Estimation of comprehensive two-dimensional gas chromatographic response from one-dimensional gas chromatography data

Trabajo presentado a la XV Reunión Científica de la Sociedad Española de Cromatografía y Técnicas Afines (SECyTA) celebrada en Castellón de la Plana del 28 al 30 de octubre de 2015Optimization of a separation in comprehensive two-dimensional gas chromatography (GC×GC) requires the selection of an appropriate set column, and the optimisation of their respective dimensions, temperature programs and flow rates. Until not so long ago, a time consuming trial and error process was the only way to select the columns and chromatographic conditions for the two GC dimensions. During the last few years, several attempts have been proposed to estimate the chromatographic response in GC×GC [1-4]. Although most of these methods are helpful contributions, some of them focussed exclusively on the retention time estimation and do not consider the effect of peak width, also essential for a correct prediction of the chromatographic separation capability. Others are based on theoretical formulas not applicable to the extreme experimental conditions used in GC×GC, or are only valid for specific types of compounds or stationary phases: these models cannot be corrected for different separation problems. In this work, modelization of retention time and peak width has been carried out from experimental 1D GC data in order to estimate the response in GC×GC separation for different column sets operated under different flows and temperatures. Several theoretical and experimental models are proposed for estimation of 1D and 2D retention time and peak width; in experimental models, 1D GC data are required together with information on column characteristics and operation conditions. Models for hold-up time, retention factor and peak width were first validated in 1D GC from the fit between experimental and calculated data. Their validation in GC×GC was carried out by using n-alkanes and a mixture of disaccharides as their trimethylsilyl oxime derivatives. Comparison of experimental and estimated data showed good results for retention time in both first and second dimension. Peak widths presented, however, some errors, caused by the no consideration on estimation of the effect of the modulator or the rather unusual chromatographic conditions used. The developed programme is very versatile as it can be used for the calculation of the chromatographic response of compounds with different polarity and volatility, analysed under different pressures and temperature ramps, and with different sets of columns. [1] J.V. Seeley, E.M. Libby, K.A.H. Edwards, S.K. Seeley, J. Chromatogr. A 1216 (2009) 1650. [2] F.L. Dorman, P.D. Schettler, L.A. Vogt, J.W. Cochran, J. Chromatogr. A 1186 (2008) 196. [3] Y. Zhao, J. Zhang, B. Wang, S.H. Kim, A. Fang, B. Bogdanov, Z. Zhou, C. McClain, X. Zhang, J. Chromatogr. A 1218 (2011) 2577. [4] S. Zhu, S. He, D.R. Worton, A.H. Goldstein, J. Chromatogr. A 1233 (2012) 147. Acknowledgements: This work has been funded by Ministerio de Economía y Competitividad (project CTQ2012-32957), Comunidad Autónoma de Madrid (Spain) and European funding from FEDER program (AVANSECAL-CM S2013/ABI-3028) and Fundación Ramón Areces. ACS thanks Ministerio de Economía y Competitividad of Spain for a Ramón y Cajal contract.CTQ2012-32957Peer reviewe

Study of the stability of packaging and storage conditions of human mesenchymal stem cell for intra-arterial clinical application in patient with critical limb ischemia

Critical limb ischemia (CLI) is associated with significant morbidity and mortality. In this study, we developed and characterized an intra-arterial cell suspension containing human mesenchymal stem cells (hMSCs) for the treatment of CLI. Equally, the stability of cells was studied in order to evaluate the optimal conditions of storage that guarantee the viability from cell processing to the administration phase. Effects of various factors, including excipients, storage temperature and time were evaluated to analyze the survival of hMSCs in the finished medicinal product. The viability of hMSCs in different packaging media was studied for 60 h at 4 °C. The best medium to maintain hMSCs viability was then selected to test storage conditions (4, 8, 25 and 37 °C; 60 h). The results showed that at 4 °C the viability was maintained above 80% for 48 h, at 8 °C decreased slightly, whereas at room temperature and 37 °C decreased drastically. Its biocompatibility was assessed by cell morphology and cell viability assays. During stability study, the stored cells did not show any change in their phenotypic or genotypic characteristics and physicochemical properties remained constant, the ability to differentiate into adipocytes and osteocytes and sterility requirements were also unaltered. Finally, our paper proposes a packing media composed of albumin 20%, glucose 5% and Ringer's lactate at a concentration of 1 × 106 cells/mL, which must be stored at 4 °C as the most suitable to maintain cell viability (>80%) and without altering their characteristics for more than 48 h. © 2013 Elsevier B.V. All rights reserved.This study was supported by Grants RD08/0010/2005 (Red TERCEL) and PI10/00964 from Institute of Heath Carlos III and TRA-120 (Ministry of Health) to BS.Peer Reviewe

Chemical modification of titanium precursor to obtain stable silica-titania sol: acetylacetone

[ES] La técnica Sol-Gel se ha utilizado para sintetizar una serie de sistemas multicomponentes, entre ellos SiO2 – TiO2. El mayor problema en la obtención de geles multicomponentes estables es la desigual velocidad de hidrólisis y condensación que presentan los alcóxidos precursores de los cationes de interés. En este trabajo se muestra cómo adicionando acetilacetona, acacH, al sistema TEOS – Ti(OBu)4 – H2O se puede obtener un sol estable. Se tomaron diferentes concentraciones de los precursores de silicio y titanio y una sola concentración de acacH. Se utilizó espectroscopia infrarroja, FTIR, para identificar los grupos funcionales presentes en el sistema y además se midió regularmente la viscosidad para determinar cualitativamente el avance de la policondensación del sistema.[EN] Sol-gel processing has become a well established technique for producing ceramic powders or glasses. This processing has been utilized to synthesize several interesting systems, e.g. the SiO2 – TiO2 system. A major concern in the stable multicomponent geles is that the hydrolysis and condensation velocities are diferent for each precursor, TEOS and Ti(OBu)4 in this work. The chemical control of these reactions is currently performed by adding complexing reagents that react with metal alkoxides at a molecular level, giving rise to new molecular precursors of different structure, reactivity and functionanality. This paper shows that stable TEOS – Ti(OBu)4 – H2O sol can be reproducibly prepared in the presence of acetylacetone. We shall then show that the acac behaves as a ligand, directly bonded to the titanium ion. Thus the formation of precipitate is avoided. Infra-red spectroscopy (FTIR) and viscosity measures were used to demostrated this behaviour of the system.Este trabajo fue financiado a través de los proyectos COLCIENCIAS N° 1103-05-605-93 y VRI-Universidad del Cauca N° 752. Agradecemos a Ecopetrol-ICP la colaboración prestada con los estudios de espectroscopia infrarroja y a la red CyTED VIII.E la ayuda económica y técnica gracias a la cual A. Mafla pudo realizar su pasantía en el ICVCSIC de Madrid-España.Peer reviewe

Impact of power ultrasound on the quality of fruits and vegetables during dehydration

Trabajo presentado en el 2015 International Congress on Ultrasonics, celebrado los días 10 a 14 de mayo de 2015 en Metz, FranciaTo date, most of dehydrated vegetables and fruits are obtained by convection preceded or not by a pre-treatment. In general, their quality is low due to the physical modi- fications, loss of vitamins, polyphenols and carbohydrates and Maillard reaction (MR). MR can originate a remarkable loss of nutritional value due to the involvement of lysine. To improve the final quality of these products, one of the alternatives is the application of power ultrasound (US). US produces mechanical effects, such as cavitation, microstream and formation of microscopic channels which facilitate the mass transport and so, the removal of water from the food. The synergistic effect of US and temperature allows carrying out dehydration at low temperatures and short times. In the present work, the influence of power US on the quality of fruits and vegetables during the pre-treatment and drying was evaluated. Chemical indicators such as pectinmethyl esterase and peroxidase enzymes, vitamin C, carbohydrates, proteins, polyphenols and 2-furoylmethylamino acids was studied. In addition, rehydration capacity, leaching losses, shrinkage and organoleptic characteristics of the final product was assessed. During blanching, similar leaching losses and enzyme inactivation were found in low temperature and prolonged conventional treatments and in US processes, but with a significant reduction in the time for the latter. Application of US in the drying of carrots and strawberries provided high-quality end-products. The quality was better as compared to marketed products and superior or equivalent to samples obtained in a convective dryer, and, in some indicators, similar to that of freeze-dried samples.Peer reviewe

Synthesis of Pd-Ag alloy membranes and their application in membrane reactors for hydrogen production and purification

Pd-Ag based membranes, self-supported and supported on porous α-Al2O3, have been studied for hydrogen selective separation. In the case of the self-supported membranes the Pd-Ag permeator tube was prepared by cold-rolling and diffusion welding technique; magnetron sputtering technique was employed for the synthesis of the membrane supported on porous α-Al2O3. The results have shown that the self supported Pd-Ag membranes are infinitively H2-selective and the H2-permeation rate through this membrane is in accordance with Sieverts´ law for detect-free meal membranes; hence, an ultra-pure hydrogen stream can be obtained. The Pd-Ag membrane supported on porous α-Al2O3 is not completely selective towards H2, but requires much less metal since it is much thinner (ca. ~50 vs. 1 µm). In this work, it was studied the water-gas shift on Pd-Ag membrane reactor, but it was also illustrated another application of palladium membranes, in the ethanol steam reforming. The use of the self-supported Pd-Ag membrane leads to enhance the H2 yield in both reactions, providing much better performances than conventional reactors.Patricia Pérez is grateful to Fundação para a Ciência e a Tecnologia (FCT) for the doctoral grant (reference: SFRH/BD/73673/2010). The authors also acknowledge financing from FCT through the project PTDC / EQU -ERQ/098730/2008

6-Methoxyquinoline complexes as lung carcinoma agents: induction of oxidative damage on A549 monolayer and multicellular spheroid model

The aim of this work was to study the antitumor effects and the mechanisms of toxic action of a series of 6-methoxyquinoline (6MQ) complexes in vitro. The Cu(II) and Zn(II) complexes (Cu6MQ and Zn6MQ) are formulated as M(6MQ) 2 Cl 2 ; the Co(II) and Ag(I) compounds (Co6MQ and Ag6MQ) are ionic with formulae [Ag(6MQ) 2 ] + NO 3 − and H(6MQ) + [Co(6MQ)Cl 3 ] − (where H(6MQ) + is the protonated ligand). We found that the copper complex, outperformed the Co(II), Zn(II) and Ag(I) complexes with a lower IC 50 (57.9 µM) in A549 cells exposed for 24 h. Cu6MQ decreased cell proliferation and induced oxidative stress detected with H 2 DCFDA at 40 µM, which reduces GSH/GSSG ratio. This redox imbalance induced oxidative DNA damage revealed by the Micronucleus test and the Comet assay, which turned into a cell cycle arrest at G2/M phase and induced apoptosis. In multicellular spheroids, the IC 50 values tripled the monolayer model (187.3 µM for 24 h). At this concentration, the proportion of live/dead cells diminished, and the spheroids could not proliferate or invade. Although Zn6MQ also decreased GSH/GSSG ratio from 200 µM and the cytotoxicity is related to oxidative stress, the induction of the hydrogen peroxide levels only doubled the control value. Zn6MQ induced S phase arrest, which relates with the increased micronucleus frequency and with the induction of necrosis. Finally, our results reveal a synergistic activity with a 1:1 ratio of both complexes in the monolayer and multicellular spheroids.Fil: Cadavid Vargas, Juan Fernando. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Villa Perez, Cristian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Ruiz, M. C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Leon, Ignacio Esteban. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Valencia Uribe, Gloria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Soria, Delia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Etcheverry, Susana Beatriz. Universidad Nacional de Colombia; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Di Virgilio, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin

Impact of power ultrasound on chemical and physicochemical quality indicators of strawberries dried by convection

[EN] A study on the quality parameters of strawberries dehydrated by convection assisted by power ultrasound (US) at 40 70 C and 30 and 60W has been carried out for the first time. In general, the quality of US-treated samples was higher than that of commercial samples. Even under the most severe conditions used (US at 70 C and 60 W), high values of vitamin C retention (>65%) and scarce advance of Maillard reaction (2-furoylmethyl derivatives of Lys and Arg < 90 mg 100 g 1 protein) were observed. Rehydration ratio was not affected by the power applied and the obtained values were similar to those of convectively-treated samples. According to the results here presented, US is a suitable example of an emerging and environmentally friendly technology that accelerates convective drying, allowing the obtainment of dried strawberries with premium quality.This work has been funded by Ministry of Economy and Competitiveness of Spain and ERDF (FEDER) (Project DPI2012-37466-C03-03), Fun-c-Food (CSD2007-00063 Consolider-INGENIO 2010), CYTED IBEROFUN (P109AC0302) and Comunidad de Valencia, Project PROMETEO/2010/062. J.G.S. also thanks CSIC and the EU for a predoctoral JAE grant. A.C.S. thanks the Spanish Ministry of Economy and Competitiveness for a Ramon y Cajal contract.Gamboa-Santos, J.; Montilla, A.; Cortijo Soria, A.; Cárcel Carrión, JA.; García Pérez, JV.; Villamiel, M. (2014). Impact of power ultrasound on chemical and physicochemical quality indicators of strawberries dried by convection. Food Chemistry. 161:40-46. https://doi.org/10.1016/j.foodchem.2014.03.106S404616

Pleiotropic functions of the tumor- and metastasis-suppressing Matrix Metalloproteinase-8 in mammary cancer in MMTV-PyMT transgenic mice

Matrix metalloproteinase-8 (MMP-8; neutrophil collagenase) is an important regulator of innate immunity which has onco-suppressive actions in numerous tumor types

Sustainable Production in the Food Industry Volume 6: Sustainable Primary Production (6): 128-149 (2021)

22 Páginas.-- 2 FigurasChallenges in the food industry relate not only to demographic pressure and environment protection, but also to new consumer demands and specific health requirements. Multidisciplinary studies on raw materials, waste valorisation, efficient green technologies, new products and biodegradable smart packaging are needed. Real-time process control, quality, safety and authenticity will rely on powerful proces analytical technology, multi-sensors and advanced computing and digitalisation systemsPeer reviewe

Development and Optimization of a Machine-Learning Prediction Model for Acute Desquamation After Breast Radiation Therapy in the Multicenter REQUITE Cohort.

Some patients with breast cancer treated by surgery and radiation therapy experience clinically significant toxicity, which may adversely affect cosmesis and quality of life. There is a paucity of validated clinical prediction models for radiation toxicity. We used machine learning (ML) algorithms to develop and optimise a clinical prediction model for acute breast desquamation after whole breast external beam radiation therapy in the prospective multicenter REQUITE cohort study. Using demographic and treatment-related features (m = 122) from patients (n = 2058) at 26 centers, we trained 8 ML algorithms with 10-fold cross-validation in a 50:50 random-split data set with class stratification to predict acute breast desquamation. Based on performance in the validation data set, the logistic model tree, random forest, and naïve Bayes models were taken forward to cost-sensitive learning optimisation. One hundred and ninety-two patients experienced acute desquamation. Resampling and cost-sensitive learning optimisation facilitated an improvement in classification performance. Based on maximising sensitivity (true positives), the "hero" model was the cost-sensitive random forest algorithm with a false-negative: false-positive misclassification penalty of 90:1 containing m = 114 predictive features. Model sensitivity and specificity were 0.77 and 0.66, respectively, with an area under the curve of 0.77 in the validation cohort. ML algorithms with resampling and cost-sensitive learning generated clinically valid prediction models for acute desquamation using patient demographic and treatment features. Further external validation and inclusion of genomic markers in ML prediction models are worthwhile, to identify patients at increased risk of toxicity who may benefit from supportive intervention or even a change in treatment plan. [Abstract copyright: © 2022 The Authors.