68 research outputs found
Design of novel compounds with the potential of dual PPARγ/α modulation for the management of metabolic syndrome
This study sought to identify a single molecule capable of managing all three manifestations of metabolic syndromeâhyperglycaemia, dyslipidaemia and hypertension. Two Protein Data Bank (PDB) depositions were selected and used to establish the baseline affinity that any designed molecule in this study should ideally exceed in order to be considered for further optimisation. These were PDB depositions 3VN2 and 2P54 describing the bound co-ordinates of the Peroxisome Proliferator Activated Receptor (PPAR) partial agonist and Angiotensin II Receptor (Ang(II)R) blocker telmisartan and of the experimental PPAR fibrate agonist GW590735 bound to their respective cognate receptors. These small molecules were extracted from their cognate receptors, docked into their non-cognate counterparts, conformational analysis performed, and the optimal conformers were selected as template scaffolds in two parallel processes. The first was a fragment based de novo approach. Here, molecular moieties from the optimal telmisartan and GW590735 scaffolds modelled in their non-cognate targets and considered critical to binding were identified and modelled, in order to produce seed structures capable of sustaining molecular growth at user-directed sites designated as H.spc atoms subsequent to their being docked within the non-cognate Ligand Binding Pockets (LBPs). The second approach was a Virtual Screening (VS) exercise. Here, the optimal telmisartan and GW590735 conformers were submitted as query molecules to VS databases both individually and in the form of a consensus pharmacophore. This VS exercise identified structurally diverse molecules which were electronically and spatially similar to the queries and which were capable of modulating the target receptors. The molecular cohorts identified through both VS and the de novo approaches were filtered for Lipinski Rule compliance. The molecules that survived filtering were then re-docked into the non-cognate PPAR and/or _LBPs, conformational analysis re-performed and the affinity of the optimal conformer measured for its cognate receptor quantified. Comparison was made to the baseline and non-cognate receptor affinities previously established, and the molecules exhibiting dual affinities exceeding baseline values were selected for further optimisation. The use of the âtried and testedâ Ang(II)R blocker and fibrate scaffolds as templates predisposes to the identification of novel structures devoid of unacceptable toxicity.peer-reviewe
Bridging the Gap Between Traditional Metadata and the Requirements of an Academic SDI for Interdisciplinary Research
Metadata has long been understood as a fundamental component of any Spatial Data Infrastructure, providing information relating to discovery, evaluation and use of
datasets and describing their quality. Having good metadata about a dataset is fundamental to using it correctly and to understanding the implications of issues such as missing data or incorrect attribution on the results obtained for any analysis carried out.
Traditionally, spatial data was created by expert users (e.g. national mapping agencies), who created metadata for the data. Increasingly, however, data used in spatial analysis comes from multiple sources and could be captured or used by nonexpert users â for example academic researchers â many of whom are from nonâGIS disciplinary backgrounds, not familiar with metadata and perhaps working in geographically dispersed teams. This paper examines the applicability of metadata in this academic context, using a multiânational coastal/environmental project as a case study. The work to date highlights a number of suggestions for good practice, issues and research questions relevant to Academic SDI, particularly given the increased levels of research data sharing and reuse required by UK and EU funders
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Using Free and Open Source GIS to Automatically Create Standards-Based Spatial Metadata in Academia - First Investigations
The importance of understanding the quality of data used in any GIS operation has increased significantly as a result of the advent of Free and Open Source (FOSS) tools and Open Data, which in turn have encouraged non-specialists to make use of GIS. Metadata (data about data) traditionally provides a description of this quality information and permits data curation, but it is frequently deemed as complex to create and maintain. Additionally, it is generally stored separately from the data, leading to issues where updates to the data are not reflected in the metadata and to users not being aware that metadata exists. This paper describes an approach to address these issues in an academic context - tightly coupling data and metadata and automating elements of standards-based metadata creation and automating keyword generation and language detection. We describe research into the potential of the FOSS packages Quantum GIS and PostGIS to support this form of metadata generation and maintenance
Integrating expertises and ambitions for data-driven digital building permits - the EUNET4DBP
The digitalization of the process for building permit (involving the use of 3D information systems) is seen as a priority in a wide part of the world. Since it is a very multidisciplinary use case, involving a variety of stakeholders tackling complex issues and topics, some of them joined their efforts and skills in the European Network for Digital Building Permit. The initial activity of the network, after a review of on-going experiences, was a workshop to share knowledge about the topics involved and to identify the main ambitions of the network with respect to three pillars (i.e. Process - Rules and Requirements - Technology) and the related requirements. It was achieved through a collective brainstorming activity guided by digital tools, whose results were further analysed in a post-processing phase. Such results are presented in this paper and will be the base for planning the future network activity. © Authors 2020
Dysbiosis in the gut microbiota in patients with inflammatory bowel disease during remission
Inflammatory bowel disease (IBD) is a chronic, relapsing, inflammatory disorder which comprises two main conditions: Crohnâs disease (CD) and ulcerative colitis (UC).
Although the etiology of IBD has not been fully elucidated, the gut microbiota is hypothesized to play a vital role in its development. The aim of this cross-sectional study was to
characterize the fecal microbiota in CD or UC patients in a state of remission to reveal
potential factors sustaining residual levels of inflammation and triggering disease relapses.
Ninety-eight IBD patients in a state of clinical remission (66 UC, 32 CD) and 97 controls
were recruited, and stool samples, as well as detailed patient data, were collected. After
DNA extraction, the variable regions V1 and V2 of the 16S rRNA gene were amplified and
sequenced. Patients with IBD had a decrease in alpha diversity compared to that of healthy
controls, and the beta diversity indices showed dissimilarity between the cohorts. Healthy
controls were associated with the beneficial organisms unclassified Akkermansia species
(Akkermansia uncl.), Oscillibacter uncl., and Coprococcus uncl., while flavonoid-degrading bacteria were associated with IBD. Network analysis identified highly central and influential disease markers and a strongly correlated network module of Enterobacteriaceae which was
associated with IBD and could act as drivers for residual inflammatory processes sustaining
and triggering IBD, even in a state of low disease activity. The microbiota in IBD patients is
significantly different from that of healthy controls, even in a state of remission, which
implicates the microbiota as an important driver of chronicity in IBD.
IMPORTANCE Dysbiosis in inflammatory bowel disease (IBD) has been implicated as a
causal or contributory factor to the pathogenesis of the disease. This study, done on
patients in remission while accounting for various confounding factors, shows significant community differences and altered community dynamics, even after acute
inflammation has subsided. A cluster of Enterobacteriaceae was linked with Crohnâs
disease, suggesting that this cluster, which contains members known to disrupt colonization resistance and form biofilms, persists during quiescence and can lead to
chronic inflammation. Flavonoid-degrading bacteria were also associated with IBD,
raising the possibility that modification of dietary flavonoids might induce and maintain remission in IBD.peer-reviewe
Microbial dynamics in newly diagnosed and treatment naĂŻve IBD patients in the Mediterranean
Background: Microbial communities have long been suspected to influence inflammatory processes in the gastrointestinal tract of patients with
inflammatory bowel disease. However, these effects are often influenced by treatments and can rarely be analyzed in treatment-naĂŻve onset
cases. Specifically, microbial differences between IBD pathologies in new onset cases have rarely been investigated and can provide novel insight into the dynamics of the microbiota in Crohnâs disease (CD) and ulcerative colitis (UC).
Methods: Fifty-six treatment-naĂŻve IBD onset patients (67.3% CD, 32.7% UC) and 97 healthy controls were recruited from the Maltese population. Stool samples were collected after diagnosis but before administration of anti-inflammatory treatments. Fecal microbial communities were
assessed via 16S rRNA gene sequencing and subjected to ecological analyses to determine disease-specific differences between pathologies
and disease subtypes or to predict future treatment options.
Results: We identified significant differences in community composition, variability, and diversity between healthy and diseased individualsâbut
only small to no differences between the newly diagnosed, treatment-naĂŻve UC and CD cohorts. Network analyses revealed massive turn-over of bacterial interactions between healthy and diseased communities, as well as between CD and UC communities, as signs of disease-specific changes of community dynamics. Furthermore, we identified taxa and community characteristics serving as predictors for prospective
treatments.
Conclusion: Untreated and newly diagnosed IBD shows clear differences from healthy microbial communities and an elevated level of disturbance, but only the network perspective revealed differences between pathologies. Furthermore, future IBD treatment is to some extent predictable by microbial community characteristics.peer-reviewe
Chemical and physical modifications of the surface of sisal agave fibre used as a reinforcement in epoxy resin : a review
A combination of sisal fibers and bio-based epoxy resin offers good potential
for producing environmentally friendly bio-composites with improved or
equivalent mechanical properties compared to those obtained using 100%
synthetic resins. However, the poor interaction between the two materials
caused by the different distribution of electrical charge over the atoms joined
by the bond in the functional groups of the chemical structure (polarity)
necessitates the modification of one of the surfaces of the constituents
through various techniques. The paper discusses available literature on
several treatments to improve the adhesion between sisal fibres and thermoset epoxy matrices by achieving favorable wettability, mechanical interlocking, and improved interaction through chemical bonding. It is shown that
fiber washing in an NaOH solution followed by rinsing and drying is the
prevalent chemical treatment. With NaOH treatments, researchers observed
cleaner fibres and this promoted better adhesion with the epoxy matrix.
Coupling agents such as silane treatments showed an improved resistance to
fiber moisture absorption. Thermal treatments affect the fiberâs morphology
by increasing the crystallinity of the cellulose leading to stiffer composites. It
was also observed that the improvement in fiber-matrix adhesion had an
adverse effect on the impact strength of the composite.peer-reviewe
ĆœELJKO HOLJEVAC GOSPIÄ U VOJNOJ KRAJINI
A range of novel heterocyclic cations
have been synthesized by
the RhÂ(III)-catalyzed oxidative CâN and CâC coupling
of 1-phenylpyrazole, 2-phenylpyridine, and 2-vinylpyridine with alkynes
(4-octyne and diphenylacetylene). The reactions proceed via initial
CâH activation, alkyne insertion, and reductive coupling, and
all three of these steps are sensitive to the substrates involved
and the reaction conditions. Density functional theory (DFT) calculations
show that CâH activation can proceed via a heteroatom-directed
process that involves displacement of acetate by the neutral substrate
to form charged intermediates. This step (which leads to cationic
CâN coupled products) is therefore favored by more polar solvents.
An alternative non-directed CâH activation is also possible
that does not involve acetate displacement and so becomes favored
in low polarity solvents, leading to CâC coupled products.
Alkyne insertion is generally more favorable for diphenylacetylene
over 4-octyne, but the reverse is true of the reductive coupling step.
The diphenylacetylene moiety can also stabilize unsaturated seven-membered
rhodacycle intermediates through extra interaction with one of the
Ph substituents. With 1-phenylpyrazole this effect is sufficient to
suppress the final CâN reductive coupling. A comparison of
a series of seven-membered rhodacycles indicates the barrier to coupling
is highly sensitive to the two groups involved and follows the trend
CâN<sup>+</sup> > CâN > CâC (i.e., involving
the formation of cationic CâN, neutral CâN, and neutral
CâC coupled products, respectively)
Pulmonary SARS-CoV-2 infection leads to para-infectious immune activation in the brain
Neurological complications, including encephalopathy and stroke, occur in a significant proportion of COVID-19 cases but viral protein is seldom detected in the brain parenchyma. To model this situation, we developed a novel low-inoculum K18-hACE2 mouse model of SARS-CoV-2 infection during which active viral replication was consistently seen in mouse lungs but not in the brain. We found that several mediators previously associated with encephalopathy in clinical samples were upregulated in the lung, including CCL2, and IL-6. In addition, several inflammatory mediations, including CCL4, IFNÎł, IL-17A, were upregulated in the brain, associated with microglial reactivity. Parallel in vitro experiments demonstrated that the filtered supernatant from SARS-CoV-2 virion exposed brain endothelial cells induced activation of uninfected microglia. This model successfully recreates SARS-CoV-2 virus-associated para-infectious brain inflammation which can be used to study the pathophysiology of the neurological complications and the identification of potential immune targets for treatment
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