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1.
Int J Phytoremediation ; 20(13): 1354-1361, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30666892

RESUMEN

The remediation of contaminated dredged sediments is necessary to eliminate the risk towards human beings or the environment when there is disposal on land. A greenhouse experiment was carried out to evaluate the chemically assisted phytoextraction to clean up dredged sediment contaminated with Cr, Cu, Pb, and Zn. The ability of castor bean and chicory to absorb, translocate, and accumulate metals from sediment to root and shoot was evaluated by applying EDTA (5 mM), NTA (5 mM), and citric acid (60 mM) to sediment, before the harvest. Citric acid 60 mM was the most effective treatment in increasing Cr, Cu, and Pb in castor bean and chicory shoot. Chicory could accumulate 1730 mg Cr kg-1 in shoot, and had greater values than one for the bioaccumulation and translocation factors when citric acid was added to the sediment. But, the Cr percentages removed per harvest of chicory were 0.05% and were lower for Cu, Pb, and Zn due to low biomass obtained. Citric acid-assisted phytoextraction with chicory can be a promising short time solution to reduce Cr concentration in sediment and reach the Cr level guide for industrial land use only if suitable agronomic practices could be implemented to increase crop yield.


Asunto(s)
Cichorium intybus , Metales Pesados/análisis , Ricinus communis , Contaminantes del Suelo/análisis , Biodegradación Ambiental , Ácido Cítrico , Ácido Edético , Humanos , Ricinus
2.
Ecotoxicol Environ Saf ; 116: 29-33, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25748519

RESUMEN

New Microtox® toxicity data of 16 ionic liquids of different cationic and anionic composition were determined. The ionic liquids 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, [BMPyr(+)][TFO(-)], 1-butyl-1-methylpyrrolidinium chloride, [BMPyr(+)][Cl(-)], hydroxypropylmethylimidazolium fluoroacetate, [HOPMIM(+)][FCH2COO(-)], and hydroxypropylmethylimidazolium glycolate [HOPMIM(+)][glycolate(-)] were found to be less toxic than conventional organic solvent such as chloroform or toluene, accoding the Microtox® toxicity assays. The toxicity of pyrrolidinium cation was lower than the imidazolium and pyridinium ones. It was found that the inclusion of an hydroxyl group in the alkyl chain length of the cation also reduce the toxicity of the ionic liquid. To sum up, the Microtox® toxicity assays can be used as screening tool to easily determined the toxicity of a wide range of ionic liquids and the toxicity data obtained could allow the obtention of structure-toxicity relationships to design less toxic ionic liquids.


Asunto(s)
Líquidos Iónicos/toxicidad , Pruebas de Toxicidad , Aniones , Cationes , Líquidos Iónicos/química
3.
Rev Med Chil ; 143(9): 1215-8, 2015 Sep.
Artículo en Español | MEDLINE | ID: mdl-26530207

RESUMEN

Ketosis prone type 2 diabetes (KPD) is presently a well-defined clinical entity, characterized by a debut with severe hyperglycemia and ketoacidosis similar to the presenting form of Type 1 diabetes mellitus (DM1). However, it appears in subjects with Type 2 diabetes mellitus (DM2) phenotype. This situation is caused by an acute, reversible dysfunction of the beta cell in individuals with insulin resistance. Once the acute stage subsides, patients behave as having a DM2 and do not require insulin treatment. They should be kept on a diet and oral hypoglycemic drugs due to their susceptibility to have recurrent acute ketotic decompensations.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Cetoacidosis Diabética/tratamiento farmacológico , Insulina Isófana/uso terapéutico , Insulina de Acción Corta/uso terapéutico , Glucemia/análisis , Humanos , Insulina Isófana/administración & dosificación , Insulina de Acción Corta/administración & dosificación , Masculino , Persona de Mediana Edad
4.
Microb Ecol ; 66(2): 335-50, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23609130

RESUMEN

Global warming is causing ice retreat in glaciers worldwide, most visibly over the last few decades in some areas of the planet. One of the most affected areas is the region of Tierra del Fuego (southern South America). Vascular plant recolonisation of recently deglaciated areas in this region is initiated by Gunnera magellanica, which forms symbiotic associations with the cyanobacterial genus Nostoc, a trait that likely confers advantages in this colonisation process. This symbiotic association in the genus Gunnera is notable as it represents the only known symbiotic relationship between angiosperms and cyanobacteria. The aim of this work was to study the genetic diversity of the Nostoc symbionts in Gunnera at three different, nested scale levels: specimen, population and region. Three different genomic regions were examined in the study: a fragment of the small subunit ribosomal RNA gene (16S), the RuBisCO large subunit gene coupled with its promoter sequence and a chaperon-like protein (rbcLX) and the ribosomal internal transcribed spacer (ITS) region. The identity of Nostoc as the symbiont was confirmed in all the infected rhizome tissue analysed. Strains isolated in the present study were closely related to strains known to form symbioses with other organisms, such as lichen-forming fungi or bryophytes. We found 12 unique haplotypes in the 16S rRNA (small subunit) region analysis, 19 unique haplotypes in the ITS region analysis and 57 in the RuBisCO proteins region (rbcLX). No genetic variability was found among Nostoc symbionts within a single host plant while Nostoc populations among different host plants within a given sampling site revealed major differences. Noteworthy, interpopulation variation was also shown between recently deglaciated soils and more ancient ones, between eastern and western sites and between northern and southern slopes of Cordillera Darwin. The cell structure of the symbiotic relationship was observed with low-temperature scanning electron microscopy, showing changes in morphology of both cyanobiont cells (differentiate more heterocysts) and plant cells (increased size). Developmental stages of the symbiosis, including cell walls and membranes and EPS matrix states, were also observed.


Asunto(s)
Biodiversidad , Magnoliopsida/microbiología , Nostoc/aislamiento & purificación , Simbiosis , Chile , Magnoliopsida/fisiología , Datos de Secuencia Molecular , Nostoc/clasificación , Nostoc/genética , Nostoc/fisiología , Filogenia
5.
J Biotechnol ; 360: 192-197, 2022 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-36343756

RESUMEN

Ionic liquids (ILs) are widely applied in many bioprocesses involving microorganisms due to their unique properties. In this work, the toxicity of imidazolium and pyrrolidinium ionic liquids towards E. coli., a bacterium for which there are limited toxicity data in the literature, was determined. For its simplicity, the nephelometry method was used to estimate ionic liquid toxicity values. The influence of the cation and the alkyl chain length of the cation and anion was analysed. Pyrrolidinium cations were seen to be less toxic than imidazolium cations, while an increase in the alkyl chain length of both pyrrolidinium and imidazolium cations increased the toxicity. Among the anions studied, dimethylphosphate ([Me2PO4]) was the less toxic, while the EC50 for the ionic liquid 1-butyl-3-methylpyrrolidinium dimethylphosphate ([C1C4Pyr][Me2PO4]) was close to 200 mM. Furthermore, a dicationic ionic liquid based on imidazolium and pyrrolidinium cations was synthetized and its toxicity toward E. coli was analysed, maintaining a growth rate of 100 % in the range 0-0.76 mM. The methodology used in this work allows to easily find the less toxic ionic liquids that are biocompatible with E. coli to be used in new bioprocesses.


Asunto(s)
Líquidos Iónicos , Líquidos Iónicos/toxicidad , Escherichia coli , Cationes
6.
Sci Total Environ ; 770: 144557, 2021 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-33508664

RESUMEN

Soils can influence climate by sequestering or emitting greenhouse gases (GHG) such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). We are far from understanding the direct influence of cryptogamic covers on soil GHG fluxes, particularly in areas free of potential anthropogenic confounding factors. We assessed the role of well-developed cryptogamic covers in soil attributes, as well as in the in-situ exchange of GHG between Antarctic soils and the atmosphere during the austral summer. We found lower values of soil organic matter, total organic carbon, and total nitrogen in bare areas than in soils covered by mosses and, particularly, lichens. These differences, together with concomitant decreases and increases in soil temperature and moisture, respectively, resulted in increases in in-situ CO2 emission (i.e. ecosystem respiration) and decreases in CH4 uptake but no significant changes in N2O fluxes. We found consistent linear positive and negative relationships between soil attributes (i.e. soil organic matter, total organic carbon and total nitrogen) and CO2 emissions and CH4 uptake, respectively, and polynomial relationships between these soil attributes and net N2O fluxes. Our results indicate that any increase in the area occupied by cryptogams in terrestrial Antarctic ecosystems (due to increased growing season and increasingly warming conditions) will likely result in parallel increases in soil fertility as well as in an enhanced capacity to emit CO2 and a decreased capacity to uptake CH4. Such changes, unless offset by parallel C uptake processes, would represent a paradigmatic example of a positive climate change feedback. Further, we show that the fate of these terrestrial ecosystems under future climate scenarios, as well as their capacity to exchange GHG with the atmosphere might depend on the relative ability of different aboveground cryptogams to thrive under the new conditions.


Asunto(s)
Gases de Efecto Invernadero , Regiones Antárticas , Dióxido de Carbono/análisis , Ecosistema , Gases de Efecto Invernadero/análisis , Metano/análisis , Óxido Nitroso/análisis , Suelo
7.
Environ Technol ; 40(18): 2425-2435, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29455622

RESUMEN

Microbial fuel cells (MFCs) are a promising technology that generates electricity from several biodegradable substrates and wastes. The main drawback of these devices is the need of using a catalyst for the oxygen reduction reaction at the cathode, which makes the process relatively expensive. In this work, two low cost materials are tested as catalysts in MFCs. A novel iron complex based on the ligand n-phenyledenparaethoxy aniline has been synthesized and its performance as catalyst in single chamber MFCs containing ionic liquids has been compared with a commercial inorganic material such as Raney nickel. The results show that both materials are suitable for bioenergy production and wastewater treatment in the systems. Raney nickel cathodes allow MFCs to reach a maximum power output of 160 mW.m-3 anode, while the iron complex offers lower values. Regarding the wastewater treatment capacity, MFCs working with Raney nickel-based cathodes reach higher values of chemical oxygen demand removal (76%) compared with the performance displayed by the cathodes based on Fe-complex (56%).


Asunto(s)
Fuentes de Energía Bioeléctrica , Catálisis , Electricidad , Electrodos , Aguas Residuales
8.
Sci Total Environ ; 634: 116-126, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29627534

RESUMEN

The present study analysed potential adverse effects of discontinuous sources of contamination, namely the discharge of a combined sewer overflow (CSO) and of runoff in an urban area, the Bay of Santander (North Iberian Peninsula). Water samples and caged mussels were used to analyse concentrations of contaminants and biological responses. Mussels (Mytilus galloprovincialis) were transplanted to a marina receiving runoff from a petrol station and to a CSO discharge site. Samples were collected in synchrony with heavy rains along 62days. Lysosomal membrane stability (LMS) and acyl-CoA oxidase (AOX) activity were measured as core biomarkers and were analysed at all sampling times. Histopathology of digestive gland and gonads, transcription levels of vitellogenin gene, volume density of black silver deposits and micronuclei formation were measured at initial and final stages of the transplant. Chemical analyses of metals, polycyclic aromatic hydrocarbons (PAHs) and endocrine disruptors were performed in water samples and mussel flesh. Mussels accumulated low concentrations of contaminants, which is in accordance with results obtained from exposure biomarkers. AOX activity decreased in all transplanted mussels after the first heavy rain, but this change seems to be related to the seasonal pattern of the enzyme activity. Mussels located close to the CSO discharge site showed a reduction in LMS after the first rain event, when compared to mussels before the transplant and to mussels from the reference location. However, this was attributable to natural environmental changes rather than to pollution. Values of the rest of analysed biomarkers were below threshold values reported for the study area.


Asunto(s)
Monitoreo del Ambiente/métodos , Mytilus/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Biomarcadores/metabolismo , Disruptores Endocrinos/metabolismo , Hidrocarburos Policíclicos Aromáticos/metabolismo , Vitelogeninas/metabolismo
10.
J Hazard Mater ; 321: 484-499, 2017 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-27669390

RESUMEN

Volatile organic compounds (VOCs) comprise a wide variety of carbon-based materials which are volatile at relatively low temperatures. Most of VOCs pose a hazard to both human health and the environment. For this reason, in the last years, big efforts have been made to develop efficient techniques for the recovery of VOCs produced from industry. The use of ionic liquids (ILs) is among the most promising separation technologies in this field. This article offers a critical overview on the use of ionic liquids for the separation of VOCs both in bulk and in immobilized form. It covers the most relevant works within this field and provides a global outlook on the limitations and future prospects of this technology. The extraction processes of VOCs by using different IL-based assemblies are described in detail and compared with conventional methods This review also underlines the advantages and limitations posed by ionic liquids according to the nature of the cation and the anions present in their structure and the stability of the membrane configurations in which ILs are used as liquid phase.

11.
Actas urol. esp ; 46(4): 238-244, mayo 2022. graf, tab
Artículo en Español | IBECS (España) | ID: ibc-203612

RESUMEN

Introducción y objetivo: La oligorrecurrencia metacrónica en el cáncer de próstata (CaP) la constituyen los pacientes que empezaron con enfermedad localizada y que, tras un tratamiento radical fallido, desarrollan oligometástasis. La radioterapia estereotáctica (SBRT) dirigida a las metástasis busca retrasar el inicio de la privación androgénica. En este estudio, mostramos nuestra experiencia para elucidar el papel de la SBRT en una población seleccionada de pacientes con oligorrecurrencia metacrónica.Material y métodos: Análisis retrospectivo de pacientes tratados con SBRT por CaP oligorrecurrente entre noviembre de 2015 y diciembre de 2020. Detallamos las características clinicopatológicas al inicio de la enfermedad (edad, PSA, estadificación, tratamiento primario), escenario clínico al diagnóstico de la oligorrecurrencia (PSA, velocidad del PSA, características de las metástasis), supervivencia libre de progresión, supervivencia hasta la resistencia a la castración, dosis y toxicidad de la SBRT. Solo 2pacientes presentaron toxicidad de grado 1.Conclusiones: La SBRT en pacientes con CaP en situación de oligorrecurrencia metacrónica constituye un tratamiento seguro y efectivo que permite retrasar el inicio de la terapia de radiación androgénica y el tiempo hasta la resistencia a la castración, con niveles bajos de toxicidad. (AU)


Introduction and objective: Metachronous oligorecurrence in prostate cancer (PCa) occurs in patients with localized disease who, after failed radical treatment, develop oligometastases. Metastasis-directed stereotactic radiotherapy (SBRT) aims to delay androgen deprivation therapy. In this study, we report our experience to elucidate the role of SBRT in a selected population of patients with metachronous oligorecurrence.Material and methods: Retrospective analysis of patients treated with SBRT for oligorecurrent PCa between November 2015 and December 2020. We detailed clinicopathological characteristics at disease onset (age, PSA, stage, primary treatment), clinical scenario at diagnosis of oligorecurrence (PSA, PSA velocity, metastases characteristics), progression-free survival, castration resistance-free survival, dose, and toxicity of SBRT.Results: Thirty-eight SBRT treatments were applied to 13 lymph node and 25 bone metastases in a total of 28 patients. After a follow-up of 34.57 months (21.17-57.59), 17 patients had radiological progression of the disease and 11 presented castration resistant PCa. PFS and CRFS were 21.93 and 44.13 months, respectively. Only 2patients presented grade 1 toxicity.ConclusionsIn patients with metachronous oligorecurrent PCa, SBRT constitutes a safe and effective treatment that allows delaying the onset of androgen deprivation therapy and the time to castration resistance, assuming low levels of toxicity. (AU)


Asunto(s)
Humanos , Masculino , Persona de Mediana Edad , Anciano , Neoplasias de la Próstata/radioterapia , Radiocirugia , Estudios Retrospectivos , Recurrencia Local de Neoplasia/radioterapia , Antagonistas de Andrógenos/uso terapéutico
12.
Mar Environ Res ; 121: 49-63, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27017466

RESUMEN

Data obtained in a pollution survey performed in estuarine areas were integrated using multivariate statistics. The sites selected for the study were areas affected by treated and untreated urban discharges, harbours or industrial activities as well as reference sites. Mussels were transplanted to each site and after different times of exposure, samples of water, sediments and mussels were collected. Biomarkers were analysed on mussels after 3 and 21 days of transplant whereas concentrations of contaminants were measured in water, sediments and mussels after 21 days of transplant. The structure of macroinvertebrate benthic communities was studied in sediment samples. Studied variables were organised into 5 datasets, each one constituting a line of evidence (LOE): contaminants in water, contaminants in sediments, contaminants accumulated by transplanted mussels, biomarkers in transplanted mussels and changes in the structure of macroinvertebrate benthic communities of each sampling site. Principal Component Analysis (PCA) identified the variables of each LOE best explaining variability among sites. In order to know how LOEs relate to each other, Pearson's correlations were performed. Contaminants in sediments were not correlated with the rest of LOEs. Contaminants in water were significantly correlated with contaminants and biomarkers in mussels and with structure of macroinvertebrate benthic communities. Similarly, significant correlations were found between contaminants and biomarkers in mussels and between biomarkers in mussels and structure of macroinvertebrate benthic communities. In conclusion, biomarker responses give relevant information on pollution in estuarine areas and provide a link between chemical and ecological statuses of water bodies in the context of the Water Framework Directive.


Asunto(s)
Bivalvos/fisiología , Ecosistema , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Animales , Estuarios , Sedimentos Geológicos/química , Hidrocarburos Policíclicos Aromáticos
13.
Bioresour Technol ; 209: 380-5, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26995319

RESUMEN

In this work, the by-product generated during the operation of cylindrical MFCs, made out of terracotta material, is investigated as a feasible means of degrading live microalgae for the first time. In addition to the low cost materials of this design, the reuse of the solution produced in the cathode renders the technology truly green and capable of generating bioenergy. In this study, the effect of a light/dark cycle or dark conditions only on the digestion of live microalgae with the catholyte is investigated. The results show that a combination of light/dark improves degradation and allows algae to be used as substrate in the anode. The addition of 12.5mL of a 1:1 mix of catholyte and microalgae (pre-digested over 5days under light/dark) to the anode, increases the power generation from 7µW to 44µW once all the organic matter in the anode had been depleted.


Asunto(s)
Fuentes de Energía Bioeléctrica , Conservación de los Recursos Energéticos/métodos , Microalgas , Electrodos , Luz
14.
Mar Pollut Bull ; 103(1-2): 301-312, 2016 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-26707886

RESUMEN

To evaluate the effects of diffuse contamination, biological measurements were applied in a scrap cargo harbour, a marina and an industrial area. Metal accumulation and biomarkers (survival in air, digestive gland and gonad histopathology, lysosomal membrane stability, intralysosomal metal accumulation, transcription of vitellogenin and MT20, peroxisome proliferation and micronuclei formation) were measured in transplanted mussels, together with metrics of benthic invertebrates. Benthic species were classified into ecological groups and univariate indexes were calculated. The marina showed high richness (16) and percentage of opportunistic species (55.1%) and low metal accumulation. Mussels in the scrap cargo harbour showed high metal accumulation, up-regulation of MT20 transcription, reduced health status (LP<6 min) and increased micronuclei frequencies (up to 11.3‰). At the industrial area, low species richness (4) and badly organised assemblages were detected and chemical analyses indicated significant amounts of bioavailable metals. Overall, selected biological measurements showed potential for the assessment of diffuse contamination.


Asunto(s)
Monitoreo del Ambiente/métodos , Estuarios , Industrias , Metales Pesados/análisis , Mytilus/efectos de los fármacos , Contaminantes Químicos del Agua/análisis , Animales , Biomarcadores/análisis , Gónadas/efectos de los fármacos , Gónadas/metabolismo , Metales Pesados/toxicidad , Mytilus/química , Mytilus/genética , España , Regulación hacia Arriba , Vitelogeninas/genética , Contaminantes Químicos del Agua/toxicidad
15.
Biochim Biophys Acta ; 603(1): 207-10, 1980 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-7448186

RESUMEN

3-O-Methylglucose accumulation by Necturus intestine was studied in the presence and absence of cytochalasin B. The effect of this agent on 3-O-methylglucose-induced changes in transepithelial potential difference was also investigated. Cytochalasin B (50 microM) blocked the rise in potential difference induced by 4 mM 3-O-methyglucose. 3-O-Methyglucose accumulation by Necturus intestine was measured; it was inhibited by cytochalasin B at concentrations of 50 and 100 microM. These results indicate that, in Necturus intestine, sodium-dependent sugar transport across the apical cell membrane is blocked by cytochalasin B.


Asunto(s)
Citocalasina B/farmacología , Intestino Delgado/efectos de los fármacos , Metilglucósidos/metabolismo , Metilglicósidos/metabolismo , Animales , Pollos , Intestino Delgado/metabolismo , Necturus
16.
J Endocrinol ; 86(1): 35-43, 1980 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7430888

RESUMEN

In segments of isolated proximal colon from bilaterally adrenalectomized and nephrectomized rats 10(-12) g angiotensin/ml added to the serosal medium stimulated fluid transfer and sodium transport whose increase was accompanied by a decrease in transepithelial potential difference and short circuit current. Transepithelial electrical resistance remained unchanged. Replacement of chloride by sulphate in the bathing medium blocked the response to angiotensin. This suggested that angiotensin stimulated a coupled NaCl transport. Administration of aldosterone also blocked the response to angiotensin, suggesting that a low concentration of endogenous aldosterone is partly responsible for the action of angiotensin. This would explain the necessity for some form of pretreatment such as bilateral adrenalectomy and nephrectomy. Hydraulic conductivity of proximal colon sacs was computed from the variation in the water flow from serosa to mucosa in response to an osmotic shock. A significant (P < 0.01) increase in the hydraulic conductivity of the proximal colon of bilaterally adrenalectomized and nephrectomized rats was found when 10(-12) g angiotensin/ml was present in the serosal bathing medium. The observed decrease in the transepithelial potential difference has been related to an action of angiotensin on the paracellular shunt pathway.


Asunto(s)
Angiotensina II/farmacología , Colon/metabolismo , Sodio/metabolismo , Agua/metabolismo , Adrenalectomía , Aldosterona/farmacología , Animales , Transporte Biológico/efectos de los fármacos , Cloruros/metabolismo , Colon/efectos de los fármacos , Conductividad Eléctrica , Técnicas In Vitro , Masculino , Nefrectomía , Concentración Osmolar , Ratas , Estimulación Química
17.
Phys Med Biol ; 45(1): 241-52, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10661595

RESUMEN

The aim of this research work has been the estimation of the stochastic risk for five barium examinations. The sample was the population attending the Radiological Service of the 'Nuestra Señora de la Victoria' University Hospital, who had been treated with some barium examinations, set in five different groups: oesophagus tract, oesophagus-gastric-duodenal tract, intestinal tract, enteroclysis and double enema. To estimate the stochastic risk, it is necessary to know the organ dose. This can be calculated from the dose-area product which allows us to determine the effective dose using software. The dose-area product is the most suitable quantity to measure in these types of examination. We have evaluated the contribution that each procedure provides to the genetically significant dose, somatically significant dose, collective effective dose, annual effective dose 'per capita' and detriment, which are useful for assessing the population risk of cancer or hereditary effects after x-ray exposure. The contribution to the genetically significant dose is 6.7 microGy, to the somatically significant dose 8.82 mSv-yr, 16.07 person-Sv for the collective effective dose, 0.03 mSv for the 'per capita' annual effective dose and the annual aggregated detriment is 0.33.


Asunto(s)
Bario , Sistema Digestivo/diagnóstico por imagen , Esófago/diagnóstico por imagen , Factores de Edad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía/estadística & datos numéricos , Factores de Riesgo , España , Procesos Estocásticos
18.
Oecologia ; 119(2): 166-174, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-28307965

RESUMEN

Acclimation to elevated CO2 was investigated in Parmelia caperata originating from the vicinity of a natural CO2 spring, where the average daytime CO2 concentration was 729 ± 39 µmol mol-1 dry air. Thalli showed no evidence of a down-regulation in photosynthetic capacity following long-term exposure to CO2 enrichment in the field; carboxylation efficiency, total Ribulose bisphosphate carboxylase/oxygenase (Rubisco) content, apparent quantum yield of CO2 assimilation, and the light-saturated rate of CO2 assimilation (measured under ambient and saturating CO2 concentrations) were similar in thalli from the naturally CO2 enriched site and an adjacent control site where the average long-term CO2 concentration was about 355 µmol mol-1. Thalli from both CO2 environments exhibited low CO2 compensation points and early saturation of CO2 uptake kinetics in response to increasing external CO2 concentrations, suggesting the presence of an active carbon-concentrating mechanism. Consistent with the lack of significant effects on photosynthetic metabolism, no changes were found in the nitrogen content of thalli following prolonged exposure to elevated CO2. Detailed intrathalline analysis revealed a decreased investment of nitrogen in Rubisco in the pyrenoid of algae located in the elongation zone of thalli originating from elevated CO2, an effect associated with a reduction in the percentage of the cell volume occupied by lipid bodies and starch grains. Although these differences did not affect the photosynthetic capacity of thalli, there was evidence of enhanced limitations to CO2 assimilation in lichens originating from the CO2-enriched site. The light-saturated rate of CO2 assimilation measured at the average growth CO2 concentration was found to be significantly lower in thalli originating from a CO2-enriched atmosphere compared with that of thalli originating and measured at ambient CO2. At lower photosynthetic photon flux densities, the light compensation point of net CO2 assimilation was significantly higher in thalli originating from elevated CO2, and this effect was associated with higher usnic acid content.

19.
Br J Radiol ; 73(871): 752-61, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11089468

RESUMEN

The objective of this work was to estimate patient doses (dose-area product, organ dose, effective dose and entrance surface dose) for barium procedures. A total of 175 procedures, in 175 patients, for five different examination categories was analysed. Dose-area product was determined using a transmission ionization chamber. Organ dose and effective dose were assessed using a knowledge of the examination and the software. For all patients, the contribution of fluoroscopy to the total dose was greater than that from radiography. Dose-area product from double contrast barium enema, enteroclysis and intestinal tract procedures was higher than that obtained for the other procedures. The average effective dose was 1.04 mSv and 13.99 mSv for oesophageal tract and enteroclysis examinations, respectively. Entrance surface dose in the oesophageal tract was 16 mGy, 10 times lower than for the other four procedures. Patient dose reduction in barium procedures may be achieved by improved training of resident radiologists, senior radiologists and other specialists in radiation protection.


Asunto(s)
Sulfato de Bario , Medios de Contraste , Sistema Digestivo/diagnóstico por imagen , Esófago/diagnóstico por imagen , Radiometría/métodos , Adulto , Fluoroscopía , Humanos , Persona de Mediana Edad , Dosis de Radiación , Protección Radiológica/normas , Valores de Referencia , España
20.
Eur J Radiol ; 33(1): 14-23, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10674785

RESUMEN

Nowadays, the radiological risk from simple X-ray procedures is well known. The purpose of this work has been to estimate the population risk from digital angiographic and interventional procedures and to compare it with the one from simple procedures in the same population. The population risk has been estimated according to the following quantities: genetically significant dose, somatic significant dose, collective effective dose, annual per caput effective dose and detriment. These have been estimated from dose area product and organ dose. Organ dose values were estimated with the Eff-Dose software. A population of 605410 people were included in the study. In 1996, 1312 patients were to digital interventional vascular procedures in Malaga, and 159 of them were selected in this research project to obtain the dose area product and organ dose. The results obtained for the quantities evaluated are: genetically significant dose, 4.1 microGy; somatic significant dose, 0.9 mSv; collective effective dose, 11.65 person-Sv: annual per caput effective dose, 0.02 mSv and detriment, 0.65 radiogenic cancers per year. These procedures supply a high radiation dose, so they should have a greater contribution to population dose and risk than simple examinations. However, our results indicate just the opposite.


Asunto(s)
Angiografía/efectos adversos , Intensificación de Imagen Radiográfica , Radiología Intervencionista , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Fluoroscopía/efectos adversos , Genes/efectos de la radiación , Gónadas/efectos de la radiación , Humanos , Esperanza de Vida , Masculino , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/etiología , Dosis de Radiación , Efectos de la Radiación , Traumatismos por Radiación/etiología , Radiografía Intervencional/efectos adversos , Factores de Riesgo
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