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Discusses a rapid method for the disruption of Candida albicans genes with polymerase chain reaction products with short regions of homology to the genome. Analyses of the disruption process; Kinetics of primer-directed disruption of newly identified sequences; Functional analyses of C. albicans genes.

In this article, we describe a researcher-practitioner partnership (RPP) that used a networked improvement community (NIC) approach to translate social-psychological interventions into educational practices to enhance student motivation and learning. Specifically, we highlight one of our first collaborative projects to develop and scale up an intervention to teach middle school students about adopting a growth mindset (Dweck, 2006) to address our practitioners' concern that many of their students lacked the belief that they could learn. Using Plan-Do-Study-Act cycles, we show how we (a) successfully adapted a previously used growth mindset intervention designed for college students into a computer app appropriate for middle school students, (b) embedded using the app in different middle school contexts to promote growth mindset thinking, and (c) linked students' growth mindset thinking to improved academic performance. We also discuss how this work was conducted as part of a networked improvement community sponsored by the Carnegie Foundation for the Advancement of Teaching called the Student Agency Improvement Community. [ABSTRACT FROM AUTHOR]

Abstract: We present a natural-language customer service application for a telephone banking call center, developed as part of the Amitiés dialogue project (Automated Multilingual Interaction with Information and Services). Our dialogue system, based on empirical data gathered from real call-center conversations, features data-driven techniques that allow for spoken language understanding despite speech recognition errors, as well as mixed system/customer initiative and spontaneous conversation. These techniques include robust named-entity extraction, slot-filling Frame Agents, vector-based task identification and dialogue act classification, a Bayesian database record selection algorithm, and a natural language generator designed with templates created from real agents’ expressions. Preliminary evaluation results indicate efficient dialogues and high user satisfaction, with performance comparable to or better than that of current conversational information systems. [Copyright &y& Elsevier]

ThePd(PPh3)4/CuI-cocatalyzed reaction ofRu(CCCCH)(PPh3)2Cp (2) with aryl iodides, Ar–I (3, Ar = C6H4CN-4 (a); C6H4Me-4(b); C6H4OMe-4 (c);2,3-dihydrobenzo[b]thiophene (d); C5H4N (e)) proceeds smoothly in diisopropylamineand under an inert atmosphere to give the substituted buta-1,3-diynylcomplexes Ru(CCCCAr)(PPh3)2Cp(4a–e) in moderate to good yield.The procedure allows the rapid preparation of a range of metal complexesof arylbuta-1,3-diynyl ligands without necessitating the prior synthesisof the individual buta-1,3-diynes as ligand precursors. Similar reactionof 2with half an equivalent of 1,4-diiodobenzene affordsthe bimetallic derivative {Ru(PPh3)2Cp}2(μ-CCCC-1,4-C6H4–CCCC) (5). In the presenceof atmospheric oxygen, homocoupling of the diynyl reagent 2takes place to provide the octa-1,3,5,7-tetrayndiyl complex {Ru(PPh3)2Cp}2(μ-CCCCCCCC)(6). Crystallographically determined molecular structuresare reported for five complexes (4a, 4b, 4d, 5, and 6). Quantum chemicalcalculations indicate that the HOMOs are mainly located on the C4–C6H4–C4andC8bridges for 5and 6, respectively,while spectroelectrochemical (UV–vis–NIR and IR) studieson 6establish that oxidation takes place at the C8bridge, likely followed by cyclodimerization reactions ofthe bridging ligand. [ABSTRACT FROM AUTHOR]

This article describes arylene-ethynylene molecular wires with 7 nm long backbones and thiolated termini. Cyclic voltammetric studies in solution reveal that the reduction waves of the fluorene, 9-[(4-pyridyl)methylene]fluorene and 9-[di(4-pyridyl)methylene]fluorene units which are embedded in the conjugated ?-systems endow these wires with n-doping characteristics. An x-ray crystal structure investigation of 2,7-diiodo-9-[bis(4-pyridinium)methylene]fluorene bis(tetrafluoroborate) 8established that protonation occurs on both nitrogens of this unit. Self-assembled monolayers of the 7 nm wire 2on gold substrates exhibit symmetrical current-voltage (I-V) characteristics when contacted by a gold scanning transmission microscope (STM) tip. The dipyridyl functionality of 2served to obtain a rectifying junction in which the diprotonated cationic wire is the electron accepting component in combination with an adjacent anionic phthalocyanine as the electron-donating layer. This ionic Au-2H22+[CuPc(SO3?)4(Na+)n]2/(4?n)bilayer assembly exhibits rectification with current ratios of 15-50 at ± 1 V. This dramatic change in I-Vcharacteristics upon simple chemical manipulation proves that the conductivity is a property of the wire molecules 2in the junction. Ab initiocalculations suggest that the molecular wires possess useful structural features which allow the conductance of the molecule to be altered by changing the properties of the side groups attached to the fluorene units. [ABSTRACT FROM AUTHOR]

Poly(9,9-dioctylfluorene-2,7-diyl-co-2,8-dihexyldibenzothiophene-S,S-dioxide-3,7-diyl) copolymers (pF-S68−10) of varying composition have been synthesized by Suzuki−Miyaura polymerization. The hexyl substituents on the dibenzothiophene-S,S-dioxide (S) units improve the solubility of the copolymers and increase the dihedral angles in the backbone; this shifts the emission deep into the blue (λmax420 nm for films of 10) and increases the photoluminescence quantum yield compared with previous pF-S copolymers containing non-alkylated S units. The backbone twist restricts formation of the intramolecular charge transfer (ICT) state for low incorporation ratios of S6units. The triplet energy of these new copolymers increases as the percentage of the S6unit increases (i.e., 15, 30, 50%: 8 → 9 → 10). The alternating copolymer 10has a sufficiently high triplet energy (ET2.46 eV for onset of phosphorescence) to host a green phosphorescent iridium guest emitter, as demonstrated in electroluminescence studies which showed emission exclusively from the guest complex. [ABSTRACT FROM AUTHOR]

Unprecedented stability has been observed in terminal aryl hexatriyne and terminal aryl octatetrayne derivatives by judicious choice of a bulky, nonplanar headgroup [viz., 4-(3,6-di- tert-butyl- N-carbazolyl)phenyl] which hinders topochemical intermolecular interactions in the crystal lattice. [ABSTRACT FROM AUTHOR]

The strong solvatochromism observed for two fluorene-dibenzothiophene-S,S-dioxide oligomers in polar solvents has been investigated using steady-state and time-resolved fluorescence techniques. A low-energy absorption band, attributed to a charge-transfer (CT) state, is identified by its red shift with increasing solvent polarity. In nonpolar solvents, the emission of these conjugated luminescent oligomers shows narrow and well-resolved features, suggesting that the emission comes from a local excited state (LE), by analogy to their conjugated fluorene-based polymer counterparts. However, in polar solvents, only a featureless broad emission is observed at longer wavelengths (CT emission). A linear correlation between the energy maximum of the fluorescence emission and the solvent orientation polarizability factor f(Lippert−Mataga equation) is observed through a large range of solvents. In ethanol, below 230 K, the emission spectra of both oligomers show dual fluorescence (LE-like and CT) with the observation of a red-edge excitation effect. The stabilization of the CT emissive state by solvent polarity is accompanied/followed by structural changes to adapt the molecular structure to the new electronic density distribution. In ethanol, above 220 K, the solvent reorganization occurs on a faster time scale (less than 10 ps at 290 K), and the structural relaxation of the molecule (CTunrelaxed→ CTRelaxed) can be followed independently. The magnitude of the forward rate constant, k1(20 °C) 20 × 109s-1, and the reaction energy barrier, Ea 3.9 kcal mol-1, close to the energy barrier for viscous flow in ethanol (3.54 kcal mol-1), show that large-amplitude molecular motions are present in the stabilization of the CT state. [ABSTRACT FROM AUTHOR]

2,5-Diphenyl-1,3,4-oxadiazole (OXD) derivatives with terminal ethynyl-(4a,b) and butadiynyl-(8a,b) substituents have been synthesized in high yields. 2-Methyl-3,5-hexadiyn-2-ol has not been exploited previously in the synthesis of terminal butadiynes. Crystals of 8a and 8b are remarkably stable to long-term storage under ambient conditions. The X-ray crystal structure of 8a reveals that the butadiyne moieties are spatially isolated by the aromatic moieties, which explains the high stability. Two series of derived π-conjugated molecules, Donor-(CC)n-OXD (n = 1, 2) and OXD-(CC)n-Donor-(CC)n-OXD (n = 1) [Donor = tetrathiafulvalene (TTF), bithiophene, 9-(4,5-dimethyl-1,3-dithiol-2-ylidene)fluorene, and triphenylamine], have been synthesized using Sonogashira reactions and characterized by X-ray crystallography, cyclic voltammetry, and optical absorption/emission spectroscopy. The electron-withdrawing effect of the OXD units is manifested by a positive shift of the donor oxidation waves in these systems: the butadiynylene spacer (n = 2) further shifts the first oxidation waves by 40–80 mV compared to analogues n = 1. The absorption spectra of TTF-OXD hybrids 10d and 11 are blue-shifted by 80 nm compared to the bithienyl-bridged derivative 10f and are similar to the butadiynyl-OXD building-block 8a, demonstrating that conjugation is disrupted by a neutral TTF unit. Solutions of the TTF-OXD and 9-(4,5-dimethyl-1,3-dithiol-2-ylidene)fluorene-OXD hybrids, 10d, 10g, 11, and 13, are only very weakly fluorescent due to quenching from the electron-donor moieties. In contrast, the triphenylamine-OXD hybrids 12a, 12b, 14a, and 14b are fluorescent; the PLQYs of the butadiynylene derivatives 14a and 14b are lower than those of the ethynylene-bridged analogues 12a and 12b. [ABSTRACT FROM AUTHOR]

Fluorene-based bridges exhibit a molecular wire-like behaviour in C60–wire–exTTF systems with a very low attenuation factor (β = 0.09 Å−1). [ABSTRACT FROM AUTHOR]

A blue-green fluorescent organic dye and red-emitting nanoparticles, based on II-VI semiconductors, have been used together in the fabrication of white organic light-emitting devices. In this work, the materials were combined in two different ways: in the form of a blend, and as separate layers deposited on the opposite sides of the substrate. The blended-layer structure provided purer white emission. However, this device also exhibited a number of disadvantages, namely a high drive voltage, a low efficiency and some colour instability. These problems could be avoided by using a device structure that was fabricated using separate dye and nanoparticle layers. [ABSTRACT FROM AUTHOR]