179 research outputs found
Numerical Prediction of Internal Flows in He/LOx Seals for Liquid Rocket Engine Cryogenic Turbopumps
Pros and Cons of the SeHCAT Test in Bile Acid Diarrhea: A More Appropriate Use of an Old Nuclear Medicine Technique
Bile acid malabsorption (BAM) causing chronic diarrhea may be due to organic as well as functional disorders, and some of them were included under the general label of diarrheic-type irritable bowel syndrome (IBS-D). The 75-selenium homocholic acid taurine (SeHCAT) test is a nuclear medicine investigation considered to be the gold standard for the diagnosis of bile acid malabsorption (BAM). Many studies demonstrate that it could be effective in the clinical workout of chronic diarrhea due to different conditions. The SeHCAT test provides a quantitative assessment to estimate the severity of BAM and the possible response to therapy with bile acid sequestrants (BASs). However, there is no general agreement regarding its cutoff value and the test is not widely available. The aim of this review is to discuss the advantages and disadvantages of the SeHCAT test in clinical practice
Land use inventory as framework for environmental accounting: an application in Italy
Land use inventories are sound measures to provide information on the area
occupied by different land use or land cover types and their changes, although
less widespread than traditional mapping; as such, they are distinctively wellestablished
tools for generating statistics on the state and the dynamics of land
use in the European Union. Italy has recently set up a land use inventory system
(IUTI) as a key instrument for accounting removals and emissions of greenhouse
gases (GHG) associated to land use, land use change and forestry (LULUCF)
activities elected by Italy under the Kyoto Protocol. IUTI adopts a statistical
sampling procedure to estimate the area covered by LULUCF land use
categories in Italy, and associated uncertainty estimates. Estimates of land use
have been so far processed for the period 1990-2008 and highlight three interlinked
land use change patterns in Italy: (i) increase in forest land for a total
uptake of 1.7% of the Italian territory; forest cover estimates, with a standard
error of 0.1%, indicate an annual increase of forestland higher over the period
1990-2000 (32 901 ha year-1) than in 2000-2008 (22 857 ha year-1); surprisingly,
also a significant deforestation rate is observed (-7000 ha year-1), due to
forest land conversion mainly into artificial areas; (ii) consumption of arable
land (-4.2% of the Italian territory) primarily due to land uptake by urban areas
and to conversions to permanent crops (mainly orchards and vineyards); (iii)
urban sprawl uptakes 1.6% of the Italian territory in this period, with a total
coverage of settlements reaching 7.1% of total land surface in Italy in 2008.
Overall, land use dynamic results in land uptake by forest land is of the same
magnitude of land uptake by urban areas, but the effects of these processes on
GHG removals (by forest sinks) and emissions (by urban areas) is expected to
be significantly different. In a broader perspective, IUTI methodology, by
providing reliable estimates and well-defined levels of statistical uncertainty
for assessing stocks and flows of land use at national level, can be further implemented
to frame other key questions for sustainable development policies,
like the set up of environmental-economic accounting systems.L'articolo è disponibile sul sito dell'editore www.sisef.i
Esophageal chemical clearance and baseline impedance values in patients with chronic autoimmune atrophic gastritis and gastro-esophageal reflux disease
Background: The factors influencing new markers of gastro-esophageal reflux disease detected by impedance-pH monitoring - mean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave (PSPW) index - need to be evaluated. Aim: To compare endoscopy-negative heartburn with chronic autoimmune atrophic gastritis (CAAG). Materials and methods: 24 patients with CAAG, 25 with non-erosive reflux disease (NERD) and 25 with functional heartburn (FH) were included. In all patients the main impedance-pH monitoring parameters were calculated. Results: CAAG and NERD patients had a number of reflux events (non-acid ones being more common among the former group) which was higher than that found in FH (p 3000 Ohm), CAAG (> 2000 Ohm) and NERD (<1000 Ohm) patients (p = 0.0046). The PSPW index was similar between CAAG and NERD patients but significantly lower in comparison to FH (p <0.0001). Conclusion: Patients with CAAG have evidence of non-acid reflux based on the high number of reflux events and confirmed by low values of MNBI and PSPW index. MNBI is a strong marker of acid/non-acid reflux-induced mucosal damage, whereas the PSPW index can reliably discriminate patients with reflux from those with FH, independently of the acidity of refluxate. (C) 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.Peer reviewe
Analysis of a Stator-Rotor-Stator Spinning Disk Reactor in Single-Phase and Two-Phase Boiling Conditions Using a Thermo-Fluid Flow Network and CFD
Cryogenic liquid propellants are used in liquid rocket engines to obtain high specific
impulse. The flow rates are controlled by turbopumps that deliver liquid propellant to the engine at
high pressure levels. Due to the very low saturation temperature of the cryogenic propellant, in the
first phases of the transient operation, in which the engine is at ambient temperature, its surfaces are
subject to boiling conditions. The effect of boiling on the heat transfer between the solid and the fluid
needs to be well characterized in order to correctly predict the cryopump metal temperature temporal
evolution and the necessary amount of propellant. With the aim of benchmarking numerical tools
against experimental data, a representative test case was chosen. This consists of a stator-rotorstator spinning disc reactor studied under single-phase and two-phase heat transfer conditions. The
numerical approaches used are represented by a 1D network solver, where the pressure drop and heat
transfer are calculated by correlations, and Computational Fluid Dynamics (CFD) simulations, carried
out with ANSYS Fluent. Both the numerical tools returned a reasonable agreement in single-phase
conditions, also thanks to the use of adequate correlations in the flow network solver and typical
conditions for the CFD simulations. Two-phase conditions on the contrary are more challenging, with
underpredictions up to 20% and 80%, respectively. The issues are ascribable to the use of correlations
that are inadequate to capture the two-phase phenomena occurring in the srs reactor and numerical
limitations in the actual implementation of the boiling model in the CFD solver
Barrett's esophagus in 2016: From pathophysiology to treatment
Esophageal complications caused by gastroesophageal reflux disease (GERD) include reflux esophagitis and Barrett's esophagus (BE). BE is a premalignant condition with an increased risk of developing esophageal adenocarcinoma (EAC). The carcinogenic sequence may progress through several steps, from normal esophageal mucosa through BE to EAC. A recent advent of functional esophageal testing (particularly multichannel intraluminal impedance and pH monitoring) has helped to improve our knowledge about GERD pathophysiology, including its complications. Those findings (when properly confirmed) might help to predict BE neoplastic progression. Over the last few decades, the incidence of EAC has continued to rise in Western populations. However, only a minority of BE patients develop EAC, opening the debate regarding the cost-effectiveness of current screening/surveillance strategies. Thus, major efforts in clinical and research practice are focused on new methods for optimal risk assessment that can stratify BE patients at low or high risk of developing EAC, which should improve the cost effectiveness of screening/surveillance programs and consequently significantly affect health-care costs. Furthermore, the area of BE therapeutic management is rapidly evolving. Endoscopic eradication therapies have been shown to be effective, and new therapeutic options for BE and EAC have emerged. The aim of the present review article is to highlight the status of screening/surveillance programs and the current progress of BE therapy. Moreover, we discuss the recent introduction of novel esophageal pathophysiological exams that have improved the knowledge of the mechanisms linking GERD to BE
3D Microfluidic model for evaluating immunotherapy efficacy by tracking dendritic cell behaviour toward tumor cells
Immunotherapy efficacy relies on the crosstalk within the tumor microenvironment between cancer and dendritic cells (DCs) resulting in the induction of a potent and effective antitumor response. DCs have the specific role of recognizing cancer cells, taking up tumor antigens (Ags) and then migrating to lymph nodes for Ag (cross)-presentation to naïve T cells. Interferon-α-conditioned DCs (IFN-DCs) exhibit marked phagocytic activity and the special ability of inducing Ag-specific T-cell response. Here, we have developed a novel microfluidic platform recreating tightly interconnected cancer and immune systems with specific 3D environmental properties, for tracking human DC behaviour toward tumor cells. By combining our microfluidic platform with advanced microscopy and a revised cell tracking analysis algorithm, it was possible to evaluate the guided efficient motion of IFN-DCs toward drug-treated cancer cells and the succeeding phagocytosis events. Overall, this platform allowed the dissection of IFN-DC-cancer cell interactions within 3D tumor spaces, with the discovery of major underlying factors such as CXCR4 involvement and underscored its potential as an innovative tool to assess the efficacy of immunotherapeutic approaches
The Impact of COVID-19 Pandemic on Psychiatric Emergencies in Two Different Settings: Emergency Room and Community Mental Health Service
Background: The SARS-CoV-2 pandemic caused a public health emergency with profound consequences on the physical and mental health of individuals. Emergency Rooms (ER) and Community Mental Health Services (CMHS) played a key role in the management of psychiatric emergencies during the pandemic. The purpose of the study was to evaluate urgent psychiatric consultations (UPCs) in the ERs of the General Hospitals and in the CMHS of a Northern Italian town during the pandemic period.
Methods: This monocentric observational study collected UPCs carried out in ER from 01/03/2020 to 28/02/2021 (the so-called “COVID-19 period”) and the demographic and clinical characteristics of patients who required UPCs in the 12-months period, comparing these data with those collected from 01/03/2019 to 29/02/2020 (the so-called “pre-COVID-19 period”). The same variables were collected for UPCs carried out in CMHS from 01/03/2020 to 31/01/2021 and compared with those collected from 01/03/2019 to 31/01/2020. The data were statistically analyzed through STATA 12-2011.
Results: In ER, we reported a 24% reduction in UPCs during the COVID-19 period (n = 909) in comparison with the pre-COVID-19 period (n = 1,194). Differently, we observed an increase of 4% in UPCs carried out in CMHS during the COVID-19 period (n = 1,214) in comparison with the previous period (n = 1,162). We observed an increase of UPCs in ER required by people who lived in psychiatric facilities or with disability pension whereas more UPCs in CMHS were required by older people or those living in other institutions compared to the previous period. In the COVID-19 period, the most frequent reasons for UPCs in ER were aggressiveness, socio-environmental maladjustment and psychiatric symptoms in organic disorders whereas in CMHS we reported an increase of UPCs for control of psychopharmacology therapy and mixed state/mania.
Conclusion: In light of our findings, we conclude that the most vulnerable people required more frequent attention and care in both ER and CMHS during pandemic, which disrupted individuals’ ability to adapt and induced many stressful reactive symptoms. In order to reduce the impact of the COVID-19 pandemic on mental health, psychological support interventions for the general population should be implemented, having particular regard for more psychologically fragile people
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