Response of the unattached 218Po activity size distribution in H2O-SO2-N2 atmospheres.

The response of the unattached 218Po activity size distribution to variations in H2O and SO2 concentration was investigated in a high-purity N2 atmosphere. Lognormal size distributions were reconstructed from screen diffusion battery data using a random search and optimization procedure. For relative humidities of 1% to 90%, SO2 concentrations of 0-6 ppm, and residence times of 38 s, median diameters of the unattached mode ranged from 0.50 (+/- 0.04) to 0.80 (+/- 0.06) nm, corresponding to diffusion coefficients of 0.1-0.05 cm2 s-1. Increases in water vapor concentration resulted in an enhanced rate of ion neutralization and suppression of ion cluster formation. Decreases in cluster diameter with increasing humidity were therefore observed. Addition of SO2 at constant relative humidity resulted in an initial increase in diameter, with a subsequent decrease. Geometric standard deviations averaged 1.05 (+/- 0.01) to 1.06 (+/- 0.01) in all cases, with the unattached fraction comprising 83% to 88% of the total distribution. Results suggest that increases in water vapor concentration enhance neutralization in the immediate vicinity of the recoil path through water radiolysis. Conversion of OH to H2OSO4 on addition of SO2 provides a binary condensable phase capable of clustering around the ion at low relative humidities, increasing particle size. High H2O and SO2 concentrations enhance neutralization through electron scavenging and subsequent ion collision near the end of the recoil path, decreasing the number of available cluster sites and suppressing cluster formation. This reduction is more significant than the increasing size of the stable ion cluster, with increasing H2O and H2SO4 concentrations as predicted by Raes, resulting in decreases in both median diameter and distribution spread.     

Intraoperative radiotherapy (IORT) is an option for patients with localized breast recurrences after previous external-beam radiotherapy

Background  

For patients suffering of recurrent breast cancer within the irradiated breast, generally mastectomy is recommended. The normal tissue tolerance does not permit a second full-dose course of radiotherapy to the entire breast after a second breast-conserving surgery (BCS). A novel option is to treat these patients with partial breast irradiation (PBI). This approach is based on the hypothesis that re-irradiation of a limited volume will be effective and result in an acceptable frequency of side effects. The following report presents a single center experience with intraoperative radiotherapy (IORT) during excision of recurrent breast cancer in the previously irradiated breast.     

The laterally extended medial hemisoleus flap for reconstruction of a tibial wound in the distal third of the leg

A soleus flap as a local reconstructive option for soft-tissue coverage of a tibial wound in the distal third of the leg has never been well recognized. In a 2-year period, seven patients underwent reconstruction of a less extensive tibial wound (4 × 3 to 10 × 4 cm) in the distal third of the leg after orthopedic trauma with the laterally extended medial hemisoleus flap. The flap was elevated with emphasis on the preservation of the most distal perforators from the posterior tibial vessels to the flap as possible while allowing adequate rotation of the flap to cover the exposed tibia and/or hardware and on the possible preservation of foot planter flexion by reconstruction of the proximal Achilles’ tendon. In this series, there was no total or partial flap loss. All patients healed their tibial wounds primarily with reliable soft-tissue coverage, evidenced fracture healing, and good cosmetic outcome during follow-up. Thus, the laterally extended medial hemisoleus flap described by the author can be a reliable option for soft-tissue coverage of a less extensive tibial wound in the distal third of the leg. It offers a more cost-effective approach for managing this unique problem and can be performed by most reconstructive surgeons without microsurgical expertise.     

The effect of sucralfate,an agent for gastroprotection on the healing of split thickness skin graft donor sites

Skin is the most commonly used tissue for the transplantation. A meticulous care of the donor site is needed to prevent scarring, delayed healing, and pain. Various agents and dressing materials have been reported to help healing of skin graft donor sites. Sucralfate is an extensively used agent, which provides acute gastroprotection and acceleration of chronic ulcer healing. In this study, we assessed the effects of topical sucralfate on the healing of the split thickness skin graft donor sites in a prospective comparative way. The study was carried out on 32 randomly chosen patients undergoing surgery for various causes and requiring split thickness skin graft resurfacing. The upper halves of the skin graft donor sites on the thighs were simply covered with paraffin gauze and the lower half was covered with sucralfate-soaked paraffin gauzes. The day of full epithelization varied from 6 to 9 days and 8–12 days on the sucralfate-applied areas and on the control sites, respectively. The mean value of the healing was 7.01 days in the studied lower halves and 10.8 days in the upper halves. The healing rate was strikingly faster and less painful on the sucralfate-applied areas. We were able to discharge patients earlier than usual, and patients’ comfort increased. It seems that sucralfate is a promising topical agent to increase the healing rate and decrease the incidence of associated problems such as pain and hypertrophic scar.     

New wound protection for rabbits

Rabbits are the experimental animals of choice in many studies including flaps, wounds, and topical trials for new pharmacological agents. Because the topical drugs and other materials used for dressing are irritating to the animal, they tend to remove dressings, bandages, drapes, insensate flaps, and also topical drugs by scratching, licking, and biting if they are within the reach of the animal. In this study, we report an easy to prepare, user-friendly, comfortable, and cheap dressing protector called a dressing shield to prevent these problems.