Matthews method

R. Matthews, Methods for calculating stress in cylindrical nuclear fuel elements, AERE-R 6585, AERE, Harwell, 1970. 

Estimating Screen Capacity Various methods of predicting screening capacity have been proposed, and each has its limitations. The throughrlow method of Matthews uses the following equation ... 

Matthews, B.W., Rossmann, M.G. Comparison of protein structures. Methods Enzymol. 115 397-420, 1985. 

The method used is described by Drysdale, Stevenson, and Sharkey.4 The methyl ester of butadienoic acid has not been described previously, but the free acid contaminated by 2-bu-tynoic acid has been prepared by Wotiz, Matthews, and Lieb 5 by carbonation of propargylmagncsium bromide. Ethyl butadienoate has been prepared by Eglinton, Jones, Mansfield, and Whiting by alkali-catalyzed isomerization of ethyl 3-butynoate prepared from 3-butynol by chromic acid oxidation and esterification. 

Methyl nitroacetate has been prepared from nitromethane through the dipotassium salt of nitroacetic acid by the classical Steinkopf method3 but in lower yield. The dipotassium salt was obtained in 45% yield. The method has been improved by Matthews and Kubler4 but the salt must be recrystallized prior to esterification. 

There are two types of data necessary to obtain accurate global estimates of vegetation carbon pools or biomass. First, it is important to have accurate data on the areal extent of major ecosystems. Matthews (29) found that calculations of global biomass were significantly influenced by the land cover data set used. Second, there must be accurate estimates of biomass density for terrestrial ecosystems. There is a wide range of estimates published for the same ecosystem, each derived by different methods (29), and none having statistical reliability (7). 

G.A. Matthews, Pesticide Apphcation Methods, Longman, London (1992). 

Despite the potential problems, two recent studies provide positive results. Matthews et al. (2000) analyzed the 5D of fluid inclusions in present-day cave carbonates from Soreq cave (Israel) using the method of thermal vacuum extraction and standard techniques on cave pool water from the same cave to estimate isotopic fractionation during measurement (Aex = 5Dextracted water - 8Dcave water). After subtracting Aex from 5D... 

Pradhan A, Jones Robin C, Daniela C, O Connor Charles J, Tarr Matthew A (2008) Gold-magnetite nanocomposite materials formed via sonochemical methods. Ultrason Sonochem 15(5) 891-897... 

The classical method for the determination of iodide in seawater was described by Sugawara [5]. Various workers [6,7] have improved the original method. Matthews and Riley [6] modified the method by concentrating iodide by means of coprecipitation with chloride using silver nitrate (0.23 g per 500 ml seawater). Treatment of the precipitate with aqueous bromine and ultrasonic agitation promote recovery of iodide as iodate which [15] when reacted with excess of iodide ions under acid conditions, yields Ij, which are determined either spectrophotometrically or by photometric titration with sodium thiosulfate. Photometric titration gave a recovery of 99.0 0.4% and a coefficient of variation of 0.4% compared with 98.5 0.6% and 0.8%, respectively, for the spectrophotometric procedure. 

One deduces the space group from the symmetry in the crystal s diffraction pattern and the systematic absence of specific reflections in that pattern. The crystal s cell dimensions are derived from the diffraction pattern for the crystal collected on X-ray film or measured with a diffractometer. An estimation of Z (the number of molecules per unit cell) can be carried out using a method called Vm proposed by Matthews. For most protein crystals the ratio of the unit cell volume and the molecular weight is a value around 2.15 AVOa. Calculation of Z by this method must yield a number of molecules per unit cell that is in agreement with the decided-upon space group. 

Layton-Matthews, D., Lesher, C. M., Burnham, O. M., Liwanag, J., Halden, N.M., Hulbert, L., Peck, D. 2007. Magmatic Ni-Cu-platinum group ele-ment deposits of the Thompson Nickel Belt. In Goodfellow, W. (ed.). Mineral Deposits of Canada A Synthesis of Major Deposit Types, District Metallogeny, the Evolution of Geological Provinces and Exploration Methods. Geological Association of Canada, Special Volume 5, 409-432. 

This method, introduced by Matsuhisa et al. (1978) and later modified by Matthews et al. (1983a), uses the measurement of both and fractionations... 

Fig. 1.7 Schematic representation of the three-isotope exchange method. Natural samples plotted on the primary mass fractionation hne (PF). Initial isotopic composition are mineral (Mo) and water (Wo) which is well removed from equilibrium with Mq in 8 0, but very close to equUibrium with Mo in 5 0. Complete isotopic equihbrium is defined by a secondary mass fractionation hne (SF) parallel to PF and passing through the bulk isotopic composition of the mineral plus water system. Isotopic compositions of partially equilibrated samples are Mf and Wf and completely equilibrated samples are Mg and Wg. Values for Me and W. can be determined by extrapolation from the measured values of M , Mf, Wo, and Wf (after Matthews et al. 1983a...

Sharma and Reed, 1976)]. In proteins the coordination number 4 is most common, where the zinc ion is typically coordinated in tetrahedral or distorted tetrahedral fashion. The coordination polyhedron of structural zinc is dominated by cysteine thiolates, and the metal ion is typically sequestered from solvent by its molecular environment the coordination polyhedron of catalytic zinc is dominated by histidine ligands, and the metal ion is exposed to bulk solvent and typically binds a solvent molecule (Vallee and Auld, 1990). The inner-sphere coordination number of catalytic zinc may increase to 5 during the course of enzymatic turnover, and several five-coordinate zinc enzyme—substrate, enzyme product, and enzyme-inhibitor complexes have been studied by high-resolution X-ray crystallographic methods (reviewed by Matthews, 1988 Christianson and Lipscomb, 1989). The coordination polyhedron of zinc in five coordinate examples may tend toward either trigonal bipyramid or octahedral-minus-one geometry. 

Carboxypeptidase A was the first zinc enzyme to yield a three-dimensional structure to the X-ray crystallographic method, and the structure of an enzyme-pseudosubstrate complex provided a model for a precatalytic zinc-carbonyl interaction (Lipscomb etai, 1968). Comparative studies have been performed between carboxypeptidase A and thermolysin based on the results of X-ray crystallographic experiments (Argosetai, 1978 Kesterand Matthews, 1977 Monzingoand Matthews, 1984 Matthews, 1988 Christianson and Lipscomb, 1988b). Models of peptide-metal interaction have recently been utilized in studies of metal ion participation in hydrolysis (see e.g., Schepartz and Breslow, 1987). In these examples a dipole-ion interaction is achieved by virtue of a chelate interaction involving the labile carbonyl and some other Lewis base (e.g.. 

Armitage P, Berry G, Matthews JNS (2002) Statistical methods in medical... 

Marayama, H., Tanaka, T. Williams, GM. (1990) Effects of the peroxisome proliferator di(2-ethylhexyl)phthalate on enzymes in rat liver and on carcinogen-induced liver altered foci in comparison to the promoter phenobarbital Toxicol. Pathol., 18, 257-267 Matsushima, T, Muramatsu, M. Haresaku, M. (1985) Mutation tests on Salmonella typhimurium by the preincubation method. Prog. Mutat. Res., 5, 181-186 Matthews, E.J., DelBalzo, T. Rundell, J.O. (1985) Assays for morphological transformation and mutation to ouabain resistance of Balb/c-3T3 cells in culture. Prog. Mutat. Res., 5, 639-650... 

It is possible that the future may also see the use of digital calculators in qualitative spectrometric analyses. Various types of punched cards have been used as a method of recording spectral data on pure compounds. The purpose of these files is to facilitate the identification of spectral data on unknown substances. Their use in infrared analysis has been covered by Mecke and Schmid (M6), Keuntzel (K3), and Baker, Wright, and Opler (B2). The last named authors describe a file of 3150 spectra which was expected eventually to be expanded to include up to 10,000 spectra. Zemany (Zl) discussed the use of edge-notched cards in cataloging mass spectra and Matthews (M4) describes a similar application in connection with X-ray diffraction powder data. These two applications made use of only hand-sorting methods the files of Baker et al. were intended to be processed by machine. 

---