214 research outputs found
Tear production, intraocular pressure and conjunctival microbiota, cytology and histology of New Zealand rabbits (Oryctolagus cuniculus)
The purpose of this study was to establish reference values for selected ophthalmic diagnostic tests in New Zealand rabbits (Oryctolagus cuniculus). A total of 22 adult male rabbits were used. The ophthalmic tests included evaluation of tear production with Schirmer tear test 1(STT1) and Endodontic absorbent paper point tear test (EAPPTT) using two different commercial brand materials. Applanation tonometry, Culture of the conjunctival bacterial flora, , conjunctival cytology and conjunctival histology were also performed. Mean (±SD) for STT1, EAPPTTa, EAPPTTb and IOP was 7.27±2.51mm/min, 12.43±1.69mm/min, 15.24±2.07mm/min, 12.89±2.80mm Hg, respectively. Staphylococcus epidermidis, Staphylococcus sp. and Bacillus sp. were predominant. The cytological evaluation revealed the presence columnar epithelial cells, superficial squamous keratinized cells, lymphocytes, heterophils, red blood cells, mucus and bacteria. The histological analysis revealed a stratified epithelium, characterized by the presence of columnar epithelial cells with a large number of goblet cells. The reported data can be used for therapeutic or experimental purposes
EuFeAs under high pressure: an antiferromagnetic bulk superconductor
We report the ac magnetic susceptibility and resistivity
measurements of EuFeAs under high pressure . By observing nearly
100% superconducting shielding and zero resistivity at = 28 kbar, we
establish that -induced superconductivity occurs at ~30 K in
EuFeAs. shows an anomalous nearly linear temperature dependence
from room temperature down to at the same . indicates that
an antiferromagnetic order of Eu moments with ~20 K persists
in the superconducting phase. The temperature dependence of the upper critical
field is also determined.Comment: To appear in J. Phys. Soc. Jpn., Vol. 78 No.
Dalitz plot analysis of the decay B±→K±K±K∓
We analyze the three-body charmless decay B-+/-->(KKK -/+)-K-+/--K-+/- using a sample of 226.0 +/- 2.5 million B (B) over bar pairs collected by the BABAR detector. We measure the total branching fraction and CP asymmetry to be B=(35.2 +/- 0.9 +/- 1.6)x10(-6) and A(CP)=(-1.7 +/- 2.6 +/- 1.5)%. We fit the Dalitz plot distribution using an isobar model and measure the magnitudes and phases of the decay coefficients. We find no evidence of CP violation for the individual components of the isobar model. The decay dynamics is dominated by the K+K- S-wave, for which we perform a partial-wave analysis in the region m(K+K-)< 2 GeV/c(2). Significant production of the f(0)(980) resonance, and of a spin zero state near 1.55 GeV/c(2) are required in the isobar model description of the data. The partial-wave analysis supports this observation.This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF and DFG (Germany), INFN (Italy), FOM (The Netherlands), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from CONACyT (Mexico), Marie Curie EIF (European Union), the A. P. Sloan Foundation, the Research Corporation, and the Alexander von Humboldt Foundation
Measurement of branching fractions and mass spectra of B -> K pi pi gamma (vol 98, art no 211804, 2007)
Adjusting survival time estimates to account for treatment switching in randomised controlled trials – a simulation study
Abstract: Background Treatment switching commonly occurs in clinical trials of novel interventions,
particularly in the advanced or metastatic cancer setting, which causes important problems for health
technology assessment. It is unclear which methods to adjust for switching are most appropriate in
realistic scenarios.
Objectives: We aimed to assess statistical approaches for adjusting survival estimates in the
presence of treatment switching in order to determine which methods are most appropriate in a range
of realistic scenarios.
Methods: We conducted a simulation study to assess the bias, mean squared error and coverage
associated with alternative switching adjustment methods across a wide range of realistic scenarios.
Results Simple methods such as censoring or excluding patients that switch always resulted in high
levels of bias. More complex randomisation-based methods (e.g. Rank Preserving Structural Failure Time Models (RPSFTM)) were unbiased only when the treatment effect was not time-dependent.
Observational-based methods: (e.g. inverse probability of censoring weights (IPCW)) coped better with time-dependent treatment effects but are heavily data reliant, are sensitive to model misspecification and often produced high levels of bias in our simulations, particularly when the proportion of patients that switched treatments was very high (approximately 90%). We introduce a
novel “two stage” method, whereby a specific disease-related time-point is used to define a secondary
baseline after which switching is permitted, allowing treatment effects to be estimated separately for
patients that switch and patients randomised to the experimental group. We find that this method can
perform well provided the treatment switching mechanism is amenable.
Conclusions: Randomisation-based methods can accurately adjust for treatment switching when the treatment effect received by patients that switch is the same as that received by patients randomised to the experimental group. When this is not the case observational-based methods or simple twostage methods should be considered, although the IPCW is prone to substantial bias when the proportion of patients that switch is greater than approximately 90%. Simple methods such as censoring or excluding patients that switch should not be used
As low as is reasonably achievable (ALARA) studies relative to the NWTS program
The history of development of the as-low-as-is-reasonably achievable (ALARA) concept and ALARA criteria for radiation exposures as applied to both off-site (environmental) and on-site (occupational) exposures at nuclear power plants are reviewed. The current status of activities within the various federal agencies directed toward developing ALARA criteria for other areas of the nuclear fuel cycle is presented. Based on the historical development, the present activities, and on discussions with numerous people involved in this area, the future development of ALARA criteria and implications for the National Waste Terminal Storage (NWTS) Program is forecast. Environmental ALARA criteria which relate to minimizing radiation to the surrounding populaltion are discussed along with current occupational ALARA criteria and quidelines for risk-benefit assessments that are under development and recommendations to assure that evolving ALARA concepts are periodically brought up to date and that such concepts be made available to those subcontractors who have responsibility for design and operation of a repository. An annotated bibliography of some 83 sources giving information on ALARA criteria and its application is included. (JRD
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