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1.
Neural Plast ; 2019: 3972918, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31015828

RESUMEN

The primary aim of this viewpoint article is to examine recent literature on fetal and neonatal processing of music. In particular, we examine the behavioral, neurophysiological, and neuroimaging literature describing fetal and neonatal music perception and processing to the first days of term equivalent life. Secondly, in light of the recent systematic reviews published on this topic, we discuss the impact of music interventions on the potential neuroplasticity pathways through which the early exposure to music, live or recorded, may impact the fetal, preterm, and full-term infant brain. We conclude with recommendations for music stimuli selection and its role within the framework of early socioemotional development and environmental enrichment.


Asunto(s)
Percepción Auditiva/fisiología , Encéfalo/crecimiento & desarrollo , Desarrollo Infantil , Música , Plasticidad Neuronal , Estimulación Acústica , Humanos , Recién Nacido , Recien Nacido Prematuro , Musicoterapia/métodos
2.
Arch Biochem Biophys ; 647: 93-103, 2018 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-29653079

RESUMEN

The adenine nucleotide translocase (ANT) of the mitochondrial inner membrane exchanges ADP for ATP. Mitochondria were isolated from human vastus lateralis muscle (n = 9). Carboxyatractyloside titration of O2 consumption rate (Jo) at clamped [ADP] of 21 µM gave ANT abundance of 0.97 ±â€¯0.14 nmol ANT/mg and a flux control coefficient of 82% ±â€¯6%. Flux control fell to 1% ±â€¯1% at saturating (2 mM) [ADP]. The KmADP for Jo was 32.4 ±â€¯1.8 µM. In terms of the free (-3) ADP anion this KmADP was 12.0 ±â€¯0.7 µM. A novel luciferase-based assay for ATP production gave KmADP of 13.1 ±â€¯1.9 µM in the absence of ATP competition. The free anion KmADP in this case was 2.0 ±â€¯0.3 µM. Targeted proteomic analyses showed significant acetylation of ANT Lysine23 and that ANT1 was the most abundant isoform. Acetylation of Lysine23 correlated positively with KmADP, r = 0.74, P = 0.022. The findings underscore the central role played by ANT in the control of oxidative phosphorylation, particularly at the energy phosphate levels associated with low ATP demand. As predicted by molecular dynamic modeling, ANT Lysine23 acetylation decreased the apparent affinity of ADP for ANT binding.


Asunto(s)
Translocador 1 del Nucleótido Adenina/metabolismo , Metabolismo Energético , Lisina/metabolismo , Mitocondrias Musculares/metabolismo , Acetilación , Adenosina Difosfato/metabolismo , Adenosina Trifosfato/metabolismo , Adulto , Femenino , Humanos , Masculino , Músculo Esquelético/metabolismo , Fosforilación Oxidativa , Consumo de Oxígeno
3.
J Nanosci Nanotechnol ; 15(12): 9766-71, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26682410

RESUMEN

Electro-optical switching can be achieved by changing the optical absorption of metal nanoparticles by adding or removing electrical charge, corresponding to increased, respectively, decreased electron density. In this work a different approach is taken by changing the photoluminescence properties as a function of electrical charge on gold nanoparticles. Whereas larger gold nanoparticles (diameter d = 5 and 10 nm), exhibiting a plasmon resonance peak in the absorption spectrum, were used to measure changes of the optical absorption spectrum upon electrical charging, for smaller gold nanoparticles (d = 2 and 5 nm) electrical charging was observed via changes of the photoluminescence. Increase and decrease in photoluminescence was observed at positive and negative applied potentials, respectively. The relation between changes of optical absorption and photoluminescence for the 5 nm particles by electrical charging provides information on the influence of the charge state on the electronic properties and therefore the optical transition probability. The reported observation that not only the optical absorption, but also the photoluminescence is affected by alteration of the electrical charge onto gold nanoparticles may open a new way towards electro-optical switching and bio-sensing.


Asunto(s)
Oro/química , Mediciones Luminiscentes , Nanopartículas del Metal/química , Electricidad
4.
Proc Natl Acad Sci U S A ; 107(45): 19549-54, 2010 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-20974959

RESUMEN

Light therapy can be an effective treatment for mood disorders, suggesting that light is able to affect mood state in the long term. As a first step to understand this effect, we hypothesized that light might also acutely influence emotion and tested whether short exposures to light modulate emotional brain responses. During functional magnetic resonance imaging, 17 healthy volunteers listened to emotional and neutral vocal stimuli while being exposed to alternating 40-s periods of blue or green ambient light. Blue (relative to green) light increased responses to emotional stimuli in the voice area of the temporal cortex and in the hippocampus. During emotional processing, the functional connectivity between the voice area, the amygdala, and the hypothalamus was selectively enhanced in the context of blue illumination, which shows that responses to emotional stimulation in the hypothalamus and amygdala are influenced by both the decoding of vocal information in the voice area and the spectral quality of ambient light. These results demonstrate the acute influence of light and its spectral quality on emotional brain processing and identify a unique network merging affective and ambient light information.


Asunto(s)
Encéfalo/fisiología , Emociones/efectos de la radiación , Luz , Fototerapia , Adulto , Amígdala del Cerebelo/fisiología , Emociones/fisiología , Femenino , Humanos , Hipotálamo/fisiología , Imagen por Resonancia Magnética , Masculino , Voz , Adulto Joven
5.
Sci Rep ; 13(1): 10900, 2023 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-37407601

RESUMEN

Humans are adept at extracting affective information from vocalizations of humans and other animals. However, the extent to which human recognition of vocal affective cues of other species is due to cross-taxa similarities in acoustic parameters or the phylogenetic closeness between species is currently unclear. To address this, we first analyzed acoustic variation in 96 affective vocalizations, taken from agonistic and affiliative contexts, of humans and three other primates-rhesus macaques (Macaca mulatta), chimpanzees and bonobos (Pan troglodytes and Pan paniscus). Acoustic analyses revealed that agonistic chimpanzee and bonobo vocalizations were similarly distant from agonistic human voices, but chimpanzee affiliative vocalizations were significantly closer to human affiliative vocalizations, than those of bonobos, indicating a potential derived vocal evolution in the bonobo lineage. Second, we asked 68 human participants to categorize and also discriminate vocalizations based on their presumed affective content. Results showed that participants reliably categorized human and chimpanzee vocalizations according to affective content, but not bonobo threat vocalizations nor any macaque vocalizations. Participants discriminated all species calls above chance level except for threat calls by bonobos and macaques. Our results highlight the importance of both phylogenetic and acoustic parameter level explanations in cross-species affective perception, drawing a more complex picture to the origin of vocal emotions.


Asunto(s)
Señales (Psicología) , Pan troglodytes , Animales , Humanos , Filogenia , Pan troglodytes/psicología , Macaca mulatta , Pan paniscus/psicología , Acústica
6.
Sci Rep ; 12(1): 17144, 2022 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-36229474

RESUMEN

Emotional prosody results from the dynamic variation of language's acoustic non-verbal aspects that allow people to convey and recognize emotions. The goal of this paper is to understand how this recognition develops from childhood to adolescence. We also aim to investigate how the ability to perceive multiple emotions in the voice matures over time. We tested 133 children and adolescents, aged between 6 and 17 years old, exposed to 4 kinds of linguistically meaningless emotional (anger, fear, happiness, and sadness) and neutral stimuli. Participants were asked to judge the type and intensity of perceived emotion on continuous scales, without a forced choice task. As predicted, a general linear mixed model analysis revealed a significant interaction effect between age and emotion. The ability to recognize emotions significantly increased with age for both emotional and neutral vocalizations. Girls recognized anger better than boys, who instead confused fear with neutral prosody more than girls. Across all ages, only marginally significant differences were found between anger, happiness, and neutral compared to sadness, which was more difficult to recognize. Finally, as age increased, participants were significantly more likely to attribute multiple emotions to emotional prosody, showing that the representation of emotional content becomes increasingly complex. The ability to identify basic emotions in prosody from linguistically meaningless stimuli develops from childhood to adolescence. Interestingly, this maturation was not only evidenced in the accuracy of emotion detection, but also in a complexification of emotion attribution in prosody.


Asunto(s)
Emociones , Voz , Adolescente , Ira , Niño , Femenino , Felicidad , Humanos , Masculino , Reconocimiento en Psicología
7.
Cereb Cortex Commun ; 2(2): tgab031, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34296176

RESUMEN

Integrating and predicting the intentions and actions of others are critical components of social interactions, but the behavioral and neural bases of such mechanisms under altered perceptual conditions are poorly understood. In the present study, we recruited expert violinists and age-matched controls with no musical training and asked them to evaluate simplified dynamic stimuli of violinists playing in a piano or forte communicative intent while undergoing functional magnetic resonance imaging. We show that expertise is needed to successfully understand and evaluate communicative intentions in spatially and temporally altered visual representations of musical performance. Frontoparietal regions-such as the dorsolateral prefrontal cortex and the inferior parietal lobule and sulcus-and various subregions of the cerebellum-such as cerebellar lobules I-IV, V, VI, VIIb, VIIIa, X-a re recruited in the process. Functional connectivity between these brain areas reveals widespread organization, particularly in the dorsolateral prefrontal cortex, inferior frontal gyrus, inferior parietal sulcus, and in the cerebellum. This network may be essential to successfully assess communicative intent in ambiguous or complex visual scenes.

8.
Nanoscale ; 12(37): 19213-19222, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32926047

RESUMEN

The decoration of semiconductor nanostructures with small metallic clusters usually leads to an improvement of their properties in sensing or catalysis. Bimetallic cluster decoration typically is claimed to be even more effective. Here, we report a detailed investigation of the effects of Au, Pt or AuPt nanocluster decoration of ZnO nanorods on charge transport, photoluminescence and UV sensitivity. ZnO nanorods were synthesized by chemical bath deposition while decoration with small nanoclusters (2-3 nm in size) was achieved by a laser-ablation based cluster beam deposition technology. The structural properties were investigated by scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy and Rutherford backscattering spectrometry, and the optoelectronic properties by current-voltage and photoluminescence measurements. The extent of band bending at the cluster-ZnO interface was quantitatively modeled through numerical simulations. The decoration of ZnO nanorods with monometallic Au or Pt nanoclusters causes a significant depletion of free electrons below the surface, leading to a reduction of UV photoluminescence, an increase of ZnO nanorod dark resistance (up to 200 times) and, as a consequence, an improved sensitivity (up to 6 times) to UV light. These effects are strongly enhanced (up to 450 and 10 times, respectively) when ZnO nanorods are decorated with bimetallic AuPt nanoclusters that substantially augment the depletion of free carriers likely due to a more efficient absorption of the gas molecules on the surface of the bimetallic AuPt nanoclusters than on that of their monometallic counterparts. The depletion of free carriers in cluster decorated ZnO nanorods is quantitatively investigated and modelled, allowing the application of these composite materials in UV sensing and light induced catalysis.

9.
Psychol Med ; 39(6): 927-38, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19000339

RESUMEN

BACKGROUND: Identification of emotional facial expression and emotional prosody (i.e. speech melody) is often impaired in schizophrenia. For facial emotion identification, a recent study suggested that the relative deficit in schizophrenia is enhanced when the presented emotion is easier to recognize. It is unclear whether this effect is specific to face processing or part of a more general emotion recognition deficit. METHOD: We used clarity-graded emotional prosodic stimuli without semantic content, and tested 25 in-patients with paranoid schizophrenia, 25 healthy control participants and 25 depressive in-patients on emotional prosody identification. Facial expression identification was used as a control task. RESULTS: Patients with paranoid schizophrenia performed worse than both control groups in identifying emotional prosody, with no specific deficit in any individual emotion category. This deficit was present in high-clarity but not in low-clarity stimuli. Performance in facial control tasks was also impaired, with identification of emotional facial expression being a better predictor of emotional prosody identification than illness-related factors. Of those, negative symptoms emerged as the best predictor for emotional prosody identification. CONCLUSIONS: This study suggests a general deficit in identifying high-clarity emotional cues. This finding is in line with the hypothesis that schizophrenia is characterized by high noise in internal representations and by increased fluctuations in cerebral networks.


Asunto(s)
Emociones , Expresión Facial , Psicología del Esquizofrénico , Adulto , Análisis de Varianza , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reconocimiento Visual de Modelos , Escalas de Valoración Psiquiátrica , Esquizofrenia Paranoide/diagnóstico , Esquizofrenia Paranoide/psicología , Percepción del Habla , Suiza , Interfaz Usuario-Computador , Adulto Joven
10.
Science ; 261(5120): 447-9, 1993 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-17770023

RESUMEN

A compound has been synthesized with the formula (rad)(2)Mn(2)[Cu(opba)](3)(DMSO)(2).2H(2)O, where rad(+) is 2-(4-N-methylpyridinium)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, opba is orthophenylenebis(oxamato), and DMSO is dimethyl sulfoxide. It consists of two nearly perpendicular graphite-like networks with edge-sharing Mn(II)(6)Cu(II)(6) hexagons. The two networks are fully interlocked with the same topological relationship as that between adjacent rings of a necklace. The compound has three kinds of spin carriers: Mn(II) and Cu(II) ions, antiferromagnetically coupled through oxamato bridges, and rad(+) radical cations, bridging the Cu(II) ions through the nitronyl nitroxide groups and forming Cu-rad chains. The temperature dependence of the magnetization reveals that below 22.5 K, the compound behaves as a magnet.

11.
Neuropsychologia ; 117: 278-286, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29936120

RESUMEN

Subthalamic deep brain stimulation (STN DBS) is an effective treatment for reducing the motor symptoms of patients with Parkinson's disease (PD), but several side effects have been reported, concerning the processing of emotions. Music has been shown to evoke powerful emotional experiences - not only basic emotions, but also complex, so-called aesthetic experiences. The goal of the present study was therefore to investigate how STN DBS influences the experience of both basic and more complex musical emotions in patients with PD. In a three-group between-participants design, we compared healthy controls (HC), patients receiving STN DBS (PD-DBS), and patients who were candidates for STN DBS and receiving medication only (PD-MO) on their assessments of subjectively experienced musical emotions. Results showed that in general, the experience of musical emotions differed only marginally between the PD-MO, PD-DBS, and HC groups. Nonetheless, we were able to discern subtle but distinct effects of PD and STN DBS in the emotional responses. Happy music, for instance, seemed to induce a heightened experience of negative emotions (tension) in PD-MO patients. STN DBS appeared to normalize this particular effect, but increased nostalgic feelings - a rather complex affective experience - in response to the same emotional stimuli. This should not be taken as indicating a bias for nostalgia in the PD-DBS subgroup, as these patients found music inducing melancholy to be less nostalgic and more joyful than HC did. In conclusion, our study showed that music elicits slightly altered emotional experiences in patients with and without STN DBS. In particular, STN DBS seems to induce less distinct emotional responses, blurring the boundaries between complex musical emotions.


Asunto(s)
Estimulación Encefálica Profunda/métodos , Emociones/fisiología , Música , Enfermedad de Parkinson , Núcleo Subtalámico/fisiología , Estimulación Acústica , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Actividad Motora/fisiología , Pruebas Neuropsicológicas , Enfermedad de Parkinson/fisiopatología , Enfermedad de Parkinson/psicología , Enfermedad de Parkinson/terapia , Escalas de Valoración Psiquiátrica , Estadísticas no Paramétricas , Resultado del Tratamiento
12.
Neuropsychologia ; 96: 96-110, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28069444

RESUMEN

One especially important feature of metrical music is that it contains periodicities that listeners' bodily rhythms can adapt to. Recent psychological frameworks have introduced the notion of rhythmic entrainment, among other mechanisms, as an emotion induction principle. In this review paper, we discuss rhythmic entrainment as an affect induction mechanism by differentiating four levels of entrainment in humans-perceptual, autonomic physiological, motor, and social-all of which could contribute to a subjective feeling component. We review the theoretical and empirical literature on rhythmic entrainment to music that supports the existence of these different levels of entrainment by describing the phenomena and characterizing the associated underlying brain processes. The goal of this review is to present the theoretical implications and empirical findings about rhythmic entrainment as an important principle at the basis of affect induction via music, since it rests upon the temporal dimension of music, which is a specificity of music as an affective stimulus.


Asunto(s)
Percepción Auditiva/fisiología , Emociones , Música , Periodicidad , Encéfalo/fisiología , Humanos
13.
Water Res ; 40(14): 2603-12, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16797670

RESUMEN

The fate of polycyclic musks (PCMs) (HHCB, AHTN, ADBI, AHDI, ATII, DPMI), UV filters (3-(4-methylbenzylidene) camphor, 4-MBC; octyl-methoxycinnamate, OMC; octocrylene, OC; octyl-triazone, OT) and biocides (permethrin, carbendazim) during wastewater treatment was studied on a full-scale plant. Average influent concentrations of OMC, HHCB, OC, AHTN, 4-MBC and OT were at 20070, 4420, 1680, 1430, 960 and 720 ng L(-1), respectively. The other PCMs, permethrin and carbendazim ranged between < limits of quantification and 670 ng L(-1). Concentrations in the water line decreased significantly for most compounds. Removal rates for PCMs ranged from 72% to 86%, for UV filters from 92% to >99% and were at 92% and 37% for permethrin and carbendazim, respectively. Removal during wastewater treatment was mainly driven by sorption onto solids and biodegradation. For anaerobic sludge digestion, elimination of PCMs, OMC and the biocides was observed.


Asunto(s)
Desinfectantes/aislamiento & purificación , Compuestos Policíclicos/aislamiento & purificación , Rayos Ultravioleta , Eliminación de Residuos Líquidos/métodos , Biodegradación Ambiental , Aguas del Alcantarillado/química , Agua/química
14.
Vet Comp Orthop Traumatol ; 19(2): 81-6, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16810349

RESUMEN

We studied the time necessary to obtain reliable kinetic data from healthy dogs trotting on a treadmill. Ten adult male Malinois Belgian Shepherd dogs were made to trot on an instrumented treadmill to record the ground reaction force for the entire body and to determine the vertical force variables (peak [PFz], impulse [IFz], stride time [Str], peak time [Tz] and contact time [Ct]). Data were collected from each dog, during three sequences per day, on three consecutive days. In order to determine the contribution of the sequence, day of measurement, and dog factors and the percentage of variance attributable to dogs, data were analyzed with a linear mixed model. The curve shapes were similar to those obtained with a floor-mounted force platform. Intra-dog coefficients of variation were between 1.57 and 3.46%. Inter-dog coefficients of variation were between 4.18 and 7.82%. A sequence effect was not noted. Each day had a significant effect on all of the data. All variables differed significantly from the first day compared to the other days. However there was not any difference between days 2 and 3. The percentage of the total variance attributable to dogs ranged from 37 to 88%. The coefficients of variation were lower than those obtained with common protocols. The treadmill locomotion remained consistent during a single session. Even if interday variation needs to be accounted for, reliable data can still be obtained after a single training session. The majority of the variation was attributable to the dog. An instrumented treadmill may be used for kinetic analysis.


Asunto(s)
Perros/fisiología , Prueba de Esfuerzo/veterinaria , Condicionamiento Físico Animal/fisiología , Carrera , Aceleración , Análisis de Varianza , Animales , Prueba de Esfuerzo/métodos , Marcha/fisiología , Hábitos , Cinética , Modelos Lineales , Masculino , Factores de Tiempo , Grabación en Video , Soporte de Peso
15.
J Phys Condens Matter ; 28(3): 035303, 2016 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-26732742

RESUMEN

Controlling the plasmon resonance frequency of metal nanostructures holds promise for both fundamental and applied research in optics. The plasmon resonance frequency depends on the number of free electrons in the metal. By adding or removing electrons to a metal nano-object, the plasmon resonance frequency shifts. In this study we indirectly change the number of free electrons in gold nanoparticles by applying an electrical potential difference over a heterostructure consisting of a ZnO layer with embedded gold nanoparticles. The potential difference induces shifts of defect energy levels in the ZnO by the electric field. This results in an exchange of electrons between particles and matrix which in turn modifies the gold nanoparticle plasmon properties. The positive charge shifts the ZnO optical absorption peak from 377 nm to 386 nm and shifts the nanoparticle plasmon from 549 nm to 542 nm. This electro-optical effect is a promising way to obtain fast optical switching in a solid state composition.

16.
J Vet Intern Med ; 30(4): 1056-64, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27279352

RESUMEN

BACKGROUND: Fecal calprotectin and immunoglobulin A (IgA) are markers of intestinal inflammation and immunity in adult dogs. HYPOTHESIS: Fecal calprotectin and IgA concentrations in puppies are not influenced by fecal moisture in puppies but by enteropathogen shedding. ANIMALS: Three hundred and twenty-four puppies. METHODS: Fecal consistency was assessed by gross examination. Fecal moisture was evaluated before and after lyophilization. Canine parvovirus and coronavirus were detected in feces by qPCR and qRT-PCR respectively. Giardia intestinalis antigen was quantified by ELISA. The standard McMaster flotation technique was used to detect eggs and oocysts in feces. Fecal calprotectin and IgA concentrations were quantified by in-house radioimmunoassays. RESULTS: For each marker (IgA and calprotectin), a strong positive correlation was observed between concentration in fresh feces and concentration in fecal dry matter. 75.6% of the puppies were found to be infected by at ≥1 of the enteropathogens evaluated. Fecal calprotectin concentration was significantly influenced by age (P = .001), with higher concentrations in younger puppies, but not by viral (P = .863) or parasitic infection (P = .791). Fecal IgA concentration was significantly influenced by enteropathogen shedding (P = .01), with a lower fecal IgA concentration in puppies shedding at ≥1 enteropathogen compared to puppies without any enteropathogen shedding, but not by age. CONCLUSIONS: Fecal calprotectin and IgA are of no diagnostic value to detect presence of enteropathogens in clinically healthy puppies or puppies with abnormal feces, but could help to better understand the maturation of digestive tract.


Asunto(s)
Tamaño Corporal/genética , Perros/fisiología , Heces/química , Inmunoglobulina A/química , Complejo de Antígeno L1 de Leucocito/química , Destete , Envejecimiento , Animales , Biomarcadores , Perros/anatomía & histología , Perros/genética , Complejo de Antígeno L1 de Leucocito/metabolismo
17.
Water Res ; 39(9): 1761-72, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15899274

RESUMEN

The occurrence and fate of five acidic drugs (Mefenamic acid, Ibuprofen, Ketoprofen, Diclofenac and Clofibric acid) were analysed in three sewage treatment plants (STP) over 4-7 consecutive days. The results point out that the five substances were persistent in wastewater effluents after municipal wastewater treatment. At the most, half of Mefenamic acid was eliminated. Ibuprofen was well removed (80%) by one sewage treatment plant. The removal of Ibuprofen is dependent on the residence time of wastewater in the STPs. A long raining period induce an important decrease of removal of Ibuprofen and Ketoprofen. Removal rates showed a great variability according to sewage treatment plants and types of treatments (e.g. biological, physico-chemical). The concentrations of Ibuprofen, Mefenamic acid and Diclofenac were relatively high in the effluents (150-2000 ng/l), showing a potential contamination of surface water. An environmental risk assessment is presented. Mefenamic acid seems to present a risk for the aquatic environment, with a ratio PEC/PNEC higher than one.


Asunto(s)
Antiinflamatorios no Esteroideos/análisis , Anticolesterolemiantes/análisis , Aguas del Alcantarillado/análisis , Contaminantes Químicos del Agua/análisis , Ácido Clofíbrico/análisis , Diclofenaco/análisis , Monitoreo del Ambiente , Concentración de Iones de Hidrógeno , Ibuprofeno/análisis , Cetoprofeno/análisis , Ácido Mefenámico/análisis , Nivel sin Efectos Adversos Observados , Medición de Riesgo , Suiza , Eliminación de Residuos Líquidos
18.
Water Res ; 39(9): 1878-86, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15899286

RESUMEN

The culturability of Escherichia coli in undersaturated drinking water with respect to CaCO3 (corrosive water) or in oversaturated water (non-corrosive water) was tested in different reactors: glass flasks (batch, "non-reactive" wall); glass reactors (chemostat, "non-reactive" wall) versus a corroded cast iron Propella reactor (chemostat, "reactive" wall) and a 15-year-old distribution system pilot (chemostat, "reactive" wall with 1% corroded cast iron and 99% cement-lined cast iron). The E. coli in E. coli-spiked drinking water was not able to maintain its culturability and colonize the experimental systems. It appears from our results that the optimal pH for maintaining E. coli culturability was around 8.2 or higher. However, in reactors with a reactive wall (corroded cast iron), the decline in E. coli culturability was slower when the pH was adjusted to 7.9 or 7.7 (i.e. a reactor fed with corrosive water; pHpHs). We tentatively deduce that corrosion products coming from chemical reactions driven by corrosive waters on the pipe wall improve E. coli culturability.


Asunto(s)
Escherichia coli/crecimiento & desarrollo , Concentración de Iones de Hidrógeno , Microbiología del Agua , Abastecimiento de Agua , Reactores Biológicos , Carbonato de Calcio , Recuento de Colonia Microbiana , Corrosión , Hierro/química , Ríos
19.
Environ Technol ; 26(2): 211-7, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15791802

RESUMEN

A washed suspension of the bacteria Escherichia coli, pre-grown on a complex culture medium, was stored in sterilized drinking water for 21 days at 25 degrees C in glass flasks in order to assess the effect of iron corrosion products on the persistenceof the bacteria in drinking water. Four conditions were tested: aerobic with 50 mM lepidocrocite (gamma-FeOOH, an insoluble iron corrosion product), anaerobic with 50 mM lepidocrocite, aerobic without lepidocrocite and anaerobic without lepidocrocite. The survival of E. coli was monitored by their cultivability and their membrane integrity (propidium iodide staining). When the samples were not supplemented with the iron oxide, the cultivability and cell integrity of the bacteria were dramatically altered: from the 10(7) initially added, only 10 CFU ml(-1) remained after 21 days; 90% of the cells exhibited membrane alteration after 2 weeks of storage. In contrast, bacteria with lepidocrocite preserved their cultivability and integrity over the 21 days of storage. In the presence of di-oxygen and without iron oxide, the alteration of cell cultivability was more pronounced than that in anaerobic conditions, suggesting that oxidative stress was part of the phenomenon. When the cells were pre-grown in a growth medium supplemented by a large excess of an easily available form of iron (ferric-citrate), the cells stored a higher amount of iron and persisted one week longer in the iron-free drinking water than cells pre-grown in the standard growth medium. Therefore, in an oligotrophic environment like drinking water, E. coli cells can find the ability to survive a long time through the presence of iron corrosion products. The necessity of controlling the corrosiveness of drinking water for sanitary reasons is therefore emphasized by this study.


Asunto(s)
Escherichia coli/crecimiento & desarrollo , Compuestos Férricos , Purificación del Agua/métodos , Corrosión , Microbiología del Agua
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