University of Madeira

About: University of Madeira is a education organization based out in Funchal, Portugal. It is known for research contribution in the topics: Population & Dendrimer. The organization has 1014 authors who have published 2759 publications receiving 59457 citations.

Fitness, Fatness, and Survival in Adults With Prediabetes

Abstract: OBJECTIVE The purpose of this study was to examine independent and joint associations of cardiorespiratory fitness (CRF) and different adiposity measures with mortality risk in individuals with pre-diabetes (or impaired fasting glucose). RESEARCH DESIGN AND METHODS We examined associations of CRF and fatness with cardiovascular disease (CVD) and all-cause mortality in a cohort of 17,044 participants (89% men) with pre-diabetes (defined as 100≤plasma fasting glucose RESULTS We identified 832 deaths (246 from CVD) during 13.9 ± 7.0 years (mean ± SD) follow-up. Normal-weight individuals who were unfit (lowest one-third) had a higher risk of all-cause (hazard ratio 1.70 [95% CI 1.32-2.18]) and CVD (1.88 [1.13-3.10]) mortality compared with the normal-weight and fit (upper two-thirds) reference group in a model adjusted for age, sex, examination year, and multiple risk factors. The mortality risk for fit individuals who were overweight or obese did not differ significantly from the reference group. Similar patterns were observed for sex-specific thirds of waist circumference and % body fat. CONCLUSIONS CRF markedly modifies the relationship between adiposity and mortality in persons with pre-diabetes. Unfit individuals have a higher and fit individuals have a lower mortality risk irrespective of adiposity level in this high risk group.

Quantification of artemisinin in Artemisia annua extracts by 1H‐NMR

Abstract: Artemisinin is a polycyclic sesquiterpene lactone that is highly effective against multidrug-resistant strains of Plasmodium falciparum, the etiological agent of the most severe form of malaria. Determination of artemisinin in the source plant, Artemisia annua, is a challenging problem since the compound is present in very low concentrations, is thermolabile and unstable, and lacks chromophoric or fluorophoric groups. The ain of this study was to develop a simple protocol for the quantification of artemisinin in a plant extract using an (1)H-NMR method. Samples were prepared by extraction of leaf material with acetone, treatment with activated charcoal to remove chlorophylls and removal of solvent. (1)H-NMR spectra were measured on samples dissolved in deuterochloroform with tert-butanol as internal standard. Quantification was carried out using the using the delta 5.864 signal of artemisinin and the delta 1.276 signal of tert-butanol. The method was optimised and fully validated against a reference standard of artemisinin. The results were compared with those obtained from the same samples quantified using an HPLC-refractive index (RI) method. The (1)H-NMR method gave a linear response for artemisinin within the range 9.85-97.99 mm (r(2) = 0.9968). Using the described method, yields of artemisinin in the range 0.77-1.06% were obtained from leaves of the A. annua hybrid CPQBA x POP, and these values were in agreement with those obtained using an HPLC-RI.

High resolution temperature independent refractive index measurement using differential white light interferometry

Abstract: In this work a fiber optic interferometric system for differential refractive index measurement is described. The system is based on a white light Mach–Zehnder configuration, with serrodyne phase modulation, used to interrogate two similar non-adiabatic tapered optical fiber sensors in a differential scheme. In this situation the system is able to measure the refractive index independent of temperature. Signal processing with low cost digital instrumentation developed in Labview environment allows a detectable change in refractive index of Δ n ≈ 1.46 × 10 −6 , which is, from the best of our knowledge the highest resolution achieved using a bare fiber taper device for a range of refractive index close to the water index. The results demonstrate the potential of the proposed scheme to operate as a self-referenced chemical and biological sensing platform.

Small-amplitude envelope solitons in nonlinear lattices.

Abstract: The general theory of small-amplitude envelope solitons in one-dimensional lattices with cubic and quartic nonlinearities is developed. It is shown for a wide diversity of interactions among particles that the dynamics of chain excitations is governed either by the nonlinear Schr\"odinger equation or by the system of coupled nonlinear Schr\"odinger equations. In particular, the theory allows the inclusion of lattices with long-range interactions and chains with a complex cell in the unique scheme, which is the envelope function approach. Classes of solitons in diatomic lattices and in chains with long-range interactions are described as particular examples. \textcopyright{} 1996 The American Physical Society.