160 research outputs found
Development of a Portable Device for Thermoelectrical Power Measurement—Application to the Inspection of Duplex Stainless Steel Components
Some cast components of the primary loop of French Pressurized Water Reactors are made of cast duplex stainless steels. The mechanical characteristics of these components, working in the temperature range from 285°C to 325°C, may be altered by thermal aging : the hardness of the materials increases whereas its toughness decreases with aging time and temperature. The metallurgical explanation of this phenomena is the unmixing of the ferritic Fe-Cr-Ni solid solution by spinodal decomposition and the precipitation of intermetallic G-phase particles rich in nickel and silicium [1]
Accumulation of Immature Langerhans Cells in Human Lymph Nodes Draining Chronically Inflamed Skin
The coordinated migration and maturation of dendritic cells (DCs) such as intraepithelial Langerhans cells (LCs) is considered critical for T cell priming in response to inflammation in the periphery. However, little is known about the role of inflammatory mediators for LC maturation and recruitment to lymph nodes in vivo. Here we show in human dermatopathic lymphadenitis (DL), which features an expanded population of LCs in one draining lymph node associated with inflammatory lesions in its tributary skin area, that the Langerin/CD207+ LCs constitute a predominant population of immature DCs, which express CD1a, and CD68, but not CD83, CD86, and DC–lysosomal-associated membrane protein (LAMP)/CD208. Using LC-type cells generated in vitro in the presence of transforming growth factor (TGF)-β1, we further found that tumor necrosis factor (TNF)-α, as a prototype proinflammatory factor, and a variety of inflammatory stimuli and bacterial products, increase Langerin expression and Langerin dependent Birbeck granules formation in cell which nevertheless lack costimulatory molecules, DC–LAMP/CD208 and potent T cell stimulatory activity but express CCR7 and respond to the lymph node homing chemokines CCL19 and CCL21. This indicates that LC migration and maturation can be independently regulated events. We suggest that during DL, inflammatory stimuli in the skin increase the migration of LCs to the lymph node but without associated maturation. Immature LCs might regulate immune responses during chronic inflammation
The XMM-Newton Wide-Field Survey in the COSMOS field (XMM-COSMOS): demography and multiwavelength properties of obscured and unobscured luminous AGN
We report the final optical identifications of the medium-depth (~60 ksec),
contiguous (2 deg^2) XMM-Newton survey of the COSMOS field. XMM-Newton has
detected ~800 X-ray sources down to limiting fluxes of ~5x10^{-16},
~3x10^{-15}, and ~7x10^{-15} erg/cm2/s in the 0.5-2 keV, 2-10 keV and 5-10 keV
bands, respectively. The work is complemented by an extensive collection of
multi-wavelength data from 24 micron to UV, available from the COSMOS survey,
for each of the X-ray sources, including spectroscopic redshifts for ~50% of
the sample, and high-quality photometric redshifts for the rest. The XMM and
multiwavelength flux limits are well matched: 1760 (98%) of the X-ray sources
have optical counterparts, 1711 (~95%) have IRAC counterparts, and 1394 (~78%)
have MIPS 24micron detections. Thanks to the redshift completeness (almost
100%) we were able to constrain the high-luminosity tail of the X-ray
luminosity function confirming that the peak of the number density of
logL_X>44.5 AGN is at z~2. Spectroscopically-identified obscured and unobscured
AGN, as well as normal and starforming galaxies, present well-defined optical
and infrared properties. We devised a robust method to identify a sample of
~150 high redshift (z>1), obscured AGN candidates for which optical
spectroscopy is not available. We were able to determine that the fraction of
the obscured AGN population at the highest (L_X>10^{44} erg s^{-1}) X-ray
luminosity is ~15-30% when selection effects are taken into account, providing
an important observational constraint for X-ray background synthesis. We
studied in detail the optical spectrum and the overall spectral energy
distribution of a prototypical Type 2 QSO, caught in a stage transitioning from
being starburst dominated to AGN dominated, which was possible to isolate only
thanks to the combination of X-ray and infrared observations.Comment: ApJ, in press. 59 pages, 14 figures, 2 Tables. A few typos corrected
and a reference added. Table 2 is also available at
http://www.mpe.mpg.de/XMMCosmos/xmm53_release ; a version of the paper in ApJ
format (27 pages) is available at
http://www.mpe.mpg.de/XMMCosmos/xmm53_release/brusa_xmmcosmos_optid.pd
Precision photometric redshift calibration for galaxy-galaxy weak lensing
Accurate photometric redshifts are among the key requirements for precision weak lensing measurements. Both the large size of the Sloan Digital Sky Survey (SDSS) and the existence of large spectroscopic redshift samples that are flux-limited beyond its depth have made it the optimal data source for developing methods to properly calibrate photometric redshifts for lensing. Here, we focus on galaxy-galaxy lensing in a survey with spectroscopic lens redshifts, as in the SDSS. We develop statistics that quantify the effect of source redshift errors on the lensing calibration and on the weighting scheme, and show how they can be used in the presence of redshift failure and sampling variance. We then demonstrate their use with 2838 source galaxies with spectroscopy from DEEP2 and zCOSMOS, evaluating several public photometric redshift algorithms, in two cases including a full p(z) for each object, and find lensing calibration biases as low as <1 per cent (due to fortuitous cancellation of two types of bias) or as high as 20 per cent for methods in active use (despite the small mean photoz bias of these algorithms). Our work demonstrates that lensing-specific statistics must be used to reliably calibrate the lensing signal, due to asymmetric effects of (frequently non-Gaussian) photoz errors. We also demonstrate that large-scale structure (LSS) can strongly impact the photoz calibration and its error estimation, due to a correlation between the LSS and the photoz errors, and argue that at least two independent degree-scale spectroscopic samples are needed to suppress its effects. Given the size of our spectroscopic sample, we can reduce the galaxy-galaxy lensing calibration error well below current SDSS statistical error
Precision photometric redshift calibration for galaxy–galaxy weak lensing
Accurate photometric redshifts are among the key requirements for precision weak lensing measurements. Both the large size of the Sloan Digital Sky Survey (SDSS) and the existence of large spectroscopic redshift samples that are flux-limited beyond its depth have made it the optimal data source for developing methods to properly calibrate photometric redshifts for lensing. Here, we focus on galaxy–galaxy lensing in a survey with spectroscopic lens redshifts, as in the SDSS. We develop statistics that quantify the effect of source redshift errors on the lensing calibration and on the weighting scheme, and show how they can be used in the presence of redshift failure and sampling variance. We then demonstrate their use with 2838 source galaxies with spectroscopy from DEEP2 and zCOSMOS, evaluating several public photometric redshift algorithms, in two cases including a full p(z) for each object, and find lensing calibration biases as low as <1 per cent (due to fortuitous cancellation of two types of bias) or as high as 20 per cent for methods in active use (despite the small mean photoz bias of these algorithms). Our work demonstrates that lensing-specific statistics must be used to reliably calibrate the lensing signal, due to asymmetric effects of (frequently non-Gaussian) photoz errors. We also demonstrate that large-scale structure (LSS) can strongly impact the photoz calibration and its error estimation, due to a correlation between the LSS and the photoz errors, and argue that at least two independent degree-scale spectroscopic samples are needed to suppress its effects. Given the size of our spectroscopic sample, we can reduce the galaxy–galaxy lensing calibration error well below current SDSS statistical errors
Analyse de la connectivité fonctionnelle cérébrale de modèles murins par extraction de motifs fréquents dans des graphes
Usefulness of Routine Fractional Flow Reserve for Clinical Management of Coronary Artery Disease in Patients With Diabetes
Importance: Approximately one-third of patients considered for coronary revascularization have diabetes, which is a major determinant of clinical outcomes, often influencing the choice of the revascularization strategy. The usefulness of fractional flow reserve (FFR) to guide treatment in this population is understudied and has been questioned.
Objective: To evaluate the usefulness and rate of major adverse cardiovascular events (MACE) of integrating FFR in management decisions for patients with diabetes who undergo coronary angiography.
Design, setting, and participants: This cross-sectional study used data from the PRIME-FFR study derived from the merger of the POST-IT study (Portuguese Study on the Evaluation of FFR-Guided Treatment of Coronary Disease [March 2012-November 2013]) and R3F study (French Study of FFR Integrated Multicenter Registries Implementation of FFR in Routine Practice [October 2008-June 2010]), 2 prospective multicenter registries that shared a common design. A population of all-comers for whom angiography disclosed ambiguous lesions was analyzed for rates, patterns, and outcomes associated with management reclassification, including revascularization deferral, in patients with vs without diabetes. Data analysis was performed from June to August 2018.
Main outcomes and measures: Death from any cause, myocardial infarction, or unplanned revascularization (MACE) at 1 year.
Results: Among 1983 patients (1503 [77%] male; mean [SD] age, 65 [10] years), 701 had diabetes, and FFR was performed for 1.4 lesions per patient (58.2% of lesions in the left anterior descending artery; mean [SD] stenosis, 56% [11%]; mean [SD] FFR, 0.81 [0.01]). Reclassification by FFR was high and similar in patients with and without diabetes (41.2% vs 37.5%, P = .13), but reclassification from medical treatment to revascularization was more frequent in the former (142 of 342 [41.5%] vs 230 of 730 [31.5%], P = .001). There was no statistical difference between the 1-year rates of MACE in reclassified (9.7%) and nonreclassified patients (12.0%) (P = .37). Among patients with diabetes, FFR-based deferral identified patients with a lower risk of MACE at 12 months (25 of 296 [8.4%]) compared with those undergoing revascularization (47 of 257 [13.1%]) (P = .04), and the rate was of the same magnitude of the observed rate among deferred patients without diabetes (7.9%, P = .87). Status of insulin treatment had no association with outcomes. Patients (6.6% of the population) in whom FFR was disregarded had the highest MACE rates regardless of diabetes status.
Conclusions and relevance: Routine integration of FFR for the management of coronary artery disease in patients with diabetes may be associated with a high rate of treatment reclassification. Management strategies guided by FFR, including revascularization deferral, may be useful for patients with diabetes.info:eu-repo/semantics/publishedVersio
Cardiovascular magnetic resonance assessment of the aortic valve stenosis: an in vivo and ex vivo study
Comparison of outcomes of percutaneous coronary intervention on proximal versus non-proximal left anterior descending coronary artery, proximal left circumflex, and proximal right coronary artery: A cross-sectional study
BACKGROUND: Previous studies have shown that lesions in proximal left anterior descending coronary artery (LAD) may develop more restenosis after balloon angioplasty than lesions in other coronary segments. However, stenting seems to have reduced this gap. In this study, we compared outcomes of percutaneous coronary intervention (PCI) on proximal LAD versus proximal left circumflex (LCX) or right coronary artery (RCA) and proximal versus non-proximal LAD. METHODS: From 1737 patients undergoing PCI between March 2004 and 2005, those with cardiogenic shock, primary PCI, total occlusions, and multivessel or multi-lesion PCI were excluded. Baseline characteristics and in-hospital outcomes were compared in 408 patients with PCI on proximal LAD versus 133 patients with PCI on proximal LCX/RCA (study I) and 244 patients with PCI on non-proximal LAD (study II). From our study populations, 449 patients in study I and 549 patients in study II participated in complete follow-up programs, and long-term PCI outcomes were compared within these groups. The statistical methods included Chi-square or Fisher's exact test, student's t-test, stratification methods, multivariate logistic regression and Cox proportional hazards model. RESULTS: In the proximal LAD vs. proximal LCX/RCA groups, smoking and multivessel disease were less frequent and drug-eluting stents were used more often (p = 0.01, p < 0.001, and p < 0.001, respectively). Patients had longer and smaller-diameter stents (p = 0.009, p < 0.001, respectively). In the proximal vs. non-proximal LAD groups, multivessel disease was less frequent (p = 0.05). Patients had larger reference vessel diameters (p < 0.001) and were more frequently treated with stents, especially direct stenting technique (p < 0.001). Angiographic success rate was higher in the proximal LAD versus proximal LCX/RCA and non-proximal LAD groups (p = 0.004 and p = 0.05, respectively). In long-term follow-up, major adverse cardiac events showed no difference. After statistical adjustment for significant demographic, angiographic or procedural characteristics, long-term PCI outcomes were still similar in the proximal LAD versus proximal LCX/RCA and non-proximal LAD groups. CONCLUSION: Despite the known worse prognosis of proximal LAD lesions, in the era of stenting, our long-term outcomes were similar in patients with PCI on proximal LAD versus proximal LCX/RCA and non-proximal LAD. Furthermore, we had better angiographic success rates in patients with PCI on proximal LAD
The close environment of 24 micron galaxies at 0.6<z<1.0 in the COSMOS field
We investigate the close environment of 203 Spitzer 24 micron-selected
sources at 0.6<z<1.0 using zCOSMOS-bright redshifts and spectra of I<22.5 AB
mag galaxies, over 1.5 sq. deg. of the COSMOS field. We quantify the degree of
passivity of the LIRG and ULIRG environments by analysing the fraction of close
neighbours with Dn(4000)>1.4. We find that LIRGs at 0.6<z<0.8 live in more
passive environments than those of other optical galaxies that have the same
stellar mass distribution. Instead, ULIRGs inhabit more active regions (e.g.
LIRGs and ULIRGs at 0.6<z<0.8 have, respectively, (42.0 +/- 4.9)% and (24.5 +/-
5.9)% of neighbours with Dn (4000)>1.4 within 1 Mpc and +/- 500 km/s). The
contrast between the activities of the close environments of LIRGs and ULIRGs
appears especially enhanced in the COSMOS field density peak at z~0.67, because
LIRGs on this peak have a larger fraction of passive neighbours, while ULIRGs
have as active close environments as those outside the large-scale structure.
The differential environmental activity is related to the differences in the
distributions of stellar mass ratios between LIRGs/ULIRGs and their close
neighbours, as well as in the general local density fields. At 0.8<z<1.0,
instead, we find no differences in the environment densities of ULIRGs and
other similarly massive galaxies, in spite of the differential activities. We
discuss a possible scenario to explain these findings.Comment: ApJ, in press. 9 pages, including 5 figure
- …