Polymer-solvent interaction parameters of SBS rubbers by inverse gas chromatography measurements

The solubility parameters of two SBS commercial rubbers with different structures (lineal and radial), and with slightly different styrene content have been determined by inverse gas chromatography technique. The Flory–Huggins interaction parameters of several polymer–solvent mixtures have also been calculated. The influence of the polymer composition, the solvent molecular weight and the temperature over these parameters have been discussed; besides, these parameters have been compared with previous ones, obtained by intrinsic viscosity measurements. From the Flory–Huggins interaction parameters, the infinite dilution activity coefficients of the solvents have been calculated and fitted to the well-known NRTL model. These NRTL binary interaction parameters have a great importance in modelling the separation steps in the process of obtaining the rubber

Radiative efficiencies for fluorinated esters: indirect global warming potentials of hydrofluoroethers

Density Functional Theory (DFT) has been used with an empirically-derived correction for the wavenumbers of vibrational band positions to predict the infrared spectra of several fluorinated esters (FESs). Radiative efficiencies (REs) were then determined using the method of Pinnock et al. and these were used with atmospheric lifetimes from the literature to determine the direct global warming potentials of FESs. FESs, in particular fluoroalkylacetates, alkylfluoroacetates and fluoroalkylformates, are potential greenhouse gases and their likely long atmospheric lifetimes and relatively large REs, compared to their parent HFEs, make them active contributors to global warming. Here, we use the concept of indirect global warming potential (indirect GWP) to assess the contribution to the warming of several commonly used HFEs emitted from the Earth's surface, explicitly taking into account that these HFEs will be converted into the corresponding FESs in the troposphere. The indirect GWP can be calculated using the radiative efficiencies and lifetimes of the HFE and its degradation FES products. We found that the GWPs of those studied HFEs which have the smallest direct GWP can be increased by 100-1600% when taking account of the cumulative effect due to the secondary FESs formed during HFE atmospheric oxidation. This effect may be particularly important for non-segregated HFEs and some segregated HFEs, which may contribute significantly more to global warming than can be concluded from examination of their direct GWPs

Dynamical and spectral properties of complex networks

Dynamical properties of complex networks are related to the spectral properties of the Laplacian matrix that describes the pattern of connectivity of the network. In particular we compute the synchronization time for different types of networks and different dynamics. We show that the main dependence of the synchronization time is on the smallest nonzero eigenvalue of the Laplacian matrix, in contrast to other proposals in terms of the spectrum of the adjacency matrix. Then, this topological property becomes the most relevant for the dynamics.Comment: 14 pages, 5 figures, to be published in New Journal of Physic

Enterprise Ionic Liquids Database (ILUAM) for Use in Aspen ONE Programs Suite with COSMO-Based Property Methods

“This document is the Accepted Manuscript version of a Published Work that appeared in final form in Industrial & Engineering Chemistry Research copyright © American Chemical Society after peer review and technical editing by the publisher . To access the final and published work see Enterprise Ionic Liquids Database (ILUAM) for Use in Aspen ONE Programs Suite with COSMO-Based Property Methods V. R. Ferro, C. Moya, D. Moreno, R. Santiago, J. de Riva, G. Pedrosa, M. Larriba, I. Diaz, and J. Palomar Industrial & Engineering Chemistry Research 2018 57 (3), 980-989 DOI: 10.1021/acs.iecr.7b04031An enterprise database of pure ionic liquids (ILs) for its use in the Aspen ONE programs is presented. The database is identified as ILUAM, and the first version (ILUAM01) contains 100 ILs composed of 30 cations and 23 anions. The IL components were introduced in Aspen Properties as pseudocomponents using information from the computational COSMO-RS method and from experimental viscosity data. ILUAM database was created to be used along with the COSMOSAC property model implemented in Aspen Plus, allowing evaluating IL process performance without needing further experimental data. Some validation tests were carried out to demonstrate the successful incorporation of ILs in the Aspen Plus property system. Then, the performance of ILUAM01 database in thermodynamic property predictions of mixtures involving ILs and conventional chemical compounds was revised in terms of activity coefficients at infinite dilution and phase equilibrium data. The property description of pure ILs and IL mixtures with conventional chemical compounds using COSMO-based/Aspen Plus approach was found with the accuracy level required in the conceptual design of new processes. ILUAM database offers the opportunity of performing systematic evaluation of potential industrial applications of ILs and their competitiveness as alternative to conventional solvents.The authors are grateful to the Comunidad de Madrid (project S2013- MAE-2800) and to the Ministerio de Economía y Competitividad of Spain (Project CTQ2014-52288-R) for financial support. M. Larriba also thanks Ministerio de Economía y Competitividad of Spain for awarding him a Juan de la Cierva-Formación Contract (Reference FJCI-2015-25343

The sequence selectivity of KSRP explains its flexibility in the recognition of the RNA targets

K-homology (KH) splicing regulator protein (KSRP) is a multi-domain RNA-binding protein that regulates different steps of mRNA metabolism, from mRNA splicing to mRNA decay, interacting with a broad range of RNA sequences. To understand how KSRP recognizes its different RNA targets it is necessary to define the general rules of KSRP–RNA interaction. We describe here a complete scaffold-independent analysis of the RNA-binding potential of the four KH domains of KSRP. The analysis shows that KH3 binds to the RNA with a significantly higher affinity than the other domains and recognizes specifically a G-rich target. It also demonstrates that the other KH domains of KSRP display different sequence preferences explaining the broad range of targets recognized by the protein. Further, KSRP shows a strong negative selectivity for sequences containing several adjacent Cytosines limiting the target choice of KSRP within single-stranded RNA regions. The in-depth analysis of the RNA-binding potential of the KH domains of KSRP provides us with an understanding of the role of low sequence specificity domains in RNA recognition by multi-domain RNA-binding proteins

Glyceraldehyde-3-phosphate dehydrogenase is overexpressed in colorectal cancer onset

Background Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an essential regulator of glycolysis used as a housekeeping marker for gene/protein normalisation. Given the pivotal role of GAPDH in tumour metabolism, our aim was to correlate its protein expression with tumour staging and prognosis of colorectal cancer. Methods GAPDH expression was immunohistochemically analysed in tumour tissues from 62 colorectal cancer (CRC) patients, and validated at mRNA level in an independent dataset comprising 98 paired stage II CRC and normal samples. Staining quantification was performed by computational image analysis, and correlations between GAPDH expression and tumour progression stage were assessed. Gene expression profiling was performed using Affymetrix microarrays. Probability of patient survival and disease-free survival were analysed by the univariate product-limit method of Kaplan-Meier. Groups were compared using Kruskal-Wallis tests. Results Overexpression of GAPDH is positively associated with early stage tumours without regional lymph node and distant metastases involved. These results were reinforced by those obtained at mRNA level. Conclusion Studying the role of GAPDH in malignant transformation can shed new light on the understanding of tumour onset and lead to the design of more efficient personalised therapies

A Survey of key methods, traits, parameters, and conditions for measuring texture in cranberry (Vaccinium macrocarpon Ait.)

In the cranberry (Vaccinium macrocarpon Ait.) industry, the textural properties and firmness of the fruit are priority traits for producing processed products, such as sweetened dried cranberry (SDC), which have gained popularity in recent years. However, there is currently no reliable methodology for screening these traits in breeding programs. In this study, we examine the key methodologies, textural traits, parameters, and conditions that are necessary to accurately and efficiently measure the texture of cranberry fruit. Double compression, single compression, puncture, shearing and Kramer shear cell methodologies were successfully implemented in cranberry, resulting in a total of 47 textural features. These features allowed the evaluation of the texture of the cranberry fruit based on key factors such as flesh, structure, and skin. This study also examined factors than can affect the performance of texture measurements, including the optimal sample size, storage time, fruit texture-size correlation, fruit temperature and orientation, optimal speed/strain combinations, and the effect of probe diameter. The results of the study suggests that certain texture traits of the compression and puncture methodologies could potentially be used to test varieties and aid in breeding program