602 research outputs found
Health economics of blood transfusion safety - focus on sub-Saharan Africa
Background and objectives. Health economics provides a standardised methodology for valid comparisons of interventions in different fields of health care. This review discusses the health economic evaluations of strategies to enhance blood product safety in sub-Saharan Africa Methods. We reviewed health economic methodology with special reference to cost-effectiveness analysis We searched the literature for cost-effectiveness in blood product safety in sub-Saharan Africa. Result HIV-antibody screening in different settings in sub-Saharan Africa showed health gains and saved costs Except for adding HIV-p24 screening, adding other tests such as nucleic acid amplification testing (NAT) to HIV-antibody screening displayed incremental cost-effectiveness ratios greater than the WHO/World Bank specified threshold for cost-effectiveness. The addition of HIV-p24 in combination with HCV antibody/antigen screening and multiplex (HBV, HCV and HIV) NAT in pools of 24 may also be cost-effective options for Ghana Conclusions From a health economic viewpoint. HIV-antibody screening should always be implemented in sub-Saharan Africa. The addition of HIV-p24 antigen screening, in combination with HCV antibody/antigen screening and multiplex (HBV. HCV and HIV) NAT in pools of 24 may be feasible options for Ghana. Suggestions for future health economic evaluations of blood transfusion safety interventions in sub-Saharan Africa are mis-transfusion, laboratory quality and donor management.(C) 2009 The International Association for Biologicals Published by Elsevier Ltd. All rights reserved
Supernova Simulations with Boltzmann Neutrino Transport: A Comparison of Methods
Accurate neutrino transport has been built into spherically symmetric
simulations of stellar core collapse and postbounce evolution. The results of
such simulations agree that spherically symmetric models with standard
microphysical input fail to explode by the delayed, neutrino-driven mechanism.
Independent groups implemented fundamentally different numerical methods to
tackle the Boltzmann neutrino transport equation. Here we present a direct and
detailed comparison of such neutrino radiation-hydrodynamical simulations for
two codes, Agile-Boltztran of the Oak Ridge-Basel group and Vertex of the
Garching group. The former solves the Boltzmann equation directly by an
implicit, general relativistic discrete angle method on the adaptive grid of a
conservative implicit hydrodynamics code with second-order TVD advection. In
contrast, the latter couples a variable Eddington factor technique with an
explicit, moving-grid, conservative high-order Riemann solver with important
relativistic effects treated by an effective gravitational potential. The
presented study is meant to test both neutrino radiation-hydrodynamics
implementations and to provide a data basis for comparisons and verifications
of supernova codes to be developed in the future. Results are discussed for
simulations of the core collapse and post-bounce evolution of a 13 solar mass
star with Newtonian gravity and a 15 solar mass star with relativistic gravity.Comment: 23 pages, 13 figures, revised version, to appear in Ap
Poor economics - Transforming challenges in transfusion medicine and science into opportunities
The prospect of cryopreservation of cellular components in the low and medium income (poor economics) part of the world absolutely needs a solid and sustainable infrastructure to build on in line with science, technology and globalization, based on rational thinking, standardization and harmonization of future advances we are currently witnessing in limited parts of the world. With the stepwise development of the healthcare stimulated by the 2012 UN Universal Health Coverage (UHC) program and supported by WHO Model List of Essential Medicines (EM) and Essential in vitro Diagnostics (ED), a slowly growing number of countries will reach a point where quality cryopreservation of cellular components becomes feasible as an advance for implementing specific health care visions, policies and strategies in line with the Sustainable Development Goals 2016-2030
Posterior lumbar interbody fusion using non resorbable poly-ether-ether-ketone versus resorbable poly-l-lactide-co-d,l-lactide fusion devices. Clinical outcome at a minimum of 2-year follow-up
Previous papers on resorbable poly-l-lactide-co-d,l-lactide (PLDLLA) cages in spinal fusion have failed to report adequately on patient-centred clinical outcome measures. Also comparison of PLDLLA cage with a traditionally applicable counterpart has not been previously reported. This is the first randomized prospective study that assesses clinical outcome of PLDLLA cage compared with a poly-ether-ether-ketone (PEEK) implant. Twenty-six patients were randomly assigned to undergo instrumented posterior lumbar interbody fusion (PLIF) whereby either a PEEK cage or a PLDLLA cage was implanted. Clinical outcome based on visual analogue scale scores for leg pain and back pain, as well as Oswestry Disability Index (ODI) and SF-36 questionnaires were documented and analysed. When compared with preoperative values, all clinical parameters have significantly improved in the PEEK group at 2Â years after surgery with the exception of SF-36 general health, SF-36 mental health and SF-36 role emotional scores. No clinical parameter showed significant improvement at 2Â years after surgery compared with preoperative values in the PLDLLA patient group. Only six patients (50%) in the PLDLLA group showed improvement in the VAS scores for leg and back pain as well as the ODI, as opposed to 10 patients (71%) in the PEEK group. One-third of the patients in the PLDLLA group actually reported worsening of their pain scores and ODI. Three cases of mild to moderate osteolysis were seen in the PLDLLA group. Following up on our preliminary report, these 2-year results confirm the superiority of the PEEK implant to the resorbable PLDLLA implant in aiding spinal fusion and alleviating symptoms following PLIF in patients with degenerative spondylolisthesis associated with either canal stenosis or foramen stenosis or both and emanating from a single lumbar segment
Instanton dominance of topological charge fluctuations in QCD?
We consider the local chirality of near-zero eigenvectors from Wilson-Dirac
and clover improved Wilson-Dirac lattice operators as proposed recently by
Horv\'ath et al. We studied finer lattices and repaired for the loss of
orthogonality due to the non-normality of the Wilson-Dirac matrix. As a result
we do see a clear double peak structure on lattices with resolutions higher
than 0.1 fm. We found that the lattice artifacts can be considerably reduced by
exploiting the biorthogonal system of left and right eigenvectors. We conclude
that the dominance of instantons on topological charge fluctuations is not
ruled out by local chirality measurements.Comment: 10 pages, 6 figure
Scanning the Topological Sectors of the QCD Vacuum with Hybrid Monte Carlo
We address a long standing issue and determine the decorrelation efficiency
of the Hybrid Monte Carlo algorithm (HMC), for full QCD with Wilson fermions,
with respect to vacuum topology. On the basis of five state-of-the art QCD
vacuum field ensembles (with 3000 to 5000 trajectories each and
m_pi/m_rho-ratios in the regime >0.56, for two sea quark flavours) we are able
to establish, for the first time, that HMC provides sufficient tunneling
between the different topological sectors of QCD. This will have an important
bearing on the prospect to determine, by lattice techniques, the topological
susceptibility of the vacuum, and topology sensitive quantities like the spin
content of the proton, or the eta' mass.Comment: 5 pages, 4 eps-figure
Decorrelating Topology with HMC
The investigation of the decorrelation efficiency of the HMC algorithm with
respect to vacuum topology is a prerequisite for trustworthy full QCD
simulations, in particular for the computation of topology sensitive
quantities. We demonstrate that for mpi/mrho ratios <= 0.69 sufficient
tunneling between the topological sectors can be achieved, for two flavours of
dynamical Wilson fermions close to the scaling region beta=5.6. Our results are
based on time series of length 5000 trajectories.Comment: change of comments: LATTICE98(confine
Epidemiological Aspects of Hepatitis B and C Markers in Blood Donors in Kazakhstan; 2000-2011
Transfusion-transmissible infections such as hepatitis B and hepatitis C are among the greatest threats to blood safety for transfusion recipients and pose a serious public health problem. The aim of this study was to assess the epidemiological aspects of hepatitis B and C in Kazakhstani donor's blood over the period 2000-2011.The data were obtained from the annual reports of the Republican Blood Center. The retrospective study was conducted from 2000 to 2011.Over the study period in the republic a growth of volumes of procured blood from 312.4 to 398.0 units was noted, in total equaled to 4,277.8 units. The proportion of blood wasted increased from 8.3% to 8.7%. In the dynamics the proportion of viral hepatitis among all causes of blood wasted decreased from 29% to 15.5% (HBV) and from 33.5% to 9.9% (HCV). The proportion of HBV and HCV in whole blood decreased considerably, in plasma and red cell concentrate the rates changed slightly. The average annual prevalence of HBV and HCV were 2.1% and 1.8%, respectively.Despite the reduction of viral hepatitis rates among blood donors in Kazakhstan the prevalence still remains high. The HBV prevalence is higher compared to HCV, which needs further investigations in the general population to address the issue
- âŠ