207 research outputs found
The evidence on the effectiveness of management for malignant pleural effusion: a systematic review.
The aim of this study was to review systematically the available evidence on pleurodesis for malignant effusion, focusing on the choice of the agents, route of delivery and other strategies to improve outcomes. Four electronic databases (MEDLINE, EMBASE, Web of Science and Cochrane Controlled Trials Register) were searched, reference lists checked and letters requesting details of unpublished trials and data sent to authors of previous trials. Studies of malignant pleural effusion in humans were selected with no language restrictions applied. Criteria for randomised clinical trial (RCT) eligibility were random allocation of patients and non-concurrent use of another experimental medication or device. Methodological quality evaluation of the trials was based on randomisation, blinding, allocation concealment and intention to treat analysis. A random effect model was used to combine the relative risk estimates of the treatment effects whenever pooling for an overall effect was considered appropriate. Forty-six RCTs with a total of 2053 patients with malignant pleural effusions were reviewed for effectiveness of pleurodesis. Talc tended to be associated with fewer recurrences when compared to bleomycin (RR, 0.64; 95% CI, 0.34-1.20) and, with more uncertainty, to tetracycline (RR, 0.50; 95% CI, 0.06-4.42). Tetracycline (or doxycycline) was not superior to bleomycin (RR, 0.92; 95% CI, 0.61-1.38). When compared with bedside talc slurry, thoracoscopic talc insufflation was associated with a reduction in recurrence (RR, 0.21; 95% CI, 0.05-0.93). Strategies such as rolling the patient after instillation of the sclerosing agent, protracted drainage of the effusion and use of larger chest tubes were not found to have any substantial advantages. Talc appears to be effective and should be the agent of choice for pleurodesis. Thoracoscopic talc insufflation is associated with fewer recurrences of effusions compared with bedside talc slurry, but this is based on two small studies. Where thoracoscopy is unavailable bedside talc pleurodesis has a high success rate and is the next best option
Magnetic inflation and stellar mass. III. revised parameters for the component stars of NSVS 07394765
We perform a new analysis of the M-dwarf–M-dwarf eclipsing binary system NSVS 07394765 in order to investigate the reported hyper-inflated radius of one of the component stars. Our analysis is based on archival photometry from the Wide Angle Search for Planets, new photometry from the 32 cm Command Module
Observatory telescope in Arizona and the 70 cm telescope at Thacher Observatory in California, and new high-resolution infrared spectra obtained with the Immersion Grating Infrared Spectrograph on the Discovery Channel Telescope. The masses and radii we measure for each component star disagree with previously reported measurements. We show that both stars are early M-type main-sequence stars without evidence for youth or hyper-inflation ( = - ☉ M M + 1 0.661 0.036 0.008 , = - ☉ M M + 2 0.608 0.028 0.003 , = - ☉ + R1 0.599 0.019 R 0.032 , = - ☉ + R2 0.625 0.027 R 0.012 ), and
we update the orbital period and eclipse ephemerides for the system. We suggest that the likely cause of the initial hyper-inflated result is the use of moderate-resolution spectroscopy for precise radial velocity measurements.Published versio
Advanced propfan analysis for the family of commuter airplanes
Advanced propfans were selected to be used throughout the family of commuters. These propulsion systems offer a 25 to 28 percent fuel savings over comparably sized turbofans operating in the 1990s. A brief study of the propulsion systems available for the family of commuters is provided and the selection of the advanced turboprops justified. The propeller and engine designs and performance are discussed. The integration of these designs are examined. Also addressed is the noise considerations and constraints due to propfan installation
Presentation of structural component designs for the family of commuter airplanes
The purpose is to present the implementation of structural commonality in the family of commuter airplanes. One of the main goals is implementation of structural commonality to as high a degree as possible. The structural layouts of those parts of the airplanes in which commonality is possible with all members of the family will be presented. The following airplane sections, which are common on all of the airplanes in the family, will be presented: common nose cone design; common wing torque box design; and common tail cone design. A proposed production and manufacturing breakdown is described. The advantages and disadvantages of implementing structural commonality and recommendations for further work will be discussed
Quantifying Astrophysical Uncertainties on Dark Matter Direct Detection Results
We attempt to estimate the uncertainty in the constraints on the spin
independent dark matter-nucleon cross section due to our lack of knowledge of
the dark matter phase space in the galaxy. We fit the density of dark matter
before investigating the possible solutions of the Jeans equation compatible
with those fits in order to understand what velocity dispersions we might
expect at the solar radius. We take into account the possibility of
non-Maxwellian velocity distributions and the possible presence of a dark disk.
Combining all these effects, we still find that the uncertainty in the
interpretation of direct detection experiments for high (>100 GeV) mass dark
matter candidates is less than an order of magnitude in cross section.Comment: 18 pages, 17 figure
Conversion of sub-tropical native vegetation to introduced conifer forest: Impacts on below-ground and above-ground carbon pools
Land-use change can have a major influence on soil organic carbon (SOC) and above-ground C pools. We assessed a change from native vegetation to introduced Pinus species plantations on C pools using eight paired sites. At each site we determined the impacts on 0–50 cm below-ground (SOC, charcoal C, organic matter C, particulate organic C, humic organic C, resistant organic C) and above-ground (litter, coarse woody debris, standing trees and woody understorey plants) C pools. In an analysis across the different study sites there was no significant difference (P > 0.05) in SOC or above-ground tree C stocks between paired native vegetation and pine plantations, although significant differences did exist at specific sites. SOC (calculated based on an equivalent soil mass basis) was higher in the pine plantations at two sites, higher in the native vegetation at two sites and did not differ for the other four sites. The site to site variation in SOC across the landscape was far greater than the variation observed with a change from native vegetation to introduced Pinus plantation. Differences between sites were not explained by soil type, although tree basal area was positively correlated with 0–50 cm SOC. In fact, in the native vegetation there was a significant linear relationship between above-ground biomass and SOC that explained 88.8% of the variation in the data. Fine litter C (0–25 mm diameter) tended to be higher in the pine forest than in the adjacent native vegetation and was significantly higher in the pine forest at five of the eight paired sites. Total litter C (0–100 mm diameter) increased significantly with plantation age (R2 = 0.64). Carbon stored in understorey woody plants (2.5–10 cm DBH) was higher in the native vegetation than in the adjacent pine forest. Total site C varied greatly across the study area from 58.8 Mg ha−1 at a native heathland site to 497.8 Mg ha−1 at a native eucalypt forest site. Our findings suggest that the effects of change from native vegetation to introduced Pinus sp. forest are highly site-specific and may be positive, negative, or have no influence on various C pools, depending on local site characteristics (e.g. plantation age and type of native vegetation)
Presentation of Class 1 designs for a family of commuter airplanes
The Class 1 configuration designs of a family of commuter aircraft are presented. The proposed aircraft will have a capacity of from 25 to 100 passengers. They are to have the following common features: (1) 2 aft fuselage mounted engines; (2) a low wing; (3) a T-tail type empennage; and (4) a tricycle type landing gear. A family concept is introduced to achieve structural, systems and handling quality commonality throughout. Implementing commonality can substantially reduce manufacturing and production costs. By achieving common system designs, maintenance costs can be reduced by permitting airlines to stock a smaller inventory of spares. Therefore, the higher degree of commonality, the lower the direct operating and life cycle costs. The attempt to implement some of the commonality requirements has caused configuration design problems, i.e., the twin-body concept was introduced. Design data are compared to existing aircraft, and the extent of structural, systems and handling qualities achieved are reviewed
A class 2 weight assessment for the implementation of commonality and preliminary structural designs for the family of commuter airplanes
The feasibility of commonality objectives are determined. Commonality is discussed in terms of weight penalties that increase the take-off weight of several members of the family of airplanes. Preliminary designs of fuselage structural members and a discussion of weight penalties due to implementation of common fuselage structure throughout the family is examined. Wing torque box designs are discussed along with structural weight penalties incurred. A landing gear design study is contained along with the weight penalties that a common gear system will impose. Implementation of common power plants throughout the family and the weight penalties that occur are discussed. The weight penalties imposed by commonality on all the airplanes in the family are summarized. Class 2 breakdowns are also presented. The feasibility of commonality based on a percentage of take-off weight increase over the Class 2 baseline weights is then assessed
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