Green composites were prepared with polypropylene matrix and 20 wt.% spent coffee ground (SCG) powder for uses as a wood plastic composite (WPC). The effects of hydrophobic treatment with palmitoyl ...chloride on SCG powder is compared with conventional surface treatment based on silanization with (3-glycidyloxypropyl) trimethoxysilane and the use of a maleated copolymer compatibilizer (polypropylene-graft-maleic anhydride, PP-g-MA) in terms of mechanical properties, morphology, thermal properties and water uptake. Composites were previously mixed in a twin-screw co-rotating extruder and subsequently subjected to injection moulding. The comparative effect of the different surface treatments and or compatibilizers on mechanical performance was studied by flexural, impact tests and dynamic mechanical thermal analysis (DMTA-torsion); in addition, the stabilizing effect of SCG was revealed by differential scanning calorimetry (DSC) and thermogravymetric analysis (TGA). As one of the main drawbacks of wood plastic composites and natural fibre reinforced plastics is the moisture gain, water uptake tests were carried out in order to quantify the effectiveness of the hydrophobization process with palmitoyl chloride. Results show a slight increase in flexural modulus for composites with both untreated and treated/compatibilized SCG powder (20 wt.%). As expected, thermal stability is improved as indicated by an increase of more than 8% in the onset degradation temperature by DSC if compared to unfilled polypropylene. Fracture analysis by scanning electron microscopy (SEM) shows better particle dispersion for PP-SCG composites with hydrophobized SCG with palmitoyl chloride treatment; in addition a remarkable decrease in water uptake is observed for composites with hydrophobized SCG.
Aim
To evaluate in a laboratory setting the effects of Endosequence BC Sealer HiFlow (Brasseler USA, Savannah, GA, USA), a novel calcium silicate‐based sealer developed for use in warm canal filling ...techniques, on human periodontal ligament stem cells (hPDLSCs).
Methodology
Eluates of EndoSequence BC Sealer HiFlow (BCHiF) (Brasseler USA), EndoSequence BC Sealer (BCS) (Brasseler USA) and AH Plus (AHP) (Dentsply DeTrey GmbH, Konstanz, Germany) were placed in contact with hPDLSCs. The characterization of the chemical elements of the root canal sealers was assessed using scanning electron microscopy and energy‐dispersive X‐ray analysis (SEM‐EDX). Inductively coupled plasma‐mass spectrometry (ICP‐MS) was used to determine the ion release of the sealers. MTT assay and wound healing techniques were used to determine cell viability and migration, respectively. Cell morphology and cell attachment were assessed using a direct contact technique of hPDLSCs onto the surface of the sealers and analysed by SEM. The bioactivity potential was carried out with the Alizarin Red and qPCR testing methods. The statistical differences were evaluated using one‐way anova and Tukey’s test (P < 0.05).
Results
ICP‐MS and EDX revealed significantly more zirconium in BCHiF than BCS (P < 0.05), whereas BCS had slightly higher levels of Ca2+ than BCHiF (P < 0.05). The cell viability assay revealed no relevant differences between BCS and BCHiF when compared with the control group (P > 0.05). Both BCS and BCHiF had similar rates of cell migration to the control group at 24 and 48 h. Cell morphology and adhesion capacity were also similar for BCS and BCHiF groups, whilst the AHP group was associated with reduced adhesion capacity. The Alizarin Red assay revealed a significant difference between the BCS and the control group (P < 0.001), as well as for the BCHiF group (P < 0.001). Finally, BCS and BCHiF promoted overexpression of osteo/cementogenic genes.
Conclusions
In general, EndoSequence BC Sealer HiFlow possesses suitable biological properties to be safely used as a root canal filling material and promote increased expression of oste/cementogenic genes by hPDLSCs.
The use of cucurbit8uril as a molecular host has emerged in the chemical literature as a reliable strategy for the creation of dynamic chemical systems, owing to its ability to form homo‐ and ...heteroternary complexes in aqueous media with appropriate molecular switches as guests. In this manner, CB8‐based supramolecular switches can be designed in a predictable and modular fashion, through the selection of appropriate guests able to condition the redox, photochemical, or pH‐triggered behavior of tailored multicomponent systems. Furthermore, CB8 allows the implementation of dual/triple and linear/orthogonal stimuli‐dependent properties into these molecular devices by a careful selection of the guests. This versatility in their design gives these supramolecular switches great potential for the rational development of new materials, in which their function is not only determined by the custom‐made stimuli‐responsiveness, but also by the transient aggregation/disaggregation of homo‐ or heteromeric building blocks.
Switch that: The capability of cucurbit8uril as a molecular host to form homo‐ and heteroternary complexes in aqueous media has fueled its use in supramolecular switches. The use of those dynamic systems is especially interesting since they can be reversibly transformed by the application of external stimuli, such as light, redox potential, or pH, and even allow the implementation of orthogonal stimuli responsiveness.
The term sepsis refers to a complex and heterogeneous syndrome. Although great progress has been made in improving the diagnosis and treatment of this condition, it continues to have a huge impact on ...morbidity and mortality worldwide. Mesenchymal stem cells are a population of multipotent cells that have immunomodulatory properties, anti-apoptotic effects, and antimicrobial activity. We studied these capacities in a porcine model of peritoneal sepsis.
We infused human adipose-derived mesenchymal stem cells (ADSCs) into a porcine model of peritoneal sepsis. Twenty piglets were treated with antibiotics alone (control group) or antibiotics plus peritoneal infusion of ADSCs at a concentration of 2 × 10
cells/kg or 4 × 10
cells/kg (low- and high-dose experimental groups, respectively). The animals were evaluated at different time points to determine their clinical status, biochemical and hematologic parameters, presence of inflammatory cytokines and chemokines in blood and peritoneal fluid, and finally by histologic analysis of the organs of the peritoneal cavity.
One day after sepsis induction, all animals presented peritonitis with bacterial infection as well as elevated C-reactive protein, haptoglobin, IL-1Ra, IL-6, and IL-1b. Xenogeneic ADSC infusion did not elicit an immune response, and peritoneal administration of the treatment was safe and feasible. One day after infusion, the two experimental groups showed a superior physical condition (e.g., mobility, feeding) and a significant increase of IL-10 and TGF-β in blood and a decrease of IL-1Ra, IL-1b, and IL-6. After 7 days, all animals treated with ADSCs had better results concerning blood biomarkers, and histopathological analysis revealed a lower degree of inflammatory cell infiltration of the organs of the peritoneal cavity.
Intraperitoneal administration of ADSCs as an adjuvant therapy for sepsis improves the outcome and diminishes the effects of peritonitis and associated organ damage by regulating the immune system and reducing intra-abdominal adhesions in a clinically relevant porcine model of abdominal sepsis.
We report chemical abundances obtained by Sloan Digital Sky Survey (SDSS)-III/Apache Point Observatory Galactic Evolution Experiment for giant stars in five globular clusters located within 2.2 kpc ...of the Galactic Centre. We detect the presence of multiple stellar populations in four of those clusters (NGC 6553, NGC 6528, Terzan 5 and Palomar 6) and find strong evidence for their presence in NGC 6522. All clusters with a large enough sample present a significant spread in the abundances of N, C, Na and Al, with the usual correlations and anticorrelations between various abundances seen in other globular clusters. Our results provide important quantitative constraints on theoretical models for self-enrichment of globular clusters, by testing their predictions for the dependence of yields of elements such as Na, N, C and Al on metallicity. They also confirm that, under the assumption that field N-rich stars originate from globular cluster destruction, they can be used as tracers of their parental systems in the high-metallicity regime.
We show that the masses of red giant stars can be well predicted from their photospheric carbon and nitrogen abundances, in conjunction with their spectroscopic stellar labels log g, T
eff, and Fe/H. ...This is qualitatively expected from mass-dependent post-main-sequence evolution. We here establish an empirical relation between these quantities by drawing on 1475 red giants with asteroseismic mass estimates from Kepler that also have spectroscopic labels from Apache Point Observatory Galactic Evolution Experiment (APOGEE) DR12. We assess the accuracy of our model, and find that it predicts stellar masses with fractional rms errors of about 14 per cent (typically 0.2 M⊙). From these masses, we derive ages with rms errors of 40 per cent. This empirical model allows us for the first time to make age determinations (in the range 1–13 Gyr) for vast numbers of giant stars across the Galaxy. We apply our model to ∼52 000 stars in APOGEE DR12, for which no direct mass and age information was previously available. We find that these estimates highlight the vertical age structure of the Milky Way disc, and that the relation of age with α/M and metallicity is broadly consistent with established expectations based on detailed studies of the solar neighbourhood.
Summary
We consider the problem of providing valid inference for a selected parameter in a sparse regression setting. It is well known that classical regression tools can be unreliable in this ...context because of the bias generated in the selection step. Many approaches have been proposed in recent years to ensure inferential validity. In this article we consider a simple alternative to data splitting based on randomizing the response vector, which allows for higher selection and inferential power than the former, and is applicable with an arbitrary selection rule. We perform a theoretical and empirical comparison of the two methods and derive a central limit theorem for the randomization approach. Our investigations show that the gain in power can be substantial.
Metabolic engineering uses enzymes as parts to build biosystems for specified tasks. Although a part's working life and failure modes are key engineering performance indicators, this is not yet so in ...metabolic engineering because it is not known how long enzymes remain functional in vivo or whether cumulative deterioration (wear-out), sudden random failure, or other causes drive replacement. Consequently, enzymes cannot be engineered to extend life and cut the high energy costs of replacement. Guided by catalyst engineering, we adopted catalytic cycles until replacement (CCR) as a metric for enzyme functional life span in vivo. CCR is the number of catalytic cycles that an enzyme mediates in vivo before failure or replacement, i.e., metabolic flux rate/protein turnover rate. We used estimated fluxes and measured protein turnover rates to calculate CCRs for ∼100-200 enzymes each from
, yeast, and
CCRs in these organisms had similar ranges (<10
to >10
) but different median values (3-4 × 10
in
and yeast versus 4 × 10
in
). In all organisms, enzymes whose substrates, products, or mechanisms can attack reactive amino acid residues had significantly lower median CCR values than other enzymes. Taken with literature on mechanism-based inactivation, the latter finding supports the proposal that 1) random active-site damage by reaction chemistry is an important cause of enzyme failure, and 2) reactive noncatalytic residues in the active-site region are likely contributors to damage susceptibility. Enzyme engineering to raise CCRs and lower replacement costs may thus be both beneficial and feasible.
Aims
The aim of this study was to investigate the dynamic changes in the bacterial structure and potential interactions of an acclimatized marine microbial community during a light crude oil ...degradation experiment.
Methods and Results
The bacterial community effectively removed 76·49% of total petroleum hydrocarbons after 30 days, as evidenced by GC‐FID and GC‐MS analyses. Short‐chain alkanes and specific aromatic compounds were completely degraded within the first 6 days. High‐throughput sequencing of 16S rRNA gene indicated that the starting bacterial community was mainly composed by Marinobacter and more than 30 non‐dominant genera. Bacterial succession was dependent on the hydrocarbon uptake with Alcanivorax becoming dominant during the highest degradation period. Sparse correlations for compositional data algorithm revealed one operational taxonomic unit (OTU) of Muricauda and an assembly of six OTUs of Alcanivorax dieselolei and Alcanivorax hongdengensis as critical keystone components for the consortium network maintenance and stability.
Conclusions
This work exhibits a stabilized marine bacterial consortium with the capability to efficiently degrade light crude oil in 6 days, under laboratory conditions. Successional and interaction patterns were observed in response to hydrocarbon consumption, highlighting potential interactions between Alcanivorax and keystone non‐dominant OTUs over time.
Significance and Impact of the Study
Our results contribute to the understanding of interactions and potential roles of specific members of hydrocarbonoclastic marine bacterial communities, which will be useful for further bioaugmentation studies concerning the associations between indigenous and introduced micro‐organisms.
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