10,796 research outputs found
Cost effectiveness analysis of laparoscopic hysterectomy compared with standard hysterectomy: results from a randomised trial
Objective: To assess the cost effectiveness of laparoscopic hysterectomy compared with conventional hysterectomy (abdominal or vaginal). Design: Cost effectiveness analysis based on two parallel trials: laparoscopic (n = 324) compared with vaginal hysterectomy (n = 163); and laparoscopic (n = 573) compared with abdominal hysterectomy (n = 286). Participants: 1346 women requiring a hysterectomy for reasons other than malignancy. Main outcome measure: One year costs estimated from NHS perspective. Health outcomes expressed in terms of QALYs based on women's responses to the EQ-5D at baseline and at three points during up to 52 weeks' follow up. Results: Laparoscopic hysterectomy cost an average of pound401 (471789; E380 437). The, probability that laparoscopic hysterectomy is cost effective was below 50% for a large range of values of willingness to pay for an additional QALY. Laparoscopic hysterectomy cost an average of pound186 (46 893; E37 813). If the NHS is willing to pay pound30 0 00 for an additional QALY, the probability that laparoscopic hysterectomy is cost effective is 56%. Conclusions: Laparoscopic hysterectomy is not cost effective relative to vaginal hysterectomy. Its cost effectiveness relative to the abdominal procedure is finely balanced
Critical chain length and superconductivity emergence in oxygen-equalized pairs of YBa2Cu3O6.30
The oxygen-order dependent emergence of superconductivity in YBa2Cu3O6+x is
studied, for the first time in a comparative way, on pair samples having the
same oxygen content and thermal history, but different Cu(1)Ox chain
arrangements deriving from their intercalated and deintercalated nature.
Structural and electronic non-equivalence of pairs samples is detected in the
critical region and found to be related, on microscopic scale, to a different
average chain length, which, on being experimentally determined by nuclear
quadrupole resonance (NQR), sheds new light on the concept of critical chain
length for hole doping efficiency.Comment: 7 RevTex pages, 2 Postscript figures. Submitted to Phys. Rev.
Land planning through GIS, RS and multicriteria decision analysis. A case study in Sardinia
During the last few years researchers and environmental planners have carried
on their preliminary studies following an interdisciplinary approach. One of the
main issues in this approach is the sustainability of economic development. As a
matter of fact, the importance of the studies related to the distribution and the
limits of natural resources is widely recognized. This can be accomplished more
easily than in present by the use of extremely powerful computer application.
The purpose of this contribution is to demonstrate the usefulness of an integrated
approach of the GIS and of the RS to planning in complex problems of decision
making. Many GIS applications are suited to the input of remote sensing and the
integration of these techniques is now accepted in landscape planning. By means
of GIS and RS, environmental information can be integrated with administrative,
political, social and economic data. GIS, RS and fuzzy logic techniques are used
to assist environmental compatibility studies and decision makin
Photophysics of pentacene-doped picene thin films
Here were report a study of picene nano-cristalline thin films doped with
pentacene molecules. The thin films were grown by supersonic molecular beam
deposition with a doping concentration that ranges between less than one
molecules of pentacene every 104 picene molecules up to about one molecule of
pentacene every 102 of picene. Morphology and opto-electronic properties of the
films were studied as a function of the concentration of dopants. The optical
response of the picene films, characterized by absorption, steady-state and
time-resolved photoluminescence measurements, changes dramatically after the
doping with pentacene. An efficient energy transfer from the picene host matrix
to the pentacene guest molecules was observed giving rise to an intense
photoluminescence coming out from pentacene. This efficient mechanism opens the
possibility to exploit applications where the excitonic states of the guest
component, pentacene, are of major interest such as MASER. The observed
mechanism could also serve as prototypical system for the study of the
photophysics of host guest systems based on different phenacenes and acenes.Comment: 15 pages, 6 figure
Macrostructural and Microstructural White Matter Alterations Are Associated with Apathy across the Clinical Alzheimer’s Disease Spectrum
Apathy is the commonest neuropsychiatric symptom in Alzheimer’s disease (AD). Previous findings suggest that apathy is caused by a communication breakdown between functional neural networks involved in motivational–affective processing. This study investigated the relationship between white matter (WM) damage and apathy in AD. Sixty-one patients with apathy (AP-PT) and 61 without apathy (NA-PT) were identified from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database and matched for cognitive status, age and education. Sixty-one cognitively unimpaired (CU) participants were also included as controls. Data on cognitive performance, cerebrospinal fluid biomarkers, brain/WM hyperintensity volumes and diffusion tensor imaging indices were compared across groups. No neurocognitive differences were found between patient groups, but the AP-PT group had more severe neuropsychiatric symptoms. Compared with CU participants, only apathetic patients had deficits on the Clock Drawing Test. AP-PT had increased WM damage, both macrostructurally, i.e., larger WM hyperintensity volume, and microstructurally, i.e., increased radial/axial diffusivity and reduced fractional anisotropy in the fornix, cingulum, anterior thalamic radiations and superior longitudinal and uncinate fasciculi. AP-PT showed signs of extensive WM damage, especially in associative tracts in the frontal lobes, fornix and cingulum. Disruption in structural connectivity might affect crucial functional inter-network communication, resulting in motivational deficits and worse cognitive decline
Inclusion of predatory journals in Scopus is inflating scholars’ metrics and advancing careers
Copper (Cu) interconnect lines are widely used in advanced, high-density integrated circuits (ICs), large-area flat panel displays, and many nano and microelectronic and optoelectronic products. Compared with aluminum (Al), Cu has many advantages, such as the higher conductivity and longer lifetime. However, Cu is difficult to etch into fine lines using the conventional plasma etching method because the reaction product is nonvolatile. Another problem of Cu interconnect lines is that it has poor adhesion to the dielectric film unless an adhesion layer is used. Recently, Kuo’s group solved the etching problem with a novel room-temperature process that consumes the Cu thin film with a plasma reaction and then removes the reaction product with a liquid solution. This method has been used in the fabrication of ICs and TFT LCDs. One of the most critical issues in applying Cu lines in products is the reliability – electromigration (EM) lifetime prediction.
As the IC keeps shrinking, the geometry effect on the lifetime of the thin Cu line is important especially for advanced products. Previously, Kuo’s group had studied temperature and mechanical bending effects on the Cu fine line’s lifetime. Geometry effects on the lifetime of the Al or Al-Cu alloy line have also been discussed before. However, there are few reports on the geometry effect on the Cu fine line prepared by the plasma-based etch process. In this research, the author investigated the relationship between the Cu line width or length and the EM failure time. The change of the line resistance with the stress time has also been studied. The capping layer effect is very important in multi-layer devices. There were some research studies on Cu capping layer before, i.e., Ag layer to protect Cu oxidation and SiN layer as interlayer dielectrics. However, few studies had been done on the TiW capping layer effect on plasma etched Cu lines. In this study, the TiW capping layer effect on lifetime has been studied
Ellipsoidal classification via semidefinite programming
We propose a classification approach exploiting relationships between ellipsoidal separation and Support-vector Machine (SVM) with quadratic kernel. By adding a (Semidefinite Programming) SDP constraint to SVM model we ensure that the chosen hyperplane in feature space represents a non-degenerate ellipsoid in input space. This allows us to exploit SDP techniques within Support-vector Regression (SVR) approaches, yielding better results in case ellipsoid-shaped separators are appropriate for classification tasks. We compare our approach with spherical separation and SVM on some classification problems
Inclusion of predatory journals in Scopus is inflating scholars’ metrics and advancing careers
Epitaxial growth and thermodynamic stability of SrIrO3/SrTiO3 heterostructures
Obtaining high-quality thin films of 5d transition metal oxides is essential
to explore the exotic semimetallic and topological phases predicted to arise
from the combination of strong electron correlations and spin-orbit coupling.
Here, we show that the transport properties of SrIrO3 thin films, grown by
pulsed laser deposition, can be optimized by considering the effect of
laser-induced modification of the SrIrO3 target surface. We further demonstrate
that bare SrIrO3 thin films are subject to degradation in air and are highly
sensitive to lithographic processing. A crystalline SrTiO3 cap layer deposited
in-situ is effective in preserving the film quality, allowing us to measure
metallic transport behavior in films with thicknesses down to 4 unit cells. In
addition, the SrTiO3 encapsulation enables the fabrication of devices such as
Hall bars without altering the film properties, allowing precise
(magneto)transport measurements on micro- and nanoscale devices.Comment: 5 pages, 3 figure
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