AgInS quantum dots for the detection of trinitrotoluene.

AgInS (AIS) quantum dots (QDs) were synthesized via a thermal decomposition reaction with dodecylamine as the ligand to help stabilize the QDs. This reaction procedure is relatively easy to implement, scalable to large batches (up to hundreds of milligrams of QDs are produced), and a convenient method for the synthesis of chalcogenide QDs. Metal powders of AgNO and In(NO), were used as the metal precursors while diethyldithiocarbamate was used as the sulfur source.

High-density biosynthetic fuels: the intersection of heterogeneous catalysis and metabolic engineering.

Biosynthetic valencene, premnaspirodiene, and natural caryophyllene were hydrogenated and evaluated as high performance fuels. The parent sesquiterpenes were then isomerized to complex mixtures of hydrocarbons with the heterogeneous acid catalyst Nafion SAC-13. High density fuels with net heats of combustion ranging from 133-141 000 Btu gal(-1), or up to 13% higher than commercial jet fuel could be generated by this approach.

Synthesis, characterization, and cure chemistry of renewable bis(cyanate) esters derived from 2-methoxy-4-methylphenol.

A series of renewable bis(cyanate) esters have been prepared from bisphenols synthesized by condensation of 2-methoxy-4-methylphenol (creosol) with formaldehyde, acetaldehyde, and propionaldehyde. The cyanate esters have been fully characterized by infrared spectroscopy, (1)H and (13)C NMR spectroscopy, and single crystal X-ray diffraction. These compounds melt from 88 to 143 °C, while cured resins have glass transition temperatures from 219 to 248 °C, water uptake (96 h, 85 °C immersion) in the range of 2.

Synthesis of renewable bisphenols from creosol.

A series of renewable bisphenols has been synthesized from creosol (2-methoxy-4-methylphenol) through stoichiometric condensation with short-chain aldehydes. Creosol can be readily produced from lignin, potentially allowing for the large scale synthesis of bisphenol A replacements from abundant waste biomass. The renewable bisphenols were isolated in good yields and purities without resorting to solvent-intense purification methods.

Exploiting conformational dynamics to facilitate formation and trapping of electron-transfer photoproducts in metal complexes.

Three new photoinduced electron donor-acceptor (D-A) systems are reported which juxtapose a Ru(II) excited-state donor with a bipyridinium acceptor via a conformationally active asymmetric aryl-substituted bipyridine ligand participating in the bridge between D and A. Across the series of complexes 1-3, steric bulk is sequentially added to tune the inter-ring dihedral angle theta between the bipyridine and the aryl substituent. Driving forces for photoinduced electron transfer (DeltaG(ET)) and back electron transfer (DeltaG(BET)) are reported based on electrochemical measurements of 1-3 as well as Franck-Condon analysis of emission spectra collected for three new donor model complexes 1'-3'.

Controlling electron transfer through the manipulation of structure and ligand-based torsional motions: a computational exploration of ruthenium donor-acceptor systems using density functional theory.

Computational studies using density functional theory (DFT) are reported for a series of donor-acceptor (DA) transition metal complexes and related excited-state and electron transfer (ET) photoproduct models. Three hybrid Hartree-Fock/DFT (HF/DFT) functionals, B3LYP, B3PW91, and PBE1PBE, are employed to characterize structural features implicated in the dynamical control of productive forward and energy wasting back ET events. Energies and optimized geometries are reported for the lowest energy singlet state in [Ru(dmb)(2)(bpy-phi-MV)](4+) (DA1), [Ru(dmb)(2)(bpy-o-tolyl-MV)](4+) (DA2), [Ru(dmb)(2)(bpy-2,6-Me(2)-phi-MV)](4+) (DA3), and [Ru(tmb)(2)(bpy-2,6-Me(2)-phi-MV)](4+) (DA3'), where dmb is 4,4'-dimethyl-2,2'-bipyridine, tmb is 4,4',5,5'-tetramethyl-2,2'-bipyridine, MV is methyl viologen, and phi is a phenylene spacer.

Ligand structure, conformational dynamics, and excited-state electron delocalization for control of photoinduced electron transfer rates in synthetic donor-bridge-acceptor systems.

Synthesis, ground-, and excited-state properties are reported for two new electron donor-bridge-acceptor (D-B-A) molecules and two new photophysical model complexes. The D-B-A molecules are [Ru(bpy)2(bpy-phi-MV)](PF6)4 (3) and [Ru(tmb)2(bpy-phi-MV)](PF6)4 (4), where bpy is 2,2'-bipyridine, tmb is 4,4',5,5'-tetramethyl-2,2'-bipyridine, MV is methyl viologen, and phi is a phenylene spacer. Their model complexes are [Ru(bpy)2(p-tol-bpy)](PF6)2 (1) and [Ru(tmb)2(p-tol-bpy)](PF6)2 (2), where p-tolyl-bpy is 4-(p-tolyl)-2,2'-bipyridine.

Nicotine activates nuclear factor of activated T cells c2 (NFATc2) and prevents cell cycle entry in T cells.

We used primary peripheral blood T cells, a population that exists in G(0) and can be stimulated to enter the cell cycle synchronously, to define more precisely the effects of nicotine on pathways that control cell cycle entry and progression. Our data show that nicotine decreased the ability of T cells to transit through the G(0)/G(1) boundary (acquire competence) and respond to progression signals. These effects were due to nuclear factor of activated T cells c2 (NFATc2)-dependent repression of cyclin-dependent kinase 4 (CDK4) expression.

Canine malignant hemangiosarcoma as a model of primitive angiogenic endothelium.

Hemangiosarcoma (HSA) is a common untreatable cancer of dogs that resembles human angiosarcoma. Detailed studies of these diseases have been historically hindered by the paucity of suitable reagents. Here, we show that expression of CD117 (c-Kit) can distinguish primitive (malignant) from mature (benign) proliferative endothelial lesions, and we describe eight independent cell lines derived from canine HSA explants.