Chain‐Growth Polymerization of Aryl Grignards Initiated by a Stabilized NHC‐Pd Precatalyst

An N‐heterocyclic carbene‐ligated palladium catalyst was discovered to mediate living, chain‐growth polymerizations of both phenylene‐ and thiophene‐based monomers. Polymerization of a fluorene‐based monomer, on the other hand, did not proceed through a living, chain‐growth pathway. Excitingly, block copolymerizations of phenylene and thiophene proceeded via a chain‐growth pathway, regardless of the order of monomer addition. Although some chain termination was observed during these copolymerizations, this pathway could be minimized when the second monomer was added shortly after consumption of the first monomer. These results suggest that the catalyst resting‐state at the end of polymerization is unstable. As a result, modifications to the NHC‐scaffold or the 3‐chloropyridine ligand will be necessary to generate an improved catalyst. A Pd catalyst that can mediate a living, chain‐growth polymerization of π‐conjugated monomers is reported. Using (IPr)Pd(3‐chloropyridine)Cl 2 as a precatalyst, both homopolymers and block copolymers of phenylene‐ and thiophene‐based monomers were prepared. Although a living, chain‐growth mechanism is observed during polymerization, the catalyst resting state is somewhat unstable after the monomer is consumed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92031/1/marc_201200096_sm_suppl.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/92031/2/842_ftp.pd

Raman scattering in pathology

Smith ZJ, Huser T, Wachsman-Hogiu S. Raman scattering in pathology. Analytical Cellular Pathology. 2012;35(3):145-163

A mus-51 RIP allele for transformation of Neurospora crassa

This report describes the construction and characterization of mus-51RIP70, an allele for high-efficiency targeted integration of transgenes into the genome of the model eukaryote Neurospora crassa. Two of the mus-51RIP70 strains investigated in this work (RZS27.10 and RZS27.18) can be obtained from the Fungal Genetics Stock Center. The two deposited strains are, to our knowledge, genetically identical and neither one is preferred over the other for use in Neurospora research

Molecular recording of mammalian embryogenesis.

Ontogeny describes the emergence of complex multicellular organisms from single totipotent cells. This field is particularly challenging in mammals, owing to the indeterminate relationship between self-renewal and differentiation, variation in progenitor field sizes, and internal gestation in these animals. Here we present a flexible, high-information, multi-channel molecular recorder with a single-cell readout and apply it as an evolving lineage tracer to assemble mouse cell-fate maps from fertilization through gastrulation. By combining lineage information with single-cell RNA sequencing profiles, we recapitulate canonical developmental relationships between different tissue types and reveal the nearly complete transcriptional convergence of endodermal cells of extra-embryonic and embryonic origins. Finally, we apply our cell-fate maps to estimate the number of embryonic progenitor cells and their degree of asymmetric partitioning during specification. Our approach enables massively parallel, high-resolution recording of lineage and other information in mammalian systems, which will facilitate the construction of a quantitative framework for understanding developmental processes

Exile Vol. XXXIII No. 2

POETRY Seams by Jennie Dawes 7 The Milky Blue Water by Mark Livengood 8-9 Patchwork by Mark Livengood 10 Belle Epoque by Karen J. Hall 21 Ballad by Zachary Smith 22-23 My Grandmother\u27s House by Karen J. Hall 24 Ghost by Jennie Dawes 27 What\u27s for Dessert? by Jennifer H. Miller 28 Dreams by Kent Lambert 31 Postmarked Fort Hill by Jennifer H. Miller 32 FICTION A Fostoria Tale by Debra Benko 13-18 The Pile by Jeff Montgomery 35-40 ARTWORK untitled by Lauren Kronish (cover) Standing by Heidi Rubin 3 Home, Part I by Heidi Rubin 4 Untitled by Dan Kirk 19 Infra-red (untitled) by Woody Woodroof 26 Florence, Italy (untitled) by Eliza Brown 29 Mwanafunzi by David Bloch 33 Joshua Tree by Susan McLain 41 CONTRIBUTOR\u27S NOTES 43 Editors share equally all editorial decisions. -2 NOTE: the artwork Home, Part I by Heidi Rubin does not appear to have been published, although it is listed in the table of contents for this issue and so is included here