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

Digestión ruminal de hierba verde y conservada de prados permanentes de montana

Se han determinado la composición química y las características de degradación ruminal de 30 muestras de forraje procedentes de los cortes de junio (20) y de septiembre (10) de un prado permanente de regadío. Las muestras de junio fueron analizadas en verde (5) o después de ser conservadas mediante diversos procedimientos (henificación (5), ensilado (5) y deshidratación (5)). En el corte de septiembre, el estudio se llevó a cabo sobre muestras en verde y henificadas. No hubo diferencias en composición química (g/kg MS) entre el forraje verde y el heno, mientras que en el ensilado se observó un incremento en el contenido en proteína bruta (131 vs. 121) y en el de pared celular (533 vs. 470) con respecto al forraje verde. Las muestras procedentes del corte de junio presentaron un mayor contenido en pared celular (479 vs. 440) y un menor contenido en proteína bruta (119 vs. 153) que las de septiembre. Los forrajes desecados (heno y deshidratado) mostraron una menor solubilidad (39,2 y 27,0 vs. 57,2 %), un ritmo de degradación más rápido (0,215 y 0,200 vs. 0,127 h~1) y un tiempo de retraso más largo (5,3 y 4,4 vs. 4,1 h) en el inicio de la degradación de los compuestos nitrogenados que los otros tipos de forrajes. La degradabilidad efectiva de la proteína fue más alta en el caso del ensilado (82,0 %), mientras que la deshidratación de la hierba dio lugar a una disminución significativa de la degradabilidad de los compuestos nitrogenados. Los valores de degradabilidad ruminal de la pared celular más altos correspondieron al heno (71,1 %). La degradabilidad y el ritmo de degradación ruminal de los forrajes procedentes del corte de septiembre fueron mayores que los de los forrajes obtenidos en el corte de juni

Neuronal and astrocytic tetraploidy is increased in drug-resistant epilepsy.

Aims: Epilepsy is one of the most prevalent neurological diseases. A third of patients with epilepsy remain drug-resistant. The exact aetiology of drug-resistant epilepsy (DRE) is still unknown. Neuronal tetraploidy has been associated with neuropathology. The aim of this study was to assess the presence of tetraploid neurons and astrocytes in DRE. Methods: For that purpose, cortex, hippocampus and amygdala samples were obtained from patients subjected to surgical resection of the epileptogenic zone. Post-mortem brain tissue of subjects without previous records of neurological, neurodegenerative or psychiatric diseases was used as control. Results: The percentage of tetraploid cells was measured by immunostaining of neurons (NeuN) or astrocytes (S100ß) followed by flow cytometry analysis. The results were confirmed by image cytometry (ImageStream X Amnis System Cytometer) and with an alternative astrocyte biomarker (NDRG2). Statistical comparison was performed using univariate tests. A total of 22 patients and 10 controls were included. Tetraploid neurons and astrocytes were found both in healthy individuals and DRE patients in the three brain areas analysed: cortex, hippocampus and amygdala. DRE patients presented a higher number of tetraploid neurons (p = 0.020) and astrocytes (p = 0.002) in the hippocampus than controls. These results were validated by image cytometry. Conclusions: We demonstrated the presence of both tetraploid neurons and astrocytes in healthy subjects as well as increased levels of both cell populations in DRE patients. Herein, we describe for the first time the presence of tetraploid astrocytes in healthy subjects. Furthermore, these results provide new insights into epilepsy, opening new avenues for future treatment.We thank the epilepsy patients who kindly donated brain samples.We are particularly grateful for the generous contribution of thepatients and the collaboration of the Biobank Network of the Regionof Murcia, BIOBANC-MUR, registered on the Registro Nacional deBiobancos with registration number B.0000859. BIOBANC-MUR issupported by the‘Instituto de Salud Carlos III’(proyectoPT20/00109), by‘Instituto Murciano de Investigacion BiosanitariaVirgen de la Arrixaca, IMIB’and by‘Consejería de Salud de la Comuni-dad Autonoma de la Region de Murcia’. We would like to thank JavierFraga and Manuel Gomez Gutierrez for their help with the study andtheir valuable comments on this manuscript. We also thank our col-leagues from the Flow Cytometry Unit of‘Instituto de MedicinaMolecular Aplicada’(IMMA, Universidad San Pablo CEU). Authorswould like to acknowledge the use of‘Servicio General de Apoyo a la8of10SANZ-GARCÍAET AL.Investigacion SAI CITOMICA of the University Zaragoza’. This studywas supported by Instituto de Salud Carlos III: PI2017/02244. PSJ isfunded by an Industrial PhD grant from‘Consejeria de Educacion eInvestigacion’of‘Comunidad de Madrid’developed in NIMGeneticsand Hospital Universitario de La Princesa (CAM.IND2017/BMD-7578).Peer reviewe

Proteinases in bone resorption: obvious and less obvious roles

Bone resorption is critical for the development and the maintenance of the skeleton, and improper regulation of bone resorption leads to pathological situations. Proteinases are necessary for this process. In this review, we show that this need of proteinases is not only because they are required for the solubilization of bone matrix, but also because they are key components of the mechanism that determines where and when bone resorption will be initiated. Moreover, there are indications that proteinases may also determine whether resorption will be followed by bone formation. Some of the proteinases involved in these different steps of the resorption processes were recently identified, as for instance cathepsin K, MMP-9 (gelatinase B), and interstitial collagenase. However, there is also increasing evidence showing that the critical proteinase(s) may vary depending on the bone type or on other factor

MONSTER: a TOF Spectrometer for beta-delayed Neutron Spetroscopy

Beta-delayed neutron (DN) data, including emission probabilities, P-n, and energy spectrum, play an important role in our understanding of nuclear structure, nuclear astrophysics and nuclear technologies. A MOdular Neutron time-of-flight SpectromeTER (MONSTER) is being built for the measurement of the neutron energy spectra and branching ratios. The TOF spectrometer will consist of one hundred liquid scintillator cells covering a significant solid angle. The MONSTER design has been optimized by using Monte Carlo (MC) techniques. The response function of the MONSTER cell has been characterized with mono-energetic neutron beams and compared to dedicated MC simulations