Synthesis frequency effect

Malinger, K.A., Ding, Y.-S., Sithambaram, S., Espinal, L., Gomez, S., and Suib, S.L. 2006. Microwave frequency effects on synthesis of cryptomelane-type manganese oxide and catalytic activity of cryptomelane precursor. Journal of Catalysis 239, 290-298. 

One of the commonalities with the formant model is that LP synthesis maintains a source/filter separation. This means that for a sequence of frames, we can res5mthesise this with a different fundamental frequency to that of the original. The benefit is that for a given transition effect that we wish to synthesise, we need only analyse one example of this we can create the full range of fundamental frequency effects by the separate control of the source. 

Okitsu K, Ashokkumar M, Grieser L (2005) Sonochemical synthesis of gold nanoparticles effects of ultrasound frequency. J Phys Chem B 109 20673-20675... 

The first possibility is an increase in the pre-exponential factor, A, which represents the probability of molecular impacts. The collision efficiency can be effectively influenced by mutual orientation of polar molecules involved in the reaction. Because this factor depends on the frequency of vibration of the atoms at the reaction interface, it could be postulated that the microwave field might affect this. Binner et al. [21] explained the increased reaction rates observed during the microwave synthesis of titanium carbide in this way ... 

A question which has occupied many catalytic scientists is whether the active site in methanol synthesis consists exclusively of reduced copper atoms or contains copper ions [57,58]. The results of Szanyi and Goodman suggest that ions may be involved, as the preoxidized surface is more active than the initially reduced one. However, the activity of these single crystal surfaces expressed in turn over frequencies (i.e. the activity per Cu atom at the surface) is a few orders of magnitude lower than those of the commercial Cu/ZnO/ALO catalyst, indicating that support-induced effects play a role. Stabilization of ionic copper sites is a likely possibility. Returning to Auger spectroscopy, Fig. 3.26 illustrates how many surface scientists use the technique in a qualitative way to monitor the surface composition. 

Other mediators which have been used in combination with diaphorase for the regeneration of NAD+ are riboflavin and Vitamin K3, which is 2,3-dimethyl-1,4-naphthoquinone. However, especially riboflavin is not stable enough for synthetic applications [40]. Better stability is exhibited by phenanthrolindiones as mediators. In combination with diaphorase, Ohshiro [41] showed the indirect electrochemical oxidation of cyclohexanol to cyclohexanone using the NAD+ dependent HLADH with a turnover frequency of two per hour. For an effective enzymatic synthesis, this turnover frequency, however, would be too small. In our own studies, we were able to accelerate the NAD(P)+ regeneration considerably by lowering the electron density within the... 

M. Narisada, T. Yoshida, M. Ohtani, K. Ezumi, M. Takasuka, Synthesis and Substituent Effects on Antibacterial Activity, Alkaline Hydrolysis Rates, and Infrared Absorption Frequencies of Some Cephem Analogues Related to Latamoxef (Moxalactam) , J. Med. Chem. 1983, 26, 1577-1582. 

Successful fusion (2) is a rare event, but the frequency can be improved by adding polyethylene glycol (PEG). To obtain only successfully fused cells, incubation is required for an extended period in a primary culture with HAT medium (3), which contains hypoxan-thine, aminopterin, and thymidine. Amino-pterin, an analogue of dihydrofolic acid, competitively inhibits dihydrofolate reductase and thus inhibits the synthesis of dTMP (see p. 402). As dTMP is essential for DNA synthesis, myeloma cells cannot survive in the presence of aminopterin. Although spleen cells are able to circumvent the inhibitory effect of aminopterin by using hypoxanthine and thymidine, they have a limited lifespan and die. Only hybridomas survive culture in HAT medium, because they possess both the immortality of the myeloma cells and the spleen cells metabolic side pathway. 

NaF was not mutagenic in bacterial assays. Although fluoride has been shown to be clas-togenic in a variety of cell types, the mechanism of clastogenicity has been attributed to the effect of fluoride on the synthesis of proteins involved in DNA synthesis and/or repair, rather than direct interaction between fluoride and DNA. In general, there was no effect on sperm morphology or the frequency of chromosomal aberrations, micronuclei, sister chromatid exchange, or DNA strand breaks in rodents treated in vivo. ... 

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