1,803 research outputs found
Density measurements in subcooled water at pressures up to 400 MPa
Despite many applications in industry and science, water is still unknown and continuously under study, since it is a complex fluid with several anomalies and especially at high pressures and low temperatures, and outside the range of stability in the so called “metastable states”.
The thermodynamic states of liquid water below the normal freezing point (supercooled water) need to be accurately studied because of the lack of accurate experimental data of the hermodynamic properties. Experimental measurements, especially of density, are also necessary because they form the basis to implement a fundamental equation of state, from which all thermodynamic properties can be calculated. The purpose of this thesis is to measure the density of cooled and supercooled water with high accuracy, i.e. both in stable and metastable states, in the temperature range of (243 and 283) K, and at high pressures, from (140 to 400) MPa, by means of a pseudo-isochoric method. The experimental apparatus mainly consists of a high pressure vessel, specifically designed for this experiment, of known volume as a function of temperature and pressure. The density of subcooled water is basically obtained by measuring, at constant mass, the equilibrium pressure by changing the temperature avoiding crystallization.
Furthermore, since the paramount goal of performing accurate experimental measurements is the development of an equation of state, a complementary activity, consisting of the implementation of a fundamental equation of state in terms of the Helmholtz energy, is carried out. Finally, an overview of how an equation of state is developed, and the practical example of fundamental equations implementation for two alkanes (n-hexadecane and n-docosane) are presented
Reference Profile Correlation Reveals Estrogen-like Trancriptional Activity of Curcumin
Background: Several secondary metabolites from herbal nutrient products act as weak estrogens (phytoestrogens), competing with endogenous estrogen for binding to the estrogen receptors and inhibiting steroid converting enzymes. However, it is still unclear whether these compounds elicit estrogen dependent transcription of genes at physiological concentrations. Methods: We compare the effects of physiological concentrations (100 nM) of the two phytoestrogens Enterolactone and Quercetin and the suspected phytoestrogen Curcumin on gene expression in the breast cancer cell line MCF7 with the effects elicited by 17-beta-estradiol (E2). Results: All three phytocompounds have weak effects on gene transcription; most of the E2 genes respond to the phytoestrogens in the same direction though to a much lesser extent and in the order Curcumin > Quercetin > Enterolactone. Gene regulation induced by these compounds was low for genes strongly induced by E2 and similar to the latter for genes only weakly regulated by the classic estrogen. Of interest with regard to the treatment of menopausal symptoms, the survival factor Birc5/survivin and the oncogene MYBL1 are strongly induced by E2 but only marginally by phytoestrogens. Conclusion: This approach demonstrates estrogenic effects of putative phytoestrogens at physiological concentrations and shows, for the first time, estrogenic effects of Curcumin. Copyright (C) 2010 S. Karger AG, Base
What about Data-Driven Business Models? Mapping the Literature and Scoping Future Avenues
The paper aims to perform an assessment of the literature at the intersection of data and business models, examining the extent to which the data-driven business model (DDBM) is considered in the current literature and how it is characterised in terms of approaches, benefits and barriers. A systematic literature review (SRL) of the available body of knowledge on these topics was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. The SRL reveals limited but rapidly growing coverage of the cutting-edge phenomenon on the part of scientific studies. In problematising the extant literature, competitive, cultural and strategic approaches are proposed together with the relative enablers fostering the adoption of each approach. Benefits and barriers to the implementation of a DDBM are also discussed across technical, organisational and financial dimensions. The insights derived from a critical review of the DDBM literature point out gaps, which may itself inform future research and theory development in this area, as well as support practitioners’ decision-making on the datatisation of business models
In Silico and In Vitro Study of Antioxidant Potential of Urolithins
In this work, quantum chemical calculations based on density functional theory (DFT) were performed to predict the antioxidant potential of four bioactive gut microbiota metabolites of the natural polyphenols ellagitannins (ETs) and ellagic acid (EA), also known as urolithins (UROs). In order to evaluate their ability to counter the effect of oxidative stress caused by reactive oxygen species (ROS), such as the hydroperoxyl radical (•OOH), different reaction mechanisms were investigated, considering water and lipid-like environments. Through our in silico results, it emerged that at physiological pH, the scavenging activity of all urolithins, except urolithin B, are higher than that of trolox and other potent antioxidants existing in nature, such as EA, α-mangostin, allicin, caffeine and melatonin. These findings were confirmed by experimental assays
Histological effects of an innovative 445 Nm Blue Laser during oral soft tissue biopsy.
Continuously evolving laser devices can be used in various fields; they are an alternative to the traditional cold blade surgery to perform biopsies of oral soft tissues. The aspect focused on in this paper is the possibility to use the 445 nm diode laser (Eltech K-Laser srl, Treviso, Italy) in complete safety, by evaluating its thermal effects during microscopy. A histological evaluation of the alteration of the peri-incisional edges on 10 samples was realized. All excisional biopsies were related to clinically unsuspected lesions and performed by the same expert operator. The surgical procedure was performed with the same laser parameters and the same pathologist evaluated the thermal effect on the samples. An average value of the detected tissue alteration was calculated; the average damage of the epithelium was 650.93 ÎĽm, while in the connective tissue it was 468.07 ÎĽm. In all the cases a clear diagnosis was possible, and no clinical complications were observed; so, the 445 nm diode laser proved to be a device that can be safely used for biopsies of clinically unsuspicious lesions. Due to the small number of cases, this in vivo preliminary experience needs to be extended
Pliocene Diatom Biomarkers in Sabrina Coast. EAIS Continental Marginal Dynamics
PNRA Tytan project, supported by the National Institute of Oceanography and Applied Geophysics (OGS), focused on the advances and retreats dynamics of the ice sheet and on variations in the glacial regime. Unit 2 focused on Diatom biomarkers and assemblages analysis on sediments of core PC03, collected during the IN2017-V01 cruise on the eastern flank of the Minang-a (or Whale) submarine Canyon. The project aims at reconstructing the depositional environment of the continental margin off the Totten Glacier and diatom data remained a key tools to constrain past ice-sheet dynamics and to forecasting future behaviour in a warming world. Preliminary dataset from diatom biostratigraphic tools allows to refer the base of the core to Pliocene while the upper part of the core records more modern EAIS dynamics, indicative of minor sedimentary evolution steps of the continental margin. Diatom assemblage analyses highlight Eocene-Oligocene reworked material and freshwater diatom inputs in Pliocene sequence, strengthening the debate about ice-sheet and paleoceanographic models, WAIS cyclic collapse and suspected Pliocene EAIS retreat into major subglacial Antarctic basins
Sabrina Coast (East Antarctica) depositional processes highlightedthrough stratigraphic and paleoenvironmental diatom analysis
The systematic survey of Antarctic margin sedimentary sequences offers, especially in poorly investigated areas,the opportunity to obtain a wide range of information on glacio-eustatic, climatic, and tectonic events. Multi-disciplinary datasets resulting from geophysical surveys and scientific coring and drilling are needed to addressquestions regarding the orbital forcing and the global response of the hydrosphere (oceans and atmosphere),cryosphere, and biosphere. The PNRA Tytan Project, embedded into the Australian project \u201cInteractions of theTotten Glacier with the Southern Ocean through multiple glacial cycles\u201d (Australian National University), aimsto understand how the Totten Glacier behaved during past Holocene and Pleistocene times of warmer climate.Insights for reconstructing the depositional and hydrodynamic environments of the continental margin off theTotten Glacier, a large outlet glacier located on the Sabrina Coast of East Antarctica, are addressed throughmicropaleontological efforts. The micropaleontological research group focused on identification of diatombiostratigraphic markers and assemblage analyses in sediment cores collected from the Sabrina Coast continentalslope during the RV Investigator mission IN2017_V01 in order to reconstruct paleoenvironments and to place ageconstraints on the sedimentary sequences.All but one of the piston cores recovered late Pleistocene sediments, documenting MIS 9 \u2013 MIS 1, withinterglacial intervals characterized by diatomaceous sediments dominated by the open water taxon Fragilariopsiskerguelensis. Glacial intervals have much lower diatom concentrations and a higher proportion of reworked forms.A single piston core, IN2017_V01_PC03, recovered a more complicated sedimentary sequence. This sequence,targeted for an older and more condensed coring location, was selected for coring based on the sub-bottomgeophysical data that indicated thinning of the upper stratigraphic section, and greater access to the underlyingsection. The results suggest a very dynamic sediment delivery system in a context of Pliocene\u2013Recent Antarcticcontinental margin. The basal section of the core is marked by Eocene-Oligocene reworked taxa while the midsection is characterized by almost barren sediments. The silty top section of the PC03 core, had diatom assem-blages similar to the other kasten and piston cores; t his sectionis characterized by modern diatom assemblagesdominated by Circum Antarctic Current and open water taxa with a variable presence of sea ice associated forms.Glacial slumping, perhaps facilitated by the presence of biogenic silica, and reworking may have removed orprevented deposition within this condensed sedimentary sequence.The presence or absence of F. kerguelensis versus F. barronii and also the presence of transitional forms betweenthese two species, confirms the much older nature of the sediments in this core as compared to the other pistoncores. In addition, Denticulopsis simonsenii much more common at the basal part of the core, may reflect ero-sional contributions from Miocene-aged sediment, while the significant contribution of F. barronii, Thalassiosiralentiginosa and Thalassiosira oliverana (var. sparsa?) versus intervals dominated by D. simonsenii may suggestdifferent sources of material
Guidelines on the diagnosis, treatment and management of visceral and renal arteries aneurysms: a joint assessment by the Italian Societies of Vascular and Endovascular Surgery (SICVE) and Medical and Interventional Radiology (SIRM)
: The objective of these Guidelines is to provide recommendations for the classification, indication, treatment and management of patients suffering from aneurysmal pathology of the visceral and renal arteries. The methodology applied was the GRADE-SIGN version, and followed the instructions of the AGREE quality of reporting checklist. Clinical questions, structured according to the PICO (Population, Intervention, Comparator, Outcome) model, were formulated, and systematic literature reviews were carried out according to them. Selected articles were evaluated through specific methodological checklists. Considered Judgments were compiled for each clinical question in which the characteristics of the body of available evidence were evaluated in order to establish recommendations. Overall, 79 clinical practice recommendations were proposed. Indications for treatment and therapeutic options were discussed for each arterial district, as well as follow-up and medical management, in both candidate patients for conservative therapy and patients who underwent treatment. The recommendations provided by these guidelines simplify and improve decision-making processes and diagnostic-therapeutic pathways of patients with visceral and renal arteries aneurysms. Their widespread use is recommended
COVID-19 in rheumatic diseases in Italy: first results from the Italian registry of the Italian Society for Rheumatology (CONTROL-19)
OBJECTIVES:
Italy was one of the first countries significantly affected by the coronavirus disease 2019 (COVID-19) epidemic. The Italian Society for Rheumatology promptly launched a retrospective and anonymised data collection to monitor COVID-19 in patients with rheumatic and musculoskeletal diseases (RMDs), the CONTROL-19 surveillance database, which is part of the COVID-19 Global Rheumatology Alliance.
METHODS:
CONTROL-19 includes patients with RMDs and proven severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) updated until May 3rd 2020. In this analysis, only molecular diagnoses were included. The data collection covered demographic data, medical history (general and RMD-related), treatments and COVID-19 related features, treatments, and outcome. In this paper, we report the first descriptive data from the CONTROL-19 registry.
RESULTS:
The population of the first 232 patients (36% males) consisted mainly of elderly patients (mean age 62.2 years), who used corticosteroids (51.7%), and suffered from multi-morbidity (median comorbidities 2). Rheumatoid arthritis was the most frequent disease (34.1%), followed by spondyloarthritis (26.3%), connective tissue disease (21.1%) and vasculitis (11.2%). Most cases had an active disease (69.4%). Clinical presentation of COVID-19 was typical, with systemic symptoms (fever and asthenia) and respiratory symptoms. The overall outcome was severe, with high frequencies of hospitalisation (69.8%), respiratory support oxygen (55.7%), non-invasive ventilation (20.9%) or mechanical ventilation (7.5%), and 19% of deaths. Male patients typically manifested a worse prognosis. Immunomodulatory treatments were not significantly associated with an increased risk of intensive care unit admission/mechanical ventilation/death.
CONCLUSIONS:
Although the report mainly includes the most severe cases, its temporal and spatial trend supports the validity of the national surveillance system. More complete data are being acquired in order to both test the hypothesis that RMD patients may have a different outcome from that of the general population and determine the safety of immunomodulatory treatments
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