N physicochemical properties

In this simple two-dimensional example the discriminant function is a straight line in the case of a set of compounds described by n physicochemical properties the discriminant function would be an -dimensional hypersurface. The discriminant function can be represented as ... 

Takayama, K., Din, Z.Z., Mukeijee, P., Cooke, P.H., Kirkland, T.N. Physicochemical properties of the lipopolysaccharide unit that activates B lymphocytes. J Biol Chem 265 (1990) 14023-14029. 

Dementieva E, Kutuzova G, Zheleznova E, Lundovskikh 1, Ugarova N. Physicochemical properties of recombinant Luciola mingrelica luciferase and its mutant forms. Biochemistry (Moscow) 1996 61 115-9. 

Suzuki H, Ono E, Ueno H, Takemoto Y and Nakamizo N, Physicochemical properties and stabilities of the highly potent calcium antagonist benidipine hydrochloride, Arzneim.-Forsch., 38(1 la), 1671-1676 (1988). 

Tokumura T, Tanaka T and Karibe N, Physicochemical properties of 2-(4-(p-fluoro-benzoyl)piperidin-l-yl)-2 -acetonaphthone hydrochloride and its gastrointestinal absorption in beagle dogs, /. Pharm. Sci. Tech. Yakuzaigaku, 54, 95-102 (1994). 

Head A J and Sabbah R 1987 Enthalpy Recommended Reference Materials for the Realization of Physicochemical Properties ed K N Marsh (Oxford Blackwell)... 

These first components of the autocorrelation coefficient of the seven physicochemical properties were put together with the other 15 descriptors, providing 22 descriptors. Pairwise correlation analysis was then performed a descriptor was eliminated if the correlation coefficient was equal or higher than 0.90, and four descriptors (molecular weight, the number of carbon atoms, and the first component of the 2D autocorrelation coefficient for the atomic polarizability and n-charge) were removed. This left 18 descriptors. 

Chemistry, physicochemical properties, and biological activities of N -oxygenated adenines 99H(51)1971. 

It is useful to compare the spectroscopic data of 1,2,4-triazine mono-A-oxides with the data for the corresponding 1,2,4-triazines. Introduction of an A-oxide group in the 1,2,4-triazine ring changes its physicochemical properties dramatically, and the analysis of these changes allows one to determine which of three nitrogens is oxidized. The most useful method in this case is NMR spectroscopy, including H, C, and N NMR. 

The physicochemical properties of carbon are highly dependent on its surface structure and chemical composition [66—68], The type and content of surface species, particle shape and size, pore-size distribution, BET surface area and pore-opening are of critical importance in the use of carbons as anode material. These properties have a major influence on (9IR, reversible capacity <2R, and the rate capability and safety of the battery. The surface chemical composition depends on the raw materials (carbon precursors), the production process, and the history of the carbon. Surface groups containing H, O, S, N, P, halogens, and other elements have been identified on carbon blacks [66, 67]. There is also ash on the surface of carbon and this typically contains Ca, Si, Fe, Al, and V. Ash and acidic oxides enhance the adsorption of the more polar compounds and electrolytes [66]. 

Burke, R. W. Velapoldl, R. A. In Recoaaended Reference Materials for the Realization of Physicochemical Properties Marsh, K. N., Ed. Blackwell Scientific Oxford, England, 1987 pp 465-489. 

CXCR2 is a member of the CXC family of chemokine receptors. IL-8 activates this receptor, and an antagonist would potentially be useful for the treatment of inflammatory diseases. Baxter et al. [58] describe the parallel optimization of binding and functional potency, physicochemical properties, ADME properties, and PK. The thiol of the HTS hit was varied with typical replacements (i.e., OH, NH2, SMe, NHAc, etc.), but this only led to inactive compounds. Variation of the substituent at N(2) showed that a benzyl moiety was required (Ph, Me substituents gave inactive compounds). Variation of the C(5) substituent showed that -substituents produced optimal activity. The optimized lead has substantially improved CXCR2 binding and functional activity as well as an excellent PK profile (Scheme 13). 

Tsai, R.-S. El Tayar N. Carrupt, R-A. Testa, B., Physicochemical properties and transport behavior of piribedil Considerations on its membrane-crossing potential, Int. J. Pharm. 80, 39 49 (1992). 

Acidic compounds with N—H bonds such as amides, carbamates, and hydan-toins, may be transformed to /V-rnannich bases to form oral prodrugs [2], These prodrugs are generally made by reacting an amide, carbamate, or hydantoin with formaldehyde and a primary or secondary aliphatic or aromatic amine (Fig. 4). The (V-mannich prodrugs tend to have better physicochemical properties than the parent compounds. The derivatives may have increased water solubility, dissolution rate, and/or lipophilicity. 

Chromium zeolites are recognised to possess, at least at the laboratory scale, notable catalytic properties like in ethylene polymerization, oxidation of hydrocarbons, cracking of cumene, disproportionation of n-heptane, and thermolysis of H20 [ 1 ]. Several factors may have an effect on the catalytic activity of the chromium catalysts, such as the oxidation state, the structure (amorphous or crystalline, mono/di-chromate or polychromates, oxides, etc.) and the interaction of the chromium species with the support which depends essentially on the catalysts preparation method. They are ruled principally by several parameters such as the metal loading, the support characteristics, and the nature of the post-treatment (calcination, reduction, etc.). The nature of metal precursor is a parameter which can affect the predominance of chromium species in zeolite. In the case of solid-state exchange, the exchange process initially takes place at the solid- solid interface between the precursor salt and zeolite grains, and the success of the exchange depends on the type of interactions developed [2]. The aim of this work is to study the effect of the chromium precursor on the physicochemical properties of chromium loaded ZSM-5 catalysts and their catalytic performance in ethylene ammoxidation to acetonitrile. 

An increase in the zeolite crystallites size would very likely produce substantial changes in the physicochemical properties of the catalyst and consequently on the selectivity for hydroisomerisation. Since the effect of the zeolite crystallites size in the nanoscale range cannot be predicted theoretically, n-hexadecane hydroisomerization was carried out on PtHBEA catalysts with different zeolite crystallites sizes. 

Kirsh YE (1998) Water soluble poly-N-vinylamides synthesis and physicochemical properties. Wiley, Chichester... 

De Maagd, P.G.-J., ten Hulscher, T.E.M., Van den Heuvel, H., Opperhuizen, A., Sijm, D.T.H.M. (1998) Physicochemical properties of polycyclic aromatic hydrocarbons aqueous solubilities, n-octanol/water partition coefficients, and Henry s law constants. Environ. Toxicol. Chem. 17, 252-257. 

Tardajos, G. Diaz Pena, M. Lainez, A. Aicart, E. J. Chem. Eng. Data 31 (1986) 492. Marsh, K. N. Recommended Reference Materials for the Realization of Physicochemical Properties, Blackwell Sci. Pub. Oxford, Relative Mol. Mass (1987). Shiohama, Y. Ogawa, H. Murakami, S. Fluid Phase Equilib. 32 (1987) 249. 

Relative contribution of each of these structures differs significantly and is determined by internal structural characteristics of the nitrones and by the influence of external factors, such as changes in polarity of solvent, formation of a hydrogen bond, and complexation and protonation. Changes in the electronic stmcture of nitrones, effected by any of these factors, which are manifested in the changes of physicochemical properties and spectral characteristics, can be explained, qualitatively, by analyzing the relative contribution of A-G structures. On the basis of a vector analysis of dipole moments of two series of nitrones (355), a quantum-chemical computation of ab initio molecular orbitals of the model nitrone CH2=N(H)0 and its tautomers, and methyl derivatives (356), it has been established that the bond in nitrones between C and N atoms is almost... 

Panov, A.G., Larsen, R.G., Totah, N.I., Larsen, S.C. and Grassian, V.H. (2000). Photooxidation of toluene and p-xylene in cation-exchanged zeolites X, Y, ZSM-5, and beta the role of zeolite physicochemical properties in product yield and selectivity. J. Phys. Chem. B 104, 5706-5714... 

LOD is defined as the lowest concentration of an analyte that produces a signal above the background signal. LOQ is defined as the minimum amount of analyte that can be reported through quantitation. For these evaluations, a 3 x signal-to-noise ratio (S/N) value was employed for the LOD and a 10 x S/N was used to evaluate LOQ. The %RSD for the LOD had to be less than 20% and for LOQ had to be less than 10%. Table 6.2 lists the parameters for the LOD and LOQ for methyl paraben and rhodamine 110 chloride under the conditions employed. It is important to note that the LOD and LOQ values were dependent upon the physicochemical properties of the analytes (molar absorptivity, quantum yield, etc.), methods employed (wavelengths employed for detection, mobile phases, etc.), and instrumental parameters. For example, the molar absorptivity of methyl paraben at 254 nm was determined to be approximately 9000 mol/L/cm and a similar result could be expected for analytes with similar molar absorptivity values when the exact methods and instrumental parameters were used. In the case of fluorescence detection, for most applications in which the analytes of interest have been tagged with tetramethylrhodamine (TAMRA), the LOD is usually about 1 nM. 

Minoura, N., Tsukada, M., and Nagura, M. (1990). Physicochemical properties of silk fibroin membrane as a biomaterial. Biomaterials 11, 430-434. 

E. A. Permyakov, V. N. Medvedkin, L. P. Kalinichenko, and E. A. Burstein, Comparative study of physicochemical properties of two pike parvalbumins by means of their intrinsic tyrosyl and phenylalanyl fluorescence, Arch. Biochem. Biophys. 227, 9-20 (1983). 

C. J. R. Thorne and N. O. Kaplan, Physicochemical properties of pig and horse heart mitochondrial malate dehydrogenase, J. Biol. Chem. 238, 1861-1868 (1963). 

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