6 research outputs found
Disease course of ulcerative proctitis in children: A population-based study on behalf of the SIGENP IBD Group
No full textBackground: The natural history of ulcerative proctitis (UP) has been poorly investigated in children. Aims: We aimed to compare the disease course of children with UP at diagnosis to the other locations and to identify extension predictors. Methods: This was a multicenter, observational study carried out from data prospectively entered in the SIGENP-IBD-Registry. Children with ulcerative colitis (UC) diagnosis and at least 1-year follow-up were included. On the basis of Paris classification UP patients were identified and compared with the other locations. Results: 872 children were enrolled (median age at diagnosis: 11.2 years; M/F: 426/446), of whom 78 (9%) with UP. Kaplan-Meier analysis demonstrated increased cumulative probabilities of disease extension in the E1 group [1 year: 20.3%; 5 years: 52.7%; 10 years: 72.4%] compared to E3 group [1 year: 8.5%; 5 years: 24.9% and 10 years: 60.1%, p=0.001]. No differences were observed comparing E1 and E2 groups [p=0.4]. Cumulative probabilities of surgery at 1, 5 and 10 years were 1.3, 2.8 and 2.8% in the E1 group and 2.5, 8 and 12.8% in the E2-E3-E4 group, respectively (p=0.1). Cox regression analysis demonstrated that PUCAI>35 at diagnosis was associated with endoscopic extension (HR=4.9; CI 95% 1.5-15.2, p=0.006). Conclusions: UP is associated with similar short and long-term outcomes compared to other locations
Endoscopic and Histologic Healing in Children With Inflammatory Bowel Diseases Treated With Thalidomide
No full textMucosal healing, determined by endoscopic evaluation, is one of the most important prognostic markers for patients with inflammatory bowel diseases. Findings from histologic evaluation, however, could complement findings from endoscopy in assessing mucosal responses to treatment. We analyzed long-term results of children treated with thalidomide to determine the association between clinical response and histology and endoscopy findings.
We collected data from 2 multicenter trials of 70 children with refractory Crohn’s disease (CD) or ulcerative colitis (UC) (2–18 years old; ileocolonic or colonic disease) given thalidomide or placebo (NCT00720538). Clinical remission and clinical response at 8 weeks were defined as a pediatric CD activity index scores 10 points or lower and a decrease of at least 50% from baseline, respecti- vely, for patients with CD; and as a pediatric UC activity index score below 10 and a decrease of at least 20 points from baseline, respectively, for patients with UC. Patients with a clinical response to 8 weeks’ treatment with thalidomide underwent endoscopic examination with biopsy collection at study weeks 12 and 52. Severity of inflammation in patients with UC was assessed by Mayo score and in patients with CD by 4-grade system. Biopsies were assessed for signs of active inflammation, erosion or ulceration, and crypt abscesses and assigned a histologic score.
Clinical remission was observed in 42 patients (60.0%) and clinical response in 45 patients (64.2%) at Week 8. At Week 52, a total of 38 patients (54.3%) were still in clinical remission or still had a clinical response; 29 patients (41.4%) had mucosal healing, defined as complete healing of erosions or ulcerations, and 20 patients (27.7%) had histologic healing, defined as complete absence of markers of inflammation. Of patients with clinical remission or clinical response, 75.3% also had mucosal healing and 52.6% also had histologic healing. The proba- bility of achieving mucosal healing decreased significantly with increasing values of erythrocyte sedimentation rate (adjusted odds ratio, 0.96; 95% CI, 0.93–0.98; P [ .006).
In a long-term analysis of data from 2 clinical trials of pediatric patients with CD or UC, 52 weeks’ treatment with thalidomide led to clinical remission in 54.3% of patients with ileocolonic or colonic disease; of these patients, 75.3% had mucosal healing and 52.6% also had histologic healing. Further studies are needed to determine how thalidomide therapy affects long-term progression of inflammatory bowel diseases. (ClinicalTrials.gov number NCT00720538)
Study of germination parameters of summer weeds: transferability of AlertInf model to Croatia
No full textThermal profiles and improved confinement accessibility in RFX-mod and TCV
No full textHumans do not live by bread alone. Physically we are puny creatures with limited prowess, but with unlimited dreams. In the last few decades humankind reached the Moon (1969) and
built airports over the sea (1994), but 925 million people are still under- or malnourished (2010). To follow his dream to ensure every human being the same adequate quality of life, humankind needs energy. The long-term world energy scenarios (50-80 years) foresee the need for reliable, sustainable and environmental friendly sources of energy. Thermonuclear fusion is one of the main actors in the energetic basket, it offers the possibility to produce large supplies of energy at relatively low costs reducing the impact on the environment. In fact, thermonuclear fusion represents a promising chance to generate energy without the emission of carbon dioxide and the production of long living radioactive wastes. Moreover, the raw materials used as fuel in the fusion reactions, deuterium and tritium, are easily available on Earth. This chance motivates the efforts on the controlled thermonuclear fusion research. Anyway, the development of nuclear fusion as an energy source is one of the most complex scientific and technical tasks ever undertaken for non-military purposes. The nuclear fusion obtained by magnetic confinement of plasma emerged in the latest years as the most promising concept to menage the power produced by fusion reactions. The studies developed in that direction, since the fifties, yielded more and more encouraging results and important breakthroughs both in physics and technology and inspired the ITER project. This experimental reactor could give, in the next few decades, the definitive answers to many questions on the scientific and technological feasibility of a fusion reactor. One of the major concerns in magnetic confinement fusion research is the quest for the best
plasma performance, which is intimately linked to two main issues: plasma confinement and boundary conditions. Both, incidentally, are connected to plasma stability. The link between confinement and boundary conditions is very strong and found many evidences. For example in the tokamak (the magnetic confinement configuration main line) the quest for a mild plasma-wall interaction a controlled recycling led to the discovery of an ameliorated operating mode with high performance. As a matter of fact, H-mode was discovered in
ASDEX the first diverted device. In RFPs (an alternative magnetic confinement configuration) a spontaneous transition to an ameliorated plasma state, the QSH state, is due to a reduced chaos obtained with an accurate control of the magnetic boundary conditions. In turn, the access to the QSH state led to a favorable edge topology characterized by better boundary conditions. The onset of the QSH state induces an edge helical ripple which reduce the plasma wall interaction. My research activity, reported in this thesis work, focused on the accessibility conditions and characterization of improved confinement regimes in TCV tokamak and RFX-mod RFP devices. In RFX-mod my research activity focused on the study and the characterization of electron temperature profiles. Temperature is one of the key parameters that qualifies fusion plasma performance and, in RFX-mod plasmas, it is mainly determined by three quantities: plasma current, electron density and plasma magnetic state. Through a large statistical analysis the temperature profile variations were investigated and related to the main macroscopic and operational plasma parameters. This analysis resulted in scaling laws for central temperature, external temperature and temperature gradient. Some further analysis was dedicated to a distinctive feature: the appearance of transport and thermal barriers which result in better plasma performance. The formation of an Internal Transport Barrier (eITB) is triggered by the growth of a dominant MHD tearing mode which, in turn, leads to a reduced magnetic chaos
in the plasma core. Starting from previous analysis, these eITBs were investigated and their influence of the whole temperature profile addressed. Besides the established phenomena related to eITBs, the occasional appearance of extremely high gradients in the external region of the plasma column was observed. Some general observations and a first speculation on the physical mechanism leading to their formation will be presented. The work ends up in a wide and general picture which tries to clear up the physics governing the temperature profile
modifications and proposes possible operations to trigger them. Present day tokamaks high performance scenarios rely on the possibility to access the high confinement mode (H-mode). Transition from the standard confinement mode (L-mode) to the H-mode is typically achieved when the external input power exceeds a threshold. This power threshold is found to strongly depend on plasma density, toroidal magnetic field and plasma size, but many experiments have shown this power threshold to also depend on plasma shape and configuration geometry. My activity at TCV aimed at the study of such dependence, in particular the influence of X-point location on H-mode power threshold was investigated. During a two months stay in 2011, a series of experiments was dedicated to such a study. Significant variations in the power threshold due to a reduction of the X-point height has been documented, in agreement with the scaling observed in other machines. Moreover, the well-established non-monotonic density dependence of the H-mode power threshold has
been measured and recorded. In this thesis work the analysis procedure followed to the TCV experimental campaign is reported
Measurement of the diffractive cross-section in deep inelastic scattering
No full textThis paper presents an analysis of the inclusive properties of diffractive deep inelastic scattering events produced in ep interactions at HERA. The events are characterised by a rapidity gap between the outgoing proton system and the remaining hadronic system. Inclusive distributions are presented and compared with Monte Carlo models for diffractive processes. The data are consistent with models where the pomeron structure function has a hard and a soft contribution. The diffractive structure function is measured as a function of xℙ, the momentum fraction lost by the proton, of β, the momentum fraction of the struck quark with respect to xℙ, and of Q2 in the range 6.3·10-
