On the thermomechanical-chemically coupled behavior of acrylic bone cements: Experimental characterization of material behavior and modeling approach

This study presents a constitutive model that is able to describe the curing phenomena of acrylic bone cements used in vertebroplasty. During the surgery the initial liquid bone cement is injected into a porous vertebra and penetrates it depending on the applied pressure. The procedure is accompanied by an exothermal phase transition from a viscous fluid to a viscoelastic solid. Moreover chemical shrinkage, thermal expansion as well as changes in temperature can be observed. After curing the bone cement stabilizes the filled vertebra within the vertebral column according to Baroud et al. (2004a). To represent this thermomechanical-chemically coupled material behavior a physically-based theory of finite viscoelasticity is developed. A multiplicative decomposition of the deformation gradient into a mechanical, thermal and chemical part, as proposed by Lion and H¨ofer (2007), forms the basis of the constitutive model. The exothermal polymerization of the bone cement is specified by an additive contribution to the free energy depending on the degree of cure. Thereby a differential equation represents the process-dependent behavior of the degree of cure. Experimental data supports the physical properties of the theory and provide information to parameterize the model. In detail, the time- and temperature-dependent exothermal curing behavior is studied with differential scanning calorimetry and with temperature-controlled rheometry. The structure of the constitutive model used to describe the material behavior of bone cement is motivated considering the experimental results

Quantitative Analysis of Candida Cell Wall Components by Flow Cytometrywith Triple-Fluorescence Staining

This work was supported by the European Commission within the FP7 Framework Programme [Fungitect-Grant No 602125]. We also thank Thomas Sauer, Vienna Biocenter Campus (VBC), Austria, for technical support at the FACS facility of the MFPL, Karl Kuchler, MFPL-Department of Medical Biochemistry, Medical University of Vienna, Max F. Perutz Laboratories, Campus Vienna Biocenter, Vienna, Austria and Ernst Thuer, Centre for Genomic Regulation, Barcelona, Spain, for advice on statistical approaches. Neil Gow acknowledges the support of the Wellcome Trust and the MRC Centre for Medical MycologyPeer reviewedPublisher PD

The impact of emotional facial expressions on reflexive attention depends on the aim of dynamic gaze changes: An ERP study

The emotional expression and gaze direction of a face are important cues for human social interactions. However, the interplay of these factors and their neural correlates are only partially understood. In the current study, we investigated ERP correlates of gaze and emotion processing following the initial presentation of faces with different emotional expressions (happy, neutral, angry) and an averted or direct gaze direction as well as following a subsequent change in gaze direction that occurred in half of the trials. We focused on the time course and scalp topography of the N170 and EPN components. The N170 amplitude was larger to averted than direct gaze for the initial face presentation and larger to gaze changes from direct to averted than from averted to direct in response to the gaze change. For the EPN component in response to the initial face presentation, we replicate classic effects of emotion, which did not interact with gaze direction. As a major new finding, changes from direct to averted gaze elicited an EPN-like effect when the face showed a happy expression. No such effect was seen for angry expressions. We conclude that happy faces reflexively attract attention when they look at the observer rather than away from the observer. These results for happy expressions are in line with the shared signal hypothesis that posits a better processing of expressions if their approach or avoidance tendency is consistent with gaze direction. However, the shared signal hypothesis is not supported by the present results for angry faces

Evolutionary emergence of infectious diseases in heterogeneous host populations

This is the final version. Available from Public Library of Science via the DOI in this record.The emergence and re-emergence of pathogens remains a major public health concern. Unfortunately, when and where pathogens will (re-)emerge is notoriously difficult to predict, as the erratic nature of those events is reinforced by the stochastic nature of pathogen evolution during the early phase of an epidemic. For instance, mutations allowing pathogens to escape host resistance may boost pathogen spread and promote emergence. Yet, the ecological factors that govern such evolutionary emergence remain elusive because of the lack of ecological realism of current theoretical frameworks and the difficulty of experimentally testing their predictions. Here, we develop a theoretical model to explore the effects of the heterogeneity of the host population on the probability of pathogen emergence, with or without pathogen evolution. We show that evolutionary emergence and the spread of escape mutations in the pathogen population is more likely to occur when the host population contains an intermediate proportion of resistant hosts. We also show that the probability of pathogen emergence rapidly declines with the diversity of resistance in the host population. Experimental tests using lytic bacteriophages infecting their bacterial hosts containing Clustered Regularly Interspaced Short Palindromic Repeat and CRISPR-associated (CRISPR-Cas) immune defenses confirm these theoretical predictions. These results suggest effective strategies for cross-species spillover and for the management of emerging infectious diseases.Natural Environment Research Council (NERC)Wellcome TrustBiotechnology & Biological Sciences Research Council (BBSRC)European CommissionMarie Curie ActionsNatural Sciences and Engineering Research Council of CanadaLeverhulme Trus

Variability in the durability of CRISPR-Cas immunity

This is the author accepted manuscript. The final version is available from Royal Society via the DOI in this record.The durability of host resistance is challenged by the ability of pathogens to escape the defence of their hosts. Understanding the variability in the durability of host resistance is of paramount importance for designing more effective control strategies against infectious diseases. Here, we study the durability of various clustered regularly interspaced short palindromic repeats-Cas (CRISPR-Cas) alleles of the bacteria Streptococcus thermophilus against lytic phages. We found substantial variability in durability among different resistant bacteria. Since the escape of the phage is driven by a mutation in the phage sequence targeted by CRISPR-Cas, we explored the fitness costs associated with these escape mutations. We found that, on average, escape mutations decrease the fitness of the phage. Yet, the magnitude of this fitness cost does not predict the durability of CRISPR-Cas immunity. We contend that this variability in the durability of resistance may be because of variations in phage mutation rate or in the proportion of lethal mutations across the phage genome. These results have important implications on the coevolutionary dynamics between bacteria and phages and for the optimal deployment of resistance strategies against pathogens and pests. Understanding the durability of CRISPR-Cas immunity may also help develop more effective gene-drive strategies based on CRISPR-Cas9 technology. This article is part of a discussion meeting issue 'The ecology and evolution of prokaryotic CRISPR-Cas adaptive immune systems'.Natural Environment Research Council (NERC)Biotechnology & Biological Sciences Research Council (BBSRC)European CommissionEuropean Molecular Biology Organization (EMBO)Leverhulme TrustNatural Sciences and Engineering Research Council of Canad

Radiative rotational lifetimes and state-resolved relative detachment cross sections from photodetachment thermometry of molecular anions in a cryogenic storage ring

Photodetachment thermometry on a beam of OH$^-$ in a cryogenic storage ring cooled to below 10 K is carried out using two-dimensional, frequency and time dependent photodetachment spectroscopy over 20 minutes of ion storage. In equilibrium with the low-level blackbody field, we find an effective radiative temperature near 15 K with about 90% of all ions in the rotational ground state. We measure the J = 1 natural lifetime (about 193 s) and determine the OH$^-$ rotational transition dipole moment with 1.5% uncertainty. We also measure rotationally dependent relative near-threshold photodetachment cross sections for photodetachment thermometry.Comment: Manuscript LaTeX with 5 pages, 3 figures, and 1 table plus LaTeX supplement with 12 pages, 3 figures and 3 tables. This article has been accepted by Physical Review Letter

Highly efficient and selective extraction of uranium from aqueous solution by a magnetic device: succinyl-ß-cyclodextrin-APTES@maghemite nanoparticles

The removal of radio-elements, notably uranium, from waste-waters is crucial for public health and environmental remediation. To this end, succinyl-ß-cyclodextrin (SßCD) is grafted onto maghemite nanoparticles (NPs) synthesized by the polyol method. The nanocomposite was well characterized. The adsorption of U(VI) by SßCD-APTES@Fe2O3 is pH-dependent with a maximum at pH 6. Adsorption occurs mainly by complex formation and displays a very good selectivity for U(VI) compared to other cations such as Cs+, K+, Na+, Mg2+ and Al3+. The data were plotted according to the Langmuir, Freundlich, Elovich, Temkin and Halsey isotherms. The Langmuir isotherm maximum adsorption capacity (qmax) is 286 mg U g-1 and higher than for other reported sorbents. Moreover, Cs-corrected STEM visualizes the uranium on the NP surface, which is consistent with the Halsey isotherm model for multilayer adsorption. The U(VI) adsorbed on SßCD-APTES@Fe2O3 is easily recovered by magnetic sedimentation and desorption performed in a small volume in order to concentrate the extract. The nanocomposite can be regenerated and re-used at least tenfold

About the Electrospray Ionization Source in Mass Spectrometry: Electrochemistry and On-chip Reactions

The present work shows that the electrochemical properties of electrospray ionization (ESI) can be used to add functions to the process. As example, we show how the choice of the electrode material can be used to study interactions between metal ions and biomolecules in mass spectrometry (MS). In positive ionization MS, an electrospray device acts as anode, which implies oxidation reactions. Sacrificial electrodes (made of copper or zinc) are used to supply the electrospray current and to produce cations that are able to react on-line with compounds of interest. Thus, the interactions between copper ions and ligands or peptides were investigated by using a copper electrode. Another example is the in situ electrogeneration of a dinuclear zinc(II) complex for the mass tagging of phosphopeptides when working with a zinc electrode. In order to perform these reactions on the same microchip, a dual-channel microsprayer was used, where one channel was dedicated to the tag electrogeneration and the other to the infusion of a phosphopeptides solution. Finally, this dual-channel microsprayer was used to study complexation at liquid-liquid interfaces in biphasic ESI-MS, such as thioether crowns and lead ions or peptides and phospholipids complexes. These examples illustrate the use of electrochemistry and on-chip reactions in ESI-MS analysis

Association of psychological distress with smoking cessation, duration of abstinence from smoking, and use of non-combustible nicotine-containing products: A cross-sectional population survey in Great Britain

BACKGROUND: Tobacco smoking cessation is associated with improvements in mental health. This study assessed psychological distress, using the K6 non-specific screening tool ((items cover feelings of nervousness, hopelessness, restlessness, depression, ‘everything an effort’ and worthlessness), by smoking status, time since quit, and use of a non-combustible nicotine product. METHODS: Monthly repeat cross-sectional household survey of adults (18 + ) from October 2020–February 2022 in Great Britain (N = 32,727). Using unadjusted and adjusted logistic regression (adjusted models included socio-demographic characteristics and ever diagnosis with a mental health condition), we assessed: associations between any/serious past-month psychological distress and smoking status and time since quit, whether these relationships were moderated by ever diagnosis with a mental health condition, and associations between distress and use of a nicotine product by people who formerly smoked. RESULTS: In the unadjusted model, those who had not smoked for > 1y and who had never smoked had lower odds of any distress (OR = 0·42, 95 % CI 0·39-0·45; OR = 0·44, 0·41-0·47) compared with those who currently smoked. Moreover, the association of lower distress in those who had not smoked for > 1y and never smoked compared with those who currently smoked was more pronounced among those who had ever been diagnosed with a mental health condition (AOR = 0·58, 0·51-0·66; AOR = 0·60, 0·53-0·67) than among those who had not (AOR = 0·86, 0·76-0·98; AOR = 0·72, 0·65-0·81). In adjusted models of people who formerly smoked, current use of any nicotine product was associated with higher odds of distress compared with not using any nicotine product (AOR 1·23, 1·06-1·42)