Estudio de la reacción de polimerización y de las propiedades de los copolímeros de metacrilato de metilo - metacrilato de alilo obtenidos por vía radical en diferentes medios

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, leída en 1975.Fac. de Ciencias QuímicasTRUEProQuestpu

Drug complexation and physicochemical properties of vinylpyrrolidone-N, N′-dimethylacrylamide copolymers

Solid dispersions of the nonsteriodal antiin-flammatory drug (NSAID) 2′,4′-difluoro-4-hydroxy-(1,1′-biphenyl)-3-carboxylic acid (DIF) with the water-soluble random copolymer poly(N-vinyl-2-pyrrolidone-co-N, N′-dimethylacrylamide) (VP-co-DMAm) were prepared by the solvent method (coevaporates) and melting DIP/VP-co-DMAm (cofused) physical mixtures. Differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were used to elucidate the possible interaction between the NSAID drug and VP-co-DMAm in cofused and coevaporated polymer-drug solid dispersions. The XRD and FTIR studies suggest the presence of physical interactions with formation of a charge transfer complex between DIF and the VP-co-DMAm copolymers as a consequence of the coevaporation or cofusion processes. In solution, dynamic and equilibrium solubility studies were determined to elucidate the mechanism of interaction between DIP and VP-co-DMAm copolymers. Thermodynamics data about the DIP: VP-co-DMAm dissolution process indicate that the coevaporated systems are more stable that the cofused systems. The dissolution of the cofused and coevaporated systems was diffusion controlled and the dissolution kinetics followed the Noyes-Whitney and the Levich equations. Molecular simulations using semiempirical quantum chemical calculations reinforce the experimental results, suggesting that the improvement in the DIF solubility could be attributed to the charge transfer complex formation between the drug and VP-co-DMAm copolymers.Fil: De Queiroz, Alvaro A.A.. Universidade Federal de Itajubá; BrasilFil: França, Écio J.. Universidade Federal de Itajubá; BrasilFil: Abraham, Gustavo Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Roman, Julio San. Instituto en Ciencia y Tecnología de Polímeros; Españ

Scalable sub-cycle pulse generation by soliton self-compression in hollow capillary fibers with a decreasing pressure gradient

Advances in the generation of the shortest optical laser pulses down to the sub-cycle regime promise to break new ground in ultrafast science. In this work, we theoretically demonstrate the potential scaling capabilities of soliton self-compression in hollow capillary fibers with a decreasing pressure gradient to generate near-infrared sub-cycle pulses in very different dispersion and nonlinearity landscapes. Independently of input pulse, gas and fiber choices, we present a simple and general route to find the optimal self-compression parameters which result in high-quality pulses. The use of a decreasing pressure gradient naturally favors the self-compression process, resulting in shorter and cleaner sub-cycle pulses, and an improvement in the robustness of the setup when compared to the traditional constant pressure approach

Grain yield definition under environmental restrictions

Trigo pan y cebada cervecera son los principales cereales de invierno sembrados en Argentina, en consonancia con su relevancia a nivel mundial. Durante el último quinquenio, el rendimiento medio logrado a nivel productivo en Argentina ha sido para trigo de 2972 kg ha-1 y para cebada de 3596 kg ha-1 , un -9% y +24% respecto al rendimiento medio mundial para el mismo período en cada cultivo. Desde 1960 a la actualidad, el aumento de rendimiento logrado en Argentina presentó una tasa de 32 kg ha-1 año-1 para trigo y de 51 kg ha-1 año-1 para cebada. Alrededor de un tercio del aumento de rendimiento logrado a campo estuvo dado por el progreso genético, en ambos cultivos, pero con fuertes variaciones a lo largo de los años. Tanto en trigo como en cebada el aumento de rendimiento por progreso genético estuvo asociado a un aumento en el número de granos m-2 , sin una tendencia definida en el peso de los granos. Las deficiencias nitrogenadas, las altas temperaturas, y los eventos de anegamiento son algunos de los estreses abióticos a los que están expuestos ambos cultivos en condiciones de campo. En el presente trabajo se describe el impacto de dichos estreses sobre la definición del rendimiento en trigo y cebada, en base a resultados propios obtenidos por los autores del presente trabajo. El número de granos logrados por m2 fue el componente numérico que explicó el rendimiento independientemente de la especie y de la naturaleza del estrés. Dado que la definición del número de granos queda supeditada a la condición ambiental alrededor de antesis, el uso de modelos de simulación es una herramienta para evaluar cuándo ocurrirá dicho evento.Bread wheat and malting barley are the main winter cereals sown in Argentine, in line with its worldwide relevance. During the last five years, the average grain yield achieved in Argentina has been 2972 kg ha-1 for wheat and 3596 kg ha-1 for barley, -9% and +24% relative to worldwide average grain yield for the same period. Yield increase achieved in Argentina from 1960 to the present time presented a rate of 32 kg ha-1 year-1 for wheat and 51 kg ha-1 year-1 for barley. About one third of the yield increase achieved in the field was explained by genetic progress, in both crops, but with strong variability over the years. The increase in grain yield due to genetic progress was associated with an increase in grain number m-2 in both wheat and barley, without a clear trend in weight grain. Nitrogenous deficiencies, high temperatures periods, and waterlogging events are some of the main abiotic stresses to which both crops are exposed under field conditions. In this work we described the impact of these stresses on the definition of grain yield in wheat and barley crops, based on results achieved by the authors of the present work. The number of grains per m2 was the main numerical component that explained grain yield variations, independently of the species and the nature of the stress. The number of grains per m2 is defined around anthesis, and the use of simulation models is a tool to evaluate when anthesis date will occur.Fil: Abeledo, Leonor Gabriela. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cerealicultura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Serrago, Roman Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cerealicultura; ArgentinaFil: de San Celedonio, Romina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Producción Vegetal; ArgentinaFil: Lo Valvo, Patricio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Producción Vegetal; ArgentinaFil: Miralles, Daniel Julio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cerealicultura; Argentin

Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide

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

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

Repositioning of the global epicentre of non-optimal cholesterol

High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe