Expanding a professional dental care system: experiences of Task Force 261 Multifunctional Medical Battalion during Operation Iraqi Freedom 07-09.

During Operation Iraqi Freedom 07-09, Task Force 261 Multifunctional Medical Battalion managed an extensive dental care system stretching throughout the Iraq theater of operations. We illustrate several of the unique challenges faced by Task Force 261's headquarters and its dental and area support companies, and describe the remedies emplaced by the Task Force. Personnel structure, the evacuation chain, supply and facility management, dental civil-military operations, detainee care, information technology applications, and public health initiatives are discussed in detail.

Solvent effects on interfacial electron transfer from Ru(4,4'-dicarboxylic acid-2,2'-bipyridine)2(NCS)2 to nanoparticulate TiO2: spectroscopy and solar photoconversion.

Resonance Raman spectra are reported for Ru(4,4'-dicarboxylic acid-2,2'-bipyridine)2(NCS)2 (commonly called "N3") in ethanol solution and adsorbed on nanoparticulate colloidal TiO2 in ethanol (EtOH) and in acetonitrile (ACN), at wavelengths within the visible absorption band of the dye. Raman cross sections of free N3 in EtOH are found to be similar to those of N3 adsorbed on colloidal TiO2 in EtOH, and are generally lower than those of N3 on TiO2 in ACN. Strong electronic coupling mediated by surface states results in red-shifted absorption spectra and enhanced Raman signals for N3 adsorbed on nanocolloidal TiO2 in ACN compared to EtOH. In contrast, the absorption spectrum of N3 on nanocrystalline TiO2 in contact with solvent is similar for ACN and EtOH. Wavelength-dependent depolarization ratios for N3 Raman bands of both free and adsorbed N3 reveal resonance enhancement via two or more excited electronic states. Luminescence spectra of N3 adsorbed on nanocrystalline films of TiO2 and ZrO2 in contact with solvent reveal that the quantum yield of electron injection phi(ET) into TiO2 decreases in the order ACN > EtOH > DMSO. Dye-sensitized solar cells were fabricated with N3 adsorbed on nanocrystalline films of TiO2 in contact with ACN, EtOH, and DMSO solutions containing LiI/LiI3 electrolyte. Photoconversion efficiencies eta were found to be 2.6% in ACN, 1.3% in DMSO, and 0.84% in EtOH. Higher short circuit currents are found in cells using ACN, while the maximum voltage is found to be largest in DMSO. It is concluded that the increased photocurrent and quantum yield of interfacial electron transfer in acetonitrile as compared to ethanol and DMSO is primarily the result of faster electron injection of N3 when adsorbed on TiO2 in the presence of ACN as opposed to EtOH or DMSO.

Counterion-dependent excitonic spectra of tetra(p-carboxyphenyl)porphyrin aggregates in acidic aqueous solution.

Aggregates of the diacid form of tetra(p-carboxyphenyl)porphyrin (TCPP) are found to be stabilized in aqueous solution at low pH in the presence of poly(vinyl alcohol). At pH values in the range from about 1 to 4, a split Soret band is observed which is independent of counterion and tentatively assigned to a dimer species. As the pH is made lower than 1, the spectra evolve to reveal the presence of porphyrin aggregates. As in the case of the well-known aggregates of the related tetra(p-sulfonatophenyl)porphyrin (TSPP) diacid, the concentration of spectroscopically distinguishable aggregates increases with increasing ionic strength or decreasing pH. Unlike aggregates of TSPP, however, TCPP aggregates below pH 1 have visible absorption spectra which depend on the counterion, which is Cl(-) or NO(3)(-) in this study. In this work, we present visible absorption, light-scattering, and resonance Raman spectra of TCPP diacid in its monomer, dimer, and aggregated forms and attempt to understand the structural basis for counterion-dependent structure and excitonic coupling in the aggregates. Evidence is presented for intercalation of inorganic counterions between porphyrin molecules in the aggregate, an effect which to our knowledge has not been previously reported.