1,853 research outputs found
High-Performance SiC–Based Solar Receivers for CSP: Component Manufacturing and Joining
Concentrated solar power (CSP) is an important option as a competitive, secure, and sustainable energy system. At the moment, cost-effective solutions are required for a wider-scale deployment of the CSP technology: in particular, the industrial exploitation of CSP has been so far hindered by limitations in the materials used for the central receiver—a key component in the system. In this context, the H2020 NEXTOWER project is focused on next-generation CSP technologies, particularly on advanced materials for high temperatures (e.g., >900 °C) and extreme applications environments (e.g., corrosive). The research activity described in this paper is focused on two industrial solutions for new SiC ceramic receivers for high thermal gradient continued operations: porous SiC and silicon-infiltrated silicon carbide ceramics (SiSiC). The new receivers should be mechanically tough and highly thermally conductive. This paper presents the activity related to the manufacturing of these components, their joining, and characterization
Percutaneous coronary intervention of unprotected left main and bifurcation in octogenarians: Subanalysis from RAIN (veRy thin stents for patients with left mAIn or bifurcatioN in real life)
Changes in protein expression in two cholangiocarcinoma cell lines undergoing formation of multicellular tumor spheroids In vitro
Epithelial-to-Mesenchymal Transition (EMT) is relevant in malignant growth and frequently
correlates with worsening disease progression due to its implications in metastases and re-
sistance to therapeutic interventions. Although EMT is known to occur in several types of
solid tumors, the information concerning tumors arising from the epithelia of the bile tract is
still limited. In order to approach the problem of EMT in cholangiocarcinoma, we decided to
investigate the changes in protein expression occurring in two cell lines under conditions
leading to growth as adherent monolayers or to formation of multicellular tumor spheroids
(MCTS), which are considered culture models that better mimic the growth characteristics
of
in-vivo
solid tumors. In our system, changes in phenotypes occur with only a decrease in
transmembrane E-cadherin and vimentin expression, minor changes in the transglutami-
nase protein/activity but with significant differences in the proteome profiles, with declining
and increasing expression in 6 and in 16 proteins identified by mass spectrometry. The aris-
ing protein patterns were analyzed based on canonical pathways and network analysis.
These results suggest that significant metabolic rearrangements occur during the conver-
sion of cholangiocarcinomas cells to the MCTS phenotype, which most likely affect the car-
bohydrate metabolism, protein folding, cytoskeletal activity, and tissue sensitivity to oxygen
Post-traumatic stress disorder among LGBTQ people: a systematic review and meta-analysis
Aims: Lesbian, gay, bisexual, transgender and queer people (LGBTQ) are at increased risk of traumatization. This systematic review aimed to summarize data regarding the risk of post-traumatic stress disorder (PTSD) for LGBTQ people and their subgroups. Methods: Medline, Scopus, PsycINFO and EMBASE were searched until September 2022. Studies reporting a comparative estimation of PTSD among LGBTQ population and the general population (i.e., heterosexual/cisgender), without restrictions on participants' age and setting for the enrolment, were identified. Meta-analyses were based on odds ratio (OR and 95% confidence intervals [CI]), estimated through inverse variance models with random effects. Results: The review process led to the selection of 27 studies, involving a total of 31,903 LGBTQ people and 273,842 controls, which were included in the quantitative synthesis. Overall, LGBTQ people showed an increased risk of PTSD (OR: 2.20 [95% CI: 1.85; 2.60]), although there was evidence of marked heterogeneity in the estimate (I2 = 91%). Among LGBTQ subgroups, transgender people showed the highest risk of PTSD (OR: 2.52 [95% CI: 2.22; 2.87]) followed by bisexual people (OR: 2.44 [95% CI: 1.05; 5.66]), although these comparisons are limited by the lack of data for other sexual and gender minorities, such as intersex people. Interestingly, the risk of PTSD for bisexual people was confirmed also considering lesbian and gay as control group (OR: 1.44 [95% CI: 1.07; 1.93]). The quality of the evidence was low. Conclusions: LGBTQ people are at higher risk of PTSD compared with their cisgender/heterosexual peers. This evidence may contribute to the public awareness on LGBTQ mental health needs and suggest supportive strategies as well as preventive interventions (e.g., supportive programs, counselling, and destigmatizing efforts) as parts of a tailored health-care planning aimed to reduce psychiatric morbidity in this at-risk population
Cerebral hemodynamics during atrial fibrillation: computational fluid dynamics (CFD) analysis of lenticulostriate arteries using 7T high-resolution magnetic resonance imaging
Atrial fibrillation (AF) is the most common cardiac arrhythmia, inducing irregular and faster heart beating. Aside from disabling symptoms - such as palpitations, chest discomfort, and reduced exercise capacity - there is growing evidence that AF increases the risk of dementia and cognitive decline, even in the absence of clinical strokes. Among the possible mechanisms, the alteration of deep cerebral hemodynamics during AF is one of the most fascinating and least investigated hypotheses. Lenticulostriate arteries (LSAs) - small perforating arteries perpendicularly departing from the anterior and middle cerebral arteries and supplying blood flow to basal ganglia - are especially involved in silent strokes and cerebral small vessel diseases, which are considered among the main vascular drivers of dementia. We propose for the first time a computational fluid dynamics analysis to investigate the AF effects on the LSAs hemodynamics by using 7 T high-resolution magnetic resonance imaging (MRI). We explored different heart rates (HRs) - from 50 to 130 bpm - in sinus rhythm and AF, exploiting MRI data from a healthy young male and internal carotid artery data from validated 0D cardiovascular-cerebral modeling as inflow condition. Our results reveal that AF induces a marked reduction of wall shear stress and flow velocity fields. This study suggests that AF at higher HR leads to a more hazardous hemodynamic scenario by increasing the atheromatosis and thrombogenesis risks in the LSAs region
Invasive versus conservative management in spontaneous coronary artery dissection: A meta-analysis and meta-regression study.
Abstract Background There is a paucity of data regarding the best treatment for spontaneous coronary artery dissection (SCAD). Purpose To compare the prognostic impact of conservative versus invasive treatment in patients with SCAD. Methods We systematically searched the literature for studies evaluating the comparative efficacy and safety of invasive revascularization versus medical therapy for the treatment of SCAD from 1990 to 2019. Random-effect meta-analysis was performed comparing clinical outcomes between the two groups. Results 24 observational studies with 1720 patients were included. After 28±14 months, a conservative approach reduced target vessel revascularization rate compared with invasive treatment (OR=0.50; 95% CI 0.28–0.90; P=0.02). No difference was found regarding all-cause mortality (OR=0.81; 95% CI 0.31–2.08; P=0.66), cardiovascular mortality (OR=0.89; 95% CI 0.15–5.40; P=0.89), myocardial infarction (OR=0.95; 95% CI 0.50–1.81; P=0.87), heart failure (OR 0.96; 95% CI 0.41–2.22; P=0.92) and SCAD recurrence (OR=0.94; 95% CI 0.52–1.72; P=0.85). The meta-regression analysis suggested that male gender, diabetes mellitus, smoking habit, prior coronary artery disease, left main coronary artery involvement and lower ejection fraction at admission are related with higher overall mortality, whereas SCAD recurrence was higher among patients with fibromuscular dysplasia. Conclusion A conservative approach provides similar clinical outcomes and lower target vessel revascularization rates compared to an invasive strategy in the setting of SCAD; therefore, when feasible, it should be preferred in this scenario. Forest plots on the study outcomes Funding Acknowledgement Type of funding source: Non
Measurement of the neutron detection efficiency of a 80% absorber - 20% scintillating fibers calorimeter
The neutron detection efficiency of a sampling calorimeter made of 1 mm
diameter scintillating fibers embedded in a lead/bismuth structure has been
measured at the neutron beam of the The Svedberg Laboratory at Uppsala. A
significant enhancement of the detection efficiency with respect to a bulk
organic scintillator detector with the same thickness is observed.Comment: 10 pages, 7 figure
Towards a Radio-guided Surgery with Decays: Uptake of a somatostatin analogue (DOTATOC) in Meningioma and High Grade Glioma
A novel radio guided surgery (RGS) technique for cerebral tumors using
radiation is being developed. Checking the availability of a
radio-tracer that can deliver a emitter to the tumor is a
fundamental step in the deployment of such technique. This paper reports a
study of the uptake of 90Y labeled (DOTATOC) in the meningioma and the high
grade glioma (HGG) and a feasibility study of the RGS technique in these cases.Comment: 21 pages, 5 figure
Heart rate variability and target organ damage in hypertensive patients
Background:
We evaluated the association between linear standard Heart Rate Variability (HRV) measures and vascular, renal and cardiac target organ damage (TOD).
Methods:
A retrospective analysis was performed including 200 patients registered in the Regione Campania network (aged 62.4 ± 12, male 64%). HRV analysis was performed by 24-h holter ECG. Renal damage was assessed by estimated glomerular filtration rate (eGFR), vascular damage by carotid intima-media thickness (IMT), and cardiac damage by left ventricular mass index.
Results:
Significantly lower values of the ratio of low to high frequency power (LF/HF) were found in the patients with moderate or severe eGFR (p-value < 0.001). Similarly, depressed values of indexes of the overall autonomic modulation on heart were found in patients with plaque compared to those with a normal IMT (p-value <0.05). These associations remained significant after adjustment for other factors known to contribute to the development of target organ damage, such as age. Moreover, depressed LF/HF was found also in patients with left ventricular hypertrophy but this association was not significant after adjustment for other factors.
Conclusions:
Depressed HRV appeared to be associated with vascular and renal TOD, suggesting the involvement of autonomic imbalance in the TOD. However, as the mechanisms by which abnormal autonomic balance may lead to TOD, and, particularly, to renal organ damage are not clearly known, further prospective studies with longitudinal design are needed to determine the association between HRV and the development of TOD
XMM-Newton and INTEGRAL analysis of the Ophiuchus cluster of galaxies
We investigated the non-thermal hard X-ray emission in the Ophiuchus cluster
of galaxies. Our aim was to characterise the physical properties of the
non-thermal component and its interaction with the cosmic microwave background.
We performed spatially resolved spectroscopy and imaging using XMM-Newton data
to model the thermal emission. Combining this with INTEGRAL ISGRI data, we
modeled the 0.6-140 keV band total emission in the central 7 arcmin region. The
models that best describe both PN and ISGRI data contain a power-law component
with a photon index in a range 2.2-2.5. This component produces ~10% of the
total flux in the 1-10 keV band. The pressure of the non-thermal electrons is
~1% of that of the thermal electrons. Our results support the scenario whereby
a relativistic electron population, which produces the recently detected radio
mini-halo in Ophiuchus, also produces the hard X-rays via inverse compton
scattering of the CMB photons. The best-fit models imply a differential
momentum spectrum of the relativistic electrons with a slope of 3.4-4.0 and a
magnetic field strength B=0.05-0.15 microG. The lack of evidence for a recent
major merger in the Ophiuchus center allows the possibility that the
relativistic electrons are produced by turbulence or hadronic collisions.Comment: Accepted for publication in Astronomy and Astrophysics, v2 includes
some text improvement
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