RESUMEN
We have investigated the coadsorption of perylene tetracarboxylic dianhydride (PTCDA) and tetraaminobenzene (TAB) on the Ag/Si(111)-square root(3) x square root(3) R30 degree surface using scanning tunneling microscopy. At room temperature, PTCDA islands with square and herringbone ordering are formed which, on exposure to TAB, are converted into an intermixed phase in which PTCDA and TAB form alternating rows. From our images, we determine the relative placement of TAB and PTCDA molecules and conclude that the row structure is stabilized by hydrogen bonding between dianhydride and diamine groups. We confirm that this hydrogen bonding junction is stable using ab initio calculations and show that the proposed geometry is consistent with calculated intermolecular dimensions.
RESUMEN
We report a novel approach to the design and development of microcantilever sensors in which photochemical hydrosilylation is used to modify the microcantilever surface. This process enables individual microcantilevers in multicantilever array chips to be modified separately by focusing the activating UV light sequentially on each particular cantilever. Photochemical hydrosilylation of 11-undecenyltriethylammonium bromide with hydrogen-terminated silicon microcantilever surfaces was carried out to yield a robust quaternary ammonium terminated organic monolayer suitable for chromate detection. The surface functionalities retain their affinity toward Cr(VI), and the organic monolayer is dense enough to generate significant surface stress upon subsequent adsorption of chromate ions from aqueous solutions.
RESUMEN
AIM: Evaluation of the effectiveness of radiosynoviorthesis (RSO) in osteoarthritis and other disorders with concomitant synovitis versus rheumatoid arthritis by means of a standardized questionnaire. PATIENTS, METHODS: 803 RSO treatments were monitored in 691 patients by standardized questionnaires of 7 centers in 3 countries. Patients were assigned to 3 groups according to their age (20-40, 41-60, 61-80 years). Additionally, the data were analyzed separately for patients with rheumatoid arthritis (group A) and those with osteoarthritis, psoriasis arthritis, pigmental villonodular synovitis or persistent effusions after joint replacement (group B). RESULTS: Ameliorations of joint pain, swelling/effusion or flexibility were found in 80% of group A and 56% of group B (p >0.01). Quality of life improved in 78% of group A and 59% of group B (p >0.01). The response rate was similar for small- and large-sized joints in group A, but significantly higher for large-sized joints in group B (p >0.01). The positive effects on joint pain, swelling/effusion or flexibility lasted longer in group A (p >0.01). Repeated RSOs were as effective as initial ones. The clinical outcome was neither influenced by age, nor gender, nor transient immobilisation for 48 hours after RSO. CONCLUSION: Although slightly more efficient in rheumatoid arthritis, RSO represents an effective treatment option also in osteoarthritis and other disorders with concomitant synovitis.