Single-site Centers Research Articles

Australian consensus statements for the regulation, production and use of faecal microbiota transplantation in clinical practice

ObjectiveFaecal microbiota transplantation (FMT) has proved to be an extremely effective treatment for recurrent Clostridioides difficile infection, and there is interest in its potential application in other gastrointestinal and systemic...

Synthesis of platinum single-site centers through metal-ligand self-assembly on powdered metal oxide supports

Developing single-site metal catalysts has been regarded as a promising strategy to improve activity and selectivity in heterogeneous catalysis. Here, we report a metal-ligand self-assembly method to create Pt single-site centers on powdered oxide supports. Impregnating Pt and a ligand 3,6-di-2-pyridyl-1,2,4,5-tetrazine (DPTZ) simultaneously (one-step) creates Pt-DPTZ single-sites on powdered MgO, Al2O3, and CeO2. MgO has the most uniform single-sites due to a strong, non-competitive support-ligand interaction, and a support-metal interaction of appropriate strength. Pt(II) centers are stabilized between the N binding pockets of DPTZ, with minimal metallic nanoparticle formation. This system was characterized by XAS, XPS, TEM, XRD, and CO adsorption. Sequential impregnation of Pt and DPTZ (two-step) was also tested on Al2O3 and CeO2, but is not as effective as the one-step method due to limited Pt accessibility and mobility. These oxide-supported Pt-DPTZ single-sites were found to be effective catalysts in hydrosilylation reactions. This work demonstrates a metal-ligand self-assembly strategy to create metal single-site centers on high surface area catalyst supports.

Certification of breast centres in Germany: proof of concept for a prototypical example of quality assurance in multidisciplinary cancer care

BackgroundThe main study objectives were: to develop a set of requirements of comprehensive breast centres; to establish a nationwide voluntary certification programme for breast centres based on such requirements, a certified quality management system (QMS), and scheduled independent, external audits and periodic recertification; and to demonstrate the general acceptance of such a certification programme with a view to introducing similar certification programmes for other major cancers.MethodsBreast centres introduced a QMS and voluntarily participated in an external certification procedure based on guideline-derived Requirements of Breast Centres specifically developed for the application procedure, all subsequent audits and recertification. All data (numbers of pending and successful applications, sites/centre, etc.) were collected by a newly founded, independent organisation for certification of cancer services delivery. Data analysis was descriptive.ResultsRequirements of Breast Centres were developed by the German Cancer Society (DKG), the German Society of Senology (DGS) and other relevant specialist medical societies in the form of a questionnaire comprising 185 essential items based on evidence-based guidelines and the European Society of Breast Cancer Specialists' (EUSOMA) requirements of specialist breast units. From late 2002 to mid 2008, the number of participating breast centres rose from 1 to 175. As of mid 2008, 77% of an estimated 50,000 new breast cancers in Germany were diagnosed and treated at certified breast centres, 78% of which were single-site centres.ConclusionNationwide voluntary certification of breast centres is feasible and well accepted in Germany. Dual certification of breast centres that involves certification of breast services to guideline-derived requirements in conjunction with independent certification of a mandatory QMS can serve as a model for other multidisciplinary site-specific cancer centres.

Reservoir Layers in High Tc Mercury Cuprates

AbstractWe put forward the hypothesis that cations with 6s electrons (Hg,Tl,Pb,Bi) in the charge reservoir layers of high Tc cuprate superconductors actively participate in the pairing interaction as negative-U centers. We further argue that the Hg-cuprates are outstanding superconductors (Tc > 160 K) because they can exist as two-ion negative-U centers, . Their electrons are less localized than in single-site centers (negative-U or bipolaron) and can have a strong pairing interaction with a smaller increase in effective mass. The centers are oriented in the x and y directions and can have phase differences compatible with the d-wave symmetry of the CuO2 planes.