474 research outputs found
The Actuator Design and the Experimental Tests of a New Technology Large Deformable Mirror for Visible Wavelengths Adaptive Optics
Recently, Adaptive Secondary Mirrors showed excellent on-sky results in the
Near Infrared wavelengths. They currently provide 30mm inter-actuator spacing
and about 1 kHz bandwidth. Pushing these devices to be operated at visible
wavelengths is a challenging task. Compared to the current systems, working in
the infrared, the more demanding requirements are the higher spatial resolution
and the greater correction bandwidth. In fact, the turbulence scale is shorter
and the parameter variation is faster. Typically, the former is not larger than
25 mm (projected on the secondary mirror) and the latter is 2 kHz, therefore
the actuator has to be more slender and faster than the current ones. With a
soft magnetic composite core, a dual-stator and a single-mover, VRALA, the
actuator discussed in this paper, attains unprecedented performances with a
negligible thermal impact. Pre-shaping the current required to deliver a given
stroke greatly simplifies the control system, whose output supplies the current
generator. As the inductance depends on the mover position, the electronics of
this generator, provided with an inductance measure circuit, works also as a
displacement sensor, supplying the control system with an accurate feed-back
signal. A preliminary prototype, built according to the several FEA
thermo-magnetic analyses, has undergone some preliminary laboratory tests. The
results of these checks, matching the design results in terms of power and
force, show that the the magnetic design addresses the severe specifications
STEPS TO A LOCALIZATION OF A STUDENT CENTRED IS AN EXPLORATORY APPROACH
In this exploratory paper we propose a particular interpretation of what “localization” and “centring” could represent within a n-fold approach, aimed to question the reality to raise analytic and methodological issues. This concern a discussion on a project of localization of an information system addressed to student\u27s needs. Our subject of analysis is the student of Trento University (Italy) that stands for the pivoting point of the comprehension and knowledge of the situated context we study. Adopting a scenario-based design we try to give the researchers and designers a useful tool embodying the questions and problems of a complex reality such student\u27s life is
AO@SW with Vrala: Simulations and Tests
Designed to actuate large correction forces on small spatial scales for the next generation deformable mirrors, VRALA is the ideal candidate for the Adaptive Optics actuators at visible wavelengths. Using its electric characteristics variations, properly supplying current commands, and optimizing the magnetic circuit geometry, the required force is delivered with a correction bandwidth of 2 kHz, and a 25 mm actuation density can be achieved. The dual-stator, single-mover soft magnetic composite core provides unprecedented performances with a negligible thermal impact. Pre-shaping the coil currents required to deliver a given stroke greatly simpli es the control system. Equipped with an inductance measure circuit, the current generator also provides the control system with an accurate feed-back signal. The Comsol non-linear model of VRALA allows to de ne the optimized geometry, to compute the dynamic response to the closed-loop control system, and to calculate the circuit inductance. The tests performed on a preliminary prototype, built according to the Comsol analyses, match the design results in terms of power and force
Immune Checkpoint Inhibitors as a Neoadjuvant/Adjuvant Treatment of Muscle-Invasive Bladder Cancer: A Systematic Review
Bladder cancer is the ninth most common cancer worldwide. Over 75% of non-muscle invasive cancer patients require conservative local treatment, while the remaining 25% of patients undergo radical cystectomy or radiotherapy. Immune checkpoint inhibitors represent a novel class of immunotherapy drugs that restore natural antitumoral immune activity via the blockage of inhibitory receptors and ligands expressed on antigen-presenting cells, T lymphocytes and tumour cells. The use of immune checkpoint inhibitors in bladder cancer has been expanded from the neoadjuvant setting, i.e., after radical cystectomy, to the adjuvant setting, i.e., before the operative time or chemotherapy, in order to improve the overall survival and to reduce the morbidity and mortality of both the disease and its treatment. However, some patients do not respond to checkpoint inhibitors. As result, the capability for identifying patients that are eligible for this immunotherapy represent one of the efforts of ongoing studies. The aim of this systematic review is to summarize the most recent evidence regarding the use of immune checkpoint inhibitors, in a neoadjuvant and adjuvant setting, in the treatment of muscle-invasive bladder cancer
The Acute Abdomen Decision Making course for the initial management of non traumatic acute abdomen: A proposition of the World Society of Emergency Surgeons
The Acute Abdomen Decision Making course® (AADM®) was developed by the World Society of Emergency Surgeons (WSES) members with the purpose to teach a systematic and concise method for approaching acute abdomen patient. It was first introduced in 2016. The course explains step by step the clinical reasoning to follow for immediate managing of the acute abdomen in emergency department with a safe and reliable method. We developed this original decision making model AADM following the Advanced Trauma Life Support (ATLS) philosophy in evaluating non-traumatic abdominal pain patient. The A-B-C-D-E-F management of non-traumatic acute abdominal pain is conceived by WSES to make easy and systematic the evaluation of patients in Emergency Department. AADM course teaches how to assess an acute abdomen patient’s diagnosis and determine the therapeutic approach to reduce unnecessary exams and hospitalizations
Neuro-Immune Hemostasis: Homeostasis and Diseases in the Central Nervous System
Coagulation and the immune system interact in several physiological and pathological conditions, including tissue repair, host defense, and homeostatic maintenance. This network plays a key role in diseases of the central nervous system (CNS) by involving several cells (CNS resident cells, platelets, endothelium, and leukocytes) and molecular pathways (protease activity, complement factors, platelet granule content). Endothelial damage prompts platelet activation and the coagulation cascade as the first physiological step to support the rescue of damaged tissues, a flawed rescuing system ultimately producing neuroinflammation. Leukocytes, platelets, and endothelial cells are sensitive to the damage and indeed can release or respond to chemokines and cytokines (platelet factor 4, CXCL4, TNF, interleukins), and growth factors (including platelet-derived growth factor, vascular endothelial growth factor, and brain-derived neurotrophic factor) with platelet activation, change in capillary permeability, migration or differentiation of leukocytes. Thrombin, plasmin, activated complement factors and matrix metalloproteinase-1 (MMP-1), furthermore, activate intracellular transduction through complement or protease-activated receptors. Impairment of the neuro-immune hemostasis network induces acute or chronic CNS pathologies related to the neurovascular unit, either directly or by the systemic activation of its main steps. Neurons, glial cells (astrocytes and microglia) and the extracellular matrix play a crucial function in a “tetrapartite” synaptic model. Taking into account the neurovascular unit, in this review we thoroughly analyzed the influence of neuro-immune hemostasis on these five elements acting as a functional unit (“pentapartite” synapse) in the adaptive and maladaptive plasticity and discuss the relevance of these events in inflammatory, cerebrovascular, Alzheimer, neoplastic and psychiatric diseases. Finally, based on the solid reviewed data, we hypothesize a model of neuro-immune hemostatic network based on protein–protein interactions. In addition, we propose that, to better understand and favor the maintenance of adaptive plasticity, it would be useful to construct predictive molecular models, able to enlighten the regulating logic of the complex molecular network, which belongs to different cellular domains. A modeling approach would help to define how nodes of the network interact with basic cellular functions, such as mitochondrial metabolism, autophagy or apoptosis. It is expected that dynamic systems biology models might help to elucidate the fine structure of molecular events generated by blood coagulation and neuro-immune responses in several CNS diseases, thereby opening the way to more effective treatments
Radiation therapy of anal canal cancer: from conformal therapy to volumetric modulated arc therapy
Assessment of Sexual Dysfunction in Cervical Cancer Patients after Different Treatment Modality: A Systematic Review
Background and Objectives: Cervical cancer is a leading cause of mortality among women. Chemo-radiation followed by interventional radiotherapy (IRT) is the standard of care for stage IB-IVA FIGO. Several studies have shown that image-guided adaptive IRT resulted in excellent local and pelvic control, but it is associated with vaginal toxicity and intercourse problems. The purpose of this review is to evaluate the dysfunctions of the sexual sphere in patients with cervical cancer undergoing different cervix cancer treatments. Materials and Methods: We performed a comprehensive literature search using Pub med, Scopus and Cochrane to identify all the full articles evaluating the dysfunctions of the sexual sphere. ClinicalTrials.gov was searched for ongoing or recently completed trials, and PROSPERO was searched for ongoing or recently completed systematic reviews. Results: One thousand three hundred fifty-six women included in five studies published from 2016 to 2022 were analyzed. The median age was 50 years (range 46-56 years). The median follow-up was 12 months (range 0-60). Cervical cancer diagnosis and treatment (radiotherapy, chemotherapy and surgery) negatively affected sexual intercourse. Sexual symptoms such as fibrosis, strictures, decreased elasticity and depth and mucosal atrophy promote sexual dysfunction by causing frigidity, lack of lubrication, arousal, orgasm and libido and dyspareunia. Conclusions: Physical, physiological and social factors all contribute to the modification of the sexual sphere. Cervical cancer survivors who were irradiated have lower sexual and vaginal function than the normal population. Although there are cures for reducing discomfort, effective communication about sexual dysfunctions following treatment is essential
The Herschel Virgo Cluster Survey XIX. Physical properties of low luminosity FIR sources at z < 0.5
Context. The star formation rate is a crucial parameter for the investigation galaxy evolution. At low redshift the cosmic star formation rate density declines smoothly, and massive active galaxies become passive, reducing their star formation activity. This implies that the bulk of the star formation rate density at low redshift is mainly driven by low mass objects.
Aims. We investigate the properties of a sample of low luminosity far-infrared sources selected at 250 μm. We have collected data from ultraviolet to far-infrared in order to perform a multiwavelengths analysis. The main goal is to investigate the correlation between star formation rate, stellar mass, and dust mass for a galaxy population with a wide range in dust content and stellar mass, including the low mass regime that most probably dominates the star formation rate density at low redshift.
Methods. We define a main sample of ~800 sources with full spectral energy distribution coverage between 0.15 <λ< 500 μm and an extended sample with ~5000 sources in which we remove the constraints on the ultraviolet and near-infrared bands. We analyze both samples with two different spectral energy distribution fitting methods: MAGPHYS and CIGALE, which interpret a galaxy spectral energy distribution as a combination of different simple stellar population libraries and dust emission templates.
Results. In the star formation rate versus stellar mass plane our samples occupy a region included between local spirals and higher redshift star forming galaxies. These galaxies represent the population that at z 3 × 1010 M⊙) do not lie on the main sequence, but show a small offset as a consequence of the decreased star formation. Low mass galaxies (M∗< 1 × 1010 M⊙) settle in the main sequence with star formation rate and stellar mass consistent with local spirals.
Conclusions. Deep Herschel data allow the identification of a mixed galaxy population with galaxies still in an assembly phase or galaxies at the beginning of their passive evolution. We find that the dust luminosity is the parameter that allow us to discriminate between these two galaxy populations. The median spectral energy distribution shows that even at low star formation rate our galaxy sample has a higher mid-infrared emission than previously predicted
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