Rotational depolarization of fluorescence in low-viscosity solutions

1993 ◽  
Vol 97 (15) ◽  
pp. 3668-3670 ◽  
Author(s):  
R. Alicki ◽  
M. Alicka ◽  
A. Kubicki
2011 ◽  
Vol 129 (4) ◽  
pp. 1462-1468 ◽  
Author(s):  
Caroline Siefarth ◽  
Oxana Tyapkova ◽  
Jonathan Beauchamp ◽  
Ute Schweiggert ◽  
Andrea Buettner ◽  
...  

2010 ◽  
Vol 28 (3) ◽  
pp. 647-661 ◽  
Author(s):  
Michael Vosseler ◽  
Michael Jugl ◽  
Roland Zengerle

1986 ◽  
Vol 57 (9) ◽  
pp. 2310-2314 ◽  
Author(s):  
D. B. Cunningham ◽  
P. H. Doe ◽  
S. D. Joshi ◽  
A. Moradi‐Araghi

2012 ◽  
Vol 30 (No. 5) ◽  
pp. 442-445 ◽  
Author(s):  
Z. Panovská ◽  
A. Váchová ◽  
J. Pokorný

The effect of thickening agents &ndash; methyl cellulose, hydroxyethyl cellulose, sodium carboxymethyl cellulose, and xanthan gum &ndash; solutions on the sensory viscosity was investigated in the concentration range of 0&ndash;0.8%. The perceived viscosity was proportional to the logarithm of kinematic viscosity in the presence of citric and malic acids. The viscosity was inversely proportional to the acidity at the viscosity levels higher than 10 mm<sup>2</sup>/s. A liquid of high viscosity thus possess lower acidity than aqueous or low-viscosity solutions. No significant differences were found between the effects of different thickening agents. &nbsp;


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1986 ◽  
Author(s):  
María Puertas-Bartolomé ◽  
Małgorzata K. Włodarczyk-Biegun ◽  
Aránzazu del Campo ◽  
Blanca Vázquez-Lasa ◽  
Julio San Román

Hydrogel-based bio-inks have recently attracted more attention for 3D printing applications in tissue engineering due to their remarkable intrinsic properties, such as a cell supporting environment. However, their usually weak mechanical properties lead to poor printability and low stability of the obtained structures. To obtain good shape fidelity, current approaches based on extrusion printing use high viscosity solutions, which can compromise cell viability. This paper presents a novel bio-printing methodology based on a dual-syringe system with a static mixing tool that allows in situ crosslinking of a two-component hydrogel-based ink in the presence of living cells. The reactive hydrogel system consists of carboxymethyl chitosan (CMCh) and partially oxidized hyaluronic acid (HAox) that undergo fast self-covalent crosslinking via Schiff base formation. This new approach allows us to use low viscosity solutions since in situ gelation provides the appropriate structural integrity to maintain the printed shape. The proposed bio-ink formulation was optimized to match crosslinking kinetics with the printing process and multi-layered 3D bio-printed scaffolds were successfully obtained. Printed scaffolds showed moderate swelling, good biocompatibility with embedded cells, and were mechanically stable after 14 days of the cell culture. We envision that this straightforward, powerful, and generalizable printing approach can be used for a wide range of materials, growth factors, or cell types, to be employed for soft tissue regeneration.


1999 ◽  
Vol 103 (38) ◽  
pp. 7575-7579 ◽  
Author(s):  
Gen Furui ◽  
Kazuki Ito ◽  
Isao Tsuyumoto ◽  
Akira Harata ◽  
Tsuguo Sawada

Author(s):  
Edward D. De-Lamater ◽  
Eric Johnson ◽  
Thad Schoen ◽  
Cecil Whitaker

Monomeric styrenes are demonstrated as excellent embedding media for electron microscopy. Monomeric styrene has extremely low viscosity and low surface tension (less than 1) affording extremely rapid penetration into the specimen. Spurr's Medium based on ERL-4206 (J.Ultra. Research 26, 31-43, 1969) is viscous, requiring gradual infiltration with increasing concentrations. Styrenes are soluble in alcohol and acetone thus fitting well into the usual dehydration procedures. Infiltration with styrene may be done directly following complete dehydration without dilution.Monomeric styrenes are usually inhibited from polymerization by a catechol, in this case, tertiary butyl catechol. Styrene polymerization is activated by Methyl Ethyl Ketone peroxide, a liquid, and probably acts by overcoming the inhibition of the catechol, acting as a source of free radical initiation.Polymerization is carried out either by a temperature of 60°C. or under ultraviolet light with wave lengths of 3400-4000 Engstroms; polymerization stops on removal from the ultraviolet light or heat and is therefore controlled by the length of exposure.


Author(s):  
Fred E. Hossler

Preparation of replicas of the complex arrangement of blood vessels in various organs and tissues has been accomplished by infusing low viscosity resins into the vasculature. Subsequent removal of the surrounding tissue by maceration leaves a model of the intricate three-dimensional anatomy of the blood vessels of the tissue not obtainable by any other procedure. When applied with care, the vascular corrosion casting technique can reveal fine details of the microvasculature including endothelial nuclear orientation and distribution (Fig. 1), locations of arteriolar sphincters (Fig. 2), venous valve anatomy (Fig. 3), and vessel size, density, and branching patterns. Because casts faithfully replicate tissue vasculature, they can be used for quantitative measurements of that vasculature. The purpose of this report is to summarize and highlight some quantitative applications of vascular corrosion casting. In each example, casts were prepared by infusing Mercox, a methyl-methacrylate resin, and macerating the tissue with 20% KOH. Casts were either mounted for conventional scanning electron microscopy, or sliced for viewing with a confocal laser microscope.


Author(s):  
S. Lehner ◽  
H.E. Bauer ◽  
R. Wurster ◽  
H. Seiler

In order to compare different microanalytical techniques commercially available cation exchange membrane SC-1 (Stantech Inc, Palo Alto), was loaded with biologically relevant elements as Na, Mg, K, and Ca, respectively, each to its highest possible concentration, given by the number concentration of exchangeable binding sites (4 % wt. for Ca). Washing in distilled water, dehydration through a graded series of ethanol, infiltration and embedding in Spurr’s low viscosity epoxy resin was followed by thin sectioning. The thin sections (thickness of about 50 nm) were prepared on carbon foils and mounted on electron microscopical finder grids.The samples were analyzed with electron microprobe JXA 50A with transmitted electron device, EDX system TN 5400, and on line operating image processing system SEM-IPS, energy filtering electron microscope CEM 902 with EELS/ESI and Auger spectrometer 545 Perkin Elmer.With EDX, a beam current of some 10-10 A and a beam diameter of about 10 nm, a minimum-detectable mass of 10-20 g Ca seems within reach.


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