Objective and Importance:
Instrumentation has become an integral component in the management of various spinal pathologies. The rate of infection varies from 2% to 20% of all instrumented spinal ...procedures. Postoperative spinal implant infection places patients at risk for pseudo-arthrosis, correction loss, spondylodiscitis, and adverse neurological sequelae and increases health-care costs.
Materials and Methods:
We performed a cohort study of 1065 patients who underwent instrumented spinal procedures in our institution between 1995 and 2014. Fifty-one patients (4.79%) contracted postoperative spinal infection. Isolated bacterial species, infection severity, diagnosis/treatment timing, surgical/medical strategy treatment, and patient's medical background were evaluated to assess their relationship with management outcome.
Results:
Multiple risk factors for postoperative spinal infection were identified. Infections may be early or delayed. C-reactive protein and magnetic resonance imaging are important diagnostic tools. Prompt diagnosis and aggressive therapy (debridement and parenteral antibiotics) were responsible for implant preservation in 49 of 51 cases, whereas implant removal noted in two cases was attributed to delayed treatment and uncontrolled infection with implant loosening or late infection with spondylodesis. Infection in the setting of instrumentation is more difficult to diagnose and treat due to biofilm.
Conclusion:
Retention of the mechanically sound implants in early-onset infection permits fusion to occur, whereas delayed treatment and multiple comorbidities will most likely result in a lack of effectiveness in eradicating the infecting pathogens. An improved understanding of the role of biofilm and the development of newer spinal implants has provided insight into the pathogenesis and management of infected spinal implants. It is important to accurately identify and treat postoperative spinal infections. The treatment is multimodal and prolonged.
Energy density, safety, and simple and environmentally friendly preparation methods are very significant aspects in the realization of a compact supercapacitor. Herein we report the use of a ...supercritical CO
-assisted gel drying process (SC-CO
) for the preparation of porous electrodes containing dispersed graphene in a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) binder membrane to sandwich in a new portable supercapacitor based on graphene oxide (GO). A GO loading of 60 wt.% was found to give the best combination of factors (porosity, wettability, mechanical and electrochemical properties). Cycling voltammetry and charge/discharge studies showed an excellent capacitance behaviour and stability in an ionic liquid electrolyte, suggesting SC-CO
processing as a promising platform to produce highly bulky and porous films for supercapacitors. The supercapacitor device delivers a very high energy density of 79.2 Wh kg
at a power density of 0.23 KW kg
(current density 0.5 A g
, specific capacitance 36.2 F g
) while that of steel remains at 50.3 Wh kg
at a power density of 2.8 KW kg
(current density 6 A g
, specific capacitance 23.5 F g
).
In this paper, we present a novel and stable electrochemical sensor made of a magnetite/graphene oxide (Fe3O4/rGO) nanocomposite. It was deposited on a glassy carbon electrode for electroanalytical ...detection of As3+, via cyclic voltammetry and square wave anodic stripping voltammetry in phosphate buffer solutions. The electrode shows a very good relation between current response and amount of arsenic in a concentration of pollutants ranging from micromolar to nanomolar. Our sensor is easy to use, inexpensive and has allowed sensitive detection of As in non-acidic media (pH=7).
In this paper, we report a systematic comparison of carbon nanotubes (CNTs) and graphene oxide (GO) adsorption and desalination efficiency at different oxidation level under electrochemical ...conditions. Particular care has been devoted to the evaluation of the energy storage performance, through a comparison with the capacitive behavior in a typical aqueous electrolyte, a solution 1M of H2SO4. The specific capacitance calculated from the Cyclic Voltammetry (CV) curve at 2mV/sec for as produced purified CNTs (CNTp), highly hydrophilic CNTs (CNTf), partially reduced CNTf (CNTftt) and GO in H2SO4 are respectively 160 F/g, 356 F/g,298 F/g and 145 F/g. We evaluate for our nanomaterials high capacitive deionization (CDI), we also demonstrate that although surface functional groups are essential to provide better contact between electrode and electrolyte leading to high capacitance, however a more preserved electrical structure allows to obtain higher performance (e.g. 135 F/g and 185 F/g for CNTf and CNTftt, respectively).
Porous graphene oxide (GO) structures at different oxidation levels have been obtained by a SC-CO sub(2) assisted process performed at 200 bar, 35 degree C and different durations up to 24 h. ...Supercritical CO sub(2) processing was aimed at exfoliating and reducing graphene oxide. Different techniques were used to characterize the materials obtained: transmission electron microscopy (TEM), Raman and FT-IR Spectroscopy, X-ray diffraction analysis and N sub(2) adsorption-desorption at 77 K. The materials with high surface area up to 930 m super(2)/g, obtained after SC-CO sub(2) treatment, exhibited unique mesoporous structure based on curve graphene sheets and a high capacitive performance with values of 253 F/g at 1 A/g and of 210 F/g at 16 A/g; moreover, a good long cycle stability in aqueous electrolytes (higher than 90% after 2 10 super(3) cycles) has been also obtained. SC-CO sub(2) processing proved to be successful and simple to be realized, producing high performance materials, characterized by high specific surface areas and supercapacitive performances.
The purpose of this in vitro study was to compare the dimensional accuracy of the pickup impression technique using a modular individual tray (MIT) and using a standard individual tray (ST) for ...multiple internal-connection implants. The roles of both materials and geometric misfits were considered.
First, because the MIT relies on the stiffness and elasticity of acrylic resin material, a preliminary investigation of the resin volume contraction during curing and polymerization was done. Then, two sets of specimens were tested to compare the accuracy of the MIT (test group) to that of the ST (control group). The linear and angular displacements of the transfer copings were measured and compared during three different stages of the impression procedure. Experimental measurements were performed with a computerized coordinate measuring machine.
The curing dynamic of the acrylic resin was strongly dependent on the physical properties of the acrylic material and the powder/liquid ratio. Specifically, an increase in the powder/liquid ratio accelerated resin polymerization (curing time decreases by 70%) and reduced the final volume contraction by 45%. However, the total shrinkage never exceeded the elastic limits of the material; hence, it did not affect the coping's stability. In the test group, linear errors were reduced by 55% and angular errors were reduced by 65%.
Linear and angular displacements of the transfer copings were significantly reduced with the MIT technique, which led to higher dimensional accuracy versus the ST group. The MIT approach, in combination with a thin and uniform amount of acrylic resin in the pickup impression technique, showed no significant permanent distortions in multiple misalignment internal-connection implants compared to the ST technique.
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