44 research outputs found

    Centrifugal melt spinning of polyvinylpyrrolidone (PVP)/triacontene copolymer fibres

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    Polyvinylpyrrolidone/1-triacontene (PVP/TA) copolymer fibre webs produced by centrifugal melt spinning were studied to determine the influence of jet rotation speed on morphology and internal structure as well as their potential utility as adsorbent capture media for disperse dye effluents. Fibres were produced at 72 C with jet head rotation speeds from 7000 to 15,000 r min-1. The fibres were characterised by means of SEM, XRD and DSC. Adsorption behaviour was investigated by means of an isothermal bottle point adsorption study using a commercial disperse dye, Dianix AC-E. Through centrifugal spinning nanofibers and microfibers could be produced with individual fibres as fine as 200–300 nm and mean fibre diameters of ca. 1–2 lm. The PVP/TA fibres were mechanically brittle with characteristic brittle tensile fracture regions observed at the fibre ends. DSC and XRD analyses suggested that this brittleness was linked to the graft chain crystallisation where the PVP/TA was in the form of a radial brush copolymer. In this structure, the triacontene branches interlock and form small lateral crystals around an amorphous backbone. As an adsorbent, the PVP/TA fibres were found to adsorb 35.4 mg g-1 compared to a benchmark figure of 30.0 mg g-1 for a granular-activated carbon adsorbent under the same application conditions. PVP/TA is highly hydrophobic and adsorbs disperse dyes through the strong ‘‘hydrophobic bonding’’ interaction. Such fibrous assemblies may have applications in the targeted adsorption and separation of non-polar species from aqueous or polar environments

    An Anomalous Type IV Secretion System in Rickettsia Is Evolutionarily Conserved

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    Bacterial type IV secretion systems (T4SSs) comprise a diverse transporter family functioning in conjugation, competence, and effector molecule (DNA and/or protein) translocation. Thirteen genome sequences from Rickettsia, obligate intracellular symbionts/pathogens of a wide range of eukaryotes, have revealed a reduced T4SS relative to the Agrobacterium tumefaciens archetype (vir). However, the Rickettsia T4SS has not been functionally characterized for its role in symbiosis/virulence, and none of its substrates are known.Superimposition of T4SS structural/functional information over previously identified Rickettsia components implicate a functional Rickettsia T4SS. virB4, virB8 and virB9 are duplicated, yet only one copy of each has the conserved features of similar genes in other T4SSs. An extraordinarily duplicated VirB6 gene encodes five hydrophobic proteins conserved only in a short region known to be involved in DNA transfer in A. tumefaciens. virB1, virB2 and virB7 are newly identified, revealing a Rickettsia T4SS lacking only virB5 relative to the vir archetype. Phylogeny estimation suggests vertical inheritance of all components, despite gene rearrangements into an archipelago of five islets. Similarities of Rickettsia VirB7/VirB9 to ComB7/ComB9 proteins of epsilon-proteobacteria, as well as phylogenetic affinities to the Legionella lvh T4SS, imply the Rickettsiales ancestor acquired a vir-like locus from distantly related bacteria, perhaps while residing in a protozoan host. Modern modifications of these systems likely reflect diversification with various eukaryotic host cells.We present the rvh (Rickettsiales vir homolog) T4SS, an evolutionary conserved transporter with an unknown role in rickettsial biology. This work lays the foundation for future laboratory characterization of this system, and also identifies the Legionella lvh T4SS as a suitable genetic model

    Narrative approach to understand people's comprehension of acquaintance rape: The role of Sex Role Stereotyping

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    One of the most unreported crimes is acquaintance rape. This may be the result of people's understanding of what rape is because of their rape script and their stereotypes of victim characteristics. These judgements may be moderated by sex role stereotyping (SRS). We utilised a narrative approach to understand low and high SRS participants' rape scripts. Young-adult participants described what they believed a typical rape was, followed by describing an acquaintance rape and then what they believed the stereotypical victim of each crime would be. A narrative analysis was conducted on the data. We found that the blitz script is still held by 44% of low SRS and 47% of high SRS people despite 90% of rapes being committed by an acquaintance. While acquaintance rape scripts existed, the emotional imagery and content of these depended on participants level of SRS. Stereotypical victim characteristics also depended on SRS: those with high SRS were more likely to endorse rape myth ideals in describing victims than those with low SRS. These results have implications for educating people about what rape is so that victims might feel more confident in reporting rape

    Early-Phase Clinical Trials in the Community: Results from the National Cancer Institute Community Cancer Centers Program Early-Phase Working Group Baseline Assessment.

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    PURPOSE: The National Cancer Institute (NCI) Community Cancer Centers Program (NCCCP) formed an Early-Phase Working Group to facilitate site participation in early-phase (EP) trials. The Working Group conducted a baseline assessment (BA) to describe the sites\u27 EP trial infrastructure and its association with accrual. METHODS: EP accrual and infrastructure data for the sites were obtained for July 2010-June 2011 and 2010, respectively. Sites with EP accrual rates at or above the median were considered high-accruing sites. Analyses were performed to identify site characteristics associated with higher accrual onto EP trials. RESULTS: Twenty-seven of the 30 NCCCP sites participated. The median number of EP trials open per site over the course of July 2010-June 2011 was 19. Median EP accrual per site was 14 patients in 1 year. Approximately half of the EP trials were Cooperative Group; most were phase II. Except for having a higher number of EP trials open (P = .04), high-accruing sites (n = 14) did not differ significantly from low-accruing sites (n = 13) in terms of any single site characteristic. High-accruing sites did have shorter institutional review board (IRB) turnaround time by 20 days, and were almost three times as likely to be a lead Community Clinical Oncology Program site (small sample size may have prevented statistical significance). Most sites had at least basic EP trial infrastructure. CONCLUSION: Community cancer centers are capable of conducting EP trials. Infrastructure and collaborations are critical components of success. This assessment provides useful information for implementing EP trials in the community
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