X-ray Dark-Field Imaging for Improved Contrast in Historical Handwritten Literature.

If ancient documents are too fragile to be opened, X-ray imaging can be used to recover the content non-destructively. As an extension to conventional attenuation imaging, dark-field imaging provides access to microscopic structural object information, which can be especially advantageous for materials with weak attenuation contrast, such as certain metal-free inks in paper. With cotton paper and different self-made inks based on authentic recipes, we produced test samples for attenuation and dark-field imaging at a metal-jet X-ray source.

Noise Reduction for Single-Shot Grating-Based Phase-Contrast Imaging at an X-ray Backlighter.

X-ray backlighters allow the capture of sharp images of fast dynamic processes due to extremely short exposure times. Moiré imaging enables simultaneously measuring the absorption and differential phase-contrast (DPC) of these processes. Acquiring images with one single shot limits the X-ray photon flux, which can result in noisy images.

Deficits in episodic memory and mental time travel in patients with post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is characterized by impairments in mnestic functions, especially in the domain of episodic memory. These alterations might affect different aspects of episodic memory functioning. Here we tested PTSD patients and healthy controls (matched for age, sex and education) in a newly developed virtual reality episodic memory test (VR-EMT), a test for mental time travel, episodic future thinking, and prospective memory (M3xT).

Platensimycin and platencin congeners from Streptomyces platensis.

Platensimycin (1a) and platencin (2) are inhibitors of FabF and FabF/H bacterial fatty acid synthase. The discovery of natural congeners is an approach that can render a better understanding of the structure-function relationships of complex natural products. The isolation and structure elucidation of nine new congeners (11-20) of platensimycin and platencin are described from a fermentation broth of Streptomyces platensis.

Isolation, structure and biological activities of platencin A(2)-A(4) from Streptomyces platensis.

Natural products serve as a great reservoir for chemical diversity and are the greatest source for antibacterial agents. Recent discoveries of platensimycin and platencin as inhibitors of bacterial fatty acid biosynthesis enzymes supplied new chemical scaffolds for potential antibacterial agents to overcome resistant pathogens. Discovery of natural congeners augment chemical modification in understanding of structure-activity relationship (SAR).

Isolation, structure and biological activities of platensimycin B4 from Streptomyces platensis.

Platensimycin and platencin are inhibitors of FabF and FabF/H bacterial fatty acid synthesis enzymes, respectively. Discovery of natural congeners provides one of the ways to understand the relationship of chemical structure and biological function. Efforts to discover the natural analogs of platensimycin by chemical screening led to the isolation of platensimycin B(4), a glucoside congener of platensimycin.