29D7 improves functional outcome following H-I injury.

<p>P7 rats underwent sham operation (Sham) or H-I brain injury by left carotid ligation and subsequent exposure to hypoxia for 2.5 h. H-I animals received an icv administration of 0.3 nmol control IgG or 29D7, 0.3 nmol prior to hypoxia. <b>A.</b> Sensorimotor function was assessed by a tape-removal test at P28, P35, and P42. Data represent mean ± SEM. *P<0.05 compared with sham; #P<0.05 compared with IgG treated group, analyzed by ANOVA and Dunnett’s multiple comparison test. <b>B.</b> Correlation between % cortical tissue loss and functional performances. Functional performance of individual animals in A was plotted against the percentage of cortical tissue loss, as exemplified in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0088962#pone-0088962-g004" target="_blank">Figure 4C</a>. <b>C.</b> Motor coordination function was assessed by a rotarod test 3 weeks after H-I injury. <i>P</i>>0.05 between groups.</p

29D7 induces phosphorylation of ERK1/2 in neurons.

<p>P7 rats received an icv injection of either IgG or 0.3(<i>n</i> = 5 per group). Coronally sectioned brain sections were immunofluorescently double-labeled with anti-phospho-ERK1/2 (pERK1/2) antibody (red) and a neuron-specific marker, NeuN (green), followed by fluorescent microscopy. Note that pERK1/2 signals are co-localized with NeuN staining (indicated by yellow signals) in the cortex ipsilateral to icv injection. Scale bar: 50 µm.</p

29D7 blocks caspase-3 activation following H-I brain injury.

<p>P7 rats underwent left carotid ligation followed by hypoxic injury for 2.5-four hours later, brain tissues were dissected from the hippocampus (A, C) and the cortex (B, D). <b>A, B.</b> Tissues were lysed and caspase-3 activity was determined by Asp-Glu-Val-Asp-7-amino-4-methyl-coumarin (DEVD-AMC) cleavage assay. Data indicate mean ± SEM. * p<0.05 compared with contralateral hemisphere; # p<0.05 compared with a IgG-treated ipsilateral hemisphere, as analyzed by ANOVA followed by Dunnett’s comparison method. <b>C, D</b>. Tissue proteins (30 µg/lane) were separated by SDS-PAGE and subjected to immunoblotting with antibodies specific to poly(ADP-ribose) polymerase (PARP), α-spectrin, and β-actin. Data shown are representative of 6 independent experiments.</p

29D7 does not affect body temperature.

<p>P7 rats underwent left common carotid ligation or sham surgery, followed by hypoxia for 2.5-I injury were treated with an icv administration of control IgG or 29D7 immediately before hypoxia. Body temperature of the pups was measured at various time points indicated using a digital infrared thermometer. Data indicate mean ± SEM. No significance between groups assessed by one way ANOVA (<i>P</i>>0.05).</p

29D7 exerts long-term neuroprotection against H-I brain injury.

<p>P7 rats underwent left carotid ligation and hypoxia for 2.5(0.1 nmol or 0.3 nmol) prior to hypoxia. Seven days later, brains were removed, coronally sectioned, and stained with cresyl violet. <b>A.</b> Representative photographs illustrating hemispheric tissue loss after H-I injury. <b>B.</b> Area tissue loss from the striatum, hippocampus, and cortex was determined by comparing the area of surviving tissue with unlesioned (right) hemisphere. Data indicate mean ± SEM. *P<0.05 compared to the IgG-treated group. <b>C.</b> Animals used in behavioral studies in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0088962#pone-0088962-g005" target="_blank">Fig. 5</a> were subjected to tissue loss analysis at P42. *P<0.05 compared to the sham-operated group; #P<0.05 compared to a control IgG-treated, H-I group.</p

29D7 increases phosphorylation of ERK1/2 and AKT in vivo.

<p>P7 rat pups received an icv injection of control IgG or 29D7 (0.3 nmol in 5 µl PBS) and the cortical tissues were dissected at various time points as indicated. Following preparation of tissue lysates, proteins (30 µg/lane) were separated by SDS-PAGE and transferred to nitrocellulose membranes. Immunoblotting was performed with antibodies specific to phosphorylated ERK1/2 (pERK1/2) and total ERK1/2, and phosphorylated AKT (pAKT) and total AKT proteins. Signal intensity was quantified by densitometry and normalized to corresponding total proteins. Since IgG treatment had no effect on the levels of pERK1/2 and pAKT (<i>P</i>>0.05) for up to 24 h, all time points of the IgG-treated groups were pooled. Data represent mean ± SEM (<i>n</i> = 4–5). *P<0.05 compared with the IgG-treated group by ANOVA followed by Dunnett’s multiple comparison (A–B). <b>C.</b> Levels of phosphorylated ERK1/2 and phosphorylated AKT were compared in male vs. female mice 2–6 h after icv injection of 29D7, 0.3 nmol (<i>n</i> = 5). N.S.: no significance between male and female mice assessed by <i>t</i>-test (<i>P</i>>0.05).</p

Tunable Exciton Dissociation and Luminescence Quantum Yield at a Wide Band Gap Nanocrystal/Quasi-Ordered Regioregular Polythiophene interface

A comprehensive understanding of the effect of polymer chain aggregation-induced molecular ordering and the resulting formation of lower excited energy structures in a conjugated polymer on exciton dissociation and recombination at the interface with a wide-bandgap semiconductor is provided through correlation between structural arrangement of the polymer chains and the consequent electrical and optoelectronic properties. A vertical diode-type photovoltaic test probe is combined with a field effect current modulating device and various spectroscopic techniques to isolate the interfacial properties from the bulk properties. Enhanced energy migration in the quasi-ordered (poly­(3-hexylthiophene)) (P3HT) film, processed through vibration-induced aggregation of polymer chains in solution state, is attributed to the presence of the aggregation-induced interchain species in which excitons are allowed to migrate through low barrier energy sites, enabling efficient iso-energetic charge transfer followed by the downhill energy transfer. We discovered that formation of nonemissive excitons that reduces the photoluminescence quantum yield in the P3HT film deactivates exciton dissociation at the donor (P3HT) close to the acceptor (ZnO) as well as in the P3HT far away from the ZnO. In other words, exciton deactivation in its film state arising from the quasi-ordered structural arrangement of polymer chains in solution is retained at the donor/acceptor interface as well as in the bulk P3HT. Effect of change in the highest occupied molecular orbital level and the resulting energy band bending at the P3HT/ZnO interface on exciton dissociation is also discussed in relation to the presence of vibration-induced aggregates in the P3HT film

Competition between Charge Transport and Energy Barrier in Injection-Limited Metal/Quantum Dot Nanocrystal Contacts

Injection-limited contacts in many of electronic devices such as light-emitting diodes (LEDs) and field effect transistors (FETs) are not easily avoided. We demonstrate that charge injection in the injection-limited contact is determined by charge transport properties as well as the charge injection energy barrier due to vacuum energy level alignment. Interestingly, injection-limited contact properties were observed at 5 nm diameter lead sulfide (PbS) quantum dot (QD)/Au contacts for which carrier injection is predicted to be energetically favorable. To probe the effect of charge transport properties on carrier injection, the electrical channel resistance of PbS nanocrystal (NC) FETs was varied through thermal annealing, photoillumination, ligand exchange, surface treatment of the gate dielectric, and use of different sized PbS NCs. Injection current through the PbS/Au contact varied with the FET mobility of PbS NC films consistent with a theoretical prediction where the net injection current is dominated by carrier mobility. This result suggests that the charge transport properties, that is, mobility, of QD NC films should be considered as a means to enhance carrier injection along with the vacuum level energy alignment at the interface between QD NCs and metal electrodes. Photocurrent microscopic images of the PbS/Au contact demonstrate the presence of a built-in potential in a two-dimensionally continuous PbS film near the metal electrodes