Current treatment of infected non-union after intramedullary nailing

Publication date: Available online 9 May 2017
Source:Injury
Author(s): H. Simpson, S.T.J. Tsang
Non-union is a devastating consequence of a fracture. Non-unions cause substantial patient morbidity with patients suffering from loss of function of the affected extremity, increased pain, and a substantial decrease in the quality of life. The management is often associated with repeated, unsuccessful operations resulting in prolonged hospital stays, which has social and economic consequences to both the patient and the healthcare system. The rates of non-union following intramedullary (IM) nailing vary according to anatomical location. There is currently no consensus regarding the treatment of infected non-unions following IM nailing, but the most common procedures reported are; exchange IM nail with antibiotic suppression or excision of the non-union, (stabilisation with external fixation or less commonly plate or IM nail) and then reconstruction of the bone defect with distraction osteogenesis or the Masquelet technique. This article explores the general principles of treatment, fixation modalities and proposes a treatment strategy for the management of infected non-unions following intramedullary nailing.



http://ift.tt/2pBOqg3

Technical considerations to avoid delayed and non-union

Publication date: Available online 9 May 2017
Source:Injury
Author(s): Tristan E. McMillan, Alan J. Johnstone
For many years intramedullary nails have been a well accepted and successful method of diaphyseal fracture fixation. However, delayed and non unions with this technique do still occur and are associated with significant patient morbidity. The reason for this can be multi-factorial. We discuss a number of technical considerations to maximise fracture reduction, fracture stability and fracture vascularity in order to achieve bony union.



http://ift.tt/2q5Tg87

Virtual Virus, a Semester–long Interdisciplinary Project on the Crossroads of Creativity and Knowledge Integration

<span class="paragraphSection"><div class="boxTitle">Abstract</div>Virtual virus is a semester–long interdisciplinary project offered as part of upper level elective course in Virology. Students are challenged to apply key concepts from multiple biological sub-disciplines to 'synthesize' a plausible virtual virus. The project is executed as a scaffolded series of hands-on sessions and mini-projects which are integrated into continuous story leading to mock conference presentation and comprehensive report modeling article publication. It complements classroom instruction helping students to meet overarching learning targets traditionally associated undergraduate virology courses such as: viral structure and function, mode of viral propagation and flow of genetic information, and virus/host interactions on the cellular and organismal level. Formal instructor and informal peer feedback were used as tools to prompt reflection and guide revisions of the final report. Student learning gains and attitudes toward the approach were studied by evaluating project work product and end of the semester survey. Outcome analysis demonstrated that students exit the course with elaborated conceptual understanding of viruses and ownership of their work. The project can be viewed as an approach to model the process of scientific discovery in fast-forward mode by combining active learning, creativity and problem solving to assemble and communicate a virtual virus story.</span>

http://ift.tt/2qVQvYa

Carbon utilization profiles of river bacterial strains facing sole carbon sources suggest metabolic interactions

<span class="paragraphSection"><div class="boxTitle">Abstract</div>Microbial communities play a key role in water self-purification. They are primary drivers of biogenic element cycles and ecosystem processes. However, these communities remain largely uncharacterized. In order to understand the diversity-heterotrophic activity relationship facing sole carbon sources, we assembled a synthetic community composed of 20 'typical' freshwater bacterial species mainly isolated from the Zenne River (Belgium). The carbon source utilization profiles of each individual strain and of the mixed community were measured in Biolog Phenotype MicroArrays PM1 and PM2A microplates that allowed testing 190 different carbon sources. Our results strongly suggest interactions occurring between our planktonic strains as our synthetic community showed metabolic properties that were not displayed by its single components. Finally, the catabolic performances of the synthetic community and a natural community from the same sampling site were compared. The synthetic community behaved like the natural one and was therefore representative of the latter in regard to carbon source consumption.</span>

http://ift.tt/2pzQbK7

Using Self-Assessment to Develop Metacognition and Self-Regulated Learners

<span class="paragraphSection"><div class="boxTitle">Abstract</div>Student success is too often challenged by a lack of metacognition and ability to self-regulate learning. This commentary argues that the use of self-assessment to increase student metacognition positively impacts student learning and self-regulation. In addition, several strategies for incorporating self-assessment will be presented.</span>

http://ift.tt/2qW04WX

Optical, Thermal, and Mechanical Characterization of Ga2Se3-Added GLS Glass

Gallium lanthanum sulfide glass (GLS) has been widely studied in the last 40 years for middle-infrared applications. In this work, the results of the substitution of selenium for sulphur in GLS glass are described. The samples are prepared via melt-quench method in an argon-purged atmosphere. A wide range of compositional substitutions are studied to define the glass-forming region of the modified material. The complete substitution of Ga₂S₃ by Ga₂Se₃ is achieved by involving new higher quenching rate techniques compared to those containing only sulfides. The samples exhibiting glassy characteristics are further characterized. In particular, the optical and thermal properties of the sample are investigated in order to understand the role of selenium in the formation of the glass. The addition of selenium to GLS glass generally results in a lower glass transition temperature and an extended transmission window. Particularly, the IR edge is found to be extended from about 9 µm for GLS glass to about 15 µm for Se-added GLS glass defined by the 50% transmission point. Furthermore, the addition of selenium does not affect the UV edge dramatically. The role of selenium is hypothesized in the glass formation to explain these changes.

Theresults of the addition of Se to gallium lanthanum sulfide(GLS) glass through the substitution of Ga₂S₃ by Ga₂Se₃ are described. An innovative open melting apparatus is used. The addition of selenium to GLS glass generally results in a lower glass transition temperature and an extended transmission window up to 15 µm with minor effect on the visible transmission.

http://ift.tt/2qVrrkg

Vertically Aligned Niobium Nanowire Arrays for Fast-Charging Micro-Supercapacitors

Planar micro-supercapacitors are attractive for system on chip technologies and surface mount devices due to their large areal capacitance and energy/power density compared to the traditional oxide-based capacitors. In the present work, a novel material, niobium nanowires, in form of vertically aligned electrodes for application in high performance planar micro-supercapacitors is introduced. Specific capacitance of up to 1 kF m⁻² (100 mF cm⁻²) with peak energy and power density of 2 kJ m⁻² (6.2 MJ m⁻³ or 1.7 mWh cm⁻³) and 150 kW m⁻² (480 MW m⁻³ or 480 W cm⁻³), respectively, is achieved. This remarkable power density, originating from the extremely low equivalent series resistance value of 0.27 Ω (2.49 µΩ m² or 24.9 mΩ cm²) and large specific capacitance, is among the highest for planar micro-supercapacitors electrodes made of nanomaterials.

Fast-charging micro-supercapacitors are made from vertically aligned niobium nanowire arrays. Thanks to the high electrical conductivity of the nanowires, the micro-supercapacitor exhibits a very small characteristic relaxation time constant of 8.4 ms. With 1 m sulfuric acid, cycling rates of up to 300 V s⁻¹ are achieved while with 1-ethyl-3-methylimidazolium tetrafluoroborate an operating voltage of up to 4 V is obtained.

http://ift.tt/2q5s49k