Observations of a streak texture in the hybrid-aligned smectic-C phase.

A novel structure was observed below the smectic-A-smectic-C phase transition in a very thin open cell having an air interface above and enforced planar anchoring at the substrate below. The structure appears as periodic dark and light streaks running perpendicular to the oily streaks, which are present in the smectic-A phase [D. Coursault et al., Soft Matter, 2016, 12, 678]. These new streaks, which we call "soapy streaks", form by extending from one oily streak to the next in discrete steps, eliminating optical evidence at visible wavelengths of the oily streaks. At lower temperatures the streaks can undulate and exhibit a sawtooth-like structure; such a structure is chiral in two dimensions. A possible scenario for the origin of these streaks is presented.

An investigation of the immunotoxicity of oil sands processed water and leachates in trout leukocytes.

Increased oil sands (OS) mining activity has raised concerns about impacts on aquatic organisms. This study sought to examine the effects of single representative compounds from OS (benzo(a)pyrene, naphthalene), a mixture of naphthenic acids (NAs), OS-processed water (OSPW) and OS leachate (OSL) extracts on rainbow trout leukocytes. Primary cultures of trout leukocytes were exposed to increasing concentrations of benzo(a)pyrene, naphthalene, NAs, OSPW and OSL for 48h at 18°C. Immunocompetence was followed by measuring changes in lymphocyte and macrophage viability and phagocytosis. Changes in the expression of 10 transcripts were also followed: interleukin 1, 2 and 6 (Il-1, Il-2 and Il-6), calreticulin (CRT), caspase 9 (Cas9), aryl hydrocarbon receptor (AhR), cyclooxygenase-2 (COX2), glutathione S-transferase (GST), catalase (CAT) and p53 tumor suppressor. The results revealed that exposure to OSPW extracts decreased the capacity of macrophages to engulf three beads or more, while the other compounds generally increased phagocytosis activity. Lymphocyte apoptosis was increased by all compounds and mixtures except naphthalene. Both OSPW and OSL induced apoptosis in macrophages. At the gene expression level, Cas9, CRT, Il-1 (inhibition) and Il-2 were specifically influenced by OSPW, while CAT, p53, COX2 and Il-1 (induction) transcripts were specifically expressed by OSL. Leukocyte exposure to OSPW produced characteristic changes in immunocompetence and genes involved in proinflammatory, apoptosis and protein damage (CRT) pathways which could not be explained by OSL, benzo(a)pyrene, naphthalene and NA mixture.

Low energy Ne ion beam induced-modifications of magnetic properties in MnAs thin films.

Investigations of the complex behavior of the magnetization of manganese arsenide thin films due to defects induced by irradiation of slow heavy ions are presented. In addition to the thermal hysteresis suppression already highlighted in Trassinelli et al (2014 Appl. Phys. Lett. 104 081906), we report here on new local magnetic features recorded by a magnetic force microscope at different temperatures close to the characteristic sample phase transition. Complementary measurements of the global magnetization in different conditions (applied magnetic field and temperatures) enable the film characterization to be completed. The obtained results suggest that the ion bombardment produces regions where the local mechanical constraints are significantly different from the average, promoting the local presence of magneto-structural phases far from the equilibrium. These regions could be responsible for the thermal hysteresis suppression previously reported, irradiation-induced defects acting as seeds in the phase transition.

[Efficiency and good tolerance of rituximab for idiopathic thrombocytopenic purpura revealing a 22q11 deletion syndrome]. / Efficacité et bonne tolérance du rituximab sur un purpura thrombopénique immunologique chronique révélant un syndrome de délétion 22q11.

INTRODUCTION: 22q11 deletion is a common genetic disorder which associates a polymalformative syndrome to dysimmune features. Autoimmunity and immune deficiency manifestations are often associated, resulting in a therapeutic challenge for this disease. CASE REPORT: We report a 28-year-old patient who presented with hemorrhagic manifestations leading to the diagnosis of severe thrombocytopenia (15,000/mm3), of both central and peripheral origin. Patient history, cardio-facial malformative syndrome, hypoparathyroidism and partial immune deficiency led to the molecular diagnosis of 22q11 deletion syndrome. After failure of polyvalent immunoglobulin infusions, rituximab alone allowed the increase of platelets to their usual level of 100-120,000/mm3 within 4 weeks and a complete clinical remission of the hemorrhagic syndrome, without any infectious complication after a 4-year follow-up. CONCLUSION: Rituximab may be an alternative to corticosteroid for the treatment of auto-immune manifestations associated with minor forms of 22q11 deletion syndrome without significant worsening of the immune deficiency.

[Analysis of the anatomical sites of 172 lower-limb venous thromboses occurring in a hormonal context in 996 young women; impact of the duplex-Doppler exploration]. / Analyse de la distribution anatomique de 172 thromboses veineuses des membres inférieurs chez 996 jeunes femmes en contexte hormonal. Impact sur l'exploration écho-Doppler.

AIM: To analyze localizations of duplex ultrasonography-diagnosed lower-limb venous thrombosis in young women in hormonal periods in order to optimize the ultrasound exploration. PATIENTS AND METHODS: From 42,018 standardized ultrasonography report forms, incremented in a database (January 2001 - July 2013), those performed for a first diagnosis of venous thrombosis in women ≤ 45 years were selected (n = 996). Among those, diagnosed venous thrombosis (n = 172) were classified into three groups: oral contraception (n = 74), pregnancy (n = 39) and post-partum period (n = 59). Clinical symptoms and thrombosis distribution were analyzed. RESULTS: In the contraception group, pulmonary symptoms at presentation were much more frequent than in the obstetrical group: 69% vs 20% (P < 0.001). The thrombosis was limited to the iliac veins in 31% (23/74) and to the left internal iliac vein in six patients. During pregnancy, the thrombosis was limited to the iliac veins in 28% (11/39), and to the left internal iliac vein in two patients. In the post-partum period, superficial venous thromboses were found more frequently (37/59). Among the 22 deep venous thromboses, nine were limited to the proximal segment, including four in the vena cava coming from a right ovarian vein thrombosis. CONCLUSION: Duplex ultrasonography in young women taking oral contraception, as during pregnancy, must target iliac venous segments, especially on the left side, otherwise one thrombosis out of three may be missed; in the post-partum period, the inferior vena cava and superficial veins are to be explored too.

Liquid crystal quenched orientational disorder at an AFM-scribed alignment surface.

A polyimide substrate was scribed using the stylus of an atomic force microscope, then covered with a nematic liquid crystal. The fiber from a near field scanning optical microscope was immersed into the liquid crystal and rastered approximately 80 nm above the surface, thereby obviating smearing effects that occur in thicker samples. By appropriate averaging of multiple data sets, a histogram of the "frozen-in" director deviation Δφ from the average easy axis was obtained, having a full-width-half-maximum of ∼0.02 rad. Additionally, the spatial autocorrelation function of Δφ was extracted, where the primary correlation length was found to be comparable to, but larger than, the liquid crystal's extrapolation length. A secondary characteristic length scale of a few µm was observed, and is thought to be an artifact due to material ejection during the scribing process. Our results demonstrate the utility of nanoscale imaging of the interface behavior inside the liquid crystal.

Genotoxic potential of several naphthenic acids and a synthetic oil sands process-affected water in rainbow trout (Oncorhynchus mykiss).

The exploitation of oil sands has raised major environmental concerns, particularly regarding the presence of high concentration in contaminants such as polycyclic aromatic hydrocarbons (PAHs) and naphthenic acids (NAs) in oil sands process-affected water (OSPW). The purpose of this study was, first to evaluate the genotoxic impact of OSPW-related compounds such as NAs and PAHs in a salmonid species and secondly to assess if OSPW exposure leads to genotoxicity. For this purpose, rainbow trout hepatocytes were exposed in vitro to environmentally relevant concentrations of synthetic NAs, naphtalene, benzo(a)pyrene, and extracts of synthetic OSPW (generated by a laboratory bitumen extraction) and of oil sands leaching water (OSLW, mimicking leaching of oil sands in river water). Primary DNA damage was assessed by the formamidopyrimidine-DNA glycolyase (Fpg)-modified comet assay. Genotoxicity was observed in hepatocytes exposed to several NAs, mixture of them, OSPW and OSLW extracts. The chemical structure of NAs influences the genotoxicity potential: among the NAs tested, the most cyclic NA was the most genotoxic. It also appears that genotoxicity was more marked for OSPW than for OSLW. Because exposure to OSPW led to oxidative DNA damage, while after exposure to several NAs, these types of DNA damage were limited, the NAs tested in this study could not be qualified as the only major contaminants responsible for OSPW genotoxicity. Notwithstanding, it should be noteworthy that exposure to NAs resulted in genotoxic impact at concentrations lower than those documented by literature for fresh OSPW. Further research is needed to explore the relationships between the chemical structure of NAs and their genotoxicity in the light of the distribution of NAs in fresh OSPW samples as well as in surface waters.

Temporal patterns of digestive enzyme activities and feeding rate in gammarids (Gammarus fossarum) exposed to inland polluted waters.

The aim of this study was to use digestive enzyme activities in Gammarus fossarum as biomarkers during active biomonitoring. Standardised gammarids were transplanted for 7 days to five sites in the Riou Mort watershed contaminated by polymetallic pollution. This experiment was conducted on seven different dates from February 2009 to June 2010. Feeding rates were tracked, along with amylase, cellulase and trypsin activities. We found that feeding rate and digestive capacity were reduced in the most polluted site, "Joany," in comparison with the reference site "Up.Lot". The results suggested that trypsin was more sensitive than the other two carbohydrases. In the four other sites, seasonal differences were observed during the 2yr but no clear pattern can be established. This study highlights the ability of G. fossarum to demonstrate environmental disturbances and suggests the use of a caging process in certain seasons. Caging organisms and feeding ad libitum is advantageous, as it reduces inter-individual variability and removes dependence on the native food fluctuations. However, confounding factors other than temperature were present, and the interpretation of digestive enzyme activities is complex.

Self-assembly of hydrophobin protein rodlets studied with atomic force spectroscopy in dynamic mode.

We have investigated the self-assembling properties of the class I hydrophobin Vmh2 isolated from the fungus Pleurotus ostreatus. Five different hydrophobin self assembled samples including monolayers, bilayers, and rodlets have been prepared by Langmuir technique and studied at the nanoscale. Local wettability and visco-elasticity of the different hydrophobins samples were obtained from atomic force spectroscopy experiments in dynamic mode performed at different, controlled relative humidity (RH) values. It was found that hydrophobins assembled either in rodlets or in bilayer films, display similar hydropathicity and viscoelasticity in contrast to the case of monolayers, whose hydropathicity and viscoelasticity depend on the adopted preparation method (Langmuir-Blodgett or Langmuir-Schaeffer). The comparison with monolayers properties evidences a rearrangement of the bilayers adsorbed onto solid substrates. It is shown that this rearrangement leads to the formation of a stable hydrophobic film, and that the rodlets structure consists in fragments of restructured proteins bilayers. Our results support the hypothesis that the observed variations in the viscoelastic properties could be ascribed to the localization of the large flexible loop, typical of Class I hydrophobins which appears free at the air interface for LB monolayers but not for the other samples. These findings should now serve future developments and applications of hydrophobin films beyond the archetypal monolayer.

A multiscale description of molecular adsorption on gold nanoparticles by nonlinear optical spectroscopy.

Nonlinear optical Sum and Difference-Frequency spectroscopies are used to probe and model the surface of thiophenol-functionalised gold nanoparticles grafted on a Si(100) substrate through two different silanization procedures. By scanning the [980-1100 cm(-1)] infrared spectral range with the CLIO Free Electron Laser, ring deformation vibrations of adsorbed thiophenol are investigated. Quantitative data analysis addresses three levels of organization: microscopic, nanoscopic and molecular. Grafting with p-aminophenyl-trimethoxysilane shows an increase of around 40% in surface density of nanoparticles (N(s)) as compared to 3-aminopropyl-triethoxysilane. The relative amplitudes of the resonant and nonresonant contributions to the SFG and DFG spectra are discussed in terms of N(s), Fresnel reflectivity factors and local amplification of the nonlinear signals by coupling to the surface plasmon of the particles. They are shown to quantitatively scale with N(s), as measured by atomic force microscopy. Vibration mode assignment is performed through a critical analysis of literature data on IR and Raman spectroscopies coupled to DFT calculations, for which a methodology specific to molecules adsorbed on gold atoms is discussed.

[Attention deficit disorder: multidisciplinary observational study over 1 year]. / Le trouble déficitaire de l'attention, avec ou sans hyperactivité (TDA/H) : une approche pluridisciplinaire longitudinale croisée de 36 enfants.

INTRODUCTION: In France, attention deficit disorder (ADHD) has traditionally met with two opposing approaches (biological and psychoanalytic). This conflict led us to conduct a multidisciplinary observational study, on a group of 36 children over a period of 1 year. METHODS: Thirty-six children with ADHD diagnostic (DSM IV), not treated by MPH were included. Initial "multi-field" evaluation (T0) consisted of: neuro-paediatric consultation (Conners questionnaire, Child Behaviour Checklist, reading and writing scores by French tests); semi-structured child psychiatric interview (DSM-IV axis I), structural hypothesis (CFTMEA), existence of narcissistic fragility, parents/child interactions; neuropsychological standardized evaluation (attention and executive functions); psychodynamic interview and projective tests (Rorscharch, CAT or TAT). A therapeutic project is proposed combining MPH and psychotherapy according to the results. A new evaluation 1 year later (T1) included a consultation and a neuropsychological evaluation. RESULTS T0: All parental questionnaires appreciating attention deficit and hyperactivity/impulsivity were significantly pathological. The neuropsychological evaluation showed usual characteristics of ADHD with individual differences. The psychiatric evaluation revealed the frequency of comorbidity in axis I (23% of children with more than two diagnoses, 57% with anxiety disorder, 23 and 3% with oppositional and conduct disorder). FOLLOW UP (T1): Thirty-one children were re-examined (20 treated by MPH and 11 not treated because of parental refusal or particular psychopathological situations). Psychoanalytical psychotherapy, proposed to 28 children, was undertaken with only 19. An improvement in scores for attention and executive tests was registered only in the treated group. DISCUSSION: The tests confirm deficits of attention and executive functions without correlation with the scores of questionnaires, underlining the need for a neuropsychological evaluation to objectify attention disorders. Projective tests refine and enrich psychiatric evaluation and showed that half of the children had borderline organization. However, structural hypotheses were heterogeneous, suggesting the need for specific therapeutic projects to be devised according to each child. The treated children were the only ones to improve attention deficit. On the other hand, the scores of anxiety are not improved by MPH, emphasizing the indications of psychotherapy if comorbidity is present. Psychotherapeutic care was carried out only among part of the population, because of parental reservations, exacerbated by differences of opinion among professionals and lack of access. CONCLUSION: This study is innovative, providing precise data on ADHD from a multidisciplinary perspective. Psychopathological comorbidity is high in this population, so the concept of ADHD cannot be limited to a cognitive point of view. These elements and doubts regarding the efficacy of behavioural therapies suggest the need for a rigorous evaluation of analytical psychotherapies independent of MPH to treat attention deficit.

Combining moiré patterns and high resolution transmission electron microscopy for in-plane thin films thickness determination.

This paper reports the coupling of HRTEM and moiré pattern observations, allowing the determination of the thickness ratio of two superimposed crystals. Pseudo-lattice fringes are observed using identical TEM experimental conditions as for observing moiré patterns. The pseudo-lattice spacing is first calculated in the dynamical theory framework in two beam conditions. This approach shows a linear behavior of the spacing as a function of the thickness ratio of the two crystals. The roles of sample crystallographic orientation and sample thickness on the thickness ratio determination are discussed from multi-beam simulations. Finally, the method is applied on a bimetallic CuAg core-shell nanoparticle of a known structure. It is demonstrated that for this particle, the thickness ratio of Cu and Ag can be determined with an error that results in a precision less than 0.75 nm on the Cu and Ag thicknesses. The advantages of the technique are the use of an in-plane sample configuration and a single HRTEM image.

Langmuir-Blodgett film of hydrophobin protein from Pleurotus ostreatus at the air-water interface.

We present results concerning the formation of Langmuir-Blodgett (LB) films of a class I hydrophobin from Pleurotus ostreatus at the air-water interface, and their structure as Langmuir-Blodgett (LB) films when deposited on silicon substrates. LB films of the hydrophobin were investigated by atomic force microscopy (AFM). We observed that the compressed film at the air-water interface exhibits a molecular depletion even at low surface pressure. In order to estimate the surface molecular concentration, we fit the experimental isotherm with Volmer's equation describing the equation of state for molecular monolayers. We found that about (1)/ 10 of the molecules contribute to the surface film formation. When transferred on silicon substrates, compact and uniform monomolecular layers about 2.5 nm thick, comparable to a typical molecular size, were observed. The monolayers coexist with protein aggregates, under the typical rodlet form with a uniform thickness of about 5.0 nm. The observed rodlets appear to be a hydrophilic bilayer and can then be responsible for the surface molecular depletion.

Radiation-induced synthesis and cryo-TEM characterization of silver nanoshells on linoleate spherical micelles.

We combine the self-assembly properties of amphiphilic molecules with the radiolysis method to produce specific sizes and shapes of metallic nano-objects. Radiolysis is used to synthesize core--shell structures consisting of nanometric linoleate spherical micelles as the core and silver as the shell. The validity of the technique is asserted by cryoelectron microscopy, which is an adequate technique for low density contrasts and core--shell structures. The shells are found to be homogeneous with a size of a few nanometers. Images are used to bring forward the hypothesis of the fabrication process.

Neuropsychological outcome in children with optic pathway tumours when first-line treatment is chemotherapy.

Standard treatment of optic pathways gliomas consists of radiotherapy and surgery when feasible. Owing to the toxicity of irradiation, chemotherapy has emerged as an interesting therapeutic option, especially in young children. This study describes the neuropsychological profile of 27 children (aged between 1.5 and 15.7 years) with optic pathways gliomas treated with chemotherapy as first-line treatment. Eight of them also received radiotherapy as salvage treatment. Eight had neurofibromatosis type 1 (NF1). Intellectual outcome was preserved in children treated with chemotherapy only (mean=107+/-17) compared to children also receiving radiotherapy (mean IQ=88+/-24) or children having NF1 and treated with chemotherapy (mean IQ=80+/-13). Scores for abstract reasoning, mental arithmetic, chessboard/coding, perception, judgement of line orientation were lower in children irradiated than in those treated only by chemotherapy. Children with Nf1 showed subnormal IQ scores with marked impairment of short- and long-term memory. With respect to long-term neuropsychological outcome, our study shows that a chemotherapy-first strategy can preserve the intellectual outcome of these patients either by avoiding the need of radiotherapy or by delaying its use as much as possible.

Investigation of cross-coupling in 1-3 piezocomposite arrays.

Plate waves inside the piezoelectric layer are much involved in the elements cross-coupling in transducer arrays for medical imaging. In this work, such waves are analyzed in 1-3 piezocomposite materials on the basis of conventional guided modes formalism in which the piezocomposite is considered as a homogeneous medium. Cross-coupling measurements have been made on two different transducer arrays using network analyzer and a laser interferometric probe. It is shown how the analysis in terms of symmetrical Lamb waves gives an interesting qualitative interpretation, explaining most of the cross-coupling amplitude variations with frequency. Results show that the 0th and 3rd symmetrical Lamb waves are mainly involved in coupling inside composite plates. The S0 mode is responsible for the inter-element coupling, whereas the S3 mode widens the effective width of the excited element.