Experimental technique for radiative-process-resolved X-ray absorption spectroscopy at the inner-shell excitation thresholds.

Partial-fluorescence-yield (PFY) x-ray absorption measurements, rising the optimized window widths of position sensitive detectors in wave-length dispersive x-ray spectrometers, have been applied for radiative process-resolved (RPR) x-ray absorption spectroscopy. We have measured PFY-absorption spectra of graphite and diamond at the C K threshold and of h-BN and c-BN at the B K threshold. Resonant elastic x-ray scattering was observed in graphite and h-BN on their PFY-absorption spectra, and excitonic x-ray scattering was observed in diamond and c-BN. These results show that PFY-absorption measurements for RPR x-ray absorption spectroscopy can provide the information about the electronic structures and the radiative-decay process in inner-shell excitation.

Gas chromatography with spectroscopic detectors.

In recent years, capillary gas chromatography (GC) with Fourier Transform Infrared (FT-IR) and/or mass spectral (MS) detection has become a primary analytical tool for qualitative and quantitative analysis of complex mixtures. Because of the wide range of applications, the analytical requirements have motivated a variety of chromatographic and detection developments. This review examines those, illustrating with applications that demonstrate the power of GC and multidimensional GC-MS, GC-FT-IR and GC-FT-IR-MS systems for solving a variety of analytical problems. In addition, the article discusses the integrated performance of such analytical systems with the aid of recent sample introduction and computer data analysis advances.

Hyperacute rejection from antibody against class II HLA antigens.

The clinical significance of anti-B-cell antibodies in kidney and pancreas transplantation remains unresolved. Here, we report an isolated hyperacute rejection of the kidney, but not the pancreas, during a simultaneous kidney-pancreas (SKP) transplant. The hyperacute rejection was due to IgG antibodies directed against class II antigens expressed on B-cells. Antibodies directed against class II antigens are generally not thought to produce hyperacute rejection, since class II antigens allegedly are minimally expressed on vascular endothelium in the kidney. The pancreas was spared and continues to function normally, suggesting that class II antigens were not strongly expressed in this pancreas. The differential susceptibility to B-cell antibodies of the two transplanted organs is noteworthy and should call attention to the danger from IgG antibodies to class II antigens in kidney transplantation.

Soft X-ray beamline specialized for actinides and radioactive materials equipped with a variably polarizing undulator.

This report presents the design of an undulator beamline at SPring-8 to be used for soft X-ray spectroscopy focused on radioactive materials. Photoemission spectroscopy experiments are carried out in a radioisotope (RI)-controlled area where actinide compounds as well as unsealed radioactive materials are usable. Intrusion of the radioactive materials into the electron storage ring or to the outside of the evacuated beamline components can be avoided by a specially devised RI protection/inspection mechanism. The combination of a variably polarizing undulator and a varied-line-spacing plane-grating monochromator provides linearly or circularly polarized soft X-rays with a high resolving power in the energy range 0.28-1.5 keV. The beamline will become operational in December 1997.

Applications of multidimensional-gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared-mass spectrometry.

Gas chromatography systems with coupled columns in a multidimensional (MD) mode have become more important for the analysis of complex mixtures, due to the increased selectivity that can be achieved by the use of multiple columns with differing stationary phases. Coupling two or more detectors can also help to increase the information content of the analysis. This review presents the various strategies used in multidimensional gas chromatography (MDGC), with Fourier transform infrared (FT-IR) and/or mass spectrometric (MS) detection, with an emphasis on applications of these techniques for analysis of components in complex matrices. © 1997 John Wiley & Sons, Inc.