PubMed · 11161207
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T L Chester, J F Parcher. 2001-01-19. Tech.Sight. Blurring the boundaries.. https://doi.org/10.1126/science.1057979
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The effect of spray drying polyethylene glycol (PEG) 4000 and lactose/PEG solutions was investigated. Micro-spherical PEG particles were successfully prepared from ethanol, which allowed lower outlet temperatures than water. The product was crystalline and consisted of rough spheres or rod like particles. In the case of lactose/PEG composites, spray dried from water, the crystallinity of both components was reduced on spray drying, the extent being dependent on the starting composition. Spray dried lactose/PEG with PEG present as 10% by weight was found to be the most amorphous of the systems prepared. Conversion to more crystalline products occurred over time, the rates of conversion being dependent on temperature and humidity. On storage at low humidity (31-34%) amorphous lactose in lactose/PEG spray dried systems converts to anhydrous crystalline lactose while at high humidity (75% RH) the monohydrate is formed. The rate of transformation of amorphous lactose to the crystalline monohydrate form, at high relative humidity, was quantified using the Avrami equation applied both to X-ray diffraction (XRD) peak intensity and heat of fusion data. Crystallisation of lactose appeared to be retarded at low PEG concentrations, where PEG was present predominantly in a non-crystalline state, but was accelerated at higher PEG contents.
A series of novel 5-[1-aryl-1,4-dihydro-6-methylpyridazin-4-one-3-yl]-2-arylamino-1,3,4-thiadiazoles, related to the fungicidal activity, were synthesized and tested in vivo against wheat leaf rust, Puccinia recondita. The preliminary bioassay indicated that they exhibited fungicidal activity and the activity was influenced by the nature of the substituents. A quantitative structure-activity relationship study showed that the hydrophobicity (Sigma(pi)) is a major positive parameter in affecting the activity; the electronic parameters (Sigmasigma, SigmaF) are the major negative parameters in affecting the activity. Especially, introducing an ortho substituent with an inductively electron-donating property is favorable to the activity.
The research work reported on the preparation, characterisation and applications of more than 50 salts of NTO has been reviewed thoroughly. A broad classification and sub classification of all these compounds has been given on the basis of nature of the compounds with which NTO forms salts. Attempt has been made to discuss the structure of these salts by summarising analytical data reported from 13C NMR. The structure as determined by IR spectroscopy as well as XRD has also been discussed briefly. A generalised mechanism for the thermolysis of the metal salts has also been given and any deviation from this has been narrated in particular cases. The kinetic details, thermodynamical and thermochemical data as well as performance parameters have also been reviewed. Thus, the futuristic potentials of these salts are analysed critically and further studies have been suggested.