Brønsted Acid Catalyzed Stereoselective Polymerization of Vinyl Ethers.

Isotactic poly(vinyl ether)s (PVEs) have recently been identified as a new class of semicrystalline thermoplastics with a valuable combination of mechanical and interfacial properties. Currently, methods to synthesize isotactic PVEs are limited to strong Lewis acids that require a high catalyst loading and limit the accessible scope of monomer substrates for polymerization. Here, we demonstrate the first Brønsted acid catalyzed stereoselective polymerization of vinyl ethers.

Mechanistic Insight into the Stereoselective Cationic Polymerization of Vinyl Ethers.

The control of the tacticity of synthetic polymers enables the realization of emergent physical properties from readily available starting materials. While stereodefined polymers derived from nonpolar vinyl monomers can be efficiently prepared using early transition metal catalysts, general methods for the stereoselective polymerization of polar vinyl monomers remain underdeveloped. We recently demonstrated asymmetric ion pairing catalysis as an effective approach to achieve stereoselective cationic polymerization of vinyl ethers.

Polar Thermoplastics with Tunable Physical Properties Enabled by the Stereoselective Copolymerization of Vinyl Ethers.

A series of isotactic, semicrystalline vinyl ether copolymers (up to 94% diads) were synthesized using a chiral BINOL-based phosphoric acid in combination with a titanium Lewis acid. This stereoselective cationic polymerization enabled the systematic tuning of both glass transition () and melting temperature () in copolymers derived from alkyl vinyl ethers (i.e.

Section E6.5 of the ACMG technical standards and guidelines: chromosome studies for solid tumor abnormalities.

Purpose: : Cytogenetic analysis of tumor tissue detects clonal abnormalities. The information obtained from these studies is utilized for diagnosis, prognosis, and patient management.

Methods: : The Working Group of the Laboratory Quality Assurance Committee of the American College of Medical Genetics provides these Standards and Guidelines for chromosome studies for solid tumors abnormalities as a resource for clinical cytogenetic laboratories.

Guidance for fluorescence in situ hybridization testing in hematologic disorders.

Fluorescence in situ hybridization (FISH) provides an important adjunct to conventional cytogenetics and molecular studies in the evaluation of chromosome abnormalities associated with hematologic malignancies. FISH employs DNA probes and methods that are generally not Food and Drug Administration-approved, and therefore, their use as analyte-specific reagents involves unique pre- and postanalytical requirements. We provide an overview of the technical parameters influencing a reliable FISH result and encourage laboratories to adopt specific procedures and policies in implementing metaphase and interphase FISH testing.