Damping and the Hartree Ensemble Approximation

We study a Hartree ensemble approximation for real-time dynamics in the toy model of 1+1 dimensional scalar field theory. Damping behavior seen in numerical simulations is compared with analytical predictions based on perturbation theory in the original (non-Hartree-approximated) model

Measuring the Pressure in the Superficial Inferior Epigastric Vein to Monitor for Venous Congestion in Deep Inferior Epigastric Artery Perforator Breast Reconstructions: A Pilot Study

During deep inferior epigastric artery perforator (DIEP) flap dissection, we noted that in many cases the superficial vein on the ipsilateral side of the flap was engorged and tense, and in others, it was empty. This led us to believe that the pressure is increased as the result of preferential outflow through the superficial vein in some cases, which could result in venous congestion of the flap if this vessel was not anastomosed. To test this hypothesis, we measured the venous pressure in the superficial venous system before and after flap dissection. The pressure in the superficial inferior epigastic vein of a DIEP flap was measured in 26 consecutive flaps to investigate the correlation between the pressure and venous congestion of the flap. The first measurement was performed at the beginning of the dissection, and the second measurement was taken after the flap had been completely raised on a single perforator. The mean increase in pressure after flap dissection was 10.6 mm Hg (mu = 10.6; range -1 to 31; O +/- 7.0 mm Hg). Clinical signs of venous congestion were observed in one case. In this case, the increase in venous pressure was with 31 mm Hg, also the highest. Although the results of this report are preliminary, they indicate that the pressure in the superficial vein of DIEP flaps might be of predictive value for venous congestion

Heme and menaquinone induced electron transport in lactic acid bacteria

<p>Abstract</p> <p>Background</p> <p>For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait.</p> <p>Results</p> <p>Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include <it>Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacilllus brevis, Lactobacillus paralimentarius, Streptococcus entericus </it>and <it>Lactococcus garviae</it>. The increased biomass production without further acidification, which are respiration associated traits, are suitable for high-throughput screening as demonstrated by the screening of 8000 <it>Lactococcus lactis </it>insertion mutants. Respiration-negative insertion-mutants were found with <it>noxA</it>, <it>bd</it>-type cytochrome and menaquinol biosynthesis gene-disruptions. Phenotypic screening and <it>in silico </it>genome analysis suggest that respiration can be considered characteristic for certain species.</p> <p>Conclusion</p> <p>We propose that the <it>cyd</it>-genes were present in the common ancestor of lactic acid bacteria, and that multiple gene-loss events best explains the observed distribution of these genes among the species.</p

Covering of an exposed vascular graft in the groin with an external oblique muscle rotational flap

Abdominal muscles, such as the oblique-and transverse muscles, find their blood supply from multiple segmental pedicles from the iliac artery. Besides its superior vascularization, its release is simple, leaving two abdominal muscles for securing abdominal wall strength. The release of the muscle and coverage of the graft requires partial muscle mobilization and is a minor reconstruction, but extension of the mobilization cranially enables coverage of larger defects. We present a case of an infected vascular graft in the groin successfully preserved through coverage with an external oblique muscle flap

Preoperative CT angiography reduces surgery time in perforator flap reconstruction

The use of perforator flaps in breast reconstructions has increased considerably in the past decade. A disadvantage of the perforator flap is difficult dissection, which results in a longer procedure. During spring 2006, we introduced CT angiography (CTA) as part of the diagnostic work-up in perforator flap reconstructions to visualise each perforator more accuratety. The main objectives were to reduce surgery time and the number of complications. A chart review was conducted 1 year after CTA introduction to investigate if these objectives were met. Materials and methods: Patients with a deep inferior epigastric perforator (DIEP) flap who underwent preoperative analysis through CTA were retrospectively evaluated. The population Results: One hundred and thirty-eight DIEP breast reconstructions were done; 70 underwent preoperative CTA analysis, and 68 had preoperative Doppler investigation. Surgery time in the CTA group was significantly lower (P <0.001) than in the control group, 264 min (SD +/- 62) versus 354 min (SD +/- 83), respectively. There was a tendency for fewer complications in the CTA group compared with the control group. All flaps were successful in the CTA group. In the control group, one flap failed and partial necrosis occurred in three flaps. The differences were not statistically significant. Conclusions: Preoperative CTA in the assessment of vascular anatomy during perforator flap reconstruction was safe and reliable. It helped reduce surgery time, and may prevent the number of postoperative complications. (C) 2008 Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons