92 research outputs found

    Plasmonic lenses for tunable ultrafast electron emitters at the nanoscale

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    Simultaneous spatiotemporal confinement of energetic electron pulses to femtosecond and nanometer scales is a topic of great interest in the scientific community, given the potential impact of such developments across a wide spectrum of scientific and industrial applications. For example, in ultrafast electron scattering, nanoscale probes would enable accurate maps of structural dynamics in materials with nanoscale heterogeneity, thereby leading to an understanding of the role of boundaries and defects on macroscopic properties. On the other hand, advances in this field are mostly limited by the brightness and size of the electron source. We present the design, fabrication, and optical characterization of bullseye plasmonic lenses for next-generation ultrafast electron sources. Using electromagnetic simulations, we examine how the interplay between light-plasmon coupling, plasmon propagation, dispersion, and resonance governs the properties of the photoemitted electron pulse. We also illustrate how the pulse duration and strength can be tuned by geometric design and predict that sub-10-fs pulses with nanoscale diameter can be achieved. We then fabricate lenses in gold films and characterize their plasmonic properties using cathodoluminescence spectromicroscopy, demonstrating suitable plasmonic behavior for ultrafast nanoscale photoemission

    Role of the microbiota in the modulation of vaccine immune responses

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    The human immune system and the microbiota co-evolve, and their balanced relationship is based on crosstalk between the two systems through the course of life. This tight association and the overall composition and richness of the microbiota play an important role in the modulation of host immunity and may impact the immune response to vaccination. The availability of innovative technologies, such as next-generation sequencing (NGS) and correlated bioinformatics tools, allows a deeper investigation of the crosstalk between the microbiota and human immune responses. This review discusses the current knowledge on the influence of the microbiota on the immune response to vaccination and novel tools to deeply analyze the impact of the microbiome on vaccine responses

    Plasmonic lenses for tunable ultrafast electron emitters at the nanoscale

    Get PDF
    Simultaneous spatiotemporal confinement of energetic electron pulses to femtosecond and nanometer scales is a topic of great interest in the scientific community, given the potential impact of such developments across a wide spectrum of scientific and industrial applications. For example, in ultrafast electron scattering, nanoscale probes would enable accurate maps of structural dynamics in materials with nanoscale heterogeneity, thereby leading to an understanding of the role of boundaries and defects on macroscopic properties. On the other hand, advances in this field are mostly limited by the brightness and size of the electron source. We present the design, fabrication, and optical characterization of bullseye plasmonic lenses for next-generation ultrafast electron sources. Using electromagnetic simulations, we examine how the interplay between light-plasmon coupling, plasmon propagation, dispersion, and resonance governs the properties of the photoemitted electron pulse. We also illustrate how the pulse duration and strength can be tuned by geometric design and predict that sub-10-fs pulses with nanoscale diameter can be achieved. We then fabricate lenses in gold films and characterize their plasmonic properties using cathodoluminescence spectromicroscopy, demonstrating suitable plasmonic behavior for ultrafast nanoscale photoemission

    Shelter from the cytokine storm: pitfalls and prospects in the development of SARS-CoV-2 vaccines for an elderly population

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    The SARS-CoV-2 pandemic urgently calls for the development of effective preventive tools. COVID-19 hits greatly the elder and more fragile fraction of the population boosting the evergreen issue of the vaccination of older people. The development of a vaccine against SARS-CoV-2 tailored for the elderly population faces the challenge of the poor immune responsiveness of the older population due to immunosenescence, comorbidities, and pharmacological treatments. Moreover, it is likely that the inflammaging phenotype associated with age could both influence vaccination efficacy and exacerbate the risk of COVID-19-related “cytokine storm syndrome” with an overlap between the factors which impact vaccination effectiveness and those that boost virulence and worsen the prognosis of SARS-CoV-2 infection. The complex and still unclear immunopathological mechanisms of SARS-CoV-2 infection, together with the progressive age-related decline of immune responses, and the lack of clear correlates of protection, make the design of vaccination strategies for older people extremely challenging. In the ongoing effort in vaccine development, different SARS-CoV-2 vaccine candidates have been developed, tested in pre-clinical and clinical studies and are undergoing clinical testing, but only a small fraction of these are currently being tested in the older fraction of the population. Recent advances in systems biology integrating clinical, immunologic, and omics data can help to identify stable and robust markers of vaccine response and move towards a better understanding of SARS-CoV-2 vaccine responses in the elderly

    Plasmonic lenses for ultrafast electron nanoemission

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    We show the capability of plasmonic lenses for next-generation ultrafast electron sources. Using electromagnetic simulations, we design structures capable of femtosecond, nanoscale electron pulses. Plasmonic properties of template-stripped gold prototypes are characterized using cathodoluminescence spectromicroscopy

    The third dose of mRNA SARS-CoV-2 vaccines enhances the spike-specific antibody and memory B cell response in myelofibrosis patients

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    Vaccination against SARS-CoV-2 using mRNA-based vaccines has been highly recommended for fragile subjects, including myelofibrosis patients (MF). Available data on the immune responsiveness of MF patients to mRNA SARS-CoV-2 vaccination, and the impact of the therapy with the JAK inhibitor ruxolitinib, are still fragmented. Here, we profile the spike-specific IgG and memory B-cell response in MF patients, treated or not with ruxolitinib, after the second and the third dose of SARS-CoV-2 BNT162b2 (BioNTech) and mRNA-1273 (Moderna) vaccines. Plasma and peripheral blood mononuclear cells samples were collected before vaccination, post the second and the third doses and tested for spike-specific antibodies, ACE2/RBD antibody inhibition binding activity and spike-specific B cells. The third vaccine dose significantly increased the spike-specific IgG titers in both ruxolitinib-treated and untreated patients, and strongly enhanced the percentage of subjects with antibodies capable of in vitro blocking ACE2/RBD interaction, from 50% up to 80%. While a very low frequency of spike-specific B cells was measured in blood 7 days after the second vaccination dose, a strong and significant increase was elicited by the third dose administration, generating a B cell response similar to the one detected in healthy controls. Despite the overall positive impact of the third dose in MF patients, two patients that were under active concomitant immunosuppressive treatment at the time of vaccination, and a patient that received lymphodepleting therapies in the past, remained low responders. The third mRNA vaccine dose strongly increases the SARS-CoV-2 specific humoral and B cell responses in MF patients, promoting a reactivation of the immune response similar to the one observed in healthy controls

    Design and testing of ultrafast plasmonic lens nanoemitters

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    Nanoscale electron pulses are increasingly in demand, including as probes of nanoscale ultrafast dynamics and for emerging light source and lithography applications. Using electromagnetic simulations, we show that gold plasmonic lenses as multiphoton photoemitters provide unique advantages, including emission from an atomically at surface, nanoscale pulse diameter regardless of laser spot size, and femtosecond-scale response time. We then present fabrication of prototypes with sub-nm roughness via e-beam lithography, as well as electro-optical characterization using cathodoluminescence spectromicroscopy. Finally, we introduce a DC photogun at LBNL built for testing ultrafast photoemitters. We discuss measurement considerations for ultrafast nanoemitters and predict that we can extract tens of pA photocurrent from a single plasmonic lens using a Ti:Sa oscillator. Altogether, this lays the groundwork to develop and test a broad class of plasmon-enhanced ultrafast nanoemitters

    Comparative efficacy and acceptability of pharmacological treatments for insomnia in adults: A systematic review and network meta-analysis

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    This is the protocol for a review and there is no abstract. The objectives are as follows: 1) To compare individual pharmacological treatments for insomnia in adults in terms of: efficacy, measured as self-rated quality of sleep or satisfaction with sleep; and acceptability of treatment. 2) To generate a clinically-useful hierarchy of available pharmacological treatments for insomnia in adults, according to their efficacy and acceptability

    Determinants of antibody persistence across doses and continents after single-dose rVSV-ZEBOV vaccination for Ebola virus disease: an observational cohort study.

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    BACKGROUND: The recombinant vesicular stomatitis virus (rVSV) vaccine expressing the Zaire Ebola virus (ZEBOV) glycoprotein is efficacious in the weeks following single-dose injection, but duration of immunity is unknown. We aimed to assess antibody persistence at 1 and 2 years in volunteers who received single-dose rVSV-ZEBOV in three previous trials. METHODS: In this observational cohort study, we prospectively followed-up participants from the African and European phase 1 rVSV-ZEBOV trials, who were vaccinated once in 2014-15 with 300 000 (low dose) or 10-50 million (high dose) plaque-forming units (pfu) of rVSV-ZEBOV vaccine to assess ZEBOV glycoprotein (IgG) antibody persistence. The primary outcome was ZEBOV glycoprotein-specific IgG geometric mean concentrations (GMCs) measured yearly by ELISA compared with 1 month (ie, 28 days) after immunisation. We report GMCs up to 2 years (Geneva, Switzerland, including neutralising antibodies up to 6 months) and 1 year (Lambaréné, Gabon; Kilifi, Kenya) after vaccination and factors associated with higher antibody persistence beyond 6 months, according to multivariable analyses. Trials and the observational study were registered at ClinicalTrials.gov (Geneva: NCT02287480 and NCT02933931; Kilifi: NCT02296983) and the Pan-African Clinical Trials Registry (Lambaréné PACTR201411000919191). FINDINGS: Of 217 vaccinees from the original studies (102 from the Geneva study, 75 from the Lambaréné study, and 40 from the Kilifi study), 197 returned and provided samples at 1 year (95 from the Geneva study, 63 from the Lambaréné, and 39 from the Kilifi study) and 90 at 2 years (all from the Geneva study). In the Geneva group, 44 (100%) of 44 participants who had been given a high dose (ie, 10-50 million pfu) of vaccine and who were seropositive at day 28 remained seropositive at 2 years, whereas 33 (89%) of 37 who had been given the low dose (ie, 300 000 pfu) remained seropositive for 2 years (p=0·042). In participants who had received a high dose, ZEBOV glycoprotein IgG GMCs decreased significantly between their peak (at 1-3 months) and month 6 after vaccination in Geneva (p0·05). Neutralising antibodies seem to be less durable, with seropositivity dropping from 64-71% at 28 days to 27-31% at 6 months in participants from the Geneva study. INTERPRETATION: Antibody responses to single-dose rVSV-ZEBOV vaccination are sustained across dose ranges and settings, a key criterion in countries where booster vaccinations would be impractical. FUNDING: The Wellcome Trust and Innovative Medicines Initiative 2 Joint Undertaking

    Comparative efficacy and acceptability of psychosocial interventions for individuals with cocaine and amphetamine addiction: A systematic review and network meta-analysis.

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    BACKGROUND: Clinical guidelines recommend psychosocial interventions for cocaine and/or amphetamine addiction as first-line treatment, but it is still unclear which intervention, if any, should be offered first. We aimed to estimate the comparative effectiveness of all available psychosocial interventions (alone or in combination) for the short- and long-term treatment of people with cocaine and/or amphetamine addiction. METHODS AND FINDINGS: We searched published and unpublished randomised controlled trials (RCTs) comparing any structured psychosocial intervention against an active control or treatment as usual (TAU) for the treatment of cocaine and/or amphetamine addiction in adults. Primary outcome measures were efficacy (proportion of patients in abstinence, assessed by urinalysis) and acceptability (proportion of patients who dropped out due to any cause) at the end of treatment, but we also measured the acute (12 weeks) and long-term (longest duration of study follow-up) effects of the interventions and the longest duration of abstinence. Odds ratios (ORs) and standardised mean differences were estimated using pairwise and network meta-analysis with random effects. The risk of bias of the included studies was assessed with the Cochrane tool, and the strength of evidence with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. We followed the PRISMA for Network Meta-Analyses (PRISMA-NMA) guidelines, and the protocol was registered in PROSPERO (CRD 42017042900). We included 50 RCTs evaluating 12 psychosocial interventions or TAU in 6,942 participants. The strength of evidence ranged from high to very low. Compared to TAU, contingency management (CM) plus community reinforcement approach was the only intervention that increased the number of abstinent patients at the end of treatment (OR 2.84, 95% CI 1.24-6.51, P = 0.013), and also at 12 weeks (OR 7.60, 95% CI 2.03-28.37, P = 0.002) and at longest follow-up (OR 3.08, 95% CI 1.33-7.17, P = 0.008). At the end of treatment, CM plus community reinforcement approach had the highest number of statistically significant results in head-to-head comparisons, being more efficacious than cognitive behavioural therapy (CBT) (OR 2.44, 95% CI 1.02-5.88, P = 0.045), non-contingent rewards (OR 3.31, 95% CI 1.32-8.28, P = 0.010), and 12-step programme plus non-contingent rewards (OR 4.07, 95% CI 1.13-14.69, P = 0.031). CM plus community reinforcement approach was also associated with fewer dropouts than TAU, both at 12 weeks and the end of treatment (OR 3.92, P < 0.001, and 3.63, P < 0.001, respectively). At the longest follow-up, community reinforcement approach was more effective than non-contingent rewards, supportive-expressive psychodynamic therapy, TAU, and 12-step programme (OR ranging between 2.71, P = 0.026, and 4.58, P = 0.001), but the combination of community reinforcement approach with CM was superior also to CBT alone, CM alone, CM plus CBT, and 12-step programme plus non-contingent rewards (ORs between 2.50, P = 0.039, and 5.22, P < 0.001). The main limitations of our study were the quality of included studies and the lack of blinding, which may have increased the risk of performance bias. However, our analyses were based on objective outcomes, which are less likely to be biased. CONCLUSIONS: To our knowledge, this network meta-analysis is the most comprehensive synthesis of data for psychosocial interventions in individuals with cocaine and/or amphetamine addiction. Our findings provide the best evidence base currently available to guide decision-making about psychosocial interventions for individuals with cocaine and/or amphetamine addiction and should inform patients, clinicians, and policy-maker
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