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BACKGROUND: Real-time prediction of histologic features of small colorectal polyps may prevent resection and/or pathologic evaluation and therefore decrease colonoscopy costs. Previous studies showed that computer-aided diagnosis (CADx) was highly accurate, though it did not outperform expert endoscopists. OBJECTIVE: To assess the diagnostic performance of histologic predictions by general endoscopists before and after assistance from CADx in a real-life setting. DESIGN: Prospective, multicenter, single-group study. (ClinicalTrials.gov: NCT04437615). SETTING: 6 centers across the United States. PARTICIPANTS: 1252 consecutive patients undergoing colonoscopy and 49 general endoscopists with variable experience in real-time prediction of polyp histologic features. INTERVENTION: Real-time use of CADx during routine colonoscopy. MEASUREMENTS: The primary end points were the sensitivity and specificity of CADx-unassisted and CADx-assisted histologic predictions for adenomas measuring 5 mm or less. For clinical purposes, additional estimates according to location and confidence level were provided. RESULTS: The CADx device made a diagnosis for 2695 polyps measuring 5 mm or less (96%) in 1252 patients. There was no difference in sensitivity between the unassisted and assisted groups (90.7% vs. 90.8%; P = 0.52). Specificity was higher in the CADx-assisted group (59.5% vs. 64.7%; P < 0.001). Among all 2695 polyps measuring 5 mm or less, 88.2% and 86.1% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be resected and discarded without pathologic evaluation. Among 743 rectosigmoid polyps measuring 5 mm or less, 49.5% and 47.9% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be left in situ without resection. LIMITATION: Decision making based on CADx might differ outside a clinical trial. CONCLUSION: CADx assistance did not result in increased sensitivity of optical diagnosis. Despite a slight increase, the specificity of CADx-assisted diagnosis remained suboptimal. PRIMARY FUNDING SOURCE: Olympus America Corporation served as the clinical study sponsor.
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Inteligencia Artificial , Pólipos del Colon , Colonoscopía , Diagnóstico por Computador , Sensibilidad y Especificidad , Humanos , Pólipos del Colon/patología , Estudios Prospectivos , Femenino , Masculino , Persona de Mediana Edad , Anciano , Adenoma/patología , Adenoma/diagnóstico , Neoplasias Colorrectales/patología , Competencia Clínica , AdultoRESUMEN
Climatic conditions have been shown as a major driver of the fate of Hg in forest ecosystems at a global scale, but less is known about climatic effects at shorter scales. This study assesses whether the concentration and pools of Hg in soils collected from seventeen Pinus pinaster stands describing a coastal-inland transect in SW Europe vary along a regional climatic gradient. In each stand, samples of the organic subhorizons (OL, OF + OH) and the mineral soil (up to 40 cm) were collected and some general physico-chemical properties and total Hg (THg) were analyzed. Total Hg was significantly higher in the OF + OH than in the OL subhorizons (98 and 38 µg kg-1, respectively), favored by a greater organic matter humification in the former. In the mineral soil, mean THg values decreased with depth, ranging from 96 µg kg-1 in the 0-5 cm layers to 54 µg kg-1 in the deepest layers (30-40 cm), respectively. The average Hg pool (PHg) was 0.30 mg m-2 in the organic horizons (92% accumulated in the OF + OH subhorizons), and 27.4 mg m-2 in the mineral soil. Changes in climatic factors, mainly precipitation, along the coast-inland transect resulted in a remarkable variation of THg in the OL subhorizons, consistent with their role as the first receiver of atmospheric Hg inputs. The high precipitation rate and the occurrence of fogs in coastal areas characterized by the oceanic influence would explain the higher THg found in the uppermost soil layers of pine stands located close to the coastline. The regional climate is key to the fate of mercury in forest ecosystems by influencing the plant growth and subsequent atmospheric Hg uptake, the atmospheric Hg transference to the soil surface (wet and dry deposition and litterfall) and the dynamics that determine net Hg accumulation in the forest floor.
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Mercurio , Pinus , Contaminantes del Suelo , Ecosistema , Suelo/química , Monitoreo del Ambiente , Mercurio/análisis , Bosques , Europa (Continente) , Contaminantes del Suelo/análisisRESUMEN
Vegetation and climate are critical in the biogeochemical cycle of Hg in forest ecosystems. The study assesses the influence of needle age and precipitation on the accumulation of Hg in needle biomass and its deposition by litterfall in thirty-one pine plantations spread throughout two biogeographical regions in SW Europe. Well-developed branches of Pinus pinaster were sampled and pine needles were classified according to 4 age classes (y0, y1, y2, y3). The concentration of total Hg (THg) was analyzed in the samples and Hg content in needle biomass and its deposition by litterfall were estimated. The concentration of total Hg (THg) increased with needle age ranging from 9.1 to 32.7 µg Hg kg-1 in the youngest and oldest needles, respectively. The rate of Hg uptake (HgR) three years after needle sprouting was 10.2 ± 2.3 µg Hg kg-1 yr-1, but it decreased with needle age probably due to a diminution in photosynthetic activity as needles get older. The average total Hg stored in needle biomass (HgWt) ranged from 5.6 to 87.8 mg Hg ha-1, with intermediate needle age classes (y1 and y2) accounting for 70% of the total Hg stored in the whole needle biomass. The average deposition flux of Hg through needle litterfall (HgLt) was 1.5 µg Hg m-2 yr-1, with the y2 and y3 needles contributing most to the total Hg flux. The spatial variation of THg, HgWt and HgLt decreased from coastal pine stands, characterized by an oceanic climate, to inland pine stands, a feature closely related to the dominant precipitation regime in the study area. Climatic conditions and needle age are the main factors affecting Hg accumulation in tree foliage, and should be considered for an accurate assessment of forest Hg pools at a regional scale and their potential consequences in the functioning of terrestrial ecosystems.
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Mercurio , Tracheophyta , Ecosistema , Monitoreo del Ambiente , Bosques , Mercurio/análisis , ÁrbolesRESUMEN
A sharp decrease in public transport demand has been observed during the COVID-19 pandemic around the world. In this context, it is relevant to understand how mode preferences have changed since the surge of COVID-19. In order to better understand how the pandemic changed mode choice, particularly regarding the impact of crowding and face mask use in public transport, we conducted a stated preference on-line and on-street survey in Santiago, Chile. Our sample is balanced in gender but has a higher proportion of individuals with college degrees and those under 45 years of age than the population of Santiago. The data collected was then used to estimate two multinomial mode choice models, a latent class model and a mixed logit model with latent variables. The models yielded a value of travel time in crowded conditions (4 pax/m2) and low face mask use (50%) of 3.0-5.1 times higher than the case with low crowding (0.5 pax/m2) and 100% face mask use. Moreover, women tend to be more sensitive than men to the use of face masks in public transport. Besides, young and low-income people are relatively less sensitive to crowding. The crowding penalization obtained is higher than in pre-pandemic models calibrated for Santiago for similar passenger densities. Also, as we expected, it grows non-linearly with passenger density. Disinfection of vehicles, as well as the perception of health risk, cleanliness, safety and comfort, were also relevant in explaining mode choice. Further research shall discuss how the change of mode preferences together with new demand patterns influence the operational design of public transport services.
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Mercury content of twelve podzols from NW Spain was studied to elucidate the main soil properties involved in the Hg accumulation of these soils. The highest average Hg concentrations (HgT) were found in the Bh and Bs horizons (64 and 105 µg kg-1), whereas the lowest occurred in the E horizons (15 µg kg-1). Moderate values of HgT were obtained for the A and C horizons (38 and 52 µg kg-1). The Hg enrichment factors revealed that the predominant origin of Hg in these soils is the atmosphere instead of the parent material. As it was shown by the PCA performed (which explained 82% of the variance of the data), the main soil characteristics involved in the pedogenetic processes of the studied podzols are organic matter and Al and Fe compounds. The stepwise linear regressions made described between 54% and 84% of the predicted Hg depending on the soil horizon. Besides a complex ensemble of biogeochemical reactions involved in the balance between input and outputs of Hg, the most influencing variable in the A horizons was organic C, moderate stability Al-humus complexes in the E horizons, Fe-humus complexes and pHw in the Bh horizons, Al-humus compounds in the Bs horizons and crystalline Al and Fe compounds in the C horizons. Therefore, Hg is mobilized from the A and E horizons bound to dissolved organic matter and precipitated in the illuvial horizons due to the saturation of the organic matter with metals. The immobilization of Hg in the subsuperficial horizons of podzols leads to different environmental benefits derived from the removal of Hg from the A horizons, more exposed to climate-induced and land use/cover changes that could potentially modify the dynamics of Hg in those superficial horizons.
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Mercurio , Contaminantes del Suelo , Monitoreo del Ambiente , Bosques , Mercurio/análisis , Suelo , Contaminantes del Suelo/análisis , EspañaRESUMEN
We studied competitive adsorption for the tetracycline antibiotics (TCs) tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC) on three bio-adsorbents (mussel shell, oak wood ash, and pine bark). The results were compared for individual systems (with antibiotics added separately) and ternary systems (with all three antibiotics added simultaneously). In all cases batch-type experiments were carried out, with 24â¯h of contact time. In the individual systems, concentrations of 200⯵molâ¯L-1 were used for each of the three antibiotics, separately. In the ternary system, all three TCs were added simultaneously, using the following total concentrations: 50, 100, 200, 400, 600⯵molâ¯L-1, each antibiotic being 1/3 of the total. Taking into account that ionic strength of a solution is related to a measure of the concentration of ions in that solution, the use of individual and ternary systems allows to compare, for each antibiotic, systems having equal concentrations and similar ionic strength (concentrations of 200⯵molâ¯L-1), and systems having different concentrations and ionic strength (200⯵molâ¯L-1 in the individual systems, and 600⯵molâ¯L-1 in the ternary systems, resulting from the sum of 200⯵molâ¯L-1 corresponding to each of the three antibiotics). Adsorption/desorption results indicated that these processes were in all cases closely related to pH values, and to carbon and non-crystalline minerals contents in the bio-adsorbents. Both oak ash and pine bark adsorbed close to 100% of TCs in individual and ternary systems, with desorption <4% for oak ash, and <12% for pine bark. However, mussel shell gave clearly poorer results, only relatively acceptable for CTC, with adsorption <56% and desorption even >30% for TC and OTC. In view of the results, oak ash and pine bark can be recommended as effective bio-adsorbents for the three TCs studied, and could be useful to retain/inactive them in wastes, and soil or liquid media receiving these emerging pollutants, thus reducing risks of damage for public health and the environment.
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Bivalvos , Clortetraciclina , Oxitetraciclina , Quercus , Contaminantes del Suelo , Adsorción , Animales , Antibacterianos , Corteza de la Planta , TetraciclinaRESUMEN
Using batch-type experiments, chromium (Cr(VI)) and fluoride (F-) sorption/desorption were studied in forest and vineyard soil samples, pyritic material, pine bark, oak ash, hemp waste and mussel shell, as well as on samples of forest and vineyard soil, and of pyritic material, individually treated with 48â¯tâ¯ha-1 of pine bark, oak ash, and mussel shell. Pine bark showed the highest Cr(VI) sorption (alwaysâ¯>â¯97% of the concentration added) and low desorption (<1.5%). Pyritic material sorbed between 55 and 98%, and desorbed between 0.6 and 9%. Forest and vineyard soils, oak ash, mussel shell and hemp waste showed Cr(VI) sorption alwaysâ¯<â¯32%, and desorption between 22 and 100%. Pine bark also showed the highest F- retention (sorption between 62 and 73%, desorption between 10 and 15%), followed by oak ash (sorption 60-69%, desorption 11-14%), forest soil (sorption 60-73%, desorption 19-36%), and pyritic material (sorption 60-67%, desorption 13-15%), whereas in vineyard sorption was 49-64%, and desorption 24-27%, and in hemp waste sorption was 26-36%, and desorption 41-59%. Sorption data showed better fitting to the Freundlich than to the Langmuir model, especially in the case of Cr(VI), indicating that multilayer sorption dominated. The addition of by-products to the forest and vineyard soils, and to the pyritic material, caused an overall increase in F- sorption, and decreased desorption. Furthermore, the pine bark amendment resulted in increases in Cr(VI) retention by both soils and the pyritic material. These results could be useful to favor the recycling of the by-products studied, aiding in the management of soils and degraded areas affected by Cr(VI) and F- pollution, and in the removal of both anions from polluted waters.
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Cromo/química , Fluoruros/química , Adsorción , Animales , Cromo/aislamiento & purificación , Granjas , Fluoruros/aislamiento & purificación , Bosques , Suelo , Contaminantes del Suelo/química , Contaminantes del Suelo/aislamiento & purificaciónRESUMEN
The effects of adding two winery wastes, perlite waste (PW) and bentonite waste (BW), to an acid vineyard soil were assessed using some chemical and biological soil properties in a field study that lasted 18 months. The addition of PW (up to 81 Mg ha-1) had neither significant nor permanent effects on soil characteristics such as the pH, organic matter content or nutrient concentrations, the amounts of copper or zinc, or the electrical conductivity. Moreover, no persistent negative effects were found on the enzymatic activities after PW application. In contrast, soil that was amended with up to 71 Mg BW ha-1 showed increases in its soil pH values, exchangeable potassium and water soluble potassium and phosphorus contents. In addition, it caused significant increases in the electrical conductivity and water-soluble Cu. In addition, the phosphomonoesterase enzymatic activity decreased significantly (up to 28%) in response to the amendment with 71 Mg BW ha-1. These results showed that adding BW and PW to the soil may be a good agronomic practice for recycling these types of wastes. However, in the case of PW, its use as a soil amendment must be performed with caution to control its possible harmful effects.
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Cobre/química , Granjas , Suelo , Fraccionamiento Químico , Fósforo , Contaminantes del SueloRESUMEN
The European Community Bureau of Reference method (BCR) was used for evaluating the effects of pine bark amendment (0, 24 and 48 g kg-1) and ageing (1 and 30 days) on Cd, Cu, Ni, Pb and Zn fractionation, on samples from an acid mine soil. In addition, the stirred flow chamber technique was applied for analyzing heavy metals desorption from the unamended and pine bark amended mine soil. When the unamended soil were not subjected to ageing, the added heavy metals were mainly accumulated as soluble fraction (>90% for Cd, Ni and Zn; 71% for Cu; and 45% for Pb). Pine bark amendment and ageing had little effect on Cd, Ni and Zn fractionation, whereas important changes were detected for Cu and Pb in response to both pine bark amendment and ageing (decrease in the soluble fractions, and increase in less mobile fractions). Desorption experiments showed that both pine bark amendment and ageing decreased heavy metals release from the mine soil. The results of this study indicate that pine bark amendment could be used to increase heavy metals retention (especially in the case of Cu and Pb) in acid mine soils, thus reducing the risks of metal transfer to uncontaminated environmental zones.
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Contaminantes del Suelo , Suelo , Fraccionamiento Químico , Metales Pesados , PinusRESUMEN
Bark from Pinus pinaster is one of the most abundant forestry wastes in Europe, and among the proposed technologies for its reutilization, the removal of heavy metals from wastewater has been gaining increasing attention. In this work, we have studied the performance of pine bark for heavy metal biosorption on competitive systems. Pb, Cu, Ni, Zn and Cd sorption and desorption at equilibrium were studied in batch experiments, whereas transport was studied in column experiments. Batch experiments were performed adding simultaneously different concentrations (0.08-3.15mM) of two or more metals in solution to pine bark samples. Column experiments were performed with 10mM solutions of two metals or a 5mM solution of the five metals. In general, the results under competitive conditions were different to those obtained in monoelemental experiments. The multi-metal batch experiments showed the adsorption sequence Pb≈Cu>Cd>Zn>Ni for lower metal doses, Pb>Cu>Cd>Zn>Ni for intermediate doses, and Pb>Cu>Cd≈Zn≈Ni for high metal doses. Desorption followed the sequence Pb
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Metales Pesados/metabolismo , Pinus/metabolismo , Corteza de la Planta/metabolismo , Adsorción , Transporte Biológico , Cadmio/metabolismo , Cadmio/farmacocinética , Cobre/metabolismo , Cobre/farmacocinética , Europa (Continente) , Agricultura Forestal , Plomo/metabolismo , Plomo/farmacocinética , Metales Pesados/análisis , Metales Pesados/farmacocinética , Níquel/metabolismo , Níquel/farmacocinética , Residuos , Zinc/metabolismo , Zinc/farmacocinéticaRESUMEN
BACKGROUND: The aim of this study was to analyze whether late-onset fetal growth restriction (FGR) alters regulatory capability in infants, and whether this can be detected using both the neonatal behavior assessment scale (NBAS) and brainstem auditory-evoked potentials (BAEP). METHODS: The diagnosis of FGR was made on Doppler examination in the third trimester of pregnancy. NBAS and BAEP measurement were performed at 1 month of corrected postnatal age. RESULTS: The group with late-onset FGR was integrated with 17 infants and the control group consisted of 14 subjects. The NBAS range of state score, which reflects organization of behavioral state, was low in infants with late-onset FGR. No differences were found in BAEP between groups. No association between NBAS and BAEP was detected. CONCLUSION: Late-onset FGR has a deleterious effect on NBAS range of state, but possibly does not alter BAEP response. It is proposed that regulatory capabilities in the neonatal period play a primary role in subtle cognitive difficulties in infants with late-onset FGR in the long term.
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Retardo del Crecimiento Fetal/psicología , Conducta del Lactante , Adolescente , Adulto , Estudios Transversales , Potenciales Evocados Auditivos del Tronco Encefálico/fisiología , Femenino , Retardo del Crecimiento Fetal/diagnóstico , Retardo del Crecimiento Fetal/epidemiología , Estudios de Seguimiento , Edad Gestacional , Humanos , Incidencia , Recién Nacido , Masculino , México/epidemiología , Embarazo , Estudios Retrospectivos , Factores de Tiempo , Ultrasonografía Doppler , Ultrasonografía Prenatal , Adulto JovenRESUMEN
The effect of bentonite waste added to a "poor" soil on its general characteristic and copper adsorption capacity was assessed. The soil was amended with different bentonite waste concentrations (0, 10, 20, 40 and 80 Mg ha(-1)) in laboratory pots, and different times of incubation of samples were tested (one day and one, four and eight months). The addition of bentonite waste increased the pH, organic matter content and phosphorus and potassium concentrations in the soil, being stable for P and K, whereas the organic matter decreased with time. Additionally, the copper sorption capacity of the soil and the energy of the Cu bonds increased with bentonite waste additions. However, the use of this type of waste in soil presented important drawbacks for waste dosages higher than 20 Mg ha(-1), such as an excessive increase of the soil pH and an increase of copper in the soil solution.
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Bentonita/química , Cobre/química , Contaminantes del Suelo/química , Suelo/química , Humanos , Concentración de Iones de Hidrógeno , Residuos Industriales , Factores de Tiempo , VinoRESUMEN
BACKGROUND: Most previous studies of the use of cervical pessaries were either retrospective or case controlled and their results showed that this intervention might be a preventive strategy for women at risk of preterm birth; no randomised controlled trials have been undertaken. We therefore undertook a randomised, controlled trial to investigate whether the insertion of a cervical pessary in women with a short cervix identified by use of routine transvaginal scanning at 20-23 weeks of gestation reduces the rate of early preterm delivery. METHODS: The Pesario Cervical para Evitar Prematuridad (PECEP) trial was undertaken in five hospitals in Spain. Pregnant women (aged 18-43 years) with a cervical length of 25 mm or less were randomly assigned according to a computer-generated allocation sequence by use of central telephone in a 1:1 ratio to the cervical pessary or expectant management (without a cervical pessary) group. Because of the nature of the intervention, this study was not masked. The primary outcome was spontaneous delivery before 34 weeks of gestation. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00706264. FINDINGS: 385 pregnant women with a short cervix were assigned to the pessary (n=192) and expectant management groups (n=193), and 190 were analysed in each group. Spontaneous delivery before 34 weeks of gestation was significantly less frequent in the pessary group than in the expectant management group (12 [6%] vs 51 [27%], odds ratio 0·18, 95% CI 0·08-0·37; p<0·0001). No serious adverse effects associated with the use of a cervical pessary were reported. INTERPRETATION: Cervical pessary use could prevent preterm birth in a population of appropriately selected at-risk women previously screened for cervical length assessment at the midtrimester scan. FUNDING: Instituto Carlos III.
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Cuello del Útero/patología , Pesarios , Nacimiento Prematuro/prevención & control , Adolescente , Adulto , Medición de Longitud Cervical , Cuello del Útero/diagnóstico por imagen , Femenino , Humanos , Embarazo , Resultado del Embarazo , Estudios Prospectivos , Factores de Riesgo , España , Estadísticas no Paramétricas , Resultado del TratamientoRESUMEN
BACKGROUND/AIM: Ultrasound marking by radiologists prior to percutaneous liver biopsy (PLB) results in biopsy site adjustment, decreased pain related complications and improved tissue yield. Minimal data exists on the impact of ultrasound marking by gastroenterologists on these parameters. The study aim was to evaluate whether ultrasound marking by gastroenterologists results in improved PLB tissue yield, fewer needle passes and decreased biopsy failure rates compared to blind biopsy, eliminating the need for a separate radiological evaluation. METHODOLOGY: All PLB performed by gastroenterologists from June 1999 to February 2003 at the University of Florida College of Medicine, Jacksonville, were reviewed retrospectively. Data collected included ultrasound marked or blind PLB, demographics, indication, number of passes performed, and specimen length, if obtained. RESULTS: Four hundred and eighty PLB were included: 328 performed with ultrasound marking and 152 blind. Ultrasound marking by gastroenterologists prior to PLB resulted in fewer passes and longer specimens as well as a decreased failure rate in ultrasound marked compared to blind PLB. CONCLUSIONS: Ultrasound marking by gastroenterologists prior to PLB provided significantly larger tissue samples, fewer needle passes and a decreased biopsy failure rate compared to blind PLB. This removes the need for a separate radiological evaluation on the procedure day.
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Biopsia/métodos , Hepatopatías/patología , Ultrasonografía Intervencional , Femenino , Gastroenterología , Humanos , Hepatopatías/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
We determined mercury retention on calcined and ground mussel shell, in presence and absence of phosphate, using batch and stirred flow chamber experiments. In batch experiments the calcined shell exhibited higher Hg adsorption, with good fitting to Freundlich equation (R2: 0.925-0.978); the presence of phosphate increased Hg adsorption; mercury desorption was 13% or lower, diminishing up to 2% under the presence of phosphates. In stirred flow chamber experiments calcined shell retained more Hg than ground shells (6300 vs. 4000-5200 micromol/kg); Hg retention increased an additional 40% on calcined shell and up to an additional 70% on ground shells when phosphates were present; mercury desorption was quite similar in all shell types (20%-34%), increasing up to 49%-60% in ground shells when phosphates were present. The higher Hg adsorption on calcined shell would be related to its calcite and dolomite concentrations; mercury-phosphate interactions would cause the increase in Hg retention when phosphates are present. Data on Hg desorption suggest that Hg retention was not easily reversible after batch experiments, increasing in the stirred flow chamber due to convective flow. Calcined and ground mussel shells could be recycled removing Hg from water, with the presence of phosphates in solution improving efficacy.
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Exoesqueleto/química , Contaminantes Ambientales/aislamiento & purificación , Mercurio/aislamiento & purificación , Mytilus/química , Adsorción , Animales , Fosfatos/químicaRESUMEN
Atmospheric mercury (Hg) is largely assimilated by vegetation and subsequently transferred to the soil by litterfall, which highlights the role of forests as one of the largest global Hg sinks within terrestrial ecosystems. We assessed the pool of Hg in the aboveground biomass (leaves, wood, bark, branches and twigs), the Hg deposition flux through litterfall over two years (by sorting fallen biomass in leaves, twigs, reproductive structures and miscellaneous) and its accumulation in the soil profile in a deciduous forest dominated by Betula alba from SW Europe. The total Hg pool in the aboveground birch biomass was in the range 532-683 mg ha-1, showing the following distribution by plant tissues: well-developed leaves (171 mg ha-1) > twigs (160 mg ha-1) > bark (159 mg ha-1) > bole wood (145 mg ha-1) > fine branches (25 mg ha-1) > thick branches (24 mg ha-1) > newly sprouted leaves (20 mg ha-1). The total Hg deposition fluxes through litterfall were 15.4 and 11.7 µg m-2 yr-1 for the two years studied, with the greatest contribution coming from birch leaves (73 %). In the soil profile, the pool of Hg in the mineral soil (37.0 mg m-2) was an order of magnitude higher than in the organic horizons (1.0 mg m-2), mostly conditioned by parameters such as soil bulk density and thickness, total C and N contents and the presence of certain Al compounds.
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Mercurio , Árboles , Árboles/química , Mercurio/análisis , Suelo , Betula , Ecosistema , Biomasa , Monitoreo del Ambiente , Bosques , BetulaceaeRESUMEN
Soils constitute the major reservoir of mercury (Hg) in terrestrial ecosystems, whose stability may be threatened by wildfires. This research attempts to look at the effect of prescribed fire on the presence of Hg in a shrubland ecosystem from NE Portugal, delving into its relationship with soil aggregate size and the molecular composition of soil organic matter (SOM). During the prescribed fire, on average 347 mg Hg ha-1 were lost from the burnt aboveground biomass of shrubs and 263 mg Hg ha-1 from the combustion of the soil organic horizon. Overall, Hg concentration and pools in the mineral soil did not show significant changes due to burning, which highlights their role as long-term Hg reservoirs. The higher Hg concentrations found in smaller aggregates (<0.2 mm) compared to coarser ones (0.5-2 mm) are favored by the higher degree of organic matter decomposition (low C/N ratio), rather than by greater total organic C contents. The Hg-enriched finest fraction of soil (<0.2 mm) could be more prone to be mobilized by erosion, whose potential arrival to water bodies increases the environmental concern for the Hg present in fire-affected soils. The SOM quality (molecular composition) and the main organic families, analyzed by Fourier-transform infrared spectroscopy in combination with multivariate statistical analysis, significantly conditioned the retention/emission of Hg in the uppermost soil layers. Thus, before the fire, Hg was strongly linked to lipid and protein fractions, while Hg appeared to be linked to aromatic-like compounds in fire-affected SOM.
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OBJECTIVES: To describe the outcome of patients with twin-to-twin transfusion syndrome and cervical length ≤ 25 mm, treated with laser and an Arabin cervical pessary. METHODS: Retrospective analysis of a consecutive series of all cases with severe twin-to-twin transfusion syndrome who underwent laser surgery: a group with cervical length above 25 mm (group A) and two groups who had a cervical length of 25 mm or less prior to the procedure. The first 8 cases (group B) were managed expectantly and the next 8 cases had a cervical pessary inserted immediately after laser surgery (group C). Gestational age at birth was the primary outcome. The secondary outcome was a composite one encompassing severe neonatal morbidity. RESULTS: The median gestational age at laser surgery was 20 weeks in all groups but the median gestational age at delivery was significantly higher in group C versus B (28 vs 32 weeks, p = 0.01). Severe neonatal morbidity was present in 18% in group C and 70% in group B (p < 0.01). CONCLUSION: Early results suggest a potential role for pessary use in prolonging gestation in cases with shortened cervix at the time of laser. A randomized trial to test this hypothesis should be performed.
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Transfusión Feto-Fetal/cirugía , Terapia por Láser/métodos , Pesarios , Nacimiento Prematuro/prevención & control , Adulto , Cuello del Útero/cirugía , Femenino , Transfusión Feto-Fetal/epidemiología , Fetoscopía/efectos adversos , Fetoscopía/métodos , Fetoscopía/estadística & datos numéricos , Humanos , Recién Nacido , Terapia por Láser/efectos adversos , Terapia por Láser/estadística & datos numéricos , Pesarios/estadística & datos numéricos , Embarazo , Resultado del Embarazo/epidemiología , Nacimiento Prematuro/epidemiología , Nacimiento Prematuro/etiología , Nacimiento Prematuro/cirugía , Estudios Retrospectivos , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: Strategies for accelerated control of rubella and congenital rubella syndrome (CRS) in Chile included mass vaccination of women of childbearing age in 1999 but did not include vaccination of adult men. METHODS: We reviewed data from Chile's integrated surveillance system for measles, rubella, and CRS from 2004 through 2009 and describe the epidemiology of rubella outbreaks and implementation of control measures in 2005 and 2007 following mass vaccination of women. Population estimates from census data were used to calculate rubella incidence rates. The age distribution of rubella cases during 2007 was compared with rubella vaccination opportunities by birth cohort to orient mass vaccination of adult men. RESULTS: In 2005, an institutional outbreak of rubella occurred among male naval recruits 18-22 years of age, with 46 confirmed cases over a 5-month period. Beginning in March 2007, rubella outbreaks among young adults in the capital of Santiago spread throughout Chile, resulting in >4000 confirmed rubella cases. Delayed control measures and rapid dissemination among young adults led to widespread transmission. From 2007 through 2009, rubella incidence was highest among adult men not included in previous vaccination strategies. Mass vaccination of men 19-29 years of age was conducted in November 2007 to interrupt rubella transmission. CONCLUSIONS: Chile's experience suggests that vaccination strategies for rubella and CRS elimination need to include both men and women.