Explicit description for the automorphism group of the Fornæss domain

Motivated by the Kohn-Nirenberg domain, J.E. Fornæss considered the germ of a domain near the origin in C² such that

     

Butatriene-hexacarbonyldiiron complexes via dehydroxylation of unsaturated diols by Fe(CO)1

Butatriene-diiron hexacarbonyl complexes have been prepared simply and in good yield from thermal reaction of Fe(CO)₁ with -butynediols or ,-diiodo--butene-1,4-diols. Geometric isomers of these complexes are usually obtained where such isomerisation is possible. Another product of reaction, derived from loss of HOH from the butynediol, is described.     

Triphenylamine derivatives with large two-photon cross-sections

[structure: see text] Triphenylamine derivatives have been synthesized and shown to exhibit large two-photon cross-sections at a wide range of wavelengths and the largest value measured by fs Z-scan experiment. Moreover, a linear relationship is noted between the two-photon cross-sections measured by ns fluorescence and fs Z-scan methods.     

Compact, actively Q-switched optical parametric oscillator

An ultracompact, actively Q -switched optical parametric oscillator (OPO) has been realized that is only 30 mm in length, based on a semimonolithic microchip laser, a quadrupole deflector, and a monolithic periodically poled lithium niobate crystal. The OPO threshold was 550 mW when Nd:YAG was used as the gain material and 590 mW for Nd:Y VO(4), giving signal pulses of as much as 8.7 muJ in energy with Nd:YAG at 1 kHz and 5.9-mu;J pulses with Nd:Y VO(4) at 5 kHz, for 1.2- and 2-W laser diode pumping, respectively. The output was single frequency and could be tuned over the range 1540-3440 nm.     

A theory for the interactions between closed shell systems

A recent theory for intermolecular interactions is modified by the exclusion of a “self-exchange” contribution and the inclusion of dispersive inte     

On Laplacian integrals with singular kernels

A class of Laplace transforms with singular kernels are manipulated into integrls more amenable to analytic evaluation.     

Direct measurement of the intermolecular forces confining a single molecule in an entangled polymer solution

We use optical tweezers to directly measure the intermolecular forces acting on a single polymer imposed by surrounding entangled polymers (115 kbp DNA, 1 mg/ml). A tubelike confining field was measured in accord with the key assumption of reptation models. A time-dependent harmonic potential opposed transverse displacement, in accord with recent simulation findings. A tube radius of 0.8 microm was determined, close to the predicted value (0.5 microm). Three relaxation modes (approximately 0.4, 5, and 34 s) were measured following transverse displacement, consistent with predicted relaxation mechanisms.     

The conformations of 13-vertex ML2C2B10 metallacarboranes: experimental and computational studies

The docosahedral metallacarboranes 4,4-(PMe(2)Ph)2-4,1,6-closo-PtC(2)B(10)H(12), 4,4-(PMe(2)Ph)2-4,1,10-closo-PtC(2)B(10)H(12), and [N(PPh(3))2][4,4-cod-4,1,10-closo-RhC(2)B(10)H(12)] were prepared by reduction/metalation of either 1,2-closo-C(2)B(10)H(12) or 1,12-closo-C(2)B(10)H(12). All three species were fully characterized, with a particular point of interest of the latter being the conformation of the {ML2} fragment relative to the carborane ligand face. Comparison with conformations previously established for six other ML(2)C(2)B(10) species of varying heteroatom patterns (4,1,2-MC(2)B(10), 4,1,6-MC(2)B(10), 4,1,10-MC(2)B(10), and 4,1,12-MC(2)B(10)) reveals clear preferences. In all cases a qualitative understanding of these was afforded by simple MO arguments applied to the model heteroarene complexes [(PH3)2PtC(2)B(4)H(6)]2- and [(PH3)2PtCB(5)H(6)]3-. Moreover, DFT calculations on [(PH3)2PtC(2)B(4)H(6)]2- in its various isomeric forms approximately reproduced the observed conformations in the 4,1,2-, 4,1,6-, and 4,1,10-MC(2)B(10) species, although analogous calculations on [(PH3)2PtCB(5)H(6)]3- did not reproduce the conformation observed in the 4,1,12-MC(2)B(10) metallacarborane. DFT calculations on (PH3)2PtC(2)B(10)H(12) yielded good agreement with experimental conformations in all four isomeric cases. Apparent discrepancies between observed and computed Pt-C distances were probed by further refinement of the 4,1,2- model to 1,2-(CH2)3-4,4-(PMe3)2-4,1,2-closo-PtC(2)B(10)H(10). This still has a more distorted structure than measured experimentally for 1,2-(CH2)3-4,4-(PMe(2)Ph)2-4,1,2-closo-PtC(2)B(10)H(10), but the structural differences lie on a very shallow potential energy surface. For the model compound a henicosahedral transition state was located 8.3 kcal mol(-1) above the ground-state structure, consistent with the fluxionality of 1,2-(CH2)3-4,4-(PMe(2)Ph)2-4,1,2-closo-PtC(2)B(10)H(10) in solution.     

A novel thiol compound, N-acetylcysteine amide, attenuates allergic airway disease by regulating activation of NF-kappaB and hypoxia-inducible factor-1alpha

Reactive oxygen species (ROS) play an important role in the pathogenesis of airway inflammation and hyperresponsiveness. Recent studies have demonstrated that antioxidants are able to reduce airway inflammation and hyperreactivity in animal models of allergic airway disease. A newly developed antioxidant, small molecular weight thiol compound, N-acetylcysteine amide (AD4) has been shown to increase cellular levels of glutathione and to attenuate oxidative stress related disorders such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. However, the effects of AD4 on allergic airway disease such as asthma are unknown. We used ovalbumin (OVA)-inhaled mice to evaluate the role of AD4 in allergic airway disease. In this study with OVA-inhaled mice, the increased ROS generation, the increased levels of Th2 cytokines and VEGF, the increased vascular permeability, the increased mucus production, and the increased airway resistance in the lungs were significantly reduced by the administration of AD4. We also found that the administration of AD4 decreased the increases of the NF-kappaB and hypoxia-inducible factor-1alpha (HIF-1alpha) levels in nuclear protein extracts of lung tissues after OVA inhalation. These results suggest that AD4 attenuates airway inflammation and hyperresponsiveness by regulating activation of NF-kappaB and HIF-1alpha as well as reducing ROS generation in allergic airway disease.