And structural instability

Alewijnse, A. E., Smit, M. J., Hoffmann, M., Verzijl, D., Timmerman, H. and Leurs, R. Constitutive activity and structural instability of the wild-type human H2 receptor. /. Neurochem. 71 799-807,1998. 

Alewijnse AE, Timmerman H, Jacobs EH, et al. The effect of mutations in the DRY motif on the constitutive activity and structural instability of the histamine H2 receptor. Mol Pharmacol 2000 57 890-898. 

Depending on the nature of the sample, different techniques of observations and sample preparations are used in electron microscopy. For particles produced in solution " or from inert gas aggregation,clusters are generally collected on a microscope grid covered with an amorphous carbon film or with micro-crystals. Particles can, however, diffuse on the substrate and structural instabilities sometimes occur during the measurements. For particles supported on a soluble substrate (NaCl, KCl, MgO, etc.), a carbon layer is evaporated onto the particles and the carbon layer containing the particles is then stripped from the substrate by interfacial dissolution. The particles are observed directly in top view. The... 

The determination of the crystal structure, and structural instabilities, by X-ray diffraction and X-ray diffuse scattering, respectively, are underway, in order to clarify the nature of the metal-insulator transition, and to allow comparisons with the mnt analog. 

Y. Saiga, K. Suekuni, B. Dua, T. Takabatake, Thermoelectric properties and structural instability of type-I clathrate BagGai Snso at high temperatures. Solid State Common. 152, 1902-1905 (2012)... 

FIGURE 2.1 Mechanisms for plasmid loss (instability). Structural instability can lead to plasmid defects segregational instability is caused by uneven distribution of plasmids to daughter cells downward selective pressure is the combination of segregational and structural instability and the observation that plasmid-free cells grow (and divide) more quickly (denoted by large cells). 

Hazards from existing structures which might arise from demolition and refurbishment - presence of asbestos, fragile materials, fire damage, post-tensioned concrete structures and structural instability... 

The frequencies of a spectrum can be divided into two parts subharmonic and harmonic (i.e., frequencies below and above the running speed). The subharmonic part of the spectrum may contain oil whirl in the journal bearings. Oil whirl is identifiable at about one-half the running speed (as are several components) due to structural resonances of the machine with the rest of the system in which it is operating and hydrodynamic instabilities in its journal bearings. Almost all subharmonic components are independent of the running speed. 

Figure 14.6 Structure and key dimensions of (a) the complex [(Fh3P)2EihCI( -02)]2 and (b) the complex [Pt(02)(PPh3)2]. The data in (b) arc of poor quality because of the difficulty of growing suitable crystals and their instability in the X-ray beam (distances 5 pm angles 2 ).

Finally, the use of the constant pressure minimization algorithm allows searching for phenomena that can be considered as precursors of pressure-induced transitions. For example, the predicted behaviour of the anatase cell constants as a function of pressure shows that the a(P) and c(P) plots are only linear for P<4 GPa, the value that is close to both the theoretical and experimental transition pressures. At higher pressures the a constant starts to grow under compression, indicating inherent structural instability. In the case of ratile there is a different precursor effect, nami y at 11 GPa the distances between the titanium atom and the two different oxygens, axial and equatorial, become equal. Once again, the pressure corresponds closely to the phase transition point. 

The utility of thallium(III) salts as oxidants for nonaromatic unsaturated systems is a consequence of the thermal and solvolytic instability of mono-alkylthallium(III) compounds, which in turn is apparently dependent on two major factors, namely, the nature of the associated anion and the structure of the alkyl group. Compounds in which the anion is a good bidentate ligand are moderately stable, for example, alkylthallium dicar-boxylates 74, 75) or bis dithiocarbamates (76). Alkylthallium dihalides, on the other hand, are extremely unstable and generally decompose instantly. Methylthallium diacetate, for example, can readily be prepared by the exchange reaction shown in Eq. (11) it is reasonably stable in the solid state, but decomposes slowly in solution and rapidly on being heated [Eq. (23)]. Treatment with chloride ion results in the immediate formation of methyl chloride and thallium(I) chloride [Eq. (24)] (55). These facts can be accommodated on the basis that the dicarboxylates are dimeric while the... 

The state of research on the two classes of acetylenic compounds described in this article, the cyclo[ ]carbons and tetraethynylethene derivatives, differs drastically. The synthesis of bulk quantities of a cyclocarbon remains a fascinating challenge in view of the expected instability of these compounds. These compounds would represent a fourth allotropic form of carbon, in addition to diamond, graphite, and the fullerenes. The full spectral characterization of macroscopic quantities of cyclo-C should provide a unique experimental calibration for the power of theoretical predictions dealing with the electronic and structural properties of conjugated n-chromophores of substantial size and number of heavy atoms. We believe that access to bulk cyclocarbon quantities will eventually be accomplished by controlled thermal or photochemical cycloreversion reactions of structurally defined, stable precursor molecules similar to those described in this review. 

Progress in molecular biology has provided a new perspective. Techniques such as the polymerase chain reaction and single-strand conformation polymorphism analysis have greatly facilitated the molecular analysis of erythroenzymopathies. These studies have clarified the correlation between the functional and structural abnormalities of the variant enzymes. In general, the mutations that induce an alteration of substrate binding site and/or enzyme instability might result in markedly altered enzyme properties and severe clinical symptoms. 

Belt-conveyor scales, 26 244—245 Belt filter press, 25 913 Belt saponification, in vinyl alcohol polymerization, 25 609-610 Benard instability, 11 764 Benazepril hydrochloride, molecular formula and structure, 5 149t Benchmark dose and margin-of-exposure method, 25 244... 

The mechanism is essentially a combination of the deformation of a round liquid jet by aerodynamic forces and the instability of the deformed jet. The liquid jet is first accelerated rapidly in the high speed air stream (Fig. 3.3b). The jet diameter is thus significantly reduced as it interacts with the surrounding air stream. The direction of the thinning capillary liquid jet is influenced by the interaction between the liquid jet and the turbulent structures of the surrounding air stream. The formation of... 

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