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1.
Phys Rev E ; 96(1-1): 012610, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29347149

RESUMEN

We present the computed phase diagram of columnar structures of soft spheres under pressure, of which the main feature is the appearance and disappearance of line slips, the shearing of adjacent spirals, as pressure is increased. A comparable experimental observation is made on a column of bubbles under forced drainage, clearly exhibiting the expected line slip.

2.
Phys Rev E ; 97(5-2): 059902, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29906839

RESUMEN

This corrects the article DOI: 10.1103/PhysRevE.96.012610.

3.
Soft Matter ; 10(36): 6990-8, 2014 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-24888513

RESUMEN

To what extent are aqueous foams prone to clogging? Foam permeability is measured as a function of particulate loading (trapped hydrophilic particles) under conditions where the particle to bubble size ratio is allowed to increase when the number of particles per bubble is fixed. In addition to experiments performed on the foam scale, we investigated experimentally and numerically the hydrodynamic resistance of a single foam node loaded with one particle. It is shown that, with respect to solid porous media, aqueous foams clog more efficiently due to two reasons: (i) the deformation of interfaces allows for larger particles to be incorporated within the interstitial network and (ii) the interfacial mobility contributes to lowering of the reduced permeability.

4.
Soft Matter ; 10(23): 4137-41, 2014 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-24752206

RESUMEN

We investigate the drainage behaviour of foamy granular suspensions. Results reveal large fluctuations in the drainage velocity as bubble size, particle size and gas volume fraction are varied for a given particle volume fraction. Particle capture is proved to control the overall drainage behaviour through the parameter λ, which compares the particle size to the size of passage through constrictions within the foam pore space. λ highlights a sharp transition: for λ < 1 particles are free to drain with the liquid, which involves the shear of the suspension in foam interstices, for λ > 1 particles are trapped and the resulting drainage velocity is strongly reduced. A phenomenological model is proposed to describe this behaviour.

5.
Soft Matter ; 10(18): 3277-83, 2014 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-24633178

RESUMEN

The drainage of particulate foams is studied under conditions where the particles are not trapped individually by constrictions of the interstitial pore space. The drainage velocity decreases continuously as the particle volume fraction φ(p) increases. The suspensions jam--and therefore drainage stops--for values φ*(p) which reveal a strong effect of the particle size. In accounting for the particular geometry of the foam, we show that φ*(p) accounts for unusual confinement effects when the particles pack into the foam network. We model quantitatively the overall behavior of the suspension--from flow to jamming--by taking into account explicitly the divergence of its effective viscosity at φ*(p). Beyond the scope of drainage, the reported jamming transition is expected to have a deep significance for all aspects related to particulate foams, from aging to mechanical properties.

6.
Epilepsy Res ; 50(3): 283-92, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12200219

RESUMEN

To analyze the spectrum of epilepsy syndromes which follow childhood febrile convulsions (FC) and to examine whether retrospective analysis of clinical features of the FC enables discrimination of patients who develop temporal lobe epilepsy (TLE) from those who develop generalized epilepsy (GE). One hundred and thirteen patients with epilepsy and antecedent FC were retrospectively analyzed. We inquired in detail about the clinical characteristics of FC (age, duration, number, focal symptoms) as well as family history, birth history, neurological status, and psychomotor development before onset of FC. Forty five (39.8%) patients had TLE, 41 (36.6%) GE, and 27 (23.9%) had extratemporal epilepsy (ETE). Patients with TLE had a significantly longer duration of FC (P< or =0.001), more often focal features (P< or =0.001), and febrile status epilepticus (P< or =0.001) than patients with GE. Age at FC, Number of FC, family history, birth history and neurological status at FC did not differ between groups. A stepwise discriminant model allowed correct assignment after cross validation in 84.2% to TLE and in 100% to GE. A broad spectrum of epilepsy syndromes follow FC. We found a strong association of prolonged and focal FC with later development of TLE. Short generalized FC were associated with GE.


Asunto(s)
Epilepsia Generalizada/etiología , Epilepsia del Lóbulo Temporal/etiología , Convulsiones Febriles/complicaciones , Adolescente , Adulto , Anciano , Análisis de Varianza , Australia/epidemiología , Lesiones Encefálicas/epidemiología , Niño , Preescolar , Estudios de Cohortes , Epilepsia Generalizada/epidemiología , Epilepsia Generalizada/genética , Epilepsia del Lóbulo Temporal/epidemiología , Epilepsia del Lóbulo Temporal/genética , Femenino , Predisposición Genética a la Enfermedad/epidemiología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Estadísticas no Paramétricas , Síndrome
7.
Eur J Med Res ; 1(11): 533-6, 1996 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-9438156

RESUMEN

In the present study we investigated the influence of two common air pollutants, sulfur dioxide (SO2) and nitrogen dioxide (NO2) on ciliary beat frequency (CBF). Ciliated cells were obtained by nose brush from 12 healthy volunteers and placed on a polycarbonate membrane which was in contact with Ringer's electrolyte solution. This allowed the supply of the cells by capillarity in parallel to the reaction of the pollutants with the cell surfaces. In an exposure chamber the cells were exposed for 30 min. at 37 degrees C either to SO2 (2.5-12.5 ppm) or to NO2 (3.0-15.0 ppm), or to a mixture of NO2 (12.0 ppm) and SO2 (2.5 or 5.0 ppm). CBF was measured by video-interference-microscopy. With SO2 we observed a dose-dependent decrease in CBF with Ringer's solution. 2.5 ppm SO2 caused a 42.8% decrease and 12.5 ppm a decline of approximately 100% (8.10 +/- 0.24 Hz vs. 0.28 +/- 0.20 Hz). In parallel, we observed a decrease in the pH-value from 7.4 to 3.6. 30 min. NO2 exposure (3.0-15.0 ppm) induced a significant dose dependent increase in CBF from 8.4 +/- 0.34 Hz to 9.4 +/- 0.44 Hz. Exposure to a mixture of SO2 and NO2 with Ringer's solution revealed that SO2 exerts a stronger influence on CBF than NO2. Exposure to both pollutants resulted in the same as exposure to SO2 alone. Our findings demonstrate a strong correlation between SO2-modified pH values and CBF. Exposure to a combination of two pollutants revealed the dominant influence of SO2 on CBF while the augmented effect of exposure to NO2 alone might be due to the oxidative potential of this gas.


Asunto(s)
Mucosa Nasal/fisiología , Dióxido de Nitrógeno/farmacología , Dióxido de Azufre/farmacología , Adulto , Cilios/efectos de los fármacos , Cilios/fisiología , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Concentración de Iones de Hidrógeno , Masculino , Mucosa Nasal/citología , Mucosa Nasal/efectos de los fármacos
9.
Padiatr Padol ; 20(3): 289-96, 1985.
Artículo en Alemán | MEDLINE | ID: mdl-4034219

RESUMEN

We report on a newborn with peracute glycine encephalopathy. The child exhibited poor feeding, incipient respiratory failure and increasing muscular hypotonia from the first few days of life onwards and was admitted to hospital at six weeks due to regression of the symptoms. Following respiratory arrest the child had to be placed on controlled ventilation and died at the age of four months in spite of therapeutic measures. Previous papers on this rare disease have described elevated CSF glycine levels, EEG patterns, CT scan and acoustic and visual evoked potentials. We have supplemented these for the first time by somatosensory evoked potentials. The following is an account of the clinical course and the therapy given.


Asunto(s)
Encefalopatías Metabólicas/patología , Glicina/metabolismo , Encéfalo/diagnóstico por imagen , Electroencefalografía , Potenciales Evocados Somatosensoriales , Glicina/sangre , Glicina/líquido cefalorraquídeo , Glicina/orina , Humanos , Recién Nacido , Tomografía Computarizada por Rayos X
10.
Padiatr Padol ; 19(3): 241-50, 1984.
Artículo en Alemán | MEDLINE | ID: mdl-6472865

RESUMEN

The EEG was studied in 46 pre-term and 43 full-term babies to evaluate its usefulness in estimating the degree of perinatal asphyxia. During the first 12 hours after a severe perinatal asphyxia isoelectric periods (IEP) of abnorm long duration are dominant in the EEG-records of pre-term and full-term babies and remain dominant in EEG-records of pre-term babies during the second 12 hour-period. During the first 12 hour-period in the EEG-records of full-term babies epileptic seizure patterns (ESP) appear sporadically, while in the second 12 hour-period they increase with respect to number and duration and often become even dominant within single records. During the second and third day of life ESP decrease in the EEG-records of full-term babies. IEP remain dominant in about 30% in the EEG-records of pre-term babies. During episodes of bradycardia with or without apnoea a three to fourfold increase of IEP is seen. Therefore an increase of number and/or duration of episodes of bradycardia does not seem to be without importance for cerebral function.


Asunto(s)
Asfixia Neonatal/fisiopatología , Electroencefalografía , Factores de Edad , Asfixia Neonatal/complicaciones , Epilepsia/etiología , Humanos , Recién Nacido , Enfermedades del Prematuro/fisiopatología
11.
Padiatr Padol ; 19(3): 311-6, 1984.
Artículo en Alemán | MEDLINE | ID: mdl-6472870

RESUMEN

Description of a rare case of sympodia in a female newborn, first child of a seventeen year old mother. In addition to typical external deformities with malformations of the bones of the lower extremities, malformations of ribs and the vertebral column, there was also an agenesis of kidneys, ureters, bladder and urethra. The colon ended blindly in the pelvis minor, the anus was imperforate. There was a genital tubercle without urogenital opening.


Asunto(s)
Anomalías Múltiples/diagnóstico por imagen , Pierna/anomalías , Anomalías Múltiples/genética , Femenino , Humanos , Recién Nacido , Cariotipificación , Radiografía , Síndrome
13.
Padiatr Padol ; 13(1): 21-9, 1978.
Artículo en Alemán | MEDLINE | ID: mdl-341041

RESUMEN

One of the first aims of the neonatal care unit of the Paediatric Department of the University of Innsbruck (Austria) consists in taking care of dangerously ill children of Tyrol including the neighbouring federal states and the alpine part of Italy (South Tyrol). From SUMMER 1974 to the end of October 1976 1342 preterm and term infants were treated. 142 of these children died (mortality rate 10.5%). In 94 patients, i. e. 6.9% mechanical ventilation was necessary. 39 of these children, i. e. 41.5% survived. Two indications of artifical ventilation were predominant: Hyaline membrane syndrome in 59 children (survival rate 49%) and apnoe in 22 children (survival rate 27%). Electroencephalography was performed in 39 children during the neonatal period. 34 of these children were severely ill (gestational age of 24 to 37 weeks), 5 children were born at term nevertheless moribund. 18 of the 23 dead children of this group showed severe alterations in electroencephalography. The cause of death of 10 of these children was cerebral bleeding as verified by autopsy. 8 of the 16 surviving children showed a regular psychomotoric development, 5 children of this group had a normal electroencephalogram.


Asunto(s)
Enfermedades del Recién Nacido/terapia , Enfermedades del Prematuro/terapia , Respiración con Presión Positiva , Insuficiencia Respiratoria/terapia , Apnea/terapia , Humanos , Enfermedad de la Membrana Hialina/mortalidad , Enfermedad de la Membrana Hialina/terapia , Recién Nacido , Enfermedades del Recién Nacido/mortalidad , Enfermedades del Prematuro/mortalidad , Insuficiencia Respiratoria/mortalidad
14.
Artículo en Alemán | MEDLINE | ID: mdl-405197

RESUMEN

Looking for long-term prognostic value of the neonatal EEG, 545 records from 125 children in the pre-term and full-term period have been checked for special criterias: 1. Periods of electrocerebral inactivity (with usual amplifier gain) 2. Relative amplitude reduction over one of the hemispheres or localized 3. Focal changes 4. Epileptic activity: focal, multifocal and generalized. 5. Unspecific rhythm of alpha- and epsilon-frequency, which can not be classified as epileptic seizure pattern. According to the pronounciation of these criterias the EEG records were classified as severely, medium, severely, moderately abnormal and as normal. Comparison was done with the results of the last control EEG and the last clinical control examination. The principal results are: 1. Children with severe EEG abnormalities have a high mortality rate (about 70%). Long periods of electrocerebral inactivity are more unfavourable quoad vitam than epileptic discharges. 2. Late sequelae as cerebral palsy, psychomotor retardation and epilepsy are to be expected in all children with severe EEG abnormalities remaining alive and in many children with medium severe EEG abnormalities. 3. The rate of normal psychomotor development increases with the decrease of EEG abnormalities. It is important to mention: 1. EEG records in the first hours and days after birth give the best information regarding a long-term prognosis. 2. In children remaining alive and not developing hypsarrhythmia the observation interval must be more than one year for an estimation of probable electroencephalographic and clinical outcome.


Asunto(s)
Encefalopatías/congénito , Electroencefalografía , Enfermedades del Recién Nacido/diagnóstico , Enfermedades del Prematuro/diagnóstico , Asfixia Neonatal/complicaciones , Encefalopatías/diagnóstico , Encefalopatías/etiología , Humanos , Recién Nacido , Pronóstico , Espasmos Infantiles/complicaciones
15.
Padiatr Padol ; 12(4): 377-84, 1977.
Artículo en Alemán | MEDLINE | ID: mdl-904945

RESUMEN

In 334 children active dorsiflexion of the feet was tested in order to screen for spasticity of the lower limbs. The conditions were: 1. The child lying supine. 2. The head turned actively and if this is not possible passively to the side of the examined foot. 3. Passive extension of the child's hip and knee of the examined side by the examinator. 4. Stimulation of the skin at the lateral and lower part of the shin, or the dorsum pedis or the anterior part of the toes and the planta pedis to provoke active dorsiflexion of the foot. Stimulation is done by the fingers of the examinator or by a slight touch with an ordinary handbrush. Dorsiflexion of the foot is graded "normal" if it surpasses 90--100 degrees, "suspicious" if it only reaches 90 degrees and "pathologic" if 90 degrees cannot be reached or if this can be done only on the medial side or if there is constant clawing of the toes even with sufficient dorsiflexion. We have examined 334 children; 260 of these were younger than one year. The results of this kind of stimulated dorsiflexion of the foot were compared with the results of the usual extensive neurological examination with regard to spasticity of the lower limbs (see literature) and with both of VOJTA's most sensible postural reactions. The following conclusions are drawn: 1. Spasticity of the lower limbs can be excluded with a high degree of probability when dorsiflexion of the feet is graded "normal". 2. If the dorsiflexion is graded "suspicious" or "pathologic" a more thorough neurological examination is warranted and if necessary short-term controls. 3. The results of this examination are in good agreement with the one of VOJTA's most sensitive postural reactions to indicate spasticity of the lower limbs.


Asunto(s)
Pierna , Trastornos del Movimiento/diagnóstico , Espasticidad Muscular/diagnóstico , Factores de Edad , Parálisis Cerebral/complicaciones , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Trastornos del Movimiento/etiología , Espasticidad Muscular/etiología , Postura
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