Translucency scanning

Fig. 28. Influence of slit/spot relation on translucency scanning. After elution the OD s follow Beer s law (Curve E). If the spot A fills the slit S completely and evenly, curve A is obtained, but with a too small spot B, a far greater error is made. The error of A and of B shows a logarithmic increase with concentration (P0).

Method. The organothiophosphorus insecticides are separated on silica gel with hexane-acetone (2 1 or 3 1). The plate is dried in air and sprayed with a solution of calcein-palladium chloride (0.0005 M palladium chloride in 0.1 M hydrochloric acid mixed with an equal volume of 10-3 Af calcein, adjusted to pH 7.2 with phosphate buffer and diluted with water to obtain a 2.0 10 4Af solution of palladium equilibrated overnight) which is diluted 1 1 with a 50% solution of acetone—water. When the plate is translucent it is dried in air and stored for 18—24 h in a closed chromatographic tank containing a beaker of a saturated solution of calcium nitrate tetrahydrate. This procedure permits the full fluorescence to develop under controlled humidity. The plate is then observed under a UV light at 365 nm, or scanned quantitatively at 365 nm (excitation) and 518 nm (emission). 

After staining, the amounts of dye taken up by the various fractions may be determined either by scanning the strip directly or by photometry of the eluted fractions. In the first method the paper acts as a source of error which is difficult to eliminate effectively, whether the paper is rendered translucent and the transmitted light is measured or whether it is untreated and the quantity of reflected light is measured. In the second method the cutting up of the paper to separate the fractions must be followed by perfect elution without influence on the color of the dye, but subsequent photometry is easy. 

An 8-year-old girl with leukemia had tonic-clonic convulsions and life-threatening encephalopathy after intravenous vincristine. After the second dose (1.5 mg/m in combination with prednisone) she developed seizures and bilateral translucencies in the CT scan. When vincristine was withdrawn in subsequent cycles, the symptoms disappeared (61). 

Because of unfavorable sorption effects on paper that cause tailing, materials with lower adsorptivity were sought. Thus, cellulose acetate [35] and nitrocellulose [36,37] membranes were introduced. Cellulose acetate can be either prepared in the laboratory by treating cellulose with acetic anhydride, or it may be purchased from commercial sources. Cellulose acetate membranes are readily soluble in phenol, glacial acetic acid, dichloromethane and acetone. In part they can be solubilized in several solvent mixtures e.g., chloroform/ethanol (9 1 v/v). For detection (optical scanning) the foil can be made translucent by immersion in cottonseed oil, decalin, liquid paraffin or Whitemore oil 120. 

Karlsson, L. M., and Liljeborg, A. (1994). Second-order stereology for pores in translucent alumina studied by confocal scanning laser microscopy. J. Microsc. (Oxford) 175, 186-194. 

One can predict whether an initially transparent PU elastomer will become only translucent in time. If the differential scanning calorimetry spectrum of the material does not show any endothermic peaks developing as the material ages, then its transparency will be permanent. 

Figure 6.2 (A) Cetyltrimethyl ammonium bromide (CTAB) mediated synthesis of Ag nanoparticles on cellulose nanocrystals (B) Free standing clay nanopaper showing a large-area and translucent sample and inset (Scanning electron image of cryo-fractmed surface for hybrid MFC/montmorrillonite nanopaper) (C) FE-SEM micrograph of the cross-section of GNP-incorporated BC membrane and (D) FE-SEM image of freeze-dried pellicle of BC/D-ChNC nanocomposite synthesized in situ. Reprinted with permission from [60] and [117],...

A tentative diagnosis of a right renal uric acid calculus was made. The patient was placed on intravenous fluids and parenteral analgesics. A CAT scan was performed, which showed a translucent calculus present in the lower right ureter close to its insertion into the urinary bladder. A serum uric acid was completed and was reported as above normal. His urine was continually monitored to note total output as well as to attempt to obtain the stone should it be passed. 

Composites of MEEP/Al were more difficult to prepare than other composites because of the extreme moisture sensitivity of the aluminum alkoxides. Nonetheless, translucent, tough films were prepared from equal weights of aluminum tri-sec-butox-ide and polymer. As with the composites discussed above, differential scanning calorimetry (DSC) revealed the glass transition at -79°C, indicating the backbone motion of a large portion of polymer segments was not perturbed by the metal oxide. 

---