Alterations in the liver of intrauterine growth retarded piglets may predispose to development of insulin resistance and obesity in later life.

Intrauterine growth retardation (IUGR) leads to increased predisposition to metabolic syndrome in adult life but the mechanisms remain obscure. Considering a significant number of functional similarities, IUGR piglets appear to be a good model to study the development of this syndrome in humans. The aim of the present study was to investigate the ultrastructure and proteomic profile of the liver in IUGR pig neonates to discover early markers of predisposition to obesity and insulin resistance. In our study intestine and liver tissue samples were investigated in 7 day old IUGR and normal body weight (NBW) littermate piglets using histometry, mass spectrometry, in-tissue cytometry analysis and confocal microscopy. Compared to NBW, the liver in IUGR neonates was characterized by a significantly enhanced ratio of Kupffer cells to hepatocytes and insulin receptor abundance as well as higher percentages of cells expressing receptors for adipokines (resistin and adiponectin), increased expression of TNF-α (as marker of inflammation), and increased expression of insulin receptor and uncoupling protein 3 (UCP3). Moreover, NBW and IUGR differed in proteomic profile, including protein metabolism (proteasomes, cathepsin D, phermitin, phosphoglucomutase), carbohydrate metabolism (hexokinase 1, phosphoglucokinase, galactokinase, aldolase B, glucose-6-phosphate isomerase), oxidative stress and chromatin organization and DNA uptake (histones, lamin a/c). Reduction of hepatocyte numbers concomitant with significant modifications of expression of key hormones and enzymes for protein and carbohydrate metabolism in IUGR neonates may predispose to insulin resistance and obesity in adult life.

Self-amplified photo-induced gap quenching in a correlated electron material.

Capturing the dynamic electronic band structure of a correlated material presents a powerful capability for uncovering the complex couplings between the electronic and structural degrees of freedom. When combined with ultrafast laser excitation, new phases of matter can result, since far-from-equilibrium excited states are instantaneously populated. Here, we elucidate a general relation between ultrafast non-equilibrium electron dynamics and the size of the characteristic energy gap in a correlated electron material. We show that carrier multiplication via impact ionization can be one of the most important processes in a gapped material, and that the speed of carrier multiplication critically depends on the size of the energy gap. In the case of the charge-density wave material 1T-TiSe2, our data indicate that carrier multiplication and gap dynamics mutually amplify each other, which explains-on a microscopic level-the extremely fast response of this material to ultrafast optical excitation.

Speedup of doping fronts in organic semiconductors through plasma instability.

The dynamics of doping transformation fronts in organic semiconductor plasma is studied for application in light-emitting electrochemical cells. We show that new fundamental effects of the plasma dynamics can significantly improve the device performance. We obtain an electrodynamic instability, which distorts the doping fronts and increases the transformation rate considerably. We explain the physical mechanism of the instability, develop theory, provide experimental evidence, perform numerical simulations, and demonstrate how the instability strength may be amplified technologically. The electrodynamic plasma instability obtained also shows interesting similarity to the hydrodynamic Darrieus-Landau instability in combustion, laser ablation, and astrophysics.