478 research outputs found
A systematic review comparing the functional changes and complications of DIEP and TRAM flaps in patients receiving breast reconstruction
Aim: Treatment for breast cancer may involve unilateral or bilateral mastectomy, with subsequent breast reconstruction surgery. Using autologous tissue flaps during reconstructive surgery is increasingly popular. The aim of this systematic review was to determine if the DIEP flap is more effective than the TRAM flap for breast reconstruction in females after a mastectomy in terms of donor site morbidity, recipient site morbidity, and functional outcome.
Methods: Studies were identified using the databases Medline and Embase and applying predefined search criteria. The limits applied were; peer-reviewed, published between January 1980 to May 2013, human trials, English language. Study inclusion followed a review of the title, abstract, and full text by two independent researchers.
Results: Two trends were identified. 1) DIEP flap surgery reduces the risk of abdominal weakness without increasing the risk of flap complications if performed by a surgeon well trained in microsurgery; 2) TRAM flap surgery remains a good alternative due to its evolution towards muscle-sparing techniques.
Conclusion: This appears to be the first systematic review in this area of research. The evidence demonstrates that DIEP flap reduces postoperative abdominal morbidity, with no increased flap complication compared to the TRAM flap if performed by a surgeon well trained in microsurgery
Development and demonstration of manufacturing processes for fabricating graphite/LARC 160 polyimide structural elements
The development and demonstration of manufacturing technologies for the structural application of Celion graphite/LARC-160 polyimide composite material is discussed. Process development and fabrication of demonstration components are discussed. Process development included establishing quality assurance of the basic composite material and processing, nondestructive inspection of fabricated components, developing processes for specific structural forms, and qualification of processes through mechanical testing. Demonstration components were fabricated. The demonstration components consisted of flat laminates, skin/stringer panels, honeycomb panels, chopped fiber compression moldings, and a technology demonstrator segment (TDS) representative of the space shuttle aft body flap
Benford Behavior of Zeckendorf Decompositions
A beautiful theorem of Zeckendorf states that every integer can be written
uniquely as the sum of non-consecutive Fibonacci numbers . A set is said to satisfy Benford's law if
the density of the elements in with leading digit is
; in other words, smaller leading digits are more
likely to occur. We prove that, as , for a randomly selected
integer in the distribution of the leading digits of the
Fibonacci summands in its Zeckendorf decomposition converge to Benford's law
almost surely. Our results hold more generally, and instead of looking at the
distribution of leading digits one obtains similar theorems concerning how
often values in sets with density are attained.Comment: Version 1.0, 12 pages, 1 figur
Gaussian Behavior of the Number of Summands in Zeckendorf Decompositions in Small Intervals
Zeckendorf's theorem states that every positive integer can be written
uniquely as a sum of non-consecutive Fibonacci numbers , with initial
terms . We consider the distribution of the number of
summands involved in such decompositions. Previous work proved that as the distribution of the number of summands in the Zeckendorf
decompositions of , appropriately normalized, converges
to the standard normal. The proofs crucially used the fact that all integers in
share the same potential summands.
We generalize these results to subintervals of as ; the analysis is significantly more involved here as different integers
have different sets of potential summands. Explicitly, fix an integer sequence
. As , for almost all the distribution of the number of summands in the Zeckendorf
decompositions of integers in the subintervals ,
appropriately normalized, converges to the standard normal. The proof follows
by showing that, with probability tending to , has at least one
appropriately located large gap between indices in its decomposition. We then
use a correspondence between this interval and to obtain
the result, since the summands are known to have Gaussian behavior in the
latter interval. % We also prove the same result for more general linear
recurrences.Comment: Version 1.0, 8 page
A systematic review of associations between environmental exposures and development of asthma in children aged up to 9 years
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.Peer reviewedPublisher PD
Superconducting Gap and Pseudogap in Iron-Based Layered Superconductor La(OF)FeAs
We report high-resolution photoemission spectroscopy of newly-discovered
iron-based layered superconductor La(OF)FeAs (Tc = 24 K). We
found that the superconducting gap shows a marked deviation from the isotropic
s-wave symmetry. The estimated gap size at 5 K is 3.6 meV in the s- or axial
p-wave case, while it is 4.1 meV in the polar p- or d-wave case. We also found
a pseudogap of 15-20 meV above Tc, which is gradually filled-in with increasing
temperature and closes at temperature far above Tc similarly to copper-oxide
high-temperature superconductors.Comment: 4 pages, 3 figures, J. Phys. Soc. Jpn. Vol. 77, No. 6 (2008), in
pres
Exploring the anthelmintic properties of Australian native shrubs with respect to their potential role in livestock grazing systems
We measured in vitro anthelmintic activity in extracts from 85 species of Australian native shrub, with a view to identifying species able to provide a degree of worm control in grazing systems. Approximately 40% of the species showed significant activity in inhibiting development of Haemonchus contortus larvae. The most active extracts showed IC50 values of 60–300 mg/ml. Pre-incubation with polyvinylpolypyrrolidine removed the activity from some extracts, implicating tannins as the bioactive agent, while in other cases the pre-incubation had no effect, indicating the presence of other anthelmintic compounds. Plant reproductive maturity (onset of flowering or fruiting) was associated with increasing anthelmintic activity in some species. Variability was observed between plants of the same species growing in different environments, while variation between individual plants of the same species within a single field suggests the existence of distinct chemotypes. Significant activity against adult H. contortus worms in vitro was also demonstrated in a limited number of extracts tested against this life stage. Our study indicates that there is potential for Australian native shrubs to play an anthelmintic role in grazing systems, and highlights some plant biology factors which will need to be considered in order to maximize any anthelmintic effects.A. C. Kotze, J. O’Grady, J. Emms, A. F. Toovey, S. Hughes, P. Jessop, M. Bennell P. E. Vercoe and D. K. Revel
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