Active comparator study

Preliminary in vitro studies with dimetacrine (120a) and sila-dimetacrine (120b) on the isolated guinea pig ileum have shown that both compounds exhibit weak histaminolytic and anticholinergic activities. Comparative studies for psychotropic activity are in progress. 

Wider range of patients than in NDA/PLA database Larger numbers of patients Active comparator study designs Supplemental efficacy studies Additional approvals in non-ICH countries Pharmacoepidemiology and pharmacoeconomics in particular healthcare environments Post-marketing commitments All of the above... 

Well-designed, head-to-head, active comparator studies are also always to be preferred over the... 

Larger numbers of patients (to detect rarer adverse events) Active comparator studies... 

Conceptual Design of MHD Repowered Plant. The first step toward MHD plant commercialization is a pilot-scale demonstration plant. Repowering of existing plants, actively under study both in the United States and elsewhere (65), allows use of existing systems at considerable cost savings compared to building a new plant from the ground up. It also ensures that the pilot scale demonstration occurs in a reaHstic utiHty environment and... 

Modification at the C(7) position of the penam ring system (other than ring opening reactions) has not been extensively studied. It was possible, however, to convert the /3-lactam to a /3-thionolactam in 1% yield as shown in Scheme 55 (75JA5628). The deblocking product (73) had greatly reduced antibacterial activity compared to the parent /3-lactam. 

Starr, 1969 approached this by investigating the "revealed preferences exhibited in society ls the result of trial and error. (Similar to the "efficient market theory" in the stock market.) Stan-conjectured that the risk of death from disease appears to determine a level of acceptable voluntary risk but that society requires a much lower level for involuntary risk. He noted that individuals seem to accept a much higher risk (by about 1000 times) if it is voluntary, e.g., sky-diving or mountain climbing, than if it is imposed, such as electric power or commercial air travel, by a correlating with the perceived benefit. From this study, a "law" of acceptable risk was found concluding that risk acceptability is proportional cube of the benefits. Figure 1.4.4-1 from Starr, 1972 shows these relationships. One aspect of revealed preferences is that these preferences do not necessarily remain constant (Starr et al., 1976). In Starr et al., 1976, it is shown that while nuclear power has the least risk of those activities compared, it also has the least perceived benefit. Clearly the public thinks that... 

The acylation of enamines derived from cyclic ketones, which can lead to the acyl ketone or ring expansion (692-694), was studied by NMR and mass spectroscopic analysis of the products (695,696). In a comparative study of the rates of diphenylketene addition to olefins, a pronounced activation was observed in enamines (697). Enamine N- and C-acylation products were obtained from reactions of Schiff s bases (698), vinylogous urethanes (699), cyanamides (699), amides (670,700), and 2-benzylidene-3-methylbenzothiazoline (672) with acid chlorides, anhydrides, and dithio-esters (699). 

The conclusion may be drawn that the data obtained of comparative studies of olefin polymerization by the one-component catalyst (TiCl2) and two-component systems (TiCl2 + AlEtxCl ) confirm the concept of monometallic active centers on the surface of titanium chlorides developed by Cossee and Arlman (170-173). 

Shigaeva MK, Savitskaya IS. 1981. Comparative study of the mutagenic activity of some organophosphoms insecticides in bacteria. Tsitol Genet 15 68-72. 

Comparative study of LB films of cytochrome P450 wild type and recombinant revealed similar surface-active properties of the samples. CD spectra have shown that the secondary structure of these proteins is practically identical. Improved thermal stability is also similar for LB films built up from these proteins. Marked differences for LB films of wild type and recombinant protein were observed in surface density and the thickness of the deposited layer. These differences can be explained by improved purity of the recombinant sample. In fact, impurity can disturb layer formation, preventing closest packing and diminishing the surface density and the average monolayer thickness. Decreased purity of... 

A comparative study [10] is made for crystal-growth kinetics of Na2HP04 in SCISR and a fluidized bed crystallizer (FBC). The details of the latter cem be found in [11]. Experiments are carried out at rigorously controlled super-saturations without nucleation. The overall growth rate coefficient, K, are determined from the measured values for the initial mean diameter, t/po, masses of seed crystals before and after growth. The results show that the values for K measured in ISC are systematically greater than those in FBC by 15 to 20%, as can be seen in Table 2. On the other hand, the values for the overall active energy measured in ISC and FBC are essentially the same. 

A comparative study ethylene/l-hexene copolymerization with [t-BuNSiMe2Flu]TiMe2 catalyst via various activators... 

Recently, the distribution of 2,3-dihydroxybenzoate decarboxylase has been found in a variety of fungal strains (unpubhshed data), and the carboxylation activity for catechol is confirmed by the reaction using resting cells (or cell-free extract) in the presence of 3M KHCO3. The detailed comparative studies of enzyme structures and catalytic properties between 2,3-dihydroxybenzoate decarboxylase and 3,4-dihyroxybenzoate decarboxylase might explain how the decarboxylases catalyze the regioselective carboxylation of catechol. 

A third way to increase both the active surface area and the number of oxygenated species at the electrode surface is to prepare alloy particles or deposits and then to dissolve the non-noble metal component. This technique, which is similar to that used to prepare Raney-type catalysts, yields very high surface area electrodes and hence some improvements in the electrocatalytic activities compared with those of pure platinum. However, it is always difficult to be sure whether the mechanism of enhancment of the activities is due to this effect or the possible presence of remaining traces of the dissolved metal. Results with PtyCr and PtSFe were encouraging, although the effect of iron is still under discussion. From studies in a recent work on the behavior of R-Fe particles for methanol electrooxidation, it was concluded that the electrocatalytic effect is due to the Fe alloyed to platinum. ... 

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