20 research outputs found
Clinical metabolomics and nutrition: the new frontier in neonatology and pediatrics.
In the pediatric clinic, nutritional research is focusing more and more on preventing the development of long-term diseases as well as supporting the repair processes important in the therapy of already fully developed diseases. Most children who are hospitalized or affected by chronic diseases could benefit from specific and careful attention to nutrition. Indeed, the state of nutrition modulates all body functions, including the different metabolic processes which, all together, have a profound effect on the development of the health and future of all individuals. Inappropriate food, even in the first periods of life, can accelerate the development of chronic metabolic diseases, especially in the pediatric age. To gain further insights into metabolic cycles and how they are connected with diet and health, nutrition and metabolomics interact to develop and apply modern technologies for metabolic assessment. In particular, nutritionists are evaluating the metabolomic approach to establish the single nutritional phenotypes, that is, the way in which diet interacts with individuals' metabolisms. This strategy offers the possibility of providing a complete definition of the individual's nutritional and health status, predict the risk of disease, and create metabolomic databases supporting the development of "personalized nutrition," in which diet is attuned to the nutritional needs of individual patients
Enhancing the separation performance of glassy PPO with the addition of a molecular sieve (ZIF-8): Gas transport at various temperatures
In this study, we prepared and characterized composite films formed by amorphous poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and particles of the size-selective Zeolitic Imidazolate Framework 8 (ZIF-8). The aim was to increase the permselectivity properties of pure PPO using readily available materials to enable the possibility to scale-up the technology developed in this work. The preparation protocol established allowed robust membranes with filler loadings as high as 45 wt% to be obtained. The thermal, morphological, and structural properties of the membranes were analyzed via DSC, SEM, TGA, and densitometry. The gas permeability and diffusivity of He, CO2, CH4, and N2 were measured at 35, 50, and 65 \ub0C. The inclusion of ZIF-8 led to a remarkable increase of the gas permeability for all gases, and to a significant decrease of the activation energy of diffusion and permeation. The permeability increased up to +800% at 45 wt% of filler, reaching values of 621 Barrer for He and 449 for CO2 at 35 \ub0C. The ideal size selectivity of the PPO membrane also increased, albeit to a lower extent, and the maximum was reached at a filler loading of 35 wt% (1.5 for He/CO2, 18 for CO2/N2, 17 for CO2/CH4, 27 for He/N2, and 24 for He/CH4). The density of the composite materials followed an additive behavior based on the pure values of PPO and ZIF-8, which indicates good adhesion between the two phases. The permeability and He/CO2 selectivity increased with temperature, which indicates that applications at higher temperatures than those inspected should be encouraged
Inelastic collisions of CaH with He at cryogenic temperatures
Using helium buffer gas cooling, we have prepared dense samples of ground-state molecular calcium monohydride (CaH X 2ÎŁ) at cryogenic temperatures. We have used optical pumping to polarise the spin state of the CaH molecules and we have measured the inelastic collisions of molecular CaH with atomic helium at temperatures from 2 to 7 K. The measured CaH electronic spin depolarisation rate coefficient increases rapidly with increasing temperature, increasing from 2 Ă 10â13 cm3 sâ1 to over 10â11 cm3 sâ1. The strong dependence of rate coefficient on temperature is attributed to the CaH population in the first excited rotational state
The Influence of Digital Technologies on Born Global Business Models
This study aims at understanding the impact of digital technologies in shaping the Born Global companiesâ business models and the influence on their internationalization path. To develop our study, we adopted an approach based on interviews with key informants from two Italian Born Global companies that have developed their internationalization path by relying on digital technologies. Our findings highlight how digital technologies and collaborative design tools can represent the basis for new business models which exploit the opportunities coming from the increasing connectivity of people and businesses. According to this perspective, new types of born global companies can be identified, with a role of âdigital-based process coordinatorâ, which support with a pivotal role the management of complex projects
Prediction of physicalâchemical properties of crude oils by 1H NMR analysis of neat samples and chemometrics
In this work, we report the feasibility study to predict the properties of neat crude oil samples from 300-MHz NMR spectral
data and partial least squares (PLS) regression models. The study was carried out on 64 crude oil samples obtained from 28
different extraction fields and aims at developing a rapid and reliable method for characterizing the crude oil in a fast and
cost-effective way. The main properties generally employed for evaluating crudesâ quality and behavior during refining were
measured and used for calibration and testing of the PLS models. Among these, the UOP characterization factor K (KUOP) used
to classify crude oils in terms of composition, density (D), total acidity number (TAN), sulfur content (S), and true boiling point
(TBP) distillation yields were investigated. Test set validation with an independent set of data was used to evaluate model
performance on the basis of standard error of prediction (SEP) statistics. Model performances are particularly good for KUOP
factor, TAN, and TPB distillation yields, whose standard error of calibration and SEP values match the analytical method
precision, while the results obtained for D and S are less accurate but still useful for predictions. Furthermore, a strategy that
reduces spectral data preprocessing and sample preparation procedures has been adopted. The models developed with such
an ample crude oil set demonstrate that this methodology can be applied with success to modern refining process requirement
High precision calculation of multipolar dynamic polarizabilities and two- and three-body dispersion coefficients of atomic hydrogen
In this paper we investigate a variationally stable procedure for multipolar dynamic polarizabilities calculation as well as the two- and three-body van der Waals coefficients of the hydrogen atom. This approach provides precise, fast convergent values for real and imaginary frequency-dependent 2 (L) -pole dynamic polarizabilities. Highly accurate two- and three-body van der Waals dispersion coefficients are calculated from dynamic polarizabilities at imaginary photon frequencies. The present approach is also precise for higher interaction orders. The results are compared with previous calculations found in the literature.Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES
Binding energies of excitons trapped by ionized donors in semiconductors
Using the hyperspherical adiabatic approach in a coupled-channel calculation, we present precise binding energies of excitons trapped by impurity donors in semiconductors within the effective-mass approximation. Energies for such three-body systems are presented as a function of the relative electron-hole mass sigma in the range 1 less than or equal to1/sigma less than or equal to6, where the Born-Oppenheimer approach is not efficiently applicable. The hyperspherical approach leads to precise energies using the intuitive picture of potential curves and nonadiabatic couplings in an ab initio procedure. We also present an estimation for a critical value of sigma (sigma (crit)) for which no bound state can be found. Comparisons are given with results of prior work by other authors