1,573 research outputs found
Four layer bandage compared with short stretch bandage for venous leg ulcers: systematic review and meta-analysis of randomised controlled trials with data from individual patients
<p><b>Objective:</b> To compare the effectiveness of two types of compression treatment (four layer bandage and short stretch bandage) in people with venous leg ulceration.</p>
<p><b>Design:</b> Systematic review and meta-analysis of patient level data.</p>
<p><b>Data:</b> sources Electronic databases (the Cochrane Central Register of Controlled Trials, the Cochrane Wounds Group Specialised Register, Medline, Embase, CINAHL, and National Research Register) and reference lists of retrieved articles searched to identify relevant trials and primary investigators. Primary investigators of eligible trials were invited to contribute raw data for re-analysis.</p>
<p><b>Review:</b> methods Randomised controlled trials of four layer bandage compared with short stretch bandage in people with venous leg ulceration were eligible for inclusion. The primary outcome for the meta-analysis was time to healing. Cox proportional hazards models were run to compare the methods in terms of time to healing with adjustment for independent predictors of healing. Secondary outcomes included incidence and number of adverse events per patient.</p>
<p><b>Results:</b> Seven eligible trials were identified (887 patients), and patient level data were retrieved for five (797 patients, 90% of known randomised patients). The four layer bandage was associated with significantly shorter time to healing: hazard ratio (95% confidence interval) from multifactorial model based on five trials was 1.31 (1.09 to 1.58), P=0.005. Larger ulcer area at baseline, more chronic ulceration, and previous ulceration were all independent predictors of delayed healing. Data from two trials showed no evidence of a difference in adverse event profiles between the two bandage types.</p>
<p><b>Conclusions:</b> Venous leg ulcers in patients treated with four layer bandages heal faster, on average, than those of people treated with the short stretch bandage. Benefits were consistent across patients with differing prognostic profiles.</p>
Radio-frequency reflectometry on an undoped AlGaAs/GaAs single electron transistor
Radio frequency reflectometry is demonstrated in a sub-micron undoped
AlGaAs/GaAs device. Undoped single electron transistors (SETs) are attractive
candidates to study single electron phenomena due to their charge stability and
robust electronic properties after thermal cycling. However these devices
require a large top-gate which is unsuitable for the fast and sensitive radio
frequency reflectometry technique. Here we demonstrate rf reflectometry is
possible in an undoped SET.Comment: Four pages, three figures, one supplementary fil
Plasma Cholesterol Ester Fatty Acids: A New Biochemical Abnormality in Obstructive Jaundice
Changes in fatty acid patterns may explain many of the observed abnormalities found in
obstructive jaundice. This study looked at fatty acids in plasma cholesterol esters, in a group of
patients with obstructive jaundice and a matched group of controls. Significant abnormalities
were demonstrated, most importantly a fall in essential fatty acids, in the jaundiced group.
Overall the saturation of this fraction, as assessed by double bond index, rose. The essential fatty
acids are important as factors in membrane function and as precursors of eicosanoids. The
abnormalities found in this study provide further evidence of the significance of EFA in patients
with obstructive jaundice
Top-Down Nationalism in Post-Soviet Kazakhstan
Kazakhstan was the most multi-ethnic country to emerge from the former Soviet Union and the only one to have its titular ethnicity as a minority. This paper examines the top-down nationalism that has occurred since independence in 1991. The government of Kazakhstan has used elements of the theories of nationalism and territoriality in their effort to build a strong and unified post-Soviet national identity. The role of language, treatment of minorities, changing demographics, and the multi-ethnic nature of Kazakhstan make this a difficult task
Malignant Pancreatic Polypeptide Secreting Tumour of Islet Cells: A Case for Aggressive Surgical Palliation
A case of a malignant pancreatic polypeptide secreting tumour is reported. The tumour was metastatic
at presentation at which time it was excised. Pancreatic duct obstruction occurred 3 years after excision causing severe pain on eating. Major palliative surgery, in the form of a pancreatico-jejunostomy, cured the severe symptoms. The patient survives, largely symptom free, over six years after original excision. This case illustrates the need for aggressive management of symptoms in tumours in which long term survival is possible despite locally advanced or metastatic disease
How Dilute are Dilute Solutions in Extensional Flows?
Submitted to J. Rheol.We investigate the concentration-dependence of the characteristic relaxation time of
dilute polymer solutions in transient uniaxial elongational flow. A series of monodisperse polystyrene solutions of five different molecular weights (1.8×10^6 ≤ M ≤ 8.3×10^6 g/mol) with concentrations spanning five orders of magnitude were dissolved in two solvents of differing solvent quality (diethyl phthalate and oligomeric styrene). Optical measurements of the rate of filament thinning and the time to break-up in each fluid are used to determine the characteristic relaxation time. A lower sensitivity limit for the measurements was determined experimentally and confirmed by comparison to numerical calculations.
Above this sensitivity limit we show that the effective relaxation time of moderately
dilute solutions (0.01 ≤ c/c* ≤ 1) in transient extensional flow rises substantially above the fitted value of the relaxation time extracted from small amplitude oscillatory shear flow and above the Zimm relaxation time computed from kinetic theory and intrinsic viscosity
measurements. This effective relaxation time exhibits a power-law scaling with the reduced
concentration (c/c*) and the magnitude of the exponent varies with the thermodynamic quality of the solvent. This scaling appears to be roughly consistent to that predicted when the dynamics of the partially elongated and overlapping polymer chains are described within the framework of blob theories for semi-dilute solutions.NASA Microgravity Fluid Dynamic
From coinductive proofs to exact real arithmetic: theory and applications
Based on a new coinductive characterization of continuous functions we
extract certified programs for exact real number computation from constructive
proofs. The extracted programs construct and combine exact real number
algorithms with respect to the binary signed digit representation of real
numbers. The data type corresponding to the coinductive definition of
continuous functions consists of finitely branching non-wellfounded trees
describing when the algorithm writes and reads digits. We discuss several
examples including the extraction of programs for polynomials up to degree two
and the definite integral of continuous maps
Multi-Orbital Molecular Compound (TTM-TTP)I_3: Effective Model and Fragment Decomposition
The electronic structure of the molecular compound (TTM-TTP)I_3, which
exhibits a peculiar intra-molecular charge ordering, has been studied using
multi-configuration ab initio calculations. First we derive an effective
Hubbard-type model based on the molecular orbitals (MOs) of TTM-TTP; we set up
a two-orbital Hamiltonian for the two MOs near the Fermi energy and determine
its full parameters: the transfer integrals, the Coulomb and exchange
interactions. The tight-binding band structure obtained from these transfer
integrals is consistent with the result of the direct band calculation based on
density functional theory. Then, by decomposing the frontier MOs into two
parts, i.e., fragments, we find that the stacked TTM-TTP molecules can be
described by a two-leg ladder model, while the inter-fragment Coulomb energies
are scaled to the inverse of their distances. This result indicates that the
fragment picture that we proposed earlier [M.-L. Bonnet et al.: J. Chem. Phys.
132 (2010) 214705] successfully describes the low-energy properties of this
compound.Comment: 5 pages, 4 figures, published versio
Is Social Psychology Really Different?
Gergen (1976), outlines a number of problems that make it difficult to apply general social psychological the ories, or to assess their validity unequivocally. These dif ficulties are not unique to social psychology, however. The application of general scientific principles has never been a simple matter, not even in the well-established physical sci ences. Moreover, there are formidable difficulties in asses sing general theoretical propositions in every field of in quiry, since empirical procedures will inevitably depend on assumptions about local field conditions, the adequacy of meas urement techniques, and the like. As a consequence, if re sults are inconsistent with theoretical expectations, there will always be some uncertainty as to where the problem lies. Social psychologists should not assume that their difficulties are totally unlike those encountered in other fields of sci entific inquiry. The problems raised by Gergen do not, con sequently, rule out the possible development and application of general social psychological theories.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69124/2/10.1177_014616727600200417.pd
On the principal bifurcation branch of a third order nonlinear long-wave equation
We study the principal bifurcation curve of a third order equation which
describes the nonlinear evolution of several systems with a long--wavelength
instability. We show that the main bifurcation branch can be derived from a
variational principle. This allows to obtain a close estimate of the complete
branch. In particular, when the bifurcation is subcritical, the large amplitude
stable branch can be found in a simple manner.Comment: 11 pages, 3 figure
- …