Extraction replication, crystals

Extraction Replication (Crystals In Fired Moly). The multilayer ceramic package that Is used by IBM has a sintering operation In which the alumlna/glass body undergoes slnterlng-wlth-a-llquld phase simultaneously with the firing of the molybdenum lands. 

X-ray or electron diffraction allows Identification of crystalline species by the long-used Hannawalt-Dow-ASTM-JCPDS system(4). Small particles can be removed for analysis in a small rotating specimen X-ray powder camera, or by extraction replication and selected area diffraction in a Transmission Electron Microscope (5). For those specimens where a residue of reactant or corrosion product is too adherent, the material may be removed for analysis by micro-bulldozing (with a microhardness Indentor), micro-jack hammering (with a needle attached to a small piezoelectric crystal on a pencil-like rod), and micro-boring (with a precision controlled dental drill)(5). 

Is Your Solder Pad Joining "Hairy" As part of a solder/flux/ cleaning procedure, the residue In Figure 10 (Insert) was produced. The residue consists of 6xl0pm leaf-like crystals on a ceramic substrate. The location of the residue prevented Its analysis In-sltu, so extraction replication(5) was used to remove some of the crystals for analysis by several small area techniques, as needed. Electron probe microanalysis showed lead, carbon and oxygen, which could Indicate many possibilities. 

Replication and shadowing techniques have been used directly in conjunction with other procedures (extraction replication [127]) or specially prepared samples (epitaxially grown crystals [128]), where specific topics are being addressed [129, 130]. Of particular note in this regard is the work of Wittmann and Lotz, who developed a decoration technique for the study of fold surface conformations in lamellar crystals [131]. 

Bassett and Keller [449] studied the in situ shape of PE crystals by extraction replication. A PE solution was evaporated directly onto... 

Eckard and Taylor reported the modifier and additive effects on the SFE of pseudoephedrine hydrochloride from Suphedrine tablets, achieving a recovery of 82% (142). Also, racemic ephedrine was resolved using supercritical CO2 (143). The temperatures for crystallization were 35-75°C and the pressures were 100-350 bar. The samples were analyzed using electrophoresis. The experimental error for the resolution was 0.3 mol%. Regarding the extraction of isomers, 13-cf5-retinoic acid and its photoisomers were extracted from pharmaceutical formulations, with CO2 modified with 5% methanol at 45°C and 329 bar (144) static and dynamic extraction times of 2.5 and 5 min, respectively, were used. The extracts were analyzed by FIPLC. The recovery of 13-cA-retinoic acid from spiked placebo forms was 98.9%, 98.9%, 98.8%, and 100% for cream, gel, capsule, and beadlet, respectively, with RSDs (four replicates) ranging from 0.6% to 0.9% its photoisomers were also extracted, with recoveries of 90.4-92.4% with RSDs (four replicates) of 1.5-3.4%. 

Cell viability is determined with the MTT (3-(4,5)-dimethylthiahiazo (-z-yl)-3, 5-di-phenytetrazoliumromide) method (Liu et al. 2008a). Consecutive threefold serial dilutions (100 pi) of compounds/extracts and reference compounds are added to cell monolayers in replicates. Blank medium is used as a control. After 3 days of incubation at 37°C, 12 pi of MTT solution (5 mg/ml in phosphate-buffered saline) is added to each well. The plate is further incubated at 37°C for 3 h to allow the formation of the formazan product. After removal of the medium, 100 pi of dimethyl sulfoxide (DMSO) is added to dissolve the formazan crystals. After 15 min, the contents of the wells are homogenized on a microplate shaker. The optical densities are then measured with a microplate spectrophotometer at a wavelength of 540 nm. The median cytotoxic concentration (CCj ) is calculated as the concentration of the tested sample that reduced the number of viable cells to 50% of the untreated control. The maximal non-cytotoxic concentration (MNCC) is defined as the maximal concentration of the sample that does not exert a cytotoxic effect and resulted in more than 90% viable cells. 

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