Ascertainment of cause-specific mortality in COPD - operations of the TORCH clinical endpoint Committee

Background: TORCH (Towards a Revolution in COPD Health) is an international multicentre, randomised, placebo-controlled clinical trial of inhaled fluticasone propionate/salmeterol combination treatment and its monotherapy components for maintenance treatment of moderately to severely impaired patients with chronic obstructive pulmonary disease (COPD). The primary outcome is all-cause mortality. Cause-specific mortality and deaths related to COPD are additional outcome measures, but systematic methods for ascertainment of these outcomes have not previously been described. Methods: A Clinical Endpoint Committee (CEC) was tasked with categorising the cause of death and the relationship of deaths to COPD in a systematic, unbiased and independent manner. The key elements of the operation of the committee were the use of predefined principles of operation and definitions of cause of death and COPD-relatedness; the independent review of cases by all members with development of a consensus opinion; and a substantial infrastructure to collect medical information. Results: 911 deaths were reviewed and consensus was reached in all. Cause-specific mortality was: cardiovascular 27%, respiratory 35%, cancer 21%, other 10% and unknown 8%. 40% of deaths were definitely or probably related to COPD. Adjudications were identical in 83% of blindly re-adjudicated cases ( = 0.80). COPD-relatedness was reproduced 84% of the time ( = 0.73). The CEC adjudication was equivalent to the primary cause of death recorded by the site investigator in 52% of cases. Conclusion: A CEC can provide standardised, reliable and informative adjudication of COPD mortality that provides information which frequently differs from data collected from assessment by site investigators.

Room-temperature ionic liquids as replacements for organic solvents in multiphase bioprocess operations

Organic solvents are widely used in a range of multiphase bioprocess operations including the liquid-liquid extraction of antibiotics and two-phase biotransformation reactions. There are, however, considerable problems associated with the safe handling of these solvents which relate to their toxic and flammable nature. In this work we have shown for the first time that room-temperature ionic liquids, such as 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6], can be successfully used in place of conventional solvents for the liquid-liquid extraction of erythromycin-A and for the Rhodococcus R312 catalyzed biotransformation of 1,3-dicyanobenzene (1,3-DCB) in a liquid-liquid, two-phase system. Extraction of erythromycin with either butyl acetate or [bmim][PF6] showed that values of the equilibrium partition coefficient, K, up to 20-25 could be obtained for both extractants. The variation of K with the extraction pH was also similar in the pH range 5-9 though differed significantly at higher pH values. Biotransformation of 1,3-DCB in both water-toluene and water-[bmim][PF6] systems showed similar profiles for the conversion of 1,3-DCB initially to 3-cyanobenzamide and then 3-cyanobenzoic acid. The initial rate of 3-cyanobenzamide production in the water-[bmim][PF6] system was somewhat lower, however, due to the reduced rate of 1,3-DCB mass transfer from the more viscous [bmim] [PF,] phase. it was also shown that the specific activity of the biocatalyst in the water-[bmim][PF6] system was almost an order of magnitude greater than in the water-toluene system which suggests that the rate of 3-cyanobenzamide production was limited by substrate mass transfer rather than the activity of the biocatalyst. (C) 2000 John Wiley & Sons, Inc.

Millimeter-Wave Soldier-to-Soldier Communications for Covert Battlefield Operations

Mobile ad hoc networking of dismounted combat personnel is expected to play an important role in the future of network-centric operations. High-speed, short-range, soldier-to-soldier wireless communications will be required to relay information on situational awareness, tactical instructions, and covert surveillance related data during special operations reconnaissance and other missions. This article presents some of the work commissioned by the U. K. Ministry of Defence to assess the feasibility of using 60 GHz millimeter-wave smart antenna technology to provide covert communications capable of meeting these stringent networking needs. Recent advances in RF front-end technology, alongside physical layer transmission schemes that could be employed in millimeter-wave soldier-mounted radio, are discussed. The introduction of covert communications between soldiers will require the development of a bespoke directive medium access layer. A number of adjustments to the IEEE 802.11 distribution coordination function that will enable directional communications are suggested. The successful implementation of future smart antenna technologies and direction of arrival-based protocols will be highly dependent on thorough knowledge of transmission channel characteristics prior to deployment. A novel approach to simulating dynamic soldier-to-soldier signal propagation using state-of-the-art animation-based technology developed for computer game design is described, and important channel metrics such as root mean square angle and delay spread for a team of four networked infantry soldiers over a range of indoor and outdoor environments is reported.

Millimeter-wave stealth radio for special operations forces

For Special Operations Forces, an important attribute of any future radio will be the ability to conceal transmissions from the enemy while transmitting large amounts of data for situational awareness and communications. These requirements will mean that military wireless systems designers will need to consider operating frequencies in the mm-wave bands: The high data rates that are achievable at these frequencies and the propagation characteristics at this wavelength will provide many benefits for the implementation of 'stealth radio'. This article discusses some of the recent advances in RF front-end technology, alongside physical layer transmission schemes that could be employed for millimeter-wave soldier-mounted radio. The operation of a hypothetical millimeter-wave soldier-to-soldier communications system that makes use of smart antenna technology is also described.