709 research outputs found

    Nitrogen Dynamics from Decomposing Litter of \u3ci\u3ePanicum maximum\u3c/i\u3e with Different Nitrogen and Phosphorus Content in Brazilian Alfissol

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    The objective of this study was to measure the dynamics (immobilization and release) of N and to evaluate the effect of the initial chemical composition of four Panicum maximum cultivars grown in a Alfisol and fertilized with different levels of nitrogen (0, 80 e 160 kg ha-1 de N) and phosphorus (0 e 200 kg ha-1), on the release of the N from the litter using the litterbags technique. There was an increase in the litter initial concentration of N with time of decomposition. The Aruana and Vencedor cultivars released about 70 and 60% of N; respectively, during the decomposition of the litter from 0 (zero) to 336 days; the Tobiatã and Tanzânia cultivars released about 30 and \u3e30% of N from the concentration of the initial litter respectively. Nitrogen fertization increased the N release, up to 20% in the highest N level tested (160 kg ha-1 of N)

    Plans to eradicate invasive mammals on an island inhabited by humans and domestic animals (Corvo, Azores, Portugal)

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    Oppel, S., Beaven, B.M., Bolton, M., Bodey, T.W., Geraldes, P., Oliveira, N., Hervias, S., Henriques, A., Silva, C

    Four-dimensional imaging and quantification of viscous flow sintering within a 3D printed bioactive glass scaffold using synchrotron X-ray tomography

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    Bioglass® was the first material to form a stable chemical bond with human tissue. Since its discovery, a key goal was to produce three-dimensional (3D) porous scaffolds which can host and guide tissue repair, in particular, regeneration of long bone defects resulting from trauma or disease. Producing 3D scaffolds from bioactive glasses is challenging because of crystallization events that occur while the glass particles densify at high temperatures. Bioactive glasses such as the 13–93 composition can be sintered by viscous flow sintering at temperatures above the glass transition onset (T_{g}) and below the crystallization temperature (T_{c}). There is, however, very little literature on viscous flow sintering of bioactive glasses, and none of which focuses on the viscous flow sintering of glass scaffolds in four dimensions (4D) (3D + time). Here, high-resolution synchrotron-sourced X-ray computed tomography (sCT) was used to capture and quantify viscous flow sintering of an additively manufactured bioactive glass scaffold in 4D. In situ sCT allowed the simultaneous quantification of individual particle (local) structural changes and the scaffold's (global) dimensional changes during the sintering cycle. Densification, calculated as change in surface area, occurred in three distinct stages, confirming classical sintering theory. Importantly, our observations show for the first time that the local and global contributions to densification are significantly different at each of these stages: local sintering dominates stages 1 and 2, while global sintering is more prevalent in stage 3. During stage 1, small particles coalesced to larger particles because of their higher driving force for viscous flow at lower temperatures, while large angular particles became less faceted (angular regions had a local small radius of curvature). A transition in the rate of sintering was then observed in which significant viscous flow occurred, resulting in large reduction of surface area, total strut volume, and interparticle porosity because the majority of the printed particles coalesced to become continuous struts (stage 2). Transition from stage 2 to stage 3 was distinctly obvious when interparticle pores became isolated and closed, while the sintering rate significantly reduced. During stage 3, at the local scale, isolated pores either became more spherical or reduced in size and disappeared depending on their initial morphology. During stage 3, sintering of the scaffolds continued at the strut level, with interstrut porosity reducing, while globally the strut diameter increased in size, suggesting overall shrinkage of the scaffold with the flow of material via the strut contacts. This study provides novel insights into viscous flow in a complex non-idealized construct, where, locally, particles are not spherical and are of a range of sizes, leading to a random distribution of interparticle porosity, while globally, predesigned porosity between the struts exists to allow the construct to support tissue growth. This is the first time that the three stages of densification have been captured at the local and global scales simultaneously. The insights provided here should accelerate the development of 3D bioactive glass scaffolds

    Leveraging Motivations, Personality, and Sensory Cues for Vertebrate Pest Management

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    Acknowledgments: We wish to thank Manaaki Whenua – Landcare Research staff, particularly Peter Millard and Bruce Warburton, for facilitating and supporting this research. Thanks to Jenna Bytheway for infographic design. This research was supported by Strategic Science Investment funding from the New Zealand Ministry of Business, Innovation and Employment’s Science and Innovation Group, awarded to Manaaki Whenua – Landcare Research. T.W.B. was supported by Marie Skłodowska-Curie grant number 747120, and A.S. was supported by National Science Foundation grant IOS 1456724.Peer reviewedPublisher PD

    Correlation between CD105 expression and postoperative recurrence and metastasis of hepatocellular carcinoma

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    BACKGROUND: Angiogenesis is one of the mechanisms most critical to the postoperative recurrence and metastasis of hepatocellular carcinoma (HCC). Thus, finding the molecular markers associated with angiogenesis may help identify patients at increased risk for recurrence and metastasis of HCC. This study was designed to investigate whether CD105 or CD34 could serve as a valid prognostic marker in patients with HCC by determining if there is a correlation between CD105 or CD34 expression and postoperative recurrence or metastasis. METHODS: Immunohistochemical staining for the CD105, CD34 and vascular endothelial growth factor (VEGF) antibodies was performed in 113 HCC tissue specimens containing paracarcinomatous tissue and in 14 normal liver tissue specimens. The quantitation of microvessels identified by anti-CD105 and anti-CD34 monoclonal antibodies and the semiquantitation of VEGF expression identified by anti-VEGF monoclonal antibody were analyzed in conjunction with the clinicopathological characteristics of the HCC and any available follow-up information about the patients from whom the specimens were obtained. RESULTS: CD105 was not expressed in the vascular endothelial cells of any normal liver tissue or paracarcinomatous liver tissue but was expressed in the vascular endothelial cells of all HCC tissue. In contrast, CD34 was expressed in the vascular endothelial cells of normal liver tissue, paracarcinomatous tissue, and HCC tissue in the following proportions of specimens: 86.7%, 93.8%, and 100%, respectively. The microvascular densities (MVDs) of HCC determined by using an anti-CD105 mAb (CD105-MVD) and an anti-CD34 mAb (CD34-MVD), were 71.7 ± 8.3 (SD) and 106.3 ± 10.4 (SD), respectively. There was a significant correlation between CD105-MVD and CD34-MVD (r = 0.248, P = 0.021). Although CD34-MVD was significantly correlated with VEGF expression (r = 0.243, P = 0.024), CD105-MVD was more closely correlated (r = 0.300, P= 0.005). The correlation between microscopic venous invasion and CD105-MVD, but not CD34-MVD, was also statistically significant (r = 0.254, P = 0.018). Univariate analysis showed that CD105-MVD was significantly correlated with the 2-year overall survival rate (P = 0.014); CD34-MVD was not (P = 0.601). Multivariate analysis confirmed that CD105-MVD was an independent prognostic factor and that CD34-MVD was not. CONCLUSION: The anti-CD105 mAb is an ideal instrument to quantify new microvessels in HCC as compared with anti-CD34 mAb. CD105-MVD as compared with CD34-MVD is relevant a significant and independent prognostic indicator for recurrence and metastasis in HCC patients

    Treating Colon Cancer With a Melanoma Vaccine? Preposterous?

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41422/1/10434_2001_Article_386.pd

    Management of febrile neutropenia in the United Kingdom: time for a national trial?

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    Recent advances in febrile neutropenia (FN) have highlighted the value of risk stratification and the evolving role of oral antibiotics with early hospital discharge in low-risk patients. The aim of this study was to survey whether these advances have been translated into routine clinical practice in the UK. Questionnaires were sent to cancer clinicians across the UK to determine clinicians' routine management of FN, including use of risk stratification, antibiotic regimen and criteria for hospital discharge. In all, 128 clinicians responded, representing 50 cancer departments (83%). Only 38% of respondents stratify patients according to risk and with substantial variation in the criteria defining ‘low-risk'. Furthermore, only 22% of clinicians use oral antibiotics as first-line treatment in any patients with FN, but this was significantly greater among clinicians who do compared to those who do not stratify patients by risk, 51 vs 4% (P<0.0001). These findings suggest a slow and/or cautious introduction of newer strategies for the management of low-risk FN in the UK. However, 84% of respondents confirmed their willingness to participate in a trial of oral antibiotics combined with early discharge in low-risk FN
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