Perfect Resonant Absorption of Guided Water Waves by Autler-Townes Splitting.

The control of guided water wave propagation based on the Autler-Townes splitting resonance concept is demonstrated experimentally, numerically, and theoretically. Complete wave absorption is achieved using an asymmetric pointlike scatterer made of two closely spaced resonant side channels connected to a guide and designed so that its energy leakage is in perfect balance with the inherent viscous losses in the system. We demonstrate that the nature of the resonators and guide junction completely controls the positions of the wave numbers at the reflection and transmission zeros on the real axis; the asymmetry of the resonators completely controls their positions on the imaginary axis. Thus, by adjusting these two independent parameters, we obtain a zero reflection and transmission.

[Impact on quality of life and autonomy of patients aged over 75 years treated with anti-PD-1 for metastatic melanoma: A single-centre prospective study]. / Impact sur la qualité de vie et l'autonomie des patients de plus de 75 ans traités par anti-PD-1 pour un mélanome métastatique : étude prospective monocentrique.

INTRODUCTION: We previously studied anti-PD-1 safety in elderly (≥80 years) patients and reported a retrospective two-centre cohort with a similar safety profile in elderly and in younger patients. Quality-of-life evaluation data is still lacking in this specific population. MATERIALS AND METHODS: A prospective, single-centre study in patients aged over 75 years presenting metastatic melanoma treated with anti-PD-1. The endpoint was monitoring of quality of life (by a specific survey) and onco-geriatric assessment at the beginning of therapy, then at 3 and 6 months (nutritional status, comorbidities, autonomy, thymic and cognitive disorders). RESULTS: Fourteen patients were included of median age 86.5 years [range: 78-94] from March to September 2018. General status was good, with a median Charlson score of 0 [extremes 0-4]. Nine patients were evaluated at 3 months and six patients at 6 months. There was no significant difference in quality-of-life scores obtained at baseline, 3 months and 6 months. DISCUSSION: This study shows that neither quality of life nor autonomy appears to be affected by anti-PD-1 treatment in patients aged over 75 years. However, these results should be interpreted with caution due to the small number of patients included, the short follow-up period and the single-centre data. Nevertheless, the prospective analysis and the complete onco-geriatric evaluation and monitoring yielded unique and original data.

Enhanced resonance of sparse arrays of Helmholtz resonators-Application to perfect absorption.

The influence of the spacing on the resonance of a periodic arrangement of Helmholtz resonators is inspected. An effective problem is used which accurately captures the properties of the resonant array within a large range of frequencies, and whose simplified version leaves an impedance condition. It is shown that the strength of the resonance is enhanced when the array becomes sparser. This degree of freedom on the radiative damping is of particular interest since it does not affect the resonance frequency nor the damping due to losses within each resonator; in addition, it does not affect the total thickness of the array. It is shown that it can be used for the design of a perfect absorbing wall.

Generalized method for retrieving effective parameters of anisotropic metamaterials.

Electromagnetic or acoustic metamaterials can be described in terms of equivalent effective, in general anisotropic, media and several techniques exist to determine the effective permeability and permittivity (or effective mass density and bulk modulus in the context of acoustics). Among these techniques, retrieval methods use the measured reflection and transmission coefficients (or scattering coefficients) for waves incident on a metamaterial slab containing few unit cells. Until now, anisotropic effective slabs have been considered in the literature but they are limited to the case where one of the axes of anisotropy is aligned with the slab interface. We propose an extension to arbitrary orientations of the principal axes of anisotropy and oblique incidence. The retrieval method is illustrated in the electromagnetic case for layered media, and in the acoustic case for array of tilted elliptical particles.

Time reversal of water waves.

We present time reversal experiments demonstrating refocusing of gravity-capillary waves in a water tank cavity. Owing to the reverberating effect of the cavity, only a few channels are sufficient to reconstruct the surface wave at the point source, even if the absorption is not negligible. Space-time-resolved measurements of the waves during the refocusing allow us to quantitatively demonstrate that the quality of the refocusing increases linearly with the number of reemitting channels. Numerical simulations corresponding to water waves at larger scales, with negligible damping, indicate the possibility of very high quality refocusing.

Different regimes for water wave turbulence.

We present an experimental study on gravity capillary wave turbulence in water. By using space-time resolved Fourier transform profilometry, the behavior of the wave energy density |η(k,ω)|(2) in the 3D (k,ω) space is inspected for various forcing frequency bandwidths and forcing amplitudes. Depending on the bandwidth, the gravity spectral slope is found to be either forcing dependent, as classically observed in laboratory experiments, or forcing independent. In the latter case, the wave spectrum is consistent with the Zakharov-Filonenko cascade predicted within wave turbulence theory.

A stable, unified model for resonant Faraday cages.

We study some effective transmission conditions able to reproduce the effect of a periodic array of Dirichlet wires on wave propagation, in particular when the array delimits an acoustic Faraday cage able to resonate. In the study of Hewett & Hewitt (2016 Proc. R. Soc. A 472, 20160062 (doi:10.1098/rspa.2016.0062)) different transmission conditions emerge from the asymptotic analysis whose validity depends on the frequency, specifically the distance to a resonance frequency of the cage. In practice, dealing with such conditions is difficult, especially if the problem is set in the time domain. In the present study, we demonstrate the validity of a simpler unified model derived in Marigo & Maurel (2016 Proc. R. Soc. A 472, 20160068 (doi:10.1098/rspa.2016.0068)), where unified means valid whatever the distance to the resonance frequencies. The effectiveness of the model is discussed in the harmonic regime owing to explicit solutions. It is also exemplified in the time domain, where a formulation guaranteeing the stability of the numerical scheme has been implemented.

Estimating the dynamic effective mass density of random composites.

The effective mass density of an inhomogeneous medium is discussed. Random configurations of circular cylindrical scatterers are considered, in various physical contexts: fluid cylinders in another fluid, elastic cylinders in a fluid or in another solid, and movable rigid cylinders in a fluid. In each case, time-harmonic waves are scattered, and an expression for the effective wavenumber due to Linton and Martin [J. Acoust. Soc. Am. 117, 3413-3423 (2005)] is used to derive the effective density in the low frequency limit, correct to second order in the area fraction occupied by the scatterers. Expressions are recovered that agree with either the Ament formula or the effective static mass density, depending upon the physical context.

One-step management of apple-peel atresia.

PURPOSE: Apple-peel atresia is a rare form of bowel atresia associating proximal jejunal atresia with a typical coil-shaped distal small bowel. Many of the children suffering from this condition are still managed with initial enterostomy followed by delayed anastomosis. PATIENTS AND METHOD: Between 2000 and 2007, we managed four patients with apple-peel atresia. Three by primary anastomosis and one by initial enterostomy with delayed anastomosis. RESULTS: Total duration of total parenteral nutrition (TPN) was an average 109 days. Survival rate was 100% with an average follow-up of 4.3 years. CONCLUSION: Nowadays, the prognosis of apple-peel atresia depends mainly on prolonged TPN-related morbidity rather than immediate postoperative complications. We therefore recommend that those infants affected be managed by primary anastomosis in order to reduce the duration of parenteral nutrition, followed by careful nutrition by teams experienced in neonatal TPN and short bowel syndrome.

[An excessive diagnosis of constipation in children complaining of abdominal pain in a pediatric emergency department: an example of practice patterns]. / Une prévalence excessive du diagnostic de constipation chez les enfants consultant pour douleurs abdominales aux urgences: un exemple d'évaluation des pratiques.

UNLABELLED: Prescriptions of abdominal x-ray and diagnosis of constipation seemed too frequent in children evaluated for abdominal pain (AP) in a paediatric emergency unit. OBJECTIVE: To evaluate the prevalence of constipation in children with AP, to determine clinical and radiological signs related to this diagnosis, and to compare frequencies of clinical criteria of functional chronic constipation (FCC) in children with AP with those of controls (children with mild traumatisms without AP). METHODS: This prospective observational study included children older than 4 years of age consulting for AP. RESULTS: Among 196 patients with AP, 53% had a diagnosis of constipation on discharge (28% isolated and 25% associated with an other diagnosis), and 88% had a plain abdominal x-ray. A faecal retention was considered by emergency practitioners in 92% of children with the diagnosis of constipation vs 22% with other diagnosis (OR=38; CI 95%: 15-101). Clinical criteria of FCC were associated with the diagnosis of constipation (OR=2.7; CI 95%: 1.4-5.2). A FCC was as prevalent in the control population as in AP population (32 vs 34%). CONCLUSION: An excessive prevalence of diagnosis of constipation was mainly associated with contestable x-ray diagnosis of faecal retention secondary to inappropriate indications of abdominal x-ray.

Scattering of sound by a vorticity filament: an experimental and numerical investigation.

A vorticity filament is investigated experimentally using the transmission of an ultrasonic wave through the flow. The analysis of the wave-front distortion provides noninvasive measurements of the vortex circulation and size. The latter is estimated by analytical calculations of the scattering of a plane wave by a vorticity filament. The case of a cylindrical wave incident on a vortex leads to similar experimental results which are successfully compared to a parabolic equation simulation. Finally, a finite-difference code based on linear acoustics is presented, in order to investigate the structure of the scattered wave numerically.

A placebo-controlled study of the effects of intravenous Buflomedil on foot skin microcirculation in patients with severe intermittent claudication.

Buflomedil hydrochloride (Buflomedil), a vasoactive drug, has been proven to improve pain-free walking distance in patients with peripheral arterial occlusive disease stage II of the lower extremities. In the present double-blind, randomized study, resting skin flux motion activity and skin flux response to a local heat stress at the hallux were assessed by laser Doppler fluxmetry (LDF) in claudicants. Twenty of 39 enrolled patients with severe intermittent claudication received a daily intravenous dose of 400 mg Buflomedil, and the other 19 patients received 0.9% NaCl as placebo over a 5-day period. Before treatment mean LDF skin resting flux, flux frequency, and flux amplitude were 2 +/- 0.8 Arbitrary Units (AU), 8.4 +/- 0.5 cycles per minute (c/min), and 0.12 +/- 0.01 AU, respectively in the Buflomedil group, and 2.3 +/- 0.3 AU, 8.7 +/- 0.7 c/min, and 0.13 +/- 0.02 AU in the placebo group (NS). Also the response to heat stress was identical in both groups: a slow initial increase of skin flux, followed by a reflex reduction, with a maximal initial flux increase to 138 +/- 12% of the resting value in the Buflomedil group, and 155 +/- 16% in the placebo group (NS). After 5 days of treatment the mean LDF skin resting flux, flux frequency, and flux amplitude were unchanged in both patient groups. The response to heating on the contrary was dramatically enhanced in the Buflomedil group (226 +/- 33%), against that in the placebo group, which remained unchanged (144 +/- 13%) after 3 minutes (P < 0.05), while after reflex reduction the flux in the Buflomedil group remained stable at 200% of resting value during further heating and was only approximately 140% in the placebo group (P < 0.05). It is concluded that Buflomedil, administered in a daily intravenous dose of 400 mg, does not alter the mean LDF skin flux and flux motion at the hallux in claudicants in resting conditions. Local skin heating on the contrary provokes a significant LDF-monitored skin flux increase, suggesting an improved capacity of cutaneous microvessel perfusion in stressed conditions.

[Preoperative prognostic factors for squamous cell carcinomas of the thoracic esophagus]. / Facteurs pronostiques préopératoires des cancers épidermoïdes de l'oesophage thoracique.

AIM OF THE STUDY: To identify preoperative survival prognostic factors in patients with resectable squamous cell carcinoma of the thoracic esophagus. POPULATION: From January 1982 to September 1999, 868 patients underwent surgery for esophageal carcinoma in our department, including 493 for squamous cell carcinoma of the thoracic esophagus. The following parameters were retrospectively included in univariate and multivariate analysis: age, sex, undernutrition, dysphagia, tumor diameter and nodal involvement on the CT-scan, preoperative treatment, surgical technique, curative resection, pTNM classification, histologic type and postoperative complications. The actuarial survival was determined. RESULTS: Survival prognostic factors were dysphagia, nodal involvement on CT-scan and depth of tumor invasion at pathological examination. Three groups of patients were identified on the two preoperative variables: group 1: patients without dysphagia (n=102), group 2: patients with dysphagia but without nodal involvement on the CT- scan (n=244), group 3: patients with dysphagia and with nodal involvement on the CT- scan (n=147). The median survivals were 62.4, 19.1 and 14.4 months in groups 1, 2 and 3, respectively, and 5-year actuarial survivals were 50%, 21% and 11% (P<0.009). CONCLUSION: Our study confirms that dysphagia and nodal involvement on the CT-scan are simple preoperative prognostic factors in patients with resectable squamous cell carcinoma of the thoracic esophagus.

[Edematous syndromes caused by capillary hyperpermeability. Diffuse angioedema]. / Les syndromes oedémateux par hyperméabilité capillaire. Angioedèmes diffus.

Edema due to increased capillary permeability (ICP) may be diffuse or localized. Local edemas (Quincke edema, angioneurotic edema) are most often allergic or very rarely due to a defect in C1-inhibitor. Generalized edemas due to ICP share the following clinical features: Fluid retention (subcutaneous edema and diffused swelling) is predominant in lower limbs; it is worsened by orthostatism and warmth and alleviated by decubitus and cold, with important weight variations between morning and evening. It is associated with enhanced thirst, hypotension, oliguria, headaches and blood volume reduction; secondary hyperaldosteronism is the main mechanism. These troubles are due to ICP, associated with lymphatic drainage abnormalities; ICP is measured by the isotopic Landis Test. This abnormality is present in several diseases. Idiopathic orthostatic edema (IOE) is frequent and often unrecognized, occurring mainly in women, often associated with luteal insufficiency. Iatrogenic complications (diuretic and laxative abuses) are frequently superimposed. ICP may be corrected by vitamins P (rutin, anthocyanosides, diosmin, Ginkgo biloba extracts...) Cyclic shock due to ICP is rare. It is characterized by cyclic edema and shock with hypovolemia, hypoproteinemia; the mechanism of shock is a severe loss of fluid and protein from the vascular bed. It is often associated with monoclonal gammapathy and complement activation. In our personal case, the trouble in CP was present all along the disease with permanent edema and low blood pressure (especially in orthostatism). Vit "P" and Ginkgo biloba extracts were able to partially improve CP and the clinical troubles. However, in spite of this treatment a fatal shock occurred after ten years follow-up. Episodic angioedema associated with eosinophilia was first described by Gleich.(ABSTRACT TRUNCATED AT 250 WORDS)

[Obstacles to stopping smoking among patients with vascular risk]. / Les difficultés de l'arrêt du tabac chez les sujets à risque vasculaire.

Despite the risk, smoking has only slightly decreased and the percentage of heavy smokers increases. The reason for the paradoxical situation has now been identified in more than 95% of the cases and is due to behaviour amplified by a pharmacological dependence on nicotine. The psycho-active effects of nicotine binding to nicotine receptors in the brain, produce a quasi constant physical dependence and a psychic dependence in certain smokers.

[Conjunctival and peri-ungual angioscopy in noninsulin-dependent diabetes mellitus. Informational value of observed anomalies]. / Angioscopies conjonctivales et péri-unguéales dans les diabètes non insulino-dépendants. Valeur informationelles des anomalies observées.

Microangiopathy is one of the most frequent and serious complications of diabetes. Its diagnosis is based on fundus of eye and fluorescein angiography findings, but several teams have emphasized the value of conjunctival angioscopy (CA) and peri-ungual capillaroscopy (PUC), describing suggestive anomalies: microectatic venous dilatation (V/A greater than 4.5), sludge on CA, "fish shoal" capillaries on PUC. Up to the present, however, the diagnostic value of these anomalies has not been evaluated based on data that are sensitive, specific and indicate predictive positive and negative values of a sign (Se, Sp, PPV, NPV). Anomalies of CA and PUC as a function of presence or absence of "diabetes" were studied in 114 patients with moderate hypertension, including 46 "diabetics" (33 with glucose regulation disorders and 13 non-insulin dependent diabetics). "Diabetes" was observed more predominantly in males of more advanced age and with a significantly higher global CA score (4.25 +/- 1.44 as against 2.65 +/- 1.35), and this in an increased manner as the "diabetes" was severe. Some anomalies had themselves a major orientation value with an Sp greater than 80% and an Se close to 40% (global score greater than 4; V/A greater than 4.5, microectasia, rheologic changes). For the fish shoal appearance the Sp was 73.5% and the Se 43.5%. The Sp was greater than 95% when at least 4 of the following 6 signs were present: global score greater than 4, V/A greater than 4.5, microectasia, rheologic disorders, fish shoal, gerontoxons. The more signs associated the more the Sp increased; the Se decreased from 40% for one sign to less than 10% for 4 associated signs.(ABSTRACT TRUNCATED AT 250 WORDS)

[Action of Buflomedil on the cutaneous microcirculation studies by a cold provocation test. Multicenter, double-blind, placebo controlled trial]. / Action du Buflomédil sur la microcirculation cutanée étudiée par un test de provocation au froid. Etude multicentrique, double aveugle versus placebo.

The aim of this multicentre trial involving 136 cardiologists was to evaluate, in double-blind versus placebo design, the vasoactive effect of Buflomedil in out-patients with a very simple cooling-test from a practical standpoint and previously described (1). The authors have selected patients having a basal pulpar temperature below 30 degrees C by cutaneous thermometer and falling after immersion of the contralateral hand in water at 4 degrees C, with out complete recovery during 10 minutes following withdrawal. This study carried out 408 eligible patients with 398 finally included in double-blind period (200 in the Buflomedil group, 198 in the placebo group). After a run-in period of 7 days with placebo in single blind, to evaluate the stability of measures, the patients were then treated with either Buflomedil 600 mg a day or placebo at the same dosage, for 14 days. The patients in both groups had a Raynaud's phenomenon and were heavy smokers (> or = 20 packs/year), having either acrocyanosis or lower limbs arterial occlusive disease. The results have shown, after 14 days of oral treatment an increase of basal temperature of 2.01 degrees C in Buflomedil group, versus only 0.82 degrees C in placebo group. This warming-up give evidence of microcirculatory blood flux increasing. This significant difference between the both groups was the same each measurement time after immersion during the recovery phase. There also was a good parallelism between the cutaneous temperature and the global clinical improvement by visual analogic scale filled out by the investigator (p < or = 0.0001) and the patients (p < or = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Cutaneous pulpar temperature and cold test. Predictive specificity and sensitivity in pharmaco-clinical studies]. / Température cutanée pulpaire et test au froid. Spécificité et sensibilité prédictives en pharmacoclinique.

The aim of this study was to measure the cutaneous pulpar temperature of the fingers and assess its evolution after one minute of controlateral hand immersion in a water bath at 4 degrees C and during 10 minutes after cooling. This test was carried out in 347 subjects (120 M, 227 F) divided in 5 groups: 117 healthy volunteers (49 M, 68 F) without any vascular diseases, 46 patients (5 M, 41 F) with acrocyanosis, 87 patients (19 M, 68 F) with Raynaud's phenomenon, 31 patients (24 M, 7 F) with peripheral arterial occlusive disease and 66 patients (23 M, 43 F) with other vascular diseases (high blood pressure and coronary disease). The mean initial temperature (TO) analysis in each group, showed that 2 groups, acrocyanosis and especially Raynaud's group, had a finger temperature significantly lower than the control group (27.4 +/- 4.8 degrees C 25.3 +/- 4.9 degrees C versus 30.5 +/- 4.9, p < 0.02). The cooling test showed 3 different cutaneous temperature reactions: subjects without any modification during and after immersion, subjects with a temperature decreasing after immersion and a normal rewarming after 10 minutes and subjects with a decreasing without any total recovery after 10 minutes. In the subjects with cold hands (initial temperature < 30 degrees C), this cooling test can isolate all patients with a temperature decreasing without any rewarming after 10 minutes with a specificity at 100% (no normal subject with cold hands were abnormal to this test).(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of smoking on blood rheology]. / Influence du tabagisme sur la rhéologie sanguine.

The aim of this study was to compare the effects of cigarette smoking on biologic and rheologic tests, chiefly on the red blood cells (RBC) in measuring the deformability by the Cell Transit Analyser (CTA) and their aggregation by using an ultrasonic interferometry method based on A-mode echography allowed for the measurement of the accumulation rate of particles in a solid plate which is related to their sedimentation rate (Echo-Cell). Nine male smoker subjects with a high nicotine addiction measured by Fagerström questionnaire (> 8) and level of carbon monoxide (CM) in the breathed out air (> 20 ppm), have been compared with ten healthy no-smoker volunteers (CM < 3 ppm). One smoker has been eliminated of statistic evaluations because his glucose level showed a diabetes (10.5 mmol/l). A nailfold capillaroscopy performed in all subjects has eliminated the patterns of latent vasculitis or scleroderma. RBC and platelets counts, hemoglobin, ionogram, gamma GT, ASAT, ALAT, uric acid, total cholesterol and glucose levels were not significantly different between the two groups. On the other hand, in the smoker group, white blood cells count, serum triglycerides and especially fibrinogen values were higher than in the non-smoker's group. RBC sedimentation rate was normal in the two groups but was higher in smoker's group too. Without consumption of alcohol, the mean RBC volume was more important in smokers (91.9 +/- 1.2 versus 87.5 +/- 0.4, p = 0.003). Rheologic tests were more pathologic in smokers. The transit time or RBC by CTA was longer than in control group (1.6 ms +/- 0.02 versus 1.2 +/- 0.05, p = 0.0003). Echo-Cell technic showed a number and size of RBC aggregates more important with a rate of speed of accumulation higher than in the control group. These results demonstrated the toxic effects of smoking alone on blood toward a propensity for thrombotic status.

[Leg volumetry: a precise method for quantification in phlebology]. / La volumétrie: une méthode précise de quantification en phlébologie.

UNLABELLED: Chronic venous insufficiency is usually quantified by venous pressure measurement, which is an invasive method. Air plethysmography has also been used, but it is expensive, time consuming and only suitable for sophisticated research laboratories. Leg volumetry might be suitable for routine use, as it is simple, inexpensive, fast, non invasive and can be performed by non medical personnel. Here, we only evaluated its practicability, accuracy and reproducibility. PATIENTS: The study group included 28 legs of 14 healthy volunteers, and 22 legs of 11 patients suffering from varicose veins. METHOD: The device used was a plexiglass boot, 50 cm high, 20 cm wide. It was filled with water at 24 +/- 2 degrees C. The leg was immersed and the volume of water displaced recorded. RESULTS: Normal legs displaced a volume of 2,449 +/- 153 ml (mean +/- SD), range: 2,080-2,720, and variability 6.2%. Patients' legs displaced a volume of 2,576 +/- 290, range: 2,110-3,120, (p = 0.05 vs normals) and variability 11.2%. Accuracy was 0.7%, as from 2 consecutive measurements of the same patients' legs by 2 different observers. Intra-individual variability was 1.3%, as recorded in 12 repeated measurements of the same leg on different mornings. In normal legs, the difference between morning and evening volumes was statistically significant (18 +/- 15 ml, p = 0.0001), a finding consistent with the deterioration of the venous function in normal extremities during daily activities. CONCLUSION: This simple, cheap, objective, non-invasive reproducible and accurate method of leg volume measurement might be useful in routine practice for chronic venous insufficiency quantification.