44,536 research outputs found
Kidney transplantation. Modern trends in kidney transplantation.
Trends in renal transplantation stem from recognition of the virtues and drawbacks of this kind of treatment and from a better appreciation of the interrelationship between transplantation and dialysis
Inlet protein aggregation: a new mechanism for lubricating film formation with model synovial fluids.
This paper reports a fundamental study of lubricant film formation with model synovial fluid components (proteins) and bovine serum (BS). The objective was to investigate the role of proteins in the lubrication process. Film thickness was measured by optical interferometry in a ball-on-disc device (mean speed range of 2-60 mm/s). A commercial cobalt-chromium (CoCrMo) metal femoral head was used as the stationary component. The results for BS showed complex time-dependent behaviour, which was not representative of a simple fluid. After a few minutes sliding BS formed a thin adherent film of 10-20 nm, which was attributed to protein absorbance at the surface. This layer was augmented by a hydrodynamic film, which often increased at slow speeds. At the end of the test deposited surface layers of 20-50 nm were measured. Imaging of the contact showed that at slow speeds an apparent 'phase boundary' formed in the inlet just in front of the Hertzian zone. This was associated with the formation of a reservoir of high-viscosity material that periodically moved through the contact forming a much thicker film. The study shows that proteins play an important role in the film-forming process and current lubrication models do not capture these mechanisms
Towards Efficient Full Pose Omnidirectionality with Overactuated MAVs
Omnidirectional MAVs are a growing field, with demonstrated advantages for
aerial interaction and uninhibited observation. While systems with complete
pose omnidirectionality and high hover efficiency have been developed
independently, a robust system that combines the two has not been demonstrated
to date. This paper presents VoliroX: a novel omnidirectional vehicle that can
exert a wrench in any orientation while maintaining efficient flight
configurations. The system design is presented, and a 6 DOF geometric control
that is robust to singularities. Flight experiments further demonstrate and
verify its capabilities.Comment: 10 pages, 6 figures, ISER 2018 conference submissio
Liver Transplantation for Budd-Chiari Syndrome
Orthotopic liver transplantation was accomplished in a 22-year-old woman dying of the Budd-Chiari syndrome. She is well and has normal liver function 16 months postoperatively. In view of the good early result, it will be appropriate to consider liver replacement for this disease in further well-selected cases. © 1976, American Medical Association. All rights reserved
Right trisegmentectomy for hepatic neoplasms
Thirty patients had right trisegmentectomy for 19 primary hepatic malignant tumors, 7 localized liver metastases and four benign lesions. A technical refinement that aided resection of bulky posterior and superior tumors was intrahepatic identification and control of the right hepatic vein. The operative mortality was 3.3%. Late hepatic insufficiency was not observed. More than one-half of the patients operated upon a year or more ago for primary hepatic malignant growths had a tumor-free state at the 12 month follow-up period. Beyond this time, there was only one recurrence. The results in children were twice as good as in adults. The results in treating localized liver metastases from distant primary sites were inferior to those in treating primary hepatic tumors. A hypothetical case was made for combining hepatic resection with adjuvant chemotherapy, even though our experience could not be construed as direct support for this practice
A Segmentation of Mall Shopping Motivations in the South African Gauteng Provincial Context
Consumer markets, globally, exhibit increasing diversity. Shopping malls that do not take cognisance of this diversity, along all appropriate dimensions, can lose market share to competitors that do. Despite extensive literature that is based on research done in other countries, absent from the South African literature is a current typology of market segmentation of mall consumers by mall shopping motivations. Using a sample of 224 mall consumers drawn from Gauteng, the economic hub of the country, k-means segmentation was used to test theory that relates different characteristics of consumers and their mall choices. On the basis of this analysis, a typology of shopping mall consumers is developed according to their preferences, or motivations, for mall shopping. Six different segments were found to be associated with different mall shopping preferences and other characteristics. These segments were classified as ‘Low Engagement Shoppers’; ‘Mean Oriented Shoppers’; ‘Brand Oriented Shoppers’; ‘Utilitarian Oriented Shoppers’ and ‘Ascetic Oriented Shoppers’. It is argued that knowledge of such typologies may be important in the South African context due to the increasing societal diversity that malls need to be able to take advantage of in an increasingly competitive environment.KIM201
Non-global Structure of the O({\alpha}_s^2) Dijet Soft Function
High energy scattering processes involving jets generically involve matrix
elements of light- like Wilson lines, known as soft functions. These describe
the structure of soft contributions to observables and encode color and
kinematic correlations between jets. We compute the dijet soft function to
O({\alpha}_s^2) as a function of the two jet invariant masses, focusing on
terms not determined by its renormalization group evolution that have a
non-separable dependence on these masses. Our results include non-global single
and double logarithms, and analytic results for the full set of non-logarithmic
contributions as well. Using a recent result for the thrust constant, we
present the complete O({\alpha}_s^2) soft function for dijet production in both
position and momentum space.Comment: 55 pages, 8 figures. v2: extended discussion of double logs in the
hard regime. v3: minor typos corrected, version published in JHEP. v4: typos
in Eq. (3.33), (3.39), (3.43) corrected; this does not affect the main
result, numerical results, or conclusion
Thermodynamic of Distorted Reissner-Nordstr\"om Black Holes in Five-dimensions
In this paper, we study mechanics and thermodynamics of distorted,
five-dimensional, electrically charged (non-extremal) black holes on the
example of a static and "axisymmetric" black hole distorted by external,
electrically neutral matter. Such a black hole is represented by the derived
here solution of the Einstein-Maxwell equations which admits an
isometry group. We study the properties of
this distorted black hole.Comment: 7 pages, submitted for the proceedings of the First Karl
Schwarzschild Meeting (Frankfurt, 2013
- …