Effect of hydration on the dielectric properties of C-S-H gel

9 páginas, 7 figuras, 1 tabla.-- Trabajo presentado a la "Gordon Research Conference: Water & Aqueous Solutions" celebrada en EE.UU. del 8 al 13 de agosto de 2010.The behavior of water dynamics confined in hydrated calcium silicate hydrate (C-S-H) gel has been investigated using broadband dielectric spectroscopy (BDS; 10−2–106 Hz) in the low-temperature range (110–250 K). Different water contents in C-S-H gel were explored (from 6 to 15 wt%) where water remains amorphous for all the studied temperatures. Three relaxation processes were found by BDS (labeled 1 to 3 from the fastest to the slowest), two of them reported here for the first time. We show that a strong change in the dielectric relaxation of C-S-H gel occurs with increasing hydration, especially at a hydration level in which a monolayer of water around the basic units of cement materials is predicted by different structural models. Below this hydration level both processes 2 and 3 have an Arrhenius temperature dependence. However, at higher hydration level, a non-Arrhenius behavior temperature dependence for process 3 over the whole accessible temperature range and, a crossover from low-temperature Arrhenius to high-temperature non-Arrhenius behavior for process 2 are observed. Characteristics of these processes will be discussed in this work.Authors gratefully acknowledge the support of Consolider (CSD2006-00053) and Etortek program. S.C. gratefully acknowledge the support of CSIC (200860I021) and S.C. S.A-I, A.A and J.C. gratefully acknowledge the support of the DYNACOP program and the Basque Government, and project IT-436-07 and the Spanish Ministry of Education, project MAT-22007-63681.Peer reviewe

Effect of hydration on the dielectric properties of C-S-H gel

9 páginas, 7 figuras, 1 tabla.-- Trabajo presentado a la "Gordon Research Conference: Water & Aqueous Solutions" celebrada en EE.UU. del 8 al 13 de agosto de 2010.The behavior of water dynamics confined in hydrated calcium silicate hydrate (C-S-H) gel has been investigated using broadband dielectric spectroscopy (BDS; 10−2–106 Hz) in the low-temperature range (110–250 K). Different water contents in C-S-H gel were explored (from 6 to 15 wt%) where water remains amorphous for all the studied temperatures. Three relaxation processes were found by BDS (labeled 1 to 3 from the fastest to the slowest), two of them reported here for the first time. We show that a strong change in the dielectric relaxation of C-S-H gel occurs with increasing hydration, especially at a hydration level in which a monolayer of water around the basic units of cement materials is predicted by different structural models. Below this hydration level both processes 2 and 3 have an Arrhenius temperature dependence. However, at higher hydration level, a non-Arrhenius behavior temperature dependence for process 3 over the whole accessible temperature range and, a crossover from low-temperature Arrhenius to high-temperature non-Arrhenius behavior for process 2 are observed. Characteristics of these processes will be discussed in this work.Authors gratefully acknowledge the support of Consolider (CSD2006-00053) and Etortek program. S.C. gratefully acknowledge the support of CSIC (200860I021) and S.C. S.A-I, A.A and J.C. gratefully acknowledge the support of the DYNACOP program and the Basque Government, and project IT-436-07 and the Spanish Ministry of Education, project MAT-22007-63681.Peer reviewe

Empresas, periódicos y periodistas en las autonomías

Esta artículo de investigacion se centra en las empresas de prensa regional y en los periodistas de las Autonomias españolas. Desde que el Estado Español se configuró como un Estado Autonómico de diecisiete comunidades Autónomas a partir de la Constitucion de 1978, la importancias de la prensa regional ha aumentado año tras año. Nuestro trabajo parte de una entrevista en profundiad a los directores y consejeros delegados de catorce periódicos regionales, que representan en torno al 20% de la difusión y del capital de la prensa en España. El objetivo de la investigación es un conocimiento profundo de la prensa regional: orientación ideológica e intereses, su evolución economica, ingresos (por venta al numero y publicidad), beneficios y cash-flow; la organizacion del trabajo de edición; la formación de los periodistas, edad, sexo, afilicación sindical, etc; y también, un breve analisis de su contenido (primera página, secciones, fuentes, importancia de la fotografía, infografía y color), etc

Cardiac troponin I release after a basketball match in elite, amateur and junior players

BACKGROUND: Available scientific data related to cardiac troponin I (cTnI) release after intermittent exercise is limited. It is also of interest to determine what personal or environmental factors mediate the exercise-induced release of cTnI. This study had two objectives: 1) to examine the individual release of cTnI to a basketball match; and 2) to establish the influence of athlete status as well as biological age on cTnI release. METHODS: Thirty-six basketball players (12 adult elite [PBA]: 27.3±4.1 years, 12 adult amateur [ABA]: 29.6±2.9 years, and 12 junior elite [JBA]: 16.6±0.9 years) participated in a simulated basketball match with serial assessment of cTnI at rest, immediately post- and at 1, 3, 6, 12, and 24 h post-exercise. RESULTS: The basketball match increased cTnI levels (pre: median [range]; 0.006 [0.001-0.026]; peak post: 0.024 [0.004-0.244] μg/L; p=0.000), with substantial individual variability in peak values. PBA and JBA players showed higher baseline and post-exercise cTnI values than ABA (all p<0.05). Peak cTnI exceeded the upper reference limit (URL) in the 26% of players (3 PBA; 6 JBA). CONCLUSIONS: The current results suggest that intermittent exercise can promote the appearance of cTnI and that this is potentially mediated by athlete status

Effect of training load on post-exercise cardiac troponin T elevations in young soccer players

Training load (TL) metrics are usually assessed to estimate the individual, physiological and psychological, acute, and adaptive responses to training. Cardiac troponins (cTn) reflect myocardial damage and are routinely analyzed for the clinical diagnosis of myocardial injury. The association between TL and post-exercise cTn elevations is scarcely investigated in young athletes, especially after playing common team sports such as soccer. The objective of this study was to assess the relationship between TL measurements during a small-sided soccer game and the subsequent increase in cTn in young players. Twenty male soccer players (age 11.9 ± 2 years, height 151 ± 13 cm, weight 43 ± 13 kg) were monitored during a 5 × 5 small-sided game and had blood samples drawn before, immediately after, and 3 h after exercise for a posterior analysis of high-sensitivity cardiac troponin T (hs-cTnT). Internal, external, and mixed metrics of TL were obtained from the rating of perceived exertion (RPE), heart rate (HR), and GPS player tracking. The results show that the concentration of hs-cTnT peaked at 3 h post-exercise in all participants. The magnitude of hs-cTnT elevation was mainly explained by the exercise duration in the maximal heart rate zone (Maximum Probability of Effect (MPE) = 92.5%), time in the high-speed zone (MPE = 90.4 %), and distance in the high-speed zone (MPE = 90.45%). Our results support the idea that common metrics of TL in soccer, easily obtained using player tracking systems, are strongly associated with the release of hs-cTnT in children and adolescents

Cardiac troponin T release after football 7 in healthy children and adults

The objective of this study was to compare the release of cardiac troponin T (cTnT) after a football 7 match between two cohorts of children and adult players. Thirty-six male football players (children = 24, adult = 12) played a football 7 match, and cTnT was measured before, and 3 h after exercise. Concentrations of cTnT were compared between groups and time, and correlated with participants’ characteristics, as well as internal and external exercise load. Cardiac troponin T was elevated in all participants (p < 0.001), and exceeded the upper reference limit for myocardial infarction in 25 (~70%) of them. Baseline concentrations were higher in adults (p < 0.001), but the elevation of cTnT was comparable between the groups (p = 0.37). Age (p < 0.001), body mass (p = 0.001) and height (p < 0.001), and training experience (p = 0.001) were associated to baseline cTnT values, while distance (p < 0.001), mean speed (p < 0.001), and peak (p = 0.013) and mean (p = 0.016) heart rate were associated to the elevation of cTnT. The present study suggests that a football 7 match evoked elevations of cTnT during the subsequent hours in healthy players regardless of their age. However, adults might present higher resting values of cTnT than children. In addition, results suggest that the exercise-induced elevations of cTnT might be mediated by exercise load but not participant characteristics

Cone pigments in a North American marsupial, the opossum (Didelphis virginiana)

Only two of the four cone opsin gene families found in vertebrates are represented in contemporary eutherian and marsupial species. Recent genetic studies of two species of South American marsupial detected the presence of representatives from two of the classes of cone opsin genes and the structures of these genes predicted cone pigments with respective peaks in the ultraviolet and long-wavelength portions of the spectrum. The Virginia opossum (Didelphis virginiana), a profoundly nocturnal animal, is the only marsupial species found in North America. The prospects for cone-based vision in this species were examined through recordings of the electroretinogram (ERG), a commonly examined retinal response to photic stimulation. Recorded under flickering-light conditions that elicit signals from cone photoreceptors, the spectral sensitivity of the opossum eye is well accounted for by contributions from the presence of a single cone pigment having peak absorption at 561–562 nm. A series of additional experiments that employed various chromatic adaptation paradigms were conducted in a search for possible contributions from a second (short-wavelength sensitive) cone pigment. We found no evidence that such a mechanism contributes to the ERG in this marsupial

Validation and optimization of AFP-based biomarker panels for early HCC detection in Latin America and Europe

Background: HCC is a major cause of cancer death worldwide. Serum biomarkers such as alpha-fetoprotein (AFP), protein induced by vitamin K absence-II, and the Gender, Age, AFP-L3, AFP, Des-gamma-carboxy prothrombin (GALAD) score have been recommended for HCC surveillance. However, inconsistent recommendations in international guidelines limit their clinical utility.Methods: In this multicenter study, over 2000 patient samples were collected in 6 Latin American and 2 European countries. The performance of the GALAD score was validated in cirrhotic cases, and optimized versions were tested for early-stage HCC and prediagnostic HCC detection.Results: The GALAD score could distinguish between HCC and cirrhosis in Latin American patients with an AUC of 0.76, sensitivity of 70%, and specificity of 83% at the conventional cutoff value of −0.63. In a European cohort, GALAD had an AUC of 0.69, sensitivity of 66%, and specificity of 72%. Optimizing the score in the 2 large multicenter cohorts revealed that AFP-L3 contributed minimally to early-stage HCC detection. Thus, we developed a modified GALAD score without AFP-L3, the ASAP (age, sex, AFP, and protein induced by vitamin K absence-II), which showed promise for early-stage HCC detection upon validation. The ASAP score also identified patients with cirrhosis at high risk for advanced-stage HCC up to 15 months before diagnosis (p &lt; 0.0001) and differentiated HCC from hemangiomas, with a specificity of 100% at 71% sensitivity.Conclusion: Our comprehensive analysis of large sample cohorts validates the GALAD score’s utility in Latin American, Spanish, and Dutch patients for early-stage HCC detection. The optimized GALAD without AFP-L3, the ASAP score, is a good alternative and shows greater promise for HCC prediction