Lawson Number

Beilstein Reference Molecular Formula Molecular Weight Lawson Number Structure Keyword Entry Date Update Date... 

General Comments (NTE) Rltd. Stereoisomers (RSI) Formula Weight (FW) Lawson Number (LN) ... 

Lawson Number (LN)-CAS Reg No (RN) Beilstein Pref RN (BPR) Other Source (OS)-... 

Some of the aspects of structure browsing with the Lawson Number (LN) are described including limitations. Use of several LN in combination, single LN, and range-searching is demonstrated for the retrieval of various analogues, including positional isomers. 

The purpose of this paper is to describe the implementation of a structure browsing tool in computerized data bases, with particular reference to the Beilstein data base as an example. The retrieval term which will form the main subject of this paper is the so-called Lawson-Number (LN). For obvious reasons, it is somewhat embarrassing for the present author to give an account of a descriptor which bears his own name. However, the driving force behind the choice of that particular name was not the author himself, but rather a combination of circumstances, the prime being that all sensible names for numbers of all descriptions had already been used up in the early days of the Beilstein Online venture. There were (and still are) the following terms in daily use in the production processes at the Beilstein Institute ... 

The LN is a recast version of the System Number, made to fit the computer age. Perhaps it would have been better to create the term New System Number , but since the number stems indirectly from the author s SANDRA (7) algorithm, the term Lawson-Number came into being on the suggestion of the Beilstein Online President C. Jochum, and such terms develop a life of their own. 

Lagrange Multiplier Method for programming problems, 289 for weapon allocation, 291 Lamb and Rutherford, 641 Lamb shift, 486,641 Lanczos form, 73 Landau, L. D., 726,759, 768 Landau-Lifshitz theory applied to magnetic structure, 762 Large numbers, weak law of, 199 Law of large numbers, weak, 199 Lawson, J. L., 170,176 Le Cone, Y., 726... 

A number of intercomparison studies of the various methods of measurement of HCHO have been carried out. As might be expected given the specificity of spectroscopic methods, the results of FTIR, DOAS, and TDLS are generally in good agreement, within 15% of their mean value in one study in a polluted atmosphere (Lawson et al., 1990). During the same study, the diacetyldihydrolutidine derivative method and the DNPH method were lower by 15-25% than the spectroscopic mean, whereas the enzymatic method was higher by 25%. 

The position of fatty acids in the triacylglycerol (TAG) structure not only significantly influences fatty acid absorption, but could provide important markers for establishing the authenticity of different oils. Lawson and Hughes (1988) determined the TAG stereospecific structure of a number of GLA rich oils,... 

A number of the CT scan studies have found a correlation between atrophy and persistent cognitive deficits or frank dementia in these neuroleptic-treated patients (DeMeyer et al., 1984 Famuyiwa et al., 1979 Golden et al., 1980 Johnstone et al., 1976 Lawson et al., 1988). Some of these studies used the Nebraska and Halstead-Reitan batteries, considered among the most sensitive for detecting brain damage and dysfunction. 

Equation 16 indicates that for bubble trains with mobile interfaces, the pressure drop is related to the number of lamellae in the train (or number of bubbles per unit length). This important observation, first noted by Hirasaki and Lawson (1),... 

Lawson (1994) examined levels of aromatic amine migration from a number of laminate samples. Specially prepared laminate pouches containing distilled water were boiled for one hour and tested for primary aromatic amine (PAA) migration using a diazotisation procedure. Olive oil migration data at the same temperature was also obtained. Results are shown in Table 16.5 (detection limit 0.3 t,g dm ). These results, if expressed using the conventional surface area to volume ratio of 6 dm per kg of food, would range between 3 and... 

In view of these many precedents it is surprising that the intramolecular displacement of the sulfur function of methionine derivatives has not been utilized for selective cleavage of methionine peptides. The method has only recently been applied to a number of methionine peptides which according to the following scheme (CXX-CXXIII) were first converted to sulfonium salts and then subjected to intramolecular (imino) lactonization and hydrolysis by short heating in water (Lawson et al., 1961). Table XV shows the strong influence of the nature of the added alkyl group on the yield in... 

Some more module configurations are reported for use in MD. Lawson and Lloyd [77] have designed a laboratory-scale MD module as shown in Figure 19.13, where the membrane was sandwiched between the two half-cells, and several hose clamps held the module together. The total area available is 9.7 cm and the smooth transitions at the module entrance as well as exit allow achievement of relatively high Reynolds numbers, whereby conventional boundary layer equations are applicable. The module does not require a support in low pressure-drop applications such as DCMD. Wider permeate channels would require a support for VMD experiments. A porous sintered stainless steel material has been used for the gas permeation experiments. 

Using this method leads to a substantial improvement in the condition number. For example, the CHELP fit using the original algorithm based on Lagrange multipliers to the electrostatic potential of butanol has an rms deviation of 0.79 kcal/mol, but a condition number of 53,000. When the method of Ffanson and Lawson is applied in conjunction with a pseudoinverse solution, we find, as do Sigfridsson and Ryde, " that the conditioning of the matrix is substantially improved. The new condition number is only 40, and the fit is of equal quality. 

Lawson, Hirayama, and Llpsky (72,246) also measured the variation in quantum efficiencies for internal conversion from S3 to Sj in several solvents and found that the values vary very markedly. The efficiencies measured were 0.45 in pure benzene, 0.37 to 0.28 in alcohols and other polar solvents, 0.25 to 0.22 in aliphatic hydrocarbons, 0.04 in n-CgF], and about zero in the gas phase. The order of effectiveness in a number of solvents paralleled the enhancement of the 0-0 band in absorption. The implication would seem to be that solvent perturbation produces state mixing and consequent enhancement of internal conversion Sjj -> Sj. ... 

A number of garlic preparations have been used to study the effect of garlic on platelet aggregation (Lawson et al., 1992). It is thought that the effects of these commercial preparations are most likely attributable to allicin, ajoenes, vinyl dithiins... 

Thus, allicin has been found to inhibit a large number of enzymes in vitro if they contain cysteine at the active sites, but otherwise very few (Lawson, in Koch and Lawson, 1996, p. 65). The reference further states that many of the explanations given for the biological effects of garlic focus on the ability of allicin to react with sulfhydryl enzymes, whatever the latter may be. Moreover, allicin was found to act against cholesterol and triglyceride synthesis. 

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