Mt. Pleasant Area Commuity Foundation

A simple amphiphile, N-cardanyltaurine amide (NCT) with different degrees of cis-unsaturation in its tail resulted in the formation of strong organogels. Interestingly, this is in contrast to the commonly accepted notion that introducing unsaturation in alkyl chains enhances fluidity in lipid assemblies. The physico-chemical and first-principles DFT calculations confirmed the pegging of 'kinked' unsaturated side chains, where the hydrophobic interlocking as in Velcro fasteners leads to a network of cylindrical micelles, resulting in self-standing organogels. Textural profile analysis and spectroscopic details substantiated the dynamic assembly to resemble a 3D network of gelators rather than being a cross-linked or polymerized matrix of monomers.

In the present work, a new magnetic nanoparticle supported N-heterocyclic carbene-palladium(ii) (NO2-NHC-Pd@Fe3O4) nanomagnetic catalyst was synthesized by a facile multistep synthesis under aerobic conditions.

Mycobacterium tuberculosis, the etiological agent of human tuberculosis, requires the non-mammalian disaccharide trehalose for growth and virulence. Recently, detectable trehalose analogues have gained attention as probes for studying trehalose metabolism and as potential diagnostic imaging agents for mycobacterial infections. Of particular interest are deoxy-[(18)F]fluoro-d-trehalose ((18)F-FDTre) analogues, which have been suggested as possible positron emission tomography (PET) probes for in vivo imaging of M. tuberculosis infection. Here, we report progress toward this objective, including the synthesis and conformational analysis of four non-radioactive deoxy-[(19)F]fluoro-d-trehalose ((19)F-FDTre) analogues, as well as evaluation of their uptake by M. smegmatis. The rapid synthesis and purification of several (19)F-FDTre analogues was accomplished in high yield using a one-step chemoenzymatic method. Conformational analysis of the (19)F-FDTre analogues using NMR and molecular modeling methods showed that fluorine substitution had a negligible effect on the conformation of the native disaccharide, suggesting that fluorinated analogues may be successfully recognized and processed by trehalose metabolic machinery in mycobacteria. To test this hypothesis and to evaluate a possible route for delivery of FDTre probes specifically to mycobacteria, we showed that (19)F-FDTre analogues are actively imported into M. smegmatis via the trehalose-specific transporter SugABC-LpqY. Finally, to demonstrate the applicability of these results to the efficient preparation and use of short-lived (18)F-FDTre PET radiotracers, we carried out (19)F-FDTre synthesis, purification, and administration to M. smegmatis in 1 hour.

Protein O-mycoloylation is a unique post-translational lipidation that was recently discovered in Corynebacterium. We describe an alkyne-modified trehalose monomycolate chemical reporter that can metabolically tag O-mycoloylated proteins in C. glutamicum, enabling their detection and identification through click chemistry.

Abstract The relationship, on a global basis, between the amount of N fixed by chemical, biological or atmospheric processes entering the terrestrial biosphere, and the total emission of nitrous oxide (N2O), has been re-examined, using known global atmospheric removal rates and concentration growth of N2O as a proxy for overall emissions. For both the pre-industrial period and in recent times, after taking into account the large-scale changes in synthetic N fertiliser production, we find an overall conversion factor of 3–5 % from newly fixed N to N2O–N. We assume the same factor to be valid for biofuel production systems. It is covered only in part by the default conversion factor for ‘direct’ emissions from agricultural crop lands (1 %) estimated by IPCC (2006), and the default factors for the ‘indirect’ emissions (following volalilization/deposition and leaching/runoff of N: 0.35–0.45 %) cited therein. However, as we show in the paper, when additional emissions included in the IPCC methodology, e.g. those from livestock production, are included, the total may not be inconsistent with that given by our “top-down” method. When the extra N2O emission from biofuel production is calculated in “CO2-equivalent” global warming terms, and compared with the quasi-cooling effect of ‘saving’ emissions of fossil fuel derived CO2, the outcome is that the production of commonly used biofuels, such as biodiesel from rapeseed and bioethanol from corn (maize), depending on N fertilizer uptake efficiency by the plants, can contribute as much or more to global warming by N2O emissions than cooling by fossil fuel savings. Crops with less N demand, such as grasses and woody coppice species, have more favourable climate impacts. This analysis only considers the conversion of biomass to biofuel. It does not take into account the use of fossil fuel on the farms and for fertilizer and pesticide production, but it also neglects the production of useful co-products. Both factors partially compensate each other. This needs to be analyzed in a full life cycle assessment.

A bicyclo[6.1.0]nonyne (BCN)-based cyclooctyne reagent bearing a photocrosslinking diazirine (DAz) group and a biotin affinity handle, BCN-DAz-Biotin, is reported. BCN-DAz-Biotin is capable of simultaneously delivering photocrosslinking and affinity tags to azide-labeled biomolecules, enabling photoactivated capture and enrichment/detection of interacting species in native contexts.

While increasing population and changing food preferences have changed agriculture in some East Asian countries to high input systems with greater use of fertilizer nitrogen and greater numbers of animals, the changes and the effects on the environment in the different countries have varied considerably. Many areas still do not use sufficient nitrogen to maximize crop yields. In China, fertilizer nitrogen input has increased from 0.54 Tg in 1961 to 28 Tg in 2005, and the animal population increased dramatically, from 27 to 1,013 million. As a result 13 Tg N was lost to the environment in 2005 as nitrous oxide, ammonia or nitrate. In Mongolia, no fertilizer nitrogen was recorded as having been used until 1970, and current use is only ∼4 Gg. The animal population has increased from 23 million in 1961 to 28 million in 2005 and adverse effects on the environment are small (96 Gg N lost). However, a combination of over-ploughing and overgrazing has resulted in soil erosion from wind and rain in both countries and loss of soil nitrogen. These and other effects of changing agricultural systems on the nitrogen cycle in East Asian countries and some approaches to reduce the impact of nitrogen on the environment are reported in this paper.

A Third South Carolina Record for the Bay-breasted Warbler (Dendroica castanea).--Ishot on October 18, 1922, in a live oak hammock within a quarter of a mile of my house a very fine adult female of the Bay-breasted Warbler in winter plumage.When I first saw it among a lot of Redstarts (Setophaga ruticilla) I believed it to be a Black-poll Warbler (Dendroica striata) and, as I had not seen one of the latter birds in autumn for many years, I collected it.Upon reaching home I at once compared it with autumnal specimens of D. striata taken by me on Sullivan's Island, S.C., on October 6, 1887, as well as with a bird taken in my yard on November 14, 1906, and found after critical comparison that I had at last taken an undoubted Bay-breasted Warbler, which is the first example ever taken on the coast.Mr. Levererr Mills Loomis• secured at Chester two specimens in nuptial plumage of D. castanea, one on May 14 1887, and the other on May 5, 1888.--AnTaV•T. W•¾•., Mount Pleasant, S.C. ' Wintering of the Yellow Palm Warbler at Prattville, Ala.--EveryJanuary or December since 1913, eight or ten Yellow Palm Warblers can be found in roadside hedges some two miles east of this place though during February and March I have failed to find them.