56 research outputs found

    Imaging high-dimensional spatial entanglement with a camera

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    The light produced by parametric down-conversion shows strong spatial entanglement that leads to violations of EPR criteria for separability. Historically, such studies have been performed by scanning a single-element, single-photon detector across a detection plane. Here we show that modern electron-multiplying charge-coupled device cameras can measure correlations in both position and momentum across a multi-pixel field of view. This capability allows us to observe entanglement of around 2,500 spatial states and demonstrate Einstein-Podolsky-Rosen type correlations by more than two orders of magnitude. More generally, our work shows that cameras can lead to important new capabilities in quantum optics and quantum information science.Comment: 5 pages, 4 figure

    Measurements in two bases are sufficient for certifying high-dimensional entanglement

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    High-dimensional encoding of quantum information provides a promising method of transcending current limitations in quantum communication. One of the central challenges in the pursuit of such an approach is the certification of high-dimensional entanglement. In particular, it is desirable to do so without resorting to inefficient full state tomography. Here, we show how carefully constructed measurements in two bases (one of which is not orthonormal) can be used to faithfully and efficiently certify bipartite high-dimensional states and their entanglement for any physical platform. To showcase the practicality of this approach under realistic conditions, we put it to the test for photons entangled in their orbital angular momentum. In our experimental setup, we are able to verify 9-dimensional entanglement for a pair of photons on a 11-dimensional subspace each, at present the highest amount certified without any assumptions on the state.Comment: 11+14 pages, 2+7 figure

    Testing foundations of quantum mechanics with photons

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    The foundational ideas of quantum mechanics continue to give rise to counterintuitive theories and physical effects that are in conflict with a classical description of Nature. Experiments with light at the single photon level have historically been at the forefront of tests of fundamental quantum theory and new developments in photonics engineering continue to enable new experiments. Here we review recent photonic experiments to test two foundational themes in quantum mechanics: wave-particle duality, central to recent complementarity and delayed-choice experiments; and Bell nonlocality where recent theoretical and technological advances have allowed all controversial loopholes to be separately addressed in different photonics experiments.Comment: 10 pages, 5 figures, published as a Nature Physics Insight review articl

    Dendritic Cells/Natural Killer Cross-Talk: A Novel Target for Human Immunodeficiency Virus Type-1 Protease Inhibitors

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    BACKGROUND: HIV-1 Protease Inhibitors, namely PIs, originally designed to inhibit HIV-1 aspartic protease, can modulate the immune response by mechanisms largely unknown, and independent from their activity on viral replication. Here, we analyzed the ability of PIs to interfere with differentiation program of monocytes toward dendritic cell (DCs) lineage, a key process in the inflammatory response. METHODOLOGY/PRINCIPAL FINDINGS: Monocytes from healthy donors were isolated and induced to differentiate in vitro in the presence or absence of saquinavir, ritonavir, nelfinavir, indinavir or amprenavir (sqv, rtv, nlfv, idv, apv, respectively). These drugs demonstrated a differential ability to sustain the generation of immature DCs (iDCs) with an altered phenotype, including low levels of CD1a, CD86, CD36 and CD209. DCs generated in the presence of rtv also failed to acquire the typical phenotype of mature DCs (mDCs), and secreted lower amounts of IL-12 and IL-15. Accordingly, these aberrant mDCs failed to support activation of autologous Natural Killer (NK) cells, and resulted highly susceptible to NK cell-mediated cytotoxicity. CONCLUSIONS/SIGNIFICANCE: Our findings uncover novel functional properties of PIs within the DC-NK cell cross-talk, unveiling the heterogeneous ability of members of this class drugs to drive the generation of atypical monocyte-derived DCs (MDDCs) showing an aberrant phenotype, a failure to respond appropriately to bacterial endotoxin, a weak ability to prime autologous NK cells, and a high susceptibility to NK cell killing. These unexpected properties might contribute to limit inflammation and viral spreading in HIV-1 infected patients under PIs treatment, and open novel therapeutical perspectives for this class drugs as immunomodulators in autoimmunity and cancer

    Cytoskeletal protein kinases: titin and its relations in mechanosensing

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    Titin, the giant elastic ruler protein of striated muscle sarcomeres, contains a catalytic kinase domain related to a family of intrasterically regulated protein kinases. The most extensively studied member of this branch of the human kinome is the Ca2+–calmodulin (CaM)-regulated myosin light-chain kinases (MLCK). However, not all kinases of the MLCK branch are functional MLCKs, and about half lack a CaM binding site in their C-terminal autoinhibitory tail (AI). A unifying feature is their association with the cytoskeleton, mostly via actin and myosin filaments. Titin kinase, similar to its invertebrate analogue twitchin kinase and likely other “MLCKs”, is not Ca2+–calmodulin-activated. Recently, local protein unfolding of the C-terminal AI has emerged as a common mechanism in the activation of CaM kinases. Single-molecule data suggested that opening of the TK active site could also be achieved by mechanical unfolding of the AI. Mechanical modulation of catalytic activity might thus allow cytoskeletal signalling proteins to act as mechanosensors, creating feedback mechanisms between cytoskeletal tension and tension generation or cellular remodelling. Similar to other MLCK-like kinases like DRAK2 and DAPK1, TK is linked to protein turnover regulation via the autophagy/lysosomal system, suggesting the MLCK-like kinases have common functions beyond contraction regulation

    Risk factors in patients with type 2 diabetes mellitus Factores de riesgo en pacientes con diabetes mellitus tipo 2 Fatores de risco em pacientes com diabetes mellitus tipo 2

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    This study was carried out to evaluate the risk factors of type 2 diabetic patients through sociodemographic data, habits of health, anthropometric and biochemist profiles, assisted at a basic public health care unit in Maringá, Paraná. Sixty-six patients, 56 women aged over than 50 years-old were interviewed. High prevalence factors for cardiovascular risk were observed, such as: overweight and obesity, hypertension, dyslipidemia, sedentariness and inadequate diet. Data suggested the need for multidisciplinary intervention programs in health care units associated to educative programs, adjusted diet intake and regular physical activity for these diabetic patients.<br>El objetivo de este estudio fue verificar los factores de riesgo de las complicaciones de la diabetes mellitus tipo 2, por medio del levantamiento de datos sociodemográficos, hábitos de salud, perfil antropométrico y bioquímico, de pacientes diabéticos tipo 2 atendidos en una Unidad Básica de Salud en la ciudad de Maringá, Paraná. Fueron entrevistados y evaluados 66 pacientes con más de 50 años; 56 eran del sexo femenino. Se verificó una elevada presencia de factores de riesgo cardiovascular en los pacientes investigados: sobrepeso y obesidad, hipertensión, dislipidemia, sedentarismo y dieta no saludable. Los resultados indican la necesidad de la implantación de programas de intervención multidisciplinares en unidades básicas de la salud asociada a prácticas educativas, estimulando la adopción de una dieta saludable y la práctica de actividad física regular para estos pacientes.<br>O objetivo deste estudo foi verificar os fatores de risco das complicações do diabetes mellitus tipo 2, por meio de levantamento de dados sociodemográficos, hábitos de saúde, perfil antropométrico e bioquímico de pacientes diabéticos tipo 2, atendidos em Unidade Básica de Saúde, na cidade de Maringá, Paraná. Foram entrevistados e avaliados 66 pacientes acima de 50 anos, sendo 56 do sexo feminino. Verificou-se elevada prevalência de fatores de risco cardiovascular nos pacientes investigados: sobrepeso e obesidade, hipertensão, dislipidemia, sedentarismo e dieta não saudável. Os resultados indicam a necessidade da implantação de programas de intervenção multidisciplinares em unidades básicas de saúde, associados a práticas educativas, estimulando a adoção de dieta saudável e a prática de atividade física regular para esses pacientes
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