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71.
72.
Abstract Three novel bisphenols containing pendant ethynyl, hexynyl, and phenylethynyl groups were synthesized and used to prepare arylene ether polymers and copolymers. When heated to 250–350°C, the ethynyl groups react. After curing, the homopolymers were brittle due to the high crosslink density. Copolymers prepared using either 10 or 30 mol% of the ethynyl-containing bisphenol and either 90 or 70 mol% of the bisphenol with no ethynyl groups were relatively tough and formed creasible films. After a thermal cure, the copolymers became insoluble and exhibited high T gs and good thin film tensile properties. 相似文献
73.
Ditte C. Andersen Ida Skovrind Marlene Louise Christensen Charlotte H. Jensen Søren P. Sheikh 《Analytical and bioanalytical chemistry》2013,405(29):9585-9591
Stem cell therapy has opened up the possibility of treating numerous degenerating diseases. However, we are still merely at the stage of identifying appropriate sources of stem cells and exploring their full differentiation potential. Thus, tracking the stem cells upon in vivo engraftment and during in vitro co-culture is very important and is an area of research embracing many pitfalls. 5-Ethynyl-2′-deoxyuridine (EdU), a rather new thymidine analog incorporated into DNA, has recently been suggested to be a novel highly valid alternative to other dyes for labeling of stem cells and subsequent tracing of their proliferation and differentiation ability. However, our results herein do not at any stage support this recommendation, since EdU severely reduces the viability of stem cells. Accordingly, we found that transplanted EdU-labeled stem cells hardly survive upon in vivo transplantation into regenerating muscle, whereas stem cells labeled in parallel with another dye survived very well and also participated in myofiber formation. Similar data were obtained upon in vitro myogenic culture, and further analysis showed that EdU reduced cell numbers by up to 88 % and increased the cell volume of remaining cells by as much as 91 %. Even at low EdU concentrations, cell survival and phenotype were substantially compromised, and the myogenic differentiation potential was inhibited. Since we examined both primary derived cells and cell lines from several species with the same result, this appears to be a common trait of EdU. We therefore suggest that EdU labeling should be avoided (or used with precaution) for stem cell tracing purposes. Figure
Myoblasts were marked with DiI (red) and EdU (purple), and injected into lesioned skeletal muscle. At day 9 following transplantation, only DiI positive cells were observed and had participated in myofibre formation as (indicated by arrowheads) visualized by red fluorescence signals inside laminin (green) positive multinucleated myofibres. EdU was toxic to the engrafted cells, suggesting that this reagent is non-applicaple for tracing of stem cells. 相似文献
74.
Dr. Romaric Gérardy Dr. Anirudh M. K. Nambiar Travis Hart Prajwal T. Mahesh Prof. Dr. Klavs F. Jensen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(43):e202201385
The implementation of self-optimizing flow reactors has been mostly limited to model reactions or known synthesis routes. In this work, a self-optimizing flow photochemistry platform is used to develop an original synthesis of the bioactive fragment of Salbutamol and derivatives. The key photochemical steps for the construction of the aryl vicinyl amino alcohol moiety consist of a C−C bond forming reaction followed by an unprecedented, high yielding (>80 %), benzylic oxidative cyclization. 相似文献
75.
Sheida Esmail Tehrani Long Quang Nguyen Giulia Garelli Bettina M. Jensen Tautgirdas Ruzgas Jenny Emnéus Stephan Sylvest Keller 《Electroanalysis》2021,33(12):2516-2528
A highly sensitive amperometric Prussian blue-based hydrogen peroxide sensor was developed using 3D pyrolytic carbon microelectrodes. A 3D printed multielectrode electrochemical cell enabled simultaneous highly reproducible Prussian blue modification on multiple carbon electrodes. The effect of oxygen plasma pre-treatment and deposition time on Prussian blue electrodeposition was studied. The amperometric response of 2D and 3D sensors to the addition of hydrogen peroxide in μM and sub-μM concentrations in phosphate buffer was investigated. A high sensitivity comparable to flow injection systems and a detection limit of 0.16 μM was demonstrated with 3D pyrolytic carbon microelectrodes at stirred batch condition 相似文献
76.
Kanyal Supriya S. Jensen David S. Dadson Andrew E. Vanfleet Richard R. Davis Robert C. Linford Matthew R. 《平面色谱法杂志一现代薄层色谱法》2014,27(3):151-156
JPC – Journal of Planar Chromatography – Modern TLC - We describe the direct, conformal, atomic layer deposition (ALD) of silica onto carbon nanotubes (CNTs) in the microfabrication of... 相似文献
77.
In the development of therapeutic proteins, analytical assessment of structural stability and integrity constitutes an important activity, as protein stability and integrity influence drug efficacy, and ultimately patient safety. Existing analytical methodologies solely rely on relative changes in optical properties such as fluorescence or scattering upon thermal or chemical perturbation. Here, we present an absolute analytical method for assessing protein stability, structure, and unfolding utilizing Taylor dispersion analysis (TDA) and LED-UV fluorescence detection. The developed TDA method measures the change in size (hydrodynamic radius) and intrinsic fluorescence of a protein during in-line denaturation with guanidinium hydrochloride (GuHCl). The conformational stability of the therapeutic antibody adalimumab and human serum albumin were characterized as a function of pH. The simple workflow and low sample consumption (40 ng protein per data point) of the methodology make it ideal for assessing protein characteristics related to stability in early drug development or when having a scarce amount of sample available. 相似文献
78.
Hendrik F. Hameka Silvio L. Emery George R. Famini James O. Jensen Joseph M. Leonard Dennis J. Reutter 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):373-388
Abstract We report the computed equilibrium geometries and vibrational infrared frequencies of a group of thirteen mercaptans and sulfides. The computations were based on the Gaussian 86 Program Package utilizing 3-21G basis sets. The theoretical bond distances and bond angles are in agreement with the available experimental data. The agreement between computed frequencies and available experimental values seems reasonable. We also used the computations as guidelines for the assignment of available experimental infrared frequencies. We believe that it is possible to make reliable frequency predictions by combining computations with available experimental data for groups of similar molecules. However, it is necessary to introduce different correction factors for different types of vibrational modes if we use 3-21G basis sets. 相似文献
79.
80.
The rotational spectra of three low-energy conformers of thiodiglycol (TDG) (HOCH2CH2SCH2CH2OH) have been measured in a molecular beam using a pulsed-nozzle Fourier-transform microwave spectrometer. To determine the likely conformational structures with ab initio approach, conformational structures of 2-(ethylthio)ethanol (HOEES) (CH3CH2SCH2CH2OH) were used as starting points together with the consideration of possible intramolecular hydrogen bonding in TDG. Three lower-energy conformers have been found for TDG at the MP2=Full/6311G** level and ab initio results agree nicely with experimentally determined rotational constants. In addition, Stark measurements were performed for two of the three conformers for dipole moment determinations, adding to our confidence of the conformational structure matches between experimental observations and ab initio calculations. Of the three lower-energy conformers, one displays a compact folded-like structure with strong hydrogen bonding between the two hydroxyl groups and the central sulfide atom. Two other conformers have relatively open chain-like structures with hydrogen bonding between each of the hydroxyl groups to the central sulfur atom, of which one has pure b-type dipole moment according to the ab initio results. 相似文献