On the use of the Galerkin method for 3D numerical modelling of the general circulation: the South Atlantic eperiment

A linear three‐dimensional hydrodynamical numerical model, with the application of the Galerkin Method for the vertical dependence, is here presented. The spherical coordinate system is used, in order to allow large‐scale simulations. The equations and mathematical development of the model are shown in detail, together with the boundary and initial conditions, and the sequence of equations' solution. The model is applied to the South Atlantic Ocean, for estimating typical seasonal circulations, and the results are summarized in maps of currents at surface and 1000 m depth, and in transport values of the Brazil Current between 30°S and 40°S. Copyright © 2002 John Wiley & Sons, Ltd.     

Catalytic desulfurization of condensed thiophenes by means of methanol

Desulfurization of dibenzothiophene, two methyldibenzothiophenes, and phenanthro[4,5-bcd]-thiophene to give 60-80% yields of hydrocarbon products was effected by means of a sulfided molydena catalyst plus methanol at 450° and a pressure of ca. one atmosphere. The methanol functions both as an in situ hydrogen donor and as a methylating agent.     

Calculation of Siegert eigenvalues for molecular systems: results for He(21,3S)+ H

The variational calculation of Siegert eigenvalues has previously been shown to provide reliable positions and widths for atomic resonances. This approach is herein extended to molecular problems, and the first such calculations for a molecular autoionizing system, He(2^1,3S)+H→ He+H⁺+e^?, are reported.     

PHOTOCHEMICAL CROSSLINKING OF ATP TO HISTONE H4

Abstract— A covalent crosslink occurs between histone H4 and the adenine moiety of ATP, when the complex they form is irradiated with UV light of Λ > 290 nm in the presence of acetone. Within 1 h of irradiation a 48% yield of crosslinked product is thus obtained. It is also shown that in the photosensitized reaction, 80% of the crosslinked product is monomeric, whereas protein precipitation and aggregation occur as a result of direct irradiation with 254 nm light.     

Evaluation of parameters critical to observing proteins inside living Escherichia coli by in-cell NMR spectroscopy

Our recently developed in-cell NMR procedure now enables one to observe protein conformations inside living cells. Optimization of the technique demonstrates that distinguishing the signals produced by a single protein species depends critically on protein overexpression levels and the correlation time in the cytoplasm. Less relevant is the selective incorporation of (15)N. Poorly expressed proteins, insoluble proteins, and proteins that cannot tumble freely due to associations within the cell cannot yet be observed. We show in-cell NMR spectra of bacterial NmerA and human calmodulin and discuss limitations of the technique as well as prospects for future applications.     

Evaluation of an Economical Sunlamp that Emits a Near Solar UV Power Spectrum for Conducting Photoimmunological and Sunscreen Immune Protection Studies

Expense and inconvenience have restricted the use of the filtered xenon are lamp (solar simulator) as a UV source for conducting large-scale animal studies. Because sunscreen immunoprotective levels are significantly affected by the UV power spectrum of the source it is imperative that a solar simulating source be used for accurate measurements of sunscreen protection levels that are relevant to human UV exposures from sunlight. However, relatively inexpensive sunlamps, e. g. the UVA-340, that emit a UV power spectrum similar to that of a solar simulator are available. Unlike FS-type UVB sunlamps, which have a significant amount of effective immunosuppressive nonsolar UV energy at wavelengths below 295 nm, the immunosuppression effectiveness spectrum of UVA-340 sunlamps was nearly identical to that of a solar simulator. The purpose of this study was to evaluate this sunlamp for conducting photoimmunological and sunscreen immune protection studies. Groups of C3H mice were exposed to a range of UVA-340 sunlamp doses (0.25 KJ/m² to 20.0 KJ/m²) to establish a dose-response curve and determine the minimum immune suppression dose (MISD) for induction of local-type suppression of contact hypersensitivity (CH). The MISD, defined as the lowest UV dose given to produce ～50% suppression of the CH response in mice, was determined to be 1.0 kJ/m² for UVA-340 sunlamps. Immune protection tests on four marketed sunscreen lotions (sun protection factors [SPF] 4, 8, 15 and 30) were then conducted with UVA-340 sunlamps using MISD as the endpoint. The immune protection factors for these sunscreens were equivalent to the level of protection predicated by their labeled SPF. These results are similar to those we have previously obtained using a solar simulator. We conclude from these data that the immunosuppressive effects of UVA-340 sunlamps are similar to those of a solar simulator; however, further studies are needed to determine if UVA-340, or similar, sunlamps are a viable alternative to the solar simulator for conducting large-scale animal experiments that require a relevant UV solar spectrum.     

Completely regioselective, highly stereoselective syntheses of cis-Bisfullerene

cis-Bisfullerene[60] adducts of 6,13-disubstituted pentacenes (R = Ph, 4'-hydroxymethylphenyl) are synthesized in 75% to 85% isolated yields under kinetically controlled Diels-Alder conditions. The cycloadditions are completely regioselective and highly stereoselective, with only traces of the diastereomeric trans-bisfullerene[60] adducts forming.     

Carbon-bound diazeniumdiolates from the reaction of nitric oxide with amidines

[reaction: see text] The enediamine tautomer of a variety of substituted amidine free bases reacts with nitric oxide (NO) to produce compounds containing a carbon-bound diazeniumdiolate [R1R2R3C-N(O)=NO-] functional group (previously called "nitrosohydroxylamines"). The new reaction has been shown to be quite general, although the nature of the products does vary. Amidines containing more than one replaceable hydrogen produce polydiazeniumdiolates as intermolecular salts, while those in which only one diazeniumdiolation can occur provide zwitterionic salts. These diazeniumdiolated amidines are shown to be useful NO donor compounds which undergo very slow spontaneous dissociation on dissolution in pH 7.4 phosphate buffer to produce mixtures of NO and nitrous oxide containing mostly NO. The most advantageous manifestation of the new discovery is the preparation of the monodiazeniumdiolated amidine zwitterions. Reaction of the medically relevant alpha-adrenergic agonists tetrahydrozoline and idazoxan produced monodiazeniumdiolated amidine zwitterions from which NO release was observed for up to 28 days and showed little sign of ending. The reaction should be applicable to a variety of pharmaceutical agents, including NO synthase inhibitors, antitumor agents, and antibacterials.     

LETTUCE SEED GERMINATION: EFFECTS OF HIGH TEMPERATURE AND OF REPEATED FAR-RED TREATMENT IN RELATION TO PHYTOCHROME

Abstract— At 37°C the active form of phytochrome in lettuce seed cannot function to promote subsequent germination. This effect of high temperature is distinct from thermal acceleration of dark reversion from the active form of phytochrome to the inactive form, and may be due to reversible denaturation of phytochrome.
Repeated brief irradiations with far-red light inhibit subsequent germination in the whole seed, whereas a similar irradiation regime results in a strong enhancement of the development of growth potential (ability to expand against an externally-imposed osmotic restraint) in the excised axial portion of the seed. A possible explanation for these two opposing results, in volving two different pigment systems with effective loci in different parts of the seed, is suggested.