A mixture approach to the acoustic properties of a macroscopically inhomogeneous porous aluminum in the equivalent fluid approximation.

The acoustic properties of an air-saturated macroscopically inhomogeneous aluminum foam in the equivalent fluid approximation are studied. A reference sample built by forcing a highly compressible melamine foam with conical shape inside a constant diameter rigid tube is studied first. In this process, a radial compression varying with depth is applied. With the help of an assumption on the compressed pore geometry, properties of the reference sample can be modelled everywhere in the thickness and it is possible to use the classical transfer matrix method as theoretical reference. In the mixture approach, the material is viewed as a mixture of two known materials placed in a patchwork configuration and with proportions of each varying with depth. The properties are derived from the use of a mixing law. For the reference sample, the classical transfer matrix method is used to validate the experimental results. These results are used to validate the mixture approach. The mixture approach is then used to characterize a porous aluminium for which only the properties of the external faces are known. A porosity profile is needed and is obtained from the simulated annealing optimization process.

Acoustical properties of air-saturated porous material with periodically distributed dead-end pores.

A theoretical and numerical study of the sound propagation in air-saturated porous media with straight main pores bearing lateral cavities (dead-ends) is presented. The lateral cavities are located at "nodes" periodically spaced along each main pore. The effect of periodicity in the distribution of the lateral cavities is studied, and the low frequency limit valid for the closely spaced dead-ends is considered separately. It is shown that the absorption coefficient and transmission loss are influenced by the viscous and thermal losses in the main pores as well as their perforation rate. The presence of long or short dead-ends significantly alters the acoustical properties of the material and can increase significantly the absorption at low frequencies (a few hundred hertz). These depend strongly on the geometry (diameter and length) of the dead-ends, on their number per node, and on the periodicity along the propagation axis. These effects are primarily due to low sound speed in the main pores and to thermal losses in the dead-end pores. The model predictions are compared with experimental results. Possible designs of materials of a few cm thicknesses displaying enhanced low frequency absorption at a few hundred hertz are proposed.

Neurodevelopmental outcomes after hypothermia therapy in the era of Bayley-III.

OBJECTIVE: Bayley-III scales are currently used to evaluate outcomes of term infants following hypothermia therapy, while all before reported outcomes in this population have used Bayley-II. Our objectives were to determine the incidence of abnormal neurodevelopmental outcomes using Bayley III and the predictive value of Magnetic resonance imaging (MRI) in infants who received systemic hypothermia. STUDY DESIGN: We conducted a prospective cohort study of inborn infants who underwent hypothermia for moderate/severe neonatal encephalopathy from October 2005-November 2011. RESULT: Eighty newborns underwent hypothermia (incidence of 1/1000). Of the survivors, 89% had Bayley-III performed around 24 months of age. An abnormal outcome using Bayley-III <85 occurred in 50%, while Bayley III <70 occurred in 13%. MRI predicted Bayley III<85 with sensitivity of 73%, specificity of 84%, positive-predictive value of 84% and negative-predictive value of 74%. CONCLUSION: A Bayley-III 85 cutoff identifies a disability rate of 50%, and MRI was predictive of abnormal outcomes. Findings can be useful for counseling of families and planning of future studies using Bayley III.

Acoustics of porous materials with partially opened porosity.

A theoretical and experimental study of the acoustic properties of porous materials containing dead-end (or partially opened) porosity was recently proposed by Dupont, Leclaire, Sicot, Gong, and Panneton [J. Appl. Phys. 110, 094903 (2011)]. The present article provides a description of partially opened porosity systems and their numerous potential applications in the general context of the study of porous materials, the classical models describing them, and the characterization techniques. It is shown that the dead-end pore effect can be treated independently and that the description of this effect can be associated with any acoustic model of porous media. Different theoretical developments describing the dead-end porosity effect are proposed. In particular, a model involving the average effective length of the dead-end pores is presented. It is also shown that if the dead-end effect can be treated separately, the transfer matrix method is particularly well suited for the description of single or multilayer systems with dead-end porosity.

[Optimized protocols for interphase FISH analysis of imprints and sections using split signal probes]. / Application de la technique de FISH interphasique avec des sondes encadrantes dites de <> à différents types de préparations histologiques et cytologiques.

Fluorescent in situ hybridization (FISH) analysis is a molecular technique allowing the detection of recurrent translocations in cancer. Several hybridization protocols were assayed in order to evaluate their performances for interphase FISH analysis of histological sections and imprints using split probes. Adult and foetal lymphoid tissues were selected. Touch imprints of fresh (EF) or frozen (EC) tissues, sections (CF) and isolated nuclei (NI) of formol-fixed paraffin-embedded tissues were performed. The cut-off values of the IGH, IGlambda, BCL-2, BCL-6, CCND1 and MYC DNA FISH split signal probes were calculated for adult reactive lymph nodes on the different histological preparations (EC, CF, CC, NI) and on several tissues for the IGH and BCL-6 probes. In reactive lymph nodes, the cut-off values of the probes were between 3 and 13% and found independent of the preparation type. Conversely, slight but significant variations of the cut-off level were observed when different foetal control tissues were assayed with the same probe set. Finally, this study provided optimized-protocols for FISH analysis of either fresh/frozen imprints or formalin-fixed paraffin-embedded sections using split signal DNA probes.

Technetium-99m HMPAO-labeled leukocyte imaging compared with endoscopy, ultrasonography, and contrast radiology in children with inflammatory bowel disease.

BACKGROUND: The purpose of this study was to evaluate retrospectively the value of leukocyte-labeled scintigraphy, ultrasonography, and contrast radiography compared with endoscopy in children suspected of having inflammatory bowel disease (IBD). METHODS: Twenty-eight children (17 boys; mean age, 10.2 years) with IBD based on standard colonoscopic, histologic, and radiologic criteria (16 with Crohn's disease, 5 with ulcerative colitis, 5 with nonspecific colitis, I with granulomatous disease, and I with Beh,cet's disease) were included. Endoscopic, ultrasonographic, and contrast radiologic examinations were realized for 28, 23, and 19 children respectively. RESULTS: Sensitivity and specificity were 75% and 92% for leukocyte-labeled scintigraphy, 39% and 90% for ultrasonography, and 58% and 83% for contrast radiography. The authors noted discontinuous uptake for 14 of 15 true-positive results for patients with Crohn's disease and continuous uptake for 4 of 4 true-positive results for patients with ulcerative colitis. A negative correlation between scan activity index and Lloyd-Still clinical score was found for 11 patients with Crohn's disease (r = -0.77). CONCLUSIONS: Leukocyte-labeled scintigraphy, a noninvasive and reproducible technique, is a useful tool in the diagnosis and therapeutic strategy of IBD, and provides information on the presence, the intensity, and the extent of the disease, particularly in the terminal ileum. Leukocyte-labeled scintigraphy may not replace colonoscopy with biopsies for diagnosis confirmation. Its reliability seems higher than that of ultrasonography.

Estado actual del tratamiento quirúrgico del cáncer colorrectal / State of the art in colorectal cancer surgery

El cáncer colorrectal es en la actualidad una de las enfermedades más importantes en los países occidentales y representa una causa muy significativa de morbilidad y mortalidad por cáncer. Es la segunda forma más común de cáncer y la segunda causa de muerte por enfermedad oncológica tomando en conjunto ambos sexos. En los últimos años, el aumento de la incidencia, su alta prevalencia en el anciano y el envejecimiento de la población han hecho despertar un considerable interés por el tratamiento de esta enfermedad. La cirugía es el único tratamiento curativo y en el momento de la presentación aproximadamente el 50 por ciento de los pacientes son tributarios de una "resección curativa", aunque la mortalidad ha cambiado poco en los últimos 50 años pues, desafortunadamente, cerca de la mitad de los pacientes mueren por enfermedad metastásica o recurrencia. La posición de la cirugía en el tratamiento y curación del cáncer colorrectal está bien establecida pero, además, continúan siendo objeto de controversia el tratamiento del cáncer complicado, otras enfermedades colónicas simultáneas, las metástasis, la recurrencia, el cáncer del tercio distal del recto y la colectomía laparoscópica (AU)

The influence of spatial inhomogeneities on neutral models of geographical variation IV. Discontinuities in the population density and migration rate.

The equilibrium structure of the infinite, one-dimensional stepping-stone model with coincident discontinuities in the population density and migration rate is investigated in the diffusion approximation. The monoecious, diploid population is subdivided into an infinite linear array of equally large, panmictic colonies that exchange gametes isotropically. The population density and the migration rate have a discontinuity at the origin, but are elsewhere uniform. Generations are discrete and nonoverlapping; the analysis is restricted to a single locus without selection; every allele mutates to new alleles at the same rate. The three dimensionless parameters in the theory are alpha=(rho(+)/rho(-))(2) (V(+)/V(-))(3/2), and beta(+/-)=4rho(+/-) 2uV(+/-), where rho(+) (rho(-)) and V(+) (V(-)) designate the population density and variance of gametic dispersion per generation to the right (left) of the discontinuity, respectively, and u denotes the mutation rate. The characteristic length on the right (left) is V(+)/(2u) (V(-)/(2u)). The probability of identity is continuous at the origin, but its partial derivatives have a discontinuity unless migration is conservative (rho(-) V(-)=rho(+) V(+)). At least for nonconservative migration, the probability of identity (including the expected homozygosity) can be nonmonotonic even if the migration rate is uniform and the population density is monotonic. Thus, there can be a nonmonotonic genetic response in a neutral model to a monotonic environment.

[A cost analysis of laparoscopic cholecystectomy compared with the open technic]. / Análisis de costes de la colecistectomía laparoscópica en comparación con la abierta.

OBJECTIVE: The aim of this study was to compare the cost of laparoscopic cholecystectomy with that of open cholecystectomy. DESIGN: We analyzed the cost of both procedures regarding hospital stay, days of work lost and the cost derived from the morbidity of the complications of each technique in two groups of patients. With these data we were able to calculate direct and indirect costs of both procedures and compare them. RESULTS: Morbidity was similar in both groups and had no influence in the cost; cost of the material used for laparoscopic cholecystectomy was higher; hospital stay and days of lost work were significantly lower for the laparoscopic procedure than for the open one. The total cost of laparoscopic cholecystectomy was 23% cheaper than that of open cholecystectomy. CONCLUSIONS: Laparoscopic cholecystectomy appears to be cheaper than open cholecystectomy. As the laparoscopic technique becomes more widespread its cost might decrease even further.

[Efficacy of oral bepridil in ventricular arrhythmias in stable coronary insufficiency]. / Efficacité du bépridil per os sur les troubles du rythme ventriculaire chez l'insuffisant coronarien stable.

The electrophysiological properties of bepridil suggest a possible ventricular antiarrhythmic effect. This prospective multicentre trial was undertaken to study the antiarrhythmic efficacy of oral bepridil on ventricular arrhythmias in patients with stable coronary insufficiency and more than 1 000 ventricular extrasystoles per 24 hours or ventricular tachycardia. The patients were divided into 3 groups according to the arrhythmias observed and the dosage used. In group I, the dosage was 300 mg/day and 12 out of 44 patients (27%) responded favourably to two criteria of efficacy (decrease of 84% of the number of ventricular extrasystoles; suppression of complex ventricular extrasystoles). In group II, the dosage was 300 mg/day, and then increased to 500 mg in non responders. Using the same criteria of efficacy, 13 out of 19 positive results were observed (68.4%). Group III comprised all cases of ventricular tachycardia; bepridil was effective in 3 out of 6 cases, associated with amiodarone in 1 case. The results demonstrate an antiarrhythmic effect of bepridil which is modest at 300 mg/day but which becomes more marked at the dosage of 500 mg/day.

[Posttraumatic infarction with a surgically treated floating thrombus of the left ventricle. Apropos of a case]. / Infarctus post-traumatique avec thrombus flottant du ventricule gauche traité chirurgicalement. A propos d'un cas.

Forty-two days after severe thoracic trauma which had led to thrombosis of the left renal artery and to nephrectomy, a 22 year old patient developed anterior wall infarction. Echocardiography and coronary and left ventricular angiography showed distal occlusion of the left anterior descending artery and the presence of a large, mobile thrombus at the left ventricular apex. The thrombus was removed surgically without any complications but a small thrombus adherent to the ventricular scar was observed postoperatively. After a discussion on the different possible physiopathological mechanisms, the authors conclude that the patient probably suffered primary myocardial contusion which led to secondary occlusion of the LAD artery, late myocardial infarction and extension of the initial intraventricular thrombus. This case illustrates the value of two-dimensional echocardiography in the detection and follow-up of ventricular thrombosis.

[Echography in pneumopericardium. Value of the subxiphoid approach]. / L'échographie dans le pneumopéricarde. Intérêt de la voie sous-xyphoïdienne.

Para-sternal echocardiography proved impossible in a case of a large pneumopericardium caused by an oesophageo-pericardial fistula. However, M mode and sector scanning showed separation of the pericardium, giving non-homogeneous echoes, and shaded echographic areas caused by the interference of air which masked all recognisable structures. This occurred in time with systole, a sign which we associate with the pneumopericardium itself.

Intermittent epidural morphine instillation for control of postoperative pain.

Opiates such as morphine have a direct spinal effect, acting at special receptor sites in the dorsal horn. When morphine is administered epidurally, it diffuses to the cord substance, producing analgesia of improved quality after a dose of 2 to 4 mg. A protracted analgesia is produced, compared with parenteral narcotics, with a median duration of effect of 12 hours in this series. Significant side effects are uncommon, but pronounced respiratory depression can occur late and careful observation is necessary. The first instance of paraplegia in association with epidural morphine anesthesia has been reported herein.

Proximal gastric vagotomy. A prospective study of 829 patients with four-year follow-up.

A prospective controlled trial of proximal gastric vagotomy (PGV) in 829 patients at three surgical services is presented. Peroperative tests of vagotomy completeness were made in two of the three groups of patients. The follow-up period was four to six years. The hospital stay after PGV averaged 9.2 days. The postoperative mortality rate was 0.2%. The reduction of gastric acidity was maintained four years after PGV. Postoperatively no patient had severe diarrhoea. The incidence of dumping after PGV was 1.5% and of gastric stasis 7.3%. Though 7% of the patients reported pyrosis after PGV, only a few required treatment. Transient dysphagia was reported by 2.5% of the patients. In about 4% of the series there were relatively mild ulcer-like symptoms postoperatively, without confirmation of ulcer. Duodenal ulcer recurred in 2% of cases during the observation period and gastric ulcer appeared in 1.5%. According to the Visick classification, 74% of the series showed grade I clinical result, 18% grade II, 4% grade III and 4% grade IV. There were no intergroup differences in Visick grades.

[Liver aspiration biopsy with a disposable instrument: Hepafix (author's transl)]. / Ponction biopsie hépatique avec un matériel jetable. Essai de l'Hépafix.

Liver aspiration biopsies performed with a new disposable instrument (Hepafix) were compared with biopsies performed with the conventional Menghini's needle in 74 patients. The diameter of the needle was the same in both groups, being either 1,4 or 1,6 mm depending upon the case. Twenty-seven of the 39 patients (69,2%) biopsied with the new instrument experienced no pain during puncture, as opposed to only 9 of the 35 patients (25,7%) biopsied with the standard needle. In non-cirrhotic patients, tissue fragments were longer with Hepafix (mean, 40 mm) than with Menghini's needle (mean, 25 mm). The authors' preference goes to Hepafix because it is less painful, responsibly cheap and carries no risk of viral contamination.