Treatment of vascular leg ulcers with leukocyte- and platelet-rich fibrin (L-PRF): A systematic review.

Objectives: This systematic review aimed to assess the efficacy of Leukocyte- and Platelet-Rich Fibrin (L-PRF) for the treatment of vascular leg ulcers. Method: Following PRISMA guidelines, a literature search was done for studies where L-PRF was used to treat vascular leg ulcers. Results: Among six included articles, a total of 76 venous leg ulcers were treated with L-PRF. None of the studies included ulcers of arterial or lymphatic origin. Fifty-seven (75.0%) of the venous ulcers completely healed at end of follow-up. Mean time to complete healing was 6.7 weeks (SD = 5.0). All non-healed ulcers showed an important reduction in wound area. No adverse effects related to L-PRF therapy were reported. Conclusions: The results suggest that L-PRF could be a safe, simple to use and effective therapeutic option for the treatment of venous leg ulcers, however, caution is advised as the results are based on small sample sizes.

Experimental and numerical investigation of heat generation and surface integrity of ZrO2 bioceramics in grinding process under MQL condition.

Zirconia bioceramics has tremendous potential in medical applications owing to biocompatibility and high mechanical properties. Meanwhile, thermal damage and surface defects limit the grindability to achieve the desired properties. Therefore, this research provides an investigation of various grinding parameters on heat generation and surface morphology using a diamond wheel. In addition, a triangular and parabolic moving heat flux is used for heat distribution analysis based on FEM-model. The parabolic model more corresponds to experimental compared to the triangular heat flux, with an average deviation of <5% and 6.5% under dry and MQL, respectively. The response surface methodology is applied to extract a statistical representation of inputs and outputs. Dry grinding temperature obtained in range of 200-540 °C, which by applying MQL, it decreased by 16-35%. Increasing cutting depth would worsen the MQL efficiency in force and temperature. Results indicate the impact of cutting depth on temperature and force is greatest, followed by the effect of feed-rate, and that of wheel speed is the least. Thus, the increasing feed-rate should be utilized to preserve the high removal rate. SEM images indicate material removal mechanism is accomplished by plastic and brittle mode. Furthermore, MQL and a combination of low depth of cut could effectively decline the surface roughness and defects formation by decreasing the brittle material removal mechanism in one step. MQL reduced surface roughness by 46% compared with dry grinding, so that its performance increase in higher cutting depth. Because at higher cutting depths, the MQL changes the prevailing chip removal mechanism from brittle to ductile-regime grinding.

Optimization and benchmarking of the thermal cycling algorithm.

Optimization plays a significant role in many areas of science and technology. Most of the industrial optimization problems have inordinately complex structures that render finding their global minima a daunting task. Therefore, designing heuristics that can efficiently solve such problems is of utmost importance. In this paper we benchmark and improve the thermal cycling algorithm [Phys. Rev. Lett. 79, 4297 (1997)PRLTAO0031-900710.1103/PhysRevLett.79.4297] that is designed to overcome energy barriers in nonconvex optimization problems by temperature cycling of a pool of candidate solutions. We perform a comprehensive parameter tuning of the algorithm and demonstrate that it competes closely with other state-of-the-art algorithms such as parallel tempering with isoenergetic cluster moves, while overwhelmingly outperforming more simplistic heuristics such as simulated annealing.