Facile Synthesis of Hydrophilic Homo-Polyacrylamides via Cu(0)-Mediated Reversible Deactivation Radical Polymerization

In this work, copper-mediated reversible deactivation radical polymerization (RDRP) of homo-polyacrylamides was conducted in aqueous solutions at 0.0 °C. Various degrees of polymerization (DP = 20, 40, 60, and 80) of well-defined water-soluble homopolymers were targeted. In the absence of any significant undesirable side reactions, the dispersity of polydiethylacrylamide (PDEA) and polydimethylacrylamide (PDMA) was narrow under controlled polymerization conditions. To accelerate the polymerization rate, disproportionation of copper bromide in the presence of a suitable ligand was performed prior to polymerization. Full conversion of the monomer was confirmed by nuclear magnetic resonance (NMR) analysis. Additionally, the linear evolution of the polymeric chains was established by narrow molecular weight distributions (MWDs). The values of theoretical and experimental number average molecular weights (Mn) were calculated, revealing a good matching and robustness of the system. The effect of decreasing the reaction temperature on the rate of polymerization was also investigated. At temperatures lower than 0.0 °C, the controlled polymerization and the rate of the process were not affected.

Accuracy of B-mode ultrasonography for detecting malignancy in canine cutaneous neoplasms: preliminary results

ABSTRACT: The aim of this study was to verify the applicability and accuracy of B-mode ultrasonography in detecting malignancy in dog cutaneous neoplasms. Forty-two neoplasms (12 benign and 30 malignant) of mesenchymal, round cells, epithelial and melanocytic origins from 24 dogs of different breeds and ages were included. The ultrasound evaluation was performed with a linear multi-frequency transducer (7.0 to 12MHz), with frequency dependent on the mass dimension. Ultrasonographic characteristics of echogenicity (hypo/hyperechogenic), echotexture (homogeneous/heterogeneous), regularity, invasiveness in adjacent tissues were classified. Dimensions were also measured to calculate the depth/width ratio. Neoplasms were classified as malignant or benign after cytological and/or histopathological analysis and the results were associated with ultrasound characteristics. There was a significant association (P<0.05) between malignancy and echogenicity, echotexture and invasiveness in adjacent tissues, so that 84.6% of hypoechogenic neoplasms, 76.9% of heterogeneous masses and 88.2% of invasive neoplasms were classified as malignant. However, for all these associations, moderate predictive values were obtained, which may be due to the small experimental number included in this study. Therefore, although it has been observed that hypoechogenic, heterogeneous and invasive neoplasms were more prone to malignancy, these findings should be used with caution until new studies are developed with a greater number and variety of cutaneous neoplasms in dogs.

Conjectures about the structure of strong- and weak-coupling expansions of a few ground-state observables in the Lieb-Liniger and Yang-Gaudin models

In this paper, we apply experimental number theory to two integrable quantum models in one dimension, the Lieb-Liniger Bose gas and the Yang-Gaudin Fermi gas with contact interactions. We identify patterns in weak- and strong-coupling series expansions of the ground-state energy, local correlation functions and pressure. Based on the most accurate data available in the literature, we make a few conjectures about their mathematical structure and extrapolate to higher orders

Microsatellite Instability Detection by Next Generation Sequencing

BACKGROUND Microsatellite instability (MSI) is a useful phenotype in cancer diagnosis and prognosis. Nevertheless, methods to detect MSI status from next generation DNA sequencing (NGS) data are underdeveloped. METHODS We developed an approach to detect the MSI phenotype using NGS (mSINGS). The method was used to evaluate mononucleotide microsatellite loci that were incidentally sequenced after targeted gene enrichment and could be applied to gene or exome capture panels designed for other purposes. For each microsatellite locus, the number of differently sized repeats in experimental samples were quantified and compared to a population of normal controls. Loci were considered unstable if the experimental number of repeats was statistically greater than in the control population. MSI status was determined by the fraction of unstable microsatellite loci. RESULTS We examined data from 324 samples generated using targeted gene capture assays of 3 different sizes, ranging from a 0.85-Mb to a 44-Mb exome design and incorporating from 15 to 2957 microsatellite markers. When we compared mSING results to MSI-PCR as a gold standard for 108 cases, we found the approach to be both diagnostically sensitive (range of 96.4% to 100% across 3 panels) and specific (range of 97.2% to 100%) for determining MSI status. The fraction of unstable microsatellite markers calculated from sequencing data correlated with the number of unstable loci detected by conventional MSI-PCR testing. CONCLUSIONS NGS data can enable highly accurate detection of MSI, even from limited capture designs. This novel approach offers several advantages over existing PCR-based methods.

(89) A New Granular Herbicide for Container, Landscape, and Field-grown Ornamentals

In 2003 and 2004, a new herbicide containing three active ingredients was evaluated for efficacy on important weed species and the tolerance of popular ornamental plant species. Currently available ornamental herbicides differ greatly in the weeds they control and tolerance of ornamental plants grown in production nurseries. This new granular product, trade name Showcase, also known by its experimental number, GF-1162, contains 2% trifluralin, 0.25% isoxaben, and 0.25% oxyfluorfen. With preemergent applications applied to pots artificially infested with weed seed, GF-1162 demonstrated exceptional control of many difficult to control species, such as spurge, groundsel, bittercress, oxalis, and crabgrass. When applied preemergence at 150 lb/acre, GF-1162 was as efficacious as current standards. At 200 lb/acre, weed control was exceptional, exceeding all products included in the trials. Ornamental tolerance to GF-1162 was comparable to that of Snapshot TG, with the exception of whorled plants. On whorled plants, such as daylily and hosta, where granular products can be retained on leaf surfaces, products containing oxyfluorfen must be applied with special precautions to immediately shake or wash granules from leaf surfaces. Even when whorled plants were injured by GF-1162, they did eventually recover. GF-1162 received a federal registration in 2004 and state registrations may be complete as early as Spring 2005, at which time this new herbicide would be made available to ornamental nurseries and lawn care companies as an alternative to current herbicide options.

The minimum Reynolds number for a turbulent boundary layer and the selection of a transition device

In the case of turbulent flow in a pipe there is a lower experimental number to the Reynolds limit for which fully developed turbulent flow occurs. From the similarity and close agreement of the curves showing the coefficient of skin friction cf as a function of the Reynolds number Rθ (based on the momentum thickness θ) for the circular pipe and flat plate, it is suggested that there should be a lower limit to Rθ for fully developed turbulent flow on a flat plate. Rather limited experimental data confirm this and place the lower limit at Rθ = 320. The choice and size of transition device is examined in relation to this minimum Rθ and an approximate theory leads to a ‘wire’ Reynolds number in fair agreement with experience.