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A comparative study of the influence of the strain rate on the dynamic mechanical behaviour of an alumina matrix with 15 and 50 % of dispersed nickel is presented. The fragmentation under high speed impact compression loads have been studied using a compression split Hopkinson pressure bar (SHPB). Dense alumina and alumina-nickel composites were processed by slip casting of water based slurries on porous moulds. Samples with the metallic phase dispersed were pre-oxidized to achieve an effective joining interface and sintered under flowing inert atmosphere. The strain rate was determined from the impact experiments. The statistics of the SHPB recovered fragments have been determined and analysed according to the exponential models of Weibull and Rosin y Rammler and the effects of the strain rate on the average fragment size are described according to the existing energy models. Finally the rupture mechanisms of the samples and the sources of fracture have been explored and compared to the quasi static mechanical behaviour of these materials.En este trabajo, se presenta un estudio comparativo de la influencia de la velocidad de deformación sobre el comportamiento mecánico a la fragmentación de materiales compuestos de una matriz de alúmina con níquel metálico disperso cuando son sometidos a elevadas velocidades de deformación. La fragmentación bajo cargas dinámicas de compresión a alta velocidad se ha realizado mediante una Barra Hopkinson (SHPB). Se ensayaron materiales compuestos de alúmina-níquel con contenidos en metal de hasta el 50 vol. %, los cuales fueron procesados coloidalmente a partir de suspensiones acuosas coladas sobre moldes porosos de alúmina. Las muestras se pre-trataron térmicamente para lograr una interfase de unión eficaz y se sinterizaron posteriormente bajo un flujo inerte de atmósfera de argón. Para cada ensayo de fragmentación dinámica se determinaba la correspondiente velocidad de deformación. Las distribuciones estadísticas de tamaños de fragmentos producidos en el impacto con la barra de Hopkinson se determinaron por métodos de tamizado y sus resultados fueron analizados de acuerdo con la función de distribución estadística de Weibull y con el modelo exponencial de Rosin y Rammler. El efecto de la velocidad de deformación sobre el tamaño medio de fragmento se analizó utilizando los modelos de energía existentes. Finalmente, se analizaron los mecanismos de rotura involucrados.

The dynamic behaviour of laminate borosilicate glasses (BSG) with polyvinylbutiral (PVB) interfaces (0,38 mm) located at different distances from the impact point have been studied and compared with monolithic glass. The mechanical behaviour under impact loads have been studied using a compression split Hopkinson pressure bar (SHPB). In these experiments, the stress-strain curves of the materials at high loading rates and the capability of transmitting and reflecting the impact energy have been determined. The influence of the position of the interface on the fragmentation statistics of the SHPB recovered fragments has also been considered and analysed according to the published theoretical models.En este trabajo se ha estudiado los comportamientos dinámicos de un vidrio monolítico de borosilicato y varios laminados de cristal de borosilicato (BSG) con intercaras de polyvinylbutiral (PVB) (0,38 mm) situados a diferentes distancias respecto del punto de impacto. Los resultados de las diferentes configuraciones de laminados se han comparado con el vidrio monolítico. El comportamiento mecánico bajo cargas de impacto se han estudiado realizando ensayos de compresión con una barra Hopkinson (SHPB). A partir de estos experimentos se obtienen las curvas tensión-deformación de los materiales a altas velocidades de carga y su capacidad de transmitir y reflejar la energía del impacto. La influencia de la posición de la interfaz en las estadísticas de la fragmentación de los fragmentos recuperados también se ha considerado y analizado de acuerdo a los modelos teóricos publicados.

Wear test has been completed on two types of layered materials: a non-reinforced enamel plate and a ceramic reinforced enamel plate. The latter has been tested in two forms: with 10 wt. % and 20 wt. % ceramic particles reinforcement. For comparison the same test has also been completed on polished steel. Wear resistance was measure using a tribometer, equipped with a chromium steel sphere of 6 mm diameter. The sphere-plate surface contact area increases with distance covered, which in the polished steel provokes exponential increments in wear values. This exponential behaviour was not observed in the enamel plates due to their greater wear resistance. The reinforcement of the enamel plates with ceramic particles increases the wear resistance. A higher percentage of ceramic reinforcement results in a greater wear resistance of the plates.Se han realizado ensayos de desgaste, tanto en placas esmaltadas sin refuerzo como en esmaltes con distinto porcentaje de carga cerámica (10 y 20% en peso), y se han comparado frente al del acero base pulido. Las medidas de resistencia a la abrasión se han obtenido utilizado un tribómetro con bola de acero al cromo de 6 mm de diámetro. El aumento de la superficie de contacto bola-placa a medida que aumenta la distancia recorrida, provoca aumentos exponenciales en los desgastes en el caso del acero pulido. Sin embargo, en el caso de las chapas esmaltadas no se observa este comportamiento, debido a la mayor resistencia al desgaste de las mismas. Cuando las capas esmaltadas están reforzadas con cargas cerámicas, la resistencia al desgaste aumenta con el porcentaje de refuerzo cerámico.

To obtain a glass-ceramic enamel layer on a ferrous material optimum condition, are achieved when the interface has a continuous structure (this structure is produced by the formation of oxides). Fundamental to the achievement of these conditions is the initial treatment of the surface plays a key role in the process, from simple degreasing operations to nickel deposition processes. The key variables that influence in the production of pores in the enamels (foam) are: the temperature, the ceramic used to obtained the pores, its weight percentage and the grain size of the said particles. It has been demonstrated that the pore size in the foam increases with the volume fraction of the ceramic used with the enamels. In practice, the temperature to obtain foam enamels is between 650 to 850 ºC, but at 825 ºC the optimum conditions are obtained. The application of glass-ceramics enamels in foam form is the construction industry where their thermal and acoustic insulating properties, resulting from this natural porosity, are sought after.Las condiciones óptimas de obtención de esmaltes vitrocerámicos sobre materiales férreos son logradas cuando la interfase presenta una estructura continua constituida por la formación de óxidos. Para la obtención de estas condiciones se considera fundamental el tratamiento primario superficial, que engloba desde simples procesos de desengrase hasta procesos de deposición de níquel. Cuando la formación de los óxidos en la interfase no tiene lugar, aparecen fenómenos de esponjamiento en estos recubrimientos, provocados por reacciones durante el proceso de cocción. Las distintas variables que influyen en la obtención de los mismos son: temperatura de cocción del esmalte, porcentaje, naturaleza y granulometría de carga cerámica utilizada. Queda demostrado que el grado de esponjamiento es mayor cuanto mayor sea la fracción volumétrica de carga en el esmalte, menor su granulometría, así como la utilización de temperaturas de cocción del esmalte entre 650 y 850 ºC, si bien las condiciones óptimas de vitrificación se consiguen en torno a los 820 ºC. Los recubrimientos vitrocerámicos esponjosos pueden ser aplicables en industrias como la construcción debido a sus propiedades como la de ser aislantes térmicos y acústicos, como consecuencia de su naturaleza porosa.

In this work, a method for obtaining copper coating on alumina is described. One of the main applications for this coating is in the electronic industry, although it can be used as well as interlayer for dissimilar bonding between metals and alumina, both by solid state joining and by active brazing. The optimal activation conditions for the alumina using Ni salts and the influence of the surface preparation on the copper coating characteristic are described. The coating application is based on an autocatalithic reduction method. The influence of the deposition rate on the adherence of the copper coating has been studied as well. A kinetic study was carried out applying gravimetric and electrochemical methods. To obtaining coating with high adherence, it was necessary to apply heat treatments after the metallization process. The main objective of them was to achieve a chemical bond between the alumina substrate and the copper coating by formation of Al-Cu spinels, instead of the single mechanical bond.En el presente trabajo se describe un método de obtención de recubrimientos de cobre sobre un cerámico tenaz como es la alúmina. Una de sus principales aplicaciones se encuentra en la industria electrónica, aunque también puede ser empleado como intermediario en la fabricación de uniones disimilares entre un metal y un cerámico mediante técnicas de unión en estado sólido o en soldadura fuerte reactiva. Se describen las condiciones óptimas de activación de la alúmina mediante sales de Ni, y la influencia que posee la preparación superficial de este substrato (Al2O3) sobre las capas de Cu obtenidas. Este proceso se realiza mediante reducción autocatalítica, habiéndose estudiado como influye la velocidad de deposición sobre la adherencia de la capa de cobre. También se realizaron estudios cinéticos del proceso de recubrimiento mediante ensayos gravimétricos y electroquímicos. Con el fin de obtener recubrimientos que tuvieran una elevada resistencia (adherencia) fue necesario aplicar tratamientos térmicos posteriores al metalizado. El principal objetivo fue que se estableciera una unión química entre la alúmina y el cobre, por formación de espinelas Al-Cu. Por este motivo, en el trabajo se describen igualmente estos aspectos de la investigación.

The SiC reinforcement particles react with the molten aluminium to form Al4C3 that is brittle and sensitive to the the humidity. This reaction degrades the properties of the SiC reinforced aluminium matrix composites. The extend of the reaction in the Al/SiC interface depends on the fabrication parameters such as the temperature, residence time, atmosphere and chemical composition of the aluminium matrix and the reinforcement. Systematic studies on the reactivity between the SiC particles and molten aluminium alloys have been performed, analysing the effect of the presence of a SiO2 layer, which was formed by oxidation on the ceramic particles before their incorporation into the melt, as a protective barrier for preventing the attack of the SiC. As well, the effect of the metal matrix composition on the interfacial reactivity has been studied employing different aluminium alloys: AA1070 (99,7% Al), A-319.0 (Al-6Si-3Cu) and A-332.0 (Al-11Si-1,5Cu). The composites were prepared by mixture of SiC particles (30 % vol. %), cold pressure and fusion at 900 ºC, varying the residence time in the furnace, which simulated a cast fabrication process. The results are compared with those obtained for a metal matrix composite (AA2014/SiC/13p).Las partículas de refuerzo de SiC reaccionan con el aluminio fundido y forman Al4C3 que es frágil y sensible al contacto con la humedad, lo que degrada las propiedades de los materiales compuestos constituidos por ambos componentes. La reacción en la intercara Al/SiC depende de varios parámetros de fabricación como temperatura, tiempo de residencia, atmósfera y composición química, tanto de la matriz de aluminio como del refuerzo de SiC. Se han realizado estudios sistemáticos de reactividad entre partículas de SiC y aluminio fundido, analizando el efecto que tiene la formación de una capa de SiO2 por oxidación de las partículas cerámicas, antes de su incorporación en el fundido, como barrera protectora para prevenir el ataque del SiC por la matriz. Se ha estudiado también el efecto de la composición de la matriz metálica en dicha reactividad, empleando para ello varias aleaciones de aluminio: AA1170 (99,7%Al), A-319.0 (Al-6Si-3Cu) y A-332.0 (Al-11Si-1,5Cu). Los materiales compuestos se prepararon mediante mezcla de partículas de SiC (30 % vol.) y polvo de las aleaciones de aluminio, prensado en frío y posterior fusión a 900ºC, variando el tiempo de residencia dentro del horno para simular un proceso de fabricación por colada. Los resultados obtenidos se comparan con los obtenidos para materiales compuestos del tipo AA 2014/SiC/20p.

The reactivity between α-SiC whiskers and an aluminium alloy (Al-Cu-Mg), both present in a metal matrix composite, has been studied when such matrix is in molten state. Using mainly transmission electron microscopy (TEM) and electron microdiffraction (ED), the nature and morphology of the reaction products generated at the α-SiC/aluminium interface, when this last melts under different condition which simulate casting and welding procedures for metal matrix composites, have been characterised. Both the formation of Al4C3 aggregates with platelet morphology generated by dissolution-reaction mechanisms, and aciculate crystals of the same carbide form by complete dissolution of the α-SiC whiskers and later Al4C3 precipitation into the molten aluminium. Ternary Al-Si carbides with high chemical stability have been also identified by TEMED (β-Al4SiC4), being its formation related with higher energetic conditions than for the Al4C3.Se realiza un estudio de la reactividad entre whiskers de α-SiC y una aleación de aluminio en estado líquido (Al-Cu-Mg), que forman parte de un material compuesto de matriz metálica. Empleando fundamentalmente técnicas de microscopía electrónica de barrido (MEB) y de transmisión (MET), junto con difracción de electrones (DE), se ha caracterizado la naturaleza y morfología de los productos de reacción que se generan en la intercara α-SiC/aluminio, cuando éste funde en diferentes condiciones que simulan procesos de fabricación y soldadura del material compuesto. Se ha observado tanto la formación de agregados de Al4C3 con morfología tabular producidos por mecanismos de disolución-reacción de los whiskers, como de cristales aciculares del mismo tipo de carburo formados por disolución total de α-SiC y precipitación en el aluminio fundido. Se ha determinado también que, en condiciones suficientemente energéticas, pueden llegar a formarse carburos ternarios de aluminio y silicio (β-Al4SiC4) que presentan mayor estabilidad química que el carburo de aluminio formado en condiciones menos energéticas.

In this work, the β or secondary relaxation of 15 glass forming systems (13 polymers and 2 low molecular weight liquids) has been analysed by means of Broadband Dielectric Spectroscopy from 10-2 Hz to 107 Hz at temperatures below and slightly above the glass transition temperature. In further analysis of the experimental results, it has been considered this relaxation as an thermally activated process with a gaussian distribution of activation energies. The results obtained in this way have been compared with recent theories that relate this phenomenology with the glass transition one.En el trabajo que se presenta, se ha medido y analizado la relajación β o secundaria en 15 sistemas formadores de vidrios (13 polímeros y 2 líquidos de bajo peso molecular) mediante Espectroscopía Dieléctrica de Banda Ancha entre 10-2 Hz y 107 Hz a temperaturas inferiores y ligeramente superiores a la de transición vítrea. En el análisis de los resultados experimentales se ha considerado la relajación β como un proceso activado térmicamente con una distribución gaussiana de energías de activación. Los resultados obtenidos de este modo han sido comparados con recientes teorías que relacionan este fenómeno con el de la transición vítrea.

Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Background: The development of fast analytical methods is crucial for the research, discovery, and confirmation of crucial biomarkers. Furthermore, the implementation of fast analytical strategies contributes to efficient and time-effective procedures. In this sense, analysis of malondialdehyde (MDA) has become an important tool for understanding the role of oxidative stress in various diseases and for evaluating the efficacy of therapeutic interventions., Results: A rapid and robust liquid chromatography tandem mass spectrometry method (HPLC-MS/MS) has been developed to determine endogenous amounts of malondialdehyde (MDA) in human urine without any associated derivatization reaction. MDA was separated in 4 min through a Urea-HILIC column and was analyzed using a triple quadrupole mass spectrometer in negative electrospray ionization mode. With a 50-fold dilution as the only sample pretreatment after alkaline hydrolysis, no matrix effect was present, which allowed for a fast and simple quantification by means of an external standard calibration with a limit of detection of 0.20 ng mL -1 . The whole methodology was validated by analyzing unspiked and spiked urine samples from ten healthy individuals and comparing with the results obtained by the standard addition method. MDA was detected in all cases, with natural concentrations varying from 0.11 ± 0.03 to 0.31 ± 0.03 mg g -1 creatinine. Accuracies were found to be satisfactory, ranging from 95 % to 101 %. The proposed method also exhibited good repeatability and reproducibility (RSD<15 %) for four quality control levels., Significance: The main significance of this method is the avoidance of a derivatization reaction for the determination of urinary MDA, this constituting a step forward when compared with previous literature. This breakthrough not only streamlines time analysis to less than 5 min per sample but also results in a more robust procedure. Consequently, the method here developed could be applied to subsequent future research involving the determination of MDA as a lipid peroxidation biomarker, where simple, rapid, and reliable methods could represent a significant improvement., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objectives: To explore the impact of using different data standardization and scale-specific re-expression methods (i.e., processes to convert standardized data into scale-specific units) in meta-analyses using standardized mean differences (SMDs)., Study Design and Setting: We used data assessed by the Short Physical Performance Battery and the Barthel Index from a meta-analysis of randomized controlled trials which synthesized evidence of physical activity effectiveness on the functional capacity of hospitalized older adults. We standardized the data using study-specific pooled standard deviations (SDs), an internal, and an external SD references. Bayesian meta-analyses were performed for each method to compare the posterior distributions of the meta-analysis parameters. Posterior estimates were re-expressed into scale-specific units applying different methods established in the Cochrane guidelines., Results: Meta-analysis estimates depend on the used standardization method. Analyses including data standardized using the largest SD reference presented lower estimates with less uncertainty in both scales. The method applied for re-expressing SMDs into scale-specific units impacted in their posterior clinical interpretation. The most similar results across models were obtained when using the same SD reference to standardize and re-express data., Conclusion: Different data standardization methods yielded different meta-analysis estimates on the SMD scale. To avoid the introduction of bias, the use of a single scale-specific SD reference to standardize data is recommended and instead of study-specific pooled sample SDs. Meta-analysis software packages may therefore change their default methods to allow this method by a single scale-specific SD. To re-express the SMDs into scale-specific units, we suggest the application of the same SD reference that was used for data standardization., Competing Interests: Declaration of competing interest Authors declare no competing interests related with this work., (Crown Copyright © 2023. Published by Elsevier Inc. All rights reserved.)

Therapeutic monitoring of drugs, particularly those with multiple metabolites, can be time-consuming and labor-intensive due to the need for different analytical methods depending on the specific metabolite or matrix of interest. In this study, we employed a heart-cutting 2D-LC separation method based on the coupling of reversed-phase and mixed-mode mechanisms to determine Favipiravir and surrogates of five main metabolites. This approach was applied to serum, plasma, urine, and human peripheral blood mononuclear cells. The method underwent validation to ensure its reliability. The findings highlight the potential of 2D-LC as a practical and efficient approach for therapeutic drug monitoring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: To compare outcomes in patients with infective endocarditis (IE) first treated in secondary hospitals and then transferred to reference centres for surgery with those in patients diagnosed in reference centres, and to evaluate the impact of surgery timing on prognosis., Methods: Analysis of a prospective cohort of patients with active IE admitted to three reference centres between 1996 and 2022 who underwent cardiac surgery in the first month after diagnosis. Multi-variable analysis was performed to evaluate the impact of transfer to reference centres and time to surgery on 30-day mortality. Adjusted ORs with 95% CIs were calculated., Results: Amongst 703 patients operated on for IE, 385 (54.8%) were referred cases. All-cause 30-day mortality did not differ significantly between referred patients and those diagnosed at reference centres (102/385 [26.5%] vs. 78/385 [24.5%], respectively; p 0.552). Variables independently associated with 30-day mortality in the whole cohort were diabetes (OR, 1.76 [95% CI, 1.15-2.69]), chronic kidney disease (OR, 1.83 [95% CI, 1.08-3.10]), Staphylococcus aureus (OR, 1.88 [95% CI, 1.18-2.98]), septic shock (OR, 2.76 [95% CI, 1.67-4.57]), heart failure (OR, 1.41 [95% CI, 0.85-2.11]), acute renal failure before surgery (OR, 1.76 [95% CI, 1.15-2.69]), and the interaction between transfer to reference centres and surgery timing (OR, 1.18 [95% CI, 1.03-1.35]). Amidst referred patients, time from diagnosis to surgery longer than a week was independently associated with 30-day mortality (OR, 2.19 [95% CI, 1.30-3.69]; p 0.003)., Conclusion: Among referred patients, surgery performed >7 days after diagnosis was associated with two-fold higher 30-day mortality., (Copyright © 2023 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

The spatiotemporal evolution of both U and Th isotopes in a mine effluent highly polluted by acid mine drainage (AMD) was evaluated. The acidic tributary, which born from the outflows of an abandoned sulfide mine, flows into the Odiel River. AMD comprises an important source of natural radionuclides, presenting concentrations of 238 U and 232 Th, two and four orders of magnitude higher, respectively, than the background values of surface continental waters. These natural radionuclides behave conservatively along the mine effluent (pH < 2.5) throughout the hydrological year. Under AMD conditions uranium is in the hexavalent state U(VI) and the main dissolved species are uranyl sulfate complexes. The polluted tributary has a significant impact on the Odiel River acidifying its waters during the low flow season and increasing up to one order of magnitude the activity concentrations of U and Th isotopes. U presented a conservative behavior in the Odiel River during the low flow season (pH ≈ 3), however it is removed from the liquid phase in the wet season (pH ≈ 6), probably due its coprecipitation/adsorption onto Al-phases. Th shows a high sensitivity to small increases of pH, and it is strongly coprecipitated/adsorbed with or onto Fe-oxyhydroxydizes in the river., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Several bifunctional chelators have been synthesized in the last years for the development of new 64 Cu-based PET agents for in vivo imaging. When designing a metal-based PET probe, it is important to achieve high stability and kinetic inertness once the radioisotope is coordinated. Different competitive assays are commonly used to evaluate the possible dissociation mechanisms that may induce Cu(II) release in the body. Among them, acid-assisted dissociation tests or transchelation challenges employing EDTA or SOD are frequently used to evaluate both solution thermodynamics and the kinetic behavior of potential metal-based systems. Despite of this, the Cu(II)/Cu(I) bioreduction pathway that could be promoted by the presence of bioreductants still remains little explored. To fill this gap we present here a detailed spectroscopic study of the kinetic behavior of different macrocyclic Cu(II) complexes. The complexes investigated include the cross-bridge cyclam derivative [Cu(CB-TE1A)] + , whose structure was determined using single-crystal X-ray diffraction. The acid-assisted dissociation mechanism was investigated using HClO 4 and HCl to analyse the effect of the counterion on the rate constants. The complexes were selected so that the effects of complex charge and coordination polyhedron could be assessed. Cyclic voltammetry experiments were conducted to investigate whether the reduction to Cu(I) falls within the window of common bioreducing agents. The most striking behavior concerns the [Cu(NO2Th)] 2+ complex, a 1,4,7-triazacyclononane derivative containing two methylthiazolyl pendant arms. This complex is extremely inert with respect to dissociation following the acid-catalyzed mechanism, but dissociates rather quickly in the presence of a bioreductant like ascorbic acid., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background & Aims: Handgrip strength is a strong predictor of the risk of mortality. The objective of this systematic review was to analyse handgrip strength measurement protocols used in all-cause and cause-specific mortality studies., Method: A systematic search of PubMed/MEDLINE, Web of Science and Scopus was conducted from inception to February 2022. Prospective cohort studies with objective measures of handgrip strength were included. Studies had to report at least one all-cause, cancer, or cardiovascular mortality outcome. The quality of the included studies was assessed using the Newcastle Ottawa Scale. Meta-regression was used to quantify the bias associated with handgrip strength values in relation to the use of different measurement protocols., Results: Forty-eight studies with a total of 3,135,473 participants (49.6% women) were included. Half of the studies controlled body position, 39.6% arm position, 33.3% elbow position, 12.5% wrist position, 13% handgrip duration, 23% hand-adjustment to dynamometer and 12.5% verbal encouragement. The number of measurements, the laterality of the hand tested, and the estimation method of the handgrip strength value varied considerably between the study protocols. The spline regression model showed a non-linear inverse association between the values of handgrip strength and the number of protocol items controlled. Handgrip strength was higher when the number of measurements per hand or arm position was not controlled. Conversely, handgrip strength was lower when elbow position was not controlled or verbal encouragement were not provided., Conclusion: In general, the protocols used to assess handgrip strength in mortality studies are incomplete and highly heterogeneous. Handgrip strength values were higher when studies controlled fewer handgrip strength measurement protocol variables. There is a need to improve the controlling of handgrip strength measurement protocols and to standardise the method to enhance the accuracy of mortality risk estimates associated with handgrip strength., Prospero Registration Number: CRD42022334929., Competing Interests: Conflicts of interest The authors declare that there are no conflicts of interest., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Multiple drivers are threatening the functioning of the microbial food webs and trophic interactions. Our understanding about how temperature, CO 2 , nutrient inputs, and solar ultraviolet radiation (UVR) availability interact to alter ecosystem functioning is scarce because research has focused on single and double interactions. Moreover, the role that the degree of in situ nutrient limitation could play in the outcome of these interactions has been largely neglected, despite it is predominant in marine ecosystems. We address these uncertainties by combining remote-sensing analyses, and a collapsed experimental design with natural microbial communities from Mediterranean Sea and Atlantic Ocean exposed to temperature, nutrients, CO 2 , and UVR interactions. At the decade scale, we found that more intense and frequent (and longer lasting) Saharan dust inputs (and marine heatwaves) were only coupled with reduced phytoplankton biomass production. When microbial communities were concurrently exposed to future temperature, CO 2 , nutrient, and UVR conditions (i.e. the drivers studied over long-term scales), we found shifts from net autotrophy [primary production:respiration (PP:R) ratio > 1] towards a metabolic equilibrium (PP:R ratio ~ 1) or even a net heterotrophy (PP:R ratio < 1), as P-limitation degree was higher (i.e. Atlantic Ocean). These changes in the metabolic balance were coupled with a weakened phytoplankton-bacteria interaction (i.e. bacterial carbon demand exceeded phytoplankton carbon supply. Our work reveals that an accentuated in situ P limitation may promote reductions both in carbon uptake and fluxes between trophic levels in microbial plankton communities under global-change conditions. We show that considering long-term series can aid in identifying major local environmental drivers (i.e. temperature and nutrients in our case), easing the design of future global-change studies, but also that the abiotic environment to which microbial plankton communities are acclimated should be taken into account to avoid biased predictions concerning the effects of multiple interacting global-change drivers on marine ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Supramolecular solvents (SUPRASs) are gaining momentum in the multi-residue analysis of liquid samples thanks to the delimited hydrophilic and hydrophobic microenvironments in their nanostructures. In this work, SUPRASs with increased hydrophilicity were synthesized with the aim of enhancing the extractability of polar compounds. For this purpose, a double-headed amphiphile, 1,2-decanediol, was self-assembled in hydro-organic media in the presence and absence of sodium chloride. The SUPRASs formed, characterized by scanning electron microscopy, consisted of sponge droplets made up of a highly convoluted three-dimensional (3D) network of amphiphile. The network contained interconnected bilayers that were intersected by similarly interconnected aqueous channels with high and nearly constant water content (∼30%, w/w). Both the inherently open structure of the sponge morphology and the increased hydrophilic-hydrophobic balance of the amphiphile, provided highly hydrophilic microenvironments into the aggregates that rendered in increased recovery factors for 15 perfluorinated compounds (PFCs, C 4 -C 18 , log P ow values from 0.4 to 11.6) in natural waters. Extraction took 15 min without further clean-up or evaporation of extracts which were readily compatible with LC-MS/MS quantitation. Absolute recoveries for PFCs, at the level of a few ng L -1 , were in the range 70-120%, except for perfluoropentanoic acid (40%) and perfluorobutane sulfonic acid (51%). Detection limits for PFCs in water were in the range 0.01-0.02 ng L -1 , which allowed their determination in slightly polluted waters (0.07-2.33 ng L -1 ). This work proves that hydrophilicity in SUPRASs can be tailored through the amphiphile and the morphology of their aggregates, and that this characteristic improves compound extractability in multi-residue analysis., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The human endometrium presents a remarkable growth dynamic with an outstanding regenerative capacity. This work aims to develop a phenomenological-based dynamic model to predict the volume changes in the functional layer of the endometrium in each phase of the menstrual cycle. This model considers changes in the endometrial tissue, the blood flow through the spiral arteries, the shedding of the endometrial cells, and the menstrual blood flow. The input variables are estrogen and progesterone; these hormone dynamics are taken from a pre-existing and validated model. Key parameters are modified in order to know their effect on the state variables. The model response was quantitatively assessed using the experimental data of the endometrial cycle reported in the literature. The proposed model provides a better insight into the interactions between ovarian hormones and the endometrial cycle by coupling both physiological processes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Polyphenols are bioactive substances of vegetal origin with a significant impact on human health. The assessment of polyphenol intake and excretion is therefore important. In this work, a new electrochemical approach based on molecularly imprinted polymer extraction and preconcentration, combined with a disposable carbon screen-printed sensor and adsorptive transfer differential pulse voltammetry detection has been proposed for quantifying of 4-hydroxyphenylacetic acid (4-HPA), which is a biomarker of flavan-3-ols intake, and other phenolic acids. The simple experimental performance has allowed the rapid data collection with relevant information about the profile of catabolites extracted. The method was validated over a concentration range of 10-200 mg L -1 , R 2  > 0.999. In the optimized conditions, the recovery value was 94% with RSD 8%. The limits of detection and quantification were 2.38 mg L -1 and 7.21 mg L -1 , respectively. The method was validated by means of a chromatographic method, being the differences between the values of the 4-HPA concentrations obtained by both methods under 1%. The proposed method showed high recoveries, low detection limit, and good accuracy, providing a fast, reliable, and cheap procedure to quantify phenolic metabolites in urine, and representing therefore a good and interesting alternative method. Also, the procedure offers other advantages, including the miniaturization, the low use of organic solvents, the ability to analyse small volumes of samples, in situ analysis and simple instrumentation requirement., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Supramolecular solvents (dubbed SUPRAS) are gaining momentum as extractants of compounds of interest from complex matrixes such as foodstuff and biological and environmental samples. However, their powerful extraction mechanism, based on multiligand ability for solute binding, fails when applied to very polar compounds, hindering their applicability to the extraction of highly polar metabolites. In this work, we introduce the synthesis, characterization, and application of a new kind of SUPRAS formed by heptafluorobutyric acid (HFBA). The polar hydrophobicity of this perfluorinated acid results in a SUPRAS, which coacervates at acidic pHs, that shows a great capability to extract amino acids and oligopeptides (recoveries in the range 81-105%) with nonpolar alkyl, cyclic or aromatic side chain substituents (with log D > -3.62). To further demonstrate the potential of this novel SUPRAS, an analytical methodology for the determination of opiorphin in real saliva samples was developed and fully validated. The HFBA-based SUPRAS was synthetized in situ from 950 µL of stabilized saliva, by the addition of 150 µL of HFBA and 400 µL of HCl 37% (v/v). The resulting SUPRAS was directly injected into a LC-MS/MS system for further quantification. Quantitative recoveries in the range of 87-110% were obtained with relative standard deviations below 20%. The HFBA-based SUPRAS is, therefore, capable of efficiently extracting opiorphin from saliva samples and shows a high potential for the determination of several amino acids and oligopeptides from biological samples., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier B.V.)

The mechanisms of infection and dispersion of Trypanosoma cruzi among animals, especially in the sylvatic environment, are still not entirely clear, and various aspects of the transmission dynamics of this parasite in the sylvatic environment are still unknown. T. cruzi is a parasite with a great biological and genetic diversity that infects a wide variety of hosts, therefore, transmission cycles of this parasite are complex. The objective of this study was to determine the prevalence of T. cruzi infection and analyze the genetic variability of the discrete typing units (DTUs) of the parasite in three non-human primate species (Alouatta palliata, Alouatta pigra, and Ateles geoffroyi) in southeastern Mexico. A total of one hundred sixty-four serum samples (42 samples of A. pigra, 41 samples of A. palliata (free-ranging) and 81 samples of A. geoffroyi (hosted in care centers)) were analyzed for the detection of anti-T. cruzi antibodies by ELISA assays. The seroprevalence of infection was 23.39% in A. palliata, 21.40% in A. pigra and 16.27% in A. geoffroyi. Additionally, presence of parasite DNA was assessed by PCR, and the identification of DTUs was performed by real-time PCR coupled to High Resolution Melting (qPCR-HRM). Different DTUs (TcI, TcII, TcIII, TcV and TcVI) were found in the analyzed monkeys. In addition, infection of monkeys was not associated with age or gender, but it was associated with the species. This study reveals the risk of infection in the study area and that the different DTUs of the parasite can coexist in the same habitat, indicating that T. cruzi transmission in the study area is very complex and involves many ecological factors. However, there is a need for long-term studies of host-parasite interactions to provide a solid understanding of the ecology of these species and to understand the dispersion strategies of T. cruzi., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This paper comprises several assays aiming to identify the basis for the bioremediation of mine-impacted water (MIW). To do so, the conditions for build anoxic microcosms for treating this effluent were varied, containing MIW, and a source of chitin, to biostimulate sulfate-reducing bacteria (SRB). The chitin sources were: commercial chitin (CHIT) and shrimp shell (SS), which in addition to chitin, contains CaCO 3 , and proteins in its composition. The CHIT assays were not successful in sulfate-reduction, even when the pH was increased with CaCO 3 . However, in all SS assays the SRB development was successful (85% sulfate removal for assay 3), including the metal-free (MF-SS) assay (75% for assay 5). High-throughput sequencing analysis revealed the structure of bacterial community in the SS assay: the most abundant genera were Clostridium and Klebsiella, both fermentative and chitinase producers; a few SRB from the genera Desulfovibrio and Desulfosporosinus were also detected. In the MF-SS assay, Desulfovibrio genuswas detected but Comamonas was dominant. It could be deduced that SS is a suitable substrate for SRB development, but CHIT is not. The sulfate-reduction process was provided by the cooperation between fermentative/chitinase-producer bacteria together with SRB, which leads to efficient MIW treatment, removing sulfate and metallic ions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The aim of this study was to quantify carbon stocks and the emission of the greenhouse gases (N 2 O and CH 4 ) in mangrove forests with different vegetation assemblies in coastal lagoons of Veracruz Mexico. The vegetation included: black mangrove BM, dominated by Avicennia germinans, white mangrove WM, dominated by Laguncularia. racemose, red mangrove RM, dominated by Rhizophora mangle and mixed mangrove MM, dominated by the three species. Soil C stocks ranged 187-671 Mg C ha 1 without significant (p = 0.149) differences among the mangroves with different vegetation. Significantly (p = 0.049) higher tree biomass C stock was observed in RM (127 Mg ha -1 ) than in MM (24.23 Mg ha -1 ). Methane emissions in RM (0.58-6.03 mg m -2  min -1 ) were significantly higher (p < 0.05) than in MM. (0.0035-0.07 mg m -2  min -1 ), in WM (-0.0026-0.029 mg m -2  min -1 ) and in BM (0.0054-0.0097 mg m -2  min -1 ),during rainy, windy and dry season.RM had the longest period of inundation, the highest soil carbon concentration, and the lowest salinity. CH 4 emissions showed a significantly positive correlation with soils carbon concentration, water level and water pH and, negative correlation with water salinity and Cl -1 concentration in soil and water. Emissions of N 2 O (0.04-3.25 μg m -2  min -1 ) were not significantly different among the mangroves with different vegetation, but they showed seasonal variations, with higher emissions during windy and dry seasons. N 2 O emissions showed significantly positive correlations with soil nitrate concentration and soil temperature. Results of this research are useful for mangrove conservation and restoration strategies to maximize carbon storage and mitigate greenhouse gas emissions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Approximately half of the area in the Spanish Central Pyrenees is dedicated to pastures. A decrease in stocking rate coupled with changes in livestock management in recent decades have favoured the expansion of Nardus grasslands, which are considered undesirable for grazing use and for diversity conservation. The objective of this study was to analyse how topsoil properties are related to grassland plant composition occurring in erosion-disturbed (chalk grasslands) and undisturbed (Nardus mat-grasslands) soils in a subalpine area of the Spanish Central Pyrenees. We selected six paired sampling points for a side-by-side comparison of both communities. At each point, we 1) estimated the plant cover of each species through inventories and 2) analysed a set of physical-chemical topsoil properties (0-5 and 5-10 cm depth). Data were analysed through multivariate analysis. We found typical species of Nardus mat-grasslands in the undisturbed sites growing on non-eroded and well-structured soils that were low in calcium and acidic, with high contents of organic matter. In turn, we found earlier-successional grassland communities growing on slopes recently affected by soil erosion processes. The species composition was mainly species from stony slope grasslands and, to a lesser extent, from the long-term snow-covered environments of the high mountains. These soils were shallower and stonier and had a less-stable structure, higher pH, and lower organic matter and calcium content than undisturbed soils. Our results suggest that the differences between both communities emerge and are maintained by soil-plant feedback mechanisms mediated in Nardus mat-grasslands through soil stabilization and acidification and in chalk grasslands through soil erosion and basification. These findings suggest that the subalpine grassland mosaic results from a model of non-equilibrium plant coexistence due to soil disturbance and inexorable succession. Management should be focused on maintaining a disturbance regime, through grazing, sufficient to prevent the spreading of Nardus mat-grasslands., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Herein we present the synthesis of two ligands containing two di(2-picolyl)amine (DPA) units linked by either a 1,1'-(pyridine-2,6-diyl)bis(3-ethylurea) (L1) or a 1,1'-(1,3-phenylene)bis(3-ethylurea) (L2) spacer. The corresponding binuclear Cu II and Zn II complexes were prepared and isolated. The X-ray structures of the L1 ligand and the [Cu 2 L1Cl 2 ] 2+ complex evidence an unusual cis/trans conformation of one of the urea groups stabilized by an intramolecular hydrogen bond with the nitrogen atom of the pyridyl spacer. The Cu II complexes form rather strong ternary complexes with phosphorylated anions. The [Cu 2 L1] 4+ complex presents a rather high affinity for pyrophosphate (logK 11  = 8.19 at pH 7, 25 °C), while [Cu 2 L2] 4+ stands out because of its strong binding to AMP 2- (logK 11  = 9.3 at pH 7, 25 °C). The interaction of the Cu II complexes with deoxyribonucleic acid from calf thymus (ct-DNA) was monitored using circular dichroism (CD) and luminescence spectroscopies. These studies revealed a quite strong interaction of the complexes with ct-DNA (K b  = (6.4 ± 0.7) × 10 3 for [Cu 2 L1] 4+ and K b  = (6.3 ± 1.0) × 10 3 for [Cu 2 L2] 4+ ). Competition experiments carried out in the presence of methyl green and BAPPA (N 1 ,N 3 -Bis(4-amidinophenyl)propane-1,3-diamine) as major and minor groove competitors, respectively, confirm that the interaction of both complexes with DNA takes place through the minor groove, in agreement with docking studies. The [Cu 2 L2] 4+ complex is quite efficient in promoting the cleavage of the double-stranded pUC19 plasmid DNA, by favoring the conversion of the supercoiled form to the nicked form following a hydrolytic mechanism., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objectives: Since the introduction of endovascular treatment for cerebral aneurysms, hospitals in which subarachnoid hemorrhage is treated show different availability and/or preferences towards both treatment modalities. The main aim is to evaluate the clinical and angiographic results according to the hospital's treatment preferences applied., Methods: This study was conducted based on use of the subarachnoid hemorrhage database of the Vascular Pathology Group of the Spanish Neurosurgery Society. Centers were classified into 3 subtypes according to an index in the relationship between endovascular and surgical treatment as: endovascular preference, high endovascular preference, and elevated surgical preference. The clinical results and angiographic results were evaluated among the 3 treatment strategies., Results: From November 2004 to December 2017, 4282 subarachnoid hemorrhage patients were selected for the study: 630 (14.7%) patients from centers with surgical preference, 2766 (64.6%) from centers with endovascular preference, and 886 (20.7%) from centers with high endovascular preference. The surgical preference group obtained the best angiographic results associated with a greater complete exclusion (odds ratio: 1.359; 95% confidence interval: 1.025-1.801; P = 0.033). The surgical preference subgroup obtained the best outcome at discharge (65.45%), followed by the high endovascular preference group (61.5%) and the endovascular preference group (57.8%) (odds ratio: 1.359; 95% confidence interval: 1.025-1.801; P = 0.033)., Conclusions: In Spain, there is significant variability in aneurysm exclusion treatment in aneurysmal subarachnoid hemorrhage. Surgical centers offer better results for both surgical and endovascular patients. A multidisciplinary approach and the maintenance of an elevated quality of surgical competence could be responsible for these results., (Copyright © 2019 Elsevier Inc. All rights reserved.)

A simple, rapid and efficient methodology was developed for the extraction and determination of heterocyclic aromatic amines (HAAs) in cigarette and forest fire ash samples based on a novel Ultrasound-Assisted Dispersive Solid-liquid Microextraction (UA-DSLME) coupled to polyurethane foam (PUF) mini-column as a clean-up strategy and on-line determination by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The optimal working conditions were found by (i) application of two-level full factorial designs and (ii) implementation of a response surface methodology based on the second-order design as central composite designs. Under optimal experimental conditions, good linearity was obtained for concentrations ranging from 8.3 to 500 ng g -1 , with correlation coefficients (r 2 ) varying from 0.995 to 0.999 for all HAAs investigated. The limits of detection and quantification resulted to be between 2.1 and 10.7 ng g -1 and 8.3-16.9 ng g -1 , respectively. The recoveries from 92.2 to 100.6% were reached and the relative standard deviations (RSDs) were lower than 9.2%. The developed method was successfully applied to the determination of HAAs in ashes generated by cigarette and forest fire combustion., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This study aims to know the basis of sulfate-reducing bacteria (SRB) and chitin source relationship for the development of a biotreatment system for mine-impacted water (MIW). The MIW consists of river water impacted by coal acid mine drainage (AMD), an extremely acid effluent, rich in sulfate and dissolved metal ions, with a high pollutant potential. Chitin was used as metal ion sorbent and biostimulant of SRB, whose anaerobic dissimilatory metabolism reduces sulfate to sulfide. Microcosms were built in an oxygen-free atmosphere using chitin from two different sources: commercial chitin and shrimp shell waste, which contains calcium carbonate, an acidity removal agent, in addition to chitin. The results indicate that the shrimp shell performs best in removing sulfate (99.75%), iron (99.04%), aluminum (98.47%), and manganese (100%) ions. The iron ion sorption kinetics of the sediments were also studied; pseudo-second order behavior was observed. High-throughput sequencing analysis revealed the present bacterial community and its abundance in the microcosms after 11 and 30 treatment days: SRB were detected but were not the majority. Thus, this research aims to contribute to the sustainable treatment MIW through the employment of an abundant and low-cost biomaterial., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Aim: To examine the association between leisure time physical activity (LTPA) and metabolic control, in adults with diabetes mellitus (DM)., Methods: A cross-sectional study was conducted in two hospitals (Santiago, Chile) with 101 type 1 (mean 34.4±12.3 years) and 100 type 2 DM (mean 57.8±5.2 years) adults. Glycated hemoglobin level (A1C) was obtained, and LTPA levels were estimated through the Global Physical Activity Questionnaire. Multiple linear regression models were fitted evaluating the independent effect of LTPA, sociodemographic, cardiovascular risk factors and other types of physical activity (PA) on metabolic control., Results: DM participants which reported no LTPA had higher levels of A1C (type 1 mean A1C: 8.8±1.5% and type 2 mean A1C: 9.2±1.4%) compared to those who fulfilled PA recommendations of ≥150min/week (type 1 mean A1C: 8.0±1.6% and type 2 mean A1C: 8.1±1.4%). Regression analysis showed that A1C levels were negatively associated with ≥150min/week on LTPA in type 1 (b=-0.25; 95%CI -0.16 to -0.01) and type 2 DM (b=-0.24; 95%CI -0.29 to -0.02) participants., Conclusion: Leisure time physical activity may be considered as an efficient and inexpensive non-pharmacological tool for DM treatment. Hence, healthcare professionals should educate and promote PA since primary-care diagnosis in addition to prevent disease-related complications., (Copyright © 2019 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.)

Supramolecular solvent (SUPRAS) extraction is gaining attraction as a sample treatment technique because of its great performance in terms of effectiveness, versatility, sample clean-up, quickness, cost and sustainability. However, the nature of SUPRASs, being formed by amphiphile molecules, results in poor compatibility with Gas Chromatography (GC). Here, we show the hitherto unexplored development of a SUPRAS with high thermal stability (HTS) suitable for subsequent direct analysis by Headspace (HS)-GC. This novel HTS-SUPRAS, based on poly-undecylenic acid -an oligomeric surfactant-, tetraglyme -a polar aprotic solvent with excellent chemical and thermal stability- and water, was fully characterized in terms of composition and physical properties such as thermal stability. Subsequently, the HTS-SUPRAS developed was further successfully applied, as a proof-of-principle, to the extraction and determination of residual solvents in pharmaceutical drugs, including several solvents (class 2C) whose analysis by HS-GC has been shown to be highly complex. Analytical performance was demonstrated as mandated by the International Council for Harmonisation of technical requirements for pharmaceuticals for human use (ICH). Furthermore, excellent recoveries (70-120%) and high precisions (<20%, expressed as relative standard deviations) were obtained for the analysis of several different drug formulations spiked with the analyzed 37 residual solvents at their respective maximum residue levels., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Tunable Resistive Pulse Sensing, TRPS, is an emerging technique used in quantification and measuring the size (particle-by-particle) of viruses, exosomes and engineered colloidal spheres in biological fluids. We study the features of TRPS to enhance size characterization and quantification of submicron-sized microplastics, also called plastic microparticles, MP, in freshwater environments. We report alterations on the detection of the resistive pulses in the TRPS caused by humic acids, HA, during the size measurement of polystyrene microspheres used as MP surrogate. We discuss the alteration of the electric field in the measuring channel of the TRPS apparatus induced by the passage of HA. TRPS is a fast and precise technique for counting and size determination of MP but needs the evaluation of the influence of the organic matter on the current blockades. We show that statistical clustering models of the magnitude distribution of the resistive pulses can help to detect and quantify changes in the pulse size distributions induced by flocculation of humic acids. Conclusions of this study indicate that TRPS can be a valuable tool to improve the knowledge of the MP fate in surface waters, in the vadose zone and groundwater., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Cervical injury is regarded as an important risk factor for preterm delivery. A prolonged second stage of labor may increase the risk of cervical injury that, in turn, may be associated with increased risk of spontaneous preterm delivery in the subsequent pregnancy., Objective: We sought to evaluate whether the duration of the second stage of labor in a term primiparous singleton delivery is associated with an increased risk of singleton spontaneous preterm delivery (<37 weeks) in the second pregnancy., Study Design: We carried out a retrospective cohort analysis of women with 2 consecutive pregnancies: a first term (≥37 weeks) delivery and second birth. Data were derived from a single institution's prospectively collected obstetrical database from January 2005 through January 2015. Duration of the second stage of labor was examined as a continuous variable, modeled based on nonparametric restricted cubic regression spline with 4 degrees of freedom. Second-stage duration was also examined as short (<30 minutes), normal (30-179 minutes), and prolonged, defined as ≥180 minutes. The association between the duration of the second stage of labor in the first term pregnancy and the risk for spontaneous preterm delivery in the second pregnancy was evaluated before and after adjusting for potential confounders based on the Cox proportional hazards regression model. Associations were expressed based on the adjusted hazard ratio and 95% confidence interval., Results: In all, 6715 women met inclusion criteria. The hazard of spontaneous preterm delivery in the second pregnancy trended higher with both shorter and longer second-stage labors. The length of the second stage of labor in the first term delivery was categorized as short (<30 minutes) in 1749 (26.0%), normal (30-179 minutes) in 4551 (67.8%), and prolonged (≥180 minutes), in 415 (6.2%) women. Of these 6715 women with a first term delivery, 4.2% (n = 279) delivered spontaneously preterm in the second pregnancy. The risks of spontaneous preterm delivery among women with prolonged (≥180 minutes) second stage of labor and normal labor duration (30-179 minutes) were 5.4% (n = 22) and 3.5% (n = 158), respectively (adjusted hazard ratio, 1.81; 95% confidence interval, 1.15-2.84). This increased risk for prolonged second stage of labor was primarily seen among women who underwent a cesarean (hazard ratio, 3.38; 95% confidence interval, 1.09-10.49), but was imprecise among women who delivered vaginally (hazard ratio, 1.52; 95% confidence interval, 0.62-3.74). The risk of spontaneous preterm delivery among women with short second stage of labor (<30 minutes) in their first term pregnancy was 5.8% (n = 99; hazard ratio, 1.28; 95% confidence interval, 0.99-1.67)., Conclusion: The risk of spontaneous preterm delivery in the second pregnancy was increased in women with a prolonged (≥180 minutes) second stage in the first term pregnancy. This risk was even greater among women who were delivered by cesarean in the first pregnancy., (Copyright © 2018. Published by Elsevier Inc.)

Monitoring of amphetamine-type stimulant (ATS) confronts clinical labs with a high number of samples involving a variety of biological matrices. Liquid chromatography-tandem mass spectrometry (LC-MS/MS), routinely used for confirmation of ATS abuse, requires of laborious and matrix-dependent sample treatment methods, this increasing analysis time and cost. In this work, a universal and single-step sample treatment, based on supramolecular solvents (SUPRAS), was proposed for simplifying ATS confirmation in seven biological matrices. The SUPRAS was synthesized in situ in the sample (900 µL of basified oral fluid, urine, serum, sweat or breast milk or 50 mg of digested hair or fingernails) by the addition of hexanol (200 µL) and tetrahydrofuran (900 µL). The mixture was vortex-shaken and centrifuged and the SUPRAS extract was subsequently analyzed by positive ion mode electrospray LC-MS/MS. The method was fully validated for amphetamine (AMP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), N-ethyl-3,4-methylenedioxyamphetamine (MDEA) and N-methyl-3,4-methylenedioxyamphetamine (MDMA). Maximum ion suppression or enhancement was 9% and 7%, respectively, and extraction recoveries (87-111%) and within- (0.1-6.7%) and between-day (0.3-9.7%) CVs were all within required values. The lower limits of quantification (LLOQ) for biological fluids (5 ng/mL), and hair and fingernails (100 ng/g) were all well below the cut-offs established by worldwide organizations. Confirmation of MDA was carried out in five urine samples that tested positive for ATS by immunoassay. The SUPRAS-LC-MS/MS methodology succeeded in developing a hitherto unexplored and universal tool for quantifying ATS in a comprehensive pool of biological matrices of interest in forensic and clinical samples., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: New mass spectrometry (MS) techniques analysing exhaled breath have the potential to better define airway diseases. Here, we present our work to profile the volatile organic compounds (VOCs) in exhaled breath from patients with chronic obstructive pulmonary disease (COPD), using real-time MS, and relate this disease-specific breath profile to functional disease markers., Methods: In a matched cohort study, patients with COPD, according to GOLD criteria, were recruited. Exhaled breath analysis by untargeted MS was performed using secondary electrospray ionization - high-resolution MS (SESI-HRMS)., Results: Exhaled breath from 22 patients with COPD (mean age 58.6 ± 6.9 years, FEV 1 58.5 ± 19.9% predicted, 32.4 ± 19.2 pack years smoking) and 14 controls (mean age 58.1 ± 8.1 years, FEV 1 102.5 ± 11.3% predicted, 23.6 ± 12.5 pack years smoking) was analysed using SESI-HRMS. From 1441 different features, 43 markers were identified that allowed discrimination between the two groups with an accuracy of 89% (CI 74-97%), a sensitivity of 93%, and a specificity of 86%. The markers were determined to be metabolites of oxidative stress processes, such as fatty acids, aldehydes and amino acids, resulting from lung muscle degradation., Conclusion: Real-time breath analysis by SESI-MS allows molecular profiling of exhaled breath, can distinguish patients with COPD from matched healthy controls and provides insights into the disease pathogenesis., Competing Interests: None., (© 2018 The Association for Mass Spectrometry: Applications to the Clinical Lab (MSACL). Published by Elsevier B.V.)