610 research outputs found

    Substituted Pentacenes and Electronic Devices Made with Substituted Pentacenes

    Get PDF
    Novel substituted pentacenes and electronic devices made with those substituted pentacenes are disclosed

    No difference in surgical outcomes between Open and Closed exposure of palatally displaced maxillary canines

    Get PDF
    Purpose: To investigate differences in the surgical outcomes between Open and Closed exposure for palatally displaced maxillary cuspids (PDC). Methods: A multicenter, RCT involving two parallel groups. The settings were one dental teaching hospital in, and two hospital units near Sheffield, UK. Participants were aged <20 years with a unilateral PDC, who provided informed consent. They were randomly allocated to either receive the Open (O) or the Closed (C) surgical procedure. The outcomes were time spent in the operating room and 10-day post-operative patient questionnaire. Statistical differences between the two techniques were tested using independent t tests for continuous variables and chi-squared tests for frequencies. Results: The final study sample was composed of 71 participants (64% females). There were no differences in the gender ratios (O: F=27, M=13; C: F=25, M=16) or mean ages of the two groups (O: 14.3 yrs SD 1.3; C: 14.1 yrs SD 1.6) at the start. The mean operating times for the Open and Closed techniques were 34.3 mins (SD 11.2) and 34.3 mins (SD 11.9) respectively (p=.986). There were no statistically significant differences between the two treatment groups for any of the patient-assessed outcomes (p>.05). Conclusions: There were no differences in the surgical outcomes investigated in this study between Open and Closed exposure for PDC

    Reactivity of vanadium oxytrichloride with [beta]-diketones and diesters as precursors for vanadium nitride and carbide

    Get PDF
    Vanadium(V) oxytrichloride was reacted with 2,4-pentanedione, diethyl malonate, and diethyl succinate under inert conditions, forming compounds: dichloro(oxo)(2,4-pentanedione) vanadium(V) [1], dichloro(oxo)(diethyl malonate) vanadium(IV) [2] and dichloro(oxo)(diethyl succinate) vanadium(IV) [3]. Compounds 1–3 are coordinated to the vanadium centre through the two carbonyl oxygen atoms of the bidentate ligand. It was determined by X-ray crystallography that the structures of the resulting complexes were significantly different, resulting in a monomeric complex (1), a tetrameric ring (2) and a 1D coordination polymer (3). Following the synthesis and isolation of 1–3, they were tested as precursors for vanadium nitride and vanadium carbide by annealing under nitrogen and argon respectively at 1200 °C for 24 h. The resulting materials were characterised by: XRD, EDS, XPS and TEM

    Second primary cancer risk - the impact of applying different definitions of multiple primaries: results from a retrospective population-based cancer registry study

    Get PDF
    Background: There is evidence that cancer survivors are at increased risk of second primary cancers. Changes in the prevalence of risk factors and diagnostic techniques may have affected more recent risks.&lt;p&gt;&lt;/p&gt; Methods: We examined the incidence of second primary cancer among adults in the West of Scotland, UK, diagnosed with cancer between 2000 and 2004 (n = 57,393). We used National Cancer Institute Surveillance Epidemiology and End Results and International Agency for Research on Cancer definitions of multiple primary cancers and estimated indirectly standardised incidence ratios (SIR) with 95% confidence intervals (CI).&lt;p&gt;&lt;/p&gt; Results: There was a high incidence of cancer during the first 60 days following diagnosis (SIR = 2.36, 95% CI = 2.12 to 2.63). When this period was excluded the risk was not raised, but it was high for some patient groups; in particular women aged &#60;50 years with breast cancer (SIR = 2.13, 95% CI = 1.58 to 2.78), patients with bladder (SIR = 1.41, 95% CI = 1.19 to 1.67) and head &#38; neck (SIR = 1.93, 95% CI = 1.67 to 2.21) cancer. Head &#38; neck cancer patients had increased risks of lung cancer (SIR = 3.75, 95% CI = 3.01 to 4.62), oesophageal (SIR = 4.62, 95% CI = 2.73 to 7.29) and other head &#38; neck tumours (SIR = 6.10, 95% CI = 4.17 to 8.61). Patients with bladder cancer had raised risks of lung (SIR = 2.18, 95% CI = 1.62 to 2.88) and prostate (SIR = 2.41, 95% CI = 1.72 to 3.30) cancer.&lt;p&gt;&lt;/p&gt; Conclusions: Relative risks of second primary cancers may be smaller than previously reported. Premenopausal women with breast cancer and patients with malignant melanomas, bladder and head &#38; neck cancers may benefit from increased surveillance and advice to avoid known risk factors

    Structured Decision-Making and Rapid Prototyping to Plan a Management Response to an Invasive Species

    Get PDF
    We developed components of a decision structure that could be used in an adaptive management framework for responding to invasion of hemlock woolly adelgid Adeleges tsugae on the Cumberland Plateau of northern Tennessee. Hemlock woolly adelgid, an invasive forest pest, was first detected in this area in 2007. We used a structured decision-making process to identify and refine the management problem, objectives, and alternative management actions, and to assess consequences and tradeoffs among selected management alternatives. We identified four fundamental objectives: 1) conserve the aquatic and terrestrial riparian conservation targets, 2) protect and preserve hemlock, 3) develop and maintain adequate budget, and 4) address public concerns. We designed two prototype responses using an iterative process. By rapidly prototyping a first solution, insights were gained and shortcomings were identified, and some of these shortcomings were incorporated and corrected in the second prototype. We found that objectives were best met when management focused on early treatment of lightly to moderately infested but relatively healthy hemlock stands with biological control agent predator beetles and insect-killing fungi. Also, depending on the cost constraint, early treatment should be coupled with silvicultural management of moderately to severely infested and declining hemlock stands to accelerate conversion to nonhemlock mature forest cover. The two most valuable contributions of the structured decision-making process were 1) clarification and expansion of our objectives, and 2) application of tools to assess tradeoffs and predict consequences of alternative actions. Predicting consequences allowed us to evaluate the influence of uncertainty on the decision. For example, we found that the expected number of mature forest stands over 30 y would be increased by 4% by resolving the uncertainty regarding predator beetle effectiveness. The adaptive management framework requires further development including identifying and evaluating uncertainty, formalizing other competing predictive models, designing a monitoring program to update the predictive models, developing a process for re-evaluating the predictive models and incorporating new management technologies, and generating support for planning and implementation

    Functional brush poly(2-ethyl-2-oxazine)s : synthesis by CROP and RAFT, thermoresponsiveness and grafting onto iron oxide nanoparticles

    Get PDF
    Brush polymers are highly functional polymeric materials combining the properties of different polymer classes and have found numerous applications, for example, in nanomedicine. Here, the synthesis of functional phosphonate‐ester‐bearing brush polymers based on poly(2‐oxazine)s is reported through a combination of cationic ring‐opening polymerization (CROP) of 2‐ethyl‐2‐oxazine and reversible addition‐fragmentation chain transfer (RAFT) polymerization. In this way, a small library of well‐defined (Đ ≤ 1.17) poly(oligo(2‐ethyl‐2‐oxazine) methacrylate) P(OEtOzMA)n brushes with tunable lower critical solution temperature (LCST) behavior and negligible cell toxicity is prepared. Upon deprotection, the phosphonic acid end‐group of the P(OEtOzMA)n brush enables the successful grafting‐onto iron oxide nanoparticles (IONPs). Colloidal stability of the particle suspension in combination with suitable magnetic resonance imaging (MRI) relaxivities demonstrates the potential of these particles for future applications as negative MRI contrast agents

    An Introduction to the Chandra Carina Complex Project

    Get PDF
    The Great Nebula in Carina provides an exceptional view into the violent massive star formation and feedback that typifies giant HII regions and starburst galaxies. We have mapped the Carina star-forming complex in X-rays, using archival Chandra data and a mosaic of 20 new 60ks pointings using the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer, as a testbed for understanding recent and ongoing star formation and to probe Carina's regions of bright diffuse X-ray emission. This study has yielded a catalog of properties of >14,000 X-ray point sources; >9800 of them have multiwavelength counterparts. Using Chandra's unsurpassed X-ray spatial resolution, we have separated these point sources from the extensive, spatially-complex diffuse emission that pervades the region; X-ray properties of this diffuse emission suggest that it traces feedback from Carina's massive stars. In this introductory paper, we motivate the survey design, describe the Chandra observations, and present some simple results, providing a foundation for the 15 papers that follow in this Special Issue and that present detailed catalogs, methods, and science results.Comment: Accepted for the ApJS Special Issue on the Chandra Carina Complex Project (CCCP), scheduled for publication in May 2011. All 16 CCCP Special Issue papers are available at http://cochise.astro.psu.edu/Carina_public/special_issue.html through 2011 at least. 43 pages; 18 figure

    An Estimate of the Incidence of Prostate Cancer in Africa: A Systematic Review and Meta-Analysis

    Get PDF
    Prostate cancer (PCa) is rated the second most common cancer and sixth leading cause of cancer deaths among men globally. Reports show that African men suffer disproportionately from PCa compared to men from other parts of the world. It is still quite difficult to accurately describe the burden of PCa in Africa due to poor cancer registration systems.We systematically reviewed the literature on prostate cancer in Africa and provided a continentwide incidence rate of PCa based on available data in the regio
    corecore