Search results for "LIX"
showing 10 items of 891 documents
Inherently Chiral Calixarenes
1994
Due to the nonplanarity of the basic 1 n -metacyclophane system, calixarenes and resorcarenes can be transformed into molecules with inherent chirality. Various attempts to achieve this goal are reviewed. Special emphasis is given to derivatives with C n -symmetry, including derivatives of spherand calixarenes and other calixarene-like macrocycles.
Milestones of complex computing facility assembling
2015
IMCS UL continues its enduring development of research e-infrastructure, participates in international projects such as GEANT, GN2, GN3, GN3+, GN4, BalticGRID, BG II and EGI-InSPIRE, has involved in CLARIN and ELIXIR ESFRI ERIC activities. Currently IMCS UL maintains Scientific Cloud unified computing facility realized as ½ PTB SAN storage (IBM DS4700 with servers); provides collocation, hosting and virtualization services. As well it operates as a node for online correlation data streaming services from Irbene radio telescope in real time, HPC resources' disposal for computing tasks, usage of Big data extracted from data storage for modeling and also for graphic data processing. In the sam…
Double- and Multi-Calixarentes
2006
Calixarenes are easily (and often selectively) functionalized and therefore they can be combined in various ways to larger molecules containing more than one calixarene substructure. In the following chapter we will try to give an overview on such multicalixarenes held together by "conventional" covalent links. Self-assembled structures are treated separately in Chapter 8. The earliest examples for double calixarenes of importance are the carcerands and hemicarcerands of D. Cram in which two resorcarene derived cavitands are combined. Due to their unique properties to include (more or less permanently) smaller molecules, they are treated separately in Chapter 10. Further combinations of cav…
Recent Developments in Calixarenes and Their Properties
1989
The increasing number of reports, monographs and patents dealing with the hemistry of inclusion compounds shows the growing interest of organic chemists in elaborating new chemical systems presenting novel physical and chemical properties. These properties are available for fundamental as well as applied research. On the one hand, basic studies on the structure and the nature of inclusion compounds provide information on the intermolecular forces implicated in organized systems and in enzyme processes. On the other hand, applications are in progress in laboratories and industries, for instance, in catalyzing chemical reactions, in transporting and extracting metallic cations, and in modifyi…
Special Calixarenes, Synthesis and Properties
1991
In the previous chapter the standard one step procedures for the synthesis of calixarenes from p-tert-butyl phenol and several p-alkyl phenols have been described. However, these procedures necessarily lead to calixarenes consisting of one single type of phenolic unit. This remains true even for those compounds in which all the terf-butyl groups are removed and replaced by other functional groups. The construction of more sophisticated, special calixarenes which could serve for instance as enzyme models, requires new synthetic approaches capable of producing molecules with selected functionalization.
“Through-space” nuclear spin–spin couplings in ferrocenyl polyphosphanes and diphosphino cavitands: A new way of gathering structural information in …
2009
Abstract Nuclear magnetic resonance is an invaluable technique for investigating a variety of important issues ranging from the determination of molecular structure to therapeutic medical imaging. In this respect, the indirect nuclear spin–spin coupling involving common nuclei such as 1 H, 13 C or 31 P provides, via the J constant, conclusive data for compound characterization in solution. This electron-mediated nuclear spin coupling is usually regarded as being transmitted by covalently bonded magnetic atoms. However, several experimental and theoretical studies, first focused on constrained organofluorides, and more recently devoted to phosphane ligands highlighted the existence of very i…
Occult Hepatitis B and Infliximab-induced HBV Reactivation
2007
Infliximab and newly diagnosed neoplasia in CD:a multicenter matched pair study
2006
Background and aims: The widespread use of anti-tumour necrosis factor α antibody (Infliximab) in Crohn's disease (CD) raises concerns about a possible cancer risk in the long term. In a matched pair study, we assessed whether Infliximab is associated with an increased risk of neoplasia. Methods: In a multicentre matched pair study, 404 CD patients treated with Infliximab (CD-IFX) were matched with 404 CD patients who had never received Infliximab (CD-C). Cases and controls were matched for sex, age (±5 years), site of CD, age at diagnosis (±5 years), immunosuppressant use, and follow up. New diagnoses of neoplasia from April 1999 to October 2004 were recorded. Results: Among the 404 CD-IFX…