Angular resolution expected from iCHORD orientation maps through a revisited ion channeling model

Crystalline orientation maps are obtained in a Focused Ion Beam (FIB) microscope using the ion CHanneling ORientation Determination (iCHORD) method, which relies on the channeling phenomenon observed in ion-induced secondary electron images. The current paper focuses on the angular resolution that can be expected from such orientation maps, obtained using a revisited ion channeling model. A specific procedure was developed to evaluate the angular resolution, based on the distribution of orientation errors when evaluating controlled sample disorientation. The main advantage is that no external reference is required. An angular resolution of 1° is obtained on a nickel based sample using standard acquisition conditions. This value fulfills most of the needs in terms of microstructural characterization usually carried out by Electron Back Scattered Diffraction.

[Mediastinitis following EBUS : about a complication after a minimally invasive investigation]

Endobronchial ultrasound (EBUS) is a minimally invasive investigation method that permits transbronchial needle aspiration (TBNA) of mediastinal and hilar lymphadenopathies in order to determine their etiology. Its indications are notably lung cancer staging and lymphadenopathy exploration in case of sarcoidosis and malignant lymphomas. The employment of EBUS-TBNA has grown over the past few years and has become an alternative to mediastinoscopy due to a lower complication rate. However, in rare cases, complications can occur as hemorrhage, infections (mediastinitis, pneumonia, pericarditis, cyst infection, sepsis) or other (pneumothorax, pneumomediastinitis). We report herein a case of a mediastinitis after endobronchial ultrasound-guided transbronchial needle aspiration which occurred in a 63-year-old patient treated by methotrexate and methylprednisolone for a rheumatoid arthritis. The symptoms appeared as fever and progressive dyspnea some days after the endoscopic procedure.

A new setup for localized implantation and live-characterization of keV energy multiply charged ions at the nanoscale

An innovative experimental setup, PELIICAEN, allowing the modification of materials and the study of the effects induced by multiply charged ion beams at the nanoscale is presented. This ultra-high vacuum (below 5 × 10^-10 mbar) apparatus is equipped with a focused ion beam column using multiply charged ions and a scanning electron microscope developed by Orsay Physics, as well as a scanning probe microscope. The dual beam approach coupled to the scanning probe microscope achieves nanometer scale in situ topological analysis of the surface modifications induced by the ion beams. Preliminary results using the different on-line characterization techniques to study the formation of nano-hillocks on silicon and mica substrates are presented to illustrate the performances of the setup.

Ordered arrays of Au catalysts by FIB assisted heterogeneous dewetting

Synthesizing Au0.8Si0.2 nanocatalysts that are homogeneous in size and have controlled position is becoming a challenging and crucial prequisite for the fabrication of ordered semiconductor nanowires. In this study, Au0.8Si0.2 nanocatalysts are synthesized via dewetting of Au layers on Si(111) during thermal annealing in an ultra-high vacuum. In the first part of the paper, the mechanism of homogeneous dewetting is analyzed as a function of the Au-deposited thickness (h Au). We distinguish three different dewetting regimes: (I) for a low thickness ([Formula: see text]), a submonolyer coverage of Au is stabilized and there is no dewetting. (II) For an intermediate thickness ([Formula: see text]), there is both dewetting and Au0.8Si0.2 phase formation. The size and density of the Au0.8Si0.2 clusters are directly related to h Au. When cooling down to room temperature, the clusters decompose and reject the Si at the Au/Si substrate interface. (III) For a large thickness ([Formula: see text]), only dewetting takes place, without forming AuSi clusters. In this regime, the dewetting is kinetically controlled by the self-diffusion of Au (activation energy ∼0.43 eV) without evidence of an Si-alloying effect. As a practical consequence, when relying solely on the homogeneous dewetting of Au/Si(111) to form the Au0.8Si0.2 catalysts (without a supply of Si atoms from vapor), regime II should be used to obtain good size and density control. In the second part of the paper, a process for ordering the catalysts using focused ion beam-(FIB) assisted dewetting (heterogeneous dewetting) is developed. We show that no matter what the FIB milling conditions and the Au nominal thickness are, dewetting is promoted by ion beam irradiation and is accompanied by the formation of Au0.8Si0.2 droplets. The droplets preferentially form on the patterned areas, while in similar annealing conditions, they do not form on the unpatterned areas. This behavior is attributed to the larger Au-Si interdiffusion in the patterned areas, which results from the Si amorphization induced by the FIB. A systematic analysis of the position of the nanodroplets shows their preferential nucleation inside the patterns, while thicker platelets of almost pure Au are observed between the patterns. The evolutions of the size homogeneity and the occupancy rate of the patterns are quantified as a function of the FIB dose and annealing temperature. Nice arrays of perfectly ordered AuSi catalysts are obtained after optimizing the FIB and dewetting conditions.

Selective growth and ordering of SiGe nanowires for band gap engineering

Selective growth and self-organization of silicon-germanium (SiGe) nanowires (NWs) on focused ion beam (FIB) patterned Si(111) substrates is reported. In its first step, the process involves the selective synthesis of Au catalysts in SiO₂-free areas; its second step involves the preferential nucleation and growth of SiGe NWs on the catalysts. The selective synthesis process is based on a simple, room-temperature reduction of gold salts (Au³⁺Cl₄⁻) in aqueous solution, which provides well-organized Au catalysts. By optimizing the reduction process, we are able to generate a bidimensional regular array of Au catalysts with self-limited sizes positioned in SiO₂-free windows opened in a SiO₂/Si(111) substrate by FIB patterning. Such Au catalysts subsequently serve as preferential nucleation and growth sites of well-organized NWs. Furthermore, these NWs with tunable position and size exhibit the relevant features and bright luminescence that would find several applications in optoelectronic nanodevices.

"Real-life" effectiveness of omalizumab in patients with severe persistent allergic asthma: The PERSIST study

OBJECTIVE

To evaluate the 16- and 52-week effectiveness of add-on omalizumab treatment under real-life heterogeneity in patients, settings, and physicians in an open-label, multicenter, pharmaco-epidemiologic study of patients with severe persistent allergic asthma in Belgium.

METHODS

Effectiveness outcomes included improvement in 2005 global initiative for asthma (GINA) classification, physician-rated global evaluation of treatment effectiveness (GETE), quality of life (Juniper asthma-related quality of life (AQLQ) and European quality of life questionnaire 5 dimensions (EQ-5D)), and severe asthma exacerbations. Patients studied included both intent-to-treat and per-protocol populations.

RESULTS

The sample (n=158) had a mean age of 48.17+/-17.18 years, and a slight majority were female (53.8%). Despite being treated with high-dose inhaled corticosteroids and long-acting beta2-agonists, all patients experienced frequent symptoms and had exacerbations in the past year. At 16 weeks, >82% had good/excellent GETE (P values <0.001), >82% had an improvement in total AQLQ scores of > or =0.5 points (P<0.001), and >91% were severe exacerbation-free (P<0.001). At 52 weeks, >72% had a good/excellent GETE rating (P<0.001), >84% had improvements in total AQLQ score of > or =0.5 points (P<0.001), >56% had minimally important improvements in EQ-5D utility scores (P=0.012), and >65% were severe exacerbation-free (P<0.001). Significant reductions in healthcare utilization compared to the one year prior to treatment were noted.

CONCLUSION

The PERSIST study shows better physician-rated effectiveness, greater improvements in quality of life, greater reductions in exacerbation rates, and greater reductions in healthcare utilization than previously reported in efficacy studies. Under real-life conditions, omalizumab is effective as add-on therapy in the treatment of patients with persistent severe allergic asthma.

Necrotising sarcoid granulomatosis: clinical, functional, endoscopical and radiographical evaluations

Necrotising sarcoid granulomatosis (NSG) is a rare disease diagnosed on the basis of pathological features. The present study reports the characteristics of 14 cases of NSG. The mean age at the appearance of first symptoms was 37 yrs and the mean delay between first symptoms and diagnosis was 1 yr. Extrarespiratory symptoms were more common (12 out of 14) than respiratory symptoms (eight out of 14). Seven patients had inflammatory syndrome. Bronchoalveolar lavage was performed in eight patients and found to be normal in three cases. Respiratory function was normal in 13 patients, but carbon monoxide diffusing capacity was slightly decreased in eight of the 11 patients tested. A computed tomography scan showed a solitary nodule in four out of 14 cases, bilateral nodules in three and infiltrates in seven. One patient died from neurological complications despite treatment with corticosteroids and immunosuppressive drugs. Two cases of relapse were observed in patients initially treated with corticosteroids, and there were two cases of relapse after surgery. No relapse occurred in the five untreated patients. During the follow-up, lung cancer was detected at 26 months and 8 yrs, respectively, after NSG diagnosis in two patients. In conclusion, no one treatment is associated with a better outcome than the others, although lung biopsy might be necessary in case of isolated nodule or cavitation. Greater vigilance is required during the follow-up.

Atomic surrounding of Co implanted in AIN at high energy

AlN bulk ceramic has been implanted with energetic Co ions. In order to accurately characterise the atomic surrounding of the implanted ions. X-ray absorption measurements were carried out at 80 K in the fluorescence mode at the Co K edge in the as-implanted and annealed states. Simulation of the EXAFS oscillations allowed us to identify a first stage where Co is inserted in the AlN matrix followed by a second stage where Co precipitates form.

Study by X-ray absorption spectroscopy of Si3N4 films after Cu or Fe implantation and thermal treatment

Si3N4 amorphous thin layers prepared by sputtering have been implanted either with Cu or with Fe ions. X-ray absorption spectroscopy was performed at the Si K edge to characterise the electronic empty states of p character, the structural state of the initial layers and the modifications around Si induced by implantation and a post-annealing treatment. We show that the energy deposition process mainly leads to a reorganisation of the second coordination shell around Si, i.e. concerns the Si-Si bonds.

Determinants of survival in pulmonary Langerhans' cell granulomatosis (histiocytosis X). Groupe d'Etude en Pathologie Interstitielle de la Société de Pathologie Thoracique du Nord

The course of pulmonary Langerhans' cell granulomatosis (pulmonary LCG) is variable, difficult to predict and ranges from spontaneous remission to progressive respiratory insufficiency and death. To identify the determinants of survival, we performed a survival analysis on 45 patients with pulmonary LCG. The patients were aged 28 +/- 10 yrs (mean +/- SD) (range 12-62 yrs), 32 males and 13 females, almost exclusively current smokers (96%), and 78% presented symptoms at the time of diagnosis. Diagnosis was made by lung biopsy in 25 patients (56%) and by bronchoalveolar lavage (BAL) analysis in 20 patients (44%). The patients were followed for a median period of 6 yrs (range 1-29 yrs) after the diagnosis. During the period of observation, 33 (73%) patients survived (median follow-up period = 5.8 yrs; range, 1-29 yrs) and 12 (27%) died or underwent lung transplantation (median follow-up period = 8.4 yrs; range 1.4 - 16.1 yrs). The median survival was approximately 13 years. A univariate analysis demonstrated that diminished survival was significantly associated with: an older age at diagnosis (p = 0.0001); a lower forced expiratory volume in one second/forced vital capacity (FEV1/FVC) ratio at diagnosis (p = 0.005); a higher residual volume/total lung volume (RV/TLC) ratio at diagnosis (p = 0.02); and steroid therapy during follow-up (p = 0.03). Additional predictive information on mortality was: age > 26 yrs (sensitivity 83%, specificity 64%); FEV1/FVC ratio < 0.66 (sensitivity 75%, specificity 86%); and a RV/TLC ratio > 0.33 (sensitivity 75%, specificity 63%). In multivariate Cox analysis, the combination of factors which gave the best prognostic value was FEV1/FVC ratio and age (p < 0.01). The present findings suggest that adverse prognosis factors at diagnosis in pulmonary Langerhans' cell granulomatosis include older age, lower FEV1/FVC ratio and higher RV/TLC ratio, with additional predictive information on mortality if aged > 26 yrs, FEV1/FVC ratio < 0.66, and RV/TLC ratio > 0.33.

Biological properties of a panel of murine monoclonal anti-Brucella antibodies

Immune sera have previously been shown to play a positive role in immune protection against murine experimental brucellosis. The protective properties of a panel of five anti-Brucella monoclonal antibodies (Mabs) were therefore assessed by estimation of the acceleration of the blood clearance of intravenously inoculated Brucella and of the reduction of splenic infection on Day 7 after infection. Three 'strongly protective', one 'weakly protective' and one 'non-protective' Mabs were identified. As a first step towards the study of the mechanism of this humoral protection, these Mabs were further compared for structural and functional properties such as immunoglobulin isotype, anti-Brucella specificity, anti-Brucella in vitro bacteriostasis, Brucella agglutination and complement fixation when complexed with tyndallized Brucella. No correlation was found between protection and either agglutination or direct bacteriostasis. On the other hand, the results observed suggest that isotypes (and especially the IgG2a isotype) could play an important role in in vivo immuno protection and that complement may be involved. However, the fact that one of the protective Mabs belongs to the IgA isotype, does not cross-react with the others in anti-Brucella epitopic specificity and does not fix complement underlines the probable diversity of the mechanisms involved.

Isolation from thyroid cells or purified plasma membranes with associated actin microfilaments. Proteins bound to actin

Plasma membranes of thyroid cells were purified from hog thyroid glands following two procedures. Their homogeneity was tested by electron microscopy and by measurements of the activity of membrane-bound enzyme markers. According to the procedure used the membrane fractions obtained present some differences in their morphological features as well as in the repartition of the activities of the membrane-bound enzyme markers. However, whatever the composition of the membrane fraction examined (membrane vesicles, single membrane sheets with junctional complexes), decoration with heavy meromyosin clearly shows the presence of actin filaments attached to these fragments. Analysis of proteins by polyacrylamide gel electrophoresis indicates the presence of about twelve major components with actin. Treatment of membranes with Triton X-100 results in an insoluble core which contains all the actin and most of the major proteins. The selective extraction of these components by buffers differing in their ionic strength, pH, or the presence or absence of ATP X Mg has been used to characterize some of the proteins associated to actin; among them are filamin, myosin, alpha-actinin, tropomyosin.

Biochemical and genetic study of D-glucitol transport and catabolism in Bacillus subtilis

The catabolic pathway of D-glucitol (sorbitol) in Bacillus subtilis Marburg 168M is characterized. It includes (i) a transport step catalyzed by a D-glucitol permease which is affected by the gutA mutations, (ii) an oxidation step of the intracellular D-glucitol catalyzed by a D-glucitol dehydrogenase, generating intracellular fructose, affected by gutB mutations, and (iii) phosphorylation of the intracellular fructose either at the C1 site or at the C6 site as described previously (A. Delobbe et al., Eur. J. Biochem., 66:485-491, 1976; A. Delobbe et al., EUR. J. Biochem. 51:503-510, 1975). Additional data are given concerning the phosphorylation of fructose by a fructokinase (fructose ATP 6-phosphotransferase), which is affected by the fruC mutation. The isolation of regulatory mutants affected in gutR that synthesize constitutively both the permease and the dehydrogenase indicates the existence of a D-glucitol operon in B. subtilis. Unlike the wild-type strain, these mutants are able to utilize D-xylitol as sole carbon source.

Fructose transport in Bacillus subtilis

The transport of fructose in Bacillus subtilis was studied in various mutant strains lacking the following activities: ATP-dependent fructokinase (fruC), the fructose 1-phosphate kinase (fruB) the phosphofructokinase (pfk), the enzyme I of the phosphoenolpyruvate phosphotransferase system (the thermosensitive mutation ptsI1), and a transport activity (fruA). Combinations of these mutations indicated that the transport of fructose in Bacillus subtilis is tightly coupled to its phosphorylation either in fructose 1-phosphate, identified in vivo and in vitro or in fructose 6-phosphate identified by indirect lines of evidence. These steps of fructose metabolism were shown to depend on the activity of the enzyme I of the phosphoenolpyruvate phosphotransferase systems. The fruA mutations affect the transport of fructose when the bacteria are submitted to catabolite repression. The mutations were localized on the chromosome of Bacillus subtilis in a cluster including the fruB gene. When grown in a medium supplemented by a mixture of potassium glutamate and succinate the fruA mutants are able to carry on the two vectorial metabolisms generating fructose 6-phosphate as well as fructose 1-phosphate. A negative search of strictly negative transport mutants in fruA strains indicated that more than two structural genes are involved in the transport of fructose.

Phosphorylation of intracellular fructose in Bacillus subtilis mediated by phosphoenolpyruvate-1-fructose phosphotransferase

Intracellular fructose provided by the sorbitol pathway in Bacillus subtilis can be phosphorylated by the phosphenolpyruvate-1-fructose phosphotransferase which is known to mediate a vectorial metabolism. The fate of this intracellular fructose was studied using mutants lacking either the fructose 1-phosphate pathway or the fructose 6-phosphate pathway. It was shown that the phosphoenolpyruvate-dependent phosphorylation needs a prior exit of the sugar into the medium, this exit being probably catalysed by a transport system. A low affinitiy intracellular phosphenolpyruvate phosphotransferase system was found, which seems to be devoid of a physiological role.

Existence of two alternative pathways for fructose and sorbitol metabolism in Bacillus subtilis Marburg

Strains of Bacillus subtilis mutated for fructose phosphotransferase system (fruA), fructose-1-phosphate kinase (fruB), fructokinase (frucC) have been tested for their catabolism of sorbitol and fructose. It is shown that the previously known pathways of sorbitol and fructose degradation in B. subtilis, e.g.: (see article) may metabolize intracellular fructose produced either by sorbitol oxidation or by fructose-1-phosphate dephosphorylation. The intracellular fructore degradation via fructose-1-phosphate kinase has been found to require the fructose phosphotransferase system which ensures a vectorial transport of fructose.