Gaussian Tunneling Model of c-Axis Twist Josephson Junctions

We calculate the critical current density $J^J_c$ for c-axis Josephson tunneling between identical high temperature superconductors twisted an angle $\phi_0$ about the c-axis. We model the tunneling matrix element squared as a Gaussian in the change of wavevector q parallel to the junction, $<|t({\bf q})|^2>\propto\exp(-{\bf q}^2a^2/2\pi^2\sigma^2)$. The $J^J_c(\phi_0)/J^J_c(0)$ obtained for the s- and extended-s-wave order parameters (OP's) are consistent with the Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ data of Li {\it et al.}, but only for strongly incoherent tunneling, $\sigma^2\ge0.25$. A $d_{x^2-y^2}$-wave OP is always inconsistent with the data. In addition, we show that the apparent conventional sum rule violation observed by Basov et al. might be understandable in terms of incoherent c-axis tunneling, provided that the OP is not $d_{x^2-y^2}$-wave.Comment: 6 pages, 6 figure

Twelve Years Of Fluconazole In Clinical Practice: Global-Trends In Species Distribution And Fluconazole Susceptibility Of Bloodstream Isolates Of Candida

We determined the species distribution and in-vitro susceptibility of 6082 bloodstream infection (BSI)isolates ofCandidaspp. collected from 250 medical centres in 32 nations over a 10-year period from 1992through 2001. The species included 3401C. albicans, 984C. glabrata, 796C. parapsilosis, 585C. tropicalis,153C. krusei,67C. lusitaniae,48C. guilliermondii,10C. famata,10C. kefyr, sixC. pelliculosa, fiveC. rugosa,fourC. lipolytica, threeC.dubliniensis, threeC. inconspicua, twoC. sakeand one isolate each ofC. lambica,C. norvegensisandC. zeylanoides. Minimum inhibitory concentration determinations were made usingthe National Committee for Clinical Laboratory Standards reference broth microdilution method.Variation in the rank order and frequency of the different species ofCandidawas observed over time andby geographic area. The proportion of BSI due toC. albicansandC. glabrataincreased andC. parapsilosisdecreased over time in Canada, the USA and Europe.C. glabratawas an infrequent cause of BSI in LatinAmerica and the Asia-Pacific region. Very little variation in fluconazole susceptibility was observedamong isolates ofC. albicans,C. tropicalisandC. parapsilosis. These species accounted for 78%of all BSIand remained highly susceptible (91–100%susceptible) to fluconazole from 1992 to 2001 irrespective ofgeographic origin. The prevalence of fluconazole resistance amongC. glabrataisolates was variable bothover time and among the various countries and regions. Resistance to fluconazole amongC. glabrataisolates was greatest in the USA and varied by US census region (range 0–23%). These observations aregenerally encouraging relative to the sustained usefulness of fluconazole as a systemically activeantifungal agent for the treatment of candida BSI.Scopu