501 research outputs found
The efficacy and safety of peripheral intravenous parenteral nutrition vs 10% glucose in preterm infants born 30 to 33âweeks' gestation: a randomised controlled trial
Background: Preterm infants born 30 to 33âweeks' gestation often require early support with intravenous fluids because of respiratory distress, hypoglycemia or feed intolerance. When full feeds are anticipated to be reached within the first week, risks associated with intravenous delivery mode and type must be carefully considered. Recommendations are for parenteral nutrition to be infused via central venous lines (because of the high osmolarity), however, given the risks associated with central lines, clinicians may opt for 10% glucose via peripheral venous catheter when the need is short-term. We therefore compare a low osmolarity peripheral intravenous parenteral nutrition (P-PN) solution with peripheral intravenous 10% glucose on growth rate in preterm infants born 30 to 33âweeks' gestation. Methods: In this parallel group, single centre, superiority, non-blinded, randomised controlled trial, 92 (P-PN 42, control 50) infants born 30âșâ° to 33âșⶠweeks' gestation, were randomised within 24âh of age, to receive either P-PN (8% glucose, 30âg/L amino acids, 500âIU/L heparin and SMOFlipidÂź) or a control of peripheral intravenous 10% glucose. Both groups received enteral feeds according to hospital protocol. The primary outcome was rate of weight gain from birth to 21âdays of age. Results: The rate of weight gain was significantly increased in P-PN infants compared with control (P-PN, nâ=â42, 18.7, SD 6.6âg/d vs control, nâ=â50, 14.8, SD 6.0âg/d; adjusted mean difference 3.9âg/d, 95% CI 1.3 to 6.6; Pâ=â0.004), with the effect maintained to discharge home. Days to regain birthweight were significantly reduced and length gain significantly increased in P-PN infants. One infant in the P-PN group had a stage 3 extravasation which rapidly resolved. Blood urea nitrogen and triglyceride levels were significantly higher in the P-PN group in the first week of life, but there were no instances of abnormally high levels. There were no significant differences in any other clinical or biochemical outcomes. Conclusion: P-PN improves the rate of weight gain to discharge home in preterm infants born 30 to 33âweeks gestation compared with peripheral intravenous 10% glucose.Hiroki Suganuma, Dennis Bonney, Chad C. Andersen, Andrew J. McPhee, Thomas R. Sullivan, Robert A. Gibson and Carmel T. Collin
L-VRAP-a lunar volatile resources analysis package for lunar exploration
The Lunar Volatile Resources Analysis Package (L-VRAP) has been conceived to deliver some of the objectives of the proposed Lunar Lander mission currently being studied by the European Space Agency. The purpose of the mission is to demonstrate and develop capability; the impetus is very much driven by a desire to lay the foundations for future human exploration of the Moon. Thus, LVRAP has design goals that consider lunar volatiles from the perspective of both their innate scientific interest and also their potential for in situ utilisation as a resource. The device is a dual mass spectrometer system and is capable of meeting the requirements of the mission with respect to detection, quantification and characterisation of volatiles. Through the use of appropriate sampling techniques, volatiles from either the regolith or atmosphere (exosphere) can be analysed. Furthermore, since L-VRAP has the capacity to determine isotopic compositions, it should be possible for the instrument to determine the sources of the volatiles that are found on the Moon (be they lunar per se, extra-lunar, or contaminants imparted by the mission itself
Progressive transformation of a flux rope to an ICME
The solar wind conditions at one astronomical unit (AU) can be strongly
disturbed by the interplanetary coronal mass ejections (ICMEs). A subset,
called magnetic clouds (MCs), is formed by twisted flux ropes that transport an
important amount of magnetic flux and helicity which is released in CMEs. At 1
AU from the Sun, the magnetic structure of MCs is generally modeled neglecting
their expansion during the spacecraft crossing. However, in some cases, MCs
present a significant expansion. We present here an analysis of the huge and
significantly expanding MC observed by the Wind spacecraft during 9 and 10
November, 2004. After determining an approximated orientation for the flux rope
using the minimum variance method, we precise the orientation of the cloud axis
relating its front and rear magnetic discontinuities using a direct method.
This method takes into account the conservation of the azimuthal magnetic flux
between the in- and out-bound branches, and is valid for a finite impact
parameter (i.e., not necessarily a small distance between the spacecraft
trajectory and the cloud axis). Moreover, using the direct method, we find that
the ICME is formed by a flux rope (MC) followed by an extended coherent
magnetic region. These observations are interpreted considering the existence
of a previous larger flux rope, which partially reconnected with its
environment in the front. These findings imply that the ejected flux rope is
progressively peeled by reconnection and transformed to the observed ICME (with
a remnant flux rope in the front part).Comment: Solar Physics (in press
Characterisation of the material and mechanical properties of atomic force microscope cantilevers with a plan-view trapezoidal geometry
Cantilever devices have found applications in numerous scientific fields and instruments, including the atomic force microscope (AFM), and as sensors to detect a wide range of chemical and biological species. The mechanical properties, in particular, the spring constant of these devices is crucial when quantifying adhesive forces, material properties of surfaces, and in determining deposited mass for sensing applications. A key component in the spring constant of a cantilever is the plan-view shape. In recent years, the trapezoidal plan-view shape has become available since it offers certain advantages to fast-scanning AFM and can improve sensor performance in fluid environments. Euler beam equations relating cantilever stiffness to the cantilever dimensions and Youngâs modulus have been proven useful and are used extensively to model cantilever mechanical behaviour and calibrate the spring constant. In this work, we derive a simple correction factor to the Euler beam equation for a beam-shaped cantilever that is applicable to any cantilever with a trapezoidal plan-view shape. This correction factor is based upon previous analytical work and simplifies the application of the previous researchers formula. A correction factor to the spring constant of an AFM cantilever is also required to calculate the torque produced by the tip when it contacts the sample surface, which is also dependent on the plan-view shape. In this work, we also derive a simple expression for the torque for triangular plan-view shaped cantilevers and show that for the current generation of trapezoidal plan-view shaped AFM cantilevers, this will be a good approximation. We shall apply both these correction factors to determine Youngâs modulus for a range of trapezoidal-shaped AFM cantilevers, which are specially designed for fast-scanning. These types of AFM probes are much smaller in size when compared to standard AFM probes. In the process of analysing the mechanical properties of these cantilevers, important insights are also gained into their spring constant calibration and dimensional factors that contribute to the variability in their spring constant.Ashley D. Slattery, Adam J. Blanch, Cameron J. Shearer, Andrew J. Stapleton, Renee V. Goreham, Sarah L. Harmer, Jamie S. Quinton, and Christopher T. Gibso
Effect of Docosahexaenoic Acid (DHA) Supplementation of Preterm Infants on Growth, Body Composition, and Blood Pressure at 7-Years Corrected Age: Follow-Up of a Randomized Controlled Trial
Aim: To determine if supplementation of infants born 0.1). High-DHA group infants were more likely to be classified as obese (relative risk 1.6 (95% CI 1.0, 2.6); p = 0.05). Conclusions: DHA supplementation of premature infants did not affect growth, body composition, or blood pressure at 7-year CA overall by sex and birthweight strata. The finding of a higher risk of obesity in children who receive high-DHA needs to be interpreted with caution due to the small number of children classified as obese.Karen P. Best, Thomas R. Sullivan, Anoja W. Gunaratne, Jacqueline F. Gould, Robert A. Gibson, Carmel T. Collins, Maria Makrides, and Tim J. Gree
Growth of late preterm infants fed nutrient-enriched formula to 120 days corrected age-A randomized controlled trial.
Objectives: We aimed to compare the effects of nutrient-enriched formula with standard term formula on rate of body weight gain of late preterm infants appropriately grown for gestational age. Study design: A multi-center, randomized, controlled trial. Late preterm infants(34â37 weeksâ gestation), with weight appropriate for gestational age (AGA), were randomized to nutrient enriched formula (NEF) with increased calories (22 kcal/30 ml) from protein, added bovine milk fat globule membrane, vitamin D and butyrate or standard term formula 20 kcal/30 ml (STF). Breastfed term infants were enrolled as an observational reference group (BFR). Primary outcome was rate of body weight gain from enrollment to 120 days corrected age (d/CA). Planned sample size was 100 infants per group. Secondary outcomes included body composition, weight, head circumference and length gain, and medically confirmed adverse events to 365 d/CA. Results: The trial was terminated early due to recruitment challenges and sample size was substantially reduced. 40 infants were randomized to NEF (n = 22) and STF (n = 18). 39 infants were enrolled in the BFR group. At 120 d/CA there was no evidence of a difference in weight gain between randomized groups (mean difference 1.77 g/day, 95% CI, â1.63 to 5.18, P = 0.31). Secondary outcomes showed a significant reduction in risk of infectious illness in the NEF group at 120 d/CA [relative risk 0.37 (95% CI, 0.16â0.85), P = 0.02]. Conclusion: We saw no difference in rate of bodyweight gain between AGA late preterm infants fed NEF compared to STF. Results should be interpreted with caution due to small sample size.Karen P. Best, Lisa N. Yelland, Carmel T. Collins, Andrew J. McPhee, Geraint B. Rogers, Jocelyn Choo, Robert A. Gibson, Teresa Murguia-Peniche, Jojy Varghese, Timothy R. Cooper, and Maria Makride
Impact of CIR Storms on Thermosphere Density Variability during the Solar Minimum of 2008
The solar minimum of 2008 was exceptionally quiet, with sunspot numbers at
their lowest in 75 years. During this unique solar minimum epoch, however,
solar wind high - speed streams emanating from near-equatorial coronal holes
occurred frequently and were the primary contributor to the recurrent
geomagnetic activity at Earth. These conditions enabled the isolation of
forcing by geomagnetic activity on the preconditioned solar minimum state of
the upper atmosphere caused by Corotating Interaction Regions (CIRs).
Thermosphere density observations around 400 km from the CHAMP satellite are
used to study the thermosphere density response to solar wind high - speed
streams/CIRs. Superposed epoch results show that thermosphere density responds
to high - speed streams globally, and the density at 400 km changes by 75% on
average. The relative changes of neutral density are comparable at different
latitudes, although its variability is largest at high latitudes. In addition,
the response of thermosphere density to high - speed streams is larger at night
than in daytime, indicating the preconditioning effect of the thermosphere
response to storms. Finally, the thermosphere density variations at the periods
of 9 and 13.5 days associated with CIRs are linked to the spatial distribution
of low - middle latitude coronal holes on the basis of the EUVI observations
from the STEREO.Comment: Solar Physics, accepted, April 2010, and the final version of this
paper will appear in the website of Solar Physics soon
Fertility, Living Arrangements, Care and Mobility
There are four main interconnecting themes around which the contributions in this book are based. This introductory chapter aims to establish the broad context for the chapters that follow by discussing each of the themes. It does so by setting these themes within the overarching demographic challenge of the twenty-first century â demographic ageing. Each chapter is introduced in the context of the specific theme to which it primarily relates and there is a summary of the data sets used by the contributors to illustrate the wide range of cross-sectional and longitudinal data analysed
Electric current circuits in astrophysics
Cosmic magnetic structures have in common that they are anchored
in a dynamo, that an external driver converts kinetic energy into internal
magnetic energy, that this magnetic energy is transported as Poynting fl ux across the magnetically dominated structure, and that the magnetic energy
is released in the form of particle acceleration, heating, bulk motion,
MHD waves, and radiation. The investigation of the electric current system is
particularly illuminating as to the course of events and the physics involved.
We demonstrate this for the radio pulsar wind, the solar flare, and terrestrial
magnetic storms
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