Effects of subretinal implant materials on the viability, apoptosis and barrier function of cultured RPE cells

Background: Subretinal microphotodiode array (MPDA) is a type of visual prosthesis used for the implantation in the subretinal space of patients with progressive photoreceptor cell loss. The present study aimed to evaluate the effect of materials for MPDA on the viability, apoptosis and barrier function of cultured pig retinal pigment epithelium (RPE) cells.Methods: Primary culture of pig RPE cells was performed and 24 pig eyes were used to start RPE culture. The third passage of the cultures was plated on different materials for MPDA and MPDAs. The tetrazolium dye-reduction assay (MTT) was used to determine RPE cell viability. Flow cytometry was measured to indicate the apoptosis rates of RPE cells on different materials. RPE cells were also cultured on microporous filters, and the transepithelial resistance and permeability of the experimental molecule were measured to determine the barrier function.Results: The data from all the methods indicated no significant difference between the materials groups and the control group, and the materials tested showed good biocompatibility.Conclusions: The materials for MPDA used in the present study had no direct toxicity to the RPE cells and did not release harmful soluble factors that affected the barrier function of RPE in vitro.

Tandem organic light-emitting diodes with an effective charge-generation connection structure

The tandem organic light-emitting diodes (OLEDs) with an effective charge-generation connection structure of Mg-doped tris(8-hydroxyquinoline) aluminum (Alq(3))/Molybdenum oxide (MoO3)-doped 3, 4, 9, 10-perylenetetracarboxylic dianhydride (PTCDA) were presented. At a current density of 50 mA/cm(2), the current efficiency of the tandem OLED with two standard NPB/Alq(3) emitting units is 4.2 cd/A, which is 1.7 times greater than that of the single EL device. The tandem OLED with the similar connection structure of Mg-doped PTCDA/MoO3-doped PTCDA was also fabricated and the influences of the different connection units on the current efficiency of the tandem OLED were discussed as well.

Effect of temperature on implant isolation characteristics of AlGaAs/GaAs multilayer heterojunction structure

Thermally stable high-resistivity regions have been formed using hydrogen ion implantation at three energies (50, 100, and 180 keV) with three corresponding doses (6 X 10(14) 1.2 X 10(15), and 3 X 10(15) cm(-2)), oxygen implantation at 280keV with 2 X 10(14) cm(-2) as well as subsequent annealing at about 600 degrees C for 10-20s, in AlGaAs/GaAs multiple epitaxial heterojunction structure. After anncaling at 600 degrees C, the sheet resistivity increases by six orders more of magnitude from the as-grown values. This creation of high resistivity is different from that of the conventional damage induced isolation by H or O single implantation which becomes ineffective when anneal is carried out at 400-600 degrees C and the mechanism there of is discussed.

Efficient tandem polymer photovoltaic cells with two subcells in parallel connection

Tandem polymer photovoltaic cells with the subcells having different absorption characteristics in series connection are widely investigated to enhance absorption coverage over the solar spectrum. Herein. we demonstrate efficient tandem polymer photovoltaic cells with the two stacked subcells comprising different band-gap conjugated polymer and fullerene derivative bulk heterojunction in parallel connection. A semitransparent metal layer combined with inorganic semiconductor compounds is utilized as the intermediate electrode of the two stacked subcells to create the required built-in potential for collecting photo-generated charges. The short-circuit current of the stacked cell is the sum of the subcells and the open-circuit voltage is similar to the subcells.

A NEW SCHEME FOR ASSIGNMENT OF A CANONICAL CONNECTION TABLE

A new algorithm for deriving canonical numbering of atoms in a molecular graph has been developed. Some graph invariants, such as node properties, degree (connectivity), topological path, the smallest node ring index, etc., are encoded together to partit

Characterization of the life history of Bangia fuscopurpurea (Bangiaceae, Rhodophyta) in connection with its cultivation in China

Bangia fuscopurpurea (Rhodophyta) was cultivated in Putian (Fujian province, China). The characteristics of the life history concerned with cultivation were investigated and the cultivation procedure was presented. The gametophytic phase (thallus) and the sporophytic phase (conchocelis) occurred alternately in the life history of B. fuscopurpurea. Young thalli produced archeospores, and the number depended on the environmental factors. Temperature affected the number of archeospore release and percent of germination, and photo flux density (PFD) mainly affected the time of spore release and germination. Thalli matured from December to February and developed into the conchocelis phase through sexual reproduction. The conchocelis grown in shells had three developmental stages: vegetative conchocelis, conchosporangiall formation and conchospore formation. Pit-connections were present in the first 2 stages but absent after conchospore formation. Vegetative conchocelis and conchosporangial. branches can transform into each other. However, conchospores only developed into the gametophytic phase. Cultivation of B. fuscopurpurea was based on characterization of the life history, consisting of 3 steps: zygotospores collection, indoor cultivation of conchocelis and outdoor cultivation of thalli. Young thalli that developed from conchospores produced numerous archeospores before December. Over 90% of the crop was from the development of archeospores. The results indicated that conchosporelings were a good source of archeospores, and the development of the large quantity of archeospores acted as a more prevailing means to increase the population size. (C) 2008 Elsevier B.V. All rights reserved.