148 research outputs found
Selective non-steroidal glucocorticoid receptor agonists attenuate inflammation but do not impair intestinal epithelial cell restitution in vitro
Introduction: Despite the excellent anti-inflammatory and immunosuppressive action of glucocorticoids (GCs), their use for the treatment of inflammatory bowel disease (IBD) still carries significant risks in terms of frequently occurring severe side effects, such as the impairment of intestinal tissue repair. The recently-introduced selective glucocorticoid receptor (GR) agonists (SEGRAs) offer anti-inflammatory action comparable to that of common GCs, but with a reduced side effect profile.
Methods: The in vitro effects of the non-steroidal SEGRAs Compound A (CpdA) and ZK216348, were investigated in intestinal epithelial cells and compared to those of Dexamethasone (Dex). GR translocation was shown by immunfluorescence and Western blot analysis. Trans-repressive effects were studied by means of NF-κB/p65 activity and IL-8 levels, trans-activation potency by reporter gene assay. Flow cytometry was used to assess apoptosis of cells exposed to SEGRAs. The effects on IEC-6 and HaCaT cell restitution were determined using an in vitro wound healing model, cell proliferation by BrdU assay. In addition, influences on the TGF-β- or EGF/ERK1/2/MAPK-pathway were evaluated by reporter gene assay, Western blot and qPCR analysis.
Results: Dex, CpdA and ZK216348 were found to be functional GR agonists. In terms of trans-repression, CpdA and ZK216348 effectively inhibited NF-κB activity and IL-8 secretion, but showed less trans-activation potency. Furthermore, unlike SEGRAs, Dex caused a dose-dependent inhibition of cell restitution with no effect on cell proliferation. These differences in epithelial restitution were TGF-β-independent but Dex inhibited the EGF/ERK1/2/MAPK-pathway important for intestinal epithelial wound healing by induction of MKP-1 and Annexin-1 which was not affected by CpdA or ZK216348.
Conclusion: Collectively, our results indicate that, while their anti-inflammatory activity is comparable to Dex, SEGRAs show fewer side effects with respect to wound healing. The fact that SEGRAs did not have a similar effect on cell restitution might be due to a different modulation of EGF/ERK1/2 MAPK signalling
Adaptive inspection planning using a digital twin for quality assurance
The integration of a digital twin into inspection planning enables a novel procedure that reduces avoidable inspection times and costs. This paper shows a method for component-specific adaption of inspection plans by feeding back data-based quality results into inspection planning. An initial evaluation of the method on a real aerospace aluminum component is carried out using a 3-axis milling process. Machine learning based quality models were implemented for the inspection features shape deviation and surface roughness. With the knowledge gained, the inspection time for the process can be reduced by up to 75 % per component
Bacterial protein complexes studied by single-molecule imaging and single-cell micromanipulation techniques in microfluidic devices
Biological systems of bacteria were investigated at the single-cell and single-molecule
level. Additionally, aspects of the techniques employed were studied.
A unifying theme in each project is the reliance on optical imaging techniques
coupled to microfluidic devices.
Hypo-osmotic shock experiments with an Escherichia coli mechanosensitive
channel deletion mutant were carried out at the single-cell level. E. coli MJF465
cells in which the three major mechanosensitive channel genes are deleted (∆mscL,
∆mscS, ∆mscK) show only 10% cell viability upon hypo-osmotic shock (from LB
+ 0.5 M NaCl into distilled water), compared to 90% viability of the wild-type
strain. Bacterial cells were trapped with optical tweezers in microfluidic devices,
enabling the first direct observation of single-cell behaviour upon hypo-osmotic
shock. Phase-contrast microscopy revealed intra-population diversity in the cells
response: Different features of lysis included cells bursting rapidly and leakage
of ribosomes, DNA and protein from the cytoplasm. Fluorescence microscopy of
hypo-osmotically-shocked GFP-expressing MJF465 cells showed either bursting
of cells, which was a rare event, or fast leakage of GFP, indicating cell membrane
ruptures. Data were analysed in terms of their kinetic behaviour and showed that
lysis occurs on a timescale of milliseconds to seconds. The implications of these
findings for the bacterial cell wall and cell membranes are discussed.
Enzymes involved in homologous recombination and repair of double-stranded
DNA (dsDNA) breaks are essential for maintaining genomic integrity in both
eukaryotes and prokaryotes. RecBCD of E. coli and AddAB, found widely in
bacteria, are involved in these processes, carrying out the same function. Both
enzymes were studied kinetically with single-molecule total internal reflection
fluorescence microscopy (TIRFM). Surface-tethered, hydrodynamically stretched
lambda-DNA molecules, stained with YOYO-1, were imaged with TIRFM in a
microfluidic flowcell. The RecBCD enzyme is a well characterised DNA helicase
and was introduced to this system for method validation purposes. The
AddAB enzyme of Bacteroides fragilis was then characterised as a helicase acting on lambda-DNA. It was found that AddAB helicase unwinds dsDNA with high
processivity of on average 14,000 bp and up to 40,000 bp for individual enzyme
complexes at an ATP-dependent rate ranging from 50-250 bp s−1 (for Mg2+-ATP
concentrations larger or equal than 0.1 mM). This activity was detected by DNA
binding dye (YOYO-1) displacement from the dsDNA and studied for different
Mg2+-ATP concentrations, flow (shear) rates and different YOYO-1 staining ratios
of DNA.
Aspects of this last experimental setup were investigated. A kinetic analysis of
intercalation of YOYO-1 into lambda-DNA is presented, occurring on a timescale
of minutes. Different flow rates and staining ratios that influence the apparent
(stretched) DNA molecule length were also examined.
Several image analysis techniques were employed to enhance the data quality
in images showing stretched lambda-DNA molecules. The Singular Value Decomposition
was found to be the most effective technique which strongly reduces the
noise in the obtained kymograph images
Changes in Key Biomechanical Parameters according to the Expertise Level in Runners at Different Running Speeds
Running has become increasingly popular worldwide. Among runners, there exists a wide range of expertise levels. Investigating the differences between runners at two extreme levels, that is novices and experts, is crucial to understand the changes that occur as a result of multiple years of training. Vertical oscillation of center of mass (CoM), stride frequency normalized to the leg length, and duty factor, which describes the step time relative to the flight time, are key biomechan- ical parameters that have been shown to be closely related to the running economy and are used to characterize the running style. The variability characteristics of these parameters may reveal valua- ble information concerning the control of human locomotion. However, how the expertise level and running speed affect the variability of these key biomechanical parameters has not yet been inves- tigated. The aim of this study was to analyze the effects of expertise level (novice vs. expert) and running speed (10 km/h vs. 15 km/h) on these parameters and their variability. It was hypothesized that expert runners would have lower vertical oscillation of CoM, normalized stride frequency, and duty factor and show less variability in these parameters. The parameters’ variability was opera- tionalized by the coefficient of variation. The mean values and variability of these key biomechani- cal parameters according to expertise level and running speed were compared with rmANOVAs. The results showed that the experts had a lower duty factor and less variable vertical oscillation of CoM and normalized stride frequency, independently of the running speed. At a higher running speed, the variability of vertical oscillation of CoM was higher, whereas that of normalized stride frequency and duty factor did not change significantly. To the best of our knowledge, this is the first study analyzing the effects of expertise level and running speed on the variability of key biomechanical parameters
Berücksichtigung von Unsicherheiten in der Zerspanung : Adaptive Prüfplanung
Data-driven prediction models are the core of adaptive test planning, but always have a model-based prediction error. For a reliable interpretation of the prediction result, the modeling of the associated uncertainty is of particu-lar importance. Therefore, this paper presents an approach for uncertainty modeling of the surface roughness Ra of 3-axis milled aluminum workpieces, whereby a Prediction Interval Coverage Probability of 92% can be achieved.Datengetriebene Prognosemodelle sind der Kern einer adaptiven Prüfplanung, besitzen jedoch stets einen modellbasierten Prognosefehler. Zur zuverlässigen Interpretation des Vorhersageergebnisses ist daher die Modellierung der einhergehenden Unsicherheit von besonderer Bedeutung. In diesem Beitrag werden drei Ansätze zur Unsicherheitsmodellierung der Oberflächenrauheit 3-achsig gefräster Werkstücke aus Aluminium vorgestellt, wobei eine hohe Erfassungswahrscheinlichkeit von 92 % erzielt werden kann
Does Higher Intensity Increase the Rate of Responders to Endurance Training When Total Energy Expenditure Remains Constant? : A Randomized Controlled Trial
Background Standardized training prescriptions often result in large variation in training response with a substantial number of individuals that show little or no response at all. The present study examined whether the response in
markers of cardiorespiratory ftness (CRF) to moderate intensity endurance training can be elevated by an increase in
training intensity.
Methods Thirty-one healthy, untrained participants (46±8 years, BMI 25.4±3.3 kg m−2
and V˙O2max
34±4 mL min−1
kg−1
) trained for 10 weeks with moderate intensity (3 day week−1
for 50 min per session at 55%
HRreserve). Hereafter, the allocation into two groups was performed by stratifed randomization for age, gender and
VO2max response. CON (continuous moderate intensity) trained for another 16 weeks at moderate intensity, INC
(increased intensity) trained energy-equivalent for 8 weeks at 70% HRreserve and then performed high-intensity interval
training (4×4) for another 8 weeks. Responders were identifed as participants with VO2max increase above the technical measurement error.
Results There was a signifcant diference in V˙O2max response between INC (3.4±2.7 mL kg−1
min−1
) and CON
(0.4±2.9 mL kg−1
min−1
) after 26 weeks of training (P=0.020). After 10 weeks of moderate training, in total 16 of 31
participants were classifed as VO2max responders (52%). After another 16 weeks continuous moderate intensity training, no further increase of responders was observed in CON. In contrast, the energy equivalent training with increasing training intensity in INC signifcantly (P=0.031) increased the number of responders to 13 of 15 (87%). The energy
equivalent higher training intensities increased the rate of responders more efectively than continued moderate
training intensities (P=0.012).
Conclusion High-intensity interval training increases the rate of response in VO2max to endurance training even when
the total energy expenditure is held constant. Maintaining moderate endurance training intensities might not be the
best choice to optimize training gains.
Trial Registration German Clinical Trials Register, DRKS00031445, Registered 08 March 2023—Retrospectively registered,
https://www.drks.de/DRKS0003144
Effects on cardiorespiratory fitness of moderate-intensity training vs. energy-matched training with increasing intensity
Introduction: The present study investigated the role of training intensity in the
dose–response relationship between endurance training and cardiorespiratory
fitness (CRF). The hypothesis was that beginners would benefit from an
increase in training intensity after an initial training phase, even if the energy
expenditure was not altered. For this purpose, 26 weeks of continuous
moderate training (control group, CON) was compared to training with
gradually increasing intensity (intervention group, INC) but constant energy
expenditure.
Methods: Thirty-one healthy, untrained subjects (13 men, 18 women; 46 ± 8
years; body mass index 25.4 ± 3.3 kg m−2
; maximum oxygen uptake, VO2max
34 ± 4 ml min−1 kg−1
) trained for 10 weeks with moderate intensity [3 days/
week for 50 min/session at 55% heart rate reserve (HRreserve)] before allocation
to one of two groups. A minimization technique was used to ensure
homogeneous groups. While group CON continued with moderate intensity
for 16 weeks, the INC group trained at 70% HRreserve for 8 weeks and
thereafter participated in a 4 × 4 training program (high-intensity interval
training, HIIT) for 8 weeks. Constant energy expenditure was ensured by
indirect calorimetry and corresponding adjustment of the training volume.
Treadmill tests were performed at baseline and after 10, 18, and 26 weeks.
Results: The INC group showed improved VO2max (3.4 ± 2.7 ml kg−1 min−1
) to a
significantly greater degree than the CON group (0.4 ± 2.9 ml kg−1 min−1
) (P =
0.020). In addition, the INC group exhibited improved Vmax (1.7 ± 0.7 km h−1
)
to a significantly greater degree than the CON group (1.0 ± 0.5 km h−1
) (P =
0.001). The reduction of resting HR was significantly larger in the INC group
(7 ± 4 bpm) than in the CON group (2 ± 6 bpm) (P = 0.001). The mean heart
rate in the submaximal exercise test was reduced significantly in the CON
group (5 ± 6 bpm; P = 0.007) and in the INC group (8 ± 7 bpm; P = 0.001),
without a significant interaction between group and time point
Environmental change impacts on the C- and N-cycle of European forests: a model comparison study [Discussion paper]
Forests are important components of the greenhouse gas balance of Europe. There is considerable uncertainty about how predicted changes to climate and nitrogen deposition will perturb the carbon and nitrogen cycles of European forests and thereby alter forest growth, carbon sequestration and N2O emission. The present study aimed to quantify the carbon and nitrogen balance, including the exchange of greenhouse gases, of European forests over the period 2010–2030, with a particular emphasis on the spatial variability of change. The analysis was carried out for two tree species: European beech and Scots pine. For this purpose, four different dynamic models were used: BASFOR, DailyDayCent, INTEGRATOR and Landscape-DNDC. These models span a range from semi-empirical to complex mechanistic. Comparison of these models allowed assessment of the extent to which model predictions depended on differences in model inputs and structure. We found a European average carbon sink of 0.160 ± 0.020 kgC m−2 yr−1 (pine) and 0.138 ± 0.062 kgC m−2 yr−1 (beech) and N2O source of 0.285 ± 0.125 kgN ha−1 yr−1 (pine) and 0.575 ± 0.105 kgN ha−1 yr−1 (beech). The European average greenhouse gas potential of the carbon source was 18 (pine) and 8 (beech) times that of the N2O source. Carbon sequestration was larger in the trees than in the soil. Carbon sequestration and forest growth were largest in central Europe and lowest in northern Sweden and Finland, N. Poland and S. Spain. No single driver was found to dominate change across Europe. Forests were found to be most sensitive to change in environmental drivers where the drivers were limiting growth, where changes were particularly large or where changes acted in concert. The models disagreed as to which environmental changes were most significant for the geographical variation in forest growth and as to which tree species showed the largest rate of carbon sequestration. Pine and beech forests were found to have differing sensitivities to environmental change, in particular the response to changes in nitrogen and precipitation, with beech forest more vulnerable to drought. There was considerable uncertainty about the geographical location of N2O emissions. Two of the models BASFOR and LandscapeDNDC had largest emissions in central Europe where nitrogen deposition and soil nitrogen were largest whereas the two other models identified different regions with large N2O emission. N2O emissions were found to be larger from beech than pine forests and were found to be particularly sensitive to forest growth
Data augmentation in natural language processing: a novel text generation approach for long and short text classifiers
In many cases of machine learning, research suggests that the development of training data might have a higher relevance than the choice and modelling of classifiers themselves. Thus, data augmentation methods have been developed to improve classifiers by artificially created training data. In NLP, there is the challenge of establishing universal rules for text transformations which provide new linguistic patterns. In this paper, we present and evaluate a text generation method suitable to increase the performance of classifiers for long and short texts. We achieved promising improvements when evaluating short as well as long text tasks with the enhancement by our text generation method. Especially with regard to small data analytics, additive accuracy gains of up to 15.53% and 3.56% are achieved within a constructed low data regime, compared to the no augmentation baseline and another data augmentation technique. As the current track of these constructed regimes is not universally applicable, we also show major improvements in several real world low data tasks (up to +4.84 F1-score). Since we are evaluating the method from many perspectives (in total 11 datasets), we also observe situations where the method might not be suitable. We discuss implications and patterns for the successful application of our approach on different types of datasets
Implications of the 750 GeV gamma-gamma Resonance as a Case Study for the International Linear Collider
If the gamma-gamma resonance at 750 GeV suggested by 2015 LHC data turns out
to be a real effect, what are the implications for the physics case and upgrade
path of the International Linear Collider? Whether or not the resonance is
confirmed, this question provides an interesting case study testing the
robustness of the ILC physics case. In this note, we address this question with
two points: (1) Almost all models proposed for the new 750 GeV particle require
additional new particles with electroweak couplings. The key elements of the
500 GeV ILC physics program---precision measurements of the Higgs boson, the
top quark, and 4-fermion interactions---will powerfully discriminate among
these models. This information will be important in conjunction with new LHC
data, or alone, if the new particles accompanying the 750 GeV resonance are
beyond the mass reach of the LHC. (2) Over a longer term, the energy upgrade of
the ILC to 1 TeV already discussed in the ILC TDR will enable experiments in
gamma-gamma and e+e- collisions to directly produce and study the 750 GeV
particle from these unique initial states.Comment: 39 pages, 5 figures, 5 tables; v2: some references adde
- …