1,598 research outputs found
Simultaneous enantiomeric separation of carfentrazone-ethyl herbicide and its hydrolysis metabolite carfentrazone by cyclodextrin electrokinetic chromatography. Analysis of agrochemical products and a degradation study
The different activity and toxicity that the enantiomers of agrochemicals may have requires the development of stereoselective analytical methodologies enabling the individual determination of each enantiomer. The aim of this work was to develop the first Electrokinetic Chromatography methodology enabling the simultaneous enantiomeric separation of carfentrazone-ethyl erbicide and its hydrolysis metabolite carfentrazone. The use of an anionic cyclodextrin as chiral selector (captisol at 2.5% (w/v)) in a 25 mM acetate buffer, at a temperature of 30 ºC, and an applied voltage (reverse polarity) of -30 kV, allowed the simultaneous separation of the four enantiomers of the two compounds studied in 6.8 min with enantiomeric resolutions of 5.0 for carfentrazone-ethyl and 5.1 for carfentrazone. Analytical characteristics of the developed method were evaluated and found adequate to achieve the quantitation of carfentrazone-ethyl and carfentrazone. Analysis of a commercial herbicide formulation showed the potential of the method for the quality control of these agrochemical products. Degradation studies for carfentrazone-ethyl revealed that no significant degradation took place in cleaned sand samples while a significant but not stereoselective degradation took place in soils for the whole period of time considered (seven days)
Development of a capillary electrophoresis method for the determination of soybean proteins in soybean-rice gluten-free dietary products. Research Article
CE has been applied for the first time to the simultaneous separation of soybean and\ud
rice proteins. Treated and untreated capillaries with different effective lengths as well\ud
as separation media at different pHs were tested. For that purpose, samples and\ud
standard solutions were prepared in 25:75 ACN–water media containing 0.3% v/v\ud
acetic acid. The use of an untreated capillary of 50 cm effective length together with an\ud
80 mM borate buffer (pH 8.5) modified with 20% v/v ACN and UV detection at 254 nm\ud
were the conditions working the best. These conditions enabled the determination of\ud
soybean proteins in gluten-free dietary commercial products elaborated with soybean\ud
protein and/or soybean flour and rice flour using the standard additions calibration\ud
method. The method was linear up to 26 mg/mL of soybean proteins, the precision\ud
(expressed as RSD) was always better than 6%, and recoveries obtained for soybean\ud
proteins when spiking commercial products were very close to 100%The authors thank the Ministry of Science and Technology\ud
(Spain) for the research project BQU2002–01199 and F. J.\ud
Cabello-Murillo for technical assistance. C.G.-R. also\ud
thanks the Ministry of Science and Technology for the\ud
Ramón y Cajal program (RYC-2003–001)
China en la gobernanza mundial: el arte de la influencia
El presente trabajo analiza las narrativas con que China pretende recuperar el lugar
que considera propio, usando su poder económico para construir una imagen de potencia
responsable e intervenir en las reglas de juego internacionales. En este camino, el
pensamiento y la cultura tradicionales han prestado al Partido Comunista chino,
fundamentos para orientar su acción, lidiar con el poder hegemónico estadounidense,
aumentar su red de alianzas, e incluso para ejercer su Coronapower en la actual pandemia.
Pero Beijing cuestiona la universalidad de valores y principios de gobernanza occidentales,
obligando a la Unión Europea y a Estados Unidos a tomar posiciones en un mundo con
características confucianas. En el siglo XXI, el Arte de la Guerra se transforman en el Arte
de la influencia y la batalla de los conceptos, porque: “como el agua amolda su fluir según
el suelo, un ejército logra su victoria según la situación del enemigo” (SunziMáster en Relaciones Internacionales y Estudios Asiático
Histone Mutants Separate R Loop Formation from Genome Instability Induction
R loops have positive physiological roles, but they can also be deleterious by causing genome instability, and the mechanisms for this are unknown. Here we identified yeast histone H3 and H4 mutations that facilitate R loops but do not cause instability. R loops containing single-stranded DNA (ssDNA), versus RNA-DNA hybrids alone, were demonstrated using ssDNA-specific human AID and bisulfite. Notably, they are similar size regardless of whether or not they induce genome instability. Contrary to mutants causing R loop-mediated instability, these histone mutants do not accumulate H3 serine-10 phosphate (H3S10-P). We propose a two-step mechanism in which, first, an altered chromatin facilitates R loops, and second, chromatin is modified, including H3S10-P, as a requisite for compromising genome integrity. Consistently, these histone mutations suppress the high H3S10 phosphorylation and genomic instability of hpr1 and sen1 mutants. Therefore, contrary to what was previously believed, R loops do not cause genome instability by themselves.European Research Council ERC2014 AdG669898Ministerio de Economía y Competitividad BFU2013-42918-P, BFU2016-75058-
X Jornadas de Trabajo en el Ámbito Social y VIII Jornadas de Interlocución Municipal. Fundación Isonomía 2009
VIII Jornadas de Interlocución Municipal. X Jornadas de Trabajo en el Ámbito Socia
Overexpression of mitochondrial if1 prevents metastatic disease of colorectal cancer by enhancing anoikis and tumor infiltration of NK cells
Increasing evidences show that the ATPase Inhibitory Factor 1 (IF1), the physiological inhibitor of the ATP synthase, is overexpressed in a large number of carcinomas contributing to metabolic reprogramming and cancer progression. Herein, we show that in contrast to the findings in other carcinomas, the overexpression of IF1 in a cohort of colorectal carcinomas (CRC) predicts less chances of disease recurrence, IF1 being an independent predictor of survival. Bioinformatic and gene expression analyses of the transcriptome of colon cancer cells with differential expression of IF1 indicate that cells overexpressing IF1 display a less aggressive behavior than IF1 silenced (shIF1) cells. Proteomic and functional in vitro migration and invasion assays confirmed the higher tumorigenic potential of shIF1 cells. Moreover, shIF1 cells have increased in vivo metastatic potential. The higher metastatic potential of shIF1 cells relies on increased cFLIP-mediated resistance to undergo anoikis after cell detachment. Furthermore, tumor spheroids of shIF1 cells have an increased ability to escape from immune surveillance by NK cells. Altogether, the results reveal that the overexpression of IF1 acts as a tumor suppressor in CRC with an important anti-metastatic role, thus supporting IF1 as a potential therapeutic target in CRCThis research was funded by grants from Ministerio de Ciencia, Innovación y Universidades
(SAF2013-41945-R, SAF2016-75916-R and SAF2016-75452-R), CIBERER-ISCIII (CB06/07/0017) and Fundación Ramón Areces, Spai
Capillary liquid-chromatography-ion trap-mass spectrometry methodology for the simultaneous quantification of four angiotensin-converting enzyme-inhibitory peptides in Prunus seed hydrolysates
Prunus genus fruit seeds are sources of highly angiotensin-l-converting enzyme (ACE)-inhibitory peptides. The presence of peptides IYSPH, IYTPH, IFSPR, and VAIP seems to be related to this activity but no previous work has demonstrated the direct relationship between the concentration of these peptides and the antihypertensive activity of hydrolysates. This work describes the development of a method for the quantification of these peptides in Prunus seeds hydrolysates based on capillary liquid chromatography-IT-MS/MS. The analytical characteristics of the method were evaluated through the study of the linearity, LOD, LOQ presence of matrix interferences, precision, and recovery. The developed methodology was applied to the determination of the four peptides in seed hydrolysates from different Prunus genus fruits: peaches (7 varieties), plums (2 varieties), nectarines (3 varieties), apricots (2 varieties), cherry, and paraguayo. Peaches and plums seed hydrolysates yielded the highest concentrations of these peptides while paraguayo one showed the lowest concentrations. A high correlation between peptides concentrations was demonstrated suggesting that the four peptides could be released from the same seed proteins
Separation and online preconcentration by multistep stacking with large-volume injection of anabolic steroids by capillary electrokinetic chromatography using charged cyclodextrins and UV-absorption detection
The separation of three common anabolic steroids (methyltestosterone, methandrostenolone and testosterone) was performed for the first time by capillary EKC. Different charged CD derivatives and bile salts were tested as dispersed phases in order to achieve the separation. A mixture of 10 mmol/L succinylated-b-CD with 1 mmol/L bCD in a 50 mmol/L borate buffer (pH 9) enabled the separation of the three anabolic steroids in less than 9 min. Concentration LODs, obtained for these compounds with low absorption of UV light, were ~5610–5 mol/L. The use of online reverse migrating sample stacking with large-volume injection (the effective length of the capillary) enabled to improve the detection sensitivity. Sensitivity enhancement factors (SEFs) ranging from 95 (for testosterone) to 149 (for methyltestosterone) were achieved by single stacking preconcentration. Then, the possibilities of multistep stacking to improve the sensitivity for these analytes were investigated. SEFs obtained by double stacking preconcentration ranged from 138 to 185, enabling concentration LODs of 2.79610–7 mol/L (for methyltestosterone), 3.47610–7 mol/L (for testosterone) and 3.56610–7 mol/L (for methandrostenolone). Although online triple stacking preconcentration was achieved, its repeatability was very poor and SEFs for the studied analytes were not calculated
A metabolite profile reveals the presence of neurodegenerative conditions according to severity of hydrocephalus
Introduction: In obstructive congenital hydrocephalus, cerebrospinal fluid accumulation is associated with high intracranial pressure (ICP), ischemia/hypoxia, metabolic impairment, neuronal damage and astrocytic reaction. The hyh mutant mice exhibit two different forms of hydrocephalus evolution: severe and moderate. A study was carried out in hyh mice to detect a metabolite profile that define the tissue response in each hydrocephalus form.
Methods: Metabolites levels in brain cortex were analyzed with 1H High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (1H HR-MAS) spectroscopy. The study was complemented with ICP recording and histopathological analysis.
Results: Mice with severe hydrocephalus were found to have higher ICP and stronger astrocytic reaction. Several metabolites including glutamate and glutamine were found to correlate with the severity of hydrocephalus. The whole metabolite profile may be explained based in differential astrocyte reactions, neurodegenerative and ischemic conditions. The glutamate transporter EAAT2 and the metabolite taurine were found as key histopathological markers for the damaged parenchyma. Conclusions: Spectroscopy allowed the detection of a metabolite profile related to intracranial pressure and hydrocephalus severity, and therefore can be useful to monitor the efficacy of experimental therapies.
Supported by Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech, and PI15/0619 (ISCIII/FEDER).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
Supported by Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech, and PI15/0619 (ISCIII/FEDER)
Fractionation of chlorinated and brominated persistent organic pollutants in several food samples by pyrenyl-silica liquid chromatography prior to GC-MS determination
A high-performance liquid chromatography (HPLC) method using a column of 2-(1-pyrenyl) ethyldimethylsilylated silica was developed in this work in order to achieve satisfactory and reproducible fractionation of polychlorinated biphenyls (PCBs) from brominated flame retardants (BFRs) (polybrominated diphenylethers, PBDEs; and polybrominated biphenyls, PBBs). After the study of different chromatographic parameters (mobile phase composition and separation temperature were the most important) an isocratic elution with isooctane:toluene (98:2, v/v) at a flow-rate of 1 mL/min, a temperature of 45 °C, and UV-detection at 225 nm was selected for fractionation of PCBs (time region, 4.0–5.8 min) from PBDEs (5.8–9.0 min) and from PBBs (5.8–11.0 min). The applicability of this method to food samples was demonstrated by fractionating PCBs from PBDEs in three food samples (cheese, milk, and fish). Interferences from PCBs (present in real samples at much higher concentrations than PBDEs) were removed in this way. In addition, by analysing these samples by gas chromatography–mass spectrometry (GC–MS) with and without previous fractionation we were able to observe an improvement in detection sensitivity for PBDEs after HPLC fractionation.The authors thank the Comunidad Autonoma de Madrid (Spain) for project S-0505/AGR/0312. B. Gomara wishes to \ud
thank the University of Alcala and CSIC for her grants and C. Zuniga for her kind help. C. García-Ruiz thanks the Ministry of Science and Technology for the Ramon y Cajal program (RYC-2003-001
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