RESUMEN
A novel quantitative analysis method for cellulose fibre was developed to understand its behaviour in biological wastewater treatment and waste sludge processes. The method developed in this study was designed using Pseudomonas aeruginosa to remove it by dissolving all the organic components except cellulose from the sludge due to needing the solubilisation of bacteria occupied almost of sludge matrix and quantifying the amount of remaining cellulose. The results of this study indicated that a combined treatment process that employed 2,000â U/L protease, 2â M hydrogen peroxide, and 2â mM potassium hydroxide after pre-treatment for floc dispersion with an ultrasonic treatment at 26â W for 1â min resulted in a solubilisation of 96% of P. aeruginosa without losing the cellulose fibre. When it was applied to the cellulose fibre added in the sludge from a municipal wastewater treatment facility, 99.5% of the cellulose fibre was recovered by using the high-speed centrifuge.
Asunto(s)
Aguas del Alcantarillado , Purificación del Agua , Celulosa , Eliminación de Residuos Líquidos , Aguas Residuales/análisisRESUMEN
A tertiary polyamide membrane was synthesized using N,N'-dimethyl-m-phenylenediamine. The durability of this membrane to chlorination by hypochlorite treatment followed by sodium hydroxide treatment was examined, and then deterioration mechanisms were proposed. The tertiary polyamide membrane demonstrated better durability to free chlorine than a conventional secondary polyamide one; however, the former was deteriorated by hypochlorite for 24 h at 2000 ppm of free chlorine below pH 7.5. The salt rejection and permeation performance of the membrane were almost unchanged, and the least chlorination of the active layer occurred during hypochlorite treatment at pH 10. These results indicated that hypochlorous acid rather than hypochlorite ion was the free chlorine species that induced membrane deterioration. The deterioration became severe as chlorination progressed, resulting in collapse of the active layer below pH 7.5. Chlorination and hydrolysis of the model tertiary amide N-methylbenzanilide and Fourier transfer infrared spectroscopy of a deteriorated membrane showed that chlorination of the tertiary polyamide occurred via direct chlorination of the benzene bound to the amidic nitrogen. Silver ion probing of the deteriorated membrane revealed that amide bond scission occurred in the active layer, which might be related to the electron deficiency of the amidic nitrogen caused by chlorination of its benzene ring.
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Nylons , Purificación del Agua , Cloro , Ácido Hipocloroso , Membranas Artificiales , ÓsmosisRESUMEN
Benthic invertebrates that inhabit the seafloor respond to anthropogenic and natural stresses, and are good indicators for assessing the benthic ecological status. We evaluated the ecosystem health of the Seto Inland Sea based on the multivariate AZTI Marine Biotic Index (M-AMBI), being its first application in a Japanese coastal sea with numerous endemic species. From the 415 locations studied, we were able to use M-AMBI in 384 sites (92.5% in all sites). The result revealed a statistically significant correlation among biotic indices including AMBI, M-AMBI, Richness, and H' (pâ¯<â¯0.01). Most of the physico-chemical parameters of the sediment (water content, total organic carbon (TOC) content, sulfide content, mud content, and oxidation-reduction potential (ORP)) were significantly correlated with each other excluding sediment temperature. The M-AMBI was significantly correlated with physico-chemical variables including water content, TOC content, sulfide content, and ORP. We found that the sites classified into the organically enriched cluster, and having high contents of TOC, mud, and sulfide and negative ORP, corresponded with sites that had significantly low M-AMBI values (bad-poor ecological status). Conversely, sites in the unpolluted sandy cluster were assigned high M-AMBI values (high-good ecological status). Therefore, M-AMBI would be a useful biotic index in Japanese coasts due to the representation of the comprehensive sediment quality.
Asunto(s)
Salud Ambiental , Monitoreo del Ambiente , Sedimentos Geológicos/química , Invertebrados/química , Animales , Carbono/química , Japón , Biología MarinaRESUMEN
A novel method was proposed to determine biofouling potential by direct analysis of a reverse osmosis (RO) membrane through fluorescence intensity analysis of biofilm formed on the membrane surface, thereby incorporating fouling tendencies of both feedwater and membrane. Evaluation of the biofouling potential on the RO membrane was done by accelerated biofilm formation through soaking of membranes in high biofouling potential waters obtained by adding microorganisms and glucose in test waters. The biofilm formed on the soaked membrane was quantified by fluorescence intensity microplate analysis. The soaking method's capability in detecting biofilm formation was confirmed when percentage coverage obtained through fluorescence microscopy and intensity values exhibited a linear correlation (R(2) = 0.96). Continuous cross-flow experiments confirmed the ability and reliability of the soaking method in giving biofouling potential on RO membranes when a good correlation (R(2) = 0.87) between intensity values of biofilms formed on the membrane during soaking and filtration conditions was obtained. Applicability of the test developed was shown when three commercially available polyamide (PA) RO membranes were assessed for biofouling potential. This new method can also be applied for the determination of biofouling potential in water with more than 3.6 mg L(-1) easily degradable organic carbon.
Asunto(s)
Fenómenos Fisiológicos Bacterianos , Biopelículas , Incrustaciones Biológicas/prevención & control , Filtración/métodos , Purificación del Agua/métodos , Filtración/instrumentación , Reproducibilidad de los Resultados , Purificación del Agua/instrumentaciónRESUMEN
Variation, run-off and degradation characteristics of the insecticide dinotefuran, (EZ)-(RS)-1-methyl-2-nitro-3-(tetrahydro-3-furyl-methyl)guanidine, in water and soil from two paddy fields after aerial application was investigated as well as in river water. Maximum concentrations of dinotefuran were 290 and 720 µg/L in the two paddy waters, 25 and 28 µg/kg dry in the two paddy soils, and 10 µg/L in the river water. Runoff ratios of dinotefuran from the paddy fields were calculated as 14%-41%. Mean half-lives of dinotefuran were 5.4 days in the paddy water and 12 days in the paddy soil. Results obtained in this study are important for the evaluation of the actual behavior of dinotefuran in paddy fields and rivers.
Asunto(s)
Biodegradación Ambiental , Guanidinas/metabolismo , Nitrocompuestos/metabolismo , Ríos/química , Contaminantes Químicos del Agua/análisis , Agricultura , Aire , Agua Dulce , Neonicotinoides , Suelo , Agua , Movimientos del AguaRESUMEN
The performance of a ferric ion mediated photochemical process for perfluorooctanoic acid (PFOA) decomposition in strongly acidic conditions of pH 2.0 was evaluated in comparison with those in weakly acidic conditions, pH 3.7 or pH 5.0, based on iron species composition and ferric ion regeneration. Complete decomposition of PFOA under UV irradiation was confirmed at pH 2.0, whereas perfluoroheptanoic acid (PFHpA) and other intermediates were accumulated in weakly acidic conditions. Iron states at each pH were evaluated using a chemical equilibrium model, Visual MINTEQ. The main iron species at pH 2.0 is Fe(3+) ion. Although Fe(3+) ion is consumed and is transformed to Fe(2+) ion by photochemical decomposition of PFOA and its intermediates, the produced Fe(2+) ion will change to Fe(3+) ion to restore chemical equilibrium. Continuous decomposition will occur at pH 2.0. However, half of the iron cannot be dissolved at pH 3.7. The main species of dissolved iron is Fe(OH)(2+). At pH 3.7 or higher pH, Fe(3+) ion will only be produced from the oxidation of Fe(2+) ion by hydroxyl radical produced by Fe(OH)(2+) under UV irradiation. These different mechanisms of Fe(3+) regeneration that prevail in strongly and weakly acidic conditions will engender different performances of the ferric ion.
Asunto(s)
Caprilatos/aislamiento & purificación , Compuestos Férricos/química , Fluorocarburos/aislamiento & purificación , Rayos Ultravioleta , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Caprilatos/química , Caprilatos/efectos de la radiación , Fluorocarburos/química , Fluorocarburos/efectos de la radiación , Concentración de Iones de Hidrógeno , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/efectos de la radiaciónRESUMEN
The characteristic distributions of 12 metals (Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Cd and Pb) were investigated in surface sediments from a small river (Niitsu River) flowing through both urban and agricultural areas by comparison with those from the upper main stream (Nodai River). Among the investigated metals, the mean concentrations of Al, Cr, Fe, Zn, Cd and Pb in the Niitsu River were significantly higher than those in the Nodai River. The investigated sites can be characterized by the principal components 1-3.
Asunto(s)
Sedimentos Geológicos/química , Metales/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , Agricultura/estadística & datos numéricos , Ciudades/estadística & datos numéricos , Monitoreo del Ambiente , Japón , Contaminación Química del Agua/estadística & datos numéricosRESUMEN
Behavior of the herbicide pyrazolynate, 4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yl p-toluenesulfonate, in paddy water and soil after application to paddy fields was investigated to evaluate the hydrolyzation to destosyl pyrazolynate (DTP), 4-(2,4-dichlorobenzoyl)-1,3-dimethyl-5-hydroxypyrazole. The respective maximum concentrations of pyrazolynate and DTP were 440-1,240 and 200-260 µg/L, respectively, in the paddy water, and 610-860 µg/kg dry and 460-730 µg/kg dry in the paddy soil. The applied pyrazolynate was drained from the paddy fields as DTP. The runoff ratios of DTP from the paddy fields were calculated as 19 % ± 14 %. The respective mean values of the half-lives of pyrazolynate and DTP were 0.87 ± 0.091 and 17 ± 1.4 days in the paddy water and 2.2 ± 0.70 and 26 ± 2.1 days in the paddy soil, respectively.
Asunto(s)
Monitoreo del Ambiente , Herbicidas/análisis , Modelos Químicos , Pirazoles/análisis , Contaminantes Químicos del Agua/análisis , Agricultura , OryzaRESUMEN
Characteristic distributions of Al, Mn, Fe, Ni, Zn, and Pb were investigated in the surface sediments of a small river (Niitsu River) flowing through both urban and agricultural areas, along with comparison with those from the upper main stream (Nodai River). The mean compositions of the most mobile metals were ordered as Zn = Mn > Ni = Pb = Fe > Al in the Niitsu River. They were Mn = Zn = Pb = Fe > Ni = Al in the Nodai River. Mn, Fe, Ni, and Zn in the Niitsu River showed higher compositions of mobile (2.9%-36%) and oxidizable (6.6%-16%) phases than those in the Nodai River. The Ni and Zn in the Niitsu River also had higher reducible phase composition (15% and 16%, respectively). In the Niitsu River, Pb had the higher oxidizable composition (29%). Over 90% of Al was in the lithogenic phase in the two rivers.
Asunto(s)
Agricultura/estadística & datos numéricos , Sedimentos Geológicos/química , Metales/análisis , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Japón , Ríos/química , Contaminación Química del Agua/estadística & datos numéricosRESUMEN
Variations in concentrations of herbicide bromobutide (RS)-2-bromo-N-(α,α-dimethylbenzyl)-3,3-dimethylbutyramide, and its metabolite bromobutide-debromo, N-(α,α-dimethylbenzyl)-3,3-dimethylbutyramide were investigated in soils from three paddy fields used for rice farming at 24 weeks after application. The bromobutide concentration was maximum within 24 h after application. That of bromobutide-debromo was maximum within 5-7 days of application. Each gradually decreased to below detection limits at 12-22 weeks after application. Bromobutide was detected up to 76-104 days after application in the paddy soils, whereas bromobutide-debromo was detected up to 125 days after application. The bromobutide composition was higher than 90 % within 6 days of application, decreasing to less than 5 % by 125 days of application. The decrease of bromobutide amount in the soil was inferred as the first-order reaction. The bromobutide half-life was calculated as 12-21 days (16 days mean) during 18-104 days following application.
Asunto(s)
Agricultura , Herbicidas/análisis , Hidrocarburos Bromados/análisis , Suelo/química , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Semivida , OryzaRESUMEN
Magnetic carbonaceous materials were produced by carbonization of a cation exchange resin loaded with ferrous or ferric iron and activation using sieved oyster shell as the activation agent. The magnetic carbonaceous material with the maximum magnetic flux density on every axis (ESS-1) was obtained from the ferric-loaded resin by carbonization at 700°C, followed by activation with the oyster shell at 900°C, and magnetization. A separate step of carbonization and activation appears to cause more of a reduction reaction of Fe to form γ-Fe(2)O(3). The Fe compound in the magnetic carbonaceous material was identified from the XRD pattern as mainly γ-Fe(2)O(3). The magnetic flux density on every axis increased linearly as the amount of the oyster shell increased. Moreover, the adsorption ability of the products was evaluated for pesticides and metal ions. Both ESS-1 and a carbonaceous material obtained from the resin without ferric ion (RC) appear to have the highest adsorption ability for lead. Furthermore, the adsorption ability of ESS-1 might decrease by blockages of the pores with the loaded Fe compounds.
Asunto(s)
Hierro/química , Metales/aislamiento & purificación , Ostreidae/química , Plaguicidas/aislamiento & purificación , Adsorción , Animales , MagnetismoRESUMEN
Two serotonin derivatives, N,N-dimethylserotonin 5-O-ß-glucoside (1a) and N-methylserotonin 5-O-ß-glucoside (1b) were isolated from immature seeds of Zanthoxylum piperitum. Their structures were determined by multi-step conversion reactions and spectroscopic analyses. Immature seeds of Z. piperitum contained extremely high levels of compounds 1a and 1b of approximately 0.29% and 0.15% (w/w), respectively.
Asunto(s)
Bufotenina/aislamiento & purificación , Semillas/química , Serotonina/análogos & derivados , Zanthoxylum/química , Glucósidos , Estructura Molecular , Serotonina/aislamiento & purificación , Antagonistas de la Serotonina/aislamiento & purificación , Análisis EspectralRESUMEN
The aim of this study was to determine whether seizure susceptibility due to antihistamines is provoked in patients with febrile seizures. The study population comprised 14 patients with simple febrile seizures and 35 patients with complex febrile seizures. Detailed clinical manifestations were compared between patients with and without administration of antihistamine. The time from fever detection to the seizure onset was significantly shorter in the antihistamine group than that in the nonantihistamine group, and the duration of seizures was significantly longer in the antihistamine group than that in nonantihistamine group. Interleukin-1beta is thought to be associated with causing febrile seizures via its dual role as a pyrogen and convulsant substance. Moreover, interleukin-1beta may activate the turnover of hypothalamic neural histamine. These considerations, along with the present results, suggest that the depletion of hypothalamic neuronal histamine induced by antihistamines may increase neuronal excitability, thereby increasing seizure susceptibility in patients with febrile seizures.
Asunto(s)
Antagonistas de los Receptores Histamínicos/efectos adversos , Convulsiones Febriles/fisiopatología , Convulsiones/inducido químicamente , Susceptibilidad a Enfermedades , Exantema Súbito/fisiopatología , Femenino , Fiebre/tratamiento farmacológico , Antagonistas de los Receptores Histamínicos/uso terapéutico , Humanos , Lactante , Gripe Humana/fisiopatología , Masculino , Estudios Retrospectivos , Factores de TiempoRESUMEN
A neonatal case of provisional neurocutaneous melanosis presenting with lissencephaly is reported. Several congenital nevi were observed on the trunk and extremities of the infant, including a giant congenital hairy nevus over the skull. Brain magnetic resonance imaging revealed a marked ventricular dilatation with pachygyria and an absent corpus callosum; however, an injection of gadolinium did not demonstrate any enhanced lesions. Histopathological investigations by a brain biopsy showed a disorganized and anomalous embryonic cerebral architecture, suggesting lissencephaly. The detailed mechanism of this combined pathology is difficult to explain; however, a developmental disturbance was suggested to be present in both the neural crest cells and the neuroepithelial cells, resulting in the development of neurocutaneous melanosis accompanied with lissencephaly.
Asunto(s)
Agenesia del Cuerpo Calloso , Lisencefalia/complicaciones , Nevo Pigmentado/congénito , Humanos , Recién Nacido , Lisencefalia/diagnóstico , Imagen por Resonancia Magnética , Masculino , Nevo Pigmentado/complicacionesRESUMEN
This case report describes multivessel coronary artery spasm refractory to oral nifedipine, intravenous isosorbide dinitrate, diltiazem and nicorandil, and intracoronary nitroglycerin. Intracoronary administration of nicorandil only transiently relieved coronary artery spasm. Prednisolone was effective in preventing coronary artery spasm.
Asunto(s)
Angina de Pecho/etiología , Estenosis Coronaria/etiología , Vasoespasmo Coronario/tratamiento farmacológico , Glucocorticoides/uso terapéutico , Prednisolona/uso terapéutico , Vasodilatadores/uso terapéutico , Administración Oral , Adulto , Angina de Pecho/tratamiento farmacológico , Angina de Pecho/patología , Angiografía Coronaria , Estenosis Coronaria/complicaciones , Estenosis Coronaria/tratamiento farmacológico , Estenosis Coronaria/patología , Vasoespasmo Coronario/complicaciones , Vasoespasmo Coronario/patología , Diltiazem/uso terapéutico , Electrocardiografía , Femenino , Glucocorticoides/administración & dosificación , Humanos , Infusiones Intravenosas , Dinitrato de Isosorbide/uso terapéutico , Nicorandil/uso terapéutico , Nifedipino/uso terapéutico , Nitroglicerina/uso terapéutico , Prednisolona/administración & dosificación , Insuficiencia del Tratamiento , Vasodilatadores/administración & dosificaciónRESUMEN
This study investigates the clinical features of epilepsy in 20 patients with brain malformation. Epileptic seizures were recognized in 15 patients, 12 of whom had their first seizure by 1 year of age. Partial seizure was the initial seizure type in 10 patients. Epileptic seizures were controlled in only four patients. Patients with holoprosencephaly and lissencephaly had seizure onset by 3 months of age, resulting in the most severe neurologic outcome. Only two patients with porencephaly had epileptic seizures, and in one of those patients the seizures were well controlled. A wide variety of clinical features of epilepsy in patients with brain malformation was found. More immature anomalous brain lesions may be associated with an enhanced capacity of epilepsy and resultant refractory seizures.
Asunto(s)
Encéfalo/anomalías , Encéfalo/crecimiento & desarrollo , Epilepsia/patología , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Malformaciones del Sistema Nervioso/patologíaAsunto(s)
Encéfalo/patología , Infecciones por Citomegalovirus/patología , Imagen por Resonancia Magnética , Complicaciones Infecciosas del Embarazo/patología , Síndrome de Rubéola Congénita/patología , Femenino , Enfermedades Fetales/patología , Lóbulo Frontal/patología , Humanos , Recién Nacido , Imagen por Resonancia Magnética/métodos , Embarazo , Tomografía Computarizada por Rayos XRESUMEN
Primary microcephaly can be accompanied by numerous migration anomalies. This experiment was undertaken to examine the pathogenesis of gray matter heterotopia and microcephaly that is produced after administering cytosine arabinoside (Ara-C) to mice. Pregnant mice were intraperitoneally injected with Ara-C at 30 mg/kg body weight on days 13.5 and 14.5 of gestation, and then their offspring were examined. On embryonic day 15.5, in the ventricular zone of the cingulate cortex, the neuroepithelial cells lacked BrdU immunoreactivity. Nestin-immunoreactive radial glial fibers and calretinin-positive subplate fibers were disrupted. TUNEL reaction was remarkable throughout the cerebral hemisphere. Subcortical heterotopia in the cingulate cortex and subependymal nodular heterotopia in the dorsolateral part of the lateral ventricles became detectable by the first day after birth. Thirty-two days after birth, microcephaly was apparent; subcortical heterotopia was observed to have increased in size while it was still located in the frontal and cingulate cortices. This experiment demonstrated that Ara-C induces neuronal apoptosis throughout the cerebral hemisphere. The immunohistochemical characteristics in the gray matter heterotopia suggest that both the subcortical and the subependymal heterotopias were formed by neurons originally committed to the neocortex. We conclude that the gray matter heterotopia that accompanies the microcephaly was produced by a disturbance of radial, tangential, and interkinetic neuronal migrations due to the toxicity of Ara-C in the immature developing brain.
Asunto(s)
Corteza Cerebral/anomalías , Corteza Cerebral/efectos de los fármacos , Coristoma/inducido químicamente , Citarabina/efectos adversos , Microcefalia/inducido químicamente , Malformaciones del Sistema Nervioso/inducido químicamente , Animales , Animales Recién Nacidos , Antimetabolitos Antineoplásicos/efectos adversos , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Biomarcadores/metabolismo , Bromodesoxiuridina , Calbindina 2 , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Movimiento Celular/efectos de los fármacos , Movimiento Celular/fisiología , Proliferación Celular/efectos de los fármacos , Corteza Cerebral/fisiopatología , Coristoma/diagnóstico , Coristoma/fisiopatología , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos ICR , Microcefalia/diagnóstico , Microcefalia/fisiopatología , Proteínas Asociadas a Microtúbulos/metabolismo , Degeneración Nerviosa/inducido químicamente , Degeneración Nerviosa/fisiopatología , Malformaciones del Sistema Nervioso/diagnóstico , Malformaciones del Sistema Nervioso/fisiopatología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Proteína G de Unión al Calcio S100/metabolismo , Células Madre/efectos de los fármacos , Células Madre/metabolismo , Células Madre/patologíaRESUMEN
The continuous performance test (CPT) is designed to measure sustained attention quantitatively. Several CPTs are used clinically. We have made changes to the conventional type of visual CPT, by displaying auditory and visual noise along with target or non-target stimuli. By influencing the recognition of the subjects in this way, the changes were intended to increase the sensitivity of detection of inattention and impulsiveness, to make CPT more useful for diagnosis, and to examine the effect of noise on AD/HD children during CPT performance. Its usefulness for AD/HD diagnosis and the reaction of AD/HD children to noise were examined using newly developed computer software. Using this CPT analysis, a significant difference was observed in all measurements, except mean reaction time, between the control and AD/HD groups, showing that it was useful as a supplementary diagnostic method for AD/HD, and was more useful in the younger age group than in the older age group, as the same for conventional CPTs. As compared to no-noise sessions, commission and omission errors both increased significantly in auditory and visual noise sessions. Thus, analyzing the changes in measurements during noise sessions will improve the diagnosis of inattention and combined AD/HD subtypes. Furthermore, it was suggested that analysis of the effects of noise on AD/HD children will benefit their handling in an educational environment. Since omission errors were decreased in AD/HD children by noise during the CPT performance as compared to the control group, noise may induce attention in AD/HD children. The present study presents new findings on the responses to noise of AD/HD children during the CPT.
Asunto(s)
Estimulación Acústica , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Atención , Ruido , Estimulación Luminosa , Envejecimiento , Niño , Humanos , Pruebas Neuropsicológicas , Valores de Referencia , Programas InformáticosRESUMEN
Hypoxic-ischemic (H-I) injury to neonatal brains can cause a life-long neuronal deficit because of increased susceptibility in the neonatal period. Excitotoxicity due to overstimulation of the N-methyl-d-aspartate receptor (NMDAR) is assumed to be the basis of the injury. However, the ontogenic profile of the susceptibility does not directly correlate with the levels of NMDAR expression. Platelet-derived growth factor B-chain (PDGF-B) has been reported to protect neurons by suppressing the NMDA-evoked current and translocating the glutamate transporter to the cell membrane. Thus, we assessed the relationship between the susceptibility to H-I injury and the expression of PDGF-B in neonatal rat brain. PDGF-B infusion before and after an intrastriatal NMDA injection significantly reduced the size of the lesions in 7-day-old rats, when they are most susceptible and the neuronal expression of PDGF-B is low. Fourteen-day-old neonatal rats were found to be resistant to NMDA injury, even though NMDARs are expressed at high levels in the brain at this age. Inhibition of PDGF-B protein synthesis by antisense oligodeoxynucleotides increased the size of the NMDA-induced lesions up to 6-fold at postnatal day 14, when PDGF-B is expressed at high levels in neurons. These data suggest that PDGF-B is an important physiological modulator of NMDAR excitability in the developing brain, and that the balance between the expression of NMDAR and PDGF-B partly determines the ontogenic susceptibility to brain injury. Enhancement of the PDGF-B/receptor signal pathway might rescue neonatal brains at risk of H-I injury.