Wound fluid ceftriaxone concentrations after local application with calcium sulphate as carrier material in the treatment of orthopaedic device-associated hip infections.

There is a considerable challenge in treating bone infections and orthopaedic device-associated infection (ODAI), partly due to impaired penetration of systemically administrated antibiotics at the site of infection. This may be circumvented by local drug administration. Knowledge of the release kinetics from any carrier material is essential for proper application. Ceftriaxone shows a particular constant release from calcium sulphate (CaSO <sub>4</sub> ) in vitro, and is particularly effective against streptococci and a large portion of Gram-negative bacteria. We present the clinical release kinetics of ceftriaxone-loaded CaSO <sub>4</sub> applied locally to treat ODAI. A total of 30 operations with ceftriaxone-loaded CaSO <sub>4</sub> had been performed in 28 patients. Ceftriaxone was applied as a single local antibiotic in 21 operations and combined with vancomycin in eight operations, and in an additional operation with vancomycin and amphotericin B. Sampling of wound fluid was performed from drains or aspirations. Ceftriaxone concentrations were measured by liquid chromatography with tandem mass spectrometry (LC-MS/MS). A total of 37 wound fluid concentrations from 16 operations performed in 14 patients were collected. The ceftriaxone concentrations remained approximately within a range of 100 to 200 mg/l up to three weeks. The median concentration was 108.9 mg/l (interquartile range 98.8 to 142.5) within the first ten days. No systemic adverse reactions were observed. Our study highlights new clinical data of locally administered ceftriaxone with CaSO <sub>4</sub> as carrier material. The near-constant release of ceftriaxone from CaSO <sub>4</sub> observed in vitro could be confirmed in vivo. The concentrations remained below known local toxicity thresholds.Cite this article: Bone Joint Res 2022;11(11):835-842

AVHRR and VISSR satellite instrument calibration results for both Cirrus and marine stratocumulus IFO periods

Accurate characterizations of some cloud parameters are dependent upon the absolute accuracy of satellite radiance measurements. Visible wavelength measurements from both the AVHRR and VISSR instruments are often used to study cloud characteristics. Both of these instruments were radiometrically calibrated prior to launch, but neither has an onboard device to monitor degradation after launch. During the FIRE/SRB cirrus Intensive Field Operation (IFO), a special effort was made to monitor calibration of these two instruments onboard the NOAA-9 and GOES-6 spacecraft. In addition, several research groups have combined their efforts to assess the long-term performance of both instruments. These results are presented, and a limited comparison is made with the ERBE calibration standard

Quantum Impurities and the Neutron Resonance Peak in YBa2Cu3O7{\bf YBa_2 Cu_3 O_7}: Ni versus Zn

The influence of magnetic (S=1) and nonmagnetic (S=0) impurities on the spin dynamics of an optimally doped high temperature superconductor is compared in two samples with almost identical superconducting transition temperatures: YBa$_2$(Cu$_{0.97}$Ni$_{0.03}$)$_3$O$_7$ (T$_c$=80 K) and YBa$_2$(Cu$_{0.99}$Zn$_{0.01}$)$_3$O$_7$ (T$_c$=78 K). In the Ni-substituted system, the magnetic resonance peak (which is observed at E$_r \simeq$40 meV in the pure system) shifts to lower energy with a preserved E$_r$/T$_c$ ratio while the shift is much smaller upon Zn substitution. By contrast Zn, but not Ni, restores significant spin fluctuations around 40 meV in the normal state. These observations are discussed in the light of models proposed for the magnetic resonance peak.Comment: 3 figures, submitted to PR

Magnetic Phase Diagram and Metal-Insulator Transition of NiS2-xSex

Magnetic phase diagram of NiS2-xSex has been reexamined by systematic studies of electrical resistivity, uniform magnetic susceptibility and neutron diffraction using single crystals grown by a chemical transport method. The electrical resistivity and the uniform magnetic susceptibility exhibit the same feature of temperature dependence over a wide Se concentration. A distinct first order metal-insulator (M-I) transition accompanied by a volume change was observed only in the antiferromagnetic ordered phase for 0.50<x<0.59. In this region, the M-I transition makes substantial effects to the thermal evolution of staggered moments. In the paramagnetic phase, the M-I transition becomes broad; both the electrical resistivity and the uniform magnetic susceptibility exhibit a broad maximum around the temperatures on the M-I transition-line extrapolated to the paramagnetic phase.Comment: 6 pages, 8 figures, corrected EPS fil

Pay What You Want as a Marketing Strategy in Monopolistic and Competitive Markets

Pay What You Want (PWYW) can be an attractive marketing strategy to price discriminate between fair-minded and selfish customers, to fully penetrate a market without giving away the product for free, and to undercut competitors that use posted prices. We report on laboratory experiments that identify causal factors determining the willingness of buyers to pay voluntarily under PWYW. Furthermore, to see how competition affects the viability of PWYW, we implement markets in which a PWYW seller competes with a traditional seller. Finally, we endogenize the market structure and let sellers choose their pricing strategy. The experimental results show that outcome-based social preferences and strategic considerations to keep the seller in the market can explain why and how much buyers pay voluntarily to a PWYW seller. We find that PWYW can be viable in isolation, but it is less successful as a competitive strategy because it does not drive traditional posted-price sellers out of the market. Instead, the existence of a posted-price competitor reduces buyers’ payments and prevents the PWYW seller from fully penetrating the market. If given the choice, the majority of sellers opt for setting a posted price rather than a PWYW pricing. We discuss the implications of these results for the use of PWYW as a marketing strategy

Highly stable perylenediimide based self-assembled monolayers studied by spectroelectrochemistry

Perylenediimide (PDI) based self-assembled monolayers (SAMs) have been studied by quartz crystal microbalance, X-ray photoelectron spectroscopy, cyclic voltammetry and spectroelectrochemistry (SEC). The high stability of PDI based SAMs has allowed probing very low signals by absorption and emission SEC and extracting voltabsorptograms. The wavelengths of absorption maxima of PDI, anion radical and dianion species. In contrast, the magnitudes of the molar extinction coefficient of the reduced forms were not preserved in SAM. The quenching of PDI fluorescence was confirmed on gold substrate

Coincidence between transcriptome analyses on different microarray platforms using a parametric framework

A parametric framework for the analysis of transcriptome data is demonstrated to yield coincident results when applied to data acquired using two different microarray platforms. Discrepancies among transcriptome studies are frequently reported, casting doubt on the reliability of collected data. The inconsistency among observations can be largely attributed to differences among the analytical frameworks employed for data analysis. The existing frameworks normalizes data against a standard determined from the data to be analyzed. In the present study, a parametric framework based on a strict model for normalization is applied to data acquired using an in-house printed chip and GeneChip. The framework is based on a common statistical characteristic of microarray data, and each data is normalized on the basis of a linear relationship with this model. In the proposed framework, the expressional changes observed and genes selected are coincident between platforms, achieving superior universality of data compared to other methods

Kondo screening of the spin and orbital magnetic moments of Fe impurities in Cu

We use x-ray magnetic circular dichroism to evidence the effect of correlations on the local impurity magnetic moment in an archetypal Kondo system, namely, a dilute Cu:Fe alloy. Applying the sum rules on the Fe L2,3 absorption edges, the evolution of the spin and orbital moments across the Kondo temperature are determined separately. The spin moment presents a crossover from a nearly temperature-independent regime below the Kondo temperature to a paramagneticlike regime above. Conversely, the weak orbital moment shows a temperature-independent behavior in the whole temperature range, suggesting different Kondo screening temperature scales for the spin and orbital moments

Monocouches auto-assemblées à fonctionnalités pérylène : relations structure / propriétés électrochimiques et spectroscopiques

Le groupement pérylène est un candidat de choix pour l’élaboration de monocouches auto-assemblées (SAMs) redox puisqu’il combine des avantages majeurs en termes de caractérisation : une réponse électrochimique réversible, un coefficient d’extinction molaire élevé (~ 50 000 M-1.cm-1), ainsi qu’une émission de fluorescence intense (rendement quantique de fluorescence ~ 100 %). Dans ce contexte, un motif pérylène diimide prolongé par une chaîne alkyl possédant un groupement terminal soufré, a été synthétisé. Le rôle de cet espaceur est primordial puisqu’il peut permettre de prévenir le couplage entre les états électroniques de la surface et du fluorophore1 et présente également l’avantage d’assurer l’assemblage des unités constitutives de la SAM. Les SAMs de pérylène ont été étudiées par microbalance à cristal de quartz et via des techniques électrochimiques et spectroscopiques couplées ou non. La modulation de la quantité d’unités redox immobilisées par dilution avec des motifs thiols a permis d\u27établir des relations de type structure/propriétés