1,085 research outputs found
An Equivalence Between Secure Network and Index Coding
We extend the equivalence between network coding and index coding by Effros,
El Rouayheb, and Langberg to the secure communication setting in the presence
of an eavesdropper. Specifically, we show that the most general versions of
secure network-coding setup by Chan and Grant and the secure index-coding setup
by Dau, Skachek, and Chee, which also include the randomised encoding setting,
are equivalent
Role of Radiotherapy in Modern Treatment of Hodgkin's Lymphoma
Hodgkin's Lymphoma was incurable until the advent of effective therapeutic radiation around the first half of the 20th century. As survival rates improved, the long-term toxicities from radiotherapy began to emerge. This together with the availability of effective chemotherapy has encouraged a combined modality approach for early-staged disease and the omission of radiotherapy in advanced-staged disease. The differing toxicities of radiotherapy and chemotherapy has promoted ongoing research to identify the utility of each of these modalities in the modern management of Hodgkin's Lymphoma.
This article will provide a critical review of the developments and indications for modern radiotherapy, in context with advances in chemotherapy, for the treatment of Hodgkin's Lymphoma
Growth rate of YBCO single grains containing Y-2411(M)
Y-Ba-Cu-O (YBCO) single grains have the potential to generate large trapped magnetic fields for a variety of engineering applications, and research on the processing and properties of this material has attracted world-wide interest. In particular, the introduction of flux pinning centres to the large grain microstructure to improve its current density, Jc, and hence trapped field, has been investigated extensively over the past decade. Y 2Ba4CuMOx [Y-2411(M)], where M = Nb, Ta, Mo, W, Ru, Zr, Bi and Ag, has been reported to form particularly effective flux pinning centres in YBCO due primarily to its ability to exist as nano-size inclusions in the superconducting phase matrix. However, the addition of the Y-2411(M) phase to the precursor composition complicates the melt-processing of single grains. We report an investigation of the growth rate of single YBCO grains containing Y-2411(Bi) phase inclusions and Y2O3. The superconducting properties of these large single grains have been measured specifically to investigate the effect of Y2O3 on broadening the growth window of these materials
Computational Fluid Dynamic Analysis of a Vibrating Turbine Blade
This study presents the numerical fluid-structure interaction (FSI) modelling of a vibrating turbine blade using the commercial software ANSYS-12.1. The study has two major aims: (i) discussion of the current state of the art of modelling FSI in gas turbine engines and (ii) development of a “tuned” one-way FSI model of a vibrating turbine blade to investigate the correlation between the pressure at the turbine casing surface and the vibrating blade motion. Firstly, the feasibility of the complete FSI coupled two-way, three-dimensional modelling of a turbine blade undergoing vibration using current commercial software is discussed. Various modelling simplifications, which reduce the full coupling between the fluid and structural domains, are then presented. The one-way FSI model of the vibrating turbine blade is introduced, which has the computational efficiency of a moving boundary CFD model. This one-way FSI model includes the corrected motion of the vibrating turbine blade under given engine flow conditions. This one-way FSI model is used to interrogate the pressure around a vibrating gas turbine blade. The results obtained show that the pressure distribution at the casing surface does not differ significantly, in its general form, from the pressure at the vibrating rotor blade tip
Bone marrow cells play only a very minor role in chronic liver regeneration induced by a choline-deficient, ethionine-supplemented diet
AbstractLiver progenitor (oval) cells have enormous potential in the treatment of patients with liver disease using a cell therapy approach, but their use is limited by their scarcity and the number of donor livers from which they can be derived. Bone marrow may be a suitable source. Previously the derivation of oval cells from bone marrow was examined in rodents using hepatotoxins and partial hepatectomy to create liver damage. These protocols induce oval cell proliferation; however, they do not produce the disease conditions that occur in humans. In this study we have used the choline-deficient, ethionine-supplemented (CDE) diet (which causes fatty liver) and viral hepatitis as models of chronic injury to evaluate the contribution of bone marrow cells to oval cells under conditions that closely mimic human liver disease pathophysiology. Following transplantation of lacZ-transgenic bone marrow cells into congenic mice, liver injury was induced and the movement of bone marrow cells to the liver monitored. Bone marrow-derived oval cells were observed in response to the CDE diet and viral injury but represented a minor fraction (0–1.6%) of the oval cell compartment, regardless of injury severity. In all situations only rare, individual bone marrow-derived oval cells were observed. We hypothesized that the bone marrow cells may replenish oval cells that are expended by protracted liver injury and regeneration; however, experiments involving a subsequent episode of chronic liver injury failed to induce proliferation of the bone marrow-derived oval cells that appeared as a result of the first episode. Bone marrow-derived hepatocytes were also observed in all injury models and controls at a frequency unrelated to that of oval cells. We conclude that during viral-and steatosis-induced liver disease the contribution of bone marrow cells to hepatocytes, either via oval cells or by independent mechanisms, is minimal and that the majority of oval cells responding to this injury are sourced from the liver
Low disordered, stable, and shallow germanium quantum wells: a playground for spin and hybrid quantum technology
Buried-channel semiconductor heterostructures are an archetype material
platform to fabricate gated semiconductor quantum devices. Sharp confinement
potential is obtained by positioning the channel near the surface, however
nearby surface states degrade the electrical properties of the starting
material. In this paper we demonstrate a two-dimensional hole gas of high
mobility ( cm/Vs) in a very shallow strained germanium
channel, which is located only 22 nm below the surface. This high mobility
leads to mean free paths , setting new benchmarks for holes in
shallow FET devices. Carriers are confined in an undoped Ge/SiGe
heterostructure with reduced background contamination, sharp interfaces, and
high uniformity. The top-gate of a dopant-less field effect transistor controls
the carrier density in the channel. The high mobility, along with a percolation
density of , light effective mass (0.09
m), and high g-factor (up to ) highlight the potential of undoped
Ge/SiGe as a low-disorder material platform for hybrid quantum technologies
Influence of carbon on intraband scattering in Mg(B1-xCx)2
We report data on the Hall coefficient (RH) of the carbon substituted
Mg(B1-xCx)2 single crystals with x in the range from 0 to 0.1. The temperature
dependences of RH obtained for the substituted crystals differ systematically
at low temperatures, but all of them converge to the value of 1.8 x 10^-10
m^3/C at room temperature. The RH(T) data together with results of the
thermoelectric power and electrical resistivity measurements are interpreted
within a quasi-classical transport approach, where the presence of four
different conducting sheets is considered. The main influence of the carbon
substitution on the transport properties in the normal state is associated with
enhanced scattering rates, rather than modified concentration of charge
carriers. Presumably the carbon substitution increases the electron-impurity
scattering mainly in the pi band.Comment: 16 pages, 3 figure
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