Ionic conduction, rectification, and selectivity in single conical nanopores

Modern track-etching methods allow the preparation of membranes containing a single charged conical nanopore that shows high ionic permselectivity due to the electrical interactions of the surface pore charges with the mobile ions in the aqueous solution. The nanopore has potential applications in electrically assisted single-particle detection, analysis, and separation of biomolecules. We present a detailed theoretical and experimental account of the effects of pore radii and electrolyte concentration on the current-voltage and current-concentration curves. The physical model used is based on the Nernst-Planck and Poisson equations. Since the validity of continuum models for the description of ion transport under different voltages and concentrations is recognized as one of the main issues in the modeling of future applications, special attention is paid to the fundamental understanding of the electrical interactions between the nanopore fixed charges and the mobile charges confined in the reduced volume of the inside [email protected]

Operación de whipple en adenocarcinoma de vesícula biliar con invasión a colédoco y duodeno.

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Association of intrinsic capacity with incidence and mortality of cardiovascular disease: prospective study in UK Biobank

Background: The World Health Organization proposed the concept of intrinsic capacity (IC; the composite of all the physical and mental capacities of the individual) as central for healthy ageing. However, little research has investigated the interaction and joint associations of IC with cardiovascular disease (CVD) incidence and CVD mortality in middle- and older-aged adults. Methods: Using data from 443 130 UK Biobank participants, we analysed seven biomarkers capturing the level of functioning of five domains of IC to calculate a total IC score (ranging from 0 [better IC] to +4 points [poor IC]). Associations between IC score and incidence of six long-term CVD conditions (hypertension, stroke/transient ischaemic attack stroke, peripheral vascular disease, atrial fibrillation/flutter, coronary artery disease and heart failure), and grouped mortality from these conditions were estimated using Cox proportional models, with a 1-year landmark analysis to triangulate the findings. Results: Over 10.6 years of follow-up, CVD morbidity grouped (n = 384 380 participants for the final analytic sample) was associated with IC scores (0 to +4): mean hazard ratio (HR) [95% confidence interval, CI] 1.11 [1.08–1.14], 1.20 [1.16–1.24], 1.29 [1.23–1.36] and 1.56 [1.45–1.59] in men (C-index = 0.68), and 1.17 [1.13–1.20], 1.30 [1.26–1.36], 1.52 [1.45–1.59] and 1.78 [1.67–1.89] in women (C-index = 0.70). In regard to mortality, our results indicated that the higher IC score (+4 points) was associated with a significant increase in subsequent CVD mortality (mean HR [95% CI]: 2.10 [1.81–2.43] in men [C-index = 0.75] and 2.29 [1.85–2.84] in women [C-index = 0.78]). Results of all sensitivity analyses by full sample, sex and age categories were largely consistent independent of major confounding factors (P < 0.001). Conclusions: IC deficit score is a powerful predictor of functional trajectories and vulnerabilities of the individual in relation to CVD incidence and premature death. Monitoring an individual's IC score may provide an early-warning system to initiate preventive efforts.This study was funded by Universidad Pública de Navarra

The effect of exercise training on mediators of inflammation in breast cancer survivors: A systematic review with meta-analysis

Several sources of evidence indicate that exercise during and after breast cancer could positively modulate the tumor microenvironment. This meta-analysis aimed to determine the effects of exercise training on mediators of inflammation in breast cancer survivors. We searched for randomized controlled trials published from January 1990 to March 2014. An inverse variance method of meta-analysis was performed using a random effects model in the presence of statistical heterogeneity. Eight high-quality trials (n = 478) were included. Exercise improved the serum concentrations of IL6 [weighted mean difference (WMD) = -0.55 pg/mL; 95% confidence interval (CI), -1.02 to -0.09], TNF? (WMD = -0.64 pg/mL; 95%CI, -1.21 to -0.06), IL8(MD= -0.49 pg/mL; 95% CI, -0.89 to -0.09), and IL2 (WMD = 1.03 pg/mL; 95% CI, 0.40 to 1.67). No significant differences were found in the serum concentrations of C-reactive protein (WMD = -0.15; 95% CI, -0.56 to 0.25) or IL10 (WMD = 0.41; 95% CI, -0.18 to 1.02). Exercise training positively modulates chronic low-grade inflammation in women with breast cancer, which may impact upon carcinogenic mechanisms and the tumor microenvironment. These findings align with the other positive effects of exercise for breast cancer survivors, reinforcing the appropriateness of exercise prescription in this population. © 2016 American Association for Cancer Research

A cross-sectional study of Colombian University students’ self-perceived lifestyle

Background: The Fantastic Lifestyle Questionnaire was designed for enabling staff working in health sciences and physical activity (PA) areas to measure lifestyles (LS) in the general population. The aim of this study was to assess the lifestyle in a sample of university students. Method: This was a cross-sectional, descriptive, observational study involving 5,921 subjects’ aged 18- to 30-years-old (3,471 females) from three Colombian cities. Was applied “Fantastic” instrument (that consists of 25 closed items on the lifestyle), translated to Spanish in versions of three and five answers. Results: Having a “good LS” was perceived by 57.4% of the females and 58.5% of the males; 14.0% of the females rating their LS as being “excellent” and males 19.3% (p  less than  0.001); 20.3% of the females and 36.6% of the males stated that they spent more than 20 min/day on PA (involving four or more times per week). Negative correlations between FANTASTIC score and weight (r = ?0.113; p  less than  0.01), body mass index (BMI) (r = ?0.152; p  less than  0.01) and waist circumference (r = ?0.178, p  less than  0.01) were observed regarding females, whilst the correlation concerning males was (r = ?0.143, p  less than  0.05) between Fantastic score and weight, (r = ?0.167 for BMI, p  less than  0.01) and (r = ?0.175, p  less than  0.01 for diastolic blood pressure). In spite of the students being evaluated referring to themselves as having a healthy LS (i.e. giving a self-perceived view of their LS), stated behaviour involving a health risk was observed in the domains concerning nutrition, PA and smoking. Conclusion: Specific diffusion, education and intervention action is thus suggested for motivating the adoption of healthy LS. © 2015, Ramírez-Vélez et al

Coude-feed stellar spectral library - atmospheric parameters

Context: Empirical libraries of stellar spectra play an important role in different fields. For example, they are used as reference for the automatic determination of atmospheric parameters, or for building synthetic stellar populations to study galaxies. The CFLIB (Coude-feed library, Indo-US) database is at present one of the most complete libraries, in terms of its coverage of the atmospheric parameters space (Teff, log g and [Fe/H]) and wavelength coverage 3460 - 9464 A at a resolution of 1 A FWHM. Although the atmospheric parameters of most of the stars were determined from detailed analyses of high-resolution spectra, for nearly 300 of the 1273 stars of the library at least one of the three parameters is missing. For the others, the measurements, compiled from the literature, are inhomogeneous. Aims: In this paper, we re-determine the atmospheric parameters, directly using the CFLIB spectra, and compare them to the previous studies. Methods: We use the ULySS program to derive the atmospheric parameters, using the ELODIE library as a reference. Results: Based on comparisons with several previous studies we conclude that our determinations are unbiased. For the 958 F,G, and K type stars the precision on Teff, log g, and [Fe/H] is respectively 43 K, 0.13 dex and 0.05 dex. For the 53 M stars they are 82 K, 0.22 dex and 0.28 dex. And, for the 260 OBA type stars the relative precision on Teff is 5.1%, and on log g, and [Fe/H] the precision is respectively 0.19 dex and 0.16 dex. These parameters will be used to re-calibrate the CFLIB fluxes and to produce synthetic spectra of stellar populations.Comment: 51 pages, accepted for publication in Astronomy and Astrophysic

Active commuting to and from university, obesity and metabolic syndrome among Colombian university students

Background: There is limited evidence concerning how active commuting (AC) is associated with health benefits in young. The aim of the study was to analyze the relationship between AC to and from campus (walking) and obesity and metabolic syndrome (MetS) in a sample of Colombian university students. Methods: A total of 784 university students (78.6% women, mean age = 20.1 ± 2.6 years old) participated in the study. The exposure variable was categorized into AC (active walker to campus) and non-AC (non/infrequent active walker to campus: car, motorcycle, or bus) to and from the university on a typical day. MetS was defined in accordance with the updated harmonized criteria of the International Diabetes Federation criteria. Results: The overall prevalence of MetS was 8.7%, and it was higher in non-AC than AC to campus. The percentage of AC was 65.3%. The commuting distances in this AC from/to university were 83.1%, 13.4% and 3.5% for < 2 km, 2- 5 km and > 5 km, respectively. Multiple logistic regressions for predicting unhealthy profile showed that male walking commuters had a lower probability of having obesity [OR = 0.45 (CI 95% 0.25–0.93)], high blood pressure [OR = 0.26 (CI 95% 0.13–0.55)] and low HDL cholesterol [OR = 0.29 (CI 95% 0.14–0.59)] than did passive commuters. Conclusions: Our results suggest that in young adulthood, a key life-stage for the development of obesity and MetS, AC could be associated with and increasing of daily physical activity levels, thereby promoting better cardiometabolic health.This study was part of the project entitled “Body Adiposity Index and Biomarkers of Endothelial and Cardiovascular Health in Adults”, which was funded by Centre for Studies on Measurement of Physical Activity, School of Medicine and Health Sciences, Universidad del Rosario (Code N° FIUR DNBG001) and Universidad de Boyacá (Code N° RECT 60)