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Another problem with the reaction of phenols with aziridines is the selectivity between O-alkylation vs C-alkylation. A recent report has identified that the use of (ArO)3B selects for C-alkylation <06OL2627>. Most of the examples reported in this paper showed less than 5% of the O-alkylation product. What is interesting about this report is the stereochemistry of the product. While the mechanism is not known, the product is formally an SNl type product. Generally less than 5% was the product of inversion of configuration (the Sn2 product). In addition to the A-tosyl, both the A-Cbz and A-Dpp aziridines gave excellent yields of aziridine-opened product. [Pg.86]

It has been reported that oxytocin, but not vasopressin, forms a stable intramolecular hydrogen bond with the Asn5 carboxamide side chain in propylene glycol and that this leads to emission from tyrosinate/2111 Time-resolved studies assigned the longest lifetime (18.5 ns) to the emission from tyrosinate. Unfortunately, lack of experimental details and data, an unrealistic lifetime attributed to tyrosinate, and uncertainties concerning the purity of the solvents raise questions about this report. [Pg.49]

An experimenter has reported that a new phase e was found to coexist in equilibrium with p, y and 8 phases at a particular set of conditions. What is your opinion about this report ... [Pg.136]

In this regard it should be pointed out that the only expert report about the possible interpretation of the blueprints of the alleged gas chambers of the Auschwitz and Birkenau crematoria ever presented to a court to date concluded that it was neither possible to identify those rooms as gas chambers nor to convert them into gas chambers. This sensational report was given in the early 1970 s in Austria, but was covered up by the media, and the court files about this report have vanished.129... [Pg.40]

The interesting thing about this report was its striking photographs, in which multiple, small, dark pigment deposits in the conjunctiva were seen in addition, the cornea had multiple, small, discrete, yellowish specks, and both lenses had anterior capsular opacities. [Pg.216]

The foregoing facts fairly summarize the information which was available to us when we undertook the investigations to be reported below. Earlier or simultaneous work on resonance absorption includes, first of all, Bethe s calculation of the absorption of uniformly distributed material in a hydrogeneous moderator. Bethe s results were adapted to the particular case of resonance absorption by uniformly distributed (i.e., not lumped) uranium and generalized to other moderators in a classified report by J. A. Wheeler (A-88). We aid not learn about this report until some time in 1943. In addition, both J. Fisk and W. Shockley, and also Eckart, treated the resonance absorption of uranium lumps embedded in a moderator. We still know very little about Fisk s and Shockley s work. Eckart s work... [Pg.166]

Aspen Holdings (2013) Aspen Pharmacare Holdings Limited Integrated Report 2013 [Online]. Available from http //financialresults.co.za/2013/aspen ir2013/ IR2013/l about this report.php [accessed 30 April 2015]. [Pg.298]

Enter the name and telephone number (including area code) of a person who can respond to questions from the public about the report. If you choose to designate the same person as both the technical and the public contact, you may enter Same as Section 3.3 in this space. This contact person does not have to be the same person who prepares the report or signs the certification statement and does not necessarily need to be someone at the location of the reporting facility. [Pg.34]

Spectral studies reported about this time were even less conclusive. " In 1953, an oxo structure was assigned to 4-monosubstituted 1,3-diphenylpyrazol-5-ones on the basis of ultraviolet and infrared spectral data. ... [Pg.41]

Little is reported about this substitution pattern. The 1,3,8,10,15,17,22,24-octasubstituted (1,3-octasubstituted) phthalocyanines are formed as structural isomers (see pp 736,737). 3,5-Dinitro-phthalonitrile (14) on heating at 180-190°C in nitrobenzene with a catalytic amount of ammonium molybdate(VI) affords phthalocyanine 15. [Pg.758]

Measurements [113,368] of interfacial (contact) potentials or calculated values of the relative work functions of reactant and of solid decomposition product under conditions expected to apply during pyrolysis have been correlated with rates of reaction by Zakharov et al. [369]. There are reservations about this approach, however, since the magnitudes of work functions of substances have been shown to vary with structure and particle size especially high values have been reported for amorphous compounds [370,371]. Kabanov [351] estimates that the electrical field in the interfacial zone of contact between reactant and decomposition product may be of the order of 104 106 V cm 1. This is sufficient to bring about decomposition. [Pg.33]

Appendix A contains a MedWatch form, which is used by health care professionals for voluntary reporting of adverse reactions and problems with tiie drag product. Is also contains advice about voluntary reporting. This form is a part of tiie FDA medical products reporting program. [Pg.689]

Unpublished results, the detailed report about this method will appear in the next future elsewhere. [Pg.91]

The active state of luminescence spectrometry today may be judged ly an examination of the 1988 issue of Fundamental Reviews of Analytical Chemistry (78), which divides its report titled Molecular Fluorescence, Phosphorescence, and Chemiluminescence Spectrometry into about 27 specialized topical areas, depending on how you choose to count all the subdivisions. This profusion of luminescence topics in Fundamental Reviews is just the tip of the iceberg, because it omits all publications not primarily concerned with analytical applications. Fundamental Reviews does, however, represent a good cross-section of the available techniques because nearly every method for using luminescence in scientific studies eventually finds a use in some form of chemical analysis. Since it would be impossible to mention here all of the current important applications and developments in the entire universe of luminescence, this report continues with a look at progress in a few current areas that seem significant to the author for their potential impact on future work. [Pg.11]

ANSWER I think that elearly it is possible that there is no neurotoxieity in humans. I think all of us would like for this to be the ease. And maybe it is the ease. We have talked about this a lot with fenfluramine, and we have done studies with paraehloroamphetamine in whieh we have given it orally to rats at relatively low doses, but still anoreetie doses, over 90 days. We have seen depletion of serotonin, but that was fully reversible depletion. It eame baek when the drug was stopped. I think there may be no neurotoxieity at the oral doses used in humans. I think that would be great if that is the ease. That would explain why there is no depression or other kinds of symptoms. But I don t feel comfortable about relying on the laek of reporting of depression as real evidence that there is no neurotoxieity. We simply need to have better data on that. [Pg.352]

Our requirements for certain applications called for the preparation of block copolymers of styrene and alkali metal methacrylates with molecular weights of about 20,000 and methacrylate contents of about 10 mol%. In this report we describe the preparation and reactions of S-b-MM and S-b-tBM. In the course of our investigation, we have found several new methods for the conversion of alkyl methacrylate blocks into methacrylic acid and/or metal methacrylate blocks. Of particular interest is the reaction with trimethylsilyl iodide. Under the same mild conditions, MM blocks are completely unreactive, while tBM blocks are cleanly converted to either methacrylic acid or metal methacrylate blocks. As a consequence of this unexpected selectivity, we also report the preparation of the new block copolymers, poly(methyl methacrylate-b-potassium methacrylate) (MM-b-MA.K) and poly(methyl methacrvlate-b-methacrylic acid) (MM-b-MA). [Pg.277]

Table I. It is probable that all the indicated yields can be improved. However, using these data as a criterion, it appears that the chloral can be replaced by its hydrate or alcoholate and that a moderate excess of fluorobenzene favors the reaction. There is one report that aluminum chloride brings about this condensation (34), but here, as with DDT, the choice condensing agents are concentrated sulfuric acid (with or without the addition of oleum), and chlorostflfonic acid (84). A moderate temperature and prolonged stirring, which must also be vigorous, increase the yield. Table I. It is probable that all the indicated yields can be improved. However, using these data as a criterion, it appears that the chloral can be replaced by its hydrate or alcoholate and that a moderate excess of fluorobenzene favors the reaction. There is one report that aluminum chloride brings about this condensation (34), but here, as with DDT, the choice condensing agents are concentrated sulfuric acid (with or without the addition of oleum), and chlorostflfonic acid (84). A moderate temperature and prolonged stirring, which must also be vigorous, increase the yield.
Soon after this report, the group of M. Yaros, also working in Boulder, was able to demonstrate ribozyme activity with a much higher performance (Illangsekare, 1995). Using a random mixture of many billions of RNA sequences, they selected one species which was able to catalyse the aminoacyl synthesis. In other words, the selected ribozyme aminoacylated its 2 (3 ) end when offered phenylalanyl-AMP the addition of Mg2+ and Ca2+ was necessary. The catalysed reaction was about 105 times faster than in the absence of ribozyme. Thus the group was able to show that a fundamental reaction of contemporary protein biosynthesis can also be catalysed by a ribozyme (see Sect. 5.3.2). The assiduous search for further activities continues. [Pg.163]


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