Photochemical cross-linking study of polymers containing diacetylene groups in their main chain and azobenzene compounds as pendant groups

Photochemical cross-linking studies at different temperatures (room temperature, Tg and maximum exothermal of crosslinking peak) are shown for three series of polymers containing diacetylene-groups in the main chain and polar chromophores derived from benzene, azo- and di-azobenzene, as pendant groups. We establish the optimal irradiation time and temperature that permit them being poled and cross-linked with minimal dye-degradation. The degradation process was followed by a diminution of the respective maximum absorption peak. These conditions could extend the mean life-time of the second order nonlinear optical properties, studied previously. Photochemical cross-linking at each polymer´s Tg (50-130°C) was the most convenient process. It took less than 10 min and was monitored by IR spectroscop

Hydrogen production in a novel configuration of UASB reactor under different hydraulic retention time

The aim of this work was to evaluate the production of hydrogen in a conventional and hybrid Upflow Anaerobic Sludge Blanket (UASB) reactors by modifying the hydraulic retention time (HRT). Both reactors operated continuously close to 135 days, with organic loading rate (OLR) of 11.26 kgCOD.m-3.d-1 at 12, 8 and 4 h. In the hybrid reactor, Biopack® rings with polyurethane foam at its center were used. The results showed that the UASB hybrid reactor achieved a stable and continuous production of over 60% of hydrogen gas at each HRT, related to carbon dioxide reduction until the end of the operation. The ANOVA and TUKEY tests, with a 95% reliability level, showed that there was a significant difference between the HRT evaluated, observing that the highest hydrogen production was obtained with 4 h of HRT. In the conventional UASB reactor, there was no stability during the operation time.El objetivo de este estudio fue evaluar la producción de hidrógeno en un reactor anaerobio de manto de lodos y flujo ascendente (UASB) convencional y otro híbrido, modificando el tiempo de retención hidráulica (TRH). Los dos reactores operaron cerca de 135 días continuamente, con una carga orgánica volumétrica de 11.26 kgDQO.m-3.d-1 y valores TRH de 12, 8 y 4 h. En el reactor híbrido se utilizaron anillos de marca Biopack, adicionando espuma de poliuretano en su centro. Los resultados mostraron que la producción de hidrógeno en el reactor UASB híbrido fue estable y superior al 60% en cada uno de los TRH, relacionada con la reducción de dióxido de carbono hasta el final de la operación. Las pruebas de ANOVA y TUKEY mostraron que existen diferencias significativas entre los TRH evaluados, con un nivel de confiabilidad del 95%, observando que la mayor producción de hidrógeno fue obtenida con un TRH de 4 h. En el reactor UASB convencional no se detectó estabilidad en la producción de hidrógeno durante el tiempo de operación

Mexican radiation dermatitis management consensus

Abstract Background: Radiotherapy (RT) is an essential element in cancer treatment: 50–70% of cancer patients receive RT at some time of the course of their disease. Of these, almost 95% experience some grade of radiation dermatitis (RD). RD can affect patient’s quality of life during and after treatment. Consequently, the management of RD is important. There are few randomized controlled clinical trials on interventions used to prevent and treat RD and no standardized consensus on RD management. A panel of opinion leaders of the Mexican Society of Radiotherapy (SOMERA) took part in a study of oncologic practice in Mexico. The following clinical guide is referenced both by the national practice reality and international evidence. Materials and methods: This RD management guide is based on input provided by 25 Mexican radiation oncologists, whose criteria were gathered using the Delphi Method and article review. Results: Twenty-one questions about experience in RD treatment were voted. More than 80% of the panel agreed with: the use of dermocosmetics/medical device in prevention and in treatment of RD grades 1–2. As for grade 3, they recommend individualizing each case and dermatologist evaluation. Topical steroids should be used when there is skin itching or pain. Consider the use of natural soaking elements. Skin care must be continued to avoid or reduce severity of late radiation skin lesions. Conclusion: This consensus was developed as a supportive educational tool that can be adapted to individual clinical needs, useful for professionals involved in the treatment of RT patients.  

Comparison of seven prognostic tools to identify low-risk pulmonary embolism in patients aged <50 years

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Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe