1,198 research outputs found
Tip Anchor Flap in Decubital Surgery
Anchoring a flap remains a key procedure in decubital surgery because a flap needs to be stable against shearing forces. This allows an early mobilization and undisturbed primary wound healing. This study evaluated a uniform group of eight paraplegic patients with sacral decubital ulcers and covered the lesions using gluteal rotation flaps with a deepithelialized tip to anchor the flap subcutaneously on the contralateral ischial tuber. Initial wound healing and recurrence after one year were evaluated. All but one flap showed uneventful wound healing, and all the flaps presented without any signs of recurrence or instability. The authors suggest that sufficient anchoring using a deepithelialized part of the flap helps to integrate and stabilize sacral rotation flap
Continuum corrections to the level density and its dependence on excitation energy, n-p asymmetry, and deformation
In the independent-particle model, the nuclear level density is determined
from the neutron and proton single-particle level densities. The
single-particle level density for the positive-energy continuum levels is
important at high excitation energies for stable nuclei and at all excitation
energies for nuclei near the drip lines. This single-particle level density is
subdivided into compound-nucleus and gas components. Two methods were
considered for this subdivision. First in the subtraction method, the
single-particle level density is determined from the scattering phase shifts.
In the Gamov method, only the narrow Gamov states or resonances are included.
The level densities calculated with these two methods are similar, both can be
approximated by the backshifted Fermi-gas expression with level-density
parameters that are dependent on A, but with very little dependence on the
neutron or proton richness of the nucleus. However, a small decrease in the
level-density parameter was predicted for some nuclei very close to the drip
lines. The largest difference between the calculations using the two methods
was the deformation dependence on the level density. The Gamov method predicts
a very strong peaking of the level density at sphericity for high excitation
energies. This leads to a suppression of deformed configurations and,
consequently, the fission rate predicted by the statistical model is reduced in
the Gamov method.Comment: 18 pages 24 figure
The Determination of Nuclear Level Densities from Experimental Information -
A novel Information Theory based method for determining the density of states
from prior information is presented. The energy dependence of the density of
states is determined from the observed number of states per energy interval and
model calculations suggest that the method is sufficiently reliable to
calculate the thermal properties of nuclei over a reasonable temperature range.Comment: 7 pages + 6 eps figures, REVTEX 3.
Institutional Experience with Voriconazole Compared with Liposomal Amphotericin B as Empiric Therapy for Febrile Neutropenia
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90034/1/phco.27.7.970.pd
A Southern Hemisphere record of global trace-metal drawdown and orbital modulation of organic-matter burial across the Cenomanian–Turonian boundary (Ocean Drilling Program Site 1138, Kerguelen Plateau)
Despite its assumed global nature, there are very few detailed stratigraphic records of the late Cenomanian to the early Turonian Oceanic Anoxic Event 2 from the Southern Hemisphere. A highly resolved record of environmental changes across the Cenomanian\u2013Turonian boundary interval is presented from Ocean Drilling Program Site 1138 on the central Kerguelen Plateau (southern Indian Ocean). The new data lead to three key observations. Firstly, detailed biostratigraphy and chemostratigraphy indicate that the record of Oceanic Anoxic Event 2 is not complete, with a hiatus spanning the onset of the event. A decrease in glauconite and highly weathered clays after the onset of Oceanic Anoxic Event 2 marks the end of the hiatus interval, which can be explained by a relative sea-level rise that increased sediment accommodation space on the Kerguelen Plateau margin. This change in depositional environment controlled the timing of the delayed peak in organic-matter burial during Oceanic Anoxic Event 2 at Site 1138 compared with other Oceanic Anoxic Event 2 locations worldwide. A second key observation is the presence of cyclic fluctuations in the quantity and composition of organic matter being buried on the central Kerguelen Plateau throughout the latter stages of Oceanic Anoxic Event 2 and the early Turonian. A close correspondence between organic matter, sedimentary elemental compositions and sediments recording sea-floor oxygenation suggests that the cycles were mainly productivity-driven phenomena. Available age-control points constrain the periodicity of the coupled changes in sedimentary parameters to ca 20 to 70 ka, suggesting a link between carbon burial and astronomically forced climatic variations (precession or obliquity) in the Southern Hemisphere mid-latitudes both during, and after, Oceanic Anoxic Event 2: fluctuations that were superimposed on the impact of global-scale processes. Finally, trace-metal data from the black-shale unit at Site 1138 provide the first evidence from outside of the proto-North Atlantic region for a global drawdown of seawater trace-metal (Mo) inventories during Oceanic Anoxic Event 2
First-Principles Anharmonic Infrared and Raman Vibrational Spectra of Materials: Fermi Resonance in Dry Ice
A new displacement-based approach to calculate stress intensity factors with the boundary element method
The analysis of cracked brittle mechanical components considering linear elastic fracture mechanics is usually reduced to the evaluation of stress intensity factors (SIFs). The SIF calculation can be carried out experimentally, theoretically or numerically. Each methodology has its own advantages but the use of numerical methods has be-come very popular. Several schemes for numerical SIF calculations have been developed, the J-integral method being one of the most widely used because of its energy-like formulation. Additionally, some variations of the J-integral method, such as displacement-based methods, are also becoming popular due to their simplicity. In this work, a simple displacement-based scheme is proposed to calculate SIFs, and its performance is compared with contour integrals. These schemes are all implemented with the Boundary Element Method (BEM) in order to exploit its advantages in crack growth modelling. Some simple examples are solved with the BEM and the calculated SIF values are compared against available solutions, showing good agreement between the different schemes
Evaluation of different deoxyribonucleic acid (DNA) extraction methods using dried blood spot for early infant diagnosis of HIV1 in Sub-Saharan Africa
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