392 research outputs found
La production scientifique issue de la formation initiale Ă la facultĂ© de mĂ©decine dâAngers entre 2002 et 2008 : de bonne qualitĂ© mais insuffisante
IntroductionLâactivitĂ© de publication scientifique issue de la formation initiale est mal connue. Nous avons Ă©valuĂ© la proportion des thĂšses et des mĂ©moires de spĂ©cialitĂ© aboutissant Ă une publication, leur impact en termes de points SIGAPS et les principaux obstacles Ă la publication de ces travaux. MĂ©thodes Les thĂšses de doctorat en mĂ©decine soutenues de 2002 à 2008 à la facultĂ© de mĂ©decine dâAngers ont Ă©tĂ© recensĂ©es Ă partir du systĂšme universitaire de documentation (SUDOC), et les mĂ©moires de spĂ©cialitĂ© directement auprĂšs des diplĂŽmĂ©s. Les publications ont Ă©tĂ© recherchĂ©es dans Medline via Pubmed, ISI Web of Knowledge et dans les trois rapports SIGAPS de 2002 à 2008. Une enquĂȘte cherchant Ă connaĂźtre les obstacles Ă la publication a Ă©tĂ© lancĂ©e auprĂšs de tous les directeurs de thĂšses et responsables de discipline impliquĂ©s. RĂ©sultats Cinq cent quatre-vingt-dix-huit thĂšses ont Ă©tĂ© soutenues, 311 (52 %) en mĂ©decine gĂ©nĂ©rale et 287 (48 %) en spĂ©cialitĂ©s. Cent soixante-cinq thĂšses ont donnĂ© lieu Ă publication (28 %) dont 97 (16 %) indexĂ©s dans Medline via Pubmed (soit 11 % en mĂ©decine gĂ©nĂ©rale et 22 % en spĂ©cialitĂ©). Trente-trois de ces 97 articles (35 %) ont Ă©tĂ© publiĂ©s dans des journaux de haute qualitĂ© classĂ©s A, B ou C de la classification SIGAPS. Ces articles issus des thĂšses ont reprĂ©sentĂ© 4,17 % du score SIGAPS du CHU calculĂ© sur un total de 2088 articles au cours de cette pĂ©riode. Deux cent quatre mĂ©moires de spĂ©cialitĂ©s ont donnĂ© lieu Ă 69 articles (33,8 %), dont 50 (24,5 %) indexĂ©s dans Medline. Les taux de publication des mĂ©moires de DES et de DESC ont Ă©tĂ© respectivement de 31 % (45/145) et de 40,7 % (24/59). Ils ont reprĂ©sentĂ© 1,9 % (432 points) du score total SIGAPS. Les principaux obstacles ressentis pour la publication ont Ă©tĂ© le manque de temps des directeurs, lâĂ©loignement des Ă©tudiants aprĂšs la soutenance et le manque de moyens logistiques. Conclusion La production scientifique issue de la formation initiale Ă la facultĂ© de mĂ©decine dâAngers a Ă©tĂ© de bonne qualitĂ© mais insuffisante quantitativement et peu contributive au financement du CHU malgrĂ© un nombre important de diplĂŽmĂ©s. Un soutien logistique mĂ©rite dâĂȘtre envisagĂ© afin de valoriser la production scientifique issue de la formation initiale
Lattice defects in microtubules: protofilament numbers vary within individual microtubules
We have used cryo-electron microscopy of vitrified specimens to study microtubules assembled both from three cycle purified tubulin (3x-tubulin) and in cell free extracts of Xenopus eggs. In vitro assembled 3x-tubulin samples have a majority of microtubules with 14 protofilaments whereas in cell extracts most microtubules have 13 protofilaments. Microtubule polymorphism was observed in both cases. The number of protofilaments can change abruptly along individual microtubules usually by single increments but double increments also occur. For 3x-tubulin, increasing the magnesium concentration decreases the proportion of 14 protofilament microtubules and decreases the average separation between transitions in these microtubules. Protofilament discontinuities may correspond to dislocation-like defects in the microtubule surface lattice
Pooled analysis of higher versus lower blood pressure targets for vasopressor therapy septic and vasodilatory shock
PURPOSE: Guidelines for shock recommend mean arterial pressure (MAP) targets for vasopressor therapy of at least 65Â mmHg and, until recently, suggested that patients with underlying chronic hypertension and atherosclerosis may benefit from higher targets. We conducted an individual patient-data meta-analysis of recent trials to determine if patient variables modify the effect of different MAP targets.
METHODS: We searched the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials for randomized controlled trials of higher versus lower blood pressure targets for vasopressor therapy in adult patients in shock (until November 2017). After obtaining individual patient data from both eligible trials, we used a modified version of the Cochrane Collaboration\u27s instrument to assess the risk of bias of included trials. The primary outcome was 28-day mortality.
RESULTS: Included trials enrolled 894 patients. Controlling for trial and site, the OR for 28-day mortality for the higher versus lower MAP targets was 1.15 (95% CI 0.87-1.52). Treatment effect varied by duration of vasopressors before randomization (interaction p = 0.017), but not by chronic hypertension, congestive heart failure or age. Risk of death increased in higher MAP groups among patients on vasopressors > 6 h before randomization (OR 3.00, 95% CI 1.33-6.74).
CONCLUSIONS: Targeting higher blood pressure targets may increase mortality in patients who have been treated with vasopressors for more than 6Â h. Lower blood pressure targets were not associated with patient-important adverse events in any subgroup, including chronically hypertensive patients
Continuous non-perturbative regularization of QED
We regularize in a continuous manner the path integral of QED by construction
of a non-local version of its action by means of a regularized form of Dirac's
functions. Since the action and the measure are both invariant under
the gauge group, this regularization scheme is intrinsically non-perturbative.
Despite the fact that the non-local action converges formally to the local one
as the cutoff goes to infinity, the regularized theory keeps trace of the
non-locality through the appearance of a quadratic divergence in the transverse
part of the polarization operator. This term which is uniquely defined by the
choice of the cutoff functions can be removed by a redefinition of the
regularized action. We notice that as for chiral fermions on the lattice, there
is an obstruction to construct a continuous and non ambiguous regularization in
four dimensions. With the help of the regularized equations of motion, we
calculate the one particle irreducible functions which are known to be
divergent by naive power counting at the one loop order.Comment: 23 pages, LaTeX, 5 Encapsulated Postscript figures. Improved and
revised version, to appear in Phys. Rev.
Trends in Metal Oxide Stability for Nanorods, Nanotubes, and Surfaces
The formation energies of nanostructures play an important role in
determining their properties, including the catalytic activity. For the case of
15 different rutile and 8 different perovskite metal oxides, we find that the
density functional theory (DFT) calculated formation energies of (2,2)
nanorods, (3,3) nanotubes, and the (110) and (100) surfaces may be described
semi-quantitatively by the fraction of metal--oxygen bonds broken and the
bonding band centers in the bulk metal oxide
Global QSAR models of skin sensitisers for regulatory purposes
Abstract Background The new European Regulation on chemical safety, REACH, (Registration, Evaluation, Authorisation and Restriction of CHemical substances), is in the process of being implemented. Many chemicals used in industry require additional testing to comply with the REACH regulations. At the same time EU member states are attempting to reduce the number of animals used in experiments under the 3 Rs policy, (refining, reducing, and replacing the use of animals in laboratory procedures). Computational techniques such as QSAR have the potential to offer an alternative for generating REACH data. The FP6 project CAESAR was aimed at developing QSAR models for 5 key toxicological endpoints of which skin sensitisation was one. Results This paper reports the development of two global QSAR models using two different computational approaches, which contribute to the hybrid model freely available online. Conclusions The QSAR models for assessing skin sensitisation have been developed and tested under stringent quality criteria to fulfil the principles laid down by the OECD. The final models, accessible from CAESAR website, offer a robust and reliable method of assessing skin sensitisation for regulatory use.</p
Tau Interaction with Tubulin and Microtubules: From Purified Proteins to Cells
International audienceMicrotubules (MTs) play an important role in many cellular processes and are dynamic structures regulated by an important network of microtubules-associated proteins, MAPs, such as Tau. Tau has been discovered as an essential factor for MTs formation in vitro, and its region implicated in binding to MTs has been identified. By contrast, the affinity, the stoichiometry, and the topology of Tau-MTs interaction remain controversial. Indeed, depending on the experiment conditions a wide range of values have been obtained. In this chapter, we focus on three biophysical methods, turbidimetry, cosedimentation assay, and Förster Resonance Energy Transfer to study Tau-tubulin interaction both in vitro and in cell. We highlight precautions that must be taken in order to avoid pitfalls and we detail the nature of the conclusions that can be drawn from these methods about Tau-tubulin interaction
SmartPilotÂź view-guided anaesthesia improves postoperative outcomes in hip fracture surgery: a randomized blinded controlled study
Background
Both under-dosage and over-dosage of general anaesthetics can harm frail patients. We hypothesised that computer-assisted anaesthesia using pharmacokinetic/pharmacodynamic models guided by SmartPilotÂź View (SPV) software could optimise depth of anaesthesia and improve outcomes in patients undergoing hip fracture surgery.
Methods
This prospective, randomized, single-centre, blinded trial included patients undergoing hip fracture surgery under general anaesthesia. In the intervention group, anaesthesia was guided using SPV with predefined targets. In the control group, anaesthesia was delivered by usual practice using the same agents (propofol, sufentanil and desflurane). The primary endpoint was the time spent in the âappropriate anaesthesia zoneâ defined as bispectral index (BIS) (blinded to the anaesthetist during surgery) of 45â60 and systolic arterial pressure of 80â140âmm Hg. Postoperative complications were recorded for one month in a blinded manner.
Results
Of 100 subjects randomised, 97 were analysed (n=47 in SPV and 50 in control group). Anaesthetic drug consumption was reduced in the SPV group (for propofol and desflurane). Intraoperative duration of low BIS (<45) was similar, but cumulative time of low systolic arterial pressure (<80âmm Hg) was significantly shorter in the SPV group (median (Q1-Q3); 3 (0â40) vs 5 (0â116)âmin, P=0.013). SPV subjects experienced fewer moderate or major postoperative complications at 30-days (8 (17)% vs 18 (36)%, P=0.035) and shorter length of hospitalisation (8 (2â20) vs 8 (2â60) days, P=0.017).
Conclusions
SmartPilotÂź View-guided anaesthesia reduces intraoperative hypotension duration, occurrence of postoperative complications and length of stay in hip fracture surgery patients
The exceptionally powerful TeV gamma-ray emitters in the Large Magellanic Cloud
The Large Magellanic Cloud, a satellite galaxy of the Milky Way, has been
observed with the High Energy Stereoscopic System (H.E.S.S.) above an energy of
100 billion electron volts for a deep exposure of 210 hours. Three sources of
different types were detected: the pulsar wind nebula of the most energetic
pulsar known N 157B, the radio-loud supernova remnant N 132D and the largest
non-thermal X-ray shell - the superbubble 30 Dor C. The unique object SN 1987A
is, surprisingly, not detected, which constrains the theoretical framework of
particle acceleration in very young supernova remnants. These detections reveal
the most energetic tip of a gamma-ray source population in an external galaxy,
and provide via 30 Dor C the unambiguous detection of gamma-ray emission from a
superbubble.Comment: Published in Science Magazine (Jan. 23, 2015). This ArXiv version has
the supplementary online material incorporated as an appendix to the main
pape
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