SuperAGILE: the hard X-ray Imager for the AGILE space mission

SuperAGILE is a coded mask experiment based on silicon microstrip detectors. It operates in the 15-45 keV nominal energy range, providing crossed one-dimensional images of the X-ray sky with an on-axis angular resolution of 6 arcmin, over a field of view in excess of 1 steradian. It was designed as the hard X-ray monitor of the AGILE space mission, a small satellite of the Italian Space Agency devoted to image the gamma-ray sky in the 30 MeV - 50 GeV energy band. The AGILE mission was launched in a low-earth orbit on 23^{rd} April 2007. In this paper we describe the SuperAGILE experiment, its construction and test processes, and its performance before flight, based on the on-ground test and calibrations.Comment: Nucl. Instr. and Meth. A, in press. Full version with figures included in the text, now available at: ftp://vesta.rm.iasf.cnr.it/pub/mferoci/ It will also be linked at the official AGILE web page

THE NUCK'S CYST: A DISEASE EASILY CONFUSED FOR INGUINAL HERNIA. A CASE REPORT.

Nuck's canal cyst is a blind end adult residual of the fetal peritoneum. These rare cyst formations are usually found in the inguinal canal and can easily be mistaken for hernia, or enlarged limph nodes. Clinically, a Nuck's canal cyst appears as a painless or moderately painful swelling in inguinal area. We report the case of a 40 years-old woman with a painless swelling in her left inguinal region, believed a groin hernia but diagnosed as a Nuck's canal cyst only after intervention. Intraoperatively, the cyst was opened and sebsequently excised, closing the abdominal wall without the use of any sort of syntetic prostetic material

OBTAINING MESENCHYMAL STEM CELLS FROM ADIPOSE TISSUE OR MURIN ORIGIN: EXPERIMENTAL STUDY.

The aim of this study was to isolate and characterize rat adipose Derived Mesenchymal Stem Cells (AD-MSCs) in order to evaluate their proliferative potential and their ability to different cell types. AD-MSCs and Derived Mesenchymal Stem Cells (BM-MSCs) have the same characteristic in terms of plasticity. The advantage of adipose tissue is that it is an easier accessible source and it offers a large amount of MSCs by less invasive surgical tecniques. MSCs were obtained from subcutaneous adipose tissue of Wistar rats. first of all microbiological controls were made to exclude the presence of bacteria of fungi in then tissue. Adipose tissue was mechanically and enzimatically fragmented and stromal cell fraction was seeded in adherent culture flasks in DMEM 20% FBS. After 48 h the medium was replaced. Cells were characterized by evaluating:1)their ability tho adhere to the plastic; 2) the clonogenic potential by Colony Forming Unit (CFU) assay, 3) their ability to differentiate in 3 mesodermal lineages (adipocytes, osteocytes and chondrocytes). AD-MSCs are able to differentiate in adipocytes, osteocytes and chondrocytes as confirmed by oil red'O staining, von Kossa staining and histological analuysis respectively. This first characterization is essential for the second part of our study in which we are planning to use AD-MSCs in vivo to restore renal function after an induced ischemic damage in experimental animals

AGILE detection of delayed gamma-ray emission from GRB 080514B

GRB 080514B is the first gamma ray burst (GRB), since the time of EGRET, for which individual photons of energy above several tens of MeV have been detected with a pair-conversion tracker telescope. This burst was discovered with the Italian AGILE gamma-ray satellite. The GRB was localized with a cooperation by AGILE and the interplanetary network (IPN). The gamma-ray imager (GRID) estimate of the position, obtained before the SuperAGILE-IPN localization, is found to be consistent with the burst position. The hard X-ray emission observed by SuperAGILE lasted about 7 s, while there is evidence that the emission above 30 MeV extends for a longer duration (at least ~13 s). Similar behavior was seen in the past from a few other GRBs observed with EGRET. However, the latter measurements were affected, during the brightest phases, by instrumental dead time effects, resulting in only lower limits to the burst intensity. Thanks to the small dead time of the AGILE/GRID we could assess that in the case of GRB 080514B the gamma-ray to X-ray flux ratio changes significantly between the prompt and extended emission phase.Comment: A&A letters, in pres

Observation of the TeV gamma-ray source MGRO J1908+06 with ARGO-YBJ

The extended gamma ray source MGRO J1908+06, discovered by the Milagro air shower detector in 2007, has been observed for about 4 years by the ARGO-YBJ experiment at TeV energies, with a statistical significance of 6.2 standard deviations. The peak of the signal is found at a position consistent with the pulsar PSR J1907+0602. Parametrizing the source shape with a two-dimensional Gauss function we estimate an extension \sigma = 0.49 \pm 0.22 degrees, consistent with a previous measurement by the Cherenkov Array H.E.S.S.. The observed energy spectrum is dN/dE = 6.1 \pm 1.4 \times 10^-13 (E/4 TeV)^{-2.54 \pm 0.36} photons cm^-2 s^-1 TeV^-1, in the energy range 1-20 TeV. The measured gamma ray flux is consistent with the results of the Milagro detector, but is 2-3 times larger than the flux previously derived by H.E.S.S. at energies of a few TeV. The continuity of the Milagro and ARGO-YBJ observations and the stable excess rate observed by ARGO-YBJ along 4 years of data taking support the identification of MGRO J1908+06 as the steady powerful TeV pulsar wind nebula of PSR J1907+0602, with an integrated luminosity above 1 TeV about 1.8 times the Crab Nebula luminosity.Comment: 6 pages, accepted for pubblication by ApJ. Replaced to correct the author lis

THE VALUE OF DIAGNOSTIC ULTRASOUND FOR DETECTING OCCULT INGUINAL HERNIA IN PATIENTS WITH GROIN PAIN

Aims: chronic groin pain caused by an occult hernia can be a difficult clinical diagnosis and may require additional investiga- tive modalities. The aim of this study was to demonstrate the accuracy of ultrasound in diagnosing occult hernia in patients with recurrent inguinal pain and a negative clinical examination. Patients and methods: over a period of three years, a total of 76 patients were referred for ultrasound examination with clini- cally suspected occult inguinal hernia. Patients with positive US scans were offered surgery, while those with negative US findings were offered further imaging or other diagnostic tests. The ultrasound examination of the inguinal region was conducted using a 5- 10 MHz linear probe. The scan was performed with the patient in the supine and erect positions, in a relaxed state, as well as during coughing and during a Valsalva manoeuvre. Results: overall, ultrasound diagnosed 31 inguinal hernias and all 31 patients with positive scans underwent surgery. Surgery confirmed the ultrasound diagnosis in 30 patients, having only 1/31 no hernia at operation (100% ultrasound sensitivity and 96.9% specificity). Patients undergoing surgery showed complete symptom resolution at a three-month follow-up. Conclusions: this study confirms that ultrasound is capable of accurately diagnosing groin hernia and this may justify its use in patients with chronic groin pain due to a suspected occult herni

Direct Evidence for Hadronic Cosmic-Ray Acceleration in the Supernova Renmant IC 443

The Supernova Remnant (SNR) IC 443 is an intermediate-age remnant well known for its radio, optical, X-ray and gamma-ray energy emissions. In this Letter we study the gamma-ray emission above 100 MeV from IC 443 as obtained by the AGILE satellite. A distinct pattern of diffuse emission in the energy range 100 MeV-3 GeV is detected across the SNR with its prominent maximum (source "A") localized in the Northeastern shell with a flux F = (47 \pm 10) 10^{-8} photons cm^{-2} s^{-1} above 100 MeV. This location is the site of the strongest shock interaction between the SNR blast wave and the dense circumstellar medium. Source "A" is not coincident with the TeV source located 0.4 degree away and associated with a dense molecular cloud complex in the SNR central region. From our observations, and from the lack of detectable diffuse TeV emission from its Northeastern rim, we demonstrate that electrons cannot be the main emitters of gamma-rays in the range 0.1-10 GeV at the site of the strongest SNR shock. The intensity, spectral characteristics, and location of the most prominent gamma-ray emission together with the absence of co-spatial detectable TeV emission are consistent only with a hadronic model of cosmic-ray acceleration in the SNR. A high-density molecular cloud (cloud "E") provides a remarkable "target" for nucleonic interactions of accelerated hadrons: our results show enhanced gamma-ray production near the molecular cloud/shocked shell interaction site. IC 443 provides the first unambiguous evidence of cosmic-ray acceleration by SNRs.Comment: 5 pages, 2 figures; accepted by ApJLetters on Jan 21, 201

Episodic Transient Gamma-Ray Emission from the Microquasar Cygnus X-1

Cygnus X-1 is the archetypal black hole (BH) binary system in our Galaxy. We report the main results of an extensive search for transient gamma-ray emission from Cygnus X-1 carried out in the energy range 100 MeV - 3 GeV by the AGILE satellite, during the period 2007 July - 2009 October. The total exposure time is about 300 days, during which the source was in the "hard" X-ray spectral state. We divided the observing intervals in 2 or 4 week periods, and searched for transient and persistent emission. We report an episode of significant transient gamma-ray emission detected on 2009, October 16 in a position compatible with Cygnus X-1 optical position. This episode, occurred during a hard spectral state of Cygnus X-1, shows that a 1-2 day time variable emission above 100 MeV can be produced during hard spectral states, having important theoretical implications for current Comptonization models for Cygnus X-1 and other microquasars. Except for this one short timescale episode, no significant gamma-ray emission was detected by AGILE. By integrating all available data we obtain a 2$\sigma$ upper limit for the total integrated flux of $F_{\gamma,U.L.} = 3 \times 10^{-8} \rm ph cm^{-2} s^{-1}$ in the energy range 100 MeV - 3 GeV. We then clearly establish the existence of a spectral cutoff in the energy range 1-100 MeV that applies to the typical hard state outside the flaring period and that confirms the historically known spectral cutoff above 1 MeV.Comment: Accepted for publication by ApJ on the 9th of Feb 2010, 5 pages, 3 figure