474 research outputs found
Magnetic properties of HO2 thin films
We report on the magnetic and transport studies of hafnium oxide thin films
grown by pulsed-laser deposition on sapphire substrates under different oxygen
pressures, ranging from 10-7 to 10-1 mbar. Some physical properties of these
thin films appear to depend on the oxygen pressure during growth: the film
grown at low oxygen pressure (P ~= 10-7 mbar) has a metallic aspect and is
conducting, with a positive Hall signal, while those grown under higher oxygen
pressures (7 x 10-5 <= P <= 0.4 mbar) are insulating. However, no intrinsic
ferromagnetic signal could be attributed to the HfO2 films, irrespective of the
oxygen pressure during the deposition.Comment: 1
Family physician involvement in cancer care follow-up: the experience of a cohort of patients with lung cancer.
PURPOSE There has been little research describing the involvement of family physicians in the follow up of patients with cancer especially during the primary treatment phase We undertook a prospective longitudinal study of patients with lung cancer to assess their family physician s involvement in their follow up at the different phases of cancer
METHODS In 5 hospitals in the province of Quebec Canada patients with a recent diagnosis of lung cancer were surveyed every 3 to 6 months whether they had metastasis or not, for a maximum of 18 months to assess aspects of their family physician s involvement in cancer care
RESULTS Of the 395 participating patients 92% had a regular family physician but only 60% had been referred to a specialist by him/her or a colleague for the diagnosis of their lung cancer A majority of patients identified the oncology team or oncologists as mainly responsible for their cancer care throughout their cancer journey except at the advanced phase where a majority attributed this role to their family physician At baseline only 16% of patients perceived a shared care pattern between their family physician and oncologists but this pro portion increased with cancer progression Most patients would have liked their family physician to be more involved in all aspects of cancer care
CONCLUSIONS Although patients perceive that the oncology team is the main party responsible for the follow up of their lung cancer they also wish their family physicians to be involved Better communication and collaboration between family physicians and the oncology team are needed to facilitate shared care in cancer follow u
Ferromagnetism in the Strong Hybridization Regime of the Periodic Anderson Model
We determine exactly the ground state of the one-dimensional periodic
Anderson model (PAM) in the strong hybridization regime. In this regime, the
low energy sector of the PAM maps into an effective Hamiltonian that has a
ferromagnetic ground state for any electron density between half and three
quarters filling. This rigorous result proves the existence of a new magnetic
state that was excluded in the previous analysis of the mixed valence systems.Comment: Accepted in Phys. Rev.
Oscillator Strengths and Predissociation Rates for Rydberg Transitions in 12C16O, 13C16O, and 13C18O Involving the E 1Pi, B 1Sigma+, and W 1Pi States
One of the processes controlling the interstellar CO abundance and the ratio
of its isotopologues is photodissociation. Accurate oscillator strengths and
predissociation rates for Rydberg transitions are needed for modeling this
process. We present results on absorption from the E ^1Pi-X ^1Sigma^+ (1-0) and
B ^1Sigma^+-X ^1Sigma^+ (6-0) bands at 1051 and 1002 \AA, respectively, and the
vibrational progression W ^1Pi-X ^1Sigma^+ (v'-0) bands with v' = 0 to 3 at
972, 956, 941, and 925 \AA, respectively. The corresponding spectra were
acquired at the high resolution (R ~ 30,000) SU5 beam line at the Super ACO
Synchrotron in Orsay, France. Spectra were obtained for the ^12C^16O, ^13C^16O,
and ^13C^18O isotopologues. These represent the most complete set of
measurements available. Comparison is made with earlier results, both empirical
and theoretical. While earlier determinations of oscillator strengths based on
absorption from synchrotron radiation tend to be somewhat smaller than ours,
the suite of measurements from a variety of techniques agree for the most part
considering the mutual uncertainties. For the bands studied here, their
relative weakness, or their significant line widths arising from
predissociation, minimizes potential problems from large optical depths at line
center in absorption measurements. Predissociating line widths could generally
be extracted from the spectra thanks to the profile simulations used in the
analysis. In many cases, these simulations allowed us to consider e and f
parity levels separately and to determine the dependence of the width on
rotational quantum number, J. Our results are consistent with earlier
determinations, especially the widths inferred from laser experiments
X-ray photodesorption of complex organic molecules in protoplanetary disks -- I. Acetonitrile CH3CN
X-rays emitted from pre-main-sequence stars at the center of protoplanetary
disks can induce nonthermal desorption from interstellar ices populating the
cold regions. This X-ray photodesorption needs to be quantified for complex
organic molecules (COMs), including acetonitrile CH3CN, which has been detected
in several disks. We experimentally estimate the X-ray photodesorption yields
of neutral species from pure CH3CN ices and from interstellar ice analogs for
which CH3CN is mixed either in a CO- or H2O-dominated ice. The ices were
irradiated at 15 K by soft X-rays (400-600 eV) from synchrotron light (SOLEIL
synchrotron). X-ray photodesorption was probed in the gas phase via quadrupole
mass spectrometry. X-ray photodesorption yields were derived from the mass
signals and were extrapolated to higher X-ray energies for astrochemical
models. X-ray photodesorption of the intact CH3CN is detected from pure CH3CN
ices and from mixed 13CO:CH3CN ices, with a yield of about 5x10^(-4)
molecules/photon at 560 eV. When mixed in H2O-dominated ices, X-ray
photodesorption of the intact CH3CN at 560 eV is below its detection limit,
which is 10^(-4) molecules/photon. Yields associated with the desorption of
HCN, CH4 , and CH3 are also provided. The derived astrophysical yields
significantly depend on the local conditions expected in protoplanetary disks.
They vary from 10^(-4) to 10(-6) molecules/photon for the X-ray photodesorption
of intact CH3CN from CO-dominated ices. Only upper limits varying from
5x10^(-5) to 5x10^(-7) molecules/photon could be derived for the X-ray
photodesorption of intact CH3CN from H2O-dominated ices. X-ray photodesorption
of intact CH3CN from interstellar ices might in part explain the abundances of
CH3CN observed in protoplanetary disks. The desorption efficiency is expected
to vary with the local physical conditions, hence with the disk region
Spectrally-resolved UV photodesorption of CH4 in pure and layered ices
Context. Methane is among the main components of the ice mantles of
insterstellar dust grains, where it is at the start of a rich solid-phase
chemical network. Quantification of the photon-induced desorption yield of
these frozen molecules and understanding of the underlying processes is
necessary to accurately model the observations and the chemical evolution of
various regions of the interstellar medium. Aims. This study aims at
experimentally determining absolute photodesorption yields for the CH4 molecule
as a function of photon energy. The influence of the ice composition is also
investigated. By studying the methane desorption from layered CH4:CO ice,
indirect desorption processes triggered by the excitation of the CO molecules
is monitored and quantified. Methods. Tunable monochromatic VUV light from the
DESIRS beamline of the SOLEIL synchrotron is used in the 7 - 13.6 eV (177 - 91
nm) range to irradiate pure CH4 or layers of CH4 deposited on top of CO ice
samples. The release of species in the gas phase is monitored by quadrupole
mass spectrometry and absolute photodesorption yields of intact CH4 are
deduced. Results. CH4 photodesorbs for photon energies higher than ~9.1 eV
(~136 nm). The photodesorption spectrum follows the absorption spectrum of CH4,
which confirms a desorption mechanism mediated by electronic transitions in the
ice. When it is deposited on top of CO, CH4 desorbs between 8 and 9 eV with a
pattern characteristic of CO absorption, indicating desorption induced by
energy transfer from CO molecules. Conclusions. The photodesorption of CH4 from
the pure ice in various interstellar environments is around 2.0 x 10^-3
molecules per incident photon. Results on CO-induced indirect desorption of CH4
provide useful insights for the generalization of this process to other
molecules co-existing with CO in ice mantles
Electronic sculpting of ligand-GPCR subtype selectivity:the case of angiotensin II
GPCR subtypes possess distinct functional
and pharmacological profiles,
and thus development of subtype-selective ligands has immense therapeutic
potential. This is especially the case for the angiotensin receptor
subtypes AT1R and AT2R, where a functional negative control has been
described and AT2R activation highlighted as an important cancer drug
target. We describe a strategy to fine-tune ligand selectivity for
the AT2R/AT1R subtypes through electronic control of ligand aromatic-prolyl
interactions. Through this strategy an AT2R high affinity (<i>K</i><sub>i</sub> = 3 nM) agonist analogue that exerted 18,000-fold
higher selectivity for AT2R versus AT1R was obtained. We show that
this compound is a negative regulator of AT1R signaling since it is
able to inhibit MCF-7 breast carcinoma cellular proliferation in the
low nanomolar range
Oscillator strengths for transitions to Rydberg levels in , and between 967 and 972 A
Absorption oscillator strengths have been determined from high-resolution
spectra in the 967-972 \AA region of three CO isotopomers for transitions to
the Rydberg levels 4{\it p}(0), 3{\it d}(1) and 4{\it p}(0),
as well as to the mixed {\it E(6)} level recently characterized by Eidelsberg
et al. (2004). Synchrotron radiation from the Super-ACO electron storage ring
at Orsay (LURE) was used as a light source. Oscillator strengths were extracted
from the recorded spectra by least-squares fitting of the experimental profiles
with synthetic spectra taking into account the homogeneous and heterogeneous
interactions of the four levels. Column densities were derived from fits to the
3{\it p}(0) absorption band whose oscillator strength is well established.
These are the first reported measurements for CO. For
CO, our results are consistent with the larger values obtained in
the most recent laboratory and astronomical studies.Comment: 9 pages 7 figures 3 tables. Accepted in A&A, date of acceptance
11/05/200
Group 3 ITI Consensus Report: Patient-reported outcome measures associated with implant dentistry
Objectives: The aim of Working Group 3 was to focus on three topics that were assessed using patient-reported outcome measures (PROMs). These topics included the following: (a) the aesthetics of tooth and implant-supported fixed dental prostheses focusing on partially edentulous patients, (b) a comparison of fixed and removable implant-retained prostheses for edentulous populations, and (c) immediate versus early/conventional loading of immediately placed implants in partially edentate patients. PROMs include ratings of satisfaction and oral health-related quality of life (QHRQoL), as well as other indicators, that is, pain, general health-related quality of life (e.g., SF-36). Materials and methods: The Consensus Conference Group 3 participants discussed the findings of the three systematic review manuscripts. Following comprehensive discussions, participants developed consensus statements and recommendations that were then discussed in larger plenary sessions. Following this, any necessary modifications were made and approved. Results: Patients were very satisfied with the aesthetics of implant-supported fixed dental prostheses and the surrounding mucosa. Implant neck design, restorative material, or use of a provisional restoration did not influence patientsâ ratings. Edentulous patients highly rate both removable and fixed implant-supported prostheses. However, they rate their ability to maintain their oral hygiene significantly higher with the removable prosthesis. Both immediate provisionalization and conventional loading receive positive patient-reported outcomes. Conclusions: Patient-reported outcome measures should be gathered in every clinical study in which the outcomes of oral rehabilitation with dental implants are investigated. PROMs, such as patientsâ satisfaction and QHRQoL, should supplement other clinical parameters in our clinical definition of success
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