6 research outputs found
Optical Modeling of Microcrystalline Silicon Deposited by Plasma-Enhanced Chemical Vapor Deposition on Low-Cost Iron-Nickel Substrates for Photovoltaic Applications
AbstractThis paper deals with the optical modeling of thin hydrogenated microcrystalline silicon films grown on flexible low-cost iron-nickel alloy substrates by low-temperature (175°C) plasma-enhanced chemical vapor deposition. This material serves as the absorber in solar cells and hence it has direct impact on the resulting solar cell performance. Since the crystallinity and the material quality of hydrogenated microcrystalline silicon films evolve during the growth, the deposited film is inhomogeneous, with a rather complex structure. Real-time spectroscopic ellipsometry has been used to trace the changing composition of the films. In-situ ellipsometric data taken for photon energies from 2.8 to 4.5eV every 50seconds enabled us to study the evolution of the monocrystalline silicon fraction of the hydrogenated microcrystalline silicon films
Novel ophiostomatalean fungi from galleries of Cyrtogenius africus (Scolytinae) infesting dying Euphorbia ingens
Euphorbia ingens trees have been dying in
large numbers in the Limpopo Province of South
Africa for approximately 15 years. The ambrosia
beetle Cyrtogenius africus is often found infesting
diseased and dying trees. The aim of this study was to
identify the ophiostomatoid fungi occurring in the
galleries of C. africus. Logs infested with this beetle
were collected from the KwaZulu-Natal, Limpopo,
Mpumalanga, and North West Provinces of South
Africa. Fungi belonging to the Ophiostomatales were
identified based on morphology and comparison of
sequence data for the b-tubulin, ITS1-5.8S-ITS2 and
LSU gene regions. A novel species of Ophiostoma and
a novel genus in the Ophiostomatales were identified.
Inoculation studies with these fungi produced lesions
in the branches of healthy E. ingens trees.Department of Science and Technology (DST), National Research Foundation (NRF) and DST/NRF Centre of Excellence in Tree Health Biotechnology (CTHB).http://link.springer.com/journal/104822017-04-28hb2016Forestry and Agricultural Biotechnology Institute (FABI)Microbiology and Plant Patholog
Chronic Delivery of a Thrombospondin-1 Mimetic Decreases Skeletal Muscle Capillarity in Mice
Angiogenesis is an essential process for normal skeletal muscle function. There is a growing body of evidence suggesting that thrombospondin-1 (TSP-1), a potent antiangiogenic protein in tumorigenesis, is an important regulator of both physiological and pathological skeletal muscle angiogenesis. We tested the hypothesis that chronic exposure to a TSP-1 mimetic (ABT-510), which targets the CD36 TSP-1 receptor, would decrease skeletal muscle capillarity as well as alter the balance between positive and negative angiogenic proteins under basal conditions. Osmotic minipumps with either ABT-510 or vehicle (5% dextrose) were implanted subcutaneously in the subscapular region of C57/BL6 mice for 14 days. When compared to the vehicle treated mice, the ABT-510 group had a 20% decrease in capillarity in the superficial region of the gastrocnemius (GA), 11% decrease in the plantaris (PLT), and a 35% decrease in the soleus (SOL). ABT-510 also decreased muscle protein expression of vascular endothelial growth factor (VEGF) in both the GA (−140%) and SOL (−62%); however there was no change in VEGF in the PLT. Serum VEGF was not altered in ABT-510 treated animals. Endogenous TSP-1 protein expression in all muscles remained unaltered. Tunnel staining revealed no difference in muscle apoptosis between ABT-510 and vehicle treated groups. These data provide evidence that the anti-angiogenic effects of TSP-1 are mediated, at least in part, via the CD36 receptor. It also suggests that under physiologic conditions the TSP-1/CD36 axis plays a role in regulating basal skeletal muscle microvessel density