The complex of apomyoglobin with the fluorescent dye coumarin 153.

Understanding a protein's dielectric response requires both a theoretical model and a well-defined experimental system. The former has already been proposed by Song (J. Chem. Phys. 116, 9359 [2002]). We suggest that the latter is provided by the complex of coumarin 153 (C153) with apomyoglobin (ApoMb). C153 has been exhaustively studied and has proven to be an excellent probe of the solvation dynamics of polar solvents. Myoglobin is one of the most thoroughly studied proteins. Myoglobins from a wide range of species have been subject to X-ray structural analysis and site-directed mutagenesis. Here, we demonstrate the existence of a robust C153-apomyglobin system by means of molecular dynamics simulations, equilibrium binding studies using a Job's plot and capillary electrophoresis, circular dichroism and time-resolved fluorescence. The reorganization energy of C153 bound to ApoMb is compared with that of C153 in bulk solvent using the method of Jordanides et al. (J. Phys. Chem. B 103, 7995 [1999]).

Tetralogy of Fallot: what operation, at which age.

BACKGROUND: The optimal management of tetralogy of Fallot is still under debate, particularly with respect to surgical approach and the age of operation. In recent times a transatrial-transpulmonary approach and primary repair in younger patients is favoured. The purpose of the present study was to analyze the result of our current surgical management by assessing the perioperative and intermediate term follow up in order to define the optimal strategy and timing of operation for our institution. METHODS: One hundred and thirty two patients with tetralogy of Fallot who underwent definitive repair between May 1993 and December 1998 were analyzed by reviewing their medical records and follow-up. Median age was 15. 5 (2.3-68.6) months and median weight was 8.8 (5-16) kg. Ten (7.57%) patients were under 6 months, 38 (28.78%) were between 6 and 12 months, 36 (27.27%) were between 12 and 18 months, 23 (17.42%) were between 18 and 24 months and 25 (18.93%) were more than 24 months age. During the study period there was a move to earlier surgery and differing methods of repair depending on the anatomy observed. Follow up was conducted by the referring cardiologist. Median follow up was 35.48 (8.07-74.93) months. RESULTS: Forty-two (31.8%) patients required a palliative procedure before total correction due to unfavourable anatomy. Subpulmonary infundibular obstruction with a fibrous component increased significantly with age (P<0.05). Operations were entirely transatrial in 14 (10.6%), transatrial and transpulmonary in 69 (52.2%), transatrial and transventricularly in 42 (31.8%) and a homograft conduit was used in seven (5.3%) patients. Younger patients had narrower pulmonary valves and required a transannular patch more frequently. All patients were in sinus rhythm, 28 (21.1%) showing right bundle branch block. Median hospital stay was 8 (5-54) days. No patient required reintervention during follow up and there was no early or late mortality. CONCLUSION: Correction of tetralogy of Fallot at younger age does not increase morbidity or mortality and has potential advantages. A surgical technique adapted to the anatomy of the right ventricular outflow tract, achieves the best results.

Stellar interferometer for figure sensing of orbiting astronomical telescopes.

An interferometric device designed to be located in the focal plane of a large astronomical telescope is presented. The prime application is for the forthcoming large space telescope. The device is to perform interferometry on the optical wavefront arising from a single star after it has propagated through the telescope. The concept of a focal plane figure sensor has been experimentally verified by fabricating and testing an operating laboratory breadboard figure sensor. A set of linear independent control equations are derived that define the operations for utilizing a focal plane figure sensor in the control loops for the positioning of the secondary mirror and for the active control of the primary mirror optical figure. A number of scientific experiments that could be preformed with the interferometer are also briefly discussed.