Connecting molecular biomarkers, mineralogical composition, and microbial diversity from Mars analog lava tubes.

Lanzarote (Canary Islands, Spain) is one of the best terrestrial analogs to Martian volcanology. Particularly, Lanzarote lava tubes may offer access to recognizably preserved chemical and morphological biosignatures valuable for astrobiology. By combining microbiological, mineralogical, and organic geochemistry tools, an in-depth characterization of speleothems and associated microbial communities in lava tubes of Lanzarote is provided. The aim is to untangle the underlying factors influencing microbial colonization in Earth's subsurface to gain insight into the possibility of similar subsurface microbial habitats on Mars and to identify biosignatures preserved in lava tubes unequivocally. The microbial communities with relevant representativeness comprise chemoorganotrophic, halophiles, and/or halotolerant bacteria that have evolved as a result of the surrounding oceanic environmental conditions. Many of these bacteria have a fundamental role in reshaping cave deposits due to their carbonatogenic ability, leaving behind an organic record that can provide evidence of past or present life. Based on functional profiling, we infer that Crossiella is involved in fluorapatite precipitation via urea hydrolysis and propose its Ca-rich precipitates as compelling biosignatures valuable for astrobiology. In this sense, analytical pyrolysis, stable isotope analysis, and chemometrics were conducted to characterize the complex organic fraction preserved in the speleothems and find relationships among organic families, microbial taxa, and precipitated minerals. We relate organic compounds with subsurface microbial taxa, showing that organic families drive the microbiota of Lanzarote lava tubes. Our data indicate that bacterial communities are important contributors to biomarker records in volcanic-hosted speleothems. Within them, the lipid fraction primarily consists of low molecular weight n-alkanes, α-alkenes, and branched-alkenes, providing further evidence that microorganisms serve as the origin of organic matter in these formations. The ongoing research in Lanzarote's lava tubes will help develop protocols, routines, and predictive models that could provide guidance on choosing locations and methodologies for searching potential biosignatures on Mars.

Norcantharidin toxicity profile: an in vivo murine study.

Norcantharidin (NCTD) is the demethylated analog of cantharidin, with allegedly reduced toxicity. However, there is still limited information regarding its posology and potential risk in its use in cancer treatment. Healthy BDF1 mice were intraperitoneally administered with norcantharidin (0, 3, 6, 12, and 25 mg/kg) every 24 h for 6 days. Survivor mice were euthanized, and the brain, lungs, kidneys, spleen, and liver were procured for enzymatic and histopathological analysis in the liver and kidney. DL50 were 8.86 mg/kg for females and 11.77 mg/kg for males. The treatments with 3.0 mg/kg and 6.0 mg/kg significantly modified the phosphorylase, alanine transaminase, and γ-glutamyl transferase activities; however, an organ-specific response was detected. A significant dose-dependent decrease was observed in the kidney for ROS, while the liver had the opposite effect. Histopathological analysis revealed a significant elevation in hepatocytes' nuclei average size and total area (3 mg/kg), as well as centrilobular vein and adjacent sinusoidal capillaries showed a significant difference. The portal triad presented a significant difference in veins and capillarity count in 6 mg/kg. Renal samples showed cortex convoluted tubules' average size significantly augmented in both doses' groups, and tubule count was found augmented in 6 mg/kg. These physiological effects of NCTD can be exploited as treatment strategies if able to operate in an established posology and proper testing.

Impact of Biochar Amendment on Soil Properties and Organic Matter Composition in Trace Element-Contaminated Soil.

The application of biochar as an organic amendment in polluted soils can facilitate their recovery by reducing the availability of contaminants. In the present work, the effect of biochar application to acid soils contaminated by heavy metal spillage is studied to assess its effect on the quantity and composition of soil organic matter (SOM), with special attention given to soil humic acids (HAs). This effect is poorly known and of great importance, as HA is one of the most active components of SOM. The field experiment was carried out in 12 field plots of fluvisols, with moderate and high contamination by trace elements (called MAS and AS, respectively), that are located in the Guadiamar Green Corridor (SW Spain), which were amended with 8 Mg·ha-1 of olive pit biochar (OB) and rice husk biochar (RB). The results indicate that 22 months after biochar application, a noticeable increase in soil water holding capacity, total organic carbon content, and soil pH were observed. The amounts of oxidisable carbon (C) and extracted HAs in the soils were not altered due to biochar addition. Thermogravimetric analyses of HAs showed an increase in the abundance of the most thermostable OM fraction of the MAS (375-650 °C), whereas the HAs of AS were enriched in the intermediate fraction (200-375 °C). Spectroscopic and chromatographic analyses indicate that the addition of biochar did not alter the composition of the organic fraction of HAs, while Cu, Fe, and as were considerably accumulated at HAs.

Fire effects on C and H isotopic composition in plant biomass and soil: Bulk and particle size fractions.

This work studies carbon (C) and hydrogen (H) isotope composition of plant biomass and soil organic matter (SOM) in an attempt to assess both, changes exerted by fire and possible inputs of charred materials to the soil after a wildfire. Isotope composition of bulk soil, soil particle size fractions and biomass of the dominant standing vegetation in the area (Quercus suber) from Doñana National Park (SW-Spain) were studied by isotope ratio mass spectrometry (IRMS). SOM C isotope composition indicates the occurrence of two SOM pools with different degree of alteration. Coarse soil fractions (>0.5 mm) were found 13C depleted with δ13C values close to those in leaf biomass, pointing to a predominance of poorly transformed SOM. Conversely, fine fractions (<0.1 mm) were found enriched in 13C as corresponds to a more humified SOM. The fire produced no changes in this trend, although a consistent 13C enrichment (c. 1‰) was observed in all soil fractions with decreasing size. Concerning H isotopes, the coarse fractions (>0.5 mm) displayed significant lower δ2H values than the intermediate and fine ones (<0.5 mm), again similar to those in leaf biomass (c. -80‰), whereas the fine fractions were found deuterium (2H)-enriched with significant higher δ2H values (c. 50‰), suggesting physical speciation of H depending on soil particle size. The fire produced a significant 2H depletion (Δ2H c. -10‰) in the finer fractions (<0.1 mm). The study of stable isotope analysis added new information and complements the results obtained by other proxies to better understand the effect of fire on SOM.

Modulation of Glial Responses by Furanocembranolides: Leptolide Diminishes Microglial Inflammation in Vitro and Ameliorates Gliosis In Vivo in a Mouse Model of Obesity and Insulin Resistance.

Neurodegenerative diseases are age-related disorders caused by progressive neuronal death in different regions of the nervous system. Neuroinflammation, modulated by glial cells, is a crucial event during the neurodegenerative process; consequently, there is an urgency to find new therapeutic products with anti-glioinflammatory properties. Five new furanocembranolides (1-5), along with leptolide, were isolated from two different extracts of Leptogorgia sp., and compound 6 was obtained from chemical transformation of leptolide. Their structures were determined based on spectroscopic evidence. These seven furanocembranolides were screened in vitro by measuring their ability to modulate interleukin-1ß (IL-1ß) production by microglial BV2 cells after LPS (lipopolysaccharide) stimulation. Leptolide and compounds 3, 4 and 6 exhibited clear anti-inflammatory effects on microglial cells, while compound 2 presented a pro-inflammatory outcome. The in vitro results prompted us to assess anti-glioinflammatory effects of leptolide in vivo in a high-fat diet-induced obese mouse model. Interestingly, leptolide treatment ameliorated both microgliosis and astrogliosis in this animal model. Taken together, our results reveal a promising direct biological effect of furanocembranolides on microglial cells as bioactive anti-inflammatory molecules. Among them, leptolide provides us a feasible therapeutic approach to treat neuroinflammation concomitant with metabolic impairment.

Effect of a wildfire and of post-fire restoration actions in the organic matter structure in soil fractions.

The impact of wildfires and of restoration actions on soil organic matter (SOM) content and structure was studied in a soil under pine (Pinus pinea) from Doñana National Park (SW Spain). Samples were collected from burnt areas before (B) and after post-fire restoration (BR) and compared with an unburnt (UB) site. Analytical pyrolysis (Py-GC/MS) was used to investigate SOM molecular composition in whole soil samples and in coarse (CF) and fine (FF) fractions. The results were interpreted using a van Krevelen graphical-statistical method. Highest total organic carbon (TOC) was found in UB soil and no differences were found between B and BR soils. The CF had the highest TOC values and FF presented differences among the three scenarios. Respect to SOM structure, the B soil was depleted in lignin and enriched in unspecific aromatics and polycyclic aromatic hydrocarbons, and in all scenarios, CF SOM consisted mainly of lignocellulose derived compounds and fatty acids. In general, FF SOM was found more altered than CF. High contribution of unspecific aromatic compounds and polycyclic aromatic hydrocarbons was observed in B-FF whereas BR-FF samples comprised considerable proportions of compounds from labile biomass, possibly due to soil mixing during rehabilitation actions. The fire caused a defunctionalisation of lignin-derived phenolics and the formation of pyrogenic compounds. The van Krevelen diagram was found useful to-at first sight-differentiate between chemical processes caused by fire and of the rehabilitation actions. Fire exerted SOM demethoxylation, dealkylation and dehydration. Our results indicate that soil management actions after the fire lead to an increase in aromaticity corresponding to the accumulation of lignin and polycyclic aromatic compounds. This suggests additional inputs from charred lignocellulosic biomass, including black carbon, that was incorporated into the soil during rehabilitation practices.

Dissolved organic matter adsorption from surface waters by granular composites versus granular activated carbon columns: An applicable approach.

Many new sorbents have been introduced as an alternative for granular activated carbon (GAC), the most common sorbent for dissolved organic matter (DOM) removal. In the current study, we developed an applicable granular composite based on a flocculant commonly employed for drinking water treatment adsorbed to montmorillonite. DOM adsorption from surface waters, Lake Kinneret and Suwannee River, with low and high specific ultraviolet absorption (SUVA), respectively, by composite and GAC columns, was studied. Adsorption of DOM from Suwannee River was significantly higher by the composite column, in comparison to the GAC column, while an opposite trend was obtained for the adsorption of DOM from Lake Kinneret. In-situ regeneration of the columns with a brine solution was extremely efficient and inefficient for the composite and GAC columns, respectively. Adsorption, of both waters, post-regeneration by the composite column was not compromised, while GAC effectiveness decreased. The opposite trend in DOM adsorption from Suwannee River and Lake Kinneret was explained by the different affinities of the sorbents towards various DOM molecules. Distinguishing between different DOM components adsorbed by GAC and the composite was supported by 13C NMR and direct pyrolysis-GC-MS measurements. Furthermore, we demonstrated that the kinetics and adsorption at the equilibrium of five organic molecules to the composite and GAC can be correlated to their chemical-physical properties. Indeed, combining the properties of both sorbents, by integrating them into a single column, yielded higher DOM removal than by the individual columns. Furthermore, since DOM removal by GAC and by the composite, increases, and decreases with temperature, respectively, the integrated column, mitigates the changes in removal, stabilizing the adsorption performance. Such an integrated filter may minimize additional seasonal and water quality fluctuations.

Fiber-optic pulseoximeter for local oxygen saturation determination using a Monte Carlo multi-layer model for calibration.

BACKGROUND AND OBJECTIVE: Local tissue oxygenation determines the relationship between the supply and the demand for oxygen by the tissue and it is an important indicator of the physiological or pathological condition of the tissue. Moreover, some therapeutic methods strongly depend on the oxygen content of the tissue. In photodynamic therapy, when molecular oxygen is present, the irradiation of the photosensitizer with light triggers the generation of reactive oxygen species that kill the target diseased cells within the treated tissue. To ensure the best possible therapy response, the tissue must be well oxygenated; hence, oxygen concentration measurement becomes a decisive factor. In this work, the design, construction and calibration of a module to locally measure the blood oxygen saturation in tissue is presented. METHODS: The system is built using a red (660-nm) and an infrared (940-nm) light emitting diodes as light sources, a photodiode as a detector, and a homemade handheld fiber optic-based reflectance pulse oximetry sensor. In addition, the developed sensor was modeled by means of multilayered Monte Carlo simulations, to study its behavior when used in different thickness and melanin content skin. RESULTS: From the simulation reflectance values, the oxygen saturation calibration curves considering different melanin concentrations and skin thicknesses were obtained for two different skin models, one comprising three skin layers and the second, assuming seven different layers for the skin. A comparison of the performances of the developed pulse oximeter sensor with a commercial one is also presented. CONCLUSIONS: A new pulseoximeter for the measurement of local oxygenation in tissue was developed. Its calibration strongly depends on the site of measurement due to the influence of tissue thickness, vascularization, and melanin content. A three-layer skin model is proved to be suitable for the calibration of the pulseoximeter in thin and medium thickness skin.

Impact of wildfires on subsurface volcanic environments: New insights into speleothem chemistry.

Siliceous speleothems frequently reported in volcanic caves have been traditionally interpreted as resulting from basalt weathering combined with the activity of microbial communities. A characteristic feature in lava tubes from Hawaii, Azores and Canary Islands is the occurrence of black jelly-like speleothems. Here we describe the formation process of siliceous black speleothems found in a lava tube from La Palma, Canary Islands, Spain, based on mineralogy, microscopy, light stable isotopes, analytical pyrolysis, NMR spectroscopy and chemometric analyses. The data indicate that the black speleothems are composed of a hydrated gel matrix of amorphous aluminum silicate materials containing charred vegetation and thermally degraded resins from pines or triterpenoids from Erica arborea, characteristic of the overlying laurel forest. This is the first observation of a connection between fire and speleothem chemistry from volcanic caves. We conclude that wildfires and organic matter from the surface area overlying caves may play an important role in the formation of speleothems found in La Palma and demonstrate that siliceous speleothems are potential archives for past fires.

Quantitative forecasting black (pyrogenic) carbon in soils by chemometric analysis of infrared spectra.

A detailed and global quantitative assessment of the distribution of pyrogenic carbon (PyC) in soils remains unaccounted due to the current lack of unbiased methods for its routine quantification in environmental samples. Conventional oxidation with potassium dichromate has been reported as a useful approach for the determination of recalcitrant C in soils. However, its inaccuracy due to the presence of residual non-polar but still non-PyC requires additional analysis by 13C solid-state nuclear magnetic resonance (NMR) spectroscopy, which is expensive and time consuming. The goal of this work is to examine the possibility of applying infrared (IR) spectroscopy as a potential alternative. Different soil type samples (paddy soil, Histic Humaquept, Leptosol and Cambisol) have been used. The soils were digested with potassium dichromate to determine the PyC content in environmental samples. Partial Least Squares (PLS) regression was used to build calibration models to predict PyC from IR spectra. A set of artificially produced samples rich in PyC was used as reference to observe in detail the IR bands derived from aromatic structures resistant to dichromate oxidation, representing black carbon. The results showed successful PLS forecasting of PyC in the different samples by using spectra in the 1800-400 cm-1 range. This lead to significant (P < 0.05) cross-validation coefficients for PyC, determined as the aryl C content of the oxidized residue. The Variable Importance for Projection (VIP) traces for the corresponding PLS regression models plotted in the whole IR range indicates the extent to which each IR band contributes to explain the aryl C and PyC contents. In fact, forecasting PyC in soils requires information from several IR regions. In addition to the expected IR bands corresponding to aryl C, other bands are informing about the patterns of oxygen-containing functional groups and the mineralogical composition characteristic of the soils with greater black carbon storage capacity. The VIP traces of the charred biomass samples confirm that aromatic bands (1620 and 1510 cm-1) are the most important in the prediction model for PyC-rich samples. These facts suggest that the mid-IR spectroscopy could be a potential tool to estimate the black carbon.

Effect of pyrolysis conditions on the total contents of polycyclic aromatic hydrocarbons in biochars produced from organic residues: Assessment of their hazard potential.

The interest of using biochar, the solid byproduct from organic waste pyrolysis, as soil conditioner is significantly increasing. Nevertheless, persistent organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), are formed during pyrolysis due to the incomplete combustion of organic matter. Consequently, these pollutants may enter the environment when biochar is incorporated into soil and cause adverse ecological effects. In this study, we examined the content of the 16 United States Environmental Protection Agency (USEPA) PAHs in biochars produced from rice husk, wood, wheat and sewage sludge residues using three different pyrolytic reactors and temperatures (400, 500 and 600 °C). The total concentration of PAHs (∑PAH) ranged from 799 to 6364 µg kg-1, being naphthalene, phenanthrene and anthracene the most abundant PAHs in all the biochars. The maximum amount of PAHs was observed for the rice husk biochar produced in the batch reactor at 400 °C, which decreased with increasing temperature. The ∑PAH value of the wood biochar produced via traditional kilns doubled compared with the wood biochar produced using the other pyrolytic reactors (5330 µg kg-1 in Kiln; 2737 µg kg-1 in batch and 1942 µg kg-1 in the rotary reactor). Looking for a more reliable risk assessment of the potential exposure of PAHs in biochar, the total toxic equivalent concentrations (TTEC) of the 14 produced biochars were calculated. When comparing the same feedstock and temperature, TTEC values indicated that the rotary reactor produced the safest biochars. In contrast, the biochars produced using the batch reactor at 400 and 500 °C have the greatest hazard potential. Our results provide valuable information on the potential risk of biochar application for human and animal health, as well as for the environment due to PAHs contamination.

Mulching-induced preservation of soil organic matter quality in a burnt eucalypt plantation in central Portugal.

Mulching has amply proven its effectiveness to mitigate post-fire soil erosion but its impacts on soil organic matter (SOM) quality and quantity continue poorly studied. The present study addressed this knowledge gap for a eucalypt plantation in central Portugal that had been burnt and, immediately after the wildfire, mulched with 13.6 Mg ha-1 of eucalypt logging residues some five years before. This was done by performing a range of analytical techniques (elemental and isotope analyses, analytical pyrolysis and 13C NMR spectroscopy) not only on the bulk soil samples but also on their humic acids (HAs) and free organic matter (FOM) fractions. While mulching reduced soil and SOM losses with 91 and 93%, respectively, it also improved SOM quality of the topsoil, in particular in terms of HAs and FOM. At 0-4 cm depth, both HAs and FOM contents were roughly twice as high in the mulched plots as in the control plots. The effects of mulching on the molecular composition of HAs and FOM fractions, however, varied markedly. Analytical pyrolysis (Py-GC/MS) revealed that mulching had led to a noticeable accumulation of labile, aliphatic SOM constituents such as carbohydrate-derived and alkyl compounds (fatty acids and n-alkanes) but that it hardly affected the composition of HAs. Even so, solid-state 13C NMR spectroscopy showed that mulching had resulted in a relative increase in aryl C in the FOM fraction, suggesting an enhanced preservation of the pyrogenic OM. Overall, the combined use of a range of analytical techniques allowed to conclude that, five years after their application, the forest logging residues had led to a greater preservation of the fire-derived pyrogenic OM (mainly aromatic compounds) in the topsoil as well as to higher contents of SOM's most labile molecular constituents (mainly carbohydrates and n-alkyl compounds). The former reflected the reduced erosion rates, while the latter was probably due to a combination of reduced erosion rates with the additional input of fresh organic matter.

Ultra-high resolution mass spectrometry of physical speciation patterns of organic matter in fire-affected soils.

Fire is one of the most important modulating factors of the environment and the forest inducing chemical and biological changes on the most reactive soil component, the soil organic matter (SOM). Assuming the complex composition of the SOM, we used an ultra-high resolution mass spectrometry analysis technique to assess the chemical composition and fire-induced alterations in soil particle size fractions (coarse and fine) from a sandy soil in a Mediterranean oak forest at Doñana National Park (Southwest Spain). Electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) showed that the coarse fraction of soils not affected by fires consisted mainly of polyphenolic compounds consistent with little-transformed SOM and fresh biomass, whereas the fine fraction was enriched in protein and lipid like homologues suggesting microbially reworked SOM. In fire-affected SOM, the coarse fraction contained a high proportion of aromatic compounds, consistent with inputs of charred litter or in situ chemical transformation of the SOM. Analysis of the fine fraction revealed two differentiated chemical families pointing to the existence of two carbon pools; a native microbial-derived moiety composed of lipids and polypeptide compounds, and a secondary, pyrogenic or thermally-altered moiety rich in aromatic compounds. This work represents the first application of ultra-high resolution mass spectrometry to study the chemical composition of SOM in different particle size fractions.

Cellular Responses of the Lichen Circinaria gyrosa in Mars-Like Conditions.

Lichens are extremely resistant organisms that colonize harsh climatic areas, some of them defined as "Mars-analog sites." There still remain many unsolved questions as to how lichens survive under such extreme conditions. Several studies have been performed to test the resistance of various lichen species under space and in simulated Mars-like conditions. The results led to the proposal that Circinaria gyrosa (Lecanoromycetes, Ascomycota) is one of the most durable astrobiological model lichens. However, although C. gyrosa has been exposed to Mars-like environmental conditions while in a latent state, it has not been exposed in its physiologically active mode. We hypothesize that the astrobiological test system "Circinaria gyrosa," could be able to be physiologically active and to survive under Mars-like conditions in a simulation chamber, based on previous studies performed at dessicated-dormant stage under simulated Mars-like conditions, that showed a complete recover of the PSII activity (Sánchez et al., 2012). Epifluorescence and confocal laser scanning microscopy (CLSM) showed that living algal cells were more abundant in samples exposed to niche conditions, which simulated the conditions in micro-fissures and micro-caves close to the surface that have limited scattered or time-dependent light exposure, than in samples exposed to full UV radiation. The medulla was not structurally affected, suggesting that the niche exposure conditions did not disturb the lichen thalli structure and morphology as revealed by field emission scanning electron microscopy (FESEM). In addition, changes in the lichen thalli chemical composition were determined by analytical pyrolysis. The chromatograms resulting from analytical pyrolysis at 500°C revealed that lichen samples exposed to niche conditions and full UV radiation consisted primarily of glycosidic compounds, lipids, and sterols, which are typical constituents of the cell walls. However, specific differences could be detected and used as markers of the UV-induced damage to the lichen membranes. Based on its viability responses after rehydration, our study shows that the test lichen survived the 30-day incubation in the Mars chamber particularly under niche conditions. However, the photobiont was not able to photosynthesize under the Mars-like conditions, which indicates that the surface of Mars is not a habitable place for C. gyrosa.

Soil-borne fungi challenge the concept of long-term biochemical recalcitrance of pyrochar.

Pyrogenic organic matter (PyOM) is assumed to be biochemically recalcitrant, but recent studies indicated a quick decrease of PyOM in post-fire soils. Regardless erosion and abiotic degradation, microbial decomposition has been the explanation for this response, but no direct proof has been provided up to now. In the present study, we were able to demonstrate for the first time that the soil-borne fungus Fusarium oxysporum is not only colonizing the pore system of pyrochar (PyC) but is also involved in the degradation of its aromatic network. We showed that PyC not only stimulates microbial degradation of soil organic matter (SOM), but is also attacked and decomposed by microorganisms. Our observations are based on the chemical and morphological alterations of a sewage-sludge derived PyC produced at 600 °C after its amendment to a Calcic Cambisol by solid-state 13C nuclear magnetic resonance spectroscopy, analytical pyrolysis, elemental analysis, field emission scanning electron microscopy and DNA-based analysis of the isolated fungi. We showed that biofilms detected in the PyC play an essential role in the degradation process. These results are indispensable for a reliable assessment of the carbon sequestration potential of PyC in soils but also for improving global C cycling models.

Chloro-Furanocembranolides from Leptogorgia sp. Improve Pancreatic Beta-Cell Proliferation.

Two new chloro-furanocembranolides (1, 2) and two new 1,4-diketo cembranolides (3, 4) were isolated from the crude extract of Leptogorgia sp. together with a new seco-furanocembranolide (5) and the known Z-deoxypukalide (6), rubifolide (7), scabrolide D (8) and epoxylophodione (9). Their structures were determined based on spectroscopic evidence. Four compounds: 1, 2, 7 and 8 were found to activate the proliferation of pancreatic insulin-producing (beta) cells.

A set of biogenetically interesting polyhalogenated acetogenins from Ptilonia magellanica.

Ptilonines A-F, pyranosylmagellanicus D-E and magellenediol are previously undescribed acetogenins isolated from the red alga Ptilonia magellanica. Their structures were determined from spectroscopic evidence. The absolute configuration of the known pyranosylmagellanicus A, was established by derivatization with (R)- and (S)-α-methoxy -α-phenylacetic acids (MPA). Ptilonines exhibit an unusual halogenation pattern, that may confer evolutionary advantages to Ptilonia magellanica, for which a biogenetic origin is proposed. The antimicrobial effect of some of these compounds was evaluated.

Assessing the effects of UVA photocatalysis on soot-coated TiO2-containing mortars.

The deposition of soot on building surfaces darkens their colour and leads to undesirable black crusts, which are one of the most serious problems on the conservation of built cultural heritage. As a preventive strategy, self-cleaning systems based on the use of titanium dioxide (TiO2) coatings have been employed on building materials for degrading organic compounds deposited on building surfaces, improving their durability and performance. In this study, the self-cleaning effect of TiO2-containing mortars coated with diesel soot has been appraised under laboratory conditions. The mortar samples were manufactured using lime putty and two different doses of TiO2 (2.5% and 5%). The lime mortars were then coated with diesel engine soot and irradiated with ultraviolet A (UVA) illumination for 30days. The photocatalytic efficiency was evaluated by visual inspection, field emission scanning electron microscopy (FESEM) and colour spectrophotometry. Changes in the chemical composition of the soot particles (including persistent organic pollutants) were assessed by analytical pyrolysis (Py-GC/MS) and solid state 13C NMR spectroscopy. The FESEM and colour spectrophotometry revealed that the soot-coated TiO2-containing mortars promoted a self-cleaning effect after UVA irradiation. The combination of analytical pyrolysis and 13C solid state NMR showed that the UVA irradiation caused the cracking of polycyclic aromatic structures and n-alkyl compounds of the diesel soot and its transformation into methyl polymers. Our findings also revealed that the inclusion of TiO2 in the lime mortar formulations catalysed these transformations promoting the self-cleaning of the soot-stained mortars. The combined action of TiO2 and UVA irradiation is a promising proxy to clean lime mortars affected by soot deposition.

Posibles factores de riesgo cardiovasculares en pacientes con hipertensión arterial en tres barrios de Esmeraldas, Ecuador / Possible cardiovascular risk factors in patients with arterial hypertension in three neighbourhoods from Esmeraldas, Ecuador

Fundamento: la hipertensión arterial se puede prevenir al modificar los factores de riesgo relacionados con el comportamiento de las personas. En la ciudad de Esmeraldas, Ecuador, no se han realizado estudios que permitan conocer qué factores inciden en esta condición médica. Objetivo: determinar los posibles factores de riesgo cardiovasculares presentes en la población hipertensa de tres barrios del cantón Esmeraldas. Métodos: se realizó un estudio descriptivo, cuantitativo y de corte transversal, desde febrero hasta agosto de 2016. La muestra estuvo constituida por 36 pacientes hipertensos de los 85 casos documentados existentes en los tres barrios, y a los que se les aplicó una encuesta con 15 preguntas cerradas. Las variables utilizadas fueron: edad biológica, factores de riesgo cardiovasculares y desconocimiento de los riesgos por parte de la muestra estudiada. Resultados: el grupo etario de mayor incidencia fue el de 41 a 60 años, el sexo femenino fue el más afectado por la hipertensión, los factores de riesgo cardiovasculares más frecuentes encontrados fueron el sedentarismo, el estrés, seguido por las dietas ricas en sodio Otro de los hallazgos encontrados fue el desconocimiento sobre la enfermedad. Conclusiones: son múltiples los factores de riesgo cardiovasculares que acompañan a la población de hipertensos observados; algunos de esos factores, como el sedentarismo o la obesidad, son determinantes directos de la respuesta al desconocimiento sobre la enfermedad y éstos, asociados a otras condicionantes, podrían incidir de forma importante en su pronóstico cardiovascular.

Background: high blood pressure can be prevented by modifying risk factors related to the behavior of people. In the city of Esmeraldas, Ecuador, studies have not been carried out to know what factors are affecting this medical condition. Objective: to determine the possible cardiovascular risk factors present in the hypertensive population of three neighborhoods of the Esmeraldas canton. Methods: a descriptive, quantitative and cross-sectional study was carried out between February and August 2016. The sample consisted of 36 hypertensive patients from the 85 documented cases in the three neighborhoods, to whom a survey with 15 closed questions was applied. The variables used were biological age, cardiovascular risk factors and lack of knowledge of the risks by the sample studied. Results: the highest incidence was found in the age group between 41 to 60 years of age, with 61,1 % and the female gender was the most affected by hypertension, with 68,3 %; The most frequent cardiovascular risk factors were sedentary lifestyle, with 63,8 % and stress with 50 %, followed by diets high in sodium with 44,4 %. Another finding was the lack of knowledge about the disease. Conclusions: there are multiple cardiovascular risk factors that accompany the hypertensive population studied; some of these factors, such as sedentary lifestyle or obesity, are direct determinants of the response to the disease, and these, associated with other conditions, could have a significant impact on their cardiovascular prognosis.