The European Bone and Joint Infection Society definition of periprosthetic joint infection is meaningful in clinical practice: a multicentric validation study with comparison with previous definitions.

BACKGROUND AND PURPOSE: A new periprosthetic joint infection (PJI) definition has recently been proposed by the European Bone and Joint Infection Society (EBJIS). The goals of this paper are to evaluate its diagnostic accuracy and compare it with previous definitions and to assess its accuracy in preoperative diagnosis. PATIENTS AND METHODS: We retrospectively evaluated a multicenter cohort of consecutive revision total hip and knee arthroplasties. Cases with minimum required diagnostic workup were classified according to EBJIS, 2018 International Consensus Meeting (ICM 2018), Infectious Diseases Society of America (IDSA), and modified 2013 Musculoskeletal Infection Society (MSIS) definitions. 2 years' minimum follow-up was required to assess clinical outcome. RESULTS: Of the 472 cases included, PJI was diagnosed in 195 (41%) cases using EBJIS; 188 (40%) cases using IDSA; 172 (36%) using ICM 2018; and 145 (31%) cases using MSIS. EBJIS defined fewer cases as intermediate (5% vs. 9%; p = 0.01) compared with ICM 2018. Specificity was determined by comparing risk of subsequent PJI after revision surgery. Infected cases were associated with higher risk of subsequent PJI in every definition. Cases classified as likely/confirmed infections using EBJIS among those classified as not infected in other definitions showed a significantly higher risk of subsequent PJI compared with concordant non-infected cases using MSIS (RR = 3, 95% CI 1-6), but not using ICM 2018 (RR = 2, CI 1-6) or IDSA (RR = 2, CI 1-5). EBJIS showed the highest agreement between pre-operative and definitive classification (k = 0.9, CI 0.8-0.9) and was better at ruling out PJI with an infection unlikely result (sensitivity 89% [84-93], negative predictive value 90% [85-93]). CONCLUSION: The newly proposed EBJIS definition emerged as the most sensitive of all major definitions. Cases classified as PJI according to the EBJIS criteria and not by other definitions seem to have increased risk of subsequent PJI compared with concordant non-infected cases. EBJIS classification is accurate in ruling out infection preoperatively.

The Campo de Dalias GNSS Network Unveils the Interaction between Roll-Back and Indentation Tectonics in the Gibraltar Arc.

The Gibraltar Arc includes the Betic and Rif Cordilleras surrounding the Alboran Sea; it is formed at the northwest-southeast Eurasia-Nubia convergent plate boundary in the westernmost Mediterranean. Since 2006, the Campo de Dalias GNSS network has monitored active tectonic deformation of the most seismically active area on the north coast of the Alboran Sea. Our results show that the residual deformation rates with respect to Eurasia range from 1.7 to 3.0 mm/year; roughly homogenous west-southwestward displacements of the northern sites occur, while the southern sites evidence irregular displacements towards the west and northwest. This deformation pattern supports simultaneous east-northeast-west-southwest extension, accommodated by normal and oblique faults, and north-northwest-south-southeast shortening that develops east-northeast-west-southwest folds. Moreover, the GNSS results point to dextral creep of the main northwest-southeast Balanegra Fault. These GNNS results thus reveal, for the first time, present-day interaction of the roll-back tectonics of the Rif-Gibraltar-Betic slab in the western part of the Gibraltar Arc with the indentation tectonics affecting the eastern and southern areas, providing new insights for improving tectonic models of arcuate orogens.

Raman scattering by confined optical phonons in Si and Ge nanostructures.

A microscopic theory of the Raman scattering based on the local bond-polarizability model is presented and applied to the analysis of phonon confinement in porous silicon and porous germanium, as well as nanowire structures. Within the linear response approximation, the Raman shift intensity is calculated by means of the displacement-displacement Green's function and the Born model, including central and non-central interatomic forces. For the porous case, the supercell method is used and ordered pores are produced by removing columns of Si or Ge atoms from their crystalline structures. This microscopic theory predicts a remarkable shift of the highest-frequency of first-order Raman peaks towards lower energies, in comparison with the crystalline case. This shift is discussed within the quantum confinement framework and quantitatively compared with the experimental results obtained from porous silicon samples, which were produced by anodizing p--type (001)-oriented crystalline Si wafers in a hydrofluoric acid bath.

Levelling profiles and a GPS network to monitor the active folding and faulting deformation in the Campo de Dalias (Betic Cordillera, southeastern Spain).

The Campo de Dalias is an area with relevant seismicity associated to the active tectonic deformations of the southern boundary of the Betic Cordillera. A non-permanent GPS network was installed to monitor, for the first time, the fault- and fold-related activity. In addition, two high precision levelling profiles were measured twice over a one-year period across the Balanegra Fault, one of the most active faults recognized in the area. The absence of significant movement of the main fault surface suggests seismogenic behaviour. The possible recurrence interval may be between 100 and 300 y. The repetitive GPS and high precision levelling monitoring of the fault surface during a long time period may help us to determine future fault behaviour with regard to the existence (or not) of a creep component, the accumulation of elastic deformation before faulting, and implications of the fold-fault relationship.