Film thickness in a ball-on-disc contact lubricated with greases, bleed oils and base oils

Three different lubricating greases and their bleed and base oils were compared in terms of film thickness in a ball-on-disc test rig through optical interferometry. The theoretical values calculated according to Hamrock's equation are in close agreement with the base oil film thickness measurements, which validates the selected experimental methodology. The grease and bleed oil film thickness under fully flooded lubrication conditions presented quite similar behaviour and levels. Therefore, the grease film thickness under full film conditions might be predicted using their bleed oil properties, namely the viscosity and pressure-viscosity coefficient. The base and bleed oil lubricant parameter LP are proportional to the measured film thickness. A relationship between grease and the corresponding bleed oil film thickness was evidenced

Barriers to HIV testing as reported by individuals newly diagnosed with HIV infection in Sweden

Despite the availability of free and anonymous HIV testing almost 60% of Swedish patients are diagnosed late. Identifying predictors of different types of barriers could inform policy makers and health care of interventions to increase testing where needed. This cross-sectional study aimed to describe and analyze barriers to HIV testing as reported by Swedish patients newly diagnosed with HIV infection. N = 285 patients completed the 18-item Barriers to HIV Testing Scale - Karolinska Version. Descriptive analysis and logistic regressions were performed to assess the prevalence of barriers and to identify predictors for the different investigated barriers. Barriers to testing were reported by 60%. Approximately 67% of patients originating from Sweden, 50% from Sub-Saharan Africa and 75% from Eastern European/East Asian countries reported barriers. Patients who were younger and patients who self-initiated HIV testing, had greater odds of reporting a barrier than older individuals and those who were offered a test through screening or by a healthcare professional. To counteract barriers that still exist on an individual level, healthcare-initiated HIV testing could be offered more broadly and information about risks for transmission and effectiveness of HIV treatment still needs to be disseminated among both people born in Sweden and different migrant groups

Investigating the Electromechanical Behavior of Unconventionally Ferroelectric Hf0.5Zr0.5O2-Based Capacitors Through Operando Nanobeam X-Ray Diffraction

Understanding various aspects of ferroelectricity in hafnia-based nanomaterials is of vital importance for the development of future nonvolatile memory and logic devices. Here, the unconventional and weak electromechanical response of epitaxial La0.67Sr0.33MnO3/Hf0.5Zr0.5O2/La0.67Sr0.33MnO3 ferroelectric capacitors is investigated, via the sensitivity offered by nanobeam X-ray diffraction experiments during application of electrical bias. It is shown that the pristine rhombohedral phase exhibits a linear piezoelectric effect with piezoelectric coefficient (|d33|) ≈ 0.5–0.8 pmV−1. It is found that the piezoelectric response is suppressed above the coercive voltage. For higher voltages, and with the onset of DC conductivity throughout the capacitor, a second-order effect is observed. The work sheds light into the electromechanical response of rhombohedral Hf0.5Zr0.5O2 and suggests its (un)correlation with ferroelectric switching

Coherent Bragg imaging of 60 nm Au nanoparticles under electrochemical control at the NanoMAX beamline

Nanoparticles are essential electrocatalysts in chemical production, water treatment and energy conversion, but engineering efficient and specific catalysts requires understanding complex structure–reactivity relations. Recent experiments have shown that Bragg coherent diffraction imaging might be a powerful tool in this regard. The technique provides three-dimensional lattice strain fields from which surface reactivity maps can be inferred. However, all experiments published so far have investigated particles an order of magnitude larger than those used in practical applications. Studying smaller particles quickly becomes demanding as the diffracted intensity falls. Here, in situ nanodiffraction data from 60 nm Au nanoparticles under electrochemical control collected at the hard X-ray nanoprobe beamline of MAX IV, NanoMAX, are presented. Two-dimensional image reconstructions of these particles are produced, and it is estimated that NanoMAX, which is now open for general users, has the requisites for three-dimensional imaging of particles of a size relevant for catalytic applications. This represents the first demonstration of coherent X-ray diffraction experiments performed at a diffraction-limited storage ring, and illustrates the importance of these new sources for experiments where coherence properties become crucial.This work was supported by the AForsk Foundation through grant 17-408. JS-G acknowledges financial support from VITC (Vicerrectorado de Investigación y Transferencia de Conocimiento) of the University of Alicante (UATALENTO16-02). The MAX IV Laboratory receives funding through the Swedish Research Council under grant no 2013-02235

Scalable In Situ Hybridization on Tissue Arrays for Validation of Novel Cancer and Tissue-Specific Biomarkers

Tissue localization of gene expression is increasingly important for accurate interpretation of large scale datasets from expression and mutational analyses. To this end, we have (1) developed a robust and scalable procedure for generation of mRNA hybridization probes, providing >95% first-pass success rate in probe generation to any human target gene and (2) adopted an automated staining procedure for analyses of formalin-fixed paraffin-embedded tissues and tissue microarrays. The in situ mRNA and protein expression patterns for genes with known as well as unknown tissue expression patterns were analyzed in normal and malignant tissues to assess procedure specificity and whether in situ hybridization can be used for validating novel antibodies. We demonstrate concordance between in situ transcript and protein expression patterns of the well-known pathology biomarkers KRT17, CHGA, MKI67, PECAM1 and VIL1, and provide independent validation for novel antibodies to the biomarkers BRD1, EZH2, JUP and SATB2. The present study provides a foundation for comprehensive in situ gene set or transcriptome analyses of human normal and tumor tissues