Ultrafast Energy Transfer from Photoexcited Tryptophan to the Haem in Cytochrome c.

We report femtosecond Fe K-edge absorption (XAS) and nonresonant X-ray emission (XES) spectra of ferric cytochrome C (Cyt c) upon excitation of the haem (>300 nm) or mixed excitation of the haem and tryptophan (<300 nm). The XAS and XES transients obtained in both excitation energy ranges show no evidence for electron transfer processes between photoexcited tryptophan (Trp) and the haem, but rather an ultrafast energy transfer, in agreement with previous ultrafast optical fluorescence and transient absorption studies. The reported ( , 115 (46), 13723-13730) decay times of Trp fluorescence in ferrous (∼350 fs) and ferric (∼700 fs) Cyt c are among the shortest ever reported for Trp in a protein.

Generation and simple characterization of flat, liquid jets.

We present an approach to determine the absolute thickness profile of flat liquid jets, which takes advantage of the information of thin film interference combined with light absorption, both captured in a single microscopic image. The feasibility of the proposed method is demonstrated on our compact experimental setup used to generate micrometer thin, free-flowing liquid jet sheets upon collision of two identical laminar cylindrical jets. Stable operation was achieved over several hours of the flat jet in vacuum (10 mbar), making the system ideally suitable for soft x-ray photon spectroscopy of liquid solutions.

Spin cascade and doming in ferric hemes: Femtosecond X-ray absorption and X-ray emission studies.

The structure-function relationship is at the heart of biology, and major protein deformations are correlated to specific functions. For ferrous heme proteins, doming is associated with the respiratory function in hemoglobin and myoglobins. Cytochrome (Cyt c) has evolved to become an important electron-transfer protein in humans.

Taking a snapshot of the triplet excited state of an OLED organometallic luminophore using X-rays.

OLED technology beyond small or expensive devices requires light-emitters, luminophores, based on earth-abundant elements. Understanding and experimental verification of charge transfer in luminophores are needed for this development. An organometallic multicore Cu complex comprising Cu-C and Cu-P bonds represents an underexplored type of luminophore.

Accurate gas-phase structure of para-dioxane by fs Raman rotational coherence spectroscopy and ab initio calculations.

p-Dioxane is non-polar, hence its rotational constants cannot be determined by microwave rotational coherence spectroscopy (RCS). We perform high-resolution gas-phase rotational spectroscopy of para-dioxane-h and -d using femtosecond time-resolved Raman RCS in a gas cell at T = 293 K and in a pulsed supersonic jet at T∼130 K. The inertial tensor of p-dioxane-h is strongly asymmetric, leading to a large number of asymmetry transients in its RCS spectrum.

Sites of failure in breast cancer patients with extracapsular invasion of axillary lymph node metastases. No need for axillary irradiation?!

Background And Purpose: Extracapsular spread (ECS) is frequent, but the specific sites of relapse are seldom given in the literature. In this study it was evaluated, if ECS might be an indicator for axillary irradiation.

Patients And Methods: After a retrospective review of pathology reports, the information about ECS was available in 254 lymph node-positive patients: ECS was absent in 34% (ECS-negative; n = 87) and present in 66% (ECS-positive; n = 167).