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Background and purposeTotal knee replacements (TKRs) are being increasingly performed in patients aged ≤ 65 years who often have high physical demands. We investigated the relation between age of the patient and prosthesis survival following primary TKR using nationwide data collected from the Finnish Arthroplasty Register.MaterialsFrom Jan 1, 1997 through Dec 31, 2003, 32,019 TKRs for primary or secondary osteoarthritis were reported to the Finnish Arthroplasty Register. The TKRs were followed until the end of 2004. During the follow-up, 909 TKRs were revised, 205 (23%) due to infection and 704 for other reasons.ResultsCrude overall implant survival improved with increasing age between the ages of 40 and 80. The 5-year survival rates were 92% and 95% in patients aged ≤ 55 and 56–65 years, respectively, compared to 97% in patients who were > 65 years of age (p < 0.001). The difference was mainly attributable to reasons other than infections. Sex, diagnosis, type of TKR (condylar, constrained, or hinge), use of patellar component, and fixation method were also associated with higher revision rates. However, the differences in prosthesis survival between the age groups ≤ 55, 56–65, and > 65 years remained after adjustment for these factors (p < 0.001).InterpretationYoung age impairs the prognosis of TKR and is associated with increased revision rates for non-infectious reasons. Diagnosis, sex, type of TKR, use of patellar component, and fixation method partly explain the differences, but the effects of physical activity, patient demands, and obesity on implant survival in younger patients warrant further research.

Halide double perovskites have gained significant attention, owing to their composition of low-toxicity elements, stability in air and long charge-carrier lifetimes. However, most double perovskites, including Cs2AgBiBr6, have wide bandgaps,...

Time-of-flight elastic recoil detection (ToF-ERD) analysis software has been developed. The software combines a Python-language graphical front-end with a C code computing back-end in a user-friendly way. The software uses a list of coincident time-offlight-energy (ToF-E) events as an input. The ToF calibration can be determined with a simple graphical procedure. The graphical interface allows the user to select different elements and isotopes from a ToF-E histogram and to convert the selections to individual elemental energy and depth profiles. The resulting sample composition can be presented as relative or absolute concentrations by integrating the depth profiles over user-defined ranges. Beam induced composition changes can be studied by displaying the eventbased data in fractions relative to the substrate reference data. Optional angular input data allows for kinematic correction of the depth profiles. This open source software is distributed under the GPL license for Linux, Mac, and Windows environments.

T. (2014). Time-of-flight -Energy spectrometer for elemental depth profiling -Jyväskylä design. Nuclear instruments and methods in physics research section B: beam interactions with materials and atoms, 337, 55-61.

I-V-VI2 ternary chalcogenides are gaining attention as earth-abundant, nontoxic, and air-stable absorbers for photovoltaic applications. However, the semiconductors explored thus far have slowly-rising absorption onsets, and their charge-carrier transport is not well understood yet. Herein, we investigate cation-disordered NaBiS2 nanocrystals, which have a steep absorption onset, with absorption coefficients reaching >105 cm−1 just above its pseudo-direct bandgap of 1.4 eV. Surprisingly, we also observe an ultrafast (picosecond-time scale) photoconductivity decay and long-lived charge-carrier population persisting for over one microsecond in NaBiS2 nanocrystals. These unusual features arise because of the localised, non-bonding S p character of the upper valence band, which leads to a high density of electronic states at the band edges, ultrafast localisation of spatially-separated electrons and holes, as well as the slow decay of trapped holes. This work reveals the critical role of cation disorder in these systems on both absorption characteristics and charge-carrier kinetics.

Atomic layer deposition (ALD) is based on self-limiting surface reactions. This and cyclic process enable the growth of conformal thin films with precise thickness control and sharp interfaces. A multilayered thin film, which is nanolaminate, can be grown using ALD with tuneable electrical and optical properties to be exploited, for example, in the microelectromechanical systems. In this work, the tunability of the residual stress, adhesion, and mechanical properties of the ALD nanolaminates composed of aluminum oxide (Al2O3) and titanium dioxide (TiO2) films on silicon were explored as a function of growth temperature (110–300 °C), film thickness (20–300 nm), bilayer thickness (0.1–100 nm), and TiO2 content (0%–100%). Al2O3 was grown from Me3Al and H2O, and TiO2 from TiCl4 and H2O. According to wafer curvature measurements, Al2O3/TiO2 nanolaminates were under tensile stress; bilayer thickness and growth temperature were the major parameters affecting the stress; the residual stress decreased with increasing bilayer thickness and ALD temperature. Hardness increased with increasing ALD temperature and decreased with increasing TiO2 fraction. Contact modulus remained approximately stable. The adhesion of the nanolaminate film was good on silicon.

Float‐zone (FZ) silicon often has grown‐in defects that are thermally activated in a broad temperature window (≈300–800 °C). These defects cause efficient electron‐hole pair recombination, which deteriorates the bulk minority carrier lifetime and thereby possible photovoltaic conversion efficiencies. Little is known so far about these defects which are possibly Si‐vacancy/nitrogen‐related (VxNy). Herein, it is shown that the defect activation takes place on sub‐second timescales, as does the destruction of the defects at higher temperatures. Complete defect annihilation, however, is not achieved until nitrogen impurities are effused from the wafer, as confirmed by secondary ion mass spectrometry. Hydrogenation experiments reveal the temporary and only partial passivation of recombination centers. In combination with deep‐level transient spectroscopy, at least two possible defect states are revealed, only one of which interacts with H. With the help of density functional theory V1N1‐centers, which induce Si dangling bonds (DBs), are proposed as one possible defect candidate. Such DBs can be passivated by H. The associated formation energy, as well as their sensitivity to light‐induced free carriers, is consistent with the experimental results. These results are anticipated to contribute to a deeper understanding of bulk‐Si defects, which are pivotal for the mitigation of solar cell degradation processes.