Comportamento di gallerie in versanti in frana

Il lavoro esamina i fattori geometrici e meccanici che influenzano i meccanismi di interazione frana-galleria, in cui si presuppone un meccanismo plastico con mobilizzazione delle resistenze nel terreno. Definite le grandezze adimensionali che governano il fenomeno utilizzando i principi dell’analisi dimensionale e del teorema di Buckingham, si è avviato uno studio parametrico di cui sono presentati alcuni risultati

Modelling of imbibition process in an embankment scale model

This paper aims to investigate the hydro-mechanical behaviour of a loosely compacted embankment during an inundation event. This study is based on the results of a centrifuge test carried out on a small-scale embankment model made of an artificially compacted clay–sand mixture. The wetting-induced displacements are analyzed and interpreted by means of a constitutive model adapted to unsaturated conditions. The numerical predictions are presented in terms of time evolutions of settlements, as well as, spatial distributions of vertical displacements. These profiles are compared to those experimentally observed in order to validate the predictive capabilities of the model on a boundary value problem. Moreover, the stress paths followed by elementary soil elements located at different depths are analyzed to emphasize the stress and strain variations due to capillary rise

Consequences on water retention properties of double-porosity features in a compacted silt

The paper deals with an experimental investigation aimed at studying microstructural features and their consequences on water retention properties of statically compacted unsaturated silt. The evolution of the microstructure of the aggregate fabric induced by compaction is investigated by studying the pore size distribution changes under different initial conditions (void ratio and water content). The material used is low plasticity silt from Jossigny near Paris, France. A series of mercury intrusion porosimetry tests (MIP) were performed at different void ratios and water contents to provide microstructural information. The arrangement of aggregation/particles and pore network was also investigated with environmental scanning electron microscopy (ESEM). The MIP data were used to determine the water retention curve on drying for the specific pore network configuration induced on compaction. The MIP data were used to formulate and calibrate a multimodal water retention model for a specific pore network configuration, which is obtained by linear superposition of subcurves of a modified van Genuchten type. The study is then complemented with controlled suction oedometer tests on compacted samples to obtain the water retention properties of the material at two different void ratios. Finally, we compare the water retention properties obtained by the simulated progression of the different pore network configurations induced on the hydraulic path with the water retention properties under suction-controlled conditions. Good agreement between the two methods for the drying path is reache

Numerical modelling of the response of an unsaturated silty soil under wetting and gravitational loading processes

This paper presents the results of a numerical study aiming at simulating the response of an unsaturated fine-grained soil under wetting and gravitational loading processes. This study is based on the results of some centrifuge tests carried out to assess the influence of partial saturation on the laterally loaded pile response. The hydro-mechanical behaviour of the silty soil is described using a constitutive model adapted to unsaturated conditions. The model predictions are compared with the measurements provided by LVDTs and laser transducers in the first phases of the experimental study. Besides validating the model, the numerical study aimed at investigating the influence of the after-compaction conditions on both the displacement field and the evolution of the more significant state variables during imbibition and gravitational loading processes. Finally, an additional analysis is conducted to determine the effects of the pile installation on the soil response

Physical modelling of piles under lateral loading in unsaturated soils

In this paper, selected aspects of an experimental study conducted in a geotechnical centrifuge are discussed. The tests aimed to explore the effects of partial saturation of soil on the response of a single pile subjected to a combination of lateral force and bending moment under drained conditions. The soil used in the experiments is a low plasticity silty soil, named B-grade kaolin, characterized by a relatively high permeability compared to the typical values for clayey soils. Two different elevations of the water table and its effects on the pile response under loading are studied. The data show a marked influence of soil partial saturation on the pile response, both under working loads and ultimate loads. In particular, under working loads, the displacement of the head of the pile is appreciably lower than that measured under saturated conditions

Internal dose assessment of 210Po using biokinetic modeling and urinary excretion measurement

The mysterious death of Mr. Alexander Litvinenko who was most possibly poisoned by Polonium-210 (210Po) in November 2006 in London attracted the attention of the public to the kinetics, dosimetry and the risk of this high radiotoxic isotope in the human body. In the present paper, the urinary excretion of seven persons who were possibly exposed to traces of 210Po was monitored. The values measured in the GSF Radioanalytical Laboratory are in the range of natural background concentration. To assess the effective dose received by those persons, the time-dependence of the organ equivalent dose and the effective dose after acute ingestion and inhalation of 210Po were calculated using the biokinetic model for polonium (Po) recommended by the International Commission on Radiological Protection (ICRP) and the one recently published by Leggett and Eckerman (L&E). The daily urinary excretion to effective dose conversion factors for ingestion and inhalation were evaluated based on the ICRP and L&E models for members of the public. The ingestion (inhalation) effective dose per unit intake integrated over one day is 1.7 × 10−8 (1.4 × 10−7) Sv Bq−1, 2.0 × 10−7 (9.6 × 10−7) Sv Bq−1 over 10 days, 5.2 × 10−7 (2.0 × 10−6) Sv Bq−1 over 30 days and 1.0 × 10−6 (3.0 × 10−6) Sv Bq−1 over 100 days. The daily urinary excretions after acute ingestion (inhalation) of 1 Bq of 210Po are 1.1 × 10−3 (1.0 × 10−4) on day 1, 2.0 × 10−3 (1.9 × 10−4) on day 10, 1.3 × 10−3 (1.7 × 10−4) on day 30 and 3.6 × 10−4 (8.3 × 10−5) Bq d−1 on day 100, respectively. The resulting committed effective doses range from 2.1 × 10−3 to 1.7 × 10−2 mSv by an assumption of ingestion and from 5.5 × 10−2 to 4.5 × 10−1 mSv by inhalation. For the case of Mr. Litvinenko, the mean organ absorbed dose as a function of time was calculated using both the above stated models. The red bone marrow, the kidneys and the liver were considered as the critical organs. Assuming a value of lethal absorbed dose of 5 Gy to the bone marrow, 6 Gy to the kidneys and 8 Gy to the liver, the amount of 210Po which Mr. Litvinenko might have ingested is therefore estimated to range from 27 to 1,408 MBq, i.e 0.2–8.5 μg, depending on the modality of intake and on different assumptions about blood absorption

Targeting of NAADP-dependent calcium signalling impairs growth and invasiveness of murine melanoma and tumor angiogenesis

We have recently identified a novel transduction pathway through which Vascular Endothelial Growth Factor (VEGF) controls experimentally induced neoangiogenesis, specifically involving endothelial VEGF receptor subtype 2 and the release of intracellular calcium from NAADP (Nicotinic Acid Adenosine Dinucleotide Phosphate) responsive acidic stores (1). We have now extended this research to an in vivo model of tumor angiogenesis and show that the pharmacologic NAADP inhibitor Ned-19 (2) impairs the vascularization, growth and metastatic spreading of the very aggressive VEGF producing murine tumor, B16 melanoma. In parallel in vitro experiments, we tested whether Ned-19 could directly affect the production of VEGF by the tumor cells, and found that treatment of B16 cells with Ned-19 unexpectedly results in increased VEGF release. These observations indicate that in our model 1) tumor angiogenesis is impaired by Ned-19 even in the presence of increased exposure to VEGF and 2) that NAADP system is active also in B16 melanoma cells. On the basis of this second observation further possible direct effects of Ned-19 on melanoma cell aggressiveness such as growth and invasivity are presently investigated and preliminary results suggest that NAADP system inhibition could potentially represent a twofold therapeutic strategy, directly targeting both tumor angiogenesis and tumor cell growth

The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019

Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe