Removable capping layer for air-sensitive GdN.

The strongly correlated rare earth nitrides display unusual coupled magnetic, electronic and superconducting properties, with predicted topological states. However, their air-sensitiveness has prevented in-depth investigations of their properties. In this paper, we show that a 100 nm thick epitaxial samarium layer provides adequate passivation of 100 nm thick thin films of gadolinium nitride (GdN), the prototypical rare earth nitride, enabling ex-situ magnetic and structural characterizations. Using reflection high-energy electron diffraction, atomic force microscopy and energy dispersive x-ray spectroscopy, we investigate the thermal desorption of the samarium layer under vacuum. We finally demonstrate successful removal of the samarium capping layer in a separate vacuum chamber after exposure to air using a combination of argon ion sputtering and thermal desorption at 400 °C, recovering the GdN surface.

Atomic scale investigation of the volume phase transition in concentrated PNIPAM microgels.

Combining elastic incoherent neutron scattering and differential scanning calorimetry, we investigate the occurrence of the volume phase transition (VPT) in very concentrated poly-(N-isopropyl-acrylamide) (PNIPAM) microgel suspensions, from a polymer weight fraction of 30 wt. % up to dry conditions. Although samples are arrested at the macroscopic scale, atomic degrees of freedom are equilibrated and can be probed in a reproducible way. A clear signature of the VPT is present as a sharp drop in the mean square displacement of PNIPAM hydrogen atoms obtained by neutron scattering. As a function of concentration, the VPT gets smoother as dry conditions are approached, whereas the VPT temperature shows a minimum at about 43 wt. %. This behavior is qualitatively confirmed by calorimetry measurements. Molecular dynamics simulations are employed to complement experimental results and gain further insights into the nature of the VPT, confirming that it involves the formation of an attractive gel state between the microgels. Overall, these results provide evidence that the VPT in PNIPAM-based systems can be detected at different time- and length-scales as well as under overcrowded conditions.

Influence of myelin proteins on the structure and dynamics of a model membrane with emphasis on the low temperature regime.

Myelin is an insulating, multi-lamellar membrane structure wrapped around selected nerve axons. Increasing the speed of nerve impulses, it is crucial for the proper functioning of the vertebrate nervous system. Human neurodegenerative diseases, such as multiple sclerosis, are linked to damage to the myelin sheath through demyelination. Myelin exhibits a well defined subset of myelin-specific proteins, whose influence on membrane dynamics, i.e., myelin flexibility and stability, has not yet been explored in detail. In a first paper [W. Knoll, J. Peters, P. Kursula, Y. Gerelli, J. Ollivier, B. Demé, M. Telling, E. Kemner, and F. Natali, Soft Matter 10, 519 (2014)] we were able to spotlight, through neutron scattering experiments, the role of peripheral nervous system myelin proteins on membrane stability at room temperature. In particular, the myelin basic protein and peripheral myelin protein 2 were found to synergistically influence the membrane structure while keeping almost unchanged the membrane mobility. Further insight is provided by this work, in which we particularly address the investigation of the membrane flexibility in the low temperature regime. We evidence a different behavior suggesting that the proton dynamics is reduced by the addition of the myelin basic protein accompanied by negligible membrane structural changes. Moreover, we address the importance of correct sample preparation and characterization for the success of the experiment and for the reliability of the obtained results.

Evidence for a stimulatory role of high doses of recombinant human follicle-stimulating hormone in the treatment of male-factor infertility.

The efficacy of recombinant human follicle-stimulating hormone (rhFSH) in the treatment of normogonadotropic patients with male-factor infertility was assessed. Forty-five infertile men with moderate/severe oligoasthenozoospermia and normal FSH, luteinizing hormone (LH) and testosterone (T) levels were treated with high rhFSH dose (300 IU) on alternate days for ≥4 months. In all, the seminal parameters, endocrine profile (FSH, LH, prolactin (PRL), total and free T and estradiol) and pregnancy rate were evaluated before, during and after rhFSH treatment. Fifteen infertile men were treated with placebo and studied in the same way, as control group. rhFSH treatment induced a marked increase in sperm count and no change in sperm motility, morphology and viability. No changes in seminal parameters were observed in the placebo group. FSH levels increased during treatment with rhFSH and not with placebo. No variations in LH, PRL, free and total T and estradiol were evidenced during treatment. A significant pregnancy rate in rhFSH versus placebo patients was also highlighted. Prolonged treatment with high rhFSH doses leads to increase sperm count and improve the spontaneous pregnancy rate in normogonadotropic infertile patients with oligoasthenozoospermia. rhFSH may represent a rational and useful tool in the treatment of male-factor infertility.

Europium nitride: a novel diluted magnetic semiconductor.

Europium nitride is semiconducting and contains nonmagnetic Eu3+, but substoichiometric EuN has Eu in a mix of 2+ and 3+ charge states. We show that at Eu2+ concentrations near 15%-20% EuN is ferromagnetic with a Curie temperature as high as 120 K. The Eu3+ polarization follows that of the Eu2+, confirming that the ferromagnetism is intrinsic to the EuN which is, thus, a novel diluted magnetic semiconductor. Transport measurements shed light on the likely exchange mechanisms.

A 60-Year-Old Man With a Migratory Lobar Consolidation After Invasive Ventilation.

CASE PRESENTATION: A 60-year-old man was referred to a pulmonologist evaluation with persistent dyspnea and cough 1 month after discharge for an acute respiratory failure caused by Legionella pneumophila pneumonia, which required invasive mechanical ventilation. Chest CT scan performed during hospitalization showed lobar consolidation of upper left lobe (Fig 1A). Bronchial culture revealed L pneumophila; the patient was treated with levofloxacin and supported with invasive mechanical ventilation for 2 weeks. Chest radiograph after extubation showed almost complete resolution of infiltrates. After 1 month, the patient still complained of dyspnea and a new chest CT scan was performed: the consolidation migrated (Fig 1B; Video 1).

Diagnostic role of internal mammary lymph node involvement in tuberculous pleurisy: a multicenter study.

BACKGROUND AND OBJECTIVES: Diagnosis of tuberculous pleurisy (TP) may be challenging and it often requires pleural biopsy. A tool able to increase pre-test probability of TP may be helpful to guide diagnostic work-up and enlargement of internal mammary lymph node (IMLN) has been suggested to play a potential role. The aim of the present investigation was to assess role of IMLN involvement in TP in a multi-centric case-control study, by comparing its prevalence and test performance to those observed in patients with infectious, non-tuberculous pleurisy (NTIP), and in controls free from respiratory diseases (CP). METHODS: A total of 419 patients, from 14 Pulmonology Units across Italy were enrolled (127 patients affected by TP, 163 affected by NTIP and 129 CP). Prevalence, accuracy and predictive values of ipsilateral IMLN involvement between cases and control groups were assessed, as well as concordance between chest computed tomography (CT scan) and thoracic ultrasound (TUS) measurements. RESULTS: The prevalence of ipsilateral IMLN involvement in TP was significantly higher than that observed in NTIP and CP groups (respectively 77.2%, 39.3% and 14.7%). Results on test performance, stratified by age, revealed a high positive predictive value in patients aged ≤50 years, while a high negative predictive value in patients aged >50 years. The comparison between CT scan and ultrasound showed moderate agreement (Kappa=0.502). CONCLUSIONS: Evaluation of IMLN involvement plays a relevant role in assessing the pre-test probability of TP. Considering the increasing global prevalence of mycobacterial infections, a tool able to guide diagnostic work-up of suspected TP is crucial, especially where local sources are limited.

Application of cupuassu shell as biosorbent for the removal of textile dyes from aqueous solution.

The cupuassu shell (Theobroma grandiflorum) which is a food residue was used in its natural form as biosorbent for the removal of C.I. Reactive Red 194 and C.I. Direct Blue 53 dyes from aqueous solutions. This biosorbent was characterized by infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption/desorption curves. The effects of pH, biosorbent dosage and shaking time on biosorption capacities were studied. In acidic pH region (pH 2.0) the biosorption of the dyes were favorable. The contact time required to obtain the equilibrium was 8 and 18 h at 298 K, for Reactive Red 194 and Direct Blue 53, respectively. The Avrami fractionary-order kinetic model provided the best fit to experimental data compared with pseudo-first-order, pseudo-second-order and chemisorption kinetic adsorption models. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Radke-Prausnitz isotherm models. For both dyes the equilibrium data were best fitted to the Sips isotherm model.

Application of carbon adsorbents prepared from Brazilian-pine fruit shell for the removal of reactive orange 16 from aqueous solution: Kinetic, equilibrium, and thermodynamic studies.

Activated (AC-PW) and non-activated (C-PW) carbonaceous materials were prepared from the Brazilian-pine fruit shell (Araucaria angustifolia) and tested as adsorbents for the removal of reactive orange 16 dye (RO-16) from aqueous effluents. The effects of shaking time, adsorbent dosage and pH on the adsorption capacity were studied. RO-16 uptake was favorable at pH values ranging from 2.0 to 3.0 and from 2.0 to 7.0 for C-PW and AC-PW, respectively. The contact time required to obtain the equilibrium using C-PW and AC-PW as adsorbents was 5 and 4h at 298 K, respectively. The fractionary-order kinetic model provided the best fit to experimental data compared with other models. Equilibrium data were better fit to the Sips isotherm model using C-PW and AC-PW as adsorbents. The enthalpy and entropy of adsorption of RO-16 were obtained from adsorption experiments ranging from 298 to 323 K.

Surviving salt fluctuations: stress and recovery in Halobacterium salinarum, an extreme halophilic Archaeon.

Halophilic proteins subjected to below about 15% salt in vitro denature through misfolding, aggregation and/or precipitation. Halobacteria, however, have been detected in environments of fluctuating salinity such as coastal salterns and even around fresh water springs in the depths of the Dead Sea. In order to identify the underlying mechanisms of low salt survival, we explored the reactivation capacity of Halobacterium (Hbt) salinarum sub-populations after incubation in low salt media and recovery in physiological salt. Respiratory oxygen consumption was assessed in stressed cells and cell viability was estimated by Live/Dead staining and flow cytometry. In vivo neutron scattering experiments showed that the recovery of Hbt salinarum sub-populations exposed to severe low salt conditions is related to a rapid retrieval of functional molecular dynamics in the proteome. In the hypothesis that the observations on Hbt salinarum have wider relevance, they could be of key ecological significance for the dispersion of extremophiles when environmental fluctuations become severe.

Pecan nutshell as biosorbent to remove Cu(II), Mn(II) and Pb(II) from aqueous solutions.

In the present study we reported for the first time the feasibility of pecan nutshell (PNS, Carya illinoensis) as an alternative biosorbent to remove Cu(II), Mn(II) and Pb(II) metallic ions from aqueous solutions. The ability of PNS to remove the metallic ions was investigated by using batch biosorption procedure. The effects such as, pH, biosorbent dosage on the adsorption capacities of PNS were studied. Four kinetic models were tested, being the adsorption kinetics better fitted to fractionary-order kinetic model. Besides that, the kinetic data were also fitted to intra-particle diffusion model, presenting three linear regions, indicating that the kinetics of adsorption should follow multiple sorption rates. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Redlich-Peterson isotherm models. Taking into account a statistical error function, the data were best fitted to Sips isotherm model. The maximum biosorption capacities of PNS were 1.35, 1.78 and 0.946mmolg(-1) for Cu(II), Mn(II) and Pb(II), respectively.

[Slow progression of a ground glass lesion - need for long term vigilance]. / Un nodule en verre dépoli d'évolution très lente: savoir rester vigilant!

INTRODUCTION: The identification of a ground-glass opacity on chest CT is a frequent problem because of the number of exams performed. OBSERVATION: We report the case of a man of 66 years with a very slowly increasing ground-glass opacity during 5 years. Although the lesion was negative for positron emission tomography and because of its increasing size and the appearance of a solid part, our patient underwent surgery. The final diagnosis was stage I adenocarcinoma. CONCLUSIONS: The management of a ground glass opacity differs from solid nodules of the lung. The rate of malignancy is high in the published studies, especially in south-east Asia. PET is not as useful as for solid nodules. Long term follow up is necessary because of the long doubling time in these neoplasms.

Brain lateralization probed by water diffusion at the atomic to micrometric scale.

Combined neutron scattering and diffusion nuclear magnetic resonance experiments have been used to reveal significant interregional asymmetries (lateralization) in bovine brain hemispheres in terms of myelin arrangement and water dynamics at micron to atomic scales. Thicker myelin sheaths were found in the left hemisphere using neutron diffraction. 4.7 T dMRI and quasi-elastic neutron experiments highlighted significant differences in the properties of water dynamics in the two hemispheres. The results were interpreted in terms of hemisphere-dependent cellular composition (number of neurons, cell distribution, etc.) as well as specificity of neurological functions (such as preferential networking).

Anomalous water dynamics in brain: a combined diffusion magnetic resonance imaging and neutron scattering investigation.

Water diffusion is an optimal tool for investigating the architecture of brain tissue on which modern medical diagnostic imaging techniques rely. However, intrinsic tissue heterogeneity causes systematic deviations from pure free-water diffusion behaviour. To date, numerous theoretical and empirical approaches have been proposed to explain the non-Gaussian profile of this process. The aim of this work is to shed light on the physics piloting water diffusion in brain tissue at the micrometre-to-atomic scale. Combined diffusion magnetic resonance imaging and first pioneering neutron scattering experiments on bovine brain tissue have been performed in order to probe diffusion distances up to macromolecular separation. The coexistence of free-like and confined water populations in brain tissue extracted from a bovine right hemisphere has been revealed at the micrometre and atomic scale. The results are relevant for improving the modelling of the physics driving intra- and extracellular water diffusion in brain, with evident benefit for the diffusion magnetic resonance imaging technique, nowadays widely used to diagnose, at the micrometre scale, brain diseases such as ischemia and tumours.

New sources and instrumentation for neutrons in biology.

Neutron radiation offers significant advantages for the study of biological molecular structure and dynamics. A broad and significant effort towards instrumental and methodological development to facilitate biology experiments at neutron sources worldwide is reviewed.

[Asymptomatic forms of the Severe Acute Respiratory Syndrome (SARS)]. / Formes pauci-symptomatiques du Syndrome Respiratoire Aigu Sévère (SRAS).

INTRODUCTION: In November 2002 an epidemic of atypical pneumonia appeared in the Chinese region of Guandong. It was subsequently given the name "Severe Acute Respiratory Syndrome" (SARS) following the occurrence of further outbreaks in Hanoi and Hong Kong in February 2003. Five cases related to the same patient source have been reported in France. CASE REPORT: We report the case of a patient of 52 years who had direct contact with a probable case of SARS. On admission the patient presented with pyrexia associated with lymphopenia and liver cell necrosis but no respiratory symptoms. The chest x-ray was normal. The thoracic CT scan showed a sub pleural ground glass appearance. Early (36 hours) PCR studies of nasopharyngeal washings were negative for the coronavirus associated with SARS. The diagnosis was confirmed serologically. CONCLUSIONS: This observation demonstrates the existence of incomplete clinical presentations of SARS. The infectivity of this asymptomatic form is unknown. Serological analyses will allow better identification. The continuing danger of seasonal recurrence, particularly in the winter, cannot be ignored. In this context the recognition of probably infectious asymptomatic forms is essential.

Bronchogenic carcinoma in patients with pulmonary histiocytosis X.

Five cases of bronchogenic carcinoma were observed among 93 patients with pulmonary histiocytosis X (Hx). Mean age at the time of diagnosis of Hx was 42 years; on the average, cancer occurred 10.5 years later. All patients were smokers and continued to smoke heavily at the time of diagnosis of cancer. Comparison of the five cases associating Hx and lung carcinoma with a group of 88 control patients suffering from Hx alone suggested that smoking played the predominant role in the pathogenesis of cancer. In fact, among the four patients with Hx and carcinoma older than 45 years, tobacco consumption was significantly greater (64.7 +/- 37 pack-year, mean +/- SD) than that of the 15 control patients of the same age with only Hx (40.8 +/- 11.6, p less than 0.01). In light of this good correlation, the diagnosis of Hx strongly advocates stopping tobacco smoking and long-term medical follow-up.

[Osteochondroplastic tracheobronchopathy: 5 cases]. / Trachéobronchopathie ostéochondroplastique: cinq observations.

Five new cases of tracheobronchopathia osteochondroplastica (TBOCP) are reported and clinical, radiological and pathological features are reviewed. TBOCP is a rare disease characterized by cartilaginous and bony nodules lining the mucosa of the trachea and major bronchi. The endoscopic features realize pathological evolution by stadiums. The prognosis is usually favourable. The etiology of TBOCP remains unknown, even though some cases were reported in association with amyloidosis.

[Cancer of the testis, sarcoidosis and neurinoma]. / Cancer du testicule, sarcoïdose et neurinome.

The association of testicular cancer, sarcoidosis and neuroma is reported. Review of the literature revealed the rarity of the association of testicular cancer and sarcoidosis which is probably a chance association, but which is important in the context of staging, as overstaging may lead to useless or even dangerous treatment.

[Operative risk in thoracic surgery]. / Le risque opératoire en chirurgie thoracique.

Operative risk is encountered daily in thoracic surgery. Preoperatively, the risk can be evaluated by the pneumologist as well as the intensive care-surgery team. The parenchymal function and the patients respiratory capacity during the post-operative period should be evaluated. It is fundamental to evaluate heart function and vascular capacity. We discuss operative risk of dissection. The risk of bronchial fistulization is estimated at 5% (pneumonectomy) and 1% (lobectomy). Immediate complications include air leaks, rhythm disorders and post-operative bleeding. Thoracic drainage is a determining factor in thoracic surgery. The main problem remains post-operative respiratory failure especially since carcinological exeresis is usually carried out in patients with bronchopathies.