•A scaling factor was defined to quantify combustion-induced effect on tip velocity.•Effects of fuel properties on this factor and radial expansion were studied.•Three cases with different fuels and ...similar ignition delay and LOL were further analyzed.•Experimental trend was verified with a developed 1D spray model.
The reacting diesel spray structure was investigated using n-dodecane, n-heptane and one binary blend of Primary Reference Fuels (80% n-heptane and 20% iso-octane in mass) based on the existing database from previous experimental results from Schlieren imaging technique in a constant pressure combustion chamber. The spray tip velocity was derived from the derivative of tip penetration versus time. The operating conditions and the injector used (single axially-oriented hole, 89mm-diameter) were chosen following the guidelines of the Engine Combustion Network. A 1D spray model was also applied here to support the analysis of experimental results. Parametric variations of injection pressure, ambient temperature and oxygen concentration have been performed for each fuel. Analysis of radial expansion and reacting tip velocity was performed in terms of an average spray radial increase (ΔR‾) and a constant (k) defining the tip penetration velocity. k values of reacting cases are always bigger than those from inert ones for both experimental and theoretical results. Based upon this parameter, quasi-steady tip penetration under the investigated conditions seems not to be affected by ambient temperature, oxygen content or fuel cetane number. Three cases with different fuels and similar ignition delay and lift-off length were further analyzed, which shows that the reactivity of the mixture has an effect on the transition timing from inert to reacting states, as well as on the initial penetration stages, but not on the quasi-steady phase. Apart from the similar tip velocity during quasi-steady phase, the full transient evolution of the tip is highly similar. The fact that this full overlap does not occur for other operating conditions indicates that early penetration stages are highly affected by the transient chemistry development, which largely depends on fuel cetane number.
A consumer study was performed in four EU countries to further clarify the acceptability of meat with boar taint. In Denmark, France, Italy and Poland, a total of 476 female consumers evaluated 8 ...meat patties from boars with varying levels of skatole (0.10–0.40μg/g fat tissue) and androstenone (0.47–2.00 μg/g fat tissue), in a pair-wise comparison with patties from castrates. Boar meat patties were always less preferred than the castrate meat patties, regardless of the level of androstenone and skatole. Acceptability of the boar meat patties decreased with increasing skatole level. In samples with low skatole levels, higher levels of androstenone also reduced acceptability among androstenone sensitive consumers. No clear threshold levels for androstenone and skatole could be identified. Maps presenting the reduction in preference due to increasing levels of skatole and androstenone, and corrected for the general acceptance of the meat product were developed, taking into account androstenone sensitivity. Further work is needed, covering the whole range of androstenone and skatole levels found in entire male pigs and for a wider set of meat products.
•Consumer and expert panel evaluations were closely correlated with skatole.•At low skatole level, preference for boar meat patties decreased with increasing androstenone level.•Effect of androstenone level was only significant for androstenone sensitive consumers.•A map presenting the reduction in preference depending on the level of androstenone and skatole was developed.•No clear threshold/rejection level for skatole or androstenone could be determined.
Rhynchocephalians, the sister group of squamates (lizards and snakes), are only represented by the single genus Sphenodon today. This taxon is often considered to represent a very conservative ...lineage. However, rhynchocephalians were common during the late Triassic to latest Jurassic periods, but rapidly declined afterwards, which is generally attributed to their supposedly adaptive inferiority to squamates and/or Mesozoic mammals, which radiated at that time. New finds of Mesozoic rhynchocephalians can thus provide important new information on the evolutionary history of the group.
A new fossil relative of Sphenodon from the latest Jurassic of southern Germany, Oenosaurus muehlheimensis gen. et sp. nov., presents a dentition that is unique amongst tetrapods. The dentition of this taxon consists of massive, continuously growing tooth plates, probably indicating a crushing dentition, thus representing a previously unknown trophic adaptation in rhynchocephalians.
The evolution of the extraordinary dentition of Oenosaurus from the already highly specialized Zahnanlage generally present in derived rhynchocephalians demonstrates an unexpected evolutionary plasticity of these animals. Together with other lines of evidence, this seriously casts doubts on the assumption that rhynchocephalians are a conservative and adaptively inferior lineage. Furthermore, the new taxon underlines the high morphological and ecological diversity of rhynchocephalians in the latest Jurassic of Europe, just before the decline of this lineage on this continent. Thus, selection pressure by radiating squamates or Mesozoic mammals alone might not be sufficient to explain the demise of the clade in the Late Mesozoic, and climate change in the course of the fragmentation of the supercontinent of Pangaea might have played a major role.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Diesel engine cold start is an important issue for current technology at low (below 0°C) temperatures and for future applications. The aim of this work is to develop a description of how, when and ...where does fuel spray ignition occur in a glow-plug assisted engine under simulated low temperature cold start conditions. In-cylinder pressure analysis is combined with high speed visualization in an optical engine. A pilot plus main injection strategy is used. Visualization results show that pilot ignition occurs in the vicinity of the glow plug, and strongly influences main combustion initiation. Main combustion starts from the pilot flame, and propagates to the rest of the combustion chamber showing a strong visible reaction zone. After end of main injection, the rapid leaning of the mixture suppresses the strong radiation, and OH radiation is observed to progress to the rest of the combustion chamber. The combustion process shows a strong scattering, which has been quantified by combustion parameters. At higher rail pressures scattering increases, which eventually inhibits combustion initiation. However, if ignition occurs at higher rail pressures, cycle performance is better.
Glioma-associated microglia and macrophages (GAMMs) are key players in creating an immunosuppressive microenvironment. They can be efficiently targeted by inhibiting the colony-stimulating factor 1 ...receptor (CSF-1R). We applied noninvasive PET/CT and PET/MRI using
F-fluoroethyltyrosine (
F-FET) (amino acid metabolism) and
-diethyl-2-4-(2-
F-fluoroethoxy)phenyl-5,7-dimethylpyrazolo1,5-
pyrimidine-3-acetamide (
F-DPA-714) (translocator protein) to understand the role of GAMMs in glioma initiation, monitor in vivo therapy-induced GAMM depletion, and observe GAMM repopulation after drug withdrawal.
C57BL/6 mice (
= 44) orthotopically implanted with syngeneic mouse GL261 glioma cells were treated with different regimens using the CSF-1R inhibitor PLX5622 (6-fluoro-
-((5-fluoro-2-methoxypyridin-3-yl)methyl)-5-((5-methyl-1H-pyrrolo2,3-bpyridin-3-yl)methyl)pyridin-2-amine) or vehicle, establishing a preconditioning model and a repopulation model, respectively. The mice underwent longitudinal PET/CT and PET/MRI.
The preconditioning model indicated similar tumor growth based on MRI (44.5% ± 24.8%),
F-FET PET (18.3% ± 11.3%), and
F-DPA-714 PET (16% ± 19.04%) volume dynamics in all groups, suggesting that GAMMs are not involved in glioma initiation. The repopulation model showed significantly reduced
F-DPA-714 uptake (-45.6% ± 18.4%), significantly reduced GAMM infiltration even after repopulation, and a significantly decreased tumor volume (-54.29% ± 8.6%) with repopulation as measured by MRI, supported by a significant reduction in
F-FET uptake (-50.2% ± 5.3%).
F-FET and
F-DPA-714 PET/MRI allow noninvasive assessment of glioma growth under various regimens of CSF-1R therapy. CSF-1R-mediated modulation of GAMMs may be of high interest as therapy or cotherapy against glioma.
Silver(I)-based coordination polymers or metal-organic frameworks (MOFs) display useful antibacterial properties, whereby distinct materials with different bonding can afford control over the release ...of silver(I) ions. Such silver(I) materials are comprised of discrete secondary building units (SBUs), and typically formed with ligands possessing only soft or borderline donors. We postulated that a linker with four potential donor groups, comprising carboxylate and soft thioether donors, 2,5-bis (allylsulfanyl) benzene dicarboxylic acid (ASBDC), could be used to form stable, highly connected coordination polymers with silver(I). Here, we describe the synthesis of a new material, (Ag
(ASBDC)), which possesses a rod-like metal node-based 3D honeycomb structure, strongly -stacked linkers, and steric bulk to protect the node. Due to the rod-like metal node and the blocking afforded by the ordered allyl groups, the material displays notable thermal and moisture stability. An interesting structural feature of (Ag
(ASBDC)) is contiguous Ag-S bonding, essentially a helical silver chalcogenide wire, which extends through the structure. These interesting structural features, coupled with the relative ease by which MOFs made with linear dicarboxylate linkers can be reticulated, suggests this may be a structure type worthy of further investigation.
A major concern caused by the discontinuation of disease modifying treatment for multiple sclerosis (MS) is a rebound of disease activity. Hypotheses about the underlying mechanism of fingolimod ...(FTY) induced exaggerated inflammatory responses are diverse. So far, vaccinations as a trigger for rebound activity following FTY suspension have not been described. However, several reports have highlighted the occurrence of neurological and autoimmune side effects after single or combined multi-vaccination procedures. Here, we describe the case of a highly active female MS patient demonstrating recurrent, severe MS relapses accompanied by extensive MRI activity, subsequent to yellow fever vaccination two months following FTY withdrawal. Blood and cerebrospinal fluid immunophenotyping indicated a B cell/plasma cell autoreactivity. Following a therapy with natalizumab the clinical, laboratory, MRI, and disease course improved significantly. This case hints towards a combined immunological mechanism characterized by molecular mimicry, bystander activation, and lymphocyte re-egress, resulting in extensive neurological impairment and shows that natalizumab represents a therapeutic option to counteract B cell mediated autoreactivity. Especially, the diagnostic and therapeutic management of this complex scenario might be instructive for clinical practice.
During the course of March and April 2020, New York City experienced a surge of a 170,000 coronavirus disease 2019 (COVID-19) cases, overwhelming hospital systems and leading to an unprecedented need ...for palliative care services.
To present a model for rapid palliative care workforce expansion under crisis conditions, using supervised advanced psychiatry trainees to provide primary palliative services in the acute care and emergency setting.
In response to the New York City COVID-19 surge, advanced psychiatry trainees at New York-Presbyterian Columbia University Irving Medical Center were rapidly trained and redeployed to a newly formed psychiatry-palliative care liaison team. Under the supervision of consultation-liaison psychiatrists (who also served as team coordinators), these trainees provided circumscribed palliative care services to patients and/or their families, including goals-of-care discussions and psychosocial support. Palliative care attendings remained available to all team members for more advanced and specialized supervision.
The psychiatry-palliative care liaison team effectively provided palliative care services during the early phase and peak of New York City's COVID-19 crisis, managing up to 16 new cases per day and provided longitudinal follow-up, thereby enabling palliative care specialists to focus on providing services requiring specialist-level palliative care expertise.
By training and supervising psychiatrists and advanced psychiatry trainees in specific palliative care roles, palliative care teams could more effectively meet markedly increased service needs of varying complexity during the COVID-19 crisis. As new geographic regions experience possible COVID-19 surges in the coming months, this may serve as a model for rapidly increasing palliative care workforce.
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