Time-resolved pump and probe x-ray absorption fine structure spectroscopy at beamline P11 at PETRA III.

We report about the development and implementation of a new setup for time-resolved X-ray absorption fine structure spectroscopy at beamline P11 utilizing the outstanding source properties of the low-emittance PETRA III synchrotron storage ring in Hamburg. Using a high intensity micrometer-sized X-ray beam in combination with two positional feedback systems, measurements were performed on the transition metal complex fac-Tris[2-phenylpyridinato-C2,N]iridium(III) also referred to as fac-Ir(ppy)3. This compound is a representative of the phosphorescent iridium(III) complexes, which play an important role in organic light emitting diode (OLED) technology. The experiment could directly prove the anticipated photoinduced charge transfer reaction. Our results further reveal that the temporal resolution of the experiment is limited by the PETRA III X-ray bunch length of ∼103 ps full width at half maximum (FWHM).

Neuronal ceroid lipofuscinosis: late infantile or Jansky Bielschowsky type--re-revisited.

Among the now eight genetic types of neuronal ceroid-lipofuscinoses (NCL), CLN1 to CLN8, CLN2 is considered classic late-infantile NCL. It was originally described by Jansky in a family of eight children with four of them affected [Jansky J (1908) Sborn Lék 13:165-196] and, subsequently, by Bielschowsky in a family of three children each of whom was affected, and, hence, termed Jansky-Bielschowsky type of NCL. Earlier, archival studies of Bielschowsky's original post-mortem tissue blocks had documented accumulation of autofluorescent lipopigments with a curvilinear ultrastructure. In a subsequent study, described here, immunohistochemical absence of the CLN2-related lysosomal enzyme tripeptidyl peptidase-I and two heterozygous mutations in the CLN2 gene could be demonstrated in these archival tissues, further corroborating the identity of Bielschowsky's familial disorder and CLN2 described by M. Bielschowsky at the beginning of the last century. Furthermore, these immunohistochemical and mutational investigations underscore the value of archival tissue studies.

Immunohistopathologic spectrum of the glial fibrillary acidic protein in neurooncology.

To conventional histologic and special staining techniques as well as electron microscopy, immunohistological methods have recently been added to characterize neuroectodermal and non-neuroectodermal tumors of both the central and the peripheral nervous system. An ever increasing panel of these morphologic techniques enables us today, to characterize precisely such tumors in or around the central and peripheral nervous system, sometimes only hampered by preservation of tissue inadequate for the respective methods.