Sodium Diisopropylamide: Aggregation, Solvation, and Stability

The solution structures, stabilities, physical properties, and reactivities of sodium diisopropyl­amide (NaDA) in a variety of coordinating solvents are described. NaDA is stable for months as a solid or as a 1.0 M solution in <i>N</i>,<i>N</i>-dimethyl­ethyl­amine (DMEA) at −20 °C. A combination of NMR spectroscopic and computational studies show that NaDA is a disolvated symmetric dimer in DMEA, <i>N,N</i>-dimethyl-<i>n</i>-butyl­amine, and <i>N</i>-methyl­pyrrolidine. Tetra­hydrofuran (THF) readily displaces DMEA, affording a tetra­solvated cyclic dimer at all THF concentrations. Dimethoxyethane (DME) and <i>N,N,N</i>′<i>,N</i>′-tetra­methyl­ethylene­diamine quantitatively displace DMEA, affording doubly chelated symmetric dimers. The trifunctional ligands <i>N,N,N</i>′<i>,N</i>″<i>,N</i>″-penta­methyl­diethylene­triamine and diglyme bind the dimer as bidentate rather than tridentate ligands. Relative rates of solvent decompositions are reported, and rate studies for the decomposition of THF and DME are consistent with monomer-based mechanisms

L'Auto-vélo : automobilisme, cyclisme, athlétisme, yachting, aérostation, escrime, hippisme / dir. Henri Desgranges

05 août 19021902/08/05 (A3,N660)

Sodium Diisopropylamide in Tetrahydrofuran: Selectivities, Rates, and Mechanisms of Arene Metalations

Sodium diisopropylamide (NaDA)-mediated metalations of arenes in tetrahydrofuran (THF)/hexane or THF/Me₂NEt solutions are described. A survey of >40 benzenoid- and pyridine-based arenes with a range of substituents demonstrates the efficacy and regioselectivity of metalation. Metalations of activated disubstituted arenes and selected monosubstituted arenes are rapid at −78 °C. Rate studies of 1,3-dimethoxybenzene and related methoxylated arenes show exclusively monomer-based orthometalations with two or three coordinated THF ligands. Rate studies of the isotopic exchange of benzene and monosubstituted arenes with weakly activating groups reveal analogous di- and trisolvated monomer-based metalations. Cooperative inductive, mesomeric, steric, and chelate effects are discussed

Sodium Diisopropylamide in Tetrahydrofuran: Selectivities, Rates, and Mechanisms of Alkene Isomerizations and Diene Metalations

Sodium diisopropylamide in tetrahydrofuran is an effective base for the metalation of 1,4-dienes and isomerization of alkenes. Dienes metalate via tetrasolvated sodium amide monomers, whereas 1-pentene is isomerized by trisolvated monomers. Facile, highly <i>Z</i>-selective isomerizations are observed for allyl ethers under conditions that compare favorably to those of existing protocols. The selectivity is independent of the substituents on the allyl ethers; rate and computational data show that the rates, mechanisms, and roles of sodium–oxygen contacts are substituent-dependent. The competing influences of substrate coordination and solvent coordination to sodium are discussed

Additional file 4: Figure S4. of Smad4 SUMOylation is essential for memory formation through upregulation of the skeletal myopathy gene TPM2

TGF-β receptor inhibition impairs spatial learning and memory. Animals were divided into two groups and received a PBS or SB525334 (1 μM) injection directly to their CA1 area. They were then subjected to: a Water maze learning. n = 7 each group, F(1,12) = 34.12, # P < 0.001. The statistical difference between the PBS group and SB525334 group for a given trial is indicated by the proper significance sign (*P < 0.05 and # P < 0.001). b Probe trial test. n = 7 each group, F(1,12) = 10.16, **P < 0.01. The representative swim pattern from each group is also shown. Data are expressed as mean ± SEM. PBS phosphate-buffered saline, SEM standard error of the mean (PDF 70 kb

Additional file 1: Figure S1. of Smad4 SUMOylation is essential for memory formation through upregulation of the skeletal myopathy gene TPM2

Smad4 is SUMO-modified by PIAS1 in the hippocampus endogenously. a Animals were divided into two groups and received control siRNA or PIAS1 siRNA (8 pmol) transfection to their CA1 area. Animals were sacrificed 48 h later and their CA1 tissue was dissected out and subjected to SUMOylation assay without the addition of E1, E1, SUMO1, and the recombinant PIAS1 protein. Left panel: Immunoblotted with anti-Smad4 antibody. Upper right panel: Immunoblotted with anti-SUMO1 antibody. Cell lysate was also subjected to western blot analysis of PIAS1 expression (lower right panel). b Quantified results of Smad4 SUMOylation. n = 5 each group, t(1,8) = 6.1, # P < 0.001. Raw data and statistics are provided as Additional file 8. c PIAS1 expression. n = 5 each group, t(1,8) = 29.31, # P < 0.001. Raw data and statistics are provided as Additional file 8. Data are expressed as mean ± SEM. (PDF 122 kb

Additional file 6: of Smad4 SUMOylation is essential for memory formation through upregulation of the skeletal myopathy gene TPM2

Raw data for Fig. 5b. (PDF 42 kb

Additional file 7: of Smad4 SUMOylation is essential for memory formation through upregulation of the skeletal myopathy gene TPM2

Raw data for Fig. 5f. (PDF 41 kb

Identification of core genes affecting IMF deposition in bovine

Intramuscular fat (IMF) content is an important economic factor in beef production. However, knowledge on the key factors controlling bovine IMF is limited. In this study, using weighted gene co-expression network analysis (WGCNA), nine modules were identified and the number of transcripts in these modules ranged from 36 to 3191. Two modules were found to be significantly associated with fat deposition and three genes (TCAP, MYH7, and TNNC1) were further identified by Protein–protein interaction (PPI), which may be the hub genes regulating bovine IMF deposition. In addition, considering the genetic variation, the PCK1 gene was found by functional enrichment analysis of overlapping genes, which was previously reported to be involved in IMF deposition. We noted that the core promoter region of buffalo PCK1 binds to transcription factors involved in lipid metabolism while cattle PCK1 binds transcription factors involved in muscle development. The results suggest that PCK1 participated in IMF deposition of buffalo and cattle in different ways. In summary, gene expression networks and new candidate genes associated with IMF deposition identified in this study. This would lay the foundation for further research into the molecular regulatory mechanisms underlying bovine IMF deposition.</p

Managing Environmental Research Data.

Environmental science researchers are now using and generating ever-increasing volumes of data and information about our natural world. It is estimated that the Environmental Protection Agency’s (EPA's) STRIVE (Science, Technology, Research and Innovation for the Environment) research funding programme will “involve more than 1,000 researchers and company-based scientists over its seven-year lifetime”1. The EPA's Environmental Research Centre (ERC) expects that large volumes of environmental data and information will be generated by projects funded by STRIVE. One of the key objectives of the STRIVE programme is to make the outcomes and data from this research available “in a coherent and timely manner which will ensure synergies across the wider research agenda and early availability of these outputs into the formulation of policy”2. Consequently, the STRIVE programme must adopt best international practice in environmental research data management. Management of these environmental research data is a core activity for the ERC with particular emphasis on the application of appropriate data management techniques to ensure their long-term availability and accessibility. Environmental research data are often irreplaceable; they are always unique particularly in the spatial location and temporal characteristics of their collection. They can also be extremely expensive and difficult to collect or generate. For these reasons the EPA and the ERC attach great importance to the ongoing development of systems that will ensure that maximum benefits are derived from research data once acquired