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S Altieri

Publications and source records attributed to S Altieri.

At least 19 recordsLinked to original sources
PubMed2006

Measurement of the Gerasimov-Drell-Hearn Integrand for 2H from 200 to 800 MeV.

A measurement of the helicity dependence of the total inclusive photoabsorption cross section on the deuteron was carried out at MAMI (Mainz) in the energy range 200<Egamma<800 MeV. The experiment used a 4pi detection system, a circularly polarized tagged photon beam and a frozen-spin target which provided longitudinally polarized deuterons. The contribution to the Gerasimov-Drell-Hearn sum rule for the deuteron determined from the data is 407+/-20(stat)+/-24(syst) mu b for 200<Egamma<800 MeV.

Journal Article↗
PubMed2005

Measurement of helicity-dependent photoabsorption cross sections on the neutron from 815 to 1825 MeV.

Helicity-dependent total photoabsorption cross sections on the deuteron have been measured for the first time at ELSA (Bonn) in the photon energy range from 815 to 1825 MeV. Circularly polarized tagged photons impinging on a longitudinally polarized LiD target have been used together with a highly efficient 4pi detector system. The data around 1 GeV are not compatible with predictions from existing multipole analyses. From the measured energy range an experimental contribution to the GDH integral on the neutron of [33.9 +/- 5.5(stat) +/- 4.5(syst)] microb is extracted.

Journal Article↗
PubMed2004

Experimental check of the Gerasimov-Drell-Hearn sum rule for 1H.

For the first time we checked the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the proton experimentally in the photon energy range from 0.2-2.9 GeV with the tagged photon facilities at MAMI (Mainz) and ELSA (Bonn). New data of the doubly polarized total cross section difference are presented in the energy range from 1.6 to 2.9 GeV. The contribution to the GDH integral from 0.2-2.9 GeV yields [254+/-5(stat)+/-12(syst)] microb with negative contributions in the Regge regime at photon energies above 2.1 GeV. This trend supports the validity of the GDH sum rule.

Journal Article↗
PubMed2004

How to study boron biodistribution in liver metastases from colorectal cancer.

The purpose of this study was to evaluate boron distribution for a safe and effective BNCT (Boron Neutron Capture Therapy) of liver metastases. Samples both from healthy and tumour liver parenchyma were analysed, after i.v. boron administration, by: alpha particles counting under neutron irradiation; morphological analysis by standard haematoxylin-eosin staining; neutron autoradiography. Our method was unaffected by the cytological heterogeneity inside tumour nodules; it demonstrated selective boron distribution in tumour tissue and predicted estimated mean therapeutic doses in tumour and safety doses in healthy tissue. The time interval for efficient BNCT was 2 to 4 hours after i.v. boron administration.

Animals↗
PubMed2003

First Measurement of the Gerasimov-Drell-Hearn Sum Rule for 1H from 0.7 to 1.8 GeV at ELSA.

To verify the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the first time experimentally, we measured the helicity dependent total photoabsorption cross section with circularly polarized real photons and longitudinally polarized nucleons in the photon energy range 0.68-1.82 GeV with the tagged photon facility at ELSA. The experiment was carried out with a 4pi detection system, a circularly polarized tagged photon beam, and a frozen spin polarized proton target. The contribution to the GDH sum rule in this photon energy range is [49.9+/-2.4(stat)+/-2.2(syst)] microb.

Journal Article↗
PubMed2003

Magnetic dichroism and spin structure of antiferromagnetic NiO(001) films.

We find that Ni L2 edge x-ray magnetic linear dichroism is fully reversed for NiO(001) films on materials with reversed lattice mismatch. We relate this phenomenon to a preferential stabilization of magnetic S domains with main spin component either in or out of the plane, via dipolar interactions. This suggests a way to selectively control spin structures in 3d systems with small spin-orbit coupling.

Journal Article↗
PubMed2002

Helicity amplitudes A1/2 and A3/2 for the D13(1520) resonance obtained from the gamma-->p-->-->ppi(0) Reaction.

The helicity dependence of the gamma-->p-->-->ppi(0) reaction has been measured for the first time in the photon-energy range from 550 to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. These data are predominantly sensitive to the D13(1520) resonance and are used to determine its helicity amplitudes.

Journal Article↗
PubMed2002

Simulations of neutron transport at low energy: a comparison between GEANT and MCNP.

The use of the simulation tool GEANT for neutron transport at energies below 20 MeV is discussed, in particular with regard to shielding and dose calculations. The reliability of the GEANT/MICAP package for neutron transport in a wide energy range has been verified by comparing the results of simulations performed with this package in a wide energy range with the prediction of MCNP-4B, a code commonly used for neutron transport at low energy. A reasonable agreement between the results of the two codes is found for the neutron flux through a slab of material (iron and ordinary concrete), as well as for the dose released in soft tissue by neutrons. These results justify the use of the GEANT/MICAP code for neutron transport in a wide range of applications, including health physics problems.

Computer Simulation↗
PubMed2001

A pilot survey of cystic fibrosis clinical manifestations in CFTR mutation heterozygotes.

A cystic fibrosis (CF) heterozygote incidence higher than in the general population has been repeatedly reported in conditions which include clinical features found in CF, like pancreatitis, disseminated bronchiectasis, and allergic bronchopulmonary aspergillosis. Some cases may be explained by an unidentified compound heterozygosity; others could be manifesting heterozygotes. This study was aimed at detecting the incidence of CF-related clinical features in a population of carriers. A group of 261 obligate heterozygotes (mean age, 44 years) and a control group, composed of 201 individuals negative for a standard mutation panel (mean age, 36 years), were surveyed for possibly CF-related conditions (asthma, bronchiectasis, pneumothorax, allergic bronchopulmonary aspergillosis, sinusitis, nasal polyps, gallstones, liver cirrhosis, diabetes, pancreatitis, bone fractures, plus hypertension). A questionnaire was administered, and the accuracy of the statements was evaluated by phone interviews. There was no difference between heterozygotes and controls, with the exception of hypertension (carriers 28/261, controls 7/201, p = 0.004), and, in males, nasal polyps (carriers 7/126, controls 0/102, p value = 0.0178), and, again, hypertension (carriers 17/126, controls 5/102, p value = 0.0407). To avoid age bias, 126 heterozygotes matched to controls of the same gender and age were separately processed: these two groups showed no significant differences. CF-related clinical manifestations in obligate CFTR mutation heterozygotes are not more represented than in individuals with a low risk of being carriers.

Adolescent↗
PubMed2001

Neonatal screening for cystic fibrosis: long-term clinical balance.

BACKGROUND/AIMS: Very few studies have been performed on the long-term clinical advantages of neonatal screening programs for cystic fibrosis (CF) and these have been inconclusive. This is a preliminary report of two observational cohort studies on this subject. METHODS: In the first study, CF patients born between 1973 and 1981 in northeastern Italy were split into 4 groups according to the modality of diagnosis: screening by meconium test (58 patients); meconium ileus (45 patients); symptoms and pancreatic insufficiency (PI; 75 patients), or symptoms and pancreatic sufficiency (PS; 19 patients). The patients were followed for up to 26 years by three CF centers sharing common treatment protocols. In the second study, two cohorts of CF patients born between 1983 and 1992 were compared. Patients from one cohort (126 patients) were born in the Veneto region, where a neonatal screening program had been established based on immunoreactive trypsinogen. Patients from the other cohort (152 patients) were born in Sicily, where an intensive program of early diagnosis by symptoms was implemented. The cohorts were comparable for CF incidence, CFTR genotypes, gender proportion and common treatment protocols. Statistical analyses were performed by Kaplan-Meier survival curves, a Cox proportional hazard model for survival and cross-sectional comparisons by 2-year periods for weight z score, height z score and body mass index. RESULTS: In the first study, the patients detected by newborn screening (PI) showed better survival and nutritional status compared to patients diagnosed through meconium ileus or symptom presentation with PI. PS patients diagnosed by symptoms showed the best outcome, but most of them had a mild genotype. In the second study, the Veneto cohort showed better outcome with regard to survival and nutritional status over 16 years of follow-up. CONCLUSIONS: Observational cohort studies cannot give definitive evidence of the clinical benefit of neonatal CF screening; however, data have been accumulated which strongly suggest a better clinical outcome for CF patients born in an area where a screening program is performed.

Adolescent↗
PubMed2000

Helicity dependence of gammap --> Npi below 450 MeV and contribution to the Gerasimov-Drell-Hearn sum rule.

The helicity dependence of the single pion photoproduction on the proton has been measured in the energy range from 200 to 450 MeV for the first time. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam, and a frozen-spin target. The data obtained provide new information for multipole analyses of pion photoproduction and determine the main contributions to the Gerasimov-Drell-Hearn sum rule and the forward spin polarizability gamma(0).

Journal Article↗
PubMed1999

Carrier testing program in a high-risk cystic fibrosis population from northeastern Italy. Active recruitment of relatives via probands' parents.

OBJECTIVE: To assess the practicability and monitor the results of an active carrier testing program among relatives of cystic fibrosis (CF) patients. METHODS: Parents of CF patients in the Veneto and Trentino regions of northeastern Italy were asked to help recruit relatives aged between 18 and 45 years for CF mutation testing. RESULTS: Of 409 enrolled CF parents, 59.6% agreed to send to the CF Center family composition data of relatives up to the third degree, and 28.8% recruited relatives to carrier testing, providing names and addresses of those who, being contacted, expressed a willingness to be tested. The participation of parents was higher if they were young and had a child recently diagnosed with CF. Recruiting parents indicated 333 close relatives (59%) for testing. When contacted by the CF Center, 170 of these 333 (51%) attended for testing. The percentage of close relatives who spontaneously asked for the test was 5.4% before the carrier testing program started; it rose to 25.3% following the introduction of the active strategy. CONCLUSIONS: The participation of the parents of CF patients is an important factor affecting the utilization of testing by relatives. Besides this, the influence of a favorable medical and cultural context (participation of gynecologists and family doctors in testing programs, genetic education of the general population) has to be considered.

Journal Article↗
PubMed1993

The epidemiology and surveillance of visceral leishmaniasis in the Campania region of Italy. The value of zymodeme typing.

Although human visceral leishmaniasis (VL) is a notifiable disease in Italy, there is evidence that the actual number of cases is far higher than that notified. A programme for active surveillance of VL in the 14 Italian endemic regions was launched by the Istituto Superiore di Sanità. We report data collected during a 3-year period of active surveillance in Campania, a south Tyrrhenian region covering 4.5% of the Italian territory. Out of 120 clinically suspected cases referred to medical and diagnostic references centres, there were 52 confirmed VL cases (17.3/year), i.e. 10-fold more than previously notified. Most of the infection sites were in rural areas or peripheral districts of towns in hilly parts of Naples province. An epidemic cluster of 10 cases was identified in a microfocus of Caserta province. The biochemical analysis of 23 Leishmania stocks showed a zymodeme composition indicating Campania as an old and well-established focus of VL. The data obtained emphasize that the present notification system for VL in Italy is inadequate.

Adolescent↗
PubMed1984

[The apex cardiogram in normal aged subjects].

In 25 healthy subjects aged 60-88 years (mean 74.5) and in 20 healthy subjects aged 16-32 years (mean 23.6) apexcardiographic indices were studied as a function of age. The apex cardiograms (ACG) were obtained using a non-calibrated displacement transducer. With the help of an interactive computer program, 17 ACG indices of systolic and diastolic function were computed. The indices were divided into 2 groups (according to the nomenclature proposed by their Authors): a) systolic indices: electromechanical ventricular interval q-C, systolic upstroke time C-E, time from the beginning of ventricular depolarization to the peak of the first ACG derivative q-dA/dt, time from the onset of systolic slope to the peak of first ACG derivative C-dA/dt, ejection fraction according to Antani et al. 1979 E.F.; b) diastolic indices: electromechanical atrial interval P-a, atrial wave length d.a., height of atrial wave as percent of total ACG deflection a/H, height of atrial wave as percent of total diastolic deflection a/D, ratio of the diastolic wave to the total ACG height D/H, total rapid filling cR, early filling period EFP, rapid filling period RFP, total apexcardiographic relaxation time TART, duration of diastolic period A2-C, total apexcardiographic relaxation time index TARTI and diastolic amplitude time index DATI. Several diastolic indices (a/D, a/H, TART, electromechanical atrial time) were markedly higher (p less than 0.001) or lower (TART and DATI, p less than 0.001) in the older group. Systolic indices showed less significant differences: the electromechanical interval lengthened in the older group (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗