2,156 research outputs found
Observation of a nanophase segregation in LiCl aqueous solutions from Transient Grating Experiments
Transient Grating experiments performed on supercooled LiCl, RH2O solutions
with R>6 reveal the existence of a strong, short time, extra signal which
superposes to the normal signal observed for the R=6 solution and other glass
forming systems. This extra signal shows up below 190 K, its shape and the
associated timescale depend only on temperature, while its intensity increases
with R. We show that the origin of this signal is a phase separation between
clusters with a low solute concentration and the remaining, more concentrated,
solution. Our analysis demonstrates that these clusters have a nanometer size
and a composition which are rather temperature independent, while increasing R
simply increases the number of these clusters.Comment: 19 pages+ 8 figures+ 2 table
Recent finding and new technologies in nephrolithiasis: a review of the recent literature
This review summarizes recent literature on advances regarding renal and ureteral
calculi, with particular focus in areas of recent advances in the overall field
of urolithiasis. Clinical management in everyday practice requires a complete
understanding of the issues regarding metabolic evaluation and subgrouping of
stone-forming patients, diagnostic procedures, effective treatment regime in
acute stone colic, medical expulsive therapy, and active stone removal. In this
review we focus on new perspectives in managing nephrolitihiasis and discuss
recentadvances, including medical expulsive therapy, new technologies, and
refinements of classical therapy such as shock wave lithotripsy, give a
fundamental modification of nephrolithiasis management. Overall, this field
appears to be the most promising, capable of new developments in ureterorenoscopy
and percutaneous approaches. Further improvements are expected from
robotic-assisted procedures, such as flexible robotics in ureterorenoscopy
Angiographic demonstration of spontaneous diffuse three vessel coronary artery spasm
AbstractThe spontaneous occurrence of diffuse three vessel coronary artery spasm was documented during routine coronary angiography in three patients with a history of variant angina. Quantitative angiographic analysis of 18 arterial segments demonstrated that the mean luminal diameter of 1.47 mm during spasm increased to 2.47 mm after the administration of nitroglycerin (p < 0.0001). The underlying coronary arteries were normal or near normal.Although multivessel spasm has previously been considered to be uncommon and its spontaneous occurrence during angiography only rarely documented, these cases suggest that it may be more common than previously recognized. In addition to important diagnostic considerations, this phenomenon may have important implications regarding the pathophysiologic role of endothelium in coronary artery spasm
Causal effects of PetroCaribe on sustainable development: a synthetic control analysis
We examine the causal effects of the energy subsidy programme PetroCaribe in the three dimensions of sustainable development: economic, social and environmental. We use the synthetic control method to construct a counterfactual and compare it to the outcomes of the beneficiary countries and thus estimate the magnitude and direction of the PetroCaribe effect. PetroCaribe had a positive effect on economic growth in most of the beneficiary countries; however, this economic boost was not followed by an improvement in social development. Environmentally, PetroCaribe did not negatively or positively impact the environmental quality of the member countries, in the sense that we do not find a significant effect on the trend of urn:x-wiley:14636786:media:manc12275:manc12275-math-0001 emissions per capita
Increased relapse rate during COVID-19 lockdown in an Italian cohort of children with juvenile idiopathic arthritis.
Objectives: Changes of routine disease management associated with COVID-19 lockdown might have potentially affected the clinical course of juvenile idiopathic arthritis (JIA). Aim of our study was to assess the rate of disease flare before and during COVID-19 lockdown to investigate its impact on disease course in JIA children.
Methods: A single-center retrospective study was conducted, including patients presenting inactive JIA between September 1st , 2018 and March 9th , 2019 (group A) and between September 1st , 2019 and March 9th , 2020 (group B). For each patient, demographic and clinical data were collected. The rate of JIA flare from March 10th , 2019 to June 30th , 2019 for group A and from March 10th , 2020 to June 30th , 2020 for group B was compared.
Results: Group A included 126 patients and group B 124 patients. Statistical analysis did not show significant differences among the two cohorts with respect to age, sex, age of JIA onset, JIA subtype, co-occurrence of uveitis, ANA positivity and past or ongoing medications. The rate of disease flare during lockdown at time of first COVID-19 pandemic wave, was significantly higher in comparison to the previous year (16.9% vs 6.3%, p=0.009).
Conclusion: Our study showed that COVID-19 lockdown was associated with a higher rate of joint inflammation in JIA children. This finding has a considerable clinical implication, since restrictive measures may be necessary in order to contain pandemics. Our data highlight the need for rearrangement in the home and healthcare management of JIA children during lockdowns
A feasibility assessment of a retrofit Molten Carbonate Fuel Cell coal-fired plant for flue gas CO<sub>2</sub> segregation
This work considers the use of a Molten Carbonate Fuel Cell (MCFC) system as a power generation and CO2 concentrator unit downstream of the coal burner of an existing production plant. In this way, the capability of MCFCs for CO2 segregation, which today is studied primarily in reference to large-scale plants, is applied to an intermediate-size plant highlighting the potential for MCFC use as a low energy method of carbon capture. A technical feasibility analysis was performed using an MCFC system-integrated model capable of determining steady-state performance across varying feed composition. The MCFC user model was implemented in Aspen Custom Modeler and integrated into the reference plant in Aspen Plus. The model considers electrochemical, thermal, and mass balance effects to simulate cell electrical and CO2 segregation performance. Results obtained suggest a specific energy requirement of 1.41 MJ kg CO2 121 significantly lower than seen in conventional Monoethanolamine (MEA) capture processes
- …