RESUMEN
We report on the development of a high-resolution and highly efficient beamline for soft X-ray resonant inelastic X-ray scattering (RIXS) located at the Taiwan Photon Source. This beamline adopts an optical design that uses an active grating monochromator (AGM) and an active grating spectrometer (AGS) to implement the energy compensation principle of grating dispersion. Active gratings are utilized to diminish defocus, coma and higher-order aberrations, as well as to decrease the slope errors caused by thermal deformation and optical polishing. The AGS is mounted on a rotatable granite platform to enable momentum-resolved RIXS measurements with scattering angles over a wide range. Several high-precision instruments developed in-house for this beamline are described briefly. The best energy resolution obtained from this AGM-AGS beamline was 12.4â meV at 530â eV, achieving a resolving power of 4.2 × 104, while the bandwidth of the incident soft X-rays was kept at 0.5â eV. To demonstrate the scientific impact of high-resolution RIXS, we present an example of momentum-resolved RIXS measurements on a high-temperature superconducting cuprate, i.e. La2-xSrxCuO4. The measurements reveal the A1g buckling phonons in superconducting cuprates, opening a new opportunity to investigate the coupling between these phonons and charge-density waves.
RESUMEN
1. There are four reducible cross-links in human placenta collagen. The principal one is dehydrodihydroxylysinorleucine. the next in abundance is dehydrohydroxylysinorleucine. The minor components are dehydrolysinonorleucine and dehydrohistidinohydroxymerodesmosine. 2. With increasing length of gestation, the collagen incorporates more tritium radioactivity into its reducible cross-links, with its maximum incorporation at the second trimester. The uptake declines thereafter. 3. Alkaline hydrolysis reveals that both dehydrodihydroxylysinonorleucine and dehydrohydroxylysinonorleucine occur in vivo partly as glycosylated complexes.
Asunto(s)
Colágeno/metabolismo , Placenta/metabolismo , Fenómenos Químicos , Química , Femenino , Edad Gestacional , Humanos , Hidrólisis , Péptidos/metabolismo , EmbarazoRESUMEN
Fifty percent of human uterine collagen has been solubilized by limited pepsin digestion. Carboxymethyl cellulose-, Bio-gel A-5m-chromatography and amino acid analysis revealed that the solubilized collagen consists of 20% Type III and 80% Type I collagen. Reduction and alkylation reactions indicated that the alpha1(III) collagen is in the tissue as a trimer with the chain composition [alpha1(III)].
Asunto(s)
Colágeno/análisis , Útero/análisis , Adulto , Aminoácidos/análisis , Femenino , HumanosRESUMEN
The intermolecular cross-links have been studied in the uterine insoluble collagen of guinea pig, pig, cow, and human beings with a single given procedure. After NaB3H4 reduction, there are three intermolecular cross-links; namely, dihydroxylysinonorleucine, hydroxylysinonorleucine, and histidinohydroxymerodesmosine. In human uterine collagen samples these reduced cross-links are present in equal amounts. The reduced intermolecular collagen cross-links of uterine leiomyoma are very similar to those of the normal uterine tissue. Dihydroxylysinonorleucine is the principal reduced cross-link in uterine collagen of guinea pig, pig, and cow. Alkaline hydrolysis reveals that dehydrodihydroxylysinonorleucine and dehydrohydroxylysinonorleucine occur in vivo as glycosylated derivatives.