TEMPERATURE ("C) 950 900 850 aoo 750 10.10 0 a l -< N -k k lo-'' s Iz w 0 W z l n 3 LL 0 0 LL Fig. 3. Autoradiograph of coarse-grained specimen with 0.001 5 in. removed from the original surface. %,a 0.82 0.86 0.90 0.94 0.98 0.102 VT ( 1 6~0~)The diffusion of 95Zr was attributed to "short circuit" paths, grain boundaries: and dislocations,' as well as volume diffusion for two reasons: (1) The data in the "tail" showed a linear relation when plotted as log of activity vs. depth; (2) an autoradiograph, made after 0.0015 in. of the specimen was ground away, showed gross inhomogeneities, Fig. 3 (for coarse-grained mate-(~2 ' -XI') 6.45 X Dt rial). "Short circuit" diffusion also may be associated with twin boundaries since they contain atomic disarraysK characteristic of short circuit paths4J Twin boundaries were abundant at room temperature but were not investigated a t the annealing temperatures in these specimens.Concentrated activity is present on part of the specimen circumference (Fig. 3) an indication that edge effects were not completelyThe data in Fig. 2 may be regarded as "effective" diffusion coefficients, including volume as well as short circuit components, although some of the short circuiting effects were removed from the data with the tail corrections noted in the foregoing. Fig. 2. Diffusion coefficients of Zr in ZrH1.a and Zrl.To. squares analysis. cients': The slope was related to the diffusion coeffilog Az -log A I --0.1086 A1 = activity a t depth XI mils. A z = activity a t depth r2 mils. D = diffusion coefficient, cm2/sec. t The diffusion coefficients and their estimated error for 2rHI.S and ZJH,,;~ are shown in an Arrhenius ~i~, 2, A leastsquares fit of these data gives values for the activation energy, Q = 33,000 f 6000 cal/mole and for the constant, DO = 1 X 10-6 to I x 10-4 cmz/sec. The diffusion coefficients for z~H~.~ are higher than those for ZrHl.iO, and a real difference may exist because of variations in impurity content and/or other factors previously noted. The Acknowledgment data were treated together since the respective errors overlapped in Fig. 2. = time of diffusion in seconds. in this specimen. R. S. Carpenter performed most of the experimental work and A. J. Moses carried out the Zr-Nb separations.
Normal Raman spectra were obtained for three crystalline forms of human insulin: 4Zn, 2Zn, and Zn-free or Na, from 1800-200 cm1. The extraction of a large number of component bands from the heavily overlapped Raman bands was accomplished by Fourier Self Deconvolution and bandfitting.Bands considered to be indicative of protein conformation, including Amide I, Amide III, tyrosine, 5-5, and C-S bands, and some which are relatively insensitive to protein structure, such as phenylalanine and histidine, are compared.The published x-ray structures of 4Zn and 2Zn insulins are used to help interpret the corresponding parameters of the extracted Raman bands, and to suggest structures in the as yet unpublished Na/human insulin crystals.
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