The electronic structure of methyl lithium

The results of SCF—MO calculations using a large Gaussian basis set are reported for methyl lithium CH₃Li. Particular attention is paid to obtaining chemically useful informa- tion from the wavefunction, and a comparison is made with the results recently reported for NH₃Li⁺, which is isoelectronic with CH₃Li. Significant differences in their electronic structures are evident on examining the electron density and density difference maps together with population analysis indices.     

Stereochemical definition and chirospecific synthesis of the peptide deformylase inhibitor Sch 382583

The recently reported natural product Sch 382583 (1), an inhibitor of peptide deformylase, has been synthesized in 16 steps from commercially available starting materials. The three chiral centers were set by a combination of chiral auxiliary and chiral pool approaches. The succinate 5 and piperazic acid 9 moieties were obtained by Evans oxazolidinone imide enolate alkylation and hydrazination/cyclization, respectively, and the aminohexanone side chain 13 was prepared via Grignard substitution of the Weinreb amide derived from l-valine. Spectroscopic data for the resulting synthetic material, compared with the data reported for the natural product, established that the previously unassigned valine ketone stereocenter (C-4) has the S-configuration.     

Ethyl glucoside in human urine following dietary exposure: detection by 1H NMR spectroscopy as a result of metabonomic screening of humans

Metabonomic screening of human urine samples using 1H NMR spectroscopy has revealed the presence of signals resulting from the excretion of ethyl glucoside. Experiments in volunteers have demonstrated that this ethyl glucoside results from dietary exposure to the compound, which is present in beverages such as rice wine and sake, rather than representing a new route for the metabolism of ethanol by humans. The limited studies undertaken in volunteers indicate that ethyl glucoside has a longer biological half life than ethanol itself. The potential problems associated with using this glucoside metabolite as a marker of ethanol consumption are considered.     

α‐Haloketal (1′R,4S,5S)‐dimethyl 2‐(1′‐bromoethyl)‐2‐(3,4‐dimethoxyphenyl)‐1,3‐dioxolane‐4,5‐dicarboxylate

The crystal structure and absolute configuration of the title compound, C₁₇H₂₁BrO₈, have been determined by X‐ray analysis. They confirmed the 1′R absolute configuration at the 1′‐bromoethyl moiety which has been assigned previously on the basis of chemical and spectroscopic data. Cohesion of the crystal can be attributed to weak intermolecular C—H?O and van der Waals interactions.     

Norfloxacin dihydrate

The antibiotic norfloxacin recrystallizes from aceto­nitrile as a dihydrate with the norfloxacin mol­ecule in a zwitterionic form, i.e. 1‐ethyl‐6‐fluoro‐1,4‐di­hydro‐4‐oxo‐7‐(1‐piperazin‐4‐io)‐3‐quinoline­carboxyl­ate dihydrate, C₁₆­H₁₈­F­N₃­O₃·­2H₂O.     

Building Teacher‐Scientist Partnerships: Teaching About Energy Through Inquiry

This study evaluated the effectiveness of teacher‐scientist partnerships for increasing the use. of inquiry in precollege classrooms. It assessed the influence of the Teaching About Energy Through Inquiry Institutes for middle and high school teachers and energy scientists on participants' attitudes about science and science education, use of inquiry instructional techniques, and student attitudes about their classroom environments. Participant surveys, institute and classroom observations, lesson plans, and interviews indicated increased appreciation for inquiry, greater confidence in teaching using inquiry, and greater use of inquiry in the classroom. Student surveys and classroom observations pointed to higher levels of student satisfaction and less friction among classmates during inquiry‐based investigations implemented after the institutes. Moreover, scientist partners reported increased familiarity with principles of science education and best teaching practice, which are essential skills and knowledge for disseminating results of scientific research to nonscientific audiences, as well as their own students. These results suggest that collaborations between teachers and research scientists can positively affect the environment for learning science in precollege and college classes. Successful collaborations are most likely to occur when equal status for teachers and scientists in the partnership is stressed and partners have the opportunity to explore inquiry‐based curricula together.     

Evaluation of Stability and Sensitivity of Cell Fluorescent Labels When Used for Cell Migration

The directed migration of mammalian cells is a foundation of development and growth. A variety of processes such as tissue development, wound healing, pathogen recognition/destruction as well as cancer metastasis are the result of regulated or dysregulated cell migration. While the ability to measure a cell’s propensity to migrate has clinical relevance in several settings, no universal protocol has been established to measure cell migration. A variety of techniques are currently used to measure migration including manual counting, flow cytometry or Coulter counting, microfluidic devices, computerized spectroscopic methods, or the use of various tracking dyes interfaced with fluorescent or non-fluorescent plate readers. In order to expedite the measurement of migration, we compared several common cytoplasmic and lipophilic cell tracking dyes to determine the best dye for determining migration of rare population of cells. CellVue® Burgundy was found to be superior over calcein AM, Cell Tracker Green CMFDA (chloromethyl fluorescein diacetate), Vybrant CFDA (carboxy fluorescein diacetate succinimidyl ester) in its retention within cells, superior to CellVue® NIR 815, PKH67, and CM DiI with regard to signal to noise ratio, and superior to PKH26 with regard to instrument versatility.