Search results for "Stability."
showing 10 items of 3015 documents
Rational backbone redesign of a fructosyl peptide oxidase to widen its active site access tunnel
2020
Fructosyl peptide oxidases (FPOXs) are enzymes currently used in enzymatic assays to measure the concentration of glycated hemoglobin and albumin in blood samples, which serve as biomarkers of diabetes. However, since FPOX are unable to work directly on glycated proteins, current enzymatic assays are based on a preliminary proteolytic digestion of the target proteins. Herein, to improve the speed and costs of the enzymatic assays for diabetes testing, we applied a rational design approach to engineer a novel enzyme with a wider access tunnel to the catalytic site, using a combination of Rosetta design and molecular dynamics simulations. Our final design, L3_35A, shows a significantly wider …
Harmonic Balance Method and Stability of Discontinuous Systems
2019
The development of the theory of discontinuous dynamical systems and differential inclusions was not only due to research in the field of abstract mathematics but also a result of studies of particular problems in mechanics. One of first methods, used for the analysis of dynamics in discontinuous mechanical systems, was the harmonic balance method developed in the thirties of the 20th century. In our work the results of analysis obtained by the method of harmonic balance, which is an approximate method, are compared with the results obtained by rigorous mathematical methods and numerical simulation. peerReviewed
Photocrosslinking of dextran and polyaspartamide derivatives: a combination suitable for colon-specific drug delivery.
2007
Abstract The aim of this study was to prepare and characterize novel hydrogels with polysaccharide–polyaminoacid structure, able to undergo an enzymatic hydrolysis in the colon and potentially useful for treating inflammatory bowel diseases (IBD). Starting materials were methacrylated dextran (DEX-MA) and methacrylated α,β-poly(N-2-hydroxyethyl)- dl -aspartamide (PHM). These polymers were photocrosslinked by exposure of their aqueous solutions at 313 nm without photoinitiators. Different samples, shaped as microparticles, were obtained as a function of polymer concentration and irradiation time. FT-IR analysis confirmed the occurrence of a co-crosslinking between DEX-MA and PHM in all exper…
The influence of yeast glycosylated proteins on tannins aggregation in model solution
2004
<p style="text-align: justify;">The incidence of glycosylated yeast proteins on tannins aggregation in model solution was investigated using the spectrophotometric method (absorbance 700 nm). Glycosylated proteins released by two commercial <em>Saccharomyces cerevisiae</em> strains (RC212 and BM 45) during alcoholic fermentation in synthetic media, glycosylated proteins extracted by Peat’s method and industrial glycosylated proteins purified and separated by chromatography on Sepharose Concanavalin A were used to visualize effects on tannins aggregation. Results showed that tannins aggregation was limited by the glycosylated proteins according to their origin and their mod…
Influence of antioxidants intercalated layered double hydroxides (AO-LDHs) on the thermo-oxidative stability of pla and pe based nanocomposites
2016
Layered double hydroxides (LDHs) are excellent host matrices for storage and delivery of antioxidants (AOs).
Towards low-energy-light-driven bistable photoswitches : ortho-fluoroaminoazobenzenes
2021
AbstractThermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure–property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the exp…
Boosting Long-Term Stability of Pure Formamidinium Perovskite Solar Cells by Ambient Air Additive Assisted Fabrication
2021
Due to the high industrial interest for perovskite-based photovoltaic devices, there is an urgent need to fabricate them under ambient atmosphere, not limited to low relative humidity (RH) conditions. The formamidinium lead iodide (FAPI) perovskite α-black phase is not stable at room temperature and is challenging to stabilize in an ambient environment. In this work, we show that pure FAPI perovskite solar cells (PSCs) have a dramatic increase of device long-term stability when prepared under ambient air compared to FAPI PSCs made under nitrogen, both fabricated with N-methylpyrrolidone (NMP). The T80 parameter, the time in which the efficiency drops to 80% of the initial value, increases f…
An Atom-Economical Approach to Functionalized Single-Walled Carbon Nanotubes: Reaction with Disulfides
2013
Owing to their unique structure, thermal stability, and mechanical and electronic properties, single-walled carbon nanotubes (SWCNTs) have been a subject of continuous and intense interest. However, various applications in many fields, such as molecular electronics, solar cells, and nanomedicine, often require the development of reproducible protocols for the chemical modification of SWCNTs. In fact, one of the main drawbacks of the use of SWCNTs is their tendency to aggregate and intrinsic poor solubility, which prevent their manipulation and limit their potential. To date, several methods have been described for the chemical functionalization of SWCNTs; however, new versatile and reliable…
Bifurcation method of stability analysis and some applications
2014
In this paper a new approach to the analysis of implicitly given function- als is developed in the frame of elastic stability theory. The approach gives an effective procedure to analyse stability behaviour, and to determine the bifur- cation points. Examples of application of the proposed approach for analysis of stability are presented, more precisely we consider the stability problem of an axially moving elastic panel, with no external applied tension, performing transverse vibrations. The analysis is applicable for many practical cases, for example, paper making and band saw blades.
A thermoelastic instability problem for axially moving plates
2016
Problems of stability and deformation of a moving web, traveling between a system of rollers at a constant velocity are considered. The plate is subjected to a combined thermomechanical loading, including pure mechanical in-plane tension and also centripetal forces. Thermal strains corresponding to thermal tension and bending of the plate are accounted for. The problem of out-of-plane thermomechanical divergence (buckling) is reduced to an eigenvalue problem, which is studied analytically.