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The validity of the anelastic approximation has recently been questioned inthe regime of rapidly-rotating compressible convection in low Prandtl numberfluids (Calkins et al. 2015). Given the broad usage and the high computationalefficiency of sound-proof approaches in this astrophysically relevant regime,this paper clarifies the conditions for a safe application. The potential ofthe alternative pseudo-incompressible approximation is investigated, which incontrast to the anelastic approximation is shown to never break down forpredicting the point of marginal stability. Its accuracy, however, decreasesclose to the parameters corresponding to the failure of the anelastic approach,which is shown to occur when the sound-crossing time of the domain exceeds arotation time scale, i.e. for rotational Mach numbers greater than one.Concerning the supercritical case, which is naturally characterised by smallerrotational Mach numbers, we find that the anelastic approximation does not showunphysical behaviour. Growth rates computed with the linearised anelasticequations converge toward the corresponding fully compressible values as theRayleigh number increases. Likewise, our fully nonlinear turbulent simulations,produced with our fully compressible and anelastic models and carried out in ahighly supercritical, rotating, compressible, low Prandtl number regime showgood agreement. However, this nonlinear test example is for only a moderatelylow convective Rossby number of 0.14.

The charge shift and triplet formation in the 9-mesityl-10-methylacridinium cation are studied. The results show that the photophysical properties do not include formation of a long-lived charge-transfer state.

Two kinds of carbon nanotubes (CNTs) are selected to investigate hole-edge reactivity such as single-wall carbon nanotubes (SWNTs) and single-wall carbon nanohorns (SWNHs). The study is helpful to the understanding of hole-edge chemistry and would enable the production of well-designed carbonaceous materials with high functionality.

The electron-transfer process in mono- (NlP1) and multichromophoric (NlP3) triphenylamine core dendrimers carrying one and three peryleneimide electron accepter chromophores, are characterized using the combination of transient absorption and fluorescence experiments performed on a femtosecond to nanosecond time scale.

The electron-transfer process of a first generation dendrimer with a triphenylamine core substituted with one peryleneimide chromophore at the rim (N1P1) was investigated by steady-state and time-resolved spectroscopic techniques in two different solvents of medium and low polarity. Single photon counting experiments showed a fast charge separation and thermally activated back reaction, which is uncommon for polyaryl bridge or long distance through-space electron transfer.

An observation of efficient intramolecular triplet-triplet energy transfer from an N,N dialkylanilino donor to an alkene acceptor in 4-(4-(propan-2-ylidene)cyclohexyl)-N,N-dimethylaniline(2) and 1-phenyl-4-cyclohexylidene-piperidine(4) using nanosecond transient absorption spectroscopy and time-resolved microwave conductivity(TRMC) is presented here. The TRMC results suggest that quantum yield of triplet formation is independent of the presence a double bond.

The photoinduced intramolecular electron transfer in two donor-bridge-acceptor systems, DPN[8cy]DCV and DPMN[8cy]DCV in which the through space (TS) distance between the donor (DPN and DPMN) and DCV acceptor groups in the ground state are approximately 5.8 angstrom is studied. The fluorescence and transient absorption techniques are used for this purpose.

A study was conducted to analyze the fluorescence of four semiflexible bridged donor-bridge-acceptor systems using a streak camera system. Experimental results indicated that compounds undergo a photoinduced harpooning procedure where long-range electron transfer establishes an extended charge-transfer species. The species transform into a compact charge-transfer type resulting from Coulombic attraction.

The chromophore of photoactive yellow protein (PYP) (i.e., 4-hydroxycinnamic acid) has been replaced by an analogue with a triple bond, rather than a double bond (by using 4-hydroxyphenylpropiolic acid in the reconstitution, yielding hybrid I) and by a 'locked' chromophore (through reconstitution with 7-hydroxycoumarin-3-carboxylic acid, in which a covalent bridge is present across the vinyl bond, resulting in hybrid II). These hybrids absorb maximally at 464 and 443 nm, respectively, which indicates that in both hybrids the deprotonated chromophore does fit into the chromophore-binding pocket. Because the triple bond cannot undergo cis/trans (or E/Z) photoisomerization and because of the presence of the lock across the vinyl double bond in hybrid II, it was predicted that these two hybrids would not be able to photocycle. Surprisingly, both are able. We have demonstrated this ability by making use of transient absorption, low-temperature absorption, and Fourier-transform infrared (FTIR) spectroscopy. Both hybrids, upon photoexcitation, display authentic photocycle signals in terms of a red-shifted intermediate; hybrid I, in addition, goes through a blue-shifted-like intermediate state, with very slow kinetics. We interpret these results as further evidence that rotation of the carbonyl group of the thioester-linked chromophore of PYP, proposed in a previous FTIR study and visualized in recent time-resolved x-ray diffraction experiments, is of critical importance for photoactivation of PYP.

Two-directional photoinduced electron transfer in the trichromophoric system 1-(4-cyanophenyl)-4-(cyanomethylene)piperidine is studied. Results show that in diethyl and acetonitrile, two charge transfer states sigmaCT and piCT are formed by transferring the electron through the sigma- or pi- bonds, respectively. The sigmaCT and piCT states are formed upon excitation while an electron exchange between the two polar states occurs in at least one direction.

A novel method of synthesizing water-soluble neutral calixarene-lanthanide complexes as well as their luminescence profiles were described. The design featured the substitution of the trichloroethyl group of the starting material N-{Tris-{{(tert-butyldimthylsilyl)oxy}methyl}methane-2-aminoacetamide by 6-(aminomethyl)chrysene or S-(2-pyridylthio)cysteamine. The addition of 2-pyridyl disulfide group in lanthanide compounds induced short wavelength excitation on 1H NMR spectra.

The ability of methylsilylene and isopropylidene sigma-spacers to act as bridges for photoexcited charge transfers in 4-cyano-4'-(dimethyamino)- and 4-cyano-4'-methoxy-substituted diphenyldimethylsilanes and 2,2-diphenylpropanes were compared. The results, which were obtained from fluorescence solvatochromism and microwave conductive measurements, showed that the charge transporting behavior of the two bridges depends on their interaction with the donor and acceptor moieties of the silanes and propanes.

The photoinduced electron transfer mechanisms in two piperidine-bridged bichromophores were investigated. The two bichromophores contain a 4-methoxyaniline or aniline as an electron donor and an N-alkylnaphthalimide as an electron acceptor. According to experiments, they are able to undergo electron transfer resulting in the (sup 3)(D+ - A-) state 'with a lifetime in the microsecond range and a charge separation of about four sigma bonds.'

The special symmetry properties of fullerene pi-system allow strong electron coupling with the tetraalkyl-p-phenylenediamine donor hydrocarbon bridge to allow photoinduced electron transfer. Photoexcitation in (C60(3)TMPD) system results in a complete intramolecular charge separation and is independent of solvent polarity. The charge separated states are not detected due to fast charge recombination. In (C60(11)DMA), the photoinduced charge separation occurs only in polar solvents like benzonitrile and the dipolar state can be detected because of the slow rate of charge recombination.

The structure of trichromophoric systems was investigated using a combination of time-resolved transient absorption spectroscopy and time-resolved microwave conductivity. The dimethoxynaphthalene primary donor and a dicyanvinyl acceptor in these systems are separated by a rigid norbornylogous bridge eight sigma-bonds in length. Donor1 and an N,N-dimethylaniline secondary donor are separated by a norbornylogous bridge of variable length. The spectra for these compounds are discussed.

A set of calix(4)arenes are prepared having three discrete sensitizer chromophores (antenna) linked to the lower rim through a short spacer. On photoexcitation of the antenna of the Eu3+ and Tb3+ complexes of the calixarenes lanthanide, emission occurs by intramolecular energy transfer. The arenes extended with antenna undergo excitation of both Eu3+ and Tb3+ luminescence at wavelengths up to 350 nanometers.

A photoinduced intramolecular electron transfer occurs in a complex of an electron donating aniline group and a fullerene unit linked by a saturated heterocyclic bridge. The fluorescence of the adduct is decayed and there is a fall in polar solvents' triplet population. A reduction in E(super 1)(sub 00) of C60 is noticed which indicates the poorer adjustability of the C60 adducts in photoinduced electron transfer systems.

Kinetic analysis of radiative charge recombination in donor-bridge-acceptor molecules reveals the influence of solvent polarity on radiative decay rate. Intensity borrowing from locally excited states explain solvent dependence of experimental radiative rates that begin from the solvent shift of the vertical energy gap. Kinetic studies help determine electronic coupling between local excitation and the change transfer state.

PURPOSE: To determine whether clinical findings-bleeding on probing, pocket depth, recession, and bacterial sampling-correlate with histologic outcomes in relatively healthy peri-implant soft tissues in people. MATERIALS AND METHODS: In this cross-sectional study, a convenience sample of 20 edentulous subjects received two endosseous mandibular implants each. The abutments were either zirconia (ZrO2) or titanium (Ti) (nonsubmerged implant placement, within-subject comparison, leftright randomization). Sulcular bacterial sampling and assessment of probing pocket depth, recession, and bleeding on probing were performed 3 months postsurgery. Mucosal biopsy specimens were obtained, and the blood vessel density and a score on an inflammation grading scale were determined. RESULTS: Simple linear and linear regression models revealed that the clinical or microbiologic parameters were not associated with either of the histologic parameters. The soft tissues impressed as healthy, regardless of the abutment material. CONCLUSIONS: The peri-implant mucosa around ZrO2 and Ti abutments was considered healthy in most situations when examined histologically after 3 months but showed variation in clinical and microbiologic parameters. [ABSTRACT FROM AUTHOR]

Purpose: A retrospective study on the performance of endosseous implants in a population of patients with severe epilepsy and additional motor and/or intellectual impairments was performed. Materials and Methods: All residents of an inpatient center for persons affected by severe, refractory epilepsy and multiple disabilities who received endosseous implants between 1991 and April 2007 were included in the study. Implant survival was analyzed using the Kaplan-Meier method. A subset of patients who were treated between 1991 and 2004 was invited to participate in a clinical and radiographic evaluation in 2004 and 2005. Results: A total of 61 patients were treated between 1991 and April 2007 (n = 134 implants). Three of these implants in three different patients failed during the observation period, demonstrating an estimated probability of functional implant survival of 97.6% (SE 1.4%) after 16 years. In patients who were seen during the clinical evaluation in 2004 (n = 76 implants), only mild inflammation of the peri-implant mucosa was generally observed (Gingival-Bleeding Index = 1), despite the fact that the level of oral hygiene was considered inadequate around 55 of 76 implants (72%). Obvious signs of drug-induced gingival hyperplasia in relation to the implants were not observed. Probing depths averaged approximately 2 mm. Stable marginal bone levels were observed on the radiographs. Conclusions: Dental implant treatment in a population of patients with severe epilepsy and additional disabilities seems to be a viable treatment option. Implant loss is rare. Although adequate plaque control was not feasible in all patients, marginal bone levels remained stable. [ABSTRACT FROM AUTHOR]