215 research outputs found
Rotational sensitivity of the "G-Pisa" gyrolaser
G-Pisa is an experiment investigating the possibility to operate a high
sensitivity laser gyroscope with area less than for improving the
performances of the mirrors suspensions of the gravitational wave antenna
Virgo. The experimental set-up consists in a He-Ne ring laser with a 4 mirrors
square cavity. The laser is pumped by an RF discharge where the RF oscillator
includes the laser plasma in order to reach a better stability. The contrast of
the Sagnac fringes is typically above 50% and a stable regime has been reached
with the laser operating both single mode or multimode. The effect of hydrogen
contamination on the laser was also checked. A low-frequency sensitivity, below
, in the range of has been
measured.Comment: 6 pages, 6 figures, presented at the EFTF-IFCS joint conference 200
Generation of an ultrastable 578 nm laser for Yb lattice clock
In this paper we described the development and the characterization of a 578 nm laser source to be the clock laser for an Ytterbium Lattice Optical clock. Two independent laser sources have been realized and the characterization of the stability with a beat note technique is presente
Effect of Water Content on the Thermal Inactivation Kinetics of Horseradish Peroxidase Freeze-Dried from Alkaline pH
The thermal inactivation of horseradish peroxidase freeze-dried from solutions of different pH (8, 10 and 11.5, measured at 25 C) and equilibrated to different water contents was studied in the temperature range from 110 to 150 C. The water contents studied (0.0, 1.4, 16.2 and 25.6 g water per 100 g of dry enzyme) corresponded to water activities of 0.0, 0.11, 0.76 and 0.88 at 4 C. The kinetics were well described by a double exponential model. The enzyme was generally more stable the lower the pH of the original solution, and for all pH values, the maximum stability was obtained at 1.4 g water/100 g dry enzyme. Values of z were generally independent of water content and of the pH of the original solution, and in the range of 15–25 °C, usually found in neutral conditions, with the exception of the enzyme freeze dried from pH 11.5 and equilibrated with phosphorus pentoxide, where a z-value of the stable fraction close to 10 C was found
Detailed X-ray spectroscopy of the magnetar 1E 2259+586
Magnetic field geometry is expected to play a fundamental role in magnetar
activity. The discovery of a phase-variable absorption feature in the X-ray
spectrum of SGR 0418+5729, interpreted as cyclotron resonant scattering,
suggests the presence of very strong non-dipolar components in the magnetic
fields of magnetars. We performed a deep XMM-Newton observation of pulsar 1E
2259+586, to search for spectral features due to intense local magnetic fields.
In the phase-averaged X-ray spectrum, we found evidence for a broad absorption
feature at very low energy (0.7 keV). If the feature is intrinsic to the
source, it might be due to resonant scattering/absorption by protons close to
star surface. The line energy implies a magnetic field of ~ 10^14 G, roughly
similar to the spin-down measure, ~ 6x10^13 G. Examination of the X-ray
phase-energy diagram shows evidence for a further absorption feature, the
energy of which strongly depends on the rotational phase (E >~ 1 keV ). Unlike
similar features detected in other magnetar sources, notably SGR 0418+5729, it
is too shallow and limited to a small phase interval to be modeled with a
narrow phase-variable cyclotron absorption line. A detailed phase-resolved
spectral analysis reveals significant phase-dependent variability in the
continuum, especially above 2 keV. We conclude that all the variability with
phase in 1E 2259+586 can be attributed to changes in the continuum properties
which appear consistent with the predictions of the Resonant Compton Scattering
model
Co-design, co-learning, and co-production of an app for pancreatic cancer patients—the “Pancreas Plus” study protocol
Background: Pancreatic cancer is a malignant and complex tumor that often leads to an adverse prognosis.
Patients need to face a challenging treatment path, which involves highly-specialized multidisciplinary
professionals. The complexity of the disease requires the development of dedicated tools to support patients
in their care journey. Co-production stands as a valuable strategy in oncological care to engage patients in
understanding their care journey and behaving accordingly to get the best possible clinical outcome.
Methods: The non-profit association Unipancreas, active in promoting the latest advances in pancreatic
cancer care and in supporting pancreatic cancer patients, has partnered with a multidisciplinary group
of professionals to conceive the brand new program “Pancreas Plus” to employ a co-design, co-learning,
and co-production path to design an app devoted to pancreatic cancer patients to assist them during their
treatment and follow-up journey. The app, which is the outcome of a multi-stakeholder engagement project,
offers health information and medical advice specifically tailored on the pancreatic cancer disease. The
article reports the research protocol, which may be replicated for the design of other e-health tools focusing
on different conditions.
Discussion: The study’s output will be an app that sees the pancreatic cancer patient as the main
beneficiary but which can gather and address the interests and needs of all meaningful stakeholders, including
clinicians, researchers, healthcare and educational institutions, and
A Large Area Fiber Optic Gyroscope on multiplexed fiber network
We describe a fiber optical gyroscope based on the Sagnac effect realized on a multiplexed telecom fiber network. Our loop encloses an area of 20 km2 and coexists with Internet data traffic. This Sagnac interferometer achieves a sensitivity of about (10-8 rad/s)/sqrt(Hz), thus approaching ring laser gyroscopes without using narrow linewidth laser nor sophisticated optics. The proposed gyroscope is sensitive enough for seismic applications, opening new possibilities for this kind of optical fiber sensors
Realization of an Ultrastable 578-nm Laser for an Yb Lattice Clock
In this paper, we describe the development of an ultrastable laser source at 578 nm, realized using frequency sum generation. This source will be used to excite the clock transition 1S0-3P0 in an ytterbium optical lattice clock experiment. Two independent ultrastable lasers have been realized, and the laser frequency noise and stability have been characterize
Interval Sentinel Lymph Nodes: An Unusual Localization in Patients with Cutaneous Melanoma
Background. Recent studies have demonstrated that there exists a great variation in the lymphatic drainage in patients with malignant melanoma. Some patients have drainage to lymph nodes outside of conventional nodal basins. The lymph nodes that exist between a primary melanoma and its regional nodal basin are defined “interval nodes”. Interval node occurs in a small minority of patients with forearm melanoma. We report our experience of the Melanoma Unit of University Hospital Spedali Civili Brescia, Italy. Methods. Lymphatic mapping using cutaneous lymphoscintigraphy (LS) has become a standard preoperative diagnostic procedure to locate the sentinel lymph nodes (SLNs) in cutaneous melanoma. We used LS to identify sentinel lymph nodes biopsy (SLNB) in 480 patients. Results. From over 2100 patients affected by cutaneous melanoma, we identified 2 interval nodes in 480 patients with SLNB . The melanomas were both located in the left forearm. The interval nodes were also both located in the left arm. Conclusion. The combination of preoperative LS and intraoperative hand-held gamma detecting probe plays a remarkable role in identifying these uncommon lymph node locations. Knowledge of the unusual drainage patterns will help to ensure the accuracy and the completeness of sentinel nodes identification
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