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Vernonia species (Asteraceae) are indigenous medicinal and food leaf vegetables commonly consumed in some African countries like Cameroon where they constitute a staple dish called "ndolé." Previous studies have demonstrated the nutritional importance of Vernonia, but there is little knowledge of their agronomic value and genetic potentials. Wide genetic variability in the genus has been established earlier through the study of its pollen. However, to the best of our understanding, no such study has been undertaken on the genetic variability of Vernonia with respect to its secondary metabolites. This study was therefore aimed at evaluating the genetic variability of Vernonia amygdalina (VAA and VALF) and V. calvoana (VCAB, VCAV, VCSB, and VCSV) morphotypes in 2016 based on secondary metabolite content and antimicrobial properties. This involved phytochemical analysis by HPLC/MS for the detection of alkaloids, flavonoids, phenols, and tannins in leaves from each of the six genotypes. Results showed that all tested genotypes are rich in phenols (18 analyzed), flavonoids, and tannins with, VAA richer in phenols (206.1 ± 3.12 µg/g of dry extract), followed by VCAV (197.9 ± 18.03 µg/g). The lowest level of flavonoid was found in VCSV (81.6 ± 7.21 µg/g), while the highest was from VCAB (132.8 ± 31.5 µg/g). VCSV (56.3 ± 4.08 µg/g) had the lowest level of tannins, while VCAB (97.8 ± 23.8 µg/g) had the highest levels. Assessment of antimicrobial activity of leaf extracts from the six genotypes was done by culture on Mueller Hinton (MH) agar and MH broth agar for bacteria and in Sabouraud dextrose agar and Sabouraud dextrose broth media for fungi, respectively. All morphotypes exhibited inhibitory activity on bacteria except VAA, with isoquercetin characteristic of VCSV. Chemotaxonomic analyses of Vernonia morphotypes highlighted the genetic diversity within species and variability of antimicrobial properties of ethanolic leaf extracts among morphotypes. These results provide baseline data in the valuation of genetic resources and the establishment of improvement programs.

Summary Background Coarctation of the aorta (CoA) is still challenging to diagnose in neonates with patent ductus arteriosus (PDA). Speckle tracking echocardiography allows reliable analysis of myocardial deformation in newborns and seems to provide important insides into regional changes in patients with left ventricular (LV) outflow tract obstruction. Aims To assess the interest of LV global longitudinal strain (GLS) measurement for predicting CoA in neonates with PDA and prenatal suspicion. Methods Prospective single-center study. Twenty-two newborns with prenatal suspicion of CoA were included. All newborns were evaluated in the first 12 hours of life. To assess the feasibility and the reproducibility of GLS, 14 healthy full-term newborns with PDA (group 3) were screened. CoA was diagnosed when DA closed, according to usual echocardiographic criteria. Results Six neonates developed CoA after DA closure (group 1) whereas 16 did not (group 2). Mean gestational age and birth weight were not different between the groups. GLS measurements were possible in 100%. Intra- and inter-observer variability of strain measurements was acceptable. GLS values were significantly lower in neonates who developed CoA (P = 0.015). To predict CoA, cut-off value of −17.42% gave the best compromise for sensitivity (83%) and specificity (72%). Aortic arch dimensions were modestly correlated with strain values. The presence of a bicuspid aortic valve was not associated with significant lower GLS values. Conclusion LV GLS analysis is a feasible and reproducible echocardiographic technique in newborns with PDA. Newborns who will develop CoA seem to have lower values of GLS than healthy neonates. Further studies are needed to confirm these preliminary results.

The study of pollen dispersal and mode of fertilization of Vernonia amygdalina and Vernonia calvoana is a prerequisite to the understanding of genetic diversity and elaboration of improvement programs for the Vernonia genus. In this study, precise experimental designs were made for morphological and biological observations on Vernonia species capitulum in order to assess the distinctive effects of each of the three possible pollen transportation agents (insects, wind and rain water) on pollination. Results obtained show that the exclusive mode of pollen dispersal is entomophilous. Even though allogamy and autogamy are observed as two possible modes of fertilization in Vernonia spp., some arguments tend to favour allogamy. However, there is no clear cut position on the issue, hence the need for confirmation by further experimentation in controlled pollination. This study paves the way for the establishment of a genetic improvement program for this genus based on the results on pollen dispersal. Key words: Vernonia species, allogamy, autogamy, pollination agent.

The mechanisms underlying pulmonary hypertension (PH) are complex and multifactorial, and involve different cell types that are interconnected through gap junctional channels. Although connexin (Cx)-43 is the most abundant gap junction protein in the heart and lungs, and critically governs intercellular signalling communication, its contribution to PH remains unknown. The focus of the present study is thus to evaluate Cx43 as a potential new target in PH.Expressions of Cx37, Cx40 and Cx43 were studied in lung specimens from patients with idiopathic pulmonary arterial hypertension (IPAH) or PH associated with chronic hypoxaemic lung diseases (chronic hypoxia-induced pulmonary hypertension (CH-PH)). Heterozygous Cx43 knockdown CD1 (Cx43+/−) and wild-type littermate (Cx43+/+) mice at 12 weeks of age were randomly divided into two groups, one of which was maintained in room air and the other exposed to hypoxia (10% oxygen) for 3 weeks. We evaluated pulmonary haemodynamics, remodelling processes in cardiac tissues and pulmonary arteries (PAs), lung inflammation and PA vasoreactivity.Cx43 levels were increased in PAs from CH-PH patients and decreased in PAs from IPAH patients; however, no difference in Cx37 or Cx40 levels was noted. Upon hypoxia treatment, the Cx43+/− mice were partially protected against CH-PH when compared to Cx43+/+ mice, with reduced pulmonary arterial muscularisation and inflammatory infiltration. Interestingly, the adaptive changes in cardiac remodelling in Cx43+/− mice were not affected. PA contraction due to endothelin-1 (ET-1) was increased in Cx43+/− mice under normoxic and hypoxic conditions.Taken together, these results indicate that targeting Cx43 may have beneficial therapeutic effects in PH without affecting compensatory cardiac hypertrophy.

For traveling waves with nonzero boundary conditions, we justify the logarithmic Korteweg-de Vries equation as the leading approximation of the Fermi-Pasta-Ulam lattice with Hertzian nonlinear potential in the limit of small anharmonicity. We prove control of the approxi- mation error for the traveling wave solutions satisfying differential advance-delay equations, as well as control of the approximation error for time-dependent solutions to the lattice equations on long but finite time intervals. We also show nonlinear metastability of the traveling waves on long but finite time intervals.

Pulmonary hypertension (PH) is a disease that affects the adult or infant population. Dehydroepiandrosterone (DHEA), a steroid hormone, has been previously shown to prevent and to reverse PH in an adult rat model. We thus investigated its effect in a rat-pup model of chronic hypoxic PH.Animals were maintained for 3 wk in a hypobaric chamber to induce PH, with or without concomitant treatment with DHEA (30 mg/kg every alternate day).DHEA significantly reduced mean pulmonary artery pressure (measured by right cardiac catheterization), pulmonary artery remodeling (evaluated by histology), and right-ventricular hypertrophy (measured by echography and by the Fulton index). At the level of the pulmonary artery smooth muscle cell (PASMC), DHEA increased activity and expression of the large-conductance Ca2+-activated potassium channel (BKCa) (assessed by means of the patch clamp technique). DHEA also inhibited both serotonin- and KCl-induced contraction and smooth muscle cell proliferation.Collectively, these results indicate that DHEA prevents PH in infant rats and may therefore be clinically relevant for the management of PH in human infants.

Dehydroepiandrosterone (DHEA) is a steroid hormone derived from cholesterol synthesized by the adrenal glands. DHEA and its 3β-sulphate ester (DHEA-S) are the most abundant circulating steroid hormones. In human, there is a clear age-related decline in serum DHEA and DHEA-S and this has suggested that a relative deficiency in these steroids may be causally related to the development of a series of diseases associated with aging including cardiovascular diseases (CVD). This commentary aims to highlight the action of DHEA in CVD and its beneficial effect in therapy. We thus discuss the possible impact of serum DHEA decline and DHEA supplementation in diseases such as hypertension, coronary artery disease and atherosclerosis. More specifically, we provide evidence for a beneficial action of DHEA in the main disease of the pulmonary circulation: pulmonary hypertension. We also examine the potential cellular mechanism of action of DHEA in terms of receptors (membrane/nuclear) and associated signaling pathways (ion channels, calcium signaling, PI3K/AKT/eNos pathway, cGMP, RhoA/RhoK pathway). We show that DHEA acts as an anti-remodeling and vasorelaxant drug. Since it is a well-tolerated and inexpensive drug, DHEA may prove to be a valuable molecule in CVD but it deserves further studies both at the molecular level and in large clinical trials.

Background Meconium aspiration syndrome (MAS) remains a frequent cause of morbidity and mortality in term newborns. Our objective was to compare two modes of high-frequency ventilation, high-frequency oscillation (HFOV), and high-frequency percussive ventilation (HFPV) with conventional mechanical ventilation (CMV) in a piglet model of MAS. Methods Fifteen newborn piglets were anesthetized, paralyzed, and intubated. Following the instillation of a 3 ml/kg solution of meconium diluted to 30%, the piglets were randomized to one of three groups: high-frequency oscillation (HFOV; Sensormedics®), HFPV (Percussionaire®), or CMV (Siemens®). Animals were ventilated for 6 hr to maintain arterial blood gases within a normal range, that is, pH 7.35–7.45, PaO2 10–16 kPa, PaCO2 4–6.6 kPa. Arterial blood gas measurements, dynCrs and dynRrs, ventilator settings, and vital signs (heart rate, arterial blood pressure, transcutaneous pulse oxygen saturation, and temperature) were collected at 30, 60, 90, 120, 180, 240, 300, and 360 min after meconium instillation. Oxygenation index (OI) ([(fraction of inspired oxygen)(mean airway pressure)(100)]/PaO2), mean airway pressure, dynamic lung function, secretions cleared and histological alterations were studied in all groups. Results Mean airway pressure and OI were significantly lower in the CV and HFPV groups compared to the HFOV group (P

It was previously shown that dehydroepiandrosterone (DHEA) reverses chronic hypoxia-induced pulmonary hypertension (PH) in rats, but whether DHEA can improve the clinical and hemodynamic status of patients with PH associated to chronic obstructive pulmonary disease (PH-COPD) has not been studied whereas it is a very severe poorly treated disease.Eight patients with PH-COPD were treated with DHEA (200mg daily orally) for 3 months. The primary end-point was the change in the 6-minute walk test (6-MWT) distance. Secondary end-points included pulmonary hemodynamics, lung function tests and tolerance of treatment.The 6-MWT increased in all cases, from 333m (median [IQR]) (257; 378) to 390m (362; 440) (P0.05). Mean pulmonary artery pressure decreased from 26mmHg (25; 27) to 21.5mmHg (20; 25) (P0.05) and pulmonary vascular resistance from 4.2UI (3.5; 4.4) to 2.6UI (2.5; 3.8) (P0.05). The carbon monoxide diffusing capacity of the lung (DLCO % predicted) increased significantly from 27.4% (20.1; 29.3) to 36.4% (14.6; 39.6) (P0.05). DHEA treatment did not change respiratory parameters of gas exchange and the 200mg per day of DHEA used was perfectly tolerated with no side effect reported.DHEA treatment significantly improves 6-MWT distance, pulmonary hemodynamics and DLCO of patients with PH-COPD, without worsening gas exchange, as do other pharmacological treatments of PH (trial registration NCT00581087).

We study the interaction of (slowly modulated) high frequency waves for multi-dimensional nonlinear Schrodinger equations with gauge invariant power-law nonlinearities and non-local perturbations. The model includes the Davey--Stewartson system in its elliptic-elliptic and hyperbolic-elliptic variant. Our analysis reveals a new localization phenomenon for non-local perturbations in the high frequency regime and allows us to infer strong instability results on the Cauchy problem in negative order Sobolev spaces, where we prove norm inflation with infinite loss of regularity by a constructive approach., Comment: 33 pages

Background— Pulmonary artery hypertension (PAH) is a proliferative disorder associated with enhanced pulmonary artery smooth muscle cell proliferation and suppressed apoptosis. The sustainability of this phenotype required the activation of a prosurvival transcription factor like signal transducers and activators of transcription-3 (STAT3) and nuclear factor of activated T cell (NFAT). Because these factors are implicated in several physiological processes, their inhibition in PAH patients could be associated with detrimental effects. Therefore, a better understanding of the mechanism accounting for their expression/activation in PAH pulmonary artery smooth muscle cells is of great therapeutic interest. Methods and Results— Using multidisciplinary and translational approaches, we demonstrated that STAT3 activation in both human and experimental models of PAH accounts for the expression of both NFATc2 and the oncoprotein kinase Pim1, which trigger NFATc2 activation. Because Pim1 expression correlates with the severity of PAH in humans and is confined to the PAH pulmonary artery smooth muscle cell, Pim1 was identified as an attractive therapeutic target for PAH. Indeed, specific Pim1 inhibition in vitro decreases pulmonary artery smooth muscle cell proliferation and promotes apoptosis, all of which are sustained by NFATc2 inhibition. In vivo, tissue-specific inhibition of Pim1 by nebulized siRNA reverses monocrotaline-induced PAH in rats, whereas Pim1 knockout mice are resistant to PAH development. Conclusion— We demonstrated for the first time that inhibition of the inappropriate activation of STAT3/Pim1 axis is a novel, specific, and attractive therapeutic strategy to reverse PAH.

Objective To determine whether nasal high frequency percussive ventilation (NHFPV) would decrease duration of transient tachypnea of the newborn (TTN) compared to nasal continuous positive airway pressure (NCPAP) in newborn infants. Methods A prospective, unmasked, randomized, controlled clinical trial was conducted in 46 eligible newborn infants who were hospitalized for TTN in the University Hospital of Bordeaux (France) between 2007 and 2009. Infants born by cesarian section ≥37 GA, ≥2,000g with diagnosis of TTN and with a transcutaneous saturation

Pulmonary arterial hypertension (PAH) is a severe disease that leads to increased pulmonary vascular resistance and right heart failure. Noninvasive methods are needed to detect changes in the pulmonary artery circulation during PAH establishment and/or treatment. Pulmonary blood flow velocity can be evaluated by dynamic MR angiography, although the relevance of such data in the context of PAH remains to be demonstrated. A novel dynamic MR angiography technique was used in this work to measure blood flow velocity in the pulmonary arteries of the same living animals, before and after the establishment of chronic hypoxia-induced PAH. Chronic hypoxia decreased significantly the blood flow velocity (43.8 ± 4.9 vs 24.3 ± 8.7 cm/s) on electrocardiography-triggered time-resolved angiograms. In parallel, chronic hypoxia-induced PAH was confirmed from invasive measurements of the mean pulmonary arterial pressure (32.1 ± 4.8 vs 12.5 ± 2.2 mmHg) and the ratio of the right ventricle weight to the left ventricle plus septum weight (Fulton index: 0.54 ± 0.06 vs 0.27 ± 0.04). This study demonstrates the potential interest of dynamic MR angiography for the investigation of experimental models and for the evaluation of treatment efficacy. Copyright © 2010 John Wiley & Sons, Ltd.

This review describes the cellular and molecular mechanism heterogeneity of dehydroepiandrosterone (DHEA) and its putative therapeutic role in vascular remodeling diseases such as pulmonary artery hypertension (PAH). PAH is characterized by enhanced pulmonary artery smooth muscle cell (PASMC) proliferation, constriction and resistance to apoptosis, all of which contribute to increase the pulmonary artery wall thickness, resistance and therefore pressure. The etiology of PAH remains elusive. Nonetheless, the implications of endothelial dysfunction (decreased nitric oxide generation and increased endothelin production etc), PASMC K(+) channel/mitochondrial axis disruption (voltage-gated K(+) channel (Kv1.5) downregulation and mitochondrial membrane potential hyperpolarization) and the activation of survival pathways such as PI3K/Akt are now accepted. Therefore, a drug able to target all of these abnormalities would be of a great therapeutic interest for the treatment of PAH. We and others have demonstrated that DHEA, a clinically available drug with a low adverse effect profile, is able to achieve these effects. In several animal models of vascular remodeling diseases such as PAH, DHEA has been demonstrated to be a good anti-proliferative and pro-apoptotic drug, decreasing vascular remodeling, and a potent vasodilator. A better understanding of the DHEA mechanisms of action may allow the development of new and better therapies to treat vascular remodeling diseases such as pulmonary hypertension.

The focusing cubic NLS is a canonical model for the propagation of laser beams. In dimensions 2 and 3, it is known that a large class of initial data leads to finite time blow-up. Now, physical experiments suggest that this blow-up does not always occur. This might be explained by the fact that some physical phenomena neglected by the standard NLS model become relevant at large intensities of the beam. Many ad hoc variants of the focusing NLS equation have been proposed to capture such effects. In this paper, we derive some of these variants from Maxwell's equations and propose some new ones. We also provide rigorous error estimates for all the models considered. Finally, we discuss some open problems related to these modified NLS equations.

Background: There is insufficient data to reliably assess the benefit of bronchodilators in ventilated premature neonates. Objectives: To compare the efficacy/tolerance of inhaled ipratropium bromide (IB) vs. terbutaline (T) and to describe factors associated with their efficacy. Methods: A cross-over randomized controlled double-blind trial including intubated neonates with respiratory distress syndrome. Two puffs of IB or T were administered at 0, 20, 40 min. Passive respiratory system resistance (Rrs) and compliance (Crs) were measured at 0, 20, 40, 60 min. A positive response was defined as a >2 individual coefficients of variation decrease in Rrs or increase in Crs. Results: Twenty-one infants (gestational age (mean ± SD): 27.3 ± 1.6 weeks; birth weight: 947 ± 250 g; postnatal age: 20 ± 9 days) were included. At 60 min, no treatment effect for Rrs and Crs could be identified (cross-over analysis). Overall data (irrespective of order of administration) showed that after 6 puffs, the decrease in Rrs was greater in the IB vs. T group (–17.0 ± 22.2% vs. –11.3 ± 26.7%, respectively (NS)). Thirty-eight percent of infants responded to IB vs. 43% to T. However, in 19% of patients, decreased Crs was observed after 6 puffs of T. No marker of a positive or paradoxical response could be identified. Treatment was well-tolerated. Conclusion: High doses of bronchodilators are required in ventilated neonates, but the positive response rate was

Spontaneous or agonist-induced contraction of airway smooth muscle can be observed very early in fetal life, thus explaining the possible occurrence of bronchospasm in very low birth weight infants within the first days of life. In an attempt to better manage such bronchospasms, the aim of the present study was to investigate the age-specific modifications in airway smooth muscle relaxation to β2-agonists and muscarinic antagonists using a combination of functional and molecular techniques. In the rat, isometric relaxation to the β2-agonist salbutamol was examined in tracheae; we also examined muscarinic receptor expression (M2R and M3R mRNA levels) in airway smooth muscle by immunochemistry, Western blotting, and real-time PCR. Compared with adults, salbutamol-induced relaxation was twofold greater in immature rat isolated tracheae preconstricted by carbachol. This effect was associated with a lower expression of M2R in the smooth muscle of immature animals (sixfold and almost twofold as assessed by immunochemistry and Western blotting, respectively). Real-time PCR data indicate that changes in M2R expression according to age occurred at a posttranscriptional level. In adult airways, there was a significantly greater functional efficacy of M2R blockade by methoctramine compared with that shown in immature rats. Because of the limited availability of human neonate lung tissue, only the molecular part of the study was performed, and we observed a qualitatively similar effect, i.e., a lower M2R expression in the neonatal airway smooth muscle, although this was quantitatively smaller. We conclude that β2-agonist-induced relaxation is enhanced in immature compared with adult airways as a result of greater postjunctional M2R expression in adult airway smooth muscle. This finding may be of importance in the clinical management of bronchoconstriction in neonates.

The purpose of this study was to evaluate the reversibility of right ventricular (RV) remodelling after pulmonary artery hypertension (PAHT) secondary to 3 wk of hypobaric hypoxia. A group of 10 adult male Wistar rats were studied and were the following: control normoxic (C), after 3 wk of chronic hypoxia (CH), and after 3 wk of exposure to hypoxia followed by 3 wk of normoxia recovery (N-RE). Mean pulmonary artery pressure was 11 ± 2 mmHg in the C group, 35 ± 2 mmHg in the CH group, and 14 ± 3 mmHg in the N-RE group. RV function was assessed by echocardiography. In the CH group, the pulmonary flow measured in Doppler mode depicted a midsystolic notch and a decrease of the pulmonary acceleration time compared with control [17 ± 1 vs. 34 ± 1 ms ( n = 10), respectively; P < 0.05]. RV thickening measured in M-mode was apparent in the CH group compared with the control group [2.84 ± 0.40 vs. 1.73 ± 0.26 mm ( n = 10), P < 0.05]. In the N-RE group, the RV wall was significantly thinner compared with the CH group [1.56 ± 0.08 vs. 1.73 ± 0.26 mm ( n = 10), P < 0.05]. The calculated RV diameter shortness fraction was not different between the CH group and C group (34 ± 4.2% vs. 36 ± 2.8%) but decreased in the N-RE group [20 ± 2.4% ( n = 10), P < 0.01]. The E-to-A wave ratio on the tricuspid Doppler inflow was significantly lower in the CH group and N-RE group compared with the C group [0.70 ± 0.8 and 0.72 ± 0.1 vs. 0.88 ± 0.2 ( n = 10), respectively; P < 0.05]. In the isolated perfused heart using the Langendorff method, RV compliance was increased in the CH group and decreased in the N-RE group. In the N-RE group, fibrous bands with metaplasia were observed on histological sections of the RV free wall. We conclude that PAHT induces nonreversible RV dysfunction with dysplasia.

Pulmonary artery (PA) hypertension was studied in a chronic hypoxic-pulmonary hypertension model (7–21 days) in the rat. Increase in PA pressure (measured by catheterism), cardiac right ventricle hypertrophy (determined by echocardiography), and PA remodeling (evaluated by histology) were almost entirely prevented after oral dehydroepiandrosterone (DHEA) administration (30 mg/kg every alternate day). Furthermore, in hypertensive rats, oral administration, or intravascular injection (into the jugular vein) of DHEA rapidly decreased PA hypertension. In PA smooth muscle cells, DHEA reduced the level of intracellular calcium (measured by microspectrofluorimetry). The effect of DHEA appears to involve a large conductance Ca 2+ -activated potassium channel (BK Ca )-dependent stimulatory mechanism, at both function and expression levels (isometric contraction and Western blot), via a redox-dependent pathway. Voltage-gated potassium (Kv) channels also may be involved because the antagonist 4-amino-pyridine blocked part of the DHEA effect. The possible pathophysiological and therapeutic significance of the results is discussed.

We describe diffraction for rapidly oscillating, periodically modulated nonlinear waves. This phenomenon arises for example when considering long-time propagation, or through perturbation of initial oscillations. We show existence and stability of solutions to variable coefficient, nonlinear hyperbolic systems, together with 3-scale multiphase infinite-order WKB asymptotics: the fast scale is that of oscillations, the slow one describes the modulation of the envelope, which is along rays for the oscillatory components, and the intermediate one corresponds to transverse diffraction. It gives rise to nonlinear Schrodinger equations on a torus for the profiles. The main difficulty resides in the fact that the coefficients in the original equations are variable: thus, phases are nonlinear, and rays are not parallel lines. This induces variable coefficients in the integro-differential system of profile equations, which in general is not solvable. We give sufficient (and, in general, necessary) geometrical coherence conditions on the phases for the formal asymptotics to be rigorously justified. Small divisors assumptions are also needed, which are generically satisfied.

As the wavelength $\varepsilon$ goes to zero, the slowly varying envelope approximation allows one to replace the fields (solutions to Maxwell equations) with profile solutions to a nonlinear Schrodinger equation (NLS). Depending on the model, this equation may be critical and focusing, and then admits explosive solutions. In this case, the approximation breaks down, and, for $\varepsilon$ fixed, the fields may be globally defined in time, and smooth. This happens in the case of Maxwell--Bloch equations [P. Donnat and J. Rauch, Arch. Ration. Mech. Anal., 136 (1996), pp. 291--303], [E. Dumas, Existence globale pour les systemes de Maxwell-Bloch, in Seminaire Ecole Polytechnique, 2002--2003, Ecole Polytechnique, Palaiseau, France], of the anharmonic oscillator with saturated nonlinearity [J. L. Joly, G. Metivier, and J. Rauch, SIAM J. Math. Anal., 227 (1996), pp. 903--913], and of propagation in a ferromagnetic medium [J. L. Joly, G. Metivier, and J. Rauch, Ann. Henri Poincare, 1 (2000), pp. 307--340], [H. ...

Ventilating patients with acute respiratory failure according to standardized recommendations can lead to varying volume-pressure (V-P) relationships and overdistension. Young children may be more susceptible than adults to overdistension, and individual evaluation of the effects of ventilator settings is therefore required. Three studies have applied indices for the detection of overdistension to dynamic V-P curves in ventilated children. Two of those studies compared these indices to those obtained using a reference technique ([quasi]-static V-P curves), and suggested that the c coefficient of a second order polynomial equation (SOPE) and the ratio of the volume-dependent elastance to total dynamic elastance (%E2) were suitable indices for estimating overdistension.

In this paper we deal with weak solutions to the Maxwell-Landau-Lifshitz equations and to the Hall-Magneto-Hydrodynamic equations. First we prove that these solutions satisfy some weak-strong uniqueness property. Then we investigate the validity of energy identities. In particular we give a sufficient condition on the regularity of weak solutions to rule out anomalous dissipation. In the case of the Hall-Magneto-Hydrodynamic equations we also give a sufficient condition to guarantee the magneto-helicity identity. Our conditions correspond to the same heuristic scaling as the one introduced by Onsager in hydrodynamic theory. Finally we examine the sign, locally, of the anomalous dissipations of weak solutions obtained by some natural approximation processes., 45 pages

The lowest energy geometric structures and electronic spin states of first row transition metal (TM) dioxygen dication molecules ([TM–O2]2+; TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) have been determined at the B3LYP/LANL2DZ level of theory (along with an extra d-type polarization function added to the O atoms). In order to further verify the spin states, CASSCF(6 + n, 9) energy points were determined (n = number of TM d electrons). It has been found that with the exception of [Sc–O2]2+, [V–O2]2+, [Co–O2]2+, and [Ni–O2]2+, all [TM–O2]2+ molecules take on a high-spin state. [Sc–O2]2+ adopts a trigonal structure, while [Ti–O2]2+-[Mn–O2]2+ are essentially linear and [Fe–O2]2+-[Zn–O2]2+ are bent. It is further noted that the O–O bond decreases from 130.0 pm to 118.1 pm as the TM changes from Sc to Zn. However, the TM–O2 bond lengths fluctuate between values of 182.2 pm for [Ni–O2]2+ and 232.2 pm for [Zn–O2]2+.

International audience; We investigate the dynamics of a chain of oscillators coupled by fully-nonlinear interaction potentials. This class of models includes Newton's cradle with Hertzian contact interactions between neighbors. By means of multiple-scale analysis, we give a rigorous asymptotic description of small amplitude solutions over large times. The envelope equation leading to approximate solutions is a discrete p-Schrödinger equation. Our results include the existence of long-lived breather solutions to the original model. For a large class of localized initial conditions, we also estimate the maximal decay of small amplitude solutions over long times.

Background and objectives Chronic hypoxemia induces pulmonary hypertension (PH) leading to cardiac insufficiency, and fish oil (EPA+DHA) seems beneficial to prevent PH. We aimed at investigating the effects of DHA from glycerophospholipids (GPL-DHA) or from algal oil (triglycerides) in preventing experimental PH and heart insufficiency. Procedure The study was conducted in Wistar males rats (n=10 per group) over 7 weeks: a control group (C) in normoxic conditions, two groups maintained in normoxic conditions for 4 weeks and under hypoxic conditions (hypobaric chamber, 0.5 Bar) for the last 3 weeks receiving no DHA (H) or 60-120 mg/kg/ day of DHA as GPL (GPL-D60, GPL-D120) or triglycerides (TG-D120). The thickness of the right ventricle (RV) and the pulmonary artery acceleration time (PAAT) were measured weekly by echocardiography. At the end of the study, pulmonary artery pressure (PAP, invasive catheterization) and the fatty acid profile of lungs and heart were determined. Statistics were done by Mann-Whitney test (p Results Hypoxemia led to i) a high increase of the thickness of the RV and RV hypertrophy, ii) a decrease in PAAT (increase in vascular resistance), ii) a change in DHA level in heart (increase) and in lungs (decrease). The DHA supplementation i) limitated the development of RV dysfunction (–19%/–24% thickness), ii) attenuated the decrease in PAAT (+41% or +76% for GPLDHA60 or 120, +46% for TG-DHA120) and the vascular resistance (–12% PAP), iii) increased DHA level slightly in heart (C: 9.3±2.0a; H: 12.4±3.0b; GPL-D60: 14.2±4.4bc; GPL-D120: 15.6±2.8c; TG-DHA120: 14.3±1.5bc) and highly in lungs (C: 2.1±0.2a; H: 1.9±0.2b; GPL-D60: 2.5±0.4c; GPL-D120: 3.5±0.9d; TG-DHA120: 3.7±0.8d). Conclusions GPL-DHA and TG-DHA partially prevented PH and cardiac remodeling. The effects seem not related only to the total level of DHA in tissues suggesting plausible changes in phospholipid classes. The author hereby declares no conflict of interest

International audience; We study a two-scale version of the Landau-Lifshitz system of ferromagnetism, introduced by Starynkevitch to modelize hysteresis: the response of the magnetization is fast compared to a slowly varying applied magnetic field. Taking the exchange term into account, in space dimension 3, we prove that, under some natural stability assumption on the equilibria of the system, the strong solutions follow the dynamics of these equilibria. We also give explicit examples of relevant equilibria and exterior magnetic fields, when the ferromagnetic medium occupies some ellipsoidal domain.

Dehydroepiandrosterone (DHEA) prevents chronic hypoxia-induced pulmonary hypertension and associated right ventricle dysfunction in rats. In this animal model, reoxygenation following hypoxia reverses pulmonary hypertension but not right ventricle dysfunction. We thus studied the effect of DHEA on the right ventricle after reoxygenation, i.e. after a normoxic recovery phase secondary to chronic hypoxia in rats. Right ventricle function was assessed in vivo by Doppler echocardiography and in vitro by the isolated perfused heart technique in three groups of animals: control, recovery (21 days of hypoxia followed by 21 days of normoxia) and recovery DHEA (30 mg · kg(-1) every 2 days during the recovery phase). Right ventricle tissue was assessed by optical and electron microscopy. DHEA abolished right ventricle diastolic dysfunction, as the echographic E wave remained close to that of controls (mean ± SD 76.5 ± 2.4 and 79.7 ± 1.7 cm · s(-1), respectively), whereas it was diminished to 40.3 ± 3.7 in the recovery group. DHEA also abolished right ventricle systolic dysfunction, as shown by the inhibition of the increase in the slope of the pressure-volume curve in isolated heart. The DHEA effect was related to cardiac myocytes proliferation. In conclusion, DHEA prevents right ventricle dysfunction in this animal model by preventing cardiomyocyte alteration.

International audience; We study the Maxwell-Bloch model, which describes the propagation of a laser through a material and the associated interaction between laser and matter (polarization of the atoms through light propagation, photon emission and absorption, etc.). The laser field is described through Maxwell's equations, a classical equation, while matter is represented at a quantum level and satisfies a quantum Liouville equation known as the Bloch model. Coupling between laser and matter is described through a quadratic source term in both equations. The model also takes into account partial relaxation effects, namely the trend of matter to return to its natural thermodynamic equilibrium. The whole system involves $6$+$N \, (N+1)/2$ unknowns, the six-dimensional electromagnetic field plus the $N \, (N+1)/2$ unknowns describing the state of matter, where $N$ is the number of atomic energy levels of the considered material. We consider at once a high-frequency and weak coupling situation, in the general case of anisotropic electromagnetic fields that are subject to diffraction. Degenerate energy levels are allowed. The whole system is stiff and involves strong nonlinearities. We show the convergence to a nonstiff, nonlinear, coupled Schrö\-din\-ger-Boltzmann model, involving $3$+$N$ unknowns. The electromagnetic field is eventually described through its envelope, one unknown vector in $\C^3$. It satisfies a Schrö\-din\-ger equation that takes into account propagation and diffraction of light inside the material. Matter on the other hand is described through a $N$-dimensional vector describing the occupation numbers of each atomic level. It satisfies a Boltzmann equation that describes the jumps of the electrons between the various atomic energy levels, as induced by the interaction with light. The rate of exchange between the atomic levels is proportional to the intensity of the laser field. The whole system is the physically natural nonlinear model. In order to provide an important and explicit example, we completely analyze the specific (two dimensional) Transverse Magnetic case, for which formulae turn out to be simpler. Technically speaking, our analysis does not enter the usual mathematical framework of geometric optics: it is more singular, and requires an \emph{ad hoc} Ansatz.

Meconium aspiration syndrome (MAS) remains a frequent cause of morbidity and mortality in term newborns. Our objective was to compare two modes of high-frequency ventilation, high-frequency oscillation (HFOV), and high-frequency percussive ventilation (HFPV) with conventional mechanical ventilation (CMV) in a piglet model of MAS.Fifteen newborn piglets were anesthetized, paralyzed, and intubated. Following the instillation of a 3 ml/kg solution of meconium diluted to 30%, the piglets were randomized to one of three groups: high-frequency oscillation (HFOV; Sensormedics®), HFPV (Percussionaire®), or CMV (Siemens®). Animals were ventilated for 6 hr to maintain arterial blood gases within a normal range, that is, pH 7.35-7.45, PaO(2) 10-16 kPa, PaCO(2) 4-6.6 kPa. Arterial blood gas measurements, dynCrs and dynRrs, ventilator settings, and vital signs (heart rate, arterial blood pressure, transcutaneous pulse oxygen saturation, and temperature) were collected at 30, 60, 90, 120, 180, 240, 300, and 360 min after meconium instillation. Oxygenation index (OI) ([(fraction of inspired oxygen)(mean airway pressure)(100)]/PaO(2) ), mean airway pressure, dynamic lung function, secretions cleared and histological alterations were studied in all groups.Mean airway pressure and OI were significantly lower in the CV and HFPV groups compared to the HFOV group (P 0.05). There was no significant difference between groups regarding lung function, amount of secretions and histological alterations.In our model of MAS in piglets, whilst effective gas exchange with a lower mean airway pressure was possible with both CMV and HFPV compared with HFOV there was no apparent difference in lung histology or secretions.

In this paper we continue the investigation of the Maxwell-Landau-Lifschitz and Maxwell-Bloch equations. In particular we extend some previous results about the Cauchy problem and the quasi-stationary limit to the case where the magnetic permeability and the electric permittivity are variable.

To determine whether nasal high frequency percussive ventilation (NHFPV) would decrease duration of transient tachypnea of the newborn (TTN) compared to nasal continuous positive airway pressure (NCPAP) in newborn infants.A prospective, unmasked, randomized, controlled clinical trial was conducted in 46 eligible newborn infants who were hospitalized for TTN in the University Hospital of Bordeaux (France) between 2007 and 2009. Infants born by cesarian section ≥37 GA, ≥2,000 g with diagnosis of TTN and with a transcutaneous saturation90% at 20 min after birth were eligible. Infants were randomized to either NHFPV or NCPAP. The primary endpoint was a reduction of the duration of TTN. Secondary endpoints were the duration of oxygen therapy and the minimal level required to obtain a saturation between 90% and 96% integrated into an index which included a time factor: [(FiO2 -21)/time of O2 therapy].In the NHFPV group the duration of TTN was half the time of NCPAP group (105 min ± 20 and 377 min ± 150, respectively; P 0.0001). There was a significant decrease in duration of oxygen supplementation in the NHFPV group (6.3 min ± 3.3) compared to the NCPAP group (19.1 min ± 8.1; P 0.001), and a significant decrease in level of oxygen supplementation [(FiO2 -0.21)/time of O2 therapy] in the NHFPV group (0.29 min(-1) ± 0.16) compared to the NCPAP group (0.46 min(-1) ± 0.50; P 0.001). There was no complication and NHFPV was as well tolerated as NCPAP.NHFPV is well tolerated and more effective than NCPAP in treatment of TTN. NHFPV might be a novel and safe tool to manage TTN. Pediatr Pulmonol.

OBJECTIVE: Infantile hemangiomas (IHs) are the most-common soft-tissue tumors of infancy. We report the use of propranolol to control the growth phase of IHs.METHODS: Propranolol was given to 32 children (21 girls; mean age at onset of treatment: 4.2 months) after clinical and ultrasound evaluations. After electrocardiographic and echocardiographic evaluations, propranolol was administered with a starting dose of 2 to 3 mg/kg per day, given in 2 or 3 divided doses. Blood pressure and heart rate were monitored during the first 6 hours of treatment. In the absence of side effects, treatment was continued at home and the child was reevaluated after 10 days of treatment and then every month. Ultrasound measurements were performed after 60 days of treatment.RESULTS: Immediate effects on color and growth were noted in all cases and were especially dramatic in cases of dyspnea, hemodynamic compromise, or palpebral occlusion. In ulcerated IHs, complete healing occurred in CONCLUSION: Propranolol administered orally at 2 to 3 mg/kg per day has a consistent, rapid, therapeutic effect, leading to considerable shortening of the natural course of IHs, with good clinical tolerance.

We describe and rigorously justify the nonlinear interaction of highly oscillatory waves in nonlinear Schrodinger equations, posed on Euclidean space or on the torus. Our scaling corresponds to a weakly nonlinear regime where the nonlinearity affects the leading order amplitude of the solution, but does not alter the rapid oscillations. We consider initial states which are superpositions of slowly modulated plane waves, and use the framework of Wiener algebras. A detailed analysis of the corresponding nonlinear wave mixing phenomena is given, including a geometric interpretation on the resonance structure for cubic nonlinearities. As an application, we recover and extend some instability results for the nonlinear Schrodinger equation on the torus in negative order Sobolev spaces., Comment: 29 pages

Bloch equations give a quantum description of the coupling between atoms and a driving electric force. It is commonly used in optics to describe the interaction of a laser beam with a sample of atoms. In this paper, we address the asymptotics of these equations for a high frequency electric field, in a weak coupling regime. The electric forcing is taken quasiperiodic in time.We prove the convergence towards a rate equation, i.e. a linear Boltzmann equation, recovering in this way the physically relevant asymptotic model. It describes the transitions amongst the various energy levels of the atoms, governed by the resonances between the electric forcing and the atoms' eigenfrequencies. We also give the explicit value for the transition rates.The present task has already been addressed in Ref. 5 in the case when the energy levels are fixed, and for different classes of electric fields. Here, we extend the study in two directions. First, we consider almost degenerate energy levels, a natural situation in practice. In this case, almost resonances might occur. Technically, this implies that the small divisor estimates needed in Ref. 5 are false, due to the fact that the Diophantine condition is unstable with respect to small perturbations. We use an appropriate ultraviolet cutoff to restore the analysis and to sort out the asymptotically relevant frequencies. Second, since the asymptotic rate equation may be singular in time, we completely analyze the initial time-layer, as well as the associated convergence towards an equilibrium state.

Impaired lung development has been demonstrated in neonatal animals exposed to hyperoxia. High lung cys-leukotriene levels may be a contributing factor towards the increase in oxygen toxicity. We investigated the effect of cysteinyl-leukotriene inhibition using the receptor antagonist, montelukast (MK, Singulair®), on hyperoxia-induced changes in lung parenchymal structure in neonatal rat pups. Rat pups were exposed to 21% O2 (air) or 50% O2 (moderate hyperoxia) from days 1–14 after birth, and were administered the cys-leukotriene receptor antagonist MK (1 mg/kg/day) or normal saline from days 4–14. Somatic growth and morphometric measurements were done on day 15. There was a significant increase in bronchoalveolar lavage fluid cysteinyl-leukotriene levels (+61.9%) when animals were exposed to hyperoxia. O2 exposure significantly decreased the specific internal surface area by 13%. There was a nonsignificant 5.8% and 19.6% increase in mean chord length and mean alveolar diameter, respectively, as well as an 8.6% decrease in lung volume to body weight ratio. Inhibition of only one arm of the arachidonic-acid cascade by MK was not sufficient to prevent these oxygen-induced changes. Pediatr Pulmonol. 2003; 35:446–451. © 2003 Wiley-Liss, Inc.

We applied to 20 paralyzed ventilated children (0.15 to 14.3 yr, six with acute respiratory distress syndrome [ARDS]) the low-flow inflation (LFI) technique providing quasi-static volume-pressure (V-P) curves and compared the assessment of overdistension (OD) on dynamic and LFI (reference) inspiratory V-P curves. Dynamic curves were obtained at the airway opening during regular constant flow ventilation (Servo 300). Then LFI curves were obtained. Two analyses were performed: First, the nonlinear coefficient c of a second order polynomial equation (SOPE) fitted to dynamic data obtained during constant flow was compared with the c of SOPE fitted to LFI curve (within tidal volume [VT]). Second, the dynamic C20/C (ratio of compliance of the last 20% of the curve (C20) to total compliance [C]) was compared with the determination of the upper inflection point (UIP) on the LFI curve. OD was defined as a negative value of c, a C20/C < 0.80, an UIP included within the VT range for that child during regular ventilation. Using LFI V-P curves as reference, SOPE offered a better detection of OD than dynamic C20/C or the determination of the UIP by graphical means. Indeed the first analysis showed a substantial agreement (kappa 0.75) between dynamic c and LFI c detection of OD whereas the second analysis showed a poor agreement (kappa 0.22) between C20/ C and LFI detection of the UIP. In conclusion, quasi-static V-P curves can easily be obtained in children with the LFI technique. SOPE offers a good detection of OD on dynamic and LFI V-P curves but the C20/C index seems to be an inadequate measure of OD.