483 research outputs found
A combined 140 years: 2005 class of retirees compiled remarkable record of service to Furman: Trzupek a natural in the classroom
(2,9-Dimethyl-1,10-phenanthroline-Îş2 N,Nâ˛)diiodidocadmium
In the title compound, [CdI2(C14H12N2)], the molÂecule sits on a crystallographic twofold axis. The coordination sphere of the CdII atom is built of two symmetry-equivalent N atoms of one 2,9-dimethyl-1,10-phenanthroline (dmphen) ligand and two symmetry-equivalent I atoms, thus forming a distorted tetraÂhedral geometry. Inversion-related molÂecules interÂact along the c-axis direction by ĎâĎ stacking interÂactions between the phenanthroline ring systems, with centroidâcentroid distances of 3.707â
(9) and 3.597â
(10)â
Ă
ESR, raman and conductivity studies on fractionated poly(2-methoxyaniline-5-sulfonic acid)
Synthesis methods used to produce poly(2-methoxyaniline-5-sulfonic acid) (PMAS), a water soluble, self-doped conducting polymer, have been shown to form two distinctly different polymer fractions with molecular weights of approximately 2 kDa and 8 -10 kDa. The low molecular weight (LMWT) PMAS fraction is redox inactive and non-conducting while the high molecular weight (HMWT) PMAS is electro-active with electrical conductivities of 0.94 0.05 S cm-1. Previous investigations have illustrated the different photochemical and electrochemical properties of these fractions, but have not correlated these properties with the structural and electronic interactions that drive them. Incomplete purification of the PMAS mixture, typically via bag dialysis, has been shown to result in a mixture of approximately 50:50 HMWT:LMWT PMAS with electrical conductivity significantly lower at approximately 0.10 to 0.26 S cm-1. The difference between the electrical conductivities of these fractions has been investigated by the controlled addition of the non-conducting LMWT PMAS fraction into the HMWT PMAS composite film with the subsequent electronic properties investigated by solid-state ESR and Raman spectroscopies. These studies illustrate strong electronic intereactions of the insulating LMWT PMAS with the emeraldine salt HMWT PMAS to substantially alter the population of the electronic charge carriers in the conducting polymer. ESR studies on these mixtures, when compared to HMWT PMAS, exhibited a lower level of electron spin in the presence of LMWT PMAS indicative of the the formation of low spin bipolarons without a change the oxidation state of the conducting HMWT fraction
Outstanding Chiroptical Features of Thin Films of Chiral Oligothiophenes
A chiral benzo[1, 2-âb:4,â5-âb']âdithiophene-âbased oligothiophene with the very uncommon chiroptical property of signal inversion on sample flipping was recently described. This property is due to the interference between linear dichroism and linear birefringence, called LDLB effect, which is theor. well understood, but to date very rarely reported in the literature. Samples with very large LDLB effect lead to the unique possibility of discriminating the direction of sample illumination (i. e., from the front or back)â. This article presents a set of analog compds., in which small structural changes are introduced to uncover which factors det. the very large LDLB effect or true CD connected to supramol. chirality. It also reveals the impact of the deposition technique, in which spin coating may exert a primary role, and results in films with outstanding chiroptical features. These features are made even more relevant due to the semiconducting properties of oligothiophenes, which are interesting for optical sensing applications
Motor coordination, working memory, and academic achievement in a normative adolescent sample: Testing a mediation model
The aim of the present study was to examine whether the relationship between motor coordination and academic achievement is mediated by working memory (WM) in a normative adolescent sample. Participants included 93 adolescents aged 12â16. The Movement Assessment Battery for Children-2 provided three indicators of motor coordination (Manual Dexterity, Aiming and Catching, and Balance), the WM Index of the Wechsler Intelligence Scale for Children-IV and the N-back paradigm provided two indicators of WM, and the Wechsler Individual Achievement Test-II provided three indicators of academic achievement (Word Reading, Spelling, and Numerical Operations). Structural equation modeling, controlling for verbal comprehension, attention deficit hyperactivity disorder symptoms, and socioeconomic status, suggested that the association between motor coordination and academic achievement may be best understood in terms of a mechanism whereby motor coordination (specifically, Aiming and Catching skills) has an indirect impact on academic outcomes via WM. These findings have important implications for the assessment and treatment of motor coordination and learning difficulties as well as in increasing the understanding of the possible neural mechanisms underpinning the relationship between these areas
Brain tissue oxygen amperometry in behaving rats demonstrates functional dissociation of dorsal and ventral hippocampus during spatial processing and anxiety
Traditionally, the function of the hippocampus (HPC) has been viewed in unitary terms, but there is growing evidence that the HPC is functionally differentiated along its septotemporal axis. Lesion studies in rodents and functional brain imaging in humans suggest a preferential role for the septal HPC in spatial learning and a preferential role for the temporal HPC in anxiety. To better enable cross-species comparison, we present an in vivo amperometric technique that measures changes in brain tissue oxygen at high temporal resolution in freely-moving rats. We recorded simultaneously from the dorsal (septal; dHPC) and ventral (temporal; vHPC) HPC during two anxiety tasks and two spatial tasks on the radial maze. We found a double-dissociation of function in the HPC, with increased vHPC signals during anxiety and increased dHPC signals during spatial processing. In addition, dHPC signals were modulated by spatial memory demands. These results add a new dimension to the growing consensus for a differentiation of HPC function, and highlight tissue oxygen amperometry as a valuable tool to aid translation between animal and human research
How Electrophilic are Ferrocenylmethyl Cations? Kinetics of their Reactions with Nucleophiles and Hydride Donors
Second-order rate constants for the reactions of the ferrocenylmethylium ions 2a - e with silyl enol ethers, allylsilanes, allylstannanes, and hydride donors have been determined photometrically and conductometrically in dichloromethane. The ferrocenylmethylium ions 2a - d (fc-CHR+, R = H, Me, Ph, An) are slightly stronger electrophiles than the tropylium ion, and their electrophilic reactivities depend only slightly on the nature of R. The bis(ferrocenyl)methylium ion 2e is a considerably weaker electrophile, comparable to the tricarbonyl(cyclohexadienyl)iron cation
KohlenwasserstoffverbrĂźckte Komplexe, XXX
Hydrocarbon-Bridged Complexes, XXX. - Nucleophilic Addition of Carbonylmetallates to Cationic Vinyl, Diene, Dienyl and Triene Complexes of Iron, Ruthenium and Cobalt: Di-, Tri-, Tetra- and Pentametallic Complexes with ,- and ,-Hydrocarbon Bridges[Note ][Herrn Professor Ekkehard Lindner zum 60. Geburtstag gewidmet.]
The reactions of [Re(CO)5]-, [Ru(CO)2Cp]-, and [Os(CO)4]2- with [Cp2(OC)2Fe2(-CO)(-1:2-CH=CH2)]+, [Cp*Ru(2:4-1,3,7-octatriene)]+, [(OC)Fe(4-diene)(5-cycloheptadienyl)]+, and [CpCo(5-cyclodienyl)]+ give the nucleophilic adducts whereas with [Mn(CO)5]-, [W(CO)3Cp]-, and [Fe(CO)2Cp]- formation of the corresponding C-C coupling products and of the metal-metal-bonded dimers is observed. The structures of Cp*Ru(-1:2:3-1,5-octadienyl)Re(CO)5 (4), [Cp* Ru(-1:2:3-1,5-octadienyl)]2Os(CO)4 (6), and of (OC)-Fe(4-1,3-cyclohexadiene) (-1:4-1,3-cycloheptadiene)Re(CO)5 (9) have been determined by X-ray diffraction
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV
A search is presented for physics beyond the standard model (BSM) in final
states with a pair of opposite-sign isolated leptons accompanied by jets and
missing transverse energy. The search uses LHC data recorded at a
center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to
an integrated luminosity of approximately 5 inverse femtobarns. Two
complementary search strategies are employed. The first probes models with a
specific dilepton production mechanism that leads to a characteristic kinematic
edge in the dilepton mass distribution. The second strategy probes models of
dilepton production with heavy, colored objects that decay to final states
including invisible particles, leading to very large hadronic activity and
missing transverse energy. No evidence for an event yield in excess of the
standard model expectations is found. Upper limits on the BSM contributions to
the signal regions are deduced from the results, which are used to exclude a
region of the parameter space of the constrained minimal supersymmetric
extension of the standard model. Additional information related to detector
efficiencies and response is provided to allow testing specific models of BSM
physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO
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