Further Studies on Lactation and Rearing of Young

The work performed in this laboratory and elsewhere during the past fifteen years has shown conclusively that a diet adequate for growth may not necessarily fulfill the requirements for lactation. The excellent work of Evans and Bishop (1) has conclusively demonstrated that a specific vitamin is required for reproduction. The fact that lactation is not normal on many synthetic and even natural diets suggests the possibility that all of the factors necessary for normal development are not known. The work in this paper was planned in order to increase our knowledge concerning the nutritional factors involved in milk secretion and rearing of young

Studies on Vitamins B and G

Considerable data have accumulated during the last decade on the role of diet in reproduction and rearing of young. The problem is an important one and merits careful consideration, because of the relation between the results on animal experiments and infant mortality and failure of milk secretion in the human and domestic animals

Results of the Cooperative Uniform Soybean Tests, 1947 Part I. North Central States

United States Department of Agriculture, Agricultural Research Administration; Bureau of Plant Industry, Soils, and Agricultural Engineering, Division of Forage Crops and Diseases Cooperating with State Agricultural Experiment Station

Results of the Cooperative Uniform Soybean Tests Part I. North Central States 1949

United States Department of Agriculture, Agricultural Research Administration; Bureau of Plant Industry, Soils, and Agricultural Engineering, Division of Forage Crops and Diseases Cooperating with State Agricultural Experiment Station

Results of the Cooperative Uniform Soybean Tests, 1946 Part I. North Central States

United States Department of Agriculture, Agricultural Research Administration; Bureau of Plant Industry, Soils, and Agricultural Engineering, Division of Forage Crops and Diseases Cooperating with State Agricultural Experiment Station

Results of the Cooperative Uniform Soybean Tests, 1945. Part I. North Central States

United States Department of Agriculture Agricultural Research Administration Bureau of Plant Industry, Soils, and Agricultural Engineering, Division of Forage Crops and Diseases Cooperating with State Agricultural Experiment Station

Combinatorial Polymer Electrospun Matrices Promote Physiologically-Relevant Cardiomyogenic Stem Cell Differentiation

Myocardial infarction results in extensive cardiomyocyte death which can lead to fatal arrhythmias or congestive heart failure. Delivery of stem cells to repopulate damaged cardiac tissue may be an attractive and innovative solution for repairing the damaged heart. Instructive polymer scaffolds with a wide range of properties have been used extensively to direct the differentiation of stem cells. In this study, we have optimized the chemical and mechanical properties of an electrospun polymer mesh for directed differentiation of embryonic stem cells (ESCs) towards a cardiomyogenic lineage. A combinatorial polymer library was prepared by copolymerizing three distinct subunits at varying molar ratios to tune the physicochemical properties of the resulting polymer: hydrophilic polyethylene glycol (PEG), hydrophobic poly(ε-caprolactone) (PCL), and negatively-charged, carboxylated PCL (CPCL). Murine ESCs were cultured on electrospun polymeric scaffolds and their differentiation to cardiomyocytes was assessed through measurements of viability, intracellular reactive oxygen species (ROS), α-myosin heavy chain expression (α-MHC), and intracellular Ca2+ signaling dynamics. Interestingly, ESCs on the most compliant substrate, 4%PEG-86%PCL-10%CPCL, exhibited the highest α-MHC expression as well as the most mature Ca2+ signaling dynamics. To investigate the role of scaffold modulus in ESC differentiation, the scaffold fiber density was reduced by altering the electrospinning parameters. The reduced modulus was found to enhance α-MHC gene expression, and promote maturation of myocyte Ca2+ handling. These data indicate that ESC-derived cardiomyocyte differentiation and maturation can be promoted by tuning the mechanical and chemical properties of polymer scaffold via copolymerization and electrospinning techniques