Analysis and simplification of chemical kinetics mechanisms with CSP-based techniques

The computational singular perturbation (CSP) method is exploited to build a comprehensive framework for analysis and simplification of chemical kinetic models. The necessity for both smart post-process tools, able to perform rational diagnostics on large numerical simulations of reactive flows, and affordable reduced kinetic mechanisms, to make the simulations feasible, is the driving force behind this work. The ultimate goal is to improve the understanding of the fundamentals of chemically reacting flows. The CSP method is a suitable candidate for extracting physical insights from reactive flows dynamics that can be employed for both the generation of simplified kinetic schemes and the calculation of smart and compact diagnostic observables. Among them, the tangential stretching rate (TSR) is an estimate of the system’s driving chemical timescale that can be profitably employed for characterising the reactive flow dynamics in terms of combustion regimes and role of transport with respect to kinetics. The potentials of TSR are extensively highlighted, starting from prototypical combustion models, such as batch reactor and unsteady laminar flamelet, and getting to real-life usage on 3-dimensional direct numerical simulation datasets. The CSP mathematical foundations are then employed for mechanism simplification purposes, where small and accurate kinetic mechanisms are sought after. An existing CSP-based simplification algorithm is improved, aiming at the minimisation of the required user knowledge, which becomes a critical feature of the algorithm when dealing with new fuels. Practical applications of the revised algorithm are shown and discussed. Finally, the focus is shifted from the quest for tight accuracy in the simplified mechanisms towards a much broader question regarding confidence in detailed kinetic schemes. Uncertainty in the kinetic model parameters, such as Arrhenius coefficients, can jeopardize the efforts spent in the reduction challenge. A new, uncertainty-aware, robust CSP simplification strategy is proposed, discussed and employed, and its robustness demonstrated in a test case involving an uncertain -in its Arrhenius pre-exponential coefficients- kinetic scheme

Model identification in reactor-based combustion closures using sparse symbolic regression

info:eu-repo/semantics/publishe

RT-DLO: Real-Time Deformable Linear Objects Instance Segmentation

Deformable Linear Objects (DLOs) such as cables, wires, ropes, and elastic tubes are numerously present both in domestic and industrial environments. Unfortunately, robotic systems handling DLOs are rare and have limited capabilities due to the challenging nature of perceiving them. Hence, we propose a novel approach named RT-DLO for real-time instance segmentation of DLOs. First, the DLOs are semantically segmented from the background. Afterward, a novel method to separate the DLO instances is applied. It employs the generation of a graph representation of the scene given the semantic mask where the graph nodes are sampled from the DLOs center-lines whereas the graph edges are selected based on topological reasoning. RT-DLO is experimentally evaluated against both DLO-specific and general-purpose instance segmentation deep learning approaches, achieving overall better performances in terms of accuracy and inference time

Evaluation of in vivo labelled dendritic cell migration in cancer patients

BACKGROUND: Dendritic Cell (DC) vaccination is a very promising therapeutic strategy in cancer patients. The immunizing ability of DC is critically influenced by their migration activity to lymphatic tissues, where they have the task of priming naïve T-cells. In the present study in vivo DC migration was investigated within the context of a clinical trial of antitumor vaccination. In particular, we compared the migration activity of mature Dendritic Cells (mDC) with that of immature Dendritic Cells (iDC) and also assessed intradermal versus subcutaneous administration. METHODS: DC were labelled with (99m)Tc-HMPAO or (111)In-Oxine, and the presence of labelled DC in regional lymph nodes was evaluated at pre-set times up to a maximum of 72 h after inoculation. Determinations were carried out in 8 patients (7 melanoma and 1 renal cell carcinoma). RESULTS: It was verified that intradermal administration resulted in about a threefold higher migration to lymph nodes than subcutaneous administration, while mDC showed, on average, a six-to eightfold higher migration than iDC. The first DC were detected in lymph nodes 20–60 min after inoculation and the maximum concentration was reached after 48–72 h. CONCLUSIONS: These data obtained in vivo provide preliminary basic information on DC with respect to their antitumor immunization activity. Further research is needed to optimize the therapeutic potential of vaccination with DC

FDG PET/CT Response Evaluation in Malignant Pleural Mesothelioma Patients Treated with Talc Pleurodesis and Chemotherapy

Purpose: Talc pleurodesis (TP) is employed worldwide for the management of persistent pneumothorax or pleural effusion, particularly of malignant origin. However, there are very little available data on 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F FDG PET/CT) response evaluation in malignant pleural mesothelioma (MPM) patients treated with TP and chemotherapy

Road traffic pollution and childhood leukemia: a nationwide case-control study in Italy

Background The association of childhood leukemia with traffic pollution was considered in a number of studies from 1989 onwards, with results not entirely consistent and little information regarding subtypes. Aim of the study We used the data of the Italian SETIL case-control on childhood leukemia to explore the risk by leukemia subtypes associated to exposure to vehicular traffic. Methods We included in the analyses 648 cases of childhood leukemia (565 Acute lymphoblastic–ALL and 80 Acute non lymphoblastic-AnLL) and 980 controls. Information on traffic exposure was collected from questionnaire interviews and from the geocoding of house addresses, for all periods of life of the children. Results We observed an increase in risk for AnLL, and at a lower extent for ALL, with indicators of exposure to traffic pollutants. In particular, the risk was associated to the report of closeness of the house to traffic lights and to the passage of trucks (OR: 1.76; 95% CI 1.03–3.01 for ALL and 6.35; 95% CI 2.59–15.6 for AnLL). The association was shown also in the analyses limited to AML and in the stratified analyses and in respect to the house in different period of life. Conclusions Results from the SETIL study provide some support to the association of traffic related exposure and risk for AnLL, but at a lesser extent for ALL. Our conclusion highlights the need for leukemia type specific analyses in future studies. Results support the need of controlling exposure from traffic pollution, even if knowledge is not complete

Prognostic and Predictive Role of Body Composition in Metastatic Neuroendocrine Tumor Patients Treated with Everolimus: A Real-World Data Analysis

Neuroendocrine tumors (NETs) are rare neoplasms frequently characterized by an up- regulation of the mammalian rapamycin targeting (mTOR) pathway resulting in uncontrolled cell proliferation. The mTOR pathway is also involved in skeletal muscle protein synthesis and in adipose tissue metabolism. Everolimus inhibits the mTOR pathway, resulting in blockade of cell growth and tumor progression. The aim of this study is to investigate the role of body composition in- dexes in patients with metastatic NETs treated with everolimus. The study population included 30 patients with well-differentiated (G1-G2), metastatic NETs treated with everolimus at the IRCCS Romagnolo Institute for the Study of Tumors (IRST) “Dino Amadori”, Meldola (FC), Italy. The body composition indexes (skeletal muscle index [SMI] and adipose tissue indexes) were assessed by measuring on a computed tomography (CT) scan the cross-sectional area at L3 at baseline and at the first radiological assessment after the start of treatment. The body mass index (BMI) was assessed at baseline. The median progression-free survival (PFS) was 8.9 months (95% confidence interval [CI]: 3.4–13.7 months). The PFS stratified by tertiles was 3.2 months (95% CI: 0.9–10.1 months) in patients with low SMI (tertile 1), 14.2 months (95% CI: 2.3 months-not estimable [NE]) in patients with intermediate SMI (tertile 2), and 9.1 months (95% CI: 2.7 months-NE) in patients with high SMI (tertile 3) (p = 0.039). Similarly, the other body composition indexes also showed a statistically significant difference in the three groups on the basis of tertiles. The median PFS was 3.2 months (95% CI: 0.9–6.7 months) in underweight patients (BMI 18.49 kg/m2) and 10.1 months (95% CI: 3.7–28.4 months) in normal-weight patients (p = 0.011). There were no significant differences in terms of overall survival. The study showed a correlation between PFS and the body composition indexes in patients with NETs treated with everolimus, underlining the role of adipose and muscle tissue in these patients

Respiratory symptoms in children living near busy roads and their relationship to vehicular traffic: results of an Italian multicenter study (SIDRIA 2)

BACKGROUND: Epidemiological studies have provided evidence that exposure to vehicular traffic increases the prevalence of respiratory symptoms and may exacerbate pre-existing asthma in children. Self-reported exposure to road traffic has been questioned as a reliable measurement of exposure to air pollutants. The aim of this study was to investigate whether there were specific effects of cars and trucks traffic on current asthma symptoms (i.e. wheezing) and cough or phlegm, and to examine the validity of self-reported traffic exposure. METHODS: The survey was conducted in 2002 in 12 centers in Northern, Center and Southern Italy, different in size, climate, latitude and level of urbanization. Standardized questionnaires filled in by parents were used to collect information on health outcomes and exposure to traffic among 33,632 6-7 and 13-14 years old children and adolescents. Three questions on traffic exposure were asked: the traffic in the zone of residence, the frequency of truck and of car traffic in the street of residence. The presence of a possible response bias for the self-reported traffic was evaluated using external validation (comparison with measurements of traffic flow in the city of Turin) and internal validations (matching by census block, in the cities of Turin, Milan and Rome). RESULTS: Overall traffic density was weakly associated with asthma symptoms but there was a stronger association with cough or phlegm (high traffic density OR = 1.24; 95% CI: 1.04, 1.49). Car and truck traffic were independently associated with cough or phlegm. The results of the external validation did not support the existence of a reporting bias for the observed associations, for all the self-reported traffic indicators examined. The internal validations showed that the observed association between traffic density in the zone of residence and respiratory symptoms did not appear to be explained by an over reporting of traffic by parents of symptomatic subjects. CONCLUSION: Children living in zones with intense traffic are at higher risk for respiratory effects. Since population characteristics are specific, the results of validation of studies on self-reported traffic exposure can not be generalized

Inquinamento atmosferico e ricoveri ospedalieri urgenti in 25 citt? italiane: risultati del progetto EpiAir2 Air pollution and urgent hospital admissions in 25 Italian cities: results from the EpiAir2 project

OBJECTIVE: to evaluate the relationship between air pollution and hospital admissions in 25 Italian cities that took part in the EpiAir (Epidemiological surveillance of air pollution effects among Italian cities) project. DESIGN: study of time series with case-crossover methodology, with adjustment for meteorological and time-dependent variables. The association air pollution hospitalisation was analyzed in each of the 25 cities involved in the study; the overall estimates of effect were obtained subsequently by means of a meta-analysis. The pollutants considered were PM10, PM2.5 (in 13 cities only), NO2 and ozone (O3); this last pollutant restricted to the summer season (April-September). SETTING AND PARTICIPANTS: the study has analyzed 2,246,448 urgent hospital admissions for non-accidental diseases in 25 Italian cities during the period 2006- 2010; 10 out of 25 cities took part also in the first phase of the project (2001-2005). MAIN OUTCOME MEASURES: urgent hospital admissions for cardiac, cerebrovascular and respiratory diseases, for all age groups, were considered. The respiratory hospital admissions were analysed also for the 0-14-year subgroup. Percentage increases risk of hospitalization associated with increments of 10 μg/m3 and interquartile range (IQR) of the concentration of each pollutant were calculated. RESULTS: reported results were related to an increment of 10 μg/m3 of air pollutant. The percent increase for PM10 for cardiac causes was 0.34% at lag 0 (95%CI 0.04-0.63), for respiratory causes 0.75%at lag 0-5 (95%CI 0.25-1.25). For PM2.5, the percent increase for respiratory causes was 1.23% at lag 0- 5 (95%CI 0.58-1.88). For NO2, the percent increase for cardiac causes was 0.57%at lag 0 (95%CI 0.13-1.02); 1.29% at lag 0-5 (95%CI 0.52-2.06) for respiratory causes. Ozone (O3) did not turned out to be positively associated neither with cardiac nor with respiratory causes as noted in the previous period (2001-2005). CONCLUSION: the results of the study confirm an association between PM10, PM2.5, and NO2 on hospital admissions among 25 Italian cities. No positive associations for ozone was noted in this period.OBIETTIVO: valutare la relazione tra inquinamento atmosferico e ricoveri ospedalieri nelle citt? italiane partecipanti alla seconda fase del progetto EpiAir (Sorveglianza epidemiologica dell\u27inquinamento atmosferico: valutazione dei rischi e degli impatti nelle citt? italiane). DISEGNO: studio di serie temporali con metodologia case-crossover, con aggiustamento per i fattori temporali e meteorologici rilevanti. L\u27associazione inquinamento atmosferico- ospedalizzazioni ? stata analizzata in ciascuna delle 25 citt? in studio, le stime complessive di effetto sono state ottenute successivamente mediante una metanalisi. Gli inquinanti considerati sono stati il particolato (PM10), il biossido di azoto (NO2) e l\u27ozono (O3), quest\u27ultimo limitatamente al semestre estivo (da aprile a settembre). In 13 citt? in cui i dati erano disponibili ? stata analizzata anche la frazione fine del particolato (PM2.5). SETTING E PARTECIPANTI: lo studio ha esaminato 2.246.448 ricoveri ospedalieri urgenti per cause naturali di pazienti residenti e ricoverati, nel periodo 2006-2010, in 25 citt? italiane, di cui 10 gi? partecipanti alla prima fase del progetto EpiAir (2001-2005). PRINCIPALIMISURE DI OUTCOME: sono stati considerati i ricoveri ospedalieri urgenti per malattie cardiache, cerebrovascolari e respiratorie per tutte le fasce di et?. I ricoveri per cause respiratorie sono stati analizzati separatamente anche per la fascia di et? 0-14 anni. L\u27esposizione ? stata valutata per incremento sia di 10 μg/m3 sia pari all\u27intervallo interquartile (IQR) della concentrazione di ciascun inquinante. RISULTATI: considerando un incremento di 10 μg/m3 per inquinante, per il PM10 ? stato osservato un incremento percentuale di rischio per patologie cardiache dello 0,34%a lag 0 (IC95% 0,04-0,63), e per patologie respiratorie dello 0,75% a lag 0-5 (IC95% 0,25-1,25). Per il PM2.5 l\u27incremento percentuale di rischio per patologie respiratorie ? risultato dell\u271,23%a lag 0-5 (IC95%0,58-1,88). Per l\u27NO2 la stima di effetto per patologie cardiache ? risultata dello 0,57% a lag 0 (IC95% 0,13-1,02), e per patologie respiratorie dell\u271,29% a lag 0-5 (IC95% 0,52-2,06). L\u27ozono non ? risultato positivamente associato n? alle patologie cardiache n? a quelle respiratorie (a differenza del periodo 2001-2005). CONCLUSIONE: i risultati dello studio confermano l\u27effetto a breve termine dell\u27inquinamento atmosferico da PM10, PM2.5 e NO2 sulla morbosit?, in particolare respiratoria, nelle citt? italiane. Non sono state rilevate associazioni positive per l\u27O3

RFC1 expansions are a common cause of idiopathic sensory neuropathy

After extensive evaluation, one-third of patients affected by polyneuropathy remain undiagnosed and are labelled as having chronic idiopathic axonal polyneuropathy, which refers to a sensory or sensory-motor, axonal, slowly progressive neuropathy of unknown origin. Since a sensory neuropathy/neuronopathy is identified in all patients with genetically confirmed RFC1 cerebellar ataxia, neuropathy, vestibular areflexia syndrome, we speculated that RFC1 expansions could underlie a fraction of idiopathic sensory neuropathies also diagnosed as chronic idiopathic axonal polyneuropathy. We retrospectively identified 225 patients diagnosed with chronic idiopathic axonal polyneuropathy (125 sensory neuropathy, 100 sensory-motor neuropathy) from our general neuropathy clinics in Italy and the UK. All patients underwent full neurological evaluation and a blood sample was collected for RFC1 testing. Biallelic RFC1 expansions were identified in 43 patients (34%) with sensory neuropathy and in none with sensory-motor neuropathy. Forty-two per cent of RFC1-positive patients had isolated sensory neuropathy or sensory neuropathy with chronic cough, while vestibular and/or cerebellar involvement, often subclinical, were identified at examination in 58%. Although the sensory ganglia are the primary pathological target of the disease, the sensory impairment was typically worse distally and symmetric, while gait and limb ataxia were absent in two-thirds of the cases. Sensory amplitudes were either globally absent (26%) or reduced in a length-dependent (30%) or non-length dependent pattern (44%). A quarter of RFC1-positive patients had previously received an alternative diagnosis, including Sj\uf6gren's syndrome, sensory chronic inflammatory demyelinating polyneuropathy and paraneoplastic neuropathy, while three cases had been treated with immune therapies