1,141 research outputs found
Flow modifying device
A swirler for a gas turbine engine combustor is disclosed for simultaneously controlling combustor flow rate, swirl angle, residence time and fuel-air ratio to provide three regimes of operation. A first regime is provided in which fuel-air ratio is less than stoichiometric, NOx is produced at one level, and combustor flow rate is high. In a second regime, fuel-air ratio is nearly stoichiometric, NOx production is less than that of the first regime, and combustor flow rate is low. In a third regime, used for example at highoff, fuel-air ratio is greater than stoichiometric and the combustor flow rate is less than in either of the other regimes
Postoperative Befunde an der Wirbelsäule
Zusammenfassung: Die postoperative Bildgebung wird klassischerweise herangezogen zur Dokumentation der korrekten Implantatlage oder um Komplikationen auszuschließen, wenn der Patient postoperativ weiterhin Beschwerden angibt. In Abhängigkeit von der Fragestellung können verschiedene Modalitäten verwendet werden - alle mit Vor- und Nachteilen. Die konventionelle Röntgenuntersuchung wird zur Dokumentation der Implantatlage, Beurteilung der Stabilität oder im Follow-up zur Frage der Instabilität oder einer Implantatfraktur verwendet, wogegen Weichteilveränderungen nicht komplett beurteilt werden können. Neben diesen Indikationen wird eine Bildgebung bei persistierenden Beschwerden (meist Schmerzen) des Patienten veranlasst. Residuelles oder rezidiviertes Bandscheibengewebe, ein Hämatom oder eine Entzündung können am besten mit der MRT beurteilt werden. Die MRT sollte unmittelbar postoperativ durchgeführt werden, um eine physiologische Granulation im Zugangsgebiet von entzündlichen Veränderungen unterscheiden zu können. Oft kann die Bildgebung allein dies nicht unterscheiden, daher ist die Bildgebung nur ein weiteres Puzzelstück. Die Computertomographie ist die Modalität der Wahl zur Beurteilung von Knochen und eine Ergänzung bei neuen Verfahren wie der bildgestützten Kypho- oder Vertebroplasti
Entzündliche Erkrankungen der Wirbelsäule und des Myelons
Zusammenfassung: Entzündliche Erkrankungen der Wirbelsäule und des Myelons haben vielfältige Ursachen. Mit Ausnahme der degenerativ bedingten entzündlichen Veränderungen der Wirbelsäule selbst sind bakteriell, viral oder autoimmun vermittelte Entzündungen eher selten. Letztere sind klinisch und bildgebend auch schwer zu evaluieren, können aber wichtige Ursachen für Schmerzen und funktionelle Störungen sein. Dies gilt besonders, wenn sie unbehandelt bleiben. Bei schweren Krankheitsverläufen wie der Spondylodiszitis oder der rheumatoiden Arthritis kann es zu ernsten neurologischen Ausfällen kommen, v.a. bei fortschreitender intraspinaler Beteiligung. Entzündungen des Myelons selbst können durch konventionelle Röntgenuntersuchungen nicht und mit der Computertomographie nur selten festgestellt werden. Hier ist die Magnetresonanztomographie das bildgebende Verfahren der ersten Wahl, um Veränderungen des Myelons frühzeitig und differenziert zu beurteile
Regulation of neutrophil function by selective targeting of glycan epitopes expressed on the integrin CD11b/CD18
Polymorphonuclear neutrophils (PMNs) play a critical role in the innate immune response to invading pathogens. However, dysregulated mucosal trafficking of PMNs and associated epithelial tissue damage is a pathological hallmark of numerous inflammatory conditions including inflammatory bowel disease. The glycoprotein CD11b/CD18 plays a well‐described role in regulating PMN transepithelial migration and PMN inflammatory functions. Previous studies have demonstrated that targeting of the N‐linked glycan Lewis X on CD11b blocks PMN transepithelial migration (TEpM). Given evidence of glycosylation‐dependent regulation of CD11b/CD18 function, we performed MALDI TOF Mass Spectrometry (MS) analyses on CD11b/CD18 purified from human PMNs. Unusual glycan epitopes identified on CD11b/CD18 included high Mannose oligosaccharides recognized by the Galanthus Nivalis lectin and biantennary galactosylated N‐glycans recognized by the Phaseolus Vulgaris erythroagglutinin lectin. Importantly, we show that selective targeting of glycans on CD11b with such lectins results in altered intracellular signaling events that inhibit TEpM and differentially affect key PMN inflammatory functions including phagocytosis, superoxide release and apoptosis. Taken together, these data demonstrate that discrete glycan motifs expressed on CD11b/CD18 such as biantennary galactose could represent novel targets for selective manipulation of CD11b function and reduction of PMN‐associated tissue damage in chronic inflammatory diseases.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154461/1/fsb220152-sup-0003-FigS3.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154461/2/fsb220152_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154461/3/fsb220152-sup-0004-TableS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154461/4/fsb220152-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154461/5/fsb220152.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154461/6/fsb220152-sup-0002-FigS2.pd
Encounters between spherical galaxies II: systems with dark halo
We performe N-body simulations of encounters between spherical systems
surrounded by a spherical halo. Following a preceding paper with a similar aim,
the initial systems include a spherical Jaffe model for the luminous matter and
a Hernquist model for the halo. The merger remnants from this sample are mainly
slowly rotating, prolate spheroids with a radially anisotropic velocity
distribution. The results are compared with real-life ellipticals and with the
models without halo in paper I. We argue that elliptical galaxies with evidence
of dark matter could be formed in the field via a merger of spheroids
surrounded by a dark matter halo, while ellipticals with no evidence of dark
matter might be formed via a merger of two spheroids in a cluster.Comment: 12 pages, 15 figures, accepted for publication in MNRAS. High res.
version avaible at http://www.iac.es/folleto/research/Publi02/preprints05.ht
Small scale systems of galaxies I. Photometric and spectroscopic properties of members
This paper is the first of a series addressed to the investigation of galaxy
formation/evolution in small scale systems of galaxies (SSSGs) which are
located in low density cosmic environments. Our algorithm for SSSG selection
includes galaxy systems of 2 or more galaxies lying within 1000 km/s and a 200
h_{100}^{-1} kpc radius volume. We present the analysis of the photometric and
spectroscopic properties of 19 member galaxies belonging to a sample of 11
SSSGs.
In the plane, early-type members may be considered "ordinary",
not "bright" galaxies in the definition given by Capaccioli et al.(1992) with a
significant fraction of galaxies having a disk or disky isophotes. We do not
detect fine structure and signatures of recent interaction events in the
early-type galaxy population, a picture also confirmed by the spectroscopy.
At odd, there are several spiral members with open arm configurations as
expected in interacting systems. At the same time, emission lines in the
spectra of spiral members fall in the HII regions regime defined with
diagnostic diagrams (Veilleux & Osterbrock 1987). None of the objects displays
unambiguous indication of nuclear activity, although fourspiral nuclei could be
ascribed to the class of Seyferts. The star formation rate seems enhanced over
the average expected in spiral galaxies only for poorer SSSGs in particular
pairs (<50 solar masses per year) but without being in the range of starburst
systems.Comment: 24 pages, including 6 figures and 6 tables. Accepted for publication
in A
A Valuable Tool for Risk Stratification in Septic Patients Admitted to ICU
The lactate/albumin ratio has been reported to be associated with mortality in
pediatric patients with sepsis. We aimed to evaluate the lactate/albumin ratio
for its prognostic relevance in a larger collective of critically ill (adult)
patients admitted to an intensive care unit (ICU). A total of 348 medical
patients admitted to a German ICU for sepsis between 2004 and 2009 were
included. Follow-up of patients was performed retrospectively between May 2013
and November 2013. The association of the lactate/albumin ratio (cut-off 0.15)
and both in-hospital and post-discharge mortality was investigated. An optimal
cut-off was calculated by means of Youden’s index. The lactate/albumin ratio
was elevated in non-survivors (p < 0.001). Patients with an increased
lactate/albumin ratio were of similar age, but clinically in a poorer
condition and had more pronounced laboratory signs of multi-organ failure. An
increased lactate/albumin ratio was associated with adverse in-hospital
mortality. An optimal cut-off of 0.15 was calculated and was associated with
adverse long-term outcome even after correction for APACHE2 and SAPS2. We
matched 99 patients with a lactate/albumin ratio >0.15 to case-controls with a
lactate/albumin ratio <0.15 corrected for APACHE2 scores: The group with a
lactate/albumin ratio >0.15 evidenced adverse in-hospital outcome in a paired
analysis with a difference of 27% (95%CI 10–43%; p < 0.01). Regarding long-
term mortality, again, patients in the group with a lactate/albumin ratio
>0.15 showed adverse outcomes (p < 0.001). An increased lactate/albumin ratio
was significantly associated with an adverse outcome in critically ill
patients admitted to an ICU, even after correction for confounders. The
lactate/albumin ratio might constitute an independent, readily available, and
important parameter for risk stratification in the critically ill. View Full-
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The Relation Between Halo Shape, Velocity Dispersion and Formation Time
We use dark matter haloes identified in the MareNostrum Universe and galaxy
groups identified in the Sloan Data Release 7 galaxy catalogue, to study the
relation between halo shape and halo dynamics, parametrizing out the mass of
the systems. A strong shape-dynamics, independent of mass, correlation is
present in the simulation data, which we find it to be due to different halo
formation times. Early formation time haloes are, at the present epoch, more
spherical and have higher velocity dispersions than late forming-time haloes.
The halo shape-dynamics correlation, albeit weaker, survives the projection in
2D (ie., among projected shape and 1-D velocity dispersion). A similar
shape-dynamics correlation, independent of mass, is also found in the SDSS DR7
groups of galaxies and in order to investigate its cause we have tested and
used, as a proxy of the group formation time, a concentration parameter. We
have found, as in the case of the simulated haloes, that less concentrated
groups, corresponding to late formation times, have lower velocity dispersions
and higher elongations than groups with higher values of concentration,
corresponding to early formation times.Comment: MNRAS in press (10 pages, 10 figures
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