Search results for "modification"
showing 10 items of 853 documents
Self treating in the moderne era
2013
In the modern era, self healing is to respond to situations created by medicine. Its effectiveness, its limits, its interventions, its practice, its tendency to medicalize existences, its inclusion in market economy are as many factors that interact with the self healing ability as attest the disruption of the patient's identity schema during interventions to repair physical trauma, chronic patient which depends on medicine, the medicalization of the aging. As well the task assigned to the modern man is to escape from enslavements, weathering effects, interferences generated by medical activities. In this sense, self healing is, on the one hand, to decrypt the aims of medicine and to determ…
Poly(sarcosine) surface modification imparts stealth-like properties to liposomes
2019
Circulation lifetime is a crucial parameter for a successful therapy with nanoparticles. Reduction and alteration of opsonization profiles by surface modification of nanoparticles is the main strategy to achieve this objective. In clinical settings, PEGylation is the most relevant strategy to enhance blood circulation, yet it has drawbacks, including hypersensitivity reactions in some patients treated with PEGylated nanoparticles, which fuel the search for alternative strategies. In this work, lipopolysarcosine derivatives (BA-pSar, bisalkyl polysarcosine) with precise chain lengths and low polydispersity indices are synthesized, characterized, and incorporated into the bilayer of preformed…
Covalent RGD modification of the inner pore surface of polycaprolactone scaffolds
2011
Scaffold production for tissue engineering was demonstrated by means of a hot compression molding technique and subsequent particulate leaching. The utilization of spherical salt particles as the pore-forming agent ensured complete interconnectivity of the porous structure. This method obviated the use of potentially toxic organic solvents. To overcome the inherent non-cell-adhesive properties of the hydrophobic polymer polycaprolactone (PCL) surface activation with a diamine was performed, followed by the covalent immobilization of the adhesion-promoting RGD-peptide. The wet-chemical approach was performed to guarantee modification throughout the entire scaffold structure. The treatment wa…
(-)-Isosteviol as a Versatile Ex-Chiral-Pool Building Block for Organic Chemistry
2013
(–)-Isosteviol is readily available in large quantities by the acidic treatment of a common alternative sweetener. The two functional groups of (–)-isosteviol are presented on the same side of the ent-beyerane scaffold with a mutual C–C distance of about 7 A. Their unique concave arrangement experiences a strong asymmetric environment due to an adjacent methyl group. Consequently, this building block has found several applications in supramolecular chemistry and organocatalysis. These areas and the chemical modification of this scaffold as well as its biological activity are surveyed.
Measurement ofΥ(1S+2S+3S)production inp+pand Au + Au collisions atsNN=200GeV
2015
Measurements of bottomonium production in heavy-ion and p + p collisions at the Relativistic Heavy Ion Collider (RHIC) are presented. The inclusive yield of the three states, (1S + 2S + 3S), was measured in the PHENIX experiment via electron-positron decay pairs at midrapidity for Au + Au and p + p collisions at root sNN = 200 GeV. The (1S + 2S + 3S) -> e(+)e(-) differential cross section at midrapidity was found to be B(ee)d sigma/dy = 108 +/- 38 (stat) +/- 15 (syst) +/- 11 (luminosity) pb in p + p collisions. The nuclear modification factor in the 30% most central Au + Au collisions indicates a suppression of the total. state yield relative to the extrapolation from p + p collision data. …
Partial Methylation at Am100 in 18S rRNA of Baker's Yeast Reveals Ribosome Heterogeneity on the Level of Eukaryotic rRNA Modification
2014
Ribosome heterogeneity is of increasing biological significance and several examples have been described for multicellular and single cells organisms. In here we show for the first time a variation in ribose methylation within the 18S rRNA of Saccharomyces cerevisiae. Using RNA-cleaving DNAzymes, we could specifically demonstrate that a significant amount of S. cerevisiae ribosomes are not methylated at 2'-O-ribose of A100 residue in the 18S rRNA. Furthermore, using LC-UV-MS/MS of a respective 18S rRNA fragment, we could not only corroborate the partial methylation at A100, but could also quantify the methylated versus non-methylated A100 residue. Here, we exhibit that only 68% of A100 in t…
A survey on tubulin and arginine methyltransferase families sheds light on p. lividus embryo as model system for antiproliferative drug development
2019
Tubulins and microtubules (MTs) represent targets for taxane-based chemotherapy. To date, several lines of evidence suggest that effectiveness of compounds binding tubulin often relies on different post-translational modifications on tubulins. Among them, methylation was recently associated to drug resistance mechanisms impairing taxanes binding. The sea urchin is recognized as a research model in several fields including fertilization, embryo development and toxicology. To date, some &alpha
Tuning the surface of nanoparticles: Impact of poly(2-ethyl-2-oxazoline) on protein adsorption in serum and cellular uptake
2016
Item does not contain fulltext Due to the adsorption of biomolecules, the control of the biodistribution of nanoparticles is still one of the major challenges of nanomedicine. Poly(2-ethyl-2-oxazoline) (PEtOx) for surface modification of nanoparticles is applied and both protein adsorption and cellular uptake of PEtOxylated nanoparticles versus nanoparticles coated with poly(ethylene glycol) (PEG) and non-coated positively and negatively charged nanoparticles are compared. Therefore, fluorescent poly(organosiloxane) nanoparticles of 15 nm radius are synthesized, which are used as a scaffold for surface modification in a grafting onto approach. With multi-angle dynamic light scattering, asym…
Use of Modified 3D Scaffolds to Improve Cell Adhesion and Drive Desired Cell Responses.
2012
In the most common approach of tissue engineering, a polymeric scaffold with a well-defined architecture has emerged as a promising platform for cells adhesion and guide their proliferation and differentiation into the desired tissue or organ. An ideal model for the regeneration should mimic clinical conditions of tissue injury, create a permissive microenvironment for diffusion of nutrients, gases and growth factors and permit angiogenesis. In this work, we used a 3D support made of synthetic resorbable polylactic acid (PLLA), which has considerable potential because of its well-known biocompatibility and biodegradability. One of the factors that influence cell adhesion to the scaffold is …
The Expanding Constellation of Histone Post-Translational Modifications in the Epigenetic Landscape
2021
The emergence of a nucleosome-based chromatin structure accompanied the evolutionary transition from prokaryotes to eukaryotes. In this scenario, histones became the heart of the complex and precisely timed coordination between chromatin architecture and functions during adaptive responses to environmental influence by means of epigenetic mechanisms. Notably, such an epigenetic machinery involves an overwhelming number of post-translational modifications at multiple residues of core and linker histones. This review aims to comprehensively describe old and recent evidence in this exciting field of research. In particular, histone post-translational modification establishing/removal mechanism…