RESUMEN
Artificial spin ice (ASI) are nanomagnetic metamaterials with a wide range of emergent properties. Through local interactions, the magnetization of the nanomagnets self-organize into extended magnetic domains. However, controlling when, where and how domains change has proven difficult, yet is crucial for technological applications. Here, we introduce astroid clocking, which offers significant control of ASI dynamics in both time and space. Astroid clocking unlocks a discrete, step-wise and gradual dynamical process within the metamaterial. Notably, our method employs global fields to selectively manipulate local features within the ASI. Sequences of these clock fields drive domain dynamics. We demonstrate, experimentally and in simulations, how astroid clocking of pinwheel ASI enables ferromagnetic domains to be gradually grown or reversed at will. Richer dynamics arise when the clock protocol allows both growth and reversal to occur simultaneously. With astroid clocking, complex spatio-temporal behaviors of magnetic metamaterials become easily controllable with high fidelity.
RESUMEN
Invasive group A streptococcal infection is an uncommon but severe disease. Bloodcultures usually yield growth of Streptococcus pyogenes and the bacteria may also be isolated from sterile sites e.g. muscle or pleura. The most serious manifestation is Streptococcal Toxic Shock Syndrome (STSS) with or without necrotizing fasciitis (NF). This condition may occur in about a fifth of the cases with a very high case-fatality rate. Preclinical data and case reports suggest that the fatality rate can be reduced by treatment of high-dose intravenous immunoglobulin. A European placebo-controlled clinical trial with immunoglobulin has been conducted but was prematurely terminated due to difficulties in patient recruitment. In our clinic we have during the last 3.5 years seen 41 patients with invasive group A streptococcal infection and 11 of these have received high-dose immunoglobulin. The indication for that treatment has been hypotension and multiorgan failure. All 11 patients but one fullfilled the criteria for STSS and 5 had NF. Most of the patients were treated with a single dose intravenous infusion of 50 g immunoglobulin. All patients were treated with both benzylpenicillin and clindamycin. Ten patients were fully recovered--case-fatality rate 9 percent. We suggest that patients with invasive group A streptococcal infections who develop STSS with or without NF should be treated with high-dose intravenous immunoglobulin.