1,221 research outputs found
Tensin1 expression and function in chronic obstructive pulmonary disease
open access articleChronic obstructive pulmonary disease (COPD) constitutes a major cause of morbidity and
mortality. Genome wide association studies have shown significant associations between airflow
obstruction or COPD with a non-synonymous SNP in the TNS1 gene, which encodes tensin1.
However, the expression, cellular distribution and function of tensin1 in human airway tissue and
cells are unknown. We therefore examined these characteristics in tissue and cells from controls
and people with COPD or asthma.
Airway tissue was immunostained for tensin1. Tensin1 expression in cultured human
airway smooth muscle cells (HASMCs) was evaluated using qRT-PCR, western blotting and
immunofluorescent staining. siRNAs were used to downregulate tensin1 expression.
Tensin1 expression was increased in the airway smooth muscle and lamina propria in COPD
tissue, but not asthma, when compared to controls. Tensin1 was expressed in HASMCs and
upregulated by TGFβ1. TGFβ1 and fibronectin increased the localisation of tensin1 to fibrillar
adhesions. Tensin1 and α-smooth muscle actin (αSMA) were strongly co-localised, and tensin1
depletion in HASMCs attenuated both αSMA expression and contraction of collagen gels.
In summary, tensin1 expression is increased in COPD airways, and may promote airway
obstruction by enhancing the expression of contractile proteins and their localisation to stress
fibres in HASMCs
Green synthesis of gamma-valerolactone (GVL) through hydrogenation of biomass-derived levulinic acid using non-noble metal catalysts : A critical review
The distinct physicochemical properties and renewable origin of gamma-valerolactone (GVL) have provided opportunities for diversifying its applications, particularly as a green solvent, excellent fuel additive, and precursor to valuable chemicals. Among the related publications found in the SCOPUS database (≈172 in the last 10 years), we focused our effort to review the conversion of levulinic acid (LA) to GVL over non-noble metal catalysts and the corresponding mechanisms (≈30 publications) as well as the applications of GVL as a solvent, fuel additive, and platform chemical (≈30 publications) mostly in the last five years (some preceding publications have also been included due to their relevance and importance in the field). The use of non-noble metals (e.g., Cu and Zr) presents a greener route of GVL synthesis than the conventional practice employing noble metals (e.g., Pd and Ru), in view of their higher abundance and milder reaction conditions needed (e.g., low pressure and temperature without H 2 involved). The significance of the catalyst characteristics in promoting catalytic transfer hydrogenation of LA to GVL is critically discussed. Structural features and acid-base properties are found to influence the activity and selectivity of catalysts. Furthermore, metal leaching in the presence of water in catalytic systems is an important issue, resulting in catalyst deactivation. Various endeavors for developing catalysts using well-dispersed metal particles along with a combination of Lewis acid and base sites are suggested for efficiently synthesizing GVL from LA
Tick holocyclotoxins trigger host paralysis by presynaptic inhibition
Ticks are important vectors of pathogens and secreted neurotoxins with approximately 69 out of 692 tick species having the ability to induce severe toxicoses in their hosts. The Australian paralysis tick (Ixodes holocyclus) is known to be one of the most virulent tick species producing a flaccid paralysis and fatalities caused by a family of neurotoxins known as holocyclotoxins (HTs). The paralysis mechanism of these toxins is temperature dependent and is thought to involve inhibition of acetylcholine levels at the neuromuscular junction. However, the target and mechanism of this inhibition remain uncharacterised. Here, we report that three members of the holocyclotoxin family; HT-1 (GenBank AY766147), HT-3 (GenBank KP096303) and HT-12 (GenBank KP963967) induce muscle paralysis by inhibiting the dependence of transmitter release on extracellular calcium. Previous study was conducted using extracts from tick salivary glands, while the present study is the first to use pure toxins from I. holocyclus. Our findings provide greater insight into the mechanisms by which these toxins act to induce paralysis
A sustainable biochar catalyst synergized with copper heteroatoms and CO2 for singlet oxygenation and electron transfer routes
We have developed a wood waste-derived biochar as a sustainable graphitic carbon catalyst for environmental remediation through catalytic pyrolysis under the synergistic effects between Cu heteroatoms and CO2, which for the first time are found to significantly enhance the oxygen functionalities, defective sites, and highly ordered sp2-hybridized carbon matrix. The copper-doped graphitic biochars (Cu-GBCs) were further characterized by XRD, FTIR, Raman, XPS, etc., revealing that the modified specific surface area, pore structure, graphitization, and active sites (i.e., defective sites and ketonic group) on the Cu-GBCs corresponded to the synergistic Cu species loading and Cu-induced carbon-matrix reformation in CO2 environment during pyrolysis. The catalytic ability of Cu-GBCs was evaluated using the ubiquitous peroxydisulfate (PDS) activation system for the removal of various organic contaminants (i.e., rhodamine B, phenol, bisphenol A, and 4-chlorophenol), and gave the highest degradation rate of 0.0312 min-1 in comparison with those of pristine GBCs and N2-pyrolyzed Cu-GBCs ranging from 0.0056 to 0.0094 min-1. The synergistic effects were attributed to the encapsulated Cu heteroatoms, evolved ketonic groups, and abundant unconfined π electrons within the carbon lattice. According to scavenger experiments, ESR analysis, and two-chamber experiments, selective and sustainable non-radical pathways (i.e., singlet oxygenation and electron transfer) mediated by the Cu-induced metastable surface complex were achieved in the Cu-GBC/PDS system. This study offers the first insights into the efficacy, sustainability, and mechanistic roles of Cu-GBCs as an emerging carbon-based catalyst for green environmental remediation
Human-Agent Teamwork in Cyber Operations: Supporting Co-evolution of Tasks and Artifacts with Luna
Abstract. In this article, we outline the general concept of coactive emergence, an iterative process whereby joint sensemaking and decision-making activities are undertaken by analysts and software agents. Then we explain our rationale for the development of the Luna software agent framework. In particular, we focus on how we use capabilities for comprehensive policy-based governance to ensure that key requirements for security, declarative specification of task-work, and built-in support for joint activity within mixed teams of humans and agents are satisfied
Bessel Process and Conformal Quantum Mechanics
Different aspects of the connection between the Bessel process and the
conformal quantum mechanics (CQM) are discussed. The meaning of the possible
generalizations of both models is investigated with respect to the other model,
including self adjoint extension of the CQM. Some other generalizations such as
the Bessel process in the wide sense and radial Ornstein- Uhlenbeck process are
discussed with respect to the underlying conformal group structure.Comment: 28 Page
The 3D Structure of N132D in the LMC: A Late-Stage Young Supernova Remnant
We have used the Wide Field Spectrograph (WiFeS) on the 2.3m telescope at
Siding Spring Observatory to map the [O III] 5007{\AA} dynamics of the young
oxygen-rich supernova remnant N132D in the Large Magellanic Cloud. From the
resultant data cube, we have been able to reconstruct the full 3D structure of
the system of [O III] filaments. The majority of the ejecta form a ring of
~12pc in diameter inclined at an angle of 25 degrees to the line of sight. We
conclude that SNR N132D is approaching the end of the reverse shock phase
before entering the fully thermalized Sedov phase of evolution. We speculate
that the ring of oxygen-rich material comes from ejecta in the equatorial plane
of a bipolar explosion, and that the overall shape of the SNR is strongly
influenced by the pre-supernova mass loss from the progenitor star. We find
tantalizing evidence of a polar jet associated with a very fast oxygen-rich
knot, and clear evidence that the central star has interacted with one or more
dense clouds in the surrounding ISM.Comment: Accepted for Publication in Astrophysics & Space Science, 18pp, 8
figure
Leveraging open innovation to improve society: past achievements and future trajectories
Open innovation (OI) is an approach which describes a purposive attempt to draw together knowledge from different contributors to develop and exploit innovation. It has become clear that OI directly benefits organisations' economic performance and resilience, but researchers, practitioners, and policy makers became also convinced that OI might be the way forward to tackle the world’s most pressing societal challenges, representing unresolved Grand Challenges, which can only be weathered by diverse sets of collaborative partners that join forces. Although anecdotal evidence points at how OI practices can be employed to achieve societal impact not only in private firms but also in public organisations, very little understanding exists -beyond anecdotal- to link OI to societal impact. This special issue has the ambition to start the discussion and establish a framework as the stepping stone to tackle this complex research gap
- …