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991.
A study was made of the activity of succinic dehydrogenase (SDH) and of the alpha-glycerophosphoric dehydrogenase (alpha-GPDH) in the peripheral blood lymphocytes and the transplant myocardium in the CBA mice in transplantation to them of the heart of newborn C57BL/6 mice into the pinna, subcutaneously. It appeared that the (see article) ratio in the myocardium and the lymphocytes of intact animals and also in the recipients of the isolinear transplant of the heart was greater than 1, but in allogenous transplantation this ratio became less than 1 on account of alpha-GPDH activation in the blood lymphocytes, which preceded the inversion in the transplant myocardium. It is supposed that the mentioned phenomenon was associated with the development of the immunological conflict. 相似文献
992.
993.
Three techniques for measuring dynamic stress intensity factor time histories of dynamically loaded stationary mode-I cracks are compared as applied to dynamically loaded pre-cracked 6Al-4V titanium alloy specimens. The three techniques are crack opening displacement (COD), dynamic strain gage measurement, and coherent gradient sensing (CGS). The stress intensity factor histories are inferred from each measurement technique and are used to obtain the critical dynamic initiation toughness as a function of loading rate (). There are significant differences in implementation and information obtained from each of the three measurement techniques, though for the tests performed all are found to yield very similar results. 相似文献
994.
High-sensitivity ion mobility spectrometry/mass spectrometry using electrodynamic ion funnel interfaces 总被引:1,自引:0,他引:1
Tang K Shvartsburg AA Lee HN Prior DC Buschbach MA Li F Tolmachev AV Anderson GA Smith RD 《Analytical chemistry》2005,77(10):3330-3339
The utility of ion mobility spectrometry (IMS) for separation of mixtures and structural characterization of ions has been demonstrated extensively, including in biological and nanoscience contexts. A major attraction of IMS is its speed, several orders of magnitude greater than that of condensed-phase separations. Nonetheless, IMS combined with mass spectrometry (MS) has remained a niche technique, substantially because of limited sensitivity resulting from ion losses at the IMS-MS junction. We have developed a new electrospray ionization (ESI)-IMS-QTOF MS instrument that incorporates electrodynamic ion funnels at both front ESI-IMS and rear IMS-QTOF interfaces. The front funnel is of the novel "hourglass" design that efficiently accumulates ions and pulses them into the IMS drift tube. Even for drift tubes of 2-m length, ion transmission through IMS and on to QTOF is essentially lossless across the range of ion masses relevant to most applications. The rf ion focusing at the IMS terminus does not degrade IMS resolving power, which exceeds 100 (for singly charged ions) and is close to the theoretical limit. The overall sensitivity of the present ESI-IMS-MS system is comparable to that of commercial ESI-MS, which should make IMS-MS suitable for analyses of complex mixtures with ultrahigh sensitivity and exceptional throughput. 相似文献
995.
Wang X Wang B Bos PJ Anderson JE Pouch JJ Miranda FA 《Journal of the Optical Society of America. A, Optics, image science, and vision》2005,22(2):346-354
Accurate modeling of a high-resolution, liquid-crystal-based, optical phased array (OPA) is demonstrated. The modeling method is extendable to cases where the array element size is close to the wavelength of light. This is accomplished through calculating an equilibrium liquid-crystal (LC) director field that takes into account the fringing electric fields in LC OPAs with small array elements and by calculating the light transmission with a finite-difference time-domain method that has been extended for use in birefringent materials. The diffraction efficiency for a test device is calculated and compared with the simulation. 相似文献
996.
The Shure and Rogers findings are examined in relation to other studies in which the factor structure of the MMPI basic scales obtained with actual data is compared to the structure based merely on item overlap among the scales. There is no direct experimental evidence that spurious correlations yield a "built-in" factor structure that is the direct cause of the structure obtained with experimental Ss in the 10 MMPI basic clinical scales. A more concervative interpretation of the Shure and Rogers findings is suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
997.
998.
The racemic14C-and3H-labeled alpha and beta derivatives of octadecyl glycerol ether (batyl alcohol) and of hexadecyl glycerol ether (chimyl alcohol)
of high specific activity were synthesized by treating the appropriate alkyl halides with a large excess of the potassium
salts of isopropylidene or benzylidene glycerol. By use of the trifluoroacetic anhydride esterification procedure, the labeled
diesters of alpha and beta octadecyl and hexadecyl glycerol ethers were prepared. The labeled monoesters of beta octadecyl
and of beta hexadecyl glycerol ethers were isolated from the reaction mixtures by silicic acid column chromatography.
Work done in partial fulfillment for PhD Degree, Department of Biochemistry, University of North Carolina. 相似文献
999.
Dasgupta PK Martinelango PK Jackson WA Anderson TA Tian K Tock RW Rajagopalan S 《Environmental science & technology》2005,39(6):1569-1575
Perchlorate, an iodide uptake inhibitor, is increasingly being detected in new places and new matrices. Perchlorate contamination has been attributed largelyto the manufacture and use of ammonium perchlorate (the oxidizer in solid fuel rockets) and/or the earlier use of Chilean nitrate as fertilizer (approximately 0.1% perchlorate). However, there are regions such as the southern high plains (Texas Panhandle) where there is no clear historical or current evidence of the extensive presence of rocket fuel or Chilean fertilizer sources. The occurrence of easily measurable concentrations of perchlorate in such places is difficult to understand. In the southern high plains groundwater, perchlorate is better correlated with iodate, known to be of atmospheric origin, compared to any other species. We show that perchlorate is readily formed by a variety of simulated atmospheric processes. For example, it is formed from chloride aerosol by electrical discharge and by exposing aqueous chloride to high concentrations of ozone. We report that perchlorate is present in many rain and snow samples. This strongly suggests that some perchlorate is formed in the atmosphere and a natural perchlorate background of atmospheric origin should exist. 相似文献
1000.