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Probes chemical stability

The spectral characteristics of protein conjugates made with Lissamine rhodamine B derivatives are of longer wavelength than those of tetramethylrhodamine—more toward the red region of the spectrum. In addition, modified proteins have better chemical stability and are somewhat easier to purify than those made from TRITC (discussed previously). Lissamine derivatives also make more photostable probes than the fluorescein derivatives (Section 1, this chapter). [Pg.422]

The relatively nonpolar squaraine rotaxane 14c was found to interact with cells in a very similar way to the well-known lipophilic dye Nile Red this probe rapidly accumulates at lipophilic sites inside a living cell, such as the endoplasmic reticulum and intracellular lipid droplets [55], The red emission band for probe 14c is quite narrow and permits the acquisition of multicolor images. It displayed high chemical stability and low toxicity. [Pg.171]

If, however, solid electrolytes remain stable when in direct contact with the reacting solid to be probed, direct in-situ determinations of /r,( ,0 are possible by spatially resolved emf measurements with miniaturized galvanic cells. Obviously, the response time of the sensor must be shorter than the characteristic time of the process to be investigated. Since the probing is confined to the contact area between sensor and sample surface, we cannot determine the component activities in the interior of a sample. This is in contrast to liquid systems where capillaries filled with a liquid electrolyte can be inserted. In order to equilibrate, the contacting sensor always perturbs the system to be measured. The perturbation capacity of a sensor and its individual response time are related to each other. However, the main limitation for the application of high-temperature solid emf sensors is their lack of chemical stability. [Pg.399]

Scanning probe lithography on metal or silicon substrates is a well known technique and can be supported by a self-assembled monolayer (SAM) [1,2], Such monolayers are of great interest e.g. for passivation of silicon surfaces [3]. Covalently bound monolayers by Si-C bonds that are formed by the reaction of 1-alkenes and a hydrogen terminated silicon surface [4,5], are known to show high thermal [6] as well as chemical stability [3,7]. [Pg.212]

The family of Ag + and Cu + superionic conductors have been extensively studied for many decades, using a wide range of experimental and computational techniques see also Chapter 7. They are principally of interest for fundamental reasons, as model systems in which to characterize the nature ofthe dynamic disorder and to probe the factors which promote high values of ionic conductivity within the solid state. Their commercial applications are generally limited by factors such as chemical stability, the high cost of silver, and their relatively high mass when compared, for example, to lithium-based compounds. [Pg.19]

A hollow-optical fiber is a prospective fiber-optic probe for infrared spectroscopy in medicine, owing to its nontoxicity and high mechanical and chemical stability [5]. However, it has been difficult to use it for remote spectroscopy because of its relatively high bending losses. Accordingly, the transmission efficiency should be improved by optimizing the fabrication conditions. [Pg.179]

In our attempts to develop more active and more stable complexes we probed the role that substituents (both on the N and C atoms of the parent macrocyclic ring) would exert on both the catalytic SOD activity and the overall chemical stability of the resultant complexes. Those structural factors that would affect these two key parameters are not immediately obvious since it was not known at the outset how derivatized ligand systems would affect catalytic activity. Thus, the number of substitutents, their placement, and their stereochemistry could all be critical design elements for maximizing catalytic activity and chemical stability. [Pg.222]

The application of laser light scattering techniques to molecular characterization of dielectric films offers the ability to directly probe chemical bonding within the film and at the film-substrate interface. Real-time measurements can be carried out under ambient conditions or in hostile environments allowing transient film stability studies to be conducted. Such laser-based techniques require only an optically clear line of sight between sample and analyzer and offer several advantages over the high vacuum surface analytical techniques commonly applied to film characterization. These include nondestructive measurement capability, rapid data acquisition time, and ability to use the optical properties of the sample to enhance the sensitivity of the measurement. [Pg.147]

Although the mechanical properties of inorganic nanotubes have not been investigated in detail so far, very good tips for scanning probe microscopy have been prepared from WS2 nanotubes [24]. Their mechanical and chemical stability is attributed to their structural perfection and rigidity. Recent data indicates that BN nanotubes exhibit Young modulus in par with carbon nanotubes [25]. This is... [Pg.241]

RNA probes RNA probes bind tighter to their complementary strands than do DNA probes. Poor stability due to ubiquitous ribonucleases has hampered more widespread use of short RNA probes, as has the difficulty of efficient chemical synthesis of long RNA oligomers. Recent advances in RNA synthetic chemistry have solved the latter problem. [Pg.3466]


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See also in sourсe #XX -- [ Pg.277 ]




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