Formation and annealing of dislocation loops induced by nitrogen implantation of ZnO

Although zinc oxide is a promising material for the fabrication of short wavelength optoelectronic devices, p-type doping is a step that remains challenging for the realization of diodes. Out of equilibrium methods such as ion implantation are expected to dope ZnO successfully provided that the non-radiative defects introduced by implantation can be annealed out. In this study, ZnO substrates are implanted with nitrogen ions, and the extended defects induced by implantation are studied by transmission electron microscopy and X-ray diffraction (XRD), before and after annealing at 900^{\circ}C. Before annealing, these defects are identified to be dislocation loops lying either in basal planes in high N concentration regions, or in prismatic planes in low N concentration regions, together with linear dislocations. An uniaxial deformation of 0.4% along the c axis, caused by the predominant basal loops, is measured by XRD in the implanted layer. After annealing, prismatic loops disappear while the density of basal loops decreases and their diameter increases. Moreover, dislocation loops disappear completely from the sub-surface region. XRD measurements show a residual deformation of only 0.05% in the implanted and annealed layer. The fact that basal loops are favoured against prismatic ones at high N concentration or high temperature is attributed to a lower stacking fault energy in these conditions. The coalescence of loops and their disappearance in the sub-surface region are ascribed to point defect diffusion. Finally, the electrical and optical properties of nitrogen-implanted ZnO are correlated with the observed structural features.Comment: 8 page

To be malnourished or not to be malnourished: that is the question!

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Pneumocystis in metastatic lung cancer, a pragmatic approach in support of prophylaxis

International audienceLung cancer prognosis has improved in the last decade, including in patients with brain metastasis. However, few of these patients who receive corticosteroids have a primary prophylaxis for pneumonia (PJP). We report the case of an 80-year-old man diagnosed with non-small cell lung cancer and concomitant symptomatic brain metastases, treated with 50 mg/day of prednisolone without any prophylaxis, who presented an acute PJP. After 72 hours of unsuccessful treatment of PJP, the patient died. In our review of this case and the existing literature, we emphasise the importance of a wide use of prophylaxis for PJP, especially in advanced lung cancer treated with corticosteroid therapy. We discuss this issue and report current evidence for primary prophylaxis by trimethoprim-sulfamethoxazole

AgrExPro : Expositions professionnelles des éleveurs laitiers bretons en relation avec la Broncho-Pneumopathie Chronique Obstructive (BPCO) - Résultats de l'étude pilote

National audienceAIRBAg (Analyse Incidence et Facteurs de Risques de la BPCO agricole) est une étude prospective incluant 1200 éleveurs laitiers bretons, dont l’un des objectifs est d’identifier les étiologies de la BPCO agricole grâce à un questionnaire professionnel. AIRBAg ne prévoit pas la mesure de l’exposition réelle des éleveurs aux aéro-contaminants : celle-ci est pourtant nécessaire pour objectiver les facteurs de risques de la BPCO agricole et proposer des mesures de prévention. répond à ces besoins par la mise en place d’une campagne de mesures individuelles de l’exposition des éleveurs aux poussières thoraciques, aux endotoxines, aux micro-organismes viables, à l’ ammoniac et aux aldéhydes .Préalablement au lancement de la campagne, une étude de faisabilité a été réalisée. Elle avait pour objectifs de tester les protocoles de mesures envisagés et d’investiguer la faisabilité de l’échantillonnage de la fraction thoracique des poussières, pour laquelle la littérature en milieu agricole reste encore peu abondante

Déterminants environnementaux des pathologies respiratoires obstructives chroniques chez les éleveurs laitiers bretons

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On-site screening of farming-induced chronic obstructive pulmonary disease with the use of an electronic mini-spirometer: results of a pilot study in Brittany, France.

International audiencePURPOSE: Dairy farming is a risk factor for the development of chronic obstructive pulmonary disease (COPD). We assessed the prevalence of farming-induced COPD (FI-COPD) using a new screening device, and we analyzed symptoms and occupational risk factors. METHODS: We performed on-site screening study of bronchial obstruction using an electronic mini-spirometer (EMS) on an entire population of dairy farmers (n = 147) from two villages in Brittany, France. Suspected bronchial obstruction (FEV1/FEV6 <0.8) was confirmed with standardized lung function tests (FEV1/FVC ≤0.7). We assessed past medical histories, respiratory symptoms, and occupational tasks of subjects with bronchial obstruction; asthmatics were defined as atopic and/or reversible; smoking-induced COPD patients were defined as non-reversible, non-atopic with smoking histories (≥5 PY); and FI-COPD patients were defined as non-reversible, non-atopic, and non-smokers. RESULTS: Using the EMS, 30.6% (n = 45) of dairy farmers were suspected of bronchial obstruction and underwent standardized spirometry. The FEV1/FEV6 ratio and FEV1/FVC ratio were in good agreement (r² = 0.66, P < 0.0001). The prevalence of confirmed bronchial obstruction was 9.5% (n = 14), which included 4 asthmatics, 3 smoking-induced COPD subjects, and 7 FI-COPD subjects. All the COPD patients were GOLD Stage II, and none were aware of their respiratory disease. Foddering duration was significantly higher in FI-COPD subjects compared with non-obstructive subjects, with 44 versus 17 min/day, respectively. CONCLUSIONS: The EMS was a convenient mean of screening for bronchial obstruction, especially in on-site settings, and allowed us to diagnose FI-COPD in a non-spontaneously complaining dairy farmer population. Foddering was considered a significant risk factor

ILD and Mediastinal Lymph Nodes A CT-Based Biomarker Beyond Nosological and Etiological Borders?

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Hypertension artérielle pulmonaire associée à la prise de léflunomide : 4 cas

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Iterative thoracentesis as first-line treatment of complicated parapneumonic effusion.

International audienceRATIONALE: Optimal management of complicated parapneumonic effusions (CPPE) remains controversial. OBJECTIVES: to assess safety and efficacy of iterative therapeutic thoracentesis (ITTC), the first-line treatment of CPPE in Rennes University Hospital. METHODS: Patients with CPPE were identified through our computerized database. We retrospectively studied all cases of CPPE initially managed with ITTC in our institution between 2001 and 2010. ITTC failure was defined by the need for additional treatment (i.e. surgery or percutaneous drainage), or death. RESULTS: Seventy-nine consecutive patients were included. The success rate was 81% (n = 64). Only 3 patients (4%) were referred to thoracic surgery. The one-year survival rate was 88%. On multivariate analysis, microorganisms observed in pleural fluid after Gram staining and first thoracentesis volume ≥450 mL were associated with ITTC failure with adjusted odds-ratios of 7.65 [95% CI, 1.44-40.67] and 6.97 [95% CI, 1.86-26.07], respectively. The main complications of ITTC were iatrogenic pneumothorax (n = 5, 6%) and vasovagal reactions (n = 3, 4%). None of the pneumothoraces required chest tube drainage, and no hemothorax or re-expansion pulmonary edema was observed. CONCLUSIONS: Although not indicated in international recommendations, ITTC is safe and effective as first-line treatment of CPPE, with limited invasiveness

EMMPRIN (CD147) regulation of MMP-9 in bronchial epithelial cells in COPD.

International audienceBACKGROUND AND OBJECTIVE: Extracellular matrix metalloproteinase inducer (EMMPRIN or CD147) induces the production of matrix metalloproteinases (MMP) such as MMP-9, which plays an important role in COPD. We determined its cellular origin and role in MMP-9 production in COPD. METHODS: Bronchial biopsies, alveolar macrophages (AM) and blood monocytes (BM) from patients with COPD, healthy smokers and non-smokers, and bronchial epithelial cells (EC) from surgically resected airways from patients with COPD were stimulated with LPS or CRP in the presence and absence of an anti-EMMPRIN blocking antibody. EMMPRIN in BAL, plasma, conditioned media and cell lysates was quantified and immunohistochemical localization of EMMPRIN was determined in bronchial biopsies. MMP-9 activity and mRNA was also determined. RESULTS: EMMPRIN levels in BAL fluid were higher in patients with COPD compared with non-smokers and smokers. There was greater EMMPRIN expression in EC from patients with COPD compared with smokers and non-smokers. EC secreted and expressed more EMMPRIN protein than BM and AM. Blocking EMMPRIN decreased MMP-9 activity in supernatant of EC, but not in those from AM and BM, and decreased MMP-9 mRNA expression in EC. CONCLUSIONS: The increased EMMPRIN expression in COPD is reflected by an increased release from bronchial EC, which are one of the main source of EMMPRIN. EMMPRIN regulates MMP-9 expression in COPD