Tailored hydrogels mimicking the native extracellular environment could help overcome the high variability in outcomes within regenerative endodontics. This study aimed to evaluate the effect of the ...chemokine-binding and antimicrobial polymer, chlorite-oxidized oxyamylose (COAM), on the microstructural properties of fibrin and self-assembling peptide (SAP) hydrogels. A further goal was to assess the influence of the microstructural differences between the hydrogels on the in vitro behavior of human dental pulp stem cells (hDPSCs). Structural and mechanical characterization of the hydrogels with and without COAM was performed by atomic force microscopy and scanning electron microscopy to characterize their microstructure (roughness and fiber length, diameter, straightness, and alignment) and by nanoindentation to measure their stiffness (elastic modulus). Then, hDPSCs were encapsulated in hydrogels with and without COAM. Cell viability and circularity were determined using confocal microscopy, and proliferation was determined using DNA quantification. Inclusion of COAM did not alter the microstructure of the fibrin hydrogels at the fiber level while affecting the SAP hydrogel microstructure (homogeneity), leading to fiber aggregation. The stiffness of the SAP hydrogels was sevenfold higher than the fibrin hydrogels. The viability and attachment of hDPSCs were significantly higher in fibrin hydrogels than in SAP hydrogels. The DNA content was significantly affected by the hydrogel type and the presence of COAM. The microstructural stability after COAM inclusion and the favorable hDPSCs' response observed in fibrin hydrogels suggest this system as a promising carrier for COAM and application in endodontic regeneration.
THE FIRST FERMI LAT SUPERNOVA REMNANT CATALOG Acero, F.; Ajello, M.; Baldini, L. ...
The Astrophysical journal. Supplement series,
05/2016, Letnik:
224, Številka:
1
Journal Article
Recenzirano
Odprti dostop
ABSTRACT To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi ...Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.
Upper limb prosthetics with multiple degrees of freedom (DoFs) are still mostly operated through the clinical standard Direct Control scheme. Machine learning control, on the other hand, allows ...controlling multiple DoFs although it requires separable and consistent electromyogram (EMG) patterns. Whereas user training can improve EMG pattern quality, conventional training methods might limit user potential. Training with serious games might lead to higher quality EMG patterns and better functional outcomes. In this explorative study we compare outcomes of serious game training with conventional training, and machine learning control with the users' own one DoF prosthesis.
Participants with upper limb absence participated in 7 training sessions where they learned to control a 3 DoF prosthesis with two grips which was fitted. Participants received either game training or conventional training. Conventional training was based on coaching, as described in the literature. Game-based training was conducted using two games that trained EMG pattern separability and functional use. Both groups also trained functional use with the prosthesis donned. The prosthesis system was controlled using a neural network regressor. Outcome measures were EMG metrics, number of DoFs used, the spherical subset of the Southampton Hand Assessment Procedure and the Clothespin Relocation Test.
Eight participants were recruited and four completed the study. Training did not lead to consistent improvements in EMG pattern quality or functional use, but some participants improved in some metrics. No differences were observed between the groups. Participants achieved consistently better results using their own prosthesis than the machine-learning controlled prosthesis used in this study.
Our explorative study showed in a small group of participants that serious game training seems to achieve similar results as conventional training. No consistent improvements were found in either group in terms of EMG metrics or functional use, which might be due to insufficient training. This study highlights the need for more research in user training for machine learning controlled prosthetics. In addition, this study contributes with more data comparing machine learning controlled prosthetics with Direct Controlled prosthetics.
Abstract
Background
Atrial fibrillation (AF) is strongly associated with older age. However, it is unclear whether, in addition to chronological age, more advanced biological ageing confers AF risk. ...Previous studies suggest AF and peripheral leukocyte telomere length (LTL, a measure of biological ageing) are associated, but this relationship and the causal relevance remains controversial.
Purpose
This study aims to explore the role of LTL in risk of AF through observational analyses and Mendelian randomisation (MR).
Methods
UK Biobank (UKB) is a large prospective study of individuals 40 to 69 years of age in which 393,018 participants have measured LTL and genetic data available. Observational associations between LTL and incident AF (ascertained in hospital admission data) were estimated using Cox proportional hazards models adjusted for potential confounders (age at LTL measurement, body mass index, physical activity, smoking status, alcohol intake, ethnicity, Townsend deprivation index, and sex). MR analyses included 195 SNPS previously shown to have conditionally independent genome-wide significant associations with measured LTL. In UKB, causal effects of genetically-predicted LTL for AF risk were estimated using the inverse-variance weighted approach. Validation was undertaken in independent data from the AFGen Consortium (Nielsen et al. 2015). Sensitivity analyses to consider the potential effects of pleiotropy were also conducted (weighted median MR, MR-Egger and Radial MR).
Results
Among 385,851 participants with available LTL measurements and without AF at baseline, 26,639 (6.9%) developed AF during follow-up. Longer measured LTL was associated with lower risk of AF (HR=0.98, 95%CI=0.97-0.99, p=0.002), with the cumulative incidence of AF by LTL quartile shown in Figure 1. However, MR analyses did not support a causal association between genetically-predicted LTL and AF (OR=1.04, 95%CI=0.96-1.14, p=0.36). Sensitivity analyses were consistent with the primary MR results, and did not suggest unbalanced pleiotropy (MR Egger intercept, p=0.54). Radial MR identified 4 outlier SNPs (associated with height, adiposity, and blood cell traits) but results remained consistent after exclusion of these variants (OR 1.00, 95%CI 0.93-1.08, p=0.90). Validation analyses in independent data were consistent with the non-significant association observed in UKB (OR=1.08, 95%CI=0.99-1.18, p=0.07; Figure 2).
Conclusion
This study combines conventional and genetic epidemiological approaches to explore the role of LTL in risk of AF. Large-scale observational analyses in UKB suggest an inverse association between LTL and AF. However, despite previous studies reporting associations between genetically-determined LTL and AF risk factors, our validated MR results do not support a causal relationship between LTL and AF, and potentially suggest observational associations are due to residual confounding.Figure 1Figure 2
The gamma -ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, and a residual all-sky ...emission component commonly called the isotropic diffuse gamma -ray background (IGRB). The IGRB comprises all extragalactic emissions too faint or too diffuse to be resolved in a given survey, as well as any residual Galactic foregrounds that are approximately isotropic. The first IGRB measurement with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) used 10 months of sky-survey data and considered an energy range between 200 MeV and 100 GeV. Improvements in event selection and characterization of cosmic-ray backgrounds, better understanding of the diffuse Galactic emission (DGE), and a longer data accumulation of 50 months allow for a refinement and extension of the IGRB measurement with the LAT, now covering the energy range from 100 MeV to 820 GeV. The IGRB spectrum shows a significant high-energy cutoff feature and can be well described over nearly four decades in energy by a power law with exponential cutoff having a spectral index of 2.32 + or - 0.02 and a break energy of (279 + or - 52) GeV using our baseline DGE model. The total intensity attributed to the IGRB is (7.2 + or - 0.6) x 10 super(-6) cm super(-2) s super(-1) sr super(-1) above 100 MeV, with an additional +15%/-30% systematic uncertainty due to the Galactic diffuse foregrounds.
Detailed information about the lives and deaths of children in antiquity is often in short supply. Childhood dietary histories are, however, recorded and maintained in the teeth of both juveniles and ...adults. Primary tooth dentinal collagen does not turn over, preserving a sequential record of dietary changes. The use of nitrogen (delta.sup.15 N) and carbon (delta.sup.13 C) isotope values of incrementally sampled dentin are used in the study of breastfeeding practices but evidence for the addition of weaning foods, both in terms of mode and, particularly, duration, has remained analytically inaccessible to date. Here, we demonstrate how the novel use hydrogen isotope (delta.sup.2 H) values of sequentially micro-sampled dentin collagen, measured from individuals excavated from a Punic cemetery, in Sardinia, Italy, can serve as a proxy for weaning food type and duration in ancient childhood diet. The weaning rate and age, based on the decline in delta.sup.15 N and delta.sup.13 C values of permanent first molars and the concomitant increase in delta.sup.2 H, appears to be broadly similar among six individuals. Hydrogen isotopes vary systematically from a low value soon after birth, rising through early childhood. The early post-birth values can be explained by the influence of .sup.2 H-depleted lipids from mother's breastmilk and the later delta.sup.2 H rise is consistent with, among other things, a substantial portion of boiled foodstuffs, such as the higher delta.sup.2 H values observed in porridge. Overall delta.sup.2 H in dentin shows great promise to elucidate infant and childhood feeding practices, and especially the introduction of supplementary foods during the weaning process.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Infectious bursal disease (IBD) is an economically important immunosuppressive disease of chickens. The IBD virus (IBDV) actively replicates in B cells and causes severe bursal damage. Generally, T ...cells are refractory to infection with IBDV but are known to promote virus clearance. However, the mechanisms of T cell mediated viral clearance are not well understood. In this study, we evaluated the molecular mechanisms of cytotoxic T cell responses in the pathogenesis of IBD in chickens. Infection of chickens with IBDV was accompanied by the infiltration of CD4
+ and CD8
+ T cells in the bursa. There was an upregulation in the gene expression of important cytolytic molecules; perforin (PFN), granzyme-A (Gzm-A), DNA repair and apoptotic proteins; high mobility proteins group (HMG) and poly (ADP-ribose) polymerase (PARP) in the bursa of Fabricius (BF) whereas expression of NK (natural killer) lysin was downregulated. Importantly, PFN producing CD4
+ and CD8
+ T cells were also detected in the bursa of IBDV-infected chickens by immunohistochemistry. The Th1 cytokines, IL-2 and IFN-γ expression was also strongly upregulated, suggesting the activation of T cells. The findings of this study highlight the mechanisms of IBD pathogenesis and the role of cytotoxic T cells in the clearance of virus-infected cells.
► Implementation of comprehensive CFD model of air-blown coal-fired updraft gasifier. ► Unsteady simulation of Wellman–Galusha gasifier. ► Time-dependent fresh coal introduction and ash removal ...considered. ► Analysis of time-dependent and averaged final syngas composition. ► Thermo-fluid dynamic analysis of gasifier during one coal-charge cycle.
A comprehensive CFD model has been developed to simulate the gasification process within an air-blown updraft coal gasifier. Updraft fixed bed gasification processes are characterized by complex behavior, since they involve different space- and time-dependent sub-processes where coal preheating, drying, de-volatilization and char reactions take place. Simplified models, such as non-dimensional ones, useful for preliminary gross mass and energy balance, are unable to correctly simulate the overall gasification phenomena and more sophisticated approaches are required.
In particular, CFD models could be used to describe in a detailed way the complex time- and space-dependent phenomena involved in the gasification process. Considering the high volume fraction of the solid phase, close to the packing condition, the Euler–Euler approach is required to model this multiphase flow. The solid phase is considered as a continua according to the kinetic and plastic theory of granular flows.
The operation of a Wellman–Galusha gasifier is investigated, considering a non-continuous loading of coal and extraction of the ash, with the aim of characterizing the space- and time-dependent behavior of the process.
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