Nuclear Structure evolution far from stability: study of 74Ni collectivity by Coulomb excitation

In recent years the availability of neutron-rich radioactive ion beams has allowed to explore new regions of the nuclear chart. Despite the most exotic nuclei have been produced with quite low intensities, new interesting results have revealed an evolution of the nuclear structure far from the valley of stability. Some of the well established fundamental properties of the uclear models, like the magic numbers, had to be reviewed in the light of new experimental observations: new features have been included in nuclear models in order to reproduce experimental data. It was recently shown, indeed, that tensor and three-body forces play an important role in breaking and creating magic numbers. One region of particular interest is the neutron-rich tail of the Ni isotopic chain. For instance the 78Ni nucleus corresponds to a double shell closure and is characterized by a large neutron excess. Some models predict that at this N/Z ratio one could expect an increase of the proton-neutron interaction strength that would modify the relative energies of the single particle states, thus reducing the Z = 28 energy gap. In such a scenario, particle-hole excitations should be strongly increased, driving to enhanced collectivity. The determination of the B(E2) values of the low-lying transitions is therefore very important to measure these features and to cons train the interaction used for the shell model calculations. In this thesis we present the measurement of the B(E2; 0+ ! 2+) transition matrix element for the first 2+ state of the 74Ni nucleus. This was done in an intermediate-energy Coulomb excitation experiment performed at NSCL (MSU) where the Coulomb excitation cross section 0+!2+ was measured, allowing to extract the B(E2 ") value. To date, 74Ni is the most xotic Ni isotope produced with enough intensity to be used as a beam for spectroscopic studies. The 74Ni beam has been produced by fragmentation of a primary 86Kr beam at 140 AMeV on a 9Be target. The primary beam was provided by the Coupled Cyclotron Facility of the NSCL and the production reaction fragments were analyzed using the A1900 fragment separator. As a matter of fact, this setup produced a secondary ”cocktailbeam“ containing 74Ni ions with an intensity of ~ 1 pps as well as higher intensity 77Zn and 75Cu fragments. An 197Au foil was used as secondary target. The scattered ions were identified by the focal plane detectors of the S800 spectrograph and coincidence gamma-rays emitted by Coulomb excited ions were detected by the 4pi CAESAR array. The results emerging from the data analysis show a different behavior with respect to the expectations. This finding opens new scenarios in the nterpretation of the shell evolution of the Z=28 isotopes. The thesis has been organized as follows: the basic concepts concerning Nuclear Structure studies far from stability and the radioactive ion beams production are introduced in chapter 1. In chapter 2 the fundamental theoretical models of Coulomb excitation are presented. In chapters 3 and 4 are respectively described the experimental setup and the data analysis of the Coulomb excitation experiment. The final results are discussed in the last section. Considerations on possible interpretation of Ni shell evolution will be presented together with some outlooks

Peritoneal dialysis catheters in pediatric patients: 10 years of experience in a single centre

Peritoneal Dialysis (PD) is one of the numerous options for chronic dialysis and in many cases when access for acute dialysis is required early in a hospital course, at any age. PD catheter can be inserted with an open or laparoscopic approach. The complication rate after catheter insertion is still high, as reported in published literature. We present the experience matured at our Centre in the last 10 years on implantation of peritoneal dialysis catheters in children, emphasising surgical complications. We conducted a retrospective study on patients who underwent PD at our Centre in a range period of 10 years. We analysed patients \u2019demographic data, past and present medical, perioperative and post-operative data, permanence of the catheter, duration of dialysis, the gap between placement and use, outcomes and complications. We compared the data, dividing patients in 2 groups: patients operated with a traditional open technique and patients operated laparoscopically. We retrospectively reviewed 29 children with an average age of 3years and 6 months. Mean age was 42 months (1 month; 8 years) for the VLS group, 18 months (11 days, 4 years) for the OT group. Mean operative time was 106 min for the VLS group; 44 min for the OT group. The Catheter permanence period was 17 days (12h-64 days). Duration of dialysis was between 48 hours and 23 days (average 8 days). In the total population, we registered 8 complications (5 minor, 3 major), the overall complication rate being 33 % (minor complication rate 21%, major complication rate 12,5 %). 6 complications occurred in patients operated laparoscopically (6/14 = 36 %); 2 complications in the OT group (2/10 = 20 %). The complication rate after PD catheter insertion is still high. Advantages and disadvantages of the open and laparoscopic approach must be known. Both minor and major complications, such as bowel perforations and occlusions, must be understood and differentiated

Domain Adaptation for Dependency Parsing at Evalita 2011

The domain adaptation task was aimed at investigating techniques for adapting state-of-the-art dependency parsing systems to new domains. Both the language dealt with, i.e. Italian, and the target domain, namely the legal domain, represent two main novelties of the task organised at Evalita 2011. In this paper, we define the task and describe how the datasets were created from different resources. In addition, we characterize the different approaches of the participating systems, report the test results, and provide a first analysis of these results

Ghrelin plasma levels after 1 year of ketogenic diet in children with refractory epilepsy

The ketogenic diet (KD) is a high-fat, low carbohydrate nutritional treatment adopted in several countries for refractory epilepsy. However, the use of KD is limited by adverse events including growth retardation. In a previous investigation, we demonstrated that ghrelin is reduced in children maintained on KD for 3 months. As ghrelin regulates growth hormone (GH) secretion, it can be hypothesized that growth retardation depends on the reduced ghrelin availability. To assess this hypothesis, in this study we evaluate ghrelin and growth during 1 year of KD. We examined a small cohort of 6 children (2 males and 4 females, age range 3\u201310.4 years) affected by refractory epilepsy, who received the KD as add-on treatment. All patients were on drug polytherapy. Endpoints of the study were: (i) ghrelin plasma levels at 0, 15, 30, 90, and 365 days from KD onset, (ii) growth, and (iii) seizure control by ketogenesis. Ghrelin levels were 1253 and 1247% of basal levels, respectively, at 90 and 365 days (P < 0.05 for both). Mean height index z scores were reduced, but not significantly, by comparing basal values with those at the end of observation. Instead, body mass index z scores slightly increased. Ketosis induced by the KD was within 2\u20135 mmol/L and satisfactorily reduced the seizure frequency (>50%) in all patients. We show that ghrelin plasma levels are consistently reduced in children with refractory epilepsy and maintained on the KD. This change was associated with low growth indexes in the majority of patients

Phase II trial of neoadjuvant pemetrexed plus cisplatin followed by surgery and radiation in the treatment of pleural mesothelioma

BACKGROUND: Malignant pleural mesothelioma is an aggressive tumor that has a poor prognosis and is resistant to unimodal approaches. Multimodal treatment has provided encouraging results. METHODS: Phase II, open-label study of the combination of chemotherapy (pemetrexed 500 mg/m(2)+cisplatin 75 mg/m(2) IV every 21 days × 3 cycles), followed by surgery (en-bloc extrapleural pneumonectomy, 3–8 weeks after chemotherapy) and hemithoracic radiation (total radiation beam 54 Gy, received 4–8 weeks post-surgery). The primary endpoint was event-free survival, defined as the time from enrollment to time of first observation of disease progression, death due to any cause, or early treatment discontinuation. RESULTS: Fifty-four treatment-naïve patients with T1-3 N0-2 malignant pleural mesothelioma were enrolled, 52 (96.3%) completed chemotherapy, 45 (83.3%) underwent surgery, 22 (40.7%) completed the whole treatment including 90-day post-radiation follow-up. The median event-free survival was 6.9 months (95%CI: 5.0-10.5), median overall survival was 15.5 months (95%CI 11.0-NA) while median time-to-tumor response was 4.8 months (95%CI: 2.5-8.0). Eighteen (33.3%) and 13 (24.1%) patients were still event-free after 1 and 2 years, respectively. The most common treatment-emergent adverse events were nausea (63.0%), anemia (51.9%) and hypertension (42.6%). Following two cardiopulmonary radiation-related deaths the protocol was amended (21 [38.9%] patients were already enrolled in the study): the total radiation beam was reduced from 54 Gy to 50.4 Gy and a more accurate selection of patients was recommended. CONCLUSIONS: The combination of pemetrexed plus cisplatin followed by surgery and hemithoracic radiation is feasible and has a manageable toxicity profile in carefully selected patients. It may be worthy of further investigation. TRIAL REGISTRATION: Clinicaltrial.com registrationID #NCT00087698

Optical and Scintillation Properties of Polydimethyl-Diphenylsiloxane Based Organic Scintillators

Polysiloxane based scintillators with high light yield have been synthesized. The polymer consists in cross-linked polydimethyl-co-diphenylsiloxane with different molar percentages of phenyl units. 2,5-diphenyl oxazole (PPO) and 2,5-bis(5-ter-butyl-2-benzoxazolyl)thiophene (BBOT) have been dispersed in the polymer as dopants. The energy transfer and scintillation capabilities have been investigated, for two different amounts of phenyl groups in the polymer network and for different concentrations of dye molecules, by means of fluorescence spectroscopy, ion beam induced luminescence (IBIL) and scintillation yield measurements with ? particles from an 241Am source. The luminescence features and the scintillation yields have been correlated to the composition of the scintillators

Global proteomic characterization of microdissected estrogen receptor positive breast tumors

We here describe two proteomic datasets deposited in ProteomeXchange via PRIDE partner repository [1] with dataset identifiers PXD000484 (defined as "training") and PXD000485 (defined as "test") that have been used for the development of a tamoxifen outcome predictive signature [2]. Both datasets comprised 56 fresh frozen estrogen receptor (ER) positive primary breast tumor specimens derived from patients who received tamoxifen as first line therapy for recurrent disease. Patient groups were defined based on time to progression (TTP) after start of tamoxifen therapy (6 months cutoff): 32 good and 24 poor treatment outcome patients were comprised in the training set, respectively. The test set included 41 good and 15 poor treatment outcome patients. All specimens were subjected to laser capture microdissection (LCM) to enrich for epithelial tumor cells prior to high resolution mass spectrometric (MS) analysis. Protein identificat

Siloxane-Based Nanocomposites Containing 6LiF Nanocrystals for Thermal Neutrons Detection

n/