Primary amido substituted diborane4 compounds and imidodiborate4 anions

Treatment of the diborane(4) compound B(2)(NMe(2))(4) with aniline or 2,6-dimethylaniline results in the primary amido compounds B(2)(NHR)(4)(R = Ph, 2,6-Me(2)C(6)H(3)); subsequent treatment with n-BuLi in toluene in each case affords the first examples of anionic imidodiborates namely Li(4)(thf)(6)B(2)(NPh)(4) and Li(4)(thf)(4)B(2)(N-2,6-Me(2)C(6)H(3))(4); all complexes have been characterised crystallographically.     

Higher-Rank Graph C *-Algebras: An Inverse Semigroup and Groupoid Approach

We provide inverse semigroup and groupoid models for the Toeplitz and Cuntz-Krieger algebras of finitely aligned higher-rank graphs. Using these models, we prove a uniqueness theorem for the Cuntz-Krieger algebra.     

High-Performance Liquid Chromatographic Determination of Cefepime and Cefazolin in Human Plasma and Dialysate

A simple high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of cefepime and cefazolin in human plasma and dialysate. For component separation, the method utilized a C₁₈ column with an aqueous mobile phase of dibasic potassium hydrogen phosphate (pH 7.0) and methanol gradient at a flow rate of 1 mL min⁻¹. The method demonstrated linearity from 2.0 to 100.0 μg mL⁻¹ (r > 0.999) with detection limit of 1 μg mL⁻¹ for both cefepime and cefazolin. The method was utilized for evaluation of plasma and dialysate samples in a clinical study evaluating the dialyzer clearance of cefepime and cefazolin using high-flux hemodialysis with varying blood flow rates in chronic kidney failure patients undergoing hemodialysis and peritoneal dialysis treatment.     

Detecting functional magnetic resonance imaging activation in white matter: Interhemispheric transfer across the corpus callosum

Background  

It is generally believed that activation in functional magnetic resonance imaging (fMRI) is restricted to gray matter. Despite this, a number of studies have reported white matter activation, particularly when the corpus callosum is targeted using interhemispheric transfer tasks. These findings suggest that fMRI signals may not be neatly confined to gray matter tissue. In the current experiment, 4 T fMRI was employed to evaluate whether it is possible to detect white matter activation. We used an interhemispheric transfer task modelled after neurological studies of callosal disconnection. It was hypothesized that white matter activation could be detected using fMRI.     

A groupoid generalisation of Leavitt path algebras

Let \(G\) be a locally compact, Hausdorff, étale groupoid whose unit space is totally disconnected. We show that the collection \(A(G)\) of locally-constant, compactly supported complex-valued functions on \(G\) is a dense \(*\) -subalgebra of \(C_c(G)\) and that it is universal for algebraic representations of the collection of compact open bisections of \(G\) . We also show that if \(G\) is the groupoid associated to a row-finite graph or \(k\) -graph with no sources, then \(A(G)\) is isomorphic to the associated Leavitt path algebra or Kumjian–Pask algebra. We prove versions of the Cuntz–Krieger and graded uniqueness theorems for \(A(G)\) .     

Conversion of nocathiacin I to nocathiacin acid by a mild and selective cleavage of dehydroalanine

Thiazolyl peptide antibiotic nocathiacin I (1) was converted to nocathiacin acid (4) in high yield by treatment with trifluoroacetic anhydride and pyridine in THF at room temperature. Two equipotent water-soluble amide analogues of nocathiacin I were readily prepared from this important and versatile carboxylic acid intermediate under mild peptide coupling conditions. The present method is useful for chemical derivatization of complex natural products that contain C-terminal dehydroalanine.     

A conservative level set method suitable for variable-order approximations and unstructured meshes

This paper presents a formulation for free-surface computations capable of handling complex phenomena, such as wave breaking, without excessive mass loss or smearing of the interface. The formulation is suitable for discretizations using finite elements of any topology and order, or other approaches such as isogeometric and finite volume methods. Furthermore, the approach builds on standard level set tools and can therefore be used to augment existing implementations of level set methods with discrete conservation properties. Implementations of the method are tested on several difficult two- and three-dimensional problems, including two incompressible air/water flow problems with available experimental results. Linear and quadratic approximations on unstructured tetrahedral and trilinear approximations on hexahedral meshes were tested. Global conservation and agreement with experiments as well as computations by other researchers are obtained.     

Simplicity of algebras associated to étale groupoids

We prove that the full C ^?-algebra of a second-countable, Hausdorff, étale, amenable groupoid is simple if and only if the groupoid is both topologically principal and minimal. We also show that if G has totally disconnected unit space, then the complex ^?-algebra of its inverse semigroup of compact open bisections, as introduced by Steinberg, is simple if and only if G is both effective and minimal.