419 research outputs found

    Dissolution Amplification by Resonance and Cavitational Stimulation at Ultrasonic and Megasonic Frequencies

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    Acoustic stimulation offers a green pathway for the extraction of valuable elements such as Si, Ca, and Mg via solubilization of minerals and industrial waste materials. Prior studies have focused on the use of ultrasonic frequencies (20-40 kHz) to stimulate dissolution, but mega sonic frequencies (≥1 MHz) offer benefits such as matching of the resonance frequencies of solute particles and an increased frequency of cavitation events. Here, based on dissolution tests of a series of minerals, it is found that dissolution under resonance conditions produced dissolution enhancements between 4x-to-6x in Si-rich materials (obsidian, albite, and quartz). Cavitational collapse induced by ultrasonic stimulation was more effective for Ca- and Mg-rich carbonate precursors (calcite and dolomite), exhibiting a significant increase in the dissolution rate as the particle size was reduced (i.e. available surface area was increased), resulting in up to a 70x increase in the dissolution rate of calcite when compared to unstimulated dissolution for particles with d50\u3c 100 μm. Cavitational collapse induced by mega sonic stimulation caused a greater dissolution enhancement than ultrasonic stimulation (1.5x vs 1.3x) for amorphous class F fly ash, despite its higher Si content because the hollow particle structure was susceptible to breakage by the rapid and high number of lower-energy mega sonic cavitation events. These results are consistent with the cavitational collapse energy following a normal distribution of energy release, with more cavitation events possessing sufficient energy to break Ca-O and Mg-O bonds than Si-O bonds, the latter of which has a bond energy approximately double the others. The effectiveness of ultrasonic dissolution enhancement increased exponentially with decreasing stacking fault energy (i.e., resistance to the creation of surface faults such as pits and dislocations), while, in turn, the effectiveness of mega sonic dissolution increased linearly with the stacking fault energy. These results give new insights into the use of acoustic frequency selections for accelerating elemental release from solutes by the use of acoustic perturbation

    Mercat de l'art, col·leccionisme i museus 2020

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    Recull de ponències presentades a la novena Jornada Mercat de l'Art, Col·leccionisme i Museus, celebrada el 2 d'octubre de 2020 a Sitges.Els capítols d'aquesta obra són: 1. El Salón de Arte del Bazar Masaveu de Oviedo (1918-1927) / Juan Carlos Aparicio Vega. 2. La col·lecció arqueològica Duran Vall-llosera / Pere Duran Vall-Llosera. 3. Un episodi rellevant de la història de l'humor gràfic català: la Col·lecció Agell del Museu Nacional d'Art de Catalunya (Barcelona) / Adela Laborda i Francesc M. Quílez i Corella. 4. Baldomero Falgueras (1915-2005), un antiquari de postguerra / Bernat Puigdollers. 5. Alexandre Soler i March (1873-1949), historiador i col·leccionista d'art medieval / Alberto Velasco González. 6. Fernando Rivière de Caralt (1904-1992), passió pel col·leccionisme / Sara Vila Gomà. 7. Francesc Fàbregas i Mas (1857-1933): metge, polític, benefactor i col·leccionista / Joan Yeguas Gassó.Des de l'octubre de 2012 s'han fet regularment de manera anual unes jornades o seminaris científics amb el títol de Mercat de l'Art, Col·leccionisme i Museus, que han donat com a resultat permanent la publicació d'uns volums amb les ponències presentades. Actualment, aquest material configura ja un veritable corpus de valuosa documentació entorn del fenomen del col·leccionisme i el mercat de l'art a Catalunya. La nostra intenció amb la realització d'aquesta jornada ha estat crear una plataforma on poder presentar uns resultats de recerca i discutir-los amb comoditat amb tots els diferents sectors vinculats a les arts: universitaris, professionals dels museus, antiquaris, galeristes, marxants, experts, restauradors, col·leccionistes i afeccionats en general. Estem convençuts de la plena complementarietat de tots aquests punts de vista perquè el progrés del col·leccionisme al llarg de la història ha anat sempre en paral·lel a la formació dels museus i a la configuració del coneixement i l'estudi de les arts. Per això, hem cregut en la utilitat d'una jornada en la qual coincidir i compartir informacions i coneixences, amb un format amable i en un lloc d'una forta empremta simbòlica en la història del col·leccionisme a Catalunya com és el Palau de Maricel de Sitges

    Role of age and comorbidities in mortality of patients with infective endocarditis

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    [Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

    Clinical guide of the Spanish Society of Nephrology on the prevention and treatment of peritoneal infection in peritoneal dialysis

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    [Resumen] Las infecciones peritoneales siguen constituyendo una complicación muy relevante de la diálisis peritoneal, por su incidencia todavía elevada y por sus importantes consecuencias clínicas, en términos de mortalidad, fracaso de la técnica y costes para el sistema sanitario. Las prácticas de prevención y tratamiento de esta complicación muestran una notable heterogeneidad derivada, entre otros factores, de la complejidad del problema y de la escasez de evidencia clínica que permitan responder de manera clara a muchas de las dudas planteadas. El propósito de este documento es proporcionar una revisión completa y actualizada de los métodos de diagnóstico, prevención y tratamiento de estas infecciones. El documento se ha elaborado tomando como referencia de partida la guía más reciente de la Sociedad Internacional de Diálisis Peritoneal (2016). Mientras que para el capítulo diagnóstico se ha adoptado una estructura más narrativa, el análisis de las medidas de prevención y tratamiento ha seguido una metodología sistemática (Grading of Recommendations, Assessment, Development and Evaluation [GRADE]), que especifica el nivel de evidencia y la fuerza de las sugerencias y recomendaciones propuestas, y facilita actualizaciones futuras de la guía. La gran extensión y numerosas recomendaciones o sugerencias emanadas de la revisión ponen de manifiesto la complejidad y gran número de facetas a tener en cuenta para un adecuado abordaje de esta importante complicación de la diálisis peritoneal.[Abstract] Peritoneal infections still represent a most feared complication of chronic peritoneal dialysis, due to their high incidence and relevant clinical consequences, including direct mortality, technique failure and a significant burden for the health system. The practices for prevention and treatment of this complication show a remarkable heterogeneity emerging, among other factors, from the complexity of the problem and from a paucity of quality evidence which could permit to respond clearly to many of the raised questions. The purpose of this document is to provide a complete and updated review of the main methods of diagnosis, prevention and treatment of these infections. The document has been elaborated taking as a reference the most recent guidelines of the International Society of Peritoneal Dialysis (2016). The diagnostic considerations are presented in a narrative style while, for prevention and therapy, we have used a systematic methodology (Grading of Recommendations, Assessment, Development and Evaluation [GRADE]), which specifies the level of evidence and the strength of the proposed suggestions and recommendations and facilitates future updates of the document. The length of the document and the many suggestions and recommendations coming out of the review underline the large number and the complexity of the factors to be taken into consideration for an adequate approach to this complication of peritoneal dialysis

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

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    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

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    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Synthetic Strategies to Tailor Active and Defect Site Structures in Lewis Acid Zeolites for Sugar Isomerization Catalysis

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    Lewis acid zeolites contain framework metal heteroatoms that catalyze sugar isomerization reactions at different turnover rates depending on the local coordination around metal centers and the polarity of their confining secondary environments. Post-synthetic modification routes that react metal precursors with framework vacancy defects in dealuminated Beta zeolites (Sn-Beta-PS-OH) are developed as an alternative synthetic strategy to the hydrothermal crystallization of Sn-Beta zeolites (Sn-Beta-HT-F). Post-synthetic routes provide the ability to systematically tailor the structural features of active and defect sites in Sn-zeolites, especially in composition ranges inaccessible to materials crystallized by hydrothermal routes (Si/Sn \u3c 100; \u3e 2 wt.% Sn), yet often result in incomplete or unselective Sn grafting within framework vacancy defects and form extraframework metal oxide domains and residual defect sites. The development of robust post-synthetic routes to prepare Sn-zeolites with intended active and defect structures has been limited by the dearth of characterization techniques to unambiguously detect and quantify such structures present in stannosilicate materials, and of mechanistic links between such structures and the turnover rates of catalytic reactions. The presence of framework Sn centers that can expand its coordination shell from four- to six-coordinate structures, and small extraframework tin oxide domains that cannot, were unambiguously detected from diffuse reflectance UV-Visible spectra of stannosilicate materials measured after dehydration treatments (523 K, 0.5 h) to discern ligand-to-metal charge transfer bands for tetrahedrally-coordinated Sn heteroatoms (\u3c 220 nm, \u3e 4.1 eV) and those for tin oxide domains (\u3e 230 nm, \u3c 4.1 eV). Liquid-phase grafting of stannic chloride in dichloromethane reflux (333 K) enables preparing Sn-Beta zeolites with higher framework Sn content (Si/Sn = 30– 144; 1.4–6.1 wt.% Sn) than grafting performed in isopropanol reflux (423 K, Si/Sn \u3e 120; 1.6 wt.% Sn). This reflects competitive adsorption of isopropanol solvents with stannic chloride at framework vacancy defects during grafting procedures, consistent with infrared spectroscopy (IR) and temperature-programmed desorption (TPD) of dealuminated Beta samples after saturation with isopropanol at reflux temperatures (423 K), and not any limitations inherent to the structure of vacancy defects within dealuminated zeolite supports that would prevent reaction with metal precursors as often proposed. This insight enabled preparing Sn-Beta zeolites with varying densities of residual defects, via dichloromethane-assisted grafting of stannic chloride to different extents, into dealuminated Beta supports of different initial Al content (Si/Al = 19–180) and mineralizing agent used for hydrothermal crystallization of the parent Al-Beta sample (e.g., fluoride or hydroxide). Preparation of low-defect Sn-Beta zeolites using post-synthetic routes (Sn-Beta-PS-F) first required the synthesis of parent Al-Beta zeolites in fluoride media to minimize residual siloxy defects (OSi−) formed during crystallization, and dilute Al content (Si/Al \u3e 100, \u3c 0.6 Al (unit cell)−1 ), to minimize the density of intrapore silanol groups formed after dealumination and high temperature oxidative treatment. The methanol packing density within microporous voids of Sn-Beta zeolites was assessed from relative volumetric uptakes at the point of micropore filling from single-component methanol (293 K) and nitrogen (77 K) adsorption isotherms, and decreased systematically among samples with increasing density of silanol groups
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