71 research outputs found
Proper time in atom interferometers: Diffractive versus specular mirrors
We compare a conventional Mach-Zehnder light-pulse atom interferometer based
on diffractive mirrors with one that uses specular reflection. In contrast to
diffractive mirrors that generate a symmetric configuration, specular mirrors
realized, for example, by evanescent fields lead under the influence of gravity
to an asymmetric geometry. In such an arrangement the interferometer phase
contains nonrelativistic signatures of proper time.Comment: 7 pages, 1 figure, 1 tabl
Atom-interferometric test of the universality of gravitational redshift and free fall
Light-pulse atom interferometers constitute powerful quantum sensors for
inertial forces. They are based on delocalised spatial superpositions and the
combination with internal transitions directly links them to atomic clocks.
Since classical tests of the gravitational redshift are based on a comparison
of two clocks localised at different positions under gravity, it is promising
to explore whether the aforementioned interferometers constitute a competitive
alternative for tests of general relativity. Here we present a specific
geometry which together with state transitions leads to a scheme that is
concurrently sensitive to both violations of the universality of free fall and
gravitational redshift, two premises of general relativity. The proposed
interferometer does not rely on a superposition of internal states, but merely
on transitions between them, and therefore generalises the concept of physical
atomic clocks and quantum-clock interferometry. An experimental realisation
seems feasible with already demonstrated techniques in state-of-the-art
facilities.Comment: 8 pages, 4 figure
Interference of Clocks: A Quantum Twin Paradox
The phase of matter waves depends on proper time and is therefore susceptible
to special-relativistic (kinematic) and gravitational time dilation (redshift).
Hence, it is conceivable that atom interferometers measure general-relativistic
time-dilation effects. In contrast to this intuition, we show that light-pulse
interferometers without internal transitions are not sensitive to gravitational
time dilation, whereas they can constitute a quantum version of the
special-relativistic twin paradox. We propose an interferometer geometry
isolating the effect that can be used for quantum-clock interferometry.Comment: 9 Pages, 2 Figure
Cyclin-Dependent Kinase 4/6 Inhibitors and Dermatologic Adverse Events: Results from the EADV Task Force "Dermatology for Cancer Patients"
Treatment with cyclin-dependent kinase 4/6 inhibitor (CDK4/6i), has demonstrated significantly improved progression-free survival in patients with hormone receptor-positive, HER2-negative, advanced breast cancer, when used in combination with endocrine therapies. However, limited data exists on its cutaneous adverse events (AE). The aim of our retrospective study was to investigate the prevalence, types and management of cutaneous AE during CDK4/6i. 79 adult advanced breast cancer patients affected by 125 skin adverse events during treatment with CDK4/6i were recruited at eleven centers. The most frequent cutaneous reactions were pruritus (49/79 patients), alopecia (25/79), and ec-zematous lesions (24/79). We showed that skin reactions are usually mild in severity, and prompt management may limit the negative impact on patients, facilitating beneficial continuation of oncologic treatment
Covid-19 seroprevalence among healthcare workers of a large covid-19 hospital in rome reveals strengths and limits of two different serological tests
Healthcare workers are at the forefront against COVID-19, worldwide. Since Fondazione Policlinico Universitario A. Gemelli (FPG) IRCCS was enlisted as a COVID-19 hospital, the healthcare workers deployed to COVID-19 wards were separated from those with limited/no exposure, whereas the administrative staff were designated to work from home. Between 4 June and 3 July 2020, an investigation was conducted to evaluate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin (IgG) antibodies among the employees of the FPG using point-of-care (POC) and venous blood tests. Sensitivity, specificity, and predictive values were determined with reverse-transcription polymerase chain reaction on nasal/oropharyngeal swabs as the diagnostic gold standard. The participants enrolled amounted to 4777. Seroprevalence was 3.66% using the POC test and 1.19% using the venous blood test, with a significant difference (p < 0.05). The POC test sensitivity and specificity were, respectively, 63.64% (95% confidence interval (CI): 62.20% to 65.04%) and 96.64% (95% CI: 96.05% to 97.13%), while those of the venous blood test were, respectively, 78.79% (95% CI: 77.58% to 79.94%) and 99.36% (95% CI: 99.07% to 99.55%). Among the low-risk populations, the POC test’s predictive values were 58.33% (positive) and 98.23% (negative), whereas those of the venous blood test were 92.86% (positive) and 98.53% (negative). According to our study, these serological tests cannot be a valid alternative to diagnose COVID-19 infection in progress
Efficacy and safety of growth hormone treatment in children with short stature: the Italian cohort of the GeNeSIS clinical study
Purpose: We examined auxological changes in growth hormone (GH)-treated children in Italy using data from the Italian cohort of the multinational observational Genetics and Neuroendocrinology of Short Stature International Study (GeNeSIS) of pediatric patients requiring GH treatment. Methods: We studied 711 children (median baseline age 9.6 years). Diagnosis associated with short stature was as determined by the investigator. Height standard deviation score (SDS) was evaluated yearly until final or near-final height (n = 78). Adverse events were assessed in all GH-treated patients. Results: The diagnosis resulting in GH treatment was GH deficiency (GHD) in 85.5 % of patients, followed by Turner syndrome (TS 6.6 %). Median starting GH dose was higher in patients with TS (0.30 mg/kg/week) than patients with GHD (0.23 mg/kg/week). Median (interquartile range) GH treatment duration was 2.6 (0.6\u20133.7) years. Mean (95 % confidence interval) final height SDS gain was 2.00 (1.27\u20132.73) for patients with organic GHD (n = 18) and 1.19 (0.97\u20131.40) for patients with idiopathic GHD (n = 41), but lower for patients with TS, 0.37 ( 120.03 to 0.77, n = 13). Final height SDS was > 122 for 94 % of organic GHD, 88 % of idiopathic GHD and 62 % of TS patients. Mean age at GH start was lower for organic GHD patients, and treatment duration was longer than for other groups, resulting in greater mean final height gain. GH-related adverse events occurred mainly in patients diagnosed with idiopathic GHD. Conclusions: Data from the Italian cohort of GeNeSIS showed auxological changes and safety of GH therapy consistent with results from international surveillance databases
Efficacy and safety of growth hormone treatment in children with short stature: the Italian cohort of the GeNeSIS clinical study
Purpose: We examined auxological changes in growth hormone (GH)-treated children in Italy using data from the Italian cohort of the multinational observational Genetics and Neuroendocrinology of Short Stature International Study (GeNeSIS) of pediatric patients requiring GH treatment. Methods: We studied 711 children (median baseline age 9.6 years). Diagnosis associated with short stature was as determined by the investigator. Height standard deviation score (SDS) was evaluated yearly until final or near-final height (n = 78). Adverse events were assessed in all GH-treated patients. Results: The diagnosis resulting in GH treatment was GH deficiency (GHD) in 85.5 % of patients, followed by Turner syndrome (TS 6.6 %). Median starting GH dose was higher in patients with TS (0.30 mg/kg/week) than patients with GHD (0.23 mg/kg/week). Median (interquartile range) GH treatment duration was 2.6 (0.6\u20133.7) years. Mean (95 % confidence interval) final height SDS gain was 2.00 (1.27\u20132.73) for patients with organic GHD (n = 18) and 1.19 (0.97\u20131.40) for patients with idiopathic GHD (n = 41), but lower for patients with TS, 0.37 ( 120.03 to 0.77, n = 13). Final height SDS was > 122 for 94 % of organic GHD, 88 % of idiopathic GHD and 62 % of TS patients. Mean age at GH start was lower for organic GHD patients, and treatment duration was longer than for other groups, resulting in greater mean final height gain. GH-related adverse events occurred mainly in patients diagnosed with idiopathic GHD. Conclusions: Data from the Italian cohort of GeNeSIS showed auxological changes and safety of GH therapy consistent with results from international surveillance databases
Terrestrial Very-Long-Baseline Atom Interferometry:Workshop Summary
This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more km-scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions
Tlm-Based Explicit Eigenvalue Approach to the Determination of the Complete Spectrum of Inhomogeneous, Closed Waveguide
In the recent past we introduced a new approach for the analysis of the propagation of hybrid modes in closed inhomogeneous waveguides of complex shape. The essential point of the method is the discretization of the Maxwell's equations by means of the modes taken at cutoff which leads to an explicit linear eigenvalue matrix equation. A requisite for improving the efficiency of the method is the fast calculation and storage of the modes at cutoff. This is obtained by using the flexible TLM method. The resulting TLM-based eigenvalue matrix algorithm is very efficient in finding the characteristics of a large number of modes as it requires very low computational effort and is free from spurious solutions. Numerical results are provided for the unilateral finline, showing very good agreement with existing dat
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