81 research outputs found

    Interferences in quantum eraser reveal geometric phases in modular and weak values

    Full text link
    In this letter, we present a new procedure to determine completely the complex modular values of arbitrary observables of pre- and post-selected ensembles, which works experimentally for all measurement strengths and all post-selected states. This procedure allows us to discuss the physics of modular and weak values in interferometric experiments involving a qubit meter. We determine both the modulus and the argument of the modular value for any measurement strength in a single step, by controlling simultaneously the visibility and the phase in a quantum eraser interference experiment. Modular and weak values are closely related. Using entangled qubits for the probed and meter systems, we show that the phase of the modular and weak values has a topological origin. This phase is completely defined by the intrinsic physical properties of the probed system and its time evolution. The physical significance of this phase can thus be used to evaluate the quantumness of weak values

    Foam films containig polyelectrolytes of different molecular architectures

    Get PDF
    Polyelektrolyten spielen eine wichtige Rolle in der Kolloidchemie und wurden sowohl als kolloidale Stabilisatoren als auch als Flockungsmittel eingehend untersucht. Weil in den meisten Anwendungen die Polyelektrolyten zwischen zwei Grenzflächen zu beobachten sind, besteht großes Interesse an systematischen Untersuchungen ihrer Eigenschaften und Interaktionen mit anderen Molekülen unter begrenztem räumlichen .Verhältnissen Die Strukturierung von Polyelektrolyten mit verschiedenartiger molekularer Architektur unter diesem .Verhältnissen wurde erforscht und in dieser Arbeit beschrieben. Diese Bedingungen (begrenzter Raum) wurden durch die Inkorporierung von Polyelektrolyten innerhalb eines Schaumfilmes zwischen zwei Tensidschichten erhalten. Grundmotivation dieser Untersuchungen war die Bestimmung der Einflüsse von dieser räumlichen Begrenzung auf die Strukturierung von Polyelektrolyten. Die Untersuchung der Strukturierung der Polyelektrolyten innerhalb des Schaumfilmes erfolgte mittels der Dünnfilm Druck Gleichgewicht Methode TFPB. Mittels disjoining Druck Messungen war es möglich den Einfluss unterschiedlicher Faktoren wie molekulare Masse, molekulare Architektur, Konzentration der Gegenionen und Ionische Stärke zu untersuchen.. Zudem wurde der Einfluß des Tensids auf die Eigenschaften der Polyelektrolyte-Schaumfilme durch Verwendung unterschiedlicher Tenside untersucht. Die experimentellen Ergebnisse zeigen dass die Strukturierung von Polyelektrolyten unter eingeschränkten räumlichen Verhältnissen gleich der in Lösung ist und durch elektrostatische Wechselwirkungen zwischen und entlang der Polyelektrolytenketten verursacht wird. Die Stabilität der Schaumfilme wird bestimmt durch die Wechselwirkungen zwischen Tensiden und Polyelektrolyten. Da auch Proteine und DNS Polyelektrolyte sind, sind Kentnisse über ihre Funktionalität unter den Bedingungen der räumlichen Begrenzung von großer Bedeutung für das Verständnis biologischer Prozesse, wie Proteinabsorption, Strukturierung von Membranproteinen usw.Polyelectrolytes play an important role in colloid science and are often exploited for their ability to act as colloidal stabilizers as well as flocculants. Since in many applications polyelectrolytes are confined between two surfaces, thus there is a strong impetus for systematic studies of properties of polyelectrolytes and interactions with other molecules in confined space. The structuring of polyelectrolytes of different molecular architectures in a confined space was investigated and these results are described in this thesis. The confined space was achieved by the incorporation of polyelectrolytes within the foam film core, between two surfactant layers. The basic motivation for this research was to estimate the influence of confinement on the structuring of polyelectrolytes. The investigation of structuring of polyelectrolytes within foam film was performed by thin film pressure balance method (TFPB). From disjoining pressure measurements it was possible to estimate influence of various factors such as molecular weight, molecular architecture, counterions concentration and ionic strength on the structuring of polyelectrolytes within the foam films. Since the foam films were prepared from different surfactants solutions the influence of surfactants on the properties of polyelectrolyte foam films are also estimated. Experimental results have shown that structuring of polyelectrolytes in the confined space is the same as in the bulk and caused by electrostatic interactions between and among chains. The stability of the foam films are determined by interactions between surfactant and polyelectrolytes. Since proteins and DNA are polyelectrolytes it must be noticed that the understanding a properties of polyelectrolytes in a confined environment is also crucial for understanding a properties of biological systems such as adsorption of proteins, confinement in lamellar phases etc

    STRESS, DEPRESSION AND BURNOUT AMONG HOSPITAL PHYSICIANS IN RIJEKA, CROATIA

    Get PDF
    Background: Six years of recent ongoing economic and structural crisis in Croatia have brought to a significant decrease of socioeconomic standard in our country, and had an important impact on the health care system. In this background we examined the prevalence of depression and burnout and their association with work stressors. Subjects and methods: Cross sectional survey was conducted with self reported questionnaires in 459 hospital physicians in Rijeka, Croatia. Physicians were divided into three groups: surgical, nonsurgical and diagnostic group. Socio-demographic and work-related characteristics questionnaire, Occupational Stress Assessment Questionnaire (OSAQ), Maslach Burnout Inventory- Human Services Survey (MBI-HSS) and Beck Depression Inventory II (BDI-II) were used. Sperman correlation and logistic regression were calculated to rank association between stressors at work with depression and burnout syndrome. Results: Response rate was 62.3%, (286/459). Every fifth doctor experienced all examined stressors in the workplace as stressful. The prevalence of moderate and severe depression was 12.2%. High levels of emotional exhaustion were 43.6%, depersonalization 33.5%, and lack of personal accomplishment 49.1%. There was no statistical difference in surgical, nonsurgical and diagnostic groups in depression and all domains of MBI-HSS. Almost all stressors were correlated with depression and burnout syndrome. Most of the perceived stressors were significant predictors of burnout syndrome and depression. Conclusions: High levels of burnout domain compared to overall results from similar studies from other countries, placed the results in our sample on the higher end of the range, while results for depression after adjustment with lower cutoff point would be similar to those usually found in research literature. Our study showed that burnout is highly prevalent among Croatian physicians. Target interventions at the workplace should be considered as one of the strategies to reduce negative impact of work stress on physicians’ mental health

    Exploiting the localized surface plasmon modes in gold triangular nanoparticles for sensing applications

    Get PDF
    In this study we investigate and exploit, for optical sensing, the surface plasmon excitation in gold triangular nanoparticles with high aspect ratios (i.e., the ratio of the edge length of the triangles with the height) prepared by nanosphere lithography. As shown previously, the shape and size of these nanoparticles were used to tune their optical properties, monitored by far field extinction spectroscopy. Interestingly, several localized surface plasmon resonances were detected in the visible and near infrared regions and were attributed to dipole and quadrupole modes. These modes, identified from numerical simulations, "red-shift'' as the aspect ratio of the particles increases. The plasmon modes observed for larger triangles exhibit unexpected sensitivity with a change in the refractive index. From experiments and numerical simulations, this higher sensitivity has been attributed to an increase of the local field enhancement for sharper tips. This new effect can provide important information for the design of particles as building blocks for sensing applications

    Molding Molecular and Material Properties by Strong Light-Matter Coupling

    Full text link
    When atoms come together and bond, we call these new states molecules, and their properties determine many aspects of our daily life. Strangely enough, it is conceivable for light and molecules to bond, creating new hybrid light-matter states with far-reaching consequences for these strongly coupled materials. Even stranger, there is no `real' light needed to obtain the effects, it simply appears from the vacuum, creating `something from nothing'. Surprisingly, the setup required to create these materials has become moderately straightforward. In its simplest form, one only needs to put a strongly absorbing material at the appropriate place between two mirrors, and quantum magic can appear. Only recently has it been discovered that strong coupling can affect a host of significant effects at a material and molecular level, which were thought to be independent of the `light' environment: phase transitions, conductivity, chemical reactions, etc. This review addresses the fundamentals of this opportunity: the quantum mechanical foundations, the relevant plasmonic and photonic structures, and a description of the various applications, connecting materials chemistry with quantum information, nonlinear optics and chemical reactivity. Ultimately, revealing the interplay between light and matter in this new regime opens attractive avenues for many applications in the material, chemical, quantum mechanical and biological realms

    Drug-eluting balloons in patients with non-ST elevation acute coronary syndrome

    Get PDF
    AbstractBackgroundWe compared efficacy of bare-metal stent (BMS) and drug-eluting balloon (DEB) combination vs BMS alone, in patients with non-ST elevation acute coronary syndrome treated with percutaneous coronary intervention (PCI).MethodsPatients with non-ST elevation myocardial infarction (NSTEMI) or unstable angina (UA) were randomized to BMS only or BMS+DEB group. Angiographic follow-up was performed after 6 months. The primary endpoints were binary in-stent restenosis (ISR) and late lumen loss (LLL) and the secondary endpoints were target lesion revascularization (TLR), stent thrombosis (ST), and new acute coronary syndrome (ACS).ResultsA total of 85 patients were enrolled, 44 (BMS) and 41 (BMS+DEB). The median age was 67 (36–84) years and 68 (80%) were male. Fifty-two patients (61.2%) had NSTEMI and 33 patients (38.8%) UA. There was no difference in patient demographics, risk factors, and clinical characteristics, except for more smokers in the BMS+DEB group 18/41 (43.9%) vs 9/44 (20.5%). At follow-up, no significant difference in binary ISR was found; p=0.593, but LLL was significantly lower in the BMS+DEB group 0.68 (0.00–2.15) mm vs 0.22 (0.00–2.35) mm; p=0.002. The difference in major adverse cardiac events (MACE) rate combining TLR, ST, and ACS, between the groups was also non-significant, 29.5% (BMS) vs 24.4% (BMS+DEB); p=0.835. One patient had a subacute ST (BMS+DEB) due to clopidogrel resistance.ConclusionPatients treated with BMS+DEB combination for non-ST elevation acute coronary syndrome had significantly less LLL in comparison to patients treated with BMS alone but without an impact on patient clinical outcomes

    Revealing the Wonder of Natural Photonics by Nonlinear Optics

    Get PDF
    Nano-optics explores linear and nonlinear phenomena at the nanoscale to advance fundamental knowledge about materials and their interaction with light in the classical and quantum domains in order to develop new photonics-based technologies. In this perspective article, we review recent progress regarding the application of nonlinear optical methods to reveal the links between photonic structures and functions of natural photonic geometries. Furthermore, nonlinear optics offers a way to unveil and exploit the complexity of the natural world for developing new materials and technologies for the generation, detection, manipulation, and storage of light at the nanoscale, as well as sensing, metrology, and communication
    • …
    corecore