Hole-filling

Murakami H, Kinoshita S, Hirata Y, Okada T and Mataga N 1992 Transient hole-burning and time-resolved fluorescence spectra of dye molecules in solution evidence for ground-state relaxation and hole-filling effect J. Chem. Phys. 97 7881-8... 

Figure 18.3 Protein crystals contain large channels and holes filled with solvent molecules, as shown in this diagram of the molecular packing in crystals of the enzyme glycolate oxidase. The subunits (colored disks) form octamers of molecular weight around 300 kDa, with a hole in the middle of each of about 15 A diameter. Between the molecules there are channels (white) of around 70 A diameter through the crystal. (Courtesy of Ylva Lindqvist, who determined the structure of this enzyme to 2.0 A resolution in the laboratory of Carl Branden, Uppsala.)...

Crystallization of proteins can be difficult to achieve and usually requires many different experiments varying a number of parameters, such as pH, temperature, protein concentration, and the nature of solvent and precipitant. Protein crystals contain large channels and holes filled with solvents, which can be used for diffusion of heavy metals into the crystals. The addition of heavy metals is necessary for the phase determination of the diffracted beams. 

Hence there are multiple solutions for the final set of 10000 compounds. The final selection can be diversity driven using for example cluster analysis based on multiple fingerprints [63], hole filling strategies by using scaffold/ring analysis (LeadScope [66], SARVision [66]) or pharmacophore analysis [67, 68]. For a review of computational approaches to diversity and similarity-based selections, see the paper of Mason and Hermsmeier [69] and the references therein. 

In Fig.la a lower slope ((j)=2.25) and higher Intercept (g=1.32) Is obtained for the low pressure region as compared to the slope (((>=2.60) and Intercept (g=1.09) for high pressure region. Since from Eq(13), a value of g close to 1 implies adherence to the solution-diffusion model. It appears that at low pressures where g = 1.32>1.0, a combined model of viscous and diffusive flow Is operative. This correlates with previous SEM studies In our laboratory (unpublished), where mlcro-pln holes were postulated to exist In the skin. The presence of such m-LcAO-p-Ln hoZ 6 In the surface can be used to explain the high g-value. Above 10 atm, the DDS-990 membrane Is compressed or compacted and the mlcro-pln holes filled. Thus g = l.O l.O implies adherence to the solution-diffusion model. 

We suggest that the rapid process corresponds to hole-filling and/or adsorption onto surfaces, and that the slow process, which follows first-order behavior, corresponds to swelling of the coal extract. Extrapolation of the linear portion of the curves shown in Figures 10 and 11 to time zero should yield the total uptake of benzene attributed to swelling. The results of this analysis are summarized in Table IV, where the total benzene uptake, M , and the uptake attributed to the hole-filling/adsorption and the swelling processes, and M., are shown. 

Finally, we note that the x and solubility parameters of the O-butylated extract are noticeably absent in Table VI. We have attempted to analyze the sorption kinetics according to the Berens-Hopfenberg model in order to correct for adsorption effects, but the treatment yielded unreasonable x parameters. The reason for this is not clear, but we believe it may be due to the fact that di sion into the extract is so rapid. Hole-filling and swelling may have comparable rates so that a separation of the two processes is not possible. 

During a drought in the summer of 1618 Henry Wicker (or Wickes) discovered on the common at Epsom, Surrey, a small hole filled with water. To his astonishment, not one of his thirsty cattle would drink there. This bitter water was found to have a healing effect on external sores and to be useful also as an internal medicament. By the middle of the seventeenth century, Epsom had become a fashionable spa, attracting famous visitors from the continent (40, 62). 

Below 146°C, two phases of Agl exist y-Agl, which has the zinc blende structure, and (3-Agl with the wurtzite structure. Both are based on a close-packed array of iodide ions with half of the tetrahedral holes filled. However, above 146°C a new phase, a-AgI, is observed where the iodide ions now have a body-centred cubic lattice. If you look back to Figure 5.7, you can see that a dramatic increase in conductivity is observed for this phase the conductivity of a-Agl is very high, 131 S m , a factor of 10 higher than that of (3- or y-AgI, comparable with the conductivity of the best conducting liquid electrolytes. How can we explain this startling phenomenon ... 

This equation, is not easily solved. Therefore, Engell used an approximation method, assuming that the concentration of electron holes in the boundary of the semiconductor and glass (the supporting medium) is proportional to the number of electron holes filled up during chemisorption. We obtain thus for... 

On 20 May 1992, a Dutch periodical published an article in which they mentioned the possibility of healing fractures with mother-of-pearl and coral. With this method painful operations could be avoided. The article was illustrated with an ancient Maya skull which showed a hole filled with mother-of-pearl. The ancient Mayas were well ahead of their time. 

If these compounds crystallized in their antistructure, which is a 2H—MoSa structure with all octahedral holes filled, semiconductivity would be feasible by assuming the cation in trigonal-prismatic coordination to be divalent and the one in octahedral coordination to be tetra-valent. 

Table Some binary structures based on close-packed arrays of anions Array Holes filled Structure type Examples Fee All octahedral Rock salt (NaCl) LiF, MgO V2 octahedral Cadmium chloride MgCl2...

Due to the transparency of the microorganisms and with absence of staining, the visualization focuses often on the membrane of the cell. A hole-filling step... 

Fig. 10. Separation of objects in contact a Original gray-level image, b Binary image, c Enhanced binary image (hole-filling), d EDM image, e Perpective view of the EDM image, f Separated microcarriers...

Fig. 11. The main steps of the treatment of the yeast image (Fig. 2 a) a Binary image just after segmentation b after hole-filling c after a 4-order erosion to remove debris d after final reconstruction...

One possible solution to this problem is to develop microscopic diffusion models for glassy polymers, similar to those already presented for rubbery polymers. Ref. (90) combines some of the results obtained with the statistical model of penetrant diffusion in rubbery polymers, presented in the first part of Section 5.1.1, with simple statistical mechanical arguments to devise a model for sorption of simple penetrants into glassy polymers. This new statistical model is claimed to be applicable at temperatures both above and below Tg. The model encompasses dual sorption modes for the glassy polymer and it has been assumed that hole"-filling is an important sorption mode above as well as below Tg. The sites of the holes are assumed to be fixed within the matrix... 

The stable form of hydroquinone is a-quinol, Qa. The unstable form which gives the clathrate is / -quinol, QP. The difference, Ap — (ilqP — /aq ), between the chemical potentials of the two forms must therefore be positive. The clathrate formed from a gas, A, will just reach stability with the a form when the pressure, P, and the fraction of the holes filled, y, are such that... 

---