116 research outputs found
On propagators and three-point functions in Landau gauge QCD and QCD-like theories
Recent progress in our studies of propagators and three-point functions in
Landau gauge for QCD and QCD-like theories is presented. Special emphasis is
put on the properties of the three-gluon vertex and the quark-gluon vertex. The
effect of unquenching is investigated. Furthermore, an exploratory study for a
large number of light flavours is described, from where clear evidence for the
qualitative behaviour of propagators in the so-called conformal window can be
extracted.Comment: 13 pages, 9 figures; Proceedings of the workshop QCD-TNT-III, ECT*
Trento, Sept. 2-6, 2013; references update
L-type calcium channel blockers and substance P induce angiogenesis of cortical vessels associated with beta-amyloid plaques in an Alzheimer mouse model
AbstractIt is well established that L-type calcium channels (LTCCs) are expressed in astroglia. However, their functional role is still speculative, especially under pathologic conditions. We recently showed that the α1 subunit-like immunoreactivity of the CaV1.2 channel is strongly expressed in reactive astrocytes around beta-amyloid plaques in 11-month-old Alzheimer transgenic (tg) mice with the amyloid precursor protein London and Swedish mutations. The aim of the present study was to examine the cellular expression of all LTCC subunits around beta-amyloid plaques by in situ hybridization using 35S-labeled oligonucleotides. Our data show that messenger RNAs (mRNAs) of the LTCC CaV1.2 α1 subunit as well as all auxiliary ÎČ and α2ÎŽ subunits, except α2ÎŽ-4, were expressed in the hippocampus of age-matched wild-type mice. It was unexpected to see, that cells directly located in the plaque core in the cortex expressed mRNAs for CaV1.2 α1, ÎČ2, ÎČ4, and α2ÎŽ-1, whereas no expression was detected in the halo. Furthermore, cells in the plaque core also expressed preprotachykinin-A mRNA, the precursor for substance P. By means of confocal microscopy, we demonstrated that collagen-IV-stained brain vessels in the cortex were associated with the plaque core and were immunoreactive for substance P. In cortical organotypic brain slices of adult Alzheimer mice, we could demonstrate that LTCC blockers increased angiogenesis, which was further potentiated by substance P. In conclusion, our data show that brain vessels associated with beta-amyloid plaques express substance P and an LTCC and may play a role in angiogenesis
How to Measure Speech Recognition Performance in the Air Traffic Control Domain? The Word Error Rate is only half of the truth
Applying Automatic Speech Recognition (ASR) in the domain
of analogue voice communication between air traffic
controllers (ATCo) and pilots has more end user requirements
than just transforming spoken words into text. It is useless,
when word recognition is perfect, as long as the semantic
interpretation is wrong. For an ATCo it is of no importance if
the words of greeting are correctly recognized. A wrong
recognition of a greeting should, however, not disturb the
correct recognition of e.g. a âdescendâ command. Recently, 14
European partners from Air Traffic Management (ATM)
domain have agreed on a common set of rules, i.e., an ontology
on how to annotate the speech utterance of an ATCo. This paper
first extends the ontology to pilot utterances and then compares
different ASR implementations on semantic level by
introducing command recognition, command recognition error,
and command rejection rates. The implementation used in this
paper achieves a command recognition rate better than 94% for
Prague Approach, even when WER is above 2.5
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Low-flow assessment of current ECMO/ECCO2R rotary blood pumps and the potential effect on hemocompatibility
Background
Extracorporeal carbon dioxide removal (ECCO2R) uses an extracorporeal circuit to directly remove carbon dioxide from the blood either in lieu of mechanical ventilation or in combination with it. While the potential benefits of the technology are leading to increasing use, there are very real risks associated with it. Several studies demonstrated major bleeding and clotting complications, often associated with hemolysis and poorer outcomes in patients receiving ECCO2R. A better understanding of the risks originating specifically from the rotary blood pump component of the circuit is urgently needed.
Methods
High-resolution computational fluid dynamics was used to calculate the hemodynamics and hemocompatibility of three current rotary blood pumps for various pump flow rates.
Results
The hydraulic efficiency dramatically decreases to 5â10% if operating at blood flow rates below 1âL/min, the pump internal flow recirculation rate increases 6â12-fold in these flow ranges, and adverse effects are increased due to multiple exposures to high shear stress. The deleterious consequences include a steep increase in hemolysis and destruction of platelets.
Conclusions
The role of blood pumps in contributing to adverse effects at the lower blood flow rates used during ECCO2R is shown here to be significant. Current rotary blood pumps should be used with caution if operated at blood flow rates below 2âL/min, because of significant and high recirculation, shear stress, and hemolysis. There is a clear and urgent need to design dedicated blood pumps which are optimized for blood flow rates in the range of 0.5â1.5âL/min
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Impact of sweep gas flow on extracorporeal CO2 removal (ECCO2R)
Background
Veno-venous extracorporeal carbon dioxide (CO2) removal (vv-ECCO2R) is increasingly being used in the setting of acute respiratory failure. Blood flow rates range in clinical practice from 200âmL/min to more than 1500âmL/min, and sweep gas flow rates range from less than 1 to more than 10âL/min. The present porcine model study was aimed at determining the impact of varying sweep gas flow rates on CO2 removal under different blood flow conditions and membrane lung surface areas.
Methods
Two different membrane lungs, with surface areas of 0.4 and 0.8m2, were used in nine pigs with experimentally-induced hypercapnia. During each experiment, the blood flow was increased stepwise from 300 to 900âmL/min, with further increases up to 1800âmL/min with the larger membrane lung in steps of 300âmL/min. Sweep gas was titrated under each condition from 2 to 8âL/min in steps of 2âL/min. Extracorporeal CO2 elimination was normalized to a PaCO2 of 45âmmHg before the membrane lung.
Results
Reversal of hypercapnia was only feasible when blood flow rates above 900âmL/min were used with a membrane lung surface area of at least 0.8m2. The membrane lung with a surface of 0.4m2 allowed a maximum normalized CO2 elimination rate of 41â±â6âmL/min with 8âL/min sweep gas flow and 900âmL blood flow/min. The increase in sweep gas flow from 2 to 8âL/min increased normalized CO2 elimination from 35â±â5 to 41â±â6 with 900âmL blood flow/min, whereas with lower blood flow rates, any increase was less effective, levelling out at 4âL sweep gas flow/min. The membrane lung with a surface area of 0.8m2 allowed a maximum normalized CO2 elimination rate of 101â±â12âmL/min with increasing influence of sweep gas flow. The delta of normalized CO2 elimination increased from 4â±â2 to 26â±â7âmL/min with blood flow rates being increased from 300 to 1800âmL/min, respectively.
Conclusions
The influence of sweep gas flow on the CO2 removal capacity of ECCO2R systems depends predominantly on blood flow rate and membrane lung surface area. In this model, considerable CO2 removal occurred only with the larger membrane lung surface of 0.8m2 and when blood flow rates of â„â900âmL/min were used
Differences in neurochemical profiles of two gadid species under ocean warming and acidification
Exposure to future ocean acidification scenarios may alter the behaviour of marine teleosts through interference with neuroreceptor functioning. So far, most studies investigated effects of ocean acidification on the behaviour of fish, either isolated or in combination with environmental temperature. However, only few physiological studies on this issue were conducted despite the putative neurophysiological origin of the CO2-induced behavioural changes. Here, we present the metabolic consequences of long-term exposure to projected ocean acidification (396â548 ÎŒatm PCO2 under control and 915â1272 ÎŒatm under treatment conditions) and parallel warming in the brain of two related fish species, polar cod (Boreogadus saida, exposed to 0 °C, 3 °C, 6 °C and 8 °C) and Atlantic cod (Gadus morhua, exposed to 3 °C, 8 °C, 12 °C and 16 °C). It has been shown that B. saida is behaviourally vulnerable to future ocean acidification scenarios, while G. morhua demonstrates behavioural resilience
Dual checkpoint blockade of CD47 and LILRB1 enhances CD20 antibody-dependent phagocytosis of lymphoma cells by macrophages
Antibody-dependent cellular phagocytosis (ADCP) by macrophages, an important effector function of tumor targeting antibodies, is hampered by âDonÂŽt Eat Me!â signals such as CD47 expressed by cancer cells. Yet, human leukocyte antigen (HLA) class I expression may also impair ADCP by engaging leukocyte immunoglobulin-like receptor subfamily B (LILRB) member 1 (LILRB1) or LILRB2. Analysis of different lymphoma cell lines revealed that the ratio of CD20 to HLA class I cell surface molecules determined the sensitivity to ADCP by the combination of rituximab and an Fc-silent variant of the CD47 antibody magrolimab (CD47-IgGÏ). To boost ADCP, Fc-silent antibodies against LILRB1 and LILRB2 were generated (LILRB1-IgGÏ and LILRB2-IgGÏ, respectively). While LILRB2-IgGÏ was not effective, LILRB1-IgGÏ significantly enhanced ADCP of lymphoma cell lines when combined with both rituximab and CD47-IgGÏ. LILRB1-IgGÏ promoted serial engulfment of lymphoma cells and potentiated ADCP by non-polarized M0 as well as polarized M1 and M2 macrophages, but required CD47 co-blockade and the presence of the CD20 antibody. Importantly, complementing rituximab and CD47-IgGÏ, LILRB1-IgGÏ increased ADCP of chronic lymphocytic leukemia (CLL) or lymphoma cells isolated from patients. Thus, dual checkpoint blockade of CD47 and LILRB1 may be promising to improve antibody therapy of CLL and lymphomas through enhancing ADCP by macrophages
Nasal versus oronasal masks for home non-invasive ventilation in patients with chronic hypercapnia:a systematic review and individual participant data meta-analysis
BACKGROUND: The optimal interface for the delivery of home non-invasive ventilation (NIV) to treat chronic respiratory failure has not yet been determined. The aim of this individual participant data (IPD) meta-analysis was to compare the effect of nasal and oronasal masks on treatment efficacy and adherence in patients with COPD and obesity hypoventilation syndrome (OHS). METHODS: We searched Medline and Cochrane Central Register of Controlled Trials for prospective randomised controlled trials (RCTs) of at least 1âmonth's duration, published between January 1994 and April 2019, that assessed NIV efficacy in patients with OHS and COPD. The main outcomes were diurnal PaCO2, PaO2 and NIV adherence (PROSPERO CRD42019132398). FINDINGS: Of 1576 articles identified, 34 RCTs met the inclusion criteria and IPD were obtained for 18. Ten RCTs were excluded because only one type of mask was used, or mask data were missing. Data from 8 RCTs, including 290 IPD, underwent meta-analysis. Oronasal masks were used in 86% of cases. There were no differences between oronasal and nasal masks for PaCO2 (0.61 mm Hg (95%âCI -2.15 to 3.38); p=0.68), PaO2 (-0.00 mm Hg (95%âCI -4.59 to 4.58); p=1) or NIV adherence (0·29âhour/day (95%âCI -0.74 to 1.32); p=0.58). There was no interaction between the underlying pathology and the effect of mask type on any outcome. INTERPRETATION: Oronasal masks are the most used interface for the delivery of home NIV in patients with OHS and COPD; however, there is no difference in the efficacy or tolerance of oronasal or nasal masks
Risk Assessment for Patients with Chronic Respiratory Conditions in the Context of the SARS-CoV-2 Pandemic Statement of the German Respiratory Society with the Support of the German Association of Chest Physicians
Assessing the risk for specific patient groups to suffer from
severe courses of COVID-19 is of major importance in the
current SARS-CoV-2 pandemic. This review focusses on the
risk for specific patient groups with chronic respiratory conditions, such as patients with asthma, chronic obstructive
pulmonary disease, cystic fibrosis (CF), sarcoidosis, interstitial lung diseases, lung cancer, sleep apnea, tuberculosis,
neuromuscular diseases, a history of pulmonary embolism,
and patients with lung transplants. Evidence and recommendations are detailed in exemplary cases. While some patient
groups with chronic respiratory conditions have an increased risk for severe courses of COVID-19, an increasing
number of studies confirm that asthma is not a risk factor
for severe COVID-19. However, other risk factors such as
higher age, obesity, male gender, diabetes, cardiovascular
diseases, chronic kidney or liver disease, cerebrovascular
and neurological disease, and various immunodeficiencies
or treatments with immunosuppressants need to be taken
into account when assessing the risk for severe COVID-19 in
patients with chronic respiratory diseases
Liver Fibrosis and Metabolic Alterations in Adults With alpha-1-antitrypsin Deficiency Caused by the Pi*ZZ Mutation
BACKGROUND & AIMS: Alpha-1 antitrypsin deficiency (AATD) is among the most common genetic disorders. Severe AATD is caused by a homozygous mutation in the SERPINA1 gene that encodes the Glu342Lys substitution (called the Pi*Z mutation,
Pi*ZZ genotype). Pi*ZZ carriers may develop lung and liver diseases. Mutation- associated lung disorders have been well studied, but less is known about the effects in liver. We assessed the liver disease burden and associated features in
adults with this form of AATD. METHODS: We collected data from 554 Pi*ZZ adults (403 in an exploratory cohort, 151 in a confirmatory cohort), in 9 European countries, with AATD who were homozygous for the Pi*Z mutation, and 234 adults without
the Pi*Z mutation (controls), all without pre-existing liver disease. We collected data on demographic parameters, comorbidities, lung- and liver-related health, and blood samples for laboratory analysis. Liver fibrosis was assessed non-invasively
via the serum tests Aspartate Aminotransferase to Platelet Ratio Index and HepaScore and via transient elastography. Liver steatosis was determined via transient elastography-based controlled attenuation parameter. We performed histologic
analyses of livers from transgenic mice that overexpress the AATD-associated Pi*Z variant. RESULTS: Serum levels of liver enzymes were significantly higher in Pi*ZZ carriers vs controls. Based on non-invasive tests for liver fibrosis, significant fibrosis
was suspected in 20%â36% of Pi*ZZ carriers, whereas signs of advanced fibrosis were 9- to 20-fold more common in Pi*ZZ carriers compared to non-carriers. Male sex; age older than 50 years; increased levels of alanine aminotransferase, aspartate
aminotransferase, or g-glutamyl transferase; and low numbers of platelets were associated with higher liver fibrosis burden. We did not find evidence for a relationship between lung function and liver fibrosis. Controlled attenuation parameter 280 dB/m, suggesting severe steatosis, was detected in 39% of Pi*ZZ carriers vs 31% of controls. Carriers of Pi*ZZ had lower serum concentrations of triglyceride and low- and very-lowdensity lipoprotein cholesterol than controls, suggesting impaired hepatic secretion of lipid. Livers from Pi*Zoverexpressing mice had steatosis and down-regulation of
genes involved in lipid secretion. CONCLUSIONS: In studies of AATD adults with the Pi*ZZ mutation, and of Pi*Z-overexpressing mice, we found evidence of liver steatosisinfo:eu-repo/semantics/publishedVersio
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