Effects of surface roughness and mineralogy on the sorption of Cm(III) on crystalline rock.

Crystalline rock is one of the host rocks considered for a future deep geological repository for highly active radiotoxic nuclear waste. The safety assessment requires reliable information on the retention behavior of minor actinides. In this work, we applied various spatially resolved techniques to investigate the sorption of Curium onto crystalline rock (granite, gneiss) thin sections from Eibenstock, Germany and Bukov, Czech Republic. We combined Raman-microscopy, calibrated autoradiography and µTRLFS (micro-focus time-resolved fluorescence spectroscopy) with vertical scanning interferometry to study in situ the impact of mineralogy and surface roughness on Cm(III) uptake and molecular speciation on the surface. Heterogeneous sorption of Cm(III) on the surface depends primarily on the mineralogy. However, for the same mineral class sorption uptake and strength of Cm(III) increases with growing surface roughness around surface holes or grain boundaries. When competitive sorption between multiple mineral phases occurs, surface roughness becomes the major retention parameter on low sorption uptake minerals. In high surface roughness areas primarily Cm(III) inner-sphere sorption complexation and surface incorporation are prominent and in selected sites formation of stable Cm(III) ternary complexes is observed. Our molecular findings confirm that predictive radionuclide modelling should implement surface roughness as a key parameter in simulations.

Evaluation of radiographic fracture position 1 year after variable angle locking volar distal radius plating: a prospective multicentre case series.

Treatment with a variable angle locking plate can, in theory, maintain near anatomic reduction of intra-articular distal radius fractures, but it is unknown to what extent reduction is maintained as measured by computed tomography. We assessed changes in radiographic fracture position 1 year post-operatively. We included 73 patients of whom 66 patients (90%) had radiographs available for review at 1 year post-operatively. We found a small (less than 2 mm or 2°) but statistically significant change in several measures. Accounting for inter-observer variability, this is probably within measurement error. We found no difference in change in fracture position or range of motion, grip strength or patient-reported outcome between the use of one or two distal rows of screws. Our results show that minimal changes in reduction can be expected after volar plate fixation in most patients. We recommend using only one screw row routinely, limiting costs, surgical time and the risk of misplacement of screws. LEVEL OF EVIDENCE: IV.

Engineered nanoparticles and their identification among natural nanoparticles.

The more nanotechnology develops, the more likely the release of engineered nanoparticles into the environment becomes. Due to a huge excess of natural nanoparticles, the identification and quantification of engineered nanoparticles pose a big challenge to analysts. Moreover, identification in a qualitative sense and quantification by mass concentration alone are not sufficient, because the potential environmental hazard arising from engineered nanoparticles is controlled by many other properties of the particles. We discuss the most important methods of fractionation and detection of both natural and engineered nanoparticles, with a focus on the chemical nature of the particles, particle concentration, and particle size. Analyses should not rely on only one method; instead, several complementary methods should, if possible, be used. Coupled techniques should be further developed and increasingly applied. Dedicated techniques that are tailored to the search for a particular sort of engineered nanoparticles are more promising than universal approaches that search for any engineered nanoparticles.

Aqueous suspensions of carbon nanotubes: surface oxidation, colloidal stability and uranium sorption.

The objective of this study is to obtain information on the behaviour of carbon nanotubes (CNTs) as potential carriers of pollutants in the case of accidental CNT release to the environment and on the properties of CNTs as a potential adsorbent material in water purification. The effects of acid treatment of CNTs on (i) the surface properties, (ii) the colloidal stability and (iii) heavy metal sorption are investigated, the latter being exemplified by uranium(VI) sorption. There is a pronounced influence of surface treatment on the behaviour of the CNTs in aqueous suspension. Results showed that acid treatment increases the amount of acidic surface groups on the CNTs. Therefore, acid treatment has an increasing effect on the colloidal stability of the CNTs and on their adsorption capacity for U(VI). Another way to stabilise colloids of pristine CNTs in aqueous suspension is the addition of humic acid.

[Isolated ulnar luxation of metacarpal V]. / Isolierte Metacarpale-V-Luxation nach ulnar.

Isolated ulnar luxation of metacarpal V without fractures at the basis or of adjunct bones is a rarely observed entity with available data in the literature based on few case reports. Careful interpretation of radiological findings leads to a correct diagnosis. Missed lesions may result in chronic pain syndrome at the site of injury. The functional role of the ligamentum metacarpale transversum profundum in this type of injury is frequently underestimated. Here, we present a case report and elucidate diagnostic pathways and treatment options based on the available literature.

[Ipsilateral knee and hip joint dislocation]. / Ipsilaterale Knie- und Hüftgelenkluxation.

Knee and hip dislocations are often serious injuries with an uncertain outcome. Simultaneous ipsilateral dislocation of the knee and hip joints is very rare; consequently, there is an inadequate amount of literature on the subject. In this case report we present a 35-year-old male patient with this combination of both injuries and discuss it in comparison with the available literature. This case report shows, that a methodical and sequential treatment can lead to good results in spite of this complex combination of injuries.

Tetanus in Switzerland 1980-1989.

Tetanus cases that occurred in Switzerland between 1980 and 1989 have been reviewed with the help of three data surveillance systems: a) morbidity data from the Federal Office of Public Health (FOPH), b) mortality data from the Swiss Federal Statistical Office (SFSO), and c) data from the Association of Swiss Hospitals and Clinics (VESKA), completed by a written enquiry to clinics which did not (or only partly) participate in the VESKA system during the study period. For every case, a questionnaire was sent to the clinic to verify the diagnosis and to obtain additional information on the circumstances of occurrence. Ninety-one cases were identified. This corresponds to a yearly incidence of 1.93 per million population between 1980-84 and 0.88 for the 1985-89 period (p < 0.01). Eighty-one percent of the cases were older than 50 years of age and women were significantly more frequently affected than men. None of the cases identified had a documented primary immunization series. Data available at the FOPH and SFSO level have been compared to data obtained through the VESKA system using the Chandra Sekhar and Deming method. It is estimated that 134 tetanus cases (95% CI: 91-197) have occurred in Switzerland between 1980 and 1989, together with 28 deaths (95% CI: 27-31). Based on these estimates, FOPH appears to detect only 6-13% of tetanus cases occurring in Switzerland. By contrast, SFSO had fairly consistent data for 81-100% of tetanus associated deaths. The low rate of tetanus reported by physicians necessitates a sustained effort to increase the understanding of epidemiological surveillance by Swiss practitioners.