Force attractor in confined comminution of granular materials.

We reveal a novel attractor in the space of contact forces that bounds the behavior of granular materials during confined comminution. The attractor is reached asymptotically as the porosity reduces and the grain size distribution attains an ultimate power law scaling. The ultimate distribution of the contact forces follows a clear log-normal distribution, distinctively different from previous observations in uncrushable systems. Supporting evidence comes both from comprehensive discrete element simulations and a theoretical Apollonian model.

Use of autologous dermal flap as mesh coverage in the treatment of large abdominal-wall defect in patients following massive weight loss: presentation of a novel surgical technique.

PURPOSE: Reconstruction of large abdominal-wall defects (AWD) in patients after massive weight loss (MWL) can be challenging. Patients are left with a sizeable amount of excess skin and subcutaneous tissue which can serve as a natural and readily available source of mesh coverage. In this article, we present our experience in the reconstruction of large AWD in patients after MWL, using autogenous dermal flaps combined with a synthetic mesh. METHOD: All patients with large AWD and MWL, diagnosed between January 2012 and December 2016, were considered to be candidates for the procedure. During the operation, an attempt was made to attain full closure of the defect above the mesh. In those patients for whom such closure was not possible, a dermal flap technique was used. Patients were closely monitored for at least 1 year. Outcome measures included early and late postoperative complications. Data are presented as mean ± standard deviation (SD). RESULTS: Over the study period, a total of 14 patients underwent a surgery involving combined mesh and dermal flap technique. Early post-operative complications included three patients who suffered from minor wound disruption and were treated with local dressings. One patient had an abdominal-wall hematoma that required an evacuation. Two patients suffered from an epidermal cyst and chronic sinuses that required surgical debridement. None of the patients experienced intra-abdominal complication, respiratory failure, or required ICU treatment. No mesh contamination or hernia recurrence was observed during the follow-up period of 22.25 ± 6.4 months. CONCLUSION: Autologous dermal flap combined with mesh technique may serve as an effective surgical alternative in patients after MWL with large AWD for whom full muscular coverage of the underlying prosthesis is not possible.

RNase III stimulates the translation of the cIII gene of bacteriophage lambda.

The bacteriophage lambda cIII gene product regulates the lysogenic pathway by stabilizing the lambda cII regulatory protein. Our results show that the expression of the lambda cIII gene is subject to specific requirements. Tests of a set of cIII-lacZ gene and operon fusions reveal that a sequence upstream of the cIII ribosome binding site is needed for cIII translation. The sequence contains an inefficient RNase III processing site. Furthermore, expression of cIII is drastically reduced in cells lacking RNase III. We have isolated a phage carrying a mutation (r1), which lies in the upstream sequence, that leads to a reduction in cIII translation and inactivates the RNase III processing site. The r1 mutant is nevertheless still dependent on RNase III for cIII translation; r1 reduces cIII translation by a factor of 3 in wild-type cells and by a factor of approximately equal to 30 in an RNase III mutant host. We propose that RNase III stimulates cIII translation by binding to the upstream sequence and thereby exposing the cIII ribosome binding site. This stimulation does not involve RNA cleavage. Consistent with this hypothesis is our finding that, in vitro, unprocessed cIII mRNA is translated, whereas RNase III-cleaved cIII mRNA is not.

The effect of cyclophosphamide on rat blastocysts in vitro and their subsequent development following transfer to pseudopregnant rats.

These investigations were undertaken to assess the effects of cyclophosphamide (CPA) on rat blastocysts. In the first set of experiments, blastocysts were exposed to 100 micrograms/ml CPA in culture for 48 h. In the second experiment, blastocysts were cultured for 48 h following injection of 20 or 40 mg/kg of CPA to pregnant rats on day 4 of gestation. In the third experiment, blastocysts were cultured for 2 h in the presence of 100 micrograms/ml of CPA and then transferred to pseudopregnant rats. The results from the first experiment revealed a clear toxic effect of CPA on blastocysts following culture. A similar effect occurred when blastocysts were harvested and cultured following in vivo injections of CPA. In the third experiment a clear embryotoxic effect (larger number of resorptions and retarded embryos in comparison to control) was found on day 13 of gestation. The origin of activation of CPA by the blastocysts could not be ascertained from the above results.