TY  - THES
A1  - Kraft, Mario
T1  - [1]- und [2]Borametallocenophane der Gruppe-4-Metalle : Synthese, Struktur und katalytische Aktivität
T1  - [1]- and [2]Borametallocenophanes of  Group 4 metals - Synthesis, Structur und catalytic Activity
N2  - In der vorliegenden Arbeit wird über die Synthese, Struktur und katalytische Aktivität von borverbrückten Gruppe 4 Metallocenophanen berichtet, die als Katalysatoren in der Ziegler-Natta-artigen Olefinpolymerisation eingesetzt werden können. Neben den bereits bekannten [1]Borametallocenophanen wurden weitere Komplexe mit unterschiedlichen Substituenten, als auch die bislang unbekannten [2]Borametallocenophane synthetisiert und charakterisiert. Vergleichende Polymerisationsstudien einer Reihe von unterschiedlich substituierten [n]Borametallocenophanen (n = 1,2) wurden unter definierten Standardbedingungen durchgeführt, um einen möglichen Einfluss der am Boratom gebundenen Substituenten zu beobachten. Weitergehende Untersuchungen bezogen sich auf den Einfluss dieser Substituenten auf sterische und elektronische Einflüsse, die mit den Polymerisationsergebnissen korreliert wurden. Hierbei wurden die sterischen Einflüsse der verschiedenen Substituenten anhand der Kristallstrukturen festgemacht; elektronische Einflüsse sollten anhand von CO Schwingungen, die mittels Infrarotspektroskopie beobachtet werden können, von korrespondierenden Carbonylkomplexen und alternativ mittels 91Zr-NMR Spektroskopie untersucht werden.
N2  - In this thesis the synthesis, structure and catalytic activity of boron bridged Group 4 metallocenophanes are reported. These type of complexes are suitable catalyst precursors for the Ziegler-Natta-type olefin polymerization. Besides the known [1]borametallocenophanes new complexes with different substituents as well as the so far unknown [2]borametallocenophanes were synthesized and characterized. A series of differently substituted [n]borametallocenophanes (n = 1,2) were used under defined polymerization conditions, to study a possible influence of the substituents at boron on the catalytic performance. Furthermore, the influence of steric and electronic parameters was evaluated. X-ray structural determinations were used to determine steric changes imposed by the different substituents. Electronic changes were analyzed with the aid of infrared spectroscopy by comparison with the corresponding carbonyl complexes and, alternatively, by 91Zr NMR spectroscopy.
KW  - Borkomplexe
KW  - Metallocene
KW  - Vierte Nebengruppe
KW  - Cyclophane
KW  - Bor
KW  - Metallocenophane
KW  - ansa-Metallocene
KW  - Olefinpolymerisation
KW  - Boron
KW  - Metallocenophanes
KW  - ansa-Metallocenes
KW  - olefin polymerization
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-14689
ER  - 
TY  - JOUR
A1  - Sitter, Magdalena
A1  - Pecks, Ulrich
A1  - Rüdiger, Mario
A1  - Friedrich, Sabine
A1  - Fill Malfertheiner, Sara
A1  - Hein, Alexander
A1  - Königbauer, Josefine T.
A1  - Becke-Jakob, Karin
A1  - Zöllkau, Janine
A1  - Ramsauer, Babett
A1  - Rathberger, Katharina
A1  - Pontones, Constanza A.
A1  - Kraft, Katrina
A1  - Meybohm, Patrick
A1  - Härtel, Christoph
A1  - Kranke, Peter
T1  - Pregnant and postpartum women requiring intensive care treatment for COVID-19 — first data from the CRONOS-registry
JF  - Journal of Clinical Medicine
N2  - (1) Background: Data on coronavirus 2 infection during pregnancy vary. We aimed to describe maternal characteristics and clinical presentation of SARS-CoV-2 positive women requiring intensive care treatment for COVID-19 during pregnancy and postpartum period based on data of a comprehensive German surveillance system in obstetric patients. (2) Methods: Data from COVID-19 Related Obstetric and Neonatal Outcome Study (CRONOS), a prospective multicenter registry for SARS-CoV-2 positive pregnant women, was analyzed with respect to ICU treatment. All women requiring intensive care treatment for COVID-19 were included and compared regarding maternal characteristics, course of disease, as well as maternal and neonatal outcomes. (3) Results: Of 2650 cases in CRONOS, 101 women (4%) had a documented ICU stay. Median maternal age was 33 (IQR, 30–36) years. COVID-19 was diagnosed at a median gestational age of 33 (IQR, 28–35) weeks. As the most invasive form of COVID-19 treatment interventions, patients received either continuous monitoring of vital signs without further treatment requirement (n = 6), insufflation of oxygen (n = 30), non-invasive ventilation (n = 22), invasive ventilation (n = 28), or escalation to extracorporeal membrane oxygenation (n = 15). No significant clinical differences were identified between patients receiving different forms of ventilatory support for COVID-19. Prevalence of preterm delivery was significantly higher in women receiving invasive respiratory treatments. Four women died of COVID-19 and six fetuses were stillborn. (4) Conclusions: Our cohort shows that progression of COVID-19 is rare in pregnant and postpartum women treated in the ICU. Preterm birth rate is high and COVID-19 requiring respiratory support increases the risk of poor maternal and neonatal outcome.
KW  - maternal critical care
KW  - COVID-19
KW  - ARDS
KW  - SARS-CoV-2
KW  - pregnancy
KW  - obstetrics
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-255257
SN  - 2077-0383
VL  - 11
IS  - 3
ER  -