596 research outputs found
First optical validation of a Schwarzschild Couder telescope: the ASTRI SST-2M Cherenkov telescope
The Cherenkov Telescope Array (CTA) represents the most advanced facility
designed for Cherenkov Astronomy. ASTRI SST-2M has been developed as a
demonstrator for the Small Size Telescope in the context of the upcoming CTA.
Its main innovation consists in the optical layout which implements the
Schwarzschild-Couder configuration and is fully validated for the first time.
The ASTRI SST-2M optical system represents the first qualified example for two
mirrors telescope for Cherenkov Astronomy.
This configuration permits to (i) maintain a high optical quality across a
large FoV (ii) de-magnify the plate scale, (iii) exploit new technological
solutions for focal plane sensors. The goal of the paper is to present the
optical qualification of the ASTRI SST-2M telescope. The qualification has been
obtained measuring the PSF sizes generated in the focal plane at various
distance from the optical axis. These values have been compared with the
performances expected by design.
After an introduction on the Gamma Astronomy from the ground, the optical
design and how it has been implemented for ASTRI SST-2M is discussed. Moreover
the description of the setup used to qualify the telescope over the full field
of view is shown.
We report the results of the first--light optical qualification. The required
specification of a flat PSF of arcmin in a large field of view ~10
deg has been demonstrated. These results validate the design specifications,
opening a new scenario for Cherenkov Gamma ray Astronomy and, in particular,
for the detection of high energy (5 - 300 TeV) gamma rays and wide-field
observations with CTA.Comment: 6 pages, 5 figure
Sivelestat relieves respiratory distress refractory to dexamethasone in all-trans retinoic acid syndrome: a report of two cases
Kawasaki K, Akaike H, Miyauchi A, Ouchi K. Sivelestat relieves respiratory distress refractory to dexamethasone in all-trans retinoic acid syndrome: a report of two cases. Treatment with all-trans retinoic acid (ATRA) improves the prognosis of patients with acute promyelocytic leukemia (APL), but ATRA syndrome may occur as a possible fatal side effect, especially in cases refractory to medication or involving pulmonary hemorrhage. We describe two patients with APL who suffered from intracranial hemorrhage. The first patient was a 16-yr-old girl who was treated with ATRA and then developed respiratory distress refractory to treatment with dexamethasone combined with anthracycline-cytarabine cytoreduction therapy. Treatment with Sivelestat, a small molecule inhibitor of neutrophil elastase, achieved rapid improvement in oxygenation and chest radiograph findings, and the patient has been in complete remission for 24 months. The second patient was a 10-yr-old boy in whom pulmonary hemorrhage developed following administration of ATRA, dexamethasone and cytoreduction therapy. Aspiration and administration of Sivelestat improved oxygenation and he remained stable. Hematological improvement was also achieved, but the patient died of brain dysfunction because of cerebral edema accompanied by intracranial bleeding. The two cases suggest that Sivelestat may be effective as an additional agent in the treatment of refractory ATRA syndrome, and, therefore, prospective randomized studies of treatment protocols are warranted
Autoimmune cytopenias in chronic lymphocytic leukemia
Chronic lymphocytic leukemia (CLL) is frequently complicated by secondary autoimmune cytopenias (AIC) represented by autoimmune hemolytic anemia (AIHA), immune thrombocytopenia (ITP), pure red cell aplasia and autoimmune granulocytopenia. The distinction of immune cytopenias from cytopenias due to bone marrow infiltration, usually associated with a worse outcome and often requiring a different treatment, is mandatory. AIHA and ITP are more frequently found in patients with unfavorable biological risk factors for CLL. AIC secondary to CLL respond less favorably to standard treatments than their primary forms, and treating the underlying CLL with chemotherapy or monoclonal antibodies may ultimately be necessary
Expected performance of the ASTRI-SST-2M telescope prototype
ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is an
Italian flagship project pursued by INAF (Istituto Nazionale di Astrofisica)
strictly linked to the development of the Cherenkov Telescope Array, CTA.
Primary goal of the ASTRI program is the design and production of an end-to-end
prototype of a Small Size Telescope for the CTA sub-array devoted to the
highest gamma-ray energy region. The prototype, named ASTRI SST-2M, will be
tested on field in Italy during 2014. This telescope will be the first
Cherenkov telescope adopting the double reflection layout in a
Schwarzschild-Couder configuration with a tessellated primary mirror and a
monolithic secondary mirror. The collected light will be focused on a compact
and light-weight camera based on silicon photo-multipliers covering a 9.6 deg
full field of view. Detailed Monte Carlo simulations have been performed to
estimate the performance of the planned telescope. The results regarding its
energy threshold, sensitivity and angular resolution are shown and discussed.Comment: In Proceedings of the 33rd International Cosmic Ray Conference
(ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223
Old and new prognostic factors in acute myeloid leukemia with deranged core-binding factor beta.
Acute myeloid leukemia (AML) with deranged core-binding factor beta (CBF\u3b2) is usually associated with a favorable prognosis with 50-70% of patients cured using contemporary treatments. We analyzed the prognostic significance of clinical features on 58 patients with CBF\u3b2-AML aged 6460 years. Increasing age was the only predictor for survival (P <0.001), with an optimal cut-point at 43 years. White blood cells (WBCs) at diagnosis emerged as an independent risk factor for relapse incidence (P\u2009=\u20090.017), with 1.1% increase of hazard for each 1.0
7 109 /L WBC increment. KIT mutations lacked prognostic value for survival and showed only a trend for relapse incidence (P\u2009=\u20090.069)
Circulating myeloid-derived suppressor cells predict disease activity and treatment response in patients with immune thrombocytopenia
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