Erythropoietin Amplifies Stroke-Induced Oligodendrogenesis in the Rat

Erythropoietin (EPO), a hematopoietic cytokine, enhances neurogenesis and angiogenesis during stroke recovery. In the present study, we examined the effect of EPO on oligodendrogenesis in a rat model of embolic focal cerebral ischemia.Recombinant human EPO (rhEPO) at a dose of 5,000 U/kg (n = 18) or saline (n = 18) was intraperitoneally administered daily for 7 days starting 24 h after stroke onset. Treatment with rhEPO augmented actively proliferating oligodendrocyte progenitor cells (OPCs) measured by NG2 immunoreactive cells within the peri-infarct white matter and the subventricular zone (SVZ), but did not protect against loss of myelinating oligodendrocytes measured by cyclic nucleotide phosphodiesterase (CNPase) positive cells 7 days after stroke. However, 28 and 42 days after stroke, treatment with rhEPO significantly increased myelinating oligodendrocytes and myelinated axons within the peri-infarct white matter. Using lentivirus to label subventricular zone (SVZ) neural progenitor cells, we found that in addition to the OPCs generated in the peri-infarct white matter, SVZ neural progenitor cells contributed to rhEPO-increased OPCs in the peri-infarct area. Using bromodeoxyuridine (BrdU) for birth-dating cells, we demonstrated that myelinating oligodendrocytes observed 28 days after stroke were derived from OPCs. Furthermore, rhEPO significantly improved neurological outcome 6 weeks after stroke. In vitro, rhEPO increased differentiation of adult SVZ neural progenitor cells into oligodendrocytes and enhanced immature oligodendrocyte cell proliferation.Our in vivo and in vitro data indicate that EPO amplifies stroke-induced oligodendrogenesis that could facilitate axonal re-myelination and lead to functional recovery after stroke

The effects of strength-based versus deficit-based self-regulated learning strategies on students' effort intentions

In two randomized experiments, one conducted online (n = 174) and one in the classroom (n = 267), we tested the effects of two types of self-regulated learning (SRL) strategies on students’ intentions to put effort into professional development activities: strength-based SRL strategies (i.e., identifying perceived relative strengths and, subsequently, selecting professional development activities to further improve those strengths) versus deficit-based SRL strategies (i.e., identifying perceived relative short- comings and, subsequently, selecting professional develop- ment activities to improve those shortcomings). Across both studies, analysis of variance revealed that, relative to students who used deficit-based SRL strategies, students who used strength-based SRL strategies were higher in perceived competence, intrinsic motivation, and effort in- tentions. Moreover, the results of multi-mediator analysis and structural equation modeling supported the hypothesis that the effect of strength-based versus deficit-based SRL strategies on students’ effort intentions was sequentially mediated by perceived competence and intrinsic motiva- tion. Implications for the application of self-regulated learning strategies in the context of professional self-de- velopment are discussed

Synthesis and photochromic studies of η 6-mesitylene ruthenium(ii) complexes bearing N-heterocyclic carbene ligands with the dithienylethene moiety

A series of half-sandwich type ruthenium(ii) complexes, [(η 6-mesitylene)Ru(NHC-L)Cl]PF 6 (NHC = N-heterocyclic carbene, L = azole and imine ligand), containing the dithienylethene moiety has been synthesized and characterized by 1H NMR, X-ray crystallography and electronic absorption spectroscopy. These complexes show photochromic properties upon UV photo-irradiation to generate the closed forms of the dithienylethene moiety. © 2011 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.link_to_subscribed_fulltex

Photochromic thienylpyridine-bis(alkynyl)borane complexes: towards readily tunable fluorescence dyes and photoswitchable materials

INORG-6

Photochromic Thienylpyridine–Bis(alkynyl)borane Complexes: Toward Readily Tunable Fluorescence Dyes and Photoswitchable Materials

A series of diarylethene-containing N ^C chelated thienylpyridine-bis(alkynyl)borane complexes has been designed and synthesized. Their photophysical and photochromic properties have been investigated and presented. The characteristic low-energy absorption band of their closed forms could be readily tuned from the visible range to the near-infrared region. © 2012 American Chemical Society.link_to_subscribed_fulltex

Metal-oxo photo-oxidants: Photochemical oxidation of hydrocarbons by trans-dioxo complexes of ruthenium(VI) and osmium(VI)

The synthesis of trans-[RuVI(L)(O)2]Y2 (Y = PF6 or ClO4) and trans-[RuIV(L)(NCO)(O)] ClO4 {L = meso-1,2,6,10,11-pentamethyl-2,6,10-triaza[11](2,6) pyridinophane} is described; irradiation of trans-[RuVI(L)(O) 2]2+ and [OsVI(CN)4(O) 2]2- (λ > 330 nm) in presence of organic substrates yielded the corresponding oxidized organic products indicating that the (dxy)1(dπ*)1 excited states of RuVI- and OsVI-oxo complexes are reactive towards epoxidation of alkenes and to oxidation of C-H bonds.link_to_subscribed_fulltex

Luminescent cyclometalated alkynylgold(III) complexes with 6-phenyl-2,2′-bipyridine derivatives: Synthesis, characterization, electrochemistry, photophysics, and computational studies

A novel class of luminescent gold(III) complexes containing various tridentate cyclometalating ligands derived from 6-phenyl-2,2′-bipyridine and alkynyl ligands, [Au(RC ̂N ̂N)(C≡C-R')] PF 6, has been successfully synthesized and characterized. One of the complexes has also been determined by X-ray crystallography. Electrochemical studies show a ligand-centered reduction originated from the cyclometalating RC ̂N ̂N ligands as well as an alkynyl-centered oxidation. The electronic absorption and photoluminescence properties of the complexes have also been investigated. In acetonitrile at room temperature, the complexes show intense absorption at higher energy region with wavelength shorter than 320 nm, and a moderately intense broad absorption band at 374-406 nm, assigned as the metal-perturbed intraligand π-π* transition of the cyclometalating RC ̂N ̂N ligand, with some charge transfer character from the aryl ring to the bipyridine moiety. Most of the complexes have been observed to show vibronic-structured emission bands at 469-550 nm in butyronitile glass at 77 K, assigned to an intraligand excited state of the RC ̂N ̂N ligand, with some charge transfer character from the aryl to the bipyridyine moiety. Insights into the origin of the absorption and emission have also been provided by density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations. © 2012 American Chemical Society.link_to_subscribed_fulltex

Spectroscopy and X-ray crystal structure of luminescent Pt2(dppm)2(CN)4 [dppm = bis(diphenylphosphino)methane]

The reaction of Pt(CN)2·xH2O with dppm [bis(diphenylphosphino)methane] in refluxing dimethylformamide (DMF) yielded Pt2(dppm)2(CN)4. The X-ray structure of this binuclear platinum(II) complex has been determined: Pt2(dppm)2(CN)4·2DMF, space group P21/n, Z = 2, a = 11.561 (1) Å, b = 17.475 (1) Å, c = 13.981 (5) Å, β = 95.34 (2)°. The Pt2(dppm)2(CN)4 molecule adopts the trans,trans geometry and consists of two platinum atoms bridged by two dppm groups, with two trans cyanide ions bonded to each platinum atom. The measured Pt⋯Pt distance is 3.301 (1) Å, indicative of a weak Pt⋯Pt bonding interaction. The UV-vis absorption spectrum of methanolic solutions of Pt2(dppm)2(CN)4 exhibits an intense band at 324 nm (εmax 10 500) and a weak band at ca. 390 nm, assigned to the 1A1g → 1B1u and 1A1g → 3B1u transitions, respectively. Excitation of Pt2-(dppm)2(CN)4 at 324 nm in degassed methanol leads to an intense emission at 425 nm with a shoulder at ca. 530 nm. The room-temperature triplet lifetime has been found to be 0.23 μs in degassed methanol. © 1989 American Chemical Society.link_to_subscribed_fulltex