Synthetic Applications of Flexible SNO-OCT Strained Alkynes and Their Use in Postpolymerization Modifications.

SNO-OCTs are eight-membered heterocyclic alkynes that have fast rates of reactivity with 1,3-dipoles. In contrast to many other reported cycloalkynes, SNO-OCTs contain multiple sites for derivatization, display stability under a variety of common reaction conditions, and offer the opportunity for strain-induced ring-opening following the initial reaction of the alkyne moiety. In this paper, we describe how the unique features of SNO-OCTs can be employed to modify an oxime-bearing styrene copolymer and introduce an array of polar functionalities into the polymer.

Fine-Tuning Strain and Electronic Activation of Strain-Promoted 1,3-Dipolar Cycloadditions with Endocyclic Sulfamates in SNO-OCTs.

The ability to achieve predictable control over the polarization of strained cycloalkynes can influence their behavior in subsequent reactions, providing opportunities to increase both rate and chemoselectivity. A series of new heterocyclic strained cyclooctynes containing a sulfamate backbone (SNO-OCTs) were prepared under mild conditions by employing ring expansions of silylated methyleneaziridines. SNO-OCT derivative 8 outpaced even a difluorinated cyclooctyne in a 1,3-dipolar cycloaddition with benzylazide.

Oxidative allene amination for the synthesis of azetidin-3-ones.

Regioselectivity in the aziridination of silyl-substituted homoallenic sulfamates is readily diverted to the distal double bond of the allene to yield endocyclic bicyclic methyleneaziridines with excellent stereocontrol. Subsequent reaction with electrophilic oxygen sources initiates facile rearrangement to densely functionalized, fused azetidin-3-ones in excellent d.r.

Ternary nylon-3 copolymers as host-defense peptide mimics: beyond hydrophobic and cationic subunits.

Host-defense peptides (HDPs) are produced by eukaryotes to defend against bacterial infection, and diverse synthetic polymers have recently been explored as mimics of these natural peptides. HDPs are rich in both hydrophobic and cationic amino acid residues, and most HDP-mimetic polymers have therefore contained binary combinations of hydrophobic and cationic subunits. However, HDP-mimetic polymers rarely duplicate the hydrophobic surface and cationic charge density found among HDPs ( Hu , K.

Field evaluation of diagnostic accuracy of an oral fluid rapid test for HIV, tested at point-of-service sites in rural Zimbabwe.

The objective of this study was to validate the use of OraQuick ADVANCE Rapid HIV-1/2 Antibody test (OraSure Technologies Inc., Bethlehem, PA) on oral fluid for a population-based HIV prevalence survey of rural youth in southeast Zimbabwe. The evaluation was conducted in patients presenting for voluntary counseling and testing at rural clinics.

Evaluation of the Partec flow cytometer against the BD FACSCalibur system for monitoring immune responses of human immunodeficiency virus-infected patients in Zimbabwe.

A single-platform volumetric flow cytometer, the Partec Cyflow SL_3, was evaluated against a BD FACSCalibur/Sysmex XT1800i dual platform for measuring CD4(+) lymphocytes, total lymphocytes, and the percentage of CD4 lymphocytes in whole-blood samples for monitoring the immune systems of human immunodeficiency virus (HIV)/AIDS patients. Statistical analyses for precision, correlation, and agreement were performed. Coefficients of variation (CV) of 5.