An Analysis of Etiological Factors for Traumatic Mandibular Osteomyelitis

Objective. The aim of this study was to analyze the factors that were associated with the development of osteomyelitis during the treatment of mandibular fractures. Material and Methods. The data of 3188 patients with mandibular fractures treated during 2002–2009 were analyzed. Traumatic osteomyelitis of the mandible was diagnosed in 207 patients. The background factors of complications were studied and compared with the control group (100 patients) not having complications after treatment of mandibular fractures. The data of clinical, roentgenologic, microbiological, and immunological investigations were analyzed. A logistic regression model was developed to identify the factors for osteomyelitis development. Results. The treatment in 6.5% of patients was complicated with osteomyelitis; 88.5% of these patients were men, and more than 80% of patients were younger than 50 years. In 86.8% of cases, Staphylococcus species were isolated, with Staphylococcus aureus accounting for 69.1% of cases. The following factors were found to be associated with osteomyelitis development: immunity dysfunction, caries-affected teeth at the fracture line, mobile fractured bones, bone fixation after more than 7 days following trauma, healthy teeth at the fracture line, insufficient bone reposition, and bone fixation after 3–7 days following trauma. Conclusion. Comparative analysis of factors influencing the treatment results revealed a great importance of immunological and dental status and microflora at the affected site. Insufficient or late reposition and fixation of fractured bone fragments play a significant role in the healing process

Femtosecond laser-ablated copper surface as a substrate for a MoS2-based hydrogen evolution reaction electrocatalyst

One of the methods to improve the performance of a heterogeneous electrocatalyst is the dispersion of a catalytic material on a suitable substrate. In this study, femtosecond laser ablation was used to prepare very rough but also ordered copper surfaces consisting of vertical, parallel ridges. Then, a molybdenum sulfide coating was electrochemically deposited onto these surfaces. It was observed by profilometry that the average roughness of the surface after coating with MoS2 had decreased, but the developed surface area still remained significantly larger than the projected surface area. The electrodes were then used as an electrocatalyst for the hydrogen evolution reaction in acidic media. These were highly efficient, reaching 10 mA cm−2 of HER current at a −181 mV overpotential and a Tafel slope of ~39 mV dec−1. Additionally, scanning electrochemical microscopy was used to observe whether hydrogen evolution would preferentially occur in certain spots, for example, on the peaks, but the obtained results suggest that the entire surface is active. Finally, the electrochemical impedance spectroscopy data showed the difference in the double-layer capacitance between the ablated and non-ablated surfaces (up to five times larger) as well as the parameters that describe the improved catalytic activity of fs-Cu/MoS2 electrodes