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Pteridines are a group of compounds synthesised by many living organisms that are involved in the metabolism of many cofactors and vitamins. Their concentration in biological fluids may be altered by various pathologies such as cancer or inflammatory bowel disease, urine being the main route of excretion. In this study, three lumazines and ten pterins were analysed in their native oxidation state using high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Their high concentration in urine samples and their good ionisation behaviour allow the use of the dilute-and-shoot method by simple filtration of the urine prior to chromatographic analysis. The final method offers excellent linearity, sensitivity and precision parameters, and a total of 135 urine samples were analysed from patients with some relevant information such as faecal calprotectin (FCP) levels, common diseases such as diabetes, hypertension and dyslipidaemia and immunological diseases such as inflammatory bowel disease (IBD). The pteridine profile was related to FCP levels without showing any correlation. In addition, pteridine levels were compared between healthy subjects and IBD, diabetic, hypertensive and dyslipidaemic patients, and significant differences were found between the two groups for some of the pteridines.

OBJECTIVE: Venous hypertension associated with a primitive basal vein of Rosenthal (BVR) has been noted as the most likely cause of idiopathic subarachnoid hemor-rhage (iSAH). Other types of venous drainage variations have been scarcely studied but may further explain the cases not associated with a BVR anomaly. Our aim was to investigate if dural venous sinus (DVS) anomalies are related with iSAH. - METHODS: A total of 76 patients diagnosed with iSAH were identified from a prospectively maintained database and their angiographic findings compared with 76 patients diagnosed with aneurysmal subarachnoid hemorrhage. -RESULTS: On top of the BVR variations, our data showed a higher prevalence of transverse sinus hypoplasia (47.4% vs. 28.9%; P = 0.019), superior petrosal sinus hypoplasia (32.9% vs. 13.2%; P = 0.003), and clival plexus hyperplasia (65.8% vs. 43.4%; P = 0.005) in patients with iSAH. Analyzing by total number of angiograms, the iSAH group showed also a higher prevalence of inferior petrosal sinus hyperplasia (36.2% vs. 25%; P = 0.003). Of the patients with iSAH without a primitive BVR, 84% harbored double dagger 1 peri-mesencephalic DVS variation and the overall number of venous drainage variations was significantly higher in patients with iSAH. CONCLUSIONS: In addition to the well-documented BVR anomalies, there seems to be a significant relationship of other DVS variations in patients with iSAH. Transverse si-n us hypoplasia, superior petrosal sinus hypoplasia, inferior petrosal sinus hyperplasia, and clival plexus hyperplasia were significantly more frequent in patients with iSAH. The presence of double dagger 3 of those variations would increase the suspicion of a nonaneurysmatic subarachnoid hemorrhage and could help avoid a second angiogram.

Este artigo, de base teórico-reflexiva e originado a partir de um recorte de uma pesquisa de mestrado, promove reflexões sobre as experiências (ciber)formativas, on-line e off-line, advindas dos movimentos de trocas e diálogos docentes que se concretizaram em grupos de discussões (GD) desenvolvidos com professores(as) dos anos finais do Ensino Fundamental e que atuam no município de Valente, Estado da Bahia. Com o objetivo voltado para a construção coletiva de conhecimento no que tange ao uso das Tecnologias da Informação e Comunicação (TIC) para mediar o ensino e a aprendizagem em sala de aula e levando em conta os discursos produzidos coletivamente, problematiza-se saberes docentes, inquietações e relatos de sucesso sobre o uso pedagógicos dos artefatos tecnológicos, ao tempo em que aciona perspectivas teóricas sobre Cibercultura, práxis, racionalidade comunicativa, practicum reflexivo, no âmbito da formação do professor. O itinerário metodológico concebido ancora-se nos fundamentos da pesquisa qualitativa e foi subdividido em dois momentos: o on-line, destinado aos encontros coletivos e presenciais sob os fundamentos do GD; e o off-line, o qual correspondeu ao acontecer de minicursos em espaço (ciber)formativo. Fruto da práxis reflexiva, do estudo resultam ponderações críticas dos professores para com o uso das TIC em seus respectivos espaços e fazeres pedagógicos, admitindo ser possível redimensionar o processo de ensino e de aprendizagem com o uso dessas tecnologias. Corroborou-se, ainda, com o entendimento de ser uma formação dialógico-reflexiva de docentes, quando estruturada e experenciada de maneira coletiva, propulsora de aprendizagens colaborativas e estimuladoras da reconfiguração da atuação pedagógica.

Introducción. Las vasculitis son enfermedades graves que suelen tener un debut muy inespecífico y un diagnóstico tardío, lo que implica una alta tasa de fracaso terapéutico. Se presenta un caso de vasculitis que puede contribuir a considerar esta enfermedad como parte del diagnóstico diferencial desde las primeras etapas del proceso de atención para garantizar un abordaje integral y un inicio temprano del tratamiento, lo que reduciría la morbimortalidad asociada a estas entidades y mejoraría la tasa de éxito de los tratamientos. Presentación del caso. Mujer caucásica de 77 años que como único antecedente presentaba hipertensión arterial de dos años de evolución y quien consultó al servicio de urgencias de una institución de segundo nivel por cuadro clínico de un mes de evolución consistente en astenia, febrícula, hiporexia y pérdida de peso. La paciente fue hospitalizada para completar la historia clínica y dados los hallazgos se sospechó de una posible translocación bacteriana secundaria a una neoplasia intestinal y se inició cobertura antibiótica empírica, pero su condición seguía empeorando. Se realizaron pruebas complementarias que no arrojaron resultados concluyentes; ante la persistencia de la fiebre, la insuficiencia renal y la anemia, se realizó una biopsia de riñón que mostró vaso arterial con necrosis fibrinoide e infiltrados de polimorfonucleares asociados, claros signos de una vasculitis activa del tipo poliangeítis microscópica. Se instauró el tratamiento indicado pero la paciente tuvo una evolución desfavorable y falleció. Conclusiones. La exposición de este caso inusual contribuye a que los profesionales de la salud consideren el diagnóstico de vasculitis desde el inicio de la atención, aun cuando la sintomatología sugiere otras patologías o incluso cuando se presentan síntomas tan inespecíficos como anemia y pérdida de peso, ya que esto ayudará a establecer un diagnóstico temprano.

Background Containment policies and other restrictions introduced by the Spanish government in response to the COVID-19 pandemic present challenges for marginalised populations, such as people who use drugs. Harm reduction centres are often linked to social services, mental health services, and infectious disease testing, in addition to tools and services that help to reduce the harms associated with injecting drugs. This study aimed to explore the impact of the pandemic on these services in four autonomous communities in Spain. Methods This is a cross-sectional study that employed a seven-section structured survey administered electronically to 20 centres in July 2020. Data from the most heavily affected months (March–June) in 2020 were compared to data from the same period in 2019. Averages were calculated with their ranges, rates, and absolute numbers. Results All 11 responding centres reported having had to adapt or modify their services during the Spanish state of alarm (14 March–21 June 2020). One centre reported complete closure for 2 months and four reported increases in their operating hours. The average number of service users across all centres decreased by 22% in comparison to the same period in the previous year and the average needle distribution decreased by 40% in comparison to 2019. Most centres reported a decrease in infectious disease testing rates (hepatitis B and C viruses, human immunodeficiency virus, and tuberculosis) for March, April, and May in 2020 compared to the previous year. Reported deaths as a result of overdose did not increase during the state of alarm, but 2/11 (18%) centres reported an increase in overdose deaths immediately after finalisation of the state of alarm. Conclusion Overall, Spanish harm reduction centres were able to continue operating and offering services by adjusting operating hours. The number of overall service users and needles distributed fell during the Spanish state of alarm lockdown period, suggesting that fewer clients accessed harm reduction services during this time, putting them at greater risk of reusing or sharing injecting equipment, overdosing, acquiring infectious diseases with decreased access to testing or discontinuing ongoing treatment such as methadone maintenance therapy, hepatitis C treatment, or antiretroviral therapy.

Background Intracranial iatrogenic aneurysms (IIAs) developing after external ventricular drain (EVD) placement or removal have been only rarely reported. Most of these reports assumed a traumatic etiology; however, some have demonstrated an inflammatory origin. We have presented the case of an IIA that developed after an EVD had been inserted to treat acute hydrocephalus secondary to a ruptured arteriovenous malformation. We also performed a literature review and discussed how these IIAs might have an inflammatory rather than a traumatic etiology and how they might lie behind some of the cases of idiopathic hemorrhage observed after EVD manipulation. Case Description A 48-year-old woman had presented with acute hydrocephalus secondary to bleeding from a vermian arteriovenous malformation. The EVD inserted for hydrocephalus management required several revisions because of malfunction. Four weeks later, a diagnostic arteriogram had incidentally revealed the existence of a 5-mm aneurysm in an anterior branch of the right callosomarginal artery, coincidental to the EVD trajectory. The patient underwent emergent endovascular treatment of the aneurysm, with complete occlusion and no complications deriving from the procedure. Conclusions IIAs associated with EVD placement or removal have been described as a rare complication of the procedure. Despite the scarce number of cases reported and the lack of histological examinations, common features such as a distal location, an incidental diagnosis, and a benign clinical course might suggest a mycotic or inflammatory origin rather than a traumatic etiology. Considering the high volume of EVDs placed annually, this complication might be more frequent than reported. Further studies investigating the association of risk factors for inflammatory aneurysms and hemorrhage incidence after EVD could provide information on this intriguing topic.

The health effects of (poly)phenols (PPs) depend upon their bioavailability that, in general, is very low and shows a high interindividual variability. The low bioavailability of PPs is mainly attributed to their low absorption in the upper gastrointestinal tract as a result of their low water solubility, their presence in foods as polymers or in glycosylated forms, and their tight bond to food matrices. Although many studies have investigated how technological and biotechnological processes affect the phenolic composition of fruits and vegetables, limited information exists regarding their effects on PP bioavailability in humans. In the present review, the effect of food processing (mechanical, thermal, and non-thermal treatments), oral-delivery nanoformulations, enzymatic hydrolysis, fermentation, co-administration with probiotics, and generation of postbiotics in PP bioavailability have been overviewed, focusing in the evidence provided in humans., This research work was supported by the Projects 19900/GERM/15 (Fundación Séneca, Murcia, Spain), AGL2015-73107-EXP (MINECO,Spain), and CSIC 201870E014. Marta Pastor acknowledges a Juan de la Cierva Training Grant 2018 with Reference FJC2018-036570-I from the Ministry of Science and Innovation of the Spanish Government

A rapid analytical procedure is proposed for determining two antimicrobial onion organosulfur compounds, propyl disulfide (PDS) and propyl propane thiosulfonate (PTSO), in animal feed. The use of PTSO as a natural ingredient in animal feed is allowed due to its antimicrobial activity against pathogenic organisms. Two analytical methodologies using gas chromatography coupled to mass spectrometry (GC-MS) are compared. After the extraction of the compounds from animal feed with acetonitrile, dispersive solid phase extraction (DSPE) as a cleaning stage with C18, or dispersive liquid-liquid microextraction (DLLME), using 100 μL of CHCl3, was tried. Both the methods were validated using a pig feed sample and the best results were achieved by DLLME. This technique provided cleaner extracts, five-times greater linear ranges and lower detection limits than simple cleaning due to the enrichment factor achieved. The relative standard deviation decreased from 22% with DSPE to 13% with DLLME. The usefulness of the DLLME-GC-MS methodology was tested by analysing 10 different samples of chicken, calf, hen, cow and fish feed. The concentrations of PDS were in the 0.1-1.7 μg g-1 range and those of PTSO were between 0.09 and 2.1 μg g-1.

The presence of benzene, toluene, ethylbenzene and xylenes (BTEX) in dyes, paints and pigments is not still regulated but might be an indicator of contamination due to the well-known health risk of these compounds. An analytical procedure based on headspace sorptive extraction using a polydimethylsiloxane stir bar, was developed for the gas chromatographic determination of BTEX in finger paint samples. Univariate and multivariate designs were used to optimize experimental parameters, including equilibrium time, desorption time, saline effect and sample mass. Thirty minutes were necessary to absorb the analytes in the polydimethylsiloxane stir bar followed by a 5 min thermal desorption step. Limits of quantification of between 0.036 and 0.12 ng g−1 depending on the compound, were obtained. BTEX were found in the finger paint samples at levels between 0.14 and 12 ng g−1.

The photocatalytic efficiency of magnetic nanoparticles using different coatings between Fe3O4 and semiconductor oxides (ZnO and TiO2) was evaluated by their capability to degrade four insecticides (etoxazole, fenpyroximate, flonicamid and metaflumizone) in water exposed to sunlight. Magnetic particles coated with SiO2 (MSPs) showed higher photodegradation activity. Sol-gel TiO2-SiO2 coated TiO2 P25 magnetic particles (MSTi2Ps) and sol-gel ZnO-SiO2 coated ZnO magnetic particles (MSZn2Ps) were more efficient than magnetic particles consisting of a silica undercoat followed by a TiO2- or ZnO- sol-gel coating as the photocatalytic layer for catalysing the removal of these pesticides. Finally, the addition of Na2S2O8 increased the photooxidation activity of both MSTi2Ps and MSZn2Ps. A comparison of the semiconductor oxides showed MSZn2Ps to be the most effective for the removal of the studied pollutants. As a consequence, the tandem MSZn2Ps/Na2S2O8 provides an interesting combination to remove pesticides in water.

Highly active transmembrane anion transporters have demonstrated their activity against antibiotic-resistant and clinically relevant bacterial strains. This type of compound offers promise as a strategy to develop novel antibacterial agents.

Background There is little verified information on global healthcare utilization by irregular migrants. Understanding how immigrants use healthcare services based on their needs is crucial to establish effective health policy. We compared healthcare utilization between irregular migrants, documented migrants, and Spanish nationals in a Spanish autonomous community. Methods This retrospective, observational study included the total adult population of Aragon, Spain: 930,131 Spanish nationals; 123,432 documented migrants; and 17,152 irregular migrants. Healthcare utilization data were compared between irregular migrants, documented migrants and Spanish nationals for the year 2011. Multivariable standard or zero-inflated negative binomial regression models were generated, adjusting for age, sex, length of stay, and morbidity burden. Results The average annual use of healthcare services was lower for irregular migrants than for documented migrants and Spanish nationals at all levels of care analyzed: primary care (0.5 vs 4 vs 6.7 visits); specialized care (0.2 vs 1.8 vs 2.9 visits); planned hospital admissions (0.3 vs 2 vs 4.23 per 100 individuals), unplanned hospital admissions (0.5 vs 3.5 vs 5.2 per 100 individuals), and emergency room visits (0.4 vs 2.8 vs 2.8 per 10 individuals). The average annual prescription drug expenditure was also lower for irregular migrants (€9) than for documented migrants (€77) and Spanish nationals (€367). These differences were only partially attenuated after adjusting for age, sex, and morbidity burden. Conclusions Under conditions of equal access, healthcare utilization is much lower among irregular migrants than Spanish nationals (and lower than that of documented migrants), regardless of country of origin or length of stay in Spain.

Background: Containment policies and other restrictions introduced by the Spanish government in response to the COVID-19 pandemic present challenges for marginalised populations, such as people who use drugs. Harm reduction centres are often linked to social services, mental health services, and infectious disease testing, in addition to tools and services that help to reduce the harms associated with injecting drugs. This study aimed to explore the impact of the pandemic on these services in four autonomous communities in Spain. Methods: This is a cross-sectional study that employed a seven-section structured survey administered electronically to 20 centres in July 2020. Data from the most heavily affected months (March–June) in 2020 were compared to data from the same period in 2019. Averages were calculated with their ranges, rates, and absolute numbers.Results: All 11 responding centres reported having had to adapt or modify their services during the Spanish state of alarm (14 March–21 June 2020). One centre reported complete closure for two months and four reported increases in their operating hours. The average number of service users across all centres decreased by 22% in comparison to the same period in the previous year and the average needle distribution decreased by 40% in comparison to 2019. Most centres reported a decrease in infectious disease testing rates (hepatitis B and C viruses [HBV, HCV], human immunodeficiency virus (HIV), and tuberculosis [TB]) for March, April, and May in 2020 compared to the previous year. Reported deaths as a result of overdose did not increase during the state of alarm, but 2/11 (18%) centres reported an increase in overdose deaths immediately after finalisation of the state of alarm.Conclusion: Overall, Spanish harm reduction centres were able to continue operating and offering services by adjusting operating hours. The number of overall service users and needles distributed fell during the Spanish state of alarm lockdown period, suggesting that fewer clients accessed harm reduction services during this time, putting them at greater risk of reusing or sharing injecting equipment, overdosing, acquiring infectious diseases with decreased access to testing or discontinuing ongoing treatment such as methadone maintenance therapy, hepatitis C treatment, or antiretroviral therapy.

Background: This study was to describe the evolution of patients who underwent surgical treatment of drug- resistant occipital lobe epilepsy (OLE) at our institution. Methods: We performed a retrospective analysis of data collected from electronic and paper clinical records of 20 patients who were diagnosed of OLE and underwent epilepsy surgery at our institution between 1998 and 2018. We also contacted patients by telephone and asked them to fill out a questionnaire about quality of life in epilepsy (QOLIE-10). Assembled data were analyzed using descriptive statistics. Results: The age at surgery ranged between 19 and 55 years. The period encompassing epilepsy onset and the date of surgery was variable. Semiology of seizures included visual symptoms in 75% of patients. In 90% of cases subdural grids, depth electrodes or a combination of both were used to plan the surgery. The most frequent neuroimaging and histopathological finding was cortical dysplasia (55%). The postoperative follow-up period was up to 15 years. The most common score on the Engel scale was I (70%). Visual deficits increased after surgery. Median score on QOLIE-10 questionnaire was 82.5 (interquartile range: 32.5). Conclusion: Surgical treatment of drug-resistant OLE offers hopeful results to those patients who have run out of pharmacological options and leads to postoperative deficits that are deemed expectable and occasionally acceptable.

Background There is little verified information on the global health status of undocumented migrants (UMs). Our aim is to compare the prevalence of the main chronic diseases and of multimorbidity in undocumented migrants, documented migrants, and Spanish nationals in a Spanish autonomous community. Methods Retrospective observational study of all users of the public health system of the region of Aragon over 1 year (2011): 930,131 Spanish nationals; 123,432 documented migrants (DMs); and 17,152 UMs. Binary logistic regression was performed to examine the association between migrant status (Spanish nationals versus DMs and UMs) and both multimorbidity and individual chronic diseases, adjusting for age and sex. Results The prevalence of individual chronic diseases in UMs was lower than in DMs and much lower than in Spanish nationals. Comparison with the corresponding group of Spanish nationals revealed odds ratios (OR) of 0.1–0.3 and 0.3–0.5 for male and female UMs, respectively (p

This work focuses on the development, validation and application of an analytical method for the determination of twenty organochlorine pesticides (OCPs) in human tissues using salting-out liquid–liquid extraction and dispersive liquid–liquid microextraction for sample preparation and gas chromatography–mass spectrometry to analyze the obtained extracts. Measurement of the concentration levels of these toxics in tissues can be used to assess the risk of the population to exposure. The linearity of the proposed method was verified in the 10–1,000 ng/g range. The sensitivity was evaluated calculating the limits of detection (LODs) for 20 OCPs (α-, β-, γ- and δ-hexachlorocyclohexane (HCH), α- and β-endosulfan, endosulfan sulfate, aldrin, dieldrin, endrin, endrin ketone, endrin aldehyde, α- and γ-chlordane, 4,4′-dichlorodiphenyltrichloroethane, 4,4′-dichlorodiphenyldichloroethylene (DDE), 4,4′-dichlorodiphenyldichloroethane, heptachlor, heptachlor epoxide and methoxychlor), most of them being found between 1.0 and 16 ng/g. The intra- and interday precisions were

This study describes the use of a magnetic multi-walled carbon nanotube composite for the preconcentration of nine parabens (methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, phenyl and benzylparaben) from water and urine samples after in situ acetylation. The enriched extracts were obtained by dispersive magnetic solid phase extraction (DMSPE) and analysed by gas chromatography with mass spectrometry (GC-MS). Several parameters affecting the adsorption (extraction time, magnetic material mass and ionic strength) and desorption (desorption solvent nature and volume, and desorption time) DMSPE steps were investigated. Matrix-matched calibration was recommended for quantification of the samples. Linearities in the 0.5-150 ng mL-1 range were obtained, depending on the compound. Under the optimal experimental conditions, the limits of detection ranged between 0.03 and 2.0 ng mL-1, depending on the sample matrix and the paraben congener. None of the samples analysed contained the above mentioned parabens. The method was validated with two water samples (harbour and wastewater treatment plant) and two urine samples spiked at two concentration levels. Recoveries in the 81-119% range were obtained.

The determination of 15 pyrethroids in soil and water samples was carried out by gas chromatography with mass spectrometry. Compounds were extracted from the soil samples (4 g) using solid-liquid extraction and then salting-out assisted liquid-liquid extraction. The acetonitrile phase obtained (0.8 mL) was used as a dispersant solvent, to which 75 μL of chloroform was added as an extractant solvent, submitting the mixture to dispersive liquid-liquid microextraction. For the analysis of water samples (40 mL), magnetic solid-phase extraction was performed using nanocomposites of magnetic nanoparticles and multiwalled carbon nanotubes as sorbent material (10 mg). The mixture was shaken for 45 min at room temperature before separation with a magnet and desorption with 3 mL of acetone using ultrasounds for 5 min. The solvent was evaporated and reconstituted with 100 μL acetonitrile before injection. Matrix-matched calibration is recommended for quantification of soil samples, while water samples can be quantified by standards calibration. The limits of detection were in the range of 0.03-0.5 ng/g (soil) and 0.09-0.24 ng/mL (water), depending on the analyte. The analyzed environmental samples did not contain the studied pyrethroids, at least above the corresponding limits of detection.

ZnO (zincite) coated magnetic particles were successfully prepared and characterized by different techniques (XRD, FE-SEM, EDX, and FTIR). The photocatalytic efficiency of the magnetic particles was assessed by their ability to degrade six fungicides in water exposed to solar irradiation. Magnetic particles composed of a silica undercoat beneath a ZnO coating (MSZPs) were more efficient than magnetic particles loaded with ZnO alone (MZPs) for catalysing the removal of these fungicides. The optimum mass ratio of SiO 2 to ZnO was about 1:2 because of almost complete coverage by ZnO surface coverage and the high photocatalytic degradation rates obtained for the studied fungicides, which was comparable to that obtained with ZnO nanopowder. However, in contrast to ZnO nanopowder, the photodissolution of Zn using MSZPs was low, with Zn 2+ concentration at the end of the experiment (0.75 mg L −1 ) below legally permitted levels in drinking water. In addition, the effect of initial concentration of fungicides was studied in order to know maximum degradation efficiency. Finally, the photodegradation activity of MSZPs was increased by the addition of Na 2 S 2 O 8 (250 mg L −1 ). Therefore, the tandem MSZPs/Na 2 S 2 O 8 provides an interesting method to degrade some organic pollutants in water.

Nitrosamines (NAs), which are catalogued as carcinogenic compounds, may be present in meat products due to the conversion of nitrites and as result of migration from elastic rubber nettings used. A method based on ultrasonic assisted extraction coupled with dispersive liquid–liquid microextraction as sample treatment and gas chromatography-mass spectrometry as separation and detection technique was proposed for the determination of twelve NAs in cooked ham samples. The method was validated by evaluating linearity (0.5–1000 ng g−1), matrix effect, sensitivity (detection limits were between 0.15 and 1.4 ng g−1) and precision, which was below 12%. Five NAs were found in the samples with levels ranging from not quantifiable to 40 ng g−1. The effect of the elastic rubber nettings on the nitrosamine content of meat was evaluated by comparing the levels found in products made with several plastics or thread in the presence of additives.

Authentication of organic olives and olive oils is of growing interest due to the marked development of organic olive agriculture worldwide. In this study, the potential of using the untargeted volatile fingerprinting of organic and conventional olives obtained with a low-cost and fast methodology based on headspace ultraviolet ion mobility spectrometry (HS-UV-IMS) was investigated for first time. The results showed the suitability of the optimised method since a 94.39% success rate of classification of olives samples was achieved. However, this HS-UV-IMS device did not provide good results for olive oil samples and so two different and more powerful analytical techniques (HS-gas chromatography coupled to IMS with tritium source (HS-GC-IMS) and capillary electrophoresis coupled to UV detector (CE-UV)) were employed respectively to analyse the volatile fingerprinting and the polar compounds extracted from organic and conventional olive oils from two varieties and harvests. It was found that both devices could provide good classification results, above 93.20%, if an adequate number of samples (n > 50) from a single harvest was used. However, it was demonstrated that CE-UV is the best option since it provided more robust classification results over years (95.76%) in comparison with HS-GC-IMS (75.16%). An improvement in classification percentages of HS-GC-IMS data was observed when samples from two harvests were separated into Picual (98.73%) and Hojiblanca (98.78%) variety sets. HS-GC-mass spectrometry with a single quadruple (HS-GC-MS) was employed to contrast the results obtained for the volatile fraction of olive and olive oils with HS-UV-IMS and HS-GC-IMS devices. Also, up to 12 compounds were identified in olive and olive oil samples using HS-GC-MS but only the 3-hexenyl acetate was able to differentiate organic and conventional olive oils.

A multiresidue method was developed to determine twenty-five fungicides belonging to three different chemical families, oxazoles, strobilurins and triazoles, in water and fruit samples, using dispersive liquid-liquid microextraction (DLLME) and liquid chromatography/tandem mass spectrometry (LC-MS2). Solid-liquid extraction with acetonitrile was used for the analysis in fruits, the extract being used as dispersant solvent in DLLME. Since some of the analytes showed high affinity for chloroform and the others were more efficiently extracted with undecanol, a mixture of both solvents was used as extractant in DLLME. After evaporation of CHCl3, the enriched phase was analyzed. Enrichment factors in the 23-119 and 12-60 ranges were obtained for waters and fruits, respectively. The approach was most sensitive for metominostrobin with limits of quantification of 1ngL-1 and 5ngkg-1 in waters and fruits, respectively, while a similar sensitivity was attained for tebuconazole in fruits. Recoveries of the fungicides varied between 86 and 116%.

Magnetic solid phase extraction (MSPE) with cobalt ferrite nanoparticles coated with oleic acid is described for the determination of alkylphenols (APs), 4-tert-butylphenol (TBP), 4-pentylphenol (PP), 4-hexylphenol (HP), 4-tert-octylphenol (TOP), 4-n-octylphenol (OP) and 4-nonylphenol (NP) in baby foods using gas chromatography with mass spectrometry (GC–MS). Prior to MSPE, the sample was treated with trichloroacetic acid, and the APs derivatized with acetic anhydride. Parameters affecting the extraction efficiency: amount of magnetic nanoparticles, extraction time and desorption conditions, were optimized. The enriched phase obtained was evaporated to dryness and the residue reconstituted in 50 μL of methanol, 1 μL of which was injected into the GC–MS. Samples were quantified applying matrix-matched calibration and using 2-chloro-5-bromoanisole as surrogate standard. The analysis of 0.5 g of sample provided detection limits in the 0.4–1.7 ng g −1 range. Some samples contained APs at levels of between 3 ng g −1 for HP and 122 ng g −1 for TOP.

An analytical procedure is proposed for determining three cyanotoxins (microcystin RR, microcystin LR, and nodularin) and two phycotoxins (domoic and okadaic acids) in seawater and algae-based food supplements. The toxins were first isolated by a salting out liquid extraction procedure. Since the concentration expected in the samples was very low, a dispersive liquid&ndash, liquid microextraction procedure was included for preconcentration. The ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate (80 mg) was used as green extractant solvent and acetonitrile as disperser solvent (0.5 mL) for a 10 mL sample volume at pH 1.5, following the principles of green analytical chemistry. Liquid chromatography with electrospray ionization and quadrupole time of flight-mass spectrometry (LC-Q-TOF-MS) was used. The selectivity of the detection system, based on accurate mass measurements, allowed the toxins to be unequivocally identified. Mass spectra for quadrupole time of flight-mass spectrometry (Q-TOF-MS) and Q-TOF-MS/MS were recorded in the positive ion mode and quantification was based on the protonated molecule. Retention times ranged between 6.2 and 17.9 min using a mobile phase composed by a mixture of methanol and formic acid (0.1%). None of the target toxins were detected in any of the seawater samples analyzed, above their corresponding detection limits. However, microcystin LR was detected in the blue green alga sample.

Polycyclic aromatic hydrocarbons (PAHs) are considered xenobiotics of a potentially carcinogenic nature, being accumulated in the fatty tissue of the body. The objective of this work was the development and validation of a new analytical method to check the bioaccumulation of these toxic compounds in human organs obtained from autopsies. The contaminants were first isolated from the tissues by salt-assisted liquid-liquid extraction in acetonitrile. Because of the low concentrations of these compounds in the human body, a dispersive liquid-liquid microextraction procedure was included. The preconcentrated samples were analyzed by gas chromatography-mass spectrometry to identify the compounds. Principal component analysis was applied to show the natural clustering of forensic samples and orthogonal partial least-squares discriminant analysis to develop a multivariate regression method, which permitted the classification of samples. The quantification limits for the 13 PAHs (acenaphthylene, fluorene, phenanthrene, anthracene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenz(a,h)anthracene, benzo(g,h,i)perylene, and indeno(1,2,3-cd)pyrene) analyzed were in the 0.06-0.44 ng g-1 range, depending on the compound, while the mean intraday relative standard deviation of about 7% demonstrated the high precision of the method. Linearity was verified in the 0.5-200 ng g-1 range, and the enrichment factors were between 55 and 122. The results provided by the analysis of seven different human organs (brain, liver, kidney, lung, heart, spleen, and abdominal fat) from eight autopsies confirmed the PAH-bioaccumulation capacity of human body, fat showing the highest degree of bioaccumulation. The present work is the first study on PAH contamination in different organs obtained from autopsies, being PAH detected in most human samples at values ranged from 0 to 19 ng g-1.

Iron is essential for most life forms. Under iron-limiting conditions, many bacteria produce and release siderophores—molecules with high affinity for iron—which are then transported into the cell in their iron-bound form, allowing incorporation of the metal into a wide range of cellular processes. However, free iron can also be a source of reactive oxygen species that cause DNA, protein, and lipid damage. Not surprisingly, iron capture is finely regulated and linked to oxidative-stress responses. Here, we provide evidence indicating that in the plant-beneficial bacterium Pseudomonas putida KT2440, the amino acid l-arginine is a metabolic connector between iron capture and oxidative stress. Mutants defective in arginine biosynthesis show reduced production and release of the siderophore pyoverdine and altered expression of certain pyoverdine-related genes, resulting in higher sensitivity to iron limitation. Although the amino acid is not part of the siderophore side chain, addition of exogenous l-arginine restores pyoverdine release in the mutants, and increased pyoverdine production is observed in the presence of polyamines (agmatine and spermidine), of which arginine is a precursor. Spermidine also has a protective role against hydrogen peroxide in P. putida, whereas defects in arginine and pyoverdine synthesis result in increased production of reactive oxygen species. IMPORTANCE The results of this study show a previously unidentified connection between arginine metabolism, siderophore turnover, and oxidative stress in Pseudomonas putida. Although the precise molecular mechanisms involved have yet to be characterized in full detail, our data are consistent with a model in which arginine biosynthesis and the derived pathway leading to polyamine production function as a homeostasis mechanism that helps maintain the balance between iron uptake and oxidative-stress response systems., This work was funded by grants BFU2016-80122-P from the Plan Estatal de I+D+I and P11-CVI-7391 from Junta de Andalucía and by EFDR funds. L.B.-M. was the recipient of a predoctoral contract from Junta de Andalucía.