Synthesis, characterization, and hydrolytic degradation of polylactide-functionalized polyoxanorbornenes

This paper describes the synthesis of polylactide-functionalized polyoxanorbornenes and their hydrolytic degradation behavior. Macromonomers with one or two exo-PLA chains as well with two endo,exo chains were prepared using tin(II) 2-ethylhexanoate as a catalyst in the presence of mono- or dialcohol derivatives of oxanorbornene. The well-characterized macromonomers were then subjected to ROMP by first, second, and modified second generation Grubbs ruthenium initiators. Investigation of these graft copolymers by SEC and NMR spectroscopy showed the presence of some uncapped PLA homopolymer, formed as a side product during the ROP of lactide. The degradation behavior showed that the presence of PLA homopolymer impurities in the graft copolymers significantly increases the rate of degradation of the final material. Therefore, a convenient procedure of graft copolymers purification to remove PLA homopolymer from the samples was developed. The degradation studies of graft copolymers with the same oxanorbornyl backbone length and different length of PLA grafts indicated that the degradation rate increased with increasing length of PLA grafts. The degradation behavior of material depends also on configuration of PLA side chains on polyoxanorbornene backbone chain. The fastest degradation was observed in the case of graft copolymers with one exo-PLA side chain

Towards hydroxylated nylon 6: linear and cyclic oligomers from a protected 6-amino-6-deoxy-DD galactonate––a novel class of carbopeptoid-cyclodextrin (CPCD)

Circular dichroism studies on a series of linear oligomers derived from a protected 6-amino-6-deoxy-D-galactonate (an epsilon-amino acid) indicated a predisposition to form a rigid structure in solution, which is comparable to a beta-sheet composed of L-amino acids; in contrast, a diastereomeric allonate series provided no evidence for secondary structure. A linear tetramer was cyclised to a 28-membered ring lactam in modest yield, which on deprotection formed a class of macrocycle with structural features of both a cyclic peptide and a cyclodextrin

Response assessment in Waldenström macroglobulinaemia: Update from the VIth International Workshop

This report represents a further update of the consensus panel criteria for the assessment of clinical response in patients with Waldenström macroglobulinaemia (WM). These criteria have been updated in light of further data demonstrating an improvement in categorical responses with new drug regimens as well as acknowledgement of the fact that such responses are predictive of overall outcome. A number of key changes are proposed but challenges do however remain and these include the variability in kinetics of immunoglobulin M (IgM) reduction with different treatment modalities and the apparent discrepancy between IgM and bone marrow/tissue response noted with some regimens. Planned sequential bone marrow assessments are encouraged in clinical trials. © 2012 Blackwell Publishing Ltd

Biologia e anatomia funcional de Donax gemmula Morrison (Bivalvia, Donacidae) do litoral de S\ue3o Paulo, Brasil

Donax gemmula Morrison, 1971 ocorre em praias arenosas da costa sudeste-sul do Brasil até o Uruguai. Espécimes foram coletados na Praia de Barequeçaba, São Sebastião, Estado de São Paulo, Brasil. O comportamento do animal foi registrado "in situ" e em aquários e a morfologia funcional a partir de espécimes dissecados sob estereomicroscópio; detalhes da anatomia foram obtidos a partir de cortes histológicos. A concha pequena, lisa, subglobosa, e o pé grande, muscular, provido de um par de músculos elevadores bem desenvolvidos, permitem escavação rápida, vital em praias sujeitas à intensa ação de ondas onde a espécie vive. Aparato bissal vestigial ocorre desde a fase juvenil à adulta e este donacídeo de vida livre, infaunal, não migra acompanhando o ritmo das marés. As margens do manto possuem prega mediana duplicada; além de tentáculos captados, as pregas medianas possuem tentáculos sensoriais filiformes, longos, estes últimos restritos à região posterior do animal. A espécie tem hábito alimentar suspensívoro seletivo, o qual é revelado pela presença de ctenídios grandes, completos e homorhábdicos, palpos labiais pequenos e muito seletivos, intestino curto, fracamente sinuoso, separado do saco do estilete cristalino, e tentáculos ramificados formando um crivo em torno da abertura inalante.<br>Donax gemmula Morrison, 1971 is a small bivalve occurring on sandy beaches throughout the Southeastern Brazilian coast to Uruguai. Live specimens were collected from Barequeçaba Beach, São Sebastião, State of São Paulo, Brazil. The animal's behaviour was recorded in situ as well as in aquaria, and its functional morphology registered from specimens dissected under stereomicroscope; details of the anatomy were obtained from histological sections. The minute, smooth subglobose shell, and the large, muscular foot provided with a pair of well-developed elevator muscles allow fast burrowing, vital in the disturbed beach environment where the species lives. A vestigial byssal apparatus is present from juvenile through the adult form and this free-living infaunal donacid does not migrate following the rising and ebbing tides. The mantle margins have the middle fold duplicated; besides captate tentacles, the middle folds bear long, filiform, sensory tentacles, the latter restricted to the rear end of the animal. The presence of complete, large, homorhabdic ctenidia; small but very selective labial palps; short and few convoluted intestine, separated from the style sac; and straining tentacles encircling the inhalant aperture reveal the selective suspension feeding habit of the species