6,640 research outputs found
Heterotopic heart transplantation in the rat receiving FK-506 alone or with cyclosporine.
In rats, FK significantly prolonged heterotopic heart graft survival over a wide dose range when given for 2 weeks starting on the day of the operation. Brief courses of FK for one to four days preoperatively, and especially beginning four days postoperatively, allowed long subsequent survival of heart grafts in otherwise untreated recipients. The seeming acceptance of the grafts with postoperative FK treatment was largely but not exclusively donor specific when tested eight days after the last FK dose by second grafts from the same donor v third-party donor grafts. FK in minimally therapeutic doses was synergistic with suboptimal doses of CyA
The fate of steroid estrogens: Partitioning during wastewater treatment and onto river sediments
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 Springer Science+Business Media B.V.The partitioning of steroid estrogens in wastewater treatment and receiving waters is likely to influence their discharge to, and persistence in, the environment. This study investigated the partitioning behaviour of steroid estrogens in both laboratory and field studies. Partitioning onto activated sludge from laboratory-scale Husmann units was rapid with equilibrium achieved after 1 h. Sorption isotherms and Kd values decreased in the order 17α-ethinyl estradiol > 17α-estradiol > estrone > estriol without a sorption limit being achieved (1/n >1). Samples from a wastewater treatment works indicated no accumulation of steroid estrogens in solids from primary or secondary biological treatment, however, a range of steroid estrogens were identified in sediment samples from the River Thames. This would indicate that partitioning in the environment may play a role in the long-term fate of estrogens, with an indication that they will be recalcitrant in anaerobic conditions.EPSR
Direct J/psi and psi' hadroproduction via fragmentation in the collinear parton model and k_T-factorization approach
The p_T-spectra for direct J/psi and psi' in hadroproduction at Tevatron
energy have been calculated based on NRQCD formalism and fragmentation
approximation in the collinear parton model and k_T-factorization approach. We
have described the CDF data and obtained a good agreement between the
predictions obtained in the parton model and k_T-factorization approach. We
performed the calculations using the relevant leading order in alpha_s hard
amplitudes and the equal values of the color-octet long-distance matrix
elements for the both models.Comment: 10 pages, Latex, 4 eps figures, epsfig.sty, graphics.st
Explaining the t tbar forward-backward asymmetry without dijet or flavor anomalies
We consider new physics explanations of the anomaly in the top quark
forward-backward asymmetry measured at the Tevatron, in the context of flavor
conserving models. The recently measured LHC dijet distributions strongly
constrain many otherwise viable models. A new scalar particle in the
antitriplet representation of flavor and color can fit the t tbar asymmetry and
cross section data at the Tevatron and avoid both low- and high-energy bounds
from flavor physics and the LHC. An s-channel resonance in uc to uc scattering
at the LHC is predicted to be not far from the current sensitivity. This model
also predicts rich top quark physics for the early LHC from decays of the new
scalar particles. Single production gives t tbar j signatures with high
transverse momentum jet, pair production leads to t tbar j j and 4 jet final
states.Comment: 7 pages, 6 figures; v2: notation clarified, references adde
Moments of Nucleon Generalized Parton Distributions in Lattice QCD
Calculation of moments of generalized parton distributions in lattice QCD
requires more powerful techniques than those previously used to calculate
moments of structure functions. Hence, we present a novel approach that
exploits the full information content from a given lattice configuration by
measuring an overdetermined set of lattice observables to provide maximal
statistical constraints on the generalized form factors at a given virtuality,
t. In an exploratory investigation using unquenched QCD configurations at
intermediate sea quark masses, we demonstrate that our new technique is
superior to conventional methods and leads to reliable numerical signals for
the n=2 flavor singlet generalized form factors up to 3 GeV^2. The contribution
from connected diagrams in the flavor singlet sector to the total quark angular
momentum is measured to an accuracy of the order of one percent.Comment: 16 pages, 8 figures, LaTeX, minor elaboration of formalism and
singular value decomposition for non-specialists and addition of several
reference
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Laboratory model tests on drag and dynamically embedded plate anchors in layered clay profiles
Layered soil profiles can complicate the ability to install a foundation and affect the performance of a foundation and therefore increase the cost of an offshore foundation. The goal of this research is to explore concepts to improve anchor performance in layered soil profiles of clay by further understanding (1) the drag trajectory and capacity for a drag embedded plate anchor in layered soil profiles; (2) the drag trajectory and capacity of tandem drag embedded plate anchor systems; and (3) the free-fall penetration trajectory and resistance of a dynamically embedded plate anchor in layered soil profiles. The methodology is to perform drag embedment and free-fall penetration tests with model anchors in a variety of test beds containing marine clays with different profiles of undrained shear strength versus depth.
For a drag embedment anchor, model tests with a single anchor in different sizes show that the ratio of normal to tangential displacement is affected by model scale, with smaller ratios applying to larger anchors. By appropriately adjusting this factor in a prediction model, the model is able to represent well the model test results and can be used rationally to predict behavior for a field-scale anchor. The drag embedment tests and analytical results in layered soil profile show that anchor can penetrate into stiff layer with shear strength 1.5 times higher than the surrounding soil and cannot penetrate into stiff layer with shear strength 5 times higher than the surrounding soil. In the layered soil profile with stiff layer of shear strength 2 to 4 times higher than the surrounding soil, the anchor may be able to penetrate the stiff layer if the pitch of the fluke as it approaches the layer is at about 30°.
For a tandem system with two drag embedded anchors, the capacity of the system can be more than twice the capacity of a single anchor provided that the spacing between two anchors is at least two fluke lengths. The second anchor in the tandem system can penetrate deeper than a single anchor and the front anchor.
For a dynamically embedded plate anchor, the strain rate effect from undrained shearing is higher than that from bearing as measured from pure normal and pure in-plane shearing tests. A calibrated predication model accounting for the strain-rate effects strain rate parameters produces results similar to the model test results, generally matching or slightly under-predicting the actual penetration in non-layered and layered soil profiles. A dynamically embedded plate anchor can penetrate through stiff layers that would cause difficulty for a conventional drag embedded anchor.Civil, Architectural, and Environmental Engineerin
Functional role of ICAM-3 polymorphism in genetic susceptibility to SARS infection.
Key Messages 1. Severe acute respiratory syndrome (SARS) patients who are homozygous for intercellular adhesion molecule-3 (ICAM-3) Gly143 showed significant association with higher lactate dehydrogenase levels and lower total white blood cell counts on admission. 2. In vitro functional studies demonstrated low level binding of ICAM-3 to DC-SIGN and a wide variation in T-cell response of the wild-type ICAM-3 genotype.published_or_final_versio
Association of a single nucleotide polymorphism in the CD209 (DC-SIGN) promoter with SARS severity.
published_or_final_versio
Searching for Exoplanets Using a Microresonator Astrocomb
Detection of weak radial velocity shifts of host stars induced by orbiting
planets is an important technique for discovering and characterizing planets
beyond our solar system. Optical frequency combs enable calibration of stellar
radial velocity shifts at levels required for detection of Earth analogs. A new
chip-based device, the Kerr soliton microcomb, has properties ideal for
ubiquitous application outside the lab and even in future space-borne
instruments. Moreover, microcomb spectra are ideally suited for astronomical
spectrograph calibration and eliminate filtering steps required by conventional
mode-locked-laser frequency combs. Here, for the calibration of astronomical
spectrographs, we demonstrate an atomic/molecular line-referenced,
near-infrared soliton microcomb. Efforts to search for the known exoplanet HD
187123b were conducted at the Keck-II telescope as a first in-the-field
demonstration of microcombs
Evidence for Colour-Octet Mechanism from CERN LEP2 gamma gamma -> J/psi + X Data
We present theoretical predictions for the transverse-momentum distribution
of J/psi mesons promptly produced in gamma gamma collisions within the
factorization formalism of nonrelativistic quantum chromodynamics, including
the contributions from both direct and resolved photons, and we perform a
conservative error analysis. The fraction of J/psi mesons from decays of
bottom-flavoured hadrons is estimated to be negligibly small. New data taken by
the DELPHI Collaboration at LEP2 nicely confirm these predictions, while they
disfavour those obtained within the traditional colour-singlet model.Comment: 11 pages (Latex), 3 figures (Postscript); updated experimental data
included, references added, accepted for publication in Phys. Rev. Let
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