Ultra-lightweight superconducting wire based on Mg, B, Ti and Al.

Actually, MgB2 is the lightest superconducting compound. Its connection with lightweight metals like Ti (as barrier) and Al (as outer sheath) would result in a superconducting wire with the minimal mass. However, pure Al is mechanically soft metal to be used in drawn or rolled composite wires, especially if applied for the outer sheath, where it cannot provide the required densification of the boron powder inside. This study reports on a lightweight MgB2 wire sheathed with aluminum stabilized by nano-sized γ-Al2O3 particles (named HITEMAL) and protected against the reaction with magnesium by Ti diffusion barrier. Electrical and mechanical properties of single-core MgB2/Ti/HITEMAL wire made by internal magnesium diffusion (IMD) into boron were studied at low temperatures. It was found that the ultra-lightweight MgB2 wire exhibited high critical current densities and also tolerances to mechanical stress. This predetermines the potential use of such lightweight superconducting wires for aviation and space applications, and for powerful offshore wind generators, where reducing the mass of the system is required.

Factors affecting mortality rate with iliac vein injuries.

Over an 8-year period, 49 patients were treated for iliac vein injuries with 25 (51%) deaths. The iliac vein injuries and their mortality rates (MR) were: common iliac vein--40% (6/15), internal iliac vein--65% (9/14), external iliac vein--29% (4/14), and two or more iliac veins--100% (6/6). This MR (51%) was much higher than those (18% to 38%) found in other series. The factors associated with this significantly increased MR were: Trauma Score less than 11 (MR = 71% or 24/35), initial OR systolic BP less than 70 mm Hg (MR = 89% or 15/17), ISS greater than 28 (MR = 65% or 24/37), 10 or more units of blood in the first 24 hours (MR = 65% or 22/34), and no obtainable BP on admission to the ED (MR = 65% or 15/22). Although the overall calculated probability of survival (Ps) by TRISS methodology was 0.43, several deaths might have been prevented by more complete resuscitation including restoration of core temperature above 34 degrees or 35 degrees C, and by packing the pelvis and closing rather than allowing three or more separate additional hypotensive episodes to occur while attempting definitive control of bleeding vessels.

Predicting and preventing infection after abdominal vascular injuries.

Of 210 patients with major intra-abdominal vascular injuries, 111 (53%) survived more than 48 hours. Of these, 41 (37%) developed serious infections resulting in death or a hospital stay exceeding 14 days (mean, 55 +/- 49) in the 33 who survived. The most frequent serious infections were intraperitoneal and resulted in a 35% mortality rate (8/23). The 111 patients surviving 48+ hours were divided into two groups based on their initial E.D. BP and injuries. The "high-risk" patients (with no obtainable blood pressure on admission, five or more injuries or a colon injury with a systolic BP of 40 to 89 mm Hg) had a serious infection rate of 63% (25/40). This was significantly higher than the serious infection rate of 23% (16/71) in the remaining 71 "low-risk" patients (p less than 0.001). The patients were then evaluated for factors which surgeons might control. In the high-risk group, resuscitation adequate to produce an initial operating room (O.R.) systolic BP greater than 70 mm Hg and early control of bleeding so that less than 10 units of blood were used resulted in a serious infection rate of only 20% (2/10) versus 77% (23/30) in the other high-risk patients (p less than 0.01). In the low-risk patients, having an initial O.R. systolic BP greater than 70 mm Hg and using less than 10 units of blood resulted in a serious infection rate of 13% (6/48) versus 43% (10/23) in the others (p less than 0.05). High-risk patients failing to meet these resuscitation goals must be watched particularly carefully for development of infections.