498 research outputs found
Classical treatment of Li2++Ar and He2++Ar collisions
Classical Trajectory Monte Carlo calculations are carried out for Li2++Ar and He2++Ar collisions, motivated by recent experiments on these systems. Cross sections for electron capture, projectile electron loss and target multiple ionization processes are evaluated and compared to the experimental values in the 75-500 keV/amy impact energy rang
Classical treatment of ion-H2O collisions with a three-center model potential
We present calculations of cross sections for one- and two-electron processes in collisions of H+, He2+, and C6+ with water molecules in the framework of the Franck-Condon approximation. We employ an independent-electron method and a classical trajectory Monte Carlo approach. Anisotropy effects related to the structure of the target are explicitly incorporated by using a three-center model potential to describe the electron-H2O+ interaction. We derive scaling laws with respect to the projectile charge. We also estimate cross sections for molecular fragmentation subsequent to electron removalThis work has been partially supported by the CCG08- UAM/ESP3990 project and the DGICYT project ENE2007- 6293
Carotid artery resection and reconstruction with superficial femoral artery transplantation: a case report
Discovery of Fragment Molecules That Bind the Human Peroxiredoxin 5 Active Site
The search for protein ligands is a crucial step in the inhibitor design process. Fragment screening represents an interesting method to rapidly find lead molecules, as it enables the exploration of a larger portion of the chemical space with a smaller number of compounds as compared to screening based on drug-sized molecules. Moreover, fragment screening usually leads to hit molecules that form few but optimal interactions with the target, thus displaying high ligand efficiencies. Here we report the screening of a homemade library composed of 200 highly diverse fragments against the human Peroxiredoxin 5 protein. Peroxiredoxins compose a family of peroxidases that share the ability to reduce peroxides through a conserved cysteine. The three-dimensional structures of these enzymes ubiquitously found throughout evolution have been extensively studied, however, their biological functions are still not well understood and to date few inhibitors have been discovered against these enzymes. Six fragments from the library were shown to bind to the Peroxiredoxin 5 active site and ligand-induced chemical shift changes were used to drive the docking of these small molecules into the protein structure. The orientation of the fragments in the binding pocket was confirmed by the study of fragment homologues, highlighting the role of hydroxyl functions that hang the ligands to the Peroxiredoxin 5 protein. Among the hit fragments, the small catechol molecule was shown to significantly inhibit Peroxiredoxin 5 activity in a thioredoxin peroxidase assay. This study reports novel data about the ligand-Peroxiredoxin interactions that will help considerably the development of potential Peroxiredoxin inhibitors
Does the engagement of clinicians and organisations in research improve healthcare performance: a three-stage review
Objective: There is a widely held assumption that engagement by clinicians and healthcare organisations in research improves healthcare performance at various levels, but little direct empirical evidence has previously been collated. The objective of this study was to address the question: Does research engagement (by clinicians and organizations) improve healthcare performance? Methods: An hourglass-shaped review was developed, consisting of three stages: (1) a planning and mapping stage; (2) a focused review concentrating on the core question of whether or not research engagement improves healthcare performance; and (3) a wider (but less systematic) review of papers identified during the two earlier stages, focusing on mechanisms. Results: Of the 33 papers included in the focused review, 28 identified improvements in health services performance. Seven out of these papers reported some improvement in health outcomes, with others reporting improved processes of care. The wider review demonstrated that mechanisms such as collaborative and action research can encourage some progress along the pathway from research engagement towards improved healthcare performance. Organisations that have deliberately integrated the research function into organisational structures demonstrate how research engagement can, among other factors, contribute to improved healthcare performance. Conclusions: Current evidence suggests that there is an association between the engagement of individuals and healthcare organisations in research and improvements in healthcare performance. The mechanisms through which research engagement might improve healthcare performance overlap and rarely act in isolation, and their effectiveness often depends on the context in which they operate. Strengths and limitations of this study • This review brings together for the first time a diverse body of literature addressing whether engaging clinicians and healthcare organisations in research is the likely to improve healthcare performance • It also explores the mechanisms through which improvement is achieved to try and understand how any improvements might come about • However, it relies on the quality and coverage of the existing literature • It is an extremely complex topic, but nonetheless one worthy of further exploration, particularly given the pressure to justify research spending in healthcare systems, and to encourage its implementation.UK National Institute for Health Research (NIHR) Service Delivery and Organisation (SDO) programme ( project number HS&DR- 10/1012/09
Learning the cell cycle with a game: Virtual experiments in cell biology
Cell Cycle Learn (CCL) is a learning game designed for undergraduate students in Biology to learn common knowledge about the cell-division cycle along with practical skills related with setting up an experiment and the scientific method in general. In CCL, learners are guided through the process of formulating hypotheses, conducting virtual experiments and analysing the results in order to validate or invalidate the hypotheses. The game has been designed in the University of Toulouse and introduced last year as part of the curriculum of a cellular biology class. This paper presents early results of an evaluation of the game enabled by questionnaires filled by the participants and game data collected during the training sessions. The results demonstrate with examples that both types of data can be used to assess the game's utility
Multi dimensional comparisons
Consultative Committee for Photometry and Radiometry (CCPR) Workshop. China 26 October 2015How to asses measurement comparisons of multidimensional quantities? An approach is presented in this workPeer Reviewe
Calibration and First light of the Diabolo photometer at the Millimetre and Infrared Testa Grigia Observatory
We have designed and built a large-throughput dual channel photometer,
Diabolo. This photometer is dedicated to the observation of millimetre
continuum diffuse sources, and in particular, of the Sunyaev-Zel'dovich effect
and of anisotropies of the 3K background. We describe the optical layout and
filtering system of the instrument, which uses two bolometric detectors for
simultaneous observations in two frequency channels at 1.2 and 2.1 mm. The
bolometers are cooled to a working temperature of 0.1 K provided by a compact
dilution cryostat. The photometric and angular responses of the instrument are
measured in the laboratory. First astronomical light was detected in March 1995
at the focus of the new Millimetre and Infrared Testa Grigia Observatory (MITO)
Telescope. The established sensitivity of the system is of 7 mK_RJ s^1/2$. For
a typical map of at least 10 beams, with one hour of integration per beam, one
can achieve the rms values of y_SZ ~ 7 10^-5 and the 3K background anisotropy
Delta T/T ~ 7 10^-5, in winter conditions. We also report on a novel bolometer
AC readout circuit which allows for the first time total power measurements on
the sky. This technique alleviates (but does not forbid) the use of chopping
with a secondary mirror. This technique and the dilution fridge concept will be
used in future scan--modulated space instrument like the ESA Planck mission
project.Comment: 10 pages, LaTeX, 12 figures, accepted for publication in Astronomy
and Astrophysics Supplement Serie
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