471 research outputs found

    Vacuum squeezed light for atomic memories at the D2 cesium line

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    We report the experimental generation of squeezed light at 852 nm, locked on the Cesium D2 line. 50% of noise reduction down to 50 kHz has been obtained with a doubly resonant optical parametric oscillator operating below threshold, using a periodically-polled KTP crystal. This light is directly utilizable with Cesium atomic ensembles for quantum networking application

    GMT: Enabling easy development and efficient execution of irregular applications on commodity clusters

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    In this poster we introduce GMT (Global Memory and Threading library), a custom runtime library that enables efficient execution of irregular applications on commodity clusters. GMT only requires a cluster with x86 nodes supporting MPI. GMT integrates the Partititioned Global Address Space (PGAS) locality-aware global data model with a fork/join control model common in single node multithreaded environments. GMT supports lightweight software multithreading to tolerate latencies for accessing data on remote nodes, and is built around data aggregation to maximize network bandwidth utilization.Peer ReviewedPostprint (author's final draft

    Glycine-Spacers Influence Functional Motifs Exposure and Self-Assembling Propensity of Functionalized Substrates Tailored for Neural Stem Cell Cultures

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    The understanding of phenomena involved in the self-assembling of bio-inspired biomaterials acting as three-dimensional scaffolds for regenerative medicine applications is a necessary step to develop effective therapies in neural tissue engineering. We investigated the self-assembled nanostructures of functionalized peptides featuring four, two or no glycine-spacers between the self-assembly sequence RADA16-I and the functional biological motif PFSSTKT. The effectiveness of their biological functionalization was assessed via in vitro experiments with neural stem cells (NSCs) and their molecular assembly was elucidated via atomic force microscopy, Raman and Fourier Transform Infrared spectroscopy. We demonstrated that glycine-spacers play a crucial role in the scaffold stability and in the exposure of the functional motifs. In particular, a glycine-spacer of four residues leads to a more stable nanostructure and to an improved exposure of the functional motif. Accordingly, the longer spacer of glycines, the more effective is the functional motif in both eliciting NSCs adhesion, improving their viability and increasing their differentiation. Therefore, optimized designing strategies of functionalized biomaterials may open, in the near future, new therapies in tissue engineering and regenerative medicine

    New "Green" approaches to the synthesis of pyrazole derivatives.

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    A novel approach to the synthesis of pyrazole derivatives from tosylhydrazones of alpha,beta-unsaturated carbonyl compounds possessing a beta-hydrogen is proposed, exploiting microwave (MW) activation coupled with solvent free reaction conditions. The cycloaddition was studied on three ketones (trans-4-phenyl-3-buten-2-one, beta-ionone and trans-chalcone). The corresponding 3,5-disubstituted-1H-pyrazoles were obtained in high yields and after short reaction times. In order to simplify and point out the green chemistry features of the method, a further improvement was achieved under the same catalytic conditions with a "one pot" synthesis of these heterocyclic compounds, starting directly from their carbonyl precursors via tosylhydrazones generated in situ. For an exhaustive study, the dielectric properties of the solid reaction mixtures were also measured, in order to obtain input data for the numerical simulation of their heating behaviour in the single mode MW cavity which was used for experimental work. In order to supply a valid methodology and tool for measuring the environmental impact, a comparative study between the synthetic route proposed and the classical synthetic route has been carried out

    Monitoring Risk Factors and Improving Adherence to Therapy in Patients With Chronic Kidney Disease (Smit-CKD Project): Pilot Observational Study

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    Background: Chronic kidney disease is a major public health issue, with about 13% of the general adult population and 30% of the elderly affected. Patients in the last stage of this disease have an almost uniquely high risk of death and cardiovascular events, with reduced adherence to therapy representing an additional risk factor for cardiovascular morbidity and mortality. Considering the increased penetration of mobile phones, a mobile app could educate patients to autonomously monitor cardiorenal risk factors. Objective: With this background in mind, we developed an integrated system of a server and app with the aim of improving self-monitoring of cardiovascular and renal risk factors and adherence to therapy. Methods: The software infrastructure for both the Smit-CKD server and Smit-CKD app was developed using standard web-oriented development methodologies preferring open source tools when available. To make the Smit-CKD app suitable for Android and iOS, platforms that allow the development of a multiplatform app starting from a single source code were used. The integrated system was field tested with the help of 22 participants. User satisfaction and adherence to therapy were measured by questionnaires specifically designed for this study; regular use of the app was measured using the daily reports available on the platform. Results: The Smit-CKD app allows the monitoring of cardiorenal risk factors, such as blood pressure, weight, and blood glucose. Collected data are transmitted in real time to the referring general practitioner. In addition, special reminders improve adherence to the medication regimen. Via the Smit-CKD server, general practitioners can monitor the clinical status of their patients and their adherence to therapy. During the test phase, 73% (16/22) of subjects entered all the required data regularly and sent feedback on drug intake. After 6 months of use, the percentage of regular intake of medications rose from 64% (14/22) to 82% (18/22). Analysis of the evaluation questionnaires showed that both the app and server components were well accepted by the users. Conclusions: Our study demonstrated that a simple mobile app, created to self-monitor modifiable cardiorenal risk factors and adherence to therapy, is well tolerated by patients affected by chronic kidney disease. Further studies are required to clarify if the use of this integrated system will have long-term effects on therapy adherence and if self-monitoring of risk factors will improve clinical outcomes in this population

    Microenvironment inflammatory infiltrate drives growth speed and outcome of hepatocellular carcinoma: a prospective clinical study

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    In HCC, tumor microenvironment, heavily influenced by the underlying chronic liver disease, etiology and stage of the tissue damage, affects tumor progression and determines the high heterogeneity of the tumor. Aim of this study was to identify the circulating and tissue components of the microenvironment immune-mediated response affecting the aggressiveness and the ensuing clinical outcome. We analyzed the baseline paired HCC and the surrounding tissue biopsies from a prospective cohort of 132 patients at the first diagnosis of HCC for immunolocalization of PD-1/PD-L1, FoxP3, E-cadherin, CLEC2 and for a panel of 82 microRNA associated with regulation of angiogenesis, cell proliferation, cell signaling, immune control and autophagy. Original microarray data were also explored. Serum samples were analyzed for a panel of 19 cytokines. Data were associated with biochemical data, histopathology and survival. Patients with a more aggressive disease and shorter survival, who we named fast-growing accordingly to the tumor doubling time, at presentation had significantly higher AFP levels, TGF-β1 and Cyphra 21-1 levels. Transcriptomic analysis evidenced a significant downregulation of CLEC2 and upregulation of several metalloproteinases. A marked local upregulation of both PD-1 and PD-L1, a concomitant FoxP3-positive lymphocytic infiltrate, a loss of E-cadherin, gain of epithelial-mesenchymal transition (EMT) phenotype and extreme poor differentiation at histology were also present. Upregulated microRNA in fast-growing HCCs are associated with TGF-β signaling, angiogenesis and inflammation. Our data show that fast HCCs are characterized not only by redundant neo-angiogenesis but also by unique features of distinctively immunosuppressed microenvironment, prominent EMT, and clear-cut activation of TGFβ1 signaling in a general background of long-standing and permanent inflammatory state

    NKp46-expressing human gut-resident intraepithelial V\u3b41 T cell subpopulation exhibits high anti-tumor activity against colorectal cancer

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    \u3b3\u3b4 T cells account for a large fraction of human intestinal intraepithelial lymphocytes (IELs) endowed with potent anti-tumor activities. However, little is known about their origin, phenotype and clinical relevance in colorectal cancer (CRC). To determine \u3b3\u3b4 IEL gut-specificity, homing and functions, \u3b3\u3b4 T cells were purified from human healthy blood, lymph nodes, liver, skin, intestine either disease-free or affected by CRC or generated from thymic precursors. The constitutive expression of NKp46 specifically identifies a new subset of cytotoxic V\u3b41 T cells representing the largest fraction of gut-resident IELs. The ontogeny and gut-tropism of NKp46pos/V\u3b41 IELs depends both on distinctive features of V\u3b41 thymic precursors and gut-environmental factors. Either the constitutive presence of NKp46 on tissue-resident V\u3b41 intestinal IELs or its induced-expression on IL-2/IL-15 activated V\u3b41 thymocytes are associated with anti-tumor functions. Higher frequencies of NKp46pos/V\u3b41 IELs in tumor-free specimens from CRC patients correlate with a lower risk of developing metastatic III/IV disease stages. Additionally, our in vitro settings reproducing CRC tumor-microenvironment inhibited the expansion of NKp46pos/V\u3b41 cells from activated thymic precursors. These results parallel the very low frequencies of NKp46pos/V\u3b41 IELs able to infiltrate CRC, thus providing new insights to either follow-up cancer progression or develop novel adoptive cellular therapies

    IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper

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    Currently, testing for immunoglobulin E (IgE) sensitization is the cornerstone of diagnostic evaluation in suspected allergic conditions. This review provides a thorough and updated critical appraisal of the most frequently used diagnostic tests, both in vivo and in vitro. It discusses skin tests, challenges, and serological and cellular in vitro tests, and provides an overview of indications, advantages and disadvantages of each in conditions such as respiratory, food, venom, drug, and occupational allergy. Skin prick testing remains the first line approach in most instances; the added value of serum specific IgE to whole allergen extracts or components, as well as the role of basophil activation tests, is evaluated. Unproven, non-validated, diagnostic tests are also discussed. Throughout the review, the reader must bear in mind the relevance of differentiating between sensitization and allergy; the latter entails not only allergic sensitization, but also clinically relevant symptoms triggered by the culprit allergen

    Coherence and recurrency: maintenance, control and integration in working memory

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    Working memory (WM), including a ‘central executive’, is used to guide behavior by internal goals or intentions. We suggest that WM is best described as a set of three interdependent functions which are implemented in the prefrontal cortex (PFC). These functions are maintenance, control of attention and integration. A model for the maintenance function is presented, and we will argue that this model can be extended to incorporate the other functions as well. Maintenance is the capacity to briefly maintain information in the absence of corresponding input, and even in the face of distracting information. We will argue that maintenance is based on recurrent loops between PFC and posterior parts of the brain, and probably within PFC as well. In these loops information can be held temporarily in an active form. We show that a model based on these structural ideas is capable of maintaining a limited number of neural patterns. Not the size, but the coherence of patterns (i.e., a chunking principle based on synchronous firing of interconnected cell assemblies) determines the maintenance capacity. A mechanism that optimizes coherent pattern segregation, also poses a limit to the number of assemblies (about four) that can concurrently reverberate. Top-down attentional control (in perception, action and memory retrieval) can be modelled by the modulation and re-entry of top-down information to posterior parts of the brain. Hierarchically organized modules in PFC create the possibility for information integration. We argue that large-scale multimodal integration of information creates an ‘episodic buffer’, and may even suffice for implementing a central executive

    Search for charged Higgs bosons in e+ee^+ e^- collisions at centre-of-mass energies between 130 and 183 GeV

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    A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at centre-of-mass energies from \mbox{130 to 183 \GeV{}}, corresponding to an integrated luminosity of 88.3 \pb. The Higgs decays into a charm and a strange quark or into a tau lepton and its associated neutrino are considered. The observed candidates are consistent with the expectations from Standard Model background processes. A lower limit of 57.5 \GeV{} on the charged Higgs mass is derived at 95\% CL, independent of the decay branching ratio \mathrm{Br(H^\pm\ra \tau\nu)}
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