Freeze-thawing method

The first studies leading to the deracemization of VANOL 93 and VAPOL 94 were carried out with 1.4 equiv. of copper chloride and 2.8 equiv. of (-)-sparteine 1 in a mixture of methanol and methylene chloride (1 3.4) de-oxygenated by an argon purge, which gave a 64% yield of (S)-VAPOL with 99% ee, and a 77% yield of (S)-VANOL with 99% ee. However, in the last case, the co-solvent was deoxygenated via a freeze-thaw method. 

FTVs Freeze-thaw vesicles LUVs prepared by freeze-thaw method, high encapsulation efficiency ... 

Hassan, C. M. and Peppas, N. A. Structure and Applications of Polyfvinyl alcohol) Hydrogels Produced by Conventional Crosslinking or by Freezing/Thawing Methods. Vol. 153, pp. 37-65. 

A typical outcome of the Helfrich analysis for charged bilayer systems is presented in Figure 24b-d in combination with experimental results for the dependence of the equilibrium radius of vesicles composed of DOPG and DOPC as a function of the ionic strength in Figure 24a. The vesicle solution was equilibrated using the freeze-thaw method [20], and the size was measured... 

Therefore now the most perspective for cryopreservation of cord blood NCs is the designing of freeze-thawing methods with no washing-out using cryoprotectants, non-penetrating into a cell. 

Dichlorotris(triphenylphosphine)osmium(II) (2.0 g) and triphenylphosph-ine (1.0 g) are combined under inert atmosphere or in a dry box in a 100-mL flask equipped with a nitrogen gas inlet and a magnetic stirring bar. To the solids are added 50 mL of toluene [previously degassed by the freeze-thaw method and repressurized by nitrogen (< 6 ppm oxygen)] and 5 mL of carbon disulfide. 

Irradiation. Irradiation was conducted in a Co source at a dose rate of about 4 X 10 rep per hour. Preirradiated starch was prepared by irradiation of starch under vacuum in a tube fitted with a break-off tip. The monomer was added to the tube after irradiation and freed from air, using the freeze-thaw technique. Then the tube was sealed and the tip broken, thus allowing the monomer to saturate the starch. For starch irradiated in the presence of monomer, the materials were thoroughly mixed, charged to a tube, evacuated using the freeze-thaw method, and immediately irradiated. 

The current encapsulation rate is still relatively low which may result in high free ATP content in the solution, causing unnecessary side effects. Further increase of encapsulation rate is possible by using a freezing-thawing method (35). 

Figures 3a and 3b show GC-PTR-MS analysis of VOCs released from plants treated by a freeze-thaw method in a leaf cuvette. Mass scans revealed the presence of most major leaf-wound VOCs (discussed in Section IV A), but, for simplicity, only the VOCs detected at M69 and M83" are shown. The main VOC at M69" in all the tested plants (Figure 3a) was...

The catalytic performance of the NCNT was tested via the Knoevenagel condensation of benzaldehyde (BA) with ethylcyanoacetate (ECA) to form ethyl-a-cyanocinnamate (ECC). The NCNT (1 g) were crushed, heated to 423 K under vacuum and maintained under these conditions for 1 h. The reactants, BA (0.01 mol) and ECA (0.01 mol), were dissolved in ethanol (50 mL) and carbondioxide was removed using the freeze-thaw method. The solution was then added to the NCNT and the reaction was performed under reflux conditions. To monitor the progress of the reaction, samples of the reaction mixture were taken regularly for GC analysis. 

Most slush hydrogen has been produced so far by means of the freeze>thaw method [22]. In this technique the gaseous phase above the liquid hydrogen is pumped to pull a vacuum until the liquid is cooled down below the freezing point (13.8 K) and a film of solid hydrogen forms on the surface. The system pressure is then stopped and the solid... 

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