c-Axis tunneling in YBa2Cu3O7-\delta/PrBa2Cu3O7-\delta superlattices

In this work we report c-axis conductance measurements done on a superlattice based on a stack of 2 layers YBa2Cu3O{7-\delta} and 7 layers PrBa2Cu3O{7-\delta} (2:7). We find that these quasi-2D structures show no clear superconducting coupling along the c-axis. Instead, we observe tunneling with a gap of \Delta_c=5.0\pm 0.5 meV for the direction perpendicular to the superconducting planes. The conductance spectrum show well defined quasi-periodic structures which are attributed to the superlattice structure. From this data we deduce a low temperature c-axis coherence length of \xi_c=0.24\pm 0.03 nm.Comment: 15 pages, 5 figures. To appear in Phys.Rev.

NORdic trial of oral Methylprednisolone as add-on therapy to Interferon beta-1a for treatment of relapsing-remitting Multiple Sclerosis (NORMIMS study): a randomised, placebo-controlled trial

Treatment of relapsing-remitting multiple sclerosis with interferon beta is only partly effective, and new more effective and safe strategies are needed. Our aim was to assess the efficacy of oral methylprednisolone as an add-on therapy to subcutaneous interferon beta-1a to reduce the yearly relapse rate in patients with relapsing-remitting multiple sclerosis. Methods: NORMIMS (NORdic trial of oral Methylprednisolone as add-on therapy to Interferon beta-1a for treatment of relapsing-remitting Multiple Sclerosis) was a randomised, placebo-controlled trial done in 29 neurology departments in Denmark, Norway, Sweden, and Finland. We enrolled outpatients with relapsing-remitting multiple sclerosis who had had at least one relapse within the previous 12 months despite subcutaneous interferon beta-1a treatment (44 microg three times per week). We randomly allocated patients by computer to add-on therapy of either 200 mg methylprednisolone or matching placebo, both given orally on 5 consecutive days every 4 weeks for at least 96 weeks. The primary outcome measure was mean yearly relapse rate. Primary analyses were by intention to treat. This trial is registered, number ISRCTN16202527. Findings: 66 patients were assigned to interferon beta and oral methylprednisolone and 64 were assigned to interferon beta and placebo. A high proportion of patients withdrew from the study before week 96 (26% [17 of 66] on methylprednisolone vs 17% [11 of 64] on placebo). The mean yearly relapse rate was 0.22 for methylprednisolone compared with 0.59 for placebo (62% reduction, 95% CI 39-77%; p<0.0001). Sleep disturbance and neurological and psychiatric symptoms were the most frequent adverse events recorded in the methylprednisolone group. Bone mineral density had not changed after 96 weeks. Interpretation: Oral methylprednisolone given in pulses every 4 weeks as an add-on therapy to subcutaneous interferon beta-1a in patients with relapsing-remitting multiple sclerosis leads to a significant reduction in relapse rate. However, because of the small number of patients and the high dropout rate, these findings need to be corroborated in larger cohorts

I am the smartest man I know: a Nobel laureate's difficult journey

A unique individual with a fascinating life story, Ivar Giaever is a scientist who won the Nobel Prize in Experimental Physics in 1973. In his own words, Giaever relates an absorbing tale of how important luck and good fortune have been in shaping his life. He narrates the story of an ordinary childhood in Norway and an unremarkable undergraduate career at university. After finishing his engineering degree, he served in the Norwegian army and married his childhood sweetheart, Inger Skramstad. His desire to make a better life for his new family led Ivar to Canada and then to the United States. Even without an advanced degree in a scientific field, Ivar was given the opportunity to work with cutting-edge scientific researchers at General Electric R&D in Schenectady, New York. While there, he completed his PhD at Rensselaer Polytechnic Institute — one of the nation's oldest technological universities. His work on superconductivity led to worldwide recognition and the Nobel Prize. This memoire is more than the story of an accomplished, world-renowned scientist: it is an engaging reminiscence of an independent, highly creative thinker and problem solver who loves games and puzzles, skiing and windsurfing, and time with friends and family. Dr Ivar Giaever's fascinating story intertwines his views on the nature of science, scientific processes, contemporary issues such as global warming, and the great benefits the Nobel Prize has afforded him. Written with humor and often tongue-in-cheek, "I am the Smartest Man I know" is one man's meditation on science, intellectual inquiry, and life itself