A critical bioenergetic switch is regulated by IGF2 during murine cartilage development.

Long bone growth requires the precise control of chondrocyte maturation from proliferation to hypertrophy during endochondral ossification, but the bioenergetic program that ensures normal cartilage development is still largely elusive. We show that chondrocytes have unique glucose metabolism signatures in these stages, and they undergo bioenergetic reprogramming from glycolysis to oxidative phosphorylation during maturation, accompanied by an upregulation of the pentose phosphate pathway. Inhibition of either oxidative phosphorylation or the pentose phosphate pathway in murine chondrocytes and bone organ cultures impaired hypertrophic differentiation, suggesting that the appropriate balance of these pathways is required for cartilage development. Insulin-like growth factor 2 (IGF2) deficiency resulted in a profound increase in oxidative phosphorylation in hypertrophic chondrocytes, suggesting that IGF2 is required to prevent overactive glucose metabolism and maintain a proper balance of metabolic pathways. Our results thus provide critical evidence of preference for a bioenergetic pathway in different stages of chondrocytes and highlight its importance as a fundamental mechanism in skeletal development.

Stable and Efficient Nanofilm Pure Evaporation on Nanopillar Surfaces.

Molecular dynamics simulations were conducted to systematically investigate how to maintain and enhance nanofilm pure evaporation on nanopillar surfaces. First, the dynamics of the evaporation meniscus and the onset and evolution of nanobubbles on nanopillar surfaces were characterized. The meniscus can be pinned at the top surface of the nanopillars during evaporation for perfectly wetting fluid. The curvature of the meniscus close to nanopillars varies dramatically. Nanobubbles do not originate from the solid surface, where there is an ultrathin nonevaporation film due to strong solid-fluid interaction, but originate and evolve from the corner of nanopillars, where there is a quick increase in potential energy of the fluid. Second, according to a parametric study, the smaller pitch between nanopillars (P) and larger diameter of nanopillars (D) are found to enhance evaporation but also raise the possibility of boiling, whereas the smaller height of nanopillars (H) is found to enhance evaporation and suppress boiling. Finally, it is revealed that the nanofilm thickness should be maintained beyond a threshold, which is 20 Å in this work, to avoid the suppression effect of disjoining pressure on evaporation. Moreover, it is revealed that whether the evaporative heat transfer is enhanced on the nanopillar surface compared with the smooth surface is also affected by the nanofilm thickness. The value of nanofilm thickness should be determined by the competition between the suppression effect on evaporation due to the decrease in the volume of supplied fluid and the existence of capillary pressure and the enhancement effect on evaporation due to the increase in the heating area. Our work serves as the guidelines to achieve stable and efficient nanofilm pure evaporative heat transfer on nanopillar surfaces.

[Fluorescent labeling of latent fingerprints with metallic ions modified ZnS/PAMAM nano-composites].

Abstract Effects of metallic ions, such as Zn2+ , Mn , Cd2+, Na+, K+, Ag, CuZ+ and PbZ, on the photoluminescence properties of ZnS(ZINC sulfide) QDs (quantum dots)/poly (amido amine) (PAMAM) dendrimer nanocomposites(NCs) with blue emission under the irradiation of UV light were studied. The results show that the effects of different metallic ions on the photoluminescence properties of the prepared ZnS QDs were different. Zn+ , Mn2+ and Cd2+ ions enhance the PL(photoluminescence) intensity; Na+ and K+ ions don't change the PL intensity obviously while Ag+, Cu2+ and Pb2+ quench it. Compared with ZnS/PAMAM NCs, fingerprints treated with ZnxCd1-x) S/PAMAM NCs emitted brighter blue light, the contrast between abstracts and fingerprints was more obvious, which shows good reference

[tMfn2 gene transfer promotes vascular smooth-muscle cells apoptosis via activation of the mitochondrial cell death pathway].

OBJECTIVE: To investigate the effect of tMfn2 gene transfer on promoting the apoptosis of vascular smooth-muscle cells (VSMCs). METHODS: VSMCs were infected by adenovirus-mediated tMfn2 (Adv-tMfn2) or adenovirus-mediated Mfn2 (Adv-Mfn2). FACS analysis, cell death ELISA and TUNEL staining were used to investigate the role of tMfn2 and Adv-Mfn2 gene transfer on VSMCs apoptosis. Western blot was used to analyze the protein expression of p-Akt, Bcl-2, Bax and cleaved caspase-9. RESULTS: FACS and ELISA results showed that tMfn2 was superior to Mfn2 in promoting VSMCs apoptosis and tMfn2 gene transfer induced VSMCs apoptosis in a time-dependent manner (P < 0.01). TUNEL staining evidenced that there were more positive-apoptotic VSMCs in tMfn2 group than that in Mfn2 group (P < 0.01). The protein expressions of phosphorylated Akt and Bcl-2 were significantly decreased, whereas Bax and cleaved caspase-9 protein expressions were significantly upregulated in tMfn2-transfected VSMCs. CONCLUSIONS: tMfn2 transfer promoted apoptosis of VSMCs in a time dependent manner via the PI3K-Akt signaling pathway and mitochondrial apoptotic pathway.