Nonclassical Applications of closo-Carborane Anions: From Main Group Chemistry and Catalysis to Energy Storage

Classically closo-carborane anions, particularly [HCB₁₁H₁₁]^- and [HCB₉H₉]^-, and their derivatives have primarily been used as weakly coordinating anions to isolate reactive intermediates, platforms for stoichiometric and catalytic functionalization, counteranions for simple Lewis acid catalysis, and components of materials like liquid crystals. The aim of this article is to educate the reader on the contemporary nonclassical applications of these anions. Specifically, this review will cover new directions in main group catalysis utilized to achieve some of the most challenging catalytic reactions such as C-F, C-H, and C-C functionalizations that are difficult or impossible to realize with transition metals. In addition, the review will cover the utilization of the clusters as dianionic C σ-bound ligands for coordination chemistry, ligand substituents for coordination chemistry and advanced catalyst design, and covalently bound spectator substituents to stabilize radicals. Furthermore, their applications as solution-based and solid-state electrolytes for Li, Na, and Mg batteries will be discussed.

Enantioselective α-Amination Enabled by a BINAM-Derived Phase-Transfer Catalyst

The enantioselective amination of carbonyl derivatives is achieved via phase-transfer of aryldiazonium salts by BINAM-derived phosphoric acids.

Chiral anion phase-transfer of aryldiazonium cations was utilized to achieve highly enantioselective α-amination of carbonyl compounds. A broad scope of indanone- and benzosuberone-derived substrates was amenable to this strategy. Critical to obtaining high levels of enantioselectivity was the use of BINAM-derived phosphoric acids. The utility of this transformation was demonstrated through facile conversion of diazene products to valuable α-amino acid derivatives.

Otitis media and associations with overweight status in toddlers

INTRODUCTION

Otitis media (OM) is a significant disease that affects nearly all children early in life. Recently, childhood overweight has become an epidemic. Past research has demonstrated that a history of OM is related to food preferences and overweight through proposed physiological mechanisms. The purpose of this study was to explore the relationship between recurrent OM (ROM)/tympanostomy tube treatment and overweight status.

METHODS

Data were analyzed from a prospective cohort of mothers and children recruited from 1991-1996 from a local health maintenance organization. ROM and tympanostomy tube status were obtained through a combination of physical exam and medical record abstraction. ROM and tympanostomy tube status were analyzed as categorical variables with weight-for-length (WFL) data from well child checks. Chi-square and logistic regression for univariate and multivariate analyses were performed.

RESULTS

11.4% of children had a WFL measure at two years of age ≥ 95 th percentile. Those children with a history of tympanostomy tube treatment had a significantly increased risk of having a WFL ≥ 95 th percentile after controlling for birth weight, maternal prenatal smoking, maternal education, and family income (OR 3.32, 95% CI 1.43-7.72). The alternative hypothesis that children with larger WFL at two month of age would have a greater number of OM episodes by two years of age was not significant.

CONCLUSION

The findings of this study are consistent with the hypothesis and prior research that OM treated with tympanostomy tubes is associated with overweight status.

Localization of a gene (MCUL1) for multiple cutaneous leiomyomata and uterine fibroids to chromosome 1q42.3-q43

Dominant transmission of multiple uterine and cutaneous smooth-muscle tumors is seen in the disorder multiple leiomyomatosis (ML). We undertook a genomewide screen of 11 families segregating ML and found evidence for linkage to chromosome 1q42.3-q43 (maximum multipoint LOD score 5.40). Haplotype construction and analysis of recombinations permitted the minimal interval containing the locus, which we have designated "MCUL1," to be refined to an approximately 14-cM region flanked by markers D1S517 and D1S2842. Allelic-loss studies of tumors indicated that MCUL1 may act as a tumor suppressor. Identification of MCUL1 should have wide interest, since this gene may harbor low-penetrance variants predisposing to the common form of uterine fibroids and/or may undergo somatic mutation in sporadic leiomyomata.

High-resolution maps of the murine Chromosome 2 region containing the cholesterol gallstone locus, Lith1

The Lith1 region on Chromosome (Chr) 2 contains a gene that markedly affects the prevalence of cholesterol gallstones in inbred mice. We report the high-resolution genetic and radiation hybrid maps of the chromosomal region surrounding Lith1, using three resources: a DNA panel from 188 progeny from two reciprocal backcrosses between C57BL/6 and Mus spretus inbred strains; 423 progeny of an N4 generation from backcrossing the susceptible C57L/J alleles at Lith1 into the resistant AKR/J strain; and the newly developed hamster-mouse T31 radiation hybrid panel. We mapped 17 microsatellite markers in the D2Mit182 to D2Mit14 region and two candidate genes for Lith1, the canalicular bile salt export pump (Bsep) also known as sister of P-glycoprotein (Spgp) and the low-density-lipoprotein-receptor-related gene megalin (Gp330). Both genetic maps were in agreement and ordered the microsatellite markers into a 10.4 +/- 1.5 cM region. The high-resolution physical map revealed ordering of microsatellite markers and relative distances between markers in almost complete agreement with the genetic maps. Mapping of Bsep revealed its location on Chr 2, homologous to the human chromosomal position (Nature Genet 20, 233-238, 1998). The radiation hybrid results also provided the highest resolution of the area containing the two candidate genes, which both mapped in the Lith1 region with close linkage, being separated by a distance of only 15 cR(3000). The total radiation hybrid map length of the region between D2Mit182 and D2Mit14 was 326 cR(3000), suggesting that 31 cR(3000) is equivalent to 1 cM in this region of Chr 2.

Studies in cutaneous immunofluorescence. II. Histological and direct immunofluorescence observations in clinically normal skin of patients with rheumatoid arthritis

Twenty patients with rheumatoid arthritis (RA) had a biopsy taken from clinically normal skin. These were examined for histological and immunological abnormalities and were compared to those of 8 patients with osteoarthritis (OA). No 'lupus band; linear deposition of immunoglobulin or complement at the dermo-epidermal interface was seen in any patient in either group. Perivascular deposits were seen in 5 out of 20 (25%) patients with RA. These were IgM in all 5 cases with additional C3 in 2 cases (10%) and additional fibrin in one case (5%). No immunoprotein deposits were seen in specimens from any OA patient. 4 of the 5 patients with perivascular immunoprotein deposits had circulating ANAs present and dilutions of 1/256 or higher but normal DNA binding. A sparse perivascular, predominantly lymphocytic infiltrate was seen in 13 out of 20 (65%) patients with RA and 3 of 8 (35%) patients with OA.

Zinc, copper and delta-aminolaevulinic acid dehydratase in vitro and in vivo

The effects of zinc and copper on delta-aminolaevulinic acid dehydratase were studied in vitro and in vivo. The in vitro addition of zinc alone to whole blood resulted in a highly significant increase in enzyme activity. The addition of copper alone had the opposite effect with a significant decrease in enzyme activity. When both elements were added to whole blood the inhibitory effect of copper was reduced. In in vivo studies of plasma zinc, plasma copper and whole blood delta-aminolaevulinic acid dehydratase, a positive correlation was found between plasma zinc and whole blood delta-aminolaevulinic acid dehydratase and a negative correlation was found between plasma copper and enzyme activity.

The use of the Psorilux 3050A machine in the management of psoriasis of the hands and feet

Eleven patients with severe psoriasis involving the palms and soles have been treated using a high-energy source of UV-A and UV-B with no additional topical or systemic photosensitizing drug. The results showed marginal benefit of UV-A alone over conventioonal topical tar therapy. The high energy output of the machine makes it essential that personnel supervising therapy are adequately protected.

Silica flour exposures in Ontario

A total of 16 cases of silicosis are reported in Ontario plants where there was exposure to silica flour. Dust counts expressed as mppcf are shown for four of these plants taken over a period of 37 years. A relationship has been obtained experimentally to permit conversion of the counts to respirable mass concentrations. Based on the information obtained, a TLV of 0.05 mg/m3 for silica flour is proposed.

System for ESR measurements at hydrostatic pressures to 60 kilobars

A single-crystal sapphire serves both as a solid microwave cavity (X band) and an anvil in a Bridgman-anvil pressure geometry. A metal gasket is used in a manner similar to its use in the diamond-anvil pressure cell, and single-crystal samples are subject to purely hydrostatic pressures. The ruby-fluorescence pressure-measurement technique is utilized. Sample size is limited to a disk approximately 0.6 mm in diameter and 0.1 mm thick. ESR data on Cr(3+) in ruby to 60 kilobars are given as an illustration of the precision and data quality. Line widths and profiles, as well as line positions, are meaningful. Very little degradation of the data is experienced at the higher pressures. The first and second derivatives of the zero-field splitting (delta) of the states in ruby with pressure are measured as ddelta/dP= (6.70+/-0.08) x 10(-4) cm(-1) kilobar(-1) and d(2)delta/dP(2)= (-2.44+/-0.30) x10(-6) cm(-1) kilobar(-2) at P=0. The gyromagnetic ratio g(11) is shown to experience a fractional change less than 2 x 10(-4) to 60 kilobars.