[ADP-Ribose] Polymerase-1 (PARP-1) activation. The present study explored the hypothesis that increased tubular expression of PARP-1 contributes to delayed renal function in suboptimal ECD kidney allografts and in non-ECD allografts that develop posttransplant acute tubular necrosis (ATN)
Islet transplantation in type I diabetes mellitus
Hintergrund
Die Inseltransplantation entwickelte sich in den letzten 15 Jahren fĂĽr eine Auswahl von Patienten mit Diabetes mellitus Typ 1 zu einer etablierten Therapieoption.
Fragestellung
Indikationsstellung, mögliche Varianten sowie Langzeitresultate der Inseltransplantation sollten aufgezeigt werden.
Material und Methoden
Die zur VerfĂĽgung stehenden Arbeiten zum kurz- und langfristigen Verlauf nach Inseltransplantation wurden zusammengestellt und bewertet.
Ergebnisse
Mit der Inseltransplantation werden hinsichtlich Glukosekontrolle [HbA1c (Hämoglobin Typ A1c)], Reduktion von Hypoglykämien und Erhaltung der Funktion der transplantierten Niere mit der Pankreastransplantation vergleichbare Resultate erzielt. Während eine langfristige Insulinunabhängigkeit trotz multipler konsekutiver Transplantationen nur selten erreicht wird, ist das Auftreten von transplantationsassoziierten Komplikationen deutlich geringer als bei der Pankreastransplantation.
Diskussion
Für Patienten mit schlechter Glukosekontrolle und rezidivierenden schweren Hypoglykämien sowie für Patienten mit geplanter Nierentransplantation sollte eine Insel- oder Pankreastransplantation erwogen werden, bei Patienten mit hohem perioperativem Risiko ist Erstere die Therapie der Wahl gegenüber der Pankreastransplantation.
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Background
Islet transplantation has become an established treatment option for a selected, small number of patients with type 1 diabetes mellitus.
Objectives
Indication, options, and long-term results of islet transplantation are presented.
Materials and methods
A compilation of original work on short- and long-term results after islet transplantation is reviewed.
Results
With islet transplantation, results regarding glucose control (HbA1c), reduction of hypoglycemia, and preservation of function of the transplanted kidney are comparable to pancreas transplantation. While long-term insulin independence is not achieved in most cases despite multiple transplantations, the occurrence of transplantation-associated complications is much lower compared to pancreas transplantation.
Conclusions
For patients with poor glycemic control and recurrent severe hypoglycemia, and for patients with a planned kidney transplantation, islet or pancreas transplantation should be evaluated. The former is the preferred option for patients with a high perioperative risk