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71.
Development and validation of an assay method for the determination of trifluoroacetic acid in a cyclosporin-like drug 总被引:1,自引:0,他引:1
An improved method for the assay of trifluoroacetic acid (TFA) in a cyclosporin-like drug substance is presented, based on ion chromatography with suppressed conductivity detection. Column fouling by the drug molecule is avoided by use of a sample preparation method in which the drug substance is precipitated at alkaline pH whilst the TFA remains in solution. The new method requires a smaller sample mass than a previous method based on headspace-GC-FID whilst achieving an improvement in sensitivity. During validation, the method's performance was found to be consistent with usual acceptance criteria, and the method was found to be robust in routine use. 相似文献
72.
ABSTRACTA 2018 update of the most accurate calculated and experimental static dipole polarizabilities of the neutral atoms in the Periodic Table from nuclear charge Z?=?1 to 120 is given. Periodic trends are analyzed and discussed. 相似文献
73.
John F. Nagle 《Journal of statistical physics》2004,117(5-6):1047-1062
The conventional way of explaining Gibbs paradox as due to the distinguishability of particles has been challenged recently and a new fundamental definition for the entropy has been proposed that gives the same entropy for distinguishable particles as for indistinguishable particles. In this paper arguments are presented that strongly favor the conventional definition of entropy and its resolution of Gibbs paradox. 相似文献
74.
Maliarik M Nagle JK Ilyukhin A Murashova E Mink J Skripkin M Glaser J Kovacs M Horváth A 《Inorganic chemistry》2007,46(11):4642-4653
The new crystalline compounds Tl2Ni(CN)4 and Tl2Pd(CN)4 were synthesized by several procedures. The structures of the compounds were determined by single-crystal X-ray diffraction. The compounds are isostructural with the previously reported platinum analogue, Tl2Pt(CN)4. A new synthetic route to the latter compound is also suggested. In contrast to the usual infinite columnar stacking of [M(CN)4]2- ions with short intrachain M-M separations, characteristic of salts of tetracyanometalates of NiII, PdII, and PtII, the structure of the thallium compounds is noncolumnar with the two TlI ions occupying axial vertices of a distorted pseudo-octahedron of the transition metal, [MTl2C4]. The Tl-M distances in the compounds are 3.0560(6), 3.1733(7), and 3.140(1) A for NiII, PdII, and PtII, respectively. The short Tl-Ni distance in Tl2Ni(CN)4 is the first example of metal-metal bonding between these two metals. The strength of the metal-metal bonds in this series of compounds was assessed by means of vibrational spectroscopy. Rigorous calculations, performed on the molecules in D4h point group symmetry, provide force constants for the Tl-M stretching vibration constants of 146.2, 139.6, and 156.2 N/m for the NiII, PdII, and PtII compounds, respectively, showing the strongest metal-metal bonding in the case of the Tl-Pt compound. Amsterdam density-functional calculations for isolated Tl2M(CN)4 molecules give Tl-M geometry-optimized distances of 2.67, 2.80, and 2.84 A for M = NiII, PdII, and PtII, respectively. These distances are all substantially shorter than the experimental values, most likely because of intermolecular Tl-N interactions in the solid compounds. Time-dependent density-functional theory calculations reveal a low-energy, allowed transition in all three compounds that involves excitation from an a1g orbital of mixed Tl 6pz-M ndz2 character to an a2u orbital of dominant Tl 6pz character. 相似文献
75.
Applied Biochemistry and Biotechnology - Modern municipal sewage waste treatment plants use conventional mechanical and biological processes to reclaim waste waters. This process has the overall... 相似文献
76.
77.
Rivard C. J. Nagle N. J. Adney W. S. Himmel M. E. 《Applied biochemistry and biotechnology》1993,39(1):107-117
Applied Biochemistry and Biotechnology - The anaerobic bioconversion of municipal solid wastes (MSW) produces both a valuable fuel product (methane) and a residue useful as a soil amendment. The... 相似文献
78.
Lorraine C. Nagle Andrea J. Ahern Declan L. Burke 《Journal of Solid State Electrochemistry》2002,6(5):320-330
Multilayer oxide films were grown on silver in base by repetitive potential cycling; however, the type of oxide obtained,
as assessed on the basis of its reduction behaviour, was dependent on the lower limit of the oxide growth cycles. Using limits
of 1.03–2.60 V (RHE) the oxide film produced was assumed to be predominantly Ag2O; reduction of the latter yielded a cathodic peak at ca. 0.8 V and a surface layer of silver microparticles of diameter ranging
from ca. 100 to 227 nm which, although relatively stable, were prone to rapid, extensive reoxidation. Altering the oxide growth
limits to 0.7–2.60 V resulted in the growth of a different type of oxide deposit which is assumed to be AgOH; reduction of
the latter occurred in a negative sweep in a random manner, i.e. in the form of cathodic spikes extending to potentials as
low as ca. –0.5 V. Both types of silver oxide species are assumed to be involved in premonolayer oxidation and electrocatalysis
at silver in base and the nature of the former process is discussed in some detail.
Electronic Publication 相似文献
79.
The cell-free extracellular matrix of human placental chorionic villi has been prepared by a procedure employing extraction of the terminal villar fragments with the detergents Triton X-100 and sodium deoxycholate. The isolated human placental extracellular matrix retains an intact, but collapsed, histoarchitecture, as observed by scanning and transmission electron microscopy. It remains intact, in large part because of the presence of continuous sheets of villar basement membranes and associated interstitial collagen fibers and scattered patches of fibrin. The staining charcteristics and chemical composition of the isolated human placental extracellular matrlix are similar to those reported for basement membranes in several tissues and indicate the presence of collagen-like and glycoprotein components in this preparation. Gel electrophoresis of urea-SDS-mercaptoethanol extracts of the matrix showed that it consists of several polypeptide components of various molecuar weights, some of which are associated into high molecular weight complexes by disulfide bonds. 相似文献
80.
Carlos S. O. Yokoi John F. Nagle Silvio R. Salinas 《Journal of statistical physics》1986,44(5-6):729-747
Using exact methods, pair-correlation functions are studied in the dimer model defined on a brick lattice. At long distances these functions exhibit strongly anisotropic algebraic decay and, near criticality, the length scales diverge differently in the two principal directions. The critical exponents are x=1/2 and y=1. These results are in agreement with deductions drawn from recent exact finite-size scaling calculations. We also interpret our results in the light of domain wall theories of commensurate-incommensurate transitions, and in particular we study the relation of the present model to the discrete version of the Pokrovsky-Talapov model introduced by Villain. 相似文献