Belgian Society for Pneumology

Abstract Downstream processing of steel products involves a large variety of heat treatments in the ferrite as well as in the austenite phase. Different from austenite conditioning in the upstream processing stage, deformation and temperature schedules are usually decoupled in downstream processing. Fundamental characteristics of microalloying elements regarding their effects on recovery, recrystallization, phase transformation, and grain growth during downstream processing will be reviewed. Relevant characteristics of microalloying elements are the atom size, the solubility and temperature stability of related carbides or nitrides, the tendency of segregating at grain boundaries, dislocations and point defects, as well as the diffusivity. The various interactions and resulting microstructural effects will be demonstrated for several industrial steel developments. The selected examples cover microalloy effects in ferrite and austenite phases, under slow and fast thermal cycles, as well as during short and long heat treatment times. Based on the observations and the related interpretation, a qualitative understanding of the microalloy interactions will be developed that is generally applicable despite the considerable variation of processes and products. It will also be highlighted how appropriate process and microalloy adaptations resulted in remarkable product optimization under industrial conditions.

Introduction: The use of complete pulmonary function tests (CPFT) is primarily based on expert opinion and international guidelines. Current interpretation strategies are using predefined cut-offs for the description of a typical pattern. We aimed to explore the diagnostic power of CPFT based on the ATS/ERS interpreting strategy. Subsequently, we investigated whether an unbiased machine learning framework integrating lung function with clinical variables may provide alternative decision trees which result in a more accurate diagnosis. Methods: Our study included data from 968 subjects admitted for the first time to a pulmonary practice. A final clinical diagnosis was based on the combination of spirometry, resistance, lung volumes and diffusion (CPFT) with other investigations that were decided at the physician9s discretion. Clinical diagnoses were separated into 10 predefined disease groups and validated by an expert panel. Results: The ATS/ERS algorithm resulted in a correct diagnostic label in 38% of the subjects. COPD was detected with an acceptable accuracy (74%) whereas all other diseases were poorly identified. The new data-based decision tree improved the general accuracy to 68% after 10-fold cross-validation when detecting most common lung diseases, with a significant higher PPV and sensitivity for COPD, asthma, ILD and neuromuscular disorder [83% and 78%, 66% and 82%, 52% and 59%, 100% and 54%, respectively]. Conclusions: Our data show that the algorithms for lung function interpretation can be improved by a computer-based choice of lung function and clinical variables and their decision making thresholds. They may provide a first step to automated interpretation of lung function.

The persistence of donor cells derived from the graft (chimerism) has been documented in various tissues after organ transplantation. It was suggested that stable chimerism might reflect a state of donor-specific tolerance. Chimerism of macrophages and lymphocytes were studied over time after lung transplantation as well as its impact on graft tolerance. Macrophages and lymphocytes were purified from bronchoalveolar lavage sequentially obtained from 24 patients between 1 and 41 months posttransplantation (20, 22, 24, and 17 patients at, respectively, 1, 3, 6, and 12 months). DNA was extracted from these cells and their recipient-donor origin was evaluated by PCR amplification of highly polymorphic DNA regions (minisatellites). We show that the remaining donor cells over the first month vary from 10 up to 50% and 5 up to 55% for lymphocytes and macrophages respectively (+/-2 SD). All patients presented some chimerism up to the 6th postoperative month. Good correlation was observed between the residual amount of donor lymphocytes and macrophages during the first 3 months (P<0.001). Patients with at least 30% donor lymphocytes at 1 month after transplantation had less rejections (> or =stage II) in the follow up (P=0.0007). The same observation is true for donor macrophages although to lower extend (P=0.02). The chimerism lost its predictive value beyond 3 months. These data demonstrate that a level of chimerism above 30% of either donor lymphocytes or macrophages at 1 month is related to a better state of graft tolerance. However, chimerism decreases markedly beyond 3 months and has then no predictive value.