26 research outputs found
Quantifying the role of riparian management to control non-point source pollution of pasture and cropland streams
Grazing management practices have the potential to mitigate some problems with sediment and phosphorus loading in pasture streams. The project demonstrated possible strategies to lessen grazing impacts on streams
Effect of platelet mediator concentrate (PMC) on Achilles tenocytes: an in vitro study
Background: Although there are many studies discussing the etiological and pathological factors leading to both, acute and chronic tendon injuries, the pathophysiology of tendon injuries is still not clearly understood. Although most lesions are uncomplicated, treatment is long and unsatisfactory due to the poor vascularity of tendon tissue. Platelet mediator concentrate (PMC) contains many growth factors derived from platelets, which can promote wound healing. In this study we investigate the effects of PMC on tenocyte proliferation and differentiation in order to provide an experimental basis for tissue regeneration strategies and to develop new treatment concepts. Methods: Using enzyme linked immunosorbent assay (ELISA) we were able to quantify the several growth factors and cytokines found in PMC. Tenocytes were isolated both from human and from mouse Achilles tendons and stimulated with PMC. CyQuant((R)) and Cell Titer Blue((R)) assays were carried out to analyze tendon growth and viability at different concentrations of PMC. Real time RT-PCR was used to analyze tenocyte gene expression with or without PMC treatment. Immunohistochemistry was carried out to detect the tenocyte-specific antibody tenomodulin (TNMD) and scleraxis (SCX). Results: We were able to detect numerous mediators such as platelet derived growth factor BB (PDGF- BB), interleukin 6 (IL- 6), vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF-a), transforming growth factor beta 1 (TGF- beta 1), and bone morphogenetic proteins 2, 4 and 7 (BMP- 4, BMP- 2, BMP- 7) in PMC. It was possible to show a positive effect of PMC on human tendon cell growth and viability in a dose-dependent manner. Furthermore, PMC treatment led to induction of gene expression of scleraxis (SCX), type I collagen A 1 (Col1A1) and TNMD by tenocytes. Conclusions: We suggest that the use of autologous PMC may be a suitable addition to conventional tendon therapy that is capable of increasing and optimizing tendon healing and reducing the risk of recurrence
Effect of platelet mediator concentrate (PMC) on Achilles tenocytes: an in vitro study
Comparative study on plant latex particles and latex coagulation in Ficus benjamina, Campanula glomerata and three Euphorbia species.
Among latex-producing plants, mainly the latex of Hevea brasiliensis has been studied in detail so far, while comprehensive comparative studies of latex coagulation mechanisms among the more than 20,000 latex-bearing plant species are lacking. In order to give new insights into the potential variety of coagulation mechanisms, the untreated natural latices of five latex-bearing plants from the families Euphorbiaceae, Moraceae and Campanulaceae were visualised using Cryo-SEM and their particle size compared using the laser diffraction method. Additionally, the laticifers of these plants species were examined in planta via Cryo-SEM. Similar latex particle sizes and shape were found in Ficus benjamina and Hevea brasiliensis. Hence, and due to other similarities, we hypothesize comparable, mainly chemical, coagulation mechanisms in these two species, whereas a physical coagulation mechanism is proposed for the latex of Euphorbia spp. The latter mechanism is based on the huge amount of densely packed particles that after evaporation of water build a large surface area, which accelerates the coagulation procedure
Quantifying the role of riparian management to control non-point source pollution of pasture and cropland streams
Grazing management practices have the potential to mitigate some problems with sediment and phosphorus loading in pasture streams. The project demonstrated possible strategies to lessen grazing impacts on streams.</p
Diffusion–reaction compartmental models formulated in a continuum mechanics framework: application to COVID-19, mathematical analysis, and numerical study
Fractures in latex droplets of <i>Ficus benjamina</i>.
<p>The solid latex particles (e.g. black arrow in a) are not destroyed by fractures. Instead, fractures run around the latex particles (a, c). However, the larger and collapsed structures (e.g. white arrow in a) are divided by fractures (b) (Cryo-SEM images).</p
Particle size distributions of the fresh latex of <i>Ficus benjamina</i> and of the three <i>Euphorbia</i> species.
<p>On the ordinate, the percentage of the volume of all particles within the respective size class related to the total volume (added volume of all particles in all size classes), is given. The latex was diluted in water and ultrasonic treatment was applied to dissolve loose aggregates before measuring. Fresh, uncoagulated latex of <i>Campanula glomerata</i> could not be measured, as it coagulates irreversibly before or while stirring in the dispersion unit. As a comparison, the particle size distribution of purified <i>H. brasiliensis</i> latex (data taken from Cornish & Brichta (2002) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0113336#pone.0113336-Cornish2" target="_blank">[27]</a>) was added. The small inserted box shows the particle size distribution of <i>F. benjamina</i> latex when transformed to the number mode.</p
Stable <i>N</i>‑Heterocyclic Carbenes with the <i>N</i>,<i>N</i>′‑Diarylquinazolin-4-one Backbone: Improved Synthesis, Electronic Properties, and Reactivity
We present a new pathway toward cationic N,N′-diaryl-substituted quinazolin-4-one derivatives,
which act as precursors for the synthesis of new N,N′-diaryl-amino-amido carbenes 5a,b that are stable under inert conditions. A tetrafluoro analogue 5c withstands isolation but can be prepared and employed in
situ. The new NHCs exhibit a strong σ-donor capacity as well
as strong π-accepting properties according to NMR and IR spectroscopic
investigations indicated by the coupling constants 1JC,H (210–214 Hz) and 77Se
NMR resonances (545–654 ppm) of suitable derivatives. Remarkably,
replacement of the hydrogen atoms of the anellated benzene ring by
fluorine atoms exerts only a small effect on the overall donor properties
of the carbene, as suggested by a small shift of the TEP values from
2053 cm–1 (5a) to 2055 cm–1 (5c). An ambiphilic reactivity of the NHCs 5 is supported by their reactions with isonitriles to provide the
respective ketenimines 13, which show unprecedented rearrangement
reactions, induced by either water or heat. The NHCs 5 also react with amines or methanol in N–H and O–H
bond activations. The mechanisms of these activation reactions were
investigated by quantum chemical calculations. Due to the apparent
blue emission of the selected derivatives, the photophysical properties
were exemplarily characterized in solution and solid state and assigned
to the underlying electronic transitions by (TD)-DFT calculations
Longitudinal fracture of a laticifer in a shoot axis of <i>Ficus benjamina</i>.
<p>Latex particles are abundant in the laticifer, but are absent in the surrounding cells (Cryo-SEM image).</p