15 research outputs found
Postoperative spinal infection mimicking systemic vasculitis with titanium-spinal implants
<p>Abstract</p> <p>Background</p> <p>Secondary systemic vasculitis after posterior spinal fusion surgery is rare. It is usually related to over-reaction of immune-system, to genetic factors, toxicity, infection or metal allergies.</p> <p>Case Description</p> <p>A 14 year-old girl with a history of extended posterior spinal fusion due to idiopathic scoliosis presented to our department with diffuse erythema and nephritis (macroscopic hemuresis and proteinuria) 5 months post surgery. The surgical trauma had no signs of inflammation or infection. The blood markers ESR and CRP were increased. Skin tests were positive for nickel allergy, which is a content of titanium alloy. The patient received corticosteroids systematically (hydrocortisone 10 mg) for 6 months, leading to total recess of skin and systemic reaction. However, a palpable mass close to the surgical wound raised the suspicion of a late infection. The patient had a second surgery consisting of surgical debridement and one stage revision of posterior spinal instrumentation. Intraoperative cultures were positive to Staphylococcus aureus. Intravenous antibiotics were administered. The patient is now free of symptoms 24 months post revision surgery without any signs of recurrence of either vasculitis or infection.</p> <p>Literature Review</p> <p>Systemic vasculitis after spinal surgery is exceptionally rare. Causative factors are broad and sometimes controversial. In general, it is associated with allergy to metal ions. This is usually addressed with metal on metal total hip bearings. In spinal surgery, titanium implants are considered to be inert and only few reports have presented cases with systemic vasculitides. Therefore, other etiologies of immune over-reaction should always be considered, such as drug toxicity, infection, or genetic predisposition.</p> <p>Purposes and Clinical Relevance</p> <p>Our purpose was to highlight the difficulties during the diagnostic work-up for systemic vasculitis and management in cases of posterior spinal surgery.</p
Controllability matters: The user experience of adaptive maps
ISSN:1384-6175ISSN:1573-762
1,3,5-Tris-(4-(Iso-Propyl)-Phenylsulfamoylmethyl)Benzene As A Potential Am(Iii) Extractant: Experimental And Theoretical Study Of Sm(Iii) Complexation And Extraction And Theoretical Correlation With Am(Iii)
The problem of legacy alkaline high-level waste (HLW) both in the US and Russia, as a result of weapons production, has prompted studies of ligands for extraction of actinides, that could be possibly used in the future together with Cs extractants for combined HLW extraction processes. The tripodal trisulphonamide ligand 1,3,5-tris-(4-(iso-propyl)-phenylsulfamoylmethyl)benzene (4-iPr-tsa), which has pre-organised functional groups for An(III) binding was synthesised and studied for potential Sm(III) and Am(III) binding and extraction by theoretical (DFT) and experimental (extraction) methods (for Sm(III) only). Both theory and experiments suggest that even though this family of ligands shows promise for Ln(III) and An(III) binding with minima for complex formation, complexation is competing with hydrolysis, and extraction is only feasible in alkaline solutions, in the presence of high concentrations of nitrate ions. Nevertheless, up to 51.8% of Sm(III) was removed under optimal conditions (NaOH = 2 × 10−4M, NaNO3 = 0.1M, [Sm]init = 5 × 10−5M). Quantum chemical calculations demonstrate that the extraction of Sm(III) and Am(III) from the aqueous phase in the form of [M·(H2O)4·(OH)2·(NO3)] to the organic phase in the form of [M·4-iPr-tsa·(H2O)3] is thermodynamically favourable. Theory also shows that Sm(III) is a reasonably good surrogate for Am(III), as the optimised structures of the Sm and Am complexes show remarkable similarities. Even though the ligand was designed with the goal of introducing favourable cation–arene interactions, along with the expected N-binding mode of the ligand in its deprotonated form, it was found that these cation–arene interactions are rather weak in this case, and coordination with O atoms of the sulphonamide, and external water molecules, is favoured instead
Removal of mercury from aqueous solutions by malt spent rootlets
Summarization: Mercury poses a severe threat to environment due to its toxicity, even at low concentrations. Biosorption
is a promising, low cost, and environmentally friendly clean up technique. Malt spent rootlets (MSR), a
brewery by-product, were used as sorbents for the removal of mercury from aquatic systems. The effect
of the solution pH, contact time between sorbent, solid to liquid ratio, and initial mercury concentration
on mercury removal were investigated experimentally. It was found that the optimum pH for the mercury
sorption onto MSR was approximately 5. Sorption kinetic experiments revealed that mercury sorption
is a relatively rapid process, where film diffusion and intra-particle diffusion play an important role.
The kinetic data were successfully described by both the pseudo-second-order and Elovich models. The
isotherm data were adequately fitted by the Langmuir model determining a monolayer capacity qmax
equal to 50 mg/g and suggesting a functional group-limited sorption process. MSR were capable of
removing significant amounts of mercury, mainly due to the carboxyl and phosphonate groups of their
surfaces.Παρουσιάστηκε στο: The Chemical Engineering Journa
1,3,5-Tris-(4-(iso-propyl)-phenylsulfamoylmethyl)benzene as a potential Am(III) extractant: experimental and theoretical study of Sm(III) complexation and extraction and theoretical correlation with Am(III)
<p>The problem of legacy alkaline high-level waste (HLW) both in the US and Russia, as a result of weapons production, has prompted studies of ligands for extraction of actinides, that could be possibly used in the future together with Cs extractants for combined HLW extraction processes. The tripodal trisulphonamide ligand 1,3,5-tris-(4-(iso-propyl)-phenylsulfamoylmethyl)benzene (4-iPr-tsa), which has pre-organised functional groups for An(III) binding was synthesised and studied for potential Sm(III) and Am(III) binding and extraction by theoretical (DFT) and experimental (extraction) methods (for Sm(III) only). Both theory and experiments suggest that even though this family of ligands shows promise for Ln(III) and An(III) binding with minima for complex formation, complexation is competing with hydrolysis, and extraction is only feasible in alkaline solutions, in the presence of high concentrations of nitrate ions. Nevertheless, up to 51.8% of Sm(III) was removed under optimal conditions (NaOH = 2 × 10<sup>−4 </sup>M, NaNO<sub>3</sub> = 0.1<sup> </sup>M, [Sm]<sub>init</sub> = 5 × 10<sup>−5 </sup>M). Quantum chemical calculations demonstrate that the extraction of Sm(III) and Am(III) from the aqueous phase in the form of [M·(H<sub>2</sub>O)<sub>4</sub>·(OH)<sub>2</sub>·(NO<sub>3</sub>)] to the organic phase in the form of [M·4-iPr-tsa·(H<sub>2</sub>O)<sub>3</sub>] is thermodynamically favourable. Theory also shows that Sm(III) is a reasonably good surrogate for Am(III), as the optimised structures of the Sm and Am complexes show remarkable similarities. Even though the ligand was designed with the goal of introducing favourable cation–arene interactions, along with the expected N-binding mode of the ligand in its deprotonated form, it was found that these cation–arene interactions are rather weak in this case, and coordination with O atoms of the sulphonamide, and external water molecules, is favoured instead.</p
Ultralow Loading Ruthenium on Alumina Monoliths for Facile, Highly Recyclable Reduction of <i>p</i>-Nitrophenol
The pervasive use of toxic nitroaromatics in industrial processes and their prevalence in industrial effluent has motivated the development of remediation strategies, among which is their catalytic reduction to the less toxic and synthetically useful aniline derivatives. While this area of research has a rich history with innumerable examples of active catalysts, the majority of systems rely on expensive precious metals and are submicron- or even a few-nanometer-sized colloidal particles. Such systems provide invaluable academic insight but are unsuitable for practical application. Herein, we report the fabrication of catalysts based on ultralow loading of the semiprecious metal ruthenium on 2–4 mm diameter spherical alumina monoliths. Ruthenium loading is achieved by atomic layer deposition (ALD) and catalytic activity is benchmarked using the ubiquitous para-nitrophenol, NaBH4 aqueous reduction protocol. Recyclability testing points to a very robust catalyst system with intrinsic ease of handling
Ultralow Loading Ruthenium on Alumina Monoliths for Facile, Highly Recyclable Reduction of p-Nitrophenol
The pervasive use of toxic nitroaromatics in industrial processes and their prevalence in industrial effluent has motivated the development of remediation strategies, among which is their catalytic reduction to the less toxic and synthetically useful aniline derivatives. While this area of research has a rich history with innumerable examples of active catalysts, the majority of systems rely on expensive precious metals and are submicron- or even a few-nanometer-sized colloidal particles. Such systems provide invaluable academic insight but are unsuitable for practical application. Herein, we report the fabrication of catalysts based on ultralow loading of the semiprecious metal ruthenium on 2–4 mm diameter spherical alumina monoliths. Ruthenium loading is achieved by atomic layer deposition (ALD) and catalytic activity is benchmarked using the ubiquitous para-nitrophenol, NaBH4 aqueous reduction protocol. Recyclability testing points to a very robust catalyst system with intrinsic ease of handling