Saturation slice

Fig. 3.7.6 DDIF spectra and SPRITE MRI images of Berea obtained in different saturation states. (A) The DDIF spectra during cocurrent imbibition at different water saturation (Sw) levels. Note the similar shape of DDIF spectra at different Sw. (B) The DDIF spectra during counter-current imbibition acquired at different water saturation levels. Note the change in the DDIF spectral shape for the different saturation levels. (C, D) A pair of images show 2D longitudinal slices from 3D...

Conical-SPRITE MRI data sets obtained during co-current imbibition. The time interval between the two images was 10.5 min. The images show a piston-like water penetration. (E, F) 2D slices from a 3D Conical-SPRITE MRI data set obtained during counter-current imbibition. The overall water saturation was 26.3%. The penetrating waterfronts have not reached the sample center. Figure from Ref. [65] with permission. 

The cores are subsequently placed in the sheer, and the slicing procedure is performed by advancing the core over an oscillating knife in a controlled environment (Figure 12.1). Cold (4°C) Krebs-Henseleit buffer (pH = 7.4, saturated with 95% O2 and 5% CO2) supplemented with 25 mM glucose is commonly used in preparing the slices [35,38 0], but Williams medium E [41], Earle s balanced salt solutions [37], Sacks preservation medium [42] and V-7 preservation buffer [43,44] are also used. 

Previously, hver shces were incubated in static organ cultures [1]. Hart et cd. [49] cultured rat hver slices for 24 h spread out on wet filter paper, floating on top of the incubation medium. Several slice-containing vessels were placed in a box with saturated 95% O2 and 5% CO2 at 37°C. However, the shces employed were rather thick (approximately 0.3 mm) and only the upper cell layers (0.2 mm) in the slice contained viable ceUs. Together with the introduction of the Krumdieck sheer [5,46], a new incubation technique for shces, the dynamic organ culture system (DOC), was introduced [35]. The main characteristic of this system is the intermittent exposure of the shce to incubation medium and the gas phase. The DOC is in fact a modified version of the Trowell incubation system [1]. 

Fig. 15. 2-D slice sections through 3-D MR images of water distribution within an initially water-saturated packing of 500-pin glass spheres. Voxel resolution is 94 pm x 94 pm x 94 pm. Data are shown before drying commenced and at three time intervals during the drying process. Only the water within the inter-particle space of the bead packing was imaged (white pixels). No signal was obtained from the solid and gas phases present.

Fig. 40. 2-D slice through a 3-D RARE image of a fixed bed of ion-exchange resin. The image has an isotropic resolution of 97.7 pm x 97.7 pm x 97.7 pm. The image slice in which the local volumes are located for the volume-selective spectroscopy study is identified. The image was acquired by saturating the bed with pure methanol. r2-contrast was exploited in the data acquisition so that signal was acquired only from the methanol in the inter-particle space. Reprinted from reference (84 with permission of Springer Science and Business Media.

Results similar to those shown in the slice of Fig. 8.22 can be obtained with the so-called NOE-NOESY sequence [36]. Here a hyperfine shifted signal, e.g. I2-CH3 of the above compound, is selectively saturated, and then the NOESY pulse sequence is applied. The NOESY difference spectrum obtained by subtracting a NOESY spectrum without presaturation of the I2-CH3 signal is shown in Fig. 8.23. Here, some more cross peaks are evident with respect to the 3D NOESY-NOESY experiment because secondary NOEs develop much more when the primary NOEs from the I2-CH3 signal evolve in a steady state experiment like the NOE-NOESY rather than in a transient-type experiment like the NOESY-NOESY. In Fig. 8.23, dipolar connectivity patterns are apparent among protons... 

The most common interfering substance, especially with alcohols of low molecular weight, is water this may result in an inaccurate interpretation of the test if applied alone. Most of the water may usually be removed by shaking with a little anhydrous calcium sulphate. Dry ethers (and also the saturated aliphatic and the simple aromatic hydrocarbons) do not react with sodium. Treat 1.0 ml of the dried compound with a small thin slice of freshly cut sodium (handle with the tongs or with a penknife) in a small dry test tube. Observe whether hydrogen is evolved and the sodium reacts. 

Acetic ester (200 gms.) is placed in a round flask and sodium in thin slices (20 gms.) is quickly added. After this a reflux condenser is fitted to the flask, and if tho reaction bocoines too vigorous the latter must be immersed in cold water. When the reaction subsides the mixture is boiled on the water-bath until no sodium remains, aud after cooling, the mixture is made acid by adding 50 per cent, acetic acid (about 100 c.c.) an equal volume of saturated brine is then added to salt out any acetic estor, which collects at the top with acetoacetic ester. This layer is placed in a distilling flask and distilled over wire... 

The P450 enzymes are found primarily in the outer membrane of the endoplasmic reticulum. Enzyme activity requires that the enzyme be integrated into a membrane that contains P450 reductase and, for some reactions, cytochrome b5. Characterization of the saturation kinetics for the P450 enzymes can be determined using a variety of enzyme preparations, including tissue slices, whole cells, microsomes, and reconstituted, purified enzymes. The more intact the in vitro preparation, the more it is likely that the environment of the enzyme will represent the in vivo environment. However, intact cell preparations do not... 

Method 1 takes advantage of the properties of a low melting temperature agarose (Bethesda Research Laboratories, Rockville, Md., USA). The gel slice is melted at 70°C and an equal volume of 10 mM Tris-HCl, (pH 7.6), 0.1 mM-EDTA added and the solution extracted with the same volume of water-saturated phenol in one or more 1.5 ml Eppendorf centrifuge tubes. After brief centrifugation the aqueous layer is removed and the phenol extraction repeated a further 2-3 times. Finally the aqueous phase is extrac-... 

Dissolve 15 mg of 4-methylumbelliferyl acetate in 100% acetone. To this solution add 30 ml of acetate buffer. Saturate several Kimwipes with the stain solution and place in direct contact with the sliced gel surface. Examine the gel with a UV light source (366 nm) soon after staining as the bands fade quickly... 

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