VEGF and IHH rescue definitive hematopoiesis in Gata-4 and Gata-6-deficient murine embryoid bodies.

Objective: Murine embryonic stem cells can be differentiated into embryoid bodies (EBs), which serve as an in vitro model recapitulating many aspects of embryonic yolk sac hematopoiesis. Differentiation of embryonic stem cells deficient in either Gata-4 or Gata-6 results in EBs with disrupted visceral endoderm (VE). While lack of VE has detrimental effects on hematopoiesis in vivo, it is unclear whether lack of VE affects hematopoiesis in EBs.

Wood cellulose preparation methods and mass spectrometric analyses of delta13C, delta18O, and nonexchangeable delta2H values in cellulose, sugar, and starch: an interlaboratory comparison.

Interlaboratory comparisons involving nine European stable isotope laboratories have shown that the routine methods of cellulose preparation resulted in data that generally agreed within the precision of the isotope ratio mass spectrometry (IRMS) method used: +/-0.2 per thousand for carbon and +/-0.3 per thousand for oxygen.