524 research outputs found

    Parenteral administration of factor Xa/IIa inhibitors limits experimental aortic aneurysm and atherosclerosis

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    Intraluminal thrombus is a consistent feature of human abdominal aortic aneurysm (AAA). Coagulation factor Xa (FXa) catalyses FII to thrombin (FIIa). We examined the effect of FXa/FIIa inhibition on experimental aortic aneurysm in apolipoprotein E-deficient (ApoE−/−) mice infused with angiotensin II (AngII). The concentration of FXa within the supra-renal aorta (SRA) correlated positively with SRA diameter. Parenteral administration of enoxaparin (FXa/IIa inhibitor) and fondaparinux (FXa inhibitor) over 14 days reduced to severity of aortic aneurysm and atherosclerosis in AngII-infused ApoE−/− mice. Enteral administration of the FIIa inhibitor dabigatran had no significant effect. Aortic protease-activated receptor (PAR)-2 expression increased in response to AngII infusion. Fondaparinux reduced SRA levels of FXa, FIIa, PAR-2, matrix metalloproteinase (MMP)2, Smad2/3 phosphorylation,and MOMA-2 positive cells in the mouse model. FXa stimulated Smad2/3 phosphorylation and MMP2 expression in aortic vascular smooth muscle cells (VSMC) in vitro. Expression of MMP2 in FXastimulated VSMC was downregulated in the presence of a PAR-2 but not a PAR-1 inhibitor. These findings suggest that FXa/FIIa inhibition limits aortic aneurysm and atherosclerosis severity due to down-regulation of vascular PAR-2-mediated Smad2/3 signalling and MMP2 expression. Inhibition of FXa/FIIa may be a potential therapy for limiting aortic aneurysm

    An Analysis of the Rapidly Rotating Bp Star HD 133880

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    HD 133880 is a rapidly rotating Bp star and host to one of the strongest magnetic fields of any Bp star. A member of the Upper Centaurus Lupus association, it is a star with a well-determined age of 16 Myr. Twelve new spectra obtained from the FEROS, ESPaDOnS, and HARPS instruments, provide sufficient material from which to re-evaluate the magnetic field and obtain a first approximation to the atmospheric abundance distributions of various elements. Using the new magnetic field measurements and optical photometry together with previously published data, we refine the period of HD 133880 to P = 0.877476 \pm 0.000009 days. The magnetic field structure was characterised by a colinear multipole expansion from the observed variations of the longitudinal and surface fields with rotational phase. This simple axisymmetric magnetic field model is based on a predominantly quadrupolar component that roughly describes the field variations. Using spectrum synthesis, we derived mean abundances for O, Mg, Si, Ti, Cr, Fe, Nd and Pr. All elements, except Mg (which has a uniform distribution), are overabundant compared to the Sun and are more abundant in the negative than in the positive magnetic hemisphere. In contrast to most Bp stars the abundance of O in HD 133880 is overabundant compared to the solar abundance ratio. In studying the Halpha and Paschen lines in the optical spectra we could not unambiguously detect information about the magnetosphere of HD 133880. However, radio emission data at both 3 and 6 cm suggests that the magnetospheric plasma is held in rigid rotation with the star by the magnetic field and further supported against collapse by the rapid rotation. Subtle differences in the shapes of the optically thick radio light curves at 3 and 6 cm suggest that the large-scale magnetic field is not fully axisymmetric at large distances from the star.Comment: Accepted for publication in MNRAS. 17 pages, 10 figure

    A phase I study of intraperitoneal nanoparticulate paclitaxel (Nanotax®) in patients with peritoneal malignancies

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    PURPOSE: This multicenter, open-label, dose-escalating, phase I study evaluated the safety, tolerability, pharmacokinetics and preliminary tumor response of a nanoparticulate formulation of paclitaxel (Nanotax®) administered intraperitoneally for multiple treatment cycles in patients with solid tumors predominantly confined to the peritoneal cavity for whom no other curative systemic therapy treatment options were available. METHODS: Twenty-one patients with peritoneal malignancies received Nanotax® in a modified dose-escalation approach utilizing an accelerated titration method. All patients enrolled had previously received chemotherapeutics and undergone surgical procedures, including 33 % with optimal debulking. Six doses (50–275 mg/m2) of Cremophor-free Nanotax® were administered intraperitoneally for one to six cycles (every 28 days). RESULTS: Intraperitoneal (IP) administration of Nanotax® did not lead to increases in toxicity over that typically associated with intravenous (IV) paclitaxel. No patient reported ≥Grade 2 neutropenia and/or ≥Grade 3 neurologic toxicities. Grade 3 thrombocytopenia unlikely related to study medication occurred in one patient. The peritoneal concentration–time profile of paclitaxel rose during the 2 days after dosing to peritoneal fluid concentrations 450–2900 times greater than peak plasma drug concentrations and remained elevated through the entire dose cycle. Best response assessments were made in 16/21 patients: Four patients were assessed as stable or had no response and twelve patients had increasing disease. Five of 21 patients with advanced cancers survived longer than 400 days after initiation of Nanotax® IP treatment. CONCLUSIONS: Compared to IV paclitaxel administration, Cremophor-free IP administration of Nanotax® provides higher and prolonged peritoneal paclitaxel levels with minimal systemic exposure and reduced toxicity

    Orphans of the AIDS epidemic? The extent, nature and circumstances of child-headed households in South Africa

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    There is widespread concern that the number of children living in “child-headed households” is rapidly increasing as a result of AIDS-related adult mortality in much of sub-Saharan Africa. Based on analyses of data from several representative national surveys over the period 2000–2007, this paper examines the extent to which this is the case in South Africa. It explores trends in the number of children living in child-only households and characterises these children relative to children living in households with adults (mixed-generation households). The findings indicate that the proportion of child-only households is relatively small (0.47% in 2006) and does not appear to be increasing. In addition, the vast majority (92.1%) of children resident in child-only households have a living parent. The findings raise critical questions about the circumstances leading to the formation of child-only households and highlight that they cannot for the main part be ascribed to HIV orphaning. Nonetheless, the number of children living in this household form is not insignificant, and their circumstances, when compared with children in mixed-generation households, indicate a range of challenges, including greater economic vulnerability and inadequate service access. We argue that a solitary focus on the HIV epidemic and its related orphaning as the cause of child-only households masks other important issues for consideration in addressing their needs, and risks the development of inappropriate policies, programmes and interventions

    Experimental and Modeling Studies of the Characteristics of Liquid Biofuels for Enhanced Combustion

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    The objectives of this project have been to develop a comprehensive set of fundamental data regarding the combustion behavior of biodiesel fuels and appropriately associated model fuels that may represent biodiesels in automotive engineering simulation. Based on the fundamental study results, an auxiliary objective was to identify differentiating characteristics of molecular fuel components that can be used to explain different fuel behavior and that may ultimately be used in the planning and design of optimal fuel-production processes. The fuels studied in this project were BQ-9000 certified biodiesel fuels that are certified for use in automotive engine applications. Prior to this project, there were no systematic experimental flame data available for such fuels. One of the key goals has been to generate such data, and to use this data in developing and verifying effective kinetic models. The models have then been reduced through automated means to enable multi-dimensional simulation of the combustion characteristics of such fuels in reciprocating engines. Such reliable kinetics models, validated against fundamental data derived from laminar flames using idealized flow models, are key to the development and design of optimal engines, engine operation and fuels. The models provide direct information about the relative contribution of different molecular constituents to the fuel performance and can be used to assess both combustion and emissions characteristics. During this project, we completed a major and thorough validation of a set of biodiesel surrogate components, allowing us to begin to evaluate the fundamental combustion characteristics for B100 fuels

    No major flaws in "Identification of individuals by trait prediction using whole-genome sequencing data"

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    In a recently published PNAS article, we studied the identifiability of genomic samples using machine learning methods [Lippert et al., 2017]. In a response, Erlich [2017] argued that our work contained major flaws. The main technical critique of Erlich [2017] builds on a simulation experiment that shows that our proposed algorithm, which uses only a genomic sample for identification, performed no better than a strategy that uses demographic variables. Below, we show why this comparison is misleading and provide a detailed discussion of the key critical points in our analyses that have been brought up in Erlich [2017] and in the media. Further, not only faces may be derived from DNA, but a wide range of phenotypes and demographic variables. In this light, the main contribution of Lippert et al. [2017] is an algorithm that identifies genomes of individuals by combining multiple DNA-based predictive models for a myriad of traits

    Using [beta]-decay to map the E2 strength in the Cd isotopes and the downfall of vibrational motion

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    Publisher's Version/PDFThe &beta; decay of 112Ag has been used to populate spin 0+ and 2+ states in 112Cd to 3 MeV excitation energy. The statistical quality obtained allows the extraction of very weak &gamma;-ray branching ratios that, combined with known level lifetimes, enables the determination of the B(E2) values or upper limits for transitions populating the proposed two-phonon states. While candidates for 3+, 4+, and 6+ three-phonon levels have been identified, there are no candidates for the 0+ and 2+&nbsp;three phonon levels, and the upper limits of the B(E2) values indicate that phonon E2 strength is not fragmented, but absent below 5ℏw2.</sub
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