Quantum-mechanical calculations of the stabilities of fluxional isomers of C_4H_7^+ in solution

Although numerous quantum calculations have been made over the years of the stabilities of the fluxional isomers of C4H7+, none have been reported for other than the gas phase (which is unrealistic for these ionic species) that exhibit exceptional fluxional properties in solution. To be sure, quantum-mechanical calculations for solutions are subject to substantial uncertainties, but nonetheless it is important to see whether the trends seen for the gas-phase C4H7+ species are also found in calculations for polar solutions. Of the C4H7+ species, commonly designated bisected-cyclopropylcarbinyl 1, unsym-bicyclobutonium-2, sym-bicyclobutonium 3, allylcarbinyl 4, and pyramidal structure 6, the most advanced gas-phase calculations available thus far suggest that the order of stability is 1 ≥ 2 ≥ 3 >> 4 >> 6 with barriers of only ~1 kcal/mol for interconversions among 1, 2, and 3. We report here that, when account is taken of solvation, 2 turns out to be slightly more stable than 1 or 3 in polar solvents. The pattern of the overall results is unexpected, in that despite substantial differences in structures and charge distributions between the primary players in the C4H7+ equilibria and the large differences in solvation energies calculated for the solvents considered, the differential solvent effects from species to species are rather small

Electroorganic Chemistry. VII. The Role of Mercuric Salts in the Electroreduction of Benzylic Bromides

Electroduction of a variety of benzylic mono- and 1,3-dibromides and of benzylmer curie halides at stirred mercury pool cathode leads to products that support a mechanism for the electro- duction of bromides that involves organomercury(I) intermediates and perhaps mercury (I) dimers. Products f ormed in the presence or absence of strongly adsorbed but eleotrochemically indifferent species suggest that monomolecular versus bimolecular reactions of the adsorbed organomercury(I) intermediates or dimers are strongly influenced by the presence of such species and that in some cases the reaction can be directed to one or another final product, providing a measure of control in synthetic applications

Electroorganic Chemistry. VI. Mechanism and Product Studies in the Electroreductoin of 1,3-Dibromides

Products of the electroreduction of 1,3-dihromopropane, 1, 3-dibromo-1 -phenylpropane, 1,3-dibromo-1,3 -diphenylpropane, enđo-4-syn-8-dibromodibenzobicyclo[3.2.1] octadiene, and 1,8-bis- (bromomethyl)naphthalene at a mercury cathode were examined. The influence of change in potential, of addition of radical and carbanion scavengers, of added adsorbable species on product distribution, and the presence of organomercurial species in the products implicate a reaction path which involves sequential one electron reductions with the intervention of organomercury(l) radicals and possible dimeric mercury(l) species

A Comparative Analysis of the Endocannabinoid System in the Retina of Mice, Tree Shrews, and Monkeys

The endocannabinoid (eCB) system is widely expressed in various parts of the central nervous system, including the retina. The localization of the key eCB receptors, particularly CB1R and CB2R, has been recently reported in rodent and primate retinas with striking interspecies differences. Little is known about the distribution of the enzymes involved in the synthesis and degradation of these eCBs. We therefore examined the expression and localization of the main components of the eCB system in the retina of mice, tree shrews, and monkeys. We found that CB1R and FAAH distributions are well-preserved among these species. However, expression of NAPE-PLD is circumscribed to the photoreceptor layer only in monkeys. In contrast, CB2R expression is variable across these species; in mice, CB2R is found in retinal neurons but not in glial cells; in tree shrews, CB2R is expressed in Müller cell processes of the outer retina and in retinal neurons of the inner retina; in monkeys, CB2R is restricted to Müller cells. Finally, the expression patterns of MAGL and DAGLα are differently expressed across species. Overall, these results provide evidence that the eCB system is differently expressed in the retina of these mammals and suggest a distinctive role of eCBs in visual processing

Intraspecific chemical variability of the leaf essential oil of Juniperus phoenicea subsp. turbinata from Corsica

The composition of 50 samples of essential oil of individual plants of Juniperus phoenicea subsp. turbinata from Corsica was investigated by GC, GC-MS and 13C NMR. [alpha]-Pinene, [beta]-phellandrene, [alpha]-terpinyl acetate, [Delta]-3-carene, myrcene and [alpha]-phellandrene were found to be the main constituents. The results were submitted to cluster analysis and discriminant analysis which allowed two groups of essential oils to be distinguished with respect to the content of [alpha]-pinene, [beta]-phellandrene and [alpha]-terpinyl acetate.http://www.sciencedirect.com/science/article/B6T4R-41TMSRJ-8/1/9a99aea13c1425fdcac449056f51c71

Composition and antimicrobial activity of the essential oil of Clinopodium ascendens (Jordan) Sampaio from Madeira

Clinopodium ascendens (Jordan) Sampaio [synonyms = Calamintha ascendens Jordan = C. officinalis Moench ssp. ascendens (Jord.) Mateo = C. sylvatica Bromf. ssp. ascendens (Jord.) P.W. Ball] is a small herbaceous plant with a very strong and distinctive mint aroma. The plant is known for its medical uses in folk medicine and as a spice in Italian kitchens. In Madeira Island, Clinopodium ascendens, known locally as ‘neveda’, grows wild along the shady paths of the Laurissilva forest. The local population uses the leaves of calamint as a mouth freshener and to alleviate headache and toothache. The essential oil obtained by hydrodistillation of the aerial parts of C. ascendens growing wild in Madeira was analysed by a combination of CC, GC, GC–MS, 1 H- and 13C-NMR. The oil was dominated by C3 oxy genated p-menthane derivatives: cis-isopulegone (75.2%), pulegone (6.9%), neoiso-isopulegol (6.0%) and trans-isopulegone (4.5%). The whole essential oil was tested against a variety of bacteria, both Gram-positive and Gram-negative, and two fungi; it exhibited remarkable activity against Escherichia coli and was active against Agrobacterium tumefasciens and Staphylococcus aureus and the phytopathogenic fungus Botrytis cinerea. It was ineffective against Streptococcus faecium, Streptococcus mutans and Candida albicans.info:eu-repo/semantics/publishedVersio

Direct identification and quantitative determination of costunolide and dehydrocostuslactone in the fixed oil of Laurus novocanariensis by13C-NMR spectroscopy

The fixed oil of Laurus novocanariensis (previously L. azorica) contains mostly glycerides together with minor non-saponifiable compounds. The direct identification and quantitative determination of costunolide and dehydrocostuslactone, two sesquiterpene lactones components of the oil that exhibit biological activities, is described. The analysis was carried out using 13C-NMR spectroscopy (signal acquisition with inverse gated decoupling of protons; diglyme as internal standard) without separation, derivatisation or any sample preparation.info:eu-repo/semantics/publishedVersio

Private Food Assistance in the Deep South: Assessing Agency Directors\u27 Knowledge of Charitable Choice

In recent years,food banking has emerged as an important tool in America\u27s fight against hunger and malnutrition. At the same time, the charitable choice provision of 1996 welfare reform law has significantly expanded the opportunity for public-private partnerships in the provision of social services. Given the new opportunities ushered in by this legislation, this study examines the knowledge that food pantry directors in Alabama and Mississippi possess about charitable choice. Our study reveals that food pantry directors are generally lacking in knowledge about key charitable choice provisions, thereby limiting the potential for this initiative to be utilized fully in this area. We conclude by discussing the implications of these findings and specifying directions for future research

Cannabinoid Receptors CB1 and CB2 Modulate the Electroretinographic Waves in Vervet Monkeys

The expression patterns of the cannabinoid receptor type 1 (CB1R) and the cannabinoid receptor type 2 (CB2R) are well documented in rodents and primates. In vervet monkeys, CB1R is present in the retinal neurons (photoreceptors, horizontal cells, bipolar cells, amacrine cells, and ganglion cells) and CB2R is exclusively found in the retinal glia (Müller cells). However, the role of these cannabinoid receptors in normal primate retinal function remains elusive. Using full-field electroretinography in adult vervet monkeys, we recorded changes in neural activity following the blockade of CB1R and CB2R by the intravitreal administration of their antagonists (AM251 and AM630, resp.) in photopic and scotopic conditions. Our results show that AM251 increases the photopic a-wave amplitude at high flash intensities, whereas AM630 increases the amplitude of both the photopic a- and b-waves. In scotopic conditions, both blockers increased the b-wave amplitude but did not change the a-wave amplitude. These findings suggest an important role of CB1R and CB2R in primate retinal function

High Dimensional Classification of Structural MRI Alzheimer’s Disease Data Based on Large Scale Regularization

In this work we use a large scale regularization approach based on penalized logistic regression to automatically classify structural MRI images (sMRI) according to cognitive status. Its performance is illustrated using sMRI data from the Alzheimer Disease Neuroimaging Initiative (ADNI) clinical database. We downloaded sMRI data from 98 subjects (49 cognitive normal and 49 patients) matched by age and sex from the ADNI website. Images were segmented and normalized using SPM8 and ANTS software packages. Classification was performed using GLMNET library implementation of penalized logistic regression based on coordinate-wise descent optimization techniques. To avoid optimistic estimates classification accuracy, sensitivity, and specificity were determined based on a combination of three-way split of the data with nested 10-fold cross-validations. One of the main features of this approach is that classification is performed based on large scale regularization. The methodology presented here was highly accurate, sensitive, and specific when automatically classifying sMRI images of cognitive normal subjects and Alzheimer disease (AD) patients. Higher levels of accuracy, sensitivity, and specificity were achieved for gray matter (GM) volume maps (85.7, 82.9, and 90%, respectively) compared to white matter volume maps (81.1, 80.6, and 82.5%, respectively). We found that GM and white matter tissues carry useful information for discriminating patients from cognitive normal subjects using sMRI brain data. Although we have demonstrated the efficacy of this voxel-wise classification method in discriminating cognitive normal subjects from AD patients, in principle it could be applied to any clinical population