5,691 research outputs found
Accounting for established predictors with the multistep elastic net
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151898/1/sim8313.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151898/2/sim8313_am.pd
Liposome-based drug delivery in breast cancer treatment
Drug delivery systems can in principle provide enhanced efficacy and/or reduced toxicity for anticancer agents. Long circulating macromolecular carriers such as liposomes can exploit the 'enhanced permeability and retention' effect for preferential extravasation from tumor vessels. Liposomal anthracyclines have achieved highly efficient drug encapsulation, resulting in significant anticancer activity with reduced cardiotoxicity, and include versions with greatly prolonged circulation such as liposomal daunorubicin and pegylated liposomal doxorubicin. Pegylated liposomal doxorubucin has shown substantial efficacy in breast cancer treatment both as monotherapy and in combination with other chemotherapeutics. Additional liposome constructs are being developed for the delivery of other drugs. The next generation of delivery systems will include true molecular targeting; immunoliposomes and other ligand-directed constructs represent an integration of biological components capable of tumor recognition with delivery technologies
6D supergravity without tensor multiplets
We systematically investigate the finite set of possible gauge groups and
matter content for N = 1 supergravity theories in six dimensions with no tensor
multiplets, focusing on nonabelian gauge groups which are a product of SU(N)
factors. We identify a number of models which obey all known low-energy
consistency conditions, but which have no known string theory realization. Many
of these models contain novel matter representations, suggesting possible new
string theory constructions. Many of the most exotic matter structures arise in
models which precisely saturate the gravitational anomaly bound on the number
of hypermultiplets. Such models have a rigid symmetry structure, in the sense
that there are no moduli which leave the full gauge group unbroken.Comment: 31 pages, latex; v2, v3: minor corrections, references adde
HFE H63D Polymorphism as a Modifier of the Effect of Cumulative Lead Exposure on Pulse Pressure: The Normative Aging Study
Background: Cumulative lead exposure is associated with a widened pulse pressure (PP; the difference between systolic and diastolic blood pressure), a marker of arterial stiffness and a predictor of cardiovascular disease. Polymorphisms in the hemochromatosis gene (HFE) have been shown to modify the impact of cumulative lead exposure on measures of adult cognition and cardiac function. Objectives: We examined whether the HFE mutations modify the impact of lead on PP in community-dwelling older men. Methods: We examined 619 participants with a total of 1,148 observations of PP from a substudy of bone lead levels (a measure of cumulative exposure, measured by in vivo K-shell X-ray fluorescence) and health in the Normative Aging Study between 1991 and 2001. Linear mixed-effects regression models with random intercepts were constructed. Results: Of the 619 subjects, 138 and 72 carried the HFE H63D and C282Y variants, respectively. After adjusting for age; education; alcohol intake; smoking; daily intakes of calcium, sodium, and potassium; total calories; family history of hypertension; diabetes; height; heart rate; high-density lipoprotein (HDL); total cholesterol:HDL ratio; and waist circumference, baseline bone lead levels were associated with steeper increases in PP in men with at least one H63D allele (p-interaction = 0.03 for tibia and 0.02 for patella) compared with men with only the wild types or C282Y variant. Conclusions: The HFE H63D polymorphism, but not the C282Y mutation, appears to enhance susceptibility to the deleterious impact of cumulative lead on PP, possibly via prooxidative or pro-inflammatory mechanisms
Partonic description of a supersymmetric p-brane
We consider supersymmetric extensions of a recently proposed partonic
description of a bosonic p-brane which reformulates the Nambu-Goto action as an
interacting multi-particle action with Filippov-Lie algebra gauge symmetry. We
construct a worldline supersymmetric action by postulating, among others, a
p-form fermion. Demanding a local worldline supersymmetry rather than the full
worldvolume supersymmetry, we circumvent a known no-go theorem against the
construction of a Ramond-Neveu-Schwarz supersymmetric action for a p-brane of
p>1. We also derive a spacetime supersymmetric Green-Schwarz extension from the
preexisting kappa-symmetric action.Comment: 1+16 pages, no figure; References added and Concluding section
expanded. Final version to appear in JHE
Worldvolume Superalgebra Of BLG Theory With Nambu-Poisson Structure
Recently it was proposed that the Bagger-Lambert-Gustavsson theory with
Nambu-Poisson structure describes an M5-brane in a three-form flux background.
In this paper we investigate the superalgebra associated with this theory. We
derive the central charges corresponding to M5-brane solitons in 3-form
backgrounds. We also show that double dimensional reduction of the superalgebra
gives rise to the Poisson bracket terms of a non-commutative D4-brane
superalgebra. We provide interpretations of the D4-brane charges in terms of
spacetime intersections.Comment: 23 pages; references added, section 4 clarification
Zigzag-shaped nickel nanowires via organometallic template-free route
In this manuscript, the formation of nickel nanowires (average size: several tens to hundreds of μm long
and 1.0-1.5 μm wide) at low temperature is found to be driven by dewetting of liquid organometallic
precursors during spin coating process and by self-assembly of Ni clusters. Elaboration of metallic thin
films by low temperature deposition technique makes the preparation process compatible with most of the
substrates. The use of iron and cobalt precursor shows that the process could be extended to other metallic
systems. In this work, AFM and SEM are used to follow the assembly of Ni clusters into straight or
zigzag lines. The formation of zigzag structure is specific to the Ni precursor at appropriate preparation
parameters. This template free process allows a control of anisotropic structures with homogeneous sizes
and angles on standard Si/SiO2 surface
Off-shell superconformal nonlinear sigma-models in three dimensions
We develop superspace techniques to construct general off-shell N=1,2,3,4
superconformal sigma-models in three space-time dimensions. The most general
N=3 and N=4 superconformal sigma-models are constructed in terms of N=2 chiral
superfields. Several superspace proofs of the folklore statement that N=3
supersymmetry implies N=4 are presented both in the on-shell and off-shell
settings. We also elaborate on (super)twistor realisations for (super)manifolds
on which the three-dimensional N-extended superconformal groups act
transitively and which include Minkowski space as a subspace.Comment: 67 pages; V2: typos corrected, one reference added, version to appear
on JHE
Stability of Mine Car Motion in Curves of Invariable and Variable Radii
We discuss our experiences adapting three recent algorithms for maximum common (connected) subgraph problems to exploit multi-core parallelism. These algorithms do not easily lend themselves to parallel search, as the search trees are extremely irregular, making balanced work distribution hard, and runtimes are very sensitive to value-ordering heuristic behaviour. Nonetheless, our results show that each algorithm can be parallelised successfully, with the threaded algorithms we create being clearly better than the sequential ones. We then look in more detail at the results, and discuss how speedups should be measured for this kind of algorithm. Because of the difficulty in quantifying an average speedup when so-called anomalous speedups (superlinear and sublinear) are common, we propose a new measure called aggregate speedup
F-theory on Genus-One Fibrations
We argue that M-theory compactified on an arbitrary genus-one fibration, that
is, an elliptic fibration which need not have a section, always has an F-theory
limit when the area of the genus-one fiber approaches zero. Such genus-one
fibrations can be easily constructed as toric hypersurfaces, and various
and models are presented as examples. To each
genus-one fibration one can associate a -function on the base as well as
an representation which together define the IIB axio-dilaton
and 7-brane content of the theory. The set of genus-one fibrations with the
same -function and representation, known as the
Tate-Shafarevich group, supplies an important degree of freedom in the
corresponding F-theory model which has not been studied carefully until now.
Six-dimensional anomaly cancellation as well as Witten's zero-mode count on
wrapped branes both imply corrections to the usual F-theory dictionary for some
of these models. In particular, neutral hypermultiplets which are localized at
codimension-two fibers can arise. (All previous known examples of localized
hypermultiplets were charged under the gauge group of the theory.) Finally, in
the absence of a section some novel monodromies of Kodaira fibers are allowed
which lead to new breaking patterns of non-Abelian gauge groups.Comment: 53 pages, 9 figures, 6 tables. v2: references adde
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