Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Preparation of phase change microcapsules with the enhanced photothermal performance

The performance of solar-thermal conversion systems can be improved by incorporation of encapsulated phase change materials. In this study, for the first time, CrodathermTM 60 as a phase change material (PCM) was successfully encapsulated within polyurea as the shell supporting material. While preparing the slurry samples, graphite nanoplatelet (GNP) sheets were also incorporated to enhance the thermal and photothermal properties of the prepared materials. The morphology and chemical properties of these capsules were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrum, respectively. The results show the spherical-like and core-shell structure of capsules with an average diameter size of 3.34 μm. No chemical interaction was observed between the core and the supporting materials. The thermal characteristics of the microencapsulated PCMs (MEPCMs), analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), indicate that the prepared samples with 0.1 weight percentage of GNP possess the latent heat of 95.5 J/g at the phase transition temperature of about 64 °C. Analyzing the rheological properties of the prepared slurry with 16 wt % of MEPCMs proves that the prepared material meet the requirements given by the heat transfer applications. The thermal storage capacity, good thermal stability, and improved photothermal performance of the prepared material make it a potential candidate for using in direct absorption solar thermal applications

Preparation of Phase Change Microcapsules with the Enhanced Photothermal Performance

The performance of solar-thermal conversion systems can be improved by incorporation of encapsulated phase change materials. In this study, for the first time, CrodathermTM 60 as a phase change material (PCM) was successfully encapsulated within polyurea as the shell supporting material. While preparing the slurry samples, graphite nanoplatelet (GNP) sheets were also incorporated to enhance the thermal and photothermal properties of the prepared materials. The morphology and chemical properties of these capsules were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrum, respectively. The results show the spherical-like and core-shell structure of capsules with an average diameter size of 3.34 μm. No chemical interaction was observed between the core and the supporting materials. The thermal characteristics of the microencapsulated PCMs (MEPCMs), analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), indicate that the prepared samples with 0.1 weight percentage of GNP possess the latent heat of 95.5 J/g at the phase transition temperature of about 64 °C. Analyzing the rheological properties of the prepared slurry with 16 wt % of MEPCMs proves that the prepared material meet the requirements given by the heat transfer applications. The thermal storage capacity, good thermal stability, and improved photothermal performance of the prepared material make it a potential candidate for using in direct absorption solar thermal applications

Polypyrrole Additional functions to bio-based façades

AbstractDue to the crisis of 2008 the construction and real estate market became more demand-driven. Architects, builders and developers are looking for high-quality solutions for the realization of sustainable buildings. Supplying SMEs experience an increasing demand for bio-based materials with lower environmental impact and additional functionality including smart functions. The development of sustainable products with higher added value is required to increase the innovation potential of the building and construction industries.Polypyrrole is a biopolymer with very interesting and yet relatively unexplored features for construction. By applying PPY to bio-based carrier materials, like wood, bamboo or bio-composites, environmentally friendly building products can be realized with multiple features. In this paper an inventory will be given of potential (smart) functions that can be added to bio-based building materials treated with PPY. Functions discussed will be the protection against micro-organisms and UV-radiation. It will allow the realization of biological multifunctional building façades without using environmentally harmful substances.Finally the adding of (smart) functions will be discussed as strategy to introduce new bio-based building components to the market. Here they will have to compete with existing products already known by the different building professionals

Encapsulation of salt hydrates by polymer coatings for low-temperature heat storage applications

Efficient and cheap storage of energy from renewable resources presents a key technology to facilitate the ongoing energy transition. Storing heat in thermochemical materials (TCMs), such as salt hydrates, provides a promising concept to meet this demand. TCMs can capture heat reversibly and loss-free by relying on equilibrium hydration reactions of the salts. Persistent bottlenecks in the full-scale application of this technology are the low mechanical resilience of salt grains and their tendency to coagulate or dissolve when in contact with water vapor. To overcome this, the salt grains can be encapsulated by a stabilizing polymer coating. Ideal coatings combine high water vapor permeability with reversible deformability to minimize the resistance for water transport and to accommodate the volumetric changes of the TCM during repetitive (de)hydration, respectively. Here, a systematic study into the applicability of commercially available polymers as coating materials is presented. Mechanical analysis and wet-cup experiments on freestanding polymer films revealed that cellulose-based coatings successfully combine permeability and ductility and meet the engineering demands for domestic TCM-based heat storage applications. The validity of using freestanding films as model system was confirmed by encapsulating granular TCMs in ethyl and hydroxyl propyl cellulose using fluidized bed coating. The permeability was retained and an enhanced structural integrity of the TCM grains during (de)hydration cycles was observed

Fracture fixation in the operative management of hip fractures (FAITH): an international, multicentre, randomised controlled trial

Background Reoperation rates are high after surgery for hip fractures. We investigated the effect of a sliding hip screw versus cancellous screws on the risk of reoperation and other key outcomes. Methods For this international, multicentre, allocation concealed randomised controlled trial, we enrolled patients aged 50 years or older with a low-energy hip fracture requiring fracture fixation from 81 clinical centres in eight countries. Patients were assigned by minimisation with a centralised computer system to receive a single large-diameter screw with a side-plate (sliding hip screw) or the present standard of care, multiple small-diameter cancellous screws. Surgeons and patients were not blinded but the data analyst, while doing the analyses, remained blinded to treatment groups. The primary outcome was hip reoperation within 24 months after initial surgery to promote fracture healing, relieve pain, treat infection, or improve function. Analyses followed the intention-to-treat principle. This study was registered with ClinicalTrials.gov, number NCT00761813. Findings Between Mar