679 research outputs found

    Resource tiered reviews – a provisional reporting checklist

    Get PDF
    AFJEM is committed to publishing review articles that will benefit acute care providers, independent of the resources available to them. As a result we have compiled a checklist aimed specifically at best evidence in the resource-restricted setting (Table 1). The aim is to guide authors in producing a report which is a combination between a clinical guideline and a systematic review. Best available evidence, using a transparent and systematic approach to find and evaluate relevant studies, is still key; but with additional focus on resource availability. In effect it will be more rigorous than a narrative review but less time-consuming than a systematic review or meta-analysis. In order to apply the content to different resource levels, authors are advised to start by describing the very best evidence available; then assume the resources for this level are not available and describe the next tier of evidence until all options are exhausted. For example, if we return to our patient with chest pain: the recommended treatment for a patient with STEMI is primary percutaneous coronary intervention; if this treatment is not available, then thrombolytics should be considered; if that is not available then antiplatelet therapy and anticoagulation should be used, and so on and so forth

    Outflows from young objects observed with the ISO-LWS I. Fine structure lines [O I] 63, [O I]145 and [C II]157 micron

    Full text link
    Far infrared fine structure line data from the ISO archive have been extracted for several hundred YSOs and their outflows, including molecular (CO) outflows, optical jets and Herbig-Haro (HH) objects. Given the importance of these lines to astrophysics, their excitation and transfer ought to be investigated in detail and, at this stage, the reliability of the diagnostic power of the fine structure transitions of O I and C II has been examined. Several issues, such as the extremely small intensity ratios of the oxygen 63 micron to 145 micron lines, are still awaiting an explanation. It is demonstrated that, in interstellar cloud conditions, the 145 micron line is prone to masing, but that this effect is likely an insufficient cause of the line ratio anomaly observed from cold dark clouds. Very optically thick emission could in principle also account for this, but would need similar, prohibitively high column densities and must therefore be abondoned as a viable explanation. One is left with [O I] 63 micron self absorption by cold and tenuous foreground gas, as has been advocated for distant luminous sources. Recent observations with the submillimeter observatory Odin support this scenario also in the case of nearby dark molecular clouds. On the basis of this large statistical material we are led to conclude that in star forming regions, the [O I] and [C II] lines generally have only limited diagnostic value.Comment: 8 pages, 8 figures (in color), to appear in Astronomy & Astrophysic

    The deep-sea hub of the ANTARES neutrino telescope

    Get PDF
    The ANTARES neutrino telescope, currently under construction at 2500 m depth off the French Mediterranean coast, will contain 12 detection lines, powered and read out through a deep-sea junction box (JB) hub. Electrical energy from the shore station is distributed through a transformer with multiple secondary windings and a plugboard with 16 deep sea-mateable electro-optic connectors. Connections are made to the JB outputs using manned or remotely operated submersible vehicles. The triply redundant power management and slow control system is based on two identical AC-powered systems, communicating with the shore through 160 Mb/s fibre G-links and a third battery-powered system using a slower link. We describe the power and slow control systems of the underwater hub

    Reactive oxygen-related diseases: therapeutic targets and emerging clinical indications

    Get PDF
    SIGNIFICANCE Enhanced levels of reactive oxygen species (ROS) have been associated with different disease states. Most attempts to validate and exploit these associations by chronic antioxidant therapies have provided disappointing results. Hence, the clinical relevance of ROS is still largely unclear. RECENT ADVANCES We are now beginning to understand the reasons for these failures, which reside in the many important physiological roles of ROS in cell signaling. To exploit ROS therapeutically, it would be essential to define and treat the disease-relevant ROS at the right moment and leave physiological ROS formation intact. This breakthrough seems now within reach. CRITICAL ISSUES Rather than antioxidants, a new generation of protein targets for classical pharmacological agents includes ROS-forming or toxifying enzymes or proteins that are oxidatively damaged and can be functionally repaired. FUTURE DIRECTIONS Linking these target proteins in future to specific disease states and providing in each case proof of principle will be essential for translating the oxidative stress concept into the clinic. Antioxid. Redox Signal. 23, 1171-1185

    On the gas temperature in circumstellar disks around A stars

    Get PDF
    In circumstellar disks or shells it is often assumed that gas and dust temperatures are equal where the latter is determined by radiative equilibrium. This paper deals with the question whether this assumption is applicable for tenous circumstellar disks around young A stars. In this paper the thin hydrostatic equilibrium models described by Kamp & Bertoldi (2000) are combined with a detailed heating/cooling balance for the gas. The most important heating and cooling processes are heating through infrared pumping, heating due to the drift velocity of dust grains, and fine structure and molecular line cooling. Throughout the whole disk gas and dust are not efficiently coupled by collisions and hence their temperatures are quite different. Most of the gas in the disk models considered here stays well below 300 K. In the temperature range below 300 K the gas chemistry is not much affected by T_gas and therefore the simplifying approximation T_gas = T_dust can be used for calculating the chemical structure of the disk. Nevertheless the gas temperature is important for the quantitative interpretation of observations, like fine structure and molecular lines.Comment: 16 pages, 31 figures, A&A accepted May 4, 200

    The gas temperature in flaring disks around pre-main sequence stars

    Full text link
    A model is presented which calculates the gas temperature and chemistry in the surface layers of flaring circumstellar disks using a code developed for photon-dominated regions. Special attention is given to the influence of dust settling. It is found that the gas temperature exceeds the dust temperature by up to several hundreds of Kelvins in the part of the disk that is optically thin to ultraviolet radiation, indicating that the common assumption that Tgas=Tdust is not valid throughout the disk. In the optically thick part, gas and dust are strongly coupled and the gas temperature equals the dust temperature. Dust settling has little effect on the chemistry in the disk, but increases the amount of hot gas deeper in the disk. The effects of the higher gas temperature on several emission lines arising in the surface layer are examined. The higher gas temperatures increase the intensities of molecular and fine-structure lines by up to an order of magnitude, and can also have an important effect on the line shapes.Comment: 14 pages, 10 figures, accepted for publication in A&

    Tracking of fluorescently labeled polymer particles reveals surface effects during shear-controlled aggregation

    Get PDF
    Surface chemistry is believed to be the key parameter affecting the aggregation and breakage of colloidal suspensions when subjected to shear. To date, only a few works dealt with the understanding of the role of the physical and chemical properties of the particles’ surface upon aggregation under shear. Previous studies suggested that surface modifications strongly affect polymer particles’ adhesion, but it was very challenging to demonstrate this effect and monitor these alterations upon prolonged exposure to shear forces. More importantly, the mechanisms leading to these changes remain elusive. In this work, shear-induced aggregation experiments of polymer colloidal particles have been devised with the specific objective of highlighting material transfer and clarifying the role of the softness of the particle’s surface. To achieve this goal, polymer particles with a core–shell structure comprising fluorescent groups have been prepared so that the surface’s softness could be tuned by the addition of monomer acting as a plasticizer and the percentage of fluorescent particles could be recorded over time via confocal microscopy to detect eventual material transfer among different particles. For the first time, material exchange occurring on the soft surface of core–shell polymer microparticles upon aggregation under shear was observed and proved. More aptly, starting from a 50% labeled/nonlabeled mixture, an increase in the percentage of particles showing a fluorescent signature was recorded over time, reaching a fraction of 70% after 5 h

    Influence of the gender on the relationship between heart rate and blood pressure

    Get PDF
    Blood Pressure (BP) and Heart Rate (HR) provide information on clin-ical condition along 24h. Both signals present circadian changes due to sympa-thetic/parasympathetic control system that influence the relationship between them. Moreover, also the gender could modify this relation, acting on both con-trol systems. Some studies, using office measurements examined the BP/HR re-lation, highlighting a direct association between the two variables, linked to sus-pected coronary heart disease. Nevertheless, till now such relation has not been studied yet using ambulatory technique that is known to lead to additional prog-nostic information about cardiovascular risks. In order to examine in a more ac-curate way this relation, in this work we evaluate the influence of gender on the BP/HR relationship by using hour-to-hour 24h ambulatory measurements. Data coming from 122 female and 50 male normotensive subjects were recorded using a Holter Blood Pressure Monitor and the parameters of the linear regression fit-ting BP/HR were calculated. Results confirmed those obtained in previous stud-ies using punctual office measures in males and underlined a significant relation between Diastolic BP and HR during each hour of the day in females; a different trend in the BP/HR relation between genders was found only during night-time. Moreover, the circadian rhythm of BP/HR is similar in both genders but with different values of HR and BP at different times of the day

    Continuum and line modeling of disks around young stars II. Line diagnostics for GASPS from the DENT grid

    Get PDF
    Aims. We want to understand the chemistry and physics of disks on the basis of a large unbiased and statistically relevant grid of disk models. One of the main goals is to explore the diagnostic power of various gas emission lines and line ratios for deriving main disk parameters such as the gas mass. Methods. We explore the results of the DENT grid (Disk Evolution with Neat Theory) that consists of 300 000 disk models with 11 free parameters. Through a statistical analysis, we search for correlations and trends in an effort to find tools for disk diagnostic. Results. All calculated quantities like species masses, temperatures, continuum and line fluxes differ by several orders of magnitude across the entire parameter space. The broad distribution of these quantities as a function of input parameters shows the limitation of using a prototype T Tauri or Herbig Ae/Be disk model. The statistical analysis of the DENT grid shows that CO gas is rarely the dominant carbon reservoir in disks. Models with large inner radii (10 times the dust condensation radius) and/or shallow surface density gradients lack massive gas phase water reservoirs. Also, 60% of the disks have gas temperatures averaged over the oxygen mass in the range between 15 and 70 K; the average gas temperatures for CO and O differ by less than a factor two. Studying the observational diagnostics, the [CII] 158 \mum fine structure line flux is very sensitive to the stellar UV flux and presence of a UV excess and it traces the outer disk radius (Rout). In the submm, the CO low J rotational lines also trace Rout. Low [OI] 63/145 line ratios (< a few) can be explained with cool atomic O gas in the uppermost surface layers leading to self-absorption in the 63 \mum line; this occurs mostly for massive non-flaring, settled disk models without UV excess. ... abbreviatedComment: 15 pages, 25 figures, accepted for publication in A&
    • …
    corecore